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 */
758 #define BARK_64K_LIMIT(what,nbytes,size)
761 # define MIN_SBRK 2048
765 # define FIRST_SBRK (48*1024)
768 /* Minimal sbrk in percents of what is already alloced. */
769 #ifndef MIN_SBRK_FRAC
770 # define MIN_SBRK_FRAC 3
773 #ifndef SBRK_ALLOW_FAILURES
774 # define SBRK_ALLOW_FAILURES 3
777 #ifndef SBRK_FAILURE_PRICE
778 # define SBRK_FAILURE_PRICE 50
781 static void morecore (int bucket);
782 # if defined(DEBUGGING)
783 static void botch (const char *diag, const char *s, const char *file, int line);
785 static void add_to_chain (void *p, MEM_SIZE size, MEM_SIZE chip);
786 static void* get_from_chain (MEM_SIZE size);
787 static void* get_from_bigger_buckets(int bucket, MEM_SIZE size);
788 static union overhead *getpages (MEM_SIZE needed, int *nblksp, int bucket);
789 static int getpages_adjacent(MEM_SIZE require);
791 #ifdef I_MACH_CTHREADS
793 # define MUTEX_LOCK(m) STMT_START { if (*m) mutex_lock(*m); } STMT_END
795 # define MUTEX_UNLOCK(m) STMT_START { if (*m) mutex_unlock(*m); } STMT_END
799 # define PTRSIZE sizeof(void*)
803 # define BITS_IN_PTR (8*PTRSIZE)
807 * nextf[i] is the pointer to the next free block of size 2^i. The
808 * smallest allocatable block is 8 bytes. The overhead information
809 * precedes the data area returned to the user.
811 #define NBUCKETS (BITS_IN_PTR*BUCKETS_PER_POW2 + 1)
812 static union overhead *nextf[NBUCKETS];
814 #if defined(PURIFY) && !defined(USE_PERL_SBRK)
815 # define USE_PERL_SBRK
819 # define sbrk(a) Perl_sbrk(a)
820 Malloc_t Perl_sbrk (int size);
822 # ifndef HAS_SBRK_PROTO /* <unistd.h> usually takes care of this */
823 extern Malloc_t sbrk(int);
827 #ifndef MIN_SBRK_FRAC1000 /* Backward compatibility */
828 # define MIN_SBRK_FRAC1000 (MIN_SBRK_FRAC * 10)
831 #ifndef START_EXTERN_C
833 # define START_EXTERN_C extern "C" {
835 # define START_EXTERN_C
841 # define END_EXTERN_C };
843 # define END_EXTERN_C
847 #include "malloc_ctl.h"
849 #ifndef NO_MALLOC_DYNAMIC_CFG
850 # define PERL_MALLOC_OPT_CHARS "FMfAPGdac"
852 # ifndef FILL_DEAD_DEFAULT
853 # define FILL_DEAD_DEFAULT 1
855 # ifndef FILL_ALIVE_DEFAULT
856 # define FILL_ALIVE_DEFAULT 1
858 # ifndef FILL_CHECK_DEFAULT
859 # define FILL_CHECK_DEFAULT 1
862 static IV MallocCfg[MallocCfg_last] = {
868 SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE, /* sbrk_goodness */
869 FILL_DEAD_DEFAULT, /* FILL_DEAD */
870 FILL_ALIVE_DEFAULT, /* FILL_ALIVE */
871 FILL_CHECK_DEFAULT, /* FILL_CHECK */
872 0, /* MallocCfg_skip_cfg_env */
873 0, /* MallocCfg_cfg_env_read */
874 0, /* MallocCfg_emergency_buffer_size */
875 0, /* MallocCfg_emergency_buffer_prepared_size */
876 0 /* MallocCfg_emergency_buffer_last_req */
878 IV *MallocCfg_ptr = MallocCfg;
880 static char* MallocCfgP[MallocCfg_last] = {
881 0, /* MallocCfgP_emergency_buffer */
882 0, /* MallocCfgP_emergency_buffer_prepared */
884 char **MallocCfgP_ptr = MallocCfgP;
888 # undef MIN_SBRK_FRAC1000
889 # undef SBRK_ALLOW_FAILURES
890 # undef SBRK_FAILURE_PRICE
892 # define MIN_SBRK MallocCfg[MallocCfg_MIN_SBRK]
893 # define FIRST_SBRK MallocCfg[MallocCfg_FIRST_SBRK]
894 # define MIN_SBRK_FRAC1000 MallocCfg[MallocCfg_MIN_SBRK_FRAC1000]
895 # define SBRK_ALLOW_FAILURES MallocCfg[MallocCfg_SBRK_ALLOW_FAILURES]
896 # define SBRK_FAILURE_PRICE MallocCfg[MallocCfg_SBRK_FAILURE_PRICE]
898 # define sbrk_goodness MallocCfg[MallocCfg_sbrk_goodness]
900 # define emergency_buffer_size MallocCfg[MallocCfg_emergency_buffer_size]
901 # define emergency_buffer_last_req MallocCfg[MallocCfg_emergency_buffer_last_req]
903 # define FILL_DEAD MallocCfg[MallocCfg_filldead]
904 # define FILL_ALIVE MallocCfg[MallocCfg_fillalive]
905 # define FILL_CHECK_CFG MallocCfg[MallocCfg_fillcheck]
906 # define FILL_CHECK (FILL_DEAD && FILL_CHECK_CFG)
908 # define emergency_buffer MallocCfgP[MallocCfgP_emergency_buffer]
909 # define emergency_buffer_prepared MallocCfgP[MallocCfgP_emergency_buffer_prepared]
911 #else /* defined(NO_MALLOC_DYNAMIC_CFG) */
914 # define FILL_ALIVE 1
915 # define FILL_CHECK 1
916 static int sbrk_goodness = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE;
918 # define NO_PERL_MALLOC_ENV
922 #ifdef DEBUGGING_MSTATS
924 * nmalloc[i] is the difference between the number of mallocs and frees
925 * for a given block size.
927 static u_int nmalloc[NBUCKETS];
928 static u_int sbrk_slack;
929 static u_int start_slack;
930 #else /* !( defined DEBUGGING_MSTATS ) */
931 # define sbrk_slack 0
934 static u_int goodsbrk;
936 #ifdef PERL_EMERGENCY_SBRK
939 # define BIG_SIZE (1<<16) /* 64K */
942 # ifdef NO_MALLOC_DYNAMIC_CFG
943 static MEM_SIZE emergency_buffer_size;
944 /* 0 if the last request for more memory succeeded.
945 Otherwise the size of the failing request. */
946 static MEM_SIZE emergency_buffer_last_req;
947 static char *emergency_buffer;
948 static char *emergency_buffer_prepared;
951 # ifndef emergency_sbrk_croak
952 # define emergency_sbrk_croak croak2
956 perl_get_emergency_buffer(IV *size)
959 /* First offense, give a possibility to recover by dieing. */
960 /* No malloc involved here: */
963 GV **gvp = (GV**)hv_fetchs(PL_defstash, "^M", FALSE);
965 if (!gvp) gvp = (GV**)hv_fetchs(PL_defstash, "\015", FALSE);
966 if (!gvp || !(sv = GvSV(*gvp)) || !SvPOK(sv)
967 || (SvLEN(sv) < (1<<LOG_OF_MIN_ARENA) - M_OVERHEAD))
968 return NULL; /* Now die die die... */
969 /* Got it, now detach SvPV: */
971 /* Check alignment: */
972 if ((PTR2UV(pv) - sizeof(union overhead)) & (NEEDED_ALIGNMENT - 1)) {
973 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
974 return NULL; /* die die die */
981 *size = malloced_size(pv) + M_OVERHEAD;
982 return pv - sizeof(union overhead);
984 # define PERL_GET_EMERGENCY_BUFFER(p) perl_get_emergency_buffer(p)
986 # ifndef NO_MALLOC_DYNAMIC_CFG
988 get_emergency_buffer(IV *size)
990 char *pv = emergency_buffer_prepared;
992 *size = MallocCfg[MallocCfg_emergency_buffer_prepared_size];
993 emergency_buffer_prepared = 0;
994 MallocCfg[MallocCfg_emergency_buffer_prepared_size] = 0;
998 /* Returns 0 on success, -1 on bad alignment, -2 if not implemented */
1000 set_emergency_buffer(char *b, IV size)
1002 if (PTR2UV(b) & (NEEDED_ALIGNMENT - 1))
1004 if (MallocCfg[MallocCfg_emergency_buffer_prepared_size])
1005 add_to_chain((void*)emergency_buffer_prepared,
1006 MallocCfg[MallocCfg_emergency_buffer_prepared_size], 0);
1007 emergency_buffer_prepared = b;
1008 MallocCfg[MallocCfg_emergency_buffer_prepared_size] = size;
1011 # define GET_EMERGENCY_BUFFER(p) get_emergency_buffer(p)
1012 # else /* NO_MALLOC_DYNAMIC_CFG */
1013 # define GET_EMERGENCY_BUFFER(p) NULL
1015 set_emergency_buffer(char *b, IV size)
1022 emergency_sbrk(MEM_SIZE size)
1024 MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA;
1026 if (size >= BIG_SIZE
1027 && (!emergency_buffer_last_req ||
1028 (size < (MEM_SIZE)emergency_buffer_last_req))) {
1029 /* Give the possibility to recover, but avoid an infinite cycle. */
1031 emergency_buffer_last_req = size;
1032 emergency_sbrk_croak("Out of memory during \"large\" request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
1035 if ((MEM_SIZE)emergency_buffer_size >= rsize) {
1036 char *old = emergency_buffer;
1038 emergency_buffer_size -= rsize;
1039 emergency_buffer += rsize;
1042 /* First offense, give a possibility to recover by dieing. */
1043 /* No malloc involved here: */
1045 char *pv = GET_EMERGENCY_BUFFER(&Size);
1048 if (emergency_buffer_size) {
1049 add_to_chain(emergency_buffer, emergency_buffer_size, 0);
1050 emergency_buffer_size = 0;
1051 emergency_buffer = NULL;
1056 pv = PERL_GET_EMERGENCY_BUFFER(&Size);
1060 return (char *)-1; /* Now die die die... */
1063 /* Check alignment: */
1064 if (PTR2UV(pv) & (NEEDED_ALIGNMENT - 1)) {
1067 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
1068 return (char *)-1; /* die die die */
1071 emergency_buffer = pv;
1072 emergency_buffer_size = Size;
1076 emergency_sbrk_croak("Out of memory during request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
1077 assert(0); /* NOTREACHED */
1081 #else /* !defined(PERL_EMERGENCY_SBRK) */
1082 # define emergency_sbrk(size) -1
1083 #endif /* defined PERL_EMERGENCY_SBRK */
1085 /* Don't use PerlIO buffered writes as they allocate memory. */
1086 #define MYMALLOC_WRITE2STDERR(s) PerlLIO_write(PerlIO_fileno(PerlIO_stderr()),s,strlen(s))
1090 #define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p),__FILE__,__LINE__);
1093 botch(const char *diag, const char *s, const char *file, int line)
1097 if (!(PERL_MAYBE_ALIVE && PERL_GET_THX))
1100 if (PerlIO_printf(PerlIO_stderr(),
1101 "assertion botched (%s?): %s %s:%d\n",
1102 diag, s, file, line) != 0) {
1103 do_write: /* Can be initializing interpreter */
1104 MYMALLOC_WRITE2STDERR("assertion botched (");
1105 MYMALLOC_WRITE2STDERR(diag);
1106 MYMALLOC_WRITE2STDERR("?): ");
1107 MYMALLOC_WRITE2STDERR(s);
1108 MYMALLOC_WRITE2STDERR(" (");
1109 MYMALLOC_WRITE2STDERR(file);
1110 MYMALLOC_WRITE2STDERR(":");
1113 char *s = linebuf + sizeof(linebuf) - 1;
1117 *--s = '0' + (n % 10);
1119 MYMALLOC_WRITE2STDERR(s);
1121 MYMALLOC_WRITE2STDERR(")\n");
1127 #define ASSERT(p, diag)
1131 /* Fill should be long enough to cover long */
1133 fill_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1135 unsigned char *e = s + nbytes;
1137 const long lfill = *(long*)fill;
1139 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1140 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1141 unsigned const char *f = fill + sizeof(long) - shift;
1142 unsigned char *e1 = s + shift;
1148 while ((unsigned char*)(lp + 1) <= e)
1150 s = (unsigned char*)lp;
1154 /* Just malloc()ed */
1155 static const unsigned char fill_feedadad[] =
1156 {0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD,
1157 0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD};
1159 static const unsigned char fill_deadbeef[] =
1160 {0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF,
1161 0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF};
1162 # define FILL_DEADBEEF(s, n) \
1163 (void)(FILL_DEAD? (fill_pat_4bytes((s), (n), fill_deadbeef), 0) : 0)
1164 # define FILL_FEEDADAD(s, n) \
1165 (void)(FILL_ALIVE? (fill_pat_4bytes((s), (n), fill_feedadad), 0) : 0)
1167 # define FILL_DEADBEEF(s, n) ((void)0)
1168 # define FILL_FEEDADAD(s, n) ((void)0)
1169 # undef MALLOC_FILL_CHECK
1172 #ifdef MALLOC_FILL_CHECK
1174 cmp_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1176 unsigned char *e = s + nbytes;
1178 const long lfill = *(long*)fill;
1180 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1181 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1182 unsigned const char *f = fill + sizeof(long) - shift;
1183 unsigned char *e1 = s + shift;
1190 while ((unsigned char*)(lp + 1) <= e)
1193 s = (unsigned char*)lp;
1195 if (*s++ != *fill++)
1199 # define FILLCHECK_DEADBEEF(s, n) \
1200 ASSERT(!FILL_CHECK || !cmp_pat_4bytes(s, n, fill_deadbeef), \
1201 "free()ed/realloc()ed-away memory was overwritten")
1203 # define FILLCHECK_DEADBEEF(s, n) ((void)0)
1207 S_adjust_size_and_find_bucket(size_t *nbytes_p)
1213 PERL_ARGS_ASSERT_ADJUST_SIZE_AND_FIND_BUCKET;
1218 * Convert amount of memory requested into
1219 * closest block size stored in hash buckets
1220 * which satisfies request. Account for
1221 * space used per block for accounting.
1224 # ifdef SMALL_BUCKET_VIA_TABLE
1226 bucket = MIN_BUCKET;
1227 else if (nbytes <= SIZE_TABLE_MAX) {
1228 bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
1233 if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
1238 POW2_OPTIMIZE_ADJUST(nbytes);
1239 nbytes += M_OVERHEAD;
1240 nbytes = (nbytes + 3) &~ 3;
1241 #if defined(PACK_MALLOC) && !defined(SMALL_BUCKET_VIA_TABLE)
1244 shiftr = (nbytes - 1) >> START_SHIFT;
1245 bucket = START_SHIFTS_BUCKET;
1246 /* apart from this loop, this is O(1) */
1247 while (shiftr >>= 1)
1248 bucket += BUCKETS_PER_POW2;
1255 Perl_malloc(size_t nbytes)
1261 #if defined(DEBUGGING) || defined(RCHECK)
1262 MEM_SIZE size = nbytes;
1265 BARK_64K_LIMIT("Allocation",nbytes,nbytes);
1267 if ((long)nbytes < 0)
1268 croak("%s", "panic: malloc");
1271 bucket = adjust_size_and_find_bucket(&nbytes);
1274 * If nothing in hash bucket right now,
1275 * request more memory from the system.
1277 if (nextf[bucket] == NULL)
1279 if ((p = nextf[bucket]) == NULL) {
1284 #if defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC)
1285 MYMALLOC_WRITE2STDERR("Out of memory!\n");
1288 char *eb = buff + sizeof(buff) - 1;
1292 MYMALLOC_WRITE2STDERR("Out of memory during request for ");
1293 #if defined(DEBUGGING) || defined(RCHECK)
1298 *--s = '0' + (n % 10);
1300 MYMALLOC_WRITE2STDERR(s);
1301 MYMALLOC_WRITE2STDERR(" bytes, total sbrk() is ");
1303 n = goodsbrk + sbrk_slack;
1305 *--s = '0' + (n % 10);
1307 MYMALLOC_WRITE2STDERR(s);
1308 MYMALLOC_WRITE2STDERR(" bytes!\n");
1309 #endif /* defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC) */
1316 /* remove from linked list */
1318 if ( (PTR2UV(p) & (MEM_ALIGNBYTES - 1))
1319 /* Can't get this low */
1320 || (p && PTR2UV(p) < (1<<LOG_OF_MIN_ARENA)) ) {
1322 PerlIO_printf(PerlIO_stderr(),
1323 "Unaligned pointer in the free chain 0x%"UVxf"\n",
1326 if ( (PTR2UV(p->ov_next) & (MEM_ALIGNBYTES - 1))
1327 || (p->ov_next && PTR2UV(p->ov_next) < (1<<LOG_OF_MIN_ARENA)) ) {
1329 PerlIO_printf(PerlIO_stderr(),
1330 "Unaligned \"next\" pointer in the free "
1331 "chain 0x%"UVxf" at 0x%"UVxf"\n",
1332 PTR2UV(p->ov_next), PTR2UV(p));
1335 nextf[bucket] = p->ov_next;
1339 DEBUG_m(PerlIO_printf(Perl_debug_log,
1340 "0x%"UVxf": (%05lu) malloc %ld bytes\n",
1341 PTR2UV((Malloc_t)(p + CHUNK_SHIFT)), (unsigned long)(PL_an++),
1344 FILLCHECK_DEADBEEF((unsigned char*)(p + CHUNK_SHIFT),
1345 BUCKET_SIZE_REAL(bucket) + RMAGIC_SZ);
1347 #ifdef IGNORE_SMALL_BAD_FREE
1348 if (bucket >= FIRST_BUCKET_WITH_CHECK)
1350 OV_MAGIC(p, bucket) = MAGIC;
1352 OV_INDEX(p) = bucket;
1356 * Record allocated size of block and
1357 * bound space with magic numbers.
1359 p->ov_rmagic = RMAGIC;
1360 if (bucket <= MAX_SHORT_BUCKET) {
1363 nbytes = size + M_OVERHEAD;
1364 p->ov_size = nbytes - 1;
1365 if ((i = nbytes & (RMAGIC_SZ-1))) {
1367 while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
1368 ((caddr_t)p + nbytes - RMAGIC_SZ)[i] = RMAGIC_C;
1370 /* Same at RMAGIC_SZ-aligned RMAGIC */
1371 nbytes = (nbytes + RMAGIC_SZ - 1) & ~(RMAGIC_SZ - 1);
1372 ((u_int *)((caddr_t)p + nbytes))[-1] = RMAGIC;
1374 FILL_FEEDADAD((unsigned char *)(p + CHUNK_SHIFT), size);
1376 return ((Malloc_t)(p + CHUNK_SHIFT));
1379 static char *last_sbrk_top;
1380 static char *last_op; /* This arena can be easily extended. */
1381 static MEM_SIZE sbrked_remains;
1383 #ifdef DEBUGGING_MSTATS
1387 struct chunk_chain_s {
1388 struct chunk_chain_s *next;
1391 static struct chunk_chain_s *chunk_chain;
1392 static int n_chunks;
1393 static char max_bucket;
1395 /* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */
1397 get_from_chain(MEM_SIZE size)
1399 struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
1400 struct chunk_chain_s **oldgoodp = NULL;
1401 long min_remain = LONG_MAX;
1404 if (elt->size >= size) {
1405 long remains = elt->size - size;
1406 if (remains >= 0 && remains < min_remain) {
1408 min_remain = remains;
1414 oldp = &( elt->next );
1417 if (!oldgoodp) return NULL;
1419 void *ret = *oldgoodp;
1420 struct chunk_chain_s *next = (*oldgoodp)->next;
1422 *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
1423 (*oldgoodp)->size = min_remain;
1424 (*oldgoodp)->next = next;
1427 void *ret = *oldgoodp;
1428 *oldgoodp = (*oldgoodp)->next;
1435 add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
1437 struct chunk_chain_s *next = chunk_chain;
1438 char *cp = (char*)p;
1441 chunk_chain = (struct chunk_chain_s *)cp;
1442 chunk_chain->size = size - chip;
1443 chunk_chain->next = next;
1448 get_from_bigger_buckets(int bucket, MEM_SIZE size)
1451 static int bucketprice[NBUCKETS];
1452 while (bucket <= max_bucket) {
1453 /* We postpone stealing from bigger buckets until we want it
1455 if (nextf[bucket] && bucketprice[bucket]++ >= price) {
1457 void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
1458 bucketprice[bucket] = 0;
1459 if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
1460 last_op = NULL; /* Disable optimization */
1462 nextf[bucket] = nextf[bucket]->ov_next;
1463 #ifdef DEBUGGING_MSTATS
1465 start_slack -= M_OVERHEAD;
1467 add_to_chain(ret, (BUCKET_SIZE_NO_SURPLUS(bucket) +
1468 POW2_OPTIMIZE_SURPLUS(bucket)),
1477 static union overhead *
1478 getpages(MEM_SIZE needed, int *nblksp, int bucket)
1481 /* Need to do (possibly expensive) system call. Try to
1482 optimize it for rare calling. */
1483 MEM_SIZE require = needed - sbrked_remains;
1485 union overhead *ovp;
1488 if (sbrk_goodness > 0) {
1489 if (!last_sbrk_top && require < (MEM_SIZE)FIRST_SBRK)
1490 require = FIRST_SBRK;
1491 else if (require < (MEM_SIZE)MIN_SBRK) require = MIN_SBRK;
1493 if (require < (Size_t)(goodsbrk * MIN_SBRK_FRAC1000 / 1000))
1494 require = goodsbrk * MIN_SBRK_FRAC1000 / 1000;
1495 require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
1502 DEBUG_m(PerlIO_printf(Perl_debug_log,
1503 "sbrk(%ld) for %ld-byte-long arena\n",
1504 (long)require, (long) needed));
1505 cp = (char *)sbrk(require);
1506 #ifdef DEBUGGING_MSTATS
1509 if (cp == last_sbrk_top) {
1510 /* Common case, anything is fine. */
1512 ovp = (union overhead *) (cp - sbrked_remains);
1513 last_op = cp - sbrked_remains;
1514 sbrked_remains = require - (needed - sbrked_remains);
1515 } else if (cp == (char *)-1) { /* no more room! */
1516 ovp = (union overhead *)emergency_sbrk(needed);
1517 if (ovp == (union overhead *)-1)
1519 if (((char*)ovp) > last_op) { /* Cannot happen with current emergency_sbrk() */
1523 } else { /* Non-continuous or first sbrk(). */
1524 long add = sbrked_remains;
1527 if (sbrked_remains) { /* Put rest into chain, we
1528 cannot use it right now. */
1529 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1533 /* Second, check alignment. */
1536 /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
1537 improve performance of memory access. */
1538 if (PTR2UV(cp) & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
1539 slack = WANTED_ALIGNMENT - (PTR2UV(cp) & (WANTED_ALIGNMENT - 1));
1544 DEBUG_m(PerlIO_printf(Perl_debug_log,
1545 "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",
1546 (long)add, (long) slack,
1547 (long) sbrked_remains));
1548 newcp = (char *)sbrk(add);
1549 #if defined(DEBUGGING_MSTATS)
1553 if (newcp != cp + require) {
1554 /* Too bad: even rounding sbrk() is not continuous.*/
1555 DEBUG_m(PerlIO_printf(Perl_debug_log,
1556 "failed to fix bad sbrk()\n"));
1560 fatalcroak("panic: Off-page sbrk\n");
1563 if (sbrked_remains) {
1565 #if defined(DEBUGGING_MSTATS)
1566 sbrk_slack += require;
1569 DEBUG_m(PerlIO_printf(Perl_debug_log,
1570 "straight sbrk(%ld)\n",
1572 cp = (char *)sbrk(require);
1573 #ifdef DEBUGGING_MSTATS
1576 if (cp == (char *)-1)
1579 sbrk_goodness = -1; /* Disable optimization!
1580 Continue with not-aligned... */
1583 require += sbrked_remains;
1587 if (last_sbrk_top) {
1588 sbrk_goodness -= SBRK_FAILURE_PRICE;
1591 ovp = (union overhead *) cp;
1593 * Round up to minimum allocation size boundary
1594 * and deduct from block count to reflect.
1597 # if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
1598 if (PTR2UV(ovp) & (NEEDED_ALIGNMENT - 1))
1599 fatalcroak("Misalignment of sbrk()\n");
1602 if (PTR2UV(ovp) & (MEM_ALIGNBYTES - 1)) {
1603 DEBUG_m(PerlIO_printf(Perl_debug_log,
1604 "fixing sbrk(): %d bytes off machine alignment\n",
1605 (int)(PTR2UV(ovp) & (MEM_ALIGNBYTES - 1))));
1606 ovp = INT2PTR(union overhead *,(PTR2UV(ovp) + MEM_ALIGNBYTES) &
1607 (MEM_ALIGNBYTES - 1));
1609 # if defined(DEBUGGING_MSTATS)
1610 /* This is only approx. if TWO_POT_OPTIMIZE: */
1611 sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
1614 ; /* Finish "else" */
1615 sbrked_remains = require - needed;
1618 #if !defined(PLAIN_MALLOC) && !defined(NO_FANCY_MALLOC)
1619 emergency_buffer_last_req = 0;
1621 last_sbrk_top = cp + require;
1622 #ifdef DEBUGGING_MSTATS
1623 goodsbrk += require;
1629 getpages_adjacent(MEM_SIZE require)
1631 if (require <= sbrked_remains) {
1632 sbrked_remains -= require;
1636 require -= sbrked_remains;
1637 /* We do not try to optimize sbrks here, we go for place. */
1638 cp = (char*) sbrk(require);
1639 #ifdef DEBUGGING_MSTATS
1641 goodsbrk += require;
1643 if (cp == last_sbrk_top) {
1645 last_sbrk_top = cp + require;
1647 if (cp == (char*)-1) { /* Out of memory */
1648 #ifdef DEBUGGING_MSTATS
1649 goodsbrk -= require;
1653 /* Report the failure: */
1655 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1657 add_to_chain((void*)cp, require, 0);
1658 sbrk_goodness -= SBRK_FAILURE_PRICE;
1670 * Allocate more memory to the indicated bucket.
1673 morecore(int bucket)
1676 union overhead *ovp;
1677 int rnu; /* 2^rnu bytes will be requested */
1678 int nblks; /* become nblks blocks of the desired size */
1679 MEM_SIZE siz, needed;
1680 static int were_called = 0;
1684 #ifndef NO_PERL_MALLOC_ENV
1686 /* It's the our first time. Initialize ourselves */
1687 were_called = 1; /* Avoid a loop */
1688 if (!MallocCfg[MallocCfg_skip_cfg_env]) {
1689 char *s = getenv("PERL_MALLOC_OPT"), *t = s, *off;
1690 const char *opts = PERL_MALLOC_OPT_CHARS;
1693 while ( t && t[0] && t[1] == '='
1694 && ((off = strchr(opts, *t))) ) {
1698 while (*t <= '9' && *t >= '0')
1699 val = 10*val + *t++ - '0';
1700 if (!*t || *t == ';') {
1701 if (MallocCfg[off - opts] != val)
1703 MallocCfg[off - opts] = val;
1710 MYMALLOC_WRITE2STDERR("Unrecognized part of PERL_MALLOC_OPT: \"");
1711 MYMALLOC_WRITE2STDERR(t);
1712 MYMALLOC_WRITE2STDERR("\"\n");
1715 MallocCfg[MallocCfg_cfg_env_read] = 1;
1719 if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
1721 croak("%s", "Out of memory during ridiculously large request");
1723 if (bucket > max_bucket)
1724 max_bucket = bucket;
1726 rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT))
1728 : (bucket >> BUCKET_POW2_SHIFT) );
1729 /* This may be overwritten later: */
1730 nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
1731 needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
1732 if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
1733 ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
1734 nextf[rnu << BUCKET_POW2_SHIFT]
1735 = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
1736 #ifdef DEBUGGING_MSTATS
1737 nmalloc[rnu << BUCKET_POW2_SHIFT]--;
1738 start_slack -= M_OVERHEAD;
1740 DEBUG_m(PerlIO_printf(Perl_debug_log,
1741 "stealing %ld bytes from %ld arena\n",
1742 (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
1743 } else if (chunk_chain
1744 && (ovp = (union overhead*) get_from_chain(needed))) {
1745 DEBUG_m(PerlIO_printf(Perl_debug_log,
1746 "stealing %ld bytes from chain\n",
1748 } else if ( (ovp = (union overhead*)
1749 get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
1751 DEBUG_m(PerlIO_printf(Perl_debug_log,
1752 "stealing %ld bytes from bigger buckets\n",
1754 } else if (needed <= sbrked_remains) {
1755 ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
1756 sbrked_remains -= needed;
1757 last_op = (char*)ovp;
1759 ovp = getpages(needed, &nblks, bucket);
1763 FILL_DEADBEEF((unsigned char*)ovp, needed);
1766 * Add new memory allocated to that on
1767 * free list for this hash bucket.
1769 siz = BUCKET_SIZE_NO_SURPLUS(bucket); /* No surplus if nblks > 1 */
1771 *(u_char*)ovp = bucket; /* Fill index. */
1772 if (bucket <= MAX_PACKED) {
1773 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1774 nblks = N_BLKS(bucket);
1775 # ifdef DEBUGGING_MSTATS
1776 start_slack += BLK_SHIFT(bucket);
1778 } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
1779 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1780 siz -= sizeof(union overhead);
1781 } else ovp++; /* One chunk per block. */
1782 #endif /* PACK_MALLOC */
1783 nextf[bucket] = ovp;
1784 #ifdef DEBUGGING_MSTATS
1785 nmalloc[bucket] += nblks;
1786 if (bucket > MAX_PACKED) {
1787 start_slack += M_OVERHEAD * nblks;
1791 while (--nblks > 0) {
1792 ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
1793 ovp = (union overhead *)((caddr_t)ovp + siz);
1795 /* Not all sbrks return zeroed memory.*/
1796 ovp->ov_next = (union overhead *)NULL;
1798 if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
1799 union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
1800 nextf[7*BUCKETS_PER_POW2] =
1801 (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2]
1802 - sizeof(union overhead));
1803 nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
1805 #endif /* !PACK_MALLOC */
1809 Perl_mfree(Malloc_t where)
1813 union overhead *ovp;
1814 char *cp = (char*)where;
1819 DEBUG_m(PerlIO_printf(Perl_debug_log,
1820 "0x%"UVxf": (%05lu) free\n",
1821 PTR2UV(cp), (unsigned long)(PL_an++)));
1826 if (PTR2UV(cp) & (MEM_ALIGNBYTES - 1))
1827 croak("%s", "wrong alignment in free()");
1829 ovp = (union overhead *)((caddr_t)cp
1830 - sizeof (union overhead) * CHUNK_SHIFT);
1832 bucket = OV_INDEX(ovp);
1834 #ifdef IGNORE_SMALL_BAD_FREE
1835 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1836 && (OV_MAGIC(ovp, bucket) != MAGIC))
1838 if (OV_MAGIC(ovp, bucket) != MAGIC)
1841 static int bad_free_warn = -1;
1842 if (bad_free_warn == -1) {
1844 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1845 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1852 if (!PERL_IS_ALIVE || !PL_curcop)
1853 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s free() ignored (RMAGIC, PERL_CORE)",
1854 ovp->ov_rmagic == RMAGIC - 1 ?
1855 "Duplicate" : "Bad");
1860 if (!PERL_IS_ALIVE || !PL_curcop)
1861 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s", "Bad free() ignored (PERL_CORE)");
1864 return; /* sanity */
1867 ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
1868 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
1870 MEM_SIZE nbytes = ovp->ov_size + 1;
1872 if ((i = nbytes & (RMAGIC_SZ-1))) {
1874 while (i--) { /* nbytes - RMAGIC_SZ is end of alloced area */
1875 ASSERT(((caddr_t)ovp + nbytes - RMAGIC_SZ)[i] == RMAGIC_C,
1876 "chunk's tail overwrite");
1879 /* Same at RMAGIC_SZ-aligned RMAGIC */
1880 nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
1881 ASSERT(((u_int *)((caddr_t)ovp + nbytes))[-1] == RMAGIC,
1882 "chunk's tail overwrite");
1883 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nbytes),
1884 BUCKET_SIZE(OV_INDEX(ovp)) - nbytes);
1886 FILL_DEADBEEF((unsigned char*)(ovp+CHUNK_SHIFT),
1887 BUCKET_SIZE_REAL(OV_INDEX(ovp)) + RMAGIC_SZ);
1888 ovp->ov_rmagic = RMAGIC - 1;
1890 ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
1891 size = OV_INDEX(ovp);
1894 ovp->ov_next = nextf[size];
1899 /* There is no need to do any locking in realloc (with an exception of
1900 trying to grow in place if we are at the end of the chain).
1901 If somebody calls us from a different thread with the same address,
1902 we are sole anyway. */
1905 Perl_realloc(void *mp, size_t nbytes)
1909 union overhead *ovp;
1913 int incr; /* 1 if does not fit, -1 if "easily" fits in a
1914 smaller bucket, otherwise 0. */
1915 char *cp = (char*)mp;
1918 MEM_SIZE size = nbytes;
1920 if ((long)nbytes < 0)
1921 croak("%s", "panic: realloc");
1924 BARK_64K_LIMIT("Reallocation",nbytes,size);
1926 return Perl_malloc(nbytes);
1928 ovp = (union overhead *)((caddr_t)cp
1929 - sizeof (union overhead) * CHUNK_SHIFT);
1930 bucket = OV_INDEX(ovp);
1932 #ifdef IGNORE_SMALL_BAD_FREE
1933 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1934 && (OV_MAGIC(ovp, bucket) != MAGIC))
1936 if (OV_MAGIC(ovp, bucket) != MAGIC)
1939 static int bad_free_warn = -1;
1940 if (bad_free_warn == -1) {
1942 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1943 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1950 if (!PERL_IS_ALIVE || !PL_curcop)
1951 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%srealloc() %signored",
1952 (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
1953 ovp->ov_rmagic == RMAGIC - 1
1954 ? "of freed memory " : "");
1959 if (!PERL_IS_ALIVE || !PL_curcop)
1960 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s",
1961 "Bad realloc() ignored");
1964 return NULL; /* sanity */
1967 onb = BUCKET_SIZE_REAL(bucket);
1969 * avoid the copy if same size block.
1970 * We are not aggressive with boundary cases. Note that it might
1971 * (for a small number of cases) give false negative if
1972 * both new size and old one are in the bucket for
1973 * FIRST_BIG_POW2, but the new one is near the lower end.
1975 * We do not try to go to 1.5 times smaller bucket so far.
1977 if (nbytes > onb) incr = 1;
1979 #ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
1980 if ( /* This is a little bit pessimal if PACK_MALLOC: */
1981 nbytes > ( (onb >> 1) - M_OVERHEAD )
1982 # ifdef TWO_POT_OPTIMIZE
1983 || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
1986 #else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
1987 prev_bucket = ( (bucket > MAX_PACKED + 1)
1988 ? bucket - BUCKETS_PER_POW2
1990 if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
1991 #endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
1995 #ifdef STRESS_REALLOC
2002 * Record new allocated size of block and
2003 * bound space with magic numbers.
2005 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
2006 int i, nb = ovp->ov_size + 1;
2008 if ((i = nb & (RMAGIC_SZ-1))) {
2010 while (i--) { /* nb - RMAGIC_SZ is end of alloced area */
2011 ASSERT(((caddr_t)ovp + nb - RMAGIC_SZ)[i] == RMAGIC_C, "chunk's tail overwrite");
2014 /* Same at RMAGIC_SZ-aligned RMAGIC */
2015 nb = (nb + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
2016 ASSERT(((u_int *)((caddr_t)ovp + nb))[-1] == RMAGIC,
2017 "chunk's tail overwrite");
2018 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nb),
2019 BUCKET_SIZE(OV_INDEX(ovp)) - nb);
2020 if (nbytes > ovp->ov_size + 1 - M_OVERHEAD)
2021 FILL_FEEDADAD((unsigned char*)cp + ovp->ov_size + 1 - M_OVERHEAD,
2022 nbytes - (ovp->ov_size + 1 - M_OVERHEAD));
2024 FILL_DEADBEEF((unsigned char*)cp + nbytes,
2025 nb - M_OVERHEAD + RMAGIC_SZ - nbytes);
2027 * Convert amount of memory requested into
2028 * closest block size stored in hash buckets
2029 * which satisfies request. Account for
2030 * space used per block for accounting.
2032 nbytes += M_OVERHEAD;
2033 ovp->ov_size = nbytes - 1;
2034 if ((i = nbytes & (RMAGIC_SZ-1))) {
2036 while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
2037 ((caddr_t)ovp + nbytes - RMAGIC_SZ)[i]
2040 /* Same at RMAGIC_SZ-aligned RMAGIC */
2041 nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ - 1);
2042 ((u_int *)((caddr_t)ovp + nbytes))[-1] = RMAGIC;
2046 DEBUG_m(PerlIO_printf(Perl_debug_log,
2047 "0x%"UVxf": (%05lu) realloc %ld bytes inplace\n",
2048 PTR2UV(res),(unsigned long)(PL_an++),
2050 } else if (incr == 1 && (cp - M_OVERHEAD == last_op)
2051 && (onb > (1 << LOG_OF_MIN_ARENA))) {
2052 MEM_SIZE require, newarena = nbytes, pow;
2055 POW2_OPTIMIZE_ADJUST(newarena);
2056 newarena = newarena + M_OVERHEAD;
2057 /* newarena = (newarena + 3) &~ 3; */
2058 shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
2059 pow = LOG_OF_MIN_ARENA + 1;
2060 /* apart from this loop, this is O(1) */
2061 while (shiftr >>= 1)
2063 newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
2064 require = newarena - onb - M_OVERHEAD;
2067 if (cp - M_OVERHEAD == last_op /* We *still* are the last chunk */
2068 && getpages_adjacent(require)) {
2069 #ifdef DEBUGGING_MSTATS
2071 nmalloc[pow * BUCKETS_PER_POW2]++;
2073 if (pow * BUCKETS_PER_POW2 > (MEM_SIZE)max_bucket)
2074 max_bucket = pow * BUCKETS_PER_POW2;
2075 *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
2084 DEBUG_m(PerlIO_printf(Perl_debug_log,
2085 "0x%"UVxf": (%05lu) realloc %ld bytes the hard way\n",
2086 PTR2UV(cp),(unsigned long)(PL_an++),
2088 if ((res = (char*)Perl_malloc(nbytes)) == NULL)
2090 if (cp != res) /* common optimization */
2091 Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
2094 return ((Malloc_t)res);
2098 Perl_calloc(size_t elements, size_t size)
2100 long sz = elements * size;
2101 Malloc_t p = Perl_malloc(sz);
2104 memset((void*)p, 0, sz);
2110 Perl_strdup(const char *s)
2112 MEM_SIZE l = strlen(s);
2113 char *s1 = (char *)Perl_malloc(l+1);
2115 return (char *)CopyD(s, s1, (MEM_SIZE)(l+1), char);
2119 Perl_putenv(char *a)
2121 /* Sometimes system's putenv conflicts with my_setenv() - this is system
2122 malloc vs Perl's free(). */
2129 while (*val && *val != '=')
2134 if (l < sizeof(buf))
2137 var = (char *)Perl_malloc(l + 1);
2138 Copy(a, var, l, char);
2140 my_setenv(var, val+1);
2147 Perl_malloced_size(void *p)
2149 union overhead * const ovp = (union overhead *)
2150 ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
2151 const int bucket = OV_INDEX(ovp);
2153 PERL_ARGS_ASSERT_MALLOCED_SIZE;
2156 /* The caller wants to have a complete control over the chunk,
2157 disable the memory checking inside the chunk. */
2158 if (bucket <= MAX_SHORT_BUCKET) {
2159 const MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
2160 ovp->ov_size = size + M_OVERHEAD - 1;
2161 *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RMAGIC_SZ)) = RMAGIC;
2164 return BUCKET_SIZE_REAL(bucket);
2169 Perl_malloc_good_size(size_t wanted)
2171 return BUCKET_SIZE_REAL(adjust_size_and_find_bucket(&wanted));
2174 # ifdef BUCKETS_ROOT2
2175 # define MIN_EVEN_REPORT 6
2177 # define MIN_EVEN_REPORT MIN_BUCKET
2181 Perl_get_mstats(pTHX_ perl_mstats_t *buf, int buflen, int level)
2183 #ifdef DEBUGGING_MSTATS
2186 struct chunk_chain_s* nextchain;
2188 PERL_ARGS_ASSERT_GET_MSTATS;
2190 buf->topbucket = buf->topbucket_ev = buf->topbucket_odd
2191 = buf->totfree = buf->total = buf->total_chain = 0;
2193 buf->minbucket = MIN_BUCKET;
2195 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2196 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
2200 buf->ntotal[i] = nmalloc[i];
2202 buf->totfree += j * BUCKET_SIZE_REAL(i);
2203 buf->total += nmalloc[i] * BUCKET_SIZE_REAL(i);
2205 i % 2 ? (buf->topbucket_odd = i) : (buf->topbucket_ev = i);
2209 nextchain = chunk_chain;
2211 buf->total_chain += nextchain->size;
2212 nextchain = nextchain->next;
2214 buf->total_sbrk = goodsbrk + sbrk_slack;
2216 buf->sbrk_good = sbrk_goodness;
2217 buf->sbrk_slack = sbrk_slack;
2218 buf->start_slack = start_slack;
2219 buf->sbrked_remains = sbrked_remains;
2221 buf->nbuckets = NBUCKETS;
2223 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2226 buf->bucket_mem_size[i] = BUCKET_SIZE_NO_SURPLUS(i);
2227 buf->bucket_available_size[i] = BUCKET_SIZE_REAL(i);
2230 #else /* defined DEBUGGING_MSTATS */
2231 PerlIO_printf(Perl_error_log, "perl not compiled with DEBUGGING_MSTATS\n");
2232 #endif /* defined DEBUGGING_MSTATS */
2233 return 0; /* XXX unused */
2236 * mstats - print out statistics about malloc
2238 * Prints two lines of numbers, one showing the length of the free list
2239 * for each size category, the second showing the number of mallocs -
2240 * frees for each size category.
2243 Perl_dump_mstats(pTHX_ const char *s)
2245 #ifdef DEBUGGING_MSTATS
2247 perl_mstats_t buffer;
2251 PERL_ARGS_ASSERT_DUMP_MSTATS;
2255 get_mstats(&buffer, NBUCKETS, 0);
2258 PerlIO_printf(Perl_error_log,
2259 "Memory allocation statistics %s (buckets %"IVdf"(%"IVdf")..%"IVdf"(%"IVdf")\n",
2261 (IV)BUCKET_SIZE_REAL(MIN_BUCKET),
2262 (IV)BUCKET_SIZE_NO_SURPLUS(MIN_BUCKET),
2263 (IV)BUCKET_SIZE_REAL(buffer.topbucket),
2264 (IV)BUCKET_SIZE_NO_SURPLUS(buffer.topbucket));
2265 PerlIO_printf(Perl_error_log, "%8"IVdf" free:", buffer.totfree);
2266 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2267 PerlIO_printf(Perl_error_log,
2268 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2270 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2273 #ifdef BUCKETS_ROOT2
2274 PerlIO_printf(Perl_error_log, "\n\t ");
2275 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; 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)),
2283 PerlIO_printf(Perl_error_log, "\n%8"IVdf" used:", buffer.total - buffer.totfree);
2284 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; 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"IVdf : " %"IVdf)),
2289 buffer.ntotal[i] - buffer.nfree[i]);
2291 #ifdef BUCKETS_ROOT2
2292 PerlIO_printf(Perl_error_log, "\n\t ");
2293 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; 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]);
2301 PerlIO_printf(Perl_error_log, "\nTotal sbrk(): %"IVdf"/%"IVdf":%"IVdf". Odd ends: pad+heads+chain+tail: %"IVdf"+%"IVdf"+%"IVdf"+%"IVdf".\n",
2302 buffer.total_sbrk, buffer.sbrks, buffer.sbrk_good,
2303 buffer.sbrk_slack, buffer.start_slack,
2304 buffer.total_chain, buffer.sbrked_remains);
2305 #else /* DEBUGGING_MSTATS */
2306 PerlIO_printf(Perl_error_log, "%s: perl not compiled with DEBUGGING_MSTATS\n",s);
2307 #endif /* DEBUGGING_MSTATS */
2310 #ifdef USE_PERL_SBRK
2312 # if defined(NeXT) || defined(__NeXT__) || defined(PURIFY)
2313 # define PERL_SBRK_VIA_MALLOC
2316 # ifdef PERL_SBRK_VIA_MALLOC
2318 /* it may seem schizophrenic to use perl's malloc and let it call system */
2319 /* malloc, the reason for that is only the 3.2 version of the OS that had */
2320 /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
2321 /* end to the cores */
2323 # ifndef SYSTEM_ALLOC
2324 # define SYSTEM_ALLOC(a) malloc(a)
2326 # ifndef SYSTEM_ALLOC_ALIGNMENT
2327 # define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
2330 # endif /* PERL_SBRK_VIA_MALLOC */
2332 static IV Perl_sbrk_oldchunk;
2333 static long Perl_sbrk_oldsize;
2335 # define PERLSBRK_32_K (1<<15)
2336 # define PERLSBRK_64_K (1<<16)
2344 if (!size) return 0;
2345 reqsize = size; /* just for the DEBUG_m statement */
2347 size = (size + 0x7ff) & ~0x7ff;
2349 if (size <= Perl_sbrk_oldsize) {
2350 got = Perl_sbrk_oldchunk;
2351 Perl_sbrk_oldchunk += size;
2352 Perl_sbrk_oldsize -= size;
2354 if (size >= PERLSBRK_32_K) {
2357 size = PERLSBRK_64_K;
2360 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2361 size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT;
2363 got = (IV)SYSTEM_ALLOC(size);
2364 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2365 got = (got + NEEDED_ALIGNMENT - 1) & ~(NEEDED_ALIGNMENT - 1);
2368 /* Chunk is small, register the rest for future allocs. */
2369 Perl_sbrk_oldchunk = got + reqsize;
2370 Perl_sbrk_oldsize = size - reqsize;
2374 DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%"UVxf"\n",
2375 size, reqsize, Perl_sbrk_oldsize, PTR2UV(got)));
2380 #endif /* ! defined USE_PERL_SBRK */
2384 * c-indentation-style: bsd
2386 * indent-tabs-mode: nil
2389 * ex: set ts=8 sts=4 sw=4 et: