Commit | Line | Data |
---|---|---|
a0d0e21e | 1 | /* malloc.c |
8d063cd8 | 2 | * |
8d063cd8 LW |
3 | */ |
4 | ||
5 | #ifndef lint | |
a687059c | 6 | #ifdef DEBUGGING |
8d063cd8 | 7 | #define RCHECK |
a687059c | 8 | #endif |
8d063cd8 LW |
9 | /* |
10 | * malloc.c (Caltech) 2/21/82 | |
11 | * Chris Kingsley, kingsley@cit-20. | |
12 | * | |
13 | * This is a very fast storage allocator. It allocates blocks of a small | |
14 | * number of different sizes, and keeps free lists of each size. Blocks that | |
15 | * don't exactly fit are passed up to the next larger size. In this | |
16 | * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long. | |
cf5c4ad8 | 17 | * If PACK_MALLOC is defined, small blocks are 2^n bytes long. |
8d063cd8 LW |
18 | * This is designed for use in a program that uses vast quantities of memory, |
19 | * but bombs when it runs out. | |
20 | */ | |
21 | ||
135863df | 22 | #include "EXTERN.h" |
135863df AB |
23 | #include "perl.h" |
24 | ||
760ac839 LW |
25 | #ifdef DEBUGGING |
26 | #undef DEBUG_m | |
27 | #define DEBUG_m(a) if (debug & 128) a | |
28 | #endif | |
29 | ||
135863df AB |
30 | /* I don't much care whether these are defined in sys/types.h--LAW */ |
31 | ||
32 | #define u_char unsigned char | |
33 | #define u_int unsigned int | |
34 | #define u_short unsigned short | |
8d063cd8 | 35 | |
cf5c4ad8 | 36 | /* 286 and atarist like big chunks, which gives too much overhead. */ |
37 | #if (defined(RCHECK) || defined(I286) || defined(atarist)) && defined(PACK_MALLOC) | |
38 | #undef PACK_MALLOC | |
39 | #endif | |
40 | ||
41 | ||
8d063cd8 | 42 | /* |
cf5c4ad8 | 43 | * The description below is applicable if PACK_MALLOC is not defined. |
44 | * | |
8d063cd8 LW |
45 | * The overhead on a block is at least 4 bytes. When free, this space |
46 | * contains a pointer to the next free block, and the bottom two bits must | |
47 | * be zero. When in use, the first byte is set to MAGIC, and the second | |
48 | * byte is the size index. The remaining bytes are for alignment. | |
49 | * If range checking is enabled and the size of the block fits | |
50 | * in two bytes, then the top two bytes hold the size of the requested block | |
51 | * plus the range checking words, and the header word MINUS ONE. | |
52 | */ | |
53 | union overhead { | |
54 | union overhead *ov_next; /* when free */ | |
85e6fe83 | 55 | #if MEM_ALIGNBYTES > 4 |
c623bd54 | 56 | double strut; /* alignment problems */ |
a687059c | 57 | #endif |
8d063cd8 LW |
58 | struct { |
59 | u_char ovu_magic; /* magic number */ | |
60 | u_char ovu_index; /* bucket # */ | |
61 | #ifdef RCHECK | |
62 | u_short ovu_size; /* actual block size */ | |
63 | u_int ovu_rmagic; /* range magic number */ | |
64 | #endif | |
65 | } ovu; | |
66 | #define ov_magic ovu.ovu_magic | |
67 | #define ov_index ovu.ovu_index | |
68 | #define ov_size ovu.ovu_size | |
69 | #define ov_rmagic ovu.ovu_rmagic | |
70 | }; | |
71 | ||
760ac839 | 72 | #ifdef DEBUGGING |
a0d0e21e LW |
73 | static void botch _((char *s)); |
74 | #endif | |
75 | static void morecore _((int bucket)); | |
76 | static int findbucket _((union overhead *freep, int srchlen)); | |
77 | ||
8d063cd8 LW |
78 | #define MAGIC 0xff /* magic # on accounting info */ |
79 | #define RMAGIC 0x55555555 /* magic # on range info */ | |
80 | #ifdef RCHECK | |
81 | #define RSLOP sizeof (u_int) | |
82 | #else | |
83 | #define RSLOP 0 | |
84 | #endif | |
85 | ||
cf5c4ad8 | 86 | #ifdef PACK_MALLOC |
87 | /* | |
88 | * In this case it is assumed that if we do sbrk() in 2K units, we | |
89 | * will get 2K aligned blocks. The bucket number of the given subblock is | |
90 | * on the boundary of 2K block which contains the subblock. | |
91 | * Several following bytes contain the magic numbers for the subblocks | |
92 | * in the block. | |
93 | * | |
94 | * Sizes of chunks are powers of 2 for chunks in buckets <= | |
95 | * MAX_PACKED, after this they are (2^n - sizeof(union overhead)) (to | |
96 | * get alignment right). | |
97 | * | |
98 | * We suppose that starts of all the chunks in a 2K block are in | |
99 | * different 2^n-byte-long chunks. If the top of the last chunk is | |
100 | * aligned on a boundary of 2K block, this means that | |
101 | * sizeof(union overhead)*"number of chunks" < 2^n, or | |
102 | * sizeof(union overhead)*2K < 4^n, or n > 6 + log2(sizeof()/2)/2, if a | |
103 | * chunk of size 2^n - overhead is used. Since this rules out n = 7 | |
104 | * for 8 byte alignment, we specialcase allocation of the first of 16 | |
105 | * 128-byte-long chunks. | |
106 | * | |
107 | * Note that with the above assumption we automatically have enough | |
108 | * place for MAGIC at the start of 2K block. Note also that we | |
109 | * overlay union overhead over the chunk, thus the start of the chunk | |
110 | * is immediately overwritten after freeing. | |
111 | */ | |
112 | # define MAX_PACKED 6 | |
113 | # define MAX_2_POT_ALGO ((1<<(MAX_PACKED + 1)) - M_OVERHEAD) | |
114 | # define TWOK_MASK ((1<<11) - 1) | |
115 | # define TWOK_MASKED(x) ((int)x & ~TWOK_MASK) | |
116 | # define TWOK_SHIFT(x) ((int)x & TWOK_MASK) | |
117 | # define OV_INDEXp(block) ((u_char*)(TWOK_MASKED(block))) | |
118 | # define OV_INDEX(block) (*OV_INDEXp(block)) | |
119 | # define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) + \ | |
120 | (TWOK_SHIFT(block)>>(bucket + 3)) + \ | |
121 | (bucket > MAX_NONSHIFT ? 1 : 0))) | |
122 | # define CHUNK_SHIFT 0 | |
123 | ||
124 | static u_char n_blks[11 - 3] = {224, 120, 62, 31, 16, 8, 4, 2}; | |
125 | static u_short blk_shift[11 - 3] = {256, 128, 64, 32, | |
126 | 16*sizeof(union overhead), | |
127 | 8*sizeof(union overhead), | |
128 | 4*sizeof(union overhead), | |
129 | 2*sizeof(union overhead), | |
130 | # define MAX_NONSHIFT 2 /* Shift 64 greater than chunk 32. */ | |
131 | }; | |
132 | ||
133 | # ifdef DEBUGGING_MSTATS | |
134 | static u_int sbrk_slack; | |
135 | static u_int start_slack; | |
136 | # endif | |
137 | ||
138 | #else /* !PACK_MALLOC */ | |
139 | ||
140 | # define OV_MAGIC(block,bucket) (block)->ov_magic | |
141 | # define OV_INDEX(block) (block)->ov_index | |
142 | # define CHUNK_SHIFT 1 | |
143 | #endif /* !PACK_MALLOC */ | |
144 | ||
145 | # define M_OVERHEAD (sizeof(union overhead) + RSLOP) | |
146 | ||
8d063cd8 | 147 | /* |
55497cff | 148 | * Big allocations are often of the size 2^n bytes. To make them a |
149 | * little bit better, make blocks of size 2^n+pagesize for big n. | |
150 | */ | |
151 | ||
152 | #ifdef TWO_POT_OPTIMIZE | |
153 | ||
154 | # define PERL_PAGESIZE 4096 | |
155 | # define FIRST_BIG_TWO_POT 14 /* 16K */ | |
156 | # define FIRST_BIG_BLOCK (1<<FIRST_BIG_TWO_POT) /* 16K */ | |
157 | /* If this value or more, check against bigger blocks. */ | |
158 | # define FIRST_BIG_BOUND (FIRST_BIG_BLOCK - M_OVERHEAD) | |
159 | /* If less than this value, goes into 2^n-overhead-block. */ | |
160 | # define LAST_SMALL_BOUND ((FIRST_BIG_BLOCK>>1) - M_OVERHEAD) | |
161 | ||
162 | #endif /* TWO_POT_OPTIMIZE */ | |
163 | ||
164 | #ifdef PERL_EMERGENCY_SBRK | |
165 | ||
166 | #ifndef BIG_SIZE | |
167 | # define BIG_SIZE (1<<16) /* 64K */ | |
168 | #endif | |
169 | ||
170 | static char *emergency_buffer; | |
171 | static MEM_SIZE emergency_buffer_size; | |
172 | ||
173 | static char * | |
174 | emergency_sbrk(size) | |
175 | MEM_SIZE size; | |
176 | { | |
177 | if (size >= BIG_SIZE) { | |
178 | /* Give the possibility to recover: */ | |
179 | die("Out of memory during request for %i bytes", size); | |
180 | /* croak may eat too much memory. */ | |
181 | } | |
182 | ||
183 | if (!emergency_buffer) { | |
184 | /* First offense, give a possibility to recover by dieing. */ | |
185 | /* No malloc involved here: */ | |
186 | GV **gvp = (GV**)hv_fetch(defstash, "^M", 2, 0); | |
187 | SV *sv; | |
188 | char *pv; | |
189 | ||
190 | if (!gvp) gvp = (GV**)hv_fetch(defstash, "\015", 1, 0); | |
191 | if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv) | |
192 | || (SvLEN(sv) < (1<<11) - M_OVERHEAD)) | |
193 | return (char *)-1; /* Now die die die... */ | |
194 | ||
195 | /* Got it, now detach SvPV: */ | |
196 | pv = SvPV(sv); | |
197 | /* Check alignment: */ | |
198 | if ((pv - M_OVERHEAD) & (1<<11 - 1)) { | |
199 | PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n"); | |
200 | return -1; /* die die die */ | |
201 | } | |
202 | ||
203 | emergency_buffer = pv - M_OVERHEAD; | |
204 | emergency_buffer_size = SvLEN(sv) + M_OVERHEAD; | |
205 | SvPOK_off(sv); | |
206 | SvREADONLY_on(sv); | |
207 | die("Out of memory!"); /* croak may eat too much memory. */ | |
208 | } else if (emergency_buffer_size >= size) { | |
209 | emergency_buffer_size -= size; | |
210 | return emergency_buffer + emergency_buffer_size; | |
211 | } | |
212 | ||
213 | return (char *)-1; /* poor guy... */ | |
214 | } | |
215 | ||
216 | #else /* !PERL_EMERGENCY_SBRK */ | |
217 | # define emergency_sbrk(size) -1 | |
218 | #endif /* !PERL_EMERGENCY_SBRK */ | |
219 | ||
220 | /* | |
8d063cd8 LW |
221 | * nextf[i] is the pointer to the next free block of size 2^(i+3). The |
222 | * smallest allocatable block is 8 bytes. The overhead information | |
223 | * precedes the data area returned to the user. | |
224 | */ | |
225 | #define NBUCKETS 30 | |
226 | static union overhead *nextf[NBUCKETS]; | |
cf5c4ad8 | 227 | |
228 | #ifdef USE_PERL_SBRK | |
229 | #define sbrk(a) Perl_sbrk(a) | |
230 | char * Perl_sbrk _((int size)); | |
231 | #else | |
8d063cd8 | 232 | extern char *sbrk(); |
cf5c4ad8 | 233 | #endif |
8d063cd8 | 234 | |
c07a80fd | 235 | #ifdef DEBUGGING_MSTATS |
8d063cd8 LW |
236 | /* |
237 | * nmalloc[i] is the difference between the number of mallocs and frees | |
238 | * for a given block size. | |
239 | */ | |
240 | static u_int nmalloc[NBUCKETS]; | |
8d063cd8 LW |
241 | #endif |
242 | ||
760ac839 | 243 | #ifdef DEBUGGING |
4dfc412b | 244 | #define ASSERT(p) if (!(p)) botch(STRINGIFY(p)); else |
ee0007ab | 245 | static void |
8d063cd8 LW |
246 | botch(s) |
247 | char *s; | |
248 | { | |
4dfc412b | 249 | PerlIO_printf(PerlIO_stderr(), "assertion botched: %s\n", s); |
8d063cd8 LW |
250 | abort(); |
251 | } | |
252 | #else | |
253 | #define ASSERT(p) | |
254 | #endif | |
255 | ||
2304df62 | 256 | Malloc_t |
8d063cd8 | 257 | malloc(nbytes) |
ee0007ab | 258 | register MEM_SIZE nbytes; |
8d063cd8 LW |
259 | { |
260 | register union overhead *p; | |
261 | register int bucket = 0; | |
ee0007ab | 262 | register MEM_SIZE shiftr; |
8d063cd8 | 263 | |
55497cff | 264 | #ifdef PERL_CORE |
45d8adaa | 265 | #ifdef DEBUGGING |
ee0007ab | 266 | MEM_SIZE size = nbytes; |
45d8adaa LW |
267 | #endif |
268 | ||
55497cff | 269 | #ifdef HAS_64K_LIMIT |
45d8adaa | 270 | if (nbytes > 0xffff) { |
760ac839 | 271 | PerlIO_printf(PerlIO_stderr(), "Allocation too large: %lx\n", (long)nbytes); |
79072805 | 272 | my_exit(1); |
45d8adaa | 273 | } |
55497cff | 274 | #endif /* HAS_64K_LIMIT */ |
45d8adaa LW |
275 | #ifdef DEBUGGING |
276 | if ((long)nbytes < 0) | |
463ee0b2 | 277 | croak("panic: malloc"); |
45d8adaa | 278 | #endif |
55497cff | 279 | #endif /* PERL_CORE */ |
45d8adaa | 280 | |
8d063cd8 LW |
281 | /* |
282 | * Convert amount of memory requested into | |
283 | * closest block size stored in hash buckets | |
284 | * which satisfies request. Account for | |
285 | * space used per block for accounting. | |
286 | */ | |
cf5c4ad8 | 287 | #ifdef PACK_MALLOC |
288 | if (nbytes > MAX_2_POT_ALGO) { | |
289 | #endif | |
55497cff | 290 | #ifdef TWO_POT_OPTIMIZE |
291 | if (nbytes >= FIRST_BIG_BOUND) { | |
292 | nbytes -= PERL_PAGESIZE; | |
293 | } | |
294 | #endif | |
cf5c4ad8 | 295 | nbytes += M_OVERHEAD; |
296 | nbytes = (nbytes + 3) &~ 3; | |
297 | #ifdef PACK_MALLOC | |
298 | } else if (nbytes == 0) { | |
299 | nbytes = 1; | |
300 | } | |
301 | #endif | |
8d063cd8 LW |
302 | shiftr = (nbytes - 1) >> 2; |
303 | /* apart from this loop, this is O(1) */ | |
304 | while (shiftr >>= 1) | |
305 | bucket++; | |
306 | /* | |
307 | * If nothing in hash bucket right now, | |
308 | * request more memory from the system. | |
309 | */ | |
310 | if (nextf[bucket] == NULL) | |
311 | morecore(bucket); | |
45d8adaa | 312 | if ((p = (union overhead *)nextf[bucket]) == NULL) { |
55497cff | 313 | #ifdef PERL_CORE |
ee0007ab | 314 | if (!nomemok) { |
760ac839 | 315 | PerlIO_puts(PerlIO_stderr(),"Out of memory!\n"); |
79072805 | 316 | my_exit(1); |
ee0007ab | 317 | } |
45d8adaa | 318 | #else |
8d063cd8 | 319 | return (NULL); |
45d8adaa LW |
320 | #endif |
321 | } | |
322 | ||
55497cff | 323 | #ifdef PERL_CORE |
760ac839 | 324 | DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%lx: (%05d) malloc %ld bytes\n", |
a0d0e21e | 325 | (unsigned long)(p+1),an++,(long)size)); |
55497cff | 326 | #endif /* PERL_CORE */ |
45d8adaa | 327 | |
8d063cd8 | 328 | /* remove from linked list */ |
bf38876a LW |
329 | #ifdef RCHECK |
330 | if (*((int*)p) & (sizeof(union overhead) - 1)) | |
760ac839 | 331 | PerlIO_printf(PerlIO_stderr(), "Corrupt malloc ptr 0x%lx at 0x%lx\n", |
a0d0e21e | 332 | (unsigned long)*((int*)p),(unsigned long)p); |
bf38876a LW |
333 | #endif |
334 | nextf[bucket] = p->ov_next; | |
cf5c4ad8 | 335 | OV_MAGIC(p, bucket) = MAGIC; |
336 | #ifndef PACK_MALLOC | |
337 | OV_INDEX(p) = bucket; | |
338 | #endif | |
c07a80fd | 339 | #ifdef DEBUGGING_MSTATS |
8d063cd8 LW |
340 | nmalloc[bucket]++; |
341 | #endif | |
342 | #ifdef RCHECK | |
343 | /* | |
344 | * Record allocated size of block and | |
345 | * bound space with magic numbers. | |
346 | */ | |
347 | if (nbytes <= 0x10000) | |
348 | p->ov_size = nbytes - 1; | |
349 | p->ov_rmagic = RMAGIC; | |
350 | *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC; | |
351 | #endif | |
cf5c4ad8 | 352 | return ((Malloc_t)(p + CHUNK_SHIFT)); |
8d063cd8 LW |
353 | } |
354 | ||
355 | /* | |
356 | * Allocate more memory to the indicated bucket. | |
357 | */ | |
a0d0e21e | 358 | static void |
8d063cd8 | 359 | morecore(bucket) |
a687059c | 360 | register int bucket; |
8d063cd8 LW |
361 | { |
362 | register union overhead *op; | |
363 | register int rnu; /* 2^rnu bytes will be requested */ | |
364 | register int nblks; /* become nblks blocks of the desired size */ | |
ee0007ab | 365 | register MEM_SIZE siz; |
cf5c4ad8 | 366 | int slack = 0; |
8d063cd8 LW |
367 | |
368 | if (nextf[bucket]) | |
369 | return; | |
55497cff | 370 | if (bucket == (sizeof(MEM_SIZE)*8 - 3)) { |
371 | croak("Allocation too large"); | |
372 | } | |
8d063cd8 LW |
373 | /* |
374 | * Insure memory is allocated | |
375 | * on a page boundary. Should | |
376 | * make getpageize call? | |
377 | */ | |
ee0007ab | 378 | #ifndef atarist /* on the atari we dont have to worry about this */ |
8d063cd8 | 379 | op = (union overhead *)sbrk(0); |
cf5c4ad8 | 380 | # ifndef I286 |
381 | # ifdef PACK_MALLOC | |
382 | if ((int)op & 0x7ff) | |
383 | (void)sbrk(slack = 2048 - ((int)op & 0x7ff)); | |
384 | # else | |
8d063cd8 | 385 | if ((int)op & 0x3ff) |
cf5c4ad8 | 386 | (void)sbrk(slack = 1024 - ((int)op & 0x3ff)); |
387 | # endif | |
388 | # if defined(DEBUGGING_MSTATS) && defined(PACK_MALLOC) | |
389 | sbrk_slack += slack; | |
390 | # endif | |
391 | # else | |
a687059c | 392 | /* The sbrk(0) call on the I286 always returns the next segment */ |
cf5c4ad8 | 393 | # endif |
ee0007ab | 394 | #endif /* atarist */ |
a687059c | 395 | |
ee0007ab | 396 | #if !(defined(I286) || defined(atarist)) |
8d063cd8 LW |
397 | /* take 2k unless the block is bigger than that */ |
398 | rnu = (bucket <= 8) ? 11 : bucket + 3; | |
a687059c LW |
399 | #else |
400 | /* take 16k unless the block is bigger than that | |
ee0007ab | 401 | (80286s like large segments!), probably good on the atari too */ |
a687059c LW |
402 | rnu = (bucket <= 11) ? 14 : bucket + 3; |
403 | #endif | |
8d063cd8 | 404 | nblks = 1 << (rnu - (bucket + 3)); /* how many blocks to get */ |
cf5c4ad8 | 405 | /* if (rnu < bucket) |
406 | rnu = bucket; Why anyone needs this? */ | |
55497cff | 407 | #ifdef TWO_POT_OPTIMIZE |
408 | op = (union overhead *)sbrk((1L << rnu) | |
409 | + ( bucket >= (FIRST_BIG_TWO_POT - 3) | |
410 | ? PERL_PAGESIZE : 0)); | |
411 | #else | |
ee0007ab | 412 | op = (union overhead *)sbrk(1L << rnu); |
55497cff | 413 | #endif |
8d063cd8 | 414 | /* no more room! */ |
55497cff | 415 | if ((int)op == -1 && |
416 | (int)(op = (union overhead *)emergency_sbrk(size)) == -1) | |
8d063cd8 LW |
417 | return; |
418 | /* | |
419 | * Round up to minimum allocation size boundary | |
420 | * and deduct from block count to reflect. | |
421 | */ | |
a687059c | 422 | #ifndef I286 |
cf5c4ad8 | 423 | # ifdef PACK_MALLOC |
424 | if ((int)op & 0x7ff) | |
425 | croak("panic: Off-page sbrk"); | |
426 | # endif | |
8d063cd8 | 427 | if ((int)op & 7) { |
ee0007ab | 428 | op = (union overhead *)(((MEM_SIZE)op + 8) &~ 7); |
8d063cd8 LW |
429 | nblks--; |
430 | } | |
a687059c LW |
431 | #else |
432 | /* Again, this should always be ok on an 80286 */ | |
433 | #endif | |
8d063cd8 LW |
434 | /* |
435 | * Add new memory allocated to that on | |
436 | * free list for this hash bucket. | |
437 | */ | |
8d063cd8 | 438 | siz = 1 << (bucket + 3); |
cf5c4ad8 | 439 | #ifdef PACK_MALLOC |
440 | *(u_char*)op = bucket; /* Fill index. */ | |
441 | if (bucket <= MAX_PACKED - 3) { | |
442 | op = (union overhead *) ((char*)op + blk_shift[bucket]); | |
443 | nblks = n_blks[bucket]; | |
444 | # ifdef DEBUGGING_MSTATS | |
445 | start_slack += blk_shift[bucket]; | |
446 | # endif | |
447 | } else if (bucket <= 11 - 1 - 3) { | |
448 | op = (union overhead *) ((char*)op + blk_shift[bucket]); | |
449 | /* nblks = n_blks[bucket]; */ | |
450 | siz -= sizeof(union overhead); | |
451 | } else op++; /* One chunk per block. */ | |
452 | #endif /* !PACK_MALLOC */ | |
453 | nextf[bucket] = op; | |
8d063cd8 LW |
454 | while (--nblks > 0) { |
455 | op->ov_next = (union overhead *)((caddr_t)op + siz); | |
456 | op = (union overhead *)((caddr_t)op + siz); | |
457 | } | |
8595d6f1 | 458 | /* Not all sbrks return zeroed memory.*/ |
cf5c4ad8 | 459 | op->ov_next = (union overhead *)NULL; |
cf5c4ad8 | 460 | #ifdef PACK_MALLOC |
461 | if (bucket == 7 - 3) { /* Special case, explanation is above. */ | |
462 | union overhead *n_op = nextf[7 - 3]->ov_next; | |
463 | nextf[7 - 3] = (union overhead *)((caddr_t)nextf[7 - 3] | |
464 | - sizeof(union overhead)); | |
465 | nextf[7 - 3]->ov_next = n_op; | |
466 | } | |
467 | #endif /* !PACK_MALLOC */ | |
8d063cd8 LW |
468 | } |
469 | ||
94b6baf5 | 470 | Free_t |
352d5a3a | 471 | free(mp) |
2304df62 | 472 | Malloc_t mp; |
8d063cd8 | 473 | { |
ee0007ab | 474 | register MEM_SIZE size; |
8d063cd8 | 475 | register union overhead *op; |
352d5a3a | 476 | char *cp = (char*)mp; |
cf5c4ad8 | 477 | #ifdef PACK_MALLOC |
478 | u_char bucket; | |
479 | #endif | |
8d063cd8 | 480 | |
55497cff | 481 | #ifdef PERL_CORE |
760ac839 | 482 | DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%lx: (%05d) free\n",(unsigned long)cp,an++)); |
55497cff | 483 | #endif /* PERL_CORE */ |
45d8adaa | 484 | |
cf5c4ad8 | 485 | if (cp == NULL) |
486 | return; | |
487 | op = (union overhead *)((caddr_t)cp | |
488 | - sizeof (union overhead) * CHUNK_SHIFT); | |
489 | #ifdef PACK_MALLOC | |
490 | bucket = OV_INDEX(op); | |
491 | #endif | |
760ac839 | 492 | #ifdef DEBUGGING |
cf5c4ad8 | 493 | ASSERT(OV_MAGIC(op, bucket) == MAGIC); /* make sure it was in use */ |
8d063cd8 | 494 | #else |
cf5c4ad8 | 495 | if (OV_MAGIC(op, bucket) != MAGIC) { |
496 | static bad_free_warn = -1; | |
497 | if (bad_free_warn == -1) { | |
498 | char *pbf = getenv("PERL_BADFREE"); | |
499 | bad_free_warn = (pbf) ? atoi(pbf) : 1; | |
500 | } | |
501 | if (!bad_free_warn) | |
502 | return; | |
8990e307 | 503 | #ifdef RCHECK |
a687059c | 504 | warn("%s free() ignored", |
8990e307 LW |
505 | op->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad"); |
506 | #else | |
507 | warn("Bad free() ignored"); | |
508 | #endif | |
8d063cd8 | 509 | return; /* sanity */ |
378cc40b | 510 | } |
8d063cd8 LW |
511 | #endif |
512 | #ifdef RCHECK | |
513 | ASSERT(op->ov_rmagic == RMAGIC); | |
cf5c4ad8 | 514 | if (OV_INDEX(op) <= 13) |
8d063cd8 | 515 | ASSERT(*(u_int *)((caddr_t)op + op->ov_size + 1 - RSLOP) == RMAGIC); |
8990e307 | 516 | op->ov_rmagic = RMAGIC - 1; |
8d063cd8 | 517 | #endif |
cf5c4ad8 | 518 | ASSERT(OV_INDEX(op) < NBUCKETS); |
519 | size = OV_INDEX(op); | |
8d063cd8 LW |
520 | op->ov_next = nextf[size]; |
521 | nextf[size] = op; | |
c07a80fd | 522 | #ifdef DEBUGGING_MSTATS |
8d063cd8 LW |
523 | nmalloc[size]--; |
524 | #endif | |
525 | } | |
526 | ||
527 | /* | |
528 | * When a program attempts "storage compaction" as mentioned in the | |
529 | * old malloc man page, it realloc's an already freed block. Usually | |
530 | * this is the last block it freed; occasionally it might be farther | |
531 | * back. We have to search all the free lists for the block in order | |
532 | * to determine its bucket: 1st we make one pass thru the lists | |
533 | * checking only the first block in each; if that fails we search | |
378cc40b | 534 | * ``reall_srchlen'' blocks in each list for a match (the variable |
8d063cd8 LW |
535 | * is extern so the caller can modify it). If that fails we just copy |
536 | * however many bytes was given to realloc() and hope it's not huge. | |
537 | */ | |
378cc40b | 538 | int reall_srchlen = 4; /* 4 should be plenty, -1 =>'s whole list */ |
8d063cd8 | 539 | |
2304df62 | 540 | Malloc_t |
352d5a3a | 541 | realloc(mp, nbytes) |
2304df62 | 542 | Malloc_t mp; |
ee0007ab | 543 | MEM_SIZE nbytes; |
8d063cd8 | 544 | { |
ee0007ab | 545 | register MEM_SIZE onb; |
8d063cd8 LW |
546 | union overhead *op; |
547 | char *res; | |
548 | register int i; | |
549 | int was_alloced = 0; | |
352d5a3a | 550 | char *cp = (char*)mp; |
8d063cd8 | 551 | |
55497cff | 552 | #ifdef PERL_CORE |
45d8adaa | 553 | #ifdef DEBUGGING |
ee0007ab | 554 | MEM_SIZE size = nbytes; |
45d8adaa LW |
555 | #endif |
556 | ||
55497cff | 557 | #ifdef HAS_64K_LIMIT |
45d8adaa | 558 | if (nbytes > 0xffff) { |
760ac839 | 559 | PerlIO_printf(PerlIO_stderr(), "Reallocation too large: %lx\n", size); |
79072805 | 560 | my_exit(1); |
45d8adaa | 561 | } |
55497cff | 562 | #endif /* HAS_64K_LIMIT */ |
45d8adaa | 563 | if (!cp) |
ee0007ab | 564 | return malloc(nbytes); |
45d8adaa LW |
565 | #ifdef DEBUGGING |
566 | if ((long)nbytes < 0) | |
463ee0b2 | 567 | croak("panic: realloc"); |
45d8adaa | 568 | #endif |
55497cff | 569 | #endif /* PERL_CORE */ |
45d8adaa | 570 | |
cf5c4ad8 | 571 | op = (union overhead *)((caddr_t)cp |
572 | - sizeof (union overhead) * CHUNK_SHIFT); | |
573 | i = OV_INDEX(op); | |
574 | if (OV_MAGIC(op, i) == MAGIC) { | |
55497cff | 575 | was_alloced = 1; |
8d063cd8 LW |
576 | } else { |
577 | /* | |
578 | * Already free, doing "compaction". | |
579 | * | |
580 | * Search for the old block of memory on the | |
581 | * free list. First, check the most common | |
582 | * case (last element free'd), then (this failing) | |
378cc40b | 583 | * the last ``reall_srchlen'' items free'd. |
8d063cd8 LW |
584 | * If all lookups fail, then assume the size of |
585 | * the memory block being realloc'd is the | |
586 | * smallest possible. | |
587 | */ | |
588 | if ((i = findbucket(op, 1)) < 0 && | |
378cc40b | 589 | (i = findbucket(op, reall_srchlen)) < 0) |
8d063cd8 LW |
590 | i = 0; |
591 | } | |
cf5c4ad8 | 592 | onb = (1L << (i + 3)) - |
593 | #ifdef PACK_MALLOC | |
594 | (i <= (MAX_PACKED - 3) ? 0 : M_OVERHEAD) | |
595 | #else | |
596 | M_OVERHEAD | |
597 | #endif | |
55497cff | 598 | #ifdef TWO_POT_OPTIMIZE |
599 | + (i >= (FIRST_BIG_TWO_POT - 3) ? PERL_PAGESIZE : 0) | |
600 | #endif | |
cf5c4ad8 | 601 | ; |
55497cff | 602 | /* |
603 | * avoid the copy if same size block. | |
604 | * We are not agressive with boundary cases. Note that it is | |
605 | * possible for small number of cases give false negative if | |
606 | * both new size and old one are in the bucket for | |
607 | * FIRST_BIG_TWO_POT, but the new one is near the lower end. | |
608 | */ | |
8d063cd8 | 609 | if (was_alloced && |
55497cff | 610 | nbytes <= onb && (nbytes > ( (onb >> 1) - M_OVERHEAD ) |
611 | #ifdef TWO_POT_OPTIMIZE | |
612 | || (i == (FIRST_BIG_TWO_POT - 3) | |
613 | && nbytes >= LAST_SMALL_BOUND ) | |
614 | #endif | |
615 | )) { | |
a687059c LW |
616 | #ifdef RCHECK |
617 | /* | |
618 | * Record new allocated size of block and | |
619 | * bound space with magic numbers. | |
620 | */ | |
cf5c4ad8 | 621 | if (OV_INDEX(op) <= 13) { |
a687059c LW |
622 | /* |
623 | * Convert amount of memory requested into | |
624 | * closest block size stored in hash buckets | |
625 | * which satisfies request. Account for | |
626 | * space used per block for accounting. | |
627 | */ | |
cf5c4ad8 | 628 | nbytes += M_OVERHEAD; |
a687059c LW |
629 | nbytes = (nbytes + 3) &~ 3; |
630 | op->ov_size = nbytes - 1; | |
631 | *((u_int *)((caddr_t)op + nbytes - RSLOP)) = RMAGIC; | |
632 | } | |
633 | #endif | |
45d8adaa | 634 | res = cp; |
a687059c | 635 | } |
45d8adaa LW |
636 | else { |
637 | if ((res = (char*)malloc(nbytes)) == NULL) | |
638 | return (NULL); | |
639 | if (cp != res) /* common optimization */ | |
ee0007ab | 640 | Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char); |
45d8adaa LW |
641 | if (was_alloced) |
642 | free(cp); | |
643 | } | |
644 | ||
55497cff | 645 | #ifdef PERL_CORE |
45d8adaa | 646 | #ifdef DEBUGGING |
a0d0e21e | 647 | if (debug & 128) { |
760ac839 LW |
648 | PerlIO_printf(PerlIO_stderr(), "0x%lx: (%05d) rfree\n",(unsigned long)res,an++); |
649 | PerlIO_printf(PerlIO_stderr(), "0x%lx: (%05d) realloc %ld bytes\n", | |
a0d0e21e LW |
650 | (unsigned long)res,an++,(long)size); |
651 | } | |
45d8adaa | 652 | #endif |
55497cff | 653 | #endif /* PERL_CORE */ |
2304df62 | 654 | return ((Malloc_t)res); |
8d063cd8 LW |
655 | } |
656 | ||
657 | /* | |
658 | * Search ``srchlen'' elements of each free list for a block whose | |
659 | * header starts at ``freep''. If srchlen is -1 search the whole list. | |
660 | * Return bucket number, or -1 if not found. | |
661 | */ | |
ee0007ab | 662 | static int |
8d063cd8 LW |
663 | findbucket(freep, srchlen) |
664 | union overhead *freep; | |
665 | int srchlen; | |
666 | { | |
667 | register union overhead *p; | |
668 | register int i, j; | |
669 | ||
670 | for (i = 0; i < NBUCKETS; i++) { | |
671 | j = 0; | |
672 | for (p = nextf[i]; p && j != srchlen; p = p->ov_next) { | |
673 | if (p == freep) | |
674 | return (i); | |
675 | j++; | |
676 | } | |
677 | } | |
678 | return (-1); | |
679 | } | |
680 | ||
cf5c4ad8 | 681 | Malloc_t |
682 | calloc(elements, size) | |
683 | register MEM_SIZE elements; | |
684 | register MEM_SIZE size; | |
685 | { | |
686 | long sz = elements * size; | |
687 | Malloc_t p = malloc(sz); | |
688 | ||
689 | if (p) { | |
690 | memset((void*)p, 0, sz); | |
691 | } | |
692 | return p; | |
693 | } | |
694 | ||
c07a80fd | 695 | #ifdef DEBUGGING_MSTATS |
8d063cd8 LW |
696 | /* |
697 | * mstats - print out statistics about malloc | |
698 | * | |
699 | * Prints two lines of numbers, one showing the length of the free list | |
700 | * for each size category, the second showing the number of mallocs - | |
701 | * frees for each size category. | |
702 | */ | |
ee0007ab | 703 | void |
c07a80fd | 704 | dump_mstats(s) |
8d063cd8 LW |
705 | char *s; |
706 | { | |
707 | register int i, j; | |
708 | register union overhead *p; | |
c07a80fd | 709 | int topbucket=0, totfree=0, totused=0; |
710 | u_int nfree[NBUCKETS]; | |
8d063cd8 | 711 | |
c07a80fd | 712 | for (i=0; i < NBUCKETS; i++) { |
8d063cd8 LW |
713 | for (j = 0, p = nextf[i]; p; p = p->ov_next, j++) |
714 | ; | |
c07a80fd | 715 | nfree[i] = j; |
716 | totfree += nfree[i] * (1 << (i + 3)); | |
8d063cd8 | 717 | totused += nmalloc[i] * (1 << (i + 3)); |
c07a80fd | 718 | if (nfree[i] || nmalloc[i]) |
719 | topbucket = i; | |
720 | } | |
721 | if (s) | |
760ac839 | 722 | PerlIO_printf(PerlIO_stderr(), "Memory allocation statistics %s (buckets 8..%d)\n", |
c07a80fd | 723 | s, (1 << (topbucket + 3)) ); |
760ac839 | 724 | PerlIO_printf(PerlIO_stderr(), " %7d free: ", totfree); |
c07a80fd | 725 | for (i=0; i <= topbucket; i++) { |
760ac839 | 726 | PerlIO_printf(PerlIO_stderr(), (i<5)?" %5d":" %3d", nfree[i]); |
8d063cd8 | 727 | } |
760ac839 | 728 | PerlIO_printf(PerlIO_stderr(), "\n %7d used: ", totused); |
c07a80fd | 729 | for (i=0; i <= topbucket; i++) { |
760ac839 | 730 | PerlIO_printf(PerlIO_stderr(), (i<5)?" %5d":" %3d", nmalloc[i]); |
c07a80fd | 731 | } |
760ac839 | 732 | PerlIO_printf(PerlIO_stderr(), "\n"); |
cf5c4ad8 | 733 | #ifdef PACK_MALLOC |
734 | if (sbrk_slack || start_slack) { | |
760ac839 | 735 | PerlIO_printf(PerlIO_stderr(), "Odd ends: %7d bytes from sbrk(), %7d from malloc.\n", |
cf5c4ad8 | 736 | sbrk_slack, start_slack); |
737 | } | |
738 | #endif | |
c07a80fd | 739 | } |
740 | #else | |
741 | void | |
742 | dump_mstats(s) | |
743 | char *s; | |
744 | { | |
8d063cd8 LW |
745 | } |
746 | #endif | |
a687059c | 747 | #endif /* lint */ |
cf5c4ad8 | 748 | |
749 | ||
750 | #ifdef USE_PERL_SBRK | |
751 | ||
760ac839 LW |
752 | # ifdef NeXT |
753 | # define PERL_SBRK_VIA_MALLOC | |
754 | # endif | |
755 | ||
756 | # ifdef PERL_SBRK_VIA_MALLOC | |
757 | # ifdef HIDEMYMALLOC | |
758 | # undef malloc | |
759 | # else | |
760 | # include "Error: -DPERL_SBRK_VIA_MALLOC requires -DHIDEMYMALLOC" | |
761 | # endif | |
cf5c4ad8 | 762 | |
763 | /* it may seem schizophrenic to use perl's malloc and let it call system */ | |
764 | /* malloc, the reason for that is only the 3.2 version of the OS that had */ | |
765 | /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */ | |
766 | /* end to the cores */ | |
767 | ||
760ac839 | 768 | # define SYSTEM_ALLOC(a) malloc(a) |
cf5c4ad8 | 769 | |
760ac839 | 770 | # endif /* PERL_SBRK_VIA_MALLOC */ |
cf5c4ad8 | 771 | |
772 | static IV Perl_sbrk_oldchunk; | |
773 | static long Perl_sbrk_oldsize; | |
774 | ||
760ac839 LW |
775 | # define PERLSBRK_32_K (1<<15) |
776 | # define PERLSBRK_64_K (1<<16) | |
cf5c4ad8 | 777 | |
778 | char * | |
779 | Perl_sbrk(size) | |
780 | int size; | |
781 | { | |
782 | IV got; | |
783 | int small, reqsize; | |
784 | ||
785 | if (!size) return 0; | |
55497cff | 786 | #ifdef PERL_CORE |
cf5c4ad8 | 787 | reqsize = size; /* just for the DEBUG_m statement */ |
788 | #endif | |
789 | if (size <= Perl_sbrk_oldsize) { | |
790 | got = Perl_sbrk_oldchunk; | |
791 | Perl_sbrk_oldchunk += size; | |
792 | Perl_sbrk_oldsize -= size; | |
793 | } else { | |
794 | if (size >= PERLSBRK_32_K) { | |
795 | small = 0; | |
796 | } else { | |
55497cff | 797 | #ifndef PERL_CORE |
cf5c4ad8 | 798 | reqsize = size; |
799 | #endif | |
800 | size = PERLSBRK_64_K; | |
801 | small = 1; | |
802 | } | |
803 | got = (IV)SYSTEM_ALLOC(size); | |
804 | if (small) { | |
805 | /* Chunk is small, register the rest for future allocs. */ | |
806 | Perl_sbrk_oldchunk = got + reqsize; | |
807 | Perl_sbrk_oldsize = size - reqsize; | |
808 | } | |
809 | } | |
810 | ||
55497cff | 811 | #ifdef PERL_CORE |
760ac839 | 812 | DEBUG_m(PerlIO_printf(PerlIO_stderr(), "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%lx\n", |
cf5c4ad8 | 813 | size, reqsize, Perl_sbrk_oldsize, got)); |
814 | #endif | |
815 | ||
816 | return (void *)got; | |
817 | } | |
818 | ||
819 | #endif /* ! defined USE_PERL_SBRK */ |