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Added several missing PERL_UNUSED_RESULT()
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a0d0e21e 1/* malloc.c
8d063cd8 2 *
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3 */
4
87c6202a 5/*
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6 * 'The Chamber of Records,' said Gimli. 'I guess that is where we now stand.'
7 *
cdad3b53 8 * [p.321 of _The Lord of the Rings_, II/v: "The Bridge of Khazad-Dûm"]
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9 */
10
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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.
15 */
16
d31a8517 17/*
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18 Here are some notes on configuring Perl's malloc.
19
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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.
26
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).
31
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.
36
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37 # Read configuration settings from malloc_cfg.h
38 HAVE_MALLOC_CFG_H undef
39
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40 # Enable code for an emergency memory pool in $^M. See perlvar.pod
41 # for a description of $^M.
b9e5552c 42 PERL_EMERGENCY_SBRK !PLAIN_MALLOC
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43
44 # Enable code for printing memory statistics.
b9e5552c 45 DEBUGGING_MSTATS !PLAIN_MALLOC
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46
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)
52
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
55 # processing.
56 TWO_POT_OPTIMIZE !PLAIN_MALLOC
57
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
61
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)
65
66 # Use table lookup to decide in which bucket a given allocation will go.
67 SMALL_BUCKET_VIA_TABLE !NO_FANCY_MALLOC
68
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69 # Use a perl-defined sbrk() instead of the (presumably broken or
70 # missing) system-supplied sbrk().
71 USE_PERL_SBRK undef
72
73 # Use system malloc() (or calloc() etc.) to emulate sbrk(). Normally
74 # only used with broken sbrk()s.
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75 PERL_SBRK_VIA_MALLOC undef
76
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77 # Which allocator to use if PERL_SBRK_VIA_MALLOC
78 SYSTEM_ALLOC(a) malloc(a)
79
9ee81ef6 80 # Minimal alignment (in bytes, should be a power of 2) of SYSTEM_ALLOC
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81 SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
82
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83 # Disable memory overwrite checking with DEBUGGING. Memory and speed
84 # optimization, error reporting pessimization.
85 NO_RCHECK undef
86
87 # Enable memory overwrite checking with DEBUGGING. Memory and speed
88 # pessimization, error reporting optimization
89 RCHECK (DEBUGGING && !NO_RCHECK)
90
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91 # Do not overwrite uninit areas with DEBUGGING. Speed
92 # optimization, error reporting pessimization
93 NO_MFILL undef
94
95 # Overwrite uninit areas with DEBUGGING. Speed
96 # pessimization, error reporting optimization
97 MALLOC_FILL (DEBUGGING && !NO_RCHECK && !NO_MFILL)
98
99 # Do not check overwritten uninit areas with DEBUGGING. Speed
100 # optimization, error reporting pessimization
101 NO_FILL_CHECK undef
102
103 # Check overwritten uninit areas with DEBUGGING. Speed
104 # pessimization, error reporting optimization
105 MALLOC_FILL_CHECK (DEBUGGING && !NO_RCHECK && !NO_FILL_CHECK)
106
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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
111
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
116
117 # Estimate of minimal memory footprint. malloc uses this value to
118 # request the most reasonable largest blocks of memory from the system.
119 FIRST_SBRK (48*1024)
120
121 # Round up sbrk()s to multiples of this.
122 MIN_SBRK 2048
123
124 # Round up sbrk()s to multiples of this percent of footprint.
125 MIN_SBRK_FRAC 3
126
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127 # Round up sbrk()s to multiples of this multiple of 1/1000 of footprint.
128 MIN_SBRK_FRAC1000 (10 * MIN_SBRK_FRAC)
129
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130 # Add this much memory to big powers of two to get the bucket size.
131 PERL_PAGESIZE 4096
132
133 # This many sbrk() discontinuities should be tolerated even
134 # from the start without deciding that sbrk() is usually
135 # discontinuous.
136 SBRK_ALLOW_FAILURES 3
137
138 # This many continuous sbrk()s compensate for one discontinuous one.
139 SBRK_FAILURE_PRICE 50
140
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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
145
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146 # Do not allow configuration of runtime options at runtime
147 NO_MALLOC_DYNAMIC_CFG undef
148
149 # Do not allow configuration of runtime options via $ENV{PERL_MALLOC_OPT}
150 NO_PERL_MALLOC_ENV undef
151
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.]
159
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160 This implementation assumes that calling PerlIO_printf() does not
161 result in any memory allocation calls (used during a panic).
162
163 */
164
741df71a 165
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166#ifdef HAVE_MALLOC_CFG_H
167# include "malloc_cfg.h"
168#endif
169
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170#ifndef NO_FANCY_MALLOC
171# ifndef SMALL_BUCKET_VIA_TABLE
172# define SMALL_BUCKET_VIA_TABLE
173# endif
174# ifndef BUCKETS_ROOT2
175# define BUCKETS_ROOT2
176# endif
177# ifndef IGNORE_SMALL_BAD_FREE
178# define IGNORE_SMALL_BAD_FREE
179# endif
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180#endif
181
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182#ifndef PLAIN_MALLOC /* Bulk enable features */
183# ifndef PACK_MALLOC
184# define PACK_MALLOC
185# endif
186# ifndef TWO_POT_OPTIMIZE
187# define TWO_POT_OPTIMIZE
188# endif
b9e5552c 189# ifndef PERL_EMERGENCY_SBRK
d720c441 190# define PERL_EMERGENCY_SBRK
e8bc2b5c 191# endif
b9e5552c 192# ifndef DEBUGGING_MSTATS
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193# define DEBUGGING_MSTATS
194# endif
195#endif
196
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)
199
562aee6b 200#define LOG_OF_MIN_ARENA 11
e8bc2b5c 201
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202#if defined(DEBUGGING) && !defined(NO_RCHECK)
203# define RCHECK
204#endif
205#if defined(DEBUGGING) && !defined(NO_RCHECK) && !defined(NO_MFILL) && !defined(MALLOC_FILL)
206# define MALLOC_FILL
207#endif
208#if defined(DEBUGGING) && !defined(NO_RCHECK) && !defined(NO_FILL_CHECK) && !defined(MALLOC_FILL_CHECK)
209# define MALLOC_FILL_CHECK
210#endif
211#if defined(RCHECK) && defined(IGNORE_SMALL_BAD_FREE)
212# undef IGNORE_SMALL_BAD_FREE
213#endif
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214/*
215 * malloc.c (Caltech) 2/21/82
216 * Chris Kingsley, kingsley@cit-20.
217 *
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.
cf5c4ad8 222 * If PACK_MALLOC is defined, small blocks are 2^n bytes long.
8d063cd8 223 * This is designed for use in a program that uses vast quantities of memory,
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224 * but bombs when it runs out.
225 *
4eb8286e 226 * Modifications Copyright Ilya Zakharevich 1996-99.
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227 *
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.)
230 *
231 * Allocations of small blocks are now table-driven to many different
486ec47a 232 * buckets. Sizes of really big buckets are increased to accommodate
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233 * common size=power-of-2 blocks. Running-out-of-memory is made into
234 * an exception. Deeply configurable and thread-safe.
235 *
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236 */
237
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238#include "EXTERN.h"
239#define PERL_IN_MALLOC_C
240#include "perl.h"
241#if defined(PERL_IMPLICIT_CONTEXT)
cea2e8a9 242# define croak Perl_croak_nocontext
b022d2d2 243# define croak2 Perl_croak_nocontext
cea2e8a9 244# define warn Perl_warn_nocontext
b022d2d2 245# define warn2 Perl_warn_nocontext
b9e5552c 246#else
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247# define croak2 croak
248# define warn2 warn
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249#endif
250#ifdef USE_ITHREADS
22f7c9c9 251# define PERL_MAYBE_ALIVE PL_thr_key
d720c441 252#else
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253# define PERL_MAYBE_ALIVE 1
254#endif
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255
256#ifndef MUTEX_LOCK
257# define MUTEX_LOCK(l)
258#endif
259
260#ifndef MUTEX_UNLOCK
261# define MUTEX_UNLOCK(l)
262#endif
263
741df71a 264#ifndef MALLOC_LOCK
efc57feb 265# define MALLOC_LOCK MUTEX_LOCK(&PL_malloc_mutex)
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266#endif
267
268#ifndef MALLOC_UNLOCK
efc57feb 269# define MALLOC_UNLOCK MUTEX_UNLOCK(&PL_malloc_mutex)
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270#endif
271
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272# ifndef fatalcroak /* make depend */
273# define fatalcroak(mess) (write(2, (mess), strlen(mess)), exit(2))
274# endif
275
760ac839 276#ifdef DEBUGGING
e8bc2b5c 277# undef DEBUG_m
51a5ed28 278# define DEBUG_m(a) \
0b250b9e 279 STMT_START { \
22f7c9c9 280 if (PERL_MAYBE_ALIVE && PERL_GET_THX) { \
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281 dTHX; \
282 if (DEBUG_m_TEST) { \
283 PL_debug &= ~DEBUG_m_FLAG; \
284 a; \
285 PL_debug |= DEBUG_m_FLAG; \
286 } \
287 } \
0b250b9e 288 } STMT_END
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289#endif
290
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291#ifdef PERL_IMPLICIT_CONTEXT
292# define PERL_IS_ALIVE aTHX
293#else
294# define PERL_IS_ALIVE TRUE
295#endif
296
297
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298/*
299 * Layout of memory:
300 * ~~~~~~~~~~~~~~~~
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.)
305 *
4ad56ec9 306 * Moreover, since the algorithm may try to "bite" smaller blocks out
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307 * of unused bigger ones, there are also regions of "irregular" size,
308 * managed separately, by a linked list chunk_chain.
309 *
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.
312 *
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.
319 *
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
322 * memory.
323 *
324 * Management of last_op:
325 * ~~~~~~~~~~~~~~~~~~~~~
326 *
327 * free() never changes the boundaries of blocks, so is not relevant.
328 *
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.
333 *
334 * malloc() may change blocks by calling morecore() only.
335 *
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();
344 *
345 * getpages() creates a new block. It marks last_op at the bottom of
346 * the chunk of memory it returns.
347 *
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.
354 *
355 * Flaws:
356 * ~~~~~
357 * get_from_bigger_buckets(): forget to increment price => Quite
358 * aggressive.
359 */
360
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361/* I don't much care whether these are defined in sys/types.h--LAW */
362
363#define u_char unsigned char
364#define u_int unsigned int
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365/*
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
369 */
135863df 370#define u_short unsigned short
8d063cd8 371
562aee6b 372#if defined(RCHECK) && defined(PACK_MALLOC)
e8bc2b5c 373# undef PACK_MALLOC
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374#endif
375
8d063cd8 376/*
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377 * The description below is applicable if PACK_MALLOC is not defined.
378 *
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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.
386 */
387union overhead {
388 union overhead *ov_next; /* when free */
85e6fe83 389#if MEM_ALIGNBYTES > 4
c623bd54 390 double strut; /* alignment problems */
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391# if MEM_ALIGNBYTES > 8
392 char sstrut[MEM_ALIGNBYTES]; /* for the sizing */
393# endif
a687059c 394#endif
8d063cd8 395 struct {
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396/*
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
399 * MachTen.
400 */
8d063cd8 401 u_char ovu_index; /* bucket # */
b72ff565 402 u_char ovu_magic; /* magic number */
8d063cd8 403#ifdef RCHECK
d0bbed78 404 /* Subtract one to fit into u_short for an extra bucket */
22f7c9c9 405 u_short ovu_size; /* block size (requested + overhead - 1) */
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406 u_int ovu_rmagic; /* range magic number */
407#endif
408 } ovu;
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
413};
414
415#define MAGIC 0xff /* magic # on accounting info */
416#define RMAGIC 0x55555555 /* magic # on range info */
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417#define RMAGIC_C 0x55 /* magic # on range info */
418
8d063cd8 419#ifdef RCHECK
d0bbed78 420# define RMAGIC_SZ sizeof (u_int) /* Overhead at end of bucket */
c2a5c2d2 421# ifdef TWO_POT_OPTIMIZE
22f7c9c9 422# define MAX_SHORT_BUCKET (12 * BUCKETS_PER_POW2) /* size-1 fits in short */
c2a5c2d2 423# else
e8bc2b5c 424# define MAX_SHORT_BUCKET (13 * BUCKETS_PER_POW2)
c2a5c2d2 425# endif
8d063cd8 426#else
d0bbed78 427# define RMAGIC_SZ 0
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428#endif
429
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430#if !defined(PACK_MALLOC) && defined(BUCKETS_ROOT2)
431# undef BUCKETS_ROOT2
432#endif
433
434#ifdef BUCKETS_ROOT2
435# define BUCKET_TABLE_SHIFT 2
436# define BUCKET_POW2_SHIFT 1
437# define BUCKETS_PER_POW2 2
438#else
439# define BUCKET_TABLE_SHIFT MIN_BUC_POW2
440# define BUCKET_POW2_SHIFT 0
441# define BUCKETS_PER_POW2 1
442#endif
443
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444#if !defined(MEM_ALIGNBYTES) || ((MEM_ALIGNBYTES > 4) && !defined(STRICT_ALIGNMENT))
445/* Figure out the alignment of void*. */
446struct aligner {
447 char c;
448 void *p;
449};
8c2f25b1 450# define ALIGN_SMALL ((IV)((caddr_t)&(((struct aligner*)0)->p)))
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451#else
452# define ALIGN_SMALL MEM_ALIGNBYTES
453#endif
454
455#define IF_ALIGN_8(yes,no) ((ALIGN_SMALL>4) ? (yes) : (no))
456
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457#ifdef BUCKETS_ROOT2
458# define MAX_BUCKET_BY_TABLE 13
a3b680e6 459static const u_short buck_size[MAX_BUCKET_BY_TABLE + 1] =
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460 {
461 0, 0, 0, 0, 4, 4, 8, 12, 16, 24, 32, 48, 64, 80,
462 };
d0bbed78 463# define BUCKET_SIZE_NO_SURPLUS(i) ((i) % 2 ? buck_size[i] : (1 << ((i) >> BUCKET_POW2_SHIFT)))
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464# define BUCKET_SIZE_REAL(i) ((i) <= MAX_BUCKET_BY_TABLE \
465 ? buck_size[i] \
466 : ((1 << ((i) >> BUCKET_POW2_SHIFT)) \
467 - MEM_OVERHEAD(i) \
468 + POW2_OPTIMIZE_SURPLUS(i)))
469#else
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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))
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473#endif
474
475
cf5c4ad8 476#ifdef PACK_MALLOC
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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.
480 *
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
483 * layouts of arenas:
484 *
485 * # One chunk only, chunksize 2^k + SOMETHING - ALIGN, k >= 11
486 *
487 * INDEX MAGIC1 UNUSED CHUNK1
488 *
489 * # Multichunk with sanity checking and chunksize 2^k-ALIGN, k>7
490 *
491 * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 CHUNK2 CHUNK3 ...
492 *
493 * # Multichunk with sanity checking and size 2^k-ALIGN, k=7
494 *
495 * INDEX MAGIC1 MAGIC2 MAGIC3 UNUSED CHUNK1 UNUSED CHUNK2 CHUNK3 ...
496 *
497 * # Multichunk with sanity checking and size up to 80
498 *
499 * INDEX UNUSED MAGIC1 UNUSED MAGIC2 UNUSED ... CHUNK1 CHUNK2 CHUNK3 ...
500 *
501 * # No sanity check (usually up to 48=byte-long buckets)
502 * INDEX UNUSED CHUNK1 CHUNK2 ...
503 *
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
486ec47a 509 * (to make size of big CHUNK accommodate allocations for powers of two
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510 * better).
511 *
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.
519 *
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.]
524 *
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.
531 *
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.
537 *
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) +
543 * ADDOFFSET.
544 *
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.
548 *
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.
555 *
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.]
561 *
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).
cf5c4ad8 567 *
4ad56ec9
IZ
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.)
cf5c4ad8 571 *
4ad56ec9
IZ
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
575 * arena.
576 *
577 * The algo of OV_MAGIC(block,bucket) keeps ADDOFFSET 0 until
578 * chunksize of 64, then makes it 1.
cf5c4ad8 579 *
4ad56ec9
IZ
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). */
e8bc2b5c
GS
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)
56431972
RB
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)))
cf5c4ad8
PP
599# define OV_INDEX(block) (*OV_INDEXp(block))
600# define OV_MAGIC(block,bucket) (*(OV_INDEXp(block) + \
e8bc2b5c
GS
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. */
608# else
609# define MIN_NEEDS_SHIFT (7*BUCKETS_PER_POW2) /* Shift 128 greater than chunk 32. */
610# endif
cf5c4ad8
PP
611# define CHUNK_SHIFT 0
612
e8bc2b5c
GS
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 \
d0bbed78 617 ? ((1<<LOG_OF_MIN_ARENA) - 1)/BUCKET_SIZE_NO_SURPLUS(bucket) \
e8bc2b5c
GS
618 : n_blks[bucket] )
619#else
620# define N_BLKS(bucket) n_blks[bucket]
621#endif
622
a3b680e6 623static const u_short n_blks[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
e8bc2b5c
GS
624 {
625# if BUCKETS_PER_POW2==1
626 0, 0,
627 (MIN_BUC_POW2==2 ? 384 : 0),
628 224, 120, 62, 31, 16, 8, 4, 2
629# else
630 0, 0, 0, 0,
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
633# endif
634 };
635
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) \
d0bbed78 640 - BUCKET_SIZE_NO_SURPLUS(bucket) * N_BLKS(bucket)) \
e8bc2b5c
GS
641 : blk_shift[bucket])
642#else
643# define BLK_SHIFT(bucket) blk_shift[bucket]
644#endif
645
a3b680e6 646static const u_short blk_shift[LOG_OF_MIN_ARENA * BUCKETS_PER_POW2] =
e8bc2b5c
GS
647 {
648# if BUCKETS_PER_POW2==1
649 0, 0,
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),
656# else
657 0, 0, 0, 0,
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),
664# endif
665 };
cf5c4ad8 666
5bbd1ef5
IZ
667# define NEEDED_ALIGNMENT 0x800 /* 2k boundaries */
668# define WANTED_ALIGNMENT 0x800 /* 2k boundaries */
669
cf5c4ad8
PP
670#else /* !PACK_MALLOC */
671
672# define OV_MAGIC(block,bucket) (block)->ov_magic
673# define OV_INDEX(block) (block)->ov_index
674# define CHUNK_SHIFT 1
e8bc2b5c 675# define MAX_PACKED -1
5bbd1ef5
IZ
676# define NEEDED_ALIGNMENT MEM_ALIGNBYTES
677# define WANTED_ALIGNMENT 0x400 /* 1k boundaries */
678
cf5c4ad8
PP
679#endif /* !PACK_MALLOC */
680
d0bbed78 681#define M_OVERHEAD (sizeof(union overhead) + RMAGIC_SZ) /* overhead at start+end */
e8bc2b5c
GS
682
683#ifdef PACK_MALLOC
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
691# else
692# define SIZE_TABLE_MAX 64
693# endif
a3b680e6 694static const char bucket_of[] =
e8bc2b5c
GS
695 {
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 */
699 6, /* 8 */
274c7500 700 IF_ALIGN_8(8,7), 8, /* 16/12, 16 */
e8bc2b5c
GS
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),
709 3,
710 4, 4,
711 5, 5, 5, 5,
712 6, 6, 6, 6,
713 6, 6, 6, 6
714# endif /* !BUCKETS_ROOT2 */
715 };
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
724# endif
725# define START_SHIFTS_BUCKET MIN_BUCKET
726# define START_SHIFT (MIN_BUC_POW2 - 1)
727#endif /* !PACK_MALLOC */
cf5c4ad8 728
8d063cd8 729/*
55497cff
PP
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.
732 */
733
734#ifdef TWO_POT_OPTIMIZE
735
5f05dabc
PP
736# ifndef PERL_PAGESIZE
737# define PERL_PAGESIZE 4096
738# endif
e8bc2b5c
GS
739# ifndef FIRST_BIG_POW2
740# define FIRST_BIG_POW2 15 /* 32K, 16K is used too often. */
5f05dabc 741# endif
e8bc2b5c 742# define FIRST_BIG_BLOCK (1<<FIRST_BIG_POW2)
55497cff
PP
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)
747
e8bc2b5c
GS
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)
752
753#else /* !TWO_POT_OPTIMIZE */
754# define POW2_OPTIMIZE_ADJUST(nbytes)
755# define POW2_OPTIMIZE_SURPLUS(bucket) 0
756#endif /* !TWO_POT_OPTIMIZE */
757
39c0d7ee 758#define BARK_64K_LIMIT(what,nbytes,size)
55497cff 759
e8bc2b5c
GS
760#ifndef MIN_SBRK
761# define MIN_SBRK 2048
762#endif
763
764#ifndef FIRST_SBRK
d720c441 765# define FIRST_SBRK (48*1024)
e8bc2b5c
GS
766#endif
767
768/* Minimal sbrk in percents of what is already alloced. */
769#ifndef MIN_SBRK_FRAC
770# define MIN_SBRK_FRAC 3
771#endif
772
773#ifndef SBRK_ALLOW_FAILURES
774# define SBRK_ALLOW_FAILURES 3
775#endif
55497cff 776
e8bc2b5c
GS
777#ifndef SBRK_FAILURE_PRICE
778# define SBRK_FAILURE_PRICE 50
55497cff
PP
779#endif
780
5aaab254 781static void morecore (int bucket);
24dd13bf 782# if defined(DEBUGGING)
9dbded1f 783static void botch (const char *diag, const char *s, const char *file, int line);
24dd13bf
JH
784# endif
785static void add_to_chain (void *p, MEM_SIZE size, MEM_SIZE chip);
786static void* get_from_chain (MEM_SIZE size);
787static void* get_from_bigger_buckets(int bucket, MEM_SIZE size);
788static union overhead *getpages (MEM_SIZE needed, int *nblksp, int bucket);
789static int getpages_adjacent(MEM_SIZE require);
790
3541dd58 791#ifdef I_MACH_CTHREADS
772fe5b3
HM
792# undef MUTEX_LOCK
793# define MUTEX_LOCK(m) STMT_START { if (*m) mutex_lock(*m); } STMT_END
794# undef MUTEX_UNLOCK
795# define MUTEX_UNLOCK(m) STMT_START { if (*m) mutex_unlock(*m); } STMT_END
3541dd58
HM
796#endif
797
22f7c9c9
JH
798#ifndef PTRSIZE
799# define PTRSIZE sizeof(void*)
800#endif
801
b022d2d2
IZ
802#ifndef BITS_IN_PTR
803# define BITS_IN_PTR (8*PTRSIZE)
804#endif
805
806/*
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.
810 */
811#define NBUCKETS (BITS_IN_PTR*BUCKETS_PER_POW2 + 1)
812static union overhead *nextf[NBUCKETS];
813
814#if defined(PURIFY) && !defined(USE_PERL_SBRK)
815# define USE_PERL_SBRK
816#endif
817
818#ifdef USE_PERL_SBRK
3f270f98 819# define sbrk(a) Perl_sbrk(a)
b022d2d2 820Malloc_t Perl_sbrk (int size);
b022d2d2 821#else
3f270f98 822# ifndef HAS_SBRK_PROTO /* <unistd.h> usually takes care of this */
b022d2d2 823extern Malloc_t sbrk(int);
3f270f98 824# endif
ef9f17be 825#endif
b022d2d2 826
22f7c9c9
JH
827#ifndef MIN_SBRK_FRAC1000 /* Backward compatibility */
828# define MIN_SBRK_FRAC1000 (MIN_SBRK_FRAC * 10)
829#endif
830
831#ifndef START_EXTERN_C
832# ifdef __cplusplus
833# define START_EXTERN_C extern "C" {
834# else
835# define START_EXTERN_C
836# endif
837#endif
838
839#ifndef END_EXTERN_C
840# ifdef __cplusplus
841# define END_EXTERN_C };
842# else
843# define END_EXTERN_C
844# endif
845#endif
846
847#include "malloc_ctl.h"
848
849#ifndef NO_MALLOC_DYNAMIC_CFG
850# define PERL_MALLOC_OPT_CHARS "FMfAPGdac"
851
41ad8e42
JH
852# ifndef FILL_DEAD_DEFAULT
853# define FILL_DEAD_DEFAULT 1
854# endif
855# ifndef FILL_ALIVE_DEFAULT
856# define FILL_ALIVE_DEFAULT 1
857# endif
858# ifndef FILL_CHECK_DEFAULT
859# define FILL_CHECK_DEFAULT 1
860# endif
861
22f7c9c9
JH
862static IV MallocCfg[MallocCfg_last] = {
863 FIRST_SBRK,
864 MIN_SBRK,
865 MIN_SBRK_FRAC,
866 SBRK_ALLOW_FAILURES,
867 SBRK_FAILURE_PRICE,
868 SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE, /* sbrk_goodness */
41ad8e42
JH
869 FILL_DEAD_DEFAULT, /* FILL_DEAD */
870 FILL_ALIVE_DEFAULT, /* FILL_ALIVE */
871 FILL_CHECK_DEFAULT, /* FILL_CHECK */
22f7c9c9
JH
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 */
877};
878IV *MallocCfg_ptr = MallocCfg;
879
6af660ee
IZ
880static char* MallocCfgP[MallocCfg_last] = {
881 0, /* MallocCfgP_emergency_buffer */
882 0, /* MallocCfgP_emergency_buffer_prepared */
883};
884char **MallocCfgP_ptr = MallocCfgP;
885
22f7c9c9
JH
886# undef MIN_SBRK
887# undef FIRST_SBRK
888# undef MIN_SBRK_FRAC1000
889# undef SBRK_ALLOW_FAILURES
890# undef SBRK_FAILURE_PRICE
891
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]
897
898# define sbrk_goodness MallocCfg[MallocCfg_sbrk_goodness]
899
900# define emergency_buffer_size MallocCfg[MallocCfg_emergency_buffer_size]
901# define emergency_buffer_last_req MallocCfg[MallocCfg_emergency_buffer_last_req]
902
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)
907
6af660ee
IZ
908# define emergency_buffer MallocCfgP[MallocCfgP_emergency_buffer]
909# define emergency_buffer_prepared MallocCfgP[MallocCfgP_emergency_buffer_prepared]
910
22f7c9c9
JH
911#else /* defined(NO_MALLOC_DYNAMIC_CFG) */
912
913# define FILL_DEAD 1
914# define FILL_ALIVE 1
915# define FILL_CHECK 1
916static int sbrk_goodness = SBRK_ALLOW_FAILURES * SBRK_FAILURE_PRICE;
917
918# define NO_PERL_MALLOC_ENV
919
920#endif
921
b022d2d2
IZ
922#ifdef DEBUGGING_MSTATS
923/*
924 * nmalloc[i] is the difference between the number of mallocs and frees
925 * for a given block size.
926 */
927static u_int nmalloc[NBUCKETS];
928static u_int sbrk_slack;
929static u_int start_slack;
930#else /* !( defined DEBUGGING_MSTATS ) */
931# define sbrk_slack 0
932#endif
933
934static u_int goodsbrk;
935
22f7c9c9 936#ifdef PERL_EMERGENCY_SBRK
febabd2a
DD
937
938# ifndef BIG_SIZE
939# define BIG_SIZE (1<<16) /* 64K */
940# endif
941
22f7c9c9 942# ifdef NO_MALLOC_DYNAMIC_CFG
55497cff 943static MEM_SIZE emergency_buffer_size;
22f7c9c9
JH
944 /* 0 if the last request for more memory succeeded.
945 Otherwise the size of the failing request. */
946static MEM_SIZE emergency_buffer_last_req;
6af660ee
IZ
947static char *emergency_buffer;
948static char *emergency_buffer_prepared;
22f7c9c9
JH
949# endif
950
951# ifndef emergency_sbrk_croak
952# define emergency_sbrk_croak croak2
953# endif
954
22f7c9c9
JH
955static char *
956perl_get_emergency_buffer(IV *size)
957{
958 dTHX;
959 /* First offense, give a possibility to recover by dieing. */
960 /* No malloc involved here: */
22f7c9c9
JH
961 SV *sv;
962 char *pv;
a4fc7abc 963 GV **gvp = (GV**)hv_fetchs(PL_defstash, "^M", FALSE);
22f7c9c9 964
a4fc7abc 965 if (!gvp) gvp = (GV**)hv_fetchs(PL_defstash, "\015", FALSE);
22f7c9c9
JH
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: */
4b1c440c 970 pv = SvPV_nolen(sv);
22f7c9c9
JH
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 */
975 }
976
977 SvPOK_off(sv);
bd61b366 978 SvPV_set(sv, NULL);
87a1ef3d
SP
979 SvCUR_set(sv, 0);
980 SvLEN_set(sv, 0);
22f7c9c9
JH
981 *size = malloced_size(pv) + M_OVERHEAD;
982 return pv - sizeof(union overhead);
983}
b9e5552c 984# define PERL_GET_EMERGENCY_BUFFER(p) perl_get_emergency_buffer(p)
22f7c9c9
JH
985
986# ifndef NO_MALLOC_DYNAMIC_CFG
987static char *
988get_emergency_buffer(IV *size)
989{
990 char *pv = emergency_buffer_prepared;
991
992 *size = MallocCfg[MallocCfg_emergency_buffer_prepared_size];
993 emergency_buffer_prepared = 0;
994 MallocCfg[MallocCfg_emergency_buffer_prepared_size] = 0;
995 return pv;
996}
997
22f7c9c9
JH
998# define GET_EMERGENCY_BUFFER(p) get_emergency_buffer(p)
999# else /* NO_MALLOC_DYNAMIC_CFG */
1000# define GET_EMERGENCY_BUFFER(p) NULL
22f7c9c9 1001# endif
55497cff 1002
cea2e8a9
GS
1003static Malloc_t
1004emergency_sbrk(MEM_SIZE size)
55497cff 1005{
28ac10b1
IZ
1006 MEM_SIZE rsize = (((size - 1)>>LOG_OF_MIN_ARENA) + 1)<<LOG_OF_MIN_ARENA;
1007
22f7c9c9 1008 if (size >= BIG_SIZE
575fbe19
SH
1009 && (!emergency_buffer_last_req ||
1010 (size < (MEM_SIZE)emergency_buffer_last_req))) {
b022d2d2 1011 /* Give the possibility to recover, but avoid an infinite cycle. */
741df71a 1012 MALLOC_UNLOCK;
22f7c9c9
JH
1013 emergency_buffer_last_req = size;
1014 emergency_sbrk_croak("Out of memory during \"large\" request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
55497cff
PP
1015 }
1016
575fbe19 1017 if ((MEM_SIZE)emergency_buffer_size >= rsize) {
28ac10b1
IZ
1018 char *old = emergency_buffer;
1019
1020 emergency_buffer_size -= rsize;
1021 emergency_buffer += rsize;
1022 return old;
1023 } else {
55497cff
PP
1024 /* First offense, give a possibility to recover by dieing. */
1025 /* No malloc involved here: */
22f7c9c9
JH
1026 IV Size;
1027 char *pv = GET_EMERGENCY_BUFFER(&Size);
28ac10b1 1028 int have = 0;
55497cff 1029
28ac10b1
IZ
1030 if (emergency_buffer_size) {
1031 add_to_chain(emergency_buffer, emergency_buffer_size, 0);
1032 emergency_buffer_size = 0;
bd61b366 1033 emergency_buffer = NULL;
28ac10b1
IZ
1034 have = 1;
1035 }
22f7c9c9
JH
1036
1037 if (!pv)
1038 pv = PERL_GET_EMERGENCY_BUFFER(&Size);
1039 if (!pv) {
28ac10b1
IZ
1040 if (have)
1041 goto do_croak;
55497cff 1042 return (char *)-1; /* Now die die die... */
28ac10b1 1043 }
22f7c9c9 1044
55497cff 1045 /* Check alignment: */
22f7c9c9
JH
1046 if (PTR2UV(pv) & (NEEDED_ALIGNMENT - 1)) {
1047 dTHX;
1048
55497cff 1049 PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");
bbce6d69 1050 return (char *)-1; /* die die die */
55497cff
PP
1051 }
1052
22f7c9c9
JH
1053 emergency_buffer = pv;
1054 emergency_buffer_size = Size;
55497cff 1055 }
28ac10b1 1056 do_croak:
741df71a 1057 MALLOC_UNLOCK;
22f7c9c9 1058 emergency_sbrk_croak("Out of memory during request for %"UVuf" bytes, total sbrk() is %"UVuf" bytes", (UV)size, (UV)(goodsbrk + sbrk_slack));
118e2215 1059 assert(0); /* NOTREACHED */
bd61b366 1060 return NULL;
55497cff
PP
1061}
1062
22f7c9c9 1063#else /* !defined(PERL_EMERGENCY_SBRK) */
55497cff 1064# define emergency_sbrk(size) -1
22f7c9c9
JH
1065#endif /* defined PERL_EMERGENCY_SBRK */
1066
7cd83f65 1067/* Don't use PerlIO buffered writes as they allocate memory. */
acfd4d8e 1068#define MYMALLOC_WRITE2STDERR(s) PERL_UNUSED_RESULT(PerlLIO_write(PerlIO_fileno(PerlIO_stderr()),s,strlen(s)))
55497cff 1069
760ac839 1070#ifdef DEBUGGING
3541dd58 1071#undef ASSERT
e7e7e0a5
DM
1072#define ASSERT(p,diag) if (!(p)) botch(diag,STRINGIFY(p),__FILE__,__LINE__);
1073
cea2e8a9 1074static void
9dbded1f 1075botch(const char *diag, const char *s, const char *file, int line)
8d063cd8 1076{
899be101 1077 dVAR;
9dbded1f 1078 dTHX;
22f7c9c9
JH
1079 if (!(PERL_MAYBE_ALIVE && PERL_GET_THX))
1080 goto do_write;
1081 else {
22f7c9c9 1082 if (PerlIO_printf(PerlIO_stderr(),
67920cb2 1083 "assertion botched (%s?): %s %s:%d\n",
066d1a89 1084 diag, s, file, line) != 0) {
22f7c9c9 1085 do_write: /* Can be initializing interpreter */
7cd83f65
CB
1086 MYMALLOC_WRITE2STDERR("assertion botched (");
1087 MYMALLOC_WRITE2STDERR(diag);
1088 MYMALLOC_WRITE2STDERR("?): ");
1089 MYMALLOC_WRITE2STDERR(s);
1090 MYMALLOC_WRITE2STDERR(" (");
1091 MYMALLOC_WRITE2STDERR(file);
1092 MYMALLOC_WRITE2STDERR(":");
6bf964e1
JH
1093 {
1094 char linebuf[10];
1095 char *s = linebuf + sizeof(linebuf) - 1;
1096 int n = line;
1097 *s = 0;
1098 do {
1099 *--s = '0' + (n % 10);
1100 } while (n /= 10);
7cd83f65 1101 MYMALLOC_WRITE2STDERR(s);
6bf964e1 1102 }
7cd83f65 1103 MYMALLOC_WRITE2STDERR(")\n");
22f7c9c9 1104 }
3028581b 1105 PerlProc_abort();
22f7c9c9 1106 }
8d063cd8
LW
1107}
1108#else
3541dd58 1109#define ASSERT(p, diag)
8d063cd8
LW
1110#endif
1111
22f7c9c9
JH
1112#ifdef MALLOC_FILL
1113/* Fill should be long enough to cover long */
1114static void
1115fill_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1116{
1117 unsigned char *e = s + nbytes;
1118 long *lp;
b464bac0 1119 const long lfill = *(long*)fill;
22f7c9c9
JH
1120
1121 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1122 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1123 unsigned const char *f = fill + sizeof(long) - shift;
1124 unsigned char *e1 = s + shift;
1125
1126 while (s < e1)
1127 *s++ = *f++;
1128 }
1129 lp = (long*)s;
1130 while ((unsigned char*)(lp + 1) <= e)
1131 *lp++ = lfill;
1132 s = (unsigned char*)lp;
1133 while (s < e)
1134 *s++ = *fill++;
1135}
1136/* Just malloc()ed */
1137static const unsigned char fill_feedadad[] =
1138 {0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD,
1139 0xFE, 0xED, 0xAD, 0xAD, 0xFE, 0xED, 0xAD, 0xAD};
1140/* Just free()ed */
1141static const unsigned char fill_deadbeef[] =
1142 {0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF,
1143 0xDE, 0xAD, 0xBE, 0xEF, 0xDE, 0xAD, 0xBE, 0xEF};
1144# define FILL_DEADBEEF(s, n) \
1145 (void)(FILL_DEAD? (fill_pat_4bytes((s), (n), fill_deadbeef), 0) : 0)
1146# define FILL_FEEDADAD(s, n) \
1147 (void)(FILL_ALIVE? (fill_pat_4bytes((s), (n), fill_feedadad), 0) : 0)
1148#else
1149# define FILL_DEADBEEF(s, n) ((void)0)
1150# define FILL_FEEDADAD(s, n) ((void)0)
1151# undef MALLOC_FILL_CHECK
1152#endif
1153
1154#ifdef MALLOC_FILL_CHECK
1155static int
1156cmp_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
1157{
1158 unsigned char *e = s + nbytes;
1159 long *lp;
b464bac0 1160 const long lfill = *(long*)fill;
22f7c9c9
JH
1161
1162 if (PTR2UV(s) & (sizeof(long)-1)) { /* Align the pattern */
1163 int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
1164 unsigned const char *f = fill + sizeof(long) - shift;
1165 unsigned char *e1 = s + shift;
1166
1167 while (s < e1)
1168 if (*s++ != *f++)
1169 return 1;
1170 }
1171 lp = (long*)s;
1172 while ((unsigned char*)(lp + 1) <= e)
1173 if (*lp++ != lfill)
1174 return 1;
1175 s = (unsigned char*)lp;
1176 while (s < e)
1177 if (*s++ != *fill++)
1178 return 1;
1179 return 0;
1180}
1181# define FILLCHECK_DEADBEEF(s, n) \
1182 ASSERT(!FILL_CHECK || !cmp_pat_4bytes(s, n, fill_deadbeef), \
1183 "free()ed/realloc()ed-away memory was overwritten")
1184#else
1185# define FILLCHECK_DEADBEEF(s, n) ((void)0)
1186#endif
1187
03f05cb4 1188STATIC int
0eccc83d 1189S_adjust_size_and_find_bucket(size_t *nbytes_p)
8d063cd8 1190{
03f05cb4 1191 MEM_SIZE shiftr;
64107180 1192 int bucket;
03f05cb4
LM
1193 size_t nbytes;
1194
1195 PERL_ARGS_ASSERT_ADJUST_SIZE_AND_FIND_BUCKET;
1196
1197 nbytes = *nbytes_p;
45d8adaa 1198
8d063cd8
LW
1199 /*
1200 * Convert amount of memory requested into
1201 * closest block size stored in hash buckets
1202 * which satisfies request. Account for
1203 * space used per block for accounting.
1204 */
cf5c4ad8 1205#ifdef PACK_MALLOC
e8bc2b5c
GS
1206# ifdef SMALL_BUCKET_VIA_TABLE
1207 if (nbytes == 0)
1208 bucket = MIN_BUCKET;
1209 else if (nbytes <= SIZE_TABLE_MAX) {
1210 bucket = bucket_of[(nbytes - 1) >> BUCKET_TABLE_SHIFT];
1211 } else
1212# else
043bf814
RB
1213 if (nbytes == 0)
1214 nbytes = 1;
e8bc2b5c
GS
1215 if (nbytes <= MAX_POW2_ALGO) goto do_shifts;
1216 else
1217# endif
55497cff 1218#endif
e8bc2b5c
GS
1219 {
1220 POW2_OPTIMIZE_ADJUST(nbytes);
1221 nbytes += M_OVERHEAD;
1222 nbytes = (nbytes + 3) &~ 3;
516a5887 1223#if defined(PACK_MALLOC) && !defined(SMALL_BUCKET_VIA_TABLE)
e8bc2b5c 1224 do_shifts:
516a5887 1225#endif
e8bc2b5c
GS
1226 shiftr = (nbytes - 1) >> START_SHIFT;
1227 bucket = START_SHIFTS_BUCKET;
1228 /* apart from this loop, this is O(1) */
1229 while (shiftr >>= 1)
1230 bucket += BUCKETS_PER_POW2;
cf5c4ad8 1231 }
64107180
NC
1232 *nbytes_p = nbytes;
1233 return bucket;
1234}
1235
1236Malloc_t
1237Perl_malloc(size_t nbytes)
1238{
1239 dVAR;
eb578fdb
KW
1240 union overhead *p;
1241 int bucket;
64107180
NC
1242
1243#if defined(DEBUGGING) || defined(RCHECK)
1244 MEM_SIZE size = nbytes;
1245#endif
1246
1247 BARK_64K_LIMIT("Allocation",nbytes,nbytes);
1248#ifdef DEBUGGING
1249 if ((long)nbytes < 0)
1250 croak("%s", "panic: malloc");
1251#endif
1252
03f05cb4 1253 bucket = adjust_size_and_find_bucket(&nbytes);
4ad56ec9 1254 MALLOC_LOCK;
8d063cd8
LW
1255 /*
1256 * If nothing in hash bucket right now,
1257 * request more memory from the system.
1258 */
1259 if (nextf[bucket] == NULL)
1260 morecore(bucket);
e8bc2b5c 1261 if ((p = nextf[bucket]) == NULL) {
741df71a 1262 MALLOC_UNLOCK;
0b250b9e
GS
1263 {
1264 dTHX;
1265 if (!PL_nomemok) {
febabd2a 1266#if defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC)
7cd83f65 1267 MYMALLOC_WRITE2STDERR("Out of memory!\n");
febabd2a 1268#else
b022d2d2
IZ
1269 char buff[80];
1270 char *eb = buff + sizeof(buff) - 1;
1271 char *s = eb;
1272 size_t n = nbytes;
1273
7cd83f65 1274 MYMALLOC_WRITE2STDERR("Out of memory during request for ");
b022d2d2
IZ
1275#if defined(DEBUGGING) || defined(RCHECK)
1276 n = size;
1277#endif
1278 *s = 0;
1279 do {
1280 *--s = '0' + (n % 10);
1281 } while (n /= 10);
7cd83f65
CB
1282 MYMALLOC_WRITE2STDERR(s);
1283 MYMALLOC_WRITE2STDERR(" bytes, total sbrk() is ");
b022d2d2
IZ
1284 s = eb;
1285 n = goodsbrk + sbrk_slack;
1286 do {
1287 *--s = '0' + (n % 10);
1288 } while (n /= 10);
7cd83f65
CB
1289 MYMALLOC_WRITE2STDERR(s);
1290 MYMALLOC_WRITE2STDERR(" bytes!\n");
febabd2a 1291#endif /* defined(PLAIN_MALLOC) && defined(NO_FANCY_MALLOC) */
0b250b9e
GS
1292 my_exit(1);
1293 }
ee0007ab 1294 }
4ad56ec9 1295 return (NULL);
45d8adaa
LW
1296 }
1297
8d063cd8 1298 /* remove from linked list */
22f7c9c9
JH
1299#ifdef DEBUGGING
1300 if ( (PTR2UV(p) & (MEM_ALIGNBYTES - 1))
1301 /* Can't get this low */
1302 || (p && PTR2UV(p) < (1<<LOG_OF_MIN_ARENA)) ) {
e8cd8248 1303 dTHX;
b900a521 1304 PerlIO_printf(PerlIO_stderr(),
7fa2f4f1
GS
1305 "Unaligned pointer in the free chain 0x%"UVxf"\n",
1306 PTR2UV(p));
1307 }
22f7c9c9
JH
1308 if ( (PTR2UV(p->ov_next) & (MEM_ALIGNBYTES - 1))
1309 || (p->ov_next && PTR2UV(p->ov_next) < (1<<LOG_OF_MIN_ARENA)) ) {
e8cd8248 1310 dTHX;
7fa2f4f1 1311 PerlIO_printf(PerlIO_stderr(),
a0288114 1312 "Unaligned \"next\" pointer in the free "
d2560b70 1313 "chain 0x%"UVxf" at 0x%"UVxf"\n",
7fa2f4f1 1314 PTR2UV(p->ov_next), PTR2UV(p));
32e30700 1315 }
bf38876a
LW
1316#endif
1317 nextf[bucket] = p->ov_next;
4ad56ec9
IZ
1318
1319 MALLOC_UNLOCK;
1320
51a5ed28
HS
1321 DEBUG_m(PerlIO_printf(Perl_debug_log,
1322 "0x%"UVxf": (%05lu) malloc %ld bytes\n",
253fdc3f 1323 PTR2UV((Malloc_t)(p + CHUNK_SHIFT)), (unsigned long)(PL_an++),
51a5ed28
HS
1324 (long)size));
1325
22f7c9c9 1326 FILLCHECK_DEADBEEF((unsigned char*)(p + CHUNK_SHIFT),
d0bbed78 1327 BUCKET_SIZE_REAL(bucket) + RMAGIC_SZ);
22f7c9c9 1328
e8bc2b5c
GS
1329#ifdef IGNORE_SMALL_BAD_FREE
1330 if (bucket >= FIRST_BUCKET_WITH_CHECK)
1331#endif
1332 OV_MAGIC(p, bucket) = MAGIC;
cf5c4ad8
PP
1333#ifndef PACK_MALLOC
1334 OV_INDEX(p) = bucket;
1335#endif
8d063cd8
LW
1336#ifdef RCHECK
1337 /*
1338 * Record allocated size of block and
1339 * bound space with magic numbers.
1340 */
8d063cd8 1341 p->ov_rmagic = RMAGIC;
e8bc2b5c
GS
1342 if (bucket <= MAX_SHORT_BUCKET) {
1343 int i;
1344
1345 nbytes = size + M_OVERHEAD;
1346 p->ov_size = nbytes - 1;
d0bbed78
IZ
1347 if ((i = nbytes & (RMAGIC_SZ-1))) {
1348 i = RMAGIC_SZ - i;
1349 while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
1350 ((caddr_t)p + nbytes - RMAGIC_SZ)[i] = RMAGIC_C;
e8bc2b5c 1351 }
d0bbed78
IZ
1352 /* Same at RMAGIC_SZ-aligned RMAGIC */
1353 nbytes = (nbytes + RMAGIC_SZ - 1) & ~(RMAGIC_SZ - 1);
1354 ((u_int *)((caddr_t)p + nbytes))[-1] = RMAGIC;
e8bc2b5c 1355 }
22f7c9c9 1356 FILL_FEEDADAD((unsigned char *)(p + CHUNK_SHIFT), size);
8d063cd8 1357#endif
cf5c4ad8 1358 return ((Malloc_t)(p + CHUNK_SHIFT));
8d063cd8
LW
1359}
1360
e8bc2b5c
GS
1361static char *last_sbrk_top;
1362static char *last_op; /* This arena can be easily extended. */
6e21dc91 1363static MEM_SIZE sbrked_remains;
e8bc2b5c
GS
1364
1365#ifdef DEBUGGING_MSTATS
1366static int sbrks;
1367#endif
1368
1369struct chunk_chain_s {
1370 struct chunk_chain_s *next;
1371 MEM_SIZE size;
1372};
1373static struct chunk_chain_s *chunk_chain;
1374static int n_chunks;
1375static char max_bucket;
1376
1377/* Cutoff a piece of one of the chunks in the chain. Prefer smaller chunk. */
cea2e8a9
GS
1378static void *
1379get_from_chain(MEM_SIZE size)
e8bc2b5c
GS
1380{
1381 struct chunk_chain_s *elt = chunk_chain, **oldp = &chunk_chain;
1382 struct chunk_chain_s **oldgoodp = NULL;
1383 long min_remain = LONG_MAX;
1384
1385 while (elt) {
1386 if (elt->size >= size) {
1387 long remains = elt->size - size;
1388 if (remains >= 0 && remains < min_remain) {
1389 oldgoodp = oldp;
1390 min_remain = remains;
1391 }
1392 if (remains == 0) {
1393 break;
1394 }
1395 }
1396 oldp = &( elt->next );
1397 elt = elt->next;
1398 }
1399 if (!oldgoodp) return NULL;
1400 if (min_remain) {
1401 void *ret = *oldgoodp;
1402 struct chunk_chain_s *next = (*oldgoodp)->next;
1403
1404 *oldgoodp = (struct chunk_chain_s *)((char*)ret + size);
1405 (*oldgoodp)->size = min_remain;
1406 (*oldgoodp)->next = next;
1407 return ret;
1408 } else {
1409 void *ret = *oldgoodp;
1410 *oldgoodp = (*oldgoodp)->next;
1411 n_chunks--;
1412 return ret;
1413 }
1414}
1415
cea2e8a9
GS
1416static void
1417add_to_chain(void *p, MEM_SIZE size, MEM_SIZE chip)
e8bc2b5c
GS
1418{
1419 struct chunk_chain_s *next = chunk_chain;
1420 char *cp = (char*)p;
1421
1422 cp += chip;
1423 chunk_chain = (struct chunk_chain_s *)cp;
1424 chunk_chain->size = size - chip;
1425 chunk_chain->next = next;
1426 n_chunks++;
1427}
1428
cea2e8a9
GS
1429static void *
1430get_from_bigger_buckets(int bucket, MEM_SIZE size)
e8bc2b5c
GS
1431{
1432 int price = 1;
1433 static int bucketprice[NBUCKETS];
1434 while (bucket <= max_bucket) {
1435 /* We postpone stealing from bigger buckets until we want it
1436 often enough. */
1437 if (nextf[bucket] && bucketprice[bucket]++ >= price) {
1438 /* Steal it! */
1439 void *ret = (void*)(nextf[bucket] - 1 + CHUNK_SHIFT);
1440 bucketprice[bucket] = 0;
1441 if (((char*)nextf[bucket]) - M_OVERHEAD == last_op) {
1442 last_op = NULL; /* Disable optimization */
1443 }
1444 nextf[bucket] = nextf[bucket]->ov_next;
1445#ifdef DEBUGGING_MSTATS
1446 nmalloc[bucket]--;
1447 start_slack -= M_OVERHEAD;
1448#endif
d0bbed78 1449 add_to_chain(ret, (BUCKET_SIZE_NO_SURPLUS(bucket) +
e8bc2b5c
GS
1450 POW2_OPTIMIZE_SURPLUS(bucket)),
1451 size);
1452 return ret;
1453 }
1454 bucket++;
1455 }
1456 return NULL;
1457}
1458
cea2e8a9 1459static union overhead *
c7374474 1460getpages(MEM_SIZE needed, int *nblksp, int bucket)
fa423c5b 1461{
899be101 1462 dVAR;
fa423c5b
IZ
1463 /* Need to do (possibly expensive) system call. Try to
1464 optimize it for rare calling. */
1465 MEM_SIZE require = needed - sbrked_remains;
1466 char *cp;
1467 union overhead *ovp;
c7374474 1468 MEM_SIZE slack = 0;
fa423c5b 1469
22f7c9c9 1470 if (sbrk_goodness > 0) {
575fbe19 1471 if (!last_sbrk_top && require < (MEM_SIZE)FIRST_SBRK)
fa423c5b 1472 require = FIRST_SBRK;
575fbe19 1473 else if (require < (MEM_SIZE)MIN_SBRK) require = MIN_SBRK;
fa423c5b 1474
8c2f25b1 1475 if (require < (Size_t)(goodsbrk * MIN_SBRK_FRAC1000 / 1000))
22f7c9c9 1476 require = goodsbrk * MIN_SBRK_FRAC1000 / 1000;
fa423c5b
IZ
1477 require = ((require - 1 + MIN_SBRK) / MIN_SBRK) * MIN_SBRK;
1478 } else {
1479 require = needed;
1480 last_sbrk_top = 0;
1481 sbrked_remains = 0;
1482 }
1483
1484 DEBUG_m(PerlIO_printf(Perl_debug_log,
1485 "sbrk(%ld) for %ld-byte-long arena\n",
1486 (long)require, (long) needed));
1487 cp = (char *)sbrk(require);
1488#ifdef DEBUGGING_MSTATS
1489 sbrks++;
1490#endif
1491 if (cp == last_sbrk_top) {
1492 /* Common case, anything is fine. */
22f7c9c9 1493 sbrk_goodness++;
fa423c5b 1494 ovp = (union overhead *) (cp - sbrked_remains);
e9397286 1495 last_op = cp - sbrked_remains;
fa423c5b
IZ
1496 sbrked_remains = require - (needed - sbrked_remains);
1497 } else if (cp == (char *)-1) { /* no more room! */
1498 ovp = (union overhead *)emergency_sbrk(needed);
1499 if (ovp == (union overhead *)-1)
1500 return 0;
e9397286
GS
1501 if (((char*)ovp) > last_op) { /* Cannot happen with current emergency_sbrk() */
1502 last_op = 0;
1503 }
fa423c5b
IZ
1504 return ovp;
1505 } else { /* Non-continuous or first sbrk(). */
1506 long add = sbrked_remains;
1507 char *newcp;
1508
1509 if (sbrked_remains) { /* Put rest into chain, we
1510 cannot use it right now. */
1511 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1512 sbrked_remains, 0);
1513 }
1514
1515 /* Second, check alignment. */
1516 slack = 0;
1517
5bbd1ef5
IZ
1518 /* WANTED_ALIGNMENT may be more than NEEDED_ALIGNMENT, but this may
1519 improve performance of memory access. */
56431972
RB
1520 if (PTR2UV(cp) & (WANTED_ALIGNMENT - 1)) { /* Not aligned. */
1521 slack = WANTED_ALIGNMENT - (PTR2UV(cp) & (WANTED_ALIGNMENT - 1));
fa423c5b
IZ
1522 add += slack;
1523 }
fa423c5b
IZ
1524
1525 if (add) {
1526 DEBUG_m(PerlIO_printf(Perl_debug_log,
1527 "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",
1528 (long)add, (long) slack,
1529 (long) sbrked_remains));
1530 newcp = (char *)sbrk(add);
1531#if defined(DEBUGGING_MSTATS)
1532 sbrks++;
1533 sbrk_slack += add;
1534#endif
1535 if (newcp != cp + require) {
1536 /* Too bad: even rounding sbrk() is not continuous.*/
1537 DEBUG_m(PerlIO_printf(Perl_debug_log,
1538 "failed to fix bad sbrk()\n"));
1539#ifdef PACK_MALLOC
1540 if (slack) {
741df71a 1541 MALLOC_UNLOCK;
5bbd1ef5 1542 fatalcroak("panic: Off-page sbrk\n");
fa423c5b
IZ
1543 }
1544#endif
1545 if (sbrked_remains) {
1546 /* Try again. */
1547#if defined(DEBUGGING_MSTATS)
1548 sbrk_slack += require;
1549#endif
1550 require = needed;
1551 DEBUG_m(PerlIO_printf(Perl_debug_log,
1552 "straight sbrk(%ld)\n",
1553 (long)require));
1554 cp = (char *)sbrk(require);
1555#ifdef DEBUGGING_MSTATS
1556 sbrks++;
1557#endif
1558 if (cp == (char *)-1)
1559 return 0;
1560 }
22f7c9c9 1561 sbrk_goodness = -1; /* Disable optimization!
fa423c5b
IZ
1562 Continue with not-aligned... */
1563 } else {
1564 cp += slack;
1565 require += sbrked_remains;
1566 }
1567 }
1568
1569 if (last_sbrk_top) {
22f7c9c9 1570 sbrk_goodness -= SBRK_FAILURE_PRICE;
fa423c5b
IZ
1571 }
1572
1573 ovp = (union overhead *) cp;
1574 /*
1575 * Round up to minimum allocation size boundary
1576 * and deduct from block count to reflect.
1577 */
1578
5bbd1ef5 1579# if NEEDED_ALIGNMENT > MEM_ALIGNBYTES
56431972 1580 if (PTR2UV(ovp) & (NEEDED_ALIGNMENT - 1))
5bbd1ef5
IZ
1581 fatalcroak("Misalignment of sbrk()\n");
1582 else
1583# endif
56431972 1584 if (PTR2UV(ovp) & (MEM_ALIGNBYTES - 1)) {
fa423c5b 1585 DEBUG_m(PerlIO_printf(Perl_debug_log,
486ec47a 1586 "fixing sbrk(): %d bytes off machine alignment\n",
56431972
RB
1587 (int)(PTR2UV(ovp) & (MEM_ALIGNBYTES - 1))));
1588 ovp = INT2PTR(union overhead *,(PTR2UV(ovp) + MEM_ALIGNBYTES) &
5bbd1ef5 1589 (MEM_ALIGNBYTES - 1));
fa423c5b
IZ
1590 (*nblksp)--;
1591# if defined(DEBUGGING_MSTATS)
1592 /* This is only approx. if TWO_POT_OPTIMIZE: */
5bbd1ef5 1593 sbrk_slack += (1 << (bucket >> BUCKET_POW2_SHIFT));
fa423c5b
IZ
1594# endif
1595 }
a0288114 1596 ; /* Finish "else" */
fa423c5b 1597 sbrked_remains = require - needed;
e9397286 1598 last_op = cp;
fa423c5b 1599 }
febabd2a 1600#if !defined(PLAIN_MALLOC) && !defined(NO_FANCY_MALLOC)
22f7c9c9 1601 emergency_buffer_last_req = 0;
febabd2a 1602#endif
fa423c5b 1603 last_sbrk_top = cp + require;
fa423c5b
IZ
1604#ifdef DEBUGGING_MSTATS
1605 goodsbrk += require;
1606#endif
1607 return ovp;
1608}
1609
cea2e8a9 1610static int
c7374474 1611getpages_adjacent(MEM_SIZE require)
fa423c5b
IZ
1612{
1613 if (require <= sbrked_remains) {
1614 sbrked_remains -= require;
1615 } else {
1616 char *cp;
1617
1618 require -= sbrked_remains;
1619 /* We do not try to optimize sbrks here, we go for place. */
1620 cp = (char*) sbrk(require);
1621#ifdef DEBUGGING_MSTATS
1622 sbrks++;
1623 goodsbrk += require;
1624#endif
1625 if (cp == last_sbrk_top) {
1626 sbrked_remains = 0;
1627 last_sbrk_top = cp + require;
1628 } else {
28ac10b1
IZ
1629 if (cp == (char*)-1) { /* Out of memory */
1630#ifdef DEBUGGING_MSTATS
1631 goodsbrk -= require;
1632#endif
1633 return 0;
1634 }
fa423c5b
IZ
1635 /* Report the failure: */
1636 if (sbrked_remains)
1637 add_to_chain((void*)(last_sbrk_top - sbrked_remains),
1638 sbrked_remains, 0);
1639 add_to_chain((void*)cp, require, 0);
22f7c9c9 1640 sbrk_goodness -= SBRK_FAILURE_PRICE;
fa423c5b
IZ
1641 sbrked_remains = 0;
1642 last_sbrk_top = 0;
1643 last_op = 0;
1644 return 0;
1645 }
1646 }
1647
1648 return 1;
1649}
1650
8d063cd8
LW
1651/*
1652 * Allocate more memory to the indicated bucket.
1653 */
cea2e8a9 1654static void
5aaab254 1655morecore(int bucket)
8d063cd8 1656{
899be101 1657 dVAR;
eb578fdb
KW
1658 union overhead *ovp;
1659 int rnu; /* 2^rnu bytes will be requested */
fa423c5b 1660 int nblks; /* become nblks blocks of the desired size */
eb578fdb 1661 MEM_SIZE siz, needed;
22f7c9c9 1662 static int were_called = 0;
8d063cd8
LW
1663
1664 if (nextf[bucket])
1665 return;
22f7c9c9
JH
1666#ifndef NO_PERL_MALLOC_ENV
1667 if (!were_called) {
1668 /* It's the our first time. Initialize ourselves */
1669 were_called = 1; /* Avoid a loop */
1670 if (!MallocCfg[MallocCfg_skip_cfg_env]) {
1671 char *s = getenv("PERL_MALLOC_OPT"), *t = s, *off;
1672 const char *opts = PERL_MALLOC_OPT_CHARS;
1673 int changed = 0;
1674
1675 while ( t && t[0] && t[1] == '='
1676 && ((off = strchr(opts, *t))) ) {
1677 IV val = 0;
1678
1679 t += 2;
1680 while (*t <= '9' && *t >= '0')
1681 val = 10*val + *t++ - '0';
1682 if (!*t || *t == ';') {
1683 if (MallocCfg[off - opts] != val)
1684 changed = 1;
1685 MallocCfg[off - opts] = val;
1686 if (*t)
1687 t++;
1688 }
1689 }
1690 if (t && *t) {
89229eb4 1691 dTHX;
7cd83f65
CB
1692 MYMALLOC_WRITE2STDERR("Unrecognized part of PERL_MALLOC_OPT: \"");
1693 MYMALLOC_WRITE2STDERR(t);
1694 MYMALLOC_WRITE2STDERR("\"\n");
22f7c9c9
JH
1695 }
1696 if (changed)
1697 MallocCfg[MallocCfg_cfg_env_read] = 1;
1698 }
1699 }
1700#endif
e8bc2b5c 1701 if (bucket == sizeof(MEM_SIZE)*8*BUCKETS_PER_POW2) {
741df71a 1702 MALLOC_UNLOCK;
d720c441 1703 croak("%s", "Out of memory during ridiculously large request");
55497cff 1704 }
d720c441 1705 if (bucket > max_bucket)
e8bc2b5c 1706 max_bucket = bucket;
d720c441 1707
e8bc2b5c
GS
1708 rnu = ( (bucket <= (LOG_OF_MIN_ARENA << BUCKET_POW2_SHIFT))
1709 ? LOG_OF_MIN_ARENA
1710 : (bucket >> BUCKET_POW2_SHIFT) );
1711 /* This may be overwritten later: */
1712 nblks = 1 << (rnu - (bucket >> BUCKET_POW2_SHIFT)); /* how many blocks to get */
1713 needed = ((MEM_SIZE)1 << rnu) + POW2_OPTIMIZE_SURPLUS(bucket);
1714 if (nextf[rnu << BUCKET_POW2_SHIFT]) { /* 2048b bucket. */
1715 ovp = nextf[rnu << BUCKET_POW2_SHIFT] - 1 + CHUNK_SHIFT;
1716 nextf[rnu << BUCKET_POW2_SHIFT]
1717 = nextf[rnu << BUCKET_POW2_SHIFT]->ov_next;
1718#ifdef DEBUGGING_MSTATS
1719 nmalloc[rnu << BUCKET_POW2_SHIFT]--;
1720 start_slack -= M_OVERHEAD;
1721#endif
1722 DEBUG_m(PerlIO_printf(Perl_debug_log,
1723 "stealing %ld bytes from %ld arena\n",
1724 (long) needed, (long) rnu << BUCKET_POW2_SHIFT));
1725 } else if (chunk_chain
1726 && (ovp = (union overhead*) get_from_chain(needed))) {
1727 DEBUG_m(PerlIO_printf(Perl_debug_log,
1728 "stealing %ld bytes from chain\n",
1729 (long) needed));
d720c441
IZ
1730 } else if ( (ovp = (union overhead*)
1731 get_from_bigger_buckets((rnu << BUCKET_POW2_SHIFT) + 1,
1732 needed)) ) {
e8bc2b5c
GS
1733 DEBUG_m(PerlIO_printf(Perl_debug_log,
1734 "stealing %ld bytes from bigger buckets\n",
1735 (long) needed));
1736 } else if (needed <= sbrked_remains) {
1737 ovp = (union overhead *)(last_sbrk_top - sbrked_remains);
1738 sbrked_remains -= needed;
1739 last_op = (char*)ovp;
fa423c5b
IZ
1740 } else
1741 ovp = getpages(needed, &nblks, bucket);
e8bc2b5c 1742
fa423c5b
IZ
1743 if (!ovp)
1744 return;
22f7c9c9 1745 FILL_DEADBEEF((unsigned char*)ovp, needed);
e8bc2b5c 1746
8d063cd8
LW
1747 /*
1748 * Add new memory allocated to that on
1749 * free list for this hash bucket.
1750 */
d0bbed78 1751 siz = BUCKET_SIZE_NO_SURPLUS(bucket); /* No surplus if nblks > 1 */
cf5c4ad8 1752#ifdef PACK_MALLOC
72aaf631 1753 *(u_char*)ovp = bucket; /* Fill index. */
e8bc2b5c
GS
1754 if (bucket <= MAX_PACKED) {
1755 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
1756 nblks = N_BLKS(bucket);
cf5c4ad8 1757# ifdef DEBUGGING_MSTATS
e8bc2b5c 1758 start_slack += BLK_SHIFT(bucket);
cf5c4ad8 1759# endif
e8bc2b5c
GS
1760 } else if (bucket < LOG_OF_MIN_ARENA * BUCKETS_PER_POW2) {
1761 ovp = (union overhead *) ((char*)ovp + BLK_SHIFT(bucket));
cf5c4ad8 1762 siz -= sizeof(union overhead);
72aaf631 1763 } else ovp++; /* One chunk per block. */
e8bc2b5c 1764#endif /* PACK_MALLOC */
72aaf631 1765 nextf[bucket] = ovp;
5f05dabc
PP
1766#ifdef DEBUGGING_MSTATS
1767 nmalloc[bucket] += nblks;
e8bc2b5c
GS
1768 if (bucket > MAX_PACKED) {
1769 start_slack += M_OVERHEAD * nblks;
1770 }
5f05dabc 1771#endif
22f7c9c9 1772
8d063cd8 1773 while (--nblks > 0) {
72aaf631
MB
1774 ovp->ov_next = (union overhead *)((caddr_t)ovp + siz);
1775 ovp = (union overhead *)((caddr_t)ovp + siz);
8d063cd8 1776 }
8595d6f1 1777 /* Not all sbrks return zeroed memory.*/
72aaf631 1778 ovp->ov_next = (union overhead *)NULL;
cf5c4ad8 1779#ifdef PACK_MALLOC
e8bc2b5c
GS
1780 if (bucket == 7*BUCKETS_PER_POW2) { /* Special case, explanation is above. */
1781 union overhead *n_op = nextf[7*BUCKETS_PER_POW2]->ov_next;
1782 nextf[7*BUCKETS_PER_POW2] =
1783 (union overhead *)((caddr_t)nextf[7*BUCKETS_PER_POW2]
1784 - sizeof(union overhead));
1785 nextf[7*BUCKETS_PER_POW2]->ov_next = n_op;
cf5c4ad8
PP
1786 }
1787#endif /* !PACK_MALLOC */
8d063cd8
LW
1788}
1789
94b6baf5 1790Free_t
667e2948 1791Perl_mfree(Malloc_t where)
cea2e8a9 1792{
899be101 1793 dVAR;
eb578fdb
KW
1794 MEM_SIZE size;
1795 union overhead *ovp;
667e2948 1796 char *cp = (char*)where;
cf5c4ad8
PP
1797#ifdef PACK_MALLOC
1798 u_char bucket;
1799#endif
8d063cd8 1800
e8bc2b5c 1801 DEBUG_m(PerlIO_printf(Perl_debug_log,
b900a521
JH
1802 "0x%"UVxf": (%05lu) free\n",
1803 PTR2UV(cp), (unsigned long)(PL_an++)));
45d8adaa 1804
cf5c4ad8
PP
1805 if (cp == NULL)
1806 return;
22f7c9c9
JH
1807#ifdef DEBUGGING
1808 if (PTR2UV(cp) & (MEM_ALIGNBYTES - 1))
1809 croak("%s", "wrong alignment in free()");
1810#endif
72aaf631 1811 ovp = (union overhead *)((caddr_t)cp
e8bc2b5c 1812 - sizeof (union overhead) * CHUNK_SHIFT);
cf5c4ad8 1813#ifdef PACK_MALLOC
72aaf631 1814 bucket = OV_INDEX(ovp);
cf5c4ad8 1815#endif
e8bc2b5c
GS
1816#ifdef IGNORE_SMALL_BAD_FREE
1817 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1818 && (OV_MAGIC(ovp, bucket) != MAGIC))
1819#else
1820 if (OV_MAGIC(ovp, bucket) != MAGIC)
1821#endif
1822 {
68dc0745 1823 static int bad_free_warn = -1;
cf5c4ad8 1824 if (bad_free_warn == -1) {
e8cd8248 1825 dTHX;
5fd9e9a4 1826 char *pbf = PerlEnv_getenv("PERL_BADFREE");
cf5c4ad8
PP
1827 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1828 }
1829 if (!bad_free_warn)
1830 return;
8990e307 1831#ifdef RCHECK
e8cd8248
GS
1832 {
1833 dTHX;
9b387841
NC
1834 if (!PERL_IS_ALIVE || !PL_curcop)
1835 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s free() ignored (RMAGIC, PERL_CORE)",
1836 ovp->ov_rmagic == RMAGIC - 1 ?
1837 "Duplicate" : "Bad");
2ba999ec 1838 }
e476b1b5 1839#else
2ba999ec
GS
1840 {
1841 dTHX;
9b387841
NC
1842 if (!PERL_IS_ALIVE || !PL_curcop)
1843 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s", "Bad free() ignored (PERL_CORE)");
2ba999ec 1844 }
e476b1b5 1845#endif
8d063cd8 1846 return; /* sanity */
e8bc2b5c 1847 }
8d063cd8 1848#ifdef RCHECK
3541dd58 1849 ASSERT(ovp->ov_rmagic == RMAGIC, "chunk's head overwrite");
e8bc2b5c
GS
1850 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
1851 int i;
1852 MEM_SIZE nbytes = ovp->ov_size + 1;
1853
d0bbed78
IZ
1854 if ((i = nbytes & (RMAGIC_SZ-1))) {
1855 i = RMAGIC_SZ - i;
1856 while (i--) { /* nbytes - RMAGIC_SZ is end of alloced area */
1857 ASSERT(((caddr_t)ovp + nbytes - RMAGIC_SZ)[i] == RMAGIC_C,
1858 "chunk's tail overwrite");
e8bc2b5c
GS
1859 }
1860 }
d0bbed78
IZ
1861 /* Same at RMAGIC_SZ-aligned RMAGIC */
1862 nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
1863 ASSERT(((u_int *)((caddr_t)ovp + nbytes))[-1] == RMAGIC,
1864 "chunk's tail overwrite");
1865 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nbytes),
1866 BUCKET_SIZE(OV_INDEX(ovp)) - nbytes);
e8bc2b5c 1867 }
d0bbed78
IZ
1868 FILL_DEADBEEF((unsigned char*)(ovp+CHUNK_SHIFT),
1869 BUCKET_SIZE_REAL(OV_INDEX(ovp)) + RMAGIC_SZ);
72aaf631 1870 ovp->ov_rmagic = RMAGIC - 1;
8d063cd8 1871#endif
3541dd58 1872 ASSERT(OV_INDEX(ovp) < NBUCKETS, "chunk's head overwrite");
72aaf631 1873 size = OV_INDEX(ovp);
4ad56ec9
IZ
1874
1875 MALLOC_LOCK;
72aaf631
MB
1876 ovp->ov_next = nextf[size];
1877 nextf[size] = ovp;
741df71a 1878 MALLOC_UNLOCK;
8d063cd8
LW
1879}
1880
4ad56ec9
IZ
1881/* There is no need to do any locking in realloc (with an exception of
1882 trying to grow in place if we are at the end of the chain).
1883 If somebody calls us from a different thread with the same address,
1884 we are sole anyway. */
8d063cd8 1885
2304df62 1886Malloc_t
86058a2d 1887Perl_realloc(void *mp, size_t nbytes)
cea2e8a9 1888{
899be101 1889 dVAR;
eb578fdb 1890 MEM_SIZE onb;
72aaf631 1891 union overhead *ovp;
d720c441
IZ
1892 char *res;
1893 int prev_bucket;
eb578fdb 1894 int bucket;
4ad56ec9
IZ
1895 int incr; /* 1 if does not fit, -1 if "easily" fits in a
1896 smaller bucket, otherwise 0. */
352d5a3a 1897 char *cp = (char*)mp;
8d063cd8 1898
b9e5552c 1899#ifdef DEBUGGING
ee0007ab 1900 MEM_SIZE size = nbytes;
45d8adaa 1901
45d8adaa 1902 if ((long)nbytes < 0)
cea2e8a9 1903 croak("%s", "panic: realloc");
45d8adaa 1904#endif
e8bc2b5c
GS
1905
1906 BARK_64K_LIMIT("Reallocation",nbytes,size);
1907 if (!cp)
86058a2d 1908 return Perl_malloc(nbytes);
45d8adaa 1909
72aaf631 1910 ovp = (union overhead *)((caddr_t)cp
e8bc2b5c
GS
1911 - sizeof (union overhead) * CHUNK_SHIFT);
1912 bucket = OV_INDEX(ovp);
4ad56ec9 1913
e8bc2b5c 1914#ifdef IGNORE_SMALL_BAD_FREE
4ad56ec9
IZ
1915 if ((bucket >= FIRST_BUCKET_WITH_CHECK)
1916 && (OV_MAGIC(ovp, bucket) != MAGIC))
e8bc2b5c 1917#else
4ad56ec9 1918 if (OV_MAGIC(ovp, bucket) != MAGIC)
e8bc2b5c 1919#endif
4ad56ec9
IZ
1920 {
1921 static int bad_free_warn = -1;
1922 if (bad_free_warn == -1) {
e8cd8248 1923 dTHX;
4ad56ec9
IZ
1924 char *pbf = PerlEnv_getenv("PERL_BADFREE");
1925 bad_free_warn = (pbf) ? atoi(pbf) : 1;
1926 }
1927 if (!bad_free_warn)
bd61b366 1928 return NULL;
4ad56ec9 1929#ifdef RCHECK
e8cd8248
GS
1930 {
1931 dTHX;
9b387841
NC
1932 if (!PERL_IS_ALIVE || !PL_curcop)
1933 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%srealloc() %signored",
1934 (ovp->ov_rmagic == RMAGIC - 1 ? "" : "Bad "),
1935 ovp->ov_rmagic == RMAGIC - 1
1936 ? "of freed memory " : "");
2ba999ec 1937 }
e476b1b5 1938#else
2ba999ec
GS
1939 {
1940 dTHX;
9b387841
NC
1941 if (!PERL_IS_ALIVE || !PL_curcop)
1942 Perl_ck_warner_d(aTHX_ packWARN(WARN_MALLOC), "%s",
1943 "Bad realloc() ignored");
2ba999ec 1944 }
e476b1b5 1945#endif
bd61b366 1946 return NULL; /* sanity */
4ad56ec9
IZ
1947 }
1948
e8bc2b5c 1949 onb = BUCKET_SIZE_REAL(bucket);
55497cff
PP
1950 /*
1951 * avoid the copy if same size block.
486ec47a 1952 * We are not aggressive with boundary cases. Note that it might
e8bc2b5c 1953 * (for a small number of cases) give false negative if
55497cff 1954 * both new size and old one are in the bucket for
e8bc2b5c
GS
1955 * FIRST_BIG_POW2, but the new one is near the lower end.
1956 *
1957 * We do not try to go to 1.5 times smaller bucket so far.
55497cff 1958 */
e8bc2b5c
GS
1959 if (nbytes > onb) incr = 1;
1960 else {
1961#ifdef DO_NOT_TRY_HARDER_WHEN_SHRINKING
1962 if ( /* This is a little bit pessimal if PACK_MALLOC: */
1963 nbytes > ( (onb >> 1) - M_OVERHEAD )
1964# ifdef TWO_POT_OPTIMIZE
1965 || (bucket == FIRST_BIG_POW2 && nbytes >= LAST_SMALL_BOUND )
1966# endif
1967 )
1968#else /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
1969 prev_bucket = ( (bucket > MAX_PACKED + 1)
1970 ? bucket - BUCKETS_PER_POW2
1971 : bucket - 1);
1972 if (nbytes > BUCKET_SIZE_REAL(prev_bucket))
1973#endif /* !DO_NOT_TRY_HARDER_WHEN_SHRINKING */
1974 incr = 0;
1975 else incr = -1;
1976 }
2ce36478 1977#ifdef STRESS_REALLOC
4ad56ec9 1978 goto hard_way;
2ce36478 1979#endif
4ad56ec9 1980 if (incr == 0) {
852c2e52 1981 inplace_label:
a687059c
LW
1982#ifdef RCHECK
1983 /*
1984 * Record new allocated size of block and
1985 * bound space with magic numbers.
1986 */
72aaf631 1987 if (OV_INDEX(ovp) <= MAX_SHORT_BUCKET) {
e8bc2b5c
GS
1988 int i, nb = ovp->ov_size + 1;
1989
d0bbed78
IZ
1990 if ((i = nb & (RMAGIC_SZ-1))) {
1991 i = RMAGIC_SZ - i;
1992 while (i--) { /* nb - RMAGIC_SZ is end of alloced area */
1993 ASSERT(((caddr_t)ovp + nb - RMAGIC_SZ)[i] == RMAGIC_C, "chunk's tail overwrite");
e8bc2b5c
GS
1994 }
1995 }
d0bbed78
IZ
1996 /* Same at RMAGIC_SZ-aligned RMAGIC */
1997 nb = (nb + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ-1);
1998 ASSERT(((u_int *)((caddr_t)ovp + nb))[-1] == RMAGIC,
1999 "chunk's tail overwrite");
2000 FILLCHECK_DEADBEEF((unsigned char*)((caddr_t)ovp + nb),
2001 BUCKET_SIZE(OV_INDEX(ovp)) - nb);
22f7c9c9
JH
2002 if (nbytes > ovp->ov_size + 1 - M_OVERHEAD)
2003 FILL_FEEDADAD((unsigned char*)cp + ovp->ov_size + 1 - M_OVERHEAD,
2004 nbytes - (ovp->ov_size + 1 - M_OVERHEAD));
2005 else
2006 FILL_DEADBEEF((unsigned char*)cp + nbytes,
d0bbed78 2007 nb - M_OVERHEAD + RMAGIC_SZ - nbytes);
a687059c
LW
2008 /*
2009 * Convert amount of memory requested into
2010 * closest block size stored in hash buckets
2011 * which satisfies request. Account for
2012 * space used per block for accounting.
2013 */
cf5c4ad8 2014 nbytes += M_OVERHEAD;
72aaf631 2015 ovp->ov_size = nbytes - 1;
d0bbed78
IZ
2016 if ((i = nbytes & (RMAGIC_SZ-1))) {
2017 i = RMAGIC_SZ - i;
2018 while (i--) /* nbytes - RMAGIC_SZ is end of alloced area */
2019 ((caddr_t)ovp + nbytes - RMAGIC_SZ)[i]
e8bc2b5c
GS
2020 = RMAGIC_C;
2021 }
d0bbed78
IZ
2022 /* Same at RMAGIC_SZ-aligned RMAGIC */
2023 nbytes = (nbytes + (RMAGIC_SZ-1)) & ~(RMAGIC_SZ - 1);
2024 ((u_int *)((caddr_t)ovp + nbytes))[-1] = RMAGIC;
a687059c
LW
2025 }
2026#endif
45d8adaa 2027 res = cp;
42ac124e 2028 DEBUG_m(PerlIO_printf(Perl_debug_log,
b900a521
JH
2029 "0x%"UVxf": (%05lu) realloc %ld bytes inplace\n",
2030 PTR2UV(res),(unsigned long)(PL_an++),
42ac124e 2031 (long)size));
e8bc2b5c
GS
2032 } else if (incr == 1 && (cp - M_OVERHEAD == last_op)
2033 && (onb > (1 << LOG_OF_MIN_ARENA))) {
2034 MEM_SIZE require, newarena = nbytes, pow;
2035 int shiftr;
2036
2037 POW2_OPTIMIZE_ADJUST(newarena);
2038 newarena = newarena + M_OVERHEAD;
2039 /* newarena = (newarena + 3) &~ 3; */
2040 shiftr = (newarena - 1) >> LOG_OF_MIN_ARENA;
2041 pow = LOG_OF_MIN_ARENA + 1;
2042 /* apart from this loop, this is O(1) */
2043 while (shiftr >>= 1)
2044 pow++;
2045 newarena = (1 << pow) + POW2_OPTIMIZE_SURPLUS(pow * BUCKETS_PER_POW2);
2046 require = newarena - onb - M_OVERHEAD;
2047
4ad56ec9
IZ
2048 MALLOC_LOCK;
2049 if (cp - M_OVERHEAD == last_op /* We *still* are the last chunk */
2050 && getpages_adjacent(require)) {
e8bc2b5c 2051#ifdef DEBUGGING_MSTATS
fa423c5b
IZ
2052 nmalloc[bucket]--;
2053 nmalloc[pow * BUCKETS_PER_POW2]++;
e8bc2b5c 2054#endif
532939df 2055 if (pow * BUCKETS_PER_POW2 > (MEM_SIZE)max_bucket)
a73918ec 2056 max_bucket = pow * BUCKETS_PER_POW2;
4d6cd4d8 2057 *(cp - M_OVERHEAD) = pow * BUCKETS_PER_POW2; /* Fill index. */
4ad56ec9 2058 MALLOC_UNLOCK;
fa423c5b 2059 goto inplace_label;
4ad56ec9
IZ
2060 } else {
2061 MALLOC_UNLOCK;
fa423c5b 2062 goto hard_way;
4ad56ec9 2063 }
e8bc2b5c
GS
2064 } else {
2065 hard_way:
42ac124e 2066 DEBUG_m(PerlIO_printf(Perl_debug_log,
b900a521
JH
2067 "0x%"UVxf": (%05lu) realloc %ld bytes the hard way\n",
2068 PTR2UV(cp),(unsigned long)(PL_an++),
42ac124e 2069 (long)size));
86058a2d 2070 if ((res = (char*)Perl_malloc(nbytes)) == NULL)
e8bc2b5c
GS
2071 return (NULL);
2072 if (cp != res) /* common optimization */
2073 Copy(cp, res, (MEM_SIZE)(nbytes<onb?nbytes:onb), char);
4ad56ec9 2074 Perl_mfree(cp);
45d8adaa 2075 }
2304df62 2076 return ((Malloc_t)res);
8d063cd8
LW
2077}
2078
cf5c4ad8 2079Malloc_t
5aaab254 2080Perl_calloc(size_t elements, size_t size)
cf5c4ad8
PP
2081{
2082 long sz = elements * size;
86058a2d 2083 Malloc_t p = Perl_malloc(sz);
cf5c4ad8
PP
2084
2085 if (p) {
2086 memset((void*)p, 0, sz);
2087 }
2088 return p;
2089}
2090
4ad56ec9
IZ
2091char *
2092Perl_strdup(const char *s)
2093{
2094 MEM_SIZE l = strlen(s);
b48f1ba5 2095 char *s1 = (char *)Perl_malloc(l+1);
4ad56ec9 2096
667e2948 2097 return (char *)CopyD(s, s1, (MEM_SIZE)(l+1), char);
4ad56ec9
IZ
2098}
2099
4ad56ec9
IZ
2100int
2101Perl_putenv(char *a)
2102{
2103 /* Sometimes system's putenv conflicts with my_setenv() - this is system
2104 malloc vs Perl's free(). */
2105 dTHX;
2106 char *var;
2107 char *val = a;
2108 MEM_SIZE l;
2109 char buf[80];
2110
2111 while (*val && *val != '=')
2112 val++;
2113 if (!*val)
2114 return -1;
2115 l = val - a;
2116 if (l < sizeof(buf))
2117 var = buf;
2118 else
667e2948 2119 var = (char *)Perl_malloc(l + 1);
4ad56ec9 2120 Copy(a, var, l, char);
b48f1ba5
GS
2121 var[l + 1] = 0;
2122 my_setenv(var, val+1);
4ad56ec9
IZ
2123 if (var != buf)
2124 Perl_mfree(var);
2125 return 0;
2126}
4ad56ec9 2127
e8bc2b5c 2128MEM_SIZE
cea2e8a9 2129Perl_malloced_size(void *p)
e8bc2b5c 2130{
44f8325f 2131 union overhead * const ovp = (union overhead *)
8d6dde3e 2132 ((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
b464bac0 2133 const int bucket = OV_INDEX(ovp);
7918f24d
NC
2134
2135 PERL_ARGS_ASSERT_MALLOCED_SIZE;
2136
8d6dde3e
IZ
2137#ifdef RCHECK
