6 Here are some notes on configuring Perl's malloc.
8 There are two macros which serve as bulk disablers of advanced
9 features of this malloc: NO_FANCY_MALLOC, PLAIN_MALLOC (undef by
10 default). Look in the list of default values below to understand
11 their exact effect. Defining NO_FANCY_MALLOC returns malloc.c to the
12 state of the malloc in Perl 5.004. Additionally defining PLAIN_MALLOC
13 returns it to the state as of Perl 5.000.
15 Note that some of the settings below may be ignored in the code based
16 on values of other macros. The PERL_CORE symbol is only defined when
17 perl itself is being compiled (so malloc can make some assumptions
18 about perl's facilities being available to it).
20 Each config option has a short description, followed by its name,
21 default value, and a comment about the default (if applicable). Some
22 options take a precise value, while the others are just boolean.
23 The boolean ones are listed first.
25 # Enable code for an emergency memory pool in $^M. See perlvar.pod
26 # for a description of $^M.
27 PERL_EMERGENCY_SBRK (!PLAIN_MALLOC && PERL_CORE)
29 # Enable code for printing memory statistics.
30 DEBUGGING_MSTATS (!PLAIN_MALLOC && PERL_CORE)
32 # Move allocation info for small buckets into separate areas.
33 # Memory optimization (especially for small allocations, of the
34 # less than 64 bytes). Since perl usually makes a large number
35 # of small allocations, this is usually a win.
36 PACK_MALLOC (!PLAIN_MALLOC && !RCHECK)
38 # Add one page to big powers of two when calculating bucket size.
39 # This is targeted at big allocations, as are common in image
41 TWO_POT_OPTIMIZE !PLAIN_MALLOC
43 # Use intermediate bucket sizes between powers-of-two. This is
44 # generally a memory optimization, and a (small) speed pessimization.
45 BUCKETS_ROOT2 !NO_FANCY_MALLOC
47 # Do not check small deallocations for bad free(). Memory
48 # and speed optimization, error reporting pessimization.
49 IGNORE_SMALL_BAD_FREE (!NO_FANCY_MALLOC && !RCHECK)
51 # Use table lookup to decide in which bucket a given allocation will go.
52 SMALL_BUCKET_VIA_TABLE !NO_FANCY_MALLOC
54 # Use a perl-defined sbrk() instead of the (presumably broken or
55 # missing) system-supplied sbrk().
58 # Use system malloc() (or calloc() etc.) to emulate sbrk(). Normally
59 # only used with broken sbrk()s.
60 PERL_SBRK_VIA_MALLOC undef
62 # Which allocator to use if PERL_SBRK_VIA_MALLOC
63 SYSTEM_ALLOC(a) malloc(a)
65 # Disable memory overwrite checking with DEBUGGING. Memory and speed
66 # optimization, error reporting pessimization.
69 # Enable memory overwrite checking with DEBUGGING. Memory and speed
70 # pessimization, error reporting optimization
71 RCHECK (DEBUGGING && !NO_RCHECK)
73 # Failed allocations bigger than this size croak (if
74 # PERL_EMERGENCY_SBRK is enabled) without touching $^M. See
75 # perlvar.pod for a description of $^M.
76 BIG_SIZE (1<<16) # 64K
78 # Starting from this power of two, add an extra page to the
79 # size of the bucket. This enables optimized allocations of sizes
80 # close to powers of 2. Note that the value is indexed at 0.
81 FIRST_BIG_POW2 15 # 32K, 16K is used too often
83 # Estimate of minimal memory footprint. malloc uses this value to
84 # request the most reasonable largest blocks of memory from the system.
87 # Round up sbrk()s to multiples of this.
90 # Round up sbrk()s to multiples of this percent of footprint.
93 # Add this much memory to big powers of two to get the bucket size.
96 # This many sbrk() discontinuities should be tolerated even
97 # from the start without deciding that sbrk() is usually
101 # This many continuous sbrk()s compensate for one discontinuous one.
102 SBRK_FAILURE_PRICE 50
104 # Some configurations may ask for 12-byte-or-so allocations which
105 # require 8-byte alignment (?!). In such situation one needs to
106 # define this to disable 12-byte bucket (will increase memory footprint)
107 STRICT_ALIGNMENT undef
109 This implementation assumes that calling PerlIO_printf() does not
110 result in any memory allocation calls (used during a panic).
114 #ifndef NO_FANCY_MALLOC
115 # ifndef SMALL_BUCKET_VIA_TABLE
116 # define SMALL_BUCKET_VIA_TABLE
118 # ifndef BUCKETS_ROOT2
119 # define BUCKETS_ROOT2
121 # ifndef IGNORE_SMALL_BAD_FREE
122 # define IGNORE_SMALL_BAD_FREE
126 #ifndef PLAIN_MALLOC /* Bulk enable features */
130 # ifndef TWO_POT_OPTIMIZE
131 # define TWO_POT_OPTIMIZE
133 # if defined(PERL_CORE) && !defined(PERL_EMERGENCY_SBRK)
134 # define PERL_EMERGENCY_SBRK
136 # if defined(PERL_CORE) && !defined(DEBUGGING_MSTATS)
137 # define DEBUGGING_MSTATS
141 #define MIN_BUC_POW2 (sizeof(void*) > 4 ? 3 : 2) /* Allow for 4-byte arena. */
142 #define MIN_BUCKET (MIN_BUC_POW2 * BUCKETS_PER_POW2)
144 #if !(defined(I286) || defined(atarist))
145 /* take 2k unless the block is bigger than that */
146 # define LOG_OF_MIN_ARENA 11
148 /* take 16k unless the block is bigger than that
149 (80286s like large segments!), probably good on the atari too */
150 # define LOG_OF_MIN_ARENA 14
154 # if defined(DEBUGGING) && !defined(NO_RCHECK)
157 # if defined(RCHECK) && defined(IGNORE_SMALL_BAD_FREE)
158 # undef IGNORE_SMALL_BAD_FREE
161 * malloc.c (Caltech) 2/21/82
162 * Chris Kingsley, kingsley@cit-20.
164 * This is a very fast storage allocator. It allocates blocks of a small
165 * number of different sizes, and keeps free lists of each size. Blocks that
166 * don't exactly fit are passed up to the next larger size. In this
167 * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
168 * If PACK_MALLOC is defined, small blocks are 2^n bytes long.
169 * This is designed for use in a program that uses vast quantities of memory,
170 * but bombs when it runs out.
