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 (register 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 */
1095 write2(const char *mess)
1097 write(2, mess, strlen(mess));
1102 #define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p),__FILE__,__LINE__);
1105 botch(const char *diag, const char *s, const char *file, int line)
1109 if (!(PERL_MAYBE_ALIVE && PERL_GET_THX))
1112 if (PerlIO_printf(PerlIO_stderr(),
1113 "assertion botched (%s?): %s %s:%d\n",
1114 diag, s, file, line) != 0) {
1115 do_write: /* Can be initializing interpreter */
1116 write2("assertion botched (");
1125 char *s = linebuf + sizeof(linebuf) - 1;
1129 *--s = '0' + (n % 10);
1139 #define ASSERT(p, diag)
1143 /* Fill should be long enough to cover long */
1145 fill_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1147 unsigned char *e = s + nbytes;
1149 const long lfill = *(long*)fill;
1151 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1152 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1153 unsigned const char *f = fill + sizeof(long) - shift;
1154 unsigned char *e1 = s + shift;
1160 while ((unsigned char*)(lp + 1) <= e)
1162 s = (unsigned char*)lp;
1166 /* Just malloc()ed */
1167 static const unsigned char fill_feedadad[] =
1168 {0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD,
1169 0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD};
1171 static const unsigned char fill_deadbeef[] =
1172 {0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF,
1173 0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF};
1174 # define FILL_DEADBEEF(s, n) \
1175 (void)(FILL_DEAD? (fill_pat_4bytes((s), (n), fill_deadbeef), 0) : 0)
1176 # define FILL_FEEDADAD(s, n) \
1177 (void)(FILL_ALIVE? (fill_pat_4bytes((s), (n), fill_feedadad), 0) : 0)
1179 # define FILL_DEADBEEF(s, n) ((void)0)
1180 # define FILL_FEEDADAD(s, n) ((void)0)
1181 # undef MALLOC_FILL_CHECK
1184 #ifdef MALLOC_FILL_CHECK
1186 cmp_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1188 unsigned char *e = s + nbytes;
1190 const long lfill = *(long*)fill;
1192 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1193 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1194 unsigned const char *f = fill + sizeof(long) - shift;
1195 unsigned char *e1 = s + shift;
1202 while ((unsigned char*)(lp + 1) <= e)
1205 s = (unsigned char*)lp;
1207 if (*s++ != *fill++)
1211 # define FILLCHECK_DEADBEEF(s, n) \
1212 ASSERT(!FILL_CHECK || !cmp_pat_4bytes(s, n, fill_deadbeef), \
1213 "free()ed/realloc()ed-away memory was overwritten")
1215 # define FILLCHECK_DEADBEEF(s, n) ((void)0)
1219 S_ajust_size_and_find_bucket(size_t *nbytes_p)
1223 size_t nbytes = *nbytes_p;
1226 * Convert amount of memory requested into
1227 * closest block size stored in hash buckets
1228 * which satisfies request. Account for
1229 * space used per block for accounting.
1232 # ifdef SMALL_BUCKET_VIA_TABLE
1234 bucket = MIN_BUCKET;
1235 else if (nbytes <= SIZE_TABLE_MAX) {
1236 bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
1241 if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
1246 POW2_OPTIMIZE_ADJUST(nbytes);
1247 nbytes += M_OVERHEAD;
1248 nbytes = (nbytes + 3) &~ 3;
1249 #if defined(PACK_MALLOC) && !defined(SMALL_BUCKET_VIA_TABLE)
1252 shiftr = (nbytes - 1) >> START_SHIFT;
1253 bucket = START_SHIFTS_BUCKET;
1254 /* apart from this loop, this is O(1) */
1255 while (shiftr >>= 1)
1256 bucket += BUCKETS_PER_POW2;
1263 Perl_malloc(size_t nbytes)
1266 register union overhead *p;
1267 register int bucket;
1269 #if defined(DEBUGGING) || defined(RCHECK)
1270 MEM_SIZE size = nbytes;
1273 BARK_64K_LIMIT("Allocation",nbytes,nbytes);
1275 if ((long)nbytes < 0)
1276 croak("%s", "panic: malloc");
1279 bucket = S_ajust_size_and_find_bucket(&nbytes);
1282 * If nothing in hash bucket right now,
1283 * request more memory from the system.