2138 /* The caller wants to have a complete control over the chunk,
2139 disable the memory checking inside the chunk. */
2140 if (bucket <= MAX_SHORT_BUCKET) {
b464bac0 2141 const MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
8d6dde3e 2142 ovp->ov_size = size + M_OVERHEAD - 1;
d0bbed78 2143 *((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RMAGIC_SZ)) = RMAGIC;
8d6dde3e
IZ
2144 }
2145#endif
e8bc2b5c
GS
2146 return BUCKET_SIZE_REAL(bucket);
2147}
2148
64107180
NC
2149
2150MEM_SIZE
2151Perl_malloc_good_size(size_t wanted)
2152{
03f05cb4 2153 return BUCKET_SIZE_REAL(adjust_size_and_find_bucket(&wanted));
64107180
NC
2154}
2155
e8bc2b5c
GS
2156# ifdef BUCKETS_ROOT2
2157# define MIN_EVEN_REPORT 6
2158# else
2159# define MIN_EVEN_REPORT MIN_BUCKET
2160# endif
827e134a
GS
2161
2162int
2163Perl_get_mstats(pTHX_ perl_mstats_t *buf, int buflen, int level)
8d063cd8 2164{
df31f264 2165#ifdef DEBUGGING_MSTATS
eb578fdb
KW
2166 int i, j;
2167 union overhead *p;
4ad56ec9 2168 struct chunk_chain_s* nextchain;
8d063cd8 2169
7918f24d
NC
2170 PERL_ARGS_ASSERT_GET_MSTATS;
2171
827e134a
GS
2172 buf->topbucket = buf->topbucket_ev = buf->topbucket_odd
2173 = buf->totfree = buf->total = buf->total_chain = 0;
2174
2175 buf->minbucket = MIN_BUCKET;
4ad56ec9 2176 MALLOC_LOCK;
e8bc2b5c 2177 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
8d063cd8
LW
2178 for (j = 0, p = nextf[i]; p; p = p->ov_next, j++)
2179 ;
827e134a
GS
2180 if (i < buflen) {
2181 buf->nfree[i] = j;
2182 buf->ntotal[i] = nmalloc[i];
2183 }
2184 buf->totfree += j * BUCKET_SIZE_REAL(i);
2185 buf->total += nmalloc[i] * BUCKET_SIZE_REAL(i);
e8bc2b5c 2186 if (nmalloc[i]) {
827e134a
GS
2187 i % 2 ? (buf->topbucket_odd = i) : (buf->topbucket_ev = i);
2188 buf->topbucket = i;
e8bc2b5c 2189 }
c07a80fd 2190 }
4ad56ec9
IZ
2191 nextchain = chunk_chain;
2192 while (nextchain) {
827e134a 2193 buf->total_chain += nextchain->size;
4ad56ec9
IZ
2194 nextchain = nextchain->next;
2195 }
827e134a
GS
2196 buf->total_sbrk = goodsbrk + sbrk_slack;
2197 buf->sbrks = sbrks;
22f7c9c9 2198 buf->sbrk_good = sbrk_goodness;
827e134a
GS
2199 buf->sbrk_slack = sbrk_slack;
2200 buf->start_slack = start_slack;
2201 buf->sbrked_remains = sbrked_remains;
4ad56ec9 2202 MALLOC_UNLOCK;
880b20b6 2203 buf->nbuckets = NBUCKETS;
827e134a
GS
2204 if (level) {
2205 for (i = MIN_BUCKET ; i < NBUCKETS; i++) {
2206 if (i >= buflen)
2207 break;
d0bbed78 2208 buf->bucket_mem_size[i] = BUCKET_SIZE_NO_SURPLUS(i);
827e134a
GS
2209 buf->bucket_available_size[i] = BUCKET_SIZE_REAL(i);
2210 }
2211 }
3128eefe 2212#else /* defined DEBUGGING_MSTATS */
2213 PerlIO_printf(Perl_error_log, "perl not compiled with DEBUGGING_MSTATS\n");
827e134a 2214#endif /* defined DEBUGGING_MSTATS */
fe52b3b7 2215 return 0; /* XXX unused */
827e134a
GS
2216}
2217/*
2218 * mstats - print out statistics about malloc
2219 *
2220 * Prints two lines of numbers, one showing the length of the free list
2221 * for each size category, the second showing the number of mallocs -
2222 * frees for each size category.
2223 */
2224void
6e9b0e18 2225Perl_dump_mstats(pTHX_ const char *s)
827e134a
GS
2226{
2227#ifdef DEBUGGING_MSTATS
eb578fdb 2228 int i;
827e134a 2229 perl_mstats_t buffer;
880b20b6
IZ
2230 UV nf[NBUCKETS];
2231 UV nt[NBUCKETS];
827e134a 2232
7918f24d
NC
2233 PERL_ARGS_ASSERT_DUMP_MSTATS;
2234
827e134a
GS
2235 buffer.nfree = nf;
2236 buffer.ntotal = nt;
2237 get_mstats(&buffer, NBUCKETS, 0);
2238
c07a80fd 2239 if (s)
bf49b057 2240 PerlIO_printf(Perl_error_log,
880b20b6 2241 "Memory allocation statistics %s (buckets %"IVdf"(%"IVdf")..%"IVdf"(%"IVdf")\n",
e8bc2b5c 2242 s,
880b20b6 2243 (IV)BUCKET_SIZE_REAL(MIN_BUCKET),
d0bbed78 2244 (IV)BUCKET_SIZE_NO_SURPLUS(MIN_BUCKET),
880b20b6 2245 (IV)BUCKET_SIZE_REAL(buffer.topbucket),
d0bbed78 2246 (IV)BUCKET_SIZE_NO_SURPLUS(buffer.topbucket));
880b20b6 2247 PerlIO_printf(Perl_error_log, "%8"IVdf" free:", buffer.totfree);
827e134a 2248 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
bf49b057 2249 PerlIO_printf(Perl_error_log,
e8bc2b5c 2250 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
880b20b6
IZ
2251 ? " %5"UVuf
2252 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
827e134a 2253 buffer.nfree[i]);
e8bc2b5c
GS
2254 }
2255#ifdef BUCKETS_ROOT2
bf49b057 2256 PerlIO_printf(Perl_error_log, "\n\t ");
827e134a 2257 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
bf49b057 2258 PerlIO_printf(Perl_error_log,
e8bc2b5c 2259 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
880b20b6
IZ
2260 ? " %5"UVuf
2261 : ((i < 12*BUCKETS_PER_POW2) ? " %3"UVuf : " %"UVuf)),
827e134a 2262 buffer.nfree[i]);
8d063cd8 2263 }
e8bc2b5c 2264#endif
880b20b6 2265 PerlIO_printf(Perl_error_log, "\n%8"IVdf" used:", buffer.total - buffer.totfree);
827e134a 2266 for (i = MIN_EVEN_REPORT; i <= buffer.topbucket; i += BUCKETS_PER_POW2) {
bf49b057 2267 PerlIO_printf(Perl_error_log,
e8bc2b5c 2268 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
880b20b6
IZ
2269 ? " %5"IVdf
2270 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
827e134a 2271 buffer.ntotal[i] - buffer.nfree[i]);
c07a80fd 2272 }
e8bc2b5c 2273#ifdef BUCKETS_ROOT2
bf49b057 2274 PerlIO_printf(Perl_error_log, "\n\t ");
827e134a 2275 for (i = MIN_BUCKET + 1; i <= buffer.topbucket_odd; i += BUCKETS_PER_POW2) {
bf49b057 2276 PerlIO_printf(Perl_error_log,
e8bc2b5c 2277 ((i < 8*BUCKETS_PER_POW2 || i == 10*BUCKETS_PER_POW2)
880b20b6
IZ
2278 ? " %5"IVdf
2279 : ((i < 12*BUCKETS_PER_POW2) ? " %3"IVdf : " %"IVdf)),
827e134a 2280 buffer.ntotal[i] - buffer.nfree[i]);
e8bc2b5c
GS
2281 }
2282#endif
880b20b6 2283 PerlIO_printf(Perl_error_log, "\nTotal sbrk(): %"IVdf"/%"IVdf":%"IVdf". Odd ends: pad+heads+chain+tail: %"IVdf"+%"IVdf"+%"IVdf"+%"IVdf".\n",
827e134a
GS
2284 buffer.total_sbrk, buffer.sbrks, buffer.sbrk_good,
2285 buffer.sbrk_slack, buffer.start_slack,
2286 buffer.total_chain, buffer.sbrked_remains);
3128eefe 2287#else /* DEBUGGING_MSTATS */
2288 PerlIO_printf(Perl_error_log, "%s: perl not compiled with DEBUGGING_MSTATS\n",s);
df31f264 2289#endif /* DEBUGGING_MSTATS */
c07a80fd 2290}
cf5c4ad8 2291
cf5c4ad8
PP
2292#ifdef USE_PERL_SBRK
2293
f05550c0 2294# if defined(PURIFY)
38ac2dc8 2295# define PERL_SBRK_VIA_MALLOC
38ac2dc8
DD
2296# endif
2297
760ac839 2298# ifdef PERL_SBRK_VIA_MALLOC
cf5c4ad8
PP
2299
2300/* it may seem schizophrenic to use perl's malloc and let it call system */
2301/* malloc, the reason for that is only the 3.2 version of the OS that had */
2302/* frequent core dumps within nxzonefreenolock. This sbrk routine put an */
2303/* end to the cores */
2304
38ac2dc8
DD
2305# ifndef SYSTEM_ALLOC
2306# define SYSTEM_ALLOC(a) malloc(a)
2307# endif
5bbd1ef5
IZ
2308# ifndef SYSTEM_ALLOC_ALIGNMENT
2309# define SYSTEM_ALLOC_ALIGNMENT MEM_ALIGNBYTES
2310# endif
cf5c4ad8 2311
760ac839 2312# endif /* PERL_SBRK_VIA_MALLOC */
cf5c4ad8
PP
2313
2314static IV Perl_sbrk_oldchunk;
2315static long Perl_sbrk_oldsize;
2316
760ac839
LW
2317# define PERLSBRK_32_K (1<<15)
2318# define PERLSBRK_64_K (1<<16)
cf5c4ad8 2319
b63effbb 2320Malloc_t
df0003d4 2321Perl_sbrk(int size)
cf5c4ad8
PP
2322{
2323 IV got;
2324 int small, reqsize;
2325
2326 if (!size) return 0;
cf5c4ad8 2327 reqsize = size; /* just for the DEBUG_m statement */
57569e04
HM
2328#ifdef PACK_MALLOC
2329 size = (size + 0x7ff) & ~0x7ff;
2330#endif
cf5c4ad8
PP
2331 if (size <= Perl_sbrk_oldsize) {
2332 got = Perl_sbrk_oldchunk;
2333 Perl_sbrk_oldchunk += size;
2334 Perl_sbrk_oldsize -= size;
2335 } else {
2336 if (size >= PERLSBRK_32_K) {
2337 small = 0;
2338 } else {
cf5c4ad8
PP
2339 size = PERLSBRK_64_K;
2340 small = 1;
2341 }
5bbd1ef5
IZ
2342# if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
2343 size += NEEDED_ALIGNMENT - SYSTEM_ALLOC_ALIGNMENT;
2344# endif
cf5c4ad8 2345 got = (IV)SYSTEM_ALLOC(size);
5bbd1ef5 2346# if NEEDED_ALIGNMENT > SYSTEM_ALLOC_ALIGNMENT
5a7d6335 2347 got = (got + NEEDED_ALIGNMENT - 1) & ~(NEEDED_ALIGNMENT - 1);
5bbd1ef5 2348# endif
cf5c4ad8
PP
2349 if (small) {
2350 /* Chunk is small, register the rest for future allocs. */
2351 Perl_sbrk_oldchunk = got + reqsize;
2352 Perl_sbrk_oldsize = size - reqsize;
2353 }
2354 }
2355
b900a521
JH
2356 DEBUG_m(PerlIO_printf(Perl_debug_log, "sbrk malloc size %ld (reqsize %ld), left size %ld, give addr 0x%"UVxf"\n",
2357 size, reqsize, Perl_sbrk_oldsize, PTR2UV(got)));
cf5c4ad8
PP
2358
2359 return (void *)got;
2360}
2361
2362#endif /* ! defined USE_PERL_SBRK */
66610fdd
RGS
2363
2364/*
2365 * Local variables:
2366 * c-indentation-style: bsd
2367 * c-basic-offset: 4
14d04a33 2368 * indent-tabs-mode: nil
66610fdd
RGS
2369 * End:
2370 *
14d04a33 2371 * ex: set ts=8 sts=4 sw=4 et:
37442d52 2372 */