6 * "'The Chamber of Records,' said Gimli. 'I guess that is where we now stand.'"
10 Here are some notes on configuring Perl's malloc. (For non-perl
13 There are two macros which serve as bulk disablers of advanced
14 features of this malloc: NO_FANCY_MALLOC, PLAIN_MALLOC (undef by
15 default). Look in the list of default values below to understand
16 their exact effect. Defining NO_FANCY_MALLOC returns malloc.c to the
17 state of the malloc in Perl 5.004. Additionally defining PLAIN_MALLOC
18 returns it to the state as of Perl 5.000.
20 Note that some of the settings below may be ignored in the code based
21 on values of other macros. The PERL_CORE symbol is only defined when
22 perl itself is being compiled (so malloc can make some assumptions
23 about perl's facilities being available to it).
25 Each config option has a short description, followed by its name,
26 default value, and a comment about the default (if applicable). Some
27 options take a precise value, while the others are just boolean.
28 The boolean ones are listed first.
30 # Read configuration settings from malloc_cfg.h
31 HAVE_MALLOC_CFG_H undef
33 # Enable code for an emergency memory pool in $^M. See perlvar.pod
34 # for a description of $^M.
35 PERL_EMERGENCY_SBRK (!PLAIN_MALLOC && (PERL_CORE || !NO_MALLOC_DYNAMIC_CFG))
37 # Enable code for printing memory statistics.
38 DEBUGGING_MSTATS (!PLAIN_MALLOC && PERL_CORE)
40 # Move allocation info for small buckets into separate areas.
41 # Memory optimization (especially for small allocations, of the
42 # less than 64 bytes). Since perl usually makes a large number
43 # of small allocations, this is usually a win.
44 PACK_MALLOC (!PLAIN_MALLOC && !RCHECK)
46 # Add one page to big powers of two when calculating bucket size.
47 # This is targeted at big allocations, as are common in image
49 TWO_POT_OPTIMIZE !PLAIN_MALLOC
51 # Use intermediate bucket sizes between powers-of-two. This is
52 # generally a memory optimization, and a (small) speed pessimization.
53 BUCKETS_ROOT2 !NO_FANCY_MALLOC
55 # Do not check small deallocations for bad free(). Memory
56 # and speed optimization, error reporting pessimization.
57 IGNORE_SMALL_BAD_FREE (!NO_FANCY_MALLOC && !RCHECK)
59 # Use table lookup to decide in which bucket a given allocation will go.
60 SMALL_BUCKET_VIA_TABLE !NO_FANCY_MALLOC
62 # Use a perl-defined sbrk() instead of the (presumably broken or
63 # missing) system-supplied sbrk().
66 # Use system malloc() (or calloc() etc.) to emulate sbrk(). Normally
67 # only used with broken sbrk()s.
68 PERL_SBRK_VIA_MALLOC undef
70 # Which allocator to use if PERL_SBRK_VIA_MALLOC
71 SYSTEM_ALLOC(a) malloc(a)
73 # Minimal alignment (in bytes, should be a power of 2) of SYSTEM_ALLOC
74 SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
76 # Disable memory overwrite checking with DEBUGGING. Memory and speed
77 # optimization, error reporting pessimization.
80 # Enable memory overwrite checking with DEBUGGING. Memory and speed
81 # pessimization, error reporting optimization
82 RCHECK (DEBUGGING && !NO_RCHECK)
84 # Do not overwrite uninit areas with DEBUGGING. Speed
85 # optimization, error reporting pessimization
88 # Overwrite uninit areas with DEBUGGING. Speed
89 # pessimization, error reporting optimization
90 MALLOC_FILL (DEBUGGING && !NO_RCHECK && !NO_MFILL)
92 # Do not check overwritten uninit areas with DEBUGGING. Speed
93 # optimization, error reporting pessimization
96 # Check overwritten uninit areas with DEBUGGING. Speed
97 # pessimization, error reporting optimization
98 MALLOC_FILL_CHECK (DEBUGGING && !NO_RCHECK && !NO_FILL_CHECK)
100 # Failed allocations bigger than this size croak (if
101 # PERL_EMERGENCY_SBRK is enabled) without touching $^M. See
102 # perlvar.pod for a description of $^M.
103 BIG_SIZE (1<<16) # 64K
105 # Starting from this power of two, add an extra page to the
106 # size of the bucket. This enables optimized allocations of sizes
107 # close to powers of 2. Note that the value is indexed at 0.
108 FIRST_BIG_POW2 15 # 32K, 16K is used too often
110 # Estimate of minimal memory footprint. malloc uses this value to
111 # request the most reasonable largest blocks of memory from the system.
114 # Round up sbrk()s to multiples of this.
117 # Round up sbrk()s to multiples of this percent of footprint.
120 # Round up sbrk()s to multiples of this multiple of 1/1000 of footprint.
121 MIN_SBRK_FRAC1000 (10 * MIN_SBRK_FRAC)
123 # Add this much memory to big powers of two to get the bucket size.
126 # This many sbrk() discontinuities should be tolerated even
127 # from the start without deciding that sbrk() is usually
129 SBRK_ALLOW_FAILURES 3
131 # This many continuous sbrk()s compensate for one discontinuous one.
132 SBRK_FAILURE_PRICE 50
134 # Some configurations may ask for 12-byte-or-so allocations which
135 # require 8-byte alignment (?!). In such situation one needs to
136 # define this to disable 12-byte bucket (will increase memory footprint)
137 STRICT_ALIGNMENT undef
139 # Do not allow configuration of runtime options at runtime
140 NO_MALLOC_DYNAMIC_CFG undef
142 # Do not allow configuration of runtime options via $ENV{PERL_MALLOC_OPT}
143 NO_PERL_MALLOC_ENV undef
145 [The variable consists of ;-separated parts of the form CODE=VALUE
146 with 1-character codes F, M, f, A, P, G, d, a, c for runtime
147 configuration of FIRST_SBRK, MIN_SBRK, MIN_SBRK_FRAC1000,
148 SBRK_ALLOW_FAILURES, SBRK_FAILURE_PRICE, sbrk_goodness,
149 filldead, fillalive, fillcheck. The last 3 are for DEBUGGING
150 build, and allow switching the tests for free()ed memory read,
151 uninit memory reads, and free()ed memory write.]
153 This implementation assumes that calling PerlIO_printf() does not
154 result in any memory allocation calls (used during a panic).
159 If used outside of Perl environment, it may be useful to redefine
160 the following macros (listed below with defaults):
162 # Type of address returned by allocation functions
165 # Type of size argument for allocation functions
166 MEM_SIZE unsigned long
171 # Maximal value in LONG
174 # Unsigned integer type big enough to keep a pointer
177 # Signed integer of the same sizeof() as UV
180 # Type of pointer with 1-byte granularity
183 # Type returned by free()
186 # Conversion of pointer to integer
187 PTR2UV(ptr) ((UV)(ptr))
189 # Conversion of integer to pointer
190 INT2PTR(type, i) ((type)(i))
192 # printf()-%-Conversion of UV to pointer
195 # printf()-%-Conversion of UV to hex pointer
201 # Very fatal condition reporting function (cannot call any )
202 fatalcroak(arg) write(2,arg,strlen(arg)) + exit(2)
204 # Fatal error reporting function
205 croak(format, arg) warn(idem) + exit(1)
207 # Fatal error reporting function
208 croak2(format, arg1, arg2) warn2(idem) + exit(1)
210 # Error reporting function
211 warn(format, arg) fprintf(stderr, idem)
213 # Error reporting function
214 warn2(format, arg1, arg2) fprintf(stderr, idem)
216 # Locking/unlocking for MT operation
217 MALLOC_LOCK MUTEX_LOCK(&PL_malloc_mutex)
218 MALLOC_UNLOCK MUTEX_UNLOCK(&PL_malloc_mutex)
220 # Locking/unlocking mutex for MT operation
225 #ifdef HAVE_MALLOC_CFG_H
226 # include "malloc_cfg.h"
229 #ifndef NO_FANCY_MALLOC
230 # ifndef SMALL_BUCKET_VIA_TABLE
231 # define SMALL_BUCKET_VIA_TABLE
233 # ifndef BUCKETS_ROOT2
234 # define BUCKETS_ROOT2
236 # ifndef IGNORE_SMALL_BAD_FREE
237 # define IGNORE_SMALL_BAD_FREE
241 #ifndef PLAIN_MALLOC /* Bulk enable features */
245 # ifndef TWO_POT_OPTIMIZE
246 # define TWO_POT_OPTIMIZE
248 # if (defined(PERL_CORE) || !defined(NO_MALLOC_DYNAMIC_CFG)) && !defined(PERL_EMERGENCY_SBRK)
249 # define PERL_EMERGENCY_SBRK
251 # if defined(PERL_CORE) && !defined(DEBUGGING_MSTATS)
252 # define DEBUGGING_MSTATS
256 #define MIN_BUC_POW2 (sizeof(void*) > 4 ? 3 : 2) /* Allow for 4-byte arena. */
257 #define MIN_BUCKET (MIN_BUC_POW2 * BUCKETS_PER_POW2)
259 #if !(defined(I286) || defined(atarist) || defined(__MINT__))
260 /* take 2k unless the block is bigger than that */
261 # define LOG_OF_MIN_ARENA 11
263 /* take 16k unless the block is bigger than that
264 (80286s like large segments!), probably good on the atari too */
265 # define LOG_OF_MIN_ARENA 14
269 # if defined(DEBUGGING) && !defined(NO_RCHECK)
272 # if defined(DEBUGGING) && !defined(NO_RCHECK) && !defined(NO_MFILL) && !defined(MALLOC_FILL)
275 # if defined(DEBUGGING) && !defined(NO_RCHECK) && !defined(NO_FILL_CHECK) && !defined(MALLOC_FILL_CHECK)
276 # define MALLOC_FILL_CHECK
278 # if defined(RCHECK) && defined(IGNORE_SMALL_BAD_FREE)
279 # undef IGNORE_SMALL_BAD_FREE
282 * malloc.c (Caltech) 2/21/82
283 * Chris Kingsley, kingsley@cit-20.
285 * This is a very fast storage allocator. It allocates blocks of a small
286 * number of different sizes, and keeps free lists of each size. Blocks that
287 * don't exactly fit are passed up to the next larger size. In this
288 * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
289 * If PACK_MALLOC is defined, small blocks are 2^n bytes long.
290 * This is designed for use in a program that uses vast quantities of memory,
291 * but bombs when it runs out.
293 * Modifications Copyright Ilya Zakharevich 1996-99.
295 * Still very quick, but much more thrifty. (Std config is 10% slower
296 * than it was, and takes 67% of old heap size for typical usage.)
298 * Allocations of small blocks are now table-driven to many different
299 * buckets. Sizes of really big buckets are increased to accomodata
300 * common size=power-of-2 blocks. Running-out-of-memory is made into
301 * an exception. Deeply configurable and thread-safe.
307 # define PERL_IN_MALLOC_C
309 # if defined(PERL_IMPLICIT_CONTEXT)
310 # define croak Perl_croak_nocontext
311 # define croak2 Perl_croak_nocontext
312 # define warn Perl_warn_nocontext
313 # define warn2 Perl_warn_nocontext
315 # define croak2 croak
318 # if defined(USE_5005THREADS) || defined(USE_ITHREADS)
319 # define PERL_MAYBE_ALIVE PL_thr_key
321 # define PERL_MAYBE_ALIVE 1
325 # include "../EXTERN.h"
326 # include "../perl.h"
336 # define Malloc_t void *
342 # define MEM_SIZE unsigned long
345 # define LONG_MAX 0x7FFFFFFF
348 # define UV unsigned long
354 # define caddr_t char *
359 # define Copy(s,d,n,t) (void)memcpy((char*)(d),(char*)(s), (n) * sizeof(t))
360 # define PerlEnv_getenv getenv
361 # define PerlIO_printf fprintf
362 # define PerlIO_stderr() stderr
363 # define PerlIO_puts(f,s) fputs(s,f)
365 # define INT2PTR(t,i) ((t)(i))
368 # define PTR2UV(p) ((UV)(p))
379 # ifndef MEM_ALIGNBYTES
380 # define MEM_ALIGNBYTES 4
383 # ifndef croak /* make depend */
384 # define croak(mess, arg) (warn((mess), (arg)), exit(1))
386 # ifndef croak2 /* make depend */
387 # define croak2(mess, arg1, arg2) (warn2((mess), (arg1), (arg2)), exit(1))
390 # define warn(mess, arg) fprintf(stderr, (mess), (arg))
393 # define warn2(mess, arg1, arg2) fprintf(stderr, (mess), (arg1), (arg2))
406 # define dTHX extern int Perl___notused PERL_UNUSED_DECL
408 # define dTHX extern int Perl___notused
410 # define WITH_THX(s) s
412 # ifndef PERL_GET_INTERP
413 # define PERL_GET_INTERP PL_curinterp
415 # define PERL_MAYBE_ALIVE 1
417 # define Perl_malloc malloc
420 # define Perl_mfree free
422 # ifndef Perl_realloc
423 # define Perl_realloc realloc
426 # define Perl_calloc calloc
429 # define Perl_strdup strdup
431 #endif /* defined PERL_CORE */
434 # define MUTEX_LOCK(l)
438 # define MUTEX_UNLOCK(l)
442 # define MALLOC_LOCK MUTEX_LOCK(&PL_malloc_mutex)
445 #ifndef MALLOC_UNLOCK
446 # define MALLOC_UNLOCK MUTEX_UNLOCK(&PL_malloc_mutex)
449 # ifndef fatalcroak /* make depend */
450 # define fatalcroak(mess) (write(2, (mess), strlen(mess)), exit(2))
455 # define DEBUG_m(a) \
457 if (PERL_MAYBE_ALIVE && PERL_GET_THX) { \
459 if (DEBUG_m_TEST) { \
460 PL_debug &= ~DEBUG_m_FLAG; \
462 PL_debug |= DEBUG_m_FLAG; \
468 #ifdef PERL_IMPLICIT_CONTEXT
469 # define PERL_IS_ALIVE aTHX
471 # define PERL_IS_ALIVE TRUE
478 * The memory is broken into "blocks" which occupy multiples of 2K (and
479 * generally speaking, have size "close" to a power of 2). The addresses
480 * of such *unused* blocks are kept in nextf[i] with big enough i. (nextf
481 * is an array of linked lists.) (Addresses of used blocks are not known.)
483 * Moreover, since the algorithm may try to "bite" smaller blocks out
484 * of unused bigger ones, there are also regions of "irregular" size,
485 * managed separately, by a linked list chunk_chain.
487 * The third type of storage is the sbrk()ed-but-not-yet-used space, its
488 * end and size are kept in last_sbrk_top and sbrked_remains.
490 * Growing blocks "in place":
491 * ~~~~~~~~~~~~~~~~~~~~~~~~~
492 * The address of the block with the greatest address is kept in last_op
493 * (if not known, last_op is 0). If it is known that the memory above
494 * last_op is not continuous, or contains a chunk from chunk_chain,
495 * last_op is set to 0.
497 * The chunk with address last_op may be grown by expanding into
498 * sbrk()ed-but-not-yet-used space, or trying to sbrk() more continuous
501 * Management of last_op:
502 * ~~~~~~~~~~~~~~~~~~~~~
504 * free() never changes the boundaries of blocks, so is not relevant.
506 * The only way realloc() may change the boundaries of blocks is if it
507 * grows a block "in place". However, in the case of success such a
508 * chunk is automatically last_op, and it remains last_op. In the case
509 * of failure getpages_adjacent() clears last_op.
511 * malloc() may change blocks by calling morecore() only.
513 * morecore() may create new blocks by:
514 * a) biting pieces from chunk_chain (cannot create one above last_op);
515 * b) biting a piece from an unused block (if block was last_op, this
516 * may create a chunk from chain above last_op, thus last_op is
517 * invalidated in such a case).
518 * c) biting of sbrk()ed-but-not-yet-used space. This creates
519 * a block which is last_op.
520 * d) Allocating new pages by calling getpages();
522 * getpages() creates a new block. It marks last_op at the bottom of
523 * the chunk of memory it returns.
525 * Active pages footprint:
526 * ~~~~~~~~~~~~~~~~~~~~~~
527 * Note that we do not need to traverse the lists in nextf[i], just take
528 * the first element of this list. However, we *need* to traverse the
529 * list in chunk_chain, but most the time it should be a very short one,
530 * so we do not step on a lot of pages we are not going to use.
534 * get_from_bigger_buckets(): forget to increment price => Quite
538 /* I don't much care whether these are defined in sys/types.h--LAW */
540 #define u_char unsigned char
541 #define u_int unsigned int
543 * I removed the definition of u_bigint which appeared to be u_bigint = UV
544 * u_bigint was only used in TWOK_MASKED and TWOK_SHIFT
545 * where I have used PTR2UV. RMB
547 #define u_short unsigned short
549 /* 286 and atarist like big chunks, which gives too much overhead. */
550 #if (defined(RCHECK) || defined(I286) || defined(atarist) || defined(__MINT__)) && defined(PACK_MALLOC)
555 * The description below is applicable if PACK_MALLOC is not defined.
557 * The overhead on a block is at least 4 bytes. When free, this space
558 * contains a pointer to the next free block, and the bottom two bits must
559 * be zero. When in use, the first byte is set to MAGIC, and the second
560 * byte is the size index. The remaining bytes are for alignment.
561 * If range checking is enabled and the size of the block fits
562 * in two bytes, then the top two bytes hold the size of the requested block
563 * plus the range checking words, and the header word MINUS ONE.
566 union overhead *ov_next; /* when free */
567 #if MEM_ALIGNBYTES > 4
568 double strut; /* alignment problems */
572 * Keep the ovu_index and ovu_magic in this order, having a char
573 * field first gives alignment indigestion in some systems, such as
576 u_char ovu_index; /* bucket # */
577 u_char ovu_magic; /* magic number */
579 u_short ovu_size; /* block size (requested + overhead - 1) */
580 u_int ovu_rmagic; /* range magic number */
583 #define ov_magic ovu.ovu_magic
584 #define ov_index ovu.ovu_index
585 #define ov_size ovu.ovu_size
586 #define ov_rmagic ovu.ovu_rmagic
589 #define MAGIC 0xff /* magic # on accounting info */
590 #define RMAGIC 0x55555555 /* magic # on range info */
591 #define RMAGIC_C 0x55 /* magic # on range info */
594 # define RSLOP sizeof (u_int)
595 # ifdef TWO_POT_OPTIMIZE
596 # define MAX_SHORT_BUCKET (12 * BUCKETS_PER_POW2) /* size-1 fits in short */
598 # define MAX_SHORT_BUCKET (13 * BUCKETS_PER_POW2)
604 #if !defined(PACK_MALLOC) && defined(BUCKETS_ROOT2)
605 # undef BUCKETS_ROOT2
609 # define BUCKET_TABLE_SHIFT 2
610 # define BUCKET_POW2_SHIFT 1
611 # define BUCKETS_PER_POW2 2
613 # define BUCKET_TABLE_SHIFT MIN_BUC_POW2
614 # define BUCKET_POW2_SHIFT 0
615 # define BUCKETS_PER_POW2 1
618 #if !defined(MEM_ALIGNBYTES) || ((MEM_ALIGNBYTES > 4) && !defined(STRICT_ALIGNMENT))
619 /* Figure out the alignment of void*. */
624 # define ALIGN_SMALL ((int)((caddr_t)&(((struct aligner*)0)->p)))
626 # define ALIGN_SMALL MEM_ALIGNBYTES
629 #define IF_ALIGN_8(yes,no) ((ALIGN_SMALL>4) ? (yes) : (no))
632 # define MAX_BUCKET_BY_TABLE 13
633 static u_short buck_size[MAX_BUCKET_BY_TABLE + 1] =
635 0, 0, 0, 0, 4, 4, 8, 12, 16, 24, 32, 48, 64, 80,
637 # define BUCKET_SIZE(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT)))
638 # define BUCKET_SIZE_REAL(i) ((i) <= MAX_BUCKET_BY_TABLE \
640 : ((1 << ((i) >> BUCKET_POW2_SHIFT)) \
642 + POW2_OPTIMIZE_SURPLUS(i)))
644 # define BUCKET_SIZE(i) (1 << ((i) >> BUCKET_POW2_SHIFT))
645 # define BUCKET_SIZE_REAL(i) (BUCKET_SIZE(i) - MEM_OVERHEAD(i) + POW2_OPTIMIZE_SURPLUS(i))
650 /* In this case there are several possible layout of arenas depending
651 * on the size. Arenas are of sizes multiple to 2K, 2K-aligned, and
652 * have a size close to a power of 2.
654 * Arenas of the size >= 4K keep one chunk only. Arenas of size 2K
655 * may keep one chunk or multiple chunks. Here are the possible
658 * # One chunk only, chunksize 2^k + SOMETHING - ALIGN, k >= 11
660 * INDEX MAGIC1 UNUSED CHUNK1
662 * # Multichunk with sanity checking and chunksize 2^k-ALIGN, k>7
664 * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 CHUNK2 CHUNK3 ...
666 * # Multichunk with sanity checking and size 2^k-ALIGN, k=7
668 * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 UNUSED CHUNK2 CHUNK3 ...
670 * # Multichunk with sanity checking and size up to 80
672 * INDEX UNUSED MAGIC1 UNUSED MAGIC2 UNUSED ... CHUNK1 CHUNK2 CHUNK3 ...
674 * # No sanity check (usually up to 48=byte-long buckets)
675 * INDEX UNUSED CHUNK1 CHUNK2 ...
677 * Above INDEX and MAGIC are one-byte-long. Sizes of UNUSED are
678 * appropriate to keep algorithms simple and memory aligned. INDEX
679 * encodes the size of the chunk, while MAGICn encodes state (used,
680 * free or non-managed-by-us-so-it-indicates-a-bug) of CHUNKn. MAGIC
681 * is used for sanity checking purposes only. SOMETHING is 0 or 4K
682 * (to make size of big CHUNK accomodate allocations for powers of two
685 * [There is no need to alignment between chunks, since C rules ensure
686 * that structs which need 2^k alignment have sizeof which is
687 * divisible by 2^k. Thus as far as the last chunk is aligned at the
688 * end of the arena, and 2K-alignment does not contradict things,
689 * everything is going to be OK for sizes of chunks 2^n and 2^n +
690 * 2^k. Say, 80-bit buckets will be 16-bit aligned, and as far as we
691 * put allocations for requests in 65..80 range, all is fine.
693 * Note, however, that standard malloc() puts more strict
694 * requirements than the above C rules. Moreover, our algorithms of
695 * realloc() may break this idyll, but we suppose that realloc() does
696 * need not change alignment.]
698 * Is very important to make calculation of the offset of MAGICm as
699 * quick as possible, since it is done on each malloc()/free(). In
700 * fact it is so quick that it has quite little effect on the speed of
701 * doing malloc()/free(). [By default] We forego such calculations
702 * for small chunks, but only to save extra 3% of memory, not because
703 * of speed considerations.
705 * Here is the algorithm [which is the same for all the allocations
706 * schemes above], see OV_MAGIC(block,bucket). Let OFFSETm be the
707 * offset of the CHUNKm from the start of ARENA. Then offset of
708 * MAGICm is (OFFSET1 >> SHIFT) + ADDOFFSET. Here SHIFT and ADDOFFSET
709 * are numbers which depend on the size of the chunks only.
711 * Let as check some sanity conditions. Numbers OFFSETm>>SHIFT are
712 * different for all the chunks in the arena if 2^SHIFT is not greater
713 * than size of the chunks in the arena. MAGIC1 will not overwrite
714 * INDEX provided ADDOFFSET is >0 if OFFSET1 < 2^SHIFT. MAGIClast
715 * will not overwrite CHUNK1 if OFFSET1 > (OFFSETlast >> SHIFT) +
718 * Make SHIFT the maximal possible (there is no point in making it
719 * smaller). Since OFFSETlast is 2K - CHUNKSIZE, above restrictions
720 * give restrictions on OFFSET1 and on ADDOFFSET.
722 * In particular, for chunks of size 2^k with k>=6 we can put
723 * ADDOFFSET to be from 0 to 2^k - 2^(11-k), and have
724 * OFFSET1==chunksize. For chunks of size 80 OFFSET1 of 2K%80=48 is
725 * large enough to have ADDOFFSET between 1 and 16 (similarly for 96,
726 * when ADDOFFSET should be 1). In particular, keeping MAGICs for
727 * these sizes gives no additional size penalty.
729 * However, for chunks of size 2^k with k<=5 this gives OFFSET1 >=
730 * ADDOFSET + 2^(11-k). Keeping ADDOFFSET 0 allows for 2^(11-k)-2^(11-2k)
731 * chunks per arena. This is smaller than 2^(11-k) - 1 which are
732 * needed if no MAGIC is kept. [In fact, having a negative ADDOFFSET
733 * would allow for slightly more buckets per arena for k=2,3.]
735 * Similarly, for chunks of size 3/2*2^k with k<=5 MAGICs would span
736 * the area up to 2^(11-k)+ADDOFFSET. For k=4 this give optimal
737 * ADDOFFSET as -7..0. For k=3 ADDOFFSET can go up to 4 (with tiny
738 * savings for negative ADDOFFSET). For k=5 ADDOFFSET can go -1..16
739 * (with no savings for negative values).
741 * In particular, keeping ADDOFFSET 0 for sizes of chunks up to 2^6
742 * leads to tiny pessimizations in case of sizes 4, 8, 12, 24, and
743 * leads to no contradictions except for size=80 (or 96.)
745 * However, it also makes sense to keep no magic for sizes 48 or less.
746 * This is what we do. In this case one needs ADDOFFSET>=1 also for
747 * chunksizes 12, 24, and 48, unless one gets one less chunk per
750 * The algo of OV_MAGIC(block,bucket) keeps ADDOFFSET 0 until
751 * chunksize of 64, then makes it 1.
753 * This allows for an additional optimization: the above scheme leads
754 * to giant overheads for sizes 128 or more (one whole chunk needs to
755 * be sacrifised to keep INDEX). Instead we use chunks not of size
756 * 2^k, but of size 2^k-ALIGN. If we pack these chunks at the end of
757 * the arena, then the beginnings are still in different 2^k-long
758 * sections of the arena if k>=7 for ALIGN==4, and k>=8 if ALIGN=8.
759 * Thus for k>7 the above algo of calculating the offset of the magic
760 * will still give different answers for different chunks. And to
761 * avoid the overrun of MAGIC1 into INDEX, one needs ADDOFFSET of >=1.
762 * In the case k=7 we just move the first chunk an extra ALIGN
763 * backward inside the ARENA (this is done once per arena lifetime,
764 * thus is not a big overhead). */
765 # define MAX_PACKED_POW2 6
766 # define MAX_PACKED (MAX_PACKED_POW2 * BUCKETS_PER_POW2 + BUCKET_POW2_SHIFT)
767 # define MAX_POW2_ALGO ((1<<(MAX_PACKED_POW2 + 1)) - M_OVERHEAD)
768 # define TWOK_MASK ((1<<LOG_OF_MIN_ARENA) - 1)
769 # define TWOK_MASKED(x) (PTR2UV(x) & ~TWOK_MASK)
770 # define TWOK_SHIFT(x) (PTR2UV(x) & TWOK_MASK)
771 # define OV_INDEXp(block) (INT2PTR(u_char*,TWOK_MASKED(block)))
772 # define OV_INDEX(block) (*OV_INDEXp(block))
773 # define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) + \
774 (TWOK_SHIFT(block)>> \
775 (bucket>>BUCKET_POW2_SHIFT)) + \
776 (bucket >= MIN_NEEDS_SHIFT ? 1 : 0)))
777 /* A bucket can have a shift smaller than it size, we need to
778 shift its magic number so it will not overwrite index: */
779 # ifdef BUCKETS_ROOT2
780 # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2 - 1) /* Shift 80 greater than chunk 64. */
782 # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2) /* Shift 128 greater than chunk 32. */
784 # define CHUNK_SHIFT 0
786 /* Number of active buckets of given ordinal. */
787 #ifdef IGNORE_SMALL_BAD_FREE
788 #define FIRST_BUCKET_WITH_CHECK (6 * BUCKETS_PER_POW2) /* 64 */
789 # define N_BLKS(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
790 ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE(bucket) \
793 # define N_BLKS(bucket) n_blks[bucket]
796 static u_short n_blks[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
798 # if BUCKETS_PER_POW2==1
800 (MIN_BUC_POW2==2 ? 384 : 0),
801 224, 120, 62, 31, 16, 8, 4, 2
804 (MIN_BUC_POW2==2 ? 384 : 0), (MIN_BUC_POW2==2 ? 384 : 0), /* 4, 4 */
805 224, 149, 120, 80, 62, 41, 31, 25, 16, 16, 8, 8, 4, 4, 2, 2
809 /* Shift of the first bucket with the given ordinal inside 2K chunk. */
810 #ifdef IGNORE_SMALL_BAD_FREE
811 # define BLK_SHIFT(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
812 ? ((1<<LOG_OF_MIN_ARENA) \
813 - BUCKET_SIZE(bucket) * N_BLKS(bucket)) \
816 # define BLK_SHIFT(bucket) blk_shift[bucket]
819 static u_short blk_shift[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
821 # if BUCKETS_PER_POW2==1
823 (MIN_BUC_POW2==2 ? 512 : 0),
824 256, 128, 64, 64, /* 8 to 64 */
825 16*sizeof(union overhead),
826 8*sizeof(union overhead),
827 4*sizeof(union overhead),
828 2*sizeof(union overhead),
831 (MIN_BUC_POW2==2 ? 512 : 0), (MIN_BUC_POW2==2 ? 512 : 0),
832 256, 260, 128, 128, 64, 80, 64, 48, /* 8 to 96 */
833 16*sizeof(union overhead), 16*sizeof(union overhead),
834 8*sizeof(union overhead), 8*sizeof(union overhead),
835 4*sizeof(union overhead), 4*sizeof(union overhead),
836 2*sizeof(union overhead), 2*sizeof(union overhead),
840 # define NEEDED_ALIGNMENT 0x800 /* 2k boundaries */
841 # define WANTED_ALIGNMENT 0x800 /* 2k boundaries */
843 #else /* !PACK_MALLOC */
845 # define OV_MAGIC(block,bucket) (block)->ov_magic
846 # define OV_INDEX(block) (block)->ov_index
847 # define CHUNK_SHIFT 1
848 # define MAX_PACKED -1
849 # define NEEDED_ALIGNMENT MEM_ALIGNBYTES
850 # define WANTED_ALIGNMENT 0x400 /* 1k boundaries */
852 #endif /* !PACK_MALLOC */
854 #define M_OVERHEAD (sizeof(union overhead) + RSLOP)
857 # define MEM_OVERHEAD(bucket) \
858 (bucket <= MAX_PACKED ? 0 : M_OVERHEAD)
859 # ifdef SMALL_BUCKET_VIA_TABLE
860 # define START_SHIFTS_BUCKET ((MAX_PACKED_POW2 + 1) * BUCKETS_PER_POW2)
861 # define START_SHIFT MAX_PACKED_POW2
862 # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */
863 # define SIZE_TABLE_MAX 80
865 # define SIZE_TABLE_MAX 64
867 static char bucket_of[] =
869 # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */
870 /* 0 to 15 in 4-byte increments. */
871 (sizeof(void*) > 4 ? 6 : 5), /* 4/8, 5-th bucket for better reports */
873 IF_ALIGN_8(8,7), 8, /* 16/12, 16 */
874 9, 9, 10, 10, /* 24, 32 */
875 11, 11, 11, 11, /* 48 */
876 12, 12, 12, 12, /* 64 */
877 13, 13, 13, 13, /* 80 */
878 13, 13, 13, 13 /* 80 */
879 # else /* !BUCKETS_ROOT2 */
880 /* 0 to 15 in 4-byte increments. */
881 (sizeof(void*) > 4 ? 3 : 2),
887 # endif /* !BUCKETS_ROOT2 */
889 # else /* !SMALL_BUCKET_VIA_TABLE */
890 # define START_SHIFTS_BUCKET MIN_BUCKET
891 # define START_SHIFT (MIN_BUC_POW2 - 1)
892 # endif /* !SMALL_BUCKET_VIA_TABLE */
893 #else /* !PACK_MALLOC */
894 # define MEM_OVERHEAD(bucket) M_OVERHEAD
895 # ifdef SMALL_BUCKET_VIA_TABLE
896 # undef SMALL_BUCKET_VIA_TABLE
898 # define START_SHIFTS_BUCKET MIN_BUCKET
899 # define START_SHIFT (MIN_BUC_POW2 - 1)
900 #endif /* !PACK_MALLOC */
903 * Big allocations are often of the size 2^n bytes. To make them a
904 * little bit better, make blocks of size 2^n+pagesize for big n.
907 #ifdef TWO_POT_OPTIMIZE
909 # ifndef PERL_PAGESIZE
910 # define PERL_PAGESIZE 4096
912 # ifndef FIRST_BIG_POW2
913 # define FIRST_BIG_POW2 15 /* 32K, 16K is used too often. */
915 # define FIRST_BIG_BLOCK (1<<FIRST_BIG_POW2)
916 /* If this value or more, check against bigger blocks. */
917 # define FIRST_BIG_BOUND (FIRST_BIG_BLOCK - M_OVERHEAD)
918 /* If less than this value, goes into 2^n-overhead-block. */
919 # define LAST_SMALL_BOUND ((FIRST_BIG_BLOCK>>1) - M_OVERHEAD)
921 # define POW2_OPTIMIZE_ADJUST(nbytes) \
922 ((nbytes >= FIRST_BIG_BOUND) ? nbytes -= PERL_PAGESIZE : 0)
923 # define POW2_OPTIMIZE_SURPLUS(bucket) \
924 ((bucket >= FIRST_BIG_POW2 * BUCKETS_PER_POW2) ? PERL_PAGESIZE : 0)
926 #else /* !TWO_POT_OPTIMIZE */
927 # define POW2_OPTIMIZE_ADJUST(nbytes)
928 # define POW2_OPTIMIZE_SURPLUS(bucket) 0
929 #endif /* !TWO_POT_OPTIMIZE */
931 #if defined(HAS_64K_LIMIT) && defined(PERL_CORE)
932 # define BARK_64K_LIMIT(what,nbytes,size) \
933 if (nbytes > 0xffff) { \
934 PerlIO_printf(PerlIO_stderr(), \
935 "%s too large: %lx\n", what, size); \
938 #else /* !HAS_64K_LIMIT || !PERL_CORE */
939 # define BARK_64K_LIMIT(what,nbytes,size)
940 #endif /* !HAS_64K_LIMIT || !PERL_CORE */
943 # define MIN_SBRK 2048
947 # define FIRST_SBRK (48*1024)
950 /* Minimal sbrk in percents of what is already alloced. */
951 #ifndef MIN_SBRK_FRAC
952 # define MIN_SBRK_FRAC 3
955 #ifndef SBRK_ALLOW_FAILURES
956 # define SBRK_ALLOW_FAILURES 3
959 #ifndef SBRK_FAILURE_PRICE
960 # define SBRK_FAILURE_PRICE 50
963 static void morecore (register int bucket);
964 # if defined(DEBUGGING)
965 static void botch (char *diag, char *s, char *file, int line);
967 static void add_to_chain (void *p, MEM_SIZE size, MEM_SIZE chip);
968 static void* get_from_chain (MEM_SIZE size);
969 static void* get_from_bigger_buckets(int bucket, MEM_SIZE size);
970 static union overhead *getpages (MEM_SIZE needed, int *nblksp, int bucket);
971 static int getpages_adjacent(MEM_SIZE require);
975 #ifdef I_MACH_CTHREADS
977 # define MUTEX_LOCK(m) STMT_START { if (*m) mutex_lock(*m); } STMT_END
979 # define MUTEX_UNLOCK(m) STMT_START { if (*m) mutex_unlock(*m); } STMT_END
982 #endif /* defined PERL_CORE */
985 # define PTRSIZE sizeof(void*)
989 # define BITS_IN_PTR (8*PTRSIZE)
993 * nextf[i] is the pointer to the next free block of size 2^i. The
994 * smallest allocatable block is 8 bytes. The overhead information
995 * precedes the data area returned to the user.
997 #define NBUCKETS (BITS_IN_PTR*BUCKETS_PER_POW2 + 1)
998 static union overhead *nextf[NBUCKETS];
1000 #if defined(PURIFY) && !defined(USE_PERL_SBRK)
1001 # define USE_PERL_SBRK
1004 #ifdef USE_PERL_SBRK
1005 # define sbrk(a) Perl_sbrk(a)
1006 Malloc_t Perl_sbrk (int size);
1008 # ifndef HAS_SBRK_PROTO /* <unistd.h> usually takes care of this */
1009 extern Malloc_t sbrk(int);
1013 #ifndef MIN_SBRK_FRAC1000 /* Backward compatibility */
1014 # define MIN_SBRK_FRAC1000 (MIN_SBRK_FRAC * 10)
1017 #ifndef START_EXTERN_C
1019 # define START_EXTERN_C extern "C" {
1021 # define START_EXTERN_C
1025 #ifndef END_EXTERN_C
1027 # define END_EXTERN_C };
1029 # define END_EXTERN_C
1033 #include "malloc_ctl.h"
1035 #ifndef NO_MALLOC_DYNAMIC_CFG
1036 # define PERL_MALLOC_OPT_CHARS "FMfAPGdac"
1038 static IV MallocCfg[MallocCfg_last] = {
1042 SBRK_ALLOW_FAILURES,
1044 SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE, /* sbrk_goodness */
1048 0, /* MallocCfg_skip_cfg_env */
1049 0, /* MallocCfg_cfg_env_read */
1050 0, /* MallocCfg_emergency_buffer_size */
1051 0, /* MallocCfg_emergency_buffer_prepared_size */
1052 0 /* MallocCfg_emergency_buffer_last_req */
1054 IV *MallocCfg_ptr = MallocCfg;
1058 # undef MIN_SBRK_FRAC1000
1059 # undef SBRK_ALLOW_FAILURES
1060 # undef SBRK_FAILURE_PRICE
1062 # define MIN_SBRK MallocCfg[MallocCfg_MIN_SBRK]
1063 # define FIRST_SBRK MallocCfg[MallocCfg_FIRST_SBRK]
1064 # define MIN_SBRK_FRAC1000 MallocCfg[MallocCfg_MIN_SBRK_FRAC1000]
1065 # define SBRK_ALLOW_FAILURES MallocCfg[MallocCfg_SBRK_ALLOW_FAILURES]
1066 # define SBRK_FAILURE_PRICE MallocCfg[MallocCfg_SBRK_FAILURE_PRICE]
1068 # define sbrk_goodness MallocCfg[MallocCfg_sbrk_goodness]
1070 # define emergency_buffer_size MallocCfg[MallocCfg_emergency_buffer_size]
1071 # define emergency_buffer_last_req MallocCfg[MallocCfg_emergency_buffer_last_req]
1073 # define FILL_DEAD MallocCfg[MallocCfg_filldead]
1074 # define FILL_ALIVE MallocCfg[MallocCfg_fillalive]
1075 # define FILL_CHECK_CFG MallocCfg[MallocCfg_fillcheck]
1076 # define FILL_CHECK (FILL_DEAD && FILL_CHECK_CFG)
1078 #else /* defined(NO_MALLOC_DYNAMIC_CFG) */
1080 # define FILL_DEAD 1
1081 # define FILL_ALIVE 1
1082 # define FILL_CHECK 1
1083 static int sbrk_goodness = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE;
1085 # define NO_PERL_MALLOC_ENV
1089 #ifdef DEBUGGING_MSTATS
1091 * nmalloc[i] is the difference between the number of mallocs and frees
1092 * for a given block size.
1094 static u_int nmalloc[NBUCKETS];
1095 static u_int sbrk_slack;
1096 static u_int start_slack;
1097 #else /* !( defined DEBUGGING_MSTATS ) */
1098 # define sbrk_slack 0
1101 static u_int goodsbrk;
1103 #ifdef PERL_EMERGENCY_SBRK
1106 # define BIG_SIZE (1<<16) /* 64K */
1109 static char *emergency_buffer;
1110 static char *emergency_buffer_prepared;
1112 # ifdef NO_MALLOC_DYNAMIC_CFG
1113 static MEM_SIZE emergency_buffer_size;
1114 /* 0 if the last request for more memory succeeded.
1115 Otherwise the size of the failing request. */
1116 static MEM_SIZE emergency_buffer_last_req;
1119 # ifndef emergency_sbrk_croak
1120 # define emergency_sbrk_croak croak2
1125 perl_get_emergency_buffer(IV *size)
1128 /* First offense, give a possibility to recover by dieing. */
1129 /* No malloc involved here: */
1130 GV **gvp = (GV**)hv_fetch(PL_defstash, "^M", 2, 0);
1135 if (!gvp) gvp = (GV**)hv_fetch(PL_defstash, "\015", 1, 0);
1136 if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv)
1137 || (SvLEN(sv) < (1<<LOG_OF_MIN_ARENA) - M_OVERHEAD))
1138 return NULL; /* Now die die die... */
1139 /* Got it, now detach SvPV: */
1141 /* Check alignment: */
1142 if ((PTR2UV(pv) - sizeof(union overhead)) & (NEEDED_ALIGNMENT - 1)) {
1143 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
1144 return NULL; /* die die die */
1149 SvCUR(sv) = SvLEN(sv) = 0;
1150 *size = malloced_size(pv) + M_OVERHEAD;
1151 return pv - sizeof(union overhead);
1153 # define PERL_GET_EMERGENCY_BUFFER(p) perl_get_emergency_buffer(p)
1155 # define PERL_GET_EMERGENCY_BUFFER(p) NULL
1156 # endif /* defined PERL_CORE */
1158 # ifndef NO_MALLOC_DYNAMIC_CFG
1160 get_emergency_buffer(IV *size)
1162 char *pv = emergency_buffer_prepared;
1164 *size = MallocCfg[MallocCfg_emergency_buffer_prepared_size];
1165 emergency_buffer_prepared = 0;
1166 MallocCfg[MallocCfg_emergency_buffer_prepared_size] = 0;
1170 /* Returns 0 on success, -1 on bad alignment, -2 if not implemented */
1172 set_emergency_buffer(char *b, IV size)
1174 if (PTR2UV(b) & (NEEDED_ALIGNMENT - 1))
1176 if (MallocCfg[MallocCfg_emergency_buffer_prepared_size])
1177 add_to_chain((void*)emergency_buffer_prepared,
1178 MallocCfg[MallocCfg_emergency_buffer_prepared_size], 0);
1179 emergency_buffer_prepared = b;
1180 MallocCfg[MallocCfg_emergency_buffer_prepared_size] = size;
1183 # define GET_EMERGENCY_BUFFER(p) get_emergency_buffer(p)
1184 # else /* NO_MALLOC_DYNAMIC_CFG */
1185 # define GET_EMERGENCY_BUFFER(p) NULL
1187 set_emergency_buffer(char *b, IV size)
1194 emergency_sbrk(MEM_SIZE size)
1196 MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA;
1198 if (size >= BIG_SIZE
1199 && (!emergency_buffer_last_req || (size < emergency_buffer_last_req))) {
1200 /* Give the possibility to recover, but avoid an infinite cycle. */
1202 emergency_buffer_last_req = size;
1203 emergency_sbrk_croak("Out of memory during \"large\" request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
1206 if (emergency_buffer_size >= rsize) {
1207 char *old = emergency_buffer;
1209 emergency_buffer_size -= rsize;
1210 emergency_buffer += rsize;
1213 /* First offense, give a possibility to recover by dieing. */
1214 /* No malloc involved here: */
1216 char *pv = GET_EMERGENCY_BUFFER(&Size);
1219 if (emergency_buffer_size) {
1220 add_to_chain(emergency_buffer, emergency_buffer_size, 0);
1221 emergency_buffer_size = 0;
1222 emergency_buffer = Nullch;
1227 pv = PERL_GET_EMERGENCY_BUFFER(&Size);
1231 return (char *)-1; /* Now die die die... */
1234 /* Check alignment: */
1235 if (PTR2UV(pv) & (NEEDED_ALIGNMENT - 1)) {
1238 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
1239 return (char *)-1; /* die die die */
1242 emergency_buffer = pv;
1243 emergency_buffer_size = Size;
1247 emergency_sbrk_croak("Out of memory during request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
1252 #else /* !defined(PERL_EMERGENCY_SBRK) */
1253 # define emergency_sbrk(size) -1
1254 #endif /* defined PERL_EMERGENCY_SBRK */
1259 write(2, mess, strlen(mess));
1264 #define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p),__FILE__,__LINE__); else
1266 botch(char *diag, char *s, char *file, int line)
1268 if (!(PERL_MAYBE_ALIVE && PERL_GET_THX))
1272 if (PerlIO_printf(PerlIO_stderr(),
1273 "assertion botched (%s?): %s%s %s:%d\n",
1274 diag, s, file, line) != 0) {
1275 do_write: /* Can be initializing interpreter */
1276 write2("assertion botched (");
1285 char *s = linebuf + sizeof(linebuf) - 1;
1289 *--s = '0' + (n % 10);
1299 #define ASSERT(p, diag)
1303 /* Fill should be long enough to cover long */
1305 fill_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1307 unsigned char *e = s + nbytes;
1309 long lfill = *(long*)fill;
1311 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1312 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1313 unsigned const char *f = fill + sizeof(long) - shift;
1314 unsigned char *e1 = s + shift;
1320 while ((unsigned char*)(lp + 1) <= e)
1322 s = (unsigned char*)lp;
1326 /* Just malloc()ed */
1327 static const unsigned char fill_feedadad[] =
1328 {0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD,
1329 0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD};
1331 static const unsigned char fill_deadbeef[] =
1332 {0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF,
1333 0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF};
1334 # define FILL_DEADBEEF(s, n) \
1335 (void)(FILL_DEAD? (fill_pat_4bytes((s), (n), fill_deadbeef), 0) : 0)
1336 # define FILL_FEEDADAD(s, n) \
1337 (void)(FILL_ALIVE? (fill_pat_4bytes((s), (n), fill_feedadad), 0) : 0)
1339 # define FILL_DEADBEEF(s, n) ((void)0)
1340 # define FILL_FEEDADAD(s, n) ((void)0)
1341 # undef MALLOC_FILL_CHECK
1344 #ifdef MALLOC_FILL_CHECK
1346 cmp_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1348 unsigned char *e = s + nbytes;
1350 long lfill = *(long*)fill;
1352 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1353 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1354 unsigned const char *f = fill + sizeof(long) - shift;
1355 unsigned char *e1 = s + shift;
1362 while ((unsigned char*)(lp + 1) <= e)
1365 s = (unsigned char*)lp;
1367 if (*s++ != *fill++)
1371 # define FILLCHECK_DEADBEEF(s, n) \
1372 ASSERT(!FILL_CHECK || !cmp_pat_4bytes(s, n, fill_deadbeef), \
1373 "free()ed/realloc()ed-away memory was overwritten")
1375 # define FILLCHECK_DEADBEEF(s, n) ((void)0)
1379 Perl_malloc(register size_t nbytes)
1381 register union overhead *p;
1382 register int bucket;
1383 register MEM_SIZE shiftr;
1385 #if defined(DEBUGGING) || defined(RCHECK)
1386 MEM_SIZE size = nbytes;
1389 BARK_64K_LIMIT("Allocation",nbytes,nbytes);
1391 if ((long)nbytes < 0)
1392 croak("%s", "panic: malloc");
1396 * Convert amount of memory requested into
1397 * closest block size stored in hash buckets
1398 * which satisfies request. Account for
1399 * space used per block for accounting.
1402 # ifdef SMALL_BUCKET_VIA_TABLE
1404 bucket = MIN_BUCKET;
1405 else if (nbytes <= SIZE_TABLE_MAX) {
1406 bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
1411 if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
1416 POW2_OPTIMIZE_ADJUST(nbytes);
1417 nbytes += M_OVERHEAD;
1418 nbytes = (nbytes + 3) &~ 3;
1419 #if defined(PACK_MALLOC) && !defined(SMALL_BUCKET_VIA_TABLE)
1422 shiftr = (nbytes - 1) >> START_SHIFT;
1423 bucket = START_SHIFTS_BUCKET;
1424 /* apart from this loop, this is O(1) */
1425 while (shiftr >>= 1)
1426 bucket += BUCKETS_PER_POW2;
1430 * If nothing in hash bucket right now,
1431 * request more memory from the system.
1433 if (nextf[bucket] == NULL)
1435 if ((p = nextf[bucket]) == NULL) {
1441 #if defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC)
1442 PerlIO_puts(PerlIO_stderr(),"Out of memory!\n");
1445 char *eb = buff + sizeof(buff) - 1;
1449 PerlIO_puts(PerlIO_stderr(),"Out of memory during request for ");
1450 #if defined(DEBUGGING) || defined(RCHECK)
1455 *--s = '0' + (n % 10);
1457 PerlIO_puts(PerlIO_stderr(),s);
1458 PerlIO_puts(PerlIO_stderr()," bytes, total sbrk() is ");
1460 n = goodsbrk + sbrk_slack;
1462 *--s = '0' + (n % 10);
1464 PerlIO_puts(PerlIO_stderr(),s);
1465 PerlIO_puts(PerlIO_stderr()," bytes!\n");
1466 #endif /* defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC) */
1474 /* remove from linked list */
1476 if ( (PTR2UV(p) & (MEM_ALIGNBYTES - 1))
1477 /* Can't get this low */
1478 || (p && PTR2UV(p) < (1<<LOG_OF_MIN_ARENA)) ) {
1480 PerlIO_printf(PerlIO_stderr(),
1481 "Unaligned pointer in the free chain 0x%"UVxf"\n",
1484 if ( (PTR2UV(p->ov_next) & (MEM_ALIGNBYTES - 1))
1485 || (p->ov_next && PTR2UV(p->ov_next) < (1<<LOG_OF_MIN_ARENA)) ) {
1487 PerlIO_printf(PerlIO_stderr(),
1488 "Unaligned `next' pointer in the free "
1489 "chain 0x%"UVxf" at 0x%"UVxf"\n",
1490 PTR2UV(p->ov_next), PTR2UV(p));
1493 nextf[bucket] = p->ov_next;
1497 DEBUG_m(PerlIO_printf(Perl_debug_log,
1498 "0x%"UVxf": (%05lu) malloc %ld bytes\n",
1499 PTR2UV((Malloc_t)(p + CHUNK_SHIFT)), (unsigned long)(PL_an++),
1502 FILLCHECK_DEADBEEF((unsigned char*)(p + CHUNK_SHIFT),
1503 BUCKET_SIZE_REAL(bucket));
1505 #ifdef IGNORE_SMALL_BAD_FREE
1506 if (bucket >= FIRST_BUCKET_WITH_CHECK)
1508 OV_MAGIC(p, bucket) = MAGIC;
1510 OV_INDEX(p) = bucket;
1514 * Record allocated size of block and
1515 * bound space with magic numbers.
1517 p->ov_rmagic = RMAGIC;
1518 if (bucket <= MAX_SHORT_BUCKET) {
1521 nbytes = size + M_OVERHEAD;
1522 p->ov_size = nbytes - 1;
1523 if ((i = nbytes & 3)) {
1526 *((char *)((caddr_t)p + nbytes - RSLOP + i)) = RMAGIC_C;
1528 nbytes = (nbytes + 3) &~ 3;
1529 *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
1531 FILL_FEEDADAD((unsigned char *)(p + CHUNK_SHIFT), size);
1533 return ((Malloc_t)(p + CHUNK_SHIFT));
1536 static char *last_sbrk_top;
1537 static char *last_op; /* This arena can be easily extended. */
1538 static MEM_SIZE sbrked_remains;
1540 #ifdef DEBUGGING_MSTATS
1544 struct chunk_chain_s {
1545 struct chunk_chain_s *next;
1548 static struct chunk_chain_s *chunk_chain;
1549 static int n_chunks;
1550 static char max_bucket;
1552 /* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */
1554 get_from_chain(MEM_SIZE size)
1556 struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
1557 struct chunk_chain_s **oldgoodp = NULL;
1558 long min_remain = LONG_MAX;
1561 if (elt->size >= size) {
1562 long remains = elt->size - size;
1563 if (remains >= 0 && remains < min_remain) {
1565 min_remain = remains;
1571 oldp = &( elt->next );
1574 if (!oldgoodp) return NULL;
1576 void *ret = *oldgoodp;
1577 struct chunk_chain_s *next = (*oldgoodp)->next;
1579 *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
1580 (*oldgoodp)->size = min_remain;
1581 (*oldgoodp)->next = next;
1584 void *ret = *oldgoodp;
1585 *oldgoodp = (*oldgoodp)->next;
1592 add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
1594 struct chunk_chain_s *next = chunk_chain;
1595 char *cp = (char*)p;
1598 chunk_chain = (struct chunk_chain_s *)cp;
1599 chunk_chain->size = size - chip;
1600 chunk_chain->next = next;
1605 get_from_bigger_buckets(int bucket, MEM_SIZE size)
1608 static int bucketprice[NBUCKETS];
1609 while (bucket <= max_bucket) {
1610 /* We postpone stealing from bigger buckets until we want it
1612 if (nextf[bucket] && bucketprice[bucket]++ >= price) {
1614 void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
1615 bucketprice[bucket] = 0;
1616 if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
1617 last_op = NULL; /* Disable optimization */
1619 nextf[bucket] = nextf[bucket]->ov_next;
1620 #ifdef DEBUGGING_MSTATS
1622 start_slack -= M_OVERHEAD;
1624 add_to_chain(ret, (BUCKET_SIZE(bucket) +
1625 POW2_OPTIMIZE_SURPLUS(bucket)),
1634 static union overhead *
1635 getpages(MEM_SIZE needed, int *nblksp, int bucket)
1637 /* Need to do (possibly expensive) system call. Try to
1638 optimize it for rare calling. */
1639 MEM_SIZE require = needed - sbrked_remains;
1641 union overhead *ovp;
1644 if (sbrk_goodness > 0) {
1645 if (!last_sbrk_top && require < FIRST_SBRK)
1646 require = FIRST_SBRK;
1647 else if (require < MIN_SBRK) require = MIN_SBRK;
1649 if (require < goodsbrk * MIN_SBRK_FRAC1000 / 1000)
1650 require = goodsbrk * MIN_SBRK_FRAC1000 / 1000;
1651 require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
1658 DEBUG_m(PerlIO_printf(Perl_debug_log,
1659 "sbrk(%ld) for %ld-byte-long arena\n",
1660 (long)require, (long) needed));
1661 cp = (char *)sbrk(require);
1662 #ifdef DEBUGGING_MSTATS
1665 if (cp == last_sbrk_top) {
1666 /* Common case, anything is fine. */
1668 ovp = (union overhead *) (cp - sbrked_remains);
1669 last_op = cp - sbrked_remains;
1670 sbrked_remains = require - (needed - sbrked_remains);
1671 } else if (cp == (char *)-1) { /* no more room! */
1672 ovp = (union overhead *)emergency_sbrk(needed);
1673 if (ovp == (union overhead *)-1)
1675 if (((char*)ovp) > last_op) { /* Cannot happen with current emergency_sbrk() */
1679 } else { /* Non-continuous or first sbrk(). */
1680 long add = sbrked_remains;
1683 if (sbrked_remains) { /* Put rest into chain, we
1684 cannot use it right now. */
1685 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1689 /* Second, check alignment. */
1692 #if !defined(atarist) && !defined(__MINT__) /* on the atari we dont have to worry about this */
1693 # ifndef I286 /* The sbrk(0) call on the I286 always returns the next segment */
1694 /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
1695 improve performance of memory access. */
1696 if (PTR2UV(cp) & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
1697 slack = WANTED_ALIGNMENT - (PTR2UV(cp) & (WANTED_ALIGNMENT - 1));
1701 #endif /* !atarist && !MINT */
1704 DEBUG_m(PerlIO_printf(Perl_debug_log,
1705 "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",
1706 (long)add, (long) slack,
1707 (long) sbrked_remains));
1708 newcp = (char *)sbrk(add);
1709 #if defined(DEBUGGING_MSTATS)
1713 if (newcp != cp + require) {
1714 /* Too bad: even rounding sbrk() is not continuous.*/
1715 DEBUG_m(PerlIO_printf(Perl_debug_log,
1716 "failed to fix bad sbrk()\n"));
1720 fatalcroak("panic: Off-page sbrk\n");
1723 if (sbrked_remains) {
1725 #if defined(DEBUGGING_MSTATS)
1726 sbrk_slack += require;
1729 DEBUG_m(PerlIO_printf(Perl_debug_log,
1730 "straight sbrk(%ld)\n",
1732 cp = (char *)sbrk(require);
1733 #ifdef DEBUGGING_MSTATS
1736 if (cp == (char *)-1)
1739 sbrk_goodness = -1; /* Disable optimization!
1740 Continue with not-aligned... */
1743 require += sbrked_remains;
1747 if (last_sbrk_top) {
1748 sbrk_goodness -= SBRK_FAILURE_PRICE;
1751 ovp = (union overhead *) cp;
1753 * Round up to minimum allocation size boundary
1754 * and deduct from block count to reflect.
1757 # if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
1758 if (PTR2UV(ovp) & (NEEDED_ALIGNMENT - 1))
1759 fatalcroak("Misalignment of sbrk()\n");
1762 #ifndef I286 /* Again, this should always be ok on an 80286 */
1763 if (PTR2UV(ovp) & (MEM_ALIGNBYTES - 1)) {
1764 DEBUG_m(PerlIO_printf(Perl_debug_log,
1765 "fixing sbrk(): %d bytes off machine alignement\n",
1766 (int)(PTR2UV(ovp) & (MEM_ALIGNBYTES - 1))));
1767 ovp = INT2PTR(union overhead *,(PTR2UV(ovp) + MEM_ALIGNBYTES) &
1768 (MEM_ALIGNBYTES - 1));
1770 # if defined(DEBUGGING_MSTATS)
1771 /* This is only approx. if TWO_POT_OPTIMIZE: */
1772 sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
1776 ; /* Finish `else' */
1777 sbrked_remains = require - needed;
1780 #if !defined(PLAIN_MALLOC) && !defined(NO_FANCY_MALLOC)
1781 emergency_buffer_last_req = 0;
1783 last_sbrk_top = cp + require;
1784 #ifdef DEBUGGING_MSTATS
1785 goodsbrk += require;
1791 getpages_adjacent(MEM_SIZE require)
1793 if (require <= sbrked_remains) {
1794 sbrked_remains -= require;
1798 require -= sbrked_remains;
1799 /* We do not try to optimize sbrks here, we go for place. */
1800 cp = (char*) sbrk(require);
1801 #ifdef DEBUGGING_MSTATS
1803 goodsbrk += require;
1805 if (cp == last_sbrk_top) {
1807 last_sbrk_top = cp + require;
1809 if (cp == (char*)-1) { /* Out of memory */
1810 #ifdef DEBUGGING_MSTATS
1811 goodsbrk -= require;
1815 /* Report the failure: */
1817 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1819 add_to_chain((void*)cp, require, 0);
1820 sbrk_goodness -= SBRK_FAILURE_PRICE;
1832 * Allocate more memory to the indicated bucket.
1835 morecore(register int bucket)
1837 register union overhead *ovp;
1838 register int rnu; /* 2^rnu bytes will be requested */
1839 int nblks; /* become nblks blocks of the desired size */
1840 register MEM_SIZE siz, needed;
1841 static int were_called = 0;
1845 #ifndef NO_PERL_MALLOC_ENV
1847 /* It's the our first time. Initialize ourselves */
1848 were_called = 1; /* Avoid a loop */
1849 if (!MallocCfg[MallocCfg_skip_cfg_env]) {
1850 char *s = getenv("PERL_MALLOC_OPT"), *t = s, *off;
1851 const char *opts = PERL_MALLOC_OPT_CHARS;
1854 while ( t && t[0] && t[1] == '='
1855 && ((off = strchr(opts, *t))) ) {
1859 while (*t <= '9' && *t >= '0')
1860 val = 10*val + *t++ - '0';
1861 if (!*t || *t == ';') {
1862 if (MallocCfg[off - opts] != val)
1864 MallocCfg[off - opts] = val;
1870 write2("Unrecognized part of PERL_MALLOC_OPT: `");
1875 MallocCfg[MallocCfg_cfg_env_read] = 1;
1879 if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
1881 croak("%s", "Out of memory during ridiculously large request");
1883 if (bucket > max_bucket)
1884 max_bucket = bucket;
1886 rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT))
1888 : (bucket >> BUCKET_POW2_SHIFT) );
1889 /* This may be overwritten later: */
1890 nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
1891 needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
1892 if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
1893 ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
1894 nextf[rnu << BUCKET_POW2_SHIFT]
1895 = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
1896 #ifdef DEBUGGING_MSTATS
1897 nmalloc[rnu << BUCKET_POW2_SHIFT]--;
1898 start_slack -= M_OVERHEAD;
1900 DEBUG_m(PerlIO_printf(Perl_debug_log,
1901 "stealing %ld bytes from %ld arena\n",
1902 (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
1903 } else if (chunk_chain
1904 && (ovp = (union overhead*) get_from_chain(needed))) {
1905 DEBUG_m(PerlIO_printf(Perl_debug_log,
1906 "stealing %ld bytes from chain\n",
1908 } else if ( (ovp = (union overhead*)
1909 get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
1911 DEBUG_m(PerlIO_printf(Perl_debug_log,
1912 "stealing %ld bytes from bigger buckets\n",
1914 } else if (needed <= sbrked_remains) {
1915 ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
1916 sbrked_remains -= needed;
1917 last_op = (char*)ovp;
1919 ovp = getpages(needed, &nblks, bucket);
1923 FILL_DEADBEEF((unsigned char*)ovp, needed);
1926 * Add new memory allocated to that on
1927 * free list for this hash bucket.
1929 siz = BUCKET_SIZE(bucket);
1931 *(u_char*)ovp = bucket; /* Fill index. */
1932 if (bucket <= MAX_PACKED) {
1933 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1934 nblks = N_BLKS(bucket);
1935 # ifdef DEBUGGING_MSTATS
1936 start_slack += BLK_SHIFT(bucket);
1938 } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
1939 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1940 siz -= sizeof(union overhead);
1941 } else ovp++; /* One chunk per block. */
1942 #endif /* PACK_MALLOC */
1943 nextf[bucket] = ovp;
1944 #ifdef DEBUGGING_MSTATS
1945 nmalloc[bucket] += nblks;
1946 if (bucket > MAX_PACKED) {
1947 start_slack += M_OVERHEAD * nblks;
1951 while (--nblks > 0) {
1952 ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
1953 ovp = (union overhead *)((caddr_t)ovp + siz);
1955 /* Not all sbrks return zeroed memory.*/
1956 ovp->ov_next = (union overhead *)NULL;
1958 if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
1959 union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
1960 nextf[7*BUCKETS_PER_POW2] =
1961 (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2]
1962 - sizeof(union overhead));
1963 nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
1965 #endif /* !PACK_MALLOC */
1969 Perl_mfree(void *mp)
1971 register MEM_SIZE size;
1972 register union overhead *ovp;
1973 char *cp = (char*)mp;
1978 DEBUG_m(PerlIO_printf(Perl_debug_log,
1979 "0x%"UVxf": (%05lu) free\n",
1980 PTR2UV(cp), (unsigned long)(PL_an++)));
1985 if (PTR2UV(cp) & (MEM_ALIGNBYTES - 1))
1986 croak("%s", "wrong alignment in free()");
1988 ovp = (union overhead *)((caddr_t)cp
1989 - sizeof (union overhead) * CHUNK_SHIFT);
1991 bucket = OV_INDEX(ovp);
1993 #ifdef IGNORE_SMALL_BAD_FREE
1994 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1995 && (OV_MAGIC(ovp, bucket) != MAGIC))
1997 if (OV_MAGIC(ovp, bucket) != MAGIC)
2000 static int bad_free_warn = -1;
2001 if (bad_free_warn == -1) {
2003 char *pbf = PerlEnv_getenv("PERL_BADFREE");
2004 bad_free_warn = (pbf) ? atoi(pbf) : 1;
2012 if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2013 Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%s free() ignored (RMAGIC, PERL_CORE)",
2014 ovp->ov_rmagic == RMAGIC - 1 ?
2015 "Duplicate" : "Bad");
2018 warn("%s free() ignored (RMAGIC)",
2019 ovp->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad");
2025 if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2026 Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%s", "Bad free() ignored (PERL_CORE)");
2029 warn("%s", "Bad free() ignored");
2032 return; /* sanity */
2035 ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
2036 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
2038 MEM_SIZE nbytes = ovp->ov_size + 1;
2040 if ((i = nbytes & 3)) {
2043 ASSERT(*((char *)((caddr_t)ovp + nbytes - RSLOP + i))
2044 == RMAGIC_C, "chunk's tail overwrite");
2047 nbytes = (nbytes + 3) &~ 3;
2048 ASSERT(*(u_int *)((caddr_t)ovp + nbytes - RSLOP) == RMAGIC, "chunk's tail overwrite");
2049 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nbytes - RSLOP + sizeof(u_int)),
2050 BUCKET_SIZE_REAL(OV_INDEX(ovp)) - (nbytes - RSLOP + sizeof(u_int)));
2052 FILL_DEADBEEF((unsigned char*)(ovp+1), BUCKET_SIZE_REAL(OV_INDEX(ovp)));
2053 ovp->ov_rmagic = RMAGIC - 1;
2055 ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
2056 size = OV_INDEX(ovp);
2059 ovp->ov_next = nextf[size];
2064 /* There is no need to do any locking in realloc (with an exception of
2065 trying to grow in place if we are at the end of the chain).
2066 If somebody calls us from a different thread with the same address,
2067 we are sole anyway. */
2070 Perl_realloc(void *mp, size_t nbytes)
2072 register MEM_SIZE onb;
2073 union overhead *ovp;
2076 register int bucket;
2077 int incr; /* 1 if does not fit, -1 if "easily" fits in a
2078 smaller bucket, otherwise 0. */
2079 char *cp = (char*)mp;
2081 #if defined(DEBUGGING) || !defined(PERL_CORE)
2082 MEM_SIZE size = nbytes;
2084 if ((long)nbytes < 0)
2085 croak("%s", "panic: realloc");
2088 BARK_64K_LIMIT("Reallocation",nbytes,size);
2090 return Perl_malloc(nbytes);
2092 ovp = (union overhead *)((caddr_t)cp
2093 - sizeof (union overhead) * CHUNK_SHIFT);
2094 bucket = OV_INDEX(ovp);
2096 #ifdef IGNORE_SMALL_BAD_FREE
2097 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
2098 && (OV_MAGIC(ovp, bucket) != MAGIC))
2100 if (OV_MAGIC(ovp, bucket) != MAGIC)
2103 static int bad_free_warn = -1;
2104 if (bad_free_warn == -1) {
2106 char *pbf = PerlEnv_getenv("PERL_BADFREE");
2107 bad_free_warn = (pbf) ? atoi(pbf) : 1;
2115 if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2116 Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%srealloc() %signored",
2117 (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
2118 ovp->ov_rmagic == RMAGIC - 1
2119 ? "of freed memory " : "");
2122 warn2("%srealloc() %signored",
2123 (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
2124 ovp->ov_rmagic == RMAGIC - 1 ? "of freed memory " : "");
2130 if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2131 Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%s",
2132 "Bad realloc() ignored");
2135 warn("%s", "Bad realloc() ignored");
2138 return Nullch; /* sanity */
2141 onb = BUCKET_SIZE_REAL(bucket);
2143 * avoid the copy if same size block.
2144 * We are not agressive with boundary cases. Note that it might
2145 * (for a small number of cases) give false negative if
2146 * both new size and old one are in the bucket for
2147 * FIRST_BIG_POW2, but the new one is near the lower end.
2149 * We do not try to go to 1.5 times smaller bucket so far.
2151 if (nbytes > onb) incr = 1;
2153 #ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
2154 if ( /* This is a little bit pessimal if PACK_MALLOC: */
2155 nbytes > ( (onb >> 1) - M_OVERHEAD )
2156 # ifdef TWO_POT_OPTIMIZE
2157 || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
2160 #else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
2161 prev_bucket = ( (bucket > MAX_PACKED + 1)
2162 ? bucket - BUCKETS_PER_POW2
2164 if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
2165 #endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
2169 #ifdef STRESS_REALLOC
2176 * Record new allocated size of block and
2177 * bound space with magic numbers.
2179 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
2180 int i, nb = ovp->ov_size + 1;
2185 ASSERT(*((char *)((caddr_t)ovp + nb - RSLOP + i)) == RMAGIC_C, "chunk's tail overwrite");
2189 ASSERT(*(u_int *)((caddr_t)ovp + nb - RSLOP) == RMAGIC, "chunk's tail overwrite");
2190 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nb - RSLOP + sizeof(u_int)),
2191 BUCKET_SIZE_REAL(OV_INDEX(ovp)) - (nb - RSLOP + sizeof(u_int)));
2192 if (nbytes > ovp->ov_size + 1 - M_OVERHEAD)
2193 FILL_FEEDADAD((unsigned char*)cp + ovp->ov_size + 1 - M_OVERHEAD,
2194 nbytes - (ovp->ov_size + 1 - M_OVERHEAD));
2196 FILL_DEADBEEF((unsigned char*)cp + nbytes,
2197 nb - M_OVERHEAD + RSLOP - nbytes);
2199 * Convert amount of memory requested into
2200 * closest block size stored in hash buckets
2201 * which satisfies request. Account for
2202 * space used per block for accounting.
2204 nbytes += M_OVERHEAD;
2205 ovp->ov_size = nbytes - 1;
2206 if ((i = nbytes & 3)) {
2209 *((char *)((caddr_t)ovp + nbytes - RSLOP + i))
2212 nbytes = (nbytes + 3) &~ 3;
2213 *((u_int *)((caddr_t)ovp + nbytes - RSLOP)) = RMAGIC;
2217 DEBUG_m(PerlIO_printf(Perl_debug_log,
2218 "0x%"UVxf": (%05lu) realloc %ld bytes inplace\n",
2219 PTR2UV(res),(unsigned long)(PL_an++),
2221 } else if (incr == 1 && (cp - M_OVERHEAD == last_op)
2222 && (onb > (1 << LOG_OF_MIN_ARENA))) {
2223 MEM_SIZE require, newarena = nbytes, pow;
2226 POW2_OPTIMIZE_ADJUST(newarena);
2227 newarena = newarena + M_OVERHEAD;
2228 /* newarena = (newarena + 3) &~ 3; */
2229 shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
2230 pow = LOG_OF_MIN_ARENA + 1;
2231 /* apart from this loop, this is O(1) */
2232 while (shiftr >>= 1)
2234 newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
2235 require = newarena - onb - M_OVERHEAD;
2238 if (cp - M_OVERHEAD == last_op /* We *still* are the last chunk */
2239 && getpages_adjacent(require)) {
2240 #ifdef DEBUGGING_MSTATS
2242 nmalloc[pow * BUCKETS_PER_POW2]++;
2244 *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
2253 DEBUG_m(PerlIO_printf(Perl_debug_log,
2254 "0x%"UVxf": (%05lu) realloc %ld bytes the hard way\n",
2255 PTR2UV(cp),(unsigned long)(PL_an++),
2257 if ((res = (char*)Perl_malloc(nbytes)) == NULL)
2259 if (cp != res) /* common optimization */
2260 Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
2263 return ((Malloc_t)res);
2267 Perl_calloc(register size_t elements, register size_t size)
2269 long sz = elements * size;
2270 Malloc_t p = Perl_malloc(sz);
2273 memset((void*)p, 0, sz);
2279 Perl_strdup(const char *s)
2281 MEM_SIZE l = strlen(s);
2282 char *s1 = (char *)Perl_malloc(l+1);
2284 Copy(s, s1, (MEM_SIZE)(l+1), char);
2290 Perl_putenv(char *a)
2292 /* Sometimes system's putenv conflicts with my_setenv() - this is system
2293 malloc vs Perl's free(). */
2300 while (*val && *val != '=')
2305 if (l < sizeof(buf))
2308 var = Perl_malloc(l + 1);
2309 Copy(a, var, l, char);
2311 my_setenv(var, val+1);
2319 Perl_malloced_size(void *p)
2321 union overhead *ovp = (union overhead *)
2322 ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
2323 int bucket = OV_INDEX(ovp);
2325 /* The caller wants to have a complete control over the chunk,
2326 disable the memory checking inside the chunk. */
2327 if (bucket <= MAX_SHORT_BUCKET) {
2328 MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
2329 ovp->ov_size = size + M_OVERHEAD - 1;
2330 *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RSLOP)) = RMAGIC;
2333 return BUCKET_SIZE_REAL(bucket);
2336 # ifdef BUCKETS_ROOT2
2337 # define MIN_EVEN_REPORT 6
2339 # define MIN_EVEN_REPORT MIN_BUCKET
2343 Perl_get_mstats(pTHX_ perl_mstats_t *buf, int buflen, int level)
2345 #ifdef DEBUGGING_MSTATS
2347 register union overhead *p;
2348 struct chunk_chain_s* nextchain;
2350 buf->topbucket = buf->topbucket_ev = buf->topbucket_odd
2351 = buf->totfree = buf->total = buf->total_chain = 0;
2353 buf->minbucket = MIN_BUCKET;
2355 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2356 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
2360 buf->ntotal[i] = nmalloc[i];
2362 buf->totfree += j * BUCKET_SIZE_REAL(i);
2363 buf->total += nmalloc[i] * BUCKET_SIZE_REAL(i);
2365 i % 2 ? (buf->topbucket_odd = i) : (buf->topbucket_ev = i);
2369 nextchain = chunk_chain;
2371 buf->total_chain += nextchain->size;
2372 nextchain = nextchain->next;
2374 buf->total_sbrk = goodsbrk + sbrk_slack;
2376 buf->sbrk_good = sbrk_goodness;
2377 buf->sbrk_slack = sbrk_slack;
2378 buf->start_slack = start_slack;
2379 buf->sbrked_remains = sbrked_remains;
2381 buf->nbuckets = NBUCKETS;
2383 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2386 buf->bucket_mem_size[i] = BUCKET_SIZE(i);
2387 buf->bucket_available_size[i] = BUCKET_SIZE_REAL(i);
2390 #endif /* defined DEBUGGING_MSTATS */
2391 return 0; /* XXX unused */
2394 * mstats - print out statistics about malloc
2396 * Prints two lines of numbers, one showing the length of the free list
2397 * for each size category, the second showing the number of mallocs -
2398 * frees for each size category.
2401 Perl_dump_mstats(pTHX_ char *s)
2403 #ifdef DEBUGGING_MSTATS
2405 perl_mstats_t buffer;
2411 get_mstats(&buffer, NBUCKETS, 0);
2414 PerlIO_printf(Perl_error_log,
2415 "Memory allocation statistics %s (buckets %"IVdf"(%"IVdf")..%"IVdf"(%"IVdf")\n",
2417 (IV)BUCKET_SIZE_REAL(MIN_BUCKET),
2418 (IV)BUCKET_SIZE(MIN_BUCKET),
2419 (IV)BUCKET_SIZE_REAL(buffer.topbucket),
2420 (IV)BUCKET_SIZE(buffer.topbucket));
2421 PerlIO_printf(Perl_error_log, "%8"IVdf" free:", buffer.totfree);
2422 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2423 PerlIO_printf(Perl_error_log,
2424 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2426 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2429 #ifdef BUCKETS_ROOT2
2430 PerlIO_printf(Perl_error_log, "\n\t ");
2431 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2432 PerlIO_printf(Perl_error_log,
2433 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2435 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2439 PerlIO_printf(Perl_error_log, "\n%8"IVdf" used:", buffer.total - buffer.totfree);
2440 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2441 PerlIO_printf(Perl_error_log,
2442 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2444 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2445 buffer.ntotal[i] - buffer.nfree[i]);
2447 #ifdef BUCKETS_ROOT2
2448 PerlIO_printf(Perl_error_log, "\n\t ");
2449 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2450 PerlIO_printf(Perl_error_log,
2451 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2453 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2454 buffer.ntotal[i] - buffer.nfree[i]);
2457 PerlIO_printf(Perl_error_log, "\nTotal sbrk(): %"IVdf"/%"IVdf":%"IVdf". Odd ends: pad+heads+chain+tail: %"IVdf"+%"IVdf"+%"IVdf"+%"IVdf".\n",
2458 buffer.total_sbrk, buffer.sbrks, buffer.sbrk_good,
2459 buffer.sbrk_slack, buffer.start_slack,
2460 buffer.total_chain, buffer.sbrked_remains);
2461 #endif /* DEBUGGING_MSTATS */
2465 #ifdef USE_PERL_SBRK
2467 # if defined(__MACHTEN_PPC__) || defined(NeXT) || defined(__NeXT__) || defined(PURIFY)
2468 # define PERL_SBRK_VIA_MALLOC
2471 # ifdef PERL_SBRK_VIA_MALLOC
2473 /* it may seem schizophrenic to use perl's malloc and let it call system */
2474 /* malloc, the reason for that is only the 3.2 version of the OS that had */
2475 /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
2476 /* end to the cores */
2478 # ifndef SYSTEM_ALLOC
2479 # define SYSTEM_ALLOC(a) malloc(a)
2481 # ifndef SYSTEM_ALLOC_ALIGNMENT
2482 # define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
2485 # endif /* PERL_SBRK_VIA_MALLOC */
2487 static IV Perl_sbrk_oldchunk;
2488 static long Perl_sbrk_oldsize;
2490 # define PERLSBRK_32_K (1<<15)
2491 # define PERLSBRK_64_K (1<<16)
2499 if (!size) return 0;
2501 reqsize = size; /* just for the DEBUG_m statement */
2504 size = (size + 0x7ff) & ~0x7ff;
2506 if (size <= Perl_sbrk_oldsize) {
2507 got = Perl_sbrk_oldchunk;
2508 Perl_sbrk_oldchunk += size;
2509 Perl_sbrk_oldsize -= size;
2511 if (size >= PERLSBRK_32_K) {
2514 size = PERLSBRK_64_K;
2517 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2518 size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT;
2520 got = (IV)SYSTEM_ALLOC(size);
2521 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2522 got = (got + NEEDED_ALIGNMENT - 1) & ~(NEEDED_ALIGNMENT - 1);
2525 /* Chunk is small, register the rest for future allocs. */
2526 Perl_sbrk_oldchunk = got + reqsize;
2527 Perl_sbrk_oldsize = size - reqsize;
2531 DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%"UVxf"\n",
2532 size, reqsize, Perl_sbrk_oldsize, PTR2UV(got)));
2537 #endif /* ! defined USE_PERL_SBRK */