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1 | /* |
2 | This is a version (aka dlmalloc) of malloc/free/realloc written by | |
3 | Doug Lea and released to the public domain, as explained at | |
4 | http://creativecommons.org/licenses/publicdomain. Send questions, | |
5 | comments, complaints, performance data, etc to dl@cs.oswego.edu | |
6 | ||
7 | * Version 2.8.3 Thu Sep 22 11:16:15 2005 Doug Lea (dl at gee) | |
8 | ||
9 | Note: There may be an updated version of this malloc obtainable at | |
10 | ftp://gee.cs.oswego.edu/pub/misc/malloc.c | |
11 | Check before installing! | |
12 | ||
13 | * Quickstart | |
14 | ||
15 | This library is all in one file to simplify the most common usage: | |
16 | ftp it, compile it (-O3), and link it into another program. All of | |
17 | the compile-time options default to reasonable values for use on | |
18 | most platforms. You might later want to step through various | |
19 | compile-time and dynamic tuning options. | |
20 | ||
21 | For convenience, an include file for code using this malloc is at: | |
22 | ftp://gee.cs.oswego.edu/pub/misc/malloc-2.8.3.h | |
23 | You don't really need this .h file unless you call functions not | |
24 | defined in your system include files. The .h file contains only the | |
25 | excerpts from this file needed for using this malloc on ANSI C/C++ | |
26 | systems, so long as you haven't changed compile-time options about | |
27 | naming and tuning parameters. If you do, then you can create your | |
28 | own malloc.h that does include all settings by cutting at the point | |
29 | indicated below. Note that you may already by default be using a C | |
30 | library containing a malloc that is based on some version of this | |
31 | malloc (for example in linux). You might still want to use the one | |
32 | in this file to customize settings or to avoid overheads associated | |
33 | with library versions. | |
34 | ||
35 | * Vital statistics: | |
36 | ||
37 | Supported pointer/size_t representation: 4 or 8 bytes | |
38 | size_t MUST be an unsigned type of the same width as | |
39 | pointers. (If you are using an ancient system that declares | |
40 | size_t as a signed type, or need it to be a different width | |
41 | than pointers, you can use a previous release of this malloc | |
42 | (e.g. 2.7.2) supporting these.) | |
43 | ||
44 | Alignment: 8 bytes (default) | |
45 | This suffices for nearly all current machines and C compilers. | |
46 | However, you can define MALLOC_ALIGNMENT to be wider than this | |
47 | if necessary (up to 128bytes), at the expense of using more space. | |
48 | ||
49 | Minimum overhead per allocated chunk: 4 or 8 bytes (if 4byte sizes) | |
50 | 8 or 16 bytes (if 8byte sizes) | |
51 | Each malloced chunk has a hidden word of overhead holding size | |
52 | and status information, and additional cross-check word | |
53 | if FOOTERS is defined. | |
54 | ||
55 | Minimum allocated size: 4-byte ptrs: 16 bytes (including overhead) | |
56 | 8-byte ptrs: 32 bytes (including overhead) | |
57 | ||
58 | Even a request for zero bytes (i.e., malloc(0)) returns a | |
59 | pointer to something of the minimum allocatable size. | |
60 | The maximum overhead wastage (i.e., number of extra bytes | |
61 | allocated than were requested in malloc) is less than or equal | |
62 | to the minimum size, except for requests >= mmap_threshold that | |
63 | are serviced via mmap(), where the worst case wastage is about | |
64 | 32 bytes plus the remainder from a system page (the minimal | |
65 | mmap unit); typically 4096 or 8192 bytes. | |
66 | ||
67 | Security: static-safe; optionally more or less | |
68 | The "security" of malloc refers to the ability of malicious | |
69 | code to accentuate the effects of errors (for example, freeing | |
70 | space that is not currently malloc'ed or overwriting past the | |
71 | ends of chunks) in code that calls malloc. This malloc | |
72 | guarantees not to modify any memory locations below the base of | |
73 | heap, i.e., static variables, even in the presence of usage | |
74 | errors. The routines additionally detect most improper frees | |
75 | and reallocs. All this holds as long as the static bookkeeping | |
76 | for malloc itself is not corrupted by some other means. This | |
77 | is only one aspect of security -- these checks do not, and | |
78 | cannot, detect all possible programming errors. | |
79 | ||
80 | If FOOTERS is defined nonzero, then each allocated chunk | |
81 | carries an additional check word to verify that it was malloced | |
82 | from its space. These check words are the same within each | |
83 | execution of a program using malloc, but differ across | |
84 | executions, so externally crafted fake chunks cannot be | |
85 | freed. This improves security by rejecting frees/reallocs that | |
86 | could corrupt heap memory, in addition to the checks preventing | |
87 | writes to statics that are always on. This may further improve | |
88 | security at the expense of time and space overhead. (Note that | |
89 | FOOTERS may also be worth using with MSPACES.) | |
90 | ||
91 | By default detected errors cause the program to abort (calling | |
92 | "abort()"). You can override this to instead proceed past | |
93 | errors by defining PROCEED_ON_ERROR. In this case, a bad free | |
94 | has no effect, and a malloc that encounters a bad address | |
95 | caused by user overwrites will ignore the bad address by | |
96 | dropping pointers and indices to all known memory. This may | |
97 | be appropriate for programs that should continue if at all | |
98 | possible in the face of programming errors, although they may | |
99 | run out of memory because dropped memory is never reclaimed. | |
100 | ||
101 | If you don't like either of these options, you can define | |
102 | CORRUPTION_ERROR_ACTION and USAGE_ERROR_ACTION to do anything | |
103 | else. And if if you are sure that your program using malloc has | |
104 | no errors or vulnerabilities, you can define INSECURE to 1, | |
105 | which might (or might not) provide a small performance improvement. | |
106 | ||
107 | Thread-safety: NOT thread-safe unless USE_LOCKS defined | |
108 | When USE_LOCKS is defined, each public call to malloc, free, | |
109 | etc is surrounded with either a pthread mutex or a win32 | |
110 | spinlock (depending on WIN32). This is not especially fast, and | |
111 | can be a major bottleneck. It is designed only to provide | |
112 | minimal protection in concurrent environments, and to provide a | |
113 | basis for extensions. If you are using malloc in a concurrent | |
114 | program, consider instead using ptmalloc, which is derived from | |
115 | a version of this malloc. (See http://www.malloc.de). | |
116 | ||
117 | System requirements: Any combination of MORECORE and/or MMAP/MUNMAP | |
118 | This malloc can use unix sbrk or any emulation (invoked using | |
119 | the CALL_MORECORE macro) and/or mmap/munmap or any emulation | |
120 | (invoked using CALL_MMAP/CALL_MUNMAP) to get and release system | |
121 | memory. On most unix systems, it tends to work best if both | |
122 | MORECORE and MMAP are enabled. On Win32, it uses emulations | |
123 | based on VirtualAlloc. It also uses common C library functions | |
124 | like memset. | |
125 | ||
126 | Compliance: I believe it is compliant with the Single Unix Specification | |
127 | (See http://www.unix.org). Also SVID/XPG, ANSI C, and probably | |
128 | others as well. | |
129 | ||
130 | * Overview of algorithms | |
131 | ||
132 | This is not the fastest, most space-conserving, most portable, or | |
133 | most tunable malloc ever written. However it is among the fastest | |
134 | while also being among the most space-conserving, portable and | |
135 | tunable. Consistent balance across these factors results in a good | |
136 | general-purpose allocator for malloc-intensive programs. | |
137 | ||
138 | In most ways, this malloc is a best-fit allocator. Generally, it | |
139 | chooses the best-fitting existing chunk for a request, with ties | |
140 | broken in approximately least-recently-used order. (This strategy | |
141 | normally maintains low fragmentation.) However, for requests less | |
142 | than 256bytes, it deviates from best-fit when there is not an | |
143 | exactly fitting available chunk by preferring to use space adjacent | |
144 | to that used for the previous small request, as well as by breaking | |
145 | ties in approximately most-recently-used order. (These enhance | |
146 | locality of series of small allocations.) And for very large requests | |
147 | (>= 256Kb by default), it relies on system memory mapping | |
148 | facilities, if supported. (This helps avoid carrying around and | |
149 | possibly fragmenting memory used only for large chunks.) | |
150 | ||
151 | All operations (except malloc_stats and mallinfo) have execution | |
152 | times that are bounded by a constant factor of the number of bits in | |
153 | a size_t, not counting any clearing in calloc or copying in realloc, | |
154 | or actions surrounding MORECORE and MMAP that have times | |
155 | proportional to the number of non-contiguous regions returned by | |
156 | system allocation routines, which is often just 1. | |
157 | ||
158 | The implementation is not very modular and seriously overuses | |
159 | macros. Perhaps someday all C compilers will do as good a job | |
160 | inlining modular code as can now be done by brute-force expansion, | |
161 | but now, enough of them seem not to. | |
162 | ||
163 | Some compilers issue a lot of warnings about code that is | |
164 | dead/unreachable only on some platforms, and also about intentional | |
165 | uses of negation on unsigned types. All known cases of each can be | |
166 | ignored. | |
167 | ||
168 | For a longer but out of date high-level description, see | |
169 | http://gee.cs.oswego.edu/dl/html/malloc.html | |
170 | ||
171 | * MSPACES | |
172 | If MSPACES is defined, then in addition to malloc, free, etc., | |
173 | this file also defines mspace_malloc, mspace_free, etc. These | |
174 | are versions of malloc routines that take an "mspace" argument | |
175 | obtained using create_mspace, to control all internal bookkeeping. | |
176 | If ONLY_MSPACES is defined, only these versions are compiled. | |
177 | So if you would like to use this allocator for only some allocations, | |
178 | and your system malloc for others, you can compile with | |
179 | ONLY_MSPACES and then do something like... | |
180 | static mspace mymspace = create_mspace(0,0); // for example | |
181 | #define mymalloc(bytes) mspace_malloc(mymspace, bytes) | |
182 | ||
183 | (Note: If you only need one instance of an mspace, you can instead | |
184 | use "USE_DL_PREFIX" to relabel the global malloc.) | |
185 | ||
186 | You can similarly create thread-local allocators by storing | |
187 | mspaces as thread-locals. For example: | |
188 | static __thread mspace tlms = 0; | |
189 | void* tlmalloc(size_t bytes) { | |
190 | if (tlms == 0) tlms = create_mspace(0, 0); | |
191 | return mspace_malloc(tlms, bytes); | |
192 | } | |
193 | void tlfree(void* mem) { mspace_free(tlms, mem); } | |
194 | ||
195 | Unless FOOTERS is defined, each mspace is completely independent. | |
196 | You cannot allocate from one and free to another (although | |
197 | conformance is only weakly checked, so usage errors are not always | |
198 | caught). If FOOTERS is defined, then each chunk carries around a tag | |
199 | indicating its originating mspace, and frees are directed to their | |
200 | originating spaces. | |
201 | ||
202 | ------------------------- Compile-time options --------------------------- | |
203 | ||
204 | Be careful in setting #define values for numerical constants of type | |
205 | size_t. On some systems, literal values are not automatically extended | |
206 | to size_t precision unless they are explicitly casted. | |
207 | ||
208 | WIN32 default: defined if _WIN32 defined | |
209 | Defining WIN32 sets up defaults for MS environment and compilers. | |
210 | Otherwise defaults are for unix. | |
211 | ||
212 | MALLOC_ALIGNMENT default: (size_t)8 | |
213 | Controls the minimum alignment for malloc'ed chunks. It must be a | |
214 | power of two and at least 8, even on machines for which smaller | |
215 | alignments would suffice. It may be defined as larger than this | |
216 | though. Note however that code and data structures are optimized for | |
217 | the case of 8-byte alignment. | |
218 | ||
219 | MSPACES default: 0 (false) | |
220 | If true, compile in support for independent allocation spaces. | |
221 | This is only supported if HAVE_MMAP is true. | |
222 | ||
223 | ONLY_MSPACES default: 0 (false) | |
224 | If true, only compile in mspace versions, not regular versions. | |
225 | ||
226 | USE_LOCKS default: 0 (false) | |
227 | Causes each call to each public routine to be surrounded with | |
228 | pthread or WIN32 mutex lock/unlock. (If set true, this can be | |
229 | overridden on a per-mspace basis for mspace versions.) | |
230 | ||
231 | FOOTERS default: 0 | |
232 | If true, provide extra checking and dispatching by placing | |
233 | information in the footers of allocated chunks. This adds | |
234 | space and time overhead. | |
235 | ||
236 | INSECURE default: 0 | |
237 | If true, omit checks for usage errors and heap space overwrites. | |
238 | ||
239 | USE_DL_PREFIX default: NOT defined | |
240 | Causes compiler to prefix all public routines with the string 'dl'. | |
241 | This can be useful when you only want to use this malloc in one part | |
242 | of a program, using your regular system malloc elsewhere. | |
243 | ||
244 | ABORT default: defined as abort() | |
245 | Defines how to abort on failed checks. On most systems, a failed | |
246 | check cannot die with an "assert" or even print an informative | |
247 | message, because the underlying print routines in turn call malloc, | |
248 | which will fail again. Generally, the best policy is to simply call | |
249 | abort(). It's not very useful to do more than this because many | |
250 | errors due to overwriting will show up as address faults (null, odd | |
251 | addresses etc) rather than malloc-triggered checks, so will also | |
252 | abort. Also, most compilers know that abort() does not return, so | |
253 | can better optimize code conditionally calling it. | |
254 | ||
255 | PROCEED_ON_ERROR default: defined as 0 (false) | |
256 | Controls whether detected bad addresses cause them to bypassed | |
257 | rather than aborting. If set, detected bad arguments to free and | |
258 | realloc are ignored. And all bookkeeping information is zeroed out | |
259 | upon a detected overwrite of freed heap space, thus losing the | |
260 | ability to ever return it from malloc again, but enabling the | |
261 | application to proceed. If PROCEED_ON_ERROR is defined, the | |
262 | static variable malloc_corruption_error_count is compiled in | |
263 | and can be examined to see if errors have occurred. This option | |
264 | generates slower code than the default abort policy. | |
265 | ||
266 | DEBUG default: NOT defined | |
267 | The DEBUG setting is mainly intended for people trying to modify | |
268 | this code or diagnose problems when porting to new platforms. | |
269 | However, it may also be able to better isolate user errors than just | |
270 | using runtime checks. The assertions in the check routines spell | |
271 | out in more detail the assumptions and invariants underlying the | |
272 | algorithms. The checking is fairly extensive, and will slow down | |
273 | execution noticeably. Calling malloc_stats or mallinfo with DEBUG | |
274 | set will attempt to check every non-mmapped allocated and free chunk | |
275 | in the course of computing the summaries. | |
276 | ||
277 | ABORT_ON_ASSERT_FAILURE default: defined as 1 (true) | |
278 | Debugging assertion failures can be nearly impossible if your | |
279 | version of the assert macro causes malloc to be called, which will | |
280 | lead to a cascade of further failures, blowing the runtime stack. | |
281 | ABORT_ON_ASSERT_FAILURE cause assertions failures to call abort(), | |
282 | which will usually make debugging easier. | |
283 | ||
284 | MALLOC_FAILURE_ACTION default: sets errno to ENOMEM, or no-op on win32 | |
285 | The action to take before "return 0" when malloc fails to be able to | |
286 | return memory because there is none available. | |
287 | ||
288 | HAVE_MORECORE default: 1 (true) unless win32 or ONLY_MSPACES | |
289 | True if this system supports sbrk or an emulation of it. | |
290 | ||
291 | MORECORE default: sbrk | |
292 | The name of the sbrk-style system routine to call to obtain more | |
293 | memory. See below for guidance on writing custom MORECORE | |
294 | functions. The type of the argument to sbrk/MORECORE varies across | |
295 | systems. It cannot be size_t, because it supports negative | |
296 | arguments, so it is normally the signed type of the same width as | |
297 | size_t (sometimes declared as "intptr_t"). It doesn't much matter | |
298 | though. Internally, we only call it with arguments less than half | |
299 | the max value of a size_t, which should work across all reasonable | |
300 | possibilities, although sometimes generating compiler warnings. See | |
301 | near the end of this file for guidelines for creating a custom | |
302 | version of MORECORE. | |
303 | ||
304 | MORECORE_CONTIGUOUS default: 1 (true) | |
305 | If true, take advantage of fact that consecutive calls to MORECORE | |
306 | with positive arguments always return contiguous increasing | |
307 | addresses. This is true of unix sbrk. It does not hurt too much to | |
308 | set it true anyway, since malloc copes with non-contiguities. | |
309 | Setting it false when definitely non-contiguous saves time | |
310 | and possibly wasted space it would take to discover this though. | |
311 | ||
312 | MORECORE_CANNOT_TRIM default: NOT defined | |
313 | True if MORECORE cannot release space back to the system when given | |
314 | negative arguments. This is generally necessary only if you are | |
315 | using a hand-crafted MORECORE function that cannot handle negative | |
316 | arguments. | |
317 | ||
318 | HAVE_MMAP default: 1 (true) | |
319 | True if this system supports mmap or an emulation of it. If so, and | |
320 | HAVE_MORECORE is not true, MMAP is used for all system | |
321 | allocation. If set and HAVE_MORECORE is true as well, MMAP is | |
322 | primarily used to directly allocate very large blocks. It is also | |
323 | used as a backup strategy in cases where MORECORE fails to provide | |
324 | space from system. Note: A single call to MUNMAP is assumed to be | |
325 | able to unmap memory that may have be allocated using multiple calls | |
326 | to MMAP, so long as they are adjacent. | |
327 | ||
328 | HAVE_MREMAP default: 1 on linux, else 0 | |
329 | If true realloc() uses mremap() to re-allocate large blocks and | |
330 | extend or shrink allocation spaces. | |
331 | ||
332 | MMAP_CLEARS default: 1 on unix | |
333 | True if mmap clears memory so calloc doesn't need to. This is true | |
334 | for standard unix mmap using /dev/zero. | |
335 | ||
336 | USE_BUILTIN_FFS default: 0 (i.e., not used) | |
337 | Causes malloc to use the builtin ffs() function to compute indices. | |
338 | Some compilers may recognize and intrinsify ffs to be faster than the | |
339 | supplied C version. Also, the case of x86 using gcc is special-cased | |
340 | to an asm instruction, so is already as fast as it can be, and so | |
341 | this setting has no effect. (On most x86s, the asm version is only | |
342 | slightly faster than the C version.) | |
343 | ||
344 | malloc_getpagesize default: derive from system includes, or 4096. | |
345 | The system page size. To the extent possible, this malloc manages | |
346 | memory from the system in page-size units. This may be (and | |
347 | usually is) a function rather than a constant. This is ignored | |
348 | if WIN32, where page size is determined using getSystemInfo during | |
349 | initialization. | |
350 | ||
351 | USE_DEV_RANDOM default: 0 (i.e., not used) | |
352 | Causes malloc to use /dev/random to initialize secure magic seed for | |
353 | stamping footers. Otherwise, the current time is used. | |
354 | ||
355 | NO_MALLINFO default: 0 | |
356 | If defined, don't compile "mallinfo". This can be a simple way | |
357 | of dealing with mismatches between system declarations and | |
358 | those in this file. | |
359 | ||
360 | MALLINFO_FIELD_TYPE default: size_t | |
361 | The type of the fields in the mallinfo struct. This was originally | |
362 | defined as "int" in SVID etc, but is more usefully defined as | |
363 | size_t. The value is used only if HAVE_USR_INCLUDE_MALLOC_H is not set | |
364 | ||
365 | REALLOC_ZERO_BYTES_FREES default: not defined | |
366 | This should be set if a call to realloc with zero bytes should | |
367 | be the same as a call to free. Some people think it should. Otherwise, | |
368 | since this malloc returns a unique pointer for malloc(0), so does | |
369 | realloc(p, 0). | |
370 | ||
371 | LACKS_UNISTD_H, LACKS_FCNTL_H, LACKS_SYS_PARAM_H, LACKS_SYS_MMAN_H | |
372 | LACKS_STRINGS_H, LACKS_STRING_H, LACKS_SYS_TYPES_H, LACKS_ERRNO_H | |
373 | LACKS_STDLIB_H default: NOT defined unless on WIN32 | |
374 | Define these if your system does not have these header files. | |
375 | You might need to manually insert some of the declarations they provide. | |
376 | ||
377 | DEFAULT_GRANULARITY default: page size if MORECORE_CONTIGUOUS, | |
378 | system_info.dwAllocationGranularity in WIN32, | |
379 | otherwise 64K. | |
380 | Also settable using mallopt(M_GRANULARITY, x) | |
381 | The unit for allocating and deallocating memory from the system. On | |
382 | most systems with contiguous MORECORE, there is no reason to | |
383 | make this more than a page. However, systems with MMAP tend to | |
384 | either require or encourage larger granularities. You can increase | |
385 | this value to prevent system allocation functions to be called so | |
386 | often, especially if they are slow. The value must be at least one | |
387 | page and must be a power of two. Setting to 0 causes initialization | |
388 | to either page size or win32 region size. (Note: In previous | |
389 | versions of malloc, the equivalent of this option was called | |
390 | "TOP_PAD") | |
391 | ||
392 | DEFAULT_TRIM_THRESHOLD default: 2MB | |
393 | Also settable using mallopt(M_TRIM_THRESHOLD, x) | |
394 | The maximum amount of unused top-most memory to keep before | |
395 | releasing via malloc_trim in free(). Automatic trimming is mainly | |
396 | useful in long-lived programs using contiguous MORECORE. Because | |
397 | trimming via sbrk can be slow on some systems, and can sometimes be | |
398 | wasteful (in cases where programs immediately afterward allocate | |
399 | more large chunks) the value should be high enough so that your | |
400 | overall system performance would improve by releasing this much | |
401 | memory. As a rough guide, you might set to a value close to the | |
402 | average size of a process (program) running on your system. | |
403 | Releasing this much memory would allow such a process to run in | |
404 | memory. Generally, it is worth tuning trim thresholds when a | |
405 | program undergoes phases where several large chunks are allocated | |
406 | and released in ways that can reuse each other's storage, perhaps | |
407 | mixed with phases where there are no such chunks at all. The trim | |
408 | value must be greater than page size to have any useful effect. To | |
409 | disable trimming completely, you can set to MAX_SIZE_T. Note that the trick | |
410 | some people use of mallocing a huge space and then freeing it at | |
411 | program startup, in an attempt to reserve system memory, doesn't | |
412 | have the intended effect under automatic trimming, since that memory | |
413 | will immediately be returned to the system. | |
414 | ||
415 | DEFAULT_MMAP_THRESHOLD default: 256K | |
416 | Also settable using mallopt(M_MMAP_THRESHOLD, x) | |
417 | The request size threshold for using MMAP to directly service a | |
418 | request. Requests of at least this size that cannot be allocated | |
419 | using already-existing space will be serviced via mmap. (If enough | |
420 | normal freed space already exists it is used instead.) Using mmap | |
421 | segregates relatively large chunks of memory so that they can be | |
422 | individually obtained and released from the host system. A request | |
423 | serviced through mmap is never reused by any other request (at least | |
424 | not directly; the system may just so happen to remap successive | |
425 | requests to the same locations). Segregating space in this way has | |
426 | the benefits that: Mmapped space can always be individually released | |
427 | back to the system, which helps keep the system level memory demands | |
428 | of a long-lived program low. Also, mapped memory doesn't become | |
429 | `locked' between other chunks, as can happen with normally allocated | |
430 | chunks, which means that even trimming via malloc_trim would not | |
431 | release them. However, it has the disadvantage that the space | |
432 | cannot be reclaimed, consolidated, and then used to service later | |
433 | requests, as happens with normal chunks. The advantages of mmap | |
434 | nearly always outweigh disadvantages for "large" chunks, but the | |
435 | value of "large" may vary across systems. The default is an | |
436 | empirically derived value that works well in most systems. You can | |
437 | disable mmap by setting to MAX_SIZE_T. | |
438 | ||
439 | */ | |
440 | ||
441 | #ifndef WIN32 | |
442 | #ifdef _WIN32 | |
443 | #define WIN32 1 | |
444 | #endif /* _WIN32 */ | |
445 | #endif /* WIN32 */ | |
446 | #ifdef WIN32 | |
447 | #define WIN32_LEAN_AND_MEAN | |
448 | #include <windows.h> | |
449 | #define HAVE_MMAP 1 | |
450 | #define HAVE_MORECORE 0 | |
451 | #define LACKS_UNISTD_H | |
452 | #define LACKS_SYS_PARAM_H | |
453 | #define LACKS_SYS_MMAN_H | |
454 | #define LACKS_STRING_H | |
455 | #define LACKS_STRINGS_H | |
456 | #define LACKS_SYS_TYPES_H | |
457 | #define LACKS_ERRNO_H | |
458 | #define MALLOC_FAILURE_ACTION | |
459 | #define MMAP_CLEARS 0 /* WINCE and some others apparently don't clear */ | |
460 | #endif /* WIN32 */ | |
461 | ||
462 | #if defined(DARWIN) || defined(_DARWIN) | |
463 | /* Mac OSX docs advise not to use sbrk; it seems better to use mmap */ | |
464 | #ifndef HAVE_MORECORE | |
465 | #define HAVE_MORECORE 0 | |
466 | #define HAVE_MMAP 1 | |
467 | #endif /* HAVE_MORECORE */ | |
468 | #endif /* DARWIN */ | |
469 | ||
470 | #ifndef LACKS_SYS_TYPES_H | |
471 | #include <sys/types.h> /* For size_t */ | |
472 | #endif /* LACKS_SYS_TYPES_H */ | |
473 | ||
474 | /* The maximum possible size_t value has all bits set */ | |
475 | #define MAX_SIZE_T (~(size_t)0) | |
476 | ||
477 | #ifndef ONLY_MSPACES | |
478 | #define ONLY_MSPACES 0 | |
479 | #endif /* ONLY_MSPACES */ | |
480 | #ifndef MSPACES | |
481 | #if ONLY_MSPACES | |
482 | #define MSPACES 1 | |
483 | #else /* ONLY_MSPACES */ | |
484 | #define MSPACES 0 | |
485 | #endif /* ONLY_MSPACES */ | |
486 | #endif /* MSPACES */ | |
487 | #ifndef MALLOC_ALIGNMENT | |
488 | #define MALLOC_ALIGNMENT ((size_t)8U) | |
489 | #endif /* MALLOC_ALIGNMENT */ | |
490 | #ifndef FOOTERS | |
491 | #define FOOTERS 0 | |
492 | #endif /* FOOTERS */ | |
493 | #ifndef ABORT | |
494 | #define ABORT abort() | |
495 | #endif /* ABORT */ | |
496 | #ifndef ABORT_ON_ASSERT_FAILURE | |
497 | #define ABORT_ON_ASSERT_FAILURE 1 | |
498 | #endif /* ABORT_ON_ASSERT_FAILURE */ | |
499 | #ifndef PROCEED_ON_ERROR | |
500 | #define PROCEED_ON_ERROR 0 | |
501 | #endif /* PROCEED_ON_ERROR */ | |
502 | #ifndef USE_LOCKS | |
503 | #define USE_LOCKS 0 | |
504 | #endif /* USE_LOCKS */ | |
505 | #ifndef INSECURE | |
506 | #define INSECURE 0 | |
507 | #endif /* INSECURE */ | |
508 | #ifndef HAVE_MMAP | |
509 | #define HAVE_MMAP 1 | |
510 | #endif /* HAVE_MMAP */ | |
511 | #ifndef MMAP_CLEARS | |
512 | #define MMAP_CLEARS 1 | |
513 | #endif /* MMAP_CLEARS */ | |
514 | #ifndef HAVE_MREMAP | |
515 | #ifdef linux | |
516 | #define HAVE_MREMAP 1 | |
517 | #else /* linux */ | |
518 | #define HAVE_MREMAP 0 | |
519 | #endif /* linux */ | |
520 | #endif /* HAVE_MREMAP */ | |
521 | #ifndef MALLOC_FAILURE_ACTION | |
522 | #define MALLOC_FAILURE_ACTION errno = ENOMEM; | |
523 | #endif /* MALLOC_FAILURE_ACTION */ | |
524 | #ifndef HAVE_MORECORE | |
525 | #if ONLY_MSPACES | |
526 | #define HAVE_MORECORE 0 | |
527 | #else /* ONLY_MSPACES */ | |
528 | #define HAVE_MORECORE 1 | |
529 | #endif /* ONLY_MSPACES */ | |
530 | #endif /* HAVE_MORECORE */ | |
531 | #if !HAVE_MORECORE | |
532 | #define MORECORE_CONTIGUOUS 0 | |
533 | #else /* !HAVE_MORECORE */ | |
534 | #ifndef MORECORE | |
535 | #define MORECORE sbrk | |
536 | #endif /* MORECORE */ | |
537 | #ifndef MORECORE_CONTIGUOUS | |
538 | #define MORECORE_CONTIGUOUS 1 | |
539 | #endif /* MORECORE_CONTIGUOUS */ | |
540 | #endif /* HAVE_MORECORE */ | |
541 | #ifndef DEFAULT_GRANULARITY | |
542 | #if MORECORE_CONTIGUOUS | |
543 | #define DEFAULT_GRANULARITY (0) /* 0 means to compute in init_mparams */ | |
544 | #else /* MORECORE_CONTIGUOUS */ | |
545 | #define DEFAULT_GRANULARITY ((size_t)64U * (size_t)1024U) | |
546 | #endif /* MORECORE_CONTIGUOUS */ | |
547 | #endif /* DEFAULT_GRANULARITY */ | |
548 | #ifndef DEFAULT_TRIM_THRESHOLD | |
549 | #ifndef MORECORE_CANNOT_TRIM | |
550 | #define DEFAULT_TRIM_THRESHOLD ((size_t)2U * (size_t)1024U * (size_t)1024U) | |
551 | #else /* MORECORE_CANNOT_TRIM */ | |
552 | #define DEFAULT_TRIM_THRESHOLD MAX_SIZE_T | |
553 | #endif /* MORECORE_CANNOT_TRIM */ | |
554 | #endif /* DEFAULT_TRIM_THRESHOLD */ | |
555 | #ifndef DEFAULT_MMAP_THRESHOLD | |
556 | #if HAVE_MMAP | |
557 | #define DEFAULT_MMAP_THRESHOLD ((size_t)256U * (size_t)1024U) | |
558 | #else /* HAVE_MMAP */ | |
559 | #define DEFAULT_MMAP_THRESHOLD MAX_SIZE_T | |
560 | #endif /* HAVE_MMAP */ | |
561 | #endif /* DEFAULT_MMAP_THRESHOLD */ | |
562 | #ifndef USE_BUILTIN_FFS | |
563 | #define USE_BUILTIN_FFS 0 | |
564 | #endif /* USE_BUILTIN_FFS */ | |
565 | #ifndef USE_DEV_RANDOM | |
566 | #define USE_DEV_RANDOM 0 | |
567 | #endif /* USE_DEV_RANDOM */ | |
568 | #ifndef NO_MALLINFO | |
569 | #define NO_MALLINFO 0 | |
570 | #endif /* NO_MALLINFO */ | |
571 | #ifndef MALLINFO_FIELD_TYPE | |
572 | #define MALLINFO_FIELD_TYPE size_t | |
573 | #endif /* MALLINFO_FIELD_TYPE */ | |
574 | ||
575 | /* | |
576 | mallopt tuning options. SVID/XPG defines four standard parameter | |
577 | numbers for mallopt, normally defined in malloc.h. None of these | |
578 | are used in this malloc, so setting them has no effect. But this | |
579 | malloc does support the following options. | |
580 | */ | |
581 | ||
582 | #define M_TRIM_THRESHOLD (-1) | |
583 | #define M_GRANULARITY (-2) | |
584 | #define M_MMAP_THRESHOLD (-3) | |
585 | ||
586 | /* ------------------------ Mallinfo declarations ------------------------ */ | |
587 | ||
588 | #if !NO_MALLINFO | |
589 | /* | |
590 | This version of malloc supports the standard SVID/XPG mallinfo | |
591 | routine that returns a struct containing usage properties and | |
592 | statistics. It should work on any system that has a | |
593 | /usr/include/malloc.h defining struct mallinfo. The main | |
594 | declaration needed is the mallinfo struct that is returned (by-copy) | |
595 | by mallinfo(). The malloinfo struct contains a bunch of fields that | |
596 | are not even meaningful in this version of malloc. These fields are | |
597 | are instead filled by mallinfo() with other numbers that might be of | |
598 | interest. | |
599 | ||
600 | HAVE_USR_INCLUDE_MALLOC_H should be set if you have a | |
601 | /usr/include/malloc.h file that includes a declaration of struct | |
602 | mallinfo. If so, it is included; else a compliant version is | |
603 | declared below. These must be precisely the same for mallinfo() to | |
604 | work. The original SVID version of this struct, defined on most | |
605 | systems with mallinfo, declares all fields as ints. But some others | |
606 | define as unsigned long. If your system defines the fields using a | |
607 | type of different width than listed here, you MUST #include your | |
608 | system version and #define HAVE_USR_INCLUDE_MALLOC_H. | |
609 | */ | |
610 | ||
611 | /* #define HAVE_USR_INCLUDE_MALLOC_H */ | |
612 | ||
613 | #ifdef HAVE_USR_INCLUDE_MALLOC_H | |
614 | #include "/usr/include/malloc.h" | |
615 | #else /* HAVE_USR_INCLUDE_MALLOC_H */ | |
616 | ||
617 | struct mallinfo { | |
618 | MALLINFO_FIELD_TYPE arena; /* non-mmapped space allocated from system */ | |
619 | MALLINFO_FIELD_TYPE ordblks; /* number of free chunks */ | |
620 | MALLINFO_FIELD_TYPE smblks; /* always 0 */ | |
621 | MALLINFO_FIELD_TYPE hblks; /* always 0 */ | |
622 | MALLINFO_FIELD_TYPE hblkhd; /* space in mmapped regions */ | |
623 | MALLINFO_FIELD_TYPE usmblks; /* maximum total allocated space */ | |
624 | MALLINFO_FIELD_TYPE fsmblks; /* always 0 */ | |
625 | MALLINFO_FIELD_TYPE uordblks; /* total allocated space */ | |
626 | MALLINFO_FIELD_TYPE fordblks; /* total free space */ | |
627 | MALLINFO_FIELD_TYPE keepcost; /* releasable (via malloc_trim) space */ | |
628 | }; | |
629 | ||
630 | #endif /* HAVE_USR_INCLUDE_MALLOC_H */ | |
631 | #endif /* NO_MALLINFO */ | |
632 | ||
633 | #ifdef __cplusplus | |
634 | extern "C" { | |
635 | #endif /* __cplusplus */ | |
636 | ||
637 | #if !ONLY_MSPACES | |
638 | ||
639 | /* ------------------- Declarations of public routines ------------------- */ | |
640 | ||
641 | #ifndef USE_DL_PREFIX | |
642 | #define dlcalloc calloc | |
643 | #define dlfree free | |
644 | #define dlmalloc malloc | |
645 | #define dlmemalign memalign | |
646 | #define dlrealloc realloc | |
647 | #define dlvalloc valloc | |
648 | #define dlpvalloc pvalloc | |
649 | #define dlmallinfo mallinfo | |
650 | #define dlmallopt mallopt | |
651 | #define dlmalloc_trim malloc_trim | |
652 | #define dlmalloc_stats malloc_stats | |
653 | #define dlmalloc_usable_size malloc_usable_size | |
654 | #define dlmalloc_footprint malloc_footprint | |
655 | #define dlmalloc_max_footprint malloc_max_footprint | |
656 | #define dlindependent_calloc independent_calloc | |
657 | #define dlindependent_comalloc independent_comalloc | |
658 | #endif /* USE_DL_PREFIX */ | |
659 | ||
660 | ||
661 | /* | |
662 | malloc(size_t n) | |
663 | Returns a pointer to a newly allocated chunk of at least n bytes, or | |
664 | null if no space is available, in which case errno is set to ENOMEM | |
665 | on ANSI C systems. | |
666 | ||
667 | If n is zero, malloc returns a minimum-sized chunk. (The minimum | |
668 | size is 16 bytes on most 32bit systems, and 32 bytes on 64bit | |
669 | systems.) Note that size_t is an unsigned type, so calls with | |
670 | arguments that would be negative if signed are interpreted as | |
671 | requests for huge amounts of space, which will often fail. The | |
672 | maximum supported value of n differs across systems, but is in all | |
673 | cases less than the maximum representable value of a size_t. | |
674 | */ | |
675 | void* dlmalloc(size_t); | |
676 | ||
677 | /* | |
678 | free(void* p) | |
679 | Releases the chunk of memory pointed to by p, that had been previously | |
680 | allocated using malloc or a related routine such as realloc. | |
681 | It has no effect if p is null. If p was not malloced or already | |
682 | freed, free(p) will by default cause the current program to abort. | |
683 | */ | |
684 | void dlfree(void*); | |
685 | ||
686 | /* | |
687 | calloc(size_t n_elements, size_t element_size); | |
688 | Returns a pointer to n_elements * element_size bytes, with all locations | |
689 | set to zero. | |
690 | */ | |
691 | void* dlcalloc(size_t, size_t); | |
692 | ||
693 | /* | |
694 | realloc(void* p, size_t n) | |
695 | Returns a pointer to a chunk of size n that contains the same data | |
696 | as does chunk p up to the minimum of (n, p's size) bytes, or null | |
697 | if no space is available. | |
698 | ||
699 | The returned pointer may or may not be the same as p. The algorithm | |
700 | prefers extending p in most cases when possible, otherwise it | |
701 | employs the equivalent of a malloc-copy-free sequence. | |
702 | ||
703 | If p is null, realloc is equivalent to malloc. | |
704 | ||
705 | If space is not available, realloc returns null, errno is set (if on | |
706 | ANSI) and p is NOT freed. | |
707 | ||
708 | if n is for fewer bytes than already held by p, the newly unused | |
709 | space is lopped off and freed if possible. realloc with a size | |
710 | argument of zero (re)allocates a minimum-sized chunk. | |
711 | ||
712 | The old unix realloc convention of allowing the last-free'd chunk | |
713 | to be used as an argument to realloc is not supported. | |
714 | */ | |
715 | ||
716 | void* dlrealloc(void*, size_t); | |
717 | ||
718 | /* | |
719 | memalign(size_t alignment, size_t n); | |
720 | Returns a pointer to a newly allocated chunk of n bytes, aligned | |
721 | in accord with the alignment argument. | |
722 | ||
723 | The alignment argument should be a power of two. If the argument is | |
724 | not a power of two, the nearest greater power is used. | |
725 | 8-byte alignment is guaranteed by normal malloc calls, so don't | |
726 | bother calling memalign with an argument of 8 or less. | |
727 | ||
728 | Overreliance on memalign is a sure way to fragment space. | |
729 | */ | |
730 | void* dlmemalign(size_t, size_t); | |
731 | ||
732 | /* | |
733 | valloc(size_t n); | |
734 | Equivalent to memalign(pagesize, n), where pagesize is the page | |
735 | size of the system. If the pagesize is unknown, 4096 is used. | |
736 | */ | |
737 | void* dlvalloc(size_t); | |
738 | ||
739 | /* | |
740 | mallopt(int parameter_number, int parameter_value) | |
741 | Sets tunable parameters The format is to provide a | |
742 | (parameter-number, parameter-value) pair. mallopt then sets the | |
743 | corresponding parameter to the argument value if it can (i.e., so | |
744 | long as the value is meaningful), and returns 1 if successful else | |
745 | 0. SVID/XPG/ANSI defines four standard param numbers for mallopt, | |
746 | normally defined in malloc.h. None of these are use in this malloc, | |
747 | so setting them has no effect. But this malloc also supports other | |
748 | options in mallopt. See below for details. Briefly, supported | |
749 | parameters are as follows (listed defaults are for "typical" | |
750 | configurations). | |
751 | ||
752 | Symbol param # default allowed param values | |
753 | M_TRIM_THRESHOLD -1 2*1024*1024 any (MAX_SIZE_T disables) | |
754 | M_GRANULARITY -2 page size any power of 2 >= page size | |
755 | M_MMAP_THRESHOLD -3 256*1024 any (or 0 if no MMAP support) | |
756 | */ | |
757 | int dlmallopt(int, int); | |
758 | ||
759 | /* | |
760 | malloc_footprint(); | |
761 | Returns the number of bytes obtained from the system. The total | |
762 | number of bytes allocated by malloc, realloc etc., is less than this | |
763 | value. Unlike mallinfo, this function returns only a precomputed | |
764 | result, so can be called frequently to monitor memory consumption. | |
765 | Even if locks are otherwise defined, this function does not use them, | |
766 | so results might not be up to date. | |
767 | */ | |
768 | size_t dlmalloc_footprint(void); | |
769 | ||
770 | /* | |
771 | malloc_max_footprint(); | |
772 | Returns the maximum number of bytes obtained from the system. This | |
773 | value will be greater than current footprint if deallocated space | |
774 | has been reclaimed by the system. The peak number of bytes allocated | |
775 | by malloc, realloc etc., is less than this value. Unlike mallinfo, | |
776 | this function returns only a precomputed result, so can be called | |
777 | frequently to monitor memory consumption. Even if locks are | |
778 | otherwise defined, this function does not use them, so results might | |
779 | not be up to date. | |
780 | */ | |
781 | size_t dlmalloc_max_footprint(void); | |
782 | ||
783 | #if !NO_MALLINFO | |
784 | /* | |
785 | mallinfo() | |
786 | Returns (by copy) a struct containing various summary statistics: | |
787 | ||
788 | arena: current total non-mmapped bytes allocated from system | |
789 | ordblks: the number of free chunks | |
790 | smblks: always zero. | |
791 | hblks: current number of mmapped regions | |
792 | hblkhd: total bytes held in mmapped regions | |
793 | usmblks: the maximum total allocated space. This will be greater | |
794 | than current total if trimming has occurred. | |
795 | fsmblks: always zero | |
796 | uordblks: current total allocated space (normal or mmapped) | |
797 | fordblks: total free space | |
798 | keepcost: the maximum number of bytes that could ideally be released | |
799 | back to system via malloc_trim. ("ideally" means that | |
800 | it ignores page restrictions etc.) | |
801 | ||
802 | Because these fields are ints, but internal bookkeeping may | |
803 | be kept as longs, the reported values may wrap around zero and | |
804 | thus be inaccurate. | |
805 | */ | |
806 | struct mallinfo dlmallinfo(void); | |
807 | #endif /* NO_MALLINFO */ | |
808 | ||
809 | /* | |
810 | independent_calloc(size_t n_elements, size_t element_size, void* chunks[]); | |
811 | ||
812 | independent_calloc is similar to calloc, but instead of returning a | |
813 | single cleared space, it returns an array of pointers to n_elements | |
814 | independent elements that can hold contents of size elem_size, each | |
815 | of which starts out cleared, and can be independently freed, | |
816 | realloc'ed etc. The elements are guaranteed to be adjacently | |
817 | allocated (this is not guaranteed to occur with multiple callocs or | |
818 | mallocs), which may also improve cache locality in some | |
819 | applications. | |
820 | ||
821 | The "chunks" argument is optional (i.e., may be null, which is | |
822 | probably the most typical usage). If it is null, the returned array | |
823 | is itself dynamically allocated and should also be freed when it is | |
824 | no longer needed. Otherwise, the chunks array must be of at least | |
825 | n_elements in length. It is filled in with the pointers to the | |
826 | chunks. | |
827 | ||
828 | In either case, independent_calloc returns this pointer array, or | |
829 | null if the allocation failed. If n_elements is zero and "chunks" | |
830 | is null, it returns a chunk representing an array with zero elements | |
831 | (which should be freed if not wanted). | |
832 | ||
833 | Each element must be individually freed when it is no longer | |
834 | needed. If you'd like to instead be able to free all at once, you | |
835 | should instead use regular calloc and assign pointers into this | |
836 | space to represent elements. (In this case though, you cannot | |
837 | independently free elements.) | |
838 | ||
839 | independent_calloc simplifies and speeds up implementations of many | |
840 | kinds of pools. It may also be useful when constructing large data | |
841 | structures that initially have a fixed number of fixed-sized nodes, | |
842 | but the number is not known at compile time, and some of the nodes | |
843 | may later need to be freed. For example: | |
844 | ||
845 | struct Node { int item; struct Node* next; }; | |
846 | ||
847 | struct Node* build_list() { | |
848 | struct Node** pool; | |
849 | int n = read_number_of_nodes_needed(); | |
850 | if (n <= 0) return 0; | |
851 | pool = (struct Node**)(independent_calloc(n, sizeof(struct Node), 0); | |
852 | if (pool == 0) die(); | |
853 | // organize into a linked list... | |
854 | struct Node* first = pool[0]; | |
855 | for (i = 0; i < n-1; ++i) | |
856 | pool[i]->next = pool[i+1]; | |
857 | free(pool); // Can now free the array (or not, if it is needed later) | |
858 | return first; | |
859 | } | |
860 | */ | |
861 | void** dlindependent_calloc(size_t, size_t, void**); | |
862 | ||
863 | /* | |
864 | independent_comalloc(size_t n_elements, size_t sizes[], void* chunks[]); | |
865 | ||
866 | independent_comalloc allocates, all at once, a set of n_elements | |
867 | chunks with sizes indicated in the "sizes" array. It returns | |
868 | an array of pointers to these elements, each of which can be | |
869 | independently freed, realloc'ed etc. The elements are guaranteed to | |
870 | be adjacently allocated (this is not guaranteed to occur with | |
871 | multiple callocs or mallocs), which may also improve cache locality | |
872 | in some applications. | |
873 | ||
874 | The "chunks" argument is optional (i.e., may be null). If it is null | |
875 | the returned array is itself dynamically allocated and should also | |
876 | be freed when it is no longer needed. Otherwise, the chunks array | |
877 | must be of at least n_elements in length. It is filled in with the | |
878 | pointers to the chunks. | |
879 | ||
880 | In either case, independent_comalloc returns this pointer array, or | |
881 | null if the allocation failed. If n_elements is zero and chunks is | |
882 | null, it returns a chunk representing an array with zero elements | |
883 | (which should be freed if not wanted). | |
884 | ||
885 | Each element must be individually freed when it is no longer | |
886 | needed. If you'd like to instead be able to free all at once, you | |
887 | should instead use a single regular malloc, and assign pointers at | |
888 | particular offsets in the aggregate space. (In this case though, you | |
889 | cannot independently free elements.) | |
890 | ||
891 | independent_comallac differs from independent_calloc in that each | |
892 | element may have a different size, and also that it does not | |
893 | automatically clear elements. | |
894 | ||
895 | independent_comalloc can be used to speed up allocation in cases | |
896 | where several structs or objects must always be allocated at the | |
897 | same time. For example: | |
898 | ||
899 | struct Head { ... } | |
900 | struct Foot { ... } | |
901 | ||
902 | void send_message(char* msg) { | |
903 | int msglen = strlen(msg); | |
904 | size_t sizes[3] = { sizeof(struct Head), msglen, sizeof(struct Foot) }; | |
905 | void* chunks[3]; | |
906 | if (independent_comalloc(3, sizes, chunks) == 0) | |
907 | die(); | |
908 | struct Head* head = (struct Head*)(chunks[0]); | |
909 | char* body = (char*)(chunks[1]); | |
910 | struct Foot* foot = (struct Foot*)(chunks[2]); | |
911 | // ... | |
912 | } | |
913 | ||
914 | In general though, independent_comalloc is worth using only for | |
915 | larger values of n_elements. For small values, you probably won't | |
916 | detect enough difference from series of malloc calls to bother. | |
917 | ||
918 | Overuse of independent_comalloc can increase overall memory usage, | |
919 | since it cannot reuse existing noncontiguous small chunks that | |
920 | might be available for some of the elements. | |
921 | */ | |
922 | void** dlindependent_comalloc(size_t, size_t*, void**); | |
923 | ||
924 | ||
925 | /* | |
926 | pvalloc(size_t n); | |
927 | Equivalent to valloc(minimum-page-that-holds(n)), that is, | |
928 | round up n to nearest pagesize. | |
929 | */ | |
930 | void* dlpvalloc(size_t); | |
931 | ||
932 | /* | |
933 | malloc_trim(size_t pad); | |
934 | ||
935 | If possible, gives memory back to the system (via negative arguments | |
936 | to sbrk) if there is unused memory at the `high' end of the malloc | |
937 | pool or in unused MMAP segments. You can call this after freeing | |
938 | large blocks of memory to potentially reduce the system-level memory | |
939 | requirements of a program. However, it cannot guarantee to reduce | |
940 | memory. Under some allocation patterns, some large free blocks of | |
941 | memory will be locked between two used chunks, so they cannot be | |
942 | given back to the system. | |
943 | ||
944 | The `pad' argument to malloc_trim represents the amount of free | |
945 | trailing space to leave untrimmed. If this argument is zero, only | |
946 | the minimum amount of memory to maintain internal data structures | |
947 | will be left. Non-zero arguments can be supplied to maintain enough | |
948 | trailing space to service future expected allocations without having | |
949 | to re-obtain memory from the system. | |
950 | ||
951 | Malloc_trim returns 1 if it actually released any memory, else 0. | |
952 | */ | |
953 | int dlmalloc_trim(size_t); | |
954 | ||
955 | /* | |
956 | malloc_usable_size(void* p); | |
957 | ||
958 | Returns the number of bytes you can actually use in | |
959 | an allocated chunk, which may be more than you requested (although | |
960 | often not) due to alignment and minimum size constraints. | |
961 | You can use this many bytes without worrying about | |
962 | overwriting other allocated objects. This is not a particularly great | |
963 | programming practice. malloc_usable_size can be more useful in | |
964 | debugging and assertions, for example: | |
965 | ||
966 | p = malloc(n); | |
967 | assert(malloc_usable_size(p) >= 256); | |
968 | */ | |
969 | size_t dlmalloc_usable_size(void*); | |
970 | ||
971 | /* | |
972 | malloc_stats(); | |
973 | Prints on stderr the amount of space obtained from the system (both | |
974 | via sbrk and mmap), the maximum amount (which may be more than | |
975 | current if malloc_trim and/or munmap got called), and the current | |
976 | number of bytes allocated via malloc (or realloc, etc) but not yet | |
977 | freed. Note that this is the number of bytes allocated, not the | |
978 | number requested. It will be larger than the number requested | |
979 | because of alignment and bookkeeping overhead. Because it includes | |
980 | alignment wastage as being in use, this figure may be greater than | |
981 | zero even when no user-level chunks are allocated. | |
982 | ||
983 | The reported current and maximum system memory can be inaccurate if | |
984 | a program makes other calls to system memory allocation functions | |
985 | (normally sbrk) outside of malloc. | |
986 | ||
987 | malloc_stats prints only the most commonly interesting statistics. | |
988 | More information can be obtained by calling mallinfo. | |
989 | */ | |
990 | void dlmalloc_stats(void); | |
991 | ||
992 | #endif /* ONLY_MSPACES */ | |
993 | ||
994 | #if MSPACES | |
995 | ||
996 | /* | |
997 | mspace is an opaque type representing an independent | |
998 | region of space that supports mspace_malloc, etc. | |
999 | */ | |
1000 | typedef void* mspace; | |
1001 | ||
1002 | /* | |
1003 | create_mspace creates and returns a new independent space with the | |
1004 | given initial capacity, or, if 0, the default granularity size. It | |
1005 | returns null if there is no system memory available to create the | |
1006 | space. If argument locked is non-zero, the space uses a separate | |
1007 | lock to control access. The capacity of the space will grow | |
1008 | dynamically as needed to service mspace_malloc requests. You can | |
1009 | control the sizes of incremental increases of this space by | |
1010 | compiling with a different DEFAULT_GRANULARITY or dynamically | |
1011 | setting with mallopt(M_GRANULARITY, value). | |
1012 | */ | |
1013 | mspace create_mspace(size_t capacity, int locked); | |
1014 | ||
1015 | /* | |
1016 | destroy_mspace destroys the given space, and attempts to return all | |
1017 | of its memory back to the system, returning the total number of | |
1018 | bytes freed. After destruction, the results of access to all memory | |
1019 | used by the space become undefined. | |
1020 | */ | |
1021 | size_t destroy_mspace(mspace msp); | |
1022 | ||
1023 | /* | |
1024 | create_mspace_with_base uses the memory supplied as the initial base | |
1025 | of a new mspace. Part (less than 128*sizeof(size_t) bytes) of this | |
1026 | space is used for bookkeeping, so the capacity must be at least this | |
1027 | large. (Otherwise 0 is returned.) When this initial space is | |
1028 | exhausted, additional memory will be obtained from the system. | |
1029 | Destroying this space will deallocate all additionally allocated | |
1030 | space (if possible) but not the initial base. | |
1031 | */ | |
1032 | mspace create_mspace_with_base(void* base, size_t capacity, int locked); | |
1033 | ||
1034 | /* | |
1035 | mspace_malloc behaves as malloc, but operates within | |
1036 | the given space. | |
1037 | */ | |
1038 | void* mspace_malloc(mspace msp, size_t bytes); | |
1039 | ||
1040 | /* | |
1041 | mspace_free behaves as free, but operates within | |
1042 | the given space. | |
1043 | ||
1044 | If compiled with FOOTERS==1, mspace_free is not actually needed. | |
1045 | free may be called instead of mspace_free because freed chunks from | |
1046 | any space are handled by their originating spaces. | |
1047 | */ | |
1048 | void mspace_free(mspace msp, void* mem); | |
1049 | ||
1050 | /* | |
1051 | mspace_realloc behaves as realloc, but operates within | |
1052 | the given space. | |
1053 | ||
1054 | If compiled with FOOTERS==1, mspace_realloc is not actually | |
1055 | needed. realloc may be called instead of mspace_realloc because | |
1056 | realloced chunks from any space are handled by their originating | |
1057 | spaces. | |
1058 | */ | |
1059 | void* mspace_realloc(mspace msp, void* mem, size_t newsize); | |
1060 | ||
1061 | /* | |
1062 | mspace_calloc behaves as calloc, but operates within | |
1063 | the given space. | |
1064 | */ | |
1065 | void* mspace_calloc(mspace msp, size_t n_elements, size_t elem_size); | |
1066 | ||
1067 | /* | |
1068 | mspace_memalign behaves as memalign, but operates within | |
1069 | the given space. | |
1070 | */ | |
1071 | void* mspace_memalign(mspace msp, size_t alignment, size_t bytes); | |
1072 | ||
1073 | /* | |
1074 | mspace_independent_calloc behaves as independent_calloc, but | |
1075 | operates within the given space. | |
1076 | */ | |
1077 | void** mspace_independent_calloc(mspace msp, size_t n_elements, | |
1078 | size_t elem_size, void* chunks[]); | |
1079 | ||
1080 | /* | |
1081 | mspace_independent_comalloc behaves as independent_comalloc, but | |
1082 | operates within the given space. | |
1083 | */ | |
1084 | void** mspace_independent_comalloc(mspace msp, size_t n_elements, | |
1085 | size_t sizes[], void* chunks[]); | |
1086 | ||
1087 | /* | |
1088 | mspace_footprint() returns the number of bytes obtained from the | |
1089 | system for this space. | |
1090 | */ | |
1091 | size_t mspace_footprint(mspace msp); | |
1092 | ||
1093 | /* | |
1094 | mspace_max_footprint() returns the peak number of bytes obtained from the | |
1095 | system for this space. | |
1096 | */ | |
1097 | size_t mspace_max_footprint(mspace msp); | |
1098 | ||
1099 | ||
1100 | #if !NO_MALLINFO | |
1101 | /* | |
1102 | mspace_mallinfo behaves as mallinfo, but reports properties of | |
1103 | the given space. | |
1104 | */ | |
1105 | struct mallinfo mspace_mallinfo(mspace msp); | |
1106 | #endif /* NO_MALLINFO */ | |
1107 | ||
1108 | /* | |
1109 | mspace_malloc_stats behaves as malloc_stats, but reports | |
1110 | properties of the given space. | |
1111 | */ | |
1112 | void mspace_malloc_stats(mspace msp); | |
1113 | ||
1114 | /* | |
1115 | mspace_trim behaves as malloc_trim, but | |
1116 | operates within the given space. | |
1117 | */ | |
1118 | int mspace_trim(mspace msp, size_t pad); | |
1119 | ||
1120 | /* | |
1121 | An alias for mallopt. | |
1122 | */ | |
1123 | int mspace_mallopt(int, int); | |
1124 | ||
1125 | #endif /* MSPACES */ | |
1126 | ||
1127 | #ifdef __cplusplus | |
1128 | }; /* end of extern "C" */ | |
1129 | #endif /* __cplusplus */ | |
1130 | ||
1131 | /* | |
1132 | ======================================================================== | |
1133 | To make a fully customizable malloc.h header file, cut everything | |
1134 | above this line, put into file malloc.h, edit to suit, and #include it | |
1135 | on the next line, as well as in programs that use this malloc. | |
1136 | ======================================================================== | |
1137 | */ | |
1138 | ||
1139 | /* #include "malloc.h" */ | |
1140 | ||
1141 | /*------------------------------ internal #includes ---------------------- */ | |
1142 | ||
1143 | #ifdef WIN32 | |
1144 | #pragma warning( disable : 4146 ) /* no "unsigned" warnings */ | |
1145 | #endif /* WIN32 */ | |
1146 | ||
1147 | #include <stdio.h> /* for printing in malloc_stats */ | |
1148 | ||
1149 | #ifndef LACKS_ERRNO_H | |
1150 | #include <errno.h> /* for MALLOC_FAILURE_ACTION */ | |
1151 | #endif /* LACKS_ERRNO_H */ | |
1152 | #if FOOTERS | |
1153 | #include <time.h> /* for magic initialization */ | |
1154 | #endif /* FOOTERS */ | |
1155 | #ifndef LACKS_STDLIB_H | |
1156 | #include <stdlib.h> /* for abort() */ | |
1157 | #endif /* LACKS_STDLIB_H */ | |
1158 | #ifdef DEBUG | |
1159 | #if ABORT_ON_ASSERT_FAILURE | |
1160 | #define assert(x) if(!(x)) ABORT | |
1161 | #else /* ABORT_ON_ASSERT_FAILURE */ | |
1162 | #include <assert.h> | |
1163 | #endif /* ABORT_ON_ASSERT_FAILURE */ | |
1164 | #else /* DEBUG */ | |
1165 | #define assert(x) | |
1166 | #endif /* DEBUG */ | |
1167 | #ifndef LACKS_STRING_H | |
1168 | #include <string.h> /* for memset etc */ | |
1169 | #endif /* LACKS_STRING_H */ | |
1170 | #if USE_BUILTIN_FFS | |
1171 | #ifndef LACKS_STRINGS_H | |
1172 | #include <strings.h> /* for ffs */ | |
1173 | #endif /* LACKS_STRINGS_H */ | |
1174 | #endif /* USE_BUILTIN_FFS */ | |
1175 | #if HAVE_MMAP | |
1176 | #ifndef LACKS_SYS_MMAN_H | |
1177 | #include <sys/mman.h> /* for mmap */ | |
1178 | #endif /* LACKS_SYS_MMAN_H */ | |
1179 | #ifndef LACKS_FCNTL_H | |
1180 | #include <fcntl.h> | |
1181 | #endif /* LACKS_FCNTL_H */ | |
1182 | #endif /* HAVE_MMAP */ | |
1183 | #if HAVE_MORECORE | |
1184 | #ifndef LACKS_UNISTD_H | |
1185 | #include <unistd.h> /* for sbrk */ | |
1186 | #else /* LACKS_UNISTD_H */ | |
1187 | #if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) | |
1188 | extern void* sbrk(ptrdiff_t); | |
1189 | #endif /* FreeBSD etc */ | |
1190 | #endif /* LACKS_UNISTD_H */ | |
1191 | #endif /* HAVE_MMAP */ | |
1192 | ||
1193 | #ifndef WIN32 | |
1194 | #ifndef malloc_getpagesize | |
1195 | # ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */ | |
1196 | # ifndef _SC_PAGE_SIZE | |
1197 | # define _SC_PAGE_SIZE _SC_PAGESIZE | |
1198 | # endif | |
1199 | # endif | |
1200 | # ifdef _SC_PAGE_SIZE | |
1201 | # define malloc_getpagesize sysconf(_SC_PAGE_SIZE) | |
1202 | # else | |
1203 | # if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE) | |
1204 | extern size_t getpagesize(); | |
1205 | # define malloc_getpagesize getpagesize() | |
1206 | # else | |
1207 | # ifdef WIN32 /* use supplied emulation of getpagesize */ | |
1208 | # define malloc_getpagesize getpagesize() | |
1209 | # else | |
1210 | # ifndef LACKS_SYS_PARAM_H | |
1211 | # include <sys/param.h> | |
1212 | # endif | |
1213 | # ifdef EXEC_PAGESIZE | |
1214 | # define malloc_getpagesize EXEC_PAGESIZE | |
1215 | # else | |
1216 | # ifdef NBPG | |
1217 | # ifndef CLSIZE | |
1218 | # define malloc_getpagesize NBPG | |
1219 | # else | |
1220 | # define malloc_getpagesize (NBPG * CLSIZE) | |
1221 | # endif | |
1222 | # else | |
1223 | # ifdef NBPC | |
1224 | # define malloc_getpagesize NBPC | |
1225 | # else | |
1226 | # ifdef PAGESIZE | |
1227 | # define malloc_getpagesize PAGESIZE | |
1228 | # else /* just guess */ | |
1229 | # define malloc_getpagesize ((size_t)4096U) | |
1230 | # endif | |
1231 | # endif | |
1232 | # endif | |
1233 | # endif | |
1234 | # endif | |
1235 | # endif | |
1236 | # endif | |
1237 | #endif | |
1238 | #endif | |
1239 | ||
1240 | /* ------------------- size_t and alignment properties -------------------- */ | |
1241 | ||
1242 | /* The byte and bit size of a size_t */ | |
1243 | #define SIZE_T_SIZE (sizeof(size_t)) | |
1244 | #define SIZE_T_BITSIZE (sizeof(size_t) << 3) | |
1245 | ||
1246 | /* Some constants coerced to size_t */ | |
1247 | /* Annoying but necessary to avoid errors on some plaftorms */ | |
1248 | #define SIZE_T_ZERO ((size_t)0) | |
1249 | #define SIZE_T_ONE ((size_t)1) | |
1250 | #define SIZE_T_TWO ((size_t)2) | |
1251 | #define TWO_SIZE_T_SIZES (SIZE_T_SIZE<<1) | |
1252 | #define FOUR_SIZE_T_SIZES (SIZE_T_SIZE<<2) | |
1253 | #define SIX_SIZE_T_SIZES (FOUR_SIZE_T_SIZES+TWO_SIZE_T_SIZES) | |
1254 | #define HALF_MAX_SIZE_T (MAX_SIZE_T / 2U) | |
1255 | ||
1256 | /* The bit mask value corresponding to MALLOC_ALIGNMENT */ | |
1257 | #define CHUNK_ALIGN_MASK (MALLOC_ALIGNMENT - SIZE_T_ONE) | |
1258 | ||
1259 | /* True if address a has acceptable alignment */ | |
1260 | #define is_aligned(A) (((size_t)((A)) & (CHUNK_ALIGN_MASK)) == 0) | |
1261 | ||
1262 | /* the number of bytes to offset an address to align it */ | |
1263 | #define align_offset(A)\ | |
1264 | ((((size_t)(A) & CHUNK_ALIGN_MASK) == 0)? 0 :\ | |
1265 | ((MALLOC_ALIGNMENT - ((size_t)(A) & CHUNK_ALIGN_MASK)) & CHUNK_ALIGN_MASK)) | |
1266 | ||
1267 | /* -------------------------- MMAP preliminaries ------------------------- */ | |
1268 | ||
1269 | /* | |
1270 | If HAVE_MORECORE or HAVE_MMAP are false, we just define calls and | |
1271 | checks to fail so compiler optimizer can delete code rather than | |
1272 | using so many "#if"s. | |
1273 | */ | |
1274 | ||
1275 | ||
1276 | /* MORECORE and MMAP must return MFAIL on failure */ | |
1277 | #define MFAIL ((void*)(MAX_SIZE_T)) | |
1278 | #define CMFAIL ((char*)(MFAIL)) /* defined for convenience */ | |
1279 | ||
1280 | #if !HAVE_MMAP | |
1281 | #define IS_MMAPPED_BIT (SIZE_T_ZERO) | |
1282 | #define USE_MMAP_BIT (SIZE_T_ZERO) | |
1283 | #define CALL_MMAP(s) MFAIL | |
1284 | #define CALL_MUNMAP(a, s) (-1) | |
1285 | #define DIRECT_MMAP(s) MFAIL | |
1286 | ||
1287 | #else /* HAVE_MMAP */ | |
1288 | #define IS_MMAPPED_BIT (SIZE_T_ONE) | |
1289 | #define USE_MMAP_BIT (SIZE_T_ONE) | |
1290 | ||
1291 | #ifndef WIN32 | |
1292 | #define CALL_MUNMAP(a, s) munmap((a), (s)) | |
1293 | #define MMAP_PROT (PROT_READ|PROT_WRITE) | |
1294 | #if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) | |
1295 | #define MAP_ANONYMOUS MAP_ANON | |
1296 | #endif /* MAP_ANON */ | |
1297 | #ifdef MAP_ANONYMOUS | |
1298 | #define MMAP_FLAGS (MAP_PRIVATE|MAP_ANONYMOUS) | |
1299 | #define CALL_MMAP(s) mmap(0, (s), MMAP_PROT, MMAP_FLAGS, -1, 0) | |
1300 | #else /* MAP_ANONYMOUS */ | |
1301 | /* | |
1302 | Nearly all versions of mmap support MAP_ANONYMOUS, so the following | |
1303 | is unlikely to be needed, but is supplied just in case. | |
1304 | */ | |
1305 | #define MMAP_FLAGS (MAP_PRIVATE) | |
1306 | static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */ | |
1307 | #define CALL_MMAP(s) ((dev_zero_fd < 0) ? \ | |
1308 | (dev_zero_fd = open("/dev/zero", O_RDWR), \ | |
1309 | mmap(0, (s), MMAP_PROT, MMAP_FLAGS, dev_zero_fd, 0)) : \ | |
1310 | mmap(0, (s), MMAP_PROT, MMAP_FLAGS, dev_zero_fd, 0)) | |
1311 | #endif /* MAP_ANONYMOUS */ | |
1312 | ||
1313 | #define DIRECT_MMAP(s) CALL_MMAP(s) | |
1314 | #else /* WIN32 */ | |
1315 | ||
1316 | /* Win32 MMAP via VirtualAlloc */ | |
1317 | static void* win32mmap(size_t size) { | |
1318 | void* ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE); | |
1319 | return (ptr != 0)? ptr: MFAIL; | |
1320 | } | |
1321 | ||
1322 | /* For direct MMAP, use MEM_TOP_DOWN to minimize interference */ | |
1323 | static void* win32direct_mmap(size_t size) { | |
1324 | void* ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT|MEM_TOP_DOWN, | |
1325 | PAGE_READWRITE); | |
1326 | return (ptr != 0)? ptr: MFAIL; | |
1327 | } | |
1328 | ||
1329 | /* This function supports releasing coalesed segments */ | |
1330 | static int win32munmap(void* ptr, size_t size) { | |
1331 | MEMORY_BASIC_INFORMATION minfo; | |
1332 | char* cptr = ptr; | |
1333 | while (size) { | |
1334 | if (VirtualQuery(cptr, &minfo, sizeof(minfo)) == 0) | |
1335 | return -1; | |
1336 | if (minfo.BaseAddress != cptr || minfo.AllocationBase != cptr || | |
1337 | minfo.State != MEM_COMMIT || minfo.RegionSize > size) | |
1338 | return -1; | |
1339 | if (VirtualFree(cptr, 0, MEM_RELEASE) == 0) | |
1340 | return -1; | |
1341 | cptr += minfo.RegionSize; | |
1342 | size -= minfo.RegionSize; | |
1343 | } | |
1344 | return 0; | |
1345 | } | |
1346 | ||
1347 | #define CALL_MMAP(s) win32mmap(s) | |
1348 | #define CALL_MUNMAP(a, s) win32munmap((a), (s)) | |
1349 | #define DIRECT_MMAP(s) win32direct_mmap(s) | |
1350 | #endif /* WIN32 */ | |
1351 | #endif /* HAVE_MMAP */ | |
1352 | ||
1353 | #if HAVE_MMAP && HAVE_MREMAP | |
1354 | #define CALL_MREMAP(addr, osz, nsz, mv) mremap((addr), (osz), (nsz), (mv)) | |
1355 | #else /* HAVE_MMAP && HAVE_MREMAP */ | |
1356 | #define CALL_MREMAP(addr, osz, nsz, mv) MFAIL | |
1357 | #endif /* HAVE_MMAP && HAVE_MREMAP */ | |
1358 | ||
1359 | #if HAVE_MORECORE | |
1360 | #define CALL_MORECORE(S) MORECORE(S) | |
1361 | #else /* HAVE_MORECORE */ | |
1362 | #define CALL_MORECORE(S) MFAIL | |
1363 | #endif /* HAVE_MORECORE */ | |
1364 | ||
1365 | /* mstate bit set if continguous morecore disabled or failed */ | |
1366 | #define USE_NONCONTIGUOUS_BIT (4U) | |
1367 | ||
1368 | /* segment bit set in create_mspace_with_base */ | |
1369 | #define EXTERN_BIT (8U) | |
1370 | ||
1371 | ||
1372 | /* --------------------------- Lock preliminaries ------------------------ */ | |
1373 | ||
1374 | #if USE_LOCKS | |
1375 | ||
1376 | /* | |
1377 | When locks are defined, there are up to two global locks: | |
1378 | ||
1379 | * If HAVE_MORECORE, morecore_mutex protects sequences of calls to | |
1380 | MORECORE. In many cases sys_alloc requires two calls, that should | |
1381 | not be interleaved with calls by other threads. This does not | |
1382 | protect against direct calls to MORECORE by other threads not | |
1383 | using this lock, so there is still code to cope the best we can on | |
1384 | interference. | |
1385 | ||
1386 | * magic_init_mutex ensures that mparams.magic and other | |
1387 | unique mparams values are initialized only once. | |
1388 | */ | |
1389 | ||
1390 | #ifndef WIN32 | |
1391 | /* By default use posix locks */ | |
1392 | #include <pthread.h> | |
1393 | #define MLOCK_T pthread_mutex_t | |
1394 | #define INITIAL_LOCK(l) pthread_mutex_init(l, NULL) | |
1395 | #define ACQUIRE_LOCK(l) pthread_mutex_lock(l) | |
1396 | #define RELEASE_LOCK(l) pthread_mutex_unlock(l) | |
1397 | ||
1398 | #if HAVE_MORECORE | |
1399 | static MLOCK_T morecore_mutex = PTHREAD_MUTEX_INITIALIZER; | |
1400 | #endif /* HAVE_MORECORE */ | |
1401 | ||
1402 | static MLOCK_T magic_init_mutex = PTHREAD_MUTEX_INITIALIZER; | |
1403 | ||
1404 | #else /* WIN32 */ | |
1405 | /* | |
1406 | Because lock-protected regions have bounded times, and there | |
1407 | are no recursive lock calls, we can use simple spinlocks. | |
1408 | */ | |
1409 | ||
1410 | #define MLOCK_T long | |
1411 | static int win32_acquire_lock (MLOCK_T *sl) { | |
1412 | for (;;) { | |
1413 | #ifdef InterlockedCompareExchangePointer | |
1414 | if (!InterlockedCompareExchange(sl, 1, 0)) | |
1415 | return 0; | |
1416 | #else /* Use older void* version */ | |
1417 | if (!InterlockedCompareExchange((void**)sl, (void*)1, (void*)0)) | |
1418 | return 0; | |
1419 | #endif /* InterlockedCompareExchangePointer */ | |
1420 | Sleep (0); | |
1421 | } | |
1422 | } | |
1423 | ||
1424 | static void win32_release_lock (MLOCK_T *sl) { | |
1425 | InterlockedExchange (sl, 0); | |
1426 | } | |
1427 | ||
1428 | #define INITIAL_LOCK(l) *(l)=0 | |
1429 | #define ACQUIRE_LOCK(l) win32_acquire_lock(l) | |
1430 | #define RELEASE_LOCK(l) win32_release_lock(l) | |
1431 | #if HAVE_MORECORE | |
1432 | static MLOCK_T morecore_mutex; | |
1433 | #endif /* HAVE_MORECORE */ | |
1434 | static MLOCK_T magic_init_mutex; | |
1435 | #endif /* WIN32 */ | |
1436 | ||
1437 | #define USE_LOCK_BIT (2U) | |
1438 | #else /* USE_LOCKS */ | |
1439 | #define USE_LOCK_BIT (0U) | |
1440 | #define INITIAL_LOCK(l) | |
1441 | #endif /* USE_LOCKS */ | |
1442 | ||
1443 | #if USE_LOCKS && HAVE_MORECORE | |
1444 | #define ACQUIRE_MORECORE_LOCK() ACQUIRE_LOCK(&morecore_mutex); | |
1445 | #define RELEASE_MORECORE_LOCK() RELEASE_LOCK(&morecore_mutex); | |
1446 | #else /* USE_LOCKS && HAVE_MORECORE */ | |
1447 | #define ACQUIRE_MORECORE_LOCK() | |
1448 | #define RELEASE_MORECORE_LOCK() | |
1449 | #endif /* USE_LOCKS && HAVE_MORECORE */ | |
1450 | ||
1451 | #if USE_LOCKS | |
1452 | #define ACQUIRE_MAGIC_INIT_LOCK() ACQUIRE_LOCK(&magic_init_mutex); | |
1453 | #define RELEASE_MAGIC_INIT_LOCK() RELEASE_LOCK(&magic_init_mutex); | |
1454 | #else /* USE_LOCKS */ | |
1455 | #define ACQUIRE_MAGIC_INIT_LOCK() | |
1456 | #define RELEASE_MAGIC_INIT_LOCK() | |
1457 | #endif /* USE_LOCKS */ | |
1458 | ||
1459 | ||
1460 | /* ----------------------- Chunk representations ------------------------ */ | |
1461 | ||
1462 | /* | |
1463 | (The following includes lightly edited explanations by Colin Plumb.) | |
1464 | ||
1465 | The malloc_chunk declaration below is misleading (but accurate and | |
1466 | necessary). It declares a "view" into memory allowing access to | |
1467 | necessary fields at known offsets from a given base. | |
1468 | ||
1469 | Chunks of memory are maintained using a `boundary tag' method as | |
1470 | originally described by Knuth. (See the paper by Paul Wilson | |
1471 | ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a survey of such | |
1472 | techniques.) Sizes of free chunks are stored both in the front of | |
1473 | each chunk and at the end. This makes consolidating fragmented | |
1474 | chunks into bigger chunks fast. The head fields also hold bits | |
1475 | representing whether chunks are free or in use. | |
1476 | ||
1477 | Here are some pictures to make it clearer. They are "exploded" to | |
1478 | show that the state of a chunk can be thought of as extending from | |
1479 | the high 31 bits of the head field of its header through the | |
1480 | prev_foot and PINUSE_BIT bit of the following chunk header. | |
1481 | ||
1482 | A chunk that's in use looks like: | |
1483 | ||
1484 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1485 | | Size of previous chunk (if P = 1) | | |
1486 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1487 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| | |
1488 | | Size of this chunk 1| +-+ | |
1489 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1490 | | | | |
1491 | +- -+ | |
1492 | | | | |
1493 | +- -+ | |
1494 | | : | |
1495 | +- size - sizeof(size_t) available payload bytes -+ | |
1496 | : | | |
1497 | chunk-> +- -+ | |
1498 | | | | |
1499 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1500 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| | |
1501 | | Size of next chunk (may or may not be in use) | +-+ | |
1502 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1503 | ||
1504 | And if it's free, it looks like this: | |
1505 | ||
1506 | chunk-> +- -+ | |
1507 | | User payload (must be in use, or we would have merged!) | | |
1508 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1509 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| | |
1510 | | Size of this chunk 0| +-+ | |
1511 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1512 | | Next pointer | | |
1513 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1514 | | Prev pointer | | |
1515 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1516 | | : | |
1517 | +- size - sizeof(struct chunk) unused bytes -+ | |
1518 | : | | |
1519 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1520 | | Size of this chunk | | |
1521 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1522 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| | |
1523 | | Size of next chunk (must be in use, or we would have merged)| +-+ | |
1524 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1525 | | : | |
1526 | +- User payload -+ | |
1527 | : | | |
1528 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1529 | |0| | |
1530 | +-+ | |
1531 | Note that since we always merge adjacent free chunks, the chunks | |
1532 | adjacent to a free chunk must be in use. | |
1533 | ||
1534 | Given a pointer to a chunk (which can be derived trivially from the | |
1535 | payload pointer) we can, in O(1) time, find out whether the adjacent | |
1536 | chunks are free, and if so, unlink them from the lists that they | |
1537 | are on and merge them with the current chunk. | |
1538 | ||
1539 | Chunks always begin on even word boundaries, so the mem portion | |
1540 | (which is returned to the user) is also on an even word boundary, and | |
1541 | thus at least double-word aligned. | |
1542 | ||
1543 | The P (PINUSE_BIT) bit, stored in the unused low-order bit of the | |
1544 | chunk size (which is always a multiple of two words), is an in-use | |
1545 | bit for the *previous* chunk. If that bit is *clear*, then the | |
1546 | word before the current chunk size contains the previous chunk | |
1547 | size, and can be used to find the front of the previous chunk. | |
1548 | The very first chunk allocated always has this bit set, preventing | |
1549 | access to non-existent (or non-owned) memory. If pinuse is set for | |
1550 | any given chunk, then you CANNOT determine the size of the | |
1551 | previous chunk, and might even get a memory addressing fault when | |
1552 | trying to do so. | |
1553 | ||
1554 | The C (CINUSE_BIT) bit, stored in the unused second-lowest bit of | |
1555 | the chunk size redundantly records whether the current chunk is | |
1556 | inuse. This redundancy enables usage checks within free and realloc, | |
1557 | and reduces indirection when freeing and consolidating chunks. | |
1558 | ||
1559 | Each freshly allocated chunk must have both cinuse and pinuse set. | |
1560 | That is, each allocated chunk borders either a previously allocated | |
1561 | and still in-use chunk, or the base of its memory arena. This is | |
1562 | ensured by making all allocations from the the `lowest' part of any | |
1563 | found chunk. Further, no free chunk physically borders another one, | |
1564 | so each free chunk is known to be preceded and followed by either | |
1565 | inuse chunks or the ends of memory. | |
1566 | ||
1567 | Note that the `foot' of the current chunk is actually represented | |
1568 | as the prev_foot of the NEXT chunk. This makes it easier to | |
1569 | deal with alignments etc but can be very confusing when trying | |
1570 | to extend or adapt this code. | |
1571 | ||
1572 | The exceptions to all this are | |
1573 | ||
1574 | 1. The special chunk `top' is the top-most available chunk (i.e., | |
1575 | the one bordering the end of available memory). It is treated | |
1576 | specially. Top is never included in any bin, is used only if | |
1577 | no other chunk is available, and is released back to the | |
1578 | system if it is very large (see M_TRIM_THRESHOLD). In effect, | |
1579 | the top chunk is treated as larger (and thus less well | |
1580 | fitting) than any other available chunk. The top chunk | |
1581 | doesn't update its trailing size field since there is no next | |
1582 | contiguous chunk that would have to index off it. However, | |
1583 | space is still allocated for it (TOP_FOOT_SIZE) to enable | |
1584 | separation or merging when space is extended. | |
1585 | ||
1586 | 3. Chunks allocated via mmap, which have the lowest-order bit | |
1587 | (IS_MMAPPED_BIT) set in their prev_foot fields, and do not set | |
1588 | PINUSE_BIT in their head fields. Because they are allocated | |
1589 | one-by-one, each must carry its own prev_foot field, which is | |
1590 | also used to hold the offset this chunk has within its mmapped | |
1591 | region, which is needed to preserve alignment. Each mmapped | |
1592 | chunk is trailed by the first two fields of a fake next-chunk | |
1593 | for sake of usage checks. | |
1594 | ||
1595 | */ | |
1596 | ||
1597 | struct malloc_chunk { | |
1598 | size_t prev_foot; /* Size of previous chunk (if free). */ | |
1599 | size_t head; /* Size and inuse bits. */ | |
1600 | struct malloc_chunk* fd; /* double links -- used only if free. */ | |
1601 | struct malloc_chunk* bk; | |
1602 | }; | |
1603 | ||
1604 | typedef struct malloc_chunk mchunk; | |
1605 | typedef struct malloc_chunk* mchunkptr; | |
1606 | typedef struct malloc_chunk* sbinptr; /* The type of bins of chunks */ | |
1607 | typedef unsigned int bindex_t; /* Described below */ | |
1608 | typedef unsigned int binmap_t; /* Described below */ | |
1609 | typedef unsigned int flag_t; /* The type of various bit flag sets */ | |
1610 | ||
1611 | /* ------------------- Chunks sizes and alignments ----------------------- */ | |
1612 | ||
1613 | #define MCHUNK_SIZE (sizeof(mchunk)) | |
1614 | ||
1615 | #if FOOTERS | |
1616 | #define CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) | |
1617 | #else /* FOOTERS */ | |
1618 | #define CHUNK_OVERHEAD (SIZE_T_SIZE) | |
1619 | #endif /* FOOTERS */ | |
1620 | ||
1621 | /* MMapped chunks need a second word of overhead ... */ | |
1622 | #define MMAP_CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) | |
1623 | /* ... and additional padding for fake next-chunk at foot */ | |
1624 | #define MMAP_FOOT_PAD (FOUR_SIZE_T_SIZES) | |
1625 | ||
1626 | /* The smallest size we can malloc is an aligned minimal chunk */ | |
1627 | #define MIN_CHUNK_SIZE\ | |
1628 | ((MCHUNK_SIZE + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) | |
1629 | ||
1630 | /* conversion from malloc headers to user pointers, and back */ | |
1631 | #define chunk2mem(p) ((void*)((char*)(p) + TWO_SIZE_T_SIZES)) | |
1632 | #define mem2chunk(mem) ((mchunkptr)((char*)(mem) - TWO_SIZE_T_SIZES)) | |
1633 | /* chunk associated with aligned address A */ | |
1634 | #define align_as_chunk(A) (mchunkptr)((A) + align_offset(chunk2mem(A))) | |
1635 | ||
1636 | /* Bounds on request (not chunk) sizes. */ | |
1637 | #define MAX_REQUEST ((-MIN_CHUNK_SIZE) << 2) | |
1638 | #define MIN_REQUEST (MIN_CHUNK_SIZE - CHUNK_OVERHEAD - SIZE_T_ONE) | |
1639 | ||
1640 | /* pad request bytes into a usable size */ | |
1641 | #define pad_request(req) \ | |
1642 | (((req) + CHUNK_OVERHEAD + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) | |
1643 | ||
1644 | /* pad request, checking for minimum (but not maximum) */ | |
1645 | #define request2size(req) \ | |
1646 | (((req) < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(req)) | |
1647 | ||
1648 | ||
1649 | /* ------------------ Operations on head and foot fields ----------------- */ | |
1650 | ||
1651 | /* | |
1652 | The head field of a chunk is or'ed with PINUSE_BIT when previous | |
1653 | adjacent chunk in use, and or'ed with CINUSE_BIT if this chunk is in | |
1654 | use. If the chunk was obtained with mmap, the prev_foot field has | |
1655 | IS_MMAPPED_BIT set, otherwise holding the offset of the base of the | |
1656 | mmapped region to the base of the chunk. | |
1657 | */ | |
1658 | ||
1659 | #define PINUSE_BIT (SIZE_T_ONE) | |
1660 | #define CINUSE_BIT (SIZE_T_TWO) | |
1661 | #define INUSE_BITS (PINUSE_BIT|CINUSE_BIT) | |
1662 | ||
1663 | /* Head value for fenceposts */ | |
1664 | #define FENCEPOST_HEAD (INUSE_BITS|SIZE_T_SIZE) | |
1665 | ||
1666 | /* extraction of fields from head words */ | |
1667 | #define cinuse(p) ((p)->head & CINUSE_BIT) | |
1668 | #define pinuse(p) ((p)->head & PINUSE_BIT) | |
1669 | #define chunksize(p) ((p)->head & ~(INUSE_BITS)) | |
1670 | ||
1671 | #define clear_pinuse(p) ((p)->head &= ~PINUSE_BIT) | |
1672 | #define clear_cinuse(p) ((p)->head &= ~CINUSE_BIT) | |
1673 | ||
1674 | /* Treat space at ptr +/- offset as a chunk */ | |
1675 | #define chunk_plus_offset(p, s) ((mchunkptr)(((char*)(p)) + (s))) | |
1676 | #define chunk_minus_offset(p, s) ((mchunkptr)(((char*)(p)) - (s))) | |
1677 | ||
1678 | /* Ptr to next or previous physical malloc_chunk. */ | |
1679 | #define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->head & ~INUSE_BITS))) | |
1680 | #define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_foot) )) | |
1681 | ||
1682 | /* extract next chunk's pinuse bit */ | |
1683 | #define next_pinuse(p) ((next_chunk(p)->head) & PINUSE_BIT) | |
1684 | ||
1685 | /* Get/set size at footer */ | |
1686 | #define get_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot) | |
1687 | #define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot = (s)) | |
1688 | ||
1689 | /* Set size, pinuse bit, and foot */ | |
1690 | #define set_size_and_pinuse_of_free_chunk(p, s)\ | |
1691 | ((p)->head = (s|PINUSE_BIT), set_foot(p, s)) | |
1692 | ||
1693 | /* Set size, pinuse bit, foot, and clear next pinuse */ | |
1694 | #define set_free_with_pinuse(p, s, n)\ | |
1695 | (clear_pinuse(n), set_size_and_pinuse_of_free_chunk(p, s)) | |
1696 | ||
1697 | #define is_mmapped(p)\ | |
1698 | (!((p)->head & PINUSE_BIT) && ((p)->prev_foot & IS_MMAPPED_BIT)) | |
1699 | ||
1700 | /* Get the internal overhead associated with chunk p */ | |
1701 | #define overhead_for(p)\ | |
1702 | (is_mmapped(p)? MMAP_CHUNK_OVERHEAD : CHUNK_OVERHEAD) | |
1703 | ||
1704 | /* Return true if malloced space is not necessarily cleared */ | |
1705 | #if MMAP_CLEARS | |
1706 | #define calloc_must_clear(p) (!is_mmapped(p)) | |
1707 | #else /* MMAP_CLEARS */ | |
1708 | #define calloc_must_clear(p) (1) | |
1709 | #endif /* MMAP_CLEARS */ | |
1710 | ||
1711 | /* ---------------------- Overlaid data structures ----------------------- */ | |
1712 | ||
1713 | /* | |
1714 | When chunks are not in use, they are treated as nodes of either | |
1715 | lists or trees. | |
1716 | ||
1717 | "Small" chunks are stored in circular doubly-linked lists, and look | |
1718 | like this: | |
1719 | ||
1720 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1721 | | Size of previous chunk | | |
1722 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1723 | `head:' | Size of chunk, in bytes |P| | |
1724 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1725 | | Forward pointer to next chunk in list | | |
1726 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1727 | | Back pointer to previous chunk in list | | |
1728 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1729 | | Unused space (may be 0 bytes long) . | |
1730 | . . | |
1731 | . | | |
1732 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1733 | `foot:' | Size of chunk, in bytes | | |
1734 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1735 | ||
1736 | Larger chunks are kept in a form of bitwise digital trees (aka | |
1737 | tries) keyed on chunksizes. Because malloc_tree_chunks are only for | |
1738 | free chunks greater than 256 bytes, their size doesn't impose any | |
1739 | constraints on user chunk sizes. Each node looks like: | |
1740 | ||
1741 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1742 | | Size of previous chunk | | |
1743 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1744 | `head:' | Size of chunk, in bytes |P| | |
1745 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1746 | | Forward pointer to next chunk of same size | | |
1747 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1748 | | Back pointer to previous chunk of same size | | |
1749 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1750 | | Pointer to left child (child[0]) | | |
1751 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1752 | | Pointer to right child (child[1]) | | |
1753 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1754 | | Pointer to parent | | |
1755 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1756 | | bin index of this chunk | | |
1757 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1758 | | Unused space . | |
1759 | . | | |
1760 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1761 | `foot:' | Size of chunk, in bytes | | |
1762 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
1763 | ||
1764 | Each tree holding treenodes is a tree of unique chunk sizes. Chunks | |
1765 | of the same size are arranged in a circularly-linked list, with only | |
1766 | the oldest chunk (the next to be used, in our FIFO ordering) | |
1767 | actually in the tree. (Tree members are distinguished by a non-null | |
1768 | parent pointer.) If a chunk with the same size an an existing node | |
1769 | is inserted, it is linked off the existing node using pointers that | |
1770 | work in the same way as fd/bk pointers of small chunks. | |
1771 | ||
1772 | Each tree contains a power of 2 sized range of chunk sizes (the | |
1773 | smallest is 0x100 <= x < 0x180), which is is divided in half at each | |
1774 | tree level, with the chunks in the smaller half of the range (0x100 | |
1775 | <= x < 0x140 for the top nose) in the left subtree and the larger | |
1776 | half (0x140 <= x < 0x180) in the right subtree. This is, of course, | |
1777 | done by inspecting individual bits. | |
1778 | ||
1779 | Using these rules, each node's left subtree contains all smaller | |
1780 | sizes than its right subtree. However, the node at the root of each | |
1781 | subtree has no particular ordering relationship to either. (The | |
1782 | dividing line between the subtree sizes is based on trie relation.) | |
1783 | If we remove the last chunk of a given size from the interior of the | |
1784 | tree, we need to replace it with a leaf node. The tree ordering | |
1785 | rules permit a node to be replaced by any leaf below it. | |
1786 | ||
1787 | The smallest chunk in a tree (a common operation in a best-fit | |
1788 | allocator) can be found by walking a path to the leftmost leaf in | |
1789 | the tree. Unlike a usual binary tree, where we follow left child | |
1790 | pointers until we reach a null, here we follow the right child | |
1791 | pointer any time the left one is null, until we reach a leaf with | |
1792 | both child pointers null. The smallest chunk in the tree will be | |
1793 | somewhere along that path. | |
1794 | ||
1795 | The worst case number of steps to add, find, or remove a node is | |
1796 | bounded by the number of bits differentiating chunks within | |
1797 | bins. Under current bin calculations, this ranges from 6 up to 21 | |
1798 | (for 32 bit sizes) or up to 53 (for 64 bit sizes). The typical case | |
1799 | is of course much better. | |
1800 | */ | |
1801 | ||
1802 | struct malloc_tree_chunk { | |
1803 | /* The first four fields must be compatible with malloc_chunk */ | |
1804 | size_t prev_foot; | |
1805 | size_t head; | |
1806 | struct malloc_tree_chunk* fd; | |
1807 | struct malloc_tree_chunk* bk; | |
1808 | ||
1809 | struct malloc_tree_chunk* child[2]; | |
1810 | struct malloc_tree_chunk* parent; | |
1811 | bindex_t index; | |
1812 | }; | |
1813 | ||
1814 | typedef struct malloc_tree_chunk tchunk; | |
1815 | typedef struct malloc_tree_chunk* tchunkptr; | |
1816 | typedef struct malloc_tree_chunk* tbinptr; /* The type of bins of trees */ | |
1817 | ||
1818 | /* A little helper macro for trees */ | |
1819 | #define leftmost_child(t) ((t)->child[0] != 0? (t)->child[0] : (t)->child[1]) | |
1820 | ||
1821 | /* ----------------------------- Segments -------------------------------- */ | |
1822 | ||
1823 | /* | |
1824 | Each malloc space may include non-contiguous segments, held in a | |
1825 | list headed by an embedded malloc_segment record representing the | |
1826 | top-most space. Segments also include flags holding properties of | |
1827 | the space. Large chunks that are directly allocated by mmap are not | |
1828 | included in this list. They are instead independently created and | |
1829 | destroyed without otherwise keeping track of them. | |
1830 | ||
1831 | Segment management mainly comes into play for spaces allocated by | |
1832 | MMAP. Any call to MMAP might or might not return memory that is | |
1833 | adjacent to an existing segment. MORECORE normally contiguously | |
1834 | extends the current space, so this space is almost always adjacent, | |
1835 | which is simpler and faster to deal with. (This is why MORECORE is | |
1836 | used preferentially to MMAP when both are available -- see | |
1837 | sys_alloc.) When allocating using MMAP, we don't use any of the | |
1838 | hinting mechanisms (inconsistently) supported in various | |
1839 | implementations of unix mmap, or distinguish reserving from | |
1840 | committing memory. Instead, we just ask for space, and exploit | |
1841 | contiguity when we get it. It is probably possible to do | |
1842 | better than this on some systems, but no general scheme seems | |
1843 | to be significantly better. | |
1844 | ||
1845 | Management entails a simpler variant of the consolidation scheme | |
1846 | used for chunks to reduce fragmentation -- new adjacent memory is | |
1847 | normally prepended or appended to an existing segment. However, | |
1848 | there are limitations compared to chunk consolidation that mostly | |
1849 | reflect the fact that segment processing is relatively infrequent | |
1850 | (occurring only when getting memory from system) and that we | |
1851 | don't expect to have huge numbers of segments: | |
1852 | ||
1853 | * Segments are not indexed, so traversal requires linear scans. (It | |
1854 | would be possible to index these, but is not worth the extra | |
1855 | overhead and complexity for most programs on most platforms.) | |
1856 | * New segments are only appended to old ones when holding top-most | |
1857 | memory; if they cannot be prepended to others, they are held in | |
1858 | different segments. | |
1859 | ||
1860 | Except for the top-most segment of an mstate, each segment record | |
1861 | is kept at the tail of its segment. Segments are added by pushing | |
1862 | segment records onto the list headed by &mstate.seg for the | |
1863 | containing mstate. | |
1864 | ||
1865 | Segment flags control allocation/merge/deallocation policies: | |
1866 | * If EXTERN_BIT set, then we did not allocate this segment, | |
1867 | and so should not try to deallocate or merge with others. | |
1868 | (This currently holds only for the initial segment passed | |
1869 | into create_mspace_with_base.) | |
1870 | * If IS_MMAPPED_BIT set, the segment may be merged with | |
1871 | other surrounding mmapped segments and trimmed/de-allocated | |
1872 | using munmap. | |
1873 | * If neither bit is set, then the segment was obtained using | |
1874 | MORECORE so can be merged with surrounding MORECORE'd segments | |
1875 | and deallocated/trimmed using MORECORE with negative arguments. | |
1876 | */ | |
1877 | ||
1878 | struct malloc_segment { | |
1879 | char* base; /* base address */ | |
1880 | size_t size; /* allocated size */ | |
1881 | struct malloc_segment* next; /* ptr to next segment */ | |
18fa3240 AO |
1882 | #if FFI_MMAP_EXEC_WRIT |
1883 | /* The mmap magic is supposed to store the address of the executable | |
1884 | segment at the very end of the requested block. */ | |
1885 | ||
1886 | # define mmap_exec_offset(b,s) (*(ptrdiff_t*)((b)+(s)-sizeof(ptrdiff_t))) | |
1887 | ||
1888 | /* We can only merge segments if their corresponding executable | |
1889 | segments are at identical offsets. */ | |
1890 | # define check_segment_merge(S,b,s) \ | |
1891 | (mmap_exec_offset((b),(s)) == (S)->exec_offset) | |
1892 | ||
1893 | # define add_segment_exec_offset(p,S) ((char*)(p) + (S)->exec_offset) | |
1894 | # define sub_segment_exec_offset(p,S) ((char*)(p) - (S)->exec_offset) | |
1895 | ||
1896 | /* The removal of sflags only works with HAVE_MORECORE == 0. */ | |
1897 | ||
1898 | # define get_segment_flags(S) (IS_MMAPPED_BIT) | |
1899 | # define set_segment_flags(S,v) \ | |
1900 | (((v) != IS_MMAPPED_BIT) ? (ABORT, (v)) : \ | |
1901 | (((S)->exec_offset = \ | |
1902 | mmap_exec_offset((S)->base, (S)->size)), \ | |
1903 | (mmap_exec_offset((S)->base + (S)->exec_offset, (S)->size) != \ | |
1904 | (S)->exec_offset) ? (ABORT, (v)) : \ | |
1905 | (mmap_exec_offset((S)->base, (S)->size) = 0), (v))) | |
1906 | ||
1907 | /* We use an offset here, instead of a pointer, because then, when | |
1908 | base changes, we don't have to modify this. On architectures | |
1909 | with segmented addresses, this might not work. */ | |
1910 | ptrdiff_t exec_offset; | |
1911 | #else | |
1912 | ||
1913 | # define get_segment_flags(S) ((S)->sflags) | |
1914 | # define set_segment_flags(S,v) ((S)->sflags = (v)) | |
1915 | # define check_segment_merge(S,b,s) (1) | |
1916 | ||
dd778331 | 1917 | flag_t sflags; /* mmap and extern flag */ |
18fa3240 | 1918 | #endif |
dd778331 AO |
1919 | }; |
1920 | ||
18fa3240 AO |
1921 | #define is_mmapped_segment(S) (get_segment_flags(S) & IS_MMAPPED_BIT) |
1922 | #define is_extern_segment(S) (get_segment_flags(S) & EXTERN_BIT) | |
dd778331 AO |
1923 | |
1924 | typedef struct malloc_segment msegment; | |
1925 | typedef struct malloc_segment* msegmentptr; | |
1926 | ||
1927 | /* ---------------------------- malloc_state ----------------------------- */ | |
1928 | ||
1929 | /* | |
1930 | A malloc_state holds all of the bookkeeping for a space. | |
1931 | The main fields are: | |
1932 | ||
1933 | Top | |
1934 | The topmost chunk of the currently active segment. Its size is | |
1935 | cached in topsize. The actual size of topmost space is | |
1936 | topsize+TOP_FOOT_SIZE, which includes space reserved for adding | |
1937 | fenceposts and segment records if necessary when getting more | |
1938 | space from the system. The size at which to autotrim top is | |
1939 | cached from mparams in trim_check, except that it is disabled if | |
1940 | an autotrim fails. | |
1941 | ||
1942 | Designated victim (dv) | |
1943 | This is the preferred chunk for servicing small requests that | |
1944 | don't have exact fits. It is normally the chunk split off most | |
1945 | recently to service another small request. Its size is cached in | |
1946 | dvsize. The link fields of this chunk are not maintained since it | |
1947 | is not kept in a bin. | |
1948 | ||
1949 | SmallBins | |
1950 | An array of bin headers for free chunks. These bins hold chunks | |
1951 | with sizes less than MIN_LARGE_SIZE bytes. Each bin contains | |
1952 | chunks of all the same size, spaced 8 bytes apart. To simplify | |
1953 | use in double-linked lists, each bin header acts as a malloc_chunk | |
1954 | pointing to the real first node, if it exists (else pointing to | |
1955 | itself). This avoids special-casing for headers. But to avoid | |
1956 | waste, we allocate only the fd/bk pointers of bins, and then use | |
1957 | repositioning tricks to treat these as the fields of a chunk. | |
1958 | ||
1959 | TreeBins | |
1960 | Treebins are pointers to the roots of trees holding a range of | |
1961 | sizes. There are 2 equally spaced treebins for each power of two | |
1962 | from TREE_SHIFT to TREE_SHIFT+16. The last bin holds anything | |
1963 | larger. | |
1964 | ||
1965 | Bin maps | |
1966 | There is one bit map for small bins ("smallmap") and one for | |
1967 | treebins ("treemap). Each bin sets its bit when non-empty, and | |
1968 | clears the bit when empty. Bit operations are then used to avoid | |
1969 | bin-by-bin searching -- nearly all "search" is done without ever | |
1970 | looking at bins that won't be selected. The bit maps | |
1971 | conservatively use 32 bits per map word, even if on 64bit system. | |
1972 | For a good description of some of the bit-based techniques used | |
1973 | here, see Henry S. Warren Jr's book "Hacker's Delight" (and | |
1974 | supplement at http://hackersdelight.org/). Many of these are | |
1975 | intended to reduce the branchiness of paths through malloc etc, as | |
1976 | well as to reduce the number of memory locations read or written. | |
1977 | ||
1978 | Segments | |
1979 | A list of segments headed by an embedded malloc_segment record | |
1980 | representing the initial space. | |
1981 | ||
1982 | Address check support | |
1983 | The least_addr field is the least address ever obtained from | |
1984 | MORECORE or MMAP. Attempted frees and reallocs of any address less | |
1985 | than this are trapped (unless INSECURE is defined). | |
1986 | ||
1987 | Magic tag | |
1988 | A cross-check field that should always hold same value as mparams.magic. | |
1989 | ||
1990 | Flags | |
1991 | Bits recording whether to use MMAP, locks, or contiguous MORECORE | |
1992 | ||
1993 | Statistics | |
1994 | Each space keeps track of current and maximum system memory | |
1995 | obtained via MORECORE or MMAP. | |
1996 | ||
1997 | Locking | |
1998 | If USE_LOCKS is defined, the "mutex" lock is acquired and released | |
1999 | around every public call using this mspace. | |
2000 | */ | |
2001 | ||
2002 | /* Bin types, widths and sizes */ | |
2003 | #define NSMALLBINS (32U) | |
2004 | #define NTREEBINS (32U) | |
2005 | #define SMALLBIN_SHIFT (3U) | |
2006 | #define SMALLBIN_WIDTH (SIZE_T_ONE << SMALLBIN_SHIFT) | |
2007 | #define TREEBIN_SHIFT (8U) | |
2008 | #define MIN_LARGE_SIZE (SIZE_T_ONE << TREEBIN_SHIFT) | |
2009 | #define MAX_SMALL_SIZE (MIN_LARGE_SIZE - SIZE_T_ONE) | |
2010 | #define MAX_SMALL_REQUEST (MAX_SMALL_SIZE - CHUNK_ALIGN_MASK - CHUNK_OVERHEAD) | |
2011 | ||
2012 | struct malloc_state { | |
2013 | binmap_t smallmap; | |
2014 | binmap_t treemap; | |
2015 | size_t dvsize; | |
2016 | size_t topsize; | |
2017 | char* least_addr; | |
2018 | mchunkptr dv; | |
2019 | mchunkptr top; | |
2020 | size_t trim_check; | |
2021 | size_t magic; | |
2022 | mchunkptr smallbins[(NSMALLBINS+1)*2]; | |
2023 | tbinptr treebins[NTREEBINS]; | |
2024 | size_t footprint; | |
2025 | size_t max_footprint; | |
2026 | flag_t mflags; | |
2027 | #if USE_LOCKS | |
2028 | MLOCK_T mutex; /* locate lock among fields that rarely change */ | |
2029 | #endif /* USE_LOCKS */ | |
2030 | msegment seg; | |
2031 | }; | |
2032 | ||
2033 | typedef struct malloc_state* mstate; | |
2034 | ||
2035 | /* ------------- Global malloc_state and malloc_params ------------------- */ | |
2036 | ||
2037 | /* | |
2038 | malloc_params holds global properties, including those that can be | |
2039 | dynamically set using mallopt. There is a single instance, mparams, | |
2040 | initialized in init_mparams. | |
2041 | */ | |
2042 | ||
2043 | struct malloc_params { | |
2044 | size_t magic; | |
2045 | size_t page_size; | |
2046 | size_t granularity; | |
2047 | size_t mmap_threshold; | |
2048 | size_t trim_threshold; | |
2049 | flag_t default_mflags; | |
2050 | }; | |
2051 | ||
2052 | static struct malloc_params mparams; | |
2053 | ||
2054 | /* The global malloc_state used for all non-"mspace" calls */ | |
2055 | static struct malloc_state _gm_; | |
2056 | #define gm (&_gm_) | |
2057 | #define is_global(M) ((M) == &_gm_) | |
2058 | #define is_initialized(M) ((M)->top != 0) | |
2059 | ||
2060 | /* -------------------------- system alloc setup ------------------------- */ | |
2061 | ||
2062 | /* Operations on mflags */ | |
2063 | ||
2064 | #define use_lock(M) ((M)->mflags & USE_LOCK_BIT) | |
2065 | #define enable_lock(M) ((M)->mflags |= USE_LOCK_BIT) | |
2066 | #define disable_lock(M) ((M)->mflags &= ~USE_LOCK_BIT) | |
2067 | ||
2068 | #define use_mmap(M) ((M)->mflags & USE_MMAP_BIT) | |
2069 | #define enable_mmap(M) ((M)->mflags |= USE_MMAP_BIT) | |
2070 | #define disable_mmap(M) ((M)->mflags &= ~USE_MMAP_BIT) | |
2071 | ||
2072 | #define use_noncontiguous(M) ((M)->mflags & USE_NONCONTIGUOUS_BIT) | |
2073 | #define disable_contiguous(M) ((M)->mflags |= USE_NONCONTIGUOUS_BIT) | |
2074 | ||
2075 | #define set_lock(M,L)\ | |
2076 | ((M)->mflags = (L)?\ | |
2077 | ((M)->mflags | USE_LOCK_BIT) :\ | |
2078 | ((M)->mflags & ~USE_LOCK_BIT)) | |
2079 | ||
2080 | /* page-align a size */ | |
2081 | #define page_align(S)\ | |
2082 | (((S) + (mparams.page_size)) & ~(mparams.page_size - SIZE_T_ONE)) | |
2083 | ||
2084 | /* granularity-align a size */ | |
2085 | #define granularity_align(S)\ | |
2086 | (((S) + (mparams.granularity)) & ~(mparams.granularity - SIZE_T_ONE)) | |
2087 | ||
2088 | #define is_page_aligned(S)\ | |
2089 | (((size_t)(S) & (mparams.page_size - SIZE_T_ONE)) == 0) | |
2090 | #define is_granularity_aligned(S)\ | |
2091 | (((size_t)(S) & (mparams.granularity - SIZE_T_ONE)) == 0) | |
2092 | ||
2093 | /* True if segment S holds address A */ | |
2094 | #define segment_holds(S, A)\ | |
2095 | ((char*)(A) >= S->base && (char*)(A) < S->base + S->size) | |
2096 | ||
2097 | /* Return segment holding given address */ | |
2098 | static msegmentptr segment_holding(mstate m, char* addr) { | |
2099 | msegmentptr sp = &m->seg; | |
2100 | for (;;) { | |
2101 | if (addr >= sp->base && addr < sp->base + sp->size) | |
2102 | return sp; | |
2103 | if ((sp = sp->next) == 0) | |
2104 | return 0; | |
2105 | } | |
2106 | } | |
2107 | ||
2108 | /* Return true if segment contains a segment link */ | |
2109 | static int has_segment_link(mstate m, msegmentptr ss) { | |
2110 | msegmentptr sp = &m->seg; | |
2111 | for (;;) { | |
2112 | if ((char*)sp >= ss->base && (char*)sp < ss->base + ss->size) | |
2113 | return 1; | |
2114 | if ((sp = sp->next) == 0) | |
2115 | return 0; | |
2116 | } | |
2117 | } | |
2118 | ||
2119 | #ifndef MORECORE_CANNOT_TRIM | |
2120 | #define should_trim(M,s) ((s) > (M)->trim_check) | |
2121 | #else /* MORECORE_CANNOT_TRIM */ | |
2122 | #define should_trim(M,s) (0) | |
2123 | #endif /* MORECORE_CANNOT_TRIM */ | |
2124 | ||
2125 | /* | |
2126 | TOP_FOOT_SIZE is padding at the end of a segment, including space | |
2127 | that may be needed to place segment records and fenceposts when new | |
2128 | noncontiguous segments are added. | |
2129 | */ | |
2130 | #define TOP_FOOT_SIZE\ | |
2131 | (align_offset(chunk2mem(0))+pad_request(sizeof(struct malloc_segment))+MIN_CHUNK_SIZE) | |
2132 | ||
2133 | ||
2134 | /* ------------------------------- Hooks -------------------------------- */ | |
2135 | ||
2136 | /* | |
2137 | PREACTION should be defined to return 0 on success, and nonzero on | |
2138 | failure. If you are not using locking, you can redefine these to do | |
2139 | anything you like. | |
2140 | */ | |
2141 | ||
2142 | #if USE_LOCKS | |
2143 | ||
2144 | /* Ensure locks are initialized */ | |
2145 | #define GLOBALLY_INITIALIZE() (mparams.page_size == 0 && init_mparams()) | |
2146 | ||
2147 | #define PREACTION(M) ((GLOBALLY_INITIALIZE() || use_lock(M))? ACQUIRE_LOCK(&(M)->mutex) : 0) | |
2148 | #define POSTACTION(M) { if (use_lock(M)) RELEASE_LOCK(&(M)->mutex); } | |
2149 | #else /* USE_LOCKS */ | |
2150 | ||
2151 | #ifndef PREACTION | |
2152 | #define PREACTION(M) (0) | |
2153 | #endif /* PREACTION */ | |
2154 | ||
2155 | #ifndef POSTACTION | |
2156 | #define POSTACTION(M) | |
2157 | #endif /* POSTACTION */ | |
2158 | ||
2159 | #endif /* USE_LOCKS */ | |
2160 | ||
2161 | /* | |
2162 | CORRUPTION_ERROR_ACTION is triggered upon detected bad addresses. | |
2163 | USAGE_ERROR_ACTION is triggered on detected bad frees and | |
2164 | reallocs. The argument p is an address that might have triggered the | |
2165 | fault. It is ignored by the two predefined actions, but might be | |
2166 | useful in custom actions that try to help diagnose errors. | |
2167 | */ | |
2168 | ||
2169 | #if PROCEED_ON_ERROR | |
2170 | ||
2171 | /* A count of the number of corruption errors causing resets */ | |
2172 | int malloc_corruption_error_count; | |
2173 | ||
2174 | /* default corruption action */ | |
2175 | static void reset_on_error(mstate m); | |
2176 | ||
2177 | #define CORRUPTION_ERROR_ACTION(m) reset_on_error(m) | |
2178 | #define USAGE_ERROR_ACTION(m, p) | |
2179 | ||
2180 | #else /* PROCEED_ON_ERROR */ | |
2181 | ||
2182 | #ifndef CORRUPTION_ERROR_ACTION | |
2183 | #define CORRUPTION_ERROR_ACTION(m) ABORT | |
2184 | #endif /* CORRUPTION_ERROR_ACTION */ | |
2185 | ||
2186 | #ifndef USAGE_ERROR_ACTION | |
2187 | #define USAGE_ERROR_ACTION(m,p) ABORT | |
2188 | #endif /* USAGE_ERROR_ACTION */ | |
2189 | ||
2190 | #endif /* PROCEED_ON_ERROR */ | |
2191 | ||
2192 | /* -------------------------- Debugging setup ---------------------------- */ | |
2193 | ||
2194 | #if ! DEBUG | |
2195 | ||
2196 | #define check_free_chunk(M,P) | |
2197 | #define check_inuse_chunk(M,P) | |
2198 | #define check_malloced_chunk(M,P,N) | |
2199 | #define check_mmapped_chunk(M,P) | |
2200 | #define check_malloc_state(M) | |
2201 | #define check_top_chunk(M,P) | |
2202 | ||
2203 | #else /* DEBUG */ | |
2204 | #define check_free_chunk(M,P) do_check_free_chunk(M,P) | |
2205 | #define check_inuse_chunk(M,P) do_check_inuse_chunk(M,P) | |
2206 | #define check_top_chunk(M,P) do_check_top_chunk(M,P) | |
2207 | #define check_malloced_chunk(M,P,N) do_check_malloced_chunk(M,P,N) | |
2208 | #define check_mmapped_chunk(M,P) do_check_mmapped_chunk(M,P) | |
2209 | #define check_malloc_state(M) do_check_malloc_state(M) | |
2210 | ||
2211 | static void do_check_any_chunk(mstate m, mchunkptr p); | |
2212 | static void do_check_top_chunk(mstate m, mchunkptr p); | |
2213 | static void do_check_mmapped_chunk(mstate m, mchunkptr p); | |
2214 | static void do_check_inuse_chunk(mstate m, mchunkptr p); | |
2215 | static void do_check_free_chunk(mstate m, mchunkptr p); | |
2216 | static void do_check_malloced_chunk(mstate m, void* mem, size_t s); | |
2217 | static void do_check_tree(mstate m, tchunkptr t); | |
2218 | static void do_check_treebin(mstate m, bindex_t i); | |
2219 | static void do_check_smallbin(mstate m, bindex_t i); | |
2220 | static void do_check_malloc_state(mstate m); | |
2221 | static int bin_find(mstate m, mchunkptr x); | |
2222 | static size_t traverse_and_check(mstate m); | |
2223 | #endif /* DEBUG */ | |
2224 | ||
2225 | /* ---------------------------- Indexing Bins ---------------------------- */ | |
2226 | ||
2227 | #define is_small(s) (((s) >> SMALLBIN_SHIFT) < NSMALLBINS) | |
2228 | #define small_index(s) ((s) >> SMALLBIN_SHIFT) | |
2229 | #define small_index2size(i) ((i) << SMALLBIN_SHIFT) | |
2230 | #define MIN_SMALL_INDEX (small_index(MIN_CHUNK_SIZE)) | |
2231 | ||
2232 | /* addressing by index. See above about smallbin repositioning */ | |
2233 | #define smallbin_at(M, i) ((sbinptr)((char*)&((M)->smallbins[(i)<<1]))) | |
2234 | #define treebin_at(M,i) (&((M)->treebins[i])) | |
2235 | ||
2236 | /* assign tree index for size S to variable I */ | |
2237 | #if defined(__GNUC__) && defined(i386) | |
2238 | #define compute_tree_index(S, I)\ | |
2239 | {\ | |
2240 | size_t X = S >> TREEBIN_SHIFT;\ | |
2241 | if (X == 0)\ | |
2242 | I = 0;\ | |
2243 | else if (X > 0xFFFF)\ | |
2244 | I = NTREEBINS-1;\ | |
2245 | else {\ | |
2246 | unsigned int K;\ | |
2247 | __asm__("bsrl %1,%0\n\t" : "=r" (K) : "rm" (X));\ | |
2248 | I = (bindex_t)((K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1)));\ | |
2249 | }\ | |
2250 | } | |
2251 | #else /* GNUC */ | |
2252 | #define compute_tree_index(S, I)\ | |
2253 | {\ | |
2254 | size_t X = S >> TREEBIN_SHIFT;\ | |
2255 | if (X == 0)\ | |
2256 | I = 0;\ | |
2257 | else if (X > 0xFFFF)\ | |
2258 | I = NTREEBINS-1;\ | |
2259 | else {\ | |
2260 | unsigned int Y = (unsigned int)X;\ | |
2261 | unsigned int N = ((Y - 0x100) >> 16) & 8;\ | |
2262 | unsigned int K = (((Y <<= N) - 0x1000) >> 16) & 4;\ | |
2263 | N += K;\ | |
2264 | N += K = (((Y <<= K) - 0x4000) >> 16) & 2;\ | |
2265 | K = 14 - N + ((Y <<= K) >> 15);\ | |
2266 | I = (K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1));\ | |
2267 | }\ | |
2268 | } | |
2269 | #endif /* GNUC */ | |
2270 | ||
2271 | /* Bit representing maximum resolved size in a treebin at i */ | |
2272 | #define bit_for_tree_index(i) \ | |
2273 | (i == NTREEBINS-1)? (SIZE_T_BITSIZE-1) : (((i) >> 1) + TREEBIN_SHIFT - 2) | |
2274 | ||
2275 | /* Shift placing maximum resolved bit in a treebin at i as sign bit */ | |
2276 | #define leftshift_for_tree_index(i) \ | |
2277 | ((i == NTREEBINS-1)? 0 : \ | |
2278 | ((SIZE_T_BITSIZE-SIZE_T_ONE) - (((i) >> 1) + TREEBIN_SHIFT - 2))) | |
2279 | ||
2280 | /* The size of the smallest chunk held in bin with index i */ | |
2281 | #define minsize_for_tree_index(i) \ | |
2282 | ((SIZE_T_ONE << (((i) >> 1) + TREEBIN_SHIFT)) | \ | |
2283 | (((size_t)((i) & SIZE_T_ONE)) << (((i) >> 1) + TREEBIN_SHIFT - 1))) | |
2284 | ||
2285 | ||
2286 | /* ------------------------ Operations on bin maps ----------------------- */ | |
2287 | ||
2288 | /* bit corresponding to given index */ | |
2289 | #define idx2bit(i) ((binmap_t)(1) << (i)) | |
2290 | ||
2291 | /* Mark/Clear bits with given index */ | |
2292 | #define mark_smallmap(M,i) ((M)->smallmap |= idx2bit(i)) | |
2293 | #define clear_smallmap(M,i) ((M)->smallmap &= ~idx2bit(i)) | |
2294 | #define smallmap_is_marked(M,i) ((M)->smallmap & idx2bit(i)) | |
2295 | ||
2296 | #define mark_treemap(M,i) ((M)->treemap |= idx2bit(i)) | |
2297 | #define clear_treemap(M,i) ((M)->treemap &= ~idx2bit(i)) | |
2298 | #define treemap_is_marked(M,i) ((M)->treemap & idx2bit(i)) | |
2299 | ||
2300 | /* index corresponding to given bit */ | |
2301 | ||
2302 | #if defined(__GNUC__) && defined(i386) | |
2303 | #define compute_bit2idx(X, I)\ | |
2304 | {\ | |
2305 | unsigned int J;\ | |
2306 | __asm__("bsfl %1,%0\n\t" : "=r" (J) : "rm" (X));\ | |
2307 | I = (bindex_t)J;\ | |
2308 | } | |
2309 | ||
2310 | #else /* GNUC */ | |
2311 | #if USE_BUILTIN_FFS | |
2312 | #define compute_bit2idx(X, I) I = ffs(X)-1 | |
2313 | ||
2314 | #else /* USE_BUILTIN_FFS */ | |
2315 | #define compute_bit2idx(X, I)\ | |
2316 | {\ | |
2317 | unsigned int Y = X - 1;\ | |
2318 | unsigned int K = Y >> (16-4) & 16;\ | |
2319 | unsigned int N = K; Y >>= K;\ | |
2320 | N += K = Y >> (8-3) & 8; Y >>= K;\ | |
2321 | N += K = Y >> (4-2) & 4; Y >>= K;\ | |
2322 | N += K = Y >> (2-1) & 2; Y >>= K;\ | |
2323 | N += K = Y >> (1-0) & 1; Y >>= K;\ | |
2324 | I = (bindex_t)(N + Y);\ | |
2325 | } | |
2326 | #endif /* USE_BUILTIN_FFS */ | |
2327 | #endif /* GNUC */ | |
2328 | ||
2329 | /* isolate the least set bit of a bitmap */ | |
2330 | #define least_bit(x) ((x) & -(x)) | |
2331 | ||
2332 | /* mask with all bits to left of least bit of x on */ | |
2333 | #define left_bits(x) ((x<<1) | -(x<<1)) | |
2334 | ||
2335 | /* mask with all bits to left of or equal to least bit of x on */ | |
2336 | #define same_or_left_bits(x) ((x) | -(x)) | |
2337 | ||
2338 | ||
2339 | /* ----------------------- Runtime Check Support ------------------------- */ | |
2340 | ||
2341 | /* | |
2342 | For security, the main invariant is that malloc/free/etc never | |
2343 | writes to a static address other than malloc_state, unless static | |
2344 | malloc_state itself has been corrupted, which cannot occur via | |
2345 | malloc (because of these checks). In essence this means that we | |
2346 | believe all pointers, sizes, maps etc held in malloc_state, but | |
2347 | check all of those linked or offsetted from other embedded data | |
2348 | structures. These checks are interspersed with main code in a way | |
2349 | that tends to minimize their run-time cost. | |
2350 | ||
2351 | When FOOTERS is defined, in addition to range checking, we also | |
2352 | verify footer fields of inuse chunks, which can be used guarantee | |
2353 | that the mstate controlling malloc/free is intact. This is a | |
2354 | streamlined version of the approach described by William Robertson | |
2355 | et al in "Run-time Detection of Heap-based Overflows" LISA'03 | |
2356 | http://www.usenix.org/events/lisa03/tech/robertson.html The footer | |
2357 | of an inuse chunk holds the xor of its mstate and a random seed, | |
2358 | that is checked upon calls to free() and realloc(). This is | |
2359 | (probablistically) unguessable from outside the program, but can be | |
2360 | computed by any code successfully malloc'ing any chunk, so does not | |
2361 | itself provide protection against code that has already broken | |
2362 | security through some other means. Unlike Robertson et al, we | |
2363 | always dynamically check addresses of all offset chunks (previous, | |
2364 | next, etc). This turns out to be cheaper than relying on hashes. | |
2365 | */ | |
2366 | ||
2367 | #if !INSECURE | |
2368 | /* Check if address a is at least as high as any from MORECORE or MMAP */ | |
2369 | #define ok_address(M, a) ((char*)(a) >= (M)->least_addr) | |
2370 | /* Check if address of next chunk n is higher than base chunk p */ | |
2371 | #define ok_next(p, n) ((char*)(p) < (char*)(n)) | |
2372 | /* Check if p has its cinuse bit on */ | |
2373 | #define ok_cinuse(p) cinuse(p) | |
2374 | /* Check if p has its pinuse bit on */ | |
2375 | #define ok_pinuse(p) pinuse(p) | |
2376 | ||
2377 | #else /* !INSECURE */ | |
2378 | #define ok_address(M, a) (1) | |
2379 | #define ok_next(b, n) (1) | |
2380 | #define ok_cinuse(p) (1) | |
2381 | #define ok_pinuse(p) (1) | |
2382 | #endif /* !INSECURE */ | |
2383 | ||
2384 | #if (FOOTERS && !INSECURE) | |
2385 | /* Check if (alleged) mstate m has expected magic field */ | |
2386 | #define ok_magic(M) ((M)->magic == mparams.magic) | |
2387 | #else /* (FOOTERS && !INSECURE) */ | |
2388 | #define ok_magic(M) (1) | |
2389 | #endif /* (FOOTERS && !INSECURE) */ | |
2390 | ||
2391 | ||
2392 | /* In gcc, use __builtin_expect to minimize impact of checks */ | |
2393 | #if !INSECURE | |
2394 | #if defined(__GNUC__) && __GNUC__ >= 3 | |
2395 | #define RTCHECK(e) __builtin_expect(e, 1) | |
2396 | #else /* GNUC */ | |
2397 | #define RTCHECK(e) (e) | |
2398 | #endif /* GNUC */ | |
2399 | #else /* !INSECURE */ | |
2400 | #define RTCHECK(e) (1) | |
2401 | #endif /* !INSECURE */ | |
2402 | ||
2403 | /* macros to set up inuse chunks with or without footers */ | |
2404 | ||
2405 | #if !FOOTERS | |
2406 | ||
2407 | #define mark_inuse_foot(M,p,s) | |
2408 | ||
2409 | /* Set cinuse bit and pinuse bit of next chunk */ | |
2410 | #define set_inuse(M,p,s)\ | |
2411 | ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ | |
2412 | ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) | |
2413 | ||
2414 | /* Set cinuse and pinuse of this chunk and pinuse of next chunk */ | |
2415 | #define set_inuse_and_pinuse(M,p,s)\ | |
2416 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ | |
2417 | ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) | |
2418 | ||
2419 | /* Set size, cinuse and pinuse bit of this chunk */ | |
2420 | #define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ | |
2421 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT)) | |
2422 | ||
2423 | #else /* FOOTERS */ | |
2424 | ||
2425 | /* Set foot of inuse chunk to be xor of mstate and seed */ | |
2426 | #define mark_inuse_foot(M,p,s)\ | |
2427 | (((mchunkptr)((char*)(p) + (s)))->prev_foot = ((size_t)(M) ^ mparams.magic)) | |
2428 | ||
2429 | #define get_mstate_for(p)\ | |
2430 | ((mstate)(((mchunkptr)((char*)(p) +\ | |
2431 | (chunksize(p))))->prev_foot ^ mparams.magic)) | |
2432 | ||
2433 | #define set_inuse(M,p,s)\ | |
2434 | ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ | |
2435 | (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT), \ | |
2436 | mark_inuse_foot(M,p,s)) | |
2437 | ||
2438 | #define set_inuse_and_pinuse(M,p,s)\ | |
2439 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ | |
2440 | (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT),\ | |
2441 | mark_inuse_foot(M,p,s)) | |
2442 | ||
2443 | #define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ | |
2444 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ | |
2445 | mark_inuse_foot(M, p, s)) | |
2446 | ||
2447 | #endif /* !FOOTERS */ | |
2448 | ||
2449 | /* ---------------------------- setting mparams -------------------------- */ | |
2450 | ||
2451 | /* Initialize mparams */ | |
2452 | static int init_mparams(void) { | |
2453 | if (mparams.page_size == 0) { | |
2454 | size_t s; | |
2455 | ||
2456 | mparams.mmap_threshold = DEFAULT_MMAP_THRESHOLD; | |
2457 | mparams.trim_threshold = DEFAULT_TRIM_THRESHOLD; | |
2458 | #if MORECORE_CONTIGUOUS | |
2459 | mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT; | |
2460 | #else /* MORECORE_CONTIGUOUS */ | |
2461 | mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT|USE_NONCONTIGUOUS_BIT; | |
2462 | #endif /* MORECORE_CONTIGUOUS */ | |
2463 | ||
2464 | #if (FOOTERS && !INSECURE) | |
2465 | { | |
2466 | #if USE_DEV_RANDOM | |
2467 | int fd; | |
2468 | unsigned char buf[sizeof(size_t)]; | |
2469 | /* Try to use /dev/urandom, else fall back on using time */ | |
2470 | if ((fd = open("/dev/urandom", O_RDONLY)) >= 0 && | |
2471 | read(fd, buf, sizeof(buf)) == sizeof(buf)) { | |
2472 | s = *((size_t *) buf); | |
2473 | close(fd); | |
2474 | } | |
2475 | else | |
2476 | #endif /* USE_DEV_RANDOM */ | |
2477 | s = (size_t)(time(0) ^ (size_t)0x55555555U); | |
2478 | ||
2479 | s |= (size_t)8U; /* ensure nonzero */ | |
2480 | s &= ~(size_t)7U; /* improve chances of fault for bad values */ | |
2481 | ||
2482 | } | |
2483 | #else /* (FOOTERS && !INSECURE) */ | |
2484 | s = (size_t)0x58585858U; | |
2485 | #endif /* (FOOTERS && !INSECURE) */ | |
2486 | ACQUIRE_MAGIC_INIT_LOCK(); | |
2487 | if (mparams.magic == 0) { | |
2488 | mparams.magic = s; | |
2489 | /* Set up lock for main malloc area */ | |
2490 | INITIAL_LOCK(&gm->mutex); | |
2491 | gm->mflags = mparams.default_mflags; | |
2492 | } | |
2493 | RELEASE_MAGIC_INIT_LOCK(); | |
2494 | ||
2495 | #ifndef WIN32 | |
2496 | mparams.page_size = malloc_getpagesize; | |
2497 | mparams.granularity = ((DEFAULT_GRANULARITY != 0)? | |
2498 | DEFAULT_GRANULARITY : mparams.page_size); | |
2499 | #else /* WIN32 */ | |
2500 | { | |
2501 | SYSTEM_INFO system_info; | |
2502 | GetSystemInfo(&system_info); | |
2503 | mparams.page_size = system_info.dwPageSize; | |
2504 | mparams.granularity = system_info.dwAllocationGranularity; | |
2505 | } | |
2506 | #endif /* WIN32 */ | |
2507 | ||
2508 | /* Sanity-check configuration: | |
2509 | size_t must be unsigned and as wide as pointer type. | |
2510 | ints must be at least 4 bytes. | |
2511 | alignment must be at least 8. | |
2512 | Alignment, min chunk size, and page size must all be powers of 2. | |
2513 | */ | |
2514 | if ((sizeof(size_t) != sizeof(char*)) || | |
2515 | (MAX_SIZE_T < MIN_CHUNK_SIZE) || | |
2516 | (sizeof(int) < 4) || | |
2517 | (MALLOC_ALIGNMENT < (size_t)8U) || | |
2518 | ((MALLOC_ALIGNMENT & (MALLOC_ALIGNMENT-SIZE_T_ONE)) != 0) || | |
2519 | ((MCHUNK_SIZE & (MCHUNK_SIZE-SIZE_T_ONE)) != 0) || | |
2520 | ((mparams.granularity & (mparams.granularity-SIZE_T_ONE)) != 0) || | |
2521 | ((mparams.page_size & (mparams.page_size-SIZE_T_ONE)) != 0)) | |
2522 | ABORT; | |
2523 | } | |
2524 | return 0; | |
2525 | } | |
2526 | ||
2527 | /* support for mallopt */ | |
2528 | static int change_mparam(int param_number, int value) { | |
2529 | size_t val = (size_t)value; | |
2530 | init_mparams(); | |
2531 | switch(param_number) { | |
2532 | case M_TRIM_THRESHOLD: | |
2533 | mparams.trim_threshold = val; | |
2534 | return 1; | |
2535 | case M_GRANULARITY: | |
2536 | if (val >= mparams.page_size && ((val & (val-1)) == 0)) { | |
2537 | mparams.granularity = val; | |
2538 | return 1; | |
2539 | } | |
2540 | else | |
2541 | return 0; | |
2542 | case M_MMAP_THRESHOLD: | |
2543 | mparams.mmap_threshold = val; | |
2544 | return 1; | |
2545 | default: | |
2546 | return 0; | |
2547 | } | |
2548 | } | |
2549 | ||
2550 | #if DEBUG | |
2551 | /* ------------------------- Debugging Support --------------------------- */ | |
2552 | ||
2553 | /* Check properties of any chunk, whether free, inuse, mmapped etc */ | |
2554 | static void do_check_any_chunk(mstate m, mchunkptr p) { | |
2555 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); | |
2556 | assert(ok_address(m, p)); | |
2557 | } | |
2558 | ||
2559 | /* Check properties of top chunk */ | |
2560 | static void do_check_top_chunk(mstate m, mchunkptr p) { | |
2561 | msegmentptr sp = segment_holding(m, (char*)p); | |
2562 | size_t sz = chunksize(p); | |
2563 | assert(sp != 0); | |
2564 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); | |
2565 | assert(ok_address(m, p)); | |
2566 | assert(sz == m->topsize); | |
2567 | assert(sz > 0); | |
2568 | assert(sz == ((sp->base + sp->size) - (char*)p) - TOP_FOOT_SIZE); | |
2569 | assert(pinuse(p)); | |
2570 | assert(!next_pinuse(p)); | |
2571 | } | |
2572 | ||
2573 | /* Check properties of (inuse) mmapped chunks */ | |
2574 | static void do_check_mmapped_chunk(mstate m, mchunkptr p) { | |
2575 | size_t sz = chunksize(p); | |
2576 | size_t len = (sz + (p->prev_foot & ~IS_MMAPPED_BIT) + MMAP_FOOT_PAD); | |
2577 | assert(is_mmapped(p)); | |
2578 | assert(use_mmap(m)); | |
2579 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); | |
2580 | assert(ok_address(m, p)); | |
2581 | assert(!is_small(sz)); | |
2582 | assert((len & (mparams.page_size-SIZE_T_ONE)) == 0); | |
2583 | assert(chunk_plus_offset(p, sz)->head == FENCEPOST_HEAD); | |
2584 | assert(chunk_plus_offset(p, sz+SIZE_T_SIZE)->head == 0); | |
2585 | } | |
2586 | ||
2587 | /* Check properties of inuse chunks */ | |
2588 | static void do_check_inuse_chunk(mstate m, mchunkptr p) { | |
2589 | do_check_any_chunk(m, p); | |
2590 | assert(cinuse(p)); | |
2591 | assert(next_pinuse(p)); | |
2592 | /* If not pinuse and not mmapped, previous chunk has OK offset */ | |
2593 | assert(is_mmapped(p) || pinuse(p) || next_chunk(prev_chunk(p)) == p); | |
2594 | if (is_mmapped(p)) | |
2595 | do_check_mmapped_chunk(m, p); | |
2596 | } | |
2597 | ||
2598 | /* Check properties of free chunks */ | |
2599 | static void do_check_free_chunk(mstate m, mchunkptr p) { | |
2600 | size_t sz = p->head & ~(PINUSE_BIT|CINUSE_BIT); | |
2601 | mchunkptr next = chunk_plus_offset(p, sz); | |
2602 | do_check_any_chunk(m, p); | |
2603 | assert(!cinuse(p)); | |
2604 | assert(!next_pinuse(p)); | |
2605 | assert (!is_mmapped(p)); | |
2606 | if (p != m->dv && p != m->top) { | |
2607 | if (sz >= MIN_CHUNK_SIZE) { | |
2608 | assert((sz & CHUNK_ALIGN_MASK) == 0); | |
2609 | assert(is_aligned(chunk2mem(p))); | |
2610 | assert(next->prev_foot == sz); | |
2611 | assert(pinuse(p)); | |
2612 | assert (next == m->top || cinuse(next)); | |
2613 | assert(p->fd->bk == p); | |
2614 | assert(p->bk->fd == p); | |
2615 | } | |
2616 | else /* markers are always of size SIZE_T_SIZE */ | |
2617 | assert(sz == SIZE_T_SIZE); | |
2618 | } | |
2619 | } | |
2620 | ||
2621 | /* Check properties of malloced chunks at the point they are malloced */ | |
2622 | static void do_check_malloced_chunk(mstate m, void* mem, size_t s) { | |
2623 | if (mem != 0) { | |
2624 | mchunkptr p = mem2chunk(mem); | |
2625 | size_t sz = p->head & ~(PINUSE_BIT|CINUSE_BIT); | |
2626 | do_check_inuse_chunk(m, p); | |
2627 | assert((sz & CHUNK_ALIGN_MASK) == 0); | |
2628 | assert(sz >= MIN_CHUNK_SIZE); | |
2629 | assert(sz >= s); | |
2630 | /* unless mmapped, size is less than MIN_CHUNK_SIZE more than request */ | |
2631 | assert(is_mmapped(p) || sz < (s + MIN_CHUNK_SIZE)); | |
2632 | } | |
2633 | } | |
2634 | ||
2635 | /* Check a tree and its subtrees. */ | |
2636 | static void do_check_tree(mstate m, tchunkptr t) { | |
2637 | tchunkptr head = 0; | |
2638 | tchunkptr u = t; | |
2639 | bindex_t tindex = t->index; | |
2640 | size_t tsize = chunksize(t); | |
2641 | bindex_t idx; | |
2642 | compute_tree_index(tsize, idx); | |
2643 | assert(tindex == idx); | |
2644 | assert(tsize >= MIN_LARGE_SIZE); | |
2645 | assert(tsize >= minsize_for_tree_index(idx)); | |
2646 | assert((idx == NTREEBINS-1) || (tsize < minsize_for_tree_index((idx+1)))); | |
2647 | ||
2648 | do { /* traverse through chain of same-sized nodes */ | |
2649 | do_check_any_chunk(m, ((mchunkptr)u)); | |
2650 | assert(u->index == tindex); | |
2651 | assert(chunksize(u) == tsize); | |
2652 | assert(!cinuse(u)); | |
2653 | assert(!next_pinuse(u)); | |
2654 | assert(u->fd->bk == u); | |
2655 | assert(u->bk->fd == u); | |
2656 | if (u->parent == 0) { | |
2657 | assert(u->child[0] == 0); | |
2658 | assert(u->child[1] == 0); | |
2659 | } | |
2660 | else { | |
2661 | assert(head == 0); /* only one node on chain has parent */ | |
2662 | head = u; | |
2663 | assert(u->parent != u); | |
2664 | assert (u->parent->child[0] == u || | |
2665 | u->parent->child[1] == u || | |
2666 | *((tbinptr*)(u->parent)) == u); | |
2667 | if (u->child[0] != 0) { | |
2668 | assert(u->child[0]->parent == u); | |
2669 | assert(u->child[0] != u); | |
2670 | do_check_tree(m, u->child[0]); | |
2671 | } | |
2672 | if (u->child[1] != 0) { | |
2673 | assert(u->child[1]->parent == u); | |
2674 | assert(u->child[1] != u); | |
2675 | do_check_tree(m, u->child[1]); | |
2676 | } | |
2677 | if (u->child[0] != 0 && u->child[1] != 0) { | |
2678 | assert(chunksize(u->child[0]) < chunksize(u->child[1])); | |
2679 | } | |
2680 | } | |
2681 | u = u->fd; | |
2682 | } while (u != t); | |
2683 | assert(head != 0); | |
2684 | } | |
2685 | ||
2686 | /* Check all the chunks in a treebin. */ | |
2687 | static void do_check_treebin(mstate m, bindex_t i) { | |
2688 | tbinptr* tb = treebin_at(m, i); | |
2689 | tchunkptr t = *tb; | |
2690 | int empty = (m->treemap & (1U << i)) == 0; | |
2691 | if (t == 0) | |
2692 | assert(empty); | |
2693 | if (!empty) | |
2694 | do_check_tree(m, t); | |
2695 | } | |
2696 | ||
2697 | /* Check all the chunks in a smallbin. */ | |
2698 | static void do_check_smallbin(mstate m, bindex_t i) { | |
2699 | sbinptr b = smallbin_at(m, i); | |
2700 | mchunkptr p = b->bk; | |
2701 | unsigned int empty = (m->smallmap & (1U << i)) == 0; | |
2702 | if (p == b) | |
2703 | assert(empty); | |
2704 | if (!empty) { | |
2705 | for (; p != b; p = p->bk) { | |
2706 | size_t size = chunksize(p); | |
2707 | mchunkptr q; | |
2708 | /* each chunk claims to be free */ | |
2709 | do_check_free_chunk(m, p); | |
2710 | /* chunk belongs in bin */ | |
2711 | assert(small_index(size) == i); | |
2712 | assert(p->bk == b || chunksize(p->bk) == chunksize(p)); | |
2713 | /* chunk is followed by an inuse chunk */ | |
2714 | q = next_chunk(p); | |
2715 | if (q->head != FENCEPOST_HEAD) | |
2716 | do_check_inuse_chunk(m, q); | |
2717 | } | |
2718 | } | |
2719 | } | |
2720 | ||
2721 | /* Find x in a bin. Used in other check functions. */ | |
2722 | static int bin_find(mstate m, mchunkptr x) { | |
2723 | size_t size = chunksize(x); | |
2724 | if (is_small(size)) { | |
2725 | bindex_t sidx = small_index(size); | |
2726 | sbinptr b = smallbin_at(m, sidx); | |
2727 | if (smallmap_is_marked(m, sidx)) { | |
2728 | mchunkptr p = b; | |
2729 | do { | |
2730 | if (p == x) | |
2731 | return 1; | |
2732 | } while ((p = p->fd) != b); | |
2733 | } | |
2734 | } | |
2735 | else { | |
2736 | bindex_t tidx; | |
2737 | compute_tree_index(size, tidx); | |
2738 | if (treemap_is_marked(m, tidx)) { | |
2739 | tchunkptr t = *treebin_at(m, tidx); | |
2740 | size_t sizebits = size << leftshift_for_tree_index(tidx); | |
2741 | while (t != 0 && chunksize(t) != size) { | |
2742 | t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; | |
2743 | sizebits <<= 1; | |
2744 | } | |
2745 | if (t != 0) { | |
2746 | tchunkptr u = t; | |
2747 | do { | |
2748 | if (u == (tchunkptr)x) | |
2749 | return 1; | |
2750 | } while ((u = u->fd) != t); | |
2751 | } | |
2752 | } | |
2753 | } | |
2754 | return 0; | |
2755 | } | |
2756 | ||
2757 | /* Traverse each chunk and check it; return total */ | |
2758 | static size_t traverse_and_check(mstate m) { | |
2759 | size_t sum = 0; | |
2760 | if (is_initialized(m)) { | |
2761 | msegmentptr s = &m->seg; | |
2762 | sum += m->topsize + TOP_FOOT_SIZE; | |
2763 | while (s != 0) { | |
2764 | mchunkptr q = align_as_chunk(s->base); | |
2765 | mchunkptr lastq = 0; | |
2766 | assert(pinuse(q)); | |
2767 | while (segment_holds(s, q) && | |
2768 | q != m->top && q->head != FENCEPOST_HEAD) { | |
2769 | sum += chunksize(q); | |
2770 | if (cinuse(q)) { | |
2771 | assert(!bin_find(m, q)); | |
2772 | do_check_inuse_chunk(m, q); | |
2773 | } | |
2774 | else { | |
2775 | assert(q == m->dv || bin_find(m, q)); | |
2776 | assert(lastq == 0 || cinuse(lastq)); /* Not 2 consecutive free */ | |
2777 | do_check_free_chunk(m, q); | |
2778 | } | |
2779 | lastq = q; | |
2780 | q = next_chunk(q); | |
2781 | } | |
2782 | s = s->next; | |
2783 | } | |
2784 | } | |
2785 | return sum; | |
2786 | } | |
2787 | ||
2788 | /* Check all properties of malloc_state. */ | |
2789 | static void do_check_malloc_state(mstate m) { | |
2790 | bindex_t i; | |
2791 | size_t total; | |
2792 | /* check bins */ | |
2793 | for (i = 0; i < NSMALLBINS; ++i) | |
2794 | do_check_smallbin(m, i); | |
2795 | for (i = 0; i < NTREEBINS; ++i) | |
2796 | do_check_treebin(m, i); | |
2797 | ||
2798 | if (m->dvsize != 0) { /* check dv chunk */ | |
2799 | do_check_any_chunk(m, m->dv); | |
2800 | assert(m->dvsize == chunksize(m->dv)); | |
2801 | assert(m->dvsize >= MIN_CHUNK_SIZE); | |
2802 | assert(bin_find(m, m->dv) == 0); | |
2803 | } | |
2804 | ||
2805 | if (m->top != 0) { /* check top chunk */ | |
2806 | do_check_top_chunk(m, m->top); | |
2807 | assert(m->topsize == chunksize(m->top)); | |
2808 | assert(m->topsize > 0); | |
2809 | assert(bin_find(m, m->top) == 0); | |
2810 | } | |
2811 | ||
2812 | total = traverse_and_check(m); | |
2813 | assert(total <= m->footprint); | |
2814 | assert(m->footprint <= m->max_footprint); | |
2815 | } | |
2816 | #endif /* DEBUG */ | |
2817 | ||
2818 | /* ----------------------------- statistics ------------------------------ */ | |
2819 | ||
2820 | #if !NO_MALLINFO | |
2821 | static struct mallinfo internal_mallinfo(mstate m) { | |
2822 | struct mallinfo nm = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; | |
2823 | if (!PREACTION(m)) { | |
2824 | check_malloc_state(m); | |
2825 | if (is_initialized(m)) { | |
2826 | size_t nfree = SIZE_T_ONE; /* top always free */ | |
2827 | size_t mfree = m->topsize + TOP_FOOT_SIZE; | |
2828 | size_t sum = mfree; | |
2829 | msegmentptr s = &m->seg; | |
2830 | while (s != 0) { | |
2831 | mchunkptr q = align_as_chunk(s->base); | |
2832 | while (segment_holds(s, q) && | |
2833 | q != m->top && q->head != FENCEPOST_HEAD) { | |
2834 | size_t sz = chunksize(q); | |
2835 | sum += sz; | |
2836 | if (!cinuse(q)) { | |
2837 | mfree += sz; | |
2838 | ++nfree; | |
2839 | } | |
2840 | q = next_chunk(q); | |
2841 | } | |
2842 | s = s->next; | |
2843 | } | |
2844 | ||
2845 | nm.arena = sum; | |
2846 | nm.ordblks = nfree; | |
2847 | nm.hblkhd = m->footprint - sum; | |
2848 | nm.usmblks = m->max_footprint; | |
2849 | nm.uordblks = m->footprint - mfree; | |
2850 | nm.fordblks = mfree; | |
2851 | nm.keepcost = m->topsize; | |
2852 | } | |
2853 | ||
2854 | POSTACTION(m); | |
2855 | } | |
2856 | return nm; | |
2857 | } | |
2858 | #endif /* !NO_MALLINFO */ | |
2859 | ||
2860 | static void internal_malloc_stats(mstate m) { | |
2861 | if (!PREACTION(m)) { | |
2862 | size_t maxfp = 0; | |
2863 | size_t fp = 0; | |
2864 | size_t used = 0; | |
2865 | check_malloc_state(m); | |
2866 | if (is_initialized(m)) { | |
2867 | msegmentptr s = &m->seg; | |
2868 | maxfp = m->max_footprint; | |
2869 | fp = m->footprint; | |
2870 | used = fp - (m->topsize + TOP_FOOT_SIZE); | |
2871 | ||
2872 | while (s != 0) { | |
2873 | mchunkptr q = align_as_chunk(s->base); | |
2874 | while (segment_holds(s, q) && | |
2875 | q != m->top && q->head != FENCEPOST_HEAD) { | |
2876 | if (!cinuse(q)) | |
2877 | used -= chunksize(q); | |
2878 | q = next_chunk(q); | |
2879 | } | |
2880 | s = s->next; | |
2881 | } | |
2882 | } | |
2883 | ||
2884 | fprintf(stderr, "max system bytes = %10lu\n", (unsigned long)(maxfp)); | |
2885 | fprintf(stderr, "system bytes = %10lu\n", (unsigned long)(fp)); | |
2886 | fprintf(stderr, "in use bytes = %10lu\n", (unsigned long)(used)); | |
2887 | ||
2888 | POSTACTION(m); | |
2889 | } | |
2890 | } | |
2891 | ||
2892 | /* ----------------------- Operations on smallbins ----------------------- */ | |
2893 | ||
2894 | /* | |
2895 | Various forms of linking and unlinking are defined as macros. Even | |
2896 | the ones for trees, which are very long but have very short typical | |
2897 | paths. This is ugly but reduces reliance on inlining support of | |
2898 | compilers. | |
2899 | */ | |
2900 | ||
2901 | /* Link a free chunk into a smallbin */ | |
2902 | #define insert_small_chunk(M, P, S) {\ | |
2903 | bindex_t I = small_index(S);\ | |
2904 | mchunkptr B = smallbin_at(M, I);\ | |
2905 | mchunkptr F = B;\ | |
2906 | assert(S >= MIN_CHUNK_SIZE);\ | |
2907 | if (!smallmap_is_marked(M, I))\ | |
2908 | mark_smallmap(M, I);\ | |
2909 | else if (RTCHECK(ok_address(M, B->fd)))\ | |
2910 | F = B->fd;\ | |
2911 | else {\ | |
2912 | CORRUPTION_ERROR_ACTION(M);\ | |
2913 | }\ | |
2914 | B->fd = P;\ | |
2915 | F->bk = P;\ | |
2916 | P->fd = F;\ | |
2917 | P->bk = B;\ | |
2918 | } | |
2919 | ||
2920 | /* Unlink a chunk from a smallbin */ | |
2921 | #define unlink_small_chunk(M, P, S) {\ | |
2922 | mchunkptr F = P->fd;\ | |
2923 | mchunkptr B = P->bk;\ | |
2924 | bindex_t I = small_index(S);\ | |
2925 | assert(P != B);\ | |
2926 | assert(P != F);\ | |
2927 | assert(chunksize(P) == small_index2size(I));\ | |
2928 | if (F == B)\ | |
2929 | clear_smallmap(M, I);\ | |
2930 | else if (RTCHECK((F == smallbin_at(M,I) || ok_address(M, F)) &&\ | |
2931 | (B == smallbin_at(M,I) || ok_address(M, B)))) {\ | |
2932 | F->bk = B;\ | |
2933 | B->fd = F;\ | |
2934 | }\ | |
2935 | else {\ | |
2936 | CORRUPTION_ERROR_ACTION(M);\ | |
2937 | }\ | |
2938 | } | |
2939 | ||
2940 | /* Unlink the first chunk from a smallbin */ | |
2941 | #define unlink_first_small_chunk(M, B, P, I) {\ | |
2942 | mchunkptr F = P->fd;\ | |
2943 | assert(P != B);\ | |
2944 | assert(P != F);\ | |
2945 | assert(chunksize(P) == small_index2size(I));\ | |
2946 | if (B == F)\ | |
2947 | clear_smallmap(M, I);\ | |
2948 | else if (RTCHECK(ok_address(M, F))) {\ | |
2949 | B->fd = F;\ | |
2950 | F->bk = B;\ | |
2951 | }\ | |
2952 | else {\ | |
2953 | CORRUPTION_ERROR_ACTION(M);\ | |
2954 | }\ | |
2955 | } | |
2956 | ||
2957 | /* Replace dv node, binning the old one */ | |
2958 | /* Used only when dvsize known to be small */ | |
2959 | #define replace_dv(M, P, S) {\ | |
2960 | size_t DVS = M->dvsize;\ | |
2961 | if (DVS != 0) {\ | |
2962 | mchunkptr DV = M->dv;\ | |
2963 | assert(is_small(DVS));\ | |
2964 | insert_small_chunk(M, DV, DVS);\ | |
2965 | }\ | |
2966 | M->dvsize = S;\ | |
2967 | M->dv = P;\ | |
2968 | } | |
2969 | ||
2970 | /* ------------------------- Operations on trees ------------------------- */ | |
2971 | ||
2972 | /* Insert chunk into tree */ | |
2973 | #define insert_large_chunk(M, X, S) {\ | |
2974 | tbinptr* H;\ | |
2975 | bindex_t I;\ | |
2976 | compute_tree_index(S, I);\ | |
2977 | H = treebin_at(M, I);\ | |
2978 | X->index = I;\ | |
2979 | X->child[0] = X->child[1] = 0;\ | |
2980 | if (!treemap_is_marked(M, I)) {\ | |
2981 | mark_treemap(M, I);\ | |
2982 | *H = X;\ | |
2983 | X->parent = (tchunkptr)H;\ | |
2984 | X->fd = X->bk = X;\ | |
2985 | }\ | |
2986 | else {\ | |
2987 | tchunkptr T = *H;\ | |
2988 | size_t K = S << leftshift_for_tree_index(I);\ | |
2989 | for (;;) {\ | |
2990 | if (chunksize(T) != S) {\ | |
2991 | tchunkptr* C = &(T->child[(K >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]);\ | |
2992 | K <<= 1;\ | |
2993 | if (*C != 0)\ | |
2994 | T = *C;\ | |
2995 | else if (RTCHECK(ok_address(M, C))) {\ | |
2996 | *C = X;\ | |
2997 | X->parent = T;\ | |
2998 | X->fd = X->bk = X;\ | |
2999 | break;\ | |
3000 | }\ | |
3001 | else {\ | |
3002 | CORRUPTION_ERROR_ACTION(M);\ | |
3003 | break;\ | |
3004 | }\ | |
3005 | }\ | |
3006 | else {\ | |
3007 | tchunkptr F = T->fd;\ | |
3008 | if (RTCHECK(ok_address(M, T) && ok_address(M, F))) {\ | |
3009 | T->fd = F->bk = X;\ | |
3010 | X->fd = F;\ | |
3011 | X->bk = T;\ | |
3012 | X->parent = 0;\ | |
3013 | break;\ | |
3014 | }\ | |
3015 | else {\ | |
3016 | CORRUPTION_ERROR_ACTION(M);\ | |
3017 | break;\ | |
3018 | }\ | |
3019 | }\ | |
3020 | }\ | |
3021 | }\ | |
3022 | } | |
3023 | ||
3024 | /* | |
3025 | Unlink steps: | |
3026 | ||
3027 | 1. If x is a chained node, unlink it from its same-sized fd/bk links | |
3028 | and choose its bk node as its replacement. | |
3029 | 2. If x was the last node of its size, but not a leaf node, it must | |
3030 | be replaced with a leaf node (not merely one with an open left or | |
3031 | right), to make sure that lefts and rights of descendents | |
3032 | correspond properly to bit masks. We use the rightmost descendent | |
3033 | of x. We could use any other leaf, but this is easy to locate and | |
3034 | tends to counteract removal of leftmosts elsewhere, and so keeps | |
3035 | paths shorter than minimally guaranteed. This doesn't loop much | |
3036 | because on average a node in a tree is near the bottom. | |
3037 | 3. If x is the base of a chain (i.e., has parent links) relink | |
3038 | x's parent and children to x's replacement (or null if none). | |
3039 | */ | |
3040 | ||
3041 | #define unlink_large_chunk(M, X) {\ | |
3042 | tchunkptr XP = X->parent;\ | |
3043 | tchunkptr R;\ | |
3044 | if (X->bk != X) {\ | |
3045 | tchunkptr F = X->fd;\ | |
3046 | R = X->bk;\ | |
3047 | if (RTCHECK(ok_address(M, F))) {\ | |
3048 | F->bk = R;\ | |
3049 | R->fd = F;\ | |
3050 | }\ | |
3051 | else {\ | |
3052 | CORRUPTION_ERROR_ACTION(M);\ | |
3053 | }\ | |
3054 | }\ | |
3055 | else {\ | |
3056 | tchunkptr* RP;\ | |
3057 | if (((R = *(RP = &(X->child[1]))) != 0) ||\ | |
3058 | ((R = *(RP = &(X->child[0]))) != 0)) {\ | |
3059 | tchunkptr* CP;\ | |
3060 | while ((*(CP = &(R->child[1])) != 0) ||\ | |
3061 | (*(CP = &(R->child[0])) != 0)) {\ | |
3062 | R = *(RP = CP);\ | |
3063 | }\ | |
3064 | if (RTCHECK(ok_address(M, RP)))\ | |
3065 | *RP = 0;\ | |
3066 | else {\ | |
3067 | CORRUPTION_ERROR_ACTION(M);\ | |
3068 | }\ | |
3069 | }\ | |
3070 | }\ | |
3071 | if (XP != 0) {\ | |
3072 | tbinptr* H = treebin_at(M, X->index);\ | |
3073 | if (X == *H) {\ | |
3074 | if ((*H = R) == 0) \ | |
3075 | clear_treemap(M, X->index);\ | |
3076 | }\ | |
3077 | else if (RTCHECK(ok_address(M, XP))) {\ | |
3078 | if (XP->child[0] == X) \ | |
3079 | XP->child[0] = R;\ | |
3080 | else \ | |
3081 | XP->child[1] = R;\ | |
3082 | }\ | |
3083 | else\ | |
3084 | CORRUPTION_ERROR_ACTION(M);\ | |
3085 | if (R != 0) {\ | |
3086 | if (RTCHECK(ok_address(M, R))) {\ | |
3087 | tchunkptr C0, C1;\ | |
3088 | R->parent = XP;\ | |
3089 | if ((C0 = X->child[0]) != 0) {\ | |
3090 | if (RTCHECK(ok_address(M, C0))) {\ | |
3091 | R->child[0] = C0;\ | |
3092 | C0->parent = R;\ | |
3093 | }\ | |
3094 | else\ | |
3095 | CORRUPTION_ERROR_ACTION(M);\ | |
3096 | }\ | |
3097 | if ((C1 = X->child[1]) != 0) {\ | |
3098 | if (RTCHECK(ok_address(M, C1))) {\ | |
3099 | R->child[1] = C1;\ | |
3100 | C1->parent = R;\ | |
3101 | }\ | |
3102 | else\ | |
3103 | CORRUPTION_ERROR_ACTION(M);\ | |
3104 | }\ | |
3105 | }\ | |
3106 | else\ | |
3107 | CORRUPTION_ERROR_ACTION(M);\ | |
3108 | }\ | |
3109 | }\ | |
3110 | } | |
3111 | ||
3112 | /* Relays to large vs small bin operations */ | |
3113 | ||
3114 | #define insert_chunk(M, P, S)\ | |
3115 | if (is_small(S)) insert_small_chunk(M, P, S)\ | |
3116 | else { tchunkptr TP = (tchunkptr)(P); insert_large_chunk(M, TP, S); } | |
3117 | ||
3118 | #define unlink_chunk(M, P, S)\ | |
3119 | if (is_small(S)) unlink_small_chunk(M, P, S)\ | |
3120 | else { tchunkptr TP = (tchunkptr)(P); unlink_large_chunk(M, TP); } | |
3121 | ||
3122 | ||
3123 | /* Relays to internal calls to malloc/free from realloc, memalign etc */ | |
3124 | ||
3125 | #if ONLY_MSPACES | |
3126 | #define internal_malloc(m, b) mspace_malloc(m, b) | |
3127 | #define internal_free(m, mem) mspace_free(m,mem); | |
3128 | #else /* ONLY_MSPACES */ | |
3129 | #if MSPACES | |
3130 | #define internal_malloc(m, b)\ | |
3131 | (m == gm)? dlmalloc(b) : mspace_malloc(m, b) | |
3132 | #define internal_free(m, mem)\ | |
3133 | if (m == gm) dlfree(mem); else mspace_free(m,mem); | |
3134 | #else /* MSPACES */ | |
3135 | #define internal_malloc(m, b) dlmalloc(b) | |
3136 | #define internal_free(m, mem) dlfree(mem) | |
3137 | #endif /* MSPACES */ | |
3138 | #endif /* ONLY_MSPACES */ | |
3139 | ||
3140 | /* ----------------------- Direct-mmapping chunks ----------------------- */ | |
3141 | ||
3142 | /* | |
3143 | Directly mmapped chunks are set up with an offset to the start of | |
3144 | the mmapped region stored in the prev_foot field of the chunk. This | |
3145 | allows reconstruction of the required argument to MUNMAP when freed, | |
3146 | and also allows adjustment of the returned chunk to meet alignment | |
3147 | requirements (especially in memalign). There is also enough space | |
3148 | allocated to hold a fake next chunk of size SIZE_T_SIZE to maintain | |
3149 | the PINUSE bit so frees can be checked. | |
3150 | */ | |
3151 | ||
3152 | /* Malloc using mmap */ | |
3153 | static void* mmap_alloc(mstate m, size_t nb) { | |
3154 | size_t mmsize = granularity_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK); | |
3155 | if (mmsize > nb) { /* Check for wrap around 0 */ | |
3156 | char* mm = (char*)(DIRECT_MMAP(mmsize)); | |
3157 | if (mm != CMFAIL) { | |
3158 | size_t offset = align_offset(chunk2mem(mm)); | |
3159 | size_t psize = mmsize - offset - MMAP_FOOT_PAD; | |
3160 | mchunkptr p = (mchunkptr)(mm + offset); | |
3161 | p->prev_foot = offset | IS_MMAPPED_BIT; | |
3162 | (p)->head = (psize|CINUSE_BIT); | |
3163 | mark_inuse_foot(m, p, psize); | |
3164 | chunk_plus_offset(p, psize)->head = FENCEPOST_HEAD; | |
3165 | chunk_plus_offset(p, psize+SIZE_T_SIZE)->head = 0; | |
3166 | ||
3167 | if (mm < m->least_addr) | |
3168 | m->least_addr = mm; | |
3169 | if ((m->footprint += mmsize) > m->max_footprint) | |
3170 | m->max_footprint = m->footprint; | |
3171 | assert(is_aligned(chunk2mem(p))); | |
3172 | check_mmapped_chunk(m, p); | |
3173 | return chunk2mem(p); | |
3174 | } | |
3175 | } | |
3176 | return 0; | |
3177 | } | |
3178 | ||
3179 | /* Realloc using mmap */ | |
3180 | static mchunkptr mmap_resize(mstate m, mchunkptr oldp, size_t nb) { | |
3181 | size_t oldsize = chunksize(oldp); | |
3182 | if (is_small(nb)) /* Can't shrink mmap regions below small size */ | |
3183 | return 0; | |
3184 | /* Keep old chunk if big enough but not too big */ | |
3185 | if (oldsize >= nb + SIZE_T_SIZE && | |
3186 | (oldsize - nb) <= (mparams.granularity << 1)) | |
3187 | return oldp; | |
3188 | else { | |
3189 | size_t offset = oldp->prev_foot & ~IS_MMAPPED_BIT; | |
3190 | size_t oldmmsize = oldsize + offset + MMAP_FOOT_PAD; | |
3191 | size_t newmmsize = granularity_align(nb + SIX_SIZE_T_SIZES + | |
3192 | CHUNK_ALIGN_MASK); | |
3193 | char* cp = (char*)CALL_MREMAP((char*)oldp - offset, | |
3194 | oldmmsize, newmmsize, 1); | |
3195 | if (cp != CMFAIL) { | |
3196 | mchunkptr newp = (mchunkptr)(cp + offset); | |
3197 | size_t psize = newmmsize - offset - MMAP_FOOT_PAD; | |
3198 | newp->head = (psize|CINUSE_BIT); | |
3199 | mark_inuse_foot(m, newp, psize); | |
3200 | chunk_plus_offset(newp, psize)->head = FENCEPOST_HEAD; | |
3201 | chunk_plus_offset(newp, psize+SIZE_T_SIZE)->head = 0; | |
3202 | ||
3203 | if (cp < m->least_addr) | |
3204 | m->least_addr = cp; | |
3205 | if ((m->footprint += newmmsize - oldmmsize) > m->max_footprint) | |
3206 | m->max_footprint = m->footprint; | |
3207 | check_mmapped_chunk(m, newp); | |
3208 | return newp; | |
3209 | } | |
3210 | } | |
3211 | return 0; | |
3212 | } | |
3213 | ||
3214 | /* -------------------------- mspace management -------------------------- */ | |
3215 | ||
3216 | /* Initialize top chunk and its size */ | |
3217 | static void init_top(mstate m, mchunkptr p, size_t psize) { | |
3218 | /* Ensure alignment */ | |
3219 | size_t offset = align_offset(chunk2mem(p)); | |
3220 | p = (mchunkptr)((char*)p + offset); | |
3221 | psize -= offset; | |
3222 | ||
3223 | m->top = p; | |
3224 | m->topsize = psize; | |
3225 | p->head = psize | PINUSE_BIT; | |
3226 | /* set size of fake trailing chunk holding overhead space only once */ | |
3227 | chunk_plus_offset(p, psize)->head = TOP_FOOT_SIZE; | |
3228 | m->trim_check = mparams.trim_threshold; /* reset on each update */ | |
3229 | } | |
3230 | ||
3231 | /* Initialize bins for a new mstate that is otherwise zeroed out */ | |
3232 | static void init_bins(mstate m) { | |
3233 | /* Establish circular links for smallbins */ | |
3234 | bindex_t i; | |
3235 | for (i = 0; i < NSMALLBINS; ++i) { | |
3236 | sbinptr bin = smallbin_at(m,i); | |
3237 | bin->fd = bin->bk = bin; | |
3238 | } | |
3239 | } | |
3240 | ||
3241 | #if PROCEED_ON_ERROR | |
3242 | ||
3243 | /* default corruption action */ | |
3244 | static void reset_on_error(mstate m) { | |
3245 | int i; | |
3246 | ++malloc_corruption_error_count; | |
3247 | /* Reinitialize fields to forget about all memory */ | |
3248 | m->smallbins = m->treebins = 0; | |
3249 | m->dvsize = m->topsize = 0; | |
3250 | m->seg.base = 0; | |
3251 | m->seg.size = 0; | |
3252 | m->seg.next = 0; | |
3253 | m->top = m->dv = 0; | |
3254 | for (i = 0; i < NTREEBINS; ++i) | |
3255 | *treebin_at(m, i) = 0; | |
3256 | init_bins(m); | |
3257 | } | |
3258 | #endif /* PROCEED_ON_ERROR */ | |
3259 | ||
3260 | /* Allocate chunk and prepend remainder with chunk in successor base. */ | |
3261 | static void* prepend_alloc(mstate m, char* newbase, char* oldbase, | |
3262 | size_t nb) { | |
3263 | mchunkptr p = align_as_chunk(newbase); | |
3264 | mchunkptr oldfirst = align_as_chunk(oldbase); | |
3265 | size_t psize = (char*)oldfirst - (char*)p; | |
3266 | mchunkptr q = chunk_plus_offset(p, nb); | |
3267 | size_t qsize = psize - nb; | |
3268 | set_size_and_pinuse_of_inuse_chunk(m, p, nb); | |
3269 | ||
3270 | assert((char*)oldfirst > (char*)q); | |
3271 | assert(pinuse(oldfirst)); | |
3272 | assert(qsize >= MIN_CHUNK_SIZE); | |
3273 | ||
3274 | /* consolidate remainder with first chunk of old base */ | |
3275 | if (oldfirst == m->top) { | |
3276 | size_t tsize = m->topsize += qsize; | |
3277 | m->top = q; | |
3278 | q->head = tsize | PINUSE_BIT; | |
3279 | check_top_chunk(m, q); | |
3280 | } | |
3281 | else if (oldfirst == m->dv) { | |
3282 | size_t dsize = m->dvsize += qsize; | |
3283 | m->dv = q; | |
3284 | set_size_and_pinuse_of_free_chunk(q, dsize); | |
3285 | } | |
3286 | else { | |
3287 | if (!cinuse(oldfirst)) { | |
3288 | size_t nsize = chunksize(oldfirst); | |
3289 | unlink_chunk(m, oldfirst, nsize); | |
3290 | oldfirst = chunk_plus_offset(oldfirst, nsize); | |
3291 | qsize += nsize; | |
3292 | } | |
3293 | set_free_with_pinuse(q, qsize, oldfirst); | |
3294 | insert_chunk(m, q, qsize); | |
3295 | check_free_chunk(m, q); | |
3296 | } | |
3297 | ||
3298 | check_malloced_chunk(m, chunk2mem(p), nb); | |
3299 | return chunk2mem(p); | |
3300 | } | |
3301 | ||
3302 | ||
3303 | /* Add a segment to hold a new noncontiguous region */ | |
3304 | static void add_segment(mstate m, char* tbase, size_t tsize, flag_t mmapped) { | |
3305 | /* Determine locations and sizes of segment, fenceposts, old top */ | |
3306 | char* old_top = (char*)m->top; | |
3307 | msegmentptr oldsp = segment_holding(m, old_top); | |
3308 | char* old_end = oldsp->base + oldsp->size; | |
3309 | size_t ssize = pad_request(sizeof(struct malloc_segment)); | |
3310 | char* rawsp = old_end - (ssize + FOUR_SIZE_T_SIZES + CHUNK_ALIGN_MASK); | |
3311 | size_t offset = align_offset(chunk2mem(rawsp)); | |
3312 | char* asp = rawsp + offset; | |
3313 | char* csp = (asp < (old_top + MIN_CHUNK_SIZE))? old_top : asp; | |
3314 | mchunkptr sp = (mchunkptr)csp; | |
3315 | msegmentptr ss = (msegmentptr)(chunk2mem(sp)); | |
3316 | mchunkptr tnext = chunk_plus_offset(sp, ssize); | |
3317 | mchunkptr p = tnext; | |
3318 | int nfences = 0; | |
3319 | ||
3320 | /* reset top to new space */ | |
3321 | init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); | |
3322 | ||
3323 | /* Set up segment record */ | |
3324 | assert(is_aligned(ss)); | |
3325 | set_size_and_pinuse_of_inuse_chunk(m, sp, ssize); | |
3326 | *ss = m->seg; /* Push current record */ | |
3327 | m->seg.base = tbase; | |
3328 | m->seg.size = tsize; | |
18fa3240 | 3329 | set_segment_flags(&m->seg, mmapped); |
dd778331 AO |
3330 | m->seg.next = ss; |
3331 | ||
3332 | /* Insert trailing fenceposts */ | |
3333 | for (;;) { | |
3334 | mchunkptr nextp = chunk_plus_offset(p, SIZE_T_SIZE); | |
3335 | p->head = FENCEPOST_HEAD; | |
3336 | ++nfences; | |
3337 | if ((char*)(&(nextp->head)) < old_end) | |
3338 | p = nextp; | |
3339 | else | |
3340 | break; | |
3341 | } | |
3342 | assert(nfences >= 2); | |
3343 | ||
3344 | /* Insert the rest of old top into a bin as an ordinary free chunk */ | |
3345 | if (csp != old_top) { | |
3346 | mchunkptr q = (mchunkptr)old_top; | |
3347 | size_t psize = csp - old_top; | |
3348 | mchunkptr tn = chunk_plus_offset(q, psize); | |
3349 | set_free_with_pinuse(q, psize, tn); | |
3350 | insert_chunk(m, q, psize); | |
3351 | } | |
3352 | ||
3353 | check_top_chunk(m, m->top); | |
3354 | } | |
3355 | ||
3356 | /* -------------------------- System allocation -------------------------- */ | |
3357 | ||
3358 | /* Get memory from system using MORECORE or MMAP */ | |
3359 | static void* sys_alloc(mstate m, size_t nb) { | |
3360 | char* tbase = CMFAIL; | |
3361 | size_t tsize = 0; | |
3362 | flag_t mmap_flag = 0; | |
3363 | ||
3364 | init_mparams(); | |
3365 | ||
3366 | /* Directly map large chunks */ | |
3367 | if (use_mmap(m) && nb >= mparams.mmap_threshold) { | |
3368 | void* mem = mmap_alloc(m, nb); | |
3369 | if (mem != 0) | |
3370 | return mem; | |
3371 | } | |
3372 | ||
3373 | /* | |
3374 | Try getting memory in any of three ways (in most-preferred to | |
3375 | least-preferred order): | |
3376 | 1. A call to MORECORE that can normally contiguously extend memory. | |
3377 | (disabled if not MORECORE_CONTIGUOUS or not HAVE_MORECORE or | |
3378 | or main space is mmapped or a previous contiguous call failed) | |
3379 | 2. A call to MMAP new space (disabled if not HAVE_MMAP). | |
3380 | Note that under the default settings, if MORECORE is unable to | |
3381 | fulfill a request, and HAVE_MMAP is true, then mmap is | |
3382 | used as a noncontiguous system allocator. This is a useful backup | |
3383 | strategy for systems with holes in address spaces -- in this case | |
3384 | sbrk cannot contiguously expand the heap, but mmap may be able to | |
3385 | find space. | |
3386 | 3. A call to MORECORE that cannot usually contiguously extend memory. | |
3387 | (disabled if not HAVE_MORECORE) | |
3388 | */ | |
3389 | ||
3390 | if (MORECORE_CONTIGUOUS && !use_noncontiguous(m)) { | |
3391 | char* br = CMFAIL; | |
3392 | msegmentptr ss = (m->top == 0)? 0 : segment_holding(m, (char*)m->top); | |
3393 | size_t asize = 0; | |
3394 | ACQUIRE_MORECORE_LOCK(); | |
3395 | ||
3396 | if (ss == 0) { /* First time through or recovery */ | |
3397 | char* base = (char*)CALL_MORECORE(0); | |
3398 | if (base != CMFAIL) { | |
3399 | asize = granularity_align(nb + TOP_FOOT_SIZE + SIZE_T_ONE); | |
3400 | /* Adjust to end on a page boundary */ | |
3401 | if (!is_page_aligned(base)) | |
3402 | asize += (page_align((size_t)base) - (size_t)base); | |
3403 | /* Can't call MORECORE if size is negative when treated as signed */ | |
3404 | if (asize < HALF_MAX_SIZE_T && | |
3405 | (br = (char*)(CALL_MORECORE(asize))) == base) { | |
3406 | tbase = base; | |
3407 | tsize = asize; | |
3408 | } | |
3409 | } | |
3410 | } | |
3411 | else { | |
3412 | /* Subtract out existing available top space from MORECORE request. */ | |
3413 | asize = granularity_align(nb - m->topsize + TOP_FOOT_SIZE + SIZE_T_ONE); | |
3414 | /* Use mem here only if it did continuously extend old space */ | |
3415 | if (asize < HALF_MAX_SIZE_T && | |
3416 | (br = (char*)(CALL_MORECORE(asize))) == ss->base+ss->size) { | |
3417 | tbase = br; | |
3418 | tsize = asize; | |
3419 | } | |
3420 | } | |
3421 | ||
3422 | if (tbase == CMFAIL) { /* Cope with partial failure */ | |
3423 | if (br != CMFAIL) { /* Try to use/extend the space we did get */ | |
3424 | if (asize < HALF_MAX_SIZE_T && | |
3425 | asize < nb + TOP_FOOT_SIZE + SIZE_T_ONE) { | |
3426 | size_t esize = granularity_align(nb + TOP_FOOT_SIZE + SIZE_T_ONE - asize); | |
3427 | if (esize < HALF_MAX_SIZE_T) { | |
3428 | char* end = (char*)CALL_MORECORE(esize); | |
3429 | if (end != CMFAIL) | |
3430 | asize += esize; | |
3431 | else { /* Can't use; try to release */ | |
18fa3240 | 3432 | (void)CALL_MORECORE(-asize); |
dd778331 AO |
3433 | br = CMFAIL; |
3434 | } | |
3435 | } | |
3436 | } | |
3437 | } | |
3438 | if (br != CMFAIL) { /* Use the space we did get */ | |
3439 | tbase = br; | |
3440 | tsize = asize; | |
3441 | } | |
3442 | else | |
3443 | disable_contiguous(m); /* Don't try contiguous path in the future */ | |
3444 | } | |
3445 | ||
3446 | RELEASE_MORECORE_LOCK(); | |
3447 | } | |
3448 | ||
3449 | if (HAVE_MMAP && tbase == CMFAIL) { /* Try MMAP */ | |
3450 | size_t req = nb + TOP_FOOT_SIZE + SIZE_T_ONE; | |
3451 | size_t rsize = granularity_align(req); | |
3452 | if (rsize > nb) { /* Fail if wraps around zero */ | |
3453 | char* mp = (char*)(CALL_MMAP(rsize)); | |
3454 | if (mp != CMFAIL) { | |
3455 | tbase = mp; | |
3456 | tsize = rsize; | |
3457 | mmap_flag = IS_MMAPPED_BIT; | |
3458 | } | |
3459 | } | |
3460 | } | |
3461 | ||
3462 | if (HAVE_MORECORE && tbase == CMFAIL) { /* Try noncontiguous MORECORE */ | |
3463 | size_t asize = granularity_align(nb + TOP_FOOT_SIZE + SIZE_T_ONE); | |
3464 | if (asize < HALF_MAX_SIZE_T) { | |
3465 | char* br = CMFAIL; | |
3466 | char* end = CMFAIL; | |
3467 | ACQUIRE_MORECORE_LOCK(); | |
3468 | br = (char*)(CALL_MORECORE(asize)); | |
3469 | end = (char*)(CALL_MORECORE(0)); | |
3470 | RELEASE_MORECORE_LOCK(); | |
3471 | if (br != CMFAIL && end != CMFAIL && br < end) { | |
3472 | size_t ssize = end - br; | |
3473 | if (ssize > nb + TOP_FOOT_SIZE) { | |
3474 | tbase = br; | |
3475 | tsize = ssize; | |
3476 | } | |
3477 | } | |
3478 | } | |
3479 | } | |
3480 | ||
3481 | if (tbase != CMFAIL) { | |
3482 | ||
3483 | if ((m->footprint += tsize) > m->max_footprint) | |
3484 | m->max_footprint = m->footprint; | |
3485 | ||
3486 | if (!is_initialized(m)) { /* first-time initialization */ | |
3487 | m->seg.base = m->least_addr = tbase; | |
3488 | m->seg.size = tsize; | |
18fa3240 | 3489 | set_segment_flags(&m->seg, mmap_flag); |
dd778331 AO |
3490 | m->magic = mparams.magic; |
3491 | init_bins(m); | |
3492 | if (is_global(m)) | |
3493 | init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); | |
3494 | else { | |
3495 | /* Offset top by embedded malloc_state */ | |
3496 | mchunkptr mn = next_chunk(mem2chunk(m)); | |
3497 | init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) -TOP_FOOT_SIZE); | |
3498 | } | |
3499 | } | |
3500 | ||
3501 | else { | |
3502 | /* Try to merge with an existing segment */ | |
3503 | msegmentptr sp = &m->seg; | |
3504 | while (sp != 0 && tbase != sp->base + sp->size) | |
3505 | sp = sp->next; | |
3506 | if (sp != 0 && | |
3507 | !is_extern_segment(sp) && | |
18fa3240 AO |
3508 | check_segment_merge(sp, tbase, tsize) && |
3509 | (get_segment_flags(sp) & IS_MMAPPED_BIT) == mmap_flag && | |
dd778331 AO |
3510 | segment_holds(sp, m->top)) { /* append */ |
3511 | sp->size += tsize; | |
3512 | init_top(m, m->top, m->topsize + tsize); | |
3513 | } | |
3514 | else { | |
3515 | if (tbase < m->least_addr) | |
3516 | m->least_addr = tbase; | |
3517 | sp = &m->seg; | |
3518 | while (sp != 0 && sp->base != tbase + tsize) | |
3519 | sp = sp->next; | |
3520 | if (sp != 0 && | |
3521 | !is_extern_segment(sp) && | |
18fa3240 AO |
3522 | check_segment_merge(sp, tbase, tsize) && |
3523 | (get_segment_flags(sp) & IS_MMAPPED_BIT) == mmap_flag) { | |
dd778331 AO |
3524 | char* oldbase = sp->base; |
3525 | sp->base = tbase; | |
3526 | sp->size += tsize; | |
3527 | return prepend_alloc(m, tbase, oldbase, nb); | |
3528 | } | |
3529 | else | |
3530 | add_segment(m, tbase, tsize, mmap_flag); | |
3531 | } | |
3532 | } | |
3533 | ||
3534 | if (nb < m->topsize) { /* Allocate from new or extended top space */ | |
3535 | size_t rsize = m->topsize -= nb; | |
3536 | mchunkptr p = m->top; | |
3537 | mchunkptr r = m->top = chunk_plus_offset(p, nb); | |
3538 | r->head = rsize | PINUSE_BIT; | |
3539 | set_size_and_pinuse_of_inuse_chunk(m, p, nb); | |
3540 | check_top_chunk(m, m->top); | |
3541 | check_malloced_chunk(m, chunk2mem(p), nb); | |
3542 | return chunk2mem(p); | |
3543 | } | |
3544 | } | |
3545 | ||
3546 | MALLOC_FAILURE_ACTION; | |
3547 | return 0; | |
3548 | } | |
3549 | ||
3550 | /* ----------------------- system deallocation -------------------------- */ | |
3551 | ||
3552 | /* Unmap and unlink any mmapped segments that don't contain used chunks */ | |
3553 | static size_t release_unused_segments(mstate m) { | |
3554 | size_t released = 0; | |
3555 | msegmentptr pred = &m->seg; | |
3556 | msegmentptr sp = pred->next; | |
3557 | while (sp != 0) { | |
3558 | char* base = sp->base; | |
3559 | size_t size = sp->size; | |
3560 | msegmentptr next = sp->next; | |
3561 | if (is_mmapped_segment(sp) && !is_extern_segment(sp)) { | |
3562 | mchunkptr p = align_as_chunk(base); | |
3563 | size_t psize = chunksize(p); | |
3564 | /* Can unmap if first chunk holds entire segment and not pinned */ | |
3565 | if (!cinuse(p) && (char*)p + psize >= base + size - TOP_FOOT_SIZE) { | |
3566 | tchunkptr tp = (tchunkptr)p; | |
3567 | assert(segment_holds(sp, (char*)sp)); | |
3568 | if (p == m->dv) { | |
3569 | m->dv = 0; | |
3570 | m->dvsize = 0; | |
3571 | } | |
3572 | else { | |
3573 | unlink_large_chunk(m, tp); | |
3574 | } | |
3575 | if (CALL_MUNMAP(base, size) == 0) { | |
3576 | released += size; | |
3577 | m->footprint -= size; | |
3578 | /* unlink obsoleted record */ | |
3579 | sp = pred; | |
3580 | sp->next = next; | |
3581 | } | |
3582 | else { /* back out if cannot unmap */ | |
3583 | insert_large_chunk(m, tp, psize); | |
3584 | } | |
3585 | } | |
3586 | } | |
3587 | pred = sp; | |
3588 | sp = next; | |
3589 | } | |
3590 | return released; | |
3591 | } | |
3592 | ||
3593 | static int sys_trim(mstate m, size_t pad) { | |
3594 | size_t released = 0; | |
3595 | if (pad < MAX_REQUEST && is_initialized(m)) { | |
3596 | pad += TOP_FOOT_SIZE; /* ensure enough room for segment overhead */ | |
3597 | ||
3598 | if (m->topsize > pad) { | |
3599 | /* Shrink top space in granularity-size units, keeping at least one */ | |
3600 | size_t unit = mparams.granularity; | |
3601 | size_t extra = ((m->topsize - pad + (unit - SIZE_T_ONE)) / unit - | |
3602 | SIZE_T_ONE) * unit; | |
3603 | msegmentptr sp = segment_holding(m, (char*)m->top); | |
3604 | ||
3605 | if (!is_extern_segment(sp)) { | |
3606 | if (is_mmapped_segment(sp)) { | |
3607 | if (HAVE_MMAP && | |
3608 | sp->size >= extra && | |
3609 | !has_segment_link(m, sp)) { /* can't shrink if pinned */ | |
3610 | size_t newsize = sp->size - extra; | |
3611 | /* Prefer mremap, fall back to munmap */ | |
3612 | if ((CALL_MREMAP(sp->base, sp->size, newsize, 0) != MFAIL) || | |
3613 | (CALL_MUNMAP(sp->base + newsize, extra) == 0)) { | |
3614 | released = extra; | |
3615 | } | |
3616 | } | |
3617 | } | |
3618 | else if (HAVE_MORECORE) { | |
3619 | if (extra >= HALF_MAX_SIZE_T) /* Avoid wrapping negative */ | |
3620 | extra = (HALF_MAX_SIZE_T) + SIZE_T_ONE - unit; | |
3621 | ACQUIRE_MORECORE_LOCK(); | |
3622 | { | |
3623 | /* Make sure end of memory is where we last set it. */ | |
3624 | char* old_br = (char*)(CALL_MORECORE(0)); | |
3625 | if (old_br == sp->base + sp->size) { | |
3626 | char* rel_br = (char*)(CALL_MORECORE(-extra)); | |
3627 | char* new_br = (char*)(CALL_MORECORE(0)); | |
3628 | if (rel_br != CMFAIL && new_br < old_br) | |
3629 | released = old_br - new_br; | |
3630 | } | |
3631 | } | |
3632 | RELEASE_MORECORE_LOCK(); | |
3633 | } | |
3634 | } | |
3635 | ||
3636 | if (released != 0) { | |
3637 | sp->size -= released; | |
3638 | m->footprint -= released; | |
3639 | init_top(m, m->top, m->topsize - released); | |
3640 | check_top_chunk(m, m->top); | |
3641 | } | |
3642 | } | |
3643 | ||
3644 | /* Unmap any unused mmapped segments */ | |
3645 | if (HAVE_MMAP) | |
3646 | released += release_unused_segments(m); | |
3647 | ||
3648 | /* On failure, disable autotrim to avoid repeated failed future calls */ | |
3649 | if (released == 0) | |
3650 | m->trim_check = MAX_SIZE_T; | |
3651 | } | |
3652 | ||
3653 | return (released != 0)? 1 : 0; | |
3654 | } | |
3655 | ||
3656 | /* ---------------------------- malloc support --------------------------- */ | |
3657 | ||
3658 | /* allocate a large request from the best fitting chunk in a treebin */ | |
3659 | static void* tmalloc_large(mstate m, size_t nb) { | |
3660 | tchunkptr v = 0; | |
3661 | size_t rsize = -nb; /* Unsigned negation */ | |
3662 | tchunkptr t; | |
3663 | bindex_t idx; | |
3664 | compute_tree_index(nb, idx); | |
3665 | ||
3666 | if ((t = *treebin_at(m, idx)) != 0) { | |
3667 | /* Traverse tree for this bin looking for node with size == nb */ | |
3668 | size_t sizebits = nb << leftshift_for_tree_index(idx); | |
3669 | tchunkptr rst = 0; /* The deepest untaken right subtree */ | |
3670 | for (;;) { | |
3671 | tchunkptr rt; | |
3672 | size_t trem = chunksize(t) - nb; | |
3673 | if (trem < rsize) { | |
3674 | v = t; | |
3675 | if ((rsize = trem) == 0) | |
3676 | break; | |
3677 | } | |
3678 | rt = t->child[1]; | |
3679 | t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; | |
3680 | if (rt != 0 && rt != t) | |
3681 | rst = rt; | |
3682 | if (t == 0) { | |
3683 | t = rst; /* set t to least subtree holding sizes > nb */ | |
3684 | break; | |
3685 | } | |
3686 | sizebits <<= 1; | |
3687 | } | |
3688 | } | |
3689 | ||
3690 | if (t == 0 && v == 0) { /* set t to root of next non-empty treebin */ | |
3691 | binmap_t leftbits = left_bits(idx2bit(idx)) & m->treemap; | |
3692 | if (leftbits != 0) { | |
3693 | bindex_t i; | |
3694 | binmap_t leastbit = least_bit(leftbits); | |
3695 | compute_bit2idx(leastbit, i); | |
3696 | t = *treebin_at(m, i); | |
3697 | } | |
3698 | } | |
3699 | ||
3700 | while (t != 0) { /* find smallest of tree or subtree */ | |
3701 | size_t trem = chunksize(t) - nb; | |
3702 | if (trem < rsize) { | |
3703 | rsize = trem; | |
3704 | v = t; | |
3705 | } | |
3706 | t = leftmost_child(t); | |
3707 | } | |
3708 | ||
3709 | /* If dv is a better fit, return 0 so malloc will use it */ | |
3710 | if (v != 0 && rsize < (size_t)(m->dvsize - nb)) { | |
3711 | if (RTCHECK(ok_address(m, v))) { /* split */ | |
3712 | mchunkptr r = chunk_plus_offset(v, nb); | |
3713 | assert(chunksize(v) == rsize + nb); | |
3714 | if (RTCHECK(ok_next(v, r))) { | |
3715 | unlink_large_chunk(m, v); | |
3716 | if (rsize < MIN_CHUNK_SIZE) | |
3717 | set_inuse_and_pinuse(m, v, (rsize + nb)); | |
3718 | else { | |
3719 | set_size_and_pinuse_of_inuse_chunk(m, v, nb); | |
3720 | set_size_and_pinuse_of_free_chunk(r, rsize); | |
3721 | insert_chunk(m, r, rsize); | |
3722 | } | |
3723 | return chunk2mem(v); | |
3724 | } | |
3725 | } | |
3726 | CORRUPTION_ERROR_ACTION(m); | |
3727 | } | |
3728 | return 0; | |
3729 | } | |
3730 | ||
3731 | /* allocate a small request from the best fitting chunk in a treebin */ | |
3732 | static void* tmalloc_small(mstate m, size_t nb) { | |
3733 | tchunkptr t, v; | |
3734 | size_t rsize; | |
3735 | bindex_t i; | |
3736 | binmap_t leastbit = least_bit(m->treemap); | |
3737 | compute_bit2idx(leastbit, i); | |
3738 | ||
3739 | v = t = *treebin_at(m, i); | |
3740 | rsize = chunksize(t) - nb; | |
3741 | ||
3742 | while ((t = leftmost_child(t)) != 0) { | |
3743 | size_t trem = chunksize(t) - nb; | |
3744 | if (trem < rsize) { | |
3745 | rsize = trem; | |
3746 | v = t; | |
3747 | } | |
3748 | } | |
3749 | ||
3750 | if (RTCHECK(ok_address(m, v))) { | |
3751 | mchunkptr r = chunk_plus_offset(v, nb); | |
3752 | assert(chunksize(v) == rsize + nb); | |
3753 | if (RTCHECK(ok_next(v, r))) { | |
3754 | unlink_large_chunk(m, v); | |
3755 | if (rsize < MIN_CHUNK_SIZE) | |
3756 | set_inuse_and_pinuse(m, v, (rsize + nb)); | |
3757 | else { | |
3758 | set_size_and_pinuse_of_inuse_chunk(m, v, nb); | |
3759 | set_size_and_pinuse_of_free_chunk(r, rsize); | |
3760 | replace_dv(m, r, rsize); | |
3761 | } | |
3762 | return chunk2mem(v); | |
3763 | } | |
3764 | } | |
3765 | ||
3766 | CORRUPTION_ERROR_ACTION(m); | |
3767 | return 0; | |
3768 | } | |
3769 | ||
3770 | /* --------------------------- realloc support --------------------------- */ | |
3771 | ||
3772 | static void* internal_realloc(mstate m, void* oldmem, size_t bytes) { | |
3773 | if (bytes >= MAX_REQUEST) { | |
3774 | MALLOC_FAILURE_ACTION; | |
3775 | return 0; | |
3776 | } | |
3777 | if (!PREACTION(m)) { | |
3778 | mchunkptr oldp = mem2chunk(oldmem); | |
3779 | size_t oldsize = chunksize(oldp); | |
3780 | mchunkptr next = chunk_plus_offset(oldp, oldsize); | |
3781 | mchunkptr newp = 0; | |
3782 | void* extra = 0; | |
3783 | ||
3784 | /* Try to either shrink or extend into top. Else malloc-copy-free */ | |
3785 | ||
3786 | if (RTCHECK(ok_address(m, oldp) && ok_cinuse(oldp) && | |
3787 | ok_next(oldp, next) && ok_pinuse(next))) { | |
3788 | size_t nb = request2size(bytes); | |
3789 | if (is_mmapped(oldp)) | |
3790 | newp = mmap_resize(m, oldp, nb); | |
3791 | else if (oldsize >= nb) { /* already big enough */ | |
3792 | size_t rsize = oldsize - nb; | |
3793 | newp = oldp; | |
3794 | if (rsize >= MIN_CHUNK_SIZE) { | |
3795 | mchunkptr remainder = chunk_plus_offset(newp, nb); | |
3796 | set_inuse(m, newp, nb); | |
3797 | set_inuse(m, remainder, rsize); | |
3798 | extra = chunk2mem(remainder); | |
3799 | } | |
3800 | } | |
3801 | else if (next == m->top && oldsize + m->topsize > nb) { | |
3802 | /* Expand into top */ | |
3803 | size_t newsize = oldsize + m->topsize; | |
3804 | size_t newtopsize = newsize - nb; | |
3805 | mchunkptr newtop = chunk_plus_offset(oldp, nb); | |
3806 | set_inuse(m, oldp, nb); | |
3807 | newtop->head = newtopsize |PINUSE_BIT; | |
3808 | m->top = newtop; | |
3809 | m->topsize = newtopsize; | |
3810 | newp = oldp; | |
3811 | } | |
3812 | } | |
3813 | else { | |
3814 | USAGE_ERROR_ACTION(m, oldmem); | |
3815 | POSTACTION(m); | |
3816 | return 0; | |
3817 | } | |
3818 | ||
3819 | POSTACTION(m); | |
3820 | ||
3821 | if (newp != 0) { | |
3822 | if (extra != 0) { | |
3823 | internal_free(m, extra); | |
3824 | } | |
3825 | check_inuse_chunk(m, newp); | |
3826 | return chunk2mem(newp); | |
3827 | } | |
3828 | else { | |
3829 | void* newmem = internal_malloc(m, bytes); | |
3830 | if (newmem != 0) { | |
3831 | size_t oc = oldsize - overhead_for(oldp); | |
3832 | memcpy(newmem, oldmem, (oc < bytes)? oc : bytes); | |
3833 | internal_free(m, oldmem); | |
3834 | } | |
3835 | return newmem; | |
3836 | } | |
3837 | } | |
3838 | return 0; | |
3839 | } | |
3840 | ||
3841 | /* --------------------------- memalign support -------------------------- */ | |
3842 | ||
3843 | static void* internal_memalign(mstate m, size_t alignment, size_t bytes) { | |
3844 | if (alignment <= MALLOC_ALIGNMENT) /* Can just use malloc */ | |
3845 | return internal_malloc(m, bytes); | |
3846 | if (alignment < MIN_CHUNK_SIZE) /* must be at least a minimum chunk size */ | |
3847 | alignment = MIN_CHUNK_SIZE; | |
3848 | if ((alignment & (alignment-SIZE_T_ONE)) != 0) {/* Ensure a power of 2 */ | |
3849 | size_t a = MALLOC_ALIGNMENT << 1; | |
3850 | while (a < alignment) a <<= 1; | |
3851 | alignment = a; | |
3852 | } | |
3853 | ||
3854 | if (bytes >= MAX_REQUEST - alignment) { | |
3855 | if (m != 0) { /* Test isn't needed but avoids compiler warning */ | |
3856 | MALLOC_FAILURE_ACTION; | |
3857 | } | |
3858 | } | |
3859 | else { | |
3860 | size_t nb = request2size(bytes); | |
3861 | size_t req = nb + alignment + MIN_CHUNK_SIZE - CHUNK_OVERHEAD; | |
3862 | char* mem = (char*)internal_malloc(m, req); | |
3863 | if (mem != 0) { | |
3864 | void* leader = 0; | |
3865 | void* trailer = 0; | |
3866 | mchunkptr p = mem2chunk(mem); | |
3867 | ||
3868 | if (PREACTION(m)) return 0; | |
3869 | if ((((size_t)(mem)) % alignment) != 0) { /* misaligned */ | |
3870 | /* | |
3871 | Find an aligned spot inside chunk. Since we need to give | |
3872 | back leading space in a chunk of at least MIN_CHUNK_SIZE, if | |
3873 | the first calculation places us at a spot with less than | |
3874 | MIN_CHUNK_SIZE leader, we can move to the next aligned spot. | |
3875 | We've allocated enough total room so that this is always | |
3876 | possible. | |
3877 | */ | |
3878 | char* br = (char*)mem2chunk((size_t)(((size_t)(mem + | |
3879 | alignment - | |
3880 | SIZE_T_ONE)) & | |
3881 | -alignment)); | |
3882 | char* pos = ((size_t)(br - (char*)(p)) >= MIN_CHUNK_SIZE)? | |
3883 | br : br+alignment; | |
3884 | mchunkptr newp = (mchunkptr)pos; | |
3885 | size_t leadsize = pos - (char*)(p); | |
3886 | size_t newsize = chunksize(p) - leadsize; | |
3887 | ||
3888 | if (is_mmapped(p)) { /* For mmapped chunks, just adjust offset */ | |
3889 | newp->prev_foot = p->prev_foot + leadsize; | |
3890 | newp->head = (newsize|CINUSE_BIT); | |
3891 | } | |
3892 | else { /* Otherwise, give back leader, use the rest */ | |
3893 | set_inuse(m, newp, newsize); | |
3894 | set_inuse(m, p, leadsize); | |
3895 | leader = chunk2mem(p); | |
3896 | } | |
3897 | p = newp; | |
3898 | } | |
3899 | ||
3900 | /* Give back spare room at the end */ | |
3901 | if (!is_mmapped(p)) { | |
3902 | size_t size = chunksize(p); | |
3903 | if (size > nb + MIN_CHUNK_SIZE) { | |
3904 | size_t remainder_size = size - nb; | |
3905 | mchunkptr remainder = chunk_plus_offset(p, nb); | |
3906 | set_inuse(m, p, nb); | |
3907 | set_inuse(m, remainder, remainder_size); | |
3908 | trailer = chunk2mem(remainder); | |
3909 | } | |
3910 | } | |
3911 | ||
3912 | assert (chunksize(p) >= nb); | |
3913 | assert((((size_t)(chunk2mem(p))) % alignment) == 0); | |
3914 | check_inuse_chunk(m, p); | |
3915 | POSTACTION(m); | |
3916 | if (leader != 0) { | |
3917 | internal_free(m, leader); | |
3918 | } | |
3919 | if (trailer != 0) { | |
3920 | internal_free(m, trailer); | |
3921 | } | |
3922 | return chunk2mem(p); | |
3923 | } | |
3924 | } | |
3925 | return 0; | |
3926 | } | |
3927 | ||
3928 | /* ------------------------ comalloc/coalloc support --------------------- */ | |
3929 | ||
3930 | static void** ialloc(mstate m, | |
3931 | size_t n_elements, | |
3932 | size_t* sizes, | |
3933 | int opts, | |
3934 | void* chunks[]) { | |
3935 | /* | |
3936 | This provides common support for independent_X routines, handling | |
3937 | all of the combinations that can result. | |
3938 | ||
3939 | The opts arg has: | |
3940 | bit 0 set if all elements are same size (using sizes[0]) | |
3941 | bit 1 set if elements should be zeroed | |
3942 | */ | |
3943 | ||
3944 | size_t element_size; /* chunksize of each element, if all same */ | |
3945 | size_t contents_size; /* total size of elements */ | |
3946 | size_t array_size; /* request size of pointer array */ | |
3947 | void* mem; /* malloced aggregate space */ | |
3948 | mchunkptr p; /* corresponding chunk */ | |
3949 | size_t remainder_size; /* remaining bytes while splitting */ | |
3950 | void** marray; /* either "chunks" or malloced ptr array */ | |
3951 | mchunkptr array_chunk; /* chunk for malloced ptr array */ | |
3952 | flag_t was_enabled; /* to disable mmap */ | |
3953 | size_t size; | |
3954 | size_t i; | |
3955 | ||
3956 | /* compute array length, if needed */ | |
3957 | if (chunks != 0) { | |
3958 | if (n_elements == 0) | |
3959 | return chunks; /* nothing to do */ | |
3960 | marray = chunks; | |
3961 | array_size = 0; | |
3962 | } | |
3963 | else { | |
3964 | /* if empty req, must still return chunk representing empty array */ | |
3965 | if (n_elements == 0) | |
3966 | return (void**)internal_malloc(m, 0); | |
3967 | marray = 0; | |
3968 | array_size = request2size(n_elements * (sizeof(void*))); | |
3969 | } | |
3970 | ||
3971 | /* compute total element size */ | |
3972 | if (opts & 0x1) { /* all-same-size */ | |
3973 | element_size = request2size(*sizes); | |
3974 | contents_size = n_elements * element_size; | |
3975 | } | |
3976 | else { /* add up all the sizes */ | |
3977 | element_size = 0; | |
3978 | contents_size = 0; | |
3979 | for (i = 0; i != n_elements; ++i) | |
3980 | contents_size += request2size(sizes[i]); | |
3981 | } | |
3982 | ||
3983 | size = contents_size + array_size; | |
3984 | ||
3985 | /* | |
3986 | Allocate the aggregate chunk. First disable direct-mmapping so | |
3987 | malloc won't use it, since we would not be able to later | |
3988 | free/realloc space internal to a segregated mmap region. | |
3989 | */ | |
3990 | was_enabled = use_mmap(m); | |
3991 | disable_mmap(m); | |
3992 | mem = internal_malloc(m, size - CHUNK_OVERHEAD); | |
3993 | if (was_enabled) | |
3994 | enable_mmap(m); | |
3995 | if (mem == 0) | |
3996 | return 0; | |
3997 | ||
3998 | if (PREACTION(m)) return 0; | |
3999 | p = mem2chunk(mem); | |
4000 | remainder_size = chunksize(p); | |
4001 | ||
4002 | assert(!is_mmapped(p)); | |
4003 | ||
4004 | if (opts & 0x2) { /* optionally clear the elements */ | |
4005 | memset((size_t*)mem, 0, remainder_size - SIZE_T_SIZE - array_size); | |
4006 | } | |
4007 | ||
4008 | /* If not provided, allocate the pointer array as final part of chunk */ | |
4009 | if (marray == 0) { | |
4010 | size_t array_chunk_size; | |
4011 | array_chunk = chunk_plus_offset(p, contents_size); | |
4012 | array_chunk_size = remainder_size - contents_size; | |
4013 | marray = (void**) (chunk2mem(array_chunk)); | |
4014 | set_size_and_pinuse_of_inuse_chunk(m, array_chunk, array_chunk_size); | |
4015 | remainder_size = contents_size; | |
4016 | } | |
4017 | ||
4018 | /* split out elements */ | |
4019 | for (i = 0; ; ++i) { | |
4020 | marray[i] = chunk2mem(p); | |
4021 | if (i != n_elements-1) { | |
4022 | if (element_size != 0) | |
4023 | size = element_size; | |
4024 | else | |
4025 | size = request2size(sizes[i]); | |
4026 | remainder_size -= size; | |
4027 | set_size_and_pinuse_of_inuse_chunk(m, p, size); | |
4028 | p = chunk_plus_offset(p, size); | |
4029 | } | |
4030 | else { /* the final element absorbs any overallocation slop */ | |
4031 | set_size_and_pinuse_of_inuse_chunk(m, p, remainder_size); | |
4032 | break; | |
4033 | } | |
4034 | } | |
4035 | ||
4036 | #if DEBUG | |
4037 | if (marray != chunks) { | |
4038 | /* final element must have exactly exhausted chunk */ | |
4039 | if (element_size != 0) { | |
4040 | assert(remainder_size == element_size); | |
4041 | } | |
4042 | else { | |
4043 | assert(remainder_size == request2size(sizes[i])); | |
4044 | } | |
4045 | check_inuse_chunk(m, mem2chunk(marray)); | |
4046 | } | |
4047 | for (i = 0; i != n_elements; ++i) | |
4048 | check_inuse_chunk(m, mem2chunk(marray[i])); | |
4049 | ||
4050 | #endif /* DEBUG */ | |
4051 | ||
4052 | POSTACTION(m); | |
4053 | return marray; | |
4054 | } | |
4055 | ||
4056 | ||
4057 | /* -------------------------- public routines ---------------------------- */ | |
4058 | ||
4059 | #if !ONLY_MSPACES | |
4060 | ||
4061 | void* dlmalloc(size_t bytes) { | |
4062 | /* | |
4063 | Basic algorithm: | |
4064 | If a small request (< 256 bytes minus per-chunk overhead): | |
4065 | 1. If one exists, use a remainderless chunk in associated smallbin. | |
4066 | (Remainderless means that there are too few excess bytes to | |
4067 | represent as a chunk.) | |
4068 | 2. If it is big enough, use the dv chunk, which is normally the | |
4069 | chunk adjacent to the one used for the most recent small request. | |
4070 | 3. If one exists, split the smallest available chunk in a bin, | |
4071 | saving remainder in dv. | |
4072 | 4. If it is big enough, use the top chunk. | |
4073 | 5. If available, get memory from system and use it | |
4074 | Otherwise, for a large request: | |
4075 | 1. Find the smallest available binned chunk that fits, and use it | |
4076 | if it is better fitting than dv chunk, splitting if necessary. | |
4077 | 2. If better fitting than any binned chunk, use the dv chunk. | |
4078 | 3. If it is big enough, use the top chunk. | |
4079 | 4. If request size >= mmap threshold, try to directly mmap this chunk. | |
4080 | 5. If available, get memory from system and use it | |
4081 | ||
4082 | The ugly goto's here ensure that postaction occurs along all paths. | |
4083 | */ | |
4084 | ||
4085 | if (!PREACTION(gm)) { | |
4086 | void* mem; | |
4087 | size_t nb; | |
4088 | if (bytes <= MAX_SMALL_REQUEST) { | |
4089 | bindex_t idx; | |
4090 | binmap_t smallbits; | |
4091 | nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes); | |
4092 | idx = small_index(nb); | |
4093 | smallbits = gm->smallmap >> idx; | |
4094 | ||
4095 | if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */ | |
4096 | mchunkptr b, p; | |
4097 | idx += ~smallbits & 1; /* Uses next bin if idx empty */ | |
4098 | b = smallbin_at(gm, idx); | |
4099 | p = b->fd; | |
4100 | assert(chunksize(p) == small_index2size(idx)); | |
4101 | unlink_first_small_chunk(gm, b, p, idx); | |
4102 | set_inuse_and_pinuse(gm, p, small_index2size(idx)); | |
4103 | mem = chunk2mem(p); | |
4104 | check_malloced_chunk(gm, mem, nb); | |
4105 | goto postaction; | |
4106 | } | |
4107 | ||
4108 | else if (nb > gm->dvsize) { | |
4109 | if (smallbits != 0) { /* Use chunk in next nonempty smallbin */ | |
4110 | mchunkptr b, p, r; | |
4111 | size_t rsize; | |
4112 | bindex_t i; | |
4113 | binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx)); | |
4114 | binmap_t leastbit = least_bit(leftbits); | |
4115 | compute_bit2idx(leastbit, i); | |
4116 | b = smallbin_at(gm, i); | |
4117 | p = b->fd; | |
4118 | assert(chunksize(p) == small_index2size(i)); | |
4119 | unlink_first_small_chunk(gm, b, p, i); | |
4120 | rsize = small_index2size(i) - nb; | |
4121 | /* Fit here cannot be remainderless if 4byte sizes */ | |
4122 | if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) | |
4123 | set_inuse_and_pinuse(gm, p, small_index2size(i)); | |
4124 | else { | |
4125 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); | |
4126 | r = chunk_plus_offset(p, nb); | |
4127 | set_size_and_pinuse_of_free_chunk(r, rsize); | |
4128 | replace_dv(gm, r, rsize); | |
4129 | } | |
4130 | mem = chunk2mem(p); | |
4131 | check_malloced_chunk(gm, mem, nb); | |
4132 | goto postaction; | |
4133 | } | |
4134 | ||
4135 | else if (gm->treemap != 0 && (mem = tmalloc_small(gm, nb)) != 0) { | |
4136 | check_malloced_chunk(gm, mem, nb); | |
4137 | goto postaction; | |
4138 | } | |
4139 | } | |
4140 | } | |
4141 | else if (bytes >= MAX_REQUEST) | |
4142 | nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */ | |
4143 | else { | |
4144 | nb = pad_request(bytes); | |
4145 | if (gm->treemap != 0 && (mem = tmalloc_large(gm, nb)) != 0) { | |
4146 | check_malloced_chunk(gm, mem, nb); | |
4147 | goto postaction; | |
4148 | } | |
4149 | } | |
4150 | ||
4151 | if (nb <= gm->dvsize) { | |
4152 | size_t rsize = gm->dvsize - nb; | |
4153 | mchunkptr p = gm->dv; | |
4154 | if (rsize >= MIN_CHUNK_SIZE) { /* split dv */ | |
4155 | mchunkptr r = gm->dv = chunk_plus_offset(p, nb); | |
4156 | gm->dvsize = rsize; | |
4157 | set_size_and_pinuse_of_free_chunk(r, rsize); | |
4158 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); | |
4159 | } | |
4160 | else { /* exhaust dv */ | |
4161 | size_t dvs = gm->dvsize; | |
4162 | gm->dvsize = 0; | |
4163 | gm->dv = 0; | |
4164 | set_inuse_and_pinuse(gm, p, dvs); | |
4165 | } | |
4166 | mem = chunk2mem(p); | |
4167 | check_malloced_chunk(gm, mem, nb); | |
4168 | goto postaction; | |
4169 | } | |
4170 | ||
4171 | else if (nb < gm->topsize) { /* Split top */ | |
4172 | size_t rsize = gm->topsize -= nb; | |
4173 | mchunkptr p = gm->top; | |
4174 | mchunkptr r = gm->top = chunk_plus_offset(p, nb); | |
4175 | r->head = rsize | PINUSE_BIT; | |
4176 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); | |
4177 | mem = chunk2mem(p); | |
4178 | check_top_chunk(gm, gm->top); | |
4179 | check_malloced_chunk(gm, mem, nb); | |
4180 | goto postaction; | |
4181 | } | |
4182 | ||
4183 | mem = sys_alloc(gm, nb); | |
4184 | ||
4185 | postaction: | |
4186 | POSTACTION(gm); | |
4187 | return mem; | |
4188 | } | |
4189 | ||
4190 | return 0; | |
4191 | } | |
4192 | ||
4193 | void dlfree(void* mem) { | |
4194 | /* | |
4195 | Consolidate freed chunks with preceeding or succeeding bordering | |
4196 | free chunks, if they exist, and then place in a bin. Intermixed | |
4197 | with special cases for top, dv, mmapped chunks, and usage errors. | |
4198 | */ | |
4199 | ||
4200 | if (mem != 0) { | |
4201 | mchunkptr p = mem2chunk(mem); | |
4202 | #if FOOTERS | |
4203 | mstate fm = get_mstate_for(p); | |
4204 | if (!ok_magic(fm)) { | |
4205 | USAGE_ERROR_ACTION(fm, p); | |
4206 | return; | |
4207 | } | |
4208 | #else /* FOOTERS */ | |
4209 | #define fm gm | |
4210 | #endif /* FOOTERS */ | |
4211 | if (!PREACTION(fm)) { | |
4212 | check_inuse_chunk(fm, p); | |
4213 | if (RTCHECK(ok_address(fm, p) && ok_cinuse(p))) { | |
4214 | size_t psize = chunksize(p); | |
4215 | mchunkptr next = chunk_plus_offset(p, psize); | |
4216 | if (!pinuse(p)) { | |
4217 | size_t prevsize = p->prev_foot; | |
4218 | if ((prevsize & IS_MMAPPED_BIT) != 0) { | |
4219 | prevsize &= ~IS_MMAPPED_BIT; | |
4220 | psize += prevsize + MMAP_FOOT_PAD; | |
4221 | if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) | |
4222 | fm->footprint -= psize; | |
4223 | goto postaction; | |
4224 | } | |
4225 | else { | |
4226 | mchunkptr prev = chunk_minus_offset(p, prevsize); | |
4227 | psize += prevsize; | |
4228 | p = prev; | |
4229 | if (RTCHECK(ok_address(fm, prev))) { /* consolidate backward */ | |
4230 | if (p != fm->dv) { | |
4231 | unlink_chunk(fm, p, prevsize); | |
4232 | } | |
4233 | else if ((next->head & INUSE_BITS) == INUSE_BITS) { | |
4234 | fm->dvsize = psize; | |
4235 | set_free_with_pinuse(p, psize, next); | |
4236 | goto postaction; | |
4237 | } | |
4238 | } | |
4239 | else | |
4240 | goto erroraction; | |
4241 | } | |
4242 | } | |
4243 | ||
4244 | if (RTCHECK(ok_next(p, next) && ok_pinuse(next))) { | |
4245 | if (!cinuse(next)) { /* consolidate forward */ | |
4246 | if (next == fm->top) { | |
4247 | size_t tsize = fm->topsize += psize; | |
4248 | fm->top = p; | |
4249 | p->head = tsize | PINUSE_BIT; | |
4250 | if (p == fm->dv) { | |
4251 | fm->dv = 0; | |
4252 | fm->dvsize = 0; | |
4253 | } | |
4254 | if (should_trim(fm, tsize)) | |
4255 | sys_trim(fm, 0); | |
4256 | goto postaction; | |
4257 | } | |
4258 | else if (next == fm->dv) { | |
4259 | size_t dsize = fm->dvsize += psize; | |
4260 | fm->dv = p; | |
4261 | set_size_and_pinuse_of_free_chunk(p, dsize); | |
4262 | goto postaction; | |
4263 | } | |
4264 | else { | |
4265 | size_t nsize = chunksize(next); | |
4266 | psize += nsize; | |
4267 | unlink_chunk(fm, next, nsize); | |
4268 | set_size_and_pinuse_of_free_chunk(p, psize); | |
4269 | if (p == fm->dv) { | |
4270 | fm->dvsize = psize; | |
4271 | goto postaction; | |
4272 | } | |
4273 | } | |
4274 | } | |
4275 | else | |
4276 | set_free_with_pinuse(p, psize, next); | |
4277 | insert_chunk(fm, p, psize); | |
4278 | check_free_chunk(fm, p); | |
4279 | goto postaction; | |
4280 | } | |
4281 | } | |
4282 | erroraction: | |
4283 | USAGE_ERROR_ACTION(fm, p); | |
4284 | postaction: | |
4285 | POSTACTION(fm); | |
4286 | } | |
4287 | } | |
4288 | #if !FOOTERS | |
4289 | #undef fm | |
4290 | #endif /* FOOTERS */ | |
4291 | } | |
4292 | ||
4293 | void* dlcalloc(size_t n_elements, size_t elem_size) { | |
4294 | void* mem; | |
4295 | size_t req = 0; | |
4296 | if (n_elements != 0) { | |
4297 | req = n_elements * elem_size; | |
4298 | if (((n_elements | elem_size) & ~(size_t)0xffff) && | |
4299 | (req / n_elements != elem_size)) | |
4300 | req = MAX_SIZE_T; /* force downstream failure on overflow */ | |
4301 | } | |
4302 | mem = dlmalloc(req); | |
4303 | if (mem != 0 && calloc_must_clear(mem2chunk(mem))) | |
4304 | memset(mem, 0, req); | |
4305 | return mem; | |
4306 | } | |
4307 | ||
4308 | void* dlrealloc(void* oldmem, size_t bytes) { | |
4309 | if (oldmem == 0) | |
4310 | return dlmalloc(bytes); | |
4311 | #ifdef REALLOC_ZERO_BYTES_FREES | |
4312 | if (bytes == 0) { | |
4313 | dlfree(oldmem); | |
4314 | return 0; | |
4315 | } | |
4316 | #endif /* REALLOC_ZERO_BYTES_FREES */ | |
4317 | else { | |
4318 | #if ! FOOTERS | |
4319 | mstate m = gm; | |
4320 | #else /* FOOTERS */ | |
4321 | mstate m = get_mstate_for(mem2chunk(oldmem)); | |
4322 | if (!ok_magic(m)) { | |
4323 | USAGE_ERROR_ACTION(m, oldmem); | |
4324 | return 0; | |
4325 | } | |
4326 | #endif /* FOOTERS */ | |
4327 | return internal_realloc(m, oldmem, bytes); | |
4328 | } | |
4329 | } | |
4330 | ||
4331 | void* dlmemalign(size_t alignment, size_t bytes) { | |
4332 | return internal_memalign(gm, alignment, bytes); | |
4333 | } | |
4334 | ||
4335 | void** dlindependent_calloc(size_t n_elements, size_t elem_size, | |
4336 | void* chunks[]) { | |
4337 | size_t sz = elem_size; /* serves as 1-element array */ | |
4338 | return ialloc(gm, n_elements, &sz, 3, chunks); | |
4339 | } | |
4340 | ||
4341 | void** dlindependent_comalloc(size_t n_elements, size_t sizes[], | |
4342 | void* chunks[]) { | |
4343 | return ialloc(gm, n_elements, sizes, 0, chunks); | |
4344 | } | |
4345 | ||
4346 | void* dlvalloc(size_t bytes) { | |
4347 | size_t pagesz; | |
4348 | init_mparams(); | |
4349 | pagesz = mparams.page_size; | |
4350 | return dlmemalign(pagesz, bytes); | |
4351 | } | |
4352 | ||
4353 | void* dlpvalloc(size_t bytes) { | |
4354 | size_t pagesz; | |
4355 | init_mparams(); | |
4356 | pagesz = mparams.page_size; | |
4357 | return dlmemalign(pagesz, (bytes + pagesz - SIZE_T_ONE) & ~(pagesz - SIZE_T_ONE)); | |
4358 | } | |
4359 | ||
4360 | int dlmalloc_trim(size_t pad) { | |
4361 | int result = 0; | |
4362 | if (!PREACTION(gm)) { | |
4363 | result = sys_trim(gm, pad); | |
4364 | POSTACTION(gm); | |
4365 | } | |
4366 | return result; | |
4367 | } | |
4368 | ||
4369 | size_t dlmalloc_footprint(void) { | |
4370 | return gm->footprint; | |
4371 | } | |
4372 | ||
4373 | size_t dlmalloc_max_footprint(void) { | |
4374 | return gm->max_footprint; | |
4375 | } | |
4376 | ||
4377 | #if !NO_MALLINFO | |
4378 | struct mallinfo dlmallinfo(void) { | |
4379 | return internal_mallinfo(gm); | |
4380 | } | |
4381 | #endif /* NO_MALLINFO */ | |
4382 | ||
4383 | void dlmalloc_stats() { | |
4384 | internal_malloc_stats(gm); | |
4385 | } | |
4386 | ||
4387 | size_t dlmalloc_usable_size(void* mem) { | |
4388 | if (mem != 0) { | |
4389 | mchunkptr p = mem2chunk(mem); | |
4390 | if (cinuse(p)) | |
4391 | return chunksize(p) - overhead_for(p); | |
4392 | } | |
4393 | return 0; | |
4394 | } | |
4395 | ||
4396 | int dlmallopt(int param_number, int value) { | |
4397 | return change_mparam(param_number, value); | |
4398 | } | |
4399 | ||
4400 | #endif /* !ONLY_MSPACES */ | |
4401 | ||
4402 | /* ----------------------------- user mspaces ---------------------------- */ | |
4403 | ||
4404 | #if MSPACES | |
4405 | ||
4406 | static mstate init_user_mstate(char* tbase, size_t tsize) { | |
4407 | size_t msize = pad_request(sizeof(struct malloc_state)); | |
4408 | mchunkptr mn; | |
4409 | mchunkptr msp = align_as_chunk(tbase); | |
4410 | mstate m = (mstate)(chunk2mem(msp)); | |
4411 | memset(m, 0, msize); | |
4412 | INITIAL_LOCK(&m->mutex); | |
4413 | msp->head = (msize|PINUSE_BIT|CINUSE_BIT); | |
4414 | m->seg.base = m->least_addr = tbase; | |
4415 | m->seg.size = m->footprint = m->max_footprint = tsize; | |
4416 | m->magic = mparams.magic; | |
4417 | m->mflags = mparams.default_mflags; | |
4418 | disable_contiguous(m); | |
4419 | init_bins(m); | |
4420 | mn = next_chunk(mem2chunk(m)); | |
4421 | init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) - TOP_FOOT_SIZE); | |
4422 | check_top_chunk(m, m->top); | |
4423 | return m; | |
4424 | } | |
4425 | ||
4426 | mspace create_mspace(size_t capacity, int locked) { | |
4427 | mstate m = 0; | |
4428 | size_t msize = pad_request(sizeof(struct malloc_state)); | |
4429 | init_mparams(); /* Ensure pagesize etc initialized */ | |
4430 | ||
4431 | if (capacity < (size_t) -(msize + TOP_FOOT_SIZE + mparams.page_size)) { | |
4432 | size_t rs = ((capacity == 0)? mparams.granularity : | |
4433 | (capacity + TOP_FOOT_SIZE + msize)); | |
4434 | size_t tsize = granularity_align(rs); | |
4435 | char* tbase = (char*)(CALL_MMAP(tsize)); | |
4436 | if (tbase != CMFAIL) { | |
4437 | m = init_user_mstate(tbase, tsize); | |
18fa3240 | 4438 | set_segment_flags(&m->seg, IS_MMAPPED_BIT); |
dd778331 AO |
4439 | set_lock(m, locked); |
4440 | } | |
4441 | } | |
4442 | return (mspace)m; | |
4443 | } | |
4444 | ||
4445 | mspace create_mspace_with_base(void* base, size_t capacity, int locked) { | |
4446 | mstate m = 0; | |
4447 | size_t msize = pad_request(sizeof(struct malloc_state)); | |
4448 | init_mparams(); /* Ensure pagesize etc initialized */ | |
4449 | ||
4450 | if (capacity > msize + TOP_FOOT_SIZE && | |
4451 | capacity < (size_t) -(msize + TOP_FOOT_SIZE + mparams.page_size)) { | |
4452 | m = init_user_mstate((char*)base, capacity); | |
18fa3240 | 4453 | set_segment_flags(&m->seg, EXTERN_BIT); |
dd778331 AO |
4454 | set_lock(m, locked); |
4455 | } | |
4456 | return (mspace)m; | |
4457 | } | |
4458 | ||
4459 | size_t destroy_mspace(mspace msp) { | |
4460 | size_t freed = 0; | |
4461 | mstate ms = (mstate)msp; | |
4462 | if (ok_magic(ms)) { | |
4463 | msegmentptr sp = &ms->seg; | |
4464 | while (sp != 0) { | |
4465 | char* base = sp->base; | |
4466 | size_t size = sp->size; | |
18fa3240 | 4467 | flag_t flag = get_segment_flags(sp); |
dd778331 AO |
4468 | sp = sp->next; |
4469 | if ((flag & IS_MMAPPED_BIT) && !(flag & EXTERN_BIT) && | |
4470 | CALL_MUNMAP(base, size) == 0) | |
4471 | freed += size; | |
4472 | } | |
4473 | } | |
4474 | else { | |
4475 | USAGE_ERROR_ACTION(ms,ms); | |
4476 | } | |
4477 | return freed; | |
4478 | } | |
4479 | ||
4480 | /* | |
4481 | mspace versions of routines are near-clones of the global | |
4482 | versions. This is not so nice but better than the alternatives. | |
4483 | */ | |
4484 | ||
4485 | ||
4486 | void* mspace_malloc(mspace msp, size_t bytes) { | |
4487 | mstate ms = (mstate)msp; | |
4488 | if (!ok_magic(ms)) { | |
4489 | USAGE_ERROR_ACTION(ms,ms); | |
4490 | return 0; | |
4491 | } | |
4492 | if (!PREACTION(ms)) { | |
4493 | void* mem; | |
4494 | size_t nb; | |
4495 | if (bytes <= MAX_SMALL_REQUEST) { | |
4496 | bindex_t idx; | |
4497 | binmap_t smallbits; | |
4498 | nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes); | |
4499 | idx = small_index(nb); | |
4500 | smallbits = ms->smallmap >> idx; | |
4501 | ||
4502 | if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */ | |
4503 | mchunkptr b, p; | |
4504 | idx += ~smallbits & 1; /* Uses next bin if idx empty */ | |
4505 | b = smallbin_at(ms, idx); | |
4506 | p = b->fd; | |
4507 | assert(chunksize(p) == small_index2size(idx)); | |
4508 | unlink_first_small_chunk(ms, b, p, idx); | |
4509 | set_inuse_and_pinuse(ms, p, small_index2size(idx)); | |
4510 | mem = chunk2mem(p); | |
4511 | check_malloced_chunk(ms, mem, nb); | |
4512 | goto postaction; | |
4513 | } | |
4514 | ||
4515 | else if (nb > ms->dvsize) { | |
4516 | if (smallbits != 0) { /* Use chunk in next nonempty smallbin */ | |
4517 | mchunkptr b, p, r; | |
4518 | size_t rsize; | |
4519 | bindex_t i; | |
4520 | binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx)); | |
4521 | binmap_t leastbit = least_bit(leftbits); | |
4522 | compute_bit2idx(leastbit, i); | |
4523 | b = smallbin_at(ms, i); | |
4524 | p = b->fd; | |
4525 | assert(chunksize(p) == small_index2size(i)); | |
4526 | unlink_first_small_chunk(ms, b, p, i); | |
4527 | rsize = small_index2size(i) - nb; | |
4528 | /* Fit here cannot be remainderless if 4byte sizes */ | |
4529 | if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) | |
4530 | set_inuse_and_pinuse(ms, p, small_index2size(i)); | |
4531 | else { | |
4532 | set_size_and_pinuse_of_inuse_chunk(ms, p, nb); | |
4533 | r = chunk_plus_offset(p, nb); | |
4534 | set_size_and_pinuse_of_free_chunk(r, rsize); | |
4535 | replace_dv(ms, r, rsize); | |
4536 | } | |
4537 | mem = chunk2mem(p); | |
4538 | check_malloced_chunk(ms, mem, nb); | |
4539 | goto postaction; | |
4540 | } | |
4541 | ||
4542 | else if (ms->treemap != 0 && (mem = tmalloc_small(ms, nb)) != 0) { | |
4543 | check_malloced_chunk(ms, mem, nb); | |
4544 | goto postaction; | |
4545 | } | |
4546 | } | |
4547 | } | |
4548 | else if (bytes >= MAX_REQUEST) | |
4549 | nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */ | |
4550 | else { | |
4551 | nb = pad_request(bytes); | |
4552 | if (ms->treemap != 0 && (mem = tmalloc_large(ms, nb)) != 0) { | |
4553 | check_malloced_chunk(ms, mem, nb); | |
4554 | goto postaction; | |
4555 | } | |
4556 | } | |
4557 | ||
4558 | if (nb <= ms->dvsize) { | |
4559 | size_t rsize = ms->dvsize - nb; | |
4560 | mchunkptr p = ms->dv; | |
4561 | if (rsize >= MIN_CHUNK_SIZE) { /* split dv */ | |
4562 | mchunkptr r = ms->dv = chunk_plus_offset(p, nb); | |
4563 | ms->dvsize = rsize; | |
4564 | set_size_and_pinuse_of_free_chunk(r, rsize); | |
4565 | set_size_and_pinuse_of_inuse_chunk(ms, p, nb); | |
4566 | } | |
4567 | else { /* exhaust dv */ | |
4568 | size_t dvs = ms->dvsize; | |
4569 | ms->dvsize = 0; | |
4570 | ms->dv = 0; | |
4571 | set_inuse_and_pinuse(ms, p, dvs); | |
4572 | } | |
4573 | mem = chunk2mem(p); | |
4574 | check_malloced_chunk(ms, mem, nb); | |
4575 | goto postaction; | |
4576 | } | |
4577 | ||
4578 | else if (nb < ms->topsize) { /* Split top */ | |
4579 | size_t rsize = ms->topsize -= nb; | |
4580 | mchunkptr p = ms->top; | |
4581 | mchunkptr r = ms->top = chunk_plus_offset(p, nb); | |
4582 | r->head = rsize | PINUSE_BIT; | |
4583 | set_size_and_pinuse_of_inuse_chunk(ms, p, nb); | |
4584 | mem = chunk2mem(p); | |
4585 | check_top_chunk(ms, ms->top); | |
4586 | check_malloced_chunk(ms, mem, nb); | |
4587 | goto postaction; | |
4588 | } | |
4589 | ||
4590 | mem = sys_alloc(ms, nb); | |
4591 | ||
4592 | postaction: | |
4593 | POSTACTION(ms); | |
4594 | return mem; | |
4595 | } | |
4596 | ||
4597 | return 0; | |
4598 | } | |
4599 | ||
4600 | void mspace_free(mspace msp, void* mem) { | |
4601 | if (mem != 0) { | |
4602 | mchunkptr p = mem2chunk(mem); | |
4603 | #if FOOTERS | |
4604 | mstate fm = get_mstate_for(p); | |
4605 | #else /* FOOTERS */ | |
4606 | mstate fm = (mstate)msp; | |
4607 | #endif /* FOOTERS */ | |
4608 | if (!ok_magic(fm)) { | |
4609 | USAGE_ERROR_ACTION(fm, p); | |
4610 | return; | |
4611 | } | |
4612 | if (!PREACTION(fm)) { | |
4613 | check_inuse_chunk(fm, p); | |
4614 | if (RTCHECK(ok_address(fm, p) && ok_cinuse(p))) { | |
4615 | size_t psize = chunksize(p); | |
4616 | mchunkptr next = chunk_plus_offset(p, psize); | |
4617 | if (!pinuse(p)) { | |
4618 | size_t prevsize = p->prev_foot; | |
4619 | if ((prevsize & IS_MMAPPED_BIT) != 0) { | |
4620 | prevsize &= ~IS_MMAPPED_BIT; | |
4621 | psize += prevsize + MMAP_FOOT_PAD; | |
4622 | if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) | |
4623 | fm->footprint -= psize; | |
4624 | goto postaction; | |
4625 | } | |
4626 | else { | |
4627 | mchunkptr prev = chunk_minus_offset(p, prevsize); | |
4628 | psize += prevsize; | |
4629 | p = prev; | |
4630 | if (RTCHECK(ok_address(fm, prev))) { /* consolidate backward */ | |
4631 | if (p != fm->dv) { | |
4632 | unlink_chunk(fm, p, prevsize); | |
4633 | } | |
4634 | else if ((next->head & INUSE_BITS) == INUSE_BITS) { | |
4635 | fm->dvsize = psize; | |
4636 | set_free_with_pinuse(p, psize, next); | |
4637 | goto postaction; | |
4638 | } | |
4639 | } | |
4640 | else | |
4641 | goto erroraction; | |
4642 | } | |
4643 | } | |
4644 | ||
4645 | if (RTCHECK(ok_next(p, next) && ok_pinuse(next))) { | |
4646 | if (!cinuse(next)) { /* consolidate forward */ | |
4647 | if (next == fm->top) { | |
4648 | size_t tsize = fm->topsize += psize; | |
4649 | fm->top = p; | |
4650 | p->head = tsize | PINUSE_BIT; | |
4651 | if (p == fm->dv) { | |
4652 | fm->dv = 0; | |
4653 | fm->dvsize = 0; | |
4654 | } | |
4655 | if (should_trim(fm, tsize)) | |
4656 | sys_trim(fm, 0); | |
4657 | goto postaction; | |
4658 | } | |
4659 | else if (next == fm->dv) { | |
4660 | size_t dsize = fm->dvsize += psize; | |
4661 | fm->dv = p; | |
4662 | set_size_and_pinuse_of_free_chunk(p, dsize); | |
4663 | goto postaction; | |
4664 | } | |
4665 | else { | |
4666 | size_t nsize = chunksize(next); | |
4667 | psize += nsize; | |
4668 | unlink_chunk(fm, next, nsize); | |
4669 | set_size_and_pinuse_of_free_chunk(p, psize); | |
4670 | if (p == fm->dv) { | |
4671 | fm->dvsize = psize; | |
4672 | goto postaction; | |
4673 | } | |
4674 | } | |
4675 | } | |
4676 | else | |
4677 | set_free_with_pinuse(p, psize, next); | |
4678 | insert_chunk(fm, p, psize); | |
4679 | check_free_chunk(fm, p); | |
4680 | goto postaction; | |
4681 | } | |
4682 | } | |
4683 | erroraction: | |
4684 | USAGE_ERROR_ACTION(fm, p); | |
4685 | postaction: | |
4686 | POSTACTION(fm); | |
4687 | } | |
4688 | } | |
4689 | } | |
4690 | ||
4691 | void* mspace_calloc(mspace msp, size_t n_elements, size_t elem_size) { | |
4692 | void* mem; | |
4693 | size_t req = 0; | |
4694 | mstate ms = (mstate)msp; | |
4695 | if (!ok_magic(ms)) { | |
4696 | USAGE_ERROR_ACTION(ms,ms); | |
4697 | return 0; | |
4698 | } | |
4699 | if (n_elements != 0) { | |
4700 | req = n_elements * elem_size; | |
4701 | if (((n_elements | elem_size) & ~(size_t)0xffff) && | |
4702 | (req / n_elements != elem_size)) | |
4703 | req = MAX_SIZE_T; /* force downstream failure on overflow */ | |
4704 | } | |
4705 | mem = internal_malloc(ms, req); | |
4706 | if (mem != 0 && calloc_must_clear(mem2chunk(mem))) | |
4707 | memset(mem, 0, req); | |
4708 | return mem; | |
4709 | } | |
4710 | ||
4711 | void* mspace_realloc(mspace msp, void* oldmem, size_t bytes) { | |
4712 | if (oldmem == 0) | |
4713 | return mspace_malloc(msp, bytes); | |
4714 | #ifdef REALLOC_ZERO_BYTES_FREES | |
4715 | if (bytes == 0) { | |
4716 | mspace_free(msp, oldmem); | |
4717 | return 0; | |
4718 | } | |
4719 | #endif /* REALLOC_ZERO_BYTES_FREES */ | |
4720 | else { | |
4721 | #if FOOTERS | |
4722 | mchunkptr p = mem2chunk(oldmem); | |
4723 | mstate ms = get_mstate_for(p); | |
4724 | #else /* FOOTERS */ | |
4725 | mstate ms = (mstate)msp; | |
4726 | #endif /* FOOTERS */ | |
4727 | if (!ok_magic(ms)) { | |
4728 | USAGE_ERROR_ACTION(ms,ms); | |
4729 | return 0; | |
4730 | } | |
4731 | return internal_realloc(ms, oldmem, bytes); | |
4732 | } | |
4733 | } | |
4734 | ||
4735 | void* mspace_memalign(mspace msp, size_t alignment, size_t bytes) { | |
4736 | mstate ms = (mstate)msp; | |
4737 | if (!ok_magic(ms)) { | |
4738 | USAGE_ERROR_ACTION(ms,ms); | |
4739 | return 0; | |
4740 | } | |
4741 | return internal_memalign(ms, alignment, bytes); | |
4742 | } | |
4743 | ||
4744 | void** mspace_independent_calloc(mspace msp, size_t n_elements, | |
4745 | size_t elem_size, void* chunks[]) { | |
4746 | size_t sz = elem_size; /* serves as 1-element array */ | |
4747 | mstate ms = (mstate)msp; | |
4748 | if (!ok_magic(ms)) { | |
4749 | USAGE_ERROR_ACTION(ms,ms); | |
4750 | return 0; | |
4751 | } | |
4752 | return ialloc(ms, n_elements, &sz, 3, chunks); | |
4753 | } | |
4754 | ||
4755 | void** mspace_independent_comalloc(mspace msp, size_t n_elements, | |
4756 | size_t sizes[], void* chunks[]) { | |
4757 | mstate ms = (mstate)msp; | |
4758 | if (!ok_magic(ms)) { | |
4759 | USAGE_ERROR_ACTION(ms,ms); | |
4760 | return 0; | |
4761 | } | |
4762 | return ialloc(ms, n_elements, sizes, 0, chunks); | |
4763 | } | |
4764 | ||
4765 | int mspace_trim(mspace msp, size_t pad) { | |
4766 | int result = 0; | |
4767 | mstate ms = (mstate)msp; | |
4768 | if (ok_magic(ms)) { | |
4769 | if (!PREACTION(ms)) { | |
4770 | result = sys_trim(ms, pad); | |
4771 | POSTACTION(ms); | |
4772 | } | |
4773 | } | |
4774 | else { | |
4775 | USAGE_ERROR_ACTION(ms,ms); | |
4776 | } | |
4777 | return result; | |
4778 | } | |
4779 | ||
4780 | void mspace_malloc_stats(mspace msp) { | |
4781 | mstate ms = (mstate)msp; | |
4782 | if (ok_magic(ms)) { | |
4783 | internal_malloc_stats(ms); | |
4784 | } | |
4785 | else { | |
4786 | USAGE_ERROR_ACTION(ms,ms); | |
4787 | } | |
4788 | } | |
4789 | ||
4790 | size_t mspace_footprint(mspace msp) { | |
4791 | size_t result; | |
4792 | mstate ms = (mstate)msp; | |
4793 | if (ok_magic(ms)) { | |
4794 | result = ms->footprint; | |
4795 | } | |
4796 | USAGE_ERROR_ACTION(ms,ms); | |
4797 | return result; | |
4798 | } | |
4799 | ||
4800 | ||
4801 | size_t mspace_max_footprint(mspace msp) { | |
4802 | size_t result; | |
4803 | mstate ms = (mstate)msp; | |
4804 | if (ok_magic(ms)) { | |
4805 | result = ms->max_footprint; | |
4806 | } | |
4807 | USAGE_ERROR_ACTION(ms,ms); | |
4808 | return result; | |
4809 | } | |
4810 | ||
4811 | ||
4812 | #if !NO_MALLINFO | |
4813 | struct mallinfo mspace_mallinfo(mspace msp) { | |
4814 | mstate ms = (mstate)msp; | |
4815 | if (!ok_magic(ms)) { | |
4816 | USAGE_ERROR_ACTION(ms,ms); | |
4817 | } | |
4818 | return internal_mallinfo(ms); | |
4819 | } | |
4820 | #endif /* NO_MALLINFO */ | |
4821 | ||
4822 | int mspace_mallopt(int param_number, int value) { | |
4823 | return change_mparam(param_number, value); | |
4824 | } | |
4825 | ||
4826 | #endif /* MSPACES */ | |
4827 | ||
4828 | /* -------------------- Alternative MORECORE functions ------------------- */ | |
4829 | ||
4830 | /* | |
4831 | Guidelines for creating a custom version of MORECORE: | |
4832 | ||
4833 | * For best performance, MORECORE should allocate in multiples of pagesize. | |
4834 | * MORECORE may allocate more memory than requested. (Or even less, | |
4835 | but this will usually result in a malloc failure.) | |
4836 | * MORECORE must not allocate memory when given argument zero, but | |
4837 | instead return one past the end address of memory from previous | |
4838 | nonzero call. | |
4839 | * For best performance, consecutive calls to MORECORE with positive | |
4840 | arguments should return increasing addresses, indicating that | |
4841 | space has been contiguously extended. | |
4842 | * Even though consecutive calls to MORECORE need not return contiguous | |
4843 | addresses, it must be OK for malloc'ed chunks to span multiple | |
4844 | regions in those cases where they do happen to be contiguous. | |
4845 | * MORECORE need not handle negative arguments -- it may instead | |
4846 | just return MFAIL when given negative arguments. | |
4847 | Negative arguments are always multiples of pagesize. MORECORE | |
4848 | must not misinterpret negative args as large positive unsigned | |
4849 | args. You can suppress all such calls from even occurring by defining | |
4850 | MORECORE_CANNOT_TRIM, | |
4851 | ||
4852 | As an example alternative MORECORE, here is a custom allocator | |
4853 | kindly contributed for pre-OSX macOS. It uses virtually but not | |
4854 | necessarily physically contiguous non-paged memory (locked in, | |
4855 | present and won't get swapped out). You can use it by uncommenting | |
4856 | this section, adding some #includes, and setting up the appropriate | |
4857 | defines above: | |
4858 | ||
4859 | #define MORECORE osMoreCore | |
4860 | ||
4861 | There is also a shutdown routine that should somehow be called for | |
4862 | cleanup upon program exit. | |
4863 | ||
4864 | #define MAX_POOL_ENTRIES 100 | |
4865 | #define MINIMUM_MORECORE_SIZE (64 * 1024U) | |
4866 | static int next_os_pool; | |
4867 | void *our_os_pools[MAX_POOL_ENTRIES]; | |
4868 | ||
4869 | void *osMoreCore(int size) | |
4870 | { | |
4871 | void *ptr = 0; | |
4872 | static void *sbrk_top = 0; | |
4873 | ||
4874 | if (size > 0) | |
4875 | { | |
4876 | if (size < MINIMUM_MORECORE_SIZE) | |
4877 | size = MINIMUM_MORECORE_SIZE; | |
4878 | if (CurrentExecutionLevel() == kTaskLevel) | |
4879 | ptr = PoolAllocateResident(size + RM_PAGE_SIZE, 0); | |
4880 | if (ptr == 0) | |
4881 | { | |
4882 | return (void *) MFAIL; | |
4883 | } | |
4884 | // save ptrs so they can be freed during cleanup | |
4885 | our_os_pools[next_os_pool] = ptr; | |
4886 | next_os_pool++; | |
4887 | ptr = (void *) ((((size_t) ptr) + RM_PAGE_MASK) & ~RM_PAGE_MASK); | |
4888 | sbrk_top = (char *) ptr + size; | |
4889 | return ptr; | |
4890 | } | |
4891 | else if (size < 0) | |
4892 | { | |
4893 | // we don't currently support shrink behavior | |
4894 | return (void *) MFAIL; | |
4895 | } | |
4896 | else | |
4897 | { | |
4898 | return sbrk_top; | |
4899 | } | |
4900 | } | |
4901 | ||
4902 | // cleanup any allocated memory pools | |
4903 | // called as last thing before shutting down driver | |
4904 | ||
4905 | void osCleanupMem(void) | |
4906 | { | |
4907 | void **ptr; | |
4908 | ||
4909 | for (ptr = our_os_pools; ptr < &our_os_pools[MAX_POOL_ENTRIES]; ptr++) | |
4910 | if (*ptr) | |
4911 | { | |
4912 | PoolDeallocate(*ptr); | |
4913 | *ptr = 0; | |
4914 | } | |
4915 | } | |
4916 | ||
4917 | */ | |
4918 | ||
4919 | ||
4920 | /* ----------------------------------------------------------------------- | |
4921 | History: | |
4922 | V2.8.3 Thu Sep 22 11:16:32 2005 Doug Lea (dl at gee) | |
4923 | * Add max_footprint functions | |
4924 | * Ensure all appropriate literals are size_t | |
4925 | * Fix conditional compilation problem for some #define settings | |
4926 | * Avoid concatenating segments with the one provided | |
4927 | in create_mspace_with_base | |
4928 | * Rename some variables to avoid compiler shadowing warnings | |
4929 | * Use explicit lock initialization. | |
4930 | * Better handling of sbrk interference. | |
4931 | * Simplify and fix segment insertion, trimming and mspace_destroy | |
4932 | * Reinstate REALLOC_ZERO_BYTES_FREES option from 2.7.x | |
4933 | * Thanks especially to Dennis Flanagan for help on these. | |
4934 | ||
4935 | V2.8.2 Sun Jun 12 16:01:10 2005 Doug Lea (dl at gee) | |
4936 | * Fix memalign brace error. | |
4937 | ||
4938 | V2.8.1 Wed Jun 8 16:11:46 2005 Doug Lea (dl at gee) | |
4939 | * Fix improper #endif nesting in C++ | |
4940 | * Add explicit casts needed for C++ | |
4941 | ||
4942 | V2.8.0 Mon May 30 14:09:02 2005 Doug Lea (dl at gee) | |
4943 | * Use trees for large bins | |
4944 | * Support mspaces | |
4945 | * Use segments to unify sbrk-based and mmap-based system allocation, | |
4946 | removing need for emulation on most platforms without sbrk. | |
4947 | * Default safety checks | |
4948 | * Optional footer checks. Thanks to William Robertson for the idea. | |
4949 | * Internal code refactoring | |
4950 | * Incorporate suggestions and platform-specific changes. | |
4951 | Thanks to Dennis Flanagan, Colin Plumb, Niall Douglas, | |
4952 | Aaron Bachmann, Emery Berger, and others. | |
4953 | * Speed up non-fastbin processing enough to remove fastbins. | |
4954 | * Remove useless cfree() to avoid conflicts with other apps. | |
4955 | * Remove internal memcpy, memset. Compilers handle builtins better. | |
4956 | * Remove some options that no one ever used and rename others. | |
4957 | ||
4958 | V2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) | |
4959 | * Fix malloc_state bitmap array misdeclaration | |
4960 | ||
4961 | V2.7.1 Thu Jul 25 10:58:03 2002 Doug Lea (dl at gee) | |
4962 | * Allow tuning of FIRST_SORTED_BIN_SIZE | |
4963 | * Use PTR_UINT as type for all ptr->int casts. Thanks to John Belmonte. | |
4964 | * Better detection and support for non-contiguousness of MORECORE. | |
4965 | Thanks to Andreas Mueller, Conal Walsh, and Wolfram Gloger | |
4966 | * Bypass most of malloc if no frees. Thanks To Emery Berger. | |
4967 | * Fix freeing of old top non-contiguous chunk im sysmalloc. | |
4968 | * Raised default trim and map thresholds to 256K. | |
4969 | * Fix mmap-related #defines. Thanks to Lubos Lunak. | |
4970 | * Fix copy macros; added LACKS_FCNTL_H. Thanks to Neal Walfield. | |
4971 | * Branch-free bin calculation | |
4972 | * Default trim and mmap thresholds now 256K. | |
4973 | ||
4974 | V2.7.0 Sun Mar 11 14:14:06 2001 Doug Lea (dl at gee) | |
4975 | * Introduce independent_comalloc and independent_calloc. | |
4976 | Thanks to Michael Pachos for motivation and help. | |
4977 | * Make optional .h file available | |
4978 | * Allow > 2GB requests on 32bit systems. | |
4979 | * new WIN32 sbrk, mmap, munmap, lock code from <Walter@GeNeSys-e.de>. | |
4980 | Thanks also to Andreas Mueller <a.mueller at paradatec.de>, | |
4981 | and Anonymous. | |
4982 | * Allow override of MALLOC_ALIGNMENT (Thanks to Ruud Waij for | |
4983 | helping test this.) | |
4984 | * memalign: check alignment arg | |
4985 | * realloc: don't try to shift chunks backwards, since this | |
4986 | leads to more fragmentation in some programs and doesn't | |
4987 | seem to help in any others. | |
4988 | * Collect all cases in malloc requiring system memory into sysmalloc | |
4989 | * Use mmap as backup to sbrk | |
4990 | * Place all internal state in malloc_state | |
4991 | * Introduce fastbins (although similar to 2.5.1) | |
4992 | * Many minor tunings and cosmetic improvements | |
4993 | * Introduce USE_PUBLIC_MALLOC_WRAPPERS, USE_MALLOC_LOCK | |
4994 | * Introduce MALLOC_FAILURE_ACTION, MORECORE_CONTIGUOUS | |
4995 | Thanks to Tony E. Bennett <tbennett@nvidia.com> and others. | |
4996 | * Include errno.h to support default failure action. | |
4997 | ||
4998 | V2.6.6 Sun Dec 5 07:42:19 1999 Doug Lea (dl at gee) | |
4999 | * return null for negative arguments | |
5000 | * Added Several WIN32 cleanups from Martin C. Fong <mcfong at yahoo.com> | |
5001 | * Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h' | |
5002 | (e.g. WIN32 platforms) | |
5003 | * Cleanup header file inclusion for WIN32 platforms | |
5004 | * Cleanup code to avoid Microsoft Visual C++ compiler complaints | |
5005 | * Add 'USE_DL_PREFIX' to quickly allow co-existence with existing | |
5006 | memory allocation routines | |
5007 | * Set 'malloc_getpagesize' for WIN32 platforms (needs more work) | |
5008 | * Use 'assert' rather than 'ASSERT' in WIN32 code to conform to | |
5009 | usage of 'assert' in non-WIN32 code | |
5010 | * Improve WIN32 'sbrk()' emulation's 'findRegion()' routine to | |
5011 | avoid infinite loop | |
5012 | * Always call 'fREe()' rather than 'free()' | |
5013 | ||
5014 | V2.6.5 Wed Jun 17 15:57:31 1998 Doug Lea (dl at gee) | |
5015 | * Fixed ordering problem with boundary-stamping | |
5016 | ||
5017 | V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee) | |
5018 | * Added pvalloc, as recommended by H.J. Liu | |
5019 | * Added 64bit pointer support mainly from Wolfram Gloger | |
5020 | * Added anonymously donated WIN32 sbrk emulation | |
5021 | * Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen | |
5022 | * malloc_extend_top: fix mask error that caused wastage after | |
5023 | foreign sbrks | |
5024 | * Add linux mremap support code from HJ Liu | |
5025 | ||
5026 | V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee) | |
5027 | * Integrated most documentation with the code. | |
5028 | * Add support for mmap, with help from | |
5029 | Wolfram Gloger (Gloger@lrz.uni-muenchen.de). | |
5030 | * Use last_remainder in more cases. | |
5031 | * Pack bins using idea from colin@nyx10.cs.du.edu | |
5032 | * Use ordered bins instead of best-fit threshhold | |
5033 | * Eliminate block-local decls to simplify tracing and debugging. | |
5034 | * Support another case of realloc via move into top | |
5035 | * Fix error occuring when initial sbrk_base not word-aligned. | |
5036 | * Rely on page size for units instead of SBRK_UNIT to | |
5037 | avoid surprises about sbrk alignment conventions. | |
5038 | * Add mallinfo, mallopt. Thanks to Raymond Nijssen | |
5039 | (raymond@es.ele.tue.nl) for the suggestion. | |
5040 | * Add `pad' argument to malloc_trim and top_pad mallopt parameter. | |
5041 | * More precautions for cases where other routines call sbrk, | |
5042 | courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de). | |
5043 | * Added macros etc., allowing use in linux libc from | |
5044 | H.J. Lu (hjl@gnu.ai.mit.edu) | |
5045 | * Inverted this history list | |
5046 | ||
5047 | V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee) | |
5048 | * Re-tuned and fixed to behave more nicely with V2.6.0 changes. | |
5049 | * Removed all preallocation code since under current scheme | |
5050 | the work required to undo bad preallocations exceeds | |
5051 | the work saved in good cases for most test programs. | |
5052 | * No longer use return list or unconsolidated bins since | |
5053 | no scheme using them consistently outperforms those that don't | |
5054 | given above changes. | |
5055 | * Use best fit for very large chunks to prevent some worst-cases. | |
5056 | * Added some support for debugging | |
5057 | ||
5058 | V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee) | |
5059 | * Removed footers when chunks are in use. Thanks to | |
5060 | Paul Wilson (wilson@cs.texas.edu) for the suggestion. | |
5061 | ||
5062 | V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee) | |
5063 | * Added malloc_trim, with help from Wolfram Gloger | |
5064 | (wmglo@Dent.MED.Uni-Muenchen.DE). | |
5065 | ||
5066 | V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g) | |
5067 | ||
5068 | V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g) | |
5069 | * realloc: try to expand in both directions | |
5070 | * malloc: swap order of clean-bin strategy; | |
5071 | * realloc: only conditionally expand backwards | |
5072 | * Try not to scavenge used bins | |
5073 | * Use bin counts as a guide to preallocation | |
5074 | * Occasionally bin return list chunks in first scan | |
5075 | * Add a few optimizations from colin@nyx10.cs.du.edu | |
5076 | ||
5077 | V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g) | |
5078 | * faster bin computation & slightly different binning | |
5079 | * merged all consolidations to one part of malloc proper | |
5080 | (eliminating old malloc_find_space & malloc_clean_bin) | |
5081 | * Scan 2 returns chunks (not just 1) | |
5082 | * Propagate failure in realloc if malloc returns 0 | |
5083 | * Add stuff to allow compilation on non-ANSI compilers | |
5084 | from kpv@research.att.com | |
5085 | ||
5086 | V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu) | |
5087 | * removed potential for odd address access in prev_chunk | |
5088 | * removed dependency on getpagesize.h | |
5089 | * misc cosmetics and a bit more internal documentation | |
5090 | * anticosmetics: mangled names in macros to evade debugger strangeness | |
5091 | * tested on sparc, hp-700, dec-mips, rs6000 | |
5092 | with gcc & native cc (hp, dec only) allowing | |
5093 | Detlefs & Zorn comparison study (in SIGPLAN Notices.) | |
5094 | ||
5095 | Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu) | |
5096 | * Based loosely on libg++-1.2X malloc. (It retains some of the overall | |
5097 | structure of old version, but most details differ.) | |
5098 | ||
5099 | */ |