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56137dbc | 1 | /* Malloc implementation for multiple threads without lock contention. |
bfff8b1b | 2 | Copyright (C) 1996-2017 Free Software Foundation, Inc. |
f65fd747 | 3 | This file is part of the GNU C Library. |
fa8d436c UD |
4 | Contributed by Wolfram Gloger <wg@malloc.de> |
5 | and Doug Lea <dl@cs.oswego.edu>, 2001. | |
f65fd747 UD |
6 | |
7 | The GNU C Library is free software; you can redistribute it and/or | |
cc7375ce RM |
8 | modify it under the terms of the GNU Lesser General Public License as |
9 | published by the Free Software Foundation; either version 2.1 of the | |
fa8d436c | 10 | License, or (at your option) any later version. |
f65fd747 UD |
11 | |
12 | The GNU C Library is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
cc7375ce | 15 | Lesser General Public License for more details. |
f65fd747 | 16 | |
cc7375ce | 17 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 PE |
18 | License along with the GNU C Library; see the file COPYING.LIB. If |
19 | not, see <http://www.gnu.org/licenses/>. */ | |
f65fd747 | 20 | |
fa8d436c UD |
21 | /* |
22 | This is a version (aka ptmalloc2) of malloc/free/realloc written by | |
23 | Doug Lea and adapted to multiple threads/arenas by Wolfram Gloger. | |
24 | ||
bb2ce416 | 25 | There have been substantial changes made after the integration into |
da2d2fb6 UD |
26 | glibc in all parts of the code. Do not look for much commonality |
27 | with the ptmalloc2 version. | |
28 | ||
fa8d436c | 29 | * Version ptmalloc2-20011215 |
fa8d436c UD |
30 | based on: |
31 | VERSION 2.7.0 Sun Mar 11 14:14:06 2001 Doug Lea (dl at gee) | |
f65fd747 | 32 | |
fa8d436c | 33 | * Quickstart |
f65fd747 | 34 | |
fa8d436c UD |
35 | In order to compile this implementation, a Makefile is provided with |
36 | the ptmalloc2 distribution, which has pre-defined targets for some | |
37 | popular systems (e.g. "make posix" for Posix threads). All that is | |
38 | typically required with regard to compiler flags is the selection of | |
39 | the thread package via defining one out of USE_PTHREADS, USE_THR or | |
40 | USE_SPROC. Check the thread-m.h file for what effects this has. | |
41 | Many/most systems will additionally require USE_TSD_DATA_HACK to be | |
42 | defined, so this is the default for "make posix". | |
f65fd747 UD |
43 | |
44 | * Why use this malloc? | |
45 | ||
46 | This is not the fastest, most space-conserving, most portable, or | |
47 | most tunable malloc ever written. However it is among the fastest | |
48 | while also being among the most space-conserving, portable and tunable. | |
49 | Consistent balance across these factors results in a good general-purpose | |
fa8d436c UD |
50 | allocator for malloc-intensive programs. |
51 | ||
52 | The main properties of the algorithms are: | |
53 | * For large (>= 512 bytes) requests, it is a pure best-fit allocator, | |
54 | with ties normally decided via FIFO (i.e. least recently used). | |
55 | * For small (<= 64 bytes by default) requests, it is a caching | |
56 | allocator, that maintains pools of quickly recycled chunks. | |
57 | * In between, and for combinations of large and small requests, it does | |
58 | the best it can trying to meet both goals at once. | |
59 | * For very large requests (>= 128KB by default), it relies on system | |
60 | memory mapping facilities, if supported. | |
61 | ||
62 | For a longer but slightly out of date high-level description, see | |
63 | http://gee.cs.oswego.edu/dl/html/malloc.html | |
64 | ||
65 | You may already by default be using a C library containing a malloc | |
66 | that is based on some version of this malloc (for example in | |
67 | linux). You might still want to use the one in this file in order to | |
68 | customize settings or to avoid overheads associated with library | |
69 | versions. | |
70 | ||
71 | * Contents, described in more detail in "description of public routines" below. | |
72 | ||
73 | Standard (ANSI/SVID/...) functions: | |
74 | malloc(size_t n); | |
75 | calloc(size_t n_elements, size_t element_size); | |
22a89187 UD |
76 | free(void* p); |
77 | realloc(void* p, size_t n); | |
fa8d436c UD |
78 | memalign(size_t alignment, size_t n); |
79 | valloc(size_t n); | |
80 | mallinfo() | |
81 | mallopt(int parameter_number, int parameter_value) | |
82 | ||
83 | Additional functions: | |
22a89187 UD |
84 | independent_calloc(size_t n_elements, size_t size, void* chunks[]); |
85 | independent_comalloc(size_t n_elements, size_t sizes[], void* chunks[]); | |
fa8d436c | 86 | pvalloc(size_t n); |
fa8d436c | 87 | malloc_trim(size_t pad); |
22a89187 | 88 | malloc_usable_size(void* p); |
fa8d436c | 89 | malloc_stats(); |
f65fd747 UD |
90 | |
91 | * Vital statistics: | |
92 | ||
fa8d436c | 93 | Supported pointer representation: 4 or 8 bytes |
a9177ff5 | 94 | Supported size_t representation: 4 or 8 bytes |
f65fd747 | 95 | Note that size_t is allowed to be 4 bytes even if pointers are 8. |
fa8d436c UD |
96 | You can adjust this by defining INTERNAL_SIZE_T |
97 | ||
98 | Alignment: 2 * sizeof(size_t) (default) | |
99 | (i.e., 8 byte alignment with 4byte size_t). This suffices for | |
100 | nearly all current machines and C compilers. However, you can | |
101 | define MALLOC_ALIGNMENT to be wider than this if necessary. | |
f65fd747 | 102 | |
fa8d436c UD |
103 | Minimum overhead per allocated chunk: 4 or 8 bytes |
104 | Each malloced chunk has a hidden word of overhead holding size | |
f65fd747 UD |
105 | and status information. |
106 | ||
107 | Minimum allocated size: 4-byte ptrs: 16 bytes (including 4 overhead) | |
72f90263 | 108 | 8-byte ptrs: 24/32 bytes (including, 4/8 overhead) |
f65fd747 UD |
109 | |
110 | When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte | |
111 | ptrs but 4 byte size) or 24 (for 8/8) additional bytes are | |
fa8d436c UD |
112 | needed; 4 (8) for a trailing size field and 8 (16) bytes for |
113 | free list pointers. Thus, the minimum allocatable size is | |
114 | 16/24/32 bytes. | |
f65fd747 UD |
115 | |
116 | Even a request for zero bytes (i.e., malloc(0)) returns a | |
117 | pointer to something of the minimum allocatable size. | |
118 | ||
fa8d436c UD |
119 | The maximum overhead wastage (i.e., number of extra bytes |
120 | allocated than were requested in malloc) is less than or equal | |
121 | to the minimum size, except for requests >= mmap_threshold that | |
122 | are serviced via mmap(), where the worst case wastage is 2 * | |
123 | sizeof(size_t) bytes plus the remainder from a system page (the | |
124 | minimal mmap unit); typically 4096 or 8192 bytes. | |
f65fd747 | 125 | |
a9177ff5 | 126 | Maximum allocated size: 4-byte size_t: 2^32 minus about two pages |
72f90263 | 127 | 8-byte size_t: 2^64 minus about two pages |
fa8d436c UD |
128 | |
129 | It is assumed that (possibly signed) size_t values suffice to | |
f65fd747 UD |
130 | represent chunk sizes. `Possibly signed' is due to the fact |
131 | that `size_t' may be defined on a system as either a signed or | |
fa8d436c UD |
132 | an unsigned type. The ISO C standard says that it must be |
133 | unsigned, but a few systems are known not to adhere to this. | |
134 | Additionally, even when size_t is unsigned, sbrk (which is by | |
135 | default used to obtain memory from system) accepts signed | |
136 | arguments, and may not be able to handle size_t-wide arguments | |
137 | with negative sign bit. Generally, values that would | |
138 | appear as negative after accounting for overhead and alignment | |
139 | are supported only via mmap(), which does not have this | |
140 | limitation. | |
141 | ||
142 | Requests for sizes outside the allowed range will perform an optional | |
143 | failure action and then return null. (Requests may also | |
144 | also fail because a system is out of memory.) | |
145 | ||
22a89187 | 146 | Thread-safety: thread-safe |
fa8d436c UD |
147 | |
148 | Compliance: I believe it is compliant with the 1997 Single Unix Specification | |
2b0fba75 | 149 | Also SVID/XPG, ANSI C, and probably others as well. |
f65fd747 UD |
150 | |
151 | * Synopsis of compile-time options: | |
152 | ||
153 | People have reported using previous versions of this malloc on all | |
154 | versions of Unix, sometimes by tweaking some of the defines | |
22a89187 | 155 | below. It has been tested most extensively on Solaris and Linux. |
fa8d436c UD |
156 | People also report using it in stand-alone embedded systems. |
157 | ||
158 | The implementation is in straight, hand-tuned ANSI C. It is not | |
159 | at all modular. (Sorry!) It uses a lot of macros. To be at all | |
160 | usable, this code should be compiled using an optimizing compiler | |
161 | (for example gcc -O3) that can simplify expressions and control | |
162 | paths. (FAQ: some macros import variables as arguments rather than | |
163 | declare locals because people reported that some debuggers | |
164 | otherwise get confused.) | |
165 | ||
166 | OPTION DEFAULT VALUE | |
167 | ||
168 | Compilation Environment options: | |
169 | ||
2a26ef3a | 170 | HAVE_MREMAP 0 |
fa8d436c UD |
171 | |
172 | Changing default word sizes: | |
173 | ||
174 | INTERNAL_SIZE_T size_t | |
fa8d436c UD |
175 | |
176 | Configuration and functionality options: | |
177 | ||
fa8d436c UD |
178 | USE_PUBLIC_MALLOC_WRAPPERS NOT defined |
179 | USE_MALLOC_LOCK NOT defined | |
180 | MALLOC_DEBUG NOT defined | |
181 | REALLOC_ZERO_BYTES_FREES 1 | |
fa8d436c UD |
182 | TRIM_FASTBINS 0 |
183 | ||
184 | Options for customizing MORECORE: | |
185 | ||
186 | MORECORE sbrk | |
187 | MORECORE_FAILURE -1 | |
a9177ff5 | 188 | MORECORE_CONTIGUOUS 1 |
fa8d436c UD |
189 | MORECORE_CANNOT_TRIM NOT defined |
190 | MORECORE_CLEARS 1 | |
a9177ff5 | 191 | MMAP_AS_MORECORE_SIZE (1024 * 1024) |
fa8d436c UD |
192 | |
193 | Tuning options that are also dynamically changeable via mallopt: | |
194 | ||
425ce2ed | 195 | DEFAULT_MXFAST 64 (for 32bit), 128 (for 64bit) |
fa8d436c UD |
196 | DEFAULT_TRIM_THRESHOLD 128 * 1024 |
197 | DEFAULT_TOP_PAD 0 | |
198 | DEFAULT_MMAP_THRESHOLD 128 * 1024 | |
199 | DEFAULT_MMAP_MAX 65536 | |
200 | ||
201 | There are several other #defined constants and macros that you | |
202 | probably don't want to touch unless you are extending or adapting malloc. */ | |
f65fd747 UD |
203 | |
204 | /* | |
22a89187 | 205 | void* is the pointer type that malloc should say it returns |
f65fd747 UD |
206 | */ |
207 | ||
22a89187 UD |
208 | #ifndef void |
209 | #define void void | |
210 | #endif /*void*/ | |
f65fd747 | 211 | |
fa8d436c UD |
212 | #include <stddef.h> /* for size_t */ |
213 | #include <stdlib.h> /* for getenv(), abort() */ | |
2a26ef3a | 214 | #include <unistd.h> /* for __libc_enable_secure */ |
f65fd747 | 215 | |
425ce2ed | 216 | #include <atomic.h> |
eb96ffb0 | 217 | #include <_itoa.h> |
e404fb16 | 218 | #include <bits/wordsize.h> |
425ce2ed | 219 | #include <sys/sysinfo.h> |
c56da3a3 | 220 | |
02d46fc4 UD |
221 | #include <ldsodefs.h> |
222 | ||
fa8d436c | 223 | #include <unistd.h> |
fa8d436c | 224 | #include <stdio.h> /* needed for malloc_stats */ |
8e58439c | 225 | #include <errno.h> |
f65fd747 | 226 | |
66274218 AJ |
227 | #include <shlib-compat.h> |
228 | ||
5d78bb43 UD |
229 | /* For uintptr_t. */ |
230 | #include <stdint.h> | |
f65fd747 | 231 | |
3e030bd5 UD |
232 | /* For va_arg, va_start, va_end. */ |
233 | #include <stdarg.h> | |
234 | ||
070906ff RM |
235 | /* For MIN, MAX, powerof2. */ |
236 | #include <sys/param.h> | |
237 | ||
ca6be165 | 238 | /* For ALIGN_UP et. al. */ |
9090848d | 239 | #include <libc-pointer-arith.h> |
8a35c3fe | 240 | |
d5c3fafc DD |
241 | /* For DIAG_PUSH/POP_NEEDS_COMMENT et al. */ |
242 | #include <libc-diag.h> | |
243 | ||
29d79486 | 244 | #include <malloc/malloc-internal.h> |
c0f62c56 | 245 | |
fa8d436c UD |
246 | /* |
247 | Debugging: | |
248 | ||
249 | Because freed chunks may be overwritten with bookkeeping fields, this | |
250 | malloc will often die when freed memory is overwritten by user | |
251 | programs. This can be very effective (albeit in an annoying way) | |
252 | in helping track down dangling pointers. | |
253 | ||
254 | If you compile with -DMALLOC_DEBUG, a number of assertion checks are | |
255 | enabled that will catch more memory errors. You probably won't be | |
256 | able to make much sense of the actual assertion errors, but they | |
257 | should help you locate incorrectly overwritten memory. The checking | |
258 | is fairly extensive, and will slow down execution | |
259 | noticeably. Calling malloc_stats or mallinfo with MALLOC_DEBUG set | |
260 | will attempt to check every non-mmapped allocated and free chunk in | |
261 | the course of computing the summmaries. (By nature, mmapped regions | |
262 | cannot be checked very much automatically.) | |
263 | ||
264 | Setting MALLOC_DEBUG may also be helpful if you are trying to modify | |
265 | this code. The assertions in the check routines spell out in more | |
266 | detail the assumptions and invariants underlying the algorithms. | |
267 | ||
268 | Setting MALLOC_DEBUG does NOT provide an automated mechanism for | |
269 | checking that all accesses to malloced memory stay within their | |
270 | bounds. However, there are several add-ons and adaptations of this | |
271 | or other mallocs available that do this. | |
f65fd747 UD |
272 | */ |
273 | ||
439bda32 WN |
274 | #ifndef MALLOC_DEBUG |
275 | #define MALLOC_DEBUG 0 | |
276 | #endif | |
277 | ||
72f90263 UD |
278 | #ifdef NDEBUG |
279 | # define assert(expr) ((void) 0) | |
280 | #else | |
281 | # define assert(expr) \ | |
282 | ((expr) \ | |
283 | ? ((void) 0) \ | |
8ba14398 | 284 | : __malloc_assert (#expr, __FILE__, __LINE__, __func__)) |
72f90263 UD |
285 | |
286 | extern const char *__progname; | |
287 | ||
288 | static void | |
289 | __malloc_assert (const char *assertion, const char *file, unsigned int line, | |
290 | const char *function) | |
291 | { | |
292 | (void) __fxprintf (NULL, "%s%s%s:%u: %s%sAssertion `%s' failed.\n", | |
293 | __progname, __progname[0] ? ": " : "", | |
294 | file, line, | |
295 | function ? function : "", function ? ": " : "", | |
296 | assertion); | |
297 | fflush (stderr); | |
298 | abort (); | |
299 | } | |
300 | #endif | |
f65fd747 | 301 | |
d5c3fafc DD |
302 | #if USE_TCACHE |
303 | /* We want 64 entries. This is an arbitrary limit, which tunables can reduce. */ | |
304 | # define TCACHE_MAX_BINS 64 | |
305 | # define MAX_TCACHE_SIZE tidx2usize (TCACHE_MAX_BINS-1) | |
306 | ||
307 | /* Only used to pre-fill the tunables. */ | |
308 | # define tidx2usize(idx) (((size_t) idx) * MALLOC_ALIGNMENT + MINSIZE - SIZE_SZ) | |
309 | ||
310 | /* When "x" is from chunksize(). */ | |
311 | # define csize2tidx(x) (((x) - MINSIZE + MALLOC_ALIGNMENT - 1) / MALLOC_ALIGNMENT) | |
312 | /* When "x" is a user-provided size. */ | |
313 | # define usize2tidx(x) csize2tidx (request2size (x)) | |
314 | ||
315 | /* With rounding and alignment, the bins are... | |
316 | idx 0 bytes 0..24 (64-bit) or 0..12 (32-bit) | |
317 | idx 1 bytes 25..40 or 13..20 | |
318 | idx 2 bytes 41..56 or 21..28 | |
319 | etc. */ | |
320 | ||
321 | /* This is another arbitrary limit, which tunables can change. Each | |
322 | tcache bin will hold at most this number of chunks. */ | |
323 | # define TCACHE_FILL_COUNT 7 | |
324 | #endif | |
325 | ||
f65fd747 | 326 | |
fa8d436c UD |
327 | /* |
328 | REALLOC_ZERO_BYTES_FREES should be set if a call to | |
329 | realloc with zero bytes should be the same as a call to free. | |
330 | This is required by the C standard. Otherwise, since this malloc | |
331 | returns a unique pointer for malloc(0), so does realloc(p, 0). | |
332 | */ | |
333 | ||
334 | #ifndef REALLOC_ZERO_BYTES_FREES | |
335 | #define REALLOC_ZERO_BYTES_FREES 1 | |
336 | #endif | |
337 | ||
338 | /* | |
339 | TRIM_FASTBINS controls whether free() of a very small chunk can | |
340 | immediately lead to trimming. Setting to true (1) can reduce memory | |
341 | footprint, but will almost always slow down programs that use a lot | |
342 | of small chunks. | |
343 | ||
344 | Define this only if you are willing to give up some speed to more | |
345 | aggressively reduce system-level memory footprint when releasing | |
346 | memory in programs that use many small chunks. You can get | |
347 | essentially the same effect by setting MXFAST to 0, but this can | |
348 | lead to even greater slowdowns in programs using many small chunks. | |
349 | TRIM_FASTBINS is an in-between compile-time option, that disables | |
350 | only those chunks bordering topmost memory from being placed in | |
351 | fastbins. | |
352 | */ | |
353 | ||
354 | #ifndef TRIM_FASTBINS | |
355 | #define TRIM_FASTBINS 0 | |
356 | #endif | |
357 | ||
358 | ||
3b49edc0 | 359 | /* Definition for getting more memory from the OS. */ |
fa8d436c UD |
360 | #define MORECORE (*__morecore) |
361 | #define MORECORE_FAILURE 0 | |
22a89187 UD |
362 | void * __default_morecore (ptrdiff_t); |
363 | void *(*__morecore)(ptrdiff_t) = __default_morecore; | |
f65fd747 | 364 | |
f65fd747 | 365 | |
22a89187 | 366 | #include <string.h> |
f65fd747 | 367 | |
fa8d436c UD |
368 | /* |
369 | MORECORE-related declarations. By default, rely on sbrk | |
370 | */ | |
09f5e163 | 371 | |
f65fd747 | 372 | |
fa8d436c UD |
373 | /* |
374 | MORECORE is the name of the routine to call to obtain more memory | |
375 | from the system. See below for general guidance on writing | |
376 | alternative MORECORE functions, as well as a version for WIN32 and a | |
377 | sample version for pre-OSX macos. | |
378 | */ | |
f65fd747 | 379 | |
fa8d436c UD |
380 | #ifndef MORECORE |
381 | #define MORECORE sbrk | |
382 | #endif | |
f65fd747 | 383 | |
fa8d436c UD |
384 | /* |
385 | MORECORE_FAILURE is the value returned upon failure of MORECORE | |
386 | as well as mmap. Since it cannot be an otherwise valid memory address, | |
387 | and must reflect values of standard sys calls, you probably ought not | |
388 | try to redefine it. | |
389 | */ | |
09f5e163 | 390 | |
fa8d436c UD |
391 | #ifndef MORECORE_FAILURE |
392 | #define MORECORE_FAILURE (-1) | |
393 | #endif | |
394 | ||
395 | /* | |
396 | If MORECORE_CONTIGUOUS is true, take advantage of fact that | |
397 | consecutive calls to MORECORE with positive arguments always return | |
398 | contiguous increasing addresses. This is true of unix sbrk. Even | |
399 | if not defined, when regions happen to be contiguous, malloc will | |
400 | permit allocations spanning regions obtained from different | |
401 | calls. But defining this when applicable enables some stronger | |
402 | consistency checks and space efficiencies. | |
403 | */ | |
f65fd747 | 404 | |
fa8d436c UD |
405 | #ifndef MORECORE_CONTIGUOUS |
406 | #define MORECORE_CONTIGUOUS 1 | |
f65fd747 UD |
407 | #endif |
408 | ||
fa8d436c UD |
409 | /* |
410 | Define MORECORE_CANNOT_TRIM if your version of MORECORE | |
411 | cannot release space back to the system when given negative | |
412 | arguments. This is generally necessary only if you are using | |
413 | a hand-crafted MORECORE function that cannot handle negative arguments. | |
414 | */ | |
415 | ||
416 | /* #define MORECORE_CANNOT_TRIM */ | |
f65fd747 | 417 | |
fa8d436c UD |
418 | /* MORECORE_CLEARS (default 1) |
419 | The degree to which the routine mapped to MORECORE zeroes out | |
420 | memory: never (0), only for newly allocated space (1) or always | |
421 | (2). The distinction between (1) and (2) is necessary because on | |
422 | some systems, if the application first decrements and then | |
423 | increments the break value, the contents of the reallocated space | |
424 | are unspecified. | |
6c8dbf00 | 425 | */ |
fa8d436c UD |
426 | |
427 | #ifndef MORECORE_CLEARS | |
6c8dbf00 | 428 | # define MORECORE_CLEARS 1 |
7cabd57c UD |
429 | #endif |
430 | ||
fa8d436c | 431 | |
a9177ff5 | 432 | /* |
fa8d436c | 433 | MMAP_AS_MORECORE_SIZE is the minimum mmap size argument to use if |
22a89187 UD |
434 | sbrk fails, and mmap is used as a backup. The value must be a |
435 | multiple of page size. This backup strategy generally applies only | |
436 | when systems have "holes" in address space, so sbrk cannot perform | |
437 | contiguous expansion, but there is still space available on system. | |
438 | On systems for which this is known to be useful (i.e. most linux | |
439 | kernels), this occurs only when programs allocate huge amounts of | |
440 | memory. Between this, and the fact that mmap regions tend to be | |
441 | limited, the size should be large, to avoid too many mmap calls and | |
442 | thus avoid running out of kernel resources. */ | |
fa8d436c UD |
443 | |
444 | #ifndef MMAP_AS_MORECORE_SIZE | |
445 | #define MMAP_AS_MORECORE_SIZE (1024 * 1024) | |
f65fd747 UD |
446 | #endif |
447 | ||
448 | /* | |
449 | Define HAVE_MREMAP to make realloc() use mremap() to re-allocate | |
2a26ef3a | 450 | large blocks. |
f65fd747 UD |
451 | */ |
452 | ||
453 | #ifndef HAVE_MREMAP | |
fa8d436c | 454 | #define HAVE_MREMAP 0 |
f65fd747 UD |
455 | #endif |
456 | ||
2ba3cfa1 FW |
457 | /* We may need to support __malloc_initialize_hook for backwards |
458 | compatibility. */ | |
459 | ||
460 | #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24) | |
461 | # define HAVE_MALLOC_INIT_HOOK 1 | |
462 | #else | |
463 | # define HAVE_MALLOC_INIT_HOOK 0 | |
464 | #endif | |
465 | ||
f65fd747 | 466 | |
f65fd747 | 467 | /* |
f65fd747 | 468 | This version of malloc supports the standard SVID/XPG mallinfo |
fa8d436c UD |
469 | routine that returns a struct containing usage properties and |
470 | statistics. It should work on any SVID/XPG compliant system that has | |
471 | a /usr/include/malloc.h defining struct mallinfo. (If you'd like to | |
472 | install such a thing yourself, cut out the preliminary declarations | |
473 | as described above and below and save them in a malloc.h file. But | |
474 | there's no compelling reason to bother to do this.) | |
f65fd747 UD |
475 | |
476 | The main declaration needed is the mallinfo struct that is returned | |
477 | (by-copy) by mallinfo(). The SVID/XPG malloinfo struct contains a | |
fa8d436c UD |
478 | bunch of fields that are not even meaningful in this version of |
479 | malloc. These fields are are instead filled by mallinfo() with | |
480 | other numbers that might be of interest. | |
f65fd747 UD |
481 | */ |
482 | ||
f65fd747 | 483 | |
fa8d436c | 484 | /* ---------- description of public routines ------------ */ |
f65fd747 UD |
485 | |
486 | /* | |
fa8d436c UD |
487 | malloc(size_t n) |
488 | Returns a pointer to a newly allocated chunk of at least n bytes, or null | |
489 | if no space is available. Additionally, on failure, errno is | |
490 | set to ENOMEM on ANSI C systems. | |
491 | ||
492 | If n is zero, malloc returns a minumum-sized chunk. (The minimum | |
493 | size is 16 bytes on most 32bit systems, and 24 or 32 bytes on 64bit | |
494 | systems.) On most systems, size_t is an unsigned type, so calls | |
495 | with negative arguments are interpreted as requests for huge amounts | |
496 | of space, which will often fail. The maximum supported value of n | |
497 | differs across systems, but is in all cases less than the maximum | |
498 | representable value of a size_t. | |
f65fd747 | 499 | */ |
3b49edc0 UD |
500 | void* __libc_malloc(size_t); |
501 | libc_hidden_proto (__libc_malloc) | |
f65fd747 | 502 | |
fa8d436c | 503 | /* |
22a89187 | 504 | free(void* p) |
fa8d436c UD |
505 | Releases the chunk of memory pointed to by p, that had been previously |
506 | allocated using malloc or a related routine such as realloc. | |
507 | It has no effect if p is null. It can have arbitrary (i.e., bad!) | |
508 | effects if p has already been freed. | |
509 | ||
510 | Unless disabled (using mallopt), freeing very large spaces will | |
511 | when possible, automatically trigger operations that give | |
512 | back unused memory to the system, thus reducing program footprint. | |
513 | */ | |
3b49edc0 UD |
514 | void __libc_free(void*); |
515 | libc_hidden_proto (__libc_free) | |
f65fd747 | 516 | |
fa8d436c UD |
517 | /* |
518 | calloc(size_t n_elements, size_t element_size); | |
519 | Returns a pointer to n_elements * element_size bytes, with all locations | |
520 | set to zero. | |
521 | */ | |
3b49edc0 | 522 | void* __libc_calloc(size_t, size_t); |
f65fd747 UD |
523 | |
524 | /* | |
22a89187 | 525 | realloc(void* p, size_t n) |
fa8d436c UD |
526 | Returns a pointer to a chunk of size n that contains the same data |
527 | as does chunk p up to the minimum of (n, p's size) bytes, or null | |
a9177ff5 | 528 | if no space is available. |
f65fd747 | 529 | |
fa8d436c UD |
530 | The returned pointer may or may not be the same as p. The algorithm |
531 | prefers extending p when possible, otherwise it employs the | |
532 | equivalent of a malloc-copy-free sequence. | |
f65fd747 | 533 | |
a9177ff5 | 534 | If p is null, realloc is equivalent to malloc. |
f65fd747 | 535 | |
fa8d436c UD |
536 | If space is not available, realloc returns null, errno is set (if on |
537 | ANSI) and p is NOT freed. | |
f65fd747 | 538 | |
fa8d436c UD |
539 | if n is for fewer bytes than already held by p, the newly unused |
540 | space is lopped off and freed if possible. Unless the #define | |
541 | REALLOC_ZERO_BYTES_FREES is set, realloc with a size argument of | |
542 | zero (re)allocates a minimum-sized chunk. | |
f65fd747 | 543 | |
3b5f801d DD |
544 | Large chunks that were internally obtained via mmap will always be |
545 | grown using malloc-copy-free sequences unless the system supports | |
546 | MREMAP (currently only linux). | |
f65fd747 | 547 | |
fa8d436c UD |
548 | The old unix realloc convention of allowing the last-free'd chunk |
549 | to be used as an argument to realloc is not supported. | |
f65fd747 | 550 | */ |
3b49edc0 UD |
551 | void* __libc_realloc(void*, size_t); |
552 | libc_hidden_proto (__libc_realloc) | |
f65fd747 | 553 | |
fa8d436c UD |
554 | /* |
555 | memalign(size_t alignment, size_t n); | |
556 | Returns a pointer to a newly allocated chunk of n bytes, aligned | |
557 | in accord with the alignment argument. | |
558 | ||
559 | The alignment argument should be a power of two. If the argument is | |
560 | not a power of two, the nearest greater power is used. | |
561 | 8-byte alignment is guaranteed by normal malloc calls, so don't | |
562 | bother calling memalign with an argument of 8 or less. | |
563 | ||
564 | Overreliance on memalign is a sure way to fragment space. | |
565 | */ | |
3b49edc0 UD |
566 | void* __libc_memalign(size_t, size_t); |
567 | libc_hidden_proto (__libc_memalign) | |
f65fd747 UD |
568 | |
569 | /* | |
fa8d436c UD |
570 | valloc(size_t n); |
571 | Equivalent to memalign(pagesize, n), where pagesize is the page | |
572 | size of the system. If the pagesize is unknown, 4096 is used. | |
573 | */ | |
3b49edc0 | 574 | void* __libc_valloc(size_t); |
fa8d436c | 575 | |
f65fd747 | 576 | |
f65fd747 | 577 | |
fa8d436c UD |
578 | /* |
579 | mallopt(int parameter_number, int parameter_value) | |
580 | Sets tunable parameters The format is to provide a | |
581 | (parameter-number, parameter-value) pair. mallopt then sets the | |
582 | corresponding parameter to the argument value if it can (i.e., so | |
583 | long as the value is meaningful), and returns 1 if successful else | |
584 | 0. SVID/XPG/ANSI defines four standard param numbers for mallopt, | |
585 | normally defined in malloc.h. Only one of these (M_MXFAST) is used | |
586 | in this malloc. The others (M_NLBLKS, M_GRAIN, M_KEEP) don't apply, | |
587 | so setting them has no effect. But this malloc also supports four | |
588 | other options in mallopt. See below for details. Briefly, supported | |
589 | parameters are as follows (listed defaults are for "typical" | |
590 | configurations). | |
591 | ||
592 | Symbol param # default allowed param values | |
593 | M_MXFAST 1 64 0-80 (0 disables fastbins) | |
594 | M_TRIM_THRESHOLD -1 128*1024 any (-1U disables trimming) | |
a9177ff5 | 595 | M_TOP_PAD -2 0 any |
fa8d436c UD |
596 | M_MMAP_THRESHOLD -3 128*1024 any (or 0 if no MMAP support) |
597 | M_MMAP_MAX -4 65536 any (0 disables use of mmap) | |
598 | */ | |
3b49edc0 UD |
599 | int __libc_mallopt(int, int); |
600 | libc_hidden_proto (__libc_mallopt) | |
fa8d436c UD |
601 | |
602 | ||
603 | /* | |
604 | mallinfo() | |
605 | Returns (by copy) a struct containing various summary statistics: | |
606 | ||
a9177ff5 RM |
607 | arena: current total non-mmapped bytes allocated from system |
608 | ordblks: the number of free chunks | |
fa8d436c | 609 | smblks: the number of fastbin blocks (i.e., small chunks that |
72f90263 | 610 | have been freed but not use resused or consolidated) |
a9177ff5 RM |
611 | hblks: current number of mmapped regions |
612 | hblkhd: total bytes held in mmapped regions | |
ca135f82 | 613 | usmblks: always 0 |
a9177ff5 | 614 | fsmblks: total bytes held in fastbin blocks |
fa8d436c | 615 | uordblks: current total allocated space (normal or mmapped) |
a9177ff5 | 616 | fordblks: total free space |
fa8d436c | 617 | keepcost: the maximum number of bytes that could ideally be released |
72f90263 UD |
618 | back to system via malloc_trim. ("ideally" means that |
619 | it ignores page restrictions etc.) | |
fa8d436c UD |
620 | |
621 | Because these fields are ints, but internal bookkeeping may | |
a9177ff5 | 622 | be kept as longs, the reported values may wrap around zero and |
fa8d436c UD |
623 | thus be inaccurate. |
624 | */ | |
3b49edc0 | 625 | struct mallinfo __libc_mallinfo(void); |
88764ae2 | 626 | |
f65fd747 | 627 | |
fa8d436c UD |
628 | /* |
629 | pvalloc(size_t n); | |
630 | Equivalent to valloc(minimum-page-that-holds(n)), that is, | |
631 | round up n to nearest pagesize. | |
632 | */ | |
3b49edc0 | 633 | void* __libc_pvalloc(size_t); |
fa8d436c UD |
634 | |
635 | /* | |
636 | malloc_trim(size_t pad); | |
637 | ||
638 | If possible, gives memory back to the system (via negative | |
639 | arguments to sbrk) if there is unused memory at the `high' end of | |
640 | the malloc pool. You can call this after freeing large blocks of | |
641 | memory to potentially reduce the system-level memory requirements | |
642 | of a program. However, it cannot guarantee to reduce memory. Under | |
643 | some allocation patterns, some large free blocks of memory will be | |
644 | locked between two used chunks, so they cannot be given back to | |
645 | the system. | |
a9177ff5 | 646 | |
fa8d436c UD |
647 | The `pad' argument to malloc_trim represents the amount of free |
648 | trailing space to leave untrimmed. If this argument is zero, | |
649 | only the minimum amount of memory to maintain internal data | |
650 | structures will be left (one page or less). Non-zero arguments | |
651 | can be supplied to maintain enough trailing space to service | |
652 | future expected allocations without having to re-obtain memory | |
653 | from the system. | |
a9177ff5 | 654 | |
fa8d436c UD |
655 | Malloc_trim returns 1 if it actually released any memory, else 0. |
656 | On systems that do not support "negative sbrks", it will always | |
c958a6a4 | 657 | return 0. |
fa8d436c | 658 | */ |
3b49edc0 | 659 | int __malloc_trim(size_t); |
fa8d436c UD |
660 | |
661 | /* | |
22a89187 | 662 | malloc_usable_size(void* p); |
fa8d436c UD |
663 | |
664 | Returns the number of bytes you can actually use in | |
665 | an allocated chunk, which may be more than you requested (although | |
666 | often not) due to alignment and minimum size constraints. | |
667 | You can use this many bytes without worrying about | |
668 | overwriting other allocated objects. This is not a particularly great | |
669 | programming practice. malloc_usable_size can be more useful in | |
670 | debugging and assertions, for example: | |
671 | ||
672 | p = malloc(n); | |
673 | assert(malloc_usable_size(p) >= 256); | |
674 | ||
675 | */ | |
3b49edc0 | 676 | size_t __malloc_usable_size(void*); |
fa8d436c UD |
677 | |
678 | /* | |
679 | malloc_stats(); | |
680 | Prints on stderr the amount of space obtained from the system (both | |
681 | via sbrk and mmap), the maximum amount (which may be more than | |
682 | current if malloc_trim and/or munmap got called), and the current | |
683 | number of bytes allocated via malloc (or realloc, etc) but not yet | |
684 | freed. Note that this is the number of bytes allocated, not the | |
685 | number requested. It will be larger than the number requested | |
686 | because of alignment and bookkeeping overhead. Because it includes | |
687 | alignment wastage as being in use, this figure may be greater than | |
688 | zero even when no user-level chunks are allocated. | |
689 | ||
690 | The reported current and maximum system memory can be inaccurate if | |
691 | a program makes other calls to system memory allocation functions | |
692 | (normally sbrk) outside of malloc. | |
693 | ||
694 | malloc_stats prints only the most commonly interesting statistics. | |
695 | More information can be obtained by calling mallinfo. | |
696 | ||
697 | */ | |
3b49edc0 | 698 | void __malloc_stats(void); |
f65fd747 | 699 | |
f7ddf3d3 UD |
700 | /* |
701 | malloc_get_state(void); | |
702 | ||
703 | Returns the state of all malloc variables in an opaque data | |
704 | structure. | |
705 | */ | |
3b49edc0 | 706 | void* __malloc_get_state(void); |
f7ddf3d3 UD |
707 | |
708 | /* | |
22a89187 | 709 | malloc_set_state(void* state); |
f7ddf3d3 UD |
710 | |
711 | Restore the state of all malloc variables from data obtained with | |
712 | malloc_get_state(). | |
713 | */ | |
3b49edc0 | 714 | int __malloc_set_state(void*); |
f7ddf3d3 | 715 | |
f7ddf3d3 UD |
716 | /* |
717 | posix_memalign(void **memptr, size_t alignment, size_t size); | |
718 | ||
719 | POSIX wrapper like memalign(), checking for validity of size. | |
720 | */ | |
721 | int __posix_memalign(void **, size_t, size_t); | |
f7ddf3d3 | 722 | |
fa8d436c UD |
723 | /* mallopt tuning options */ |
724 | ||
f65fd747 | 725 | /* |
fa8d436c UD |
726 | M_MXFAST is the maximum request size used for "fastbins", special bins |
727 | that hold returned chunks without consolidating their spaces. This | |
728 | enables future requests for chunks of the same size to be handled | |
729 | very quickly, but can increase fragmentation, and thus increase the | |
730 | overall memory footprint of a program. | |
731 | ||
732 | This malloc manages fastbins very conservatively yet still | |
733 | efficiently, so fragmentation is rarely a problem for values less | |
734 | than or equal to the default. The maximum supported value of MXFAST | |
735 | is 80. You wouldn't want it any higher than this anyway. Fastbins | |
736 | are designed especially for use with many small structs, objects or | |
737 | strings -- the default handles structs/objects/arrays with sizes up | |
738 | to 8 4byte fields, or small strings representing words, tokens, | |
739 | etc. Using fastbins for larger objects normally worsens | |
740 | fragmentation without improving speed. | |
741 | ||
742 | M_MXFAST is set in REQUEST size units. It is internally used in | |
743 | chunksize units, which adds padding and alignment. You can reduce | |
744 | M_MXFAST to 0 to disable all use of fastbins. This causes the malloc | |
745 | algorithm to be a closer approximation of fifo-best-fit in all cases, | |
746 | not just for larger requests, but will generally cause it to be | |
747 | slower. | |
f65fd747 UD |
748 | */ |
749 | ||
750 | ||
fa8d436c UD |
751 | /* M_MXFAST is a standard SVID/XPG tuning option, usually listed in malloc.h */ |
752 | #ifndef M_MXFAST | |
a9177ff5 | 753 | #define M_MXFAST 1 |
fa8d436c | 754 | #endif |
f65fd747 | 755 | |
fa8d436c | 756 | #ifndef DEFAULT_MXFAST |
425ce2ed | 757 | #define DEFAULT_MXFAST (64 * SIZE_SZ / 4) |
10dc2a90 UD |
758 | #endif |
759 | ||
10dc2a90 | 760 | |
fa8d436c UD |
761 | /* |
762 | M_TRIM_THRESHOLD is the maximum amount of unused top-most memory | |
763 | to keep before releasing via malloc_trim in free(). | |
764 | ||
765 | Automatic trimming is mainly useful in long-lived programs. | |
766 | Because trimming via sbrk can be slow on some systems, and can | |
767 | sometimes be wasteful (in cases where programs immediately | |
768 | afterward allocate more large chunks) the value should be high | |
769 | enough so that your overall system performance would improve by | |
770 | releasing this much memory. | |
771 | ||
772 | The trim threshold and the mmap control parameters (see below) | |
773 | can be traded off with one another. Trimming and mmapping are | |
774 | two different ways of releasing unused memory back to the | |
775 | system. Between these two, it is often possible to keep | |
776 | system-level demands of a long-lived program down to a bare | |
777 | minimum. For example, in one test suite of sessions measuring | |
778 | the XF86 X server on Linux, using a trim threshold of 128K and a | |
779 | mmap threshold of 192K led to near-minimal long term resource | |
780 | consumption. | |
781 | ||
782 | If you are using this malloc in a long-lived program, it should | |
783 | pay to experiment with these values. As a rough guide, you | |
784 | might set to a value close to the average size of a process | |
785 | (program) running on your system. Releasing this much memory | |
786 | would allow such a process to run in memory. Generally, it's | |
787 | worth it to tune for trimming rather tham memory mapping when a | |
788 | program undergoes phases where several large chunks are | |
789 | allocated and released in ways that can reuse each other's | |
790 | storage, perhaps mixed with phases where there are no such | |
791 | chunks at all. And in well-behaved long-lived programs, | |
792 | controlling release of large blocks via trimming versus mapping | |
793 | is usually faster. | |
794 | ||
795 | However, in most programs, these parameters serve mainly as | |
796 | protection against the system-level effects of carrying around | |
797 | massive amounts of unneeded memory. Since frequent calls to | |
798 | sbrk, mmap, and munmap otherwise degrade performance, the default | |
799 | parameters are set to relatively high values that serve only as | |
800 | safeguards. | |
801 | ||
802 | The trim value It must be greater than page size to have any useful | |
a9177ff5 | 803 | effect. To disable trimming completely, you can set to |
fa8d436c UD |
804 | (unsigned long)(-1) |
805 | ||
806 | Trim settings interact with fastbin (MXFAST) settings: Unless | |
807 | TRIM_FASTBINS is defined, automatic trimming never takes place upon | |
808 | freeing a chunk with size less than or equal to MXFAST. Trimming is | |
809 | instead delayed until subsequent freeing of larger chunks. However, | |
810 | you can still force an attempted trim by calling malloc_trim. | |
811 | ||
812 | Also, trimming is not generally possible in cases where | |
813 | the main arena is obtained via mmap. | |
814 | ||
815 | Note that the trick some people use of mallocing a huge space and | |
816 | then freeing it at program startup, in an attempt to reserve system | |
817 | memory, doesn't have the intended effect under automatic trimming, | |
818 | since that memory will immediately be returned to the system. | |
819 | */ | |
820 | ||
821 | #define M_TRIM_THRESHOLD -1 | |
822 | ||
823 | #ifndef DEFAULT_TRIM_THRESHOLD | |
824 | #define DEFAULT_TRIM_THRESHOLD (128 * 1024) | |
825 | #endif | |
826 | ||
827 | /* | |
828 | M_TOP_PAD is the amount of extra `padding' space to allocate or | |
829 | retain whenever sbrk is called. It is used in two ways internally: | |
830 | ||
831 | * When sbrk is called to extend the top of the arena to satisfy | |
832 | a new malloc request, this much padding is added to the sbrk | |
833 | request. | |
834 | ||
835 | * When malloc_trim is called automatically from free(), | |
836 | it is used as the `pad' argument. | |
837 | ||
838 | In both cases, the actual amount of padding is rounded | |
839 | so that the end of the arena is always a system page boundary. | |
840 | ||
841 | The main reason for using padding is to avoid calling sbrk so | |
842 | often. Having even a small pad greatly reduces the likelihood | |
843 | that nearly every malloc request during program start-up (or | |
844 | after trimming) will invoke sbrk, which needlessly wastes | |
845 | time. | |
846 | ||
847 | Automatic rounding-up to page-size units is normally sufficient | |
848 | to avoid measurable overhead, so the default is 0. However, in | |
849 | systems where sbrk is relatively slow, it can pay to increase | |
850 | this value, at the expense of carrying around more memory than | |
851 | the program needs. | |
852 | */ | |
10dc2a90 | 853 | |
fa8d436c | 854 | #define M_TOP_PAD -2 |
10dc2a90 | 855 | |
fa8d436c UD |
856 | #ifndef DEFAULT_TOP_PAD |
857 | #define DEFAULT_TOP_PAD (0) | |
858 | #endif | |
f65fd747 | 859 | |
1d05c2fb UD |
860 | /* |
861 | MMAP_THRESHOLD_MAX and _MIN are the bounds on the dynamically | |
862 | adjusted MMAP_THRESHOLD. | |
863 | */ | |
864 | ||
865 | #ifndef DEFAULT_MMAP_THRESHOLD_MIN | |
866 | #define DEFAULT_MMAP_THRESHOLD_MIN (128 * 1024) | |
867 | #endif | |
868 | ||
869 | #ifndef DEFAULT_MMAP_THRESHOLD_MAX | |
e404fb16 UD |
870 | /* For 32-bit platforms we cannot increase the maximum mmap |
871 | threshold much because it is also the minimum value for the | |
bd2c2341 UD |
872 | maximum heap size and its alignment. Going above 512k (i.e., 1M |
873 | for new heaps) wastes too much address space. */ | |
e404fb16 | 874 | # if __WORDSIZE == 32 |
bd2c2341 | 875 | # define DEFAULT_MMAP_THRESHOLD_MAX (512 * 1024) |
e404fb16 | 876 | # else |
bd2c2341 | 877 | # define DEFAULT_MMAP_THRESHOLD_MAX (4 * 1024 * 1024 * sizeof(long)) |
e404fb16 | 878 | # endif |
1d05c2fb UD |
879 | #endif |
880 | ||
fa8d436c UD |
881 | /* |
882 | M_MMAP_THRESHOLD is the request size threshold for using mmap() | |
883 | to service a request. Requests of at least this size that cannot | |
884 | be allocated using already-existing space will be serviced via mmap. | |
885 | (If enough normal freed space already exists it is used instead.) | |
886 | ||
887 | Using mmap segregates relatively large chunks of memory so that | |
888 | they can be individually obtained and released from the host | |
889 | system. A request serviced through mmap is never reused by any | |
890 | other request (at least not directly; the system may just so | |
891 | happen to remap successive requests to the same locations). | |
892 | ||
893 | Segregating space in this way has the benefits that: | |
894 | ||
a9177ff5 RM |
895 | 1. Mmapped space can ALWAYS be individually released back |
896 | to the system, which helps keep the system level memory | |
897 | demands of a long-lived program low. | |
fa8d436c UD |
898 | 2. Mapped memory can never become `locked' between |
899 | other chunks, as can happen with normally allocated chunks, which | |
900 | means that even trimming via malloc_trim would not release them. | |
901 | 3. On some systems with "holes" in address spaces, mmap can obtain | |
902 | memory that sbrk cannot. | |
903 | ||
904 | However, it has the disadvantages that: | |
905 | ||
906 | 1. The space cannot be reclaimed, consolidated, and then | |
907 | used to service later requests, as happens with normal chunks. | |
908 | 2. It can lead to more wastage because of mmap page alignment | |
909 | requirements | |
910 | 3. It causes malloc performance to be more dependent on host | |
911 | system memory management support routines which may vary in | |
912 | implementation quality and may impose arbitrary | |
913 | limitations. Generally, servicing a request via normal | |
914 | malloc steps is faster than going through a system's mmap. | |
915 | ||
916 | The advantages of mmap nearly always outweigh disadvantages for | |
917 | "large" chunks, but the value of "large" varies across systems. The | |
918 | default is an empirically derived value that works well in most | |
919 | systems. | |
1d05c2fb UD |
920 | |
921 | ||
922 | Update in 2006: | |
923 | The above was written in 2001. Since then the world has changed a lot. | |
924 | Memory got bigger. Applications got bigger. The virtual address space | |
925 | layout in 32 bit linux changed. | |
926 | ||
927 | In the new situation, brk() and mmap space is shared and there are no | |
928 | artificial limits on brk size imposed by the kernel. What is more, | |
929 | applications have started using transient allocations larger than the | |
930 | 128Kb as was imagined in 2001. | |
931 | ||
932 | The price for mmap is also high now; each time glibc mmaps from the | |
933 | kernel, the kernel is forced to zero out the memory it gives to the | |
934 | application. Zeroing memory is expensive and eats a lot of cache and | |
935 | memory bandwidth. This has nothing to do with the efficiency of the | |
936 | virtual memory system, by doing mmap the kernel just has no choice but | |
937 | to zero. | |
938 | ||
939 | In 2001, the kernel had a maximum size for brk() which was about 800 | |
940 | megabytes on 32 bit x86, at that point brk() would hit the first | |
941 | mmaped shared libaries and couldn't expand anymore. With current 2.6 | |
942 | kernels, the VA space layout is different and brk() and mmap | |
943 | both can span the entire heap at will. | |
944 | ||
945 | Rather than using a static threshold for the brk/mmap tradeoff, | |
946 | we are now using a simple dynamic one. The goal is still to avoid | |
947 | fragmentation. The old goals we kept are | |
948 | 1) try to get the long lived large allocations to use mmap() | |
949 | 2) really large allocations should always use mmap() | |
950 | and we're adding now: | |
951 | 3) transient allocations should use brk() to avoid forcing the kernel | |
952 | having to zero memory over and over again | |
953 | ||
954 | The implementation works with a sliding threshold, which is by default | |
955 | limited to go between 128Kb and 32Mb (64Mb for 64 bitmachines) and starts | |
956 | out at 128Kb as per the 2001 default. | |
957 | ||
958 | This allows us to satisfy requirement 1) under the assumption that long | |
959 | lived allocations are made early in the process' lifespan, before it has | |
960 | started doing dynamic allocations of the same size (which will | |
961 | increase the threshold). | |
962 | ||
963 | The upperbound on the threshold satisfies requirement 2) | |
964 | ||
965 | The threshold goes up in value when the application frees memory that was | |
966 | allocated with the mmap allocator. The idea is that once the application | |
967 | starts freeing memory of a certain size, it's highly probable that this is | |
968 | a size the application uses for transient allocations. This estimator | |
969 | is there to satisfy the new third requirement. | |
970 | ||
f65fd747 UD |
971 | */ |
972 | ||
fa8d436c | 973 | #define M_MMAP_THRESHOLD -3 |
f65fd747 | 974 | |
fa8d436c | 975 | #ifndef DEFAULT_MMAP_THRESHOLD |
1d05c2fb | 976 | #define DEFAULT_MMAP_THRESHOLD DEFAULT_MMAP_THRESHOLD_MIN |
fa8d436c UD |
977 | #endif |
978 | ||
979 | /* | |
980 | M_MMAP_MAX is the maximum number of requests to simultaneously | |
981 | service using mmap. This parameter exists because | |
982 | some systems have a limited number of internal tables for | |
983 | use by mmap, and using more than a few of them may degrade | |
984 | performance. | |
985 | ||
986 | The default is set to a value that serves only as a safeguard. | |
22a89187 | 987 | Setting to 0 disables use of mmap for servicing large requests. |
fa8d436c | 988 | */ |
f65fd747 | 989 | |
fa8d436c UD |
990 | #define M_MMAP_MAX -4 |
991 | ||
992 | #ifndef DEFAULT_MMAP_MAX | |
fa8d436c | 993 | #define DEFAULT_MMAP_MAX (65536) |
f65fd747 UD |
994 | #endif |
995 | ||
100351c3 | 996 | #include <malloc.h> |
f65fd747 | 997 | |
fa8d436c UD |
998 | #ifndef RETURN_ADDRESS |
999 | #define RETURN_ADDRESS(X_) (NULL) | |
9ae6fc54 | 1000 | #endif |
431c33c0 | 1001 | |
fa8d436c UD |
1002 | /* Forward declarations. */ |
1003 | struct malloc_chunk; | |
1004 | typedef struct malloc_chunk* mchunkptr; | |
431c33c0 | 1005 | |
fa8d436c | 1006 | /* Internal routines. */ |
f65fd747 | 1007 | |
22a89187 | 1008 | static void* _int_malloc(mstate, size_t); |
425ce2ed | 1009 | static void _int_free(mstate, mchunkptr, int); |
22a89187 | 1010 | static void* _int_realloc(mstate, mchunkptr, INTERNAL_SIZE_T, |
6e4b2107 | 1011 | INTERNAL_SIZE_T); |
22a89187 | 1012 | static void* _int_memalign(mstate, size_t, size_t); |
10ad46bc OB |
1013 | static void* _mid_memalign(size_t, size_t, void *); |
1014 | ||
ac3ed168 | 1015 | static void malloc_printerr(const char *str) __attribute__ ((noreturn)); |
fa8d436c | 1016 | |
0c71122c FW |
1017 | static void* mem2mem_check(void *p, size_t sz); |
1018 | static void top_check(void); | |
1019 | static void munmap_chunk(mchunkptr p); | |
a9177ff5 | 1020 | #if HAVE_MREMAP |
0c71122c | 1021 | static mchunkptr mremap_chunk(mchunkptr p, size_t new_size); |
a9177ff5 | 1022 | #endif |
fa8d436c | 1023 | |
22a89187 UD |
1024 | static void* malloc_check(size_t sz, const void *caller); |
1025 | static void free_check(void* mem, const void *caller); | |
1026 | static void* realloc_check(void* oldmem, size_t bytes, | |
1027 | const void *caller); | |
1028 | static void* memalign_check(size_t alignment, size_t bytes, | |
1029 | const void *caller); | |
f65fd747 | 1030 | |
fa8d436c | 1031 | /* ------------------ MMAP support ------------------ */ |
f65fd747 | 1032 | |
f65fd747 | 1033 | |
fa8d436c | 1034 | #include <fcntl.h> |
fa8d436c | 1035 | #include <sys/mman.h> |
f65fd747 | 1036 | |
fa8d436c UD |
1037 | #if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) |
1038 | # define MAP_ANONYMOUS MAP_ANON | |
1039 | #endif | |
f65fd747 | 1040 | |
fa8d436c | 1041 | #ifndef MAP_NORESERVE |
3b49edc0 | 1042 | # define MAP_NORESERVE 0 |
f65fd747 UD |
1043 | #endif |
1044 | ||
fa8d436c | 1045 | #define MMAP(addr, size, prot, flags) \ |
3b49edc0 | 1046 | __mmap((addr), (size), (prot), (flags)|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0) |
f65fd747 | 1047 | |
f65fd747 UD |
1048 | |
1049 | /* | |
fa8d436c | 1050 | ----------------------- Chunk representations ----------------------- |
f65fd747 UD |
1051 | */ |
1052 | ||
1053 | ||
fa8d436c UD |
1054 | /* |
1055 | This struct declaration is misleading (but accurate and necessary). | |
1056 | It declares a "view" into memory allowing access to necessary | |
1057 | fields at known offsets from a given base. See explanation below. | |
1058 | */ | |
1059 | ||
1060 | struct malloc_chunk { | |
1061 | ||
e9c4fe93 FW |
1062 | INTERNAL_SIZE_T mchunk_prev_size; /* Size of previous chunk (if free). */ |
1063 | INTERNAL_SIZE_T mchunk_size; /* Size in bytes, including overhead. */ | |
fa8d436c UD |
1064 | |
1065 | struct malloc_chunk* fd; /* double links -- used only if free. */ | |
f65fd747 | 1066 | struct malloc_chunk* bk; |
7ecfbd38 UD |
1067 | |
1068 | /* Only used for large blocks: pointer to next larger size. */ | |
1069 | struct malloc_chunk* fd_nextsize; /* double links -- used only if free. */ | |
1070 | struct malloc_chunk* bk_nextsize; | |
f65fd747 UD |
1071 | }; |
1072 | ||
f65fd747 UD |
1073 | |
1074 | /* | |
f65fd747 UD |
1075 | malloc_chunk details: |
1076 | ||
1077 | (The following includes lightly edited explanations by Colin Plumb.) | |
1078 | ||
1079 | Chunks of memory are maintained using a `boundary tag' method as | |
1080 | described in e.g., Knuth or Standish. (See the paper by Paul | |
1081 | Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a | |
1082 | survey of such techniques.) Sizes of free chunks are stored both | |
1083 | in the front of each chunk and at the end. This makes | |
1084 | consolidating fragmented chunks into bigger chunks very fast. The | |
1085 | size fields also hold bits representing whether chunks are free or | |
1086 | in use. | |
1087 | ||
1088 | An allocated chunk looks like this: | |
1089 | ||
1090 | ||
1091 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
ae9166f2 | 1092 | | Size of previous chunk, if unallocated (P clear) | |
72f90263 | 1093 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
ae9166f2 | 1094 | | Size of chunk, in bytes |A|M|P| |
f65fd747 | 1095 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
72f90263 UD |
1096 | | User data starts here... . |
1097 | . . | |
1098 | . (malloc_usable_size() bytes) . | |
1099 | . | | |
f65fd747 | 1100 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
ae9166f2 FW |
1101 | | (size of chunk, but used for application data) | |
1102 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1103 | | Size of next chunk, in bytes |A|0|1| | |
72f90263 | 1104 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
f65fd747 UD |
1105 | |
1106 | Where "chunk" is the front of the chunk for the purpose of most of | |
1107 | the malloc code, but "mem" is the pointer that is returned to the | |
1108 | user. "Nextchunk" is the beginning of the next contiguous chunk. | |
1109 | ||
6f65e668 | 1110 | Chunks always begin on even word boundaries, so the mem portion |
f65fd747 | 1111 | (which is returned to the user) is also on an even word boundary, and |
fa8d436c | 1112 | thus at least double-word aligned. |
f65fd747 UD |
1113 | |
1114 | Free chunks are stored in circular doubly-linked lists, and look like this: | |
1115 | ||
1116 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
ae9166f2 | 1117 | | Size of previous chunk, if unallocated (P clear) | |
72f90263 | 1118 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
ae9166f2 | 1119 | `head:' | Size of chunk, in bytes |A|0|P| |
f65fd747 | 1120 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
72f90263 UD |
1121 | | Forward pointer to next chunk in list | |
1122 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1123 | | Back pointer to previous chunk in list | | |
1124 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1125 | | Unused space (may be 0 bytes long) . | |
1126 | . . | |
1127 | . | | |
f65fd747 UD |
1128 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1129 | `foot:' | Size of chunk, in bytes | | |
72f90263 | 1130 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
ae9166f2 FW |
1131 | | Size of next chunk, in bytes |A|0|0| |
1132 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
f65fd747 UD |
1133 | |
1134 | The P (PREV_INUSE) bit, stored in the unused low-order bit of the | |
1135 | chunk size (which is always a multiple of two words), is an in-use | |
1136 | bit for the *previous* chunk. If that bit is *clear*, then the | |
1137 | word before the current chunk size contains the previous chunk | |
1138 | size, and can be used to find the front of the previous chunk. | |
fa8d436c UD |
1139 | The very first chunk allocated always has this bit set, |
1140 | preventing access to non-existent (or non-owned) memory. If | |
1141 | prev_inuse is set for any given chunk, then you CANNOT determine | |
1142 | the size of the previous chunk, and might even get a memory | |
1143 | addressing fault when trying to do so. | |
f65fd747 | 1144 | |
ae9166f2 FW |
1145 | The A (NON_MAIN_ARENA) bit is cleared for chunks on the initial, |
1146 | main arena, described by the main_arena variable. When additional | |
1147 | threads are spawned, each thread receives its own arena (up to a | |
1148 | configurable limit, after which arenas are reused for multiple | |
1149 | threads), and the chunks in these arenas have the A bit set. To | |
1150 | find the arena for a chunk on such a non-main arena, heap_for_ptr | |
1151 | performs a bit mask operation and indirection through the ar_ptr | |
1152 | member of the per-heap header heap_info (see arena.c). | |
1153 | ||
f65fd747 | 1154 | Note that the `foot' of the current chunk is actually represented |
fa8d436c UD |
1155 | as the prev_size of the NEXT chunk. This makes it easier to |
1156 | deal with alignments etc but can be very confusing when trying | |
1157 | to extend or adapt this code. | |
f65fd747 | 1158 | |
ae9166f2 | 1159 | The three exceptions to all this are: |
f65fd747 | 1160 | |
fa8d436c | 1161 | 1. The special chunk `top' doesn't bother using the |
72f90263 UD |
1162 | trailing size field since there is no next contiguous chunk |
1163 | that would have to index off it. After initialization, `top' | |
1164 | is forced to always exist. If it would become less than | |
1165 | MINSIZE bytes long, it is replenished. | |
f65fd747 UD |
1166 | |
1167 | 2. Chunks allocated via mmap, which have the second-lowest-order | |
72f90263 | 1168 | bit M (IS_MMAPPED) set in their size fields. Because they are |
ae9166f2 FW |
1169 | allocated one-by-one, each must contain its own trailing size |
1170 | field. If the M bit is set, the other bits are ignored | |
1171 | (because mmapped chunks are neither in an arena, nor adjacent | |
1172 | to a freed chunk). The M bit is also used for chunks which | |
1173 | originally came from a dumped heap via malloc_set_state in | |
1174 | hooks.c. | |
1175 | ||
1176 | 3. Chunks in fastbins are treated as allocated chunks from the | |
1177 | point of view of the chunk allocator. They are consolidated | |
1178 | with their neighbors only in bulk, in malloc_consolidate. | |
f65fd747 UD |
1179 | */ |
1180 | ||
1181 | /* | |
fa8d436c UD |
1182 | ---------- Size and alignment checks and conversions ---------- |
1183 | */ | |
f65fd747 | 1184 | |
fa8d436c | 1185 | /* conversion from malloc headers to user pointers, and back */ |
f65fd747 | 1186 | |
22a89187 | 1187 | #define chunk2mem(p) ((void*)((char*)(p) + 2*SIZE_SZ)) |
fa8d436c | 1188 | #define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ)) |
f65fd747 | 1189 | |
fa8d436c | 1190 | /* The smallest possible chunk */ |
7ecfbd38 | 1191 | #define MIN_CHUNK_SIZE (offsetof(struct malloc_chunk, fd_nextsize)) |
f65fd747 | 1192 | |
fa8d436c | 1193 | /* The smallest size we can malloc is an aligned minimal chunk */ |
f65fd747 | 1194 | |
fa8d436c UD |
1195 | #define MINSIZE \ |
1196 | (unsigned long)(((MIN_CHUNK_SIZE+MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK)) | |
f65fd747 | 1197 | |
fa8d436c | 1198 | /* Check if m has acceptable alignment */ |
f65fd747 | 1199 | |
073f560e UD |
1200 | #define aligned_OK(m) (((unsigned long)(m) & MALLOC_ALIGN_MASK) == 0) |
1201 | ||
1202 | #define misaligned_chunk(p) \ | |
1203 | ((uintptr_t)(MALLOC_ALIGNMENT == 2 * SIZE_SZ ? (p) : chunk2mem (p)) \ | |
1204 | & MALLOC_ALIGN_MASK) | |
f65fd747 | 1205 | |
f65fd747 | 1206 | |
a9177ff5 | 1207 | /* |
fa8d436c UD |
1208 | Check if a request is so large that it would wrap around zero when |
1209 | padded and aligned. To simplify some other code, the bound is made | |
1210 | low enough so that adding MINSIZE will also not wrap around zero. | |
6c8dbf00 | 1211 | */ |
f65fd747 | 1212 | |
fa8d436c | 1213 | #define REQUEST_OUT_OF_RANGE(req) \ |
6c8dbf00 OB |
1214 | ((unsigned long) (req) >= \ |
1215 | (unsigned long) (INTERNAL_SIZE_T) (-2 * MINSIZE)) | |
f65fd747 | 1216 | |
fa8d436c | 1217 | /* pad request bytes into a usable size -- internal version */ |
f65fd747 | 1218 | |
fa8d436c UD |
1219 | #define request2size(req) \ |
1220 | (((req) + SIZE_SZ + MALLOC_ALIGN_MASK < MINSIZE) ? \ | |
1221 | MINSIZE : \ | |
1222 | ((req) + SIZE_SZ + MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK) | |
f65fd747 | 1223 | |
fa8d436c | 1224 | /* Same, except also perform argument check */ |
f65fd747 | 1225 | |
fa8d436c | 1226 | #define checked_request2size(req, sz) \ |
6c8dbf00 OB |
1227 | if (REQUEST_OUT_OF_RANGE (req)) { \ |
1228 | __set_errno (ENOMEM); \ | |
1229 | return 0; \ | |
1230 | } \ | |
1231 | (sz) = request2size (req); | |
f65fd747 UD |
1232 | |
1233 | /* | |
6c8dbf00 OB |
1234 | --------------- Physical chunk operations --------------- |
1235 | */ | |
f65fd747 | 1236 | |
10dc2a90 | 1237 | |
fa8d436c UD |
1238 | /* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */ |
1239 | #define PREV_INUSE 0x1 | |
f65fd747 | 1240 | |
fa8d436c | 1241 | /* extract inuse bit of previous chunk */ |
e9c4fe93 | 1242 | #define prev_inuse(p) ((p)->mchunk_size & PREV_INUSE) |
f65fd747 | 1243 | |
f65fd747 | 1244 | |
fa8d436c UD |
1245 | /* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */ |
1246 | #define IS_MMAPPED 0x2 | |
f65fd747 | 1247 | |
fa8d436c | 1248 | /* check for mmap()'ed chunk */ |
e9c4fe93 | 1249 | #define chunk_is_mmapped(p) ((p)->mchunk_size & IS_MMAPPED) |
f65fd747 | 1250 | |
f65fd747 | 1251 | |
fa8d436c UD |
1252 | /* size field is or'ed with NON_MAIN_ARENA if the chunk was obtained |
1253 | from a non-main arena. This is only set immediately before handing | |
1254 | the chunk to the user, if necessary. */ | |
1255 | #define NON_MAIN_ARENA 0x4 | |
f65fd747 | 1256 | |
ae9166f2 | 1257 | /* Check for chunk from main arena. */ |
e9c4fe93 FW |
1258 | #define chunk_main_arena(p) (((p)->mchunk_size & NON_MAIN_ARENA) == 0) |
1259 | ||
1260 | /* Mark a chunk as not being on the main arena. */ | |
1261 | #define set_non_main_arena(p) ((p)->mchunk_size |= NON_MAIN_ARENA) | |
f65fd747 UD |
1262 | |
1263 | ||
a9177ff5 | 1264 | /* |
6c8dbf00 | 1265 | Bits to mask off when extracting size |
f65fd747 | 1266 | |
6c8dbf00 OB |
1267 | Note: IS_MMAPPED is intentionally not masked off from size field in |
1268 | macros for which mmapped chunks should never be seen. This should | |
1269 | cause helpful core dumps to occur if it is tried by accident by | |
1270 | people extending or adapting this malloc. | |
1271 | */ | |
1272 | #define SIZE_BITS (PREV_INUSE | IS_MMAPPED | NON_MAIN_ARENA) | |
f65fd747 | 1273 | |
fa8d436c | 1274 | /* Get size, ignoring use bits */ |
e9c4fe93 | 1275 | #define chunksize(p) (chunksize_nomask (p) & ~(SIZE_BITS)) |
f65fd747 | 1276 | |
e9c4fe93 FW |
1277 | /* Like chunksize, but do not mask SIZE_BITS. */ |
1278 | #define chunksize_nomask(p) ((p)->mchunk_size) | |
f65fd747 | 1279 | |
fa8d436c | 1280 | /* Ptr to next physical malloc_chunk. */ |
e9c4fe93 FW |
1281 | #define next_chunk(p) ((mchunkptr) (((char *) (p)) + chunksize (p))) |
1282 | ||
1283 | /* Size of the chunk below P. Only valid if prev_inuse (P). */ | |
1284 | #define prev_size(p) ((p)->mchunk_prev_size) | |
1285 | ||
1286 | /* Set the size of the chunk below P. Only valid if prev_inuse (P). */ | |
1287 | #define set_prev_size(p, sz) ((p)->mchunk_prev_size = (sz)) | |
f65fd747 | 1288 | |
e9c4fe93 FW |
1289 | /* Ptr to previous physical malloc_chunk. Only valid if prev_inuse (P). */ |
1290 | #define prev_chunk(p) ((mchunkptr) (((char *) (p)) - prev_size (p))) | |
f65fd747 | 1291 | |
fa8d436c | 1292 | /* Treat space at ptr + offset as a chunk */ |
6c8dbf00 | 1293 | #define chunk_at_offset(p, s) ((mchunkptr) (((char *) (p)) + (s))) |
fa8d436c UD |
1294 | |
1295 | /* extract p's inuse bit */ | |
6c8dbf00 | 1296 | #define inuse(p) \ |
e9c4fe93 | 1297 | ((((mchunkptr) (((char *) (p)) + chunksize (p)))->mchunk_size) & PREV_INUSE) |
f65fd747 | 1298 | |
fa8d436c | 1299 | /* set/clear chunk as being inuse without otherwise disturbing */ |
6c8dbf00 | 1300 | #define set_inuse(p) \ |
e9c4fe93 | 1301 | ((mchunkptr) (((char *) (p)) + chunksize (p)))->mchunk_size |= PREV_INUSE |
f65fd747 | 1302 | |
6c8dbf00 | 1303 | #define clear_inuse(p) \ |
e9c4fe93 | 1304 | ((mchunkptr) (((char *) (p)) + chunksize (p)))->mchunk_size &= ~(PREV_INUSE) |
f65fd747 UD |
1305 | |
1306 | ||
fa8d436c | 1307 | /* check/set/clear inuse bits in known places */ |
6c8dbf00 | 1308 | #define inuse_bit_at_offset(p, s) \ |
e9c4fe93 | 1309 | (((mchunkptr) (((char *) (p)) + (s)))->mchunk_size & PREV_INUSE) |
f65fd747 | 1310 | |
6c8dbf00 | 1311 | #define set_inuse_bit_at_offset(p, s) \ |
e9c4fe93 | 1312 | (((mchunkptr) (((char *) (p)) + (s)))->mchunk_size |= PREV_INUSE) |
f65fd747 | 1313 | |
6c8dbf00 | 1314 | #define clear_inuse_bit_at_offset(p, s) \ |
e9c4fe93 | 1315 | (((mchunkptr) (((char *) (p)) + (s)))->mchunk_size &= ~(PREV_INUSE)) |
f65fd747 | 1316 | |
f65fd747 | 1317 | |
fa8d436c | 1318 | /* Set size at head, without disturbing its use bit */ |
e9c4fe93 | 1319 | #define set_head_size(p, s) ((p)->mchunk_size = (((p)->mchunk_size & SIZE_BITS) | (s))) |
f65fd747 | 1320 | |
fa8d436c | 1321 | /* Set size/use field */ |
e9c4fe93 | 1322 | #define set_head(p, s) ((p)->mchunk_size = (s)) |
f65fd747 | 1323 | |
fa8d436c | 1324 | /* Set size at footer (only when chunk is not in use) */ |
e9c4fe93 | 1325 | #define set_foot(p, s) (((mchunkptr) ((char *) (p) + (s)))->mchunk_prev_size = (s)) |
f65fd747 UD |
1326 | |
1327 | ||
e9c4fe93 FW |
1328 | #pragma GCC poison mchunk_size |
1329 | #pragma GCC poison mchunk_prev_size | |
1330 | ||
fa8d436c | 1331 | /* |
6c8dbf00 | 1332 | -------------------- Internal data structures -------------------- |
fa8d436c UD |
1333 | |
1334 | All internal state is held in an instance of malloc_state defined | |
1335 | below. There are no other static variables, except in two optional | |
a9177ff5 | 1336 | cases: |
6c8dbf00 OB |
1337 | * If USE_MALLOC_LOCK is defined, the mALLOC_MUTEx declared above. |
1338 | * If mmap doesn't support MAP_ANONYMOUS, a dummy file descriptor | |
22a89187 | 1339 | for mmap. |
fa8d436c UD |
1340 | |
1341 | Beware of lots of tricks that minimize the total bookkeeping space | |
1342 | requirements. The result is a little over 1K bytes (for 4byte | |
1343 | pointers and size_t.) | |
6c8dbf00 | 1344 | */ |
f65fd747 UD |
1345 | |
1346 | /* | |
6c8dbf00 | 1347 | Bins |
fa8d436c UD |
1348 | |
1349 | An array of bin headers for free chunks. Each bin is doubly | |
1350 | linked. The bins are approximately proportionally (log) spaced. | |
1351 | There are a lot of these bins (128). This may look excessive, but | |
1352 | works very well in practice. Most bins hold sizes that are | |
1353 | unusual as malloc request sizes, but are more usual for fragments | |
1354 | and consolidated sets of chunks, which is what these bins hold, so | |
1355 | they can be found quickly. All procedures maintain the invariant | |
1356 | that no consolidated chunk physically borders another one, so each | |
1357 | chunk in a list is known to be preceeded and followed by either | |
1358 | inuse chunks or the ends of memory. | |
1359 | ||
1360 | Chunks in bins are kept in size order, with ties going to the | |
1361 | approximately least recently used chunk. Ordering isn't needed | |
1362 | for the small bins, which all contain the same-sized chunks, but | |
1363 | facilitates best-fit allocation for larger chunks. These lists | |
1364 | are just sequential. Keeping them in order almost never requires | |
1365 | enough traversal to warrant using fancier ordered data | |
a9177ff5 | 1366 | structures. |
fa8d436c UD |
1367 | |
1368 | Chunks of the same size are linked with the most | |
1369 | recently freed at the front, and allocations are taken from the | |
1370 | back. This results in LRU (FIFO) allocation order, which tends | |
1371 | to give each chunk an equal opportunity to be consolidated with | |
1372 | adjacent freed chunks, resulting in larger free chunks and less | |
1373 | fragmentation. | |
1374 | ||
1375 | To simplify use in double-linked lists, each bin header acts | |
1376 | as a malloc_chunk. This avoids special-casing for headers. | |
1377 | But to conserve space and improve locality, we allocate | |
1378 | only the fd/bk pointers of bins, and then use repositioning tricks | |
a9177ff5 | 1379 | to treat these as the fields of a malloc_chunk*. |
6c8dbf00 | 1380 | */ |
f65fd747 | 1381 | |
6c8dbf00 | 1382 | typedef struct malloc_chunk *mbinptr; |
f65fd747 | 1383 | |
fa8d436c | 1384 | /* addressing -- note that bin_at(0) does not exist */ |
41999a1a UD |
1385 | #define bin_at(m, i) \ |
1386 | (mbinptr) (((char *) &((m)->bins[((i) - 1) * 2])) \ | |
6c8dbf00 | 1387 | - offsetof (struct malloc_chunk, fd)) |
f65fd747 | 1388 | |
fa8d436c | 1389 | /* analog of ++bin */ |
6c8dbf00 | 1390 | #define next_bin(b) ((mbinptr) ((char *) (b) + (sizeof (mchunkptr) << 1))) |
f65fd747 | 1391 | |
fa8d436c UD |
1392 | /* Reminders about list directionality within bins */ |
1393 | #define first(b) ((b)->fd) | |
1394 | #define last(b) ((b)->bk) | |
f65fd747 | 1395 | |
fa8d436c | 1396 | /* Take a chunk off a bin list */ |
fff94fa2 | 1397 | #define unlink(AV, P, BK, FD) { \ |
17f487b7 | 1398 | if (__builtin_expect (chunksize(P) != prev_size (next_chunk(P)), 0)) \ |
ac3ed168 | 1399 | malloc_printerr ("corrupted size vs. prev_size"); \ |
6c8dbf00 OB |
1400 | FD = P->fd; \ |
1401 | BK = P->bk; \ | |
1402 | if (__builtin_expect (FD->bk != P || BK->fd != P, 0)) \ | |
ac3ed168 | 1403 | malloc_printerr ("corrupted double-linked list"); \ |
6c8dbf00 OB |
1404 | else { \ |
1405 | FD->bk = BK; \ | |
1406 | BK->fd = FD; \ | |
e9c4fe93 | 1407 | if (!in_smallbin_range (chunksize_nomask (P)) \ |
6c8dbf00 | 1408 | && __builtin_expect (P->fd_nextsize != NULL, 0)) { \ |
52ffbdf2 FW |
1409 | if (__builtin_expect (P->fd_nextsize->bk_nextsize != P, 0) \ |
1410 | || __builtin_expect (P->bk_nextsize->fd_nextsize != P, 0)) \ | |
ac3ed168 | 1411 | malloc_printerr ("corrupted double-linked list (not small)"); \ |
6c8dbf00 OB |
1412 | if (FD->fd_nextsize == NULL) { \ |
1413 | if (P->fd_nextsize == P) \ | |
1414 | FD->fd_nextsize = FD->bk_nextsize = FD; \ | |
1415 | else { \ | |
1416 | FD->fd_nextsize = P->fd_nextsize; \ | |
1417 | FD->bk_nextsize = P->bk_nextsize; \ | |
1418 | P->fd_nextsize->bk_nextsize = FD; \ | |
1419 | P->bk_nextsize->fd_nextsize = FD; \ | |
1420 | } \ | |
1421 | } else { \ | |
1422 | P->fd_nextsize->bk_nextsize = P->bk_nextsize; \ | |
1423 | P->bk_nextsize->fd_nextsize = P->fd_nextsize; \ | |
1424 | } \ | |
1425 | } \ | |
1426 | } \ | |
fa8d436c | 1427 | } |
f65fd747 | 1428 | |
fa8d436c | 1429 | /* |
6c8dbf00 | 1430 | Indexing |
fa8d436c UD |
1431 | |
1432 | Bins for sizes < 512 bytes contain chunks of all the same size, spaced | |
1433 | 8 bytes apart. Larger bins are approximately logarithmically spaced: | |
f65fd747 | 1434 | |
fa8d436c UD |
1435 | 64 bins of size 8 |
1436 | 32 bins of size 64 | |
1437 | 16 bins of size 512 | |
1438 | 8 bins of size 4096 | |
1439 | 4 bins of size 32768 | |
1440 | 2 bins of size 262144 | |
1441 | 1 bin of size what's left | |
f65fd747 | 1442 | |
fa8d436c UD |
1443 | There is actually a little bit of slop in the numbers in bin_index |
1444 | for the sake of speed. This makes no difference elsewhere. | |
f65fd747 | 1445 | |
fa8d436c UD |
1446 | The bins top out around 1MB because we expect to service large |
1447 | requests via mmap. | |
b5a2bbe6 L |
1448 | |
1449 | Bin 0 does not exist. Bin 1 is the unordered list; if that would be | |
1450 | a valid chunk size the small bins are bumped up one. | |
6c8dbf00 | 1451 | */ |
f65fd747 | 1452 | |
fa8d436c UD |
1453 | #define NBINS 128 |
1454 | #define NSMALLBINS 64 | |
1d47e92f | 1455 | #define SMALLBIN_WIDTH MALLOC_ALIGNMENT |
b5a2bbe6 L |
1456 | #define SMALLBIN_CORRECTION (MALLOC_ALIGNMENT > 2 * SIZE_SZ) |
1457 | #define MIN_LARGE_SIZE ((NSMALLBINS - SMALLBIN_CORRECTION) * SMALLBIN_WIDTH) | |
f65fd747 | 1458 | |
fa8d436c | 1459 | #define in_smallbin_range(sz) \ |
6c8dbf00 | 1460 | ((unsigned long) (sz) < (unsigned long) MIN_LARGE_SIZE) |
f65fd747 | 1461 | |
1d47e92f | 1462 | #define smallbin_index(sz) \ |
6c8dbf00 | 1463 | ((SMALLBIN_WIDTH == 16 ? (((unsigned) (sz)) >> 4) : (((unsigned) (sz)) >> 3))\ |
b5a2bbe6 | 1464 | + SMALLBIN_CORRECTION) |
f65fd747 | 1465 | |
1d47e92f | 1466 | #define largebin_index_32(sz) \ |
6c8dbf00 OB |
1467 | (((((unsigned long) (sz)) >> 6) <= 38) ? 56 + (((unsigned long) (sz)) >> 6) :\ |
1468 | ((((unsigned long) (sz)) >> 9) <= 20) ? 91 + (((unsigned long) (sz)) >> 9) :\ | |
1469 | ((((unsigned long) (sz)) >> 12) <= 10) ? 110 + (((unsigned long) (sz)) >> 12) :\ | |
1470 | ((((unsigned long) (sz)) >> 15) <= 4) ? 119 + (((unsigned long) (sz)) >> 15) :\ | |
1471 | ((((unsigned long) (sz)) >> 18) <= 2) ? 124 + (((unsigned long) (sz)) >> 18) :\ | |
1472 | 126) | |
f65fd747 | 1473 | |
b5a2bbe6 | 1474 | #define largebin_index_32_big(sz) \ |
6c8dbf00 OB |
1475 | (((((unsigned long) (sz)) >> 6) <= 45) ? 49 + (((unsigned long) (sz)) >> 6) :\ |
1476 | ((((unsigned long) (sz)) >> 9) <= 20) ? 91 + (((unsigned long) (sz)) >> 9) :\ | |
1477 | ((((unsigned long) (sz)) >> 12) <= 10) ? 110 + (((unsigned long) (sz)) >> 12) :\ | |
1478 | ((((unsigned long) (sz)) >> 15) <= 4) ? 119 + (((unsigned long) (sz)) >> 15) :\ | |
1479 | ((((unsigned long) (sz)) >> 18) <= 2) ? 124 + (((unsigned long) (sz)) >> 18) :\ | |
1480 | 126) | |
b5a2bbe6 | 1481 | |
1d47e92f UD |
1482 | // XXX It remains to be seen whether it is good to keep the widths of |
1483 | // XXX the buckets the same or whether it should be scaled by a factor | |
1484 | // XXX of two as well. | |
1485 | #define largebin_index_64(sz) \ | |
6c8dbf00 OB |
1486 | (((((unsigned long) (sz)) >> 6) <= 48) ? 48 + (((unsigned long) (sz)) >> 6) :\ |
1487 | ((((unsigned long) (sz)) >> 9) <= 20) ? 91 + (((unsigned long) (sz)) >> 9) :\ | |
1488 | ((((unsigned long) (sz)) >> 12) <= 10) ? 110 + (((unsigned long) (sz)) >> 12) :\ | |
1489 | ((((unsigned long) (sz)) >> 15) <= 4) ? 119 + (((unsigned long) (sz)) >> 15) :\ | |
1490 | ((((unsigned long) (sz)) >> 18) <= 2) ? 124 + (((unsigned long) (sz)) >> 18) :\ | |
1491 | 126) | |
1d47e92f UD |
1492 | |
1493 | #define largebin_index(sz) \ | |
b5a2bbe6 L |
1494 | (SIZE_SZ == 8 ? largebin_index_64 (sz) \ |
1495 | : MALLOC_ALIGNMENT == 16 ? largebin_index_32_big (sz) \ | |
1496 | : largebin_index_32 (sz)) | |
1d47e92f | 1497 | |
fa8d436c | 1498 | #define bin_index(sz) \ |
6c8dbf00 | 1499 | ((in_smallbin_range (sz)) ? smallbin_index (sz) : largebin_index (sz)) |
f65fd747 | 1500 | |
f65fd747 UD |
1501 | |
1502 | /* | |
6c8dbf00 | 1503 | Unsorted chunks |
fa8d436c UD |
1504 | |
1505 | All remainders from chunk splits, as well as all returned chunks, | |
1506 | are first placed in the "unsorted" bin. They are then placed | |
1507 | in regular bins after malloc gives them ONE chance to be used before | |
1508 | binning. So, basically, the unsorted_chunks list acts as a queue, | |
1509 | with chunks being placed on it in free (and malloc_consolidate), | |
1510 | and taken off (to be either used or placed in bins) in malloc. | |
1511 | ||
1512 | The NON_MAIN_ARENA flag is never set for unsorted chunks, so it | |
1513 | does not have to be taken into account in size comparisons. | |
6c8dbf00 | 1514 | */ |
f65fd747 | 1515 | |
fa8d436c | 1516 | /* The otherwise unindexable 1-bin is used to hold unsorted chunks. */ |
6c8dbf00 | 1517 | #define unsorted_chunks(M) (bin_at (M, 1)) |
f65fd747 | 1518 | |
fa8d436c | 1519 | /* |
6c8dbf00 | 1520 | Top |
fa8d436c UD |
1521 | |
1522 | The top-most available chunk (i.e., the one bordering the end of | |
1523 | available memory) is treated specially. It is never included in | |
1524 | any bin, is used only if no other chunk is available, and is | |
1525 | released back to the system if it is very large (see | |
1526 | M_TRIM_THRESHOLD). Because top initially | |
1527 | points to its own bin with initial zero size, thus forcing | |
1528 | extension on the first malloc request, we avoid having any special | |
1529 | code in malloc to check whether it even exists yet. But we still | |
1530 | need to do so when getting memory from system, so we make | |
1531 | initial_top treat the bin as a legal but unusable chunk during the | |
1532 | interval between initialization and the first call to | |
3b49edc0 | 1533 | sysmalloc. (This is somewhat delicate, since it relies on |
fa8d436c | 1534 | the 2 preceding words to be zero during this interval as well.) |
6c8dbf00 | 1535 | */ |
f65fd747 | 1536 | |
fa8d436c | 1537 | /* Conveniently, the unsorted bin can be used as dummy top on first call */ |
6c8dbf00 | 1538 | #define initial_top(M) (unsorted_chunks (M)) |
f65fd747 | 1539 | |
fa8d436c | 1540 | /* |
6c8dbf00 | 1541 | Binmap |
f65fd747 | 1542 | |
fa8d436c UD |
1543 | To help compensate for the large number of bins, a one-level index |
1544 | structure is used for bin-by-bin searching. `binmap' is a | |
1545 | bitvector recording whether bins are definitely empty so they can | |
1546 | be skipped over during during traversals. The bits are NOT always | |
1547 | cleared as soon as bins are empty, but instead only | |
1548 | when they are noticed to be empty during traversal in malloc. | |
6c8dbf00 | 1549 | */ |
f65fd747 | 1550 | |
fa8d436c UD |
1551 | /* Conservatively use 32 bits per map word, even if on 64bit system */ |
1552 | #define BINMAPSHIFT 5 | |
1553 | #define BITSPERMAP (1U << BINMAPSHIFT) | |
1554 | #define BINMAPSIZE (NBINS / BITSPERMAP) | |
f65fd747 | 1555 | |
fa8d436c | 1556 | #define idx2block(i) ((i) >> BINMAPSHIFT) |
6c8dbf00 | 1557 | #define idx2bit(i) ((1U << ((i) & ((1U << BINMAPSHIFT) - 1)))) |
f65fd747 | 1558 | |
6c8dbf00 OB |
1559 | #define mark_bin(m, i) ((m)->binmap[idx2block (i)] |= idx2bit (i)) |
1560 | #define unmark_bin(m, i) ((m)->binmap[idx2block (i)] &= ~(idx2bit (i))) | |
1561 | #define get_binmap(m, i) ((m)->binmap[idx2block (i)] & idx2bit (i)) | |
f65fd747 | 1562 | |
fa8d436c | 1563 | /* |
6c8dbf00 | 1564 | Fastbins |
fa8d436c UD |
1565 | |
1566 | An array of lists holding recently freed small chunks. Fastbins | |
1567 | are not doubly linked. It is faster to single-link them, and | |
1568 | since chunks are never removed from the middles of these lists, | |
1569 | double linking is not necessary. Also, unlike regular bins, they | |
1570 | are not even processed in FIFO order (they use faster LIFO) since | |
1571 | ordering doesn't much matter in the transient contexts in which | |
1572 | fastbins are normally used. | |
1573 | ||
1574 | Chunks in fastbins keep their inuse bit set, so they cannot | |
1575 | be consolidated with other free chunks. malloc_consolidate | |
1576 | releases all chunks in fastbins and consolidates them with | |
a9177ff5 | 1577 | other free chunks. |
6c8dbf00 | 1578 | */ |
f65fd747 | 1579 | |
6c8dbf00 | 1580 | typedef struct malloc_chunk *mfastbinptr; |
425ce2ed | 1581 | #define fastbin(ar_ptr, idx) ((ar_ptr)->fastbinsY[idx]) |
f65fd747 | 1582 | |
fa8d436c | 1583 | /* offset 2 to use otherwise unindexable first 2 bins */ |
425ce2ed | 1584 | #define fastbin_index(sz) \ |
6c8dbf00 | 1585 | ((((unsigned int) (sz)) >> (SIZE_SZ == 8 ? 4 : 3)) - 2) |
425ce2ed | 1586 | |
f65fd747 | 1587 | |
fa8d436c | 1588 | /* The maximum fastbin request size we support */ |
425ce2ed | 1589 | #define MAX_FAST_SIZE (80 * SIZE_SZ / 4) |
f65fd747 | 1590 | |
6c8dbf00 | 1591 | #define NFASTBINS (fastbin_index (request2size (MAX_FAST_SIZE)) + 1) |
f65fd747 UD |
1592 | |
1593 | /* | |
6c8dbf00 OB |
1594 | FASTBIN_CONSOLIDATION_THRESHOLD is the size of a chunk in free() |
1595 | that triggers automatic consolidation of possibly-surrounding | |
1596 | fastbin chunks. This is a heuristic, so the exact value should not | |
1597 | matter too much. It is defined at half the default trim threshold as a | |
1598 | compromise heuristic to only attempt consolidation if it is likely | |
1599 | to lead to trimming. However, it is not dynamically tunable, since | |
1600 | consolidation reduces fragmentation surrounding large chunks even | |
1601 | if trimming is not used. | |
1602 | */ | |
f65fd747 | 1603 | |
fa8d436c | 1604 | #define FASTBIN_CONSOLIDATION_THRESHOLD (65536UL) |
f65fd747 UD |
1605 | |
1606 | /* | |
6c8dbf00 OB |
1607 | Since the lowest 2 bits in max_fast don't matter in size comparisons, |
1608 | they are used as flags. | |
1609 | */ | |
f65fd747 | 1610 | |
fa8d436c | 1611 | /* |
6c8dbf00 OB |
1612 | FASTCHUNKS_BIT held in max_fast indicates that there are probably |
1613 | some fastbin chunks. It is set true on entering a chunk into any | |
1614 | fastbin, and cleared only in malloc_consolidate. | |
f65fd747 | 1615 | |
6c8dbf00 OB |
1616 | The truth value is inverted so that have_fastchunks will be true |
1617 | upon startup (since statics are zero-filled), simplifying | |
1618 | initialization checks. | |
1619 | */ | |
f65fd747 | 1620 | |
fa8d436c | 1621 | #define FASTCHUNKS_BIT (1U) |
f65fd747 | 1622 | |
6c8dbf00 | 1623 | #define have_fastchunks(M) (((M)->flags & FASTCHUNKS_BIT) == 0) |
425ce2ed UD |
1624 | #define clear_fastchunks(M) catomic_or (&(M)->flags, FASTCHUNKS_BIT) |
1625 | #define set_fastchunks(M) catomic_and (&(M)->flags, ~FASTCHUNKS_BIT) | |
f65fd747 UD |
1626 | |
1627 | /* | |
6c8dbf00 OB |
1628 | NONCONTIGUOUS_BIT indicates that MORECORE does not return contiguous |
1629 | regions. Otherwise, contiguity is exploited in merging together, | |
1630 | when possible, results from consecutive MORECORE calls. | |
f65fd747 | 1631 | |
6c8dbf00 OB |
1632 | The initial value comes from MORECORE_CONTIGUOUS, but is |
1633 | changed dynamically if mmap is ever used as an sbrk substitute. | |
1634 | */ | |
f65fd747 | 1635 | |
fa8d436c | 1636 | #define NONCONTIGUOUS_BIT (2U) |
f65fd747 | 1637 | |
6c8dbf00 OB |
1638 | #define contiguous(M) (((M)->flags & NONCONTIGUOUS_BIT) == 0) |
1639 | #define noncontiguous(M) (((M)->flags & NONCONTIGUOUS_BIT) != 0) | |
1640 | #define set_noncontiguous(M) ((M)->flags |= NONCONTIGUOUS_BIT) | |
9bf248c6 | 1641 | #define set_contiguous(M) ((M)->flags &= ~NONCONTIGUOUS_BIT) |
f65fd747 | 1642 | |
eac43cbb FW |
1643 | /* Maximum size of memory handled in fastbins. */ |
1644 | static INTERNAL_SIZE_T global_max_fast; | |
1645 | ||
a9177ff5 RM |
1646 | /* |
1647 | Set value of max_fast. | |
fa8d436c UD |
1648 | Use impossibly small value if 0. |
1649 | Precondition: there are no existing fastbin chunks. | |
1650 | Setting the value clears fastchunk bit but preserves noncontiguous bit. | |
6c8dbf00 | 1651 | */ |
f65fd747 | 1652 | |
9bf248c6 | 1653 | #define set_max_fast(s) \ |
991eda1e | 1654 | global_max_fast = (((s) == 0) \ |
6c8dbf00 | 1655 | ? SMALLBIN_WIDTH : ((s + SIZE_SZ) & ~MALLOC_ALIGN_MASK)) |
f65fd747 | 1656 | |
eac43cbb FW |
1657 | static inline INTERNAL_SIZE_T |
1658 | get_max_fast (void) | |
1659 | { | |
1660 | /* Tell the GCC optimizers that global_max_fast is never larger | |
1661 | than MAX_FAST_SIZE. This avoids out-of-bounds array accesses in | |
1662 | _int_malloc after constant propagation of the size parameter. | |
1663 | (The code never executes because malloc preserves the | |
1664 | global_max_fast invariant, but the optimizers may not recognize | |
1665 | this.) */ | |
1666 | if (global_max_fast > MAX_FAST_SIZE) | |
1667 | __builtin_unreachable (); | |
1668 | return global_max_fast; | |
1669 | } | |
f65fd747 UD |
1670 | |
1671 | /* | |
fa8d436c | 1672 | ----------- Internal state representation and initialization ----------- |
6c8dbf00 | 1673 | */ |
f65fd747 | 1674 | |
6c8dbf00 OB |
1675 | struct malloc_state |
1676 | { | |
fa8d436c | 1677 | /* Serialize access. */ |
cbb47fa1 | 1678 | __libc_lock_define (, mutex); |
9bf248c6 UD |
1679 | |
1680 | /* Flags (formerly in max_fast). */ | |
1681 | int flags; | |
f65fd747 | 1682 | |
fa8d436c | 1683 | /* Fastbins */ |
6c8dbf00 | 1684 | mfastbinptr fastbinsY[NFASTBINS]; |
f65fd747 | 1685 | |
fa8d436c | 1686 | /* Base of the topmost chunk -- not otherwise kept in a bin */ |
6c8dbf00 | 1687 | mchunkptr top; |
f65fd747 | 1688 | |
fa8d436c | 1689 | /* The remainder from the most recent split of a small request */ |
6c8dbf00 | 1690 | mchunkptr last_remainder; |
f65fd747 | 1691 | |
fa8d436c | 1692 | /* Normal bins packed as described above */ |
6c8dbf00 | 1693 | mchunkptr bins[NBINS * 2 - 2]; |
f65fd747 | 1694 | |
fa8d436c | 1695 | /* Bitmap of bins */ |
6c8dbf00 | 1696 | unsigned int binmap[BINMAPSIZE]; |
f65fd747 | 1697 | |
fa8d436c UD |
1698 | /* Linked list */ |
1699 | struct malloc_state *next; | |
f65fd747 | 1700 | |
a62719ba | 1701 | /* Linked list for free arenas. Access to this field is serialized |
90c400bd | 1702 | by free_list_lock in arena.c. */ |
425ce2ed | 1703 | struct malloc_state *next_free; |
425ce2ed | 1704 | |
a62719ba | 1705 | /* Number of threads attached to this arena. 0 if the arena is on |
90c400bd FW |
1706 | the free list. Access to this field is serialized by |
1707 | free_list_lock in arena.c. */ | |
a62719ba FW |
1708 | INTERNAL_SIZE_T attached_threads; |
1709 | ||
fa8d436c UD |
1710 | /* Memory allocated from the system in this arena. */ |
1711 | INTERNAL_SIZE_T system_mem; | |
1712 | INTERNAL_SIZE_T max_system_mem; | |
1713 | }; | |
f65fd747 | 1714 | |
6c8dbf00 OB |
1715 | struct malloc_par |
1716 | { | |
fa8d436c | 1717 | /* Tunable parameters */ |
6c8dbf00 OB |
1718 | unsigned long trim_threshold; |
1719 | INTERNAL_SIZE_T top_pad; | |
1720 | INTERNAL_SIZE_T mmap_threshold; | |
1721 | INTERNAL_SIZE_T arena_test; | |
1722 | INTERNAL_SIZE_T arena_max; | |
fa8d436c UD |
1723 | |
1724 | /* Memory map support */ | |
6c8dbf00 OB |
1725 | int n_mmaps; |
1726 | int n_mmaps_max; | |
1727 | int max_n_mmaps; | |
1d05c2fb UD |
1728 | /* the mmap_threshold is dynamic, until the user sets |
1729 | it manually, at which point we need to disable any | |
1730 | dynamic behavior. */ | |
6c8dbf00 | 1731 | int no_dyn_threshold; |
fa8d436c | 1732 | |
fa8d436c | 1733 | /* Statistics */ |
6c8dbf00 | 1734 | INTERNAL_SIZE_T mmapped_mem; |
6c8dbf00 | 1735 | INTERNAL_SIZE_T max_mmapped_mem; |
fa8d436c UD |
1736 | |
1737 | /* First address handed out by MORECORE/sbrk. */ | |
6c8dbf00 | 1738 | char *sbrk_base; |
d5c3fafc DD |
1739 | |
1740 | #if USE_TCACHE | |
1741 | /* Maximum number of buckets to use. */ | |
1742 | size_t tcache_bins; | |
1743 | size_t tcache_max_bytes; | |
1744 | /* Maximum number of chunks in each bucket. */ | |
1745 | size_t tcache_count; | |
1746 | /* Maximum number of chunks to remove from the unsorted list, which | |
1747 | aren't used to prefill the cache. */ | |
1748 | size_t tcache_unsorted_limit; | |
1749 | #endif | |
fa8d436c | 1750 | }; |
f65fd747 | 1751 | |
fa8d436c UD |
1752 | /* There are several instances of this struct ("arenas") in this |
1753 | malloc. If you are adapting this malloc in a way that does NOT use | |
1754 | a static or mmapped malloc_state, you MUST explicitly zero-fill it | |
1755 | before using. This malloc relies on the property that malloc_state | |
1756 | is initialized to all zeroes (as is true of C statics). */ | |
f65fd747 | 1757 | |
02d46fc4 | 1758 | static struct malloc_state main_arena = |
6c8dbf00 | 1759 | { |
400e1226 | 1760 | .mutex = _LIBC_LOCK_INITIALIZER, |
a62719ba FW |
1761 | .next = &main_arena, |
1762 | .attached_threads = 1 | |
6c8dbf00 | 1763 | }; |
f65fd747 | 1764 | |
4cf6c72f FW |
1765 | /* These variables are used for undumping support. Chunked are marked |
1766 | as using mmap, but we leave them alone if they fall into this | |
1e8a8875 FW |
1767 | range. NB: The chunk size for these chunks only includes the |
1768 | initial size field (of SIZE_SZ bytes), there is no trailing size | |
1769 | field (unlike with regular mmapped chunks). */ | |
4cf6c72f FW |
1770 | static mchunkptr dumped_main_arena_start; /* Inclusive. */ |
1771 | static mchunkptr dumped_main_arena_end; /* Exclusive. */ | |
1772 | ||
1773 | /* True if the pointer falls into the dumped arena. Use this after | |
1774 | chunk_is_mmapped indicates a chunk is mmapped. */ | |
1775 | #define DUMPED_MAIN_ARENA_CHUNK(p) \ | |
1776 | ((p) >= dumped_main_arena_start && (p) < dumped_main_arena_end) | |
1777 | ||
fa8d436c | 1778 | /* There is only one instance of the malloc parameters. */ |
f65fd747 | 1779 | |
02d46fc4 | 1780 | static struct malloc_par mp_ = |
6c8dbf00 OB |
1781 | { |
1782 | .top_pad = DEFAULT_TOP_PAD, | |
1783 | .n_mmaps_max = DEFAULT_MMAP_MAX, | |
1784 | .mmap_threshold = DEFAULT_MMAP_THRESHOLD, | |
1785 | .trim_threshold = DEFAULT_TRIM_THRESHOLD, | |
1786 | #define NARENAS_FROM_NCORES(n) ((n) * (sizeof (long) == 4 ? 2 : 8)) | |
1787 | .arena_test = NARENAS_FROM_NCORES (1) | |
d5c3fafc DD |
1788 | #if USE_TCACHE |
1789 | , | |
1790 | .tcache_count = TCACHE_FILL_COUNT, | |
1791 | .tcache_bins = TCACHE_MAX_BINS, | |
1792 | .tcache_max_bytes = tidx2usize (TCACHE_MAX_BINS-1), | |
1793 | .tcache_unsorted_limit = 0 /* No limit. */ | |
1794 | #endif | |
6c8dbf00 | 1795 | }; |
f65fd747 | 1796 | |
fa8d436c | 1797 | /* |
6c8dbf00 | 1798 | Initialize a malloc_state struct. |
f65fd747 | 1799 | |
6c8dbf00 OB |
1800 | This is called only from within malloc_consolidate, which needs |
1801 | be called in the same contexts anyway. It is never called directly | |
1802 | outside of malloc_consolidate because some optimizing compilers try | |
1803 | to inline it at all call points, which turns out not to be an | |
1804 | optimization at all. (Inlining it in malloc_consolidate is fine though.) | |
1805 | */ | |
f65fd747 | 1806 | |
6c8dbf00 OB |
1807 | static void |
1808 | malloc_init_state (mstate av) | |
fa8d436c | 1809 | { |
6c8dbf00 | 1810 | int i; |
fa8d436c | 1811 | mbinptr bin; |
a9177ff5 | 1812 | |
fa8d436c | 1813 | /* Establish circular links for normal bins */ |
6c8dbf00 OB |
1814 | for (i = 1; i < NBINS; ++i) |
1815 | { | |
1816 | bin = bin_at (av, i); | |
1817 | bin->fd = bin->bk = bin; | |
1818 | } | |
f65fd747 | 1819 | |
fa8d436c UD |
1820 | #if MORECORE_CONTIGUOUS |
1821 | if (av != &main_arena) | |
1822 | #endif | |
6c8dbf00 | 1823 | set_noncontiguous (av); |
9bf248c6 | 1824 | if (av == &main_arena) |
6c8dbf00 | 1825 | set_max_fast (DEFAULT_MXFAST); |
9bf248c6 | 1826 | av->flags |= FASTCHUNKS_BIT; |
f65fd747 | 1827 | |
6c8dbf00 | 1828 | av->top = initial_top (av); |
fa8d436c | 1829 | } |
e9b3e3c5 | 1830 | |
a9177ff5 | 1831 | /* |
fa8d436c | 1832 | Other internal utilities operating on mstates |
6c8dbf00 | 1833 | */ |
f65fd747 | 1834 | |
6c8dbf00 OB |
1835 | static void *sysmalloc (INTERNAL_SIZE_T, mstate); |
1836 | static int systrim (size_t, mstate); | |
1837 | static void malloc_consolidate (mstate); | |
7e3be507 | 1838 | |
404d4cef RM |
1839 | |
1840 | /* -------------- Early definitions for debugging hooks ---------------- */ | |
1841 | ||
1842 | /* Define and initialize the hook variables. These weak definitions must | |
1843 | appear before any use of the variables in a function (arena.c uses one). */ | |
1844 | #ifndef weak_variable | |
404d4cef RM |
1845 | /* In GNU libc we want the hook variables to be weak definitions to |
1846 | avoid a problem with Emacs. */ | |
22a89187 | 1847 | # define weak_variable weak_function |
404d4cef RM |
1848 | #endif |
1849 | ||
1850 | /* Forward declarations. */ | |
6c8dbf00 OB |
1851 | static void *malloc_hook_ini (size_t sz, |
1852 | const void *caller) __THROW; | |
1853 | static void *realloc_hook_ini (void *ptr, size_t sz, | |
1854 | const void *caller) __THROW; | |
1855 | static void *memalign_hook_ini (size_t alignment, size_t sz, | |
1856 | const void *caller) __THROW; | |
404d4cef | 1857 | |
2ba3cfa1 | 1858 | #if HAVE_MALLOC_INIT_HOOK |
92e1ab0e FW |
1859 | void weak_variable (*__malloc_initialize_hook) (void) = NULL; |
1860 | compat_symbol (libc, __malloc_initialize_hook, | |
1861 | __malloc_initialize_hook, GLIBC_2_0); | |
2ba3cfa1 FW |
1862 | #endif |
1863 | ||
a222d91a | 1864 | void weak_variable (*__free_hook) (void *__ptr, |
6c8dbf00 | 1865 | const void *) = NULL; |
a222d91a | 1866 | void *weak_variable (*__malloc_hook) |
6c8dbf00 | 1867 | (size_t __size, const void *) = malloc_hook_ini; |
a222d91a | 1868 | void *weak_variable (*__realloc_hook) |
6c8dbf00 OB |
1869 | (void *__ptr, size_t __size, const void *) |
1870 | = realloc_hook_ini; | |
a222d91a | 1871 | void *weak_variable (*__memalign_hook) |
6c8dbf00 OB |
1872 | (size_t __alignment, size_t __size, const void *) |
1873 | = memalign_hook_ini; | |
06d6611a | 1874 | void weak_variable (*__after_morecore_hook) (void) = NULL; |
404d4cef RM |
1875 | |
1876 | ||
854278df UD |
1877 | /* ------------------ Testing support ----------------------------------*/ |
1878 | ||
1879 | static int perturb_byte; | |
1880 | ||
af102d95 | 1881 | static void |
e8349efd OB |
1882 | alloc_perturb (char *p, size_t n) |
1883 | { | |
1884 | if (__glibc_unlikely (perturb_byte)) | |
1885 | memset (p, perturb_byte ^ 0xff, n); | |
1886 | } | |
1887 | ||
af102d95 | 1888 | static void |
e8349efd OB |
1889 | free_perturb (char *p, size_t n) |
1890 | { | |
1891 | if (__glibc_unlikely (perturb_byte)) | |
1892 | memset (p, perturb_byte, n); | |
1893 | } | |
1894 | ||
854278df UD |
1895 | |
1896 | ||
3ea5be54 AO |
1897 | #include <stap-probe.h> |
1898 | ||
fa8d436c UD |
1899 | /* ------------------- Support for multiple arenas -------------------- */ |
1900 | #include "arena.c" | |
f65fd747 | 1901 | |
fa8d436c | 1902 | /* |
6c8dbf00 | 1903 | Debugging support |
f65fd747 | 1904 | |
6c8dbf00 OB |
1905 | These routines make a number of assertions about the states |
1906 | of data structures that should be true at all times. If any | |
1907 | are not true, it's very likely that a user program has somehow | |
1908 | trashed memory. (It's also possible that there is a coding error | |
1909 | in malloc. In which case, please report it!) | |
1910 | */ | |
ee74a442 | 1911 | |
6c8dbf00 | 1912 | #if !MALLOC_DEBUG |
d8f00d46 | 1913 | |
6c8dbf00 OB |
1914 | # define check_chunk(A, P) |
1915 | # define check_free_chunk(A, P) | |
1916 | # define check_inuse_chunk(A, P) | |
1917 | # define check_remalloced_chunk(A, P, N) | |
1918 | # define check_malloced_chunk(A, P, N) | |
1919 | # define check_malloc_state(A) | |
d8f00d46 | 1920 | |
fa8d436c | 1921 | #else |
ca34d7a7 | 1922 | |
6c8dbf00 OB |
1923 | # define check_chunk(A, P) do_check_chunk (A, P) |
1924 | # define check_free_chunk(A, P) do_check_free_chunk (A, P) | |
1925 | # define check_inuse_chunk(A, P) do_check_inuse_chunk (A, P) | |
1926 | # define check_remalloced_chunk(A, P, N) do_check_remalloced_chunk (A, P, N) | |
1927 | # define check_malloced_chunk(A, P, N) do_check_malloced_chunk (A, P, N) | |
1928 | # define check_malloc_state(A) do_check_malloc_state (A) | |
ca34d7a7 | 1929 | |
fa8d436c | 1930 | /* |
6c8dbf00 OB |
1931 | Properties of all chunks |
1932 | */ | |
ca34d7a7 | 1933 | |
6c8dbf00 OB |
1934 | static void |
1935 | do_check_chunk (mstate av, mchunkptr p) | |
ca34d7a7 | 1936 | { |
6c8dbf00 | 1937 | unsigned long sz = chunksize (p); |
fa8d436c | 1938 | /* min and max possible addresses assuming contiguous allocation */ |
6c8dbf00 OB |
1939 | char *max_address = (char *) (av->top) + chunksize (av->top); |
1940 | char *min_address = max_address - av->system_mem; | |
fa8d436c | 1941 | |
6c8dbf00 OB |
1942 | if (!chunk_is_mmapped (p)) |
1943 | { | |
1944 | /* Has legal address ... */ | |
1945 | if (p != av->top) | |
1946 | { | |
1947 | if (contiguous (av)) | |
1948 | { | |
1949 | assert (((char *) p) >= min_address); | |
1950 | assert (((char *) p + sz) <= ((char *) (av->top))); | |
1951 | } | |
1952 | } | |
1953 | else | |
1954 | { | |
1955 | /* top size is always at least MINSIZE */ | |
1956 | assert ((unsigned long) (sz) >= MINSIZE); | |
1957 | /* top predecessor always marked inuse */ | |
1958 | assert (prev_inuse (p)); | |
1959 | } | |
fa8d436c | 1960 | } |
4cf6c72f | 1961 | else if (!DUMPED_MAIN_ARENA_CHUNK (p)) |
6c8dbf00 OB |
1962 | { |
1963 | /* address is outside main heap */ | |
1964 | if (contiguous (av) && av->top != initial_top (av)) | |
1965 | { | |
1966 | assert (((char *) p) < min_address || ((char *) p) >= max_address); | |
1967 | } | |
1968 | /* chunk is page-aligned */ | |
e9c4fe93 | 1969 | assert (((prev_size (p) + sz) & (GLRO (dl_pagesize) - 1)) == 0); |
6c8dbf00 OB |
1970 | /* mem is aligned */ |
1971 | assert (aligned_OK (chunk2mem (p))); | |
fa8d436c | 1972 | } |
eb406346 UD |
1973 | } |
1974 | ||
fa8d436c | 1975 | /* |
6c8dbf00 OB |
1976 | Properties of free chunks |
1977 | */ | |
ee74a442 | 1978 | |
6c8dbf00 OB |
1979 | static void |
1980 | do_check_free_chunk (mstate av, mchunkptr p) | |
67c94753 | 1981 | { |
6c8dbf00 OB |
1982 | INTERNAL_SIZE_T sz = p->size & ~(PREV_INUSE | NON_MAIN_ARENA); |
1983 | mchunkptr next = chunk_at_offset (p, sz); | |
67c94753 | 1984 | |
6c8dbf00 | 1985 | do_check_chunk (av, p); |
67c94753 | 1986 | |
fa8d436c | 1987 | /* Chunk must claim to be free ... */ |
6c8dbf00 OB |
1988 | assert (!inuse (p)); |
1989 | assert (!chunk_is_mmapped (p)); | |
67c94753 | 1990 | |
fa8d436c | 1991 | /* Unless a special marker, must have OK fields */ |
6c8dbf00 OB |
1992 | if ((unsigned long) (sz) >= MINSIZE) |
1993 | { | |
1994 | assert ((sz & MALLOC_ALIGN_MASK) == 0); | |
1995 | assert (aligned_OK (chunk2mem (p))); | |
1996 | /* ... matching footer field */ | |
e9c4fe93 | 1997 | assert (prev_size (p) == sz); |
6c8dbf00 OB |
1998 | /* ... and is fully consolidated */ |
1999 | assert (prev_inuse (p)); | |
2000 | assert (next == av->top || inuse (next)); | |
2001 | ||
2002 | /* ... and has minimally sane links */ | |
2003 | assert (p->fd->bk == p); | |
2004 | assert (p->bk->fd == p); | |
2005 | } | |
fa8d436c | 2006 | else /* markers are always of size SIZE_SZ */ |
6c8dbf00 | 2007 | assert (sz == SIZE_SZ); |
67c94753 | 2008 | } |
67c94753 | 2009 | |
fa8d436c | 2010 | /* |
6c8dbf00 OB |
2011 | Properties of inuse chunks |
2012 | */ | |
fa8d436c | 2013 | |
6c8dbf00 OB |
2014 | static void |
2015 | do_check_inuse_chunk (mstate av, mchunkptr p) | |
f65fd747 | 2016 | { |
fa8d436c | 2017 | mchunkptr next; |
f65fd747 | 2018 | |
6c8dbf00 | 2019 | do_check_chunk (av, p); |
f65fd747 | 2020 | |
6c8dbf00 | 2021 | if (chunk_is_mmapped (p)) |
fa8d436c | 2022 | return; /* mmapped chunks have no next/prev */ |
ca34d7a7 | 2023 | |
fa8d436c | 2024 | /* Check whether it claims to be in use ... */ |
6c8dbf00 | 2025 | assert (inuse (p)); |
10dc2a90 | 2026 | |
6c8dbf00 | 2027 | next = next_chunk (p); |
10dc2a90 | 2028 | |
fa8d436c | 2029 | /* ... and is surrounded by OK chunks. |
6c8dbf00 OB |
2030 | Since more things can be checked with free chunks than inuse ones, |
2031 | if an inuse chunk borders them and debug is on, it's worth doing them. | |
2032 | */ | |
2033 | if (!prev_inuse (p)) | |
2034 | { | |
2035 | /* Note that we cannot even look at prev unless it is not inuse */ | |
2036 | mchunkptr prv = prev_chunk (p); | |
2037 | assert (next_chunk (prv) == p); | |
2038 | do_check_free_chunk (av, prv); | |
2039 | } | |
fa8d436c | 2040 | |
6c8dbf00 OB |
2041 | if (next == av->top) |
2042 | { | |
2043 | assert (prev_inuse (next)); | |
2044 | assert (chunksize (next) >= MINSIZE); | |
2045 | } | |
2046 | else if (!inuse (next)) | |
2047 | do_check_free_chunk (av, next); | |
10dc2a90 UD |
2048 | } |
2049 | ||
fa8d436c | 2050 | /* |
6c8dbf00 OB |
2051 | Properties of chunks recycled from fastbins |
2052 | */ | |
fa8d436c | 2053 | |
6c8dbf00 OB |
2054 | static void |
2055 | do_check_remalloced_chunk (mstate av, mchunkptr p, INTERNAL_SIZE_T s) | |
10dc2a90 | 2056 | { |
6c8dbf00 | 2057 | INTERNAL_SIZE_T sz = p->size & ~(PREV_INUSE | NON_MAIN_ARENA); |
fa8d436c | 2058 | |
6c8dbf00 OB |
2059 | if (!chunk_is_mmapped (p)) |
2060 | { | |
2061 | assert (av == arena_for_chunk (p)); | |
e9c4fe93 | 2062 | if (chunk_main_arena (p)) |
6c8dbf00 | 2063 | assert (av == &main_arena); |
e9c4fe93 FW |
2064 | else |
2065 | assert (av != &main_arena); | |
6c8dbf00 | 2066 | } |
fa8d436c | 2067 | |
6c8dbf00 | 2068 | do_check_inuse_chunk (av, p); |
fa8d436c UD |
2069 | |
2070 | /* Legal size ... */ | |
6c8dbf00 OB |
2071 | assert ((sz & MALLOC_ALIGN_MASK) == 0); |
2072 | assert ((unsigned long) (sz) >= MINSIZE); | |
fa8d436c | 2073 | /* ... and alignment */ |
6c8dbf00 | 2074 | assert (aligned_OK (chunk2mem (p))); |
fa8d436c | 2075 | /* chunk is less than MINSIZE more than request */ |
6c8dbf00 OB |
2076 | assert ((long) (sz) - (long) (s) >= 0); |
2077 | assert ((long) (sz) - (long) (s + MINSIZE) < 0); | |
10dc2a90 UD |
2078 | } |
2079 | ||
fa8d436c | 2080 | /* |
6c8dbf00 OB |
2081 | Properties of nonrecycled chunks at the point they are malloced |
2082 | */ | |
fa8d436c | 2083 | |
6c8dbf00 OB |
2084 | static void |
2085 | do_check_malloced_chunk (mstate av, mchunkptr p, INTERNAL_SIZE_T s) | |
10dc2a90 | 2086 | { |
fa8d436c | 2087 | /* same as recycled case ... */ |
6c8dbf00 | 2088 | do_check_remalloced_chunk (av, p, s); |
10dc2a90 | 2089 | |
fa8d436c | 2090 | /* |
6c8dbf00 OB |
2091 | ... plus, must obey implementation invariant that prev_inuse is |
2092 | always true of any allocated chunk; i.e., that each allocated | |
2093 | chunk borders either a previously allocated and still in-use | |
2094 | chunk, or the base of its memory arena. This is ensured | |
2095 | by making all allocations from the `lowest' part of any found | |
2096 | chunk. This does not necessarily hold however for chunks | |
2097 | recycled via fastbins. | |
2098 | */ | |
2099 | ||
2100 | assert (prev_inuse (p)); | |
fa8d436c | 2101 | } |
10dc2a90 | 2102 | |
f65fd747 | 2103 | |
fa8d436c | 2104 | /* |
6c8dbf00 | 2105 | Properties of malloc_state. |
f65fd747 | 2106 | |
6c8dbf00 OB |
2107 | This may be useful for debugging malloc, as well as detecting user |
2108 | programmer errors that somehow write into malloc_state. | |
f65fd747 | 2109 | |
6c8dbf00 OB |
2110 | If you are extending or experimenting with this malloc, you can |
2111 | probably figure out how to hack this routine to print out or | |
2112 | display chunk addresses, sizes, bins, and other instrumentation. | |
2113 | */ | |
f65fd747 | 2114 | |
6c8dbf00 OB |
2115 | static void |
2116 | do_check_malloc_state (mstate av) | |
fa8d436c UD |
2117 | { |
2118 | int i; | |
2119 | mchunkptr p; | |
2120 | mchunkptr q; | |
2121 | mbinptr b; | |
fa8d436c UD |
2122 | unsigned int idx; |
2123 | INTERNAL_SIZE_T size; | |
2124 | unsigned long total = 0; | |
2125 | int max_fast_bin; | |
f65fd747 | 2126 | |
fa8d436c | 2127 | /* internal size_t must be no wider than pointer type */ |
6c8dbf00 | 2128 | assert (sizeof (INTERNAL_SIZE_T) <= sizeof (char *)); |
f65fd747 | 2129 | |
fa8d436c | 2130 | /* alignment is a power of 2 */ |
6c8dbf00 | 2131 | assert ((MALLOC_ALIGNMENT & (MALLOC_ALIGNMENT - 1)) == 0); |
f65fd747 | 2132 | |
fa8d436c | 2133 | /* cannot run remaining checks until fully initialized */ |
6c8dbf00 | 2134 | if (av->top == 0 || av->top == initial_top (av)) |
fa8d436c | 2135 | return; |
f65fd747 | 2136 | |
fa8d436c | 2137 | /* pagesize is a power of 2 */ |
8a35c3fe | 2138 | assert (powerof2(GLRO (dl_pagesize))); |
f65fd747 | 2139 | |
fa8d436c | 2140 | /* A contiguous main_arena is consistent with sbrk_base. */ |
6c8dbf00 OB |
2141 | if (av == &main_arena && contiguous (av)) |
2142 | assert ((char *) mp_.sbrk_base + av->system_mem == | |
2143 | (char *) av->top + chunksize (av->top)); | |
fa8d436c UD |
2144 | |
2145 | /* properties of fastbins */ | |
2146 | ||
2147 | /* max_fast is in allowed range */ | |
6c8dbf00 OB |
2148 | assert ((get_max_fast () & ~1) <= request2size (MAX_FAST_SIZE)); |
2149 | ||
2150 | max_fast_bin = fastbin_index (get_max_fast ()); | |
2151 | ||
2152 | for (i = 0; i < NFASTBINS; ++i) | |
2153 | { | |
2154 | p = fastbin (av, i); | |
2155 | ||
2156 | /* The following test can only be performed for the main arena. | |
2157 | While mallopt calls malloc_consolidate to get rid of all fast | |
2158 | bins (especially those larger than the new maximum) this does | |
2159 | only happen for the main arena. Trying to do this for any | |
2160 | other arena would mean those arenas have to be locked and | |
2161 | malloc_consolidate be called for them. This is excessive. And | |
2162 | even if this is acceptable to somebody it still cannot solve | |
2163 | the problem completely since if the arena is locked a | |
2164 | concurrent malloc call might create a new arena which then | |
2165 | could use the newly invalid fast bins. */ | |
2166 | ||
2167 | /* all bins past max_fast are empty */ | |
2168 | if (av == &main_arena && i > max_fast_bin) | |
2169 | assert (p == 0); | |
2170 | ||
2171 | while (p != 0) | |
2172 | { | |
2173 | /* each chunk claims to be inuse */ | |
2174 | do_check_inuse_chunk (av, p); | |
2175 | total += chunksize (p); | |
2176 | /* chunk belongs in this bin */ | |
2177 | assert (fastbin_index (chunksize (p)) == i); | |
2178 | p = p->fd; | |
2179 | } | |
fa8d436c | 2180 | } |
fa8d436c UD |
2181 | |
2182 | if (total != 0) | |
6c8dbf00 OB |
2183 | assert (have_fastchunks (av)); |
2184 | else if (!have_fastchunks (av)) | |
2185 | assert (total == 0); | |
fa8d436c UD |
2186 | |
2187 | /* check normal bins */ | |
6c8dbf00 OB |
2188 | for (i = 1; i < NBINS; ++i) |
2189 | { | |
2190 | b = bin_at (av, i); | |
2191 | ||
2192 | /* binmap is accurate (except for bin 1 == unsorted_chunks) */ | |
2193 | if (i >= 2) | |
2194 | { | |
2195 | unsigned int binbit = get_binmap (av, i); | |
2196 | int empty = last (b) == b; | |
2197 | if (!binbit) | |
2198 | assert (empty); | |
2199 | else if (!empty) | |
2200 | assert (binbit); | |
2201 | } | |
2202 | ||
2203 | for (p = last (b); p != b; p = p->bk) | |
2204 | { | |
2205 | /* each chunk claims to be free */ | |
2206 | do_check_free_chunk (av, p); | |
2207 | size = chunksize (p); | |
2208 | total += size; | |
2209 | if (i >= 2) | |
2210 | { | |
2211 | /* chunk belongs in bin */ | |
2212 | idx = bin_index (size); | |
2213 | assert (idx == i); | |
2214 | /* lists are sorted */ | |
2215 | assert (p->bk == b || | |
2216 | (unsigned long) chunksize (p->bk) >= (unsigned long) chunksize (p)); | |
2217 | ||
2218 | if (!in_smallbin_range (size)) | |
2219 | { | |
2220 | if (p->fd_nextsize != NULL) | |
2221 | { | |
2222 | if (p->fd_nextsize == p) | |
2223 | assert (p->bk_nextsize == p); | |
2224 | else | |
2225 | { | |
2226 | if (p->fd_nextsize == first (b)) | |
2227 | assert (chunksize (p) < chunksize (p->fd_nextsize)); | |
2228 | else | |
2229 | assert (chunksize (p) > chunksize (p->fd_nextsize)); | |
2230 | ||
2231 | if (p == first (b)) | |
2232 | assert (chunksize (p) > chunksize (p->bk_nextsize)); | |
2233 | else | |
2234 | assert (chunksize (p) < chunksize (p->bk_nextsize)); | |
2235 | } | |
2236 | } | |
2237 | else | |
2238 | assert (p->bk_nextsize == NULL); | |
2239 | } | |
2240 | } | |
2241 | else if (!in_smallbin_range (size)) | |
2242 | assert (p->fd_nextsize == NULL && p->bk_nextsize == NULL); | |
2243 | /* chunk is followed by a legal chain of inuse chunks */ | |
2244 | for (q = next_chunk (p); | |
2245 | (q != av->top && inuse (q) && | |
2246 | (unsigned long) (chunksize (q)) >= MINSIZE); | |
2247 | q = next_chunk (q)) | |
2248 | do_check_inuse_chunk (av, q); | |
2249 | } | |
fa8d436c | 2250 | } |
f65fd747 | 2251 | |
fa8d436c | 2252 | /* top chunk is OK */ |
6c8dbf00 | 2253 | check_chunk (av, av->top); |
fa8d436c UD |
2254 | } |
2255 | #endif | |
2256 | ||
2257 | ||
2258 | /* ----------------- Support for debugging hooks -------------------- */ | |
2259 | #include "hooks.c" | |
2260 | ||
2261 | ||
2262 | /* ----------- Routines dealing with system allocation -------------- */ | |
2263 | ||
2264 | /* | |
6c8dbf00 OB |
2265 | sysmalloc handles malloc cases requiring more memory from the system. |
2266 | On entry, it is assumed that av->top does not have enough | |
2267 | space to service request for nb bytes, thus requiring that av->top | |
2268 | be extended or replaced. | |
2269 | */ | |
fa8d436c | 2270 | |
6c8dbf00 OB |
2271 | static void * |
2272 | sysmalloc (INTERNAL_SIZE_T nb, mstate av) | |
f65fd747 | 2273 | { |
6c8dbf00 | 2274 | mchunkptr old_top; /* incoming value of av->top */ |
fa8d436c | 2275 | INTERNAL_SIZE_T old_size; /* its size */ |
6c8dbf00 | 2276 | char *old_end; /* its end address */ |
f65fd747 | 2277 | |
6c8dbf00 OB |
2278 | long size; /* arg to first MORECORE or mmap call */ |
2279 | char *brk; /* return value from MORECORE */ | |
f65fd747 | 2280 | |
6c8dbf00 OB |
2281 | long correction; /* arg to 2nd MORECORE call */ |
2282 | char *snd_brk; /* 2nd return val */ | |
f65fd747 | 2283 | |
fa8d436c UD |
2284 | INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of new space */ |
2285 | INTERNAL_SIZE_T end_misalign; /* partial page left at end of new space */ | |
6c8dbf00 | 2286 | char *aligned_brk; /* aligned offset into brk */ |
f65fd747 | 2287 | |
6c8dbf00 OB |
2288 | mchunkptr p; /* the allocated/returned chunk */ |
2289 | mchunkptr remainder; /* remainder from allocation */ | |
2290 | unsigned long remainder_size; /* its size */ | |
fa8d436c | 2291 | |
fa8d436c | 2292 | |
8a35c3fe | 2293 | size_t pagesize = GLRO (dl_pagesize); |
6c8dbf00 | 2294 | bool tried_mmap = false; |
fa8d436c UD |
2295 | |
2296 | ||
fa8d436c | 2297 | /* |
6c8dbf00 OB |
2298 | If have mmap, and the request size meets the mmap threshold, and |
2299 | the system supports mmap, and there are few enough currently | |
2300 | allocated mmapped regions, try to directly map this request | |
2301 | rather than expanding top. | |
2302 | */ | |
2303 | ||
fff94fa2 SP |
2304 | if (av == NULL |
2305 | || ((unsigned long) (nb) >= (unsigned long) (mp_.mmap_threshold) | |
2306 | && (mp_.n_mmaps < mp_.n_mmaps_max))) | |
6c8dbf00 OB |
2307 | { |
2308 | char *mm; /* return value from mmap call*/ | |
a9177ff5 | 2309 | |
6c8dbf00 OB |
2310 | try_mmap: |
2311 | /* | |
2312 | Round up size to nearest page. For mmapped chunks, the overhead | |
2313 | is one SIZE_SZ unit larger than for normal chunks, because there | |
2314 | is no following chunk whose prev_size field could be used. | |
2315 | ||
2316 | See the front_misalign handling below, for glibc there is no | |
2317 | need for further alignments unless we have have high alignment. | |
2318 | */ | |
2319 | if (MALLOC_ALIGNMENT == 2 * SIZE_SZ) | |
8a35c3fe | 2320 | size = ALIGN_UP (nb + SIZE_SZ, pagesize); |
6c8dbf00 | 2321 | else |
8a35c3fe | 2322 | size = ALIGN_UP (nb + SIZE_SZ + MALLOC_ALIGN_MASK, pagesize); |
6c8dbf00 OB |
2323 | tried_mmap = true; |
2324 | ||
2325 | /* Don't try if size wraps around 0 */ | |
2326 | if ((unsigned long) (size) > (unsigned long) (nb)) | |
2327 | { | |
2328 | mm = (char *) (MMAP (0, size, PROT_READ | PROT_WRITE, 0)); | |
2329 | ||
2330 | if (mm != MAP_FAILED) | |
2331 | { | |
2332 | /* | |
2333 | The offset to the start of the mmapped region is stored | |
2334 | in the prev_size field of the chunk. This allows us to adjust | |
2335 | returned start address to meet alignment requirements here | |
2336 | and in memalign(), and still be able to compute proper | |
2337 | address argument for later munmap in free() and realloc(). | |
2338 | */ | |
2339 | ||
2340 | if (MALLOC_ALIGNMENT == 2 * SIZE_SZ) | |
2341 | { | |
2342 | /* For glibc, chunk2mem increases the address by 2*SIZE_SZ and | |
2343 | MALLOC_ALIGN_MASK is 2*SIZE_SZ-1. Each mmap'ed area is page | |
2344 | aligned and therefore definitely MALLOC_ALIGN_MASK-aligned. */ | |
2345 | assert (((INTERNAL_SIZE_T) chunk2mem (mm) & MALLOC_ALIGN_MASK) == 0); | |
2346 | front_misalign = 0; | |
2347 | } | |
2348 | else | |
2349 | front_misalign = (INTERNAL_SIZE_T) chunk2mem (mm) & MALLOC_ALIGN_MASK; | |
2350 | if (front_misalign > 0) | |
2351 | { | |
2352 | correction = MALLOC_ALIGNMENT - front_misalign; | |
2353 | p = (mchunkptr) (mm + correction); | |
e9c4fe93 | 2354 | set_prev_size (p, correction); |
6c8dbf00 OB |
2355 | set_head (p, (size - correction) | IS_MMAPPED); |
2356 | } | |
2357 | else | |
2358 | { | |
2359 | p = (mchunkptr) mm; | |
681421f3 | 2360 | set_prev_size (p, 0); |
6c8dbf00 OB |
2361 | set_head (p, size | IS_MMAPPED); |
2362 | } | |
2363 | ||
2364 | /* update statistics */ | |
2365 | ||
2366 | int new = atomic_exchange_and_add (&mp_.n_mmaps, 1) + 1; | |
2367 | atomic_max (&mp_.max_n_mmaps, new); | |
2368 | ||
2369 | unsigned long sum; | |
2370 | sum = atomic_exchange_and_add (&mp_.mmapped_mem, size) + size; | |
2371 | atomic_max (&mp_.max_mmapped_mem, sum); | |
2372 | ||
2373 | check_chunk (av, p); | |
2374 | ||
2375 | return chunk2mem (p); | |
2376 | } | |
2377 | } | |
fa8d436c | 2378 | } |
fa8d436c | 2379 | |
fff94fa2 SP |
2380 | /* There are no usable arenas and mmap also failed. */ |
2381 | if (av == NULL) | |
2382 | return 0; | |
2383 | ||
fa8d436c UD |
2384 | /* Record incoming configuration of top */ |
2385 | ||
6c8dbf00 OB |
2386 | old_top = av->top; |
2387 | old_size = chunksize (old_top); | |
2388 | old_end = (char *) (chunk_at_offset (old_top, old_size)); | |
fa8d436c | 2389 | |
6c8dbf00 | 2390 | brk = snd_brk = (char *) (MORECORE_FAILURE); |
fa8d436c | 2391 | |
a9177ff5 | 2392 | /* |
fa8d436c UD |
2393 | If not the first time through, we require old_size to be |
2394 | at least MINSIZE and to have prev_inuse set. | |
6c8dbf00 | 2395 | */ |
fa8d436c | 2396 | |
6c8dbf00 OB |
2397 | assert ((old_top == initial_top (av) && old_size == 0) || |
2398 | ((unsigned long) (old_size) >= MINSIZE && | |
2399 | prev_inuse (old_top) && | |
8a35c3fe | 2400 | ((unsigned long) old_end & (pagesize - 1)) == 0)); |
fa8d436c UD |
2401 | |
2402 | /* Precondition: not enough current space to satisfy nb request */ | |
6c8dbf00 | 2403 | assert ((unsigned long) (old_size) < (unsigned long) (nb + MINSIZE)); |
a9177ff5 | 2404 | |
72f90263 | 2405 | |
6c8dbf00 OB |
2406 | if (av != &main_arena) |
2407 | { | |
2408 | heap_info *old_heap, *heap; | |
2409 | size_t old_heap_size; | |
2410 | ||
2411 | /* First try to extend the current heap. */ | |
2412 | old_heap = heap_for_ptr (old_top); | |
2413 | old_heap_size = old_heap->size; | |
2414 | if ((long) (MINSIZE + nb - old_size) > 0 | |
2415 | && grow_heap (old_heap, MINSIZE + nb - old_size) == 0) | |
2416 | { | |
2417 | av->system_mem += old_heap->size - old_heap_size; | |
6c8dbf00 OB |
2418 | set_head (old_top, (((char *) old_heap + old_heap->size) - (char *) old_top) |
2419 | | PREV_INUSE); | |
2420 | } | |
2421 | else if ((heap = new_heap (nb + (MINSIZE + sizeof (*heap)), mp_.top_pad))) | |
2422 | { | |
2423 | /* Use a newly allocated heap. */ | |
2424 | heap->ar_ptr = av; | |
2425 | heap->prev = old_heap; | |
2426 | av->system_mem += heap->size; | |
6c8dbf00 OB |
2427 | /* Set up the new top. */ |
2428 | top (av) = chunk_at_offset (heap, sizeof (*heap)); | |
2429 | set_head (top (av), (heap->size - sizeof (*heap)) | PREV_INUSE); | |
2430 | ||
2431 | /* Setup fencepost and free the old top chunk with a multiple of | |
2432 | MALLOC_ALIGNMENT in size. */ | |
2433 | /* The fencepost takes at least MINSIZE bytes, because it might | |
2434 | become the top chunk again later. Note that a footer is set | |
2435 | up, too, although the chunk is marked in use. */ | |
2436 | old_size = (old_size - MINSIZE) & ~MALLOC_ALIGN_MASK; | |
2437 | set_head (chunk_at_offset (old_top, old_size + 2 * SIZE_SZ), 0 | PREV_INUSE); | |
2438 | if (old_size >= MINSIZE) | |
2439 | { | |
2440 | set_head (chunk_at_offset (old_top, old_size), (2 * SIZE_SZ) | PREV_INUSE); | |
2441 | set_foot (chunk_at_offset (old_top, old_size), (2 * SIZE_SZ)); | |
2442 | set_head (old_top, old_size | PREV_INUSE | NON_MAIN_ARENA); | |
2443 | _int_free (av, old_top, 1); | |
2444 | } | |
2445 | else | |
2446 | { | |
2447 | set_head (old_top, (old_size + 2 * SIZE_SZ) | PREV_INUSE); | |
2448 | set_foot (old_top, (old_size + 2 * SIZE_SZ)); | |
2449 | } | |
2450 | } | |
2451 | else if (!tried_mmap) | |
2452 | /* We can at least try to use to mmap memory. */ | |
2453 | goto try_mmap; | |
fa8d436c | 2454 | } |
6c8dbf00 | 2455 | else /* av == main_arena */ |
fa8d436c | 2456 | |
fa8d436c | 2457 | |
6c8dbf00 OB |
2458 | { /* Request enough space for nb + pad + overhead */ |
2459 | size = nb + mp_.top_pad + MINSIZE; | |
a9177ff5 | 2460 | |
6c8dbf00 OB |
2461 | /* |
2462 | If contiguous, we can subtract out existing space that we hope to | |
2463 | combine with new space. We add it back later only if | |
2464 | we don't actually get contiguous space. | |
2465 | */ | |
a9177ff5 | 2466 | |
6c8dbf00 OB |
2467 | if (contiguous (av)) |
2468 | size -= old_size; | |
fa8d436c | 2469 | |
6c8dbf00 OB |
2470 | /* |
2471 | Round to a multiple of page size. | |
2472 | If MORECORE is not contiguous, this ensures that we only call it | |
2473 | with whole-page arguments. And if MORECORE is contiguous and | |
2474 | this is not first time through, this preserves page-alignment of | |
2475 | previous calls. Otherwise, we correct to page-align below. | |
2476 | */ | |
fa8d436c | 2477 | |
8a35c3fe | 2478 | size = ALIGN_UP (size, pagesize); |
fa8d436c | 2479 | |
6c8dbf00 OB |
2480 | /* |
2481 | Don't try to call MORECORE if argument is so big as to appear | |
2482 | negative. Note that since mmap takes size_t arg, it may succeed | |
2483 | below even if we cannot call MORECORE. | |
2484 | */ | |
2485 | ||
2486 | if (size > 0) | |
2487 | { | |
2488 | brk = (char *) (MORECORE (size)); | |
2489 | LIBC_PROBE (memory_sbrk_more, 2, brk, size); | |
2490 | } | |
2491 | ||
2492 | if (brk != (char *) (MORECORE_FAILURE)) | |
2493 | { | |
2494 | /* Call the `morecore' hook if necessary. */ | |
2495 | void (*hook) (void) = atomic_forced_read (__after_morecore_hook); | |
2496 | if (__builtin_expect (hook != NULL, 0)) | |
2497 | (*hook)(); | |
2498 | } | |
2499 | else | |
2500 | { | |
2501 | /* | |
2502 | If have mmap, try using it as a backup when MORECORE fails or | |
2503 | cannot be used. This is worth doing on systems that have "holes" in | |
2504 | address space, so sbrk cannot extend to give contiguous space, but | |
2505 | space is available elsewhere. Note that we ignore mmap max count | |
2506 | and threshold limits, since the space will not be used as a | |
2507 | segregated mmap region. | |
2508 | */ | |
2509 | ||
2510 | /* Cannot merge with old top, so add its size back in */ | |
2511 | if (contiguous (av)) | |
8a35c3fe | 2512 | size = ALIGN_UP (size + old_size, pagesize); |
6c8dbf00 OB |
2513 | |
2514 | /* If we are relying on mmap as backup, then use larger units */ | |
2515 | if ((unsigned long) (size) < (unsigned long) (MMAP_AS_MORECORE_SIZE)) | |
2516 | size = MMAP_AS_MORECORE_SIZE; | |
2517 | ||
2518 | /* Don't try if size wraps around 0 */ | |
2519 | if ((unsigned long) (size) > (unsigned long) (nb)) | |
2520 | { | |
2521 | char *mbrk = (char *) (MMAP (0, size, PROT_READ | PROT_WRITE, 0)); | |
2522 | ||
2523 | if (mbrk != MAP_FAILED) | |
2524 | { | |
2525 | /* We do not need, and cannot use, another sbrk call to find end */ | |
2526 | brk = mbrk; | |
2527 | snd_brk = brk + size; | |
2528 | ||
2529 | /* | |
2530 | Record that we no longer have a contiguous sbrk region. | |
2531 | After the first time mmap is used as backup, we do not | |
2532 | ever rely on contiguous space since this could incorrectly | |
2533 | bridge regions. | |
2534 | */ | |
2535 | set_noncontiguous (av); | |
2536 | } | |
2537 | } | |
2538 | } | |
2539 | ||
2540 | if (brk != (char *) (MORECORE_FAILURE)) | |
2541 | { | |
2542 | if (mp_.sbrk_base == 0) | |
2543 | mp_.sbrk_base = brk; | |
2544 | av->system_mem += size; | |
2545 | ||
2546 | /* | |
2547 | If MORECORE extends previous space, we can likewise extend top size. | |
2548 | */ | |
2549 | ||
2550 | if (brk == old_end && snd_brk == (char *) (MORECORE_FAILURE)) | |
2551 | set_head (old_top, (size + old_size) | PREV_INUSE); | |
2552 | ||
2553 | else if (contiguous (av) && old_size && brk < old_end) | |
ac3ed168 FW |
2554 | /* Oops! Someone else killed our space.. Can't touch anything. */ |
2555 | malloc_printerr ("break adjusted to free malloc space"); | |
6c8dbf00 OB |
2556 | |
2557 | /* | |
2558 | Otherwise, make adjustments: | |
2559 | ||
2560 | * If the first time through or noncontiguous, we need to call sbrk | |
2561 | just to find out where the end of memory lies. | |
2562 | ||
2563 | * We need to ensure that all returned chunks from malloc will meet | |
2564 | MALLOC_ALIGNMENT | |
2565 | ||
2566 | * If there was an intervening foreign sbrk, we need to adjust sbrk | |
2567 | request size to account for fact that we will not be able to | |
2568 | combine new space with existing space in old_top. | |
2569 | ||
2570 | * Almost all systems internally allocate whole pages at a time, in | |
2571 | which case we might as well use the whole last page of request. | |
2572 | So we allocate enough more memory to hit a page boundary now, | |
2573 | which in turn causes future contiguous calls to page-align. | |
2574 | */ | |
2575 | ||
2576 | else | |
2577 | { | |
2578 | front_misalign = 0; | |
2579 | end_misalign = 0; | |
2580 | correction = 0; | |
2581 | aligned_brk = brk; | |
2582 | ||
2583 | /* handle contiguous cases */ | |
2584 | if (contiguous (av)) | |
2585 | { | |
2586 | /* Count foreign sbrk as system_mem. */ | |
2587 | if (old_size) | |
2588 | av->system_mem += brk - old_end; | |
2589 | ||
2590 | /* Guarantee alignment of first new chunk made from this space */ | |
2591 | ||
2592 | front_misalign = (INTERNAL_SIZE_T) chunk2mem (brk) & MALLOC_ALIGN_MASK; | |
2593 | if (front_misalign > 0) | |
2594 | { | |
2595 | /* | |
2596 | Skip over some bytes to arrive at an aligned position. | |
2597 | We don't need to specially mark these wasted front bytes. | |
2598 | They will never be accessed anyway because | |
2599 | prev_inuse of av->top (and any chunk created from its start) | |
2600 | is always true after initialization. | |
2601 | */ | |
2602 | ||
2603 | correction = MALLOC_ALIGNMENT - front_misalign; | |
2604 | aligned_brk += correction; | |
2605 | } | |
2606 | ||
2607 | /* | |
2608 | If this isn't adjacent to existing space, then we will not | |
2609 | be able to merge with old_top space, so must add to 2nd request. | |
2610 | */ | |
2611 | ||
2612 | correction += old_size; | |
2613 | ||
2614 | /* Extend the end address to hit a page boundary */ | |
2615 | end_misalign = (INTERNAL_SIZE_T) (brk + size + correction); | |
8a35c3fe | 2616 | correction += (ALIGN_UP (end_misalign, pagesize)) - end_misalign; |
6c8dbf00 OB |
2617 | |
2618 | assert (correction >= 0); | |
2619 | snd_brk = (char *) (MORECORE (correction)); | |
2620 | ||
2621 | /* | |
2622 | If can't allocate correction, try to at least find out current | |
2623 | brk. It might be enough to proceed without failing. | |
2624 | ||
2625 | Note that if second sbrk did NOT fail, we assume that space | |
2626 | is contiguous with first sbrk. This is a safe assumption unless | |
2627 | program is multithreaded but doesn't use locks and a foreign sbrk | |
2628 | occurred between our first and second calls. | |
2629 | */ | |
2630 | ||
2631 | if (snd_brk == (char *) (MORECORE_FAILURE)) | |
2632 | { | |
2633 | correction = 0; | |
2634 | snd_brk = (char *) (MORECORE (0)); | |
2635 | } | |
2636 | else | |
2637 | { | |
2638 | /* Call the `morecore' hook if necessary. */ | |
2639 | void (*hook) (void) = atomic_forced_read (__after_morecore_hook); | |
2640 | if (__builtin_expect (hook != NULL, 0)) | |
2641 | (*hook)(); | |
2642 | } | |
2643 | } | |
2644 | ||
2645 | /* handle non-contiguous cases */ | |
2646 | else | |
2647 | { | |
2648 | if (MALLOC_ALIGNMENT == 2 * SIZE_SZ) | |
2649 | /* MORECORE/mmap must correctly align */ | |
2650 | assert (((unsigned long) chunk2mem (brk) & MALLOC_ALIGN_MASK) == 0); | |
2651 | else | |
2652 | { | |
2653 | front_misalign = (INTERNAL_SIZE_T) chunk2mem (brk) & MALLOC_ALIGN_MASK; | |
2654 | if (front_misalign > 0) | |
2655 | { | |
2656 | /* | |
2657 | Skip over some bytes to arrive at an aligned position. | |
2658 | We don't need to specially mark these wasted front bytes. | |
2659 | They will never be accessed anyway because | |
2660 | prev_inuse of av->top (and any chunk created from its start) | |
2661 | is always true after initialization. | |
2662 | */ | |
2663 | ||
2664 | aligned_brk += MALLOC_ALIGNMENT - front_misalign; | |
2665 | } | |
2666 | } | |
2667 | ||
2668 | /* Find out current end of memory */ | |
2669 | if (snd_brk == (char *) (MORECORE_FAILURE)) | |
2670 | { | |
2671 | snd_brk = (char *) (MORECORE (0)); | |
2672 | } | |
2673 | } | |
2674 | ||
2675 | /* Adjust top based on results of second sbrk */ | |
2676 | if (snd_brk != (char *) (MORECORE_FAILURE)) | |
2677 | { | |
2678 | av->top = (mchunkptr) aligned_brk; | |
2679 | set_head (av->top, (snd_brk - aligned_brk + correction) | PREV_INUSE); | |
2680 | av->system_mem += correction; | |
2681 | ||
2682 | /* | |
2683 | If not the first time through, we either have a | |
2684 | gap due to foreign sbrk or a non-contiguous region. Insert a | |
2685 | double fencepost at old_top to prevent consolidation with space | |
2686 | we don't own. These fenceposts are artificial chunks that are | |
2687 | marked as inuse and are in any case too small to use. We need | |
2688 | two to make sizes and alignments work out. | |
2689 | */ | |
2690 | ||
2691 | if (old_size != 0) | |
2692 | { | |
2693 | /* | |
2694 | Shrink old_top to insert fenceposts, keeping size a | |
2695 | multiple of MALLOC_ALIGNMENT. We know there is at least | |
2696 | enough space in old_top to do this. | |
2697 | */ | |
2698 | old_size = (old_size - 4 * SIZE_SZ) & ~MALLOC_ALIGN_MASK; | |
2699 | set_head (old_top, old_size | PREV_INUSE); | |
2700 | ||
2701 | /* | |
2702 | Note that the following assignments completely overwrite | |
2703 | old_top when old_size was previously MINSIZE. This is | |
2704 | intentional. We need the fencepost, even if old_top otherwise gets | |
2705 | lost. | |
2706 | */ | |
e9c4fe93 FW |
2707 | set_head (chunk_at_offset (old_top, old_size), |
2708 | (2 * SIZE_SZ) | PREV_INUSE); | |
2709 | set_head (chunk_at_offset (old_top, old_size + 2 * SIZE_SZ), | |
2710 | (2 * SIZE_SZ) | PREV_INUSE); | |
6c8dbf00 OB |
2711 | |
2712 | /* If possible, release the rest. */ | |
2713 | if (old_size >= MINSIZE) | |
2714 | { | |
2715 | _int_free (av, old_top, 1); | |
2716 | } | |
2717 | } | |
2718 | } | |
2719 | } | |
2720 | } | |
2721 | } /* if (av != &main_arena) */ | |
2722 | ||
2723 | if ((unsigned long) av->system_mem > (unsigned long) (av->max_system_mem)) | |
fa8d436c | 2724 | av->max_system_mem = av->system_mem; |
6c8dbf00 | 2725 | check_malloc_state (av); |
a9177ff5 | 2726 | |
fa8d436c UD |
2727 | /* finally, do the allocation */ |
2728 | p = av->top; | |
6c8dbf00 | 2729 | size = chunksize (p); |
fa8d436c UD |
2730 | |
2731 | /* check that one of the above allocation paths succeeded */ | |
6c8dbf00 OB |
2732 | if ((unsigned long) (size) >= (unsigned long) (nb + MINSIZE)) |
2733 | { | |
2734 | remainder_size = size - nb; | |
2735 | remainder = chunk_at_offset (p, nb); | |
2736 | av->top = remainder; | |
2737 | set_head (p, nb | PREV_INUSE | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
2738 | set_head (remainder, remainder_size | PREV_INUSE); | |
2739 | check_malloced_chunk (av, p, nb); | |
2740 | return chunk2mem (p); | |
2741 | } | |
fa8d436c UD |
2742 | |
2743 | /* catch all failure paths */ | |
8e58439c | 2744 | __set_errno (ENOMEM); |
fa8d436c UD |
2745 | return 0; |
2746 | } | |
2747 | ||
2748 | ||
2749 | /* | |
6c8dbf00 OB |
2750 | systrim is an inverse of sorts to sysmalloc. It gives memory back |
2751 | to the system (via negative arguments to sbrk) if there is unused | |
2752 | memory at the `high' end of the malloc pool. It is called | |
2753 | automatically by free() when top space exceeds the trim | |
2754 | threshold. It is also called by the public malloc_trim routine. It | |
2755 | returns 1 if it actually released any memory, else 0. | |
2756 | */ | |
fa8d436c | 2757 | |
6c8dbf00 OB |
2758 | static int |
2759 | systrim (size_t pad, mstate av) | |
fa8d436c | 2760 | { |
6c8dbf00 OB |
2761 | long top_size; /* Amount of top-most memory */ |
2762 | long extra; /* Amount to release */ | |
2763 | long released; /* Amount actually released */ | |
2764 | char *current_brk; /* address returned by pre-check sbrk call */ | |
2765 | char *new_brk; /* address returned by post-check sbrk call */ | |
8a35c3fe | 2766 | size_t pagesize; |
6c8dbf00 | 2767 | long top_area; |
fa8d436c | 2768 | |
8a35c3fe | 2769 | pagesize = GLRO (dl_pagesize); |
6c8dbf00 | 2770 | top_size = chunksize (av->top); |
a9177ff5 | 2771 | |
4b5b548c FS |
2772 | top_area = top_size - MINSIZE - 1; |
2773 | if (top_area <= pad) | |
2774 | return 0; | |
2775 | ||
ca6be165 CD |
2776 | /* Release in pagesize units and round down to the nearest page. */ |
2777 | extra = ALIGN_DOWN(top_area - pad, pagesize); | |
a9177ff5 | 2778 | |
51a7380b WN |
2779 | if (extra == 0) |
2780 | return 0; | |
2781 | ||
4b5b548c | 2782 | /* |
6c8dbf00 OB |
2783 | Only proceed if end of memory is where we last set it. |
2784 | This avoids problems if there were foreign sbrk calls. | |
2785 | */ | |
2786 | current_brk = (char *) (MORECORE (0)); | |
2787 | if (current_brk == (char *) (av->top) + top_size) | |
2788 | { | |
2789 | /* | |
2790 | Attempt to release memory. We ignore MORECORE return value, | |
2791 | and instead call again to find out where new end of memory is. | |
2792 | This avoids problems if first call releases less than we asked, | |
2793 | of if failure somehow altered brk value. (We could still | |
2794 | encounter problems if it altered brk in some very bad way, | |
2795 | but the only thing we can do is adjust anyway, which will cause | |
2796 | some downstream failure.) | |
2797 | */ | |
2798 | ||
2799 | MORECORE (-extra); | |
2800 | /* Call the `morecore' hook if necessary. */ | |
2801 | void (*hook) (void) = atomic_forced_read (__after_morecore_hook); | |
2802 | if (__builtin_expect (hook != NULL, 0)) | |
2803 | (*hook)(); | |
2804 | new_brk = (char *) (MORECORE (0)); | |
2805 | ||
2806 | LIBC_PROBE (memory_sbrk_less, 2, new_brk, extra); | |
2807 | ||
2808 | if (new_brk != (char *) MORECORE_FAILURE) | |
2809 | { | |
2810 | released = (long) (current_brk - new_brk); | |
2811 | ||
2812 | if (released != 0) | |
2813 | { | |
2814 | /* Success. Adjust top. */ | |
2815 | av->system_mem -= released; | |
2816 | set_head (av->top, (top_size - released) | PREV_INUSE); | |
2817 | check_malloc_state (av); | |
2818 | return 1; | |
2819 | } | |
2820 | } | |
fa8d436c | 2821 | } |
fa8d436c | 2822 | return 0; |
f65fd747 UD |
2823 | } |
2824 | ||
431c33c0 | 2825 | static void |
6c8dbf00 | 2826 | munmap_chunk (mchunkptr p) |
f65fd747 | 2827 | { |
6c8dbf00 | 2828 | INTERNAL_SIZE_T size = chunksize (p); |
f65fd747 | 2829 | |
6c8dbf00 | 2830 | assert (chunk_is_mmapped (p)); |
8e635611 | 2831 | |
4cf6c72f FW |
2832 | /* Do nothing if the chunk is a faked mmapped chunk in the dumped |
2833 | main arena. We never free this memory. */ | |
2834 | if (DUMPED_MAIN_ARENA_CHUNK (p)) | |
2835 | return; | |
2836 | ||
e9c4fe93 FW |
2837 | uintptr_t block = (uintptr_t) p - prev_size (p); |
2838 | size_t total_size = prev_size (p) + size; | |
8e635611 UD |
2839 | /* Unfortunately we have to do the compilers job by hand here. Normally |
2840 | we would test BLOCK and TOTAL-SIZE separately for compliance with the | |
2841 | page size. But gcc does not recognize the optimization possibility | |
2842 | (in the moment at least) so we combine the two values into one before | |
2843 | the bit test. */ | |
6c8dbf00 | 2844 | if (__builtin_expect (((block | total_size) & (GLRO (dl_pagesize) - 1)) != 0, 0)) |
ac3ed168 | 2845 | malloc_printerr ("munmap_chunk(): invalid pointer"); |
f65fd747 | 2846 | |
c6e4925d OB |
2847 | atomic_decrement (&mp_.n_mmaps); |
2848 | atomic_add (&mp_.mmapped_mem, -total_size); | |
f65fd747 | 2849 | |
6ef76f3b UD |
2850 | /* If munmap failed the process virtual memory address space is in a |
2851 | bad shape. Just leave the block hanging around, the process will | |
2852 | terminate shortly anyway since not much can be done. */ | |
6c8dbf00 | 2853 | __munmap ((char *) block, total_size); |
f65fd747 UD |
2854 | } |
2855 | ||
2856 | #if HAVE_MREMAP | |
2857 | ||
431c33c0 | 2858 | static mchunkptr |
6c8dbf00 | 2859 | mremap_chunk (mchunkptr p, size_t new_size) |
f65fd747 | 2860 | { |
8a35c3fe | 2861 | size_t pagesize = GLRO (dl_pagesize); |
e9c4fe93 | 2862 | INTERNAL_SIZE_T offset = prev_size (p); |
6c8dbf00 | 2863 | INTERNAL_SIZE_T size = chunksize (p); |
f65fd747 UD |
2864 | char *cp; |
2865 | ||
6c8dbf00 OB |
2866 | assert (chunk_is_mmapped (p)); |
2867 | assert (((size + offset) & (GLRO (dl_pagesize) - 1)) == 0); | |
f65fd747 UD |
2868 | |
2869 | /* Note the extra SIZE_SZ overhead as in mmap_chunk(). */ | |
8a35c3fe | 2870 | new_size = ALIGN_UP (new_size + offset + SIZE_SZ, pagesize); |
f65fd747 | 2871 | |
68f3802d UD |
2872 | /* No need to remap if the number of pages does not change. */ |
2873 | if (size + offset == new_size) | |
2874 | return p; | |
2875 | ||
6c8dbf00 OB |
2876 | cp = (char *) __mremap ((char *) p - offset, size + offset, new_size, |
2877 | MREMAP_MAYMOVE); | |
f65fd747 | 2878 | |
6c8dbf00 OB |
2879 | if (cp == MAP_FAILED) |
2880 | return 0; | |
f65fd747 | 2881 | |
6c8dbf00 | 2882 | p = (mchunkptr) (cp + offset); |
f65fd747 | 2883 | |
6c8dbf00 | 2884 | assert (aligned_OK (chunk2mem (p))); |
f65fd747 | 2885 | |
e9c4fe93 | 2886 | assert (prev_size (p) == offset); |
6c8dbf00 | 2887 | set_head (p, (new_size - offset) | IS_MMAPPED); |
f65fd747 | 2888 | |
c6e4925d OB |
2889 | INTERNAL_SIZE_T new; |
2890 | new = atomic_exchange_and_add (&mp_.mmapped_mem, new_size - size - offset) | |
6c8dbf00 | 2891 | + new_size - size - offset; |
c6e4925d | 2892 | atomic_max (&mp_.max_mmapped_mem, new); |
f65fd747 UD |
2893 | return p; |
2894 | } | |
f65fd747 UD |
2895 | #endif /* HAVE_MREMAP */ |
2896 | ||
fa8d436c | 2897 | /*------------------------ Public wrappers. --------------------------------*/ |
f65fd747 | 2898 | |
d5c3fafc DD |
2899 | #if USE_TCACHE |
2900 | ||
2901 | /* We overlay this structure on the user-data portion of a chunk when | |
2902 | the chunk is stored in the per-thread cache. */ | |
2903 | typedef struct tcache_entry | |
2904 | { | |
2905 | struct tcache_entry *next; | |
2906 | } tcache_entry; | |
2907 | ||
2908 | /* There is one of these for each thread, which contains the | |
2909 | per-thread cache (hence "tcache_perthread_struct"). Keeping | |
2910 | overall size low is mildly important. Note that COUNTS and ENTRIES | |
2911 | are redundant (we could have just counted the linked list each | |
2912 | time), this is for performance reasons. */ | |
2913 | typedef struct tcache_perthread_struct | |
2914 | { | |
2915 | char counts[TCACHE_MAX_BINS]; | |
2916 | tcache_entry *entries[TCACHE_MAX_BINS]; | |
2917 | } tcache_perthread_struct; | |
2918 | ||
1e26d351 | 2919 | static __thread bool tcache_shutting_down = false; |
d5c3fafc DD |
2920 | static __thread tcache_perthread_struct *tcache = NULL; |
2921 | ||
2922 | /* Caller must ensure that we know tc_idx is valid and there's room | |
2923 | for more chunks. */ | |
2924 | static void | |
2925 | tcache_put (mchunkptr chunk, size_t tc_idx) | |
2926 | { | |
2927 | tcache_entry *e = (tcache_entry *) chunk2mem (chunk); | |
2928 | assert (tc_idx < TCACHE_MAX_BINS); | |
2929 | e->next = tcache->entries[tc_idx]; | |
2930 | tcache->entries[tc_idx] = e; | |
2931 | ++(tcache->counts[tc_idx]); | |
2932 | } | |
2933 | ||
2934 | /* Caller must ensure that we know tc_idx is valid and there's | |
2935 | available chunks to remove. */ | |
2936 | static void * | |
2937 | tcache_get (size_t tc_idx) | |
2938 | { | |
2939 | tcache_entry *e = tcache->entries[tc_idx]; | |
2940 | assert (tc_idx < TCACHE_MAX_BINS); | |
2941 | assert (tcache->entries[tc_idx] > 0); | |
2942 | tcache->entries[tc_idx] = e->next; | |
2943 | --(tcache->counts[tc_idx]); | |
2944 | return (void *) e; | |
2945 | } | |
2946 | ||
2947 | static void __attribute__ ((section ("__libc_thread_freeres_fn"))) | |
2948 | tcache_thread_freeres (void) | |
2949 | { | |
2950 | int i; | |
2951 | tcache_perthread_struct *tcache_tmp = tcache; | |
2952 | ||
2953 | if (!tcache) | |
2954 | return; | |
2955 | ||
1e26d351 | 2956 | /* Disable the tcache and prevent it from being reinitialized. */ |
d5c3fafc | 2957 | tcache = NULL; |
1e26d351 | 2958 | tcache_shutting_down = true; |
d5c3fafc | 2959 | |
1e26d351 CD |
2960 | /* Free all of the entries and the tcache itself back to the arena |
2961 | heap for coalescing. */ | |
d5c3fafc DD |
2962 | for (i = 0; i < TCACHE_MAX_BINS; ++i) |
2963 | { | |
2964 | while (tcache_tmp->entries[i]) | |
2965 | { | |
2966 | tcache_entry *e = tcache_tmp->entries[i]; | |
2967 | tcache_tmp->entries[i] = e->next; | |
2968 | __libc_free (e); | |
2969 | } | |
2970 | } | |
2971 | ||
2972 | __libc_free (tcache_tmp); | |
d5c3fafc DD |
2973 | } |
2974 | text_set_element (__libc_thread_subfreeres, tcache_thread_freeres); | |
2975 | ||
2976 | static void | |
2977 | tcache_init(void) | |
2978 | { | |
2979 | mstate ar_ptr; | |
2980 | void *victim = 0; | |
2981 | const size_t bytes = sizeof (tcache_perthread_struct); | |
2982 | ||
2983 | if (tcache_shutting_down) | |
2984 | return; | |
2985 | ||
2986 | arena_get (ar_ptr, bytes); | |
2987 | victim = _int_malloc (ar_ptr, bytes); | |
2988 | if (!victim && ar_ptr != NULL) | |
2989 | { | |
2990 | ar_ptr = arena_get_retry (ar_ptr, bytes); | |
2991 | victim = _int_malloc (ar_ptr, bytes); | |
2992 | } | |
2993 | ||
2994 | ||
2995 | if (ar_ptr != NULL) | |
2996 | __libc_lock_unlock (ar_ptr->mutex); | |
2997 | ||
2998 | /* In a low memory situation, we may not be able to allocate memory | |
2999 | - in which case, we just keep trying later. However, we | |
3000 | typically do this very early, so either there is sufficient | |
3001 | memory, or there isn't enough memory to do non-trivial | |
3002 | allocations anyway. */ | |
3003 | if (victim) | |
3004 | { | |
3005 | tcache = (tcache_perthread_struct *) victim; | |
3006 | memset (tcache, 0, sizeof (tcache_perthread_struct)); | |
3007 | } | |
3008 | ||
3009 | } | |
3010 | ||
3011 | #define MAYBE_INIT_TCACHE() \ | |
3012 | if (__glibc_unlikely (tcache == NULL)) \ | |
3013 | tcache_init(); | |
3014 | ||
3015 | #else | |
3016 | #define MAYBE_INIT_TCACHE() | |
3017 | #endif | |
3018 | ||
6c8dbf00 OB |
3019 | void * |
3020 | __libc_malloc (size_t bytes) | |
fa8d436c UD |
3021 | { |
3022 | mstate ar_ptr; | |
22a89187 | 3023 | void *victim; |
f65fd747 | 3024 | |
a222d91a | 3025 | void *(*hook) (size_t, const void *) |
f3eeb3fc | 3026 | = atomic_forced_read (__malloc_hook); |
bfacf1af | 3027 | if (__builtin_expect (hook != NULL, 0)) |
fa8d436c | 3028 | return (*hook)(bytes, RETURN_ADDRESS (0)); |
d5c3fafc DD |
3029 | #if USE_TCACHE |
3030 | /* int_free also calls request2size, be careful to not pad twice. */ | |
3031 | size_t tbytes = request2size (bytes); | |
3032 | size_t tc_idx = csize2tidx (tbytes); | |
3033 | ||
3034 | MAYBE_INIT_TCACHE (); | |
3035 | ||
3036 | DIAG_PUSH_NEEDS_COMMENT; | |
3037 | if (tc_idx < mp_.tcache_bins | |
3038 | /*&& tc_idx < TCACHE_MAX_BINS*/ /* to appease gcc */ | |
3039 | && tcache | |
3040 | && tcache->entries[tc_idx] != NULL) | |
3041 | { | |
3042 | return tcache_get (tc_idx); | |
3043 | } | |
3044 | DIAG_POP_NEEDS_COMMENT; | |
3045 | #endif | |
f65fd747 | 3046 | |
94c5a52a | 3047 | arena_get (ar_ptr, bytes); |
425ce2ed | 3048 | |
6c8dbf00 | 3049 | victim = _int_malloc (ar_ptr, bytes); |
fff94fa2 SP |
3050 | /* Retry with another arena only if we were able to find a usable arena |
3051 | before. */ | |
3052 | if (!victim && ar_ptr != NULL) | |
6c8dbf00 OB |
3053 | { |
3054 | LIBC_PROBE (memory_malloc_retry, 1, bytes); | |
3055 | ar_ptr = arena_get_retry (ar_ptr, bytes); | |
fff94fa2 | 3056 | victim = _int_malloc (ar_ptr, bytes); |
60f0e64b | 3057 | } |
fff94fa2 SP |
3058 | |
3059 | if (ar_ptr != NULL) | |
4bf5f222 | 3060 | __libc_lock_unlock (ar_ptr->mutex); |
fff94fa2 | 3061 | |
6c8dbf00 OB |
3062 | assert (!victim || chunk_is_mmapped (mem2chunk (victim)) || |
3063 | ar_ptr == arena_for_chunk (mem2chunk (victim))); | |
fa8d436c | 3064 | return victim; |
f65fd747 | 3065 | } |
6c8dbf00 | 3066 | libc_hidden_def (__libc_malloc) |
f65fd747 | 3067 | |
fa8d436c | 3068 | void |
6c8dbf00 | 3069 | __libc_free (void *mem) |
f65fd747 | 3070 | { |
fa8d436c UD |
3071 | mstate ar_ptr; |
3072 | mchunkptr p; /* chunk corresponding to mem */ | |
3073 | ||
a222d91a | 3074 | void (*hook) (void *, const void *) |
f3eeb3fc | 3075 | = atomic_forced_read (__free_hook); |
6c8dbf00 OB |
3076 | if (__builtin_expect (hook != NULL, 0)) |
3077 | { | |
3078 | (*hook)(mem, RETURN_ADDRESS (0)); | |
3079 | return; | |
3080 | } | |
f65fd747 | 3081 | |
fa8d436c UD |
3082 | if (mem == 0) /* free(0) has no effect */ |
3083 | return; | |
f65fd747 | 3084 | |
6c8dbf00 | 3085 | p = mem2chunk (mem); |
f65fd747 | 3086 | |
6c8dbf00 OB |
3087 | if (chunk_is_mmapped (p)) /* release mmapped memory. */ |
3088 | { | |
4cf6c72f FW |
3089 | /* See if the dynamic brk/mmap threshold needs adjusting. |
3090 | Dumped fake mmapped chunks do not affect the threshold. */ | |
6c8dbf00 | 3091 | if (!mp_.no_dyn_threshold |
e9c4fe93 FW |
3092 | && chunksize_nomask (p) > mp_.mmap_threshold |
3093 | && chunksize_nomask (p) <= DEFAULT_MMAP_THRESHOLD_MAX | |
4cf6c72f | 3094 | && !DUMPED_MAIN_ARENA_CHUNK (p)) |
6c8dbf00 OB |
3095 | { |
3096 | mp_.mmap_threshold = chunksize (p); | |
3097 | mp_.trim_threshold = 2 * mp_.mmap_threshold; | |
3098 | LIBC_PROBE (memory_mallopt_free_dyn_thresholds, 2, | |
3099 | mp_.mmap_threshold, mp_.trim_threshold); | |
3100 | } | |
3101 | munmap_chunk (p); | |
3102 | return; | |
3103 | } | |
f65fd747 | 3104 | |
d5c3fafc DD |
3105 | MAYBE_INIT_TCACHE (); |
3106 | ||
6c8dbf00 OB |
3107 | ar_ptr = arena_for_chunk (p); |
3108 | _int_free (ar_ptr, p, 0); | |
f65fd747 | 3109 | } |
3b49edc0 | 3110 | libc_hidden_def (__libc_free) |
f65fd747 | 3111 | |
6c8dbf00 OB |
3112 | void * |
3113 | __libc_realloc (void *oldmem, size_t bytes) | |
f65fd747 | 3114 | { |
fa8d436c | 3115 | mstate ar_ptr; |
6c8dbf00 | 3116 | INTERNAL_SIZE_T nb; /* padded request size */ |
f65fd747 | 3117 | |
6c8dbf00 | 3118 | void *newp; /* chunk to return */ |
f65fd747 | 3119 | |
a222d91a | 3120 | void *(*hook) (void *, size_t, const void *) = |
f3eeb3fc | 3121 | atomic_forced_read (__realloc_hook); |
bfacf1af | 3122 | if (__builtin_expect (hook != NULL, 0)) |
fa8d436c | 3123 | return (*hook)(oldmem, bytes, RETURN_ADDRESS (0)); |
f65fd747 | 3124 | |
fa8d436c | 3125 | #if REALLOC_ZERO_BYTES_FREES |
6c8dbf00 OB |
3126 | if (bytes == 0 && oldmem != NULL) |
3127 | { | |
3128 | __libc_free (oldmem); return 0; | |
3129 | } | |
f65fd747 | 3130 | #endif |
f65fd747 | 3131 | |
fa8d436c | 3132 | /* realloc of null is supposed to be same as malloc */ |
6c8dbf00 OB |
3133 | if (oldmem == 0) |
3134 | return __libc_malloc (bytes); | |
f65fd747 | 3135 | |
78ac92ad | 3136 | /* chunk corresponding to oldmem */ |
6c8dbf00 | 3137 | const mchunkptr oldp = mem2chunk (oldmem); |
78ac92ad | 3138 | /* its size */ |
6c8dbf00 | 3139 | const INTERNAL_SIZE_T oldsize = chunksize (oldp); |
f65fd747 | 3140 | |
fff94fa2 SP |
3141 | if (chunk_is_mmapped (oldp)) |
3142 | ar_ptr = NULL; | |
3143 | else | |
d5c3fafc DD |
3144 | { |
3145 | MAYBE_INIT_TCACHE (); | |
3146 | ar_ptr = arena_for_chunk (oldp); | |
3147 | } | |
fff94fa2 | 3148 | |
4cf6c72f FW |
3149 | /* Little security check which won't hurt performance: the allocator |
3150 | never wrapps around at the end of the address space. Therefore | |
3151 | we can exclude some size values which might appear here by | |
3152 | accident or by "design" from some intruder. We need to bypass | |
3153 | this check for dumped fake mmap chunks from the old main arena | |
3154 | because the new malloc may provide additional alignment. */ | |
3155 | if ((__builtin_expect ((uintptr_t) oldp > (uintptr_t) -oldsize, 0) | |
3156 | || __builtin_expect (misaligned_chunk (oldp), 0)) | |
3157 | && !DUMPED_MAIN_ARENA_CHUNK (oldp)) | |
ac3ed168 | 3158 | malloc_printerr ("realloc(): invalid pointer"); |
dc165f7b | 3159 | |
6c8dbf00 | 3160 | checked_request2size (bytes, nb); |
f65fd747 | 3161 | |
6c8dbf00 OB |
3162 | if (chunk_is_mmapped (oldp)) |
3163 | { | |
4cf6c72f FW |
3164 | /* If this is a faked mmapped chunk from the dumped main arena, |
3165 | always make a copy (and do not free the old chunk). */ | |
3166 | if (DUMPED_MAIN_ARENA_CHUNK (oldp)) | |
3167 | { | |
3168 | /* Must alloc, copy, free. */ | |
3169 | void *newmem = __libc_malloc (bytes); | |
3170 | if (newmem == 0) | |
3171 | return NULL; | |
3172 | /* Copy as many bytes as are available from the old chunk | |
1e8a8875 FW |
3173 | and fit into the new size. NB: The overhead for faked |
3174 | mmapped chunks is only SIZE_SZ, not 2 * SIZE_SZ as for | |
3175 | regular mmapped chunks. */ | |
3176 | if (bytes > oldsize - SIZE_SZ) | |
3177 | bytes = oldsize - SIZE_SZ; | |
4cf6c72f FW |
3178 | memcpy (newmem, oldmem, bytes); |
3179 | return newmem; | |
3180 | } | |
3181 | ||
6c8dbf00 | 3182 | void *newmem; |
f65fd747 | 3183 | |
fa8d436c | 3184 | #if HAVE_MREMAP |
6c8dbf00 OB |
3185 | newp = mremap_chunk (oldp, nb); |
3186 | if (newp) | |
3187 | return chunk2mem (newp); | |
f65fd747 | 3188 | #endif |
6c8dbf00 OB |
3189 | /* Note the extra SIZE_SZ overhead. */ |
3190 | if (oldsize - SIZE_SZ >= nb) | |
3191 | return oldmem; /* do nothing */ | |
3192 | ||
3193 | /* Must alloc, copy, free. */ | |
3194 | newmem = __libc_malloc (bytes); | |
3195 | if (newmem == 0) | |
3196 | return 0; /* propagate failure */ | |
fa8d436c | 3197 | |
6c8dbf00 OB |
3198 | memcpy (newmem, oldmem, oldsize - 2 * SIZE_SZ); |
3199 | munmap_chunk (oldp); | |
3200 | return newmem; | |
3201 | } | |
3202 | ||
4bf5f222 | 3203 | __libc_lock_lock (ar_ptr->mutex); |
f65fd747 | 3204 | |
6c8dbf00 | 3205 | newp = _int_realloc (ar_ptr, oldp, oldsize, nb); |
f65fd747 | 3206 | |
4bf5f222 | 3207 | __libc_lock_unlock (ar_ptr->mutex); |
6c8dbf00 OB |
3208 | assert (!newp || chunk_is_mmapped (mem2chunk (newp)) || |
3209 | ar_ptr == arena_for_chunk (mem2chunk (newp))); | |
07014fca UD |
3210 | |
3211 | if (newp == NULL) | |
3212 | { | |
3213 | /* Try harder to allocate memory in other arenas. */ | |
35fed6f1 | 3214 | LIBC_PROBE (memory_realloc_retry, 2, bytes, oldmem); |
6c8dbf00 | 3215 | newp = __libc_malloc (bytes); |
07014fca | 3216 | if (newp != NULL) |
6c8dbf00 OB |
3217 | { |
3218 | memcpy (newp, oldmem, oldsize - SIZE_SZ); | |
3219 | _int_free (ar_ptr, oldp, 0); | |
3220 | } | |
07014fca UD |
3221 | } |
3222 | ||
fa8d436c UD |
3223 | return newp; |
3224 | } | |
3b49edc0 | 3225 | libc_hidden_def (__libc_realloc) |
f65fd747 | 3226 | |
6c8dbf00 OB |
3227 | void * |
3228 | __libc_memalign (size_t alignment, size_t bytes) | |
10ad46bc OB |
3229 | { |
3230 | void *address = RETURN_ADDRESS (0); | |
3231 | return _mid_memalign (alignment, bytes, address); | |
3232 | } | |
3233 | ||
3234 | static void * | |
3235 | _mid_memalign (size_t alignment, size_t bytes, void *address) | |
fa8d436c UD |
3236 | { |
3237 | mstate ar_ptr; | |
22a89187 | 3238 | void *p; |
f65fd747 | 3239 | |
a222d91a | 3240 | void *(*hook) (size_t, size_t, const void *) = |
f3eeb3fc | 3241 | atomic_forced_read (__memalign_hook); |
bfacf1af | 3242 | if (__builtin_expect (hook != NULL, 0)) |
10ad46bc | 3243 | return (*hook)(alignment, bytes, address); |
f65fd747 | 3244 | |
10ad46bc | 3245 | /* If we need less alignment than we give anyway, just relay to malloc. */ |
6c8dbf00 OB |
3246 | if (alignment <= MALLOC_ALIGNMENT) |
3247 | return __libc_malloc (bytes); | |
1228ed5c | 3248 | |
fa8d436c | 3249 | /* Otherwise, ensure that it is at least a minimum chunk size */ |
6c8dbf00 OB |
3250 | if (alignment < MINSIZE) |
3251 | alignment = MINSIZE; | |
f65fd747 | 3252 | |
a56ee40b WN |
3253 | /* If the alignment is greater than SIZE_MAX / 2 + 1 it cannot be a |
3254 | power of 2 and will cause overflow in the check below. */ | |
3255 | if (alignment > SIZE_MAX / 2 + 1) | |
3256 | { | |
3257 | __set_errno (EINVAL); | |
3258 | return 0; | |
3259 | } | |
3260 | ||
b73ed247 WN |
3261 | /* Check for overflow. */ |
3262 | if (bytes > SIZE_MAX - alignment - MINSIZE) | |
3263 | { | |
3264 | __set_errno (ENOMEM); | |
3265 | return 0; | |
3266 | } | |
3267 | ||
10ad46bc OB |
3268 | |
3269 | /* Make sure alignment is power of 2. */ | |
6c8dbf00 OB |
3270 | if (!powerof2 (alignment)) |
3271 | { | |
3272 | size_t a = MALLOC_ALIGNMENT * 2; | |
3273 | while (a < alignment) | |
3274 | a <<= 1; | |
3275 | alignment = a; | |
3276 | } | |
10ad46bc | 3277 | |
6c8dbf00 | 3278 | arena_get (ar_ptr, bytes + alignment + MINSIZE); |
6c8dbf00 OB |
3279 | |
3280 | p = _int_memalign (ar_ptr, alignment, bytes); | |
fff94fa2 | 3281 | if (!p && ar_ptr != NULL) |
6c8dbf00 OB |
3282 | { |
3283 | LIBC_PROBE (memory_memalign_retry, 2, bytes, alignment); | |
3284 | ar_ptr = arena_get_retry (ar_ptr, bytes); | |
fff94fa2 | 3285 | p = _int_memalign (ar_ptr, alignment, bytes); |
f65fd747 | 3286 | } |
fff94fa2 SP |
3287 | |
3288 | if (ar_ptr != NULL) | |
4bf5f222 | 3289 | __libc_lock_unlock (ar_ptr->mutex); |
fff94fa2 | 3290 | |
6c8dbf00 OB |
3291 | assert (!p || chunk_is_mmapped (mem2chunk (p)) || |
3292 | ar_ptr == arena_for_chunk (mem2chunk (p))); | |
fa8d436c | 3293 | return p; |
f65fd747 | 3294 | } |
380d7e87 | 3295 | /* For ISO C11. */ |
3b49edc0 UD |
3296 | weak_alias (__libc_memalign, aligned_alloc) |
3297 | libc_hidden_def (__libc_memalign) | |
f65fd747 | 3298 | |
6c8dbf00 OB |
3299 | void * |
3300 | __libc_valloc (size_t bytes) | |
fa8d436c | 3301 | { |
6c8dbf00 | 3302 | if (__malloc_initialized < 0) |
fa8d436c | 3303 | ptmalloc_init (); |
8088488d | 3304 | |
10ad46bc | 3305 | void *address = RETURN_ADDRESS (0); |
8a35c3fe CD |
3306 | size_t pagesize = GLRO (dl_pagesize); |
3307 | return _mid_memalign (pagesize, bytes, address); | |
fa8d436c | 3308 | } |
f65fd747 | 3309 | |
6c8dbf00 OB |
3310 | void * |
3311 | __libc_pvalloc (size_t bytes) | |
fa8d436c | 3312 | { |
6c8dbf00 | 3313 | if (__malloc_initialized < 0) |
fa8d436c | 3314 | ptmalloc_init (); |
8088488d | 3315 | |
10ad46bc | 3316 | void *address = RETURN_ADDRESS (0); |
8a35c3fe CD |
3317 | size_t pagesize = GLRO (dl_pagesize); |
3318 | size_t rounded_bytes = ALIGN_UP (bytes, pagesize); | |
dba38551 | 3319 | |
1159a193 | 3320 | /* Check for overflow. */ |
8a35c3fe | 3321 | if (bytes > SIZE_MAX - 2 * pagesize - MINSIZE) |
1159a193 WN |
3322 | { |
3323 | __set_errno (ENOMEM); | |
3324 | return 0; | |
3325 | } | |
3326 | ||
8a35c3fe | 3327 | return _mid_memalign (pagesize, rounded_bytes, address); |
fa8d436c | 3328 | } |
f65fd747 | 3329 | |
6c8dbf00 OB |
3330 | void * |
3331 | __libc_calloc (size_t n, size_t elem_size) | |
f65fd747 | 3332 | { |
d6285c9f CD |
3333 | mstate av; |
3334 | mchunkptr oldtop, p; | |
3335 | INTERNAL_SIZE_T bytes, sz, csz, oldtopsize; | |
6c8dbf00 | 3336 | void *mem; |
d6285c9f CD |
3337 | unsigned long clearsize; |
3338 | unsigned long nclears; | |
3339 | INTERNAL_SIZE_T *d; | |
0950889b UD |
3340 | |
3341 | /* size_t is unsigned so the behavior on overflow is defined. */ | |
3342 | bytes = n * elem_size; | |
d9af917d UD |
3343 | #define HALF_INTERNAL_SIZE_T \ |
3344 | (((INTERNAL_SIZE_T) 1) << (8 * sizeof (INTERNAL_SIZE_T) / 2)) | |
6c8dbf00 OB |
3345 | if (__builtin_expect ((n | elem_size) >= HALF_INTERNAL_SIZE_T, 0)) |
3346 | { | |
3347 | if (elem_size != 0 && bytes / elem_size != n) | |
3348 | { | |
3349 | __set_errno (ENOMEM); | |
3350 | return 0; | |
3351 | } | |
d9af917d | 3352 | } |
0950889b | 3353 | |
a222d91a | 3354 | void *(*hook) (size_t, const void *) = |
f3eeb3fc | 3355 | atomic_forced_read (__malloc_hook); |
6c8dbf00 OB |
3356 | if (__builtin_expect (hook != NULL, 0)) |
3357 | { | |
d6285c9f CD |
3358 | sz = bytes; |
3359 | mem = (*hook)(sz, RETURN_ADDRESS (0)); | |
3360 | if (mem == 0) | |
3361 | return 0; | |
3362 | ||
3363 | return memset (mem, 0, sz); | |
7799b7b3 | 3364 | } |
f65fd747 | 3365 | |
d6285c9f CD |
3366 | sz = bytes; |
3367 | ||
d5c3fafc DD |
3368 | MAYBE_INIT_TCACHE (); |
3369 | ||
d6285c9f | 3370 | arena_get (av, sz); |
fff94fa2 SP |
3371 | if (av) |
3372 | { | |
3373 | /* Check if we hand out the top chunk, in which case there may be no | |
3374 | need to clear. */ | |
d6285c9f | 3375 | #if MORECORE_CLEARS |
fff94fa2 SP |
3376 | oldtop = top (av); |
3377 | oldtopsize = chunksize (top (av)); | |
d6285c9f | 3378 | # if MORECORE_CLEARS < 2 |
fff94fa2 SP |
3379 | /* Only newly allocated memory is guaranteed to be cleared. */ |
3380 | if (av == &main_arena && | |
3381 | oldtopsize < mp_.sbrk_base + av->max_system_mem - (char *) oldtop) | |
3382 | oldtopsize = (mp_.sbrk_base + av->max_system_mem - (char *) oldtop); | |
d6285c9f | 3383 | # endif |
fff94fa2 SP |
3384 | if (av != &main_arena) |
3385 | { | |
3386 | heap_info *heap = heap_for_ptr (oldtop); | |
3387 | if (oldtopsize < (char *) heap + heap->mprotect_size - (char *) oldtop) | |
3388 | oldtopsize = (char *) heap + heap->mprotect_size - (char *) oldtop; | |
3389 | } | |
3390 | #endif | |
3391 | } | |
3392 | else | |
d6285c9f | 3393 | { |
fff94fa2 SP |
3394 | /* No usable arenas. */ |
3395 | oldtop = 0; | |
3396 | oldtopsize = 0; | |
d6285c9f | 3397 | } |
d6285c9f CD |
3398 | mem = _int_malloc (av, sz); |
3399 | ||
3400 | ||
3401 | assert (!mem || chunk_is_mmapped (mem2chunk (mem)) || | |
3402 | av == arena_for_chunk (mem2chunk (mem))); | |
3403 | ||
fff94fa2 | 3404 | if (mem == 0 && av != NULL) |
d6285c9f CD |
3405 | { |
3406 | LIBC_PROBE (memory_calloc_retry, 1, sz); | |
3407 | av = arena_get_retry (av, sz); | |
fff94fa2 | 3408 | mem = _int_malloc (av, sz); |
d6285c9f | 3409 | } |
fff94fa2 SP |
3410 | |
3411 | if (av != NULL) | |
4bf5f222 | 3412 | __libc_lock_unlock (av->mutex); |
fff94fa2 SP |
3413 | |
3414 | /* Allocation failed even after a retry. */ | |
3415 | if (mem == 0) | |
3416 | return 0; | |
3417 | ||
d6285c9f CD |
3418 | p = mem2chunk (mem); |
3419 | ||
3420 | /* Two optional cases in which clearing not necessary */ | |
3421 | if (chunk_is_mmapped (p)) | |
3422 | { | |
3423 | if (__builtin_expect (perturb_byte, 0)) | |
3424 | return memset (mem, 0, sz); | |
3425 | ||
3426 | return mem; | |
3427 | } | |
3428 | ||
3429 | csz = chunksize (p); | |
3430 | ||
3431 | #if MORECORE_CLEARS | |
3432 | if (perturb_byte == 0 && (p == oldtop && csz > oldtopsize)) | |
3433 | { | |
3434 | /* clear only the bytes from non-freshly-sbrked memory */ | |
3435 | csz = oldtopsize; | |
3436 | } | |
3437 | #endif | |
3438 | ||
3439 | /* Unroll clear of <= 36 bytes (72 if 8byte sizes). We know that | |
3440 | contents have an odd number of INTERNAL_SIZE_T-sized words; | |
3441 | minimally 3. */ | |
3442 | d = (INTERNAL_SIZE_T *) mem; | |
3443 | clearsize = csz - SIZE_SZ; | |
3444 | nclears = clearsize / sizeof (INTERNAL_SIZE_T); | |
3445 | assert (nclears >= 3); | |
3446 | ||
3447 | if (nclears > 9) | |
3448 | return memset (d, 0, clearsize); | |
3449 | ||
3450 | else | |
3451 | { | |
3452 | *(d + 0) = 0; | |
3453 | *(d + 1) = 0; | |
3454 | *(d + 2) = 0; | |
3455 | if (nclears > 4) | |
3456 | { | |
3457 | *(d + 3) = 0; | |
3458 | *(d + 4) = 0; | |
3459 | if (nclears > 6) | |
3460 | { | |
3461 | *(d + 5) = 0; | |
3462 | *(d + 6) = 0; | |
3463 | if (nclears > 8) | |
3464 | { | |
3465 | *(d + 7) = 0; | |
3466 | *(d + 8) = 0; | |
3467 | } | |
3468 | } | |
3469 | } | |
3470 | } | |
3471 | ||
3472 | return mem; | |
fa8d436c | 3473 | } |
f65fd747 | 3474 | |
f65fd747 | 3475 | /* |
6c8dbf00 OB |
3476 | ------------------------------ malloc ------------------------------ |
3477 | */ | |
f65fd747 | 3478 | |
6c8dbf00 OB |
3479 | static void * |
3480 | _int_malloc (mstate av, size_t bytes) | |
f65fd747 | 3481 | { |
fa8d436c | 3482 | INTERNAL_SIZE_T nb; /* normalized request size */ |
6c8dbf00 OB |
3483 | unsigned int idx; /* associated bin index */ |
3484 | mbinptr bin; /* associated bin */ | |
f65fd747 | 3485 | |
6c8dbf00 | 3486 | mchunkptr victim; /* inspected/selected chunk */ |
fa8d436c | 3487 | INTERNAL_SIZE_T size; /* its size */ |
6c8dbf00 | 3488 | int victim_index; /* its bin index */ |
f65fd747 | 3489 | |
6c8dbf00 OB |
3490 | mchunkptr remainder; /* remainder from a split */ |
3491 | unsigned long remainder_size; /* its size */ | |
8a4b65b4 | 3492 | |
6c8dbf00 OB |
3493 | unsigned int block; /* bit map traverser */ |
3494 | unsigned int bit; /* bit map traverser */ | |
3495 | unsigned int map; /* current word of binmap */ | |
8a4b65b4 | 3496 | |
6c8dbf00 OB |
3497 | mchunkptr fwd; /* misc temp for linking */ |
3498 | mchunkptr bck; /* misc temp for linking */ | |
8a4b65b4 | 3499 | |
d5c3fafc DD |
3500 | #if USE_TCACHE |
3501 | size_t tcache_unsorted_count; /* count of unsorted chunks processed */ | |
3502 | #endif | |
3503 | ||
fa8d436c | 3504 | /* |
6c8dbf00 OB |
3505 | Convert request size to internal form by adding SIZE_SZ bytes |
3506 | overhead plus possibly more to obtain necessary alignment and/or | |
3507 | to obtain a size of at least MINSIZE, the smallest allocatable | |
3508 | size. Also, checked_request2size traps (returning 0) request sizes | |
3509 | that are so large that they wrap around zero when padded and | |
3510 | aligned. | |
3511 | */ | |
f65fd747 | 3512 | |
6c8dbf00 | 3513 | checked_request2size (bytes, nb); |
f65fd747 | 3514 | |
fff94fa2 SP |
3515 | /* There are no usable arenas. Fall back to sysmalloc to get a chunk from |
3516 | mmap. */ | |
3517 | if (__glibc_unlikely (av == NULL)) | |
3518 | { | |
3519 | void *p = sysmalloc (nb, av); | |
3520 | if (p != NULL) | |
3521 | alloc_perturb (p, bytes); | |
3522 | return p; | |
3523 | } | |
3524 | ||
fa8d436c | 3525 | /* |
6c8dbf00 OB |
3526 | If the size qualifies as a fastbin, first check corresponding bin. |
3527 | This code is safe to execute even if av is not yet initialized, so we | |
3528 | can try it without checking, which saves some time on this fast path. | |
3529 | */ | |
f65fd747 | 3530 | |
d5c3fafc DD |
3531 | #define REMOVE_FB(fb, victim, pp) \ |
3532 | do \ | |
3533 | { \ | |
3534 | victim = pp; \ | |
3535 | if (victim == NULL) \ | |
3536 | break; \ | |
3537 | } \ | |
3538 | while ((pp = catomic_compare_and_exchange_val_acq (fb, victim->fd, victim)) \ | |
3539 | != victim); \ | |
3540 | ||
6c8dbf00 OB |
3541 | if ((unsigned long) (nb) <= (unsigned long) (get_max_fast ())) |
3542 | { | |
3543 | idx = fastbin_index (nb); | |
3544 | mfastbinptr *fb = &fastbin (av, idx); | |
3545 | mchunkptr pp = *fb; | |
d5c3fafc | 3546 | REMOVE_FB (fb, victim, pp); |
6c8dbf00 OB |
3547 | if (victim != 0) |
3548 | { | |
3549 | if (__builtin_expect (fastbin_index (chunksize (victim)) != idx, 0)) | |
ac3ed168 | 3550 | malloc_printerr ("malloc(): memory corruption (fast)"); |
6c8dbf00 | 3551 | check_remalloced_chunk (av, victim, nb); |
d5c3fafc DD |
3552 | #if USE_TCACHE |
3553 | /* While we're here, if we see other chunks of the same size, | |
3554 | stash them in the tcache. */ | |
3555 | size_t tc_idx = csize2tidx (nb); | |
3556 | if (tcache && tc_idx < mp_.tcache_bins) | |
3557 | { | |
3558 | mchunkptr tc_victim; | |
3559 | ||
3560 | /* While bin not empty and tcache not full, copy chunks over. */ | |
3561 | while (tcache->counts[tc_idx] < mp_.tcache_count | |
3562 | && (pp = *fb) != NULL) | |
3563 | { | |
3564 | REMOVE_FB (fb, tc_victim, pp); | |
3565 | if (tc_victim != 0) | |
3566 | { | |
3567 | tcache_put (tc_victim, tc_idx); | |
3568 | } | |
3569 | } | |
3570 | } | |
3571 | #endif | |
6c8dbf00 OB |
3572 | void *p = chunk2mem (victim); |
3573 | alloc_perturb (p, bytes); | |
3574 | return p; | |
3575 | } | |
fa8d436c | 3576 | } |
f65fd747 | 3577 | |
fa8d436c | 3578 | /* |
6c8dbf00 OB |
3579 | If a small request, check regular bin. Since these "smallbins" |
3580 | hold one size each, no searching within bins is necessary. | |
3581 | (For a large request, we need to wait until unsorted chunks are | |
3582 | processed to find best fit. But for small ones, fits are exact | |
3583 | anyway, so we can check now, which is faster.) | |
3584 | */ | |
3585 | ||
3586 | if (in_smallbin_range (nb)) | |
3587 | { | |
3588 | idx = smallbin_index (nb); | |
3589 | bin = bin_at (av, idx); | |
3590 | ||
3591 | if ((victim = last (bin)) != bin) | |
3592 | { | |
3593 | if (victim == 0) /* initialization check */ | |
3594 | malloc_consolidate (av); | |
3595 | else | |
3596 | { | |
3597 | bck = victim->bk; | |
ac3ed168 FW |
3598 | if (__glibc_unlikely (bck->fd != victim)) |
3599 | malloc_printerr | |
3600 | ("malloc(): smallbin double linked list corrupted"); | |
6c8dbf00 OB |
3601 | set_inuse_bit_at_offset (victim, nb); |
3602 | bin->bk = bck; | |
3603 | bck->fd = bin; | |
3604 | ||
3605 | if (av != &main_arena) | |
e9c4fe93 | 3606 | set_non_main_arena (victim); |
6c8dbf00 | 3607 | check_malloced_chunk (av, victim, nb); |
d5c3fafc DD |
3608 | #if USE_TCACHE |
3609 | /* While we're here, if we see other chunks of the same size, | |
3610 | stash them in the tcache. */ | |
3611 | size_t tc_idx = csize2tidx (nb); | |
3612 | if (tcache && tc_idx < mp_.tcache_bins) | |
3613 | { | |
3614 | mchunkptr tc_victim; | |
3615 | ||
3616 | /* While bin not empty and tcache not full, copy chunks over. */ | |
3617 | while (tcache->counts[tc_idx] < mp_.tcache_count | |
3618 | && (tc_victim = last (bin)) != bin) | |
3619 | { | |
3620 | if (tc_victim != 0) | |
3621 | { | |
3622 | bck = tc_victim->bk; | |
3623 | set_inuse_bit_at_offset (tc_victim, nb); | |
3624 | if (av != &main_arena) | |
3625 | set_non_main_arena (tc_victim); | |
3626 | bin->bk = bck; | |
3627 | bck->fd = bin; | |
3628 | ||
3629 | tcache_put (tc_victim, tc_idx); | |
3630 | } | |
3631 | } | |
3632 | } | |
3633 | #endif | |
6c8dbf00 OB |
3634 | void *p = chunk2mem (victim); |
3635 | alloc_perturb (p, bytes); | |
3636 | return p; | |
3637 | } | |
3638 | } | |
fa8d436c | 3639 | } |
f65fd747 | 3640 | |
a9177ff5 | 3641 | /* |
fa8d436c UD |
3642 | If this is a large request, consolidate fastbins before continuing. |
3643 | While it might look excessive to kill all fastbins before | |
3644 | even seeing if there is space available, this avoids | |
3645 | fragmentation problems normally associated with fastbins. | |
3646 | Also, in practice, programs tend to have runs of either small or | |
a9177ff5 | 3647 | large requests, but less often mixtures, so consolidation is not |
fa8d436c UD |
3648 | invoked all that often in most programs. And the programs that |
3649 | it is called frequently in otherwise tend to fragment. | |
6c8dbf00 | 3650 | */ |
7799b7b3 | 3651 | |
6c8dbf00 OB |
3652 | else |
3653 | { | |
3654 | idx = largebin_index (nb); | |
3655 | if (have_fastchunks (av)) | |
3656 | malloc_consolidate (av); | |
3657 | } | |
f65fd747 | 3658 | |
fa8d436c | 3659 | /* |
6c8dbf00 OB |
3660 | Process recently freed or remaindered chunks, taking one only if |
3661 | it is exact fit, or, if this a small request, the chunk is remainder from | |
3662 | the most recent non-exact fit. Place other traversed chunks in | |
3663 | bins. Note that this step is the only place in any routine where | |
3664 | chunks are placed in bins. | |
3665 | ||
3666 | The outer loop here is needed because we might not realize until | |
3667 | near the end of malloc that we should have consolidated, so must | |
3668 | do so and retry. This happens at most once, and only when we would | |
3669 | otherwise need to expand memory to service a "small" request. | |
3670 | */ | |
3671 | ||
d5c3fafc DD |
3672 | #if USE_TCACHE |
3673 | INTERNAL_SIZE_T tcache_nb = 0; | |
3674 | size_t tc_idx = csize2tidx (nb); | |
3675 | if (tcache && tc_idx < mp_.tcache_bins) | |
3676 | tcache_nb = nb; | |
3677 | int return_cached = 0; | |
3678 | ||
3679 | tcache_unsorted_count = 0; | |
3680 | #endif | |
3681 | ||
6c8dbf00 OB |
3682 | for (;; ) |
3683 | { | |
3684 | int iters = 0; | |
3685 | while ((victim = unsorted_chunks (av)->bk) != unsorted_chunks (av)) | |
3686 | { | |
3687 | bck = victim->bk; | |
e9c4fe93 FW |
3688 | if (__builtin_expect (chunksize_nomask (victim) <= 2 * SIZE_SZ, 0) |
3689 | || __builtin_expect (chunksize_nomask (victim) | |
3690 | > av->system_mem, 0)) | |
ac3ed168 | 3691 | malloc_printerr ("malloc(): memory corruption"); |
6c8dbf00 OB |
3692 | size = chunksize (victim); |
3693 | ||
3694 | /* | |
3695 | If a small request, try to use last remainder if it is the | |
3696 | only chunk in unsorted bin. This helps promote locality for | |
3697 | runs of consecutive small requests. This is the only | |
3698 | exception to best-fit, and applies only when there is | |
3699 | no exact fit for a small chunk. | |
3700 | */ | |
3701 | ||
3702 | if (in_smallbin_range (nb) && | |
3703 | bck == unsorted_chunks (av) && | |
3704 | victim == av->last_remainder && | |
3705 | (unsigned long) (size) > (unsigned long) (nb + MINSIZE)) | |
3706 | { | |
3707 | /* split and reattach remainder */ | |
3708 | remainder_size = size - nb; | |
3709 | remainder = chunk_at_offset (victim, nb); | |
3710 | unsorted_chunks (av)->bk = unsorted_chunks (av)->fd = remainder; | |
3711 | av->last_remainder = remainder; | |
3712 | remainder->bk = remainder->fd = unsorted_chunks (av); | |
3713 | if (!in_smallbin_range (remainder_size)) | |
3714 | { | |
3715 | remainder->fd_nextsize = NULL; | |
3716 | remainder->bk_nextsize = NULL; | |
3717 | } | |
3718 | ||
3719 | set_head (victim, nb | PREV_INUSE | | |
3720 | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
3721 | set_head (remainder, remainder_size | PREV_INUSE); | |
3722 | set_foot (remainder, remainder_size); | |
3723 | ||
3724 | check_malloced_chunk (av, victim, nb); | |
3725 | void *p = chunk2mem (victim); | |
3726 | alloc_perturb (p, bytes); | |
3727 | return p; | |
3728 | } | |
3729 | ||
3730 | /* remove from unsorted list */ | |
3731 | unsorted_chunks (av)->bk = bck; | |
3732 | bck->fd = unsorted_chunks (av); | |
3733 | ||
3734 | /* Take now instead of binning if exact fit */ | |
3735 | ||
3736 | if (size == nb) | |
3737 | { | |
3738 | set_inuse_bit_at_offset (victim, size); | |
3739 | if (av != &main_arena) | |
e9c4fe93 | 3740 | set_non_main_arena (victim); |
d5c3fafc DD |
3741 | #if USE_TCACHE |
3742 | /* Fill cache first, return to user only if cache fills. | |
3743 | We may return one of these chunks later. */ | |
3744 | if (tcache_nb | |
3745 | && tcache->counts[tc_idx] < mp_.tcache_count) | |
3746 | { | |
3747 | tcache_put (victim, tc_idx); | |
3748 | return_cached = 1; | |
3749 | continue; | |
3750 | } | |
3751 | else | |
3752 | { | |
3753 | #endif | |
6c8dbf00 OB |
3754 | check_malloced_chunk (av, victim, nb); |
3755 | void *p = chunk2mem (victim); | |
3756 | alloc_perturb (p, bytes); | |
3757 | return p; | |
d5c3fafc DD |
3758 | #if USE_TCACHE |
3759 | } | |
3760 | #endif | |
6c8dbf00 OB |
3761 | } |
3762 | ||
3763 | /* place chunk in bin */ | |
3764 | ||
3765 | if (in_smallbin_range (size)) | |
3766 | { | |
3767 | victim_index = smallbin_index (size); | |
3768 | bck = bin_at (av, victim_index); | |
3769 | fwd = bck->fd; | |
3770 | } | |
3771 | else | |
3772 | { | |
3773 | victim_index = largebin_index (size); | |
3774 | bck = bin_at (av, victim_index); | |
3775 | fwd = bck->fd; | |
3776 | ||
3777 | /* maintain large bins in sorted order */ | |
3778 | if (fwd != bck) | |
3779 | { | |
3780 | /* Or with inuse bit to speed comparisons */ | |
3781 | size |= PREV_INUSE; | |
3782 | /* if smaller than smallest, bypass loop below */ | |
e9c4fe93 FW |
3783 | assert (chunk_main_arena (bck->bk)); |
3784 | if ((unsigned long) (size) | |
3785 | < (unsigned long) chunksize_nomask (bck->bk)) | |
6c8dbf00 OB |
3786 | { |
3787 | fwd = bck; | |
3788 | bck = bck->bk; | |
3789 | ||
3790 | victim->fd_nextsize = fwd->fd; | |
3791 | victim->bk_nextsize = fwd->fd->bk_nextsize; | |
3792 | fwd->fd->bk_nextsize = victim->bk_nextsize->fd_nextsize = victim; | |
3793 | } | |
3794 | else | |
3795 | { | |
e9c4fe93 FW |
3796 | assert (chunk_main_arena (fwd)); |
3797 | while ((unsigned long) size < chunksize_nomask (fwd)) | |
6c8dbf00 OB |
3798 | { |
3799 | fwd = fwd->fd_nextsize; | |
e9c4fe93 | 3800 | assert (chunk_main_arena (fwd)); |
6c8dbf00 OB |
3801 | } |
3802 | ||
e9c4fe93 FW |
3803 | if ((unsigned long) size |
3804 | == (unsigned long) chunksize_nomask (fwd)) | |
6c8dbf00 OB |
3805 | /* Always insert in the second position. */ |
3806 | fwd = fwd->fd; | |
3807 | else | |
3808 | { | |
3809 | victim->fd_nextsize = fwd; | |
3810 | victim->bk_nextsize = fwd->bk_nextsize; | |
3811 | fwd->bk_nextsize = victim; | |
3812 | victim->bk_nextsize->fd_nextsize = victim; | |
3813 | } | |
3814 | bck = fwd->bk; | |
3815 | } | |
3816 | } | |
3817 | else | |
3818 | victim->fd_nextsize = victim->bk_nextsize = victim; | |
3819 | } | |
3820 | ||
3821 | mark_bin (av, victim_index); | |
3822 | victim->bk = bck; | |
3823 | victim->fd = fwd; | |
3824 | fwd->bk = victim; | |
3825 | bck->fd = victim; | |
3826 | ||
d5c3fafc DD |
3827 | #if USE_TCACHE |
3828 | /* If we've processed as many chunks as we're allowed while | |
3829 | filling the cache, return one of the cached ones. */ | |
3830 | ++tcache_unsorted_count; | |
3831 | if (return_cached | |
3832 | && mp_.tcache_unsorted_limit > 0 | |
3833 | && tcache_unsorted_count > mp_.tcache_unsorted_limit) | |
3834 | { | |
3835 | return tcache_get (tc_idx); | |
3836 | } | |
3837 | #endif | |
3838 | ||
6c8dbf00 OB |
3839 | #define MAX_ITERS 10000 |
3840 | if (++iters >= MAX_ITERS) | |
3841 | break; | |
3842 | } | |
fa8d436c | 3843 | |
d5c3fafc DD |
3844 | #if USE_TCACHE |
3845 | /* If all the small chunks we found ended up cached, return one now. */ | |
3846 | if (return_cached) | |
3847 | { | |
3848 | return tcache_get (tc_idx); | |
3849 | } | |
3850 | #endif | |
3851 | ||
a9177ff5 | 3852 | /* |
6c8dbf00 OB |
3853 | If a large request, scan through the chunks of current bin in |
3854 | sorted order to find smallest that fits. Use the skip list for this. | |
3855 | */ | |
3856 | ||
3857 | if (!in_smallbin_range (nb)) | |
3858 | { | |
3859 | bin = bin_at (av, idx); | |
3860 | ||
3861 | /* skip scan if empty or largest chunk is too small */ | |
e9c4fe93 FW |
3862 | if ((victim = first (bin)) != bin |
3863 | && (unsigned long) chunksize_nomask (victim) | |
3864 | >= (unsigned long) (nb)) | |
6c8dbf00 OB |
3865 | { |
3866 | victim = victim->bk_nextsize; | |
3867 | while (((unsigned long) (size = chunksize (victim)) < | |
3868 | (unsigned long) (nb))) | |
3869 | victim = victim->bk_nextsize; | |
3870 | ||
3871 | /* Avoid removing the first entry for a size so that the skip | |
3872 | list does not have to be rerouted. */ | |
e9c4fe93 FW |
3873 | if (victim != last (bin) |
3874 | && chunksize_nomask (victim) | |
3875 | == chunksize_nomask (victim->fd)) | |
6c8dbf00 OB |
3876 | victim = victim->fd; |
3877 | ||
3878 | remainder_size = size - nb; | |
fff94fa2 | 3879 | unlink (av, victim, bck, fwd); |
6c8dbf00 OB |
3880 | |
3881 | /* Exhaust */ | |
3882 | if (remainder_size < MINSIZE) | |
3883 | { | |
3884 | set_inuse_bit_at_offset (victim, size); | |
3885 | if (av != &main_arena) | |
e9c4fe93 | 3886 | set_non_main_arena (victim); |
6c8dbf00 OB |
3887 | } |
3888 | /* Split */ | |
3889 | else | |
3890 | { | |
3891 | remainder = chunk_at_offset (victim, nb); | |
3892 | /* We cannot assume the unsorted list is empty and therefore | |
3893 | have to perform a complete insert here. */ | |
3894 | bck = unsorted_chunks (av); | |
3895 | fwd = bck->fd; | |
ac3ed168 FW |
3896 | if (__glibc_unlikely (fwd->bk != bck)) |
3897 | malloc_printerr ("malloc(): corrupted unsorted chunks"); | |
6c8dbf00 OB |
3898 | remainder->bk = bck; |
3899 | remainder->fd = fwd; | |
3900 | bck->fd = remainder; | |
3901 | fwd->bk = remainder; | |
3902 | if (!in_smallbin_range (remainder_size)) | |
3903 | { | |
3904 | remainder->fd_nextsize = NULL; | |
3905 | remainder->bk_nextsize = NULL; | |
3906 | } | |
3907 | set_head (victim, nb | PREV_INUSE | | |
3908 | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
3909 | set_head (remainder, remainder_size | PREV_INUSE); | |
3910 | set_foot (remainder, remainder_size); | |
3911 | } | |
3912 | check_malloced_chunk (av, victim, nb); | |
3913 | void *p = chunk2mem (victim); | |
3914 | alloc_perturb (p, bytes); | |
3915 | return p; | |
3916 | } | |
3917 | } | |
f65fd747 | 3918 | |
6c8dbf00 OB |
3919 | /* |
3920 | Search for a chunk by scanning bins, starting with next largest | |
3921 | bin. This search is strictly by best-fit; i.e., the smallest | |
3922 | (with ties going to approximately the least recently used) chunk | |
3923 | that fits is selected. | |
3924 | ||
3925 | The bitmap avoids needing to check that most blocks are nonempty. | |
3926 | The particular case of skipping all bins during warm-up phases | |
3927 | when no chunks have been returned yet is faster than it might look. | |
3928 | */ | |
3929 | ||
3930 | ++idx; | |
3931 | bin = bin_at (av, idx); | |
3932 | block = idx2block (idx); | |
3933 | map = av->binmap[block]; | |
3934 | bit = idx2bit (idx); | |
3935 | ||
3936 | for (;; ) | |
3937 | { | |
3938 | /* Skip rest of block if there are no more set bits in this block. */ | |
3939 | if (bit > map || bit == 0) | |
3940 | { | |
3941 | do | |
3942 | { | |
3943 | if (++block >= BINMAPSIZE) /* out of bins */ | |
3944 | goto use_top; | |
3945 | } | |
3946 | while ((map = av->binmap[block]) == 0); | |
3947 | ||
3948 | bin = bin_at (av, (block << BINMAPSHIFT)); | |
3949 | bit = 1; | |
3950 | } | |
3951 | ||
3952 | /* Advance to bin with set bit. There must be one. */ | |
3953 | while ((bit & map) == 0) | |
3954 | { | |
3955 | bin = next_bin (bin); | |
3956 | bit <<= 1; | |
3957 | assert (bit != 0); | |
3958 | } | |
3959 | ||
3960 | /* Inspect the bin. It is likely to be non-empty */ | |
3961 | victim = last (bin); | |
3962 | ||
3963 | /* If a false alarm (empty bin), clear the bit. */ | |
3964 | if (victim == bin) | |
3965 | { | |
3966 | av->binmap[block] = map &= ~bit; /* Write through */ | |
3967 | bin = next_bin (bin); | |
3968 | bit <<= 1; | |
3969 | } | |
3970 | ||
3971 | else | |
3972 | { | |
3973 | size = chunksize (victim); | |
3974 | ||
3975 | /* We know the first chunk in this bin is big enough to use. */ | |
3976 | assert ((unsigned long) (size) >= (unsigned long) (nb)); | |
3977 | ||
3978 | remainder_size = size - nb; | |
3979 | ||
3980 | /* unlink */ | |
fff94fa2 | 3981 | unlink (av, victim, bck, fwd); |
6c8dbf00 OB |
3982 | |
3983 | /* Exhaust */ | |
3984 | if (remainder_size < MINSIZE) | |
3985 | { | |
3986 | set_inuse_bit_at_offset (victim, size); | |
3987 | if (av != &main_arena) | |
e9c4fe93 | 3988 | set_non_main_arena (victim); |
6c8dbf00 OB |
3989 | } |
3990 | ||
3991 | /* Split */ | |
3992 | else | |
3993 | { | |
3994 | remainder = chunk_at_offset (victim, nb); | |
3995 | ||
3996 | /* We cannot assume the unsorted list is empty and therefore | |
3997 | have to perform a complete insert here. */ | |
3998 | bck = unsorted_chunks (av); | |
3999 | fwd = bck->fd; | |
ac3ed168 FW |
4000 | if (__glibc_unlikely (fwd->bk != bck)) |
4001 | malloc_printerr ("malloc(): corrupted unsorted chunks 2"); | |
6c8dbf00 OB |
4002 | remainder->bk = bck; |
4003 | remainder->fd = fwd; | |
4004 | bck->fd = remainder; | |
4005 | fwd->bk = remainder; | |
4006 | ||
4007 | /* advertise as last remainder */ | |
4008 | if (in_smallbin_range (nb)) | |
4009 | av->last_remainder = remainder; | |
4010 | if (!in_smallbin_range (remainder_size)) | |
4011 | { | |
4012 | remainder->fd_nextsize = NULL; | |
4013 | remainder->bk_nextsize = NULL; | |
4014 | } | |
4015 | set_head (victim, nb | PREV_INUSE | | |
4016 | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
4017 | set_head (remainder, remainder_size | PREV_INUSE); | |
4018 | set_foot (remainder, remainder_size); | |
4019 | } | |
4020 | check_malloced_chunk (av, victim, nb); | |
4021 | void *p = chunk2mem (victim); | |
4022 | alloc_perturb (p, bytes); | |
4023 | return p; | |
4024 | } | |
4025 | } | |
4026 | ||
4027 | use_top: | |
4028 | /* | |
4029 | If large enough, split off the chunk bordering the end of memory | |
4030 | (held in av->top). Note that this is in accord with the best-fit | |
4031 | search rule. In effect, av->top is treated as larger (and thus | |
4032 | less well fitting) than any other available chunk since it can | |
4033 | be extended to be as large as necessary (up to system | |
4034 | limitations). | |
4035 | ||
4036 | We require that av->top always exists (i.e., has size >= | |
4037 | MINSIZE) after initialization, so if it would otherwise be | |
4038 | exhausted by current request, it is replenished. (The main | |
4039 | reason for ensuring it exists is that we may need MINSIZE space | |
4040 | to put in fenceposts in sysmalloc.) | |
4041 | */ | |
4042 | ||
4043 | victim = av->top; | |
4044 | size = chunksize (victim); | |
4045 | ||
4046 | if ((unsigned long) (size) >= (unsigned long) (nb + MINSIZE)) | |
4047 | { | |
4048 | remainder_size = size - nb; | |
4049 | remainder = chunk_at_offset (victim, nb); | |
4050 | av->top = remainder; | |
4051 | set_head (victim, nb | PREV_INUSE | | |
4052 | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
4053 | set_head (remainder, remainder_size | PREV_INUSE); | |
4054 | ||
4055 | check_malloced_chunk (av, victim, nb); | |
4056 | void *p = chunk2mem (victim); | |
4057 | alloc_perturb (p, bytes); | |
4058 | return p; | |
4059 | } | |
4060 | ||
4061 | /* When we are using atomic ops to free fast chunks we can get | |
4062 | here for all block sizes. */ | |
4063 | else if (have_fastchunks (av)) | |
4064 | { | |
4065 | malloc_consolidate (av); | |
4066 | /* restore original bin index */ | |
4067 | if (in_smallbin_range (nb)) | |
4068 | idx = smallbin_index (nb); | |
4069 | else | |
4070 | idx = largebin_index (nb); | |
4071 | } | |
f65fd747 | 4072 | |
6c8dbf00 OB |
4073 | /* |
4074 | Otherwise, relay to handle system-dependent cases | |
4075 | */ | |
425ce2ed | 4076 | else |
6c8dbf00 OB |
4077 | { |
4078 | void *p = sysmalloc (nb, av); | |
4079 | if (p != NULL) | |
4080 | alloc_perturb (p, bytes); | |
4081 | return p; | |
4082 | } | |
425ce2ed | 4083 | } |
fa8d436c | 4084 | } |
f65fd747 | 4085 | |
fa8d436c | 4086 | /* |
6c8dbf00 OB |
4087 | ------------------------------ free ------------------------------ |
4088 | */ | |
f65fd747 | 4089 | |
78ac92ad | 4090 | static void |
6c8dbf00 | 4091 | _int_free (mstate av, mchunkptr p, int have_lock) |
f65fd747 | 4092 | { |
fa8d436c | 4093 | INTERNAL_SIZE_T size; /* its size */ |
6c8dbf00 OB |
4094 | mfastbinptr *fb; /* associated fastbin */ |
4095 | mchunkptr nextchunk; /* next contiguous chunk */ | |
fa8d436c | 4096 | INTERNAL_SIZE_T nextsize; /* its size */ |
6c8dbf00 | 4097 | int nextinuse; /* true if nextchunk is used */ |
fa8d436c | 4098 | INTERNAL_SIZE_T prevsize; /* size of previous contiguous chunk */ |
6c8dbf00 OB |
4099 | mchunkptr bck; /* misc temp for linking */ |
4100 | mchunkptr fwd; /* misc temp for linking */ | |
fa8d436c | 4101 | |
6c8dbf00 | 4102 | size = chunksize (p); |
f65fd747 | 4103 | |
37fa1953 UD |
4104 | /* Little security check which won't hurt performance: the |
4105 | allocator never wrapps around at the end of the address space. | |
4106 | Therefore we can exclude some size values which might appear | |
4107 | here by accident or by "design" from some intruder. */ | |
dc165f7b | 4108 | if (__builtin_expect ((uintptr_t) p > (uintptr_t) -size, 0) |
073f560e | 4109 | || __builtin_expect (misaligned_chunk (p), 0)) |
ac3ed168 | 4110 | malloc_printerr ("free(): invalid pointer"); |
347c92e9 L |
4111 | /* We know that each chunk is at least MINSIZE bytes in size or a |
4112 | multiple of MALLOC_ALIGNMENT. */ | |
a1ffb40e | 4113 | if (__glibc_unlikely (size < MINSIZE || !aligned_OK (size))) |
ac3ed168 | 4114 | malloc_printerr ("free(): invalid size"); |
f65fd747 | 4115 | |
37fa1953 | 4116 | check_inuse_chunk(av, p); |
f65fd747 | 4117 | |
d5c3fafc DD |
4118 | #if USE_TCACHE |
4119 | { | |
4120 | size_t tc_idx = csize2tidx (size); | |
4121 | ||
4122 | if (tcache | |
4123 | && tc_idx < mp_.tcache_bins | |
4124 | && tcache->counts[tc_idx] < mp_.tcache_count) | |
4125 | { | |
4126 | tcache_put (p, tc_idx); | |
4127 | return; | |
4128 | } | |
4129 | } | |
4130 | #endif | |
4131 | ||
37fa1953 UD |
4132 | /* |
4133 | If eligible, place chunk on a fastbin so it can be found | |
4134 | and used quickly in malloc. | |
4135 | */ | |
6bf4302e | 4136 | |
9bf248c6 | 4137 | if ((unsigned long)(size) <= (unsigned long)(get_max_fast ()) |
6bf4302e | 4138 | |
37fa1953 UD |
4139 | #if TRIM_FASTBINS |
4140 | /* | |
4141 | If TRIM_FASTBINS set, don't place chunks | |
4142 | bordering top into fastbins | |
4143 | */ | |
4144 | && (chunk_at_offset(p, size) != av->top) | |
4145 | #endif | |
4146 | ) { | |
fa8d436c | 4147 | |
e9c4fe93 FW |
4148 | if (__builtin_expect (chunksize_nomask (chunk_at_offset (p, size)) |
4149 | <= 2 * SIZE_SZ, 0) | |
893e6098 UD |
4150 | || __builtin_expect (chunksize (chunk_at_offset (p, size)) |
4151 | >= av->system_mem, 0)) | |
4152 | { | |
bec466d9 UD |
4153 | /* We might not have a lock at this point and concurrent modifications |
4154 | of system_mem might have let to a false positive. Redo the test | |
4155 | after getting the lock. */ | |
24cffce7 FW |
4156 | if (!have_lock |
4157 | || ({ __libc_lock_lock (av->mutex); | |
e9c4fe93 | 4158 | chunksize_nomask (chunk_at_offset (p, size)) <= 2 * SIZE_SZ |
24cffce7 FW |
4159 | || chunksize (chunk_at_offset (p, size)) >= av->system_mem; |
4160 | })) | |
ac3ed168 | 4161 | malloc_printerr ("free(): invalid next size (fast)"); |
bec466d9 | 4162 | if (! have_lock) |
24cffce7 | 4163 | __libc_lock_unlock (av->mutex); |
893e6098 UD |
4164 | } |
4165 | ||
e8349efd | 4166 | free_perturb (chunk2mem(p), size - 2 * SIZE_SZ); |
425ce2ed | 4167 | |
37fa1953 | 4168 | set_fastchunks(av); |
90a3055e UD |
4169 | unsigned int idx = fastbin_index(size); |
4170 | fb = &fastbin (av, idx); | |
425ce2ed | 4171 | |
362b47fe MK |
4172 | /* Atomically link P to its fastbin: P->FD = *FB; *FB = P; */ |
4173 | mchunkptr old = *fb, old2; | |
5f24d53a | 4174 | unsigned int old_idx = ~0u; |
425ce2ed UD |
4175 | do |
4176 | { | |
362b47fe MK |
4177 | /* Check that the top of the bin is not the record we are going to add |
4178 | (i.e., double free). */ | |
425ce2ed | 4179 | if (__builtin_expect (old == p, 0)) |
ac3ed168 | 4180 | malloc_printerr ("double free or corruption (fasttop)"); |
362b47fe MK |
4181 | /* Check that size of fastbin chunk at the top is the same as |
4182 | size of the chunk that we are adding. We can dereference OLD | |
4183 | only if we have the lock, otherwise it might have already been | |
4184 | deallocated. See use of OLD_IDX below for the actual check. */ | |
4185 | if (have_lock && old != NULL) | |
5f24d53a | 4186 | old_idx = fastbin_index(chunksize(old)); |
362b47fe | 4187 | p->fd = old2 = old; |
425ce2ed | 4188 | } |
362b47fe | 4189 | while ((old = catomic_compare_and_exchange_val_rel (fb, p, old2)) != old2); |
5f24d53a | 4190 | |
362b47fe | 4191 | if (have_lock && old != NULL && __builtin_expect (old_idx != idx, 0)) |
ac3ed168 | 4192 | malloc_printerr ("invalid fastbin entry (free)"); |
37fa1953 | 4193 | } |
f65fd747 | 4194 | |
37fa1953 UD |
4195 | /* |
4196 | Consolidate other non-mmapped chunks as they arrive. | |
4197 | */ | |
fa8d436c | 4198 | |
37fa1953 | 4199 | else if (!chunk_is_mmapped(p)) { |
24cffce7 | 4200 | if (!have_lock) |
4bf5f222 | 4201 | __libc_lock_lock (av->mutex); |
425ce2ed | 4202 | |
37fa1953 | 4203 | nextchunk = chunk_at_offset(p, size); |
fa8d436c | 4204 | |
37fa1953 UD |
4205 | /* Lightweight tests: check whether the block is already the |
4206 | top block. */ | |
a1ffb40e | 4207 | if (__glibc_unlikely (p == av->top)) |
ac3ed168 | 4208 | malloc_printerr ("double free or corruption (top)"); |
37fa1953 UD |
4209 | /* Or whether the next chunk is beyond the boundaries of the arena. */ |
4210 | if (__builtin_expect (contiguous (av) | |
4211 | && (char *) nextchunk | |
4212 | >= ((char *) av->top + chunksize(av->top)), 0)) | |
ac3ed168 | 4213 | malloc_printerr ("double free or corruption (out)"); |
37fa1953 | 4214 | /* Or whether the block is actually not marked used. */ |
a1ffb40e | 4215 | if (__glibc_unlikely (!prev_inuse(nextchunk))) |
ac3ed168 | 4216 | malloc_printerr ("double free or corruption (!prev)"); |
fa8d436c | 4217 | |
37fa1953 | 4218 | nextsize = chunksize(nextchunk); |
e9c4fe93 | 4219 | if (__builtin_expect (chunksize_nomask (nextchunk) <= 2 * SIZE_SZ, 0) |
893e6098 | 4220 | || __builtin_expect (nextsize >= av->system_mem, 0)) |
ac3ed168 | 4221 | malloc_printerr ("free(): invalid next size (normal)"); |
fa8d436c | 4222 | |
e8349efd | 4223 | free_perturb (chunk2mem(p), size - 2 * SIZE_SZ); |
854278df | 4224 | |
37fa1953 UD |
4225 | /* consolidate backward */ |
4226 | if (!prev_inuse(p)) { | |
e9c4fe93 | 4227 | prevsize = prev_size (p); |
37fa1953 UD |
4228 | size += prevsize; |
4229 | p = chunk_at_offset(p, -((long) prevsize)); | |
fff94fa2 | 4230 | unlink(av, p, bck, fwd); |
37fa1953 | 4231 | } |
a9177ff5 | 4232 | |
37fa1953 UD |
4233 | if (nextchunk != av->top) { |
4234 | /* get and clear inuse bit */ | |
4235 | nextinuse = inuse_bit_at_offset(nextchunk, nextsize); | |
4236 | ||
4237 | /* consolidate forward */ | |
4238 | if (!nextinuse) { | |
fff94fa2 | 4239 | unlink(av, nextchunk, bck, fwd); |
37fa1953 UD |
4240 | size += nextsize; |
4241 | } else | |
4242 | clear_inuse_bit_at_offset(nextchunk, 0); | |
10dc2a90 | 4243 | |
fa8d436c | 4244 | /* |
37fa1953 UD |
4245 | Place the chunk in unsorted chunk list. Chunks are |
4246 | not placed into regular bins until after they have | |
4247 | been given one chance to be used in malloc. | |
fa8d436c | 4248 | */ |
f65fd747 | 4249 | |
37fa1953 UD |
4250 | bck = unsorted_chunks(av); |
4251 | fwd = bck->fd; | |
a1ffb40e | 4252 | if (__glibc_unlikely (fwd->bk != bck)) |
ac3ed168 | 4253 | malloc_printerr ("free(): corrupted unsorted chunks"); |
37fa1953 | 4254 | p->fd = fwd; |
7ecfbd38 UD |
4255 | p->bk = bck; |
4256 | if (!in_smallbin_range(size)) | |
4257 | { | |
4258 | p->fd_nextsize = NULL; | |
4259 | p->bk_nextsize = NULL; | |
4260 | } | |
37fa1953 UD |
4261 | bck->fd = p; |
4262 | fwd->bk = p; | |
8a4b65b4 | 4263 | |
37fa1953 UD |
4264 | set_head(p, size | PREV_INUSE); |
4265 | set_foot(p, size); | |
4266 | ||
4267 | check_free_chunk(av, p); | |
4268 | } | |
4269 | ||
4270 | /* | |
4271 | If the chunk borders the current high end of memory, | |
4272 | consolidate into top | |
4273 | */ | |
4274 | ||
4275 | else { | |
4276 | size += nextsize; | |
4277 | set_head(p, size | PREV_INUSE); | |
4278 | av->top = p; | |
4279 | check_chunk(av, p); | |
4280 | } | |
4281 | ||
4282 | /* | |
4283 | If freeing a large space, consolidate possibly-surrounding | |
4284 | chunks. Then, if the total unused topmost memory exceeds trim | |
4285 | threshold, ask malloc_trim to reduce top. | |
4286 | ||
4287 | Unless max_fast is 0, we don't know if there are fastbins | |
4288 | bordering top, so we cannot tell for sure whether threshold | |
4289 | has been reached unless fastbins are consolidated. But we | |
4290 | don't want to consolidate on each free. As a compromise, | |
4291 | consolidation is performed if FASTBIN_CONSOLIDATION_THRESHOLD | |
4292 | is reached. | |
4293 | */ | |
fa8d436c | 4294 | |
37fa1953 UD |
4295 | if ((unsigned long)(size) >= FASTBIN_CONSOLIDATION_THRESHOLD) { |
4296 | if (have_fastchunks(av)) | |
4297 | malloc_consolidate(av); | |
fa8d436c | 4298 | |
37fa1953 | 4299 | if (av == &main_arena) { |
a9177ff5 | 4300 | #ifndef MORECORE_CANNOT_TRIM |
37fa1953 UD |
4301 | if ((unsigned long)(chunksize(av->top)) >= |
4302 | (unsigned long)(mp_.trim_threshold)) | |
3b49edc0 | 4303 | systrim(mp_.top_pad, av); |
fa8d436c | 4304 | #endif |
37fa1953 UD |
4305 | } else { |
4306 | /* Always try heap_trim(), even if the top chunk is not | |
4307 | large, because the corresponding heap might go away. */ | |
4308 | heap_info *heap = heap_for_ptr(top(av)); | |
fa8d436c | 4309 | |
37fa1953 UD |
4310 | assert(heap->ar_ptr == av); |
4311 | heap_trim(heap, mp_.top_pad); | |
fa8d436c | 4312 | } |
fa8d436c | 4313 | } |
10dc2a90 | 4314 | |
24cffce7 | 4315 | if (!have_lock) |
4bf5f222 | 4316 | __libc_lock_unlock (av->mutex); |
37fa1953 UD |
4317 | } |
4318 | /* | |
22a89187 | 4319 | If the chunk was allocated via mmap, release via munmap(). |
37fa1953 UD |
4320 | */ |
4321 | ||
4322 | else { | |
c120d94d | 4323 | munmap_chunk (p); |
fa8d436c | 4324 | } |
10dc2a90 UD |
4325 | } |
4326 | ||
fa8d436c UD |
4327 | /* |
4328 | ------------------------- malloc_consolidate ------------------------- | |
4329 | ||
4330 | malloc_consolidate is a specialized version of free() that tears | |
4331 | down chunks held in fastbins. Free itself cannot be used for this | |
4332 | purpose since, among other things, it might place chunks back onto | |
4333 | fastbins. So, instead, we need to use a minor variant of the same | |
4334 | code. | |
a9177ff5 | 4335 | |
fa8d436c UD |
4336 | Also, because this routine needs to be called the first time through |
4337 | malloc anyway, it turns out to be the perfect place to trigger | |
4338 | initialization code. | |
4339 | */ | |
4340 | ||
fa8d436c | 4341 | static void malloc_consolidate(mstate av) |
10dc2a90 | 4342 | { |
fa8d436c UD |
4343 | mfastbinptr* fb; /* current fastbin being consolidated */ |
4344 | mfastbinptr* maxfb; /* last fastbin (for loop control) */ | |
4345 | mchunkptr p; /* current chunk being consolidated */ | |
4346 | mchunkptr nextp; /* next chunk to consolidate */ | |
4347 | mchunkptr unsorted_bin; /* bin header */ | |
4348 | mchunkptr first_unsorted; /* chunk to link to */ | |
4349 | ||
4350 | /* These have same use as in free() */ | |
4351 | mchunkptr nextchunk; | |
4352 | INTERNAL_SIZE_T size; | |
4353 | INTERNAL_SIZE_T nextsize; | |
4354 | INTERNAL_SIZE_T prevsize; | |
4355 | int nextinuse; | |
4356 | mchunkptr bck; | |
4357 | mchunkptr fwd; | |
10dc2a90 | 4358 | |
fa8d436c UD |
4359 | /* |
4360 | If max_fast is 0, we know that av hasn't | |
4361 | yet been initialized, in which case do so below | |
4362 | */ | |
10dc2a90 | 4363 | |
9bf248c6 | 4364 | if (get_max_fast () != 0) { |
fa8d436c | 4365 | clear_fastchunks(av); |
10dc2a90 | 4366 | |
fa8d436c | 4367 | unsorted_bin = unsorted_chunks(av); |
10dc2a90 | 4368 | |
fa8d436c UD |
4369 | /* |
4370 | Remove each chunk from fast bin and consolidate it, placing it | |
4371 | then in unsorted bin. Among other reasons for doing this, | |
4372 | placing in unsorted bin avoids needing to calculate actual bins | |
4373 | until malloc is sure that chunks aren't immediately going to be | |
4374 | reused anyway. | |
4375 | */ | |
a9177ff5 | 4376 | |
425ce2ed | 4377 | maxfb = &fastbin (av, NFASTBINS - 1); |
425ce2ed | 4378 | fb = &fastbin (av, 0); |
fa8d436c | 4379 | do { |
b43f552a | 4380 | p = atomic_exchange_acq (fb, NULL); |
425ce2ed | 4381 | if (p != 0) { |
72f90263 UD |
4382 | do { |
4383 | check_inuse_chunk(av, p); | |
4384 | nextp = p->fd; | |
4385 | ||
4386 | /* Slightly streamlined version of consolidation code in free() */ | |
e9c4fe93 | 4387 | size = chunksize (p); |
72f90263 UD |
4388 | nextchunk = chunk_at_offset(p, size); |
4389 | nextsize = chunksize(nextchunk); | |
4390 | ||
4391 | if (!prev_inuse(p)) { | |
e9c4fe93 | 4392 | prevsize = prev_size (p); |
72f90263 UD |
4393 | size += prevsize; |
4394 | p = chunk_at_offset(p, -((long) prevsize)); | |
fff94fa2 | 4395 | unlink(av, p, bck, fwd); |
72f90263 UD |
4396 | } |
4397 | ||
4398 | if (nextchunk != av->top) { | |
4399 | nextinuse = inuse_bit_at_offset(nextchunk, nextsize); | |
4400 | ||
4401 | if (!nextinuse) { | |
4402 | size += nextsize; | |
fff94fa2 | 4403 | unlink(av, nextchunk, bck, fwd); |
72f90263 | 4404 | } else |
fa8d436c | 4405 | clear_inuse_bit_at_offset(nextchunk, 0); |
a9177ff5 | 4406 | |
72f90263 UD |
4407 | first_unsorted = unsorted_bin->fd; |
4408 | unsorted_bin->fd = p; | |
4409 | first_unsorted->bk = p; | |
a9177ff5 | 4410 | |
72f90263 | 4411 | if (!in_smallbin_range (size)) { |
7ecfbd38 UD |
4412 | p->fd_nextsize = NULL; |
4413 | p->bk_nextsize = NULL; | |
4414 | } | |
4415 | ||
72f90263 UD |
4416 | set_head(p, size | PREV_INUSE); |
4417 | p->bk = unsorted_bin; | |
4418 | p->fd = first_unsorted; | |
4419 | set_foot(p, size); | |
4420 | } | |
a9177ff5 | 4421 | |
72f90263 UD |
4422 | else { |
4423 | size += nextsize; | |
4424 | set_head(p, size | PREV_INUSE); | |
4425 | av->top = p; | |
4426 | } | |
a9177ff5 | 4427 | |
72f90263 | 4428 | } while ( (p = nextp) != 0); |
a9177ff5 | 4429 | |
fa8d436c UD |
4430 | } |
4431 | } while (fb++ != maxfb); | |
4432 | } | |
4433 | else { | |
4434 | malloc_init_state(av); | |
4435 | check_malloc_state(av); | |
4436 | } | |
4437 | } | |
10dc2a90 | 4438 | |
fa8d436c UD |
4439 | /* |
4440 | ------------------------------ realloc ------------------------------ | |
4441 | */ | |
f65fd747 | 4442 | |
22a89187 | 4443 | void* |
4c8b8cc3 UD |
4444 | _int_realloc(mstate av, mchunkptr oldp, INTERNAL_SIZE_T oldsize, |
4445 | INTERNAL_SIZE_T nb) | |
fa8d436c | 4446 | { |
fa8d436c UD |
4447 | mchunkptr newp; /* chunk to return */ |
4448 | INTERNAL_SIZE_T newsize; /* its size */ | |
22a89187 | 4449 | void* newmem; /* corresponding user mem */ |
f65fd747 | 4450 | |
fa8d436c | 4451 | mchunkptr next; /* next contiguous chunk after oldp */ |
f65fd747 | 4452 | |
fa8d436c UD |
4453 | mchunkptr remainder; /* extra space at end of newp */ |
4454 | unsigned long remainder_size; /* its size */ | |
f65fd747 | 4455 | |
fa8d436c UD |
4456 | mchunkptr bck; /* misc temp for linking */ |
4457 | mchunkptr fwd; /* misc temp for linking */ | |
2ed5fd9a | 4458 | |
fa8d436c UD |
4459 | unsigned long copysize; /* bytes to copy */ |
4460 | unsigned int ncopies; /* INTERNAL_SIZE_T words to copy */ | |
a9177ff5 | 4461 | INTERNAL_SIZE_T* s; /* copy source */ |
fa8d436c | 4462 | INTERNAL_SIZE_T* d; /* copy destination */ |
f65fd747 | 4463 | |
6dd6a580 | 4464 | /* oldmem size */ |
e9c4fe93 | 4465 | if (__builtin_expect (chunksize_nomask (oldp) <= 2 * SIZE_SZ, 0) |
76761b63 | 4466 | || __builtin_expect (oldsize >= av->system_mem, 0)) |
ac3ed168 | 4467 | malloc_printerr ("realloc(): invalid old size"); |
76761b63 | 4468 | |
6c8dbf00 | 4469 | check_inuse_chunk (av, oldp); |
f65fd747 | 4470 | |
4c8b8cc3 | 4471 | /* All callers already filter out mmap'ed chunks. */ |
6c8dbf00 | 4472 | assert (!chunk_is_mmapped (oldp)); |
f65fd747 | 4473 | |
6c8dbf00 OB |
4474 | next = chunk_at_offset (oldp, oldsize); |
4475 | INTERNAL_SIZE_T nextsize = chunksize (next); | |
e9c4fe93 | 4476 | if (__builtin_expect (chunksize_nomask (next) <= 2 * SIZE_SZ, 0) |
22a89187 | 4477 | || __builtin_expect (nextsize >= av->system_mem, 0)) |
ac3ed168 | 4478 | malloc_printerr ("realloc(): invalid next size"); |
22a89187 | 4479 | |
6c8dbf00 OB |
4480 | if ((unsigned long) (oldsize) >= (unsigned long) (nb)) |
4481 | { | |
4482 | /* already big enough; split below */ | |
fa8d436c | 4483 | newp = oldp; |
6c8dbf00 | 4484 | newsize = oldsize; |
7799b7b3 | 4485 | } |
f65fd747 | 4486 | |
6c8dbf00 OB |
4487 | else |
4488 | { | |
4489 | /* Try to expand forward into top */ | |
4490 | if (next == av->top && | |
4491 | (unsigned long) (newsize = oldsize + nextsize) >= | |
4492 | (unsigned long) (nb + MINSIZE)) | |
4493 | { | |
4494 | set_head_size (oldp, nb | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
4495 | av->top = chunk_at_offset (oldp, nb); | |
4496 | set_head (av->top, (newsize - nb) | PREV_INUSE); | |
4497 | check_inuse_chunk (av, oldp); | |
4498 | return chunk2mem (oldp); | |
4499 | } | |
4500 | ||
4501 | /* Try to expand forward into next chunk; split off remainder below */ | |
4502 | else if (next != av->top && | |
4503 | !inuse (next) && | |
4504 | (unsigned long) (newsize = oldsize + nextsize) >= | |
4505 | (unsigned long) (nb)) | |
4506 | { | |
4507 | newp = oldp; | |
fff94fa2 | 4508 | unlink (av, next, bck, fwd); |
6c8dbf00 OB |
4509 | } |
4510 | ||
4511 | /* allocate, copy, free */ | |
4512 | else | |
4513 | { | |
4514 | newmem = _int_malloc (av, nb - MALLOC_ALIGN_MASK); | |
4515 | if (newmem == 0) | |
4516 | return 0; /* propagate failure */ | |
4517 | ||
4518 | newp = mem2chunk (newmem); | |
4519 | newsize = chunksize (newp); | |
4520 | ||
4521 | /* | |
4522 | Avoid copy if newp is next chunk after oldp. | |
4523 | */ | |
4524 | if (newp == next) | |
4525 | { | |
4526 | newsize += oldsize; | |
4527 | newp = oldp; | |
4528 | } | |
4529 | else | |
4530 | { | |
4531 | /* | |
4532 | Unroll copy of <= 36 bytes (72 if 8byte sizes) | |
4533 | We know that contents have an odd number of | |
4534 | INTERNAL_SIZE_T-sized words; minimally 3. | |
4535 | */ | |
4536 | ||
4537 | copysize = oldsize - SIZE_SZ; | |
4538 | s = (INTERNAL_SIZE_T *) (chunk2mem (oldp)); | |
4539 | d = (INTERNAL_SIZE_T *) (newmem); | |
4540 | ncopies = copysize / sizeof (INTERNAL_SIZE_T); | |
4541 | assert (ncopies >= 3); | |
4542 | ||
4543 | if (ncopies > 9) | |
4544 | memcpy (d, s, copysize); | |
4545 | ||
4546 | else | |
4547 | { | |
4548 | *(d + 0) = *(s + 0); | |
4549 | *(d + 1) = *(s + 1); | |
4550 | *(d + 2) = *(s + 2); | |
4551 | if (ncopies > 4) | |
4552 | { | |
4553 | *(d + 3) = *(s + 3); | |
4554 | *(d + 4) = *(s + 4); | |
4555 | if (ncopies > 6) | |
4556 | { | |
4557 | *(d + 5) = *(s + 5); | |
4558 | *(d + 6) = *(s + 6); | |
4559 | if (ncopies > 8) | |
4560 | { | |
4561 | *(d + 7) = *(s + 7); | |
4562 | *(d + 8) = *(s + 8); | |
4563 | } | |
4564 | } | |
4565 | } | |
4566 | } | |
4567 | ||
4568 | _int_free (av, oldp, 1); | |
4569 | check_inuse_chunk (av, newp); | |
4570 | return chunk2mem (newp); | |
4571 | } | |
4572 | } | |
fa8d436c | 4573 | } |
f65fd747 | 4574 | |
22a89187 | 4575 | /* If possible, free extra space in old or extended chunk */ |
f65fd747 | 4576 | |
6c8dbf00 | 4577 | assert ((unsigned long) (newsize) >= (unsigned long) (nb)); |
f65fd747 | 4578 | |
22a89187 | 4579 | remainder_size = newsize - nb; |
10dc2a90 | 4580 | |
6c8dbf00 OB |
4581 | if (remainder_size < MINSIZE) /* not enough extra to split off */ |
4582 | { | |
4583 | set_head_size (newp, newsize | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
4584 | set_inuse_bit_at_offset (newp, newsize); | |
4585 | } | |
4586 | else /* split remainder */ | |
4587 | { | |
4588 | remainder = chunk_at_offset (newp, nb); | |
4589 | set_head_size (newp, nb | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
4590 | set_head (remainder, remainder_size | PREV_INUSE | | |
4591 | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
4592 | /* Mark remainder as inuse so free() won't complain */ | |
4593 | set_inuse_bit_at_offset (remainder, remainder_size); | |
4594 | _int_free (av, remainder, 1); | |
4595 | } | |
22a89187 | 4596 | |
6c8dbf00 OB |
4597 | check_inuse_chunk (av, newp); |
4598 | return chunk2mem (newp); | |
fa8d436c UD |
4599 | } |
4600 | ||
4601 | /* | |
6c8dbf00 OB |
4602 | ------------------------------ memalign ------------------------------ |
4603 | */ | |
fa8d436c | 4604 | |
6c8dbf00 OB |
4605 | static void * |
4606 | _int_memalign (mstate av, size_t alignment, size_t bytes) | |
fa8d436c UD |
4607 | { |
4608 | INTERNAL_SIZE_T nb; /* padded request size */ | |
6c8dbf00 OB |
4609 | char *m; /* memory returned by malloc call */ |
4610 | mchunkptr p; /* corresponding chunk */ | |
4611 | char *brk; /* alignment point within p */ | |
4612 | mchunkptr newp; /* chunk to return */ | |
fa8d436c UD |
4613 | INTERNAL_SIZE_T newsize; /* its size */ |
4614 | INTERNAL_SIZE_T leadsize; /* leading space before alignment point */ | |
6c8dbf00 OB |
4615 | mchunkptr remainder; /* spare room at end to split off */ |
4616 | unsigned long remainder_size; /* its size */ | |
fa8d436c | 4617 | INTERNAL_SIZE_T size; |
f65fd747 | 4618 | |
f65fd747 | 4619 | |
f65fd747 | 4620 | |
6c8dbf00 | 4621 | checked_request2size (bytes, nb); |
fa8d436c UD |
4622 | |
4623 | /* | |
6c8dbf00 OB |
4624 | Strategy: find a spot within that chunk that meets the alignment |
4625 | request, and then possibly free the leading and trailing space. | |
4626 | */ | |
fa8d436c UD |
4627 | |
4628 | ||
4629 | /* Call malloc with worst case padding to hit alignment. */ | |
4630 | ||
6c8dbf00 OB |
4631 | m = (char *) (_int_malloc (av, nb + alignment + MINSIZE)); |
4632 | ||
4633 | if (m == 0) | |
4634 | return 0; /* propagate failure */ | |
4635 | ||
4636 | p = mem2chunk (m); | |
4637 | ||
4638 | if ((((unsigned long) (m)) % alignment) != 0) /* misaligned */ | |
4639 | ||
4640 | { /* | |
4641 | Find an aligned spot inside chunk. Since we need to give back | |
4642 | leading space in a chunk of at least MINSIZE, if the first | |
4643 | calculation places us at a spot with less than MINSIZE leader, | |
4644 | we can move to the next aligned spot -- we've allocated enough | |
4645 | total room so that this is always possible. | |
4646 | */ | |
4647 | brk = (char *) mem2chunk (((unsigned long) (m + alignment - 1)) & | |
4648 | - ((signed long) alignment)); | |
4649 | if ((unsigned long) (brk - (char *) (p)) < MINSIZE) | |
4650 | brk += alignment; | |
4651 | ||
4652 | newp = (mchunkptr) brk; | |
4653 | leadsize = brk - (char *) (p); | |
4654 | newsize = chunksize (p) - leadsize; | |
4655 | ||
4656 | /* For mmapped chunks, just adjust offset */ | |
4657 | if (chunk_is_mmapped (p)) | |
4658 | { | |
e9c4fe93 | 4659 | set_prev_size (newp, prev_size (p) + leadsize); |
6c8dbf00 OB |
4660 | set_head (newp, newsize | IS_MMAPPED); |
4661 | return chunk2mem (newp); | |
4662 | } | |
4663 | ||
4664 | /* Otherwise, give back leader, use the rest */ | |
4665 | set_head (newp, newsize | PREV_INUSE | | |
4666 | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
4667 | set_inuse_bit_at_offset (newp, newsize); | |
4668 | set_head_size (p, leadsize | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
4669 | _int_free (av, p, 1); | |
4670 | p = newp; | |
4671 | ||
4672 | assert (newsize >= nb && | |
4673 | (((unsigned long) (chunk2mem (p))) % alignment) == 0); | |
f65fd747 | 4674 | } |
f65fd747 | 4675 | |
f65fd747 | 4676 | /* Also give back spare room at the end */ |
6c8dbf00 OB |
4677 | if (!chunk_is_mmapped (p)) |
4678 | { | |
4679 | size = chunksize (p); | |
4680 | if ((unsigned long) (size) > (unsigned long) (nb + MINSIZE)) | |
4681 | { | |
4682 | remainder_size = size - nb; | |
4683 | remainder = chunk_at_offset (p, nb); | |
4684 | set_head (remainder, remainder_size | PREV_INUSE | | |
4685 | (av != &main_arena ? NON_MAIN_ARENA : 0)); | |
4686 | set_head_size (p, nb); | |
4687 | _int_free (av, remainder, 1); | |
4688 | } | |
fa8d436c | 4689 | } |
f65fd747 | 4690 | |
6c8dbf00 OB |
4691 | check_inuse_chunk (av, p); |
4692 | return chunk2mem (p); | |
f65fd747 UD |
4693 | } |
4694 | ||
f65fd747 | 4695 | |
fa8d436c | 4696 | /* |
6c8dbf00 OB |
4697 | ------------------------------ malloc_trim ------------------------------ |
4698 | */ | |
8a4b65b4 | 4699 | |
6c8dbf00 OB |
4700 | static int |
4701 | mtrim (mstate av, size_t pad) | |
f65fd747 | 4702 | { |
fa8d436c | 4703 | /* Ensure initialization/consolidation */ |
68631c8e UD |
4704 | malloc_consolidate (av); |
4705 | ||
6c8dbf00 | 4706 | const size_t ps = GLRO (dl_pagesize); |
68631c8e UD |
4707 | int psindex = bin_index (ps); |
4708 | const size_t psm1 = ps - 1; | |
4709 | ||
4710 | int result = 0; | |
4711 | for (int i = 1; i < NBINS; ++i) | |
4712 | if (i == 1 || i >= psindex) | |
4713 | { | |
6c8dbf00 | 4714 | mbinptr bin = bin_at (av, i); |
68631c8e | 4715 | |
6c8dbf00 OB |
4716 | for (mchunkptr p = last (bin); p != bin; p = p->bk) |
4717 | { | |
4718 | INTERNAL_SIZE_T size = chunksize (p); | |
68631c8e | 4719 | |
6c8dbf00 OB |
4720 | if (size > psm1 + sizeof (struct malloc_chunk)) |
4721 | { | |
4722 | /* See whether the chunk contains at least one unused page. */ | |
4723 | char *paligned_mem = (char *) (((uintptr_t) p | |
4724 | + sizeof (struct malloc_chunk) | |
4725 | + psm1) & ~psm1); | |
68631c8e | 4726 | |
6c8dbf00 OB |
4727 | assert ((char *) chunk2mem (p) + 4 * SIZE_SZ <= paligned_mem); |
4728 | assert ((char *) p + size > paligned_mem); | |
68631c8e | 4729 | |
6c8dbf00 OB |
4730 | /* This is the size we could potentially free. */ |
4731 | size -= paligned_mem - (char *) p; | |
68631c8e | 4732 | |
6c8dbf00 OB |
4733 | if (size > psm1) |
4734 | { | |
439bda32 | 4735 | #if MALLOC_DEBUG |
6c8dbf00 OB |
4736 | /* When debugging we simulate destroying the memory |
4737 | content. */ | |
4738 | memset (paligned_mem, 0x89, size & ~psm1); | |
68631c8e | 4739 | #endif |
6c8dbf00 | 4740 | __madvise (paligned_mem, size & ~psm1, MADV_DONTNEED); |
68631c8e | 4741 | |
6c8dbf00 OB |
4742 | result = 1; |
4743 | } | |
4744 | } | |
4745 | } | |
68631c8e | 4746 | } |
8a4b65b4 | 4747 | |
a9177ff5 | 4748 | #ifndef MORECORE_CANNOT_TRIM |
3b49edc0 | 4749 | return result | (av == &main_arena ? systrim (pad, av) : 0); |
6c8dbf00 | 4750 | |
8a4b65b4 | 4751 | #else |
68631c8e | 4752 | return result; |
f65fd747 | 4753 | #endif |
f65fd747 UD |
4754 | } |
4755 | ||
f65fd747 | 4756 | |
3b49edc0 | 4757 | int |
6c8dbf00 | 4758 | __malloc_trim (size_t s) |
3b49edc0 UD |
4759 | { |
4760 | int result = 0; | |
4761 | ||
6c8dbf00 | 4762 | if (__malloc_initialized < 0) |
3b49edc0 UD |
4763 | ptmalloc_init (); |
4764 | ||
4765 | mstate ar_ptr = &main_arena; | |
4766 | do | |
4767 | { | |
4bf5f222 | 4768 | __libc_lock_lock (ar_ptr->mutex); |
3b49edc0 | 4769 | result |= mtrim (ar_ptr, s); |
4bf5f222 | 4770 | __libc_lock_unlock (ar_ptr->mutex); |
3b49edc0 UD |
4771 | |
4772 | ar_ptr = ar_ptr->next; | |
4773 | } | |
4774 | while (ar_ptr != &main_arena); | |
4775 | ||
4776 | return result; | |
4777 | } | |
4778 | ||
4779 | ||
f65fd747 | 4780 | /* |
6c8dbf00 OB |
4781 | ------------------------- malloc_usable_size ------------------------- |
4782 | */ | |
f65fd747 | 4783 | |
3b49edc0 | 4784 | static size_t |
6c8dbf00 | 4785 | musable (void *mem) |
f65fd747 UD |
4786 | { |
4787 | mchunkptr p; | |
6c8dbf00 OB |
4788 | if (mem != 0) |
4789 | { | |
4790 | p = mem2chunk (mem); | |
4791 | ||
4792 | if (__builtin_expect (using_malloc_checking == 1, 0)) | |
4793 | return malloc_check_get_size (p); | |
4794 | ||
4795 | if (chunk_is_mmapped (p)) | |
073f8214 FW |
4796 | { |
4797 | if (DUMPED_MAIN_ARENA_CHUNK (p)) | |
4798 | return chunksize (p) - SIZE_SZ; | |
4799 | else | |
4800 | return chunksize (p) - 2 * SIZE_SZ; | |
4801 | } | |
6c8dbf00 OB |
4802 | else if (inuse (p)) |
4803 | return chunksize (p) - SIZE_SZ; | |
4804 | } | |
fa8d436c | 4805 | return 0; |
f65fd747 UD |
4806 | } |
4807 | ||
3b49edc0 UD |
4808 | |
4809 | size_t | |
6c8dbf00 | 4810 | __malloc_usable_size (void *m) |
3b49edc0 UD |
4811 | { |
4812 | size_t result; | |
4813 | ||
6c8dbf00 | 4814 | result = musable (m); |
3b49edc0 UD |
4815 | return result; |
4816 | } | |
4817 | ||
fa8d436c | 4818 | /* |
6c8dbf00 OB |
4819 | ------------------------------ mallinfo ------------------------------ |
4820 | Accumulate malloc statistics for arena AV into M. | |
4821 | */ | |
f65fd747 | 4822 | |
bedee953 | 4823 | static void |
6c8dbf00 | 4824 | int_mallinfo (mstate av, struct mallinfo *m) |
f65fd747 | 4825 | { |
6dd67bd5 | 4826 | size_t i; |
f65fd747 UD |
4827 | mbinptr b; |
4828 | mchunkptr p; | |
f65fd747 | 4829 | INTERNAL_SIZE_T avail; |
fa8d436c UD |
4830 | INTERNAL_SIZE_T fastavail; |
4831 | int nblocks; | |
4832 | int nfastblocks; | |
f65fd747 | 4833 | |
fa8d436c | 4834 | /* Ensure initialization */ |
6c8dbf00 OB |
4835 | if (av->top == 0) |
4836 | malloc_consolidate (av); | |
8a4b65b4 | 4837 | |
6c8dbf00 | 4838 | check_malloc_state (av); |
8a4b65b4 | 4839 | |
fa8d436c | 4840 | /* Account for top */ |
6c8dbf00 | 4841 | avail = chunksize (av->top); |
fa8d436c | 4842 | nblocks = 1; /* top always exists */ |
f65fd747 | 4843 | |
fa8d436c UD |
4844 | /* traverse fastbins */ |
4845 | nfastblocks = 0; | |
4846 | fastavail = 0; | |
4847 | ||
6c8dbf00 OB |
4848 | for (i = 0; i < NFASTBINS; ++i) |
4849 | { | |
4850 | for (p = fastbin (av, i); p != 0; p = p->fd) | |
4851 | { | |
4852 | ++nfastblocks; | |
4853 | fastavail += chunksize (p); | |
4854 | } | |
fa8d436c | 4855 | } |
fa8d436c UD |
4856 | |
4857 | avail += fastavail; | |
f65fd747 | 4858 | |
fa8d436c | 4859 | /* traverse regular bins */ |
6c8dbf00 OB |
4860 | for (i = 1; i < NBINS; ++i) |
4861 | { | |
4862 | b = bin_at (av, i); | |
4863 | for (p = last (b); p != b; p = p->bk) | |
4864 | { | |
4865 | ++nblocks; | |
4866 | avail += chunksize (p); | |
4867 | } | |
fa8d436c | 4868 | } |
f65fd747 | 4869 | |
bedee953 PP |
4870 | m->smblks += nfastblocks; |
4871 | m->ordblks += nblocks; | |
4872 | m->fordblks += avail; | |
4873 | m->uordblks += av->system_mem - avail; | |
4874 | m->arena += av->system_mem; | |
4875 | m->fsmblks += fastavail; | |
4876 | if (av == &main_arena) | |
4877 | { | |
4878 | m->hblks = mp_.n_mmaps; | |
4879 | m->hblkhd = mp_.mmapped_mem; | |
ca135f82 | 4880 | m->usmblks = 0; |
6c8dbf00 | 4881 | m->keepcost = chunksize (av->top); |
bedee953 | 4882 | } |
fa8d436c | 4883 | } |
f65fd747 | 4884 | |
3b49edc0 | 4885 | |
6c8dbf00 | 4886 | struct mallinfo |
9dd346ff | 4887 | __libc_mallinfo (void) |
3b49edc0 UD |
4888 | { |
4889 | struct mallinfo m; | |
bedee953 | 4890 | mstate ar_ptr; |
3b49edc0 | 4891 | |
6c8dbf00 | 4892 | if (__malloc_initialized < 0) |
3b49edc0 | 4893 | ptmalloc_init (); |
bedee953 | 4894 | |
6c8dbf00 | 4895 | memset (&m, 0, sizeof (m)); |
bedee953 | 4896 | ar_ptr = &main_arena; |
6c8dbf00 OB |
4897 | do |
4898 | { | |
4bf5f222 | 4899 | __libc_lock_lock (ar_ptr->mutex); |
6c8dbf00 | 4900 | int_mallinfo (ar_ptr, &m); |
4bf5f222 | 4901 | __libc_lock_unlock (ar_ptr->mutex); |
bedee953 | 4902 | |
6c8dbf00 OB |
4903 | ar_ptr = ar_ptr->next; |
4904 | } | |
4905 | while (ar_ptr != &main_arena); | |
bedee953 | 4906 | |
3b49edc0 UD |
4907 | return m; |
4908 | } | |
4909 | ||
fa8d436c | 4910 | /* |
6c8dbf00 OB |
4911 | ------------------------------ malloc_stats ------------------------------ |
4912 | */ | |
f65fd747 | 4913 | |
3b49edc0 | 4914 | void |
60d2f8f3 | 4915 | __malloc_stats (void) |
f65fd747 | 4916 | { |
8a4b65b4 | 4917 | int i; |
fa8d436c | 4918 | mstate ar_ptr; |
fa8d436c | 4919 | unsigned int in_use_b = mp_.mmapped_mem, system_b = in_use_b; |
8a4b65b4 | 4920 | |
6c8dbf00 | 4921 | if (__malloc_initialized < 0) |
a234e27d | 4922 | ptmalloc_init (); |
8dab36a1 UD |
4923 | _IO_flockfile (stderr); |
4924 | int old_flags2 = ((_IO_FILE *) stderr)->_flags2; | |
4925 | ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL; | |
6c8dbf00 OB |
4926 | for (i = 0, ar_ptr = &main_arena;; i++) |
4927 | { | |
4928 | struct mallinfo mi; | |
4929 | ||
4930 | memset (&mi, 0, sizeof (mi)); | |
4bf5f222 | 4931 | __libc_lock_lock (ar_ptr->mutex); |
6c8dbf00 OB |
4932 | int_mallinfo (ar_ptr, &mi); |
4933 | fprintf (stderr, "Arena %d:\n", i); | |
4934 | fprintf (stderr, "system bytes = %10u\n", (unsigned int) mi.arena); | |
4935 | fprintf (stderr, "in use bytes = %10u\n", (unsigned int) mi.uordblks); | |
fa8d436c | 4936 | #if MALLOC_DEBUG > 1 |
6c8dbf00 OB |
4937 | if (i > 0) |
4938 | dump_heap (heap_for_ptr (top (ar_ptr))); | |
fa8d436c | 4939 | #endif |
6c8dbf00 OB |
4940 | system_b += mi.arena; |
4941 | in_use_b += mi.uordblks; | |
4bf5f222 | 4942 | __libc_lock_unlock (ar_ptr->mutex); |
6c8dbf00 OB |
4943 | ar_ptr = ar_ptr->next; |
4944 | if (ar_ptr == &main_arena) | |
4945 | break; | |
4946 | } | |
4947 | fprintf (stderr, "Total (incl. mmap):\n"); | |
4948 | fprintf (stderr, "system bytes = %10u\n", system_b); | |
4949 | fprintf (stderr, "in use bytes = %10u\n", in_use_b); | |
4950 | fprintf (stderr, "max mmap regions = %10u\n", (unsigned int) mp_.max_n_mmaps); | |
4951 | fprintf (stderr, "max mmap bytes = %10lu\n", | |
4952 | (unsigned long) mp_.max_mmapped_mem); | |
8dab36a1 UD |
4953 | ((_IO_FILE *) stderr)->_flags2 |= old_flags2; |
4954 | _IO_funlockfile (stderr); | |
f65fd747 UD |
4955 | } |
4956 | ||
f65fd747 UD |
4957 | |
4958 | /* | |
6c8dbf00 OB |
4959 | ------------------------------ mallopt ------------------------------ |
4960 | */ | |
be7991c0 SP |
4961 | static inline int |
4962 | __always_inline | |
4963 | do_set_trim_threshold (size_t value) | |
4964 | { | |
4965 | LIBC_PROBE (memory_mallopt_trim_threshold, 3, value, mp_.trim_threshold, | |
4966 | mp_.no_dyn_threshold); | |
4967 | mp_.trim_threshold = value; | |
4968 | mp_.no_dyn_threshold = 1; | |
4969 | return 1; | |
4970 | } | |
4971 | ||
4972 | static inline int | |
4973 | __always_inline | |
4974 | do_set_top_pad (size_t value) | |
4975 | { | |
4976 | LIBC_PROBE (memory_mallopt_top_pad, 3, value, mp_.top_pad, | |
4977 | mp_.no_dyn_threshold); | |
4978 | mp_.top_pad = value; | |
4979 | mp_.no_dyn_threshold = 1; | |
4980 | return 1; | |
4981 | } | |
4982 | ||
4983 | static inline int | |
4984 | __always_inline | |
4985 | do_set_mmap_threshold (size_t value) | |
4986 | { | |
4987 | /* Forbid setting the threshold too high. */ | |
4988 | if (value <= HEAP_MAX_SIZE / 2) | |
4989 | { | |
4990 | LIBC_PROBE (memory_mallopt_mmap_threshold, 3, value, mp_.mmap_threshold, | |
4991 | mp_.no_dyn_threshold); | |
4992 | mp_.mmap_threshold = value; | |
4993 | mp_.no_dyn_threshold = 1; | |
4994 | return 1; | |
4995 | } | |
4996 | return 0; | |
4997 | } | |
4998 | ||
4999 | static inline int | |
5000 | __always_inline | |
5001 | do_set_mmaps_max (int32_t value) | |
5002 | { | |
5003 | LIBC_PROBE (memory_mallopt_mmap_max, 3, value, mp_.n_mmaps_max, | |
5004 | mp_.no_dyn_threshold); | |
5005 | mp_.n_mmaps_max = value; | |
5006 | mp_.no_dyn_threshold = 1; | |
5007 | return 1; | |
5008 | } | |
5009 | ||
5010 | static inline int | |
5011 | __always_inline | |
5012 | do_set_mallopt_check (int32_t value) | |
5013 | { | |
be7991c0 SP |
5014 | return 1; |
5015 | } | |
5016 | ||
5017 | static inline int | |
5018 | __always_inline | |
5019 | do_set_perturb_byte (int32_t value) | |
5020 | { | |
5021 | LIBC_PROBE (memory_mallopt_perturb, 2, value, perturb_byte); | |
5022 | perturb_byte = value; | |
5023 | return 1; | |
5024 | } | |
5025 | ||
5026 | static inline int | |
5027 | __always_inline | |
5028 | do_set_arena_test (size_t value) | |
5029 | { | |
5030 | LIBC_PROBE (memory_mallopt_arena_test, 2, value, mp_.arena_test); | |
5031 | mp_.arena_test = value; | |
5032 | return 1; | |
5033 | } | |
5034 | ||
5035 | static inline int | |
5036 | __always_inline | |
5037 | do_set_arena_max (size_t value) | |
5038 | { | |
5039 | LIBC_PROBE (memory_mallopt_arena_max, 2, value, mp_.arena_max); | |
5040 | mp_.arena_max = value; | |
5041 | return 1; | |
5042 | } | |
5043 | ||
d5c3fafc DD |
5044 | #if USE_TCACHE |
5045 | static inline int | |
5046 | __always_inline | |
5047 | do_set_tcache_max (size_t value) | |
5048 | { | |
5049 | if (value >= 0 && value <= MAX_TCACHE_SIZE) | |
5050 | { | |
5051 | LIBC_PROBE (memory_tunable_tcache_max_bytes, 2, value, mp_.tcache_max_bytes); | |
5052 | mp_.tcache_max_bytes = value; | |
5053 | mp_.tcache_bins = csize2tidx (request2size(value)) + 1; | |
5054 | } | |
5055 | return 1; | |
5056 | } | |
5057 | ||
5058 | static inline int | |
5059 | __always_inline | |
5060 | do_set_tcache_count (size_t value) | |
5061 | { | |
5062 | LIBC_PROBE (memory_tunable_tcache_count, 2, value, mp_.tcache_count); | |
5063 | mp_.tcache_count = value; | |
5064 | return 1; | |
5065 | } | |
5066 | ||
5067 | static inline int | |
5068 | __always_inline | |
5069 | do_set_tcache_unsorted_limit (size_t value) | |
5070 | { | |
5071 | LIBC_PROBE (memory_tunable_tcache_unsorted_limit, 2, value, mp_.tcache_unsorted_limit); | |
5072 | mp_.tcache_unsorted_limit = value; | |
5073 | return 1; | |
5074 | } | |
5075 | #endif | |
f65fd747 | 5076 | |
6c8dbf00 OB |
5077 | int |
5078 | __libc_mallopt (int param_number, int value) | |
f65fd747 | 5079 | { |
fa8d436c UD |
5080 | mstate av = &main_arena; |
5081 | int res = 1; | |
f65fd747 | 5082 | |
6c8dbf00 | 5083 | if (__malloc_initialized < 0) |
0cb71e02 | 5084 | ptmalloc_init (); |
4bf5f222 | 5085 | __libc_lock_lock (av->mutex); |
fa8d436c | 5086 | /* Ensure initialization/consolidation */ |
6c8dbf00 | 5087 | malloc_consolidate (av); |
2f6d1f1b | 5088 | |
3ea5be54 AO |
5089 | LIBC_PROBE (memory_mallopt, 2, param_number, value); |
5090 | ||
6c8dbf00 OB |
5091 | switch (param_number) |
5092 | { | |
5093 | case M_MXFAST: | |
5094 | if (value >= 0 && value <= MAX_FAST_SIZE) | |
5095 | { | |
5096 | LIBC_PROBE (memory_mallopt_mxfast, 2, value, get_max_fast ()); | |
5097 | set_max_fast (value); | |
5098 | } | |
5099 | else | |
5100 | res = 0; | |
5101 | break; | |
5102 | ||
5103 | case M_TRIM_THRESHOLD: | |
be7991c0 | 5104 | do_set_trim_threshold (value); |
6c8dbf00 OB |
5105 | break; |
5106 | ||
5107 | case M_TOP_PAD: | |
be7991c0 | 5108 | do_set_top_pad (value); |
6c8dbf00 OB |
5109 | break; |
5110 | ||
5111 | case M_MMAP_THRESHOLD: | |
be7991c0 | 5112 | res = do_set_mmap_threshold (value); |
6c8dbf00 OB |
5113 | break; |
5114 | ||
5115 | case M_MMAP_MAX: | |
be7991c0 | 5116 | do_set_mmaps_max (value); |
6c8dbf00 OB |
5117 | break; |
5118 | ||
5119 | case M_CHECK_ACTION: | |
be7991c0 | 5120 | do_set_mallopt_check (value); |
6c8dbf00 OB |
5121 | break; |
5122 | ||
5123 | case M_PERTURB: | |
be7991c0 | 5124 | do_set_perturb_byte (value); |
6c8dbf00 OB |
5125 | break; |
5126 | ||
5127 | case M_ARENA_TEST: | |
5128 | if (value > 0) | |
be7991c0 | 5129 | do_set_arena_test (value); |
6c8dbf00 OB |
5130 | break; |
5131 | ||
5132 | case M_ARENA_MAX: | |
5133 | if (value > 0) | |
62222284 | 5134 | do_set_arena_max (value); |
6c8dbf00 OB |
5135 | break; |
5136 | } | |
4bf5f222 | 5137 | __libc_lock_unlock (av->mutex); |
fa8d436c | 5138 | return res; |
b22fc5f5 | 5139 | } |
3b49edc0 | 5140 | libc_hidden_def (__libc_mallopt) |
b22fc5f5 | 5141 | |
10dc2a90 | 5142 | |
a9177ff5 | 5143 | /* |
6c8dbf00 OB |
5144 | -------------------- Alternative MORECORE functions -------------------- |
5145 | */ | |
10dc2a90 | 5146 | |
b22fc5f5 | 5147 | |
fa8d436c | 5148 | /* |
6c8dbf00 | 5149 | General Requirements for MORECORE. |
b22fc5f5 | 5150 | |
6c8dbf00 | 5151 | The MORECORE function must have the following properties: |
b22fc5f5 | 5152 | |
6c8dbf00 | 5153 | If MORECORE_CONTIGUOUS is false: |
10dc2a90 | 5154 | |
6c8dbf00 | 5155 | * MORECORE must allocate in multiples of pagesize. It will |
fa8d436c | 5156 | only be called with arguments that are multiples of pagesize. |
10dc2a90 | 5157 | |
6c8dbf00 | 5158 | * MORECORE(0) must return an address that is at least |
fa8d436c | 5159 | MALLOC_ALIGNMENT aligned. (Page-aligning always suffices.) |
10dc2a90 | 5160 | |
6c8dbf00 | 5161 | else (i.e. If MORECORE_CONTIGUOUS is true): |
10dc2a90 | 5162 | |
6c8dbf00 | 5163 | * Consecutive calls to MORECORE with positive arguments |
fa8d436c UD |
5164 | return increasing addresses, indicating that space has been |
5165 | contiguously extended. | |
10dc2a90 | 5166 | |
6c8dbf00 | 5167 | * MORECORE need not allocate in multiples of pagesize. |
fa8d436c | 5168 | Calls to MORECORE need not have args of multiples of pagesize. |
10dc2a90 | 5169 | |
6c8dbf00 | 5170 | * MORECORE need not page-align. |
10dc2a90 | 5171 | |
6c8dbf00 | 5172 | In either case: |
10dc2a90 | 5173 | |
6c8dbf00 | 5174 | * MORECORE may allocate more memory than requested. (Or even less, |
fa8d436c | 5175 | but this will generally result in a malloc failure.) |
10dc2a90 | 5176 | |
6c8dbf00 | 5177 | * MORECORE must not allocate memory when given argument zero, but |
fa8d436c UD |
5178 | instead return one past the end address of memory from previous |
5179 | nonzero call. This malloc does NOT call MORECORE(0) | |
5180 | until at least one call with positive arguments is made, so | |
5181 | the initial value returned is not important. | |
10dc2a90 | 5182 | |
6c8dbf00 | 5183 | * Even though consecutive calls to MORECORE need not return contiguous |
fa8d436c UD |
5184 | addresses, it must be OK for malloc'ed chunks to span multiple |
5185 | regions in those cases where they do happen to be contiguous. | |
10dc2a90 | 5186 | |
6c8dbf00 | 5187 | * MORECORE need not handle negative arguments -- it may instead |
fa8d436c UD |
5188 | just return MORECORE_FAILURE when given negative arguments. |
5189 | Negative arguments are always multiples of pagesize. MORECORE | |
5190 | must not misinterpret negative args as large positive unsigned | |
5191 | args. You can suppress all such calls from even occurring by defining | |
5192 | MORECORE_CANNOT_TRIM, | |
10dc2a90 | 5193 | |
6c8dbf00 OB |
5194 | There is some variation across systems about the type of the |
5195 | argument to sbrk/MORECORE. If size_t is unsigned, then it cannot | |
5196 | actually be size_t, because sbrk supports negative args, so it is | |
5197 | normally the signed type of the same width as size_t (sometimes | |
5198 | declared as "intptr_t", and sometimes "ptrdiff_t"). It doesn't much | |
5199 | matter though. Internally, we use "long" as arguments, which should | |
5200 | work across all reasonable possibilities. | |
5201 | ||
5202 | Additionally, if MORECORE ever returns failure for a positive | |
5203 | request, then mmap is used as a noncontiguous system allocator. This | |
5204 | is a useful backup strategy for systems with holes in address spaces | |
5205 | -- in this case sbrk cannot contiguously expand the heap, but mmap | |
5206 | may be able to map noncontiguous space. | |
5207 | ||
5208 | If you'd like mmap to ALWAYS be used, you can define MORECORE to be | |
5209 | a function that always returns MORECORE_FAILURE. | |
5210 | ||
5211 | If you are using this malloc with something other than sbrk (or its | |
5212 | emulation) to supply memory regions, you probably want to set | |
5213 | MORECORE_CONTIGUOUS as false. As an example, here is a custom | |
5214 | allocator kindly contributed for pre-OSX macOS. It uses virtually | |
5215 | but not necessarily physically contiguous non-paged memory (locked | |
5216 | in, present and won't get swapped out). You can use it by | |
5217 | uncommenting this section, adding some #includes, and setting up the | |
5218 | appropriate defines above: | |
5219 | ||
5220 | *#define MORECORE osMoreCore | |
5221 | *#define MORECORE_CONTIGUOUS 0 | |
5222 | ||
5223 | There is also a shutdown routine that should somehow be called for | |
5224 | cleanup upon program exit. | |
5225 | ||
5226 | *#define MAX_POOL_ENTRIES 100 | |
5227 | *#define MINIMUM_MORECORE_SIZE (64 * 1024) | |
5228 | static int next_os_pool; | |
5229 | void *our_os_pools[MAX_POOL_ENTRIES]; | |
5230 | ||
5231 | void *osMoreCore(int size) | |
5232 | { | |
fa8d436c UD |
5233 | void *ptr = 0; |
5234 | static void *sbrk_top = 0; | |
ca34d7a7 | 5235 | |
fa8d436c UD |
5236 | if (size > 0) |
5237 | { | |
5238 | if (size < MINIMUM_MORECORE_SIZE) | |
6c8dbf00 | 5239 | size = MINIMUM_MORECORE_SIZE; |
fa8d436c | 5240 | if (CurrentExecutionLevel() == kTaskLevel) |
6c8dbf00 | 5241 | ptr = PoolAllocateResident(size + RM_PAGE_SIZE, 0); |
fa8d436c UD |
5242 | if (ptr == 0) |
5243 | { | |
6c8dbf00 | 5244 | return (void *) MORECORE_FAILURE; |
fa8d436c UD |
5245 | } |
5246 | // save ptrs so they can be freed during cleanup | |
5247 | our_os_pools[next_os_pool] = ptr; | |
5248 | next_os_pool++; | |
5249 | ptr = (void *) ((((unsigned long) ptr) + RM_PAGE_MASK) & ~RM_PAGE_MASK); | |
5250 | sbrk_top = (char *) ptr + size; | |
5251 | return ptr; | |
5252 | } | |
5253 | else if (size < 0) | |
5254 | { | |
5255 | // we don't currently support shrink behavior | |
5256 | return (void *) MORECORE_FAILURE; | |
5257 | } | |
5258 | else | |
5259 | { | |
5260 | return sbrk_top; | |
431c33c0 | 5261 | } |
6c8dbf00 | 5262 | } |
ca34d7a7 | 5263 | |
6c8dbf00 OB |
5264 | // cleanup any allocated memory pools |
5265 | // called as last thing before shutting down driver | |
ca34d7a7 | 5266 | |
6c8dbf00 OB |
5267 | void osCleanupMem(void) |
5268 | { | |
fa8d436c | 5269 | void **ptr; |
ca34d7a7 | 5270 | |
fa8d436c UD |
5271 | for (ptr = our_os_pools; ptr < &our_os_pools[MAX_POOL_ENTRIES]; ptr++) |
5272 | if (*ptr) | |
5273 | { | |
6c8dbf00 OB |
5274 | PoolDeallocate(*ptr); |
5275 | * ptr = 0; | |
fa8d436c | 5276 | } |
6c8dbf00 | 5277 | } |
ee74a442 | 5278 | |
6c8dbf00 | 5279 | */ |
f65fd747 | 5280 | |
7e3be507 | 5281 | |
3e030bd5 UD |
5282 | /* Helper code. */ |
5283 | ||
ae7f5313 UD |
5284 | extern char **__libc_argv attribute_hidden; |
5285 | ||
3e030bd5 | 5286 | static void |
ac3ed168 | 5287 | malloc_printerr (const char *str) |
3e030bd5 | 5288 | { |
ec2c1fce FW |
5289 | __libc_message (do_abort, "%s\n", str); |
5290 | __builtin_unreachable (); | |
3e030bd5 UD |
5291 | } |
5292 | ||
a204dbb2 UD |
5293 | /* We need a wrapper function for one of the additions of POSIX. */ |
5294 | int | |
5295 | __posix_memalign (void **memptr, size_t alignment, size_t size) | |
5296 | { | |
5297 | void *mem; | |
5298 | ||
5299 | /* Test whether the SIZE argument is valid. It must be a power of | |
5300 | two multiple of sizeof (void *). */ | |
de02bd05 | 5301 | if (alignment % sizeof (void *) != 0 |
fc56e970 | 5302 | || !powerof2 (alignment / sizeof (void *)) |
de02bd05 | 5303 | || alignment == 0) |
a204dbb2 UD |
5304 | return EINVAL; |
5305 | ||
10ad46bc OB |
5306 | |
5307 | void *address = RETURN_ADDRESS (0); | |
5308 | mem = _mid_memalign (alignment, size, address); | |
a204dbb2 | 5309 | |
6c8dbf00 OB |
5310 | if (mem != NULL) |
5311 | { | |
5312 | *memptr = mem; | |
5313 | return 0; | |
5314 | } | |
a204dbb2 UD |
5315 | |
5316 | return ENOMEM; | |
5317 | } | |
5318 | weak_alias (__posix_memalign, posix_memalign) | |
5319 | ||
20c13899 OB |
5320 | |
5321 | int | |
c52ff39e | 5322 | __malloc_info (int options, FILE *fp) |
bb066545 | 5323 | { |
20c13899 OB |
5324 | /* For now, at least. */ |
5325 | if (options != 0) | |
5326 | return EINVAL; | |
bb066545 | 5327 | |
20c13899 OB |
5328 | int n = 0; |
5329 | size_t total_nblocks = 0; | |
5330 | size_t total_nfastblocks = 0; | |
5331 | size_t total_avail = 0; | |
5332 | size_t total_fastavail = 0; | |
5333 | size_t total_system = 0; | |
5334 | size_t total_max_system = 0; | |
5335 | size_t total_aspace = 0; | |
5336 | size_t total_aspace_mprotect = 0; | |
bb066545 | 5337 | |
6c8dbf00 | 5338 | |
6c8dbf00 | 5339 | |
987c0269 OB |
5340 | if (__malloc_initialized < 0) |
5341 | ptmalloc_init (); | |
bb066545 | 5342 | |
987c0269 | 5343 | fputs ("<malloc version=\"1\">\n", fp); |
bb066545 | 5344 | |
987c0269 OB |
5345 | /* Iterate over all arenas currently in use. */ |
5346 | mstate ar_ptr = &main_arena; | |
5347 | do | |
5348 | { | |
5349 | fprintf (fp, "<heap nr=\"%d\">\n<sizes>\n", n++); | |
8b35e35d | 5350 | |
987c0269 OB |
5351 | size_t nblocks = 0; |
5352 | size_t nfastblocks = 0; | |
5353 | size_t avail = 0; | |
5354 | size_t fastavail = 0; | |
5355 | struct | |
5356 | { | |
5357 | size_t from; | |
5358 | size_t to; | |
5359 | size_t total; | |
5360 | size_t count; | |
5361 | } sizes[NFASTBINS + NBINS - 1]; | |
5362 | #define nsizes (sizeof (sizes) / sizeof (sizes[0])) | |
6c8dbf00 | 5363 | |
4bf5f222 | 5364 | __libc_lock_lock (ar_ptr->mutex); |
bb066545 | 5365 | |
987c0269 OB |
5366 | for (size_t i = 0; i < NFASTBINS; ++i) |
5367 | { | |
5368 | mchunkptr p = fastbin (ar_ptr, i); | |
5369 | if (p != NULL) | |
5370 | { | |
5371 | size_t nthissize = 0; | |
5372 | size_t thissize = chunksize (p); | |
5373 | ||
5374 | while (p != NULL) | |
5375 | { | |
5376 | ++nthissize; | |
5377 | p = p->fd; | |
5378 | } | |
5379 | ||
5380 | fastavail += nthissize * thissize; | |
5381 | nfastblocks += nthissize; | |
5382 | sizes[i].from = thissize - (MALLOC_ALIGNMENT - 1); | |
5383 | sizes[i].to = thissize; | |
5384 | sizes[i].count = nthissize; | |
5385 | } | |
5386 | else | |
5387 | sizes[i].from = sizes[i].to = sizes[i].count = 0; | |
bb066545 | 5388 | |
987c0269 OB |
5389 | sizes[i].total = sizes[i].count * sizes[i].to; |
5390 | } | |
bb066545 | 5391 | |
bb066545 | 5392 | |
987c0269 OB |
5393 | mbinptr bin; |
5394 | struct malloc_chunk *r; | |
bb066545 | 5395 | |
987c0269 OB |
5396 | for (size_t i = 1; i < NBINS; ++i) |
5397 | { | |
5398 | bin = bin_at (ar_ptr, i); | |
5399 | r = bin->fd; | |
5400 | sizes[NFASTBINS - 1 + i].from = ~((size_t) 0); | |
5401 | sizes[NFASTBINS - 1 + i].to = sizes[NFASTBINS - 1 + i].total | |
5402 | = sizes[NFASTBINS - 1 + i].count = 0; | |
5403 | ||
5404 | if (r != NULL) | |
5405 | while (r != bin) | |
5406 | { | |
e9c4fe93 | 5407 | size_t r_size = chunksize_nomask (r); |
987c0269 | 5408 | ++sizes[NFASTBINS - 1 + i].count; |
e9c4fe93 | 5409 | sizes[NFASTBINS - 1 + i].total += r_size; |
987c0269 | 5410 | sizes[NFASTBINS - 1 + i].from |
e9c4fe93 | 5411 | = MIN (sizes[NFASTBINS - 1 + i].from, r_size); |
987c0269 | 5412 | sizes[NFASTBINS - 1 + i].to = MAX (sizes[NFASTBINS - 1 + i].to, |
e9c4fe93 | 5413 | r_size); |
987c0269 OB |
5414 | |
5415 | r = r->fd; | |
5416 | } | |
5417 | ||
5418 | if (sizes[NFASTBINS - 1 + i].count == 0) | |
5419 | sizes[NFASTBINS - 1 + i].from = 0; | |
5420 | nblocks += sizes[NFASTBINS - 1 + i].count; | |
5421 | avail += sizes[NFASTBINS - 1 + i].total; | |
5422 | } | |
bb066545 | 5423 | |
4bf5f222 | 5424 | __libc_lock_unlock (ar_ptr->mutex); |
da2d2fb6 | 5425 | |
987c0269 OB |
5426 | total_nfastblocks += nfastblocks; |
5427 | total_fastavail += fastavail; | |
0588a9cb | 5428 | |
987c0269 OB |
5429 | total_nblocks += nblocks; |
5430 | total_avail += avail; | |
0588a9cb | 5431 | |
987c0269 OB |
5432 | for (size_t i = 0; i < nsizes; ++i) |
5433 | if (sizes[i].count != 0 && i != NFASTBINS) | |
5434 | fprintf (fp, " \ | |
5435 | <size from=\"%zu\" to=\"%zu\" total=\"%zu\" count=\"%zu\"/>\n", | |
5436 | sizes[i].from, sizes[i].to, sizes[i].total, sizes[i].count); | |
fdfd175d | 5437 | |
987c0269 OB |
5438 | if (sizes[NFASTBINS].count != 0) |
5439 | fprintf (fp, "\ | |
5440 | <unsorted from=\"%zu\" to=\"%zu\" total=\"%zu\" count=\"%zu\"/>\n", | |
5441 | sizes[NFASTBINS].from, sizes[NFASTBINS].to, | |
5442 | sizes[NFASTBINS].total, sizes[NFASTBINS].count); | |
fdfd175d | 5443 | |
987c0269 OB |
5444 | total_system += ar_ptr->system_mem; |
5445 | total_max_system += ar_ptr->max_system_mem; | |
bb066545 | 5446 | |
987c0269 OB |
5447 | fprintf (fp, |
5448 | "</sizes>\n<total type=\"fast\" count=\"%zu\" size=\"%zu\"/>\n" | |
5449 | "<total type=\"rest\" count=\"%zu\" size=\"%zu\"/>\n" | |
5450 | "<system type=\"current\" size=\"%zu\"/>\n" | |
5451 | "<system type=\"max\" size=\"%zu\"/>\n", | |
5452 | nfastblocks, fastavail, nblocks, avail, | |
5453 | ar_ptr->system_mem, ar_ptr->max_system_mem); | |
346bc35c | 5454 | |
987c0269 OB |
5455 | if (ar_ptr != &main_arena) |
5456 | { | |
5457 | heap_info *heap = heap_for_ptr (top (ar_ptr)); | |
5458 | fprintf (fp, | |
5459 | "<aspace type=\"total\" size=\"%zu\"/>\n" | |
5460 | "<aspace type=\"mprotect\" size=\"%zu\"/>\n", | |
5461 | heap->size, heap->mprotect_size); | |
5462 | total_aspace += heap->size; | |
5463 | total_aspace_mprotect += heap->mprotect_size; | |
5464 | } | |
5465 | else | |
5466 | { | |
5467 | fprintf (fp, | |
5468 | "<aspace type=\"total\" size=\"%zu\"/>\n" | |
5469 | "<aspace type=\"mprotect\" size=\"%zu\"/>\n", | |
5470 | ar_ptr->system_mem, ar_ptr->system_mem); | |
5471 | total_aspace += ar_ptr->system_mem; | |
5472 | total_aspace_mprotect += ar_ptr->system_mem; | |
5473 | } | |
bb066545 | 5474 | |
987c0269 | 5475 | fputs ("</heap>\n", fp); |
bb066545 UD |
5476 | ar_ptr = ar_ptr->next; |
5477 | } | |
5478 | while (ar_ptr != &main_arena); | |
5479 | ||
5480 | fprintf (fp, | |
62a58816 SP |
5481 | "<total type=\"fast\" count=\"%zu\" size=\"%zu\"/>\n" |
5482 | "<total type=\"rest\" count=\"%zu\" size=\"%zu\"/>\n" | |
9fa76613 | 5483 | "<total type=\"mmap\" count=\"%d\" size=\"%zu\"/>\n" |
62a58816 SP |
5484 | "<system type=\"current\" size=\"%zu\"/>\n" |
5485 | "<system type=\"max\" size=\"%zu\"/>\n" | |
5486 | "<aspace type=\"total\" size=\"%zu\"/>\n" | |
5487 | "<aspace type=\"mprotect\" size=\"%zu\"/>\n" | |
5488 | "</malloc>\n", | |
5489 | total_nfastblocks, total_fastavail, total_nblocks, total_avail, | |
4d653a59 | 5490 | mp_.n_mmaps, mp_.mmapped_mem, |
62a58816 SP |
5491 | total_system, total_max_system, |
5492 | total_aspace, total_aspace_mprotect); | |
bb066545 UD |
5493 | |
5494 | return 0; | |
5495 | } | |
c52ff39e | 5496 | weak_alias (__malloc_info, malloc_info) |
bb066545 UD |
5497 | |
5498 | ||
eba19d2b | 5499 | strong_alias (__libc_calloc, __calloc) weak_alias (__libc_calloc, calloc) |
eba19d2b UD |
5500 | strong_alias (__libc_free, __free) strong_alias (__libc_free, free) |
5501 | strong_alias (__libc_malloc, __malloc) strong_alias (__libc_malloc, malloc) | |
5502 | strong_alias (__libc_memalign, __memalign) | |
5503 | weak_alias (__libc_memalign, memalign) | |
5504 | strong_alias (__libc_realloc, __realloc) strong_alias (__libc_realloc, realloc) | |
5505 | strong_alias (__libc_valloc, __valloc) weak_alias (__libc_valloc, valloc) | |
5506 | strong_alias (__libc_pvalloc, __pvalloc) weak_alias (__libc_pvalloc, pvalloc) | |
5507 | strong_alias (__libc_mallinfo, __mallinfo) | |
5508 | weak_alias (__libc_mallinfo, mallinfo) | |
5509 | strong_alias (__libc_mallopt, __mallopt) weak_alias (__libc_mallopt, mallopt) | |
7e3be507 UD |
5510 | |
5511 | weak_alias (__malloc_stats, malloc_stats) | |
5512 | weak_alias (__malloc_usable_size, malloc_usable_size) | |
5513 | weak_alias (__malloc_trim, malloc_trim) | |
7e3be507 | 5514 | |
025b33ae FW |
5515 | #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_26) |
5516 | compat_symbol (libc, __libc_free, cfree, GLIBC_2_0); | |
5517 | #endif | |
f65fd747 | 5518 | |
fa8d436c | 5519 | /* ------------------------------------------------------------ |
6c8dbf00 | 5520 | History: |
f65fd747 | 5521 | |
6c8dbf00 | 5522 | [see ftp://g.oswego.edu/pub/misc/malloc.c for the history of dlmalloc] |
f65fd747 | 5523 | |
6c8dbf00 | 5524 | */ |
fa8d436c UD |
5525 | /* |
5526 | * Local variables: | |
5527 | * c-basic-offset: 2 | |
5528 | * End: | |
5529 | */ |