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/* ---------- To make a malloc.h, start cutting here ------------ */
2
 
3
/*
4
  A version of malloc/free/realloc written by Doug Lea and released to the
5
  public domain.  Send questions/comments/complaints/performance data
6
  to dl@cs.oswego.edu
7
 
8
* VERSION 2.6.4  Thu Nov 28 07:54:55 1996  Doug Lea  (dl at gee)
9
 
10
   Note: There may be an updated version of this malloc obtainable at
11
           ftp://g.oswego.edu/pub/misc/malloc.c
12
         Check before installing!
13
 
14
* Why use this malloc?
15
 
16
  This is not the fastest, most space-conserving, most portable, or
17
  most tunable malloc ever written. However it is among the fastest
18
  while also being among the most space-conserving, portable and tunable.
19
  Consistent balance across these factors results in a good general-purpose
20
  allocator. For a high-level description, see
21
     http://g.oswego.edu/dl/html/malloc.html
22
 
23
* Synopsis of public routines
24
 
25
  (Much fuller descriptions are contained in the program documentation below.)
26
 
27
  malloc(size_t n);
28
     Return a pointer to a newly allocated chunk of at least n bytes, or null
29
     if no space is available.
30
  free(Void_t* p);
31
     Release the chunk of memory pointed to by p, or no effect if p is null.
32
  realloc(Void_t* p, size_t n);
33
     Return a pointer to a chunk of size n that contains the same data
34
     as does chunk p up to the minimum of (n, p's size) bytes, or null
35
     if no space is available. The returned pointer may or may not be
36
     the same as p. If p is null, equivalent to malloc.  Unless the
37
     #define REALLOC_ZERO_BYTES_FREES below is set, realloc with a
38
     size argument of zero (re)allocates a minimum-sized chunk.
39
  memalign(size_t alignment, size_t n);
40
     Return a pointer to a newly allocated chunk of n bytes, aligned
41
     in accord with the alignment argument, which must be a power of
42
     two.
43
  valloc(size_t n);
44
     Equivalent to memalign(pagesize, n), where pagesize is the page
45
     size of the system (or as near to this as can be figured out from
46
     all the includes/defines below.)
47
  pvalloc(size_t n);
48
     Equivalent to valloc(minimum-page-that-holds(n)), that is,
49
     round up n to nearest pagesize.
50
  calloc(size_t unit, size_t quantity);
51
     Returns a pointer to quantity * unit bytes, with all locations
52
     set to zero.
53
  cfree(Void_t* p);
54
     Equivalent to free(p).
55
  malloc_trim(size_t pad);
56
     Release all but pad bytes of freed top-most memory back
57
     to the system. Return 1 if successful, else 0.
58
  malloc_usable_size(Void_t* p);
59
     Report the number usable allocated bytes associated with allocated
60
     chunk p. This may or may not report more bytes than were requested,
61
     due to alignment and minimum size constraints.
62
  malloc_stats();
63
     Prints brief summary statistics on stderr.
64
  mallinfo()
65
     Returns (by copy) a struct containing various summary statistics.
66
  mallopt(int parameter_number, int parameter_value)
67
     Changes one of the tunable parameters described below. Returns
68
     1 if successful in changing the parameter, else 0.
69
 
70
* Vital statistics:
71
 
72
  Alignment:                            8-byte
73
       8 byte alignment is currently hardwired into the design.  This
74
       seems to suffice for all current machines and C compilers.
75
 
76
  Assumed pointer representation:       4 or 8 bytes
77
       Code for 8-byte pointers is untested by me but has worked
78
       reliably by Wolfram Gloger, who contributed most of the
79
       changes supporting this.
80
 
81
  Assumed size_t  representation:       4 or 8 bytes
82
       Note that size_t is allowed to be 4 bytes even if pointers are 8.
83
 
84
  Minimum overhead per allocated chunk: 4 or 8 bytes
85
       Each malloced chunk has a hidden overhead of 4 bytes holding size
86
       and status information.
87
 
88
  Minimum allocated size: 4-byte ptrs:  16 bytes    (including 4 overhead)
89
                          8-byte ptrs:  24/32 bytes (including, 4/8 overhead)
90
 
91
       When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte
92
       ptrs but 4 byte size) or 24 (for 8/8) additional bytes are
93
       needed; 4 (8) for a trailing size field
94
       and 8 (16) bytes for free list pointers. Thus, the minimum
95
       allocatable size is 16/24/32 bytes.
96
 
97
       Even a request for zero bytes (i.e., malloc(0)) returns a
98
       pointer to something of the minimum allocatable size.
99
 
100
  Maximum allocated size: 4-byte size_t: 2^31 -  8 bytes
101
                          8-byte size_t: 2^63 - 16 bytes
102
 
103
       It is assumed that (possibly signed) size_t bit values suffice to
104
       represent chunk sizes. `Possibly signed' is due to the fact
105
       that `size_t' may be defined on a system as either a signed or
106
       an unsigned type. To be conservative, values that would appear
107
       as negative numbers are avoided.
108
       Requests for sizes with a negative sign bit will return a
109
       minimum-sized chunk.
110
 
111
  Maximum overhead wastage per allocated chunk: normally 15 bytes
112
 
113
       Alignnment demands, plus the minimum allocatable size restriction
114
       make the normal worst-case wastage 15 bytes (i.e., up to 15
115
       more bytes will be allocated than were requested in malloc), with
116
       two exceptions:
117
         1. Because requests for zero bytes allocate non-zero space,
118
            the worst case wastage for a request of zero bytes is 24 bytes.
119
         2. For requests >= mmap_threshold that are serviced via
120
            mmap(), the worst case wastage is 8 bytes plus the remainder
121
            from a system page (the minimal mmap unit); typically 4096 bytes.
122
 
123
* Limitations
124
 
125
    Here are some features that are NOT currently supported
126
 
127
    * No user-definable hooks for callbacks and the like.
128
    * No automated mechanism for fully checking that all accesses
129
      to malloced memory stay within their bounds.
130
    * No support for compaction.
131
 
132
* Synopsis of compile-time options:
133
 
134
    People have reported using previous versions of this malloc on all
135
    versions of Unix, sometimes by tweaking some of the defines
136
    below. It has been tested most extensively on Solaris and
137
    Linux. It is also reported to work on WIN32 platforms.
138
    People have also reported adapting this malloc for use in
139
    stand-alone embedded systems.
140
 
141
    The implementation is in straight, hand-tuned ANSI C.  Among other
142
    consequences, it uses a lot of macros.  Because of this, to be at
143
    all usable, this code should be compiled using an optimizing compiler
144
    (for example gcc -O2) that can simplify expressions and control
145
    paths.
146
 
147
  __STD_C                  (default: derived from C compiler defines)
148
     Nonzero if using ANSI-standard C compiler, a C++ compiler, or
149
     a C compiler sufficiently close to ANSI to get away with it.
150
  DEBUG                    (default: NOT defined)
151
     Define to enable debugging. Adds fairly extensive assertion-based
152
     checking to help track down memory errors, but noticeably slows down
153
     execution.
154
  SEPARATE_OBJECTS         (default: NOT defined)
155
     Define this to compile into separate .o files.  You must then
156
     compile malloc.c several times, defining a DEFINE_* macro each
157
     time.  The list of DEFINE_* macros appears below.
158
  MALLOC_LOCK              (default: NOT defined)
159
  MALLOC_UNLOCK            (default: NOT defined)
160
     Define these to C expressions which are run to lock and unlock
161
     the malloc data structures.  Calls may be nested; that is,
162
     MALLOC_LOCK may be called more than once before the corresponding
163
     MALLOC_UNLOCK calls.  MALLOC_LOCK must avoid waiting for a lock
164
     that it already holds.
165
  MALLOC_ALIGNMENT          (default: NOT defined)
166
     Define this to 16 if you need 16 byte alignment instead of 8 byte alignment
167
     which is the normal default.
168
  SIZE_T_SMALLER_THAN_LONG (default: NOT defined)
169
     Define this when the platform you are compiling has sizeof(long) > sizeof(size_t).
170
     The option causes some extra code to be generated to handle operations
171
     that use size_t operands and have long results.
172
  REALLOC_ZERO_BYTES_FREES (default: NOT defined)
173
     Define this if you think that realloc(p, 0) should be equivalent
174
     to free(p). Otherwise, since malloc returns a unique pointer for
175
     malloc(0), so does realloc(p, 0).
176
  HAVE_MEMCPY               (default: defined)
177
     Define if you are not otherwise using ANSI STD C, but still
178
     have memcpy and memset in your C library and want to use them.
179
     Otherwise, simple internal versions are supplied.
180
  USE_MEMCPY               (default: 1 if HAVE_MEMCPY is defined, 0 otherwise)
181
     Define as 1 if you want the C library versions of memset and
182
     memcpy called in realloc and calloc (otherwise macro versions are used).
183
     At least on some platforms, the simple macro versions usually
184
     outperform libc versions.
185
  HAVE_MMAP                 (default: defined as 1)
186
     Define to non-zero to optionally make malloc() use mmap() to
187
     allocate very large blocks.
188
  HAVE_MREMAP                 (default: defined as 0 unless Linux libc set)
189
     Define to non-zero to optionally make realloc() use mremap() to
190
     reallocate very large blocks.
191
  malloc_getpagesize        (default: derived from system #includes)
192
     Either a constant or routine call returning the system page size.
193
  HAVE_USR_INCLUDE_MALLOC_H (default: NOT defined)
194
     Optionally define if you are on a system with a /usr/include/malloc.h
195
     that declares struct mallinfo. It is not at all necessary to
196
     define this even if you do, but will ensure consistency.
197
  INTERNAL_SIZE_T           (default: size_t)
198
     Define to a 32-bit type (probably `unsigned int') if you are on a
199
     64-bit machine, yet do not want or need to allow malloc requests of
200
     greater than 2^31 to be handled. This saves space, especially for
201
     very small chunks.
202
  INTERNAL_LINUX_C_LIB      (default: NOT defined)
203
     Defined only when compiled as part of Linux libc.
204
     Also note that there is some odd internal name-mangling via defines
205
     (for example, internally, `malloc' is named `mALLOc') needed
206
     when compiling in this case. These look funny but don't otherwise
207
     affect anything.
208
  INTERNAL_NEWLIB           (default: NOT defined)
209
     Defined only when compiled as part of the Cygnus newlib
210
     distribution.
211
  WIN32                     (default: undefined)
212
     Define this on MS win (95, nt) platforms to compile in sbrk emulation.
213
  LACKS_UNISTD_H            (default: undefined)
214
     Define this if your system does not have a <unistd.h>.
215
  MORECORE                  (default: sbrk)
216
     The name of the routine to call to obtain more memory from the system.
217
  MORECORE_FAILURE          (default: -1)
218
     The value returned upon failure of MORECORE.
219
  MORECORE_CLEARS           (default 1)
220
     True (1) if the routine mapped to MORECORE zeroes out memory (which
221
     holds for sbrk).
222
  DEFAULT_TRIM_THRESHOLD
223
  DEFAULT_TOP_PAD
224
  DEFAULT_MMAP_THRESHOLD
225
  DEFAULT_MMAP_MAX
226
     Default values of tunable parameters (described in detail below)
227
     controlling interaction with host system routines (sbrk, mmap, etc).
228
     These values may also be changed dynamically via mallopt(). The
229
     preset defaults are those that give best performance for typical
230
     programs/systems.
231
 
232
 
233
*/
234
 
235
 
236
 
237
 
238
/* Preliminaries */
239
 
240
#ifndef __STD_C
241
#ifdef __STDC__
242
#define __STD_C     1
243
#else
244
#if __cplusplus
245
#define __STD_C     1
246
#else
247
#define __STD_C     0
248
#endif /*__cplusplus*/
249
#endif /*__STDC__*/
250
#endif /*__STD_C*/
251
 
252
#ifndef Void_t
253
#if __STD_C
254
#define Void_t      void
255
#else
256
#define Void_t      char
257
#endif
258
#endif /*Void_t*/
259
 
260
#if __STD_C
261
#include <stddef.h>   /* for size_t */
262
#else
263
#include <sys/types.h>
264
#endif
265
 
266
#ifdef __cplusplus
267
extern "C" {
268
#endif
269
 
270
#include <stdio.h>    /* needed for malloc_stats */
271
 
272
 
273
/*
274
  Compile-time options
275
*/
276
 
277
 
278
/*
279
 
280
  Special defines for Cygnus newlib distribution.
281
 
282
 */
283
 
284
#ifdef INTERNAL_NEWLIB
285
 
286
#include <sys/config.h>
287
 
288
/*
289
  In newlib, all the publically visible routines take a reentrancy
290
  pointer.  We don't currently do anything much with it, but we do
291
  pass it to the lock routine.
292
 */
293
 
294
#include <reent.h>
295
 
296
#define POINTER_UINT unsigned _POINTER_INT
297
#define SEPARATE_OBJECTS
298
#define HAVE_MMAP 0
299
#define MORECORE(size) _sbrk_r(reent_ptr, (size))
300
#define MORECORE_CLEARS 0
301
#define MALLOC_LOCK __malloc_lock(reent_ptr)
302
#define MALLOC_UNLOCK __malloc_unlock(reent_ptr)
303
 
304
#ifndef _WIN32
305
#ifdef SMALL_MEMORY
306
#define malloc_getpagesize (128)
307
#else
308
#define malloc_getpagesize (4096)
309
#endif
310
#endif
311
 
312
#if __STD_C
313
extern void __malloc_lock(struct _reent *);
314
extern void __malloc_unlock(struct _reent *);
315
#else
316
extern void __malloc_lock();
317
extern void __malloc_unlock();
318
#endif
319
 
320
#if __STD_C
321
#define RARG struct _reent *reent_ptr,
322
#define RONEARG struct _reent *reent_ptr
323
#else
324
#define RARG reent_ptr
325
#define RONEARG reent_ptr
326
#define RDECL struct _reent *reent_ptr;
327
#endif
328
 
329
#define RCALL reent_ptr,
330
#define RONECALL reent_ptr
331
 
332
#else /* ! INTERNAL_NEWLIB */
333
 
334
#define POINTER_UINT unsigned long
335
#define RARG
336
#define RONEARG
337
#define RDECL
338
#define RCALL
339
#define RONECALL
340
 
341
#endif /* ! INTERNAL_NEWLIB */
342
 
343
/*
344
    Debugging:
345
 
346
    Because freed chunks may be overwritten with link fields, this
347
    malloc will often die when freed memory is overwritten by user
348
    programs.  This can be very effective (albeit in an annoying way)
349
    in helping track down dangling pointers.
350
 
351
    If you compile with -DDEBUG, a number of assertion checks are
352
    enabled that will catch more memory errors. You probably won't be
353
    able to make much sense of the actual assertion errors, but they
354
    should help you locate incorrectly overwritten memory.  The
355
    checking is fairly extensive, and will slow down execution
356
    noticeably. Calling malloc_stats or mallinfo with DEBUG set will
357
    attempt to check every non-mmapped allocated and free chunk in the
358
    course of computing the summmaries. (By nature, mmapped regions
359
    cannot be checked very much automatically.)
360
 
361
    Setting DEBUG may also be helpful if you are trying to modify
362
    this code. The assertions in the check routines spell out in more
363
    detail the assumptions and invariants underlying the algorithms.
364
 
365
*/
366
 
367
#if DEBUG 
368
#include <assert.h>
369
#else
370
#define assert(x) ((void)0)
371
#endif
372
 
373
 
374
/*
375
  SEPARATE_OBJECTS should be defined if you want each function to go
376
  into a separate .o file.  You must then compile malloc.c once per
377
  function, defining the appropriate DEFINE_ macro.  See below for the
378
  list of macros.
379
 */
380
 
381
#ifndef SEPARATE_OBJECTS
382
#define DEFINE_MALLOC
383
#define DEFINE_FREE
384
#define DEFINE_REALLOC
385
#define DEFINE_CALLOC
386
#define DEFINE_CFREE
387
#define DEFINE_MEMALIGN
388
#define DEFINE_VALLOC
389
#define DEFINE_PVALLOC
390
#define DEFINE_MALLINFO
391
#define DEFINE_MALLOC_STATS
392
#define DEFINE_MALLOC_USABLE_SIZE
393
#define DEFINE_MALLOPT
394
 
395
#define STATIC static
396
#else
397
#define STATIC
398
#endif
399
 
400
/*
401
   Define MALLOC_LOCK and MALLOC_UNLOCK to C expressions to run to
402
   lock and unlock the malloc data structures.  MALLOC_LOCK may be
403
   called recursively.
404
 */
405
 
406
#ifndef MALLOC_LOCK
407
#define MALLOC_LOCK
408
#endif
409
 
410
#ifndef MALLOC_UNLOCK
411
#define MALLOC_UNLOCK
412
#endif
413
 
414
/*
415
  INTERNAL_SIZE_T is the word-size used for internal bookkeeping
416
  of chunk sizes. On a 64-bit machine, you can reduce malloc
417
  overhead by defining INTERNAL_SIZE_T to be a 32 bit `unsigned int'
418
  at the expense of not being able to handle requests greater than
419
  2^31. This limitation is hardly ever a concern; you are encouraged
420
  to set this. However, the default version is the same as size_t.
421
*/
422
 
423
#ifndef INTERNAL_SIZE_T
424
#define INTERNAL_SIZE_T size_t
425
#endif
426
 
427
/*
428
  Following is needed on implementations whereby long > size_t.
429
  The problem is caused because the code performs subtractions of
430
  size_t values and stores the result in long values.  In the case
431
  where long > size_t and the first value is actually less than
432
  the second value, the resultant value is positive.  For example,
433
  (long)(x - y) where x = 0 and y is 1 ends up being 0x00000000FFFFFFFF
434
  which is 2*31 - 1 instead of 0xFFFFFFFFFFFFFFFF.  This is due to the
435
  fact that assignment from unsigned to signed won't sign extend.
436
*/
437
 
438
#ifdef SIZE_T_SMALLER_THAN_LONG
439
#define long_sub_size_t(x, y) ( (x < y) ? -((long)(y - x)) : (x - y) );
440
#else
441
#define long_sub_size_t(x, y) ( (long)(x - y) )
442
#endif
443
 
444
/*
445
  REALLOC_ZERO_BYTES_FREES should be set if a call to
446
  realloc with zero bytes should be the same as a call to free.
447
  Some people think it should. Otherwise, since this malloc
448
  returns a unique pointer for malloc(0), so does realloc(p, 0).
449
*/
450
 
451
 
452
/*   #define REALLOC_ZERO_BYTES_FREES */
453
 
454
 
455
/*
456
  WIN32 causes an emulation of sbrk to be compiled in
457
  mmap-based options are not currently supported in WIN32.
458
*/
459
 
460
/* #define WIN32 */
461
#ifdef WIN32
462
#define MORECORE wsbrk
463
#define HAVE_MMAP 0
464
#endif
465
 
466
 
467
/*
468
  HAVE_MEMCPY should be defined if you are not otherwise using
469
  ANSI STD C, but still have memcpy and memset in your C library
470
  and want to use them in calloc and realloc. Otherwise simple
471
  macro versions are defined here.
472
 
473
  USE_MEMCPY should be defined as 1 if you actually want to
474
  have memset and memcpy called. People report that the macro
475
  versions are often enough faster than libc versions on many
476
  systems that it is better to use them.
477
 
478
*/
479
 
480
#define HAVE_MEMCPY 
481
 
482
#ifndef USE_MEMCPY
483
#ifdef HAVE_MEMCPY
484
#define USE_MEMCPY 1
485
#else
486
#define USE_MEMCPY 0
487
#endif
488
#endif
489
 
490
#if (__STD_C || defined(HAVE_MEMCPY)) 
491
 
492
#if __STD_C
493
void* memset(void*, int, size_t);
494
void* memcpy(void*, const void*, size_t);
495
#else
496
Void_t* memset();
497
Void_t* memcpy();
498
#endif
499
#endif
500
 
501
#if USE_MEMCPY
502
 
503
/* The following macros are only invoked with (2n+1)-multiples of
504
   INTERNAL_SIZE_T units, with a positive integer n. This is exploited
505
   for fast inline execution when n is small. */
506
 
507
#define MALLOC_ZERO(charp, nbytes)                                            \
508
do {                                                                          \
509
  INTERNAL_SIZE_T mzsz = (nbytes);                                            \
510
  if(mzsz <= 9*sizeof(mzsz)) {                                                \
511
    INTERNAL_SIZE_T* mz = (INTERNAL_SIZE_T*) (charp);                         \
512
    if(mzsz >= 5*sizeof(mzsz)) {     *mz++ = 0;                               \
513
                                     *mz++ = 0;                               \
514
      if(mzsz >= 7*sizeof(mzsz)) {   *mz++ = 0;                               \
515
                                     *mz++ = 0;                               \
516
        if(mzsz >= 9*sizeof(mzsz)) { *mz++ = 0;                               \
517
                                     *mz++ = 0; }}}                           \
518
                                     *mz++ = 0;                               \
519
                                     *mz++ = 0;                               \
520
                                     *mz   = 0;                               \
521
  } else memset((charp), 0, mzsz);                                            \
522
} while(0)
523
 
524
#define MALLOC_COPY(dest,src,nbytes)                                          \
525
do {                                                                          \
526
  INTERNAL_SIZE_T mcsz = (nbytes);                                            \
527
  if(mcsz <= 9*sizeof(mcsz)) {                                                \
528
    INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) (src);                        \
529
    INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) (dest);                       \
530
    if(mcsz >= 5*sizeof(mcsz)) {     *mcdst++ = *mcsrc++;                     \
531
                                     *mcdst++ = *mcsrc++;                     \
532
      if(mcsz >= 7*sizeof(mcsz)) {   *mcdst++ = *mcsrc++;                     \
533
                                     *mcdst++ = *mcsrc++;                     \
534
        if(mcsz >= 9*sizeof(mcsz)) { *mcdst++ = *mcsrc++;                     \
535
                                     *mcdst++ = *mcsrc++; }}}                 \
536
                                     *mcdst++ = *mcsrc++;                     \
537
                                     *mcdst++ = *mcsrc++;                     \
538
                                     *mcdst   = *mcsrc  ;                     \
539
  } else memcpy(dest, src, mcsz);                                             \
540
} while(0)
541
 
542
#else /* !USE_MEMCPY */
543
 
544
/* Use Duff's device for good zeroing/copying performance. */
545
 
546
#define MALLOC_ZERO(charp, nbytes)                                            \
547
do {                                                                          \
548
  INTERNAL_SIZE_T* mzp = (INTERNAL_SIZE_T*)(charp);                           \
549
  long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn;                         \
550
  if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; }             \
551
  switch (mctmp) {                                                            \
552
    case 0: for(;;) { *mzp++ = 0;                                             \
553
    case 7:           *mzp++ = 0;                                             \
554
    case 6:           *mzp++ = 0;                                             \
555
    case 5:           *mzp++ = 0;                                             \
556
    case 4:           *mzp++ = 0;                                             \
557
    case 3:           *mzp++ = 0;                                             \
558
    case 2:           *mzp++ = 0;                                             \
559
    case 1:           *mzp++ = 0; if(mcn <= 0) break; mcn--; }                \
560
  }                                                                           \
561
} while(0)
562
 
563
#define MALLOC_COPY(dest,src,nbytes)                                          \
564
do {                                                                          \
565
  INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) src;                            \
566
  INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) dest;                           \
567
  long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn;                         \
568
  if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; }             \
569
  switch (mctmp) {                                                            \
570
    case 0: for(;;) { *mcdst++ = *mcsrc++;                                    \
571
    case 7:           *mcdst++ = *mcsrc++;                                    \
572
    case 6:           *mcdst++ = *mcsrc++;                                    \
573
    case 5:           *mcdst++ = *mcsrc++;                                    \
574
    case 4:           *mcdst++ = *mcsrc++;                                    \
575
    case 3:           *mcdst++ = *mcsrc++;                                    \
576
    case 2:           *mcdst++ = *mcsrc++;                                    \
577
    case 1:           *mcdst++ = *mcsrc++; if(mcn <= 0) break; mcn--; }       \
578
  }                                                                           \
579
} while(0)
580
 
581
#endif
582
 
583
 
584
/*
585
  Define HAVE_MMAP to optionally make malloc() use mmap() to
586
  allocate very large blocks.  These will be returned to the
587
  operating system immediately after a free().
588
*/
589
 
590
#ifndef HAVE_MMAP
591
#define HAVE_MMAP 1
592
#endif
593
 
594
/*
595
  Define HAVE_MREMAP to make realloc() use mremap() to re-allocate
596
  large blocks.  This is currently only possible on Linux with
597
  kernel versions newer than 1.3.77.
598
*/
599
 
600
#ifndef HAVE_MREMAP
601
#ifdef INTERNAL_LINUX_C_LIB
602
#define HAVE_MREMAP 1
603
#else
604
#define HAVE_MREMAP 0
605
#endif
606
#endif
607
 
608
#if HAVE_MMAP
609
 
610
#include <unistd.h>
611
#include <fcntl.h>
612
#include <sys/mman.h>
613
 
614
#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
615
#define MAP_ANONYMOUS MAP_ANON
616
#endif
617
 
618
#endif /* HAVE_MMAP */
619
 
620
/*
621
  Access to system page size. To the extent possible, this malloc
622
  manages memory from the system in page-size units.
623
 
624
  The following mechanics for getpagesize were adapted from
625
  bsd/gnu getpagesize.h
626
*/
627
 
628
#ifndef LACKS_UNISTD_H
629
#  include <unistd.h>
630
#endif
631
 
632
#ifndef malloc_getpagesize
633
#  ifdef _SC_PAGESIZE         /* some SVR4 systems omit an underscore */
634
#    ifndef _SC_PAGE_SIZE
635
#      define _SC_PAGE_SIZE _SC_PAGESIZE
636
#    endif
637
#  endif
638
#  ifdef _SC_PAGE_SIZE
639
#    define malloc_getpagesize sysconf(_SC_PAGE_SIZE)
640
#  else
641
#    if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE)
642
       extern size_t getpagesize();
643
#      define malloc_getpagesize getpagesize()
644
#    else
645
#      include <sys/param.h>
646
#      ifdef EXEC_PAGESIZE
647
#        define malloc_getpagesize EXEC_PAGESIZE
648
#      else
649
#        ifdef NBPG
650
#          ifndef CLSIZE
651
#            define malloc_getpagesize NBPG
652
#          else
653
#            define malloc_getpagesize (NBPG * CLSIZE)
654
#          endif
655
#        else 
656
#          ifdef NBPC
657
#            define malloc_getpagesize NBPC
658
#          else
659
#            ifdef PAGESIZE
660
#              define malloc_getpagesize PAGESIZE
661
#            else
662
#              define malloc_getpagesize (4096) /* just guess */
663
#            endif
664
#          endif
665
#        endif 
666
#      endif
667
#    endif 
668
#  endif
669
#endif
670
 
671
 
672
 
673
/*
674
 
675
  This version of malloc supports the standard SVID/XPG mallinfo
676
  routine that returns a struct containing the same kind of
677
  information you can get from malloc_stats. It should work on
678
  any SVID/XPG compliant system that has a /usr/include/malloc.h
679
  defining struct mallinfo. (If you'd like to install such a thing
680
  yourself, cut out the preliminary declarations as described above
681
  and below and save them in a malloc.h file. But there's no
682
  compelling reason to bother to do this.)
683
 
684
  The main declaration needed is the mallinfo struct that is returned
685
  (by-copy) by mallinfo().  The SVID/XPG malloinfo struct contains a
686
  bunch of fields, most of which are not even meaningful in this
687
  version of malloc. Some of these fields are are instead filled by
688
  mallinfo() with other numbers that might possibly be of interest.
689
 
690
  HAVE_USR_INCLUDE_MALLOC_H should be set if you have a
691
  /usr/include/malloc.h file that includes a declaration of struct
692
  mallinfo.  If so, it is included; else an SVID2/XPG2 compliant
693
  version is declared below.  These must be precisely the same for
694
  mallinfo() to work.
695
 
696
*/
697
 
698
/* #define HAVE_USR_INCLUDE_MALLOC_H */
699
 
700
#if HAVE_USR_INCLUDE_MALLOC_H
701
#include "/usr/include/malloc.h"
702
#else
703
 
704
/* SVID2/XPG mallinfo structure */
705
 
706
struct mallinfo {
707
  int arena;    /* total space allocated from system */
708
  int ordblks;  /* number of non-inuse chunks */
709
  int smblks;   /* unused -- always zero */
710
  int hblks;    /* number of mmapped regions */
711
  int hblkhd;   /* total space in mmapped regions */
712
  int usmblks;  /* unused -- always zero */
713
  int fsmblks;  /* unused -- always zero */
714
  int uordblks; /* total allocated space */
715
  int fordblks; /* total non-inuse space */
716
  int keepcost; /* top-most, releasable (via malloc_trim) space */
717
};
718
 
719
/* SVID2/XPG mallopt options */
720
 
721
#define M_MXFAST  1    /* UNUSED in this malloc */
722
#define M_NLBLKS  2    /* UNUSED in this malloc */
723
#define M_GRAIN   3    /* UNUSED in this malