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