6 * 'The Chamber of Records,' said Gimli. 'I guess that is where we now stand.'
8 * [p.321 of _The Lord of the Rings_, II/v: "The Bridge of Khazad-Dûm"]
11 /* This file contains Perl's own implementation of the malloc library.
12 * It is used if Configure decides that, on your platform, Perl's
13 * version is better than the OS's, or if you give Configure the
14 * -Dusemymalloc command-line option.
18 Here are some notes on configuring Perl's malloc.
20 There are two macros which serve as bulk disablers of advanced
21 features of this malloc: NO_FANCY_MALLOC, PLAIN_MALLOC (undef by
22 default). Look in the list of default values below to understand
23 their exact effect. Defining NO_FANCY_MALLOC returns malloc.c to the
24 state of the malloc in Perl 5.004. Additionally defining PLAIN_MALLOC
25 returns it to the state as of Perl 5.000.
27 Note that some of the settings below may be ignored in the code based
28 on values of other macros. The PERL_CORE symbol is only defined when
29 perl itself is being compiled (so malloc can make some assumptions
30 about perl's facilities being available to it).
32 Each config option has a short description, followed by its name,
33 default value, and a comment about the default (if applicable). Some
34 options take a precise value, while the others are just boolean.
35 The boolean ones are listed first.
37 # Read configuration settings from malloc_cfg.h
38 HAVE_MALLOC_CFG_H undef
40 # Enable code for an emergency memory pool in $^M. See perlvar.pod
41 # for a description of $^M.
42 PERL_EMERGENCY_SBRK !PLAIN_MALLOC
44 # Enable code for printing memory statistics.
45 DEBUGGING_MSTATS !PLAIN_MALLOC
47 # Move allocation info for small buckets into separate areas.
48 # Memory optimization (especially for small allocations, of the
49 # less than 64 bytes). Since perl usually makes a large number
50 # of small allocations, this is usually a win.
51 PACK_MALLOC (!PLAIN_MALLOC && !RCHECK)
53 # Add one page to big powers of two when calculating bucket size.
54 # This is targeted at big allocations, as are common in image
56 TWO_POT_OPTIMIZE !PLAIN_MALLOC
58 # Use intermediate bucket sizes between powers-of-two. This is
59 # generally a memory optimization, and a (small) speed pessimization.
60 BUCKETS_ROOT2 !NO_FANCY_MALLOC
62 # Do not check small deallocations for bad free(). Memory
63 # and speed optimization, error reporting pessimization.
64 IGNORE_SMALL_BAD_FREE (!NO_FANCY_MALLOC && !RCHECK)
66 # Use table lookup to decide in which bucket a given allocation will go.
67 SMALL_BUCKET_VIA_TABLE !NO_FANCY_MALLOC
69 # Use a perl-defined sbrk() instead of the (presumably broken or
70 # missing) system-supplied sbrk().
73 # Use system malloc() (or calloc() etc.) to emulate sbrk(). Normally
74 # only used with broken sbrk()s.
75 PERL_SBRK_VIA_MALLOC undef
77 # Which allocator to use if PERL_SBRK_VIA_MALLOC
78 SYSTEM_ALLOC(a) malloc(a)
80 # Minimal alignment (in bytes, should be a power of 2) of SYSTEM_ALLOC
81 SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
83 # Disable memory overwrite checking with DEBUGGING. Memory and speed
84 # optimization, error reporting pessimization.
87 # Enable memory overwrite checking with DEBUGGING. Memory and speed
88 # pessimization, error reporting optimization
89 RCHECK (DEBUGGING && !NO_RCHECK)
91 # Do not overwrite uninit areas with DEBUGGING. Speed
92 # optimization, error reporting pessimization
95 # Overwrite uninit areas with DEBUGGING. Speed
96 # pessimization, error reporting optimization
97 MALLOC_FILL (DEBUGGING && !NO_RCHECK && !NO_MFILL)
99 # Do not check overwritten uninit areas with DEBUGGING. Speed
100 # optimization, error reporting pessimization
103 # Check overwritten uninit areas with DEBUGGING. Speed
104 # pessimization, error reporting optimization
105 MALLOC_FILL_CHECK (DEBUGGING && !NO_RCHECK && !NO_FILL_CHECK)
107 # Failed allocations bigger than this size croak (if
108 # PERL_EMERGENCY_SBRK is enabled) without touching $^M. See
109 # perlvar.pod for a description of $^M.
110 BIG_SIZE (1<<16) # 64K
112 # Starting from this power of two, add an extra page to the
113 # size of the bucket. This enables optimized allocations of sizes
114 # close to powers of 2. Note that the value is indexed at 0.
115 FIRST_BIG_POW2 15 # 32K, 16K is used too often
117 # Estimate of minimal memory footprint. malloc uses this value to
118 # request the most reasonable largest blocks of memory from the system.
121 # Round up sbrk()s to multiples of this.
124 # Round up sbrk()s to multiples of this percent of footprint.
127 # Round up sbrk()s to multiples of this multiple of 1/1000 of footprint.
128 MIN_SBRK_FRAC1000 (10 * MIN_SBRK_FRAC)
130 # Add this much memory to big powers of two to get the bucket size.
133 # This many sbrk() discontinuities should be tolerated even
134 # from the start without deciding that sbrk() is usually
136 SBRK_ALLOW_FAILURES 3
138 # This many continuous sbrk()s compensate for one discontinuous one.
139 SBRK_FAILURE_PRICE 50
141 # Some configurations may ask for 12-byte-or-so allocations which
142 # require 8-byte alignment (?!). In such situation one needs to
143 # define this to disable 12-byte bucket (will increase memory footprint)
144 STRICT_ALIGNMENT undef
146 # Do not allow configuration of runtime options at runtime
147 NO_MALLOC_DYNAMIC_CFG undef
149 # Do not allow configuration of runtime options via $ENV{PERL_MALLOC_OPT}
150 NO_PERL_MALLOC_ENV undef
152 [The variable consists of ;-separated parts of the form CODE=VALUE
153 with 1-character codes F, M, f, A, P, G, d, a, c for runtime
154 configuration of FIRST_SBRK, MIN_SBRK, MIN_SBRK_FRAC1000,
155 SBRK_ALLOW_FAILURES, SBRK_FAILURE_PRICE, sbrk_goodness,
156 filldead, fillalive, fillcheck. The last 3 are for DEBUGGING
157 build, and allow switching the tests for free()ed memory read,
158 uninit memory reads, and free()ed memory write.]
160 This implementation assumes that calling PerlIO_printf() does not
161 result in any memory allocation calls (used during a panic).
166 #ifdef HAVE_MALLOC_CFG_H
167 # include "malloc_cfg.h"
170 #ifndef NO_FANCY_MALLOC
171 # ifndef SMALL_BUCKET_VIA_TABLE
172 # define SMALL_BUCKET_VIA_TABLE
174 # ifndef BUCKETS_ROOT2
175 # define BUCKETS_ROOT2
177 # ifndef IGNORE_SMALL_BAD_FREE
178 # define IGNORE_SMALL_BAD_FREE
182 #ifndef PLAIN_MALLOC /* Bulk enable features */
186 # ifndef TWO_POT_OPTIMIZE
187 # define TWO_POT_OPTIMIZE
189 # ifndef PERL_EMERGENCY_SBRK
190 # define PERL_EMERGENCY_SBRK
192 # ifndef DEBUGGING_MSTATS
193 # define DEBUGGING_MSTATS
197 #define MIN_BUC_POW2 (sizeof(void*) > 4 ? 3 : 2) /* Allow for 4-byte arena. */
198 #define MIN_BUCKET (MIN_BUC_POW2 * BUCKETS_PER_POW2)
200 #if !(defined(I286) || defined(atarist))
201 /* take 2k unless the block is bigger than that */
202 # define LOG_OF_MIN_ARENA 11
204 /* take 16k unless the block is bigger than that
205 (80286s like large segments!), probably good on the atari too */
206 # define LOG_OF_MIN_ARENA 14
209 #if defined(DEBUGGING) && !defined(NO_RCHECK)
212 #if defined(DEBUGGING) && !defined(NO_RCHECK) && !defined(NO_MFILL) && !defined(MALLOC_FILL)
215 #if defined(DEBUGGING) && !defined(NO_RCHECK) && !defined(NO_FILL_CHECK) && !defined(MALLOC_FILL_CHECK)
216 # define MALLOC_FILL_CHECK
218 #if defined(RCHECK) && defined(IGNORE_SMALL_BAD_FREE)
219 # undef IGNORE_SMALL_BAD_FREE
222 * malloc.c (Caltech) 2/21/82
223 * Chris Kingsley, kingsley@cit-20.
225 * This is a very fast storage allocator. It allocates blocks of a small
226 * number of different sizes, and keeps free lists of each size. Blocks that
227 * don't exactly fit are passed up to the next larger size. In this
228 * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
229 * If PACK_MALLOC is defined, small blocks are 2^n bytes long.
230 * This is designed for use in a program that uses vast quantities of memory,
231 * but bombs when it runs out.
233 * Modifications Copyright Ilya Zakharevich 1996-99.
235 * Still very quick, but much more thrifty. (Std config is 10% slower
236 * than it was, and takes 67% of old heap size for typical usage.)
238 * Allocations of small blocks are now table-driven to many different
239 * buckets. Sizes of really big buckets are increased to accommodate
240 * common size=power-of-2 blocks. Running-out-of-memory is made into
241 * an exception. Deeply configurable and thread-safe.
