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 #define LOG_OF_MIN_ARENA 11
202 #if defined(DEBUGGING) && !defined(NO_RCHECK)
205 #if defined(DEBUGGING) && !defined(NO_RCHECK) && !defined(NO_MFILL) && !defined(MALLOC_FILL)
208 #if defined(DEBUGGING) && !defined(NO_RCHECK) && !defined(NO_FILL_CHECK) && !defined(MALLOC_FILL_CHECK)
209 # define MALLOC_FILL_CHECK
211 #if defined(RCHECK) && defined(IGNORE_SMALL_BAD_FREE)
212 # undef IGNORE_SMALL_BAD_FREE
215 * malloc.c (Caltech) 2/21/82
216 * Chris Kingsley, kingsley@cit-20.
218 * This is a very fast storage allocator. It allocates blocks of a small
219 * number of different sizes, and keeps free lists of each size. Blocks that
220 * don't exactly fit are passed up to the next larger size. In this
221 * implementation, the available sizes are 2^n-4 (or 2^n-12) bytes long.
222 * If PACK_MALLOC is defined, small blocks are 2^n bytes long.
223 * This is designed for use in a program that uses vast quantities of memory,
224 * but bombs when it runs out.
226 * Modifications Copyright Ilya Zakharevich 1996-99.
228 * Still very quick, but much more thrifty. (Std config is 10% slower
229 * than it was, and takes 67% of old heap size for typical usage.)
231 * Allocations of small blocks are now table-driven to many different
232 * buckets. Sizes of really big buckets are increased to accommodate
233 * common size=power-of-2 blocks. Running-out-of-memory is made into
234 * an exception. Deeply configurable and thread-safe.
239 #define PERL_IN_MALLOC_C
241 #if defined(PERL_IMPLICIT_CONTEXT)
242 # define croak Perl_croak_nocontext
243 # define croak2 Perl_croak_nocontext
244 # define warn Perl_warn_nocontext
245 # define warn2 Perl_warn_nocontext
247 # define croak2 croak
251 # define PERL_MAYBE_ALIVE PL_thr_key
253 # define PERL_MAYBE_ALIVE 1
257 # define MUTEX_LOCK(l)
261 # define MUTEX_UNLOCK(l)
265 # define MALLOC_LOCK MUTEX_LOCK(&PL_malloc_mutex)
268 #ifndef MALLOC_UNLOCK
269 # define MALLOC_UNLOCK MUTEX_UNLOCK(&PL_malloc_mutex)
272 # ifndef fatalcroak /* make depend */
273 # define fatalcroak(mess) (write(2, (mess), strlen(mess)), exit(2))
278 # define DEBUG_m(a) \
280 if (PERL_MAYBE_ALIVE && PERL_GET_THX) { \
282 if (DEBUG_m_TEST) { \
283 PL_debug &= ~DEBUG_m_FLAG; \
285 PL_debug |= DEBUG_m_FLAG; \
291 #ifdef PERL_IMPLICIT_CONTEXT
292 # define PERL_IS_ALIVE aTHX
294 # define PERL_IS_ALIVE TRUE
301 * The memory is broken into "blocks" which occupy multiples of 2K (and
302 * generally speaking, have size "close" to a power of 2). The addresses
303 * of such *unused* blocks are kept in nextf[i] with big enough i. (nextf
304 * is an array of linked lists.) (Addresses of used blocks are not known.)
306 * Moreover, since the algorithm may try to "bite" smaller blocks out
307 * of unused bigger ones, there are also regions of "irregular" size,
308 * managed separately, by a linked list chunk_chain.
310 * The third type of storage is the sbrk()ed-but-not-yet-used space, its
311 * end and size are kept in last_sbrk_top and sbrked_remains.
313 * Growing blocks "in place":
314 * ~~~~~~~~~~~~~~~~~~~~~~~~~
315 * The address of the block with the greatest address is kept in last_op
316 * (if not known, last_op is 0). If it is known that the memory above
317 * last_op is not continuous, or contains a chunk from chunk_chain,
318 * last_op is set to 0.
320 * The chunk with address last_op may be grown by expanding into
321 * sbrk()ed-but-not-yet-used space, or trying to sbrk() more continuous
324 * Management of last_op:
325 * ~~~~~~~~~~~~~~~~~~~~~
327 * free() never changes the boundaries of blocks, so is not relevant.
329 * The only way realloc() may change the boundaries of blocks is if it
330 * grows a block "in place". However, in the case of success such a
331 * chunk is automatically last_op, and it remains last_op. In the case
332 * of failure getpages_adjacent() clears last_op.
334 * malloc() may change blocks by calling morecore() only.
336 * morecore() may create new blocks by:
337 * a) biting pieces from chunk_chain (cannot create one above last_op);
338 * b) biting a piece from an unused block (if block was last_op, this
339 * may create a chunk from chain above last_op, thus last_op is
340 * invalidated in such a case).
341 * c) biting of sbrk()ed-but-not-yet-used space. This creates
342 * a block which is last_op.
343 * d) Allocating new pages by calling getpages();
345 * getpages() creates a new block. It marks last_op at the bottom of
346 * the chunk of memory it returns.
348 * Active pages footprint:
349 * ~~~~~~~~~~~~~~~~~~~~~~
350 * Note that we do not need to traverse the lists in nextf[i], just take
351 * the first element of this list. However, we *need* to traverse the
352 * list in chunk_chain, but most the time it should be a very short one,
353 * so we do not step on a lot of pages we are not going to use.
357 * get_from_bigger_buckets(): forget to increment price => Quite
361 /* I don't much care whether these are defined in sys/types.h--LAW */
363 #define u_char unsigned char
364 #define u_int unsigned int
366 * I removed the definition of u_bigint which appeared to be u_bigint = UV
367 * u_bigint was only used in TWOK_MASKED and TWOK_SHIFT
368 * where I have used PTR2UV. RMB
370 #define u_short unsigned short
372 #if defined(RCHECK) && defined(PACK_MALLOC)
377 * The description below is applicable if PACK_MALLOC is not defined.
379 * The overhead on a block is at least 4 bytes. When free, this space
380 * contains a pointer to the next free block, and the bottom two bits must
381 * be zero. When in use, the first byte is set to MAGIC, and the second
382 * byte is the size index. The remaining bytes are for alignment.
383 * If range checking is enabled and the size of the block fits
384 * in two bytes, then the top two bytes hold the size of the requested block
385 * plus the range checking words, and the header word MINUS ONE.
388 union overhead *ov_next; /* when free */
389 #if MEM_ALIGNBYTES > 4
390 double strut; /* alignment problems */
391 # if MEM_ALIGNBYTES > 8
392 char sstrut[MEM_ALIGNBYTES]; /* for the sizing */
397 * Keep the ovu_index and ovu_magic in this order, having a char
398 * field first gives alignment indigestion in some systems, such as
401 u_char ovu_index; /* bucket # */
402 u_char ovu_magic; /* magic number */
404 /* Subtract one to fit into u_short for an extra bucket */
405 u_short ovu_size; /* block size (requested + overhead - 1) */
406 u_int ovu_rmagic; /* range magic number */
409 #define ov_magic ovu.ovu_magic
410 #define ov_index ovu.ovu_index
411 #define ov_size ovu.ovu_size
412 #define ov_rmagic ovu.ovu_rmagic
415 #define MAGIC 0xff /* magic # on accounting info */
416 #define RMAGIC 0x55555555 /* magic # on range info */
417 #define RMAGIC_C 0x55 /* magic # on range info */
420 # define RMAGIC_SZ sizeof (u_int) /* Overhead at end of bucket */
421 # ifdef TWO_POT_OPTIMIZE
422 # define MAX_SHORT_BUCKET (12 * BUCKETS_PER_POW2) /* size-1 fits in short */
424 # define MAX_SHORT_BUCKET (13 * BUCKETS_PER_POW2)
430 #if !defined(PACK_MALLOC) && defined(BUCKETS_ROOT2)
431 # undef BUCKETS_ROOT2
435 # define BUCKET_TABLE_SHIFT 2
436 # define BUCKET_POW2_SHIFT 1
437 # define BUCKETS_PER_POW2 2
439 # define BUCKET_TABLE_SHIFT MIN_BUC_POW2
440 # define BUCKET_POW2_SHIFT 0
441 # define BUCKETS_PER_POW2 1
444 #if !defined(MEM_ALIGNBYTES) || ((MEM_ALIGNBYTES > 4) && !defined(STRICT_ALIGNMENT))
445 /* Figure out the alignment of void*. */
450 # define ALIGN_SMALL ((IV)((caddr_t)&(((struct aligner*)0)->p)))
452 # define ALIGN_SMALL MEM_ALIGNBYTES
455 #define IF_ALIGN_8(yes,no) ((ALIGN_SMALL>4) ? (yes) : (no))
458 # define MAX_BUCKET_BY_TABLE 13
459 static const u_short buck_size[MAX_BUCKET_BY_TABLE + 1] =
461 0, 0, 0, 0, 4, 4, 8, 12, 16, 24, 32, 48, 64, 80,
463 # define BUCKET_SIZE_NO_SURPLUS(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT)))
464 # define BUCKET_SIZE_REAL(i) ((i) <= MAX_BUCKET_BY_TABLE \
466 : ((1 << ((i) >> BUCKET_POW2_SHIFT)) \
468 + POW2_OPTIMIZE_SURPLUS(i)))
470 # define BUCKET_SIZE_NO_SURPLUS(i) (1 << ((i) >> BUCKET_POW2_SHIFT))
471 # define BUCKET_SIZE(i) (BUCKET_SIZE_NO_SURPLUS(i) + POW2_OPTIMIZE_SURPLUS(i))
472 # define BUCKET_SIZE_REAL(i) (BUCKET_SIZE(i) - MEM_OVERHEAD(i))
477 /* In this case there are several possible layout of arenas depending
478 * on the size. Arenas are of sizes multiple to 2K, 2K-aligned, and
479 * have a size close to a power of 2.
481 * Arenas of the size >= 4K keep one chunk only. Arenas of size 2K
482 * may keep one chunk or multiple chunks. Here are the possible
485 * # One chunk only, chunksize 2^k + SOMETHING - ALIGN, k >= 11
487 * INDEX MAGIC1 UNUSED CHUNK1
489 * # Multichunk with sanity checking and chunksize 2^k-ALIGN, k>7
491 * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 CHUNK2 CHUNK3 ...
493 * # Multichunk with sanity checking and size 2^k-ALIGN, k=7
495 * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 UNUSED CHUNK2 CHUNK3 ...
497 * # Multichunk with sanity checking and size up to 80
499 * INDEX UNUSED MAGIC1 UNUSED MAGIC2 UNUSED ... CHUNK1 CHUNK2 CHUNK3 ...
501 * # No sanity check (usually up to 48=byte-long buckets)
502 * INDEX UNUSED CHUNK1 CHUNK2 ...
504 * Above INDEX and MAGIC are one-byte-long. Sizes of UNUSED are
505 * appropriate to keep algorithms simple and memory aligned. INDEX
506 * encodes the size of the chunk, while MAGICn encodes state (used,
507 * free or non-managed-by-us-so-it-indicates-a-bug) of CHUNKn. MAGIC
508 * is used for sanity checking purposes only. SOMETHING is 0 or 4K
509 * (to make size of big CHUNK accommodate allocations for powers of two
512 * [There is no need to alignment between chunks, since C rules ensure
513 * that structs which need 2^k alignment have sizeof which is
514 * divisible by 2^k. Thus as far as the last chunk is aligned at the
515 * end of the arena, and 2K-alignment does not contradict things,
516 * everything is going to be OK for sizes of chunks 2^n and 2^n +
517 * 2^k. Say, 80-bit buckets will be 16-bit aligned, and as far as we
518 * put allocations for requests in 65..80 range, all is fine.
520 * Note, however, that standard malloc() puts more strict
521 * requirements than the above C rules. Moreover, our algorithms of
522 * realloc() may break this idyll, but we suppose that realloc() does
523 * need not change alignment.]
525 * Is very important to make calculation of the offset of MAGICm as
526 * quick as possible, since it is done on each malloc()/free(). In
527 * fact it is so quick that it has quite little effect on the speed of
528 * doing malloc()/free(). [By default] We forego such calculations
529 * for small chunks, but only to save extra 3% of memory, not because
530 * of speed considerations.
532 * Here is the algorithm [which is the same for all the allocations
533 * schemes above], see OV_MAGIC(block,bucket). Let OFFSETm be the
534 * offset of the CHUNKm from the start of ARENA. Then offset of
535 * MAGICm is (OFFSET1 >> SHIFT) + ADDOFFSET. Here SHIFT and ADDOFFSET
536 * are numbers which depend on the size of the chunks only.
538 * Let as check some sanity conditions. Numbers OFFSETm>>SHIFT are
539 * different for all the chunks in the arena if 2^SHIFT is not greater
540 * than size of the chunks in the arena. MAGIC1 will not overwrite
541 * INDEX provided ADDOFFSET is >0 if OFFSET1 < 2^SHIFT. MAGIClast
542 * will not overwrite CHUNK1 if OFFSET1 > (OFFSETlast >> SHIFT) +
545 * Make SHIFT the maximal possible (there is no point in making it
546 * smaller). Since OFFSETlast is 2K - CHUNKSIZE, above restrictions
547 * give restrictions on OFFSET1 and on ADDOFFSET.
549 * In particular, for chunks of size 2^k with k>=6 we can put
550 * ADDOFFSET to be from 0 to 2^k - 2^(11-k), and have
551 * OFFSET1==chunksize. For chunks of size 80 OFFSET1 of 2K%80=48 is
552 * large enough to have ADDOFFSET between 1 and 16 (similarly for 96,
553 * when ADDOFFSET should be 1). In particular, keeping MAGICs for
554 * these sizes gives no additional size penalty.
556 * However, for chunks of size 2^k with k<=5 this gives OFFSET1 >=
557 * ADDOFSET + 2^(11-k). Keeping ADDOFFSET 0 allows for 2^(11-k)-2^(11-2k)
558 * chunks per arena. This is smaller than 2^(11-k) - 1 which are
559 * needed if no MAGIC is kept. [In fact, having a negative ADDOFFSET
560 * would allow for slightly more buckets per arena for k=2,3.]
562 * Similarly, for chunks of size 3/2*2^k with k<=5 MAGICs would span
563 * the area up to 2^(11-k)+ADDOFFSET. For k=4 this give optimal
564 * ADDOFFSET as -7..0. For k=3 ADDOFFSET can go up to 4 (with tiny
565 * savings for negative ADDOFFSET). For k=5 ADDOFFSET can go -1..16
566 * (with no savings for negative values).
568 * In particular, keeping ADDOFFSET 0 for sizes of chunks up to 2^6
569 * leads to tiny pessimizations in case of sizes 4, 8, 12, 24, and
570 * leads to no contradictions except for size=80 (or 96.)
572 * However, it also makes sense to keep no magic for sizes 48 or less.
573 * This is what we do. In this case one needs ADDOFFSET>=1 also for
574 * chunksizes 12, 24, and 48, unless one gets one less chunk per
577 * The algo of OV_MAGIC(block,bucket) keeps ADDOFFSET 0 until
578 * chunksize of 64, then makes it 1.
580 * This allows for an additional optimization: the above scheme leads
581 * to giant overheads for sizes 128 or more (one whole chunk needs to
582 * be sacrifised to keep INDEX). Instead we use chunks not of size
583 * 2^k, but of size 2^k-ALIGN. If we pack these chunks at the end of
584 * the arena, then the beginnings are still in different 2^k-long
585 * sections of the arena if k>=7 for ALIGN==4, and k>=8 if ALIGN=8.
586 * Thus for k>7 the above algo of calculating the offset of the magic
587 * will still give different answers for different chunks. And to
588 * avoid the overrun of MAGIC1 into INDEX, one needs ADDOFFSET of >=1.
589 * In the case k=7 we just move the first chunk an extra ALIGN
590 * backward inside the ARENA (this is done once per arena lifetime,
591 * thus is not a big overhead). */
592 # define MAX_PACKED_POW2 6
593 # define MAX_PACKED (MAX_PACKED_POW2 * BUCKETS_PER_POW2 + BUCKET_POW2_SHIFT)
594 # define MAX_POW2_ALGO ((1<<(MAX_PACKED_POW2 + 1)) - M_OVERHEAD)
595 # define TWOK_MASK ((1<<LOG_OF_MIN_ARENA) - 1)
596 # define TWOK_MASKED(x) (PTR2UV(x) & ~TWOK_MASK)
597 # define TWOK_SHIFT(x) (PTR2UV(x) & TWOK_MASK)
598 # define OV_INDEXp(block) (INT2PTR(u_char*,TWOK_MASKED(block)))
599 # define OV_INDEX(block) (*OV_INDEXp(block))
600 # define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) + \
601 (TWOK_SHIFT(block)>> \
602 (bucket>>BUCKET_POW2_SHIFT)) + \
603 (bucket >= MIN_NEEDS_SHIFT ? 1 : 0)))
604 /* A bucket can have a shift smaller than it size, we need to
605 shift its magic number so it will not overwrite index: */
606 # ifdef BUCKETS_ROOT2
607 # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2 - 1) /* Shift 80 greater than chunk 64. */
609 # define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2) /* Shift 128 greater than chunk 32. */
611 # define CHUNK_SHIFT 0
613 /* Number of active buckets of given ordinal. */
614 #ifdef IGNORE_SMALL_BAD_FREE
615 #define FIRST_BUCKET_WITH_CHECK (6 * BUCKETS_PER_POW2) /* 64 */
616 # define N_BLKS(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
617 ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE_NO_SURPLUS(bucket) \
620 # define N_BLKS(bucket) n_blks[bucket]
623 static const u_short n_blks[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
625 # if BUCKETS_PER_POW2==1
627 (MIN_BUC_POW2==2 ? 384 : 0),
628 224, 120, 62, 31, 16, 8, 4, 2
631 (MIN_BUC_POW2==2 ? 384 : 0), (MIN_BUC_POW2==2 ? 384 : 0), /* 4, 4 */
632 224, 149, 120, 80, 62, 41, 31, 25, 16, 16, 8, 8, 4, 4, 2, 2
636 /* Shift of the first bucket with the given ordinal inside 2K chunk. */
637 #ifdef IGNORE_SMALL_BAD_FREE
638 # define BLK_SHIFT(bucket) ( (bucket) < FIRST_BUCKET_WITH_CHECK \
639 ? ((1<<LOG_OF_MIN_ARENA) \
640 - BUCKET_SIZE_NO_SURPLUS(bucket) * N_BLKS(bucket)) \
643 # define BLK_SHIFT(bucket) blk_shift[bucket]
646 static const u_short blk_shift[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
648 # if BUCKETS_PER_POW2==1
650 (MIN_BUC_POW2==2 ? 512 : 0),
651 256, 128, 64, 64, /* 8 to 64 */
652 16*sizeof(union overhead),
653 8*sizeof(union overhead),
654 4*sizeof(union overhead),
655 2*sizeof(union overhead),
658 (MIN_BUC_POW2==2 ? 512 : 0), (MIN_BUC_POW2==2 ? 512 : 0),
659 256, 260, 128, 128, 64, 80, 64, 48, /* 8 to 96 */
660 16*sizeof(union overhead), 16*sizeof(union overhead),
661 8*sizeof(union overhead), 8*sizeof(union overhead),
662 4*sizeof(union overhead), 4*sizeof(union overhead),
663 2*sizeof(union overhead), 2*sizeof(union overhead),
667 # define NEEDED_ALIGNMENT 0x800 /* 2k boundaries */
668 # define WANTED_ALIGNMENT 0x800 /* 2k boundaries */
670 #else /* !PACK_MALLOC */
672 # define OV_MAGIC(block,bucket) (block)->ov_magic
673 # define OV_INDEX(block) (block)->ov_index
674 # define CHUNK_SHIFT 1
675 # define MAX_PACKED -1
676 # define NEEDED_ALIGNMENT MEM_ALIGNBYTES
677 # define WANTED_ALIGNMENT 0x400 /* 1k boundaries */
679 #endif /* !PACK_MALLOC */
681 #define M_OVERHEAD (sizeof(union overhead) + RMAGIC_SZ) /* overhead at start+end */
684 # define MEM_OVERHEAD(bucket) \
685 (bucket <= MAX_PACKED ? 0 : M_OVERHEAD)
686 # ifdef SMALL_BUCKET_VIA_TABLE
687 # define START_SHIFTS_BUCKET ((MAX_PACKED_POW2 + 1) * BUCKETS_PER_POW2)
688 # define START_SHIFT MAX_PACKED_POW2
689 # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */
690 # define SIZE_TABLE_MAX 80
692 # define SIZE_TABLE_MAX 64
694 static const char bucket_of[] =
696 # ifdef BUCKETS_ROOT2 /* Chunks of size 3*2^n. */
697 /* 0 to 15 in 4-byte increments. */
698 (sizeof(void*) > 4 ? 6 : 5), /* 4/8, 5-th bucket for better reports */
700 IF_ALIGN_8(8,7), 8, /* 16/12, 16 */
701 9, 9, 10, 10, /* 24, 32 */
702 11, 11, 11, 11, /* 48 */
703 12, 12, 12, 12, /* 64 */
704 13, 13, 13, 13, /* 80 */
705 13, 13, 13, 13 /* 80 */
706 # else /* !BUCKETS_ROOT2 */
707 /* 0 to 15 in 4-byte increments. */
708 (sizeof(void*) > 4 ? 3 : 2),
714 # endif /* !BUCKETS_ROOT2 */
716 # else /* !SMALL_BUCKET_VIA_TABLE */
717 # define START_SHIFTS_BUCKET MIN_BUCKET
718 # define START_SHIFT (MIN_BUC_POW2 - 1)
719 # endif /* !SMALL_BUCKET_VIA_TABLE */
720 #else /* !PACK_MALLOC */
721 # define MEM_OVERHEAD(bucket) M_OVERHEAD
722 # ifdef SMALL_BUCKET_VIA_TABLE
723 # undef SMALL_BUCKET_VIA_TABLE
725 # define START_SHIFTS_BUCKET MIN_BUCKET
726 # define START_SHIFT (MIN_BUC_POW2 - 1)
727 #endif /* !PACK_MALLOC */
730 * Big allocations are often of the size 2^n bytes. To make them a
731 * little bit better, make blocks of size 2^n+pagesize for big n.
734 #ifdef TWO_POT_OPTIMIZE
736 # ifndef PERL_PAGESIZE
737 # define PERL_PAGESIZE 4096
739 # ifndef FIRST_BIG_POW2
740 # define FIRST_BIG_POW2 15 /* 32K, 16K is used too often. */
742 # define FIRST_BIG_BLOCK (1<<FIRST_BIG_POW2)
743 /* If this value or more, check against bigger blocks. */
744 # define FIRST_BIG_BOUND (FIRST_BIG_BLOCK - M_OVERHEAD)
745 /* If less than this value, goes into 2^n-overhead-block. */
746 # define LAST_SMALL_BOUND ((FIRST_BIG_BLOCK>>1) - M_OVERHEAD)
748 # define POW2_OPTIMIZE_ADJUST(nbytes) \
749 ((nbytes >= FIRST_BIG_BOUND) ? nbytes -= PERL_PAGESIZE : 0)
750 # define POW2_OPTIMIZE_SURPLUS(bucket) \
751 ((bucket >= FIRST_BIG_POW2 * BUCKETS_PER_POW2) ? PERL_PAGESIZE : 0)
753 #else /* !TWO_POT_OPTIMIZE */
754 # define POW2_OPTIMIZE_ADJUST(nbytes)
755 # define POW2_OPTIMIZE_SURPLUS(bucket) 0
756 #endif /* !TWO_POT_OPTIMIZE */
759 # define BARK_64K_LIMIT(what,nbytes,size) \
760 if (nbytes > 0xffff) { \
761 PerlIO_printf(PerlIO_stderr(), \
762 "%s too large: %lx\n", what, size); \
765 #else /* !HAS_64K_LIMIT */
766 # define BARK_64K_LIMIT(what,nbytes,size)
767 #endif /* !HAS_64K_LIMIT */
770 # define MIN_SBRK 2048
774 # define FIRST_SBRK (48*1024)
777 /* Minimal sbrk in percents of what is already alloced. */
778 #ifndef MIN_SBRK_FRAC
779 # define MIN_SBRK_FRAC 3
782 #ifndef SBRK_ALLOW_FAILURES
783 # define SBRK_ALLOW_FAILURES 3
786 #ifndef SBRK_FAILURE_PRICE
787 # define SBRK_FAILURE_PRICE 50
790 static void morecore (int bucket);
791 # if defined(DEBUGGING)
792 static void botch (const char *diag, const char *s, const char *file, int line);
794 static void add_to_chain (void *p, MEM_SIZE size, MEM_SIZE chip);
795 static void* get_from_chain (MEM_SIZE size);
796 static void* get_from_bigger_buckets(int bucket, MEM_SIZE size);
797 static union overhead *getpages (MEM_SIZE needed, int *nblksp, int bucket);
798 static int getpages_adjacent(MEM_SIZE require);
800 #ifdef I_MACH_CTHREADS
802 # define MUTEX_LOCK(m) STMT_START { if (*m) mutex_lock(*m); } STMT_END
804 # define MUTEX_UNLOCK(m) STMT_START { if (*m) mutex_unlock(*m); } STMT_END
808 # define PTRSIZE sizeof(void*)
812 # define BITS_IN_PTR (8*PTRSIZE)
816 * nextf[i] is the pointer to the next free block of size 2^i. The
817 * smallest allocatable block is 8 bytes. The overhead information
818 * precedes the data area returned to the user.
820 #define NBUCKETS (BITS_IN_PTR*BUCKETS_PER_POW2 + 1)
821 static union overhead *nextf[NBUCKETS];
823 #if defined(PURIFY) && !defined(USE_PERL_SBRK)
824 # define USE_PERL_SBRK
828 # define sbrk(a) Perl_sbrk(a)
829 Malloc_t Perl_sbrk (int size);
831 # ifndef HAS_SBRK_PROTO /* <unistd.h> usually takes care of this */
832 extern Malloc_t sbrk(int);
836 #ifndef MIN_SBRK_FRAC1000 /* Backward compatibility */
837 # define MIN_SBRK_FRAC1000 (MIN_SBRK_FRAC * 10)
840 #ifndef START_EXTERN_C
842 # define START_EXTERN_C extern "C" {
844 # define START_EXTERN_C
850 # define END_EXTERN_C };
852 # define END_EXTERN_C
856 #include "malloc_ctl.h"
858 #ifndef NO_MALLOC_DYNAMIC_CFG
859 # define PERL_MALLOC_OPT_CHARS "FMfAPGdac"
861 # ifndef FILL_DEAD_DEFAULT
862 # define FILL_DEAD_DEFAULT 1
864 # ifndef FILL_ALIVE_DEFAULT
865 # define FILL_ALIVE_DEFAULT 1
867 # ifndef FILL_CHECK_DEFAULT
868 # define FILL_CHECK_DEFAULT 1
871 static IV MallocCfg[MallocCfg_last] = {
877 SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE, /* sbrk_goodness */
878 FILL_DEAD_DEFAULT, /* FILL_DEAD */
879 FILL_ALIVE_DEFAULT, /* FILL_ALIVE */
880 FILL_CHECK_DEFAULT, /* FILL_CHECK */
881 0, /* MallocCfg_skip_cfg_env */
882 0, /* MallocCfg_cfg_env_read */
883 0, /* MallocCfg_emergency_buffer_size */
884 0, /* MallocCfg_emergency_buffer_prepared_size */
885 0 /* MallocCfg_emergency_buffer_last_req */
887 IV *MallocCfg_ptr = MallocCfg;
889 static char* MallocCfgP[MallocCfg_last] = {
890 0, /* MallocCfgP_emergency_buffer */
891 0, /* MallocCfgP_emergency_buffer_prepared */
893 char **MallocCfgP_ptr = MallocCfgP;
897 # undef MIN_SBRK_FRAC1000
898 # undef SBRK_ALLOW_FAILURES
899 # undef SBRK_FAILURE_PRICE
901 # define MIN_SBRK MallocCfg[MallocCfg_MIN_SBRK]
902 # define FIRST_SBRK MallocCfg[MallocCfg_FIRST_SBRK]
903 # define MIN_SBRK_FRAC1000 MallocCfg[MallocCfg_MIN_SBRK_FRAC1000]
904 # define SBRK_ALLOW_FAILURES MallocCfg[MallocCfg_SBRK_ALLOW_FAILURES]
905 # define SBRK_FAILURE_PRICE MallocCfg[MallocCfg_SBRK_FAILURE_PRICE]
907 # define sbrk_goodness MallocCfg[MallocCfg_sbrk_goodness]
909 # define emergency_buffer_size MallocCfg[MallocCfg_emergency_buffer_size]
910 # define emergency_buffer_last_req MallocCfg[MallocCfg_emergency_buffer_last_req]
912 # define FILL_DEAD MallocCfg[MallocCfg_filldead]
913 # define FILL_ALIVE MallocCfg[MallocCfg_fillalive]
914 # define FILL_CHECK_CFG MallocCfg[MallocCfg_fillcheck]
915 # define FILL_CHECK (FILL_DEAD && FILL_CHECK_CFG)
917 # define emergency_buffer MallocCfgP[MallocCfgP_emergency_buffer]
918 # define emergency_buffer_prepared MallocCfgP[MallocCfgP_emergency_buffer_prepared]
920 #else /* defined(NO_MALLOC_DYNAMIC_CFG) */
923 # define FILL_ALIVE 1
924 # define FILL_CHECK 1
925 static int sbrk_goodness = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE;
927 # define NO_PERL_MALLOC_ENV
931 #ifdef DEBUGGING_MSTATS
933 * nmalloc[i] is the difference between the number of mallocs and frees
934 * for a given block size.
936 static u_int nmalloc[NBUCKETS];
937 static u_int sbrk_slack;
938 static u_int start_slack;
939 #else /* !( defined DEBUGGING_MSTATS ) */
940 # define sbrk_slack 0
943 static u_int goodsbrk;
945 #ifdef PERL_EMERGENCY_SBRK
948 # define BIG_SIZE (1<<16) /* 64K */
951 # ifdef NO_MALLOC_DYNAMIC_CFG
952 static MEM_SIZE emergency_buffer_size;
953 /* 0 if the last request for more memory succeeded.
954 Otherwise the size of the failing request. */
955 static MEM_SIZE emergency_buffer_last_req;
956 static char *emergency_buffer;
957 static char *emergency_buffer_prepared;
960 # ifndef emergency_sbrk_croak
961 # define emergency_sbrk_croak croak2
965 perl_get_emergency_buffer(IV *size)
968 /* First offense, give a possibility to recover by dieing. */
969 /* No malloc involved here: */
972 GV **gvp = (GV**)hv_fetchs(PL_defstash, "^M", FALSE);
974 if (!gvp) gvp = (GV**)hv_fetchs(PL_defstash, "\015", FALSE);
975 if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv)
976 || (SvLEN(sv) < (1<<LOG_OF_MIN_ARENA) - M_OVERHEAD))
977 return NULL; /* Now die die die... */
978 /* Got it, now detach SvPV: */
980 /* Check alignment: */
981 if ((PTR2UV(pv) - sizeof(union overhead)) & (NEEDED_ALIGNMENT - 1)) {
982 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
983 return NULL; /* die die die */
990 *size = malloced_size(pv) + M_OVERHEAD;
991 return pv - sizeof(union overhead);
993 # define PERL_GET_EMERGENCY_BUFFER(p) perl_get_emergency_buffer(p)
995 # ifndef NO_MALLOC_DYNAMIC_CFG
997 get_emergency_buffer(IV *size)
999 char *pv = emergency_buffer_prepared;
1001 *size = MallocCfg[MallocCfg_emergency_buffer_prepared_size];
1002 emergency_buffer_prepared = 0;
1003 MallocCfg[MallocCfg_emergency_buffer_prepared_size] = 0;
1007 /* Returns 0 on success, -1 on bad alignment, -2 if not implemented */
1009 set_emergency_buffer(char *b, IV size)
1011 if (PTR2UV(b) & (NEEDED_ALIGNMENT - 1))
1013 if (MallocCfg[MallocCfg_emergency_buffer_prepared_size])
1014 add_to_chain((void*)emergency_buffer_prepared,
1015 MallocCfg[MallocCfg_emergency_buffer_prepared_size], 0);
1016 emergency_buffer_prepared = b;
1017 MallocCfg[MallocCfg_emergency_buffer_prepared_size] = size;
1020 # define GET_EMERGENCY_BUFFER(p) get_emergency_buffer(p)
1021 # else /* NO_MALLOC_DYNAMIC_CFG */
1022 # define GET_EMERGENCY_BUFFER(p) NULL
1024 set_emergency_buffer(char *b, IV size)
1031 emergency_sbrk(MEM_SIZE size)
1033 MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA;
1035 if (size >= BIG_SIZE
1036 && (!emergency_buffer_last_req ||
1037 (size < (MEM_SIZE)emergency_buffer_last_req))) {
1038 /* Give the possibility to recover, but avoid an infinite cycle. */
1040 emergency_buffer_last_req = size;
1041 emergency_sbrk_croak("Out of memory during \"large\" request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
1044 if ((MEM_SIZE)emergency_buffer_size >= rsize) {
1045 char *old = emergency_buffer;
1047 emergency_buffer_size -= rsize;
1048 emergency_buffer += rsize;
1051 /* First offense, give a possibility to recover by dieing. */
1052 /* No malloc involved here: */
1054 char *pv = GET_EMERGENCY_BUFFER(&Size);
1057 if (emergency_buffer_size) {
1058 add_to_chain(emergency_buffer, emergency_buffer_size, 0);
1059 emergency_buffer_size = 0;
1060 emergency_buffer = NULL;
1065 pv = PERL_GET_EMERGENCY_BUFFER(&Size);
1069 return (char *)-1; /* Now die die die... */
1072 /* Check alignment: */
1073 if (PTR2UV(pv) & (NEEDED_ALIGNMENT - 1)) {
1076 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
1077 return (char *)-1; /* die die die */
1080 emergency_buffer = pv;
1081 emergency_buffer_size = Size;
1085 emergency_sbrk_croak("Out of memory during request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
1086 assert(0); /* NOTREACHED */
1090 #else /* !defined(PERL_EMERGENCY_SBRK) */
1091 # define emergency_sbrk(size) -1
1092 #endif /* defined PERL_EMERGENCY_SBRK */
1094 /* Don't use PerlIO buffered writes as they allocate memory. */
1095 #define MYMALLOC_WRITE2STDERR(s) PerlLIO_write(PerlIO_fileno(PerlIO_stderr()),s,strlen(s))
1099 #define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p),__FILE__,__LINE__);
1102 botch(const char *diag, const char *s, const char *file, int line)
1106 if (!(PERL_MAYBE_ALIVE && PERL_GET_THX))
1109 if (PerlIO_printf(PerlIO_stderr(),
1110 "assertion botched (%s?): %s %s:%d\n",
1111 diag, s, file, line) != 0) {
1112 do_write: /* Can be initializing interpreter */
1113 MYMALLOC_WRITE2STDERR("assertion botched (");
1114 MYMALLOC_WRITE2STDERR(diag);
1115 MYMALLOC_WRITE2STDERR("?): ");
1116 MYMALLOC_WRITE2STDERR(s);
1117 MYMALLOC_WRITE2STDERR(" (");
1118 MYMALLOC_WRITE2STDERR(file);
1119 MYMALLOC_WRITE2STDERR(":");
1122 char *s = linebuf + sizeof(linebuf) - 1;
1126 *--s = '0' + (n % 10);
1128 MYMALLOC_WRITE2STDERR(s);
1130 MYMALLOC_WRITE2STDERR(")\n");
1136 #define ASSERT(p, diag)
1140 /* Fill should be long enough to cover long */
1142 fill_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1144 unsigned char *e = s + nbytes;
1146 const long lfill = *(long*)fill;
1148 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1149 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1150 unsigned const char *f = fill + sizeof(long) - shift;
1151 unsigned char *e1 = s + shift;
1157 while ((unsigned char*)(lp + 1) <= e)
1159 s = (unsigned char*)lp;
1163 /* Just malloc()ed */
1164 static const unsigned char fill_feedadad[] =
1165 {0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD,
1166 0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD};
1168 static const unsigned char fill_deadbeef[] =
1169 {0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF,
1170 0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF};
1171 # define FILL_DEADBEEF(s, n) \
1172 (void)(FILL_DEAD? (fill_pat_4bytes((s), (n), fill_deadbeef), 0) : 0)
1173 # define FILL_FEEDADAD(s, n) \
1174 (void)(FILL_ALIVE? (fill_pat_4bytes((s), (n), fill_feedadad), 0) : 0)
1176 # define FILL_DEADBEEF(s, n) ((void)0)
1177 # define FILL_FEEDADAD(s, n) ((void)0)
1178 # undef MALLOC_FILL_CHECK
1181 #ifdef MALLOC_FILL_CHECK
1183 cmp_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1185 unsigned char *e = s + nbytes;
1187 const long lfill = *(long*)fill;
1189 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1190 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1191 unsigned const char *f = fill + sizeof(long) - shift;
1192 unsigned char *e1 = s + shift;
1199 while ((unsigned char*)(lp + 1) <= e)
1202 s = (unsigned char*)lp;
1204 if (*s++ != *fill++)
1208 # define FILLCHECK_DEADBEEF(s, n) \
1209 ASSERT(!FILL_CHECK || !cmp_pat_4bytes(s, n, fill_deadbeef), \
1210 "free()ed/realloc()ed-away memory was overwritten")
1212 # define FILLCHECK_DEADBEEF(s, n) ((void)0)
1216 S_adjust_size_and_find_bucket(size_t *nbytes_p)
1222 PERL_ARGS_ASSERT_ADJUST_SIZE_AND_FIND_BUCKET;
1227 * Convert amount of memory requested into
1228 * closest block size stored in hash buckets
1229 * which satisfies request. Account for
1230 * space used per block for accounting.
1233 # ifdef SMALL_BUCKET_VIA_TABLE
1235 bucket = MIN_BUCKET;
1236 else if (nbytes <= SIZE_TABLE_MAX) {
1237 bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
1242 if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
1247 POW2_OPTIMIZE_ADJUST(nbytes);
1248 nbytes += M_OVERHEAD;
1249 nbytes = (nbytes + 3) &~ 3;
1250 #if defined(PACK_MALLOC) && !defined(SMALL_BUCKET_VIA_TABLE)
1253 shiftr = (nbytes - 1) >> START_SHIFT;
1254 bucket = START_SHIFTS_BUCKET;
1255 /* apart from this loop, this is O(1) */
1256 while (shiftr >>= 1)
1257 bucket += BUCKETS_PER_POW2;
1264 Perl_malloc(size_t nbytes)
1270 #if defined(DEBUGGING) || defined(RCHECK)
1271 MEM_SIZE size = nbytes;
1274 BARK_64K_LIMIT("Allocation",nbytes,nbytes);
1276 if ((long)nbytes < 0)
1277 croak("%s", "panic: malloc");
1280 bucket = adjust_size_and_find_bucket(&nbytes);
1283 * If nothing in hash bucket right now,
1284 * request more memory from the system.
1286 if (nextf[bucket] == NULL)
1288 if ((p = nextf[bucket]) == NULL) {
1293 #if defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC)
1294 MYMALLOC_WRITE2STDERR("Out of memory!\n");
1297 char *eb = buff + sizeof(buff) - 1;
1301 MYMALLOC_WRITE2STDERR("Out of memory during request for ");
1302 #if defined(DEBUGGING) || defined(RCHECK)
1307 *--s = '0' + (n % 10);
1309 MYMALLOC_WRITE2STDERR(s);
1310 MYMALLOC_WRITE2STDERR(" bytes, total sbrk() is ");
1312 n = goodsbrk + sbrk_slack;
1314 *--s = '0' + (n % 10);
1316 MYMALLOC_WRITE2STDERR(s);
1317 MYMALLOC_WRITE2STDERR(" bytes!\n");
1318 #endif /* defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC) */
1325 /* remove from linked list */
1327 if ( (PTR2UV(p) & (MEM_ALIGNBYTES - 1))
1328 /* Can't get this low */
1329 || (p && PTR2UV(p) < (1<<LOG_OF_MIN_ARENA)) ) {
1331 PerlIO_printf(PerlIO_stderr(),
1332 "Unaligned pointer in the free chain 0x%"UVxf"\n",
1335 if ( (PTR2UV(p->ov_next) & (MEM_ALIGNBYTES - 1))
1336 || (p->ov_next && PTR2UV(p->ov_next) < (1<<LOG_OF_MIN_ARENA)) ) {
1338 PerlIO_printf(PerlIO_stderr(),
1339 "Unaligned \"next\" pointer in the free "
1340 "chain 0x%"UVxf" at 0x%"UVxf"\n",
1341 PTR2UV(p->ov_next), PTR2UV(p));
1344 nextf[bucket] = p->ov_next;
1348 DEBUG_m(PerlIO_printf(Perl_debug_log,
1349 "0x%"UVxf": (%05lu) malloc %ld bytes\n",
1350 PTR2UV((Malloc_t)(p + CHUNK_SHIFT)), (unsigned long)(PL_an++),
1353 FILLCHECK_DEADBEEF((unsigned char*)(p + CHUNK_SHIFT),
1354 BUCKET_SIZE_REAL(bucket) + RMAGIC_SZ);
1356 #ifdef IGNORE_SMALL_BAD_FREE
1357 if (bucket >= FIRST_BUCKET_WITH_CHECK)
1359 OV_MAGIC(p, bucket) = MAGIC;
1361 OV_INDEX(p) = bucket;
1365 * Record allocated size of block and
1366 * bound space with magic numbers.
1368 p->ov_rmagic = RMAGIC;
1369 if (bucket <= MAX_SHORT_BUCKET) {
1372 nbytes = size + M_OVERHEAD;
1373 p->ov_size = nbytes - 1;
1374 if ((i = nbytes & (RMAGIC_SZ-1))) {
1376 while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
1377 ((caddr_t)p + nbytes - RMAGIC_SZ)[i] = RMAGIC_C;
1379 /* Same at RMAGIC_SZ-aligned RMAGIC */
1380 nbytes = (nbytes + RMAGIC_SZ - 1) & ~(RMAGIC_SZ - 1);
1381 ((u_int *)((caddr_t)p + nbytes))[-1] = RMAGIC;
1383 FILL_FEEDADAD((unsigned char *)(p + CHUNK_SHIFT), size);
1385 return ((Malloc_t)(p + CHUNK_SHIFT));
1388 static char *last_sbrk_top;
1389 static char *last_op; /* This arena can be easily extended. */
1390 static MEM_SIZE sbrked_remains;
1392 #ifdef DEBUGGING_MSTATS
1396 struct chunk_chain_s {
1397 struct chunk_chain_s *next;
1400 static struct chunk_chain_s *chunk_chain;
1401 static int n_chunks;
1402 static char max_bucket;
1404 /* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */
1406 get_from_chain(MEM_SIZE size)
1408 struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
1409 struct chunk_chain_s **oldgoodp = NULL;
1410 long min_remain = LONG_MAX;
1413 if (elt->size >= size) {
1414 long remains = elt->size - size;
1415 if (remains >= 0 && remains < min_remain) {
1417 min_remain = remains;
1423 oldp = &( elt->next );
1426 if (!oldgoodp) return NULL;
1428 void *ret = *oldgoodp;
1429 struct chunk_chain_s *next = (*oldgoodp)->next;
1431 *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
1432 (*oldgoodp)->size = min_remain;
1433 (*oldgoodp)->next = next;
1436 void *ret = *oldgoodp;
1437 *oldgoodp = (*oldgoodp)->next;
1444 add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
1446 struct chunk_chain_s *next = chunk_chain;
1447 char *cp = (char*)p;
1450 chunk_chain = (struct chunk_chain_s *)cp;
1451 chunk_chain->size = size - chip;
1452 chunk_chain->next = next;
1457 get_from_bigger_buckets(int bucket, MEM_SIZE size)
1460 static int bucketprice[NBUCKETS];
1461 while (bucket <= max_bucket) {
1462 /* We postpone stealing from bigger buckets until we want it
1464 if (nextf[bucket] && bucketprice[bucket]++ >= price) {
1466 void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
1467 bucketprice[bucket] = 0;
1468 if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
1469 last_op = NULL; /* Disable optimization */
1471 nextf[bucket] = nextf[bucket]->ov_next;
1472 #ifdef DEBUGGING_MSTATS
1474 start_slack -= M_OVERHEAD;
1476 add_to_chain(ret, (BUCKET_SIZE_NO_SURPLUS(bucket) +
1477 POW2_OPTIMIZE_SURPLUS(bucket)),
1486 static union overhead *
1487 getpages(MEM_SIZE needed, int *nblksp, int bucket)
1490 /* Need to do (possibly expensive) system call. Try to
1491 optimize it for rare calling. */
1492 MEM_SIZE require = needed - sbrked_remains;
1494 union overhead *ovp;
1497 if (sbrk_goodness > 0) {
1498 if (!last_sbrk_top && require < (MEM_SIZE)FIRST_SBRK)
1499 require = FIRST_SBRK;
1500 else if (require < (MEM_SIZE)MIN_SBRK) require = MIN_SBRK;
1502 if (require < (Size_t)(goodsbrk * MIN_SBRK_FRAC1000 / 1000))
1503 require = goodsbrk * MIN_SBRK_FRAC1000 / 1000;
1504 require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
1511 DEBUG_m(PerlIO_printf(Perl_debug_log,
1512 "sbrk(%ld) for %ld-byte-long arena\n",
1513 (long)require, (long) needed));
1514 cp = (char *)sbrk(require);
1515 #ifdef DEBUGGING_MSTATS
1518 if (cp == last_sbrk_top) {
1519 /* Common case, anything is fine. */
1521 ovp = (union overhead *) (cp - sbrked_remains);
1522 last_op = cp - sbrked_remains;
1523 sbrked_remains = require - (needed - sbrked_remains);
1524 } else if (cp == (char *)-1) { /* no more room! */
1525 ovp = (union overhead *)emergency_sbrk(needed);
1526 if (ovp == (union overhead *)-1)
1528 if (((char*)ovp) > last_op) { /* Cannot happen with current emergency_sbrk() */
1532 } else { /* Non-continuous or first sbrk(). */
1533 long add = sbrked_remains;
1536 if (sbrked_remains) { /* Put rest into chain, we
1537 cannot use it right now. */
1538 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1542 /* Second, check alignment. */
1545 /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
1546 improve performance of memory access. */
1547 if (PTR2UV(cp) & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
1548 slack = WANTED_ALIGNMENT - (PTR2UV(cp) & (WANTED_ALIGNMENT - 1));
1553 DEBUG_m(PerlIO_printf(Perl_debug_log,
1554 "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",
1555 (long)add, (long) slack,
1556 (long) sbrked_remains));
1557 newcp = (char *)sbrk(add);
1558 #if defined(DEBUGGING_MSTATS)
1562 if (newcp != cp + require) {
1563 /* Too bad: even rounding sbrk() is not continuous.*/
1564 DEBUG_m(PerlIO_printf(Perl_debug_log,
1565 "failed to fix bad sbrk()\n"));
1569 fatalcroak("panic: Off-page sbrk\n");
1572 if (sbrked_remains) {
1574 #if defined(DEBUGGING_MSTATS)
1575 sbrk_slack += require;
1578 DEBUG_m(PerlIO_printf(Perl_debug_log,
1579 "straight sbrk(%ld)\n",
1581 cp = (char *)sbrk(require);
1582 #ifdef DEBUGGING_MSTATS
1585 if (cp == (char *)-1)
1588 sbrk_goodness = -1; /* Disable optimization!
1589 Continue with not-aligned... */
1592 require += sbrked_remains;
1596 if (last_sbrk_top) {
1597 sbrk_goodness -= SBRK_FAILURE_PRICE;
1600 ovp = (union overhead *) cp;
1602 * Round up to minimum allocation size boundary
1603 * and deduct from block count to reflect.
1606 # if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
1607 if (PTR2UV(ovp) & (NEEDED_ALIGNMENT - 1))
1608 fatalcroak("Misalignment of sbrk()\n");
1611 if (PTR2UV(ovp) & (MEM_ALIGNBYTES - 1)) {
1612 DEBUG_m(PerlIO_printf(Perl_debug_log,
1613 "fixing sbrk(): %d bytes off machine alignment\n",
1614 (int)(PTR2UV(ovp) & (MEM_ALIGNBYTES - 1))));
1615 ovp = INT2PTR(union overhead *,(PTR2UV(ovp) + MEM_ALIGNBYTES) &
1616 (MEM_ALIGNBYTES - 1));
1618 # if defined(DEBUGGING_MSTATS)
1619 /* This is only approx. if TWO_POT_OPTIMIZE: */
1620 sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
1623 ; /* Finish "else" */
1624 sbrked_remains = require - needed;
1627 #if !defined(PLAIN_MALLOC) && !defined(NO_FANCY_MALLOC)
1628 emergency_buffer_last_req = 0;
1630 last_sbrk_top = cp + require;
1631 #ifdef DEBUGGING_MSTATS
1632 goodsbrk += require;
1638 getpages_adjacent(MEM_SIZE require)
1640 if (require <= sbrked_remains) {
1641 sbrked_remains -= require;
1645 require -= sbrked_remains;
1646 /* We do not try to optimize sbrks here, we go for place. */
1647 cp = (char*) sbrk(require);
1648 #ifdef DEBUGGING_MSTATS
1650 goodsbrk += require;
1652 if (cp == last_sbrk_top) {
1654 last_sbrk_top = cp + require;
1656 if (cp == (char*)-1) { /* Out of memory */
1657 #ifdef DEBUGGING_MSTATS
1658 goodsbrk -= require;
1662 /* Report the failure: */
1664 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1666 add_to_chain((void*)cp, require, 0);
1667 sbrk_goodness -= SBRK_FAILURE_PRICE;
1679 * Allocate more memory to the indicated bucket.
1682 morecore(int bucket)
1685 union overhead *ovp;
1686 int rnu; /* 2^rnu bytes will be requested */
1687 int nblks; /* become nblks blocks of the desired size */
1688 MEM_SIZE siz, needed;
1689 static int were_called = 0;
1693 #ifndef NO_PERL_MALLOC_ENV
1695 /* It's the our first time. Initialize ourselves */
1696 were_called = 1; /* Avoid a loop */
1697 if (!MallocCfg[MallocCfg_skip_cfg_env]) {
1698 char *s = getenv("PERL_MALLOC_OPT"), *t = s, *off;
1699 const char *opts = PERL_MALLOC_OPT_CHARS;
1702 while ( t && t[0] && t[1] == '='
1703 && ((off = strchr(opts, *t))) ) {
1707 while (*t <= '9' && *t >= '0')
1708 val = 10*val + *t++ - '0';
1709 if (!*t || *t == ';') {
1710 if (MallocCfg[off - opts] != val)
1712 MallocCfg[off - opts] = val;
1719 MYMALLOC_WRITE2STDERR("Unrecognized part of PERL_MALLOC_OPT: \"");
1720 MYMALLOC_WRITE2STDERR(t);
1721 MYMALLOC_WRITE2STDERR("\"\n");
1724 MallocCfg[MallocCfg_cfg_env_read] = 1;
1728 if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
1730 croak("%s", "Out of memory during ridiculously large request");
1732 if (bucket > max_bucket)
1733 max_bucket = bucket;
1735 rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT))
1737 : (bucket >> BUCKET_POW2_SHIFT) );
1738 /* This may be overwritten later: */
1739 nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
1740 needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
1741 if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
1742 ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
1743 nextf[rnu << BUCKET_POW2_SHIFT]
1744 = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
1745 #ifdef DEBUGGING_MSTATS
1746 nmalloc[rnu << BUCKET_POW2_SHIFT]--;
1747 start_slack -= M_OVERHEAD;
1749 DEBUG_m(PerlIO_printf(Perl_debug_log,
1750 "stealing %ld bytes from %ld arena\n",
1751 (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
1752 } else if (chunk_chain
1753 && (ovp = (union overhead*) get_from_chain(needed))) {
1754 DEBUG_m(PerlIO_printf(Perl_debug_log,
1755 "stealing %ld bytes from chain\n",
1757 } else if ( (ovp = (union overhead*)
1758 get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
1760 DEBUG_m(PerlIO_printf(Perl_debug_log,
1761 "stealing %ld bytes from bigger buckets\n",
1763 } else if (needed <= sbrked_remains) {
1764 ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
1765 sbrked_remains -= needed;
1766 last_op = (char*)ovp;
1768 ovp = getpages(needed, &nblks, bucket);
1772 FILL_DEADBEEF((unsigned char*)ovp, needed);
1775 * Add new memory allocated to that on
1776 * free list for this hash bucket.
1778 siz = BUCKET_SIZE_NO_SURPLUS(bucket); /* No surplus if nblks > 1 */
1780 *(u_char*)ovp = bucket; /* Fill index. */
1781 if (bucket <= MAX_PACKED) {
1782 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1783 nblks = N_BLKS(bucket);
1784 # ifdef DEBUGGING_MSTATS
1785 start_slack += BLK_SHIFT(bucket);
1787 } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
1788 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1789 siz -= sizeof(union overhead);
1790 } else ovp++; /* One chunk per block. */
1791 #endif /* PACK_MALLOC */
1792 nextf[bucket] = ovp;
1793 #ifdef DEBUGGING_MSTATS
1794 nmalloc[bucket] += nblks;
1795 if (bucket > MAX_PACKED) {
1796 start_slack += M_OVERHEAD * nblks;
1800 while (--nblks > 0) {
1801 ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
1802 ovp = (union overhead *)((caddr_t)ovp + siz);
1804 /* Not all sbrks return zeroed memory.*/
1805 ovp->ov_next = (union overhead *)NULL;
1807 if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
1808 union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
1809 nextf[7*BUCKETS_PER_POW2] =
1810 (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2]
1811 - sizeof(union overhead));
1812 nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
1814 #endif /* !PACK_MALLOC */
1818 Perl_mfree(Malloc_t where)
1822 union overhead *ovp;
1823 char *cp = (char*)where;
1828 DEBUG_m(PerlIO_printf(Perl_debug_log,
1829 "0x%"UVxf": (%05lu) free\n",
1830 PTR2UV(cp), (unsigned long)(PL_an++)));
1835 if (PTR2UV(cp) & (MEM_ALIGNBYTES - 1))
1836 croak("%s", "wrong alignment in free()");
1838 ovp = (union overhead *)((caddr_t)cp
1839 - sizeof (union overhead) * CHUNK_SHIFT);
1841 bucket = OV_INDEX(ovp);
1843 #ifdef IGNORE_SMALL_BAD_FREE
1844 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1845 && (OV_MAGIC(ovp, bucket) != MAGIC))
1847 if (OV_MAGIC(ovp, bucket) != MAGIC)
1850 static int bad_free_warn = -1;
1851 if (bad_free_warn == -1) {
1853 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1854 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1861 if (!PERL_IS_ALIVE || !PL_curcop)
1862 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s free() ignored (RMAGIC, PERL_CORE)",
1863 ovp->ov_rmagic == RMAGIC - 1 ?
1864 "Duplicate" : "Bad");
1869 if (!PERL_IS_ALIVE || !PL_curcop)
1870 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s", "Bad free() ignored (PERL_CORE)");
1873 return; /* sanity */
1876 ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
1877 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
1879 MEM_SIZE nbytes = ovp->ov_size + 1;
1881 if ((i = nbytes & (RMAGIC_SZ-1))) {
1883 while (i--) { /* nbytes - RMAGIC_SZ is end of alloced area */
1884 ASSERT(((caddr_t)ovp + nbytes - RMAGIC_SZ)[i] == RMAGIC_C,
1885 "chunk's tail overwrite");
1888 /* Same at RMAGIC_SZ-aligned RMAGIC */
1889 nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
1890 ASSERT(((u_int *)((caddr_t)ovp + nbytes))[-1] == RMAGIC,
1891 "chunk's tail overwrite");
1892 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nbytes),
1893 BUCKET_SIZE(OV_INDEX(ovp)) - nbytes);
1895 FILL_DEADBEEF((unsigned char*)(ovp+CHUNK_SHIFT),
1896 BUCKET_SIZE_REAL(OV_INDEX(ovp)) + RMAGIC_SZ);
1897 ovp->ov_rmagic = RMAGIC - 1;
1899 ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
1900 size = OV_INDEX(ovp);
1903 ovp->ov_next = nextf[size];
1908 /* There is no need to do any locking in realloc (with an exception of
1909 trying to grow in place if we are at the end of the chain).
1910 If somebody calls us from a different thread with the same address,
1911 we are sole anyway. */
1914 Perl_realloc(void *mp, size_t nbytes)
1918 union overhead *ovp;
1922 int incr; /* 1 if does not fit, -1 if "easily" fits in a
1923 smaller bucket, otherwise 0. */
1924 char *cp = (char*)mp;
1927 MEM_SIZE size = nbytes;
1929 if ((long)nbytes < 0)
1930 croak("%s", "panic: realloc");
1933 BARK_64K_LIMIT("Reallocation",nbytes,size);
1935 return Perl_malloc(nbytes);
1937 ovp = (union overhead *)((caddr_t)cp
1938 - sizeof (union overhead) * CHUNK_SHIFT);
1939 bucket = OV_INDEX(ovp);
1941 #ifdef IGNORE_SMALL_BAD_FREE
1942 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1943 && (OV_MAGIC(ovp, bucket) != MAGIC))
1945 if (OV_MAGIC(ovp, bucket) != MAGIC)
1948 static int bad_free_warn = -1;
1949 if (bad_free_warn == -1) {
1951 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1952 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1959 if (!PERL_IS_ALIVE || !PL_curcop)
1960 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%srealloc() %signored",
1961 (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
1962 ovp->ov_rmagic == RMAGIC - 1
1963 ? "of freed memory " : "");
1968 if (!PERL_IS_ALIVE || !PL_curcop)
1969 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s",
1970 "Bad realloc() ignored");
1973 return NULL; /* sanity */
1976 onb = BUCKET_SIZE_REAL(bucket);
1978 * avoid the copy if same size block.
1979 * We are not aggressive with boundary cases. Note that it might
1980 * (for a small number of cases) give false negative if
1981 * both new size and old one are in the bucket for
1982 * FIRST_BIG_POW2, but the new one is near the lower end.
1984 * We do not try to go to 1.5 times smaller bucket so far.
1986 if (nbytes > onb) incr = 1;
1988 #ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
1989 if ( /* This is a little bit pessimal if PACK_MALLOC: */
1990 nbytes > ( (onb >> 1) - M_OVERHEAD )
1991 # ifdef TWO_POT_OPTIMIZE
1992 || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
1995 #else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
1996 prev_bucket = ( (bucket > MAX_PACKED + 1)
1997 ? bucket - BUCKETS_PER_POW2
1999 if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
2000 #endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
2004 #ifdef STRESS_REALLOC
2011 * Record new allocated size of block and
2012 * bound space with magic numbers.
2014 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
2015 int i, nb = ovp->ov_size + 1;
2017 if ((i = nb & (RMAGIC_SZ-1))) {
2019 while (i--) { /* nb - RMAGIC_SZ is end of alloced area */
2020 ASSERT(((caddr_t)ovp + nb - RMAGIC_SZ)[i] == RMAGIC_C, "chunk's tail overwrite");
2023 /* Same at RMAGIC_SZ-aligned RMAGIC */
2024 nb = (nb + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
2025 ASSERT(((u_int *)((caddr_t)ovp + nb))[-1] == RMAGIC,
2026 "chunk's tail overwrite");
2027 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nb),
2028 BUCKET_SIZE(OV_INDEX(ovp)) - nb);
2029 if (nbytes > ovp->ov_size + 1 - M_OVERHEAD)
2030 FILL_FEEDADAD((unsigned char*)cp + ovp->ov_size + 1 - M_OVERHEAD,
2031 nbytes - (ovp->ov_size + 1 - M_OVERHEAD));
2033 FILL_DEADBEEF((unsigned char*)cp + nbytes,
2034 nb - M_OVERHEAD + RMAGIC_SZ - nbytes);
2036 * Convert amount of memory requested into
2037 * closest block size stored in hash buckets
2038 * which satisfies request. Account for
2039 * space used per block for accounting.
2041 nbytes += M_OVERHEAD;
2042 ovp->ov_size = nbytes - 1;
2043 if ((i = nbytes & (RMAGIC_SZ-1))) {
2045 while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
2046 ((caddr_t)ovp + nbytes - RMAGIC_SZ)[i]
2049 /* Same at RMAGIC_SZ-aligned RMAGIC */
2050 nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ - 1);
2051 ((u_int *)((caddr_t)ovp + nbytes))[-1] = RMAGIC;
2055 DEBUG_m(PerlIO_printf(Perl_debug_log,
2056 "0x%"UVxf": (%05lu) realloc %ld bytes inplace\n",
2057 PTR2UV(res),(unsigned long)(PL_an++),
2059 } else if (incr == 1 && (cp - M_OVERHEAD == last_op)
2060 && (onb > (1 << LOG_OF_MIN_ARENA))) {
2061 MEM_SIZE require, newarena = nbytes, pow;
2064 POW2_OPTIMIZE_ADJUST(newarena);
2065 newarena = newarena + M_OVERHEAD;
2066 /* newarena = (newarena + 3) &~ 3; */
2067 shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
2068 pow = LOG_OF_MIN_ARENA + 1;
2069 /* apart from this loop, this is O(1) */
2070 while (shiftr >>= 1)
2072 newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
2073 require = newarena - onb - M_OVERHEAD;
2076 if (cp - M_OVERHEAD == last_op /* We *still* are the last chunk */
2077 && getpages_adjacent(require)) {
2078 #ifdef DEBUGGING_MSTATS
2080 nmalloc[pow * BUCKETS_PER_POW2]++;
2082 if (pow * BUCKETS_PER_POW2 > (MEM_SIZE)max_bucket)
2083 max_bucket = pow * BUCKETS_PER_POW2;
2084 *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
2093 DEBUG_m(PerlIO_printf(Perl_debug_log,
2094 "0x%"UVxf": (%05lu) realloc %ld bytes the hard way\n",
2095 PTR2UV(cp),(unsigned long)(PL_an++),
2097 if ((res = (char*)Perl_malloc(nbytes)) == NULL)
2099 if (cp != res) /* common optimization */
2100 Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
2103 return ((Malloc_t)res);
2107 Perl_calloc(size_t elements, size_t size)
2109 long sz = elements * size;
2110 Malloc_t p = Perl_malloc(sz);
2113 memset((void*)p, 0, sz);
2119 Perl_strdup(const char *s)
2121 MEM_SIZE l = strlen(s);
2122 char *s1 = (char *)Perl_malloc(l+1);
2124 return (char *)CopyD(s, s1, (MEM_SIZE)(l+1), char);
2128 Perl_putenv(char *a)
2130 /* Sometimes system's putenv conflicts with my_setenv() - this is system
2131 malloc vs Perl's free(). */
2138 while (*val && *val != '=')
2143 if (l < sizeof(buf))
2146 var = (char *)Perl_malloc(l + 1);
2147 Copy(a, var, l, char);
2149 my_setenv(var, val+1);
2156 Perl_malloced_size(void *p)
2158 union overhead * const ovp = (union overhead *)
2159 ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
2160 const int bucket = OV_INDEX(ovp);
2162 PERL_ARGS_ASSERT_MALLOCED_SIZE;
2165 /* The caller wants to have a complete control over the chunk,
2166 disable the memory checking inside the chunk. */
2167 if (bucket <= MAX_SHORT_BUCKET) {
2168 const MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
2169 ovp->ov_size = size + M_OVERHEAD - 1;
2170 *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RMAGIC_SZ)) = RMAGIC;
2173 return BUCKET_SIZE_REAL(bucket);
2178 Perl_malloc_good_size(size_t wanted)
2180 return BUCKET_SIZE_REAL(adjust_size_and_find_bucket(&wanted));
2183 # ifdef BUCKETS_ROOT2
2184 # define MIN_EVEN_REPORT 6
2186 # define MIN_EVEN_REPORT MIN_BUCKET
2190 Perl_get_mstats(pTHX_ perl_mstats_t *buf, int buflen, int level)
2192 #ifdef DEBUGGING_MSTATS
2195 struct chunk_chain_s* nextchain;
2197 PERL_ARGS_ASSERT_GET_MSTATS;
2199 buf->topbucket = buf->topbucket_ev = buf->topbucket_odd
2200 = buf->totfree = buf->total = buf->total_chain = 0;
2202 buf->minbucket = MIN_BUCKET;
2204 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2205 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
2209 buf->ntotal[i] = nmalloc[i];
2211 buf->totfree += j * BUCKET_SIZE_REAL(i);
2212 buf->total += nmalloc[i] * BUCKET_SIZE_REAL(i);
2214 i % 2 ? (buf->topbucket_odd = i) : (buf->topbucket_ev = i);
2218 nextchain = chunk_chain;
2220 buf->total_chain += nextchain->size;
2221 nextchain = nextchain->next;
2223 buf->total_sbrk = goodsbrk + sbrk_slack;
2225 buf->sbrk_good = sbrk_goodness;
2226 buf->sbrk_slack = sbrk_slack;
2227 buf->start_slack = start_slack;
2228 buf->sbrked_remains = sbrked_remains;
2230 buf->nbuckets = NBUCKETS;
2232 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2235 buf->bucket_mem_size[i] = BUCKET_SIZE_NO_SURPLUS(i);
2236 buf->bucket_available_size[i] = BUCKET_SIZE_REAL(i);
2239 #else /* defined DEBUGGING_MSTATS */
2240 PerlIO_printf(Perl_error_log, "perl not compiled with DEBUGGING_MSTATS\n");
2241 #endif /* defined DEBUGGING_MSTATS */
2242 return 0; /* XXX unused */
2245 * mstats - print out statistics about malloc
2247 * Prints two lines of numbers, one showing the length of the free list
2248 * for each size category, the second showing the number of mallocs -
2249 * frees for each size category.
2252 Perl_dump_mstats(pTHX_ const char *s)
2254 #ifdef DEBUGGING_MSTATS
2256 perl_mstats_t buffer;
2260 PERL_ARGS_ASSERT_DUMP_MSTATS;
2264 get_mstats(&buffer, NBUCKETS, 0);
2267 PerlIO_printf(Perl_error_log,
2268 "Memory allocation statistics %s (buckets %"IVdf"(%"IVdf")..%"IVdf"(%"IVdf")\n",
2270 (IV)BUCKET_SIZE_REAL(MIN_BUCKET),
2271 (IV)BUCKET_SIZE_NO_SURPLUS(MIN_BUCKET),
2272 (IV)BUCKET_SIZE_REAL(buffer.topbucket),
2273 (IV)BUCKET_SIZE_NO_SURPLUS(buffer.topbucket));
2274 PerlIO_printf(Perl_error_log, "%8"IVdf" free:", buffer.totfree);
2275 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2276 PerlIO_printf(Perl_error_log,
2277 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2279 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2282 #ifdef BUCKETS_ROOT2
2283 PerlIO_printf(Perl_error_log, "\n\t ");
2284 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2285 PerlIO_printf(Perl_error_log,
2286 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2288 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2292 PerlIO_printf(Perl_error_log, "\n%8"IVdf" used:", buffer.total - buffer.totfree);
2293 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2294 PerlIO_printf(Perl_error_log,
2295 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2297 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2298 buffer.ntotal[i] - buffer.nfree[i]);
2300 #ifdef BUCKETS_ROOT2
2301 PerlIO_printf(Perl_error_log, "\n\t ");
2302 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2303 PerlIO_printf(Perl_error_log,
2304 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2306 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2307 buffer.ntotal[i] - buffer.nfree[i]);
2310 PerlIO_printf(Perl_error_log, "\nTotal sbrk(): %"IVdf"/%"IVdf":%"IVdf". Odd ends: pad+heads+chain+tail: %"IVdf"+%"IVdf"+%"IVdf"+%"IVdf".\n",
2311 buffer.total_sbrk, buffer.sbrks, buffer.sbrk_good,
2312 buffer.sbrk_slack, buffer.start_slack,
2313 buffer.total_chain, buffer.sbrked_remains);
2314 #else /* DEBUGGING_MSTATS */
2315 PerlIO_printf(Perl_error_log, "%s: perl not compiled with DEBUGGING_MSTATS\n",s);
2316 #endif /* DEBUGGING_MSTATS */
2319 #ifdef USE_PERL_SBRK
2321 # if defined(NeXT) || defined(__NeXT__) || defined(PURIFY)
2322 # define PERL_SBRK_VIA_MALLOC
2325 # ifdef PERL_SBRK_VIA_MALLOC
2327 /* it may seem schizophrenic to use perl's malloc and let it call system */
2328 /* malloc, the reason for that is only the 3.2 version of the OS that had */
2329 /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
2330 /* end to the cores */
2332 # ifndef SYSTEM_ALLOC
2333 # define SYSTEM_ALLOC(a) malloc(a)
2335 # ifndef SYSTEM_ALLOC_ALIGNMENT
2336 # define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
2339 # endif /* PERL_SBRK_VIA_MALLOC */
2341 static IV Perl_sbrk_oldchunk;
2342 static long Perl_sbrk_oldsize;
2344 # define PERLSBRK_32_K (1<<15)
2345 # define PERLSBRK_64_K (1<<16)
2353 if (!size) return 0;
2354 reqsize = size; /* just for the DEBUG_m statement */
2356 size = (size + 0x7ff) & ~0x7ff;
2358 if (size <= Perl_sbrk_oldsize) {
2359 got = Perl_sbrk_oldchunk;
2360 Perl_sbrk_oldchunk += size;
2361 Perl_sbrk_oldsize -= size;
2363 if (size >= PERLSBRK_32_K) {
2366 size = PERLSBRK_64_K;
2369 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2370 size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT;
2372 got = (IV)SYSTEM_ALLOC(size);
2373 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2374 got = (got + NEEDED_ALIGNMENT - 1) & ~(NEEDED_ALIGNMENT - 1);
2377 /* Chunk is small, register the rest for future allocs. */
2378 Perl_sbrk_oldchunk = got + reqsize;
2379 Perl_sbrk_oldsize = size - reqsize;
2383 DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%"UVxf"\n",
2384 size, reqsize, Perl_sbrk_oldsize, PTR2UV(got)));
2389 #endif /* ! defined USE_PERL_SBRK */
2393 * c-indentation-style: bsd
2395 * indent-tabs-mode: nil
2398 * ex: set ts=8 sts=4 sw=4 et: