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))
1274 if (PerlIO_printf(PerlIO_stderr(),
1275 "assertion botched (%s?): %s%s %s:%d\n",
1276 diag, s, file, line) != 0) {
1277 do_write: /* Can be initializing interpreter */
1278 write2("assertion botched (");
1285 sprintf(linebuf, "%d", line);
1293 #define ASSERT(p, diag)
1297 /* Fill should be long enough to cover long */
1299 fill_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1301 unsigned char *e = s + nbytes;
1303 long lfill = *(long*)fill;
1305 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1306 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1307 unsigned const char *f = fill + sizeof(long) - shift;
1308 unsigned char *e1 = s + shift;
1314 while ((unsigned char*)(lp + 1) <= e)
1316 s = (unsigned char*)lp;
1320 /* Just malloc()ed */
1321 static const unsigned char fill_feedadad[] =
1322 {0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD,
1323 0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD};
1325 static const unsigned char fill_deadbeef[] =
1326 {0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF,
1327 0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF};
1328 # define FILL_DEADBEEF(s, n) \
1329 (void)(FILL_DEAD? (fill_pat_4bytes((s), (n), fill_deadbeef), 0) : 0)
1330 # define FILL_FEEDADAD(s, n) \
1331 (void)(FILL_ALIVE? (fill_pat_4bytes((s), (n), fill_feedadad), 0) : 0)
1333 # define FILL_DEADBEEF(s, n) ((void)0)
1334 # define FILL_FEEDADAD(s, n) ((void)0)
1335 # undef MALLOC_FILL_CHECK
1338 #ifdef MALLOC_FILL_CHECK
1340 cmp_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1342 unsigned char *e = s + nbytes;
1344 long lfill = *(long*)fill;
1346 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1347 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1348 unsigned const char *f = fill + sizeof(long) - shift;
1349 unsigned char *e1 = s + shift;
1356 while ((unsigned char*)(lp + 1) <= e)
1359 s = (unsigned char*)lp;
1361 if (*s++ != *fill++)
1365 # define FILLCHECK_DEADBEEF(s, n) \
1366 ASSERT(!FILL_CHECK || !cmp_pat_4bytes(s, n, fill_deadbeef), \
1367 "free()ed/realloc()ed-away memory was overwritten")
1369 # define FILLCHECK_DEADBEEF(s, n) ((void)0)
1373 Perl_malloc(register size_t nbytes)
1375 register union overhead *p;
1376 register int bucket;
1377 register MEM_SIZE shiftr;
1379 #if defined(DEBUGGING) || defined(RCHECK)
1380 MEM_SIZE size = nbytes;
1383 BARK_64K_LIMIT("Allocation",nbytes,nbytes);
1385 if ((long)nbytes < 0)
1386 croak("%s", "panic: malloc");
1390 * Convert amount of memory requested into
1391 * closest block size stored in hash buckets
1392 * which satisfies request. Account for
1393 * space used per block for accounting.
1396 # ifdef SMALL_BUCKET_VIA_TABLE
1398 bucket = MIN_BUCKET;
1399 else if (nbytes <= SIZE_TABLE_MAX) {
1400 bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
1405 if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
1410 POW2_OPTIMIZE_ADJUST(nbytes);
1411 nbytes += M_OVERHEAD;
1412 nbytes = (nbytes + 3) &~ 3;
1413 #if defined(PACK_MALLOC) && !defined(SMALL_BUCKET_VIA_TABLE)
1416 shiftr = (nbytes - 1) >> START_SHIFT;
1417 bucket = START_SHIFTS_BUCKET;
1418 /* apart from this loop, this is O(1) */
1419 while (shiftr >>= 1)
1420 bucket += BUCKETS_PER_POW2;
1424 * If nothing in hash bucket right now,
1425 * request more memory from the system.
1427 if (nextf[bucket] == NULL)
1429 if ((p = nextf[bucket]) == NULL) {
1435 #if defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC)
1436 PerlIO_puts(PerlIO_stderr(),"Out of memory!\n");
1439 char *eb = buff + sizeof(buff) - 1;
1443 PerlIO_puts(PerlIO_stderr(),"Out of memory during request for ");
1444 #if defined(DEBUGGING) || defined(RCHECK)
1449 *--s = '0' + (n % 10);
1451 PerlIO_puts(PerlIO_stderr(),s);
1452 PerlIO_puts(PerlIO_stderr()," bytes, total sbrk() is ");
1454 n = goodsbrk + sbrk_slack;
1456 *--s = '0' + (n % 10);
1458 PerlIO_puts(PerlIO_stderr(),s);
1459 PerlIO_puts(PerlIO_stderr()," bytes!\n");
1460 #endif /* defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC) */
1468 /* remove from linked list */
1470 if ( (PTR2UV(p) & (MEM_ALIGNBYTES - 1))
1471 /* Can't get this low */
1472 || (p && PTR2UV(p) < (1<<LOG_OF_MIN_ARENA)) ) {
1474 PerlIO_printf(PerlIO_stderr(),
1475 "Unaligned pointer in the free chain 0x%"UVxf"\n",
1478 if ( (PTR2UV(p->ov_next) & (MEM_ALIGNBYTES - 1))
1479 || (p->ov_next && PTR2UV(p->ov_next) < (1<<LOG_OF_MIN_ARENA)) ) {
1481 PerlIO_printf(PerlIO_stderr(),
1482 "Unaligned `next' pointer in the free "
1483 "chain 0x%"UVxf" at 0x%"UVxf"\n",
1484 PTR2UV(p->ov_next), PTR2UV(p));
1487 nextf[bucket] = p->ov_next;
1491 DEBUG_m(PerlIO_printf(Perl_debug_log,
1492 "0x%"UVxf": (%05lu) malloc %ld bytes\n",
1493 PTR2UV((Malloc_t)(p + CHUNK_SHIFT)), (unsigned long)(PL_an++),
1496 FILLCHECK_DEADBEEF((unsigned char*)(p + CHUNK_SHIFT),
1497 BUCKET_SIZE_REAL(bucket));
1499 #ifdef IGNORE_SMALL_BAD_FREE
1500 if (bucket >= FIRST_BUCKET_WITH_CHECK)
1502 OV_MAGIC(p, bucket) = MAGIC;
1504 OV_INDEX(p) = bucket;
1508 * Record allocated size of block and
1509 * bound space with magic numbers.
1511 p->ov_rmagic = RMAGIC;
1512 if (bucket <= MAX_SHORT_BUCKET) {
1515 nbytes = size + M_OVERHEAD;
1516 p->ov_size = nbytes - 1;
1517 if ((i = nbytes & 3)) {
1520 *((char *)((caddr_t)p + nbytes - RSLOP + i)) = RMAGIC_C;
1522 nbytes = (nbytes + 3) &~ 3;
1523 *((u_int *)((caddr_t)p + nbytes - RSLOP)) = RMAGIC;
1525 FILL_FEEDADAD((unsigned char *)(p + CHUNK_SHIFT), size);
1527 return ((Malloc_t)(p + CHUNK_SHIFT));
1530 static char *last_sbrk_top;
1531 static char *last_op; /* This arena can be easily extended. */
1532 static MEM_SIZE sbrked_remains;
1534 #ifdef DEBUGGING_MSTATS
1538 struct chunk_chain_s {
1539 struct chunk_chain_s *next;
1542 static struct chunk_chain_s *chunk_chain;
1543 static int n_chunks;
1544 static char max_bucket;
1546 /* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */
1548 get_from_chain(MEM_SIZE size)
1550 struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
1551 struct chunk_chain_s **oldgoodp = NULL;
1552 long min_remain = LONG_MAX;
1555 if (elt->size >= size) {
1556 long remains = elt->size - size;
1557 if (remains >= 0 && remains < min_remain) {
1559 min_remain = remains;
1565 oldp = &( elt->next );
1568 if (!oldgoodp) return NULL;
1570 void *ret = *oldgoodp;
1571 struct chunk_chain_s *next = (*oldgoodp)->next;
1573 *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
1574 (*oldgoodp)->size = min_remain;
1575 (*oldgoodp)->next = next;
1578 void *ret = *oldgoodp;
1579 *oldgoodp = (*oldgoodp)->next;
1586 add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
1588 struct chunk_chain_s *next = chunk_chain;
1589 char *cp = (char*)p;
1592 chunk_chain = (struct chunk_chain_s *)cp;
1593 chunk_chain->size = size - chip;
1594 chunk_chain->next = next;
1599 get_from_bigger_buckets(int bucket, MEM_SIZE size)
1602 static int bucketprice[NBUCKETS];
1603 while (bucket <= max_bucket) {
1604 /* We postpone stealing from bigger buckets until we want it
1606 if (nextf[bucket] && bucketprice[bucket]++ >= price) {
1608 void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
1609 bucketprice[bucket] = 0;
1610 if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
1611 last_op = NULL; /* Disable optimization */
1613 nextf[bucket] = nextf[bucket]->ov_next;
1614 #ifdef DEBUGGING_MSTATS
1616 start_slack -= M_OVERHEAD;
1618 add_to_chain(ret, (BUCKET_SIZE(bucket) +
1619 POW2_OPTIMIZE_SURPLUS(bucket)),
1628 static union overhead *
1629 getpages(MEM_SIZE needed, int *nblksp, int bucket)
1631 /* Need to do (possibly expensive) system call. Try to
1632 optimize it for rare calling. */
1633 MEM_SIZE require = needed - sbrked_remains;
1635 union overhead *ovp;
1638 if (sbrk_goodness > 0) {
1639 if (!last_sbrk_top && require < FIRST_SBRK)
1640 require = FIRST_SBRK;
1641 else if (require < MIN_SBRK) require = MIN_SBRK;
1643 if (require < goodsbrk * MIN_SBRK_FRAC1000 / 1000)
1644 require = goodsbrk * MIN_SBRK_FRAC1000 / 1000;
1645 require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
1652 DEBUG_m(PerlIO_printf(Perl_debug_log,
1653 "sbrk(%ld) for %ld-byte-long arena\n",
1654 (long)require, (long) needed));
1655 cp = (char *)sbrk(require);
1656 #ifdef DEBUGGING_MSTATS
1659 if (cp == last_sbrk_top) {
1660 /* Common case, anything is fine. */
1662 ovp = (union overhead *) (cp - sbrked_remains);
1663 last_op = cp - sbrked_remains;
1664 sbrked_remains = require - (needed - sbrked_remains);
1665 } else if (cp == (char *)-1) { /* no more room! */
1666 ovp = (union overhead *)emergency_sbrk(needed);
1667 if (ovp == (union overhead *)-1)
1669 if (((char*)ovp) > last_op) { /* Cannot happen with current emergency_sbrk() */
1673 } else { /* Non-continuous or first sbrk(). */
1674 long add = sbrked_remains;
1677 if (sbrked_remains) { /* Put rest into chain, we
1678 cannot use it right now. */
1679 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1683 /* Second, check alignment. */
1686 #if !defined(atarist) && !defined(__MINT__) /* on the atari we dont have to worry about this */
1687 # ifndef I286 /* The sbrk(0) call on the I286 always returns the next segment */
1688 /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
1689 improve performance of memory access. */
1690 if (PTR2UV(cp) & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
1691 slack = WANTED_ALIGNMENT - (PTR2UV(cp) & (WANTED_ALIGNMENT - 1));
1695 #endif /* !atarist && !MINT */
1698 DEBUG_m(PerlIO_printf(Perl_debug_log,
1699 "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",
1700 (long)add, (long) slack,
1701 (long) sbrked_remains));
1702 newcp = (char *)sbrk(add);
1703 #if defined(DEBUGGING_MSTATS)
1707 if (newcp != cp + require) {
1708 /* Too bad: even rounding sbrk() is not continuous.*/
1709 DEBUG_m(PerlIO_printf(Perl_debug_log,
1710 "failed to fix bad sbrk()\n"));
1714 fatalcroak("panic: Off-page sbrk\n");
1717 if (sbrked_remains) {
1719 #if defined(DEBUGGING_MSTATS)
1720 sbrk_slack += require;
1723 DEBUG_m(PerlIO_printf(Perl_debug_log,
1724 "straight sbrk(%ld)\n",
1726 cp = (char *)sbrk(require);
1727 #ifdef DEBUGGING_MSTATS
1730 if (cp == (char *)-1)
1733 sbrk_goodness = -1; /* Disable optimization!
1734 Continue with not-aligned... */
1737 require += sbrked_remains;
1741 if (last_sbrk_top) {
1742 sbrk_goodness -= SBRK_FAILURE_PRICE;
1745 ovp = (union overhead *) cp;
1747 * Round up to minimum allocation size boundary
1748 * and deduct from block count to reflect.
1751 # if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
1752 if (PTR2UV(ovp) & (NEEDED_ALIGNMENT - 1))
1753 fatalcroak("Misalignment of sbrk()\n");
1756 #ifndef I286 /* Again, this should always be ok on an 80286 */
1757 if (PTR2UV(ovp) & (MEM_ALIGNBYTES - 1)) {
1758 DEBUG_m(PerlIO_printf(Perl_debug_log,
1759 "fixing sbrk(): %d bytes off machine alignement\n",
1760 (int)(PTR2UV(ovp) & (MEM_ALIGNBYTES - 1))));
1761 ovp = INT2PTR(union overhead *,(PTR2UV(ovp) + MEM_ALIGNBYTES) &
1762 (MEM_ALIGNBYTES - 1));
1764 # if defined(DEBUGGING_MSTATS)
1765 /* This is only approx. if TWO_POT_OPTIMIZE: */
1766 sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
1770 ; /* Finish `else' */
1771 sbrked_remains = require - needed;
1774 #if !defined(PLAIN_MALLOC) && !defined(NO_FANCY_MALLOC)
1775 emergency_buffer_last_req = 0;
1777 last_sbrk_top = cp + require;
1778 #ifdef DEBUGGING_MSTATS
1779 goodsbrk += require;
1785 getpages_adjacent(MEM_SIZE require)
1787 if (require <= sbrked_remains) {
1788 sbrked_remains -= require;
1792 require -= sbrked_remains;
1793 /* We do not try to optimize sbrks here, we go for place. */
1794 cp = (char*) sbrk(require);
1795 #ifdef DEBUGGING_MSTATS
1797 goodsbrk += require;
1799 if (cp == last_sbrk_top) {
1801 last_sbrk_top = cp + require;
1803 if (cp == (char*)-1) { /* Out of memory */
1804 #ifdef DEBUGGING_MSTATS
1805 goodsbrk -= require;
1809 /* Report the failure: */
1811 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1813 add_to_chain((void*)cp, require, 0);
1814 sbrk_goodness -= SBRK_FAILURE_PRICE;
1826 * Allocate more memory to the indicated bucket.
1829 morecore(register int bucket)
1831 register union overhead *ovp;
1832 register int rnu; /* 2^rnu bytes will be requested */
1833 int nblks; /* become nblks blocks of the desired size */
1834 register MEM_SIZE siz, needed;
1835 static int were_called = 0;
1839 #ifndef NO_PERL_MALLOC_ENV
1841 /* It's the our first time. Initialize ourselves */
1842 were_called = 1; /* Avoid a loop */
1843 if (!MallocCfg[MallocCfg_skip_cfg_env]) {
1844 char *s = getenv("PERL_MALLOC_OPT"), *t = s, *off;
1845 const char *opts = PERL_MALLOC_OPT_CHARS;
1848 while ( t && t[0] && t[1] == '='
1849 && ((off = strchr(opts, *t))) ) {
1853 while (*t <= '9' && *t >= '0')
1854 val = 10*val + *t++ - '0';
1855 if (!*t || *t == ';') {
1856 if (MallocCfg[off - opts] != val)
1858 MallocCfg[off - opts] = val;
1864 write2("Unrecognized part of PERL_MALLOC_OPT: `");
1869 MallocCfg[MallocCfg_cfg_env_read] = 1;
1873 if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
1875 croak("%s", "Out of memory during ridiculously large request");
1877 if (bucket > max_bucket)
1878 max_bucket = bucket;
1880 rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT))
1882 : (bucket >> BUCKET_POW2_SHIFT) );
1883 /* This may be overwritten later: */
1884 nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
1885 needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
1886 if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
1887 ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
1888 nextf[rnu << BUCKET_POW2_SHIFT]
1889 = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
1890 #ifdef DEBUGGING_MSTATS
1891 nmalloc[rnu << BUCKET_POW2_SHIFT]--;
1892 start_slack -= M_OVERHEAD;
1894 DEBUG_m(PerlIO_printf(Perl_debug_log,
1895 "stealing %ld bytes from %ld arena\n",
1896 (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
1897 } else if (chunk_chain
1898 && (ovp = (union overhead*) get_from_chain(needed))) {
1899 DEBUG_m(PerlIO_printf(Perl_debug_log,
1900 "stealing %ld bytes from chain\n",
1902 } else if ( (ovp = (union overhead*)
1903 get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
1905 DEBUG_m(PerlIO_printf(Perl_debug_log,
1906 "stealing %ld bytes from bigger buckets\n",
1908 } else if (needed <= sbrked_remains) {
1909 ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
1910 sbrked_remains -= needed;
1911 last_op = (char*)ovp;
1913 ovp = getpages(needed, &nblks, bucket);
1917 FILL_DEADBEEF((unsigned char*)ovp, needed);
1920 * Add new memory allocated to that on
1921 * free list for this hash bucket.
1923 siz = BUCKET_SIZE(bucket);
1925 *(u_char*)ovp = bucket; /* Fill index. */
1926 if (bucket <= MAX_PACKED) {
1927 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1928 nblks = N_BLKS(bucket);
1929 # ifdef DEBUGGING_MSTATS
1930 start_slack += BLK_SHIFT(bucket);
1932 } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
1933 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1934 siz -= sizeof(union overhead);
1935 } else ovp++; /* One chunk per block. */
1936 #endif /* PACK_MALLOC */
1937 nextf[bucket] = ovp;
1938 #ifdef DEBUGGING_MSTATS
1939 nmalloc[bucket] += nblks;
1940 if (bucket > MAX_PACKED) {
1941 start_slack += M_OVERHEAD * nblks;
1945 while (--nblks > 0) {
1946 ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
1947 ovp = (union overhead *)((caddr_t)ovp + siz);
1949 /* Not all sbrks return zeroed memory.*/
1950 ovp->ov_next = (union overhead *)NULL;
1952 if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
1953 union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
1954 nextf[7*BUCKETS_PER_POW2] =
1955 (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2]
1956 - sizeof(union overhead));
1957 nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
1959 #endif /* !PACK_MALLOC */
1963 Perl_mfree(void *mp)
1965 register MEM_SIZE size;
1966 register union overhead *ovp;
1967 char *cp = (char*)mp;
1972 DEBUG_m(PerlIO_printf(Perl_debug_log,
1973 "0x%"UVxf": (%05lu) free\n",
1974 PTR2UV(cp), (unsigned long)(PL_an++)));
1979 if (PTR2UV(cp) & (MEM_ALIGNBYTES - 1))
1980 croak("%s", "wrong alignment in free()");
1982 ovp = (union overhead *)((caddr_t)cp
1983 - sizeof (union overhead) * CHUNK_SHIFT);
1985 bucket = OV_INDEX(ovp);
1987 #ifdef IGNORE_SMALL_BAD_FREE
1988 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1989 && (OV_MAGIC(ovp, bucket) != MAGIC))
1991 if (OV_MAGIC(ovp, bucket) != MAGIC)
1994 static int bad_free_warn = -1;
1995 if (bad_free_warn == -1) {
1997 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1998 bad_free_warn = (pbf) ? atoi(pbf) : 1;
2006 if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2007 Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%s free() ignored (RMAGIC, PERL_CORE)",
2008 ovp->ov_rmagic == RMAGIC - 1 ?
2009 "Duplicate" : "Bad");
2012 warn("%s free() ignored (RMAGIC)",
2013 ovp->ov_rmagic == RMAGIC - 1 ? "Duplicate" : "Bad");
2019 if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2020 Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%s", "Bad free() ignored (PERL_CORE)");
2023 warn("%s", "Bad free() ignored");
2026 return; /* sanity */
2029 ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
2030 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
2032 MEM_SIZE nbytes = ovp->ov_size + 1;
2034 if ((i = nbytes & 3)) {
2037 ASSERT(*((char *)((caddr_t)ovp + nbytes - RSLOP + i))
2038 == RMAGIC_C, "chunk's tail overwrite");
2041 nbytes = (nbytes + 3) &~ 3;
2042 ASSERT(*(u_int *)((caddr_t)ovp + nbytes - RSLOP) == RMAGIC, "chunk's tail overwrite");
2043 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nbytes - RSLOP + sizeof(u_int)),
2044 BUCKET_SIZE_REAL(OV_INDEX(ovp)) - (nbytes - RSLOP + sizeof(u_int)));
2046 FILL_DEADBEEF((unsigned char*)(ovp+1), BUCKET_SIZE_REAL(OV_INDEX(ovp)));
2047 ovp->ov_rmagic = RMAGIC - 1;
2049 ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
2050 size = OV_INDEX(ovp);
2053 ovp->ov_next = nextf[size];
2058 /* There is no need to do any locking in realloc (with an exception of
2059 trying to grow in place if we are at the end of the chain).
2060 If somebody calls us from a different thread with the same address,
2061 we are sole anyway. */
2064 Perl_realloc(void *mp, size_t nbytes)
2066 register MEM_SIZE onb;
2067 union overhead *ovp;
2070 register int bucket;
2071 int incr; /* 1 if does not fit, -1 if "easily" fits in a
2072 smaller bucket, otherwise 0. */
2073 char *cp = (char*)mp;
2075 #if defined(DEBUGGING) || !defined(PERL_CORE)
2076 MEM_SIZE size = nbytes;
2078 if ((long)nbytes < 0)
2079 croak("%s", "panic: realloc");
2082 BARK_64K_LIMIT("Reallocation",nbytes,size);
2084 return Perl_malloc(nbytes);
2086 ovp = (union overhead *)((caddr_t)cp
2087 - sizeof (union overhead) * CHUNK_SHIFT);
2088 bucket = OV_INDEX(ovp);
2090 #ifdef IGNORE_SMALL_BAD_FREE
2091 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
2092 && (OV_MAGIC(ovp, bucket) != MAGIC))
2094 if (OV_MAGIC(ovp, bucket) != MAGIC)
2097 static int bad_free_warn = -1;
2098 if (bad_free_warn == -1) {
2100 char *pbf = PerlEnv_getenv("PERL_BADFREE");
2101 bad_free_warn = (pbf) ? atoi(pbf) : 1;
2109 if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2110 Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%srealloc() %signored",
2111 (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
2112 ovp->ov_rmagic == RMAGIC - 1
2113 ? "of freed memory " : "");
2116 warn2("%srealloc() %signored",
2117 (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
2118 ovp->ov_rmagic == RMAGIC - 1 ? "of freed memory " : "");
2124 if (!PERL_IS_ALIVE || !PL_curcop || ckWARN_d(WARN_MALLOC))
2125 Perl_warner(aTHX_ packWARN(WARN_MALLOC), "%s",
2126 "Bad realloc() ignored");
2129 warn("%s", "Bad realloc() ignored");
2132 return Nullch; /* sanity */
2135 onb = BUCKET_SIZE_REAL(bucket);
2137 * avoid the copy if same size block.
2138 * We are not agressive with boundary cases. Note that it might
2139 * (for a small number of cases) give false negative if
2140 * both new size and old one are in the bucket for
2141 * FIRST_BIG_POW2, but the new one is near the lower end.
2143 * We do not try to go to 1.5 times smaller bucket so far.
2145 if (nbytes > onb) incr = 1;
2147 #ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
2148 if ( /* This is a little bit pessimal if PACK_MALLOC: */
2149 nbytes > ( (onb >> 1) - M_OVERHEAD )
2150 # ifdef TWO_POT_OPTIMIZE
2151 || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
2154 #else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
2155 prev_bucket = ( (bucket > MAX_PACKED + 1)
2156 ? bucket - BUCKETS_PER_POW2
2158 if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
2159 #endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
2163 #ifdef STRESS_REALLOC
2170 * Record new allocated size of block and
2171 * bound space with magic numbers.
2173 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
2174 int i, nb = ovp->ov_size + 1;
2179 ASSERT(*((char *)((caddr_t)ovp + nb - RSLOP + i)) == RMAGIC_C, "chunk's tail overwrite");
2183 ASSERT(*(u_int *)((caddr_t)ovp + nb - RSLOP) == RMAGIC, "chunk's tail overwrite");
2184 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nb - RSLOP + sizeof(u_int)),
2185 BUCKET_SIZE_REAL(OV_INDEX(ovp)) - (nb - RSLOP + sizeof(u_int)));
2186 if (nbytes > ovp->ov_size + 1 - M_OVERHEAD)
2187 FILL_FEEDADAD((unsigned char*)cp + ovp->ov_size + 1 - M_OVERHEAD,
2188 nbytes - (ovp->ov_size + 1 - M_OVERHEAD));
2190 FILL_DEADBEEF((unsigned char*)cp + nbytes,
2191 nb - M_OVERHEAD + RSLOP - nbytes);
2193 * Convert amount of memory requested into
2194 * closest block size stored in hash buckets
2195 * which satisfies request. Account for
2196 * space used per block for accounting.
2198 nbytes += M_OVERHEAD;
2199 ovp->ov_size = nbytes - 1;
2200 if ((i = nbytes & 3)) {
2203 *((char *)((caddr_t)ovp + nbytes - RSLOP + i))
2206 nbytes = (nbytes + 3) &~ 3;
2207 *((u_int *)((caddr_t)ovp + nbytes - RSLOP)) = RMAGIC;
2211 DEBUG_m(PerlIO_printf(Perl_debug_log,
2212 "0x%"UVxf": (%05lu) realloc %ld bytes inplace\n",
2213 PTR2UV(res),(unsigned long)(PL_an++),
2215 } else if (incr == 1 && (cp - M_OVERHEAD == last_op)
2216 && (onb > (1 << LOG_OF_MIN_ARENA))) {
2217 MEM_SIZE require, newarena = nbytes, pow;
2220 POW2_OPTIMIZE_ADJUST(newarena);
2221 newarena = newarena + M_OVERHEAD;
2222 /* newarena = (newarena + 3) &~ 3; */
2223 shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
2224 pow = LOG_OF_MIN_ARENA + 1;
2225 /* apart from this loop, this is O(1) */
2226 while (shiftr >>= 1)
2228 newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
2229 require = newarena - onb - M_OVERHEAD;
2232 if (cp - M_OVERHEAD == last_op /* We *still* are the last chunk */
2233 && getpages_adjacent(require)) {
2234 #ifdef DEBUGGING_MSTATS
2236 nmalloc[pow * BUCKETS_PER_POW2]++;
2238 *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
2247 DEBUG_m(PerlIO_printf(Perl_debug_log,
2248 "0x%"UVxf": (%05lu) realloc %ld bytes the hard way\n",
2249 PTR2UV(cp),(unsigned long)(PL_an++),
2251 if ((res = (char*)Perl_malloc(nbytes)) == NULL)
2253 if (cp != res) /* common optimization */
2254 Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
2257 return ((Malloc_t)res);
2261 Perl_calloc(register size_t elements, register size_t size)
2263 long sz = elements * size;
2264 Malloc_t p = Perl_malloc(sz);
2267 memset((void*)p, 0, sz);
2273 Perl_strdup(const char *s)
2275 MEM_SIZE l = strlen(s);
2276 char *s1 = (char *)Perl_malloc(l+1);
2278 Copy(s, s1, (MEM_SIZE)(l+1), char);
2284 Perl_putenv(char *a)
2286 /* Sometimes system's putenv conflicts with my_setenv() - this is system
2287 malloc vs Perl's free(). */
2294 while (*val && *val != '=')
2299 if (l < sizeof(buf))
2302 var = Perl_malloc(l + 1);
2303 Copy(a, var, l, char);
2305 my_setenv(var, val+1);
2313 Perl_malloced_size(void *p)
2315 union overhead *ovp = (union overhead *)
2316 ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
2317 int bucket = OV_INDEX(ovp);
2319 /* The caller wants to have a complete control over the chunk,
2320 disable the memory checking inside the chunk. */
2321 if (bucket <= MAX_SHORT_BUCKET) {
2322 MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
2323 ovp->ov_size = size + M_OVERHEAD - 1;
2324 *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RSLOP)) = RMAGIC;
2327 return BUCKET_SIZE_REAL(bucket);
2330 # ifdef BUCKETS_ROOT2
2331 # define MIN_EVEN_REPORT 6
2333 # define MIN_EVEN_REPORT MIN_BUCKET
2337 Perl_get_mstats(pTHX_ perl_mstats_t *buf, int buflen, int level)
2339 #ifdef DEBUGGING_MSTATS
2341 register union overhead *p;
2342 struct chunk_chain_s* nextchain;
2344 buf->topbucket = buf->topbucket_ev = buf->topbucket_odd
2345 = buf->totfree = buf->total = buf->total_chain = 0;
2347 buf->minbucket = MIN_BUCKET;
2349 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2350 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
2354 buf->ntotal[i] = nmalloc[i];
2356 buf->totfree += j * BUCKET_SIZE_REAL(i);
2357 buf->total += nmalloc[i] * BUCKET_SIZE_REAL(i);
2359 i % 2 ? (buf->topbucket_odd = i) : (buf->topbucket_ev = i);
2363 nextchain = chunk_chain;
2365 buf->total_chain += nextchain->size;
2366 nextchain = nextchain->next;
2368 buf->total_sbrk = goodsbrk + sbrk_slack;
2370 buf->sbrk_good = sbrk_goodness;
2371 buf->sbrk_slack = sbrk_slack;
2372 buf->start_slack = start_slack;
2373 buf->sbrked_remains = sbrked_remains;
2375 buf->nbuckets = NBUCKETS;
2377 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2380 buf->bucket_mem_size[i] = BUCKET_SIZE(i);
2381 buf->bucket_available_size[i] = BUCKET_SIZE_REAL(i);
2384 #endif /* defined DEBUGGING_MSTATS */
2385 return 0; /* XXX unused */
2388 * mstats - print out statistics about malloc
2390 * Prints two lines of numbers, one showing the length of the free list
2391 * for each size category, the second showing the number of mallocs -
2392 * frees for each size category.
2395 Perl_dump_mstats(pTHX_ char *s)
2397 #ifdef DEBUGGING_MSTATS
2399 perl_mstats_t buffer;
2405 get_mstats(&buffer, NBUCKETS, 0);
2408 PerlIO_printf(Perl_error_log,
2409 "Memory allocation statistics %s (buckets %"IVdf"(%"IVdf")..%"IVdf"(%"IVdf")\n",
2411 (IV)BUCKET_SIZE_REAL(MIN_BUCKET),
2412 (IV)BUCKET_SIZE(MIN_BUCKET),
2413 (IV)BUCKET_SIZE_REAL(buffer.topbucket),
2414 (IV)BUCKET_SIZE(buffer.topbucket));
2415 PerlIO_printf(Perl_error_log, "%8"IVdf" free:", buffer.totfree);
2416 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2417 PerlIO_printf(Perl_error_log,
2418 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2420 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2423 #ifdef BUCKETS_ROOT2
2424 PerlIO_printf(Perl_error_log, "\n\t ");
2425 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2426 PerlIO_printf(Perl_error_log,
2427 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2429 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2433 PerlIO_printf(Perl_error_log, "\n%8"IVdf" used:", buffer.total - buffer.totfree);
2434 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2435 PerlIO_printf(Perl_error_log,
2436 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2438 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2439 buffer.ntotal[i] - buffer.nfree[i]);
2441 #ifdef BUCKETS_ROOT2
2442 PerlIO_printf(Perl_error_log, "\n\t ");
2443 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2444 PerlIO_printf(Perl_error_log,
2445 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2447 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2448 buffer.ntotal[i] - buffer.nfree[i]);
2451 PerlIO_printf(Perl_error_log, "\nTotal sbrk(): %"IVdf"/%"IVdf":%"IVdf". Odd ends: pad+heads+chain+tail: %"IVdf"+%"IVdf"+%"IVdf"+%"IVdf".\n",
2452 buffer.total_sbrk, buffer.sbrks, buffer.sbrk_good,
2453 buffer.sbrk_slack, buffer.start_slack,
2454 buffer.total_chain, buffer.sbrked_remains);
2455 #endif /* DEBUGGING_MSTATS */
2459 #ifdef USE_PERL_SBRK
2461 # if defined(__MACHTEN_PPC__) || defined(NeXT) || defined(__NeXT__) || defined(PURIFY)
2462 # define PERL_SBRK_VIA_MALLOC
2465 # ifdef PERL_SBRK_VIA_MALLOC
2467 /* it may seem schizophrenic to use perl's malloc and let it call system */
2468 /* malloc, the reason for that is only the 3.2 version of the OS that had */
2469 /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
2470 /* end to the cores */
2472 # ifndef SYSTEM_ALLOC
2473 # define SYSTEM_ALLOC(a) malloc(a)
2475 # ifndef SYSTEM_ALLOC_ALIGNMENT
2476 # define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
2479 # endif /* PERL_SBRK_VIA_MALLOC */
2481 static IV Perl_sbrk_oldchunk;
2482 static long Perl_sbrk_oldsize;
2484 # define PERLSBRK_32_K (1<<15)
2485 # define PERLSBRK_64_K (1<<16)
2493 if (!size) return 0;
2495 reqsize = size; /* just for the DEBUG_m statement */
2498 size = (size + 0x7ff) & ~0x7ff;
2500 if (size <= Perl_sbrk_oldsize) {
2501 got = Perl_sbrk_oldchunk;
2502 Perl_sbrk_oldchunk += size;
2503 Perl_sbrk_oldsize -= size;
2505 if (size >= PERLSBRK_32_K) {
2508 size = PERLSBRK_64_K;
2511 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2512 size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT;
2514 got = (IV)SYSTEM_ALLOC(size);
2515 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2516 got = (got + NEEDED_ALIGNMENT - 1) & ~(NEEDED_ALIGNMENT - 1);
2519 /* Chunk is small, register the rest for future allocs. */
2520 Perl_sbrk_oldchunk = got + reqsize;
2521 Perl_sbrk_oldsize = size - reqsize;
2525 DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%"UVxf"\n",
2526 size, reqsize, Perl_sbrk_oldsize, PTR2UV(got)));
2531 #endif /* ! defined USE_PERL_SBRK */