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3996f34b UD |
1 | /* Profiling of shared libraries. |
2 | Copyright (C) 1997 Free Software Foundation, Inc. | |
3 | This file is part of the GNU C Library. | |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. | |
9a0a462c | 5 | Based on the BSD mcount implementation. |
3996f34b UD |
6 | |
7 | The GNU C Library is free software; you can redistribute it and/or | |
8 | modify it under the terms of the GNU Library General Public License as | |
9 | published by the Free Software Foundation; either version 2 of the | |
10 | License, or (at your option) any later version. | |
11 | ||
12 | The GNU C Library is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Library General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Library General Public | |
18 | License along with the GNU C Library; see the file COPYING.LIB. If not, | |
19 | write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | #include <errno.h> | |
23 | #include <fcntl.h> | |
24 | #include <inttypes.h> | |
25 | #include <link.h> | |
26 | #include <stdio.h> | |
27 | #include <stdlib.h> | |
28 | #include <string.h> | |
29 | #include <unistd.h> | |
30 | #include <sys/gmon.h> | |
31 | #include <sys/gmon_out.h> | |
32 | #include <sys/mman.h> | |
650425ce | 33 | #include <sys/param.h> |
3996f34b | 34 | #include <sys/stat.h> |
9a0a462c | 35 | #include <atomicity.h> |
3996f34b UD |
36 | |
37 | /* The LD_PROFILE feature has to be implemented different to the | |
38 | normal profiling using the gmon/ functions. The problem is that an | |
39 | arbitrary amount of processes simulataneously can be run using | |
40 | profiling and all write the results in the same file. To provide | |
41 | this mechanism one could implement a complicated mechanism to merge | |
42 | the content of two profiling runs or one could extend the file | |
43 | format to allow more than one data set. For the second solution we | |
44 | would have the problem that the file can grow in size beyond any | |
45 | limit and both solutions have the problem that the concurrency of | |
46 | writing the results is a big problem. | |
47 | ||
48 | Another much simpler method is to use mmap to map the same file in | |
49 | all using programs and modify the data in the mmap'ed area and so | |
50 | also automatically on the disk. Using the MAP_SHARED option of | |
51 | mmap(2) this can be done without big problems in more than one | |
52 | file. | |
53 | ||
54 | This approach is very different from the normal profiling. We have | |
55 | to use the profiling data in exactly the way they are expected to | |
0413b54c UD |
56 | be written to disk. But the normal format used by gprof is not usable |
57 | to do this. It is optimized for size. It writes the tags as single | |
58 | bytes but this means that the following 32/64 bit values are | |
59 | unaligned. | |
60 | ||
61 | Therefore we use a new format. This will look like this | |
62 | ||
63 | 0 1 2 3 <- byte is 32 bit word | |
64 | 0000 g m o n | |
65 | 0004 *version* <- GMON_SHOBJ_VERSION | |
66 | 0008 00 00 00 00 | |
67 | 000c 00 00 00 00 | |
68 | 0010 00 00 00 00 | |
69 | ||
70 | 0014 *tag* <- GMON_TAG_TIME_HIST | |
71 | 0018 ?? ?? ?? ?? | |
72 | ?? ?? ?? ?? <- 32/64 bit LowPC | |
73 | 0018+A ?? ?? ?? ?? | |
74 | ?? ?? ?? ?? <- 32/64 bit HighPC | |
75 | 0018+2*A *histsize* | |
76 | 001c+2*A *profrate* | |
77 | 0020+2*A s e c o | |
78 | 0024+2*A n d s \0 | |
79 | 0028+2*A \0 \0 \0 \0 | |
80 | 002c+2*A \0 \0 \0 | |
81 | 002f+2*A s | |
82 | ||
83 | 0030+2*A ?? ?? ?? ?? <- Count data | |
84 | ... ... | |
85 | 0030+2*A+K ?? ?? ?? ?? | |
86 | ||
87 | 0030+2*A+K *tag* <- GMON_TAG_CG_ARC | |
88 | 0034+2*A+K *lastused* | |
89 | 0038+2*A+K ?? ?? ?? ?? | |
90 | ?? ?? ?? ?? <- FromPC#1 | |
91 | 0038+3*A+K ?? ?? ?? ?? | |
92 | ?? ?? ?? ?? <- ToPC#1 | |
93 | 0038+4*A+K ?? ?? ?? ?? <- Count#1 | |
94 | ... ... ... | |
95 | 0038+(2*(CN-1)+2)*A+(CN-1)*4+K ?? ?? ?? ?? | |
96 | ?? ?? ?? ?? <- FromPC#CGN | |
97 | 0038+(2*(CN-1)+3)*A+(CN-1)*4+K ?? ?? ?? ?? | |
98 | ?? ?? ?? ?? <- ToPC#CGN | |
99 | 0038+(2*CN+2)*A+(CN-1)*4+K ?? ?? ?? ?? <- Count#CGN | |
100 | ||
650425ce | 101 | We put (for now?) no basic block information in the file since this would |
0413b54c UD |
102 | introduce rase conditions among all the processes who want to write them. |
103 | ||
104 | `K' is the number of count entries which is computed as | |
105 | ||
106 | textsize / HISTFRACTION | |
107 | ||
108 | `CG' in the above table is the number of call graph arcs. Normally, | |
109 | the table is sparse and the profiling code writes out only the those | |
110 | entries which are really used in the program run. But since we must | |
111 | not extend this table (the profiling file) we'll keep them all here. | |
112 | So CN can be executed in advance as | |
113 | ||
114 | MINARCS <= textsize*(ARCDENSITY/100) <= MAXARCS | |
115 | ||
116 | Now the remaining question is: how to build the data structures we can | |
117 | work with from this data. We need the from set and must associate the | |
118 | froms with all the associated tos. We will do this by constructing this | |
119 | data structures at the program start. To do this we'll simply visit all | |
120 | entries in the call graph table and add it to the appropriate list. */ | |
3996f34b UD |
121 | |
122 | extern char *_strerror_internal __P ((int, char *buf, size_t)); | |
123 | ||
124 | extern int __profile_frequency __P ((void)); | |
125 | ||
3996f34b UD |
126 | /* We define a special type to address the elements of the arc table. |
127 | This is basically the `gmon_cg_arc_record' format but it includes | |
128 | the room for the tag and it uses real types. */ | |
129 | struct here_cg_arc_record | |
130 | { | |
0413b54c UD |
131 | uintptr_t from_pc; |
132 | uintptr_t self_pc; | |
133 | uint32_t count; | |
134 | } __attribute__ ((packed)); | |
3996f34b UD |
135 | |
136 | static struct here_cg_arc_record *data; | |
137 | ||
0413b54c UD |
138 | /* This is the number of entry which have been incorporated in the toset. */ |
139 | static uint32_t narcs; | |
140 | /* This is a pointer to the object representing the number of entries | |
141 | currently in the mmaped file. At no point of time this has to be the | |
142 | same as NARCS. If it is equal all entries from the file are in our | |
143 | lists. */ | |
650425ce | 144 | static volatile uint32_t *narcsp; |
0413b54c UD |
145 | |
146 | /* Description of the currently profiled object. */ | |
650425ce | 147 | static long int state = GMON_PROF_OFF; |
3996f34b | 148 | |
0413b54c UD |
149 | static volatile uint16_t *kcount; |
150 | static size_t kcountsize; | |
151 | ||
9a0a462c | 152 | struct here_fromstruct |
0413b54c UD |
153 | { |
154 | struct here_cg_arc_record volatile *here; | |
155 | uint16_t link; | |
156 | }; | |
157 | ||
9a0a462c | 158 | static uint16_t *tos; |
0413b54c | 159 | static size_t tossize; |
9a0a462c UD |
160 | |
161 | static struct here_fromstruct *froms; | |
162 | static size_t fromssize; | |
163 | static size_t fromlimit; | |
164 | static size_t fromidx; | |
0413b54c UD |
165 | |
166 | static uintptr_t lowpc; | |
167 | static uintptr_t highpc; | |
168 | static size_t textsize; | |
169 | static unsigned int hashfraction; | |
170 | static unsigned int log_hashfraction; | |
171 | ||
172 | /* This is the information about the mmaped memory. */ | |
173 | static struct gmon_hdr *addr; | |
174 | static off_t expected_size; | |
175 | ||
9a0a462c UD |
176 | /* See profil(2) where this is described. */ |
177 | static int s_scale; | |
178 | #define SCALE_1_TO_1 0x10000L | |
179 | ||
180 | ||
0413b54c UD |
181 | \f |
182 | /* Set up profiling data to profile object desribed by MAP. The output | |
183 | file is found (or created) in OUTPUT_DIR. */ | |
3996f34b UD |
184 | void |
185 | _dl_start_profile (struct link_map *map, const char *output_dir) | |
186 | { | |
187 | char *filename; | |
188 | int fd; | |
189 | struct stat st; | |
190 | const ElfW(Phdr) *ph; | |
191 | ElfW(Addr) mapstart = ~((ElfW(Addr)) 0); | |
192 | ElfW(Addr) mapend = 0; | |
3996f34b UD |
193 | struct gmon_hdr gmon_hdr; |
194 | struct gmon_hist_hdr hist_hdr; | |
9a0a462c | 195 | char *hist, *cp; |
0413b54c | 196 | size_t idx; |
3996f34b UD |
197 | |
198 | /* Compute the size of the sections which contain program code. */ | |
199 | for (ph = map->l_phdr; ph < &map->l_phdr[map->l_phnum]; ++ph) | |
200 | if (ph->p_type == PT_LOAD && (ph->p_flags & PF_X)) | |
201 | { | |
202 | ElfW(Addr) start = (ph->p_vaddr & ~(_dl_pagesize - 1)); | |
203 | ElfW(Addr) end = ((ph->p_vaddr + ph->p_memsz + _dl_pagesize - 1) | |
204 | & ~(_dl_pagesize - 1)); | |
205 | ||
206 | if (start < mapstart) | |
207 | mapstart = start; | |
208 | if (end > mapend) | |
209 | mapend = end; | |
210 | } | |
211 | ||
212 | /* Now we can compute the size of the profiling data. This is done | |
213 | with the same formulars as in `monstartup' (see gmon.c). */ | |
0413b54c UD |
214 | state = GMON_PROF_OFF; |
215 | lowpc = ROUNDDOWN (mapstart + map->l_addr, | |
9a0a462c | 216 | HISTFRACTION * sizeof (HISTCOUNTER)); |
0413b54c | 217 | highpc = ROUNDUP (mapend + map->l_addr, |
9a0a462c | 218 | HISTFRACTION * sizeof (HISTCOUNTER)); |
0413b54c UD |
219 | textsize = highpc - lowpc; |
220 | kcountsize = textsize / HISTFRACTION; | |
221 | hashfraction = HASHFRACTION; | |
3996f34b UD |
222 | if ((HASHFRACTION & (HASHFRACTION - 1)) == 0) |
223 | /* If HASHFRACTION is a power of two, mcount can use shifting | |
224 | instead of integer division. Precompute shift amount. */ | |
0413b54c UD |
225 | log_hashfraction = __builtin_ffs (hashfraction * sizeof (*froms)) - 1; |
226 | else | |
227 | log_hashfraction = -1; | |
9a0a462c UD |
228 | tossize = textsize / HASHFRACTION; |
229 | fromlimit = textsize * ARCDENSITY / 100; | |
230 | if (fromlimit < MINARCS) | |
231 | fromlimit = MINARCS; | |
232 | if (fromlimit > MAXARCS) | |
233 | fromlimit = MAXARCS; | |
234 | fromssize = fromlimit * sizeof (struct here_fromstruct); | |
3996f34b UD |
235 | |
236 | expected_size = (sizeof (struct gmon_hdr) | |
0413b54c | 237 | + 4 + sizeof (struct gmon_hist_hdr) + kcountsize |
9a0a462c | 238 | + 4 + 4 + fromssize * sizeof (struct here_cg_arc_record)); |
3996f34b UD |
239 | |
240 | /* Create the gmon_hdr we expect or write. */ | |
241 | memset (&gmon_hdr, '\0', sizeof (struct gmon_hdr)); | |
242 | memcpy (&gmon_hdr.cookie[0], GMON_MAGIC, sizeof (gmon_hdr.cookie)); | |
0413b54c | 243 | *(int32_t *) gmon_hdr.version = GMON_SHOBJ_VERSION; |
3996f34b UD |
244 | |
245 | /* Create the hist_hdr we expect or write. */ | |
246 | *(char **) hist_hdr.low_pc = (char *) mapstart; | |
247 | *(char **) hist_hdr.high_pc = (char *) mapend; | |
0413b54c | 248 | *(int32_t *) hist_hdr.hist_size = kcountsize / sizeof (HISTCOUNTER); |
3996f34b UD |
249 | *(int32_t *) hist_hdr.prof_rate = __profile_frequency (); |
250 | strncpy (hist_hdr.dimen, "seconds", sizeof (hist_hdr.dimen)); | |
251 | hist_hdr.dimen_abbrev = 's'; | |
252 | ||
253 | /* First determine the output name. We write in the directory | |
254 | OUTPUT_DIR and the name is composed from the shared objects | |
255 | soname (or the file name) and the ending ".profile". */ | |
256 | filename = (char *) alloca (strlen (output_dir) + 1 + strlen (_dl_profile) | |
257 | + sizeof ".profile"); | |
9a0a462c UD |
258 | cp = __stpcpy (filename, output_dir); |
259 | *cp++ = '/'; | |
260 | __stpcpy (__stpcpy (cp, _dl_profile), ".profile"); | |
3996f34b UD |
261 | |
262 | fd = __open (filename, O_RDWR | O_CREAT, 0666); | |
263 | if (fd == -1) | |
650425ce | 264 | { |
86187531 | 265 | /* We cannot write the profiling data so don't do anything. */ |
650425ce UD |
266 | char buf[400]; |
267 | _dl_sysdep_message (filename, ": cannot open file: ", | |
268 | _strerror_internal (errno, buf, sizeof buf), | |
269 | "\n", NULL); | |
270 | return; | |
271 | } | |
3996f34b UD |
272 | |
273 | if (fstat (fd, &st) < 0 || !S_ISREG (st.st_mode)) | |
274 | { | |
275 | /* Not stat'able or not a regular file => don't use it. */ | |
650425ce UD |
276 | char buf[400]; |
277 | int errnum = errno; | |
278 | __close (fd); | |
279 | _dl_sysdep_message (filename, ": cannot stat file: ", | |
280 | _strerror_internal (errnum, buf, sizeof buf), | |
281 | "\n", NULL); | |
3996f34b UD |
282 | return; |
283 | } | |
284 | ||
285 | /* Test the size. If it does not match what we expect from the size | |
286 | values in the map MAP we don't use it and warn the user. */ | |
287 | if (st.st_size == 0) | |
288 | { | |
289 | /* We have to create the file. */ | |
290 | char buf[_dl_pagesize]; | |
291 | ||
292 | memset (buf, '\0', _dl_pagesize); | |
293 | ||
294 | if (__lseek (fd, expected_size & ~(_dl_pagesize - 1), SEEK_SET) == -1) | |
295 | { | |
296 | char buf[400]; | |
297 | int errnum; | |
298 | cannot_create: | |
299 | errnum = errno; | |
300 | __close (fd); | |
650425ce UD |
301 | _dl_sysdep_message (filename, ": cannot create file: ", |
302 | _strerror_internal (errnum, buf, sizeof buf), | |
303 | "\n", NULL); | |
3996f34b UD |
304 | return; |
305 | } | |
306 | ||
307 | if (TEMP_FAILURE_RETRY (__write (fd, buf, (expected_size | |
308 | & (_dl_pagesize - 1)))) < 0) | |
309 | goto cannot_create; | |
310 | } | |
311 | else if (st.st_size != expected_size) | |
312 | { | |
313 | __close (fd); | |
314 | wrong_format: | |
0413b54c UD |
315 | |
316 | if (addr != NULL) | |
317 | __munmap ((void *) addr, expected_size); | |
318 | ||
650425ce UD |
319 | _dl_sysdep_message (filename, |
320 | ": file is no correct profile data file for `", | |
321 | _dl_profile, "'\n", NULL); | |
3996f34b UD |
322 | return; |
323 | } | |
324 | ||
0413b54c UD |
325 | addr = (struct gmon_hdr *) __mmap (NULL, expected_size, PROT_READ|PROT_WRITE, |
326 | MAP_SHARED|MAP_FILE, fd, 0); | |
327 | if (addr == (struct gmon_hdr *) MAP_FAILED) | |
3996f34b UD |
328 | { |
329 | char buf[400]; | |
330 | int errnum = errno; | |
331 | __close (fd); | |
650425ce UD |
332 | _dl_sysdep_message (filename, ": cannot map file: ", |
333 | _strerror_internal (errnum, buf, sizeof buf), | |
334 | "\n", NULL); | |
3996f34b UD |
335 | return; |
336 | } | |
337 | ||
338 | /* We don't need the file desriptor anymore. */ | |
339 | __close (fd); | |
340 | ||
341 | /* Pointer to data after the header. */ | |
342 | hist = (char *) (addr + 1); | |
0413b54c UD |
343 | kcount = (uint16_t *) ((char *) hist + sizeof (uint32_t) |
344 | + sizeof (struct gmon_hist_hdr)); | |
3996f34b UD |
345 | |
346 | /* Compute pointer to array of the arc information. */ | |
650425ce UD |
347 | narcsp = (uint32_t *) ((char *) kcount + kcountsize + sizeof (uint32_t)); |
348 | data = (struct here_cg_arc_record *) ((char *) narcsp + sizeof (uint32_t)); | |
3996f34b UD |
349 | |
350 | if (st.st_size == 0) | |
351 | { | |
352 | /* Create the signature. */ | |
3996f34b UD |
353 | memcpy (addr, &gmon_hdr, sizeof (struct gmon_hdr)); |
354 | ||
0413b54c UD |
355 | *(uint32_t *) hist = GMON_TAG_TIME_HIST; |
356 | memcpy (hist + sizeof (uint32_t), &hist_hdr, | |
357 | sizeof (struct gmon_hist_hdr)); | |
3996f34b | 358 | |
650425ce | 359 | narcsp[-1] = GMON_TAG_CG_ARC; |
3996f34b UD |
360 | } |
361 | else | |
362 | { | |
363 | /* Test the signature in the file. */ | |
364 | if (memcmp (addr, &gmon_hdr, sizeof (struct gmon_hdr)) != 0 | |
0413b54c UD |
365 | || *(uint32_t *) hist != GMON_TAG_TIME_HIST |
366 | || memcmp (hist + sizeof (uint32_t), &hist_hdr, | |
367 | sizeof (struct gmon_hist_hdr)) != 0 | |
650425ce | 368 | || narcsp[-1] != GMON_TAG_CG_ARC) |
3996f34b UD |
369 | goto wrong_format; |
370 | } | |
371 | ||
0413b54c | 372 | /* Allocate memory for the froms data and the pointer to the tos records. */ |
9a0a462c | 373 | tos = (uint16_t *) calloc (tossize + fromssize, 1); |
650425ce | 374 | if (tos == NULL) |
0413b54c UD |
375 | { |
376 | __munmap ((void *) addr, expected_size); | |
650425ce | 377 | _dl_sysdep_fatal ("Out of memory while initializing profiler\n", NULL); |
0413b54c UD |
378 | /* NOTREACHED */ |
379 | } | |
380 | ||
9a0a462c UD |
381 | froms = (struct here_fromstruct *) ((char *) tos + tossize); |
382 | fromidx = 0; | |
0413b54c UD |
383 | |
384 | /* Now we have to process all the arc count entries. BTW: it is | |
385 | not critical whether the *NARCSP value changes meanwhile. Before | |
386 | we enter a new entry in to toset we will check that everything is | |
387 | available in TOS. This happens in _dl_mcount. | |
388 | ||
389 | Loading the entries in reverse order should help to get the most | |
390 | frequently used entries at the front of the list. */ | |
650425ce | 391 | for (idx = narcs = MIN (*narcsp, fromlimit); idx > 0; ) |
0413b54c | 392 | { |
9a0a462c UD |
393 | size_t to_index; |
394 | size_t newfromidx; | |
0413b54c | 395 | --idx; |
650425ce | 396 | to_index = (data[idx].self_pc / (hashfraction * sizeof (*tos))); |
9a0a462c UD |
397 | newfromidx = fromidx++; |
398 | froms[newfromidx].here = &data[idx]; | |
399 | froms[newfromidx].link = tos[to_index]; | |
400 | tos[to_index] = newfromidx; | |
0413b54c UD |
401 | } |
402 | ||
9a0a462c UD |
403 | /* Setup counting data. */ |
404 | if (kcountsize < highpc - lowpc) | |
405 | s_scale = ((double) kcountsize / (highpc - lowpc)) * SCALE_1_TO_1; | |
406 | else | |
407 | s_scale = SCALE_1_TO_1; | |
408 | ||
409 | /* Start the profiler. */ | |
410 | __profil ((void *) kcount, kcountsize, lowpc, s_scale); | |
411 | ||
3996f34b | 412 | /* Turn on profiling. */ |
0413b54c | 413 | state = GMON_PROF_ON; |
3996f34b UD |
414 | } |
415 | ||
416 | ||
417 | void | |
418 | _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc) | |
419 | { | |
9a0a462c UD |
420 | uint16_t *topcindex; |
421 | size_t i, fromindex; | |
422 | struct here_fromstruct *fromp; | |
423 | ||
424 | if (! compare_and_swap (&state, GMON_PROF_ON, GMON_PROF_BUSY)) | |
3996f34b | 425 | return; |
3996f34b UD |
426 | |
427 | /* Compute relative addresses. The shared object can be loaded at | |
428 | any address. The value of frompc could be anything. We cannot | |
429 | restrict it in any way, just set to a fixed value (0) in case it | |
430 | is outside the allowed range. These calls show up as calls from | |
431 | <external> in the gprof output. */ | |
0413b54c UD |
432 | frompc -= lowpc; |
433 | if (frompc >= textsize) | |
3996f34b | 434 | frompc = 0; |
0413b54c UD |
435 | selfpc -= lowpc; |
436 | if (selfpc >= textsize) | |
437 | goto done; | |
438 | ||
9a0a462c UD |
439 | /* Getting here we now have to find out whether the location was |
440 | already used. If yes we are lucky and only have to increment a | |
441 | counter (this also has to be atomic). If the entry is new things | |
442 | are getting complicated... */ | |
443 | ||
444 | /* Avoid integer divide if possible. */ | |
445 | if ((HASHFRACTION & (HASHFRACTION - 1)) == 0) | |
446 | i = selfpc >> log_hashfraction; | |
447 | else | |
448 | i = selfpc / (hashfraction * sizeof (*tos)); | |
449 | ||
450 | topcindex = &tos[i]; | |
451 | fromindex = *topcindex; | |
452 | ||
453 | if (fromindex == 0) | |
454 | goto check_new_or_add; | |
455 | ||
456 | fromp = &froms[fromindex]; | |
457 | ||
458 | /* We have to look through the chain of arcs whether there is already | |
459 | an entry for our arc. */ | |
460 | while (fromp->here->from_pc == frompc) | |
461 | { | |
462 | if (fromp->link != 0) | |
463 | do | |
464 | fromp = &froms[fromp->link]; | |
465 | while (fromp->link != 0 && fromp->here->from_pc != frompc); | |
466 | ||
650425ce | 467 | if (fromp->here->from_pc != frompc) |
9a0a462c UD |
468 | { |
469 | topcindex = &fromp->link; | |
470 | ||
471 | check_new_or_add: | |
472 | /* Our entry is not among the entries we read so far from the | |
473 | data file. Now see whether we have to update the list. */ | |
650425ce | 474 | while (narcs != *narcsp && narcs < fromlimit) |
9a0a462c UD |
475 | { |
476 | size_t to_index; | |
477 | size_t newfromidx; | |
650425ce | 478 | to_index = (data[narcs].self_pc |
9a0a462c UD |
479 | / (hashfraction * sizeof (*tos))); |
480 | newfromidx = fromidx++; | |
481 | froms[newfromidx].here = &data[narcs]; | |
482 | froms[newfromidx].link = tos[to_index]; | |
483 | tos[to_index] = newfromidx; | |
484 | ++narcs; | |
485 | } | |
486 | ||
487 | /* If we still have no entry stop searching and insert. */ | |
488 | if (*topcindex == 0) | |
489 | { | |
650425ce | 490 | size_t newarc = 1 + exchange_and_add (narcsp, 1); |
9a0a462c UD |
491 | |
492 | /* In rare cases it could happen that all entries in FROMS are | |
493 | occupied. So we cannot count this anymore. */ | |
650425ce | 494 | if (newarc >= fromlimit) |
9a0a462c UD |
495 | goto done; |
496 | ||
650425ce | 497 | fromp = &froms[*topcindex = fromidx++]; |
9a0a462c | 498 | |
650425ce UD |
499 | fromp->here = &data[newarc]; |
500 | data[newarc].from_pc = frompc; | |
501 | data[newarc].self_pc = selfpc; | |
502 | data[newarc].count = 0; | |
9a0a462c | 503 | fromp->link = 0; |
650425ce UD |
504 | |
505 | narcs++; | |
9a0a462c UD |
506 | |
507 | break; | |
508 | } | |
509 | ||
510 | fromp = &froms[*topcindex]; | |
511 | } | |
512 | else | |
513 | /* Found in. */ | |
514 | break; | |
515 | } | |
516 | ||
517 | /* Increment the counter. */ | |
518 | atomic_add (&fromp->here->count, 1); | |
3996f34b | 519 | |
0413b54c UD |
520 | done: |
521 | state = GMON_PROF_ON; | |
3996f34b | 522 | } |