178 # include "../EXTERN.h"
179 # include "../perl.h"
186 # define Malloc_t void *
189 # define MEM_SIZE unsigned long
192 # define LONG_MAX 0x7FFFFFFF
195 # define UV unsigned long
198 # define caddr_t char *
203 # define Copy(s,d,n,t) (void)memcpy((char*)(d),(char*)(s), (n) * sizeof(t))
204 # define PerlEnv_getenv getenv
205 # define PerlIO_printf fprintf
206 # define PerlIO_stderr() stderr
208 # ifndef croak /* make depend */
209 # define croak(mess, arg) warn((mess), (arg)); exit(1);
212 # define warn(mess, arg) fprintf(stderr, (mess), (arg));
224 # define MUTEX_LOCK(l)
228 # define MUTEX_UNLOCK(l)
233 # define DEBUG_m(a) if (PL_debug & 128) a
236 /* I don't much care whether these are defined in sys/types.h--LAW */
238 #define u_char unsigned char
239 #define u_int unsigned int
242 # define u_bigint UV /* Needs to eat *void. */
244 # define u_bigint unsigned long /* Needs to eat *void. */
247 #define u_short unsigned short
249 /* 286 and atarist like big chunks, which gives too much overhead. */
250 #if (defined(RCHECK) || defined(I286) || defined(atarist)) && defined(PACK_MALLOC)
255 * The description below is applicable if PACK_MALLOC is not defined.
257 * The overhead on a block is at least 4 bytes. When free, this space
258 * contains a pointer to the next free block, and the bottom two bits must
259 * be zero. When in use, the first byte is set to MAGIC, and the second
260 * byte is the size index. The remaining bytes are for alignment.
261 * If range checking is enabled and the size of the block fits
262 * in two bytes, then the top two bytes hold the size of the requested block
263 * plus the range checking words, and the header word MINUS ONE.
266 union overhead *ov_next; /* when free */
267 #if MEM_ALIGNBYTES > 4
268 double strut; /* alignment problems */
271 u_char ovu_magic; /* magic number */
272 u_char ovu_index; /* bucket # */
274 u_short ovu_size; /* actual block size */
275 u_int ovu_rmagic; /* range magic number */
278 #define ov_magic ovu.ovu_magic
279 #define ov_index ovu.ovu_index
280 #define ov_size ovu.ovu_size
281 #define ov_rmagic ovu.ovu_rmagic
285 static void botch _((char *diag, char *s));
287 static void morecore _((int bucket));
288 static int findbucket _((union overhead *freep, int srchlen));
289 static void add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip);
291 #define MAGIC 0xff /* magic # on accounting info */
292 #define RMAGIC 0x55555555 /* magic # on range info */
293 #define RMAGIC_C 0x55 /* magic # on range info */
296 # define RSLOP sizeof (u_int)
297 # ifdef TWO_POT_OPTIMIZE
298 # define MAX_SHORT_BUCKET (12 * BUCKETS_PER_POW2)
300 # define MAX_SHORT_BUCKET (13 * BUCKETS_PER_POW2)
306 #if !defined(PACK_MALLOC) && defined(BUCKETS_ROOT2)
307 # undef BUCKETS_ROOT2
311 # define BUCKET_TABLE_SHIFT 2
312 # define BUCKET_POW2_SHIFT 1
313 # define BUCKETS_PER_POW2 2
315 # define BUCKET_TABLE_SHIFT MIN_BUC_POW2
316 # define BUCKET_POW2_SHIFT 0
317 # define BUCKETS_PER_POW2 1
320 #if !defined(MEM_ALIGNBYTES) || ((MEM_ALIGNBYTES > 4) && !defined(STRICT_ALIGNMENT))
321 /* Figure out the alignment of void*. */
326 # define ALIGN_SMALL ((int)((caddr_t)&(((struct aligner*)0)->p)))
328 # define ALIGN_SMALL MEM_ALIGNBYTES
331 #define IF_ALIGN_8(yes,no) ((ALIGN_SMALL>4) ? (yes) : (no))
334 # define MAX_BUCKET_BY_TABLE 13
335 static u_short buck_size[MAX_BUCKET_BY_TABLE + 1] =
337 0, 0, 0, 0, 4, 4, 8, 12, 16, 24, 32, 48, 64, 80,
339 # define BUCKET_SIZE(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT)))
340 # define BUCKET_SIZE_REAL(i) ((i) <= MAX_BUCKET_BY_TABLE \
342 : ((1 << ((i) >> BUCKET_POW2_SHIFT)) \
344 + POW2_OPTIMIZE_SURPLUS(i)))
346 # define BUCKET_SIZE(i) (1 << ((i) >> BUCKET_POW2_SHIFT))
347 # define BUCKET_SIZE_REAL(i) (BUCKET_SIZE(i) - MEM_OVERHEAD(i) + POW2_OPTIMIZE_SURPLUS(i))
352 /* In this case it is assumed that if we do sbrk() in 2K units, we
353 * will get 2K aligned arenas (at least after some initial
354 * alignment). The bucket number of the given subblock is on the start
355 * of 2K arena which contains the subblock. Several following bytes
356 * contain the magic numbers for the subblocks in the block.
358 * Sizes of chunks are powers of 2 for chunks in buckets <=
359 * MAX_PACKED, after this they are (2^n - sizeof(union overhead)) (to
360 * get alignment right).
362 * Consider an arena for 2^n with n>MAX_PACKED. We suppose that
363 * starts of all the chunks in a 2K arena are in different
364 * 2^n-byte-long chunks. If the top of the last chunk is aligned on a
365 * boundary of 2K block, this means that sizeof(union
366 * overhead)*"number of chunks" < 2^n, or sizeof(union overhead)*2K <
367 * 4^n, or n > 6 + log2(sizeof()/2)/2, since a chunk of size 2^n -
368 * overhead is used. Since this rules out n = 7 for 8 byte alignment,
369 * we specialcase allocation of the first of 16 128-byte-long chunks.