1285 if (nextf[bucket] == NULL)
1287 if ((p = nextf[bucket]) == NULL) {
1292 #if defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC)
1293 PerlIO_puts(PerlIO_stderr(),"Out of memory!\n");
1296 char *eb = buff + sizeof(buff) - 1;
1300 PerlIO_puts(PerlIO_stderr(),"Out of memory during request for ");
1301 #if defined(DEBUGGING) || defined(RCHECK)
1306 *--s = '0' + (n % 10);
1308 PerlIO_puts(PerlIO_stderr(),s);
1309 PerlIO_puts(PerlIO_stderr()," bytes, total sbrk() is ");
1311 n = goodsbrk + sbrk_slack;
1313 *--s = '0' + (n % 10);
1315 PerlIO_puts(PerlIO_stderr(),s);
1316 PerlIO_puts(PerlIO_stderr()," bytes!\n");
1317 #endif /* defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC) */
1324 /* remove from linked list */
1326 if ( (PTR2UV(p) & (MEM_ALIGNBYTES - 1))
1327 /* Can't get this low */
1328 || (p && PTR2UV(p) < (1<<LOG_OF_MIN_ARENA)) ) {
1330 PerlIO_printf(PerlIO_stderr(),
1331 "Unaligned pointer in the free chain 0x%"UVxf"\n",
1334 if ( (PTR2UV(p->ov_next) & (MEM_ALIGNBYTES - 1))
1335 || (p->ov_next && PTR2UV(p->ov_next) < (1<<LOG_OF_MIN_ARENA)) ) {
1337 PerlIO_printf(PerlIO_stderr(),
1338 "Unaligned \"next\" pointer in the free "
1339 "chain 0x%"UVxf" at 0x%"UVxf"\n",
1340 PTR2UV(p->ov_next), PTR2UV(p));
1343 nextf[bucket] = p->ov_next;
1347 DEBUG_m(PerlIO_printf(Perl_debug_log,
1348 "0x%"UVxf": (%05lu) malloc %ld bytes\n",
1349 PTR2UV((Malloc_t)(p + CHUNK_SHIFT)), (unsigned long)(PL_an++),
1352 FILLCHECK_DEADBEEF((unsigned char*)(p + CHUNK_SHIFT),
1353 BUCKET_SIZE_REAL(bucket) + RMAGIC_SZ);
1355 #ifdef IGNORE_SMALL_BAD_FREE
1356 if (bucket >= FIRST_BUCKET_WITH_CHECK)
1358 OV_MAGIC(p, bucket) = MAGIC;
1360 OV_INDEX(p) = bucket;
1364 * Record allocated size of block and
1365 * bound space with magic numbers.
1367 p->ov_rmagic = RMAGIC;
1368 if (bucket <= MAX_SHORT_BUCKET) {
1371 nbytes = size + M_OVERHEAD;
1372 p->ov_size = nbytes - 1;
1373 if ((i = nbytes & (RMAGIC_SZ-1))) {
1375 while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
1376 ((caddr_t)p + nbytes - RMAGIC_SZ)[i] = RMAGIC_C;
1378 /* Same at RMAGIC_SZ-aligned RMAGIC */
1379 nbytes = (nbytes + RMAGIC_SZ - 1) & ~(RMAGIC_SZ - 1);
1380 ((u_int *)((caddr_t)p + nbytes))[-1] = RMAGIC;
1382 FILL_FEEDADAD((unsigned char *)(p + CHUNK_SHIFT), size);
1384 return ((Malloc_t)(p + CHUNK_SHIFT));
1387 static char *last_sbrk_top;
1388 static char *last_op; /* This arena can be easily extended. */
1389 static MEM_SIZE sbrked_remains;
1391 #ifdef DEBUGGING_MSTATS
1395 struct chunk_chain_s {
1396 struct chunk_chain_s *next;
1399 static struct chunk_chain_s *chunk_chain;
1400 static int n_chunks;
1401 static char max_bucket;
1403 /* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */
1405 get_from_chain(MEM_SIZE size)
1407 struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
1408 struct chunk_chain_s **oldgoodp = NULL;
1409 long min_remain = LONG_MAX;
1412 if (elt->size >= size) {
1413 long remains = elt->size - size;
1414 if (remains >= 0 && remains < min_remain) {
1416 min_remain = remains;
1422 oldp = &( elt->next );
1425 if (!oldgoodp) return NULL;
1427 void *ret = *oldgoodp;
1428 struct chunk_chain_s *next = (*oldgoodp)->next;
1430 *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
1431 (*oldgoodp)->size = min_remain;
1432 (*oldgoodp)->next = next;
1435 void *ret = *oldgoodp;
1436 *oldgoodp = (*oldgoodp)->next;
1443 add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
1445 struct chunk_chain_s *next = chunk_chain;
1446 char *cp = (char*)p;
1449 chunk_chain = (struct chunk_chain_s *)cp;
1450 chunk_chain->size = size - chip;
1451 chunk_chain->next = next;
1456 get_from_bigger_buckets(int bucket, MEM_SIZE size)
1459 static int bucketprice[NBUCKETS];
1460 while (bucket <= max_bucket) {
1461 /* We postpone stealing from bigger buckets until we want it
1463 if (nextf[bucket] && bucketprice[bucket]++ >= price) {
1465 void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
1466 bucketprice[bucket] = 0;
1467 if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
1468 last_op = NULL; /* Disable optimization */
1470 nextf[bucket] = nextf[bucket]->ov_next;
1471 #ifdef DEBUGGING_MSTATS
1473 start_slack -= M_OVERHEAD;
1475 add_to_chain(ret, (BUCKET_SIZE_NO_SURPLUS(bucket) +
1476 POW2_OPTIMIZE_SURPLUS(bucket)),
1485 static union overhead *
1486 getpages(MEM_SIZE needed, int *nblksp, int bucket)
1489 /* Need to do (possibly expensive) system call. Try to
1490 optimize it for rare calling. */
1491 MEM_SIZE require = needed - sbrked_remains;
1493 union overhead *ovp;
1496 if (sbrk_goodness > 0) {
1497 if (!last_sbrk_top && require < (MEM_SIZE)FIRST_SBRK)
1498 require = FIRST_SBRK;
1499 else if (require < (MEM_SIZE)MIN_SBRK) require = MIN_SBRK;
1501 if (require < (Size_t)(goodsbrk * MIN_SBRK_FRAC1000 / 1000))
1502 require = goodsbrk * MIN_SBRK_FRAC1000 / 1000;
1503 require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
1510 DEBUG_m(PerlIO_printf(Perl_debug_log,
1511 "sbrk(%ld) for %ld-byte-long arena\n",
1512 (long)require, (long) needed));
1513 cp = (char *)sbrk(require);
1514 #ifdef DEBUGGING_MSTATS
1517 if (cp == last_sbrk_top) {
1518 /* Common case, anything is fine. */
1520 ovp = (union overhead *) (cp - sbrked_remains);
1521 last_op = cp - sbrked_remains;
1522 sbrked_remains = require - (needed - sbrked_remains);
1523 } else if (cp == (char *)-1) { /* no more room! */
1524 ovp = (union overhead *)emergency_sbrk(needed);
1525 if (ovp == (union overhead *)-1)
1527 if (((char*)ovp) > last_op) { /* Cannot happen with current emergency_sbrk() */
1531 } else { /* Non-continuous or first sbrk(). */
1532 long add = sbrked_remains;
1535 if (sbrked_remains) { /* Put rest into chain, we
1536 cannot use it right now. */
1537 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1541 /* Second, check alignment. */
1544 /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
1545 improve performance of memory access. */
1546 if (PTR2UV(cp) & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
1547 slack = WANTED_ALIGNMENT - (PTR2UV(cp) & (WANTED_ALIGNMENT - 1));
1552 DEBUG_m(PerlIO_printf(Perl_debug_log,
1553 "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",
1554 (long)add, (long) slack,
1555 (long) sbrked_remains));
1556 newcp = (char *)sbrk(add);
1557 #if defined(DEBUGGING_MSTATS)
1561 if (newcp != cp + require) {
1562 /* Too bad: even rounding sbrk() is not continuous.*/
1563 DEBUG_m(PerlIO_printf(Perl_debug_log,
1564 "failed to fix bad sbrk()\n"));
1568 fatalcroak("panic: Off-page sbrk\n");
1571 if (sbrked_remains) {
1573 #if defined(DEBUGGING_MSTATS)
1574 sbrk_slack += require;
1577 DEBUG_m(PerlIO_printf(Perl_debug_log,
1578 "straight sbrk(%ld)\n",
1580 cp = (char *)sbrk(require);
1581 #ifdef DEBUGGING_MSTATS
1584 if (cp == (char *)-1)
1587 sbrk_goodness = -1; /* Disable optimization!
1588 Continue with not-aligned... */
1591 require += sbrked_remains;
1595 if (last_sbrk_top) {
1596 sbrk_goodness -= SBRK_FAILURE_PRICE;
1599 ovp = (union overhead *) cp;
1601 * Round up to minimum allocation size boundary
1602 * and deduct from block count to reflect.
1605 # if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
1606 if (PTR2UV(ovp) & (NEEDED_ALIGNMENT - 1))
1607 fatalcroak("Misalignment of sbrk()\n");
1610 if (PTR2UV(ovp) & (MEM_ALIGNBYTES - 1)) {
1611 DEBUG_m(PerlIO_printf(Perl_debug_log,
1612 "fixing sbrk(): %d bytes off machine alignment\n",
1613 (int)(PTR2UV(ovp) & (MEM_ALIGNBYTES - 1))));
1614 ovp = INT2PTR(union overhead *,(PTR2UV(ovp) + MEM_ALIGNBYTES) &
1615 (MEM_ALIGNBYTES - 1));
1617 # if defined(DEBUGGING_MSTATS)
1618 /* This is only approx. if TWO_POT_OPTIMIZE: */
1619 sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
1622 ; /* Finish "else" */
1623 sbrked_remains = require - needed;
1626 #if !defined(PLAIN_MALLOC) && !defined(NO_FANCY_MALLOC)
1627 emergency_buffer_last_req = 0;
1629 last_sbrk_top = cp + require;
1630 #ifdef DEBUGGING_MSTATS
1631 goodsbrk += require;
1637 getpages_adjacent(MEM_SIZE require)
1639 if (require <= sbrked_remains) {
1640 sbrked_remains -= require;
1644 require -= sbrked_remains;
1645 /* We do not try to optimize sbrks here, we go for place. */
1646 cp = (char*) sbrk(require);
1647 #ifdef DEBUGGING_MSTATS
1649 goodsbrk += require;
1651 if (cp == last_sbrk_top) {
1653 last_sbrk_top = cp + require;
1655 if (cp == (char*)-1) { /* Out of memory */
1656 #ifdef DEBUGGING_MSTATS
1657 goodsbrk -= require;
1661 /* Report the failure: */
1663 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1665 add_to_chain((void*)cp, require, 0);
1666 sbrk_goodness -= SBRK_FAILURE_PRICE;
1678 * Allocate more memory to the indicated bucket.
1681 morecore(register int bucket)
1684 register union overhead *ovp;
1685 register int rnu; /* 2^rnu bytes will be requested */
1686 int nblks; /* become nblks blocks of the desired size */
1687 register MEM_SIZE siz, needed;
1688 static int were_called = 0;
1692 #ifndef NO_PERL_MALLOC_ENV
1694 /* It's the our first time. Initialize ourselves */
1695 were_called = 1; /* Avoid a loop */
1696 if (!MallocCfg[MallocCfg_skip_cfg_env]) {
1697 char *s = getenv("PERL_MALLOC_OPT"), *t = s, *off;
1698 const char *opts = PERL_MALLOC_OPT_CHARS;
1701 while ( t && t[0] && t[1] == '='
1702 && ((off = strchr(opts, *t))) ) {
1706 while (*t <= '9' && *t >= '0')
1707 val = 10*val + *t++ - '0';
1708 if (!*t || *t == ';') {
1709 if (MallocCfg[off - opts] != val)
1711 MallocCfg[off - opts] = val;
1717 write2("Unrecognized part of PERL_MALLOC_OPT: \"");
1722 MallocCfg[MallocCfg_cfg_env_read] = 1;
1726 if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
1728 croak("%s", "Out of memory during ridiculously large request");
1730 if (bucket > max_bucket)
1731 max_bucket = bucket;
1733 rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT))
1735 : (bucket >> BUCKET_POW2_SHIFT) );
1736 /* This may be overwritten later: */
1737 nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
1738 needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
1739 if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
1740 ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
1741 nextf[rnu << BUCKET_POW2_SHIFT]
1742 = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
1743 #ifdef DEBUGGING_MSTATS
1744 nmalloc[rnu << BUCKET_POW2_SHIFT]--;
1745 start_slack -= M_OVERHEAD;
1747 DEBUG_m(PerlIO_printf(Perl_debug_log,
1748 "stealing %ld bytes from %ld arena\n",
1749 (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
1750 } else if (chunk_chain
1751 && (ovp = (union overhead*) get_from_chain(needed))) {
1752 DEBUG_m(PerlIO_printf(Perl_debug_log,
1753 "stealing %ld bytes from chain\n",
1755 } else if ( (ovp = (union overhead*)
1756 get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
1758 DEBUG_m(PerlIO_printf(Perl_debug_log,
1759 "stealing %ld bytes from bigger buckets\n",
1761 } else if (needed <= sbrked_remains) {
1762 ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
1763 sbrked_remains -= needed;
1764 last_op = (char*)ovp;
1766 ovp = getpages(needed, &nblks, bucket);
1770 FILL_DEADBEEF((unsigned char*)ovp, needed);
1773 * Add new memory allocated to that on
1774 * free list for this hash bucket.
1776 siz = BUCKET_SIZE_NO_SURPLUS(bucket); /* No surplus if nblks > 1 */
1778 *(u_char*)ovp = bucket; /* Fill index. */
1779 if (bucket <= MAX_PACKED) {
1780 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1781 nblks = N_BLKS(bucket);
1782 # ifdef DEBUGGING_MSTATS
1783 start_slack += BLK_SHIFT(bucket);
1785 } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
1786 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1787 siz -= sizeof(union overhead);
1788 } else ovp++; /* One chunk per block. */
1789 #endif /* PACK_MALLOC */
1790 nextf[bucket] = ovp;
1791 #ifdef DEBUGGING_MSTATS
1792 nmalloc[bucket] += nblks;
1793 if (bucket > MAX_PACKED) {
1794 start_slack += M_OVERHEAD * nblks;
1798 while (--nblks > 0) {
1799 ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
1800 ovp = (union overhead *)((caddr_t)ovp + siz);
1802 /* Not all sbrks return zeroed memory.*/
1803 ovp->ov_next = (union overhead *)NULL;
1805 if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
1806 union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
1807 nextf[7*BUCKETS_PER_POW2] =
1808 (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2]
1809 - sizeof(union overhead));
1810 nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
1812 #endif /* !PACK_MALLOC */
1816 Perl_mfree(Malloc_t where)
1819 register MEM_SIZE size;
1820 register union overhead *ovp;
1821 char *cp = (char*)where;
1826 DEBUG_m(PerlIO_printf(Perl_debug_log,
1827 "0x%"UVxf": (%05lu) free\n",
1828 PTR2UV(cp), (unsigned long)(PL_an++)));
1833 if (PTR2UV(cp) & (MEM_ALIGNBYTES - 1))
1834 croak("%s", "wrong alignment in free()");
1836 ovp = (union overhead *)((caddr_t)cp
1837 - sizeof (union overhead) * CHUNK_SHIFT);
1839 bucket = OV_INDEX(ovp);
1841 #ifdef IGNORE_SMALL_BAD_FREE
1842 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1843 && (OV_MAGIC(ovp, bucket) != MAGIC))
1845 if (OV_MAGIC(ovp, bucket) != MAGIC)
1848 static int bad_free_warn = -1;
1849 if (bad_free_warn == -1) {
1851 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1852 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1859 if (!PERL_IS_ALIVE || !PL_curcop)
1860 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s free() ignored (RMAGIC, PERL_CORE)",
1861 ovp->ov_rmagic == RMAGIC - 1 ?
1862 "Duplicate" : "Bad");
1867 if (!PERL_IS_ALIVE || !PL_curcop)
1868 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s", "Bad free() ignored (PERL_CORE)");
1871 return; /* sanity */
1874 ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
1875 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
1877 MEM_SIZE nbytes = ovp->ov_size + 1;
1879 if ((i = nbytes & (RMAGIC_SZ-1))) {
1881 while (i--) { /* nbytes - RMAGIC_SZ is end of alloced area */
1882 ASSERT(((caddr_t)ovp + nbytes - RMAGIC_SZ)[i] == RMAGIC_C,
1883 "chunk's tail overwrite");
1886 /* Same at RMAGIC_SZ-aligned RMAGIC */
1887 nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
1888 ASSERT(((u_int *)((caddr_t)ovp + nbytes))[-1] == RMAGIC,
1889 "chunk's tail overwrite");
1890 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nbytes),
1891 BUCKET_SIZE(OV_INDEX(ovp)) - nbytes);
1893 FILL_DEADBEEF((unsigned char*)(ovp+CHUNK_SHIFT),
1894 BUCKET_SIZE_REAL(OV_INDEX(ovp)) + RMAGIC_SZ);
1895 ovp->ov_rmagic = RMAGIC - 1;
1897 ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
1898 size = OV_INDEX(ovp);
1901 ovp->ov_next = nextf[size];
1906 /* There is no need to do any locking in realloc (with an exception of
1907 trying to grow in place if we are at the end of the chain).
1908 If somebody calls us from a different thread with the same address,
1909 we are sole anyway. */
1912 Perl_realloc(void *mp, size_t nbytes)
1915 register MEM_SIZE onb;
1916 union overhead *ovp;
1919 register int bucket;
1920 int incr; /* 1 if does not fit, -1 if "easily" fits in a
1921 smaller bucket, otherwise 0. */
1922 char *cp = (char*)mp;
1925 MEM_SIZE size = nbytes;
1927 if ((long)nbytes < 0)
1928 croak("%s", "panic: realloc");
1931 BARK_64K_LIMIT("Reallocation",nbytes,size);
1933 return Perl_malloc(nbytes);
1935 ovp = (union overhead *)((caddr_t)cp
1936 - sizeof (union overhead) * CHUNK_SHIFT);
1937 bucket = OV_INDEX(ovp);
1939 #ifdef IGNORE_SMALL_BAD_FREE
1940 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1941 && (OV_MAGIC(ovp, bucket) != MAGIC))
1943 if (OV_MAGIC(ovp, bucket) != MAGIC)
1946 static int bad_free_warn = -1;
1947 if (bad_free_warn == -1) {
1949 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1950 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1957 if (!PERL_IS_ALIVE || !PL_curcop)
1958 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%srealloc() %signored",
1959 (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
1960 ovp->ov_rmagic == RMAGIC - 1
1961 ? "of freed memory " : "");
1966 if (!PERL_IS_ALIVE || !PL_curcop)
1967 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s",
1968 "Bad realloc() ignored");
1971 return NULL; /* sanity */
1974 onb = BUCKET_SIZE_REAL(bucket);
1976 * avoid the copy if same size block.
1977 * We are not aggressive with boundary cases. Note that it might
1978 * (for a small number of cases) give false negative if
1979 * both new size and old one are in the bucket for
1980 * FIRST_BIG_POW2, but the new one is near the lower end.
1982 * We do not try to go to 1.5 times smaller bucket so far.
1984 if (nbytes > onb) incr = 1;
1986 #ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
1987 if ( /* This is a little bit pessimal if PACK_MALLOC: */
1988 nbytes > ( (onb >> 1) - M_OVERHEAD )
1989 # ifdef TWO_POT_OPTIMIZE
1990 || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
1993 #else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
1994 prev_bucket = ( (bucket > MAX_PACKED + 1)
1995 ? bucket - BUCKETS_PER_POW2
1997 if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
1998 #endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
2002 #ifdef STRESS_REALLOC
2009 * Record new allocated size of block and
2010 * bound space with magic numbers.
2012 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
2013 int i, nb = ovp->ov_size + 1;
2015 if ((i = nb & (RMAGIC_SZ-1))) {
2017 while (i--) { /* nb - RMAGIC_SZ is end of alloced area */
2018 ASSERT(((caddr_t)ovp + nb - RMAGIC_SZ)[i] == RMAGIC_C, "chunk's tail overwrite");
2021 /* Same at RMAGIC_SZ-aligned RMAGIC */
2022 nb = (nb + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
2023 ASSERT(((u_int *)((caddr_t)ovp + nb))[-1] == RMAGIC,
2024 "chunk's tail overwrite");
2025 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nb),
2026 BUCKET_SIZE(OV_INDEX(ovp)) - nb);
2027 if (nbytes > ovp->ov_size + 1 - M_OVERHEAD)
2028 FILL_FEEDADAD((unsigned char*)cp + ovp->ov_size + 1 - M_OVERHEAD,
2029 nbytes - (ovp->ov_size + 1 - M_OVERHEAD));
2031 FILL_DEADBEEF((unsigned char*)cp + nbytes,
2032 nb - M_OVERHEAD + RMAGIC_SZ - nbytes);
2034 * Convert amount of memory requested into
2035 * closest block size stored in hash buckets
2036 * which satisfies request. Account for
2037 * space used per block for accounting.
2039 nbytes += M_OVERHEAD;
2040 ovp->ov_size = nbytes - 1;
2041 if ((i = nbytes & (RMAGIC_SZ-1))) {
2043 while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
2044 ((caddr_t)ovp + nbytes - RMAGIC_SZ)[i]
2047 /* Same at RMAGIC_SZ-aligned RMAGIC */
2048 nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ - 1);
2049 ((u_int *)((caddr_t)ovp + nbytes))[-1] = RMAGIC;
2053 DEBUG_m(PerlIO_printf(Perl_debug_log,
2054 "0x%"UVxf": (%05lu) realloc %ld bytes inplace\n",
2055 PTR2UV(res),(unsigned long)(PL_an++),
2057 } else if (incr == 1 && (cp - M_OVERHEAD == last_op)
2058 && (onb > (1 << LOG_OF_MIN_ARENA))) {
2059 MEM_SIZE require, newarena = nbytes, pow;
2062 POW2_OPTIMIZE_ADJUST(newarena);
2063 newarena = newarena + M_OVERHEAD;
2064 /* newarena = (newarena + 3) &~ 3; */
2065 shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
2066 pow = LOG_OF_MIN_ARENA + 1;
2067 /* apart from this loop, this is O(1) */
2068 while (shiftr >>= 1)
2070 newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
2071 require = newarena - onb - M_OVERHEAD;
2074 if (cp - M_OVERHEAD == last_op /* We *still* are the last chunk */
2075 && getpages_adjacent(require)) {
2076 #ifdef DEBUGGING_MSTATS
2078 nmalloc[pow * BUCKETS_PER_POW2]++;
2080 if (pow * BUCKETS_PER_POW2 > (MEM_SIZE)max_bucket)
2081 max_bucket = pow * BUCKETS_PER_POW2;
2082 *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
2091 DEBUG_m(PerlIO_printf(Perl_debug_log,
2092 "0x%"UVxf": (%05lu) realloc %ld bytes the hard way\n",
2093 PTR2UV(cp),(unsigned long)(PL_an++),
2095 if ((res = (char*)Perl_malloc(nbytes)) == NULL)
2097 if (cp != res) /* common optimization */
2098 Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
2101 return ((Malloc_t)res);
2105 Perl_calloc(register size_t elements, register size_t size)
2107 long sz = elements * size;
2108 Malloc_t p = Perl_malloc(sz);
2111 memset((void*)p, 0, sz);
2117 Perl_strdup(const char *s)
2119 MEM_SIZE l = strlen(s);
2120 char *s1 = (char *)Perl_malloc(l+1);
2122 return (char *)CopyD(s, s1, (MEM_SIZE)(l+1), char);
2126 Perl_putenv(char *a)
2128 /* Sometimes system's putenv conflicts with my_setenv() - this is system
2129 malloc vs Perl's free(). */
2136 while (*val && *val != '=')
2141 if (l < sizeof(buf))
2144 var = (char *)Perl_malloc(l + 1);
2145 Copy(a, var, l, char);
2147 my_setenv(var, val+1);
2154 Perl_malloced_size(void *p)
2156 union overhead * const ovp = (union overhead *)
2157 ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
2158 const int bucket = OV_INDEX(ovp);
2160 PERL_ARGS_ASSERT_MALLOCED_SIZE;
2163 /* The caller wants to have a complete control over the chunk,
2164 disable the memory checking inside the chunk. */
2165 if (bucket <= MAX_SHORT_BUCKET) {
2166 const MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
2167 ovp->ov_size = size + M_OVERHEAD - 1;
2168 *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RMAGIC_SZ)) = RMAGIC;
2171 return BUCKET_SIZE_REAL(bucket);
2176 Perl_malloc_good_size(size_t wanted)
2178 return BUCKET_SIZE_REAL(S_ajust_size_and_find_bucket(&wanted));
2181 # ifdef BUCKETS_ROOT2
2182 # define MIN_EVEN_REPORT 6
2184 # define MIN_EVEN_REPORT MIN_BUCKET
2188 Perl_get_mstats(pTHX_ perl_mstats_t *buf, int buflen, int level)
2190 #ifdef DEBUGGING_MSTATS
2192 register union overhead *p;
2193 struct chunk_chain_s* nextchain;
2195 PERL_ARGS_ASSERT_GET_MSTATS;
2197 buf->topbucket = buf->topbucket_ev = buf->topbucket_odd
2198 = buf->totfree = buf->total = buf->total_chain = 0;
2200 buf->minbucket = MIN_BUCKET;
2202 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2203 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
2207 buf->ntotal[i] = nmalloc[i];
2209 buf->totfree += j * BUCKET_SIZE_REAL(i);
2210 buf->total += nmalloc[i] * BUCKET_SIZE_REAL(i);
2212 i % 2 ? (buf->topbucket_odd = i) : (buf->topbucket_ev = i);
2216 nextchain = chunk_chain;
2218 buf->total_chain += nextchain->size;
2219 nextchain = nextchain->next;
2221 buf->total_sbrk = goodsbrk + sbrk_slack;
2223 buf->sbrk_good = sbrk_goodness;
2224 buf->sbrk_slack = sbrk_slack;
2225 buf->start_slack = start_slack;
2226 buf->sbrked_remains = sbrked_remains;
2228 buf->nbuckets = NBUCKETS;
2230 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2233 buf->bucket_mem_size[i] = BUCKET_SIZE_NO_SURPLUS(i);
2234 buf->bucket_available_size[i] = BUCKET_SIZE_REAL(i);
2237 #else /* defined DEBUGGING_MSTATS */
2238 PerlIO_printf(Perl_error_log, "perl not compiled with DEBUGGING_MSTATS\n");
2239 #endif /* defined DEBUGGING_MSTATS */
2240 return 0; /* XXX unused */
2243 * mstats - print out statistics about malloc
2245 * Prints two lines of numbers, one showing the length of the free list
2246 * for each size category, the second showing the number of mallocs -
2247 * frees for each size category.
2250 Perl_dump_mstats(pTHX_ const char *s)
2252 #ifdef DEBUGGING_MSTATS
2254 perl_mstats_t buffer;
2258 PERL_ARGS_ASSERT_DUMP_MSTATS;
2262 get_mstats(&buffer, NBUCKETS, 0);
2265 PerlIO_printf(Perl_error_log,
2266 "Memory allocation statistics %s (buckets %"IVdf"(%"IVdf")..%"IVdf"(%"IVdf")\n",
2268 (IV)BUCKET_SIZE_REAL(MIN_BUCKET),
2269 (IV)BUCKET_SIZE_NO_SURPLUS(MIN_BUCKET),
2270 (IV)BUCKET_SIZE_REAL(buffer.topbucket),
2271 (IV)BUCKET_SIZE_NO_SURPLUS(buffer.topbucket));
2272 PerlIO_printf(Perl_error_log, "%8"IVdf" free:", buffer.totfree);
2273 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2274 PerlIO_printf(Perl_error_log,
2275 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2277 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2280 #ifdef BUCKETS_ROOT2
2281 PerlIO_printf(Perl_error_log, "\n\t ");
2282 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2283 PerlIO_printf(Perl_error_log,
2284 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2286 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
2290 PerlIO_printf(Perl_error_log, "\n%8"IVdf" used:", buffer.total - buffer.totfree);
2291 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
2292 PerlIO_printf(Perl_error_log,
2293 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2295 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2296 buffer.ntotal[i] - buffer.nfree[i]);
2298 #ifdef BUCKETS_ROOT2
2299 PerlIO_printf(Perl_error_log, "\n\t ");
2300 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
2301 PerlIO_printf(Perl_error_log,
2302 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
2304 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
2305 buffer.ntotal[i] - buffer.nfree[i]);
2308 PerlIO_printf(Perl_error_log, "\nTotal sbrk(): %"IVdf"/%"IVdf":%"IVdf". Odd ends: pad+heads+chain+tail: %"IVdf"+%"IVdf"+%"IVdf"+%"IVdf".\n",
2309 buffer.total_sbrk, buffer.sbrks, buffer.sbrk_good,
2310 buffer.sbrk_slack, buffer.start_slack,
2311 buffer.total_chain, buffer.sbrked_remains);
2312 #else /* DEBUGGING_MSTATS */
2313 PerlIO_printf(Perl_error_log, "%s: perl not compiled with DEBUGGING_MSTATS\n",s);
2314 #endif /* DEBUGGING_MSTATS */
2317 #ifdef USE_PERL_SBRK
2319 # if defined(NeXT) || defined(__NeXT__) || defined(PURIFY)
2320 # define PERL_SBRK_VIA_MALLOC
2323 # ifdef PERL_SBRK_VIA_MALLOC
2325 /* it may seem schizophrenic to use perl's malloc and let it call system */
2326 /* malloc, the reason for that is only the 3.2 version of the OS that had */
2327 /* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
2328 /* end to the cores */
2330 # ifndef SYSTEM_ALLOC
2331 # define SYSTEM_ALLOC(a) malloc(a)
2333 # ifndef SYSTEM_ALLOC_ALIGNMENT
2334 # define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
2337 # endif /* PERL_SBRK_VIA_MALLOC */
2339 static IV Perl_sbrk_oldchunk;
2340 static long Perl_sbrk_oldsize;
2342 # define PERLSBRK_32_K (1<<15)
2343 # define PERLSBRK_64_K (1<<16)
2351 if (!size) return 0;
2352 reqsize = size; /* just for the DEBUG_m statement */
2354 size = (size + 0x7ff) & ~0x7ff;
2356 if (size <= Perl_sbrk_oldsize) {
2357 got = Perl_sbrk_oldchunk;
2358 Perl_sbrk_oldchunk += size;
2359 Perl_sbrk_oldsize -= size;
2361 if (size >= PERLSBRK_32_K) {
2364 size = PERLSBRK_64_K;
2367 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2368 size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT;
2370 got = (IV)SYSTEM_ALLOC(size);
2371 # if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2372 got = (got + NEEDED_ALIGNMENT - 1) & ~(NEEDED_ALIGNMENT - 1);
2375 /* Chunk is small, register the rest for future allocs. */
2376 Perl_sbrk_oldchunk = got + reqsize;
2377 Perl_sbrk_oldsize = size - reqsize;
2381 DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%"UVxf"\n",
2382 size, reqsize, Perl_sbrk_oldsize, PTR2UV(got)));
2387 #endif /* ! defined USE_PERL_SBRK */
2391 * c-indentation-style: bsd
2393 * indent-tabs-mode: nil
2396 * ex: set ts=8 sts=4 sw=4 et: