Commit | Line | Data |
a0d0e21e |
1 | /* malloc.c |
8d063cd8 |
2 | * |
8d063cd8 |
3 | */ |
4 | |
3562ef9b |
5 | #if defined(PERL_CORE) && !defined(DEBUGGING_MSTATS) |
6 | # define DEBUGGING_MSTATS |
7 | #endif |
8 | |
8d063cd8 |
9 | #ifndef lint |
1944739a |
10 | # if defined(DEBUGGING) && !defined(NO_RCHECK) |
11 | # define RCHECK |
12 | # endif |
8d063cd8 |
13 | /* |
14 | * malloc.c (Caltech) 2/21/82 |
15 | * Chris Kingsley, kingsley@cit-20. |
16 | * |
17 | * This is a very fast storage allocator. It allocates blocks of a small |
18 | * number of different sizes, and keeps free lists of each size. Blocks that |
19 | * don't exactly fit are passed up to the next larger size. In this |
20 | * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long. |
cf5c4ad8 |
21 | * If PACK_MALLOC is defined, small blocks are 2^n bytes long. |
8d063cd8 |
22 | * This is designed for use in a program that uses vast quantities of memory, |
23 | * but bombs when it runs out. |
24 | */ |
25 | |
135863df |
26 | #include "EXTERN.h" |
135863df |
27 | #include "perl.h" |
28 | |
760ac839 |
29 | #ifdef DEBUGGING |
30 | #undef DEBUG_m |
31 | #define DEBUG_m(a) if (debug & 128) a |
32 | #endif |
33 | |
135863df |
34 | /* I don't much care whether these are defined in sys/types.h--LAW */ |
35 | |
36 | #define u_char unsigned char |
37 | #define u_int unsigned int |
38 | #define u_short unsigned short |
8d063cd8 |
39 | |
cf5c4ad8 |
40 | /* 286 and atarist like big chunks, which gives too much overhead. */ |
41 | #if (defined(RCHECK) || defined(I286) || defined(atarist)) && defined(PACK_MALLOC) |
42 | #undef PACK_MALLOC |
43 | #endif |
44 | |
45 | |
8d063cd8 |
46 | /* |
cf5c4ad8 |
47 | * The description below is applicable if PACK_MALLOC is not defined. |
48 | * |
8d063cd8 |
49 | * The overhead on a block is at least 4 bytes. When free, this space |
50 | * contains a pointer to the next free block, and the bottom two bits must |
51 | * be zero. When in use, the first byte is set to MAGIC, and the second |
52 | * byte is the size index. The remaining bytes are for alignment. |
53 | * If range checking is enabled and the size of the block fits |
54 | * in two bytes, then the top two bytes hold the size of the requested block |
55 | * plus the range checking words, and the header word MINUS ONE. |
56 | */ |
57 | union overhead { |
58 | union overhead *ov_next; /* when free */ |
85e6fe83 |
59 | #if MEM_ALIGNBYTES > 4 |
c623bd54 |
60 | double strut; /* alignment problems */ |
a687059c |
61 | #endif |
8d063cd8 |
62 | struct { |
63 | u_char ovu_magic; /* magic number */ |
64 | u_char ovu_index; /* bucket # */ |
65 | #ifdef RCHECK |
66 | u_short ovu_size; /* actual block size */ |
67 | u_int ovu_rmagic; /* range magic number */ |
68 | #endif |
69 | } ovu; |
70 | #define ov_magic ovu.ovu_magic |
71 | #define ov_index ovu.ovu_index |
72 | #define ov_size ovu.ovu_size |
73 | #define ov_rmagic ovu.ovu_rmagic |
74 | }; |
75 | |
760ac839 |
76 | #ifdef DEBUGGING |
a0d0e21e |
77 | static void botch _((char *s)); |
78 | #endif |
79 | static void morecore _((int bucket)); |
80 | static int findbucket _((union overhead *freep, int srchlen)); |
81 | |
8d063cd8 |
82 | #define MAGIC 0xff /* magic # on accounting info */ |
83 | #define RMAGIC 0x55555555 /* magic # on range info */ |
84 | #ifdef RCHECK |
c2a5c2d2 |
85 | # define RSLOP sizeof (u_int) |
86 | # ifdef TWO_POT_OPTIMIZE |
87 | # define MAX_SHORT_BUCKET 12 |
88 | # else |
89 | # define MAX_SHORT_BUCKET 13 |
90 | # endif |
8d063cd8 |
91 | #else |
c2a5c2d2 |
92 | # define RSLOP 0 |
8d063cd8 |
93 | #endif |
94 | |
cf5c4ad8 |
95 | #ifdef PACK_MALLOC |
96 | /* |
97 | * In this case it is assumed that if we do sbrk() in 2K units, we |
98 | * will get 2K aligned blocks. The bucket number of the given subblock is |
99 | * on the boundary of 2K block which contains the subblock. |
100 | * Several following bytes contain the magic numbers for the subblocks |
101 | * in the block. |
102 | * |
103 | * Sizes of chunks are powers of 2 for chunks in buckets <= |
104 | * MAX_PACKED, after this they are (2^n - sizeof(union overhead)) (to |
105 | * get alignment right). |
106 | * |
107 | * We suppose that starts of all the chunks in a 2K block are in |
108 | * different 2^n-byte-long chunks. If the top of the last chunk is |
109 | * aligned on a boundary of 2K block, this means that |
110 | * sizeof(union overhead)*"number of chunks" < 2^n, or |
111 | * sizeof(union overhead)*2K < 4^n, or n > 6 + log2(sizeof()/2)/2, if a |
112 | * chunk of size 2^n - overhead is used. Since this rules out n = 7 |
113 | * for 8 byte alignment, we specialcase allocation of the first of 16 |
114 | * 128-byte-long chunks. |
115 | * |
116 | * Note that with the above assumption we automatically have enough |
117 | * place for MAGIC at the start of 2K block. Note also that we |
118 | * overlay union overhead over the chunk, thus the start of the chunk |
119 | * is immediately overwritten after freeing. |
120 | */ |
121 | # define MAX_PACKED 6 |
122 | # define MAX_2_POT_ALGO ((1<<(MAX_PACKED + 1)) - M_OVERHEAD) |
123 | # define TWOK_MASK ((1<<11) - 1) |
ff68c719 |
124 | # define TWOK_MASKED(x) ((u_int)(x) & ~TWOK_MASK) |
125 | # define TWOK_SHIFT(x) ((u_int)(x) & TWOK_MASK) |
cf5c4ad8 |
126 | # define OV_INDEXp(block) ((u_char*)(TWOK_MASKED(block))) |
127 | # define OV_INDEX(block) (*OV_INDEXp(block)) |
128 | # define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) + \ |
129 | (TWOK_SHIFT(block)>>(bucket + 3)) + \ |
130 | (bucket > MAX_NONSHIFT ? 1 : 0))) |
131 | # define CHUNK_SHIFT 0 |
132 | |
133 | static u_char n_blks[11 - 3] = {224, 120, 62, 31, 16, 8, 4, 2}; |
134 | static u_short blk_shift[11 - 3] = {256, 128, 64, 32, |
135 | 16*sizeof(union overhead), |
136 | 8*sizeof(union overhead), |
137 | 4*sizeof(union overhead), |
138 | 2*sizeof(union overhead), |
139 | # define MAX_NONSHIFT 2 /* Shift 64 greater than chunk 32. */ |
140 | }; |
141 | |
cf5c4ad8 |
142 | #else /* !PACK_MALLOC */ |
143 | |
144 | # define OV_MAGIC(block,bucket) (block)->ov_magic |
145 | # define OV_INDEX(block) (block)->ov_index |
146 | # define CHUNK_SHIFT 1 |
147 | #endif /* !PACK_MALLOC */ |
148 | |
149 | # define M_OVERHEAD (sizeof(union overhead) + RSLOP) |
150 | |
8d063cd8 |
151 | /* |
55497cff |
152 | * Big allocations are often of the size 2^n bytes. To make them a |
153 | * little bit better, make blocks of size 2^n+pagesize for big n. |
154 | */ |
155 | |
156 | #ifdef TWO_POT_OPTIMIZE |
157 | |
5f05dabc |
158 | # ifndef PERL_PAGESIZE |
159 | # define PERL_PAGESIZE 4096 |
160 | # endif |
161 | # ifndef FIRST_BIG_TWO_POT |
162 | # define FIRST_BIG_TWO_POT 14 /* 16K */ |
163 | # endif |
55497cff |
164 | # define FIRST_BIG_BLOCK (1<<FIRST_BIG_TWO_POT) /* 16K */ |
165 | /* If this value or more, check against bigger blocks. */ |
166 | # define FIRST_BIG_BOUND (FIRST_BIG_BLOCK - M_OVERHEAD) |
167 | /* If less than this value, goes into 2^n-overhead-block. */ |
168 | # define LAST_SMALL_BOUND ((FIRST_BIG_BLOCK>>1) - M_OVERHEAD) |
169 | |
170 | #endif /* TWO_POT_OPTIMIZE */ |
171 | |
72e5b9db |
172 | #if defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE) |
55497cff |
173 | |
174 | #ifndef BIG_SIZE |
175 | # define BIG_SIZE (1<<16) /* 64K */ |
176 | #endif |
177 | |
178 | static char *emergency_buffer; |
179 | static MEM_SIZE emergency_buffer_size; |
180 | |
181 | static char * |
182 | emergency_sbrk(size) |
183 | MEM_SIZE size; |
184 | { |
185 | if (size >= BIG_SIZE) { |
186 | /* Give the possibility to recover: */ |
187 | die("Out of memory during request for %i bytes", size); |
188 | /* croak may eat too much memory. */ |
189 | } |
190 | |
191 | if (!emergency_buffer) { |
192 | /* First offense, give a possibility to recover by dieing. */ |