371 * Note that with the above assumption we automatically have enough
372 * place for MAGIC at the start of 2K block. Note also that we
373 * overlay union overhead over the chunk, thus the start of small chunks
374 * is immediately overwritten after freeing. */
375 # define MAX_PACKED_POW2 6
376 # define MAX_PACKED (MAX_PACKED_POW2 * BUCKETS_PER_POW2 + BUCKET_POW2_SHIFT)
377 # define MAX_POW2_ALGO ((1<<(MAX_PACKED_POW2 + 1)) - M_OVERHEAD)
378 # define TWOK_MASK ((1<<LOG_OF_MIN_ARENA) - 1)
379 # define TWOK_MASKED(x) ((u_bigint)(x) & ~TWOK_MASK)
380 # define TWOK_SHIFT(x) ((u_bigint)(x) & TWOK_MASK)
381 # define OV_INDEXp(block) ((u_char*)(TWOK_MASKED(block)))
382 # define OV_INDEX(block) (*OV_INDEXp(block))
383 # define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) + \
384 (TWOK_SHIFT(block)>> \
385 (bucket>>BUCKET_POW2_SHIFT)) + \
386 (bucket >= MIN_NEEDS_SHIFT ? 1 : 0)))
387 /* A bucket can have a shift smaller than it size, we need to
388 shift its magic number so it will not overwrite index: */
389 # ifdef BUCKETS_ROOT2
390 # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2 - 1) /* Shift 80 greater than chunk 64. */
392 # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2) /* Shift 128 greater than chunk 32. */
394 # define CHUNK_SHIFT 0
396 /* Number of active buckets of given ordinal. */
397 #ifdef IGNORE_SMALL_BAD_FREE
398 #define FIRST_BUCKET_WITH_CHECK (6 * BUCKETS_PER_POW2) /* 64 */
399 # define N_BLKS(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
400 ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE(bucket) \
403 # define N_BLKS(bucket) n_blks[bucket]
406 static u_short n_blks[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
408 # if BUCKETS_PER_POW2==1
410 (MIN_BUC_POW2==2 ? 384 : 0),
411 224, 120, 62, 31, 16, 8, 4, 2
414 (MIN_BUC_POW2==2 ? 384 : 0), (MIN_BUC_POW2==2 ? 384 : 0), /* 4, 4 */
415 224, 149, 120, 80, 62, 41, 31, 25, 16, 16, 8, 8, 4, 4, 2, 2
419 /* Shift of the first bucket with the given ordinal inside 2K chunk. */
420 #ifdef IGNORE_SMALL_BAD_FREE
421 # define BLK_SHIFT(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
422 ? ((1<<LOG_OF_MIN_ARENA) \
423 - BUCKET_SIZE(bucket) * N_BLKS(bucket)) \
426 # define BLK_SHIFT(bucket) blk_shift[bucket]
429 static u_short blk_shift[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
431 # if BUCKETS_PER_POW2==1
433 (MIN_BUC_POW2==2 ? 512 : 0),
434 256, 128, 64, 64, /* 8 to 64 */
435 16*sizeof(union overhead),
436 8*sizeof(union overhead),
437 4*sizeof(union overhead),
438 2*sizeof(union overhead),
441 (MIN_BUC_POW2==2 ? 512 : 0), (MIN_BUC_POW2==2 ? 512 : 0),
442 256, 260, 128, 128, 64, 80, 64, 48, /* 8 to 96 */
443 16*sizeof(union overhead), 16*sizeof(union overhead),
444 8*sizeof(union overhead), 8*sizeof(union overhead),
445 4*sizeof(union overhead), 4*sizeof(union overhead),
446 2*sizeof(union overhead), 2*sizeof(union overhead),
450 #else /* !PACK_MALLOC */
452 # define OV_MAGIC(block,bucket) (block)->ov_magic
453 # define OV_INDEX(block) (block)->ov_index
454 # define CHUNK_SHIFT 1
455 # define MAX_PACKED -1
456 #endif /* !PACK_MALLOC */
458 #define M_OVERHEAD (sizeof(union overhead) + RSLOP)
461 # define MEM_OVERHEAD(bucket) \
462 (bucket <= MAX_PACKED ? 0 : M_OVERHEAD)
463 # ifdef SMALL_BUCKET_VIA_TABLE
464 # define START_SHIFTS_BUCKET ((MAX_PACKED_POW2 + 1) * BUCKETS_PER_POW2)
465 # define START_SHIFT MAX_PACKED_POW2
466 # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */
467 # define SIZE_TABLE_MAX 80
469 # define SIZE_TABLE_MAX 64
471 static char bucket_of[] =
473 # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */
474 /* 0 to 15 in 4-byte increments. */
475 (sizeof(void*) > 4 ? 6 : 5), /* 4/8, 5-th bucket for better reports */
477 IF_ALIGN_8(8,7), 8, /* 16/12, 16 */
478 9, 9, 10, 10, /* 24, 32 */
479 11, 11, 11, 11, /* 48 */
480 12, 12, 12, 12, /* 64 */
481 13, 13, 13, 13, /* 80 */
482 13, 13, 13, 13 /* 80 */
483 # else /* !BUCKETS_ROOT2 */
484 /* 0 to 15 in 4-byte increments. */
485 (sizeof(void*) > 4 ? 3 : 2),
491 # endif /* !BUCKETS_ROOT2 */
493 # else /* !SMALL_BUCKET_VIA_TABLE */
494 # define START_SHIFTS_BUCKET MIN_BUCKET
495 # define START_SHIFT (MIN_BUC_POW2 - 1)
496 # endif /* !SMALL_BUCKET_VIA_TABLE */
497 #else /* !PACK_MALLOC */
498 # define MEM_OVERHEAD(bucket) M_OVERHEAD
499 # ifdef SMALL_BUCKET_VIA_TABLE
500 # undef SMALL_BUCKET_VIA_TABLE
502 # define START_SHIFTS_BUCKET MIN_BUCKET
503 # define START_SHIFT (MIN_BUC_POW2 - 1)
504 #endif /* !PACK_MALLOC */
507 * Big allocations are often of the size 2^n bytes. To make them a
508 * little bit better, make blocks of size 2^n+pagesize for big n.
511 #ifdef TWO_POT_OPTIMIZE
513 # ifndef PERL_PAGESIZE
514 # define PERL_PAGESIZE 4096
516 # ifndef FIRST_BIG_POW2
517 # define FIRST_BIG_POW2 15 /* 32K, 16K is used too often. */
519 # define FIRST_BIG_BLOCK (1<<FIRST_BIG_POW2)
520 /* If this value or more, check against bigger blocks. */
521 # define FIRST_BIG_BOUND (FIRST_BIG_BLOCK - M_OVERHEAD)
522 /* If less than this value, goes into 2^n-overhead-block. */
523 # define LAST_SMALL_BOUND ((FIRST_BIG_BLOCK>>1) - M_OVERHEAD)
525 # define POW2_OPTIMIZE_ADJUST(nbytes) \
526 ((nbytes >= FIRST_BIG_BOUND) ? nbytes -= PERL_PAGESIZE : 0)
527 # define POW2_OPTIMIZE_SURPLUS(bucket) \
528 ((bucket >= FIRST_BIG_POW2 * BUCKETS_PER_POW2) ? PERL_PAGESIZE : 0)
530 #else /* !TWO_POT_OPTIMIZE */
531 # define POW2_OPTIMIZE_ADJUST(nbytes)
532 # define POW2_OPTIMIZE_SURPLUS(bucket) 0
533 #endif /* !TWO_POT_OPTIMIZE */
535 #if defined(HAS_64K_LIMIT) && defined(PERL_CORE)
536 # define BARK_64K_LIMIT(what,nbytes,size) \
537 if (nbytes > 0xffff) { \
538 PerlIO_printf(PerlIO_stderr(), \
539 "%s too large: %lx\n", what, size); \
542 #else /* !HAS_64K_LIMIT || !PERL_CORE */
543 # define BARK_64K_LIMIT(what,nbytes,size)
544 #endif /* !HAS_64K_LIMIT || !PERL_CORE */
547 # define MIN_SBRK 2048
551 # define FIRST_SBRK (48*1024)
554 /* Minimal sbrk in percents of what is already alloced. */
555 #ifndef MIN_SBRK_FRAC
556 # define MIN_SBRK_FRAC 3
559 #ifndef SBRK_ALLOW_FAILURES
560 # define SBRK_ALLOW_FAILURES 3
563 #ifndef SBRK_FAILURE_PRICE
564 # define SBRK_FAILURE_PRICE 50
567 #if defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)
570 # define BIG_SIZE (1<<16) /* 64K */
573 static char *emergency_buffer;
574 static MEM_SIZE emergency_buffer_size;
575 static Malloc_t emergency_sbrk(MEM_SIZE size);
578 emergency_sbrk(MEM_SIZE size)
580 MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA;
582 if (size >= BIG_SIZE) {
583 /* Give the possibility to recover: */
584 MUTEX_UNLOCK(&PL_malloc_mutex);
585 croak("Out of memory during \"large\" request for %i bytes", size);
588 if (emergency_buffer_size >= rsize) {
589 char *old = emergency_buffer;
591 emergency_buffer_size -= rsize;
592 emergency_buffer += rsize;
596 /* First offense, give a possibility to recover by dieing. */
597 /* No malloc involved here: */
598 GV **gvp = (GV**)hv_fetch(PL_defstash, "^M", 2, 0);
603 if (emergency_buffer_size) {
604 add_to_chain(emergency_buffer, emergency_buffer_size, 0);
605 emergency_buffer_size = 0;
606 emergency_buffer = Nullch;
609 if (!gvp) gvp = (GV**)hv_fetch(PL_defstash, "\015", 1, 0);
610 if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv)
611 || (SvLEN(sv) < (1<<LOG_OF_MIN_ARENA) - M_OVERHEAD)) {
614 return (char *)-1; /* Now die die die... */
616 /* Got it, now detach SvPV: */
617 pv = SvPV(sv, PL_na);
618 /* Check alignment: */
619 if (((UV)(pv - sizeof(union overhead))) & ((1<<LOG_OF_MIN_ARENA) - 1)) {
620 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
621 return (char *)-1; /* die die die */
624 emergency_buffer = pv - sizeof(union overhead);
625 emergency_buffer_size = malloced_size(pv) + M_OVERHEAD;
628 SvCUR(sv) = SvLEN(sv) = 0;
631 MUTEX_UNLOCK(&PL_malloc_mutex);
632 croak("Out of memory during request for %i bytes", size);
635 #else /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */
636 # define emergency_sbrk(size) -1
637 #endif /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */
640 * nextf[i] is the pointer to the next free block of size 2^i. The
641 * smallest allocatable block is 8 bytes. The overhead information
642 * precedes the data area returned to the user.
644 #define NBUCKETS (32*BUCKETS_PER_POW2 + 1)
645 static union overhead *nextf[NBUCKETS];
648 #define sbrk(a) Perl_sbrk(a)
649 Malloc_t Perl_sbrk _((int size));
651 #ifdef DONT_DECLARE_STD
656 extern Malloc_t sbrk(int);
660 #ifdef DEBUGGING_MSTATS
662 * nmalloc[i] is the difference between the number of mallocs and frees
663 * for a given block size.
665 static u_int nmalloc[NBUCKETS];
666 static u_int sbrk_slack;
667 static u_int start_slack;
670 static u_int goodsbrk;
673 #define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p)); else
675 botch(char *diag, char *s)
677 PerlIO_printf(PerlIO_stderr(), "assertion botched (%s?): %s\n", diag, s);
681 #define ASSERT(p, diag)
685 malloc(register size_t nbytes)
687 register union overhead *p;
689 register MEM_SIZE shiftr;
691 #if defined(DEBUGGING) || defined(RCHECK)
692 MEM_SIZE size = nbytes;
695 BARK_64K_LIMIT("Allocation",nbytes,nbytes);
697 if ((long)nbytes < 0)
698 croak("%s", "panic: malloc");
701 MUTEX_LOCK(&PL_malloc_mutex);
703 * Convert amount of memory requested into
704 * closest block size stored in hash buckets
705 * which satisfies request. Account for
706 * space used per block for accounting.
709 # ifdef SMALL_BUCKET_VIA_TABLE
712 else if (nbytes <= SIZE_TABLE_MAX) {
713 bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
718 if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
723 POW2_OPTIMIZE_ADJUST(nbytes);
724 nbytes += M_OVERHEAD;
725 nbytes = (nbytes + 3) &~ 3;
727 shiftr = (nbytes - 1) >> START_SHIFT;
728 bucket = START_SHIFTS_BUCKET;
729 /* apart from this loop, this is O(1) */
731 bucket += BUCKETS_PER_POW2;
734 * If nothing in hash bucket right now,
735 * request more memory from the system.
737 if (nextf[bucket] == NULL)
739 if ((p = nextf[bucket]) == NULL) {
740 MUTEX_UNLOCK(&PL_malloc_mutex);
743 PerlIO_puts(PerlIO_stderr(),"Out of memory!\n");
751 DEBUG_m(PerlIO_printf(Perl_debug_log,
752 "0x%lx: (%05lu) malloc %ld bytes\n",
753 (unsigned long)(p+1), (unsigned long)(PL_an++),
756 /* remove from linked list */
758 if (((UV)p) & (MEM_ALIGNBYTES - 1))
759 PerlIO_printf(PerlIO_stderr(), "Corrupt malloc ptr 0x%lx at 0x%lx\n",
760 (unsigned long)*((int*)p),(unsigned long)p);
762 nextf[bucket] = p->ov_next;
763 #ifdef IGNORE_SMALL_BAD_FREE
764 if (bucket >= FIRST_BUCKET_WITH_CHECK)
766 OV_MAGIC(p, bucket) = MAGIC;
768 OV_INDEX(p) = bucket;
772 * Record allocated size of block and
773 * bound space with magic numbers.
775 p->ov_rmagic = RMAGIC;
776 if (bucket <= MAX_SHORT_BUCKET) {
779 nbytes = size + M_OVERHEAD;
780 p->ov_size = nbytes - 1;
781 if ((i = nbytes & 3)) {
784 *((char *)((caddr_t)p + nbytes - RSLOP + i)) = RMAGIC_C;
786 nbytes = (nbytes + 3) &~ 3;
787 *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
790 MUTEX_UNLOCK(&PL_malloc_mutex);
791 return ((Malloc_t)(p + CHUNK_SHIFT));
794 static char *last_sbrk_top;
795 static char *last_op; /* This arena can be easily extended. */
796 static int sbrked_remains;
797 static int sbrk_good = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE;
799 #ifdef DEBUGGING_MSTATS
803 struct chunk_chain_s {
804 struct chunk_chain_s *next;
807 static struct chunk_chain_s *chunk_chain;
809 static char max_bucket;
811 /* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */
813 get_from_chain(MEM_SIZE size)
815 struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
816 struct chunk_chain_s **oldgoodp = NULL;
817 long min_remain = LONG_MAX;
820 if (elt->size >= size) {
821 long remains = elt->size - size;
822 if (remains >= 0 && remains < min_remain) {
824 min_remain = remains;
830 oldp = &( elt->next );
833 if (!oldgoodp) return NULL;
835 void *ret = *oldgoodp;
836 struct chunk_chain_s *next = (*oldgoodp)->next;
838 *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
839 (*oldgoodp)->size = min_remain;
840 (*oldgoodp)->next = next;
843 void *ret = *oldgoodp;
844 *oldgoodp = (*oldgoodp)->next;
851 add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
853 struct chunk_chain_s *next = chunk_chain;
857 chunk_chain = (struct chunk_chain_s *)cp;
858 chunk_chain->size = size - chip;
859 chunk_chain->next = next;
864 get_from_bigger_buckets(int bucket, MEM_SIZE size)
867 static int bucketprice[NBUCKETS];
868 while (bucket <= max_bucket) {
869 /* We postpone stealing from bigger buckets until we want it
871 if (nextf[bucket] && bucketprice[bucket]++ >= price) {
873 void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
874 bucketprice[bucket] = 0;
875 if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
876 last_op = NULL; /* Disable optimization */
878 nextf[bucket] = nextf[bucket]->ov_next;
879 #ifdef DEBUGGING_MSTATS
881 start_slack -= M_OVERHEAD;
883 add_to_chain(ret, (BUCKET_SIZE(bucket) +
884 POW2_OPTIMIZE_SURPLUS(bucket)),
893 static union overhead *
894 getpages(int needed, int *nblksp, int bucket)
896 /* Need to do (possibly expensive) system call. Try to
897 optimize it for rare calling. */
898 MEM_SIZE require = needed - sbrked_remains;
904 if (!last_sbrk_top && require < FIRST_SBRK)
905 require = FIRST_SBRK;
906 else if (require < MIN_SBRK) require = MIN_SBRK;
908 if (require < goodsbrk * MIN_SBRK_FRAC / 100)
909 require = goodsbrk * MIN_SBRK_FRAC / 100;
910 require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
917 DEBUG_m(PerlIO_printf(Perl_debug_log,
918 "sbrk(%ld) for %ld-byte-long arena\n",
919 (long)require, (long) needed));
920 cp = (char *)sbrk(require);
921 #ifdef DEBUGGING_MSTATS
924 if (cp == last_sbrk_top) {
925 /* Common case, anything is fine. */
927 ovp = (union overhead *) (cp - sbrked_remains);
928 sbrked_remains = require - (needed - sbrked_remains);
929 } else if (cp == (char *)-1) { /* no more room! */
930 ovp = (union overhead *)emergency_sbrk(needed);
931 if (ovp == (union overhead *)-1)
934 } else { /* Non-continuous or first sbrk(). */
935 long add = sbrked_remains;
938 if (sbrked_remains) { /* Put rest into chain, we
939 cannot use it right now. */
940 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
944 /* Second, check alignment. */
947 #ifndef atarist /* on the atari we dont have to worry about this */
948 # ifndef I286 /* The sbrk(0) call on the I286 always returns the next segment */
950 /* CHUNK_SHIFT is 1 for PACK_MALLOC, 0 otherwise. */
951 if ((UV)cp & (0x7FF >> CHUNK_SHIFT)) { /* Not aligned. */
952 slack = (0x800 >> CHUNK_SHIFT)
953 - ((UV)cp & (0x7FF >> CHUNK_SHIFT));
960 DEBUG_m(PerlIO_printf(Perl_debug_log,
961 "sbrk(%ld) to fix non-continuous/off-page sbrk:\n\t%ld for alignement,\t%ld were assumed to come from the tail of the previous sbrk\n",
962 (long)add, (long) slack,
963 (long) sbrked_remains));
964 newcp = (char *)sbrk(add);
965 #if defined(DEBUGGING_MSTATS)
969 if (newcp != cp + require) {
970 /* Too bad: even rounding sbrk() is not continuous.*/
971 DEBUG_m(PerlIO_printf(Perl_debug_log,
972 "failed to fix bad sbrk()\n"));
975 MUTEX_UNLOCK(&PL_malloc_mutex);
976 croak("%s", "panic: Off-page sbrk");
979 if (sbrked_remains) {
981 #if defined(DEBUGGING_MSTATS)
982 sbrk_slack += require;
985 DEBUG_m(PerlIO_printf(Perl_debug_log,
986 "straight sbrk(%ld)\n",
988 cp = (char *)sbrk(require);
989 #ifdef DEBUGGING_MSTATS
992 if (cp == (char *)-1)
995 sbrk_good = -1; /* Disable optimization!
996 Continue with not-aligned... */
999 require += sbrked_remains;
1003 if (last_sbrk_top) {
1004 sbrk_good -= SBRK_FAILURE_PRICE;
1007 ovp = (union overhead *) cp;
1009 * Round up to minimum allocation size boundary
1010 * and deduct from block count to reflect.
1013 #ifndef I286 /* Again, this should always be ok on an 80286 */
1015 ovp = (union overhead *)(((UV)ovp + 8) & ~7);
1016 DEBUG_m(PerlIO_printf(Perl_debug_log,
1017 "fixing sbrk(): %d bytes off machine alignement\n",
1018 (int)((UV)ovp & 7)));
1020 # if defined(DEBUGGING_MSTATS)
1021 /* This is only approx. if TWO_POT_OPTIMIZE: */
1022 sbrk_slack += (1 << bucket);
1026 sbrked_remains = require - needed;
1028 last_sbrk_top = cp + require;
1029 last_op = (char*) cp;
1030 #ifdef DEBUGGING_MSTATS
1031 goodsbrk += require;
1037 getpages_adjacent(int require)
1039 if (require <= sbrked_remains) {
1040 sbrked_remains -= require;
1044 require -= sbrked_remains;
1045 /* We do not try to optimize sbrks here, we go for place. */
1046 cp = (char*) sbrk(require);
1047 #ifdef DEBUGGING_MSTATS
1049 goodsbrk += require;
1051 if (cp == last_sbrk_top) {
1053 last_sbrk_top = cp + require;
1055 if (cp == (char*)-1) { /* Out of memory */
1056 #ifdef DEBUGGING_MSTATS
1057 goodsbrk -= require;
1061 /* Report the failure: */
1063 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1065 add_to_chain((void*)cp, require, 0);
1066 sbrk_good -= SBRK_FAILURE_PRICE;
1078 * Allocate more memory to the indicated bucket.
1081 morecore(register int bucket)
1083 register union overhead *ovp;
1084 register int rnu; /* 2^rnu bytes will be requested */
1085 int nblks; /* become nblks blocks of the desired size */
1086 register MEM_SIZE siz, needed;
1090 if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
1091 MUTEX_UNLOCK(&PL_malloc_mutex);
1092 croak("%s", "Out of memory during ridiculously large request");
1094 if (bucket > max_bucket)
1095 max_bucket = bucket;
1097 rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT))
1099 : (bucket >> BUCKET_POW2_SHIFT) );
1100 /* This may be overwritten later: */
1101 nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
1102 needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
1103 if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
1104 ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
1105 nextf[rnu << BUCKET_POW2_SHIFT]
1106 = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
1107 #ifdef DEBUGGING_MSTATS
1108 nmalloc[rnu << BUCKET_POW2_SHIFT]--;
1109 start_slack -= M_OVERHEAD;
1111 DEBUG_m(PerlIO_printf(Perl_debug_log,
1112 "stealing %ld bytes from %ld arena\n",
1113 (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
1114 } else if (chunk_chain
1115 && (ovp = (union overhead*) get_from_chain(needed))) {
1116 DEBUG_m(PerlIO_printf(Perl_debug_log,
1117 "stealing %ld bytes from chain\n",
1119 } else if ( (ovp = (union overhead*)
1120 get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
1122 DEBUG_m(PerlIO_printf(Perl_debug_log,
1123 "stealing %ld bytes from bigger buckets\n",
1125 } else if (needed <= sbrked_remains) {
1126 ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
1127 sbrked_remains -= needed;
1128 last_op = (char*)ovp;
1130 ovp = getpages(needed, &nblks, bucket);
1136 * Add new memory allocated to that on
1137 * free list for this hash bucket.
1139 siz = BUCKET_SIZE(bucket);
1141 *(u_char*)ovp = bucket; /* Fill index. */
1142 if (bucket <= MAX_PACKED) {
1143 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1144 nblks = N_BLKS(bucket);
1145 # ifdef DEBUGGING_MSTATS
1146 start_slack += BLK_SHIFT(bucket);
1148 } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
1149 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1150 siz -= sizeof(union overhead);
1151 } else ovp++; /* One chunk per block. */
1152 #endif /* PACK_MALLOC */
1153 nextf[bucket] = ovp;
1154 #ifdef DEBUGGING_MSTATS
1155 nmalloc[bucket] += nblks;
1156 if (bucket > MAX_PACKED) {
1157 start_slack += M_OVERHEAD * nblks;
1160 while (--nblks > 0) {
1161 ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
1162 ovp = (union overhead *)((caddr_t)ovp + siz);
1164 /* Not all sbrks return zeroed memory.*/
1165 ovp->ov_next = (union overhead *)NULL;
1167 if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
1168 union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
1169 nextf[7*BUCKETS_PER_POW2] =
1170 (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2]
1171 - sizeof(union overhead));
1172 nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
1174 #endif /* !PACK_MALLOC */
1180 register MEM_SIZE size;
1181 register union overhead *ovp;
1182 char *cp = (char*)mp;
1187 DEBUG_m(PerlIO_printf(Perl_debug_log,
1188 "0x%lx: (%05lu) free\n",
1189 (unsigned long)cp, (unsigned long)(PL_an++)));
1193 ovp = (union overhead *)((caddr_t)cp
1194 - sizeof (union overhead) * CHUNK_SHIFT);
1196 bucket = OV_INDEX(ovp);
1198 #ifdef IGNORE_SMALL_BAD_FREE
1199 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1200 && (OV_MAGIC(ovp, bucket) != MAGIC))
1202 if (OV_MAGIC(ovp, bucket) != MAGIC)
1205 static int bad_free_warn = -1;
1206 if (bad_free_warn == -1) {
1207 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1208 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1213 warn("%s free() ignored",
1214 ovp->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad");
1216 warn("%s", "Bad free() ignored");
1218 return; /* sanity */
1220 MUTEX_LOCK(&PL_malloc_mutex);
1222 ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
1223 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
1225 MEM_SIZE nbytes = ovp->ov_size + 1;
1227 if ((i = nbytes & 3)) {
1230 ASSERT(*((char *)((caddr_t)ovp + nbytes - RSLOP + i))
1231 == RMAGIC_C, "chunk's tail overwrite");
1234 nbytes = (nbytes + 3) &~ 3;
1235 ASSERT(*(u_int *)((caddr_t)ovp + nbytes - RSLOP) == RMAGIC, "chunk's tail overwrite");
1237 ovp->ov_rmagic = RMAGIC - 1;
1239 ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
1240 size = OV_INDEX(ovp);
1241 ovp->ov_next = nextf[size];
1243 MUTEX_UNLOCK(&PL_malloc_mutex);
1247 * When a program attempts "storage compaction" as mentioned in the
1248 * old malloc man page, it realloc's an already freed block. Usually
1249 * this is the last block it freed; occasionally it might be farther
1250 * back. We have to search all the free lists for the block in order
1251 * to determine its bucket: 1st we make one pass thru the lists
1252 * checking only the first block in each; if that fails we search
1253 * ``reall_srchlen'' blocks in each list for a match (the variable
1254 * is extern so the caller can modify it). If that fails we just copy
1255 * however many bytes was given to realloc() and hope it's not huge.
1257 #define reall_srchlen 4 /* 4 should be plenty, -1 =>'s whole list */
1260 realloc(void *mp, size_t nbytes)
1262 register MEM_SIZE onb;
1263 union overhead *ovp;
1266 register int bucket;
1267 int was_alloced = 0, incr;
1268 char *cp = (char*)mp;
1270 #if defined(DEBUGGING) || !defined(PERL_CORE)
1271 MEM_SIZE size = nbytes;
1273 if ((long)nbytes < 0)
1274 croak("%s", "panic: realloc");
1277 BARK_64K_LIMIT("Reallocation",nbytes,size);
1279 return malloc(nbytes);
1281 MUTEX_LOCK(&PL_malloc_mutex);
1282 ovp = (union overhead *)((caddr_t)cp
1283 - sizeof (union overhead) * CHUNK_SHIFT);
1284 bucket = OV_INDEX(ovp);
1285 #ifdef IGNORE_SMALL_BAD_FREE
1286 if ((bucket < FIRST_BUCKET_WITH_CHECK)
1287 || (OV_MAGIC(ovp, bucket) == MAGIC))
1289 if (OV_MAGIC(ovp, bucket) == MAGIC)
1295 * Already free, doing "compaction".
1297 * Search for the old block of memory on the
1298 * free list. First, check the most common
1299 * case (last element free'd), then (this failing)
1300 * the last ``reall_srchlen'' items free'd.
1301 * If all lookups fail, then assume the size of
1302 * the memory block being realloc'd is the
1303 * smallest possible.
1305 if ((bucket = findbucket(ovp, 1)) < 0 &&
1306 (bucket = findbucket(ovp, reall_srchlen)) < 0)
1309 onb = BUCKET_SIZE_REAL(bucket);
1311 * avoid the copy if same size block.
1312 * We are not agressive with boundary cases. Note that it might
1313 * (for a small number of cases) give false negative if
1314 * both new size and old one are in the bucket for
1315 * FIRST_BIG_POW2, but the new one is near the lower end.
1317 * We do not try to go to 1.5 times smaller bucket so far.
1319 if (nbytes > onb) incr = 1;
1321 #ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
1322 if ( /* This is a little bit pessimal if PACK_MALLOC: */
1323 nbytes > ( (onb >> 1) - M_OVERHEAD )
1324 # ifdef TWO_POT_OPTIMIZE
1325 || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
1328 #else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
1329 prev_bucket = ( (bucket > MAX_PACKED + 1)
1330 ? bucket - BUCKETS_PER_POW2
1332 if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
1333 #endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
1338 #ifdef STRESS_REALLOC
1339 || 1 /* always do it the hard way */
1342 else if (incr == 0) {
1346 * Record new allocated size of block and
1347 * bound space with magic numbers.
1349 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
1350 int i, nb = ovp->ov_size + 1;
1355 ASSERT(*((char *)((caddr_t)ovp + nb - RSLOP + i)) == RMAGIC_C, "chunk's tail overwrite");
1359 ASSERT(*(u_int *)((caddr_t)ovp + nb - RSLOP) == RMAGIC, "chunk's tail overwrite");
1361 * Convert amount of memory requested into
1362 * closest block size stored in hash buckets
1363 * which satisfies request. Account for
1364 * space used per block for accounting.
1366 nbytes += M_OVERHEAD;
1367 ovp->ov_size = nbytes - 1;
1368 if ((i = nbytes & 3)) {
1371 *((char *)((caddr_t)ovp + nbytes - RSLOP + i))
1374 nbytes = (nbytes + 3) &~ 3;
1375 *((u_int *)((caddr_t)ovp + nbytes - RSLOP)) = RMAGIC;
1379 MUTEX_UNLOCK(&PL_malloc_mutex);
1380 DEBUG_m(PerlIO_printf(Perl_debug_log,
1381 "0x%lx: (%05lu) realloc %ld bytes inplace\n",
1382 (unsigned long)res,(unsigned long)(PL_an++),
1384 } else if (incr == 1 && (cp - M_OVERHEAD == last_op)
1385 && (onb > (1 << LOG_OF_MIN_ARENA))) {
1386 MEM_SIZE require, newarena = nbytes, pow;
1389 POW2_OPTIMIZE_ADJUST(newarena);
1390 newarena = newarena + M_OVERHEAD;
1391 /* newarena = (newarena + 3) &~ 3; */
1392 shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
1393 pow = LOG_OF_MIN_ARENA + 1;
1394 /* apart from this loop, this is O(1) */
1395 while (shiftr >>= 1)
1397 newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
1398 require = newarena - onb - M_OVERHEAD;
1400 if (getpages_adjacent(require)) {
1401 #ifdef DEBUGGING_MSTATS
1403 nmalloc[pow * BUCKETS_PER_POW2]++;
1405 *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
1411 MUTEX_UNLOCK(&PL_malloc_mutex);
1412 DEBUG_m(PerlIO_printf(Perl_debug_log,
1413 "0x%lx: (%05lu) realloc %ld bytes the hard way\n",
1414 (unsigned long)cp,(unsigned long)(PL_an++),
1416 if ((res = (char*)malloc(nbytes)) == NULL)
1418 if (cp != res) /* common optimization */
1419 Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
1423 return ((Malloc_t)res);
1427 * Search ``srchlen'' elements of each free list for a block whose
1428 * header starts at ``freep''. If srchlen is -1 search the whole list.
1429 * Return bucket number, or -1 if not found.
