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) || defined(__MINT__))
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(__MINT__)) && 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 #ifdef MUTEX_INIT_CALLS_MALLOC
575 # define MUTEX_LOCK(m) STMT_START { if (*m) mutex_lock(*m); } STMT_END
577 # define MUTEX_UNLOCK(m) STMT_START { if (*m) mutex_unlock(*m); } STMT_END
580 static char *emergency_buffer;
581 static MEM_SIZE emergency_buffer_size;
582 static Malloc_t emergency_sbrk(MEM_SIZE size);
585 emergency_sbrk(MEM_SIZE size)
587 MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA;
589 if (size >= BIG_SIZE) {
590 /* Give the possibility to recover: */
591 MUTEX_UNLOCK(&PL_malloc_mutex);
592 croak("Out of memory during \"large\" request for %i bytes", size);
595 if (emergency_buffer_size >= rsize) {
596 char *old = emergency_buffer;
598 emergency_buffer_size -= rsize;
599 emergency_buffer += rsize;
603 /* First offense, give a possibility to recover by dieing. */
604 /* No malloc involved here: */
605 GV **gvp = (GV**)hv_fetch(PL_defstash, "^M", 2, 0);
611 if (emergency_buffer_size) {
612 add_to_chain(emergency_buffer, emergency_buffer_size, 0);
613 emergency_buffer_size = 0;
614 emergency_buffer = Nullch;
617 if (!gvp) gvp = (GV**)hv_fetch(PL_defstash, "\015", 1, 0);
618 if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv)
619 || (SvLEN(sv) < (1<<LOG_OF_MIN_ARENA) - M_OVERHEAD)) {
622 return (char *)-1; /* Now die die die... */
624 /* Got it, now detach SvPV: */
626 /* Check alignment: */
627 if (((UV)(pv - sizeof(union overhead))) & ((1<<LOG_OF_MIN_ARENA) - 1)) {
628 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
629 return (char *)-1; /* die die die */
632 emergency_buffer = pv - sizeof(union overhead);
633 emergency_buffer_size = malloced_size(pv) + M_OVERHEAD;
636 SvCUR(sv) = SvLEN(sv) = 0;
639 MUTEX_UNLOCK(&PL_malloc_mutex);
640 croak("Out of memory during request for %i bytes", size);
643 #else /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */
644 # define emergency_sbrk(size) -1
645 #endif /* !(defined(PERL_EMERGENCY_SBRK) && defined(PERL_CORE)) */
648 * nextf[i] is the pointer to the next free block of size 2^i. The
649 * smallest allocatable block is 8 bytes. The overhead information
650 * precedes the data area returned to the user.
652 #define NBUCKETS (32*BUCKETS_PER_POW2 + 1)
653 static union overhead *nextf[NBUCKETS];
656 #define sbrk(a) Perl_sbrk(a)
657 Malloc_t Perl_sbrk _((int size));
659 #ifdef DONT_DECLARE_STD
664 extern Malloc_t sbrk(int);
668 #ifdef DEBUGGING_MSTATS
670 * nmalloc[i] is the difference between the number of mallocs and frees
671 * for a given block size.
673 static u_int nmalloc[NBUCKETS];
674 static u_int sbrk_slack;
675 static u_int start_slack;
678 static u_int goodsbrk;
682 #define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p)); else
684 botch(char *diag, char *s)
686 PerlIO_printf(PerlIO_stderr(), "assertion botched (%s?): %s\n", diag, s);
690 #define ASSERT(p, diag)
694 malloc(register size_t nbytes)
696 register union overhead *p;
698 register MEM_SIZE shiftr;
700 #if defined(DEBUGGING) || defined(RCHECK)
701 MEM_SIZE size = nbytes;
704 BARK_64K_LIMIT("Allocation",nbytes,nbytes);
706 if ((long)nbytes < 0)
707 croak("%s", "panic: malloc");
710 MUTEX_LOCK(&PL_malloc_mutex);
712 * Convert amount of memory requested into
713 * closest block size stored in hash buckets
714 * which satisfies request. Account for
715 * space used per block for accounting.
718 # ifdef SMALL_BUCKET_VIA_TABLE
721 else if (nbytes <= SIZE_TABLE_MAX) {
722 bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
727 if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
732 POW2_OPTIMIZE_ADJUST(nbytes);
733 nbytes += M_OVERHEAD;
734 nbytes = (nbytes + 3) &~ 3;
736 shiftr = (nbytes - 1) >> START_SHIFT;
737 bucket = START_SHIFTS_BUCKET;
738 /* apart from this loop, this is O(1) */
740 bucket += BUCKETS_PER_POW2;
743 * If nothing in hash bucket right now,
744 * request more memory from the system.
746 if (nextf[bucket] == NULL)
748 if ((p = nextf[bucket]) == NULL) {
749 MUTEX_UNLOCK(&PL_malloc_mutex);
752 PerlIO_puts(PerlIO_stderr(),"Out of memory!\n");
760 DEBUG_m(PerlIO_printf(Perl_debug_log,
761 "0x%lx: (%05lu) malloc %ld bytes\n",
762 (unsigned long)(p+1), (unsigned long)(PL_an++),
765 /* remove from linked list */
767 if (((UV)p) & (MEM_ALIGNBYTES - 1))
768 PerlIO_printf(PerlIO_stderr(), "Corrupt malloc ptr 0x%lx at 0x%lx\n",
769 (unsigned long)*((int*)p),(unsigned long)p);
771 nextf[bucket] = p->ov_next;
772 #ifdef IGNORE_SMALL_BAD_FREE
773 if (bucket >= FIRST_BUCKET_WITH_CHECK)
775 OV_MAGIC(p, bucket) = MAGIC;
777 OV_INDEX(p) = bucket;
781 * Record allocated size of block and
782 * bound space with magic numbers.
784 p->ov_rmagic = RMAGIC;
785 if (bucket <= MAX_SHORT_BUCKET) {
788 nbytes = size + M_OVERHEAD;
789 p->ov_size = nbytes - 1;
790 if ((i = nbytes & 3)) {
793 *((char *)((caddr_t)p + nbytes - RSLOP + i)) = RMAGIC_C;
795 nbytes = (nbytes + 3) &~ 3;
796 *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
799 MUTEX_UNLOCK(&PL_malloc_mutex);
800 return ((Malloc_t)(p + CHUNK_SHIFT));
803 static char *last_sbrk_top;
804 static char *last_op; /* This arena can be easily extended. */
805 static int sbrked_remains;
806 static int sbrk_good = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE;
808 #ifdef DEBUGGING_MSTATS
812 struct chunk_chain_s {
813 struct chunk_chain_s *next;
816 static struct chunk_chain_s *chunk_chain;
818 static char max_bucket;
820 /* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */
822 get_from_chain(MEM_SIZE size)
824 struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
825 struct chunk_chain_s **oldgoodp = NULL;
826 long min_remain = LONG_MAX;
829 if (elt->size >= size) {
830 long remains = elt->size - size;
831 if (remains >= 0 && remains < min_remain) {
833 min_remain = remains;
839 oldp = &( elt->next );
842 if (!oldgoodp) return NULL;
844 void *ret = *oldgoodp;
845 struct chunk_chain_s *next = (*oldgoodp)->next;
847 *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
848 (*oldgoodp)->size = min_remain;
849 (*oldgoodp)->next = next;
852 void *ret = *oldgoodp;
853 *oldgoodp = (*oldgoodp)->next;
860 add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
862 struct chunk_chain_s *next = chunk_chain;
866 chunk_chain = (struct chunk_chain_s *)cp;
867 chunk_chain->size = size - chip;
868 chunk_chain->next = next;
873 get_from_bigger_buckets(int bucket, MEM_SIZE size)
876 static int bucketprice[NBUCKETS];
877 while (bucket <= max_bucket) {
878 /* We postpone stealing from bigger buckets until we want it
880 if (nextf[bucket] && bucketprice[bucket]++ >= price) {
882 void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
883 bucketprice[bucket] = 0;
884 if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
885 last_op = NULL; /* Disable optimization */
887 nextf[bucket] = nextf[bucket]->ov_next;
888 #ifdef DEBUGGING_MSTATS
890 start_slack -= M_OVERHEAD;
892 add_to_chain(ret, (BUCKET_SIZE(bucket) +
893 POW2_OPTIMIZE_SURPLUS(bucket)),
902 static union overhead *
903 getpages(int needed, int *nblksp, int bucket)
905 /* Need to do (possibly expensive) system call. Try to
906 optimize it for rare calling. */
907 MEM_SIZE require = needed - sbrked_remains;
913 if (!last_sbrk_top && require < FIRST_SBRK)
914 require = FIRST_SBRK;
915 else if (require < MIN_SBRK) require = MIN_SBRK;
917 if (require < goodsbrk * MIN_SBRK_FRAC / 100)
918 require = goodsbrk * MIN_SBRK_FRAC / 100;
919 require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
926 DEBUG_m(PerlIO_printf(Perl_debug_log,
927 "sbrk(%ld) for %ld-byte-long arena\n",
928 (long)require, (long) needed));
929 cp = (char *)sbrk(require);
930 #ifdef DEBUGGING_MSTATS
933 if (cp == last_sbrk_top) {
934 /* Common case, anything is fine. */
936 ovp = (union overhead *) (cp - sbrked_remains);
937 sbrked_remains = require - (needed - sbrked_remains);
938 } else if (cp == (char *)-1) { /* no more room! */
939 ovp = (union overhead *)emergency_sbrk(needed);
940 if (ovp == (union overhead *)-1)
943 } else { /* Non-continuous or first sbrk(). */
944 long add = sbrked_remains;
947 if (sbrked_remains) { /* Put rest into chain, we
948 cannot use it right now. */
949 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
953 /* Second, check alignment. */
956 #if !defined(atarist) && !defined(__MINT__) /* on the atari we dont have to worry about this */
957 # ifndef I286 /* The sbrk(0) call on the I286 always returns the next segment */
959 /* CHUNK_SHIFT is 1 for PACK_MALLOC, 0 otherwise. */
960 if ((UV)cp & (0x7FF >> CHUNK_SHIFT)) { /* Not aligned. */
961 slack = (0x800 >> CHUNK_SHIFT)
962 - ((UV)cp & (0x7FF >> CHUNK_SHIFT));
966 #endif /* !atarist && !MINT */
969 DEBUG_m(PerlIO_printf(Perl_debug_log,
970 "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",
971 (long)add, (long) slack,
972 (long) sbrked_remains));
973 newcp = (char *)sbrk(add);
974 #if defined(DEBUGGING_MSTATS)
978 if (newcp != cp + require) {
979 /* Too bad: even rounding sbrk() is not continuous.*/
980 DEBUG_m(PerlIO_printf(Perl_debug_log,
981 "failed to fix bad sbrk()\n"));
984 MUTEX_UNLOCK(&PL_malloc_mutex);
985 croak("%s", "panic: Off-page sbrk");
988 if (sbrked_remains) {
990 #if defined(DEBUGGING_MSTATS)
991 sbrk_slack += require;
994 DEBUG_m(PerlIO_printf(Perl_debug_log,
995 "straight sbrk(%ld)\n",
997 cp = (char *)sbrk(require);
998 #ifdef DEBUGGING_MSTATS
1001 if (cp == (char *)-1)
1004 sbrk_good = -1; /* Disable optimization!
1005 Continue with not-aligned... */
1008 require += sbrked_remains;
1012 if (last_sbrk_top) {
1013 sbrk_good -= SBRK_FAILURE_PRICE;
1016 ovp = (union overhead *) cp;
1018 * Round up to minimum allocation size boundary
1019 * and deduct from block count to reflect.
1022 #ifndef I286 /* Again, this should always be ok on an 80286 */
1024 ovp = (union overhead *)(((UV)ovp + 8) & ~7);
1025 DEBUG_m(PerlIO_printf(Perl_debug_log,
1026 "fixing sbrk(): %d bytes off machine alignement\n",
1027 (int)((UV)ovp & 7)));
1029 # if defined(DEBUGGING_MSTATS)
1030 /* This is only approx. if TWO_POT_OPTIMIZE: */
1031 sbrk_slack += (1 << bucket);
1035 sbrked_remains = require - needed;
1037 last_sbrk_top = cp + require;
1038 last_op = (char*) cp;
1039 #ifdef DEBUGGING_MSTATS
1040 goodsbrk += require;
1046 getpages_adjacent(int require)
1048 if (require <= sbrked_remains) {
1049 sbrked_remains -= require;
1053 require -= sbrked_remains;
1054 /* We do not try to optimize sbrks here, we go for place. */
1055 cp = (char*) sbrk(require);
1056 #ifdef DEBUGGING_MSTATS
1058 goodsbrk += require;
1060 if (cp == last_sbrk_top) {
1062 last_sbrk_top = cp + require;
1064 if (cp == (char*)-1) { /* Out of memory */
1065 #ifdef DEBUGGING_MSTATS
1066 goodsbrk -= require;
1070 /* Report the failure: */
1072 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1074 add_to_chain((void*)cp, require, 0);
1075 sbrk_good -= SBRK_FAILURE_PRICE;
1087 * Allocate more memory to the indicated bucket.
1090 morecore(register int bucket)
1092 register union overhead *ovp;
1093 register int rnu; /* 2^rnu bytes will be requested */
1094 int nblks; /* become nblks blocks of the desired size */
1095 register MEM_SIZE siz, needed;
1099 if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
1100 MUTEX_UNLOCK(&PL_malloc_mutex);
1101 croak("%s", "Out of memory during ridiculously large request");
1103 if (bucket > max_bucket)
1104 max_bucket = bucket;
1106 rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT))
1108 : (bucket >> BUCKET_POW2_SHIFT) );
1109 /* This may be overwritten later: */
1110 nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
1111 needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
1112 if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
1113 ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
1114 nextf[rnu << BUCKET_POW2_SHIFT]
1115 = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
1116 #ifdef DEBUGGING_MSTATS
1117 nmalloc[rnu << BUCKET_POW2_SHIFT]--;
1118 start_slack -= M_OVERHEAD;
1120 DEBUG_m(PerlIO_printf(Perl_debug_log,
1121 "stealing %ld bytes from %ld arena\n",
1122 (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
1123 } else if (chunk_chain
1124 && (ovp = (union overhead*) get_from_chain(needed))) {
1125 DEBUG_m(PerlIO_printf(Perl_debug_log,
1126 "stealing %ld bytes from chain\n",
1128 } else if ( (ovp = (union overhead*)
1129 get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
1131 DEBUG_m(PerlIO_printf(Perl_debug_log,
1132 "stealing %ld bytes from bigger buckets\n",
1134 } else if (needed <= sbrked_remains) {
1135 ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
1136 sbrked_remains -= needed;
1137 last_op = (char*)ovp;
1139 ovp = getpages(needed, &nblks, bucket);
1145 * Add new memory allocated to that on
1146 * free list for this hash bucket.
1148 siz = BUCKET_SIZE(bucket);
1150 *(u_char*)ovp = bucket; /* Fill index. */
1151 if (bucket <= MAX_PACKED) {
1152 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1153 nblks = N_BLKS(bucket);
1154 # ifdef DEBUGGING_MSTATS
1155 start_slack += BLK_SHIFT(bucket);
1157 } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
1158 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1159 siz -= sizeof(union overhead);
1160 } else ovp++; /* One chunk per block. */
1161 #endif /* PACK_MALLOC */
1162 nextf[bucket] = ovp;
1163 #ifdef DEBUGGING_MSTATS
1164 nmalloc[bucket] += nblks;
1165 if (bucket > MAX_PACKED) {
1166 start_slack += M_OVERHEAD * nblks;
1169 while (--nblks > 0) {
1170 ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
1171 ovp = (union overhead *)((caddr_t)ovp + siz);
1173 /* Not all sbrks return zeroed memory.*/
1174 ovp->ov_next = (union overhead *)NULL;
1176 if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
1177 union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
1178 nextf[7*BUCKETS_PER_POW2] =
1179 (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2]
1180 - sizeof(union overhead));
1181 nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
1183 #endif /* !PACK_MALLOC */
1189 register MEM_SIZE size;
1190 register union overhead *ovp;
1191 char *cp = (char*)mp;
1196 DEBUG_m(PerlIO_printf(Perl_debug_log,
1197 "0x%lx: (%05lu) free\n",
1198 (unsigned long)cp, (unsigned long)(PL_an++)));
1202 ovp = (union overhead *)((caddr_t)cp
1203 - sizeof (union overhead) * CHUNK_SHIFT);
1205 bucket = OV_INDEX(ovp);
1207 #ifdef IGNORE_SMALL_BAD_FREE
1208 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1209 && (OV_MAGIC(ovp, bucket) != MAGIC))
1211 if (OV_MAGIC(ovp, bucket) != MAGIC)
1214 static int bad_free_warn = -1;
1215 if (bad_free_warn == -1) {
1216 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1217 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1222 warn("%s free() ignored",
1223 ovp->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad");
1225 warn("%s", "Bad free() ignored");
1227 return; /* sanity */
1229 MUTEX_LOCK(&PL_malloc_mutex);
1231 ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
1232 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
1234 MEM_SIZE nbytes = ovp->ov_size + 1;
1236 if ((i = nbytes & 3)) {
1239 ASSERT(*((char *)((caddr_t)ovp + nbytes - RSLOP + i))
1240 == RMAGIC_C, "chunk's tail overwrite");
1243 nbytes = (nbytes + 3) &~ 3;
1244 ASSERT(*(u_int *)((caddr_t)ovp + nbytes - RSLOP) == RMAGIC, "chunk's tail overwrite");
1246 ovp->ov_rmagic = RMAGIC - 1;
1248 ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
1249 size = OV_INDEX(ovp);
1250 ovp->ov_next = nextf[size];
1252 MUTEX_UNLOCK(&PL_malloc_mutex);
1256 * When a program attempts "storage compaction" as mentioned in the
1257 * old malloc man page, it realloc's an already freed block. Usually
1258 * this is the last block it freed; occasionally it might be farther
1259 * back. We have to search all the free lists for the block in order
1260 * to determine its bucket: 1st we make one pass thru the lists
1261 * checking only the first block in each; if that fails we search
1262 * ``reall_srchlen'' blocks in each list for a match (the variable
1263 * is extern so the caller can modify it). If that fails we just copy
1264 * however many bytes was given to realloc() and hope it's not huge.
1266 int reall_srchlen = 4; /* 4 should be plenty, -1 =>'s whole list */
1269 realloc(void *mp, size_t nbytes)
1271 register MEM_SIZE onb;
1272 union overhead *ovp;
1275 register int bucket;
1276 int was_alloced = 0, incr;
1277 char *cp = (char*)mp;
1279 #if defined(DEBUGGING) || !defined(PERL_CORE)
1280 MEM_SIZE size = nbytes;
1282 if ((long)nbytes < 0)
1283 croak("%s", "panic: realloc");
1286 BARK_64K_LIMIT("Reallocation",nbytes,size);
1288 return malloc(nbytes);
1290 MUTEX_LOCK(&PL_malloc_mutex);
1291 ovp = (union overhead *)((caddr_t)cp
1292 - sizeof (union overhead) * CHUNK_SHIFT);
1293 bucket = OV_INDEX(ovp);
1294 #ifdef IGNORE_SMALL_BAD_FREE
1295 if ((bucket < FIRST_BUCKET_WITH_CHECK)
1296 || (OV_MAGIC(ovp, bucket) == MAGIC))
1298 if (OV_MAGIC(ovp, bucket) == MAGIC)
1304 * Already free, doing "compaction".
1306 * Search for the old block of memory on the
1307 * free list. First, check the most common
1308 * case (last element free'd), then (this failing)
1309 * the last ``reall_srchlen'' items free'd.
1310 * If all lookups fail, then assume the size of
1311 * the memory block being realloc'd is the
1312 * smallest possible.
1314 if ((bucket = findbucket(ovp, 1)) < 0 &&
1315 (bucket = findbucket(ovp, reall_srchlen)) < 0)
1318 onb = BUCKET_SIZE_REAL(bucket);
1320 * avoid the copy if same size block.
1321 * We are not agressive with boundary cases. Note that it might
1322 * (for a small number of cases) give false negative if
1323 * both new size and old one are in the bucket for
1324 * FIRST_BIG_POW2, but the new one is near the lower end.
1326 * We do not try to go to 1.5 times smaller bucket so far.
1328 if (nbytes > onb) incr = 1;
1330 #ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
1331 if ( /* This is a little bit pessimal if PACK_MALLOC: */
1332 nbytes > ( (onb >> 1) - M_OVERHEAD )
1333 # ifdef TWO_POT_OPTIMIZE
1334 || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
1337 #else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
1338 prev_bucket = ( (bucket > MAX_PACKED + 1)
1339 ? bucket - BUCKETS_PER_POW2
1341 if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
1342 #endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
1347 #ifdef STRESS_REALLOC
1348 || 1 /* always do it the hard way */
1351 else if (incr == 0) {
1355 * Record new allocated size of block and
1356 * bound space with magic numbers.
1358 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
1359 int i, nb = ovp->ov_size + 1;
1364 ASSERT(*((char *)((caddr_t)ovp + nb - RSLOP + i)) == RMAGIC_C, "chunk's tail overwrite");
1368 ASSERT(*(u_int *)((caddr_t)ovp + nb - RSLOP) == RMAGIC, "chunk's tail overwrite");
1370 * Convert amount of memory requested into
1371 * closest block size stored in hash buckets
1372 * which satisfies request. Account for
1373 * space used per block for accounting.
1375 nbytes += M_OVERHEAD;
1376 ovp->ov_size = nbytes - 1;
1377 if ((i = nbytes & 3)) {
1380 *((char *)((caddr_t)ovp + nbytes - RSLOP + i))
1383 nbytes = (nbytes + 3) &~ 3;
1384 *((u_int *)((caddr_t)ovp + nbytes - RSLOP)) = RMAGIC;
1388 MUTEX_UNLOCK(&PL_malloc_mutex);
1389 DEBUG_m(PerlIO_printf(Perl_debug_log,
1390 "0x%lx: (%05lu) realloc %ld bytes inplace\n",
1391 (unsigned long)res,(unsigned long)(PL_an++),
1393 } else if (incr == 1 && (cp - M_OVERHEAD == last_op)
1394 && (onb > (1 << LOG_OF_MIN_ARENA))) {
1395 MEM_SIZE require, newarena = nbytes, pow;
1398 POW2_OPTIMIZE_ADJUST(newarena);
1399 newarena = newarena + M_OVERHEAD;
1400 /* newarena = (newarena + 3) &~ 3; */
1401 shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
1402 pow = LOG_OF_MIN_ARENA + 1;
1403 /* apart from this loop, this is O(1) */
1404 while (shiftr >>= 1)
1406 newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
1407 require = newarena - onb - M_OVERHEAD;
1409 if (getpages_adjacent(require)) {
1410 #ifdef DEBUGGING_MSTATS
1412 nmalloc[pow * BUCKETS_PER_POW2]++;
1414 *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
1420 MUTEX_UNLOCK(&PL_malloc_mutex);
1421 DEBUG_m(PerlIO_printf(Perl_debug_log,
1422 "0x%lx: (%05lu) realloc %ld bytes the hard way\n",
1423 (unsigned long)cp,(unsigned long)(PL_an++),
1425 if ((res = (char*)malloc(nbytes)) == NULL)
1427 if (cp != res) /* common optimization */
1428 Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
1432 return ((Malloc_t)res);
1436 * Search ``srchlen'' elements of each free list for a block whose
1437 * header starts at ``freep''. If srchlen is -1 search the whole list.
1438 * Return bucket number, or -1 if not found.
1441 findbucket(union overhead *freep, int srchlen)
1443 register union overhead *p;
1446 for (i = 0; i < NBUCKETS; i++) {
1448 for (p = nextf[i]; p && j != srchlen; p = p->ov_next) {
1458 calloc(register size_t elements, register size_t size)
1460 long sz = elements * size;
1461 Malloc_t p = malloc(sz);
1464 memset((void*)p, 0, sz);
1470 malloced_size(void *p)
1472 union overhead *ovp = (union overhead *)
1473 ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
1474 int bucket = OV_INDEX(ovp);
1476 /* The caller wants to have a complete control over the chunk,
1477 disable the memory checking inside the chunk. */
1478 if (bucket <= MAX_SHORT_BUCKET) {
1479 MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
1480 ovp->ov_size = size + M_OVERHEAD - 1;
1481 *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RSLOP)) = RMAGIC;
1484 return BUCKET_SIZE_REAL(bucket);
1487 #ifdef DEBUGGING_MSTATS
1489 # ifdef BUCKETS_ROOT2
1490 # define MIN_EVEN_REPORT 6
1492 # define MIN_EVEN_REPORT MIN_BUCKET
1495 * mstats - print out statistics about malloc
1497 * Prints two lines of numbers, one showing the length of the free list
1498 * for each size category, the second showing the number of mallocs -
1499 * frees for each size category.
1502 dump_mstats(char *s)
1505 register union overhead *p;
1506 int topbucket=0, topbucket_ev=0, topbucket_odd=0, totfree=0, total=0;
1507 u_int nfree[NBUCKETS];
1508 int total_chain = 0;
1509 struct chunk_chain_s* nextchain = chunk_chain;
1511 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
1512 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
1515 totfree += nfree[i] * BUCKET_SIZE_REAL(i);
1516 total += nmalloc[i] * BUCKET_SIZE_REAL(i);
1518 i % 2 ? (topbucket_odd = i) : (topbucket_ev = i);
1523 PerlIO_printf(PerlIO_stderr(),
1524 "Memory allocation statistics %s (buckets %ld(%ld)..%ld(%ld)\n",
1526 (long)BUCKET_SIZE_REAL(MIN_BUCKET),
1527 (long)BUCKET_SIZE(MIN_BUCKET),
1528 (long)BUCKET_SIZE_REAL(topbucket), (long)BUCKET_SIZE(topbucket));
1529 PerlIO_printf(PerlIO_stderr(), "%8d free:", totfree);
1530 for (i = MIN_EVEN_REPORT; i <= topbucket; 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")),
1537 #ifdef BUCKETS_ROOT2
1538 PerlIO_printf(PerlIO_stderr(), "\n\t ");
1539 for (i = MIN_BUCKET + 1; i <= topbucket_odd; 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")),
1547 PerlIO_printf(PerlIO_stderr(), "\n%8d used:", total - totfree);
1548 for (i = MIN_EVEN_REPORT; i <= topbucket; 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]);
1555 #ifdef BUCKETS_ROOT2
1556 PerlIO_printf(PerlIO_stderr(), "\n\t ");
1557 for (i = MIN_BUCKET + 1; i <= topbucket_odd; i += BUCKETS_PER_POW2) {
1558 PerlIO_printf(PerlIO_stderr(),
1559 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
1561 : ((i < 12*BUCKETS_PER_POW2) ? " %3d" : " %d")),
1562 nmalloc[i] - nfree[i]);
1566 total_chain += nextchain->size;
1567 nextchain = nextchain->next;
1569 PerlIO_printf(PerlIO_stderr(), "\nTotal sbrk(): %d/%d:%d. Odd ends: pad+heads+chain+tail: %d+%d+%d+%d.\n",
1570 goodsbrk + sbrk_slack, sbrks, sbrk_good, sbrk_slack,
1571 start_slack, total_chain, sbrked_remains);
1575 dump_mstats(char *s)
1582 #ifdef USE_PERL_SBRK
1584 # if defined(__MACHTEN_PPC__) || defined(__NeXT__)
1585 # define PERL_SBRK_VIA_MALLOC
1587 * MachTen's malloc() returns a buffer aligned on a two-byte boundary.
1588 * While this is adequate, it may slow down access to longer data
1589 * types by forcing multiple memory accesses. It also causes
1590 * complaints when RCHECK is in force. So we allocate six bytes
1591 * more than we need to, and return an address rounded up to an
1592 * eight-byte boundary.
1594 * 980701 Dominic Dunlop <domo@computer.org>
1596 # define SYSTEM_ALLOC(a) ((void *)(((unsigned)malloc((a)+6)+6)&~7))
1599 # ifdef PERL_SBRK_VIA_MALLOC
1600 # if defined(HIDEMYMALLOC) || defined(EMBEDMYMALLOC)
1601 # undef malloc /* Expose names that */
1602 # undef calloc /* HIDEMYMALLOC hides */
1606 # include "Error: -DPERL_SBRK_VIA_MALLOC needs -D(HIDE|EMBED)MYMALLOC"
1609 /* it may seem schizophrenic to use perl's malloc and let it call system */
1610 /* malloc, the reason for that is only the 3.2 version of the OS that had */
1611 /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
1612 /* end to the cores */
1614 # ifndef SYSTEM_ALLOC
1615 # define SYSTEM_ALLOC(a) malloc(a)
1618 # endif /* PERL_SBRK_VIA_MALLOC */
1620 static IV Perl_sbrk_oldchunk;
1621 static long Perl_sbrk_oldsize;
1623 # define PERLSBRK_32_K (1<<15)
1624 # define PERLSBRK_64_K (1<<16)
1632 if (!size) return 0;
1634 reqsize = size; /* just for the DEBUG_m statement */
1637 size = (size + 0x7ff) & ~0x7ff;
1639 if (size <= Perl_sbrk_oldsize) {
1640 got = Perl_sbrk_oldchunk;
1641 Perl_sbrk_oldchunk += size;
1642 Perl_sbrk_oldsize -= size;
1644 if (size >= PERLSBRK_32_K) {
1647 size = PERLSBRK_64_K;
1650 got = (IV)SYSTEM_ALLOC(size);
1652 got = (got + 0x7ff) & ~0x7ff;
1655 /* Chunk is small, register the rest for future allocs. */
1656 Perl_sbrk_oldchunk = got + reqsize;
1657 Perl_sbrk_oldsize = size - reqsize;
1661 DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%lx\n",
1662 size, reqsize, Perl_sbrk_oldsize, got));
1667 #endif /* ! defined USE_PERL_SBRK */