193 | /* No malloc involved here: */ |
194 | GV **gvp = (GV**)hv_fetch(defstash, "^M", 2, 0); |
195 | SV *sv; |
196 | char *pv; |
197 | |
198 | if (!gvp) gvp = (GV**)hv_fetch(defstash, "\015", 1, 0); |
199 | if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv) |
200 | || (SvLEN(sv) < (1<<11) - M_OVERHEAD)) |
201 | return (char *)-1; /* Now die die die... */ |
202 | |
203 | /* Got it, now detach SvPV: */ |
bbce6d69 |
204 | pv = SvPV(sv, na); |
55497cff |
205 | /* Check alignment: */ |
ff68c719 |
206 | if (((u_int)(pv - M_OVERHEAD)) & ((1<<11) - 1)) { |
55497cff |
207 | PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n"); |
bbce6d69 |
208 | return (char *)-1; /* die die die */ |
55497cff |
209 | } |
210 | |
211 | emergency_buffer = pv - M_OVERHEAD; |
212 | emergency_buffer_size = SvLEN(sv) + M_OVERHEAD; |
213 | SvPOK_off(sv); |
214 | SvREADONLY_on(sv); |
215 | die("Out of memory!"); /* croak may eat too much memory. */ |
ff68c719 |
216 | } |
217 | else if (emergency_buffer_size >= size) { |
55497cff |
218 | emergency_buffer_size -= size; |
219 | return emergency_buffer + emergency_buffer_size; |
220 | } |
221 | |
222 | return (char *)-1; /* poor guy... */ |
223 | } |
224 | |
72e5b9db |
225 | #else /* !(defined(TWO_POT_OPTIMIZE) && defined(PERL_CORE)) */ |
55497cff |
226 | # define emergency_sbrk(size) -1 |
72e5b9db |
227 | #endif /* !(defined(TWO_POT_OPTIMIZE) && defined(PERL_CORE)) */ |
55497cff |
228 | |
229 | /* |
8d063cd8 |
230 | * nextf[i] is the pointer to the next free block of size 2^(i+3). The |
231 | * smallest allocatable block is 8 bytes. The overhead information |
232 | * precedes the data area returned to the user. |
233 | */ |
234 | #define NBUCKETS 30 |
235 | static union overhead *nextf[NBUCKETS]; |
cf5c4ad8 |
236 | |
237 | #ifdef USE_PERL_SBRK |
238 | #define sbrk(a) Perl_sbrk(a) |
239 | char * Perl_sbrk _((int size)); |
240 | #else |
8d063cd8 |
241 | extern char *sbrk(); |
cf5c4ad8 |
242 | #endif |
8d063cd8 |
243 | |
c07a80fd |
244 | #ifdef DEBUGGING_MSTATS |
8d063cd8 |
245 | /* |
246 | * nmalloc[i] is the difference between the number of mallocs and frees |
247 | * for a given block size. |
248 | */ |
249 | static u_int nmalloc[NBUCKETS]; |
5f05dabc |
250 | static u_int goodsbrk; |
251 | static u_int sbrk_slack; |
252 | static u_int start_slack; |
8d063cd8 |
253 | #endif |
254 | |
760ac839 |
255 | #ifdef DEBUGGING |
4dfc412b |
256 | #define ASSERT(p) if (!(p)) botch(STRINGIFY(p)); else |
ee0007ab |
257 | static void |
8d063cd8 |
258 | botch(s) |
259 | char *s; |
260 | { |
4dfc412b |
261 | PerlIO_printf(PerlIO_stderr(), "assertion botched: %s\n", s); |
8d063cd8 |
262 | abort(); |
263 | } |
264 | #else |
265 | #define ASSERT(p) |
266 | #endif |
267 | |
2304df62 |
268 | Malloc_t |
8d063cd8 |
269 | malloc(nbytes) |
ee0007ab |
270 | register MEM_SIZE nbytes; |
8d063cd8 |
271 | { |
272 | register union overhead *p; |
273 | register int bucket = 0; |
ee0007ab |
274 | register MEM_SIZE shiftr; |
8d063cd8 |
275 | |
c2a5c2d2 |
276 | #if defined(DEBUGGING) || defined(RCHECK) |
ee0007ab |
277 | MEM_SIZE size = nbytes; |
45d8adaa |
278 | #endif |
279 | |
043bf814 |
280 | #ifdef PERL_CORE |
55497cff |
281 | #ifdef HAS_64K_LIMIT |
45d8adaa |
282 | if (nbytes > 0xffff) { |
043bf814 |
283 | PerlIO_printf(PerlIO_stderr(), |
284 | "Allocation too large: %lx\n", (long)nbytes); |
79072805 |
285 | my_exit(1); |
45d8adaa |
286 | } |
55497cff |
287 | #endif /* HAS_64K_LIMIT */ |
45d8adaa |
288 | #ifdef DEBUGGING |
289 | if ((long)nbytes < 0) |
043bf814 |
290 | croak("panic: malloc"); |
45d8adaa |
291 | #endif |
55497cff |
292 | #endif /* PERL_CORE */ |
45d8adaa |
293 | |
8d063cd8 |
294 | /* |
295 | * Convert amount of memory requested into |
296 | * closest block size stored in hash buckets |
297 | * which satisfies request. Account for |
298 | * space used per block for accounting. |
299 | */ |
cf5c4ad8 |
300 | #ifdef PACK_MALLOC |
043bf814 |
301 | if (nbytes == 0) |
302 | nbytes = 1; |
303 | else if (nbytes > MAX_2_POT_ALGO) |
cf5c4ad8 |
304 | #endif |
043bf814 |
305 | { |
55497cff |
306 | #ifdef TWO_POT_OPTIMIZE |
043bf814 |
307 | if (nbytes >= FIRST_BIG_BOUND) |
308 | nbytes -= PERL_PAGESIZE; |
55497cff |
309 | #endif |
043bf814 |
310 | nbytes += M_OVERHEAD; |
311 | nbytes = (nbytes + 3) &~ 3; |
cf5c4ad8 |
312 | } |
8d063cd8 |
313 | shiftr = (nbytes - 1) >> 2; |
314 | /* apart from this loop, this is O(1) */ |
315 | while (shiftr >>= 1) |
316 | bucket++; |
317 | /* |
318 | * If nothing in hash bucket right now, |
319 | * request more memory from the system. |
320 | */ |
321 | if (nextf[bucket] == NULL) |
322 | morecore(bucket); |
45d8adaa |
323 | if ((p = (union overhead *)nextf[bucket]) == NULL) { |
55497cff |
324 | #ifdef PERL_CORE |
ee0007ab |
325 | if (!nomemok) { |
760ac839 |
326 | PerlIO_puts(PerlIO_stderr(),"Out of memory!\n"); |
79072805 |
327 | my_exit(1); |
ee0007ab |
328 | } |
45d8adaa |
329 | #else |
8d063cd8 |
330 | return (NULL); |
45d8adaa |
331 | #endif |
332 | } |
333 | |
55497cff |
334 | #ifdef PERL_CORE |
68dc0745 |
335 | DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%lx: (%05lu) malloc %ld bytes\n", |
336 | (unsigned long)(p+1),(unsigned long)(an++),(long)size)); |
55497cff |
337 | #endif /* PERL_CORE */ |
45d8adaa |
338 | |
8d063cd8 |
339 | /* remove from linked list */ |
bf38876a |
340 | #ifdef RCHECK |
341 | if (*((int*)p) & (sizeof(union overhead) - 1)) |
760ac839 |
342 | PerlIO_printf(PerlIO_stderr(), "Corrupt malloc ptr 0x%lx at 0x%lx\n", |
a0d0e21e |
343 | (unsigned long)*((int*)p),(unsigned long)p); |
bf38876a |
344 | #endif |
345 | nextf[bucket] = p->ov_next; |
cf5c4ad8 |
346 | OV_MAGIC(p, bucket) = MAGIC; |
347 | #ifndef PACK_MALLOC |
348 | OV_INDEX(p) = bucket; |
349 | #endif |
8d063cd8 |
350 | #ifdef RCHECK |
351 | /* |
352 | * Record allocated size of block and |
353 | * bound space with magic numbers. |
354 | */ |
c2a5c2d2 |
355 | nbytes = (size + M_OVERHEAD + 3) &~ 3; |
8d063cd8 |
356 | if (nbytes <= 0x10000) |
357 | p->ov_size = nbytes - 1; |
358 | p->ov_rmagic = RMAGIC; |
359 | *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC; |
360 | #endif |
cf5c4ad8 |
361 | return ((Malloc_t)(p + CHUNK_SHIFT)); |
8d063cd8 |
362 | } |
363 | |
364 | /* |
365 | * Allocate more memory to the indicated bucket. |
366 | */ |
a0d0e21e |
367 | static void |
8d063cd8 |
368 | morecore(bucket) |
a687059c |
369 | register int bucket; |
8d063cd8 |
370 | { |
371 | register union overhead *op; |
372 | register int rnu; /* 2^rnu bytes will be requested */ |
373 | register int nblks; /* become nblks blocks of the desired size */ |
bbce6d69 |
374 | register MEM_SIZE siz, needed; |
cf5c4ad8 |
375 | int slack = 0; |
8d063cd8 |
376 | |
377 | if (nextf[bucket]) |
378 | return; |
55497cff |
379 | if (bucket == (sizeof(MEM_SIZE)*8 - 3)) { |
380 | croak("Allocation too large"); |
381 | } |
8d063cd8 |
382 | /* |
383 | * Insure memory is allocated |
384 | * on a page boundary. Should |
385 | * make getpageize call? |
386 | */ |
ee0007ab |
387 | #ifndef atarist /* on the atari we dont have to worry about this */ |
8d063cd8 |
388 | op = (union overhead *)sbrk(0); |
cf5c4ad8 |
389 | # ifndef I286 |
c030ccd9 |
390 | if ((UV)op & (0x7FF >> CHUNK_SHIFT)) { |
391 | slack = (0x800 >> CHUNK_SHIFT) - ((UV)op & (0x7FF >> CHUNK_SHIFT)); |
392 | (void)sbrk(slack); |
5f05dabc |
393 | # if defined(DEBUGGING_MSTATS) |
c030ccd9 |
394 | sbrk_slack += slack; |
cf5c4ad8 |
395 | # endif |
c030ccd9 |
396 | } |
cf5c4ad8 |
397 | # else |
a687059c |
398 | /* The sbrk(0) call on the I286 always returns the next segment */ |
cf5c4ad8 |
399 | # endif |
ee0007ab |
400 | #endif /* atarist */ |
a687059c |
401 | |
ee0007ab |
402 | #if !(defined(I286) || defined(atarist)) |
8d063cd8 |
403 | /* take 2k unless the block is bigger than that */ |
404 | rnu = (bucket <= 8) ? 11 : bucket + 3; |
a687059c |
405 | #else |
406 | /* take 16k unless the block is bigger than that |
ee0007ab |
407 | (80286s like large segments!), probably good on the atari too */ |
a687059c |
408 | rnu = (bucket <= 11) ? 14 : bucket + 3; |
409 | #endif |
8d063cd8 |
410 | nblks = 1 << (rnu - (bucket + 3)); /* how many blocks to get */ |
bbce6d69 |
411 | needed = (MEM_SIZE)1 << rnu; |
55497cff |
412 | #ifdef TWO_POT_OPTIMIZE |
bbce6d69 |
413 | needed += (bucket >= (FIRST_BIG_TWO_POT - 3) ? PERL_PAGESIZE : 0); |
55497cff |
414 | #endif |
bbce6d69 |
415 | op = (union overhead *)sbrk(needed); |
8d063cd8 |
416 | /* no more room! */ |
ff68c719 |
417 | if (op == (union overhead *)-1) { |
418 | op = (union overhead *)emergency_sbrk(needed); |
419 | if (op == (union overhead *)-1) |
8d063cd8 |
420 | return; |
ff68c719 |
421 | } |
5f05dabc |
422 | #ifdef DEBUGGING_MSTATS |
423 | goodsbrk += needed; |
424 | #endif |
8d063cd8 |
425 | /* |
426 | * Round up to minimum allocation size boundary |
427 | * and deduct from block count to reflect. |
428 | */ |
a687059c |
429 | #ifndef I286 |
cf5c4ad8 |
430 | # ifdef PACK_MALLOC |
c030ccd9 |
431 | if ((UV)op & 0x7FF) |
cf5c4ad8 |
432 | croak("panic: Off-page sbrk"); |
433 | # endif |
c030ccd9 |
434 | if ((UV)op & 7) { |
435 | op = (union overhead *)(((UV)op + 8) & ~7); |
8d063cd8 |
436 | nblks--; |
437 | } |
a687059c |
438 | #else |
439 | /* Again, this should always be ok on an 80286 */ |
440 | #endif |
8d063cd8 |
441 | /* |
442 | * Add new memory allocated to that on |
443 | * free list for this hash bucket. |
444 | */ |
8d063cd8 |
445 | siz = 1 << (bucket + 3); |
cf5c4ad8 |
446 | #ifdef PACK_MALLOC |
447 | *(u_char*)op = bucket; /* Fill index. */ |
448 | if (bucket <= MAX_PACKED - 3) { |
449 | op = (union overhead *) ((char*)op + blk_shift[bucket]); |
450 | nblks = n_blks[bucket]; |
451 | # ifdef DEBUGGING_MSTATS |
452 | start_slack += blk_shift[bucket]; |
453 | # endif |
454 | } else if (bucket <= 11 - 1 - 3) { |
455 | op = (union overhead *) ((char*)op + blk_shift[bucket]); |
456 | /* nblks = n_blks[bucket]; */ |
457 | siz -= sizeof(union overhead); |
458 | } else op++; /* One chunk per block. */ |
459 | #endif /* !PACK_MALLOC */ |
460 | nextf[bucket] = op; |
5f05dabc |
461 | #ifdef DEBUGGING_MSTATS |
462 | nmalloc[bucket] += nblks; |
463 | #endif |
8d063cd8 |
464 | while (--nblks > 0) { |
465 | op->ov_next = (union overhead *)((caddr_t)op + siz); |
466 | op = (union overhead *)((caddr_t)op + siz); |
467 | } |
8595d6f1 |
468 | /* Not all sbrks return zeroed memory.*/ |
cf5c4ad8 |
469 | op->ov_next = (union overhead *)NULL; |
cf5c4ad8 |
470 | #ifdef PACK_MALLOC |
471 | if (bucket == 7 - 3) { /* Special case, explanation is above. */ |
472 | union overhead *n_op = nextf[7 - 3]->ov_next; |
473 | nextf[7 - 3] = (union overhead *)((caddr_t)nextf[7 - 3] |
474 | - sizeof(union overhead)); |
475 | nextf[7 - 3]->ov_next = n_op; |
476 | } |
477 | #endif /* !PACK_MALLOC */ |
8d063cd8 |
478 | } |
479 | |
94b6baf5 |
480 | Free_t |
352d5a3a |
481 | free(mp) |
2304df62 |
482 | Malloc_t mp; |
8d063cd8 |
483 | { |
ee0007ab |
484 | register MEM_SIZE size; |
8d063cd8 |
485 | register union overhead *op; |
352d5a3a |
486 | char *cp = (char*)mp; |
cf5c4ad8 |
487 | #ifdef PACK_MALLOC |
488 | u_char bucket; |
489 | #endif |
8d063cd8 |
490 | |
55497cff |
491 | #ifdef PERL_CORE |
68dc0745 |
492 | DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%lx: (%05lu) free\n",(unsigned long)cp,(unsigned long)(an++))); |
55497cff |
493 | #endif /* PERL_CORE */ |
45d8adaa |
494 | |
cf5c4ad8 |
495 | if (cp == NULL) |
496 | return; |
497 | op = (union overhead *)((caddr_t)cp |
498 | - sizeof (union overhead) * CHUNK_SHIFT); |
499 | #ifdef PACK_MALLOC |
500 | bucket = OV_INDEX(op); |
501 | #endif |
cf5c4ad8 |
502 | if (OV_MAGIC(op, bucket) != MAGIC) { |
68dc0745 |
503 | static int bad_free_warn = -1; |
cf5c4ad8 |
504 | if (bad_free_warn == -1) { |
505 | char *pbf = getenv("PERL_BADFREE"); |
506 | bad_free_warn = (pbf) ? atoi(pbf) : 1; |
507 | } |
508 | if (!bad_free_warn) |
509 | return; |
8990e307 |
510 | #ifdef RCHECK |
a687059c |
511 | warn("%s free() ignored", |
8990e307 |
512 | op->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad"); |
513 | #else |
514 | warn("Bad free() ignored"); |
515 | #endif |
8d063cd8 |
516 | return; /* sanity */ |
378cc40b |
517 | } |
8d063cd8 |
518 | #ifdef RCHECK |
519 | ASSERT(op->ov_rmagic == RMAGIC); |
c2a5c2d2 |
520 | if (OV_INDEX(op) <= MAX_SHORT_BUCKET) |
8d063cd8 |
521 | ASSERT(*(u_int *)((caddr_t)op + op->ov_size + 1 - RSLOP) == RMAGIC); |
8990e307 |
522 | op->ov_rmagic = RMAGIC - 1; |
8d063cd8 |
523 | #endif |
cf5c4ad8 |
524 | ASSERT(OV_INDEX(op) < NBUCKETS); |
525 | size = OV_INDEX(op); |
8d063cd8 |
526 | op->ov_next = nextf[size]; |
527 | nextf[size] = op; |
8d063cd8 |
528 | } |
529 | |
530 | /* |
531 | * When a program attempts "storage compaction" as mentioned in the |
532 | * old malloc man page, it realloc's an already freed block. Usually |
533 | * this is the last block it freed; occasionally it might be farther |
534 | * back. We have to search all the free lists for the block in order |
535 | * to determine its bucket: 1st we make one pass thru the lists |
536 | * checking only the first block in each; if that fails we search |
378cc40b |
537 | * ``reall_srchlen'' blocks in each list for a match (the variable |
8d063cd8 |
538 | * is extern so the caller can modify it). If that fails we just copy |
539 | * however many bytes was given to realloc() and hope it's not huge. |
540 | */ |
378cc40b |
541 | int reall_srchlen = 4; /* 4 should be plenty, -1 =>'s whole list */ |
8d063cd8 |
542 | |
2304df62 |
543 | Malloc_t |
352d5a3a |
544 | realloc(mp, nbytes) |
2304df62 |
545 | Malloc_t mp; |
ee0007ab |
546 | MEM_SIZE nbytes; |
8d063cd8 |
547 | { |
ee0007ab |
548 | register MEM_SIZE onb; |
8d063cd8 |
549 | union overhead *op; |
550 | char *res; |
551 | register int i; |
552 | int was_alloced = 0; |
352d5a3a |
553 | char *cp = (char*)mp; |
8d063cd8 |
554 | |
45d8adaa |
555 | #ifdef DEBUGGING |
ee0007ab |
556 | MEM_SIZE size = nbytes; |
45d8adaa |
557 | #endif |
558 | |
043bf814 |
559 | #ifdef PERL_CORE |
55497cff |
560 | #ifdef HAS_64K_LIMIT |
45d8adaa |
561 | if (nbytes > 0xffff) { |
043bf814 |
562 | PerlIO_printf(PerlIO_stderr(), |
563 | "Reallocation too large: %lx\n", size); |
79072805 |
564 | my_exit(1); |
45d8adaa |
565 | } |
55497cff |
566 | #endif /* HAS_64K_LIMIT */ |
45d8adaa |
567 | if (!cp) |
ee0007ab |
568 | return malloc(nbytes); |
45d8adaa |
569 | #ifdef DEBUGGING |
570 | if ((long)nbytes < 0) |
463ee0b2 |
571 | croak("panic: realloc"); |
45d8adaa |
572 | #endif |
55497cff |
573 | #endif /* PERL_CORE */ |
45d8adaa |
574 | |
cf5c4ad8 |
575 | op = (union overhead *)((caddr_t)cp |
576 | - sizeof (union overhead) * CHUNK_SHIFT); |
577 | i = OV_INDEX(op); |
578 | if (OV_MAGIC(op, i) == MAGIC) { |
55497cff |
579 | was_alloced = 1; |
8d063cd8 |
580 | } else { |
581 | /* |
582 | * Already free, doing "compaction". |
583 | * |
584 | * Search for the old block of memory on the |
585 | * free list. First, check the most common |
586 | * case (last element free'd), then (this failing) |
378cc40b |
587 | * the last ``reall_srchlen'' items free'd. |
8d063cd8 |
588 | * If all lookups fail, then assume the size of |
589 | * the memory block being realloc'd is the |
590 | * smallest possible. |
591 | */ |
592 | if ((i = findbucket(op, 1)) < 0 && |
378cc40b |
593 | (i = findbucket(op, reall_srchlen)) < 0) |
8d063cd8 |
594 | i = 0; |
595 | } |
cf5c4ad8 |
596 | onb = (1L << (i + 3)) - |
597 | #ifdef PACK_MALLOC |
598 | (i <= (MAX_PACKED - 3) ? 0 : M_OVERHEAD) |
599 | #else |
600 | M_OVERHEAD |
601 | #endif |
55497cff |
602 | #ifdef TWO_POT_OPTIMIZE |
603 | + (i >= (FIRST_BIG_TWO_POT - 3) ? PERL_PAGESIZE : 0) |
604 | #endif |
cf5c4ad8 |
605 | ; |
55497cff |
606 | /* |
607 | * avoid the copy if same size block. |
608 | * We are not agressive with boundary cases. Note that it is |
609 | * possible for small number of cases give false negative if |
610 | * both new size and old one are in the bucket for |
611 | * FIRST_BIG_TWO_POT, but the new one is near the lower end. |
612 | */ |
8d063cd8 |
613 | if (was_alloced && |
55497cff |
614 | nbytes <= onb && (nbytes > ( (onb >> 1) - M_OVERHEAD ) |
615 | #ifdef TWO_POT_OPTIMIZE |
616 | || (i == (FIRST_BIG_TWO_POT - 3) |
617 | && nbytes >= LAST_SMALL_BOUND ) |
618 | #endif |
619 | )) { |
a687059c |
620 | #ifdef RCHECK |
621 | /* |
622 | * Record new allocated size of block and |
623 | * bound space with magic numbers. |
624 | */ |
c2a5c2d2 |
625 | if (OV_INDEX(op) <= MAX_SHORT_BUCKET) { |
a687059c |
626 | /* |
627 | * Convert amount of memory requested into |
628 | * closest block size stored in hash buckets |
629 | * which satisfies request. Account for |
630 | * space used per block for accounting. |
631 | */ |
cf5c4ad8 |
632 | nbytes += M_OVERHEAD; |
a687059c |
633 | nbytes = (nbytes + 3) &~ 3; |
634 | op->ov_size = nbytes - 1; |
635 | *((u_int *)((caddr_t)op + nbytes - RSLOP)) = RMAGIC; |
636 | } |
637 | #endif |
45d8adaa |
638 | res = cp; |
a687059c |
639 | } |
45d8adaa |
640 | else { |
641 | if ((res = (char*)malloc(nbytes)) == NULL) |
642 | return (NULL); |
643 | if (cp != res) /* common optimization */ |
ee0007ab |
644 | Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char); |
45d8adaa |
645 | if (was_alloced) |
646 | free(cp); |
647 | } |
648 | |
55497cff |
649 | #ifdef PERL_CORE |
45d8adaa |
650 | #ifdef DEBUGGING |
a0d0e21e |
651 | if (debug & 128) { |
68dc0745 |
652 | PerlIO_printf(PerlIO_stderr(), "0x%lx: (%05lu) rfree\n",(unsigned long)res,(unsigned long)(an++)); |
653 | PerlIO_printf(PerlIO_stderr(), "0x%lx: (%05lu) realloc %ld bytes\n", |
654 | (unsigned long)res,(unsigned long)(an++),(long)size); |
a0d0e21e |
655 | } |
45d8adaa |
656 | #endif |
55497cff |
657 | #endif /* PERL_CORE */ |
2304df62 |
658 | return ((Malloc_t)res); |
8d063cd8 |
659 | } |
660 | |
661 | /* |
662 | * Search ``srchlen'' elements of each free list for a block whose |
663 | * header starts at ``freep''. If srchlen is -1 search the whole list. |
664 | * Return bucket number, or -1 if not found. |
665 | */ |
ee0007ab |
666 | static int |
8d063cd8 |
667 | findbucket(freep, srchlen) |
668 | union overhead *freep; |
669 | int srchlen; |
670 | { |
671 | register union overhead *p; |
672 | register int i, j; |
673 | |
674 | for (i = 0; i < NBUCKETS; i++) { |
675 | j = 0; |
676 | for (p = nextf[i]; p && j != srchlen; p = p->ov_next) { |
677 | if (p == freep) |
678 | return (i); |
679 | j++; |
680 | } |
681 | } |
682 | return (-1); |
683 | } |
684 | |
cf5c4ad8 |
685 | Malloc_t |
686 | calloc(elements, size) |
687 | register MEM_SIZE elements; |
688 | register MEM_SIZE size; |
689 | { |
690 | long sz = elements * size; |
691 | Malloc_t p = malloc(sz); |
692 | |
693 | if (p) { |
694 | memset((void*)p, 0, sz); |
695 | } |
696 | return p; |
697 | } |
698 | |
c07a80fd |
699 | #ifdef DEBUGGING_MSTATS |
8d063cd8 |
700 | /* |
701 | * mstats - print out statistics about malloc |
702 | * |
703 | * Prints two lines of numbers, one showing the length of the free list |
704 | * for each size category, the second showing the number of mallocs - |
705 | * frees for each size category. |
706 | */ |
ee0007ab |
707 | void |
c07a80fd |
708 | dump_mstats(s) |
8d063cd8 |
709 | char *s; |
710 | { |
711 | register int i, j; |
712 | register union overhead *p; |
5f05dabc |
713 | int topbucket=0, totfree=0, total=0; |
c07a80fd |
714 | u_int nfree[NBUCKETS]; |
8d063cd8 |
715 | |
c07a80fd |
716 | for (i=0; i < NBUCKETS; i++) { |
8d063cd8 |
717 | for (j = 0, p = nextf[i]; p; p = p->ov_next, j++) |
718 | ; |
c07a80fd |
719 | nfree[i] = j; |
720 | totfree += nfree[i] * (1 << (i + 3)); |
5f05dabc |
721 | total += nmalloc[i] * (1 << (i + 3)); |
722 | if (nmalloc[i]) |
c07a80fd |
723 | topbucket = i; |
724 | } |
725 | if (s) |
760ac839 |
726 | PerlIO_printf(PerlIO_stderr(), "Memory allocation statistics %s (buckets 8..%d)\n", |
c07a80fd |
727 | s, (1 << (topbucket + 3)) ); |
5f05dabc |
728 | PerlIO_printf(PerlIO_stderr(), "%8d free:", totfree); |
c07a80fd |
729 | for (i=0; i <= topbucket; i++) { |
5f05dabc |
730 | PerlIO_printf(PerlIO_stderr(), (i<5 || i==7)?" %5d": (i<9)?" %3d":" %d", nfree[i]); |
8d063cd8 |
731 | } |
5f05dabc |
732 | PerlIO_printf(PerlIO_stderr(), "\n%8d used:", total - totfree); |
c07a80fd |
733 | for (i=0; i <= topbucket; i++) { |
5f05dabc |
734 | PerlIO_printf(PerlIO_stderr(), (i<5 || i==7)?" %5d": (i<9)?" %3d":" %d", nmalloc[i] - nfree[i]); |
c07a80fd |
735 | } |
5f05dabc |
736 | PerlIO_printf(PerlIO_stderr(), "\nTotal sbrk(): %8d. Odd ends: sbrk(): %7d, malloc(): %7d bytes.\n", |
737 | goodsbrk + sbrk_slack, sbrk_slack, start_slack); |
c07a80fd |
738 | } |
739 | #else |
740 | void |
741 | dump_mstats(s) |
742 | char *s; |
743 | { |
8d063cd8 |
744 | } |
745 | #endif |
a687059c |
746 | #endif /* lint */ |
cf5c4ad8 |
747 | |
748 | |
749 | #ifdef USE_PERL_SBRK |
750 | |
760ac839 |
751 | # ifdef NeXT |
752 | # define PERL_SBRK_VIA_MALLOC |
753 | # endif |
754 | |
755 | # ifdef PERL_SBRK_VIA_MALLOC |
72e5b9db |
756 | # if defined(HIDEMYMALLOC) || defined(EMBEDMYMALLOC) |
760ac839 |
757 | # undef malloc |
758 | # else |
72e5b9db |
759 | # include "Error: -DPERL_SBRK_VIA_MALLOC needs -D(HIDE|EMBED)MYMALLOC" |
760ac839 |
760 | # endif |
cf5c4ad8 |
761 | |
762 | /* it may seem schizophrenic to use perl's malloc and let it call system */ |
763 | /* malloc, the reason for that is only the 3.2 version of the OS that had */ |
764 | /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */ |
765 | /* end to the cores */ |
766 | |
760ac839 |
767 | # define SYSTEM_ALLOC(a) malloc(a) |
cf5c4ad8 |
768 | |
760ac839 |
769 | # endif /* PERL_SBRK_VIA_MALLOC */ |
cf5c4ad8 |
770 | |
771 | static IV Perl_sbrk_oldchunk; |
772 | static long Perl_sbrk_oldsize; |
773 | |
760ac839 |
774 | # define PERLSBRK_32_K (1<<15) |
775 | # define PERLSBRK_64_K (1<<16) |
cf5c4ad8 |
776 | |
777 | char * |
778 | Perl_sbrk(size) |
779 | int size; |
780 | { |
781 | IV got; |
782 | int small, reqsize; |
783 | |
784 | if (!size) return 0; |
55497cff |
785 | #ifdef PERL_CORE |
cf5c4ad8 |
786 | reqsize = size; /* just for the DEBUG_m statement */ |
787 | #endif |
57569e04 |
788 | #ifdef PACK_MALLOC |
789 | size = (size + 0x7ff) & ~0x7ff; |
790 | #endif |
cf5c4ad8 |
791 | if (size <= Perl_sbrk_oldsize) { |
792 | got = Perl_sbrk_oldchunk; |
793 | Perl_sbrk_oldchunk += size; |
794 | Perl_sbrk_oldsize -= size; |
795 | } else { |
796 | if (size >= PERLSBRK_32_K) { |
797 | small = 0; |
798 | } else { |
55497cff |
799 | #ifndef PERL_CORE |
cf5c4ad8 |
800 | reqsize = size; |
801 | #endif |
802 | size = PERLSBRK_64_K; |
803 | small = 1; |
804 | } |
805 | got = (IV)SYSTEM_ALLOC(size); |
57569e04 |
806 | #ifdef PACK_MALLOC |
807 | got = (got + 0x7ff) & ~0x7ff; |
808 | #endif |
cf5c4ad8 |
809 | if (small) { |
810 | /* Chunk is small, register the rest for future allocs. */ |
811 | Perl_sbrk_oldchunk = got + reqsize; |
812 | Perl_sbrk_oldsize = size - reqsize; |
813 | } |
814 | } |
815 | |
55497cff |
816 | #ifdef PERL_CORE |
760ac839 |
817 | DEBUG_m(PerlIO_printf(PerlIO_stderr(), "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%lx\n", |
cf5c4ad8 |
818 | size, reqsize, Perl_sbrk_oldsize, got)); |
819 | #endif |
820 | |
821 | return (void *)got; |
822 | } |
823 | |
824 | #endif /* ! defined USE_PERL_SBRK */ |