1432 findbucket(union overhead *freep, int srchlen)
1434 register union overhead *p;
1437 for (i = 0; i < NBUCKETS; i++) {
1439 for (p = nextf[i]; p && j != srchlen; p = p->ov_next) {
1449 calloc(register size_t elements, register size_t size)
1451 long sz = elements * size;
1452 Malloc_t p = malloc(sz);
1455 memset((void*)p, 0, sz);
1461 malloced_size(void *p)
1463 union overhead *ovp = (union overhead *)
1464 ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
1465 int bucket = OV_INDEX(ovp);
1467 /* The caller wants to have a complete control over the chunk,
1468 disable the memory checking inside the chunk. */
1469 if (bucket <= MAX_SHORT_BUCKET) {
1470 MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
1471 ovp->ov_size = size + M_OVERHEAD - 1;
1472 *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RSLOP)) = RMAGIC;
1475 return BUCKET_SIZE_REAL(bucket);
1478 #ifdef DEBUGGING_MSTATS
1480 # ifdef BUCKETS_ROOT2
1481 # define MIN_EVEN_REPORT 6
1483 # define MIN_EVEN_REPORT MIN_BUCKET
1486 * mstats - print out statistics about malloc
1488 * Prints two lines of numbers, one showing the length of the free list
1489 * for each size category, the second showing the number of mallocs -
1490 * frees for each size category.
1493 dump_mstats(char *s)
1496 register union overhead *p;
1497 int topbucket=0, topbucket_ev=0, topbucket_odd=0, totfree=0, total=0;
1498 u_int nfree[NBUCKETS];
1499 int total_chain = 0;
1500 struct chunk_chain_s* nextchain = chunk_chain;
1502 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
1503 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
1506 totfree += nfree[i] * BUCKET_SIZE_REAL(i);
1507 total += nmalloc[i] * BUCKET_SIZE_REAL(i);
1509 i % 2 ? (topbucket_odd = i) : (topbucket_ev = i);
1514 PerlIO_printf(PerlIO_stderr(),
1515 "Memory allocation statistics %s (buckets %ld(%ld)..%ld(%ld)\n",
1517 (long)BUCKET_SIZE_REAL(MIN_BUCKET),
1518 (long)BUCKET_SIZE(MIN_BUCKET),
1519 (long)BUCKET_SIZE_REAL(topbucket), (long)BUCKET_SIZE(topbucket));
1520 PerlIO_printf(PerlIO_stderr(), "%8d free:", totfree);
1521 for (i = MIN_EVEN_REPORT; i <= topbucket; i += BUCKETS_PER_POW2) {
1522 PerlIO_printf(PerlIO_stderr(),
1523 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
1525 : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")),
1528 #ifdef BUCKETS_ROOT2
1529 PerlIO_printf(PerlIO_stderr(), "\n\t ");
1530 for (i = MIN_BUCKET + 1; i <= topbucket_odd; i += BUCKETS_PER_POW2) {
1531 PerlIO_printf(PerlIO_stderr(),
1532 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
1534 : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")),
1538 PerlIO_printf(PerlIO_stderr(), "\n%8d used:", total - totfree);
1539 for (i = MIN_EVEN_REPORT; i <= topbucket; i += BUCKETS_PER_POW2) {
1540 PerlIO_printf(PerlIO_stderr(),
1541 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
1543 : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")),
1544 nmalloc[i] - nfree[i]);
1546 #ifdef BUCKETS_ROOT2
1547 PerlIO_printf(PerlIO_stderr(), "\n\t ");
1548 for (i = MIN_BUCKET + 1; i <= topbucket_odd; i += BUCKETS_PER_POW2) {
1549 PerlIO_printf(PerlIO_stderr(),
1550 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
1552 : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")),
1553 nmalloc[i] - nfree[i]);
1557 total_chain += nextchain->size;
1558 nextchain = nextchain->next;
1560 PerlIO_printf(PerlIO_stderr(), "\nTotal sbrk(): %d/%d:%d. Odd ends: pad+heads+chain+tail: %d+%d+%d+%d.\n",
1561 goodsbrk + sbrk_slack, sbrks, sbrk_good, sbrk_slack,
1562 start_slack, total_chain, sbrked_remains);
1566 dump_mstats(char *s)
1573 #ifdef USE_PERL_SBRK
1575 # if defined(__MACHTEN_PPC__) || defined(__NeXT__)
1576 # define PERL_SBRK_VIA_MALLOC
1578 * MachTen's malloc() returns a buffer aligned on a two-byte boundary.
1579 * While this is adequate, it may slow down access to longer data
1580 * types by forcing multiple memory accesses. It also causes
1581 * complaints when RCHECK is in force. So we allocate six bytes
1582 * more than we need to, and return an address rounded up to an
1583 * eight-byte boundary.
1585 * 980701 Dominic Dunlop <domo@computer.org>
1587 # define SYSTEM_ALLOC(a) ((void *)(((unsigned)malloc((a)+6)+6)&~7))
1590 # ifdef PERL_SBRK_VIA_MALLOC
1591 # if defined(HIDEMYMALLOC) || defined(EMBEDMYMALLOC)
1592 # undef malloc /* Expose names that */
1593 # undef calloc /* HIDEMYMALLOC hides */
1597 # include "Error: -DPERL_SBRK_VIA_MALLOC needs -D(HIDE|EMBED)MYMALLOC"
1600 /* it may seem schizophrenic to use perl's malloc and let it call system */
1601 /* malloc, the reason for that is only the 3.2 version of the OS that had */
1602 /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
1603 /* end to the cores */
1605 # ifndef SYSTEM_ALLOC
1606 # define SYSTEM_ALLOC(a) malloc(a)
1609 # endif /* PERL_SBRK_VIA_MALLOC */
1611 static IV Perl_sbrk_oldchunk;
1612 static long Perl_sbrk_oldsize;
1614 # define PERLSBRK_32_K (1<<15)
1615 # define PERLSBRK_64_K (1<<16)
1623 if (!size) return 0;
1625 reqsize = size; /* just for the DEBUG_m statement */
1628 size = (size + 0x7ff) & ~0x7ff;
1630 if (size <= Perl_sbrk_oldsize) {
1631 got = Perl_sbrk_oldchunk;
1632 Perl_sbrk_oldchunk += size;
1633 Perl_sbrk_oldsize -= size;
1635 if (size >= PERLSBRK_32_K) {
1638 size = PERLSBRK_64_K;
1641 got = (IV)SYSTEM_ALLOC(size);
1643 got = (got + 0x7ff) & ~0x7ff;
1646 /* Chunk is small, register the rest for future allocs. */
1647 Perl_sbrk_oldchunk = got + reqsize;
1648 Perl_sbrk_oldsize = size - reqsize;
1652 DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%lx\n",
1653 size, reqsize, Perl_sbrk_oldsize, got));
1658 #endif /* ! defined USE_PERL_SBRK */