246 #define PERL_IN_MALLOC_C
248 #if defined(PERL_IMPLICIT_CONTEXT)
249 # define croak Perl_croak_nocontext
250 # define croak2 Perl_croak_nocontext
251 # define warn Perl_warn_nocontext
252 # define warn2 Perl_warn_nocontext
254 # define croak2 croak
258 # define PERL_MAYBE_ALIVE PL_thr_key
260 # define PERL_MAYBE_ALIVE 1
264 # define MUTEX_LOCK(l)
268 # define MUTEX_UNLOCK(l)
272 # define MALLOC_LOCK MUTEX_LOCK(&PL_malloc_mutex)
275 #ifndef MALLOC_UNLOCK
276 # define MALLOC_UNLOCK MUTEX_UNLOCK(&PL_malloc_mutex)
279 # ifndef fatalcroak /* make depend */
280 # define fatalcroak(mess) (write(2, (mess), strlen(mess)), exit(2))
285 # define DEBUG_m(a) \
287 if (PERL_MAYBE_ALIVE && PERL_GET_THX) { \
289 if (DEBUG_m_TEST) { \
290 PL_debug &= ~DEBUG_m_FLAG; \
292 PL_debug |= DEBUG_m_FLAG; \
298 #ifdef PERL_IMPLICIT_CONTEXT
299 # define PERL_IS_ALIVE aTHX
301 # define PERL_IS_ALIVE TRUE
308 * The memory is broken into "blocks" which occupy multiples of 2K (and
309 * generally speaking, have size "close" to a power of 2). The addresses
310 * of such *unused* blocks are kept in nextf[i] with big enough i. (nextf
311 * is an array of linked lists.) (Addresses of used blocks are not known.)
313 * Moreover, since the algorithm may try to "bite" smaller blocks out
314 * of unused bigger ones, there are also regions of "irregular" size,
315 * managed separately, by a linked list chunk_chain.
317 * The third type of storage is the sbrk()ed-but-not-yet-used space, its
318 * end and size are kept in last_sbrk_top and sbrked_remains.
320 * Growing blocks "in place":
321 * ~~~~~~~~~~~~~~~~~~~~~~~~~
322 * The address of the block with the greatest address is kept in last_op
323 * (if not known, last_op is 0). If it is known that the memory above
324 * last_op is not continuous, or contains a chunk from chunk_chain,
325 * last_op is set to 0.
327 * The chunk with address last_op may be grown by expanding into
328 * sbrk()ed-but-not-yet-used space, or trying to sbrk() more continuous
331 * Management of last_op:
332 * ~~~~~~~~~~~~~~~~~~~~~
334 * free() never changes the boundaries of blocks, so is not relevant.
336 * The only way realloc() may change the boundaries of blocks is if it
337 * grows a block "in place". However, in the case of success such a
338 * chunk is automatically last_op, and it remains last_op. In the case
339 * of failure getpages_adjacent() clears last_op.
341 * malloc() may change blocks by calling morecore() only.
343 * morecore() may create new blocks by:
344 * a) biting pieces from chunk_chain (cannot create one above last_op);
345 * b) biting a piece from an unused block (if block was last_op, this
346 * may create a chunk from chain above last_op, thus last_op is
347 * invalidated in such a case).
348 * c) biting of sbrk()ed-but-not-yet-used space. This creates
349 * a block which is last_op.
350 * d) Allocating new pages by calling getpages();
352 * getpages() creates a new block. It marks last_op at the bottom of
353 * the chunk of memory it returns.
355 * Active pages footprint:
356 * ~~~~~~~~~~~~~~~~~~~~~~
357 * Note that we do not need to traverse the lists in nextf[i], just take
358 * the first element of this list. However, we *need* to traverse the
359 * list in chunk_chain, but most the time it should be a very short one,
360 * so we do not step on a lot of pages we are not going to use.
364 * get_from_bigger_buckets(): forget to increment price => Quite
368 /* I don't much care whether these are defined in sys/types.h--LAW */
370 #define u_char unsigned char
371 #define u_int unsigned int
373 * I removed the definition of u_bigint which appeared to be u_bigint = UV
374 * u_bigint was only used in TWOK_MASKED and TWOK_SHIFT
375 * where I have used PTR2UV. RMB
377 #define u_short unsigned short
379 /* 286 and atarist like big chunks, which gives too much overhead. */
380 #if (defined(RCHECK) || defined(I286) || defined(atarist)) && defined(PACK_MALLOC)
385 * The description below is applicable if PACK_MALLOC is not defined.
387 * The overhead on a block is at least 4 bytes. When free, this space
388 * contains a pointer to the next free block, and the bottom two bits must
389 * be zero. When in use, the first byte is set to MAGIC, and the second
390 * byte is the size index. The remaining bytes are for alignment.
391 * If range checking is enabled and the size of the block fits
392 * in two bytes, then the top two bytes hold the size of the requested block
393 * plus the range checking words, and the header word MINUS ONE.
396 union overhead *ov_next; /* when free */
397 #if MEM_ALIGNBYTES > 4
398 double strut; /* alignment problems */
399 # if MEM_ALIGNBYTES > 8
400 char sstrut[MEM_ALIGNBYTES]; /* for the sizing */
405 * Keep the ovu_index and ovu_magic in this order, having a char
406 * field first gives alignment indigestion in some systems, such as
409 u_char ovu_index; /* bucket # */
410 u_char ovu_magic; /* magic number */
412 /* Subtract one to fit into u_short for an extra bucket */
413 u_short ovu_size; /* block size (requested + overhead - 1) */
414 u_int ovu_rmagic; /* range magic number */
417 #define ov_magic ovu.ovu_magic
418 #define ov_index ovu.ovu_index
419 #define ov_size ovu.ovu_size
420 #define ov_rmagic ovu.ovu_rmagic
423 #define MAGIC 0xff /* magic # on accounting info */
424 #define RMAGIC 0x55555555 /* magic # on range info */
425 #define RMAGIC_C 0x55 /* magic # on range info */
428 # define RMAGIC_SZ sizeof (u_int) /* Overhead at end of bucket */
429 # ifdef TWO_POT_OPTIMIZE
430 # define MAX_SHORT_BUCKET (12 * BUCKETS_PER_POW2) /* size-1 fits in short */
432 # define MAX_SHORT_BUCKET (13 * BUCKETS_PER_POW2)
438 #if !defined(PACK_MALLOC) && defined(BUCKETS_ROOT2)
439 # undef BUCKETS_ROOT2
443 # define BUCKET_TABLE_SHIFT 2
444 # define BUCKET_POW2_SHIFT 1
445 # define BUCKETS_PER_POW2 2
447 # define BUCKET_TABLE_SHIFT MIN_BUC_POW2
448 # define BUCKET_POW2_SHIFT 0
449 # define BUCKETS_PER_POW2 1
452 #if !defined(MEM_ALIGNBYTES) || ((MEM_ALIGNBYTES > 4) && !defined(STRICT_ALIGNMENT))
453 /* Figure out the alignment of void*. */
458 # define ALIGN_SMALL ((int)((caddr_t)&(((struct aligner*)0)->p)))
460 # define ALIGN_SMALL MEM_ALIGNBYTES
463 #define IF_ALIGN_8(yes,no) ((ALIGN_SMALL>4) ? (yes) : (no))
466 # define MAX_BUCKET_BY_TABLE 13
467 static const u_short buck_size[MAX_BUCKET_BY_TABLE + 1] =
469 0, 0, 0, 0, 4, 4, 8, 12, 16, 24, 32, 48, 64, 80,
471 # define BUCKET_SIZE_NO_SURPLUS(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT)))
472 # define BUCKET_SIZE_REAL(i) ((i) <= MAX_BUCKET_BY_TABLE \
474 : ((1 << ((i) >> BUCKET_POW2_SHIFT)) \
476 + POW2_OPTIMIZE_SURPLUS(i)))
478 # define BUCKET_SIZE_NO_SURPLUS(i) (1 << ((i) >> BUCKET_POW2_SHIFT))
479 # define BUCKET_SIZE(i) (BUCKET_SIZE_NO_SURPLUS(i) + POW2_OPTIMIZE_SURPLUS(i))
480 # define BUCKET_SIZE_REAL(i) (BUCKET_SIZE(i) - MEM_OVERHEAD(i))
485 /* In this case there are several possible layout of arenas depending
486 * on the size. Arenas are of sizes multiple to 2K, 2K-aligned, and
487 * have a size close to a power of 2.
489 * Arenas of the size >= 4K keep one chunk only. Arenas of size 2K
490 * may keep one chunk or multiple chunks. Here are the possible
493 * # One chunk only, chunksize 2^k + SOMETHING - ALIGN, k >= 11
495 * INDEX MAGIC1 UNUSED CHUNK1
497 * # Multichunk with sanity checking and chunksize 2^k-ALIGN, k>7
499 * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 CHUNK2 CHUNK3 ...
501 * # Multichunk with sanity checking and size 2^k-ALIGN, k=7
503 * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 UNUSED CHUNK2 CHUNK3 ...
505 * # Multichunk with sanity checking and size up to 80
507 * INDEX UNUSED MAGIC1 UNUSED MAGIC2 UNUSED ... CHUNK1 CHUNK2 CHUNK3 ...
509 * # No sanity check (usually up to 48=byte-long buckets)
510 * INDEX UNUSED CHUNK1 CHUNK2 ...
512 * Above INDEX and MAGIC are one-byte-long. Sizes of UNUSED are
513 * appropriate to keep algorithms simple and memory aligned. INDEX
514 * encodes the size of the chunk, while MAGICn encodes state (used,
515 * free or non-managed-by-us-so-it-indicates-a-bug) of CHUNKn. MAGIC
516 * is used for sanity checking purposes only. SOMETHING is 0 or 4K
517 * (to make size of big CHUNK accommodate allocations for powers of two
520 * [There is no need to alignment between chunks, since C rules ensure
521 * that structs which need 2^k alignment have sizeof which is
522 * divisible by 2^k. Thus as far as the last chunk is aligned at the
523 * end of the arena, and 2K-alignment does not contradict things,
524 * everything is going to be OK for sizes of chunks 2^n and 2^n +
525 * 2^k. Say, 80-bit buckets will be 16-bit aligned, and as far as we
526 * put allocations for requests in 65..80 range, all is fine.
528 * Note, however, that standard malloc() puts more strict
529 * requirements than the above C rules. Moreover, our algorithms of
530 * realloc() may break this idyll, but we suppose that realloc() does
531 * need not change alignment.]
533 * Is very important to make calculation of the offset of MAGICm as
534 * quick as possible, since it is done on each malloc()/free(). In
535 * fact it is so quick that it has quite little effect on the speed of
536 * doing malloc()/free(). [By default] We forego such calculations
537 * for small chunks, but only to save extra 3% of memory, not because
538 * of speed considerations.
540 * Here is the algorithm [which is the same for all the allocations
541 * schemes above], see OV_MAGIC(block,bucket). Let OFFSETm be the
542 * offset of the CHUNKm from the start of ARENA. Then offset of
543 * MAGICm is (OFFSET1 >> SHIFT) + ADDOFFSET. Here SHIFT and ADDOFFSET
544 * are numbers which depend on the size of the chunks only.
546 * Let as check some sanity conditions. Numbers OFFSETm>>SHIFT are
547 * different for all the chunks in the arena if 2^SHIFT is not greater
548 * than size of the chunks in the arena. MAGIC1 will not overwrite
549 * INDEX provided ADDOFFSET is >0 if OFFSET1 < 2^SHIFT. MAGIClast
550 * will not overwrite CHUNK1 if OFFSET1 > (OFFSETlast >> SHIFT) +
553 * Make SHIFT the maximal possible (there is no point in making it
554 * smaller). Since OFFSETlast is 2K - CHUNKSIZE, above restrictions
555 * give restrictions on OFFSET1 and on ADDOFFSET.
557 * In particular, for chunks of size 2^k with k>=6 we can put
558 * ADDOFFSET to be from 0 to 2^k - 2^(11-k), and have
559 * OFFSET1==chunksize. For chunks of size 80 OFFSET1 of 2K%80=48 is
560 * large enough to have ADDOFFSET between 1 and 16 (similarly for 96,
561 * when ADDOFFSET should be 1). In particular, keeping MAGICs for
562 * these sizes gives no additional size penalty.
564 * However, for chunks of size 2^k with k<=5 this gives OFFSET1 >=
565 * ADDOFSET + 2^(11-k). Keeping ADDOFFSET 0 allows for 2^(11-k)-2^(11-2k)
566 * chunks per arena. This is smaller than 2^(11-k) - 1 which are
567 * needed if no MAGIC is kept. [In fact, having a negative ADDOFFSET
568 * would allow for slightly more buckets per arena for k=2,3.]
570 * Similarly, for chunks of size 3/2*2^k with k<=5 MAGICs would span
571 * the area up to 2^(11-k)+ADDOFFSET. For k=4 this give optimal
572 * ADDOFFSET as -7..0. For k=3 ADDOFFSET can go up to 4 (with tiny
573 * savings for negative ADDOFFSET). For k=5 ADDOFFSET can go -1..16
574 * (with no savings for negative values).
576 * In particular, keeping ADDOFFSET 0 for sizes of chunks up to 2^6
577 * leads to tiny pessimizations in case of sizes 4, 8, 12, 24, and
578 * leads to no contradictions except for size=80 (or 96.)
580 * However, it also makes sense to keep no magic for sizes 48 or less.
581 * This is what we do. In this case one needs ADDOFFSET>=1 also for
582 * chunksizes 12, 24, and 48, unless one gets one less chunk per
585 * The algo of OV_MAGIC(block,bucket) keeps ADDOFFSET 0 until
586 * chunksize of 64, then makes it 1.
588 * This allows for an additional optimization: the above scheme leads
589 * to giant overheads for sizes 128 or more (one whole chunk needs to
590 * be sacrifised to keep INDEX). Instead we use chunks not of size
591 * 2^k, but of size 2^k-ALIGN. If we pack these chunks at the end of
592 * the arena, then the beginnings are still in different 2^k-long
593 * sections of the arena if k>=7 for ALIGN==4, and k>=8 if ALIGN=8.
594 * Thus for k>7 the above algo of calculating the offset of the magic
595 * will still give different answers for different chunks. And to
596 * avoid the overrun of MAGIC1 into INDEX, one needs ADDOFFSET of >=1.
597 * In the case k=7 we just move the first chunk an extra ALIGN
598 * backward inside the ARENA (this is done once per arena lifetime,
599 * thus is not a big overhead). */
600 # define MAX_PACKED_POW2 6
601 # define MAX_PACKED (MAX_PACKED_POW2 * BUCKETS_PER_POW2 + BUCKET_POW2_SHIFT)
602 # define MAX_POW2_ALGO ((1<<(MAX_PACKED_POW2 + 1)) - M_OVERHEAD)
603 # define TWOK_MASK ((1<<LOG_OF_MIN_ARENA) - 1)
604 # define TWOK_MASKED(x) (PTR2UV(x) & ~TWOK_MASK)
605 # define TWOK_SHIFT(x) (PTR2UV(x) & TWOK_MASK)
606 # define OV_INDEXp(block) (INT2PTR(u_char*,TWOK_MASKED(block)))
607 # define OV_INDEX(block) (*OV_INDEXp(block))
608 # define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) + \
609 (TWOK_SHIFT(block)>> \
610 (bucket>>BUCKET_POW2_SHIFT)) + \
611 (bucket >= MIN_NEEDS_SHIFT ? 1 : 0)))
612 /* A bucket can have a shift smaller than it size, we need to
613 shift its magic number so it will not overwrite index: */
614 # ifdef BUCKETS_ROOT2
615 # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2 - 1) /* Shift 80 greater than chunk 64. */
617 # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2) /* Shift 128 greater than chunk 32. */
619 # define CHUNK_SHIFT 0
621 /* Number of active buckets of given ordinal. */
622 #ifdef IGNORE_SMALL_BAD_FREE
623 #define FIRST_BUCKET_WITH_CHECK (6 * BUCKETS_PER_POW2) /* 64 */
624 # define N_BLKS(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
625 ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE_NO_SURPLUS(bucket) \
628 # define N_BLKS(bucket) n_blks[bucket]
631 static const u_short n_blks[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
633 # if BUCKETS_PER_POW2==1
635 (MIN_BUC_POW2==2 ? 384 : 0),
636 224, 120, 62, 31, 16, 8, 4, 2
639 (MIN_BUC_POW2==2 ? 384 : 0), (MIN_BUC_POW2==2 ? 384 : 0), /* 4, 4 */
640 224, 149, 120, 80, 62, 41, 31, 25, 16, 16, 8, 8, 4, 4, 2, 2
644 /* Shift of the first bucket with the given ordinal inside 2K chunk. */
645 #ifdef IGNORE_SMALL_BAD_FREE
646 # define BLK_SHIFT(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
647 ? ((1<<LOG_OF_MIN_ARENA) \
648 - BUCKET_SIZE_NO_SURPLUS(bucket) * N_BLKS(bucket)) \
651 # define BLK_SHIFT(bucket) blk_shift[bucket]
654 static const u_short blk_shift[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
656 # if BUCKETS_PER_POW2==1
658 (MIN_BUC_POW2==2 ? 512 : 0),
659 256, 128, 64, 64, /* 8 to 64 */
660 16*sizeof(union overhead),
661 8*sizeof(union overhead),
662 4*sizeof(union overhead),
663 2*sizeof(union overhead),
666 (MIN_BUC_POW2==2 ? 512 : 0), (MIN_BUC_POW2==2 ? 512 : 0),
667 256, 260, 128, 128, 64, 80, 64, 48, /* 8 to 96 */
668 16*sizeof(union overhead), 16*sizeof(union overhead),
669 8*sizeof(union overhead), 8*sizeof(union overhead),
670 4*sizeof(union overhead), 4*sizeof(union overhead),
671 2*sizeof(union overhead), 2*sizeof(union overhead),
675 # define NEEDED_ALIGNMENT 0x800 /* 2k boundaries */
676 # define WANTED_ALIGNMENT 0x800 /* 2k boundaries */
678 #else /* !PACK_MALLOC */
680 # define OV_MAGIC(block,bucket) (block)->ov_magic
681 # define OV_INDEX(block) (block)->ov_index
682 # define CHUNK_SHIFT 1
683 # define MAX_PACKED -1
684 # define NEEDED_ALIGNMENT MEM_ALIGNBYTES
685 # define WANTED_ALIGNMENT 0x400 /* 1k boundaries */
687 #endif /* !PACK_MALLOC */
689 #define M_OVERHEAD (sizeof(union overhead) + RMAGIC_SZ) /* overhead at start+end */
692 # define MEM_OVERHEAD(bucket) \
693 (bucket <= MAX_PACKED ? 0 : M_OVERHEAD)
694 # ifdef SMALL_BUCKET_VIA_TABLE
695 # define START_SHIFTS_BUCKET ((MAX_PACKED_POW2 + 1) * BUCKETS_PER_POW2)
696 # define START_SHIFT MAX_PACKED_POW2
697 # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */
698 # define SIZE_TABLE_MAX 80
700 # define SIZE_TABLE_MAX 64
702 static const char bucket_of[] =
704 # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */
705 /* 0 to 15 in 4-byte increments. */
706 (sizeof(void*) > 4 ? 6 : 5), /* 4/8, 5-th bucket for better reports */
708 IF_ALIGN_8(8,7), 8, /* 16/12, 16 */
709 9, 9, 10, 10, /* 24, 32 */
710 11, 11, 11, 11, /* 48 */
711 12, 12, 12, 12, /* 64 */
712 13, 13, 13, 13, /* 80 */
713 13, 13, 13, 13 /* 80 */
714 # else /* !BUCKETS_ROOT2 */
715 /* 0 to 15 in 4-byte increments. */
716 (sizeof(void*) > 4 ? 3 : 2),
722 # endif /* !BUCKETS_ROOT2 */
724 # else /* !SMALL_BUCKET_VIA_TABLE */
725 # define START_SHIFTS_BUCKET MIN_BUCKET
726 # define START_SHIFT (MIN_BUC_POW2 - 1)
727 # endif /* !SMALL_BUCKET_VIA_TABLE */
728 #else /* !PACK_MALLOC */
729 # define MEM_OVERHEAD(bucket) M_OVERHEAD
730 # ifdef SMALL_BUCKET_VIA_TABLE
731 # undef SMALL_BUCKET_VIA_TABLE
733 # define START_SHIFTS_BUCKET MIN_BUCKET
734 # define START_SHIFT (MIN_BUC_POW2 - 1)
735 #endif /* !PACK_MALLOC */
738 * Big allocations are often of the size 2^n bytes. To make them a
739 * little bit better, make blocks of size 2^n+pagesize for big n.
742 #ifdef TWO_POT_OPTIMIZE
744 # ifndef PERL_PAGESIZE
745 # define PERL_PAGESIZE 4096
747 # ifndef FIRST_BIG_POW2
748 # define FIRST_BIG_POW2 15 /* 32K, 16K is used too often. */
750 # define FIRST_BIG_BLOCK (1<<FIRST_BIG_POW2)
751 /* If this value or more, check against bigger blocks. */
752 # define FIRST_BIG_BOUND (FIRST_BIG_BLOCK - M_OVERHEAD)
753 /* If less than this value, goes into 2^n-overhead-block. */
754 # define LAST_SMALL_BOUND ((FIRST_BIG_BLOCK>>1) - M_OVERHEAD)
756 # define POW2_OPTIMIZE_ADJUST(nbytes) \
757 ((nbytes >= FIRST_BIG_BOUND) ? nbytes -= PERL_PAGESIZE : 0)
758 # define POW2_OPTIMIZE_SURPLUS(bucket) \
759 ((bucket >= FIRST_BIG_POW2 * BUCKETS_PER_POW2) ? PERL_PAGESIZE : 0)
761 #else /* !TWO_POT_OPTIMIZE */
762 # define POW2_OPTIMIZE_ADJUST(nbytes)
763 # define POW2_OPTIMIZE_SURPLUS(bucket) 0
764 #endif /* !TWO_POT_OPTIMIZE */
767 # define BARK_64K_LIMIT(what,nbytes,size) \
768 if (nbytes > 0xffff) { \
769 PerlIO_printf(PerlIO_stderr(), \
770 "%s too large: %lx\n", what, size); \
773 #else /* !HAS_64K_LIMIT */
774 # define BARK_64K_LIMIT(what,nbytes,size)
775 #endif /* !HAS_64K_LIMIT */
778 # define MIN_SBRK 2048
782 # define FIRST_SBRK (48*1024)
785 /* Minimal sbrk in percents of what is already alloced. */
786 #ifndef MIN_SBRK_FRAC
787 # define MIN_SBRK_FRAC 3
790 #ifndef SBRK_ALLOW_FAILURES
791 # define SBRK_ALLOW_FAILURES 3
794 #ifndef SBRK_FAILURE_PRICE
795 # define SBRK_FAILURE_PRICE 50
798 static void morecore (register int bucket);
799 # if defined(DEBUGGING)
800 static void botch (const char *diag, const char *s, const char *file, int line);
802 static void add_to_chain (void *p, MEM_SIZE size, MEM_SIZE chip);
803 static void* get_from_chain (MEM_SIZE size);
804 static void* get_from_bigger_buckets(int bucket, MEM_SIZE size);
805 static union overhead *getpages (MEM_SIZE needed, int *nblksp, int bucket);
806 static int getpages_adjacent(MEM_SIZE require);
808 #ifdef I_MACH_CTHREADS
810 # define MUTEX_LOCK(m) STMT_START { if (*m) mutex_lock(*m); } STMT_END
812 # define MUTEX_UNLOCK(m) STMT_START { if (*m) mutex_unlock(*m); } STMT_END
816 # define PTRSIZE sizeof(void*)
820 # define BITS_IN_PTR (8*PTRSIZE)
824 * nextf[i] is the pointer to the next free block of size 2^i. The
825 * smallest allocatable block is 8 bytes. The overhead information
826 * precedes the data area returned to the user.
828 #define NBUCKETS (BITS_IN_PTR*BUCKETS_PER_POW2 + 1)
829 static union overhead *nextf[NBUCKETS];
831 #if defined(PURIFY) && !defined(USE_PERL_SBRK)
832 # define USE_PERL_SBRK
836 # define sbrk(a) Perl_sbrk(a)
837 Malloc_t Perl_sbrk (int size);
839 # ifndef HAS_SBRK_PROTO /* <unistd.h> usually takes care of this */
840 extern Malloc_t sbrk(int);
844 #ifndef MIN_SBRK_FRAC1000 /* Backward compatibility */
845 # define MIN_SBRK_FRAC1000 (MIN_SBRK_FRAC * 10)
848 #ifndef START_EXTERN_C
850 # define START_EXTERN_C extern "C" {
852 # define START_EXTERN_C
858 # define END_EXTERN_C };
860 # define END_EXTERN_C
864 #include "malloc_ctl.h"
866 #ifndef NO_MALLOC_DYNAMIC_CFG
867 # define PERL_MALLOC_OPT_CHARS "FMfAPGdac"
869 # ifndef FILL_DEAD_DEFAULT
870 # define FILL_DEAD_DEFAULT 1
872 # ifndef FILL_ALIVE_DEFAULT
873 # define FILL_ALIVE_DEFAULT 1
875 # ifndef FILL_CHECK_DEFAULT
876 # define FILL_CHECK_DEFAULT 1
879 static IV MallocCfg[MallocCfg_last] = {
885 SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE, /* sbrk_goodness */
886 FILL_DEAD_DEFAULT, /* FILL_DEAD */
887 FILL_ALIVE_DEFAULT, /* FILL_ALIVE */
888 FILL_CHECK_DEFAULT, /* FILL_CHECK */
889 0, /* MallocCfg_skip_cfg_env */
890 0, /* MallocCfg_cfg_env_read */
891 0, /* MallocCfg_emergency_buffer_size */
892 0, /* MallocCfg_emergency_buffer_prepared_size */
893 0 /* MallocCfg_emergency_buffer_last_req */
895 IV *MallocCfg_ptr = MallocCfg;
897 static char* MallocCfgP[MallocCfg_last] = {
898 0, /* MallocCfgP_emergency_buffer */
899 0, /* MallocCfgP_emergency_buffer_prepared */
901 char **MallocCfgP_ptr = MallocCfgP;
905 # undef MIN_SBRK_FRAC1000
906 # undef SBRK_ALLOW_FAILURES
907 # undef SBRK_FAILURE_PRICE
909 # define MIN_SBRK MallocCfg[MallocCfg_MIN_SBRK]
910 # define FIRST_SBRK MallocCfg[MallocCfg_FIRST_SBRK]
911 # define MIN_SBRK_FRAC1000 MallocCfg[MallocCfg_MIN_SBRK_FRAC1000]
912 # define SBRK_ALLOW_FAILURES MallocCfg[MallocCfg_SBRK_ALLOW_FAILURES]
913 # define SBRK_FAILURE_PRICE MallocCfg[MallocCfg_SBRK_FAILURE_PRICE]
915 # define sbrk_goodness MallocCfg[MallocCfg_sbrk_goodness]
917 # define emergency_buffer_size MallocCfg[MallocCfg_emergency_buffer_size]
918 # define emergency_buffer_last_req MallocCfg[MallocCfg_emergency_buffer_last_req]
920 # define FILL_DEAD MallocCfg[MallocCfg_filldead]
921 # define FILL_ALIVE MallocCfg[MallocCfg_fillalive]
922 # define FILL_CHECK_CFG MallocCfg[MallocCfg_fillcheck]
923 # define FILL_CHECK (FILL_DEAD && FILL_CHECK_CFG)
925 # define emergency_buffer MallocCfgP[MallocCfgP_emergency_buffer]
926 # define emergency_buffer_prepared MallocCfgP[MallocCfgP_emergency_buffer_prepared]
928 #else /* defined(NO_MALLOC_DYNAMIC_CFG) */
931 # define FILL_ALIVE 1
932 # define FILL_CHECK 1
933 static int sbrk_goodness = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE;
935 # define NO_PERL_MALLOC_ENV
939 #ifdef DEBUGGING_MSTATS
941 * nmalloc[i] is the difference between the number of mallocs and frees
942 * for a given block size.
944 static u_int nmalloc[NBUCKETS];
945 static u_int sbrk_slack;
946 static u_int start_slack;
947 #else /* !( defined DEBUGGING_MSTATS ) */
948 # define sbrk_slack 0
951 static u_int goodsbrk;
953 #ifdef PERL_EMERGENCY_SBRK
956 # define BIG_SIZE (1<<16) /* 64K */
959 # ifdef NO_MALLOC_DYNAMIC_CFG
960 static MEM_SIZE emergency_buffer_size;
961 /* 0 if the last request for more memory succeeded.
962 Otherwise the size of the failing request. */
963 static MEM_SIZE emergency_buffer_last_req;
964 static char *emergency_buffer;
965 static char *emergency_buffer_prepared;
968 # ifndef emergency_sbrk_croak
969 # define emergency_sbrk_croak croak2
973 perl_get_emergency_buffer(IV *size)
976 /* First offense, give a possibility to recover by dieing. */
977 /* No malloc involved here: */
980 GV **gvp = (GV**)hv_fetchs(PL_defstash, "^M", FALSE);
982 if (!gvp) gvp = (GV**)hv_fetchs(PL_defstash, "\015", FALSE);
983 if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv)
984 || (SvLEN(sv) < (1<<LOG_OF_MIN_ARENA) - M_OVERHEAD))
985 return NULL; /* Now die die die... */
986 /* Got it, now detach SvPV: */
988 /* Check alignment: */
989 if ((PTR2UV(pv) - sizeof(union overhead)) & (NEEDED_ALIGNMENT - 1)) {
990 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
991 return NULL; /* die die die */
998 *size = malloced_size(pv) + M_OVERHEAD;
999 return pv - sizeof(union overhead);
1001 # define PERL_GET_EMERGENCY_BUFFER(p) perl_get_emergency_buffer(p)
1003 # ifndef NO_MALLOC_DYNAMIC_CFG
1005 get_emergency_buffer(IV *size)
1007 char *pv = emergency_buffer_prepared;
1009 *size = MallocCfg[MallocCfg_emergency_buffer_prepared_size];
1010 emergency_buffer_prepared = 0;
1011 MallocCfg[MallocCfg_emergency_buffer_prepared_size] = 0;
1015 /* Returns 0 on success, -1 on bad alignment, -2 if not implemented */
1017 set_emergency_buffer(char *b, IV size)
1019 if (PTR2UV(b) & (NEEDED_ALIGNMENT - 1))
1021 if (MallocCfg[MallocCfg_emergency_buffer_prepared_size])
1022 add_to_chain((void*)emergency_buffer_prepared,
1023 MallocCfg[MallocCfg_emergency_buffer_prepared_size], 0);
1024 emergency_buffer_prepared = b;
1025 MallocCfg[MallocCfg_emergency_buffer_prepared_size] = size;
1028 # define GET_EMERGENCY_BUFFER(p) get_emergency_buffer(p)
1029 # else /* NO_MALLOC_DYNAMIC_CFG */
1030 # define GET_EMERGENCY_BUFFER(p) NULL
1032 set_emergency_buffer(char *b, IV size)
1039 emergency_sbrk(MEM_SIZE size)
1041 MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA;
1043 if (size >= BIG_SIZE
1044 && (!emergency_buffer_last_req ||
1045 (size < (MEM_SIZE)emergency_buffer_last_req))) {
1046 /* Give the possibility to recover, but avoid an infinite cycle. */
1048 emergency_buffer_last_req = size;
1049 emergency_sbrk_croak("Out of memory during \"large\" request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
1052 if ((MEM_SIZE)emergency_buffer_size >= rsize) {
1053 char *old = emergency_buffer;
1055 emergency_buffer_size -= rsize;
1056 emergency_buffer += rsize;
1059 /* First offense, give a possibility to recover by dieing. */
1060 /* No malloc involved here: */
1062 char *pv = GET_EMERGENCY_BUFFER(&Size);
1065 if (emergency_buffer_size) {
1066 add_to_chain(emergency_buffer, emergency_buffer_size, 0);
1067 emergency_buffer_size = 0;
1068 emergency_buffer = NULL;
1073 pv = PERL_GET_EMERGENCY_BUFFER(&Size);
1077 return (char *)-1; /* Now die die die... */
1080 /* Check alignment: */
1081 if (PTR2UV(pv) & (NEEDED_ALIGNMENT - 1)) {
1084 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
1085 return (char *)-1; /* die die die */
1088 emergency_buffer = pv;
1089 emergency_buffer_size = Size;
1093 emergency_sbrk_croak("Out of memory during request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
1094 assert(0); /* NOTREACHED */
1098 #else /* !defined(PERL_EMERGENCY_SBRK) */
1099 # define emergency_sbrk(size) -1
1100 #endif /* defined PERL_EMERGENCY_SBRK */
1103 write2(const char *mess)
1105 write(2, mess, strlen(mess));
1110 #define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p),__FILE__,__LINE__);
1113 botch(const char *diag, const char *s, const char *file, int line)
1117 if (!(PERL_MAYBE_ALIVE && PERL_GET_THX))
1120 if (PerlIO_printf(PerlIO_stderr(),
1121 "assertion botched (%s?): %s %s:%d\n",
1122 diag, s, file, line) != 0) {
1123 do_write: /* Can be initializing interpreter */
1124 write2("assertion botched (");
1133 char *s = linebuf + sizeof(linebuf) - 1;
1137 *--s = '0' + (n % 10);
1147 #define ASSERT(p, diag)
1151 /* Fill should be long enough to cover long */
1153 fill_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1155 unsigned char *e = s + nbytes;
1157 const long lfill = *(long*)fill;
1159 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1160 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1161 unsigned const char *f = fill + sizeof(long) - shift;
1162 unsigned char *e1 = s + shift;
1168 while ((unsigned char*)(lp + 1) <= e)
1170 s = (unsigned char*)lp;
1174 /* Just malloc()ed */
1175 static const unsigned char fill_feedadad[] =
1176 {0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD,
1177 0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD};
1179 static const unsigned char fill_deadbeef[] =
1180 {0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF,
1181 0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF};
1182 # define FILL_DEADBEEF(s, n) \
1183 (void)(FILL_DEAD? (fill_pat_4bytes((s), (n), fill_deadbeef), 0) : 0)
1184 # define FILL_FEEDADAD(s, n) \
1185 (void)(FILL_ALIVE? (fill_pat_4bytes((s), (n), fill_feedadad), 0) : 0)
1187 # define FILL_DEADBEEF(s, n) ((void)0)
1188 # define FILL_FEEDADAD(s, n) ((void)0)
1189 # undef MALLOC_FILL_CHECK
1192 #ifdef MALLOC_FILL_CHECK
1194 cmp_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1196 unsigned char *e = s + nbytes;
1198 const long lfill = *(long*)fill;
1200 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1201 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1202 unsigned const char *f = fill + sizeof(long) - shift;
1203 unsigned char *e1 = s + shift;
1210 while ((unsigned char*)(lp + 1) <= e)
1213 s = (unsigned char*)lp;
1215 if (*s++ != *fill++)
1219 # define FILLCHECK_DEADBEEF(s, n) \
1220 ASSERT(!FILL_CHECK || !cmp_pat_4bytes(s, n, fill_deadbeef), \
1221 "free()ed/realloc()ed-away memory was overwritten")
1223 # define FILLCHECK_DEADBEEF(s, n) ((void)0)
1227 S_ajust_size_and_find_bucket(size_t *nbytes_p)
1231 size_t nbytes = *nbytes_p;
1234 * Convert amount of memory requested into
1235 * closest block size stored in hash buckets
1236 * which satisfies request. Account for
1237 * space used per block for accounting.
1240 # ifdef SMALL_BUCKET_VIA_TABLE
1242 bucket = MIN_BUCKET;
1243 else if (nbytes <= SIZE_TABLE_MAX) {
1244 bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
1249 if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
1254 POW2_OPTIMIZE_ADJUST(nbytes);
1255 nbytes += M_OVERHEAD;
1256 nbytes = (nbytes + 3) &~ 3;
1257 #if defined(PACK_MALLOC) && !defined(SMALL_BUCKET_VIA_TABLE)
1260 shiftr = (nbytes - 1) >> START_SHIFT;
1261 bucket = START_SHIFTS_BUCKET;
1262 /* apart from this loop, this is O(1) */
1263 while (shiftr >>= 1)
1264 bucket += BUCKETS_PER_POW2;
1271 Perl_malloc(size_t nbytes)
1274 register union overhead *p;
1275 register int bucket;
1277 #if defined(DEBUGGING) || defined(RCHECK)
1278 MEM_SIZE size = nbytes;
1281 BARK_64K_LIMIT("Allocation",nbytes,nbytes);
1283 if ((long)nbytes < 0)
1284 croak("%s", "panic: malloc");
1287 bucket = S_ajust_size_and_find_bucket(&nbytes);
1290 * If nothing in hash bucket right now,
1291 * request more memory from the system.
1293 if (nextf[bucket] == NULL)
1295 if ((p = nextf[bucket]) == NULL) {
1300 #if defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC)
1301 PerlIO_puts(PerlIO_stderr(),"Out of memory!\n");
1304 char *eb = buff + sizeof(buff) - 1;
1308 PerlIO_puts(PerlIO_stderr(),"Out of memory during request for ");
1309 #if defined(DEBUGGING) || defined(RCHECK)
1314 *--s = '0' + (n % 10);
1316 PerlIO_puts(PerlIO_stderr(),s);
1317 PerlIO_puts(PerlIO_stderr()," bytes, total sbrk() is ");
1319 n = goodsbrk + sbrk_slack;
1321 *--s = '0' + (n % 10);
1323 PerlIO_puts(PerlIO_stderr(),s);
1324 PerlIO_puts(PerlIO_stderr()," bytes!\n");
1325 #endif /* defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC) */
1332 /* remove from linked list */
1334 if ( (PTR2UV(p) & (MEM_ALIGNBYTES - 1))
1335 /* Can't get this low */
1336 || (p && PTR2UV(p) < (1<<LOG_OF_MIN_ARENA)) ) {
1338 PerlIO_printf(PerlIO_stderr(),
1339 "Unaligned pointer in the free chain 0x%"UVxf"\n",
1342 if ( (PTR2UV(p->ov_next) & (MEM_ALIGNBYTES - 1))
1343 || (p->ov_next && PTR2UV(p->ov_next) < (1<<LOG_OF_MIN_ARENA)) ) {
1345 PerlIO_printf(PerlIO_stderr(),
1346 "Unaligned \"next\" pointer in the free "
1347 "chain 0x%"UVxf" at 0x%"UVxf"\n",
1348 PTR2UV(p->ov_next), PTR2UV(p));
1351 nextf[bucket] = p->ov_next;
1355 DEBUG_m(PerlIO_printf(Perl_debug_log,
1356 "0x%"UVxf": (%05lu) malloc %ld bytes\n",
1357 PTR2UV((Malloc_t)(p + CHUNK_SHIFT)), (unsigned long)(PL_an++),
1360 FILLCHECK_DEADBEEF((unsigned char*)(p + CHUNK_SHIFT),
1361 BUCKET_SIZE_REAL(bucket) + RMAGIC_SZ);
1363 #ifdef IGNORE_SMALL_BAD_FREE
1364 if (bucket >= FIRST_BUCKET_WITH_CHECK)
1366 OV_MAGIC(p, bucket) = MAGIC;
1368 OV_INDEX(p) = bucket;
1372 * Record allocated size of block and
1373 * bound space with magic numbers.
1375 p->ov_rmagic = RMAGIC;
1376 if (bucket <= MAX_SHORT_BUCKET) {
1379 nbytes = size + M_OVERHEAD;
1380 p->ov_size = nbytes - 1;
1381 if ((i = nbytes & (RMAGIC_SZ-1))) {
1383 while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
1384 ((caddr_t)p + nbytes - RMAGIC_SZ)[i] = RMAGIC_C;
1386 /* Same at RMAGIC_SZ-aligned RMAGIC */
1387 nbytes = (nbytes + RMAGIC_SZ - 1) & ~(RMAGIC_SZ - 1);
1388 ((u_int *)((caddr_t)p + nbytes))[-1] = RMAGIC;
1390 FILL_FEEDADAD((unsigned char *)(p + CHUNK_SHIFT), size);
1392 return ((Malloc_t)(p + CHUNK_SHIFT));
1395 static char *last_sbrk_top;
1396 static char *last_op; /* This arena can be easily extended. */
1397 static MEM_SIZE sbrked_remains;
1399 #ifdef DEBUGGING_MSTATS
1403 struct chunk_chain_s {
1404 struct chunk_chain_s *next;
1407 static struct chunk_chain_s *chunk_chain;
1408 static int n_chunks;
1409 static char max_bucket;
1411 /* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */
1413 get_from_chain(MEM_SIZE size)
1415 struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
1416 struct chunk_chain_s **oldgoodp = NULL;
1417 long min_remain = LONG_MAX;
1420 if (elt->size >= size) {
1421 long remains = elt->size - size;
1422 if (remains >= 0 && remains < min_remain) {
1424 min_remain = remains;
1430 oldp = &( elt->next );
1433 if (!oldgoodp) return NULL;
1435 void *ret = *oldgoodp;
1436 struct chunk_chain_s *next = (*oldgoodp)->next;
1438 *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
1439 (*oldgoodp)->size = min_remain;
1440 (*oldgoodp)->next = next;
1443 void *ret = *oldgoodp;
1444 *oldgoodp = (*oldgoodp)->next;
1451 add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
1453 struct chunk_chain_s *next = chunk_chain;
1454 char *cp = (char*)p;
1457 chunk_chain = (struct chunk_chain_s *)cp;
1458 chunk_chain->size = size - chip;
1459 chunk_chain->next = next;
1464 get_from_bigger_buckets(int bucket, MEM_SIZE size)
1467 static int bucketprice[NBUCKETS];
1468 while (bucket <= max_bucket) {
1469 /* We postpone stealing from bigger buckets until we want it
1471 if (nextf[bucket] && bucketprice[bucket]++ >= price) {
1473 void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
1474 bucketprice[bucket] = 0;
1475 if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
1476 last_op = NULL; /* Disable optimization */
1478 nextf[bucket] = nextf[bucket]->ov_next;
1479 #ifdef DEBUGGING_MSTATS
1481 start_slack -= M_OVERHEAD;
1483 add_to_chain(ret, (BUCKET_SIZE_NO_SURPLUS(bucket) +
1484 POW2_OPTIMIZE_SURPLUS(bucket)),
1493 static union overhead *
1494 getpages(MEM_SIZE needed, int *nblksp, int bucket)
1497 /* Need to do (possibly expensive) system call. Try to
1498 optimize it for rare calling. */
1499 MEM_SIZE require = needed - sbrked_remains;
1501 union overhead *ovp;
1504 if (sbrk_goodness > 0) {
1505 if (!last_sbrk_top && require < (MEM_SIZE)FIRST_SBRK)
1506 require = FIRST_SBRK;
1507 else if (require < (MEM_SIZE)MIN_SBRK) require = MIN_SBRK;
1509 if (require < goodsbrk * MIN_SBRK_FRAC1000 / 1000)
1510 require = goodsbrk * MIN_SBRK_FRAC1000 / 1000;
1511 require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
1518 DEBUG_m(PerlIO_printf(Perl_debug_log,
1519 "sbrk(%ld) for %ld-byte-long arena\n",
1520 (long)require, (long) needed));
1521 cp = (char *)sbrk(require);
1522 #ifdef DEBUGGING_MSTATS
1525 if (cp == last_sbrk_top) {
1526 /* Common case, anything is fine. */
1528 ovp = (union overhead *) (cp - sbrked_remains);
1529 last_op = cp - sbrked_remains;
1530 sbrked_remains = require - (needed - sbrked_remains);
1531 } else if (cp == (char *)-1) { /* no more room! */
1532 ovp = (union overhead *)emergency_sbrk(needed);
1533 if (ovp == (union overhead *)-1)
1535 if (((char*)ovp) > last_op) { /* Cannot happen with current emergency_sbrk() */
1539 } else { /* Non-continuous or first sbrk(). */
1540 long add = sbrked_remains;
1543 if (sbrked_remains) { /* Put rest into chain, we
1544 cannot use it right now. */
1545 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1549 /* Second, check alignment. */
1552 #if !defined(atarist) /* on the atari we dont have to worry about this */
1553 # ifndef I286 /* The sbrk(0) call on the I286 always returns the next segment */
1554 /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
1555 improve performance of memory access. */
1556 if (PTR2UV(cp) & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
1557 slack = WANTED_ALIGNMENT - (PTR2UV(cp) & (WANTED_ALIGNMENT - 1));
1561 #endif /* !atarist */
1564 DEBUG_m(PerlIO_printf(Perl_debug_log,
1565 "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",
1566 (long)add, (long) slack,
1567 (long) sbrked_remains));
1568 newcp = (char *)sbrk(add);
1569 #if defined(DEBUGGING_MSTATS)
1573 if (newcp != cp + require) {
1574 /* Too bad: even rounding sbrk() is not continuous.*/
1575 DEBUG_m(PerlIO_printf(Perl_debug_log,
1576 "failed to fix bad sbrk()\n"));
1580 fatalcroak("panic: Off-page sbrk\n");
1583 if (sbrked_remains) {
1585 #if defined(DEBUGGING_MSTATS)
1586 sbrk_slack += require;
1589 DEBUG_m(PerlIO_printf(Perl_debug_log,
1590 "straight sbrk(%ld)\n",
1592 cp = (char *)sbrk(require);
1593 #ifdef DEBUGGING_MSTATS
1596 if (cp == (char *)-1)
1599 sbrk_goodness = -1; /* Disable optimization!
1600 Continue with not-aligned... */
1603 require += sbrked_remains;
1607 if (last_sbrk_top) {
1608 sbrk_goodness -= SBRK_FAILURE_PRICE;
1611 ovp = (union overhead *) cp;
1613 * Round up to minimum allocation size boundary
1614 * and deduct from block count to reflect.
1617 # if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
1618 if (PTR2UV(ovp) & (NEEDED_ALIGNMENT - 1))
1619 fatalcroak("Misalignment of sbrk()\n");
1622 #ifndef I286 /* Again, this should always be ok on an 80286 */
1623 if (PTR2UV(ovp) & (MEM_ALIGNBYTES - 1)) {
1624 DEBUG_m(PerlIO_printf(Perl_debug_log,
1625 "fixing sbrk(): %d bytes off machine alignment\n",
1626 (int)(PTR2UV(ovp) & (MEM_ALIGNBYTES - 1))));
1627 ovp = INT2PTR(union overhead *,(PTR2UV(ovp) + MEM_ALIGNBYTES) &
1628 (MEM_ALIGNBYTES - 1));
1630 # if defined(DEBUGGING_MSTATS)
1631 /* This is only approx. if TWO_POT_OPTIMIZE: */
1632 sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
1636 ; /* Finish "else" */
1637 sbrked_remains = require - needed;
1640 #if !defined(PLAIN_MALLOC) && !defined(NO_FANCY_MALLOC)
1641 emergency_buffer_last_req = 0;
1643 last_sbrk_top = cp + require;
1644 #ifdef DEBUGGING_MSTATS
1645 goodsbrk += require;
1651 getpages_adjacent(MEM_SIZE require)
1653 if (require <= sbrked_remains) {
1654 sbrked_remains -= require;
1658 require -= sbrked_remains;
1659 /* We do not try to optimize sbrks here, we go for place. */
1660 cp = (char*) sbrk(require);
1661 #ifdef DEBUGGING_MSTATS
1663 goodsbrk += require;
1665 if (cp == last_sbrk_top) {
1667 last_sbrk_top = cp + require;
1669 if (cp == (char*)-1) { /* Out of memory */
1670 #ifdef DEBUGGING_MSTATS
1671 goodsbrk -= require;
1675 /* Report the failure: */
1677 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1679 add_to_chain((void*)cp, require, 0);
1680 sbrk_goodness -= SBRK_FAILURE_PRICE;
1692 * Allocate more memory to the indicated bucket.
1695 morecore(register int bucket)
1698 register union overhead *ovp;
1699 register int rnu; /* 2^rnu bytes will be requested */
1700 int nblks; /* become nblks blocks of the desired size */
1701 register MEM_SIZE siz, needed;
1702 static int were_called = 0;
1706 #ifndef NO_PERL_MALLOC_ENV
1708 /* It's the our first time. Initialize ourselves */
1709 were_called = 1; /* Avoid a loop */
1710 if (!MallocCfg[MallocCfg_skip_cfg_env]) {
1711 char *s = getenv("PERL_MALLOC_OPT"), *t = s, *off;
1712 const char *opts = PERL_MALLOC_OPT_CHARS;
1715 while ( t && t[0] && t[1] == '='
1716 && ((off = strchr(opts, *t))) ) {
1720 while (*t <= '9' && *t >= '0')
1721 val = 10*val + *t++ - '0';
1722 if (!*t || *t == ';') {
1723 if (MallocCfg[off - opts] != val)
1725 MallocCfg[off - opts] = val;
1731 write2("Unrecognized part of PERL_MALLOC_OPT: \"");
1736 MallocCfg[MallocCfg_cfg_env_read] = 1;
1740 if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
1742 croak("%s", "Out of memory during ridiculously large request");
1744 if (bucket > max_bucket)
1745 max_bucket = bucket;
1747 rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT))
1749 : (bucket >> BUCKET_POW2_SHIFT) );
1750 /* This may be overwritten later: */
1751 nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
1752 needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
1753 if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
1754 ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
1755 nextf[rnu << BUCKET_POW2_SHIFT]
1756 = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
1757 #ifdef DEBUGGING_MSTATS
1758 nmalloc[rnu << BUCKET_POW2_SHIFT]--;
1759 start_slack -= M_OVERHEAD;
1761 DEBUG_m(PerlIO_printf(Perl_debug_log,
1762 "stealing %ld bytes from %ld arena\n",
1763 (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
1764 } else if (chunk_chain
1765 && (ovp = (union overhead*) get_from_chain(needed))) {
1766 DEBUG_m(PerlIO_printf(Perl_debug_log,
1767 "stealing %ld bytes from chain\n",
1769 } else if ( (ovp = (union overhead*)
1770 get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
1772 DEBUG_m(PerlIO_printf(Perl_debug_log,
1773 "stealing %ld bytes from bigger buckets\n",
1775 } else if (needed <= sbrked_remains) {
1776 ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
1777 sbrked_remains -= needed;
1778 last_op = (char*)ovp;
1780 ovp = getpages(needed, &nblks, bucket);
1784 FILL_DEADBEEF((unsigned char*)ovp, needed);
1787 * Add new memory allocated to that on
1788 * free list for this hash bucket.
1790 siz = BUCKET_SIZE_NO_SURPLUS(bucket); /* No surplus if nblks > 1 */
1792 *(u_char*)ovp = bucket; /* Fill index. */
1793 if (bucket <= MAX_PACKED) {
1794 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1795 nblks = N_BLKS(bucket);
1796 # ifdef DEBUGGING_MSTATS
1797 start_slack += BLK_SHIFT(bucket);
1799 } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
1800 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1801 siz -= sizeof(union overhead);
1802 } else ovp++; /* One chunk per block. */
1803 #endif /* PACK_MALLOC */
1804 nextf[bucket] = ovp;
1805 #ifdef DEBUGGING_MSTATS
1806 nmalloc[bucket] += nblks;
1807 if (bucket > MAX_PACKED) {
1808 start_slack += M_OVERHEAD * nblks;
1812 while (--nblks > 0) {
1813 ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
1814 ovp = (union overhead *)((caddr_t)ovp + siz);
1816 /* Not all sbrks return zeroed memory.*/
1817 ovp->ov_next = (union overhead *)NULL;
1819 if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
1820 union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
1821 nextf[7*BUCKETS_PER_POW2] =
1822 (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2]
1823 - sizeof(union overhead));
1824 nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
1826 #endif /* !PACK_MALLOC */
1830 Perl_mfree(Malloc_t where)
1833 register MEM_SIZE size;
1834 register union overhead *ovp;
1835 char *cp = (char*)where;
1840 DEBUG_m(PerlIO_printf(Perl_debug_log,
1841 "0x%"UVxf": (%05lu) free\n",
1842 PTR2UV(cp), (unsigned long)(PL_an++)));
1847 if (PTR2UV(cp) & (MEM_ALIGNBYTES - 1))
1848 croak("%s", "wrong alignment in free()");
1850 ovp = (union overhead *)((caddr_t)cp
1851 - sizeof (union overhead) * CHUNK_SHIFT);
1853 bucket = OV_INDEX(ovp);
1855 #ifdef IGNORE_SMALL_BAD_FREE
1856 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1857 && (OV_MAGIC(ovp, bucket) != MAGIC))
1859 if (OV_MAGIC(ovp, bucket) != MAGIC)
1862 static int bad_free_warn = -1;
1863 if (bad_free_warn == -1) {
1865 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1866 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1873 if (!PERL_IS_ALIVE || !PL_curcop)
1874 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s free() ignored (RMAGIC, PERL_CORE)",
1875 ovp->ov_rmagic == RMAGIC - 1 ?
1876 "Duplicate" : "Bad");
1881 if (!PERL_IS_ALIVE || !PL_curcop)
1882 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s", "Bad free() ignored (PERL_CORE)");
1885 return; /* sanity */
1888 ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
1889 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
1891 MEM_SIZE nbytes = ovp->ov_size + 1;
1893 if ((i = nbytes & (RMAGIC_SZ-1))) {
1895 while (i--) { /* nbytes - RMAGIC_SZ is end of alloced area */
1896 ASSERT(((caddr_t)ovp + nbytes - RMAGIC_SZ)[i] == RMAGIC_C,
1897 "chunk's tail overwrite");
1900 /* Same at RMAGIC_SZ-aligned RMAGIC */
1901 nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
1902 ASSERT(((u_int *)((caddr_t)ovp + nbytes))[-1] == RMAGIC,
1903 "chunk's tail overwrite");
1904 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nbytes),
1905 BUCKET_SIZE(OV_INDEX(ovp)) - nbytes);
1907 FILL_DEADBEEF((unsigned char*)(ovp+CHUNK_SHIFT),
1908 BUCKET_SIZE_REAL(OV_INDEX(ovp)) + RMAGIC_SZ);
1909 ovp->ov_rmagic = RMAGIC - 1;
1911 ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
1912 size = OV_INDEX(ovp);
1915 ovp->ov_next = nextf[size];
1920 /* There is no need to do any locking in realloc (with an exception of
1921 trying to grow in place if we are at the end of the chain).
1922 If somebody calls us from a different thread with the same address,
1923 we are sole anyway. */
1926 Perl_realloc(void *mp, size_t nbytes)
1929 register MEM_SIZE onb;
1930 union overhead *ovp;
1933 register int bucket;
1934 int incr; /* 1 if does not fit, -1 if "easily" fits in a
1935 smaller bucket, otherwise 0. */
1936 char *cp = (char*)mp;
1939 MEM_SIZE size = nbytes;
1941 if ((long)nbytes < 0)
1942 croak("%s", "panic: realloc");
1945 BARK_64K_LIMIT("Reallocation",nbytes,size);
1947 return Perl_malloc(nbytes);
1949 ovp = (union overhead *)((caddr_t)cp
1950 - sizeof (union overhead) * CHUNK_SHIFT);
1951 bucket = OV_INDEX(ovp);
1953 #ifdef IGNORE_SMALL_BAD_FREE
1954 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1955 && (OV_MAGIC(ovp, bucket) != MAGIC))
1957 if (OV_MAGIC(ovp, bucket) != MAGIC)
1960 static int bad_free_warn = -1;
1961 if (bad_free_warn == -1) {
1963 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1964 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1971 if (!PERL_IS_ALIVE || !PL_curcop)
1972 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%srealloc() %signored",
1973 (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
1974 ovp->ov_rmagic == RMAGIC - 1
1975 ? "of freed memory " : "");
1980 if (!PERL_IS_ALIVE || !PL_curcop)
1981 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s",
1982 "Bad realloc() ignored");
1985 return NULL; /* sanity */
1988 onb = BUCKET_SIZE_REAL(bucket);
1990 * avoid the copy if same size block.
1991 * We are not aggressive with boundary cases. Note that it might
1992 * (for a small number of cases) give false negative if
1993 * both new size and old one are in the bucket for
1994 * FIRST_BIG_POW2, but the new one is near the lower end.
1996 * We do not try to go to 1.5 times smaller bucket so far.
1998 if (nbytes > onb) incr = 1;
2000 #ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
2001 if ( /* This is a little bit pessimal if PACK_MALLOC: */
2002 nbytes > ( (onb >> 1) - M_OVERHEAD )
2003 # ifdef TWO_POT_OPTIMIZE
2004 || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
2007 #else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
2008 prev_bucket = ( (bucket > MAX_PACKED + 1)
2009 ? bucket - BUCKETS_PER_POW2
2011 if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
2012 #endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
2016 #ifdef STRESS_REALLOC
2023 * Record new allocated size of block and
2024 * bound space with magic numbers.
2026 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
2027 int i, nb = ovp->ov_size + 1;
2029 if ((i = nb & (RMAGIC_SZ-1))) {
2031 while (i--) { /* nb - RMAGIC_SZ is end of alloced area */
2032 ASSERT(((caddr_t)ovp + nb - RMAGIC_SZ)[i] == RMAGIC_C, "chunk's tail overwrite");
2035 /* Same at RMAGIC_SZ-aligned RMAGIC */
2036 nb = (nb + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
2037 ASSERT(((u_int *)((caddr_t)ovp + nb))[-1] == RMAGIC,
2038 "chunk's tail overwrite");
2039 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nb),
2040 BUCKET_SIZE(OV_INDEX(ovp)) - nb);
2041 if (nbytes > ovp->ov_size + 1 - M_OVERHEAD)
2042 FILL_FEEDADAD((unsigned char*)cp + ovp->ov_size + 1 - M_OVERHEAD,
2043 nbytes - (ovp->ov_size + 1 - M_OVERHEAD));
2045 FILL_DEADBEEF((unsigned char*)cp + nbytes,
2046 nb - M_OVERHEAD + RMAGIC_SZ - nbytes);
2048 * Convert amount of memory requested into
2049 * closest block size stored in hash buckets
2050 * which satisfies request. Account for
2051 * space used per block for accounting.
2053 nbytes += M_OVERHEAD;
2054 ovp->ov_size = nbytes - 1;
2055 if ((i = nbytes & (RMAGIC_SZ-1))) {
2057 while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
2058 ((caddr_t)ovp + nbytes - RMAGIC_SZ)[i]
2061 /* Same at RMAGIC_SZ-aligned RMAGIC */
2062 nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ - 1);
2063 ((u_int *)((caddr_t)ovp + nbytes))[-1] = RMAGIC;
2067 DEBUG_m(PerlIO_printf(Perl_debug_log,
2068 "0x%"UVxf": (%05lu) realloc %ld bytes inplace\n",
2069 PTR2UV(res),(unsigned long)(PL_an++),
2071 } else if (incr == 1 && (cp - M_OVERHEAD == last_op)
2072 && (onb > (1 << LOG_OF_MIN_ARENA))) {
2073 MEM_SIZE require, newarena = nbytes, pow;
2076 POW2_OPTIMIZE_ADJUST(newarena);
2077 newarena = newarena + M_OVERHEAD;
2078 /* newarena = (newarena + 3) &~ 3; */
2079 shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
2080 pow = LOG_OF_MIN_ARENA + 1;
2081 /* apart from this loop, this is O(1) */
2082 while (shiftr >>= 1)
2084 newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
2085 require = newarena - onb - M_OVERHEAD;
2088 if (cp - M_OVERHEAD == last_op /* We *still* are the last chunk */
2089 && getpages_adjacent(require)) {
2090 #ifdef DEBUGGING_MSTATS
2092 nmalloc[pow * BUCKETS_PER_POW2]++;
2094 if (pow * BUCKETS_PER_POW2 > (MEM_SIZE)max_bucket)
2095 max_bucket = pow * BUCKETS_PER_POW2;
2096 *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
2105 DEBUG_m(PerlIO_printf(Perl_debug_log,
2106 "0x%"UVxf": (%05lu) realloc %ld bytes the hard way\n",
2107 PTR2UV(cp),(unsigned long)(PL_an++),
2109 if ((res = (char*)Perl_malloc(nbytes)) == NULL)
2111 if (cp != res) /* common optimization */
2112 Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
2115 return ((Malloc_t)res);
2119 Perl_calloc(register size_t elements, register size_t size)
2121 long sz = elements * size;
2122 Malloc_t p = Perl_malloc(sz);
2125 memset((void*)p, 0, sz);
2131 Perl_strdup(const char *s)
2133 MEM_SIZE l = strlen(s);
2134 char *s1 = (char *)Perl_malloc(l+1);
2136 return (char *)CopyD(s, s1, (MEM_SIZE)(l+1), char);
2140 Perl_putenv(char *a)
2142 /* Sometimes system's putenv conflicts with my_setenv() - this is system
2143 malloc vs Perl's free(). */
2150 while (*val && *val != '=')
2155 if (l < sizeof(buf))
2158 var = (char *)Perl_malloc(l + 1);
2159 Copy(a, var, l, char);
2161 my_setenv(var, val+1);
2168 Perl_malloced_size(void *p)
2170 union overhead * const ovp = (union overhead *)
2171 ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
2172 const int bucket = OV_INDEX(ovp);
2174 PERL_ARGS_ASSERT_MALLOCED_SIZE;
2177 /* The caller wants to have a complete control over the chunk,
2178 disable the memory checking inside the chunk. */
2179 if (bucket <= MAX_SHORT_BUCKET) {
2180 const MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
2181 ovp->ov_size = size + M_OVERHEAD - 1;
2182 *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RMAGIC_SZ)) = RMAGIC;
2185 return BUCKET_SIZE_REAL(bucket);
2190 Perl_malloc_good_size(size_t wanted)
2192 return BUCKET_SIZE_REAL(S_ajust_size_and_find_bucket(&wanted));
2195 # ifdef BUCKETS_ROOT2
2196 # define MIN_EVEN_REPORT 6
2198 # define MIN_EVEN_REPORT MIN_BUCKET
2202 Perl_get_mstats(pTHX_ perl_mstats_t *buf, int buflen, int level)
2204 #ifdef DEBUGGING_MSTATS
2206 register union overhead *p;
2207 struct chunk_chain_s* nextchain;
2209 PERL_ARGS_ASSERT_GET_MSTATS;
2211 buf->topbucket = buf->topbucket_ev = buf->topbucket_odd
2212 = buf->totfree = buf->total = buf->total_chain = 0;
2214 buf->minbucket = MIN_BUCKET;
2216 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2217 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
2221 buf->ntotal[i] = nmalloc[i];
2223 buf->totfree += j * BUCKET_SIZE_REAL(i);
2224 buf->total += nmalloc[i] * BUCKET_SIZE_REAL(i);
2226 i % 2 ? (buf->topbucket_odd = i) : (buf->topbucket_ev = i);
2230 nextchain = chunk_chain;
2232 buf->total_chain += nextchain->size;
2233 nextchain = nextchain->next;
2235 buf->total_sbrk = goodsbrk + sbrk_slack;
2237 buf->sbrk_good = sbrk_goodness;
2238 buf->sbrk_slack = sbrk_slack;
2239 buf->start_slack = start_slack;
2240 buf->sbrked_remains = sbrked_remains;
2242 buf->nbuckets = NBUCKETS;
2244 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2247 buf->bucket_mem_size[i] = BUCKET_SIZE_NO_SURPLUS(i);
2248 buf->bucket_available_size[i] = BUCKET_SIZE_REAL(i);
2251 #else /* defined DEBUGGING_MSTATS */
2252 PerlIO_printf(Perl_error_log, "perl not compiled with DEBUGGING_MSTATS\n");
2253 #endif /* defined DEBUGGING_MSTATS */
2254 return 0; /* XXX unused */
2257 * mstats - print out statistics about malloc
2259 * Prints two lines of numbers, one showing the length of the free list
2260 * for each size category, the second showing the number of mallocs -
2261 * frees for each size category.
2264 Perl_dump_mstats(pTHX_ const char *s)
2266 #ifdef DEBUGGING_MSTATS
2268 perl_mstats_t buffer;
2272 PERL_ARGS_ASSERT_DUMP_MSTATS;
2276 get_mstats(&buffer, NBUCKETS, 0);
2279 PerlIO_printf(Perl_error_log,
2280 "Memory allocation statistics %s (buckets %"IVdf"(%"IVdf")..%"IVdf"(%"IVdf")\n",
2282 (IV)BUCKET_SIZE_REAL(MIN_BUCKET),
2283 (IV)BUCKET_SIZE_NO_SURPLUS(MIN_BUCKET),
2284 (IV)BUCKET_SIZE_REAL(buffer.topbucket),
2285 (IV)BUCKET_SIZE_NO_SURPLUS(buffer.topbucket));
2286 PerlIO_printf(Perl_error_log, "%8"IVdf" free:", buffer.totfree);
2287 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2288 PerlIO_printf(Perl_error_log,
2289 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2291 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2294 #ifdef BUCKETS_ROOT2
2295 PerlIO_printf(Perl_error_log, "\n\t ");
2296 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2297 PerlIO_printf(Perl_error_log,
2298 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2300 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2304 PerlIO_printf(Perl_error_log, "\n%8"IVdf" used:", buffer.total - buffer.totfree);
2305 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2306 PerlIO_printf(Perl_error_log,
2307 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2309 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2310 buffer.ntotal[i] - buffer.nfree[i]);
2312 #ifdef BUCKETS_ROOT2
2313 PerlIO_printf(Perl_error_log, "\n\t ");
2314 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2315 PerlIO_printf(Perl_error_log,
2316 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2318 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2319 buffer.ntotal[i] - buffer.nfree[i]);
2322 PerlIO_printf(Perl_error_log, "\nTotal sbrk(): %"IVdf"/%"IVdf":%"IVdf". Odd ends: pad+heads+chain+tail: %"IVdf"+%"IVdf"+%"IVdf"+%"IVdf".\n",
2323 buffer.total_sbrk, buffer.sbrks, buffer.sbrk_good,
2324 buffer.sbrk_slack, buffer.start_slack,
2325 buffer.total_chain, buffer.sbrked_remains);
2326 #else /* DEBUGGING_MSTATS */
2327 PerlIO_printf(Perl_error_log, "%s: perl not compiled with DEBUGGING_MSTATS\n",s);
2328 #endif /* DEBUGGING_MSTATS */
2331 #ifdef USE_PERL_SBRK
2333 # if defined(NeXT) || defined(__NeXT__) || defined(PURIFY)
2334 # define PERL_SBRK_VIA_MALLOC
2337 # ifdef PERL_SBRK_VIA_MALLOC
2339 /* it may seem schizophrenic to use perl's malloc and let it call system */
2340 /* malloc, the reason for that is only the 3.2 version of the OS that had */
2341 /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
2342 /* end to the cores */
2344 # ifndef SYSTEM_ALLOC
2345 # define SYSTEM_ALLOC(a) malloc(a)
2347 # ifndef SYSTEM_ALLOC_ALIGNMENT
2348 # define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
2351 # endif /* PERL_SBRK_VIA_MALLOC */
2353 static IV Perl_sbrk_oldchunk;
2354 static long Perl_sbrk_oldsize;
2356 # define PERLSBRK_32_K (1<<15)
2357 # define PERLSBRK_64_K (1<<16)
2365 if (!size) return 0;
2366 reqsize = size; /* just for the DEBUG_m statement */
2368 size = (size + 0x7ff) & ~0x7ff;
2370 if (size <= Perl_sbrk_oldsize) {
2371 got = Perl_sbrk_oldchunk;
2372 Perl_sbrk_oldchunk += size;
2373 Perl_sbrk_oldsize -= size;
2375 if (size >= PERLSBRK_32_K) {
2378 size = PERLSBRK_64_K;
2381 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2382 size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT;
2384 got = (IV)SYSTEM_ALLOC(size);
2385 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2386 got = (got + NEEDED_ALIGNMENT - 1) & ~(NEEDED_ALIGNMENT - 1);
2389 /* Chunk is small, register the rest for future allocs. */
2390 Perl_sbrk_oldchunk = got + reqsize;
2391 Perl_sbrk_oldsize = size - reqsize;
2395 DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%"UVxf"\n",
2396 size, reqsize, Perl_sbrk_oldsize, PTR2UV(got)));
2401 #endif /* ! defined USE_PERL_SBRK */
2405 * c-indentation-style: bsd
2407 * indent-tabs-mode: nil
2410 * ex: set ts=8 sts=4 sw=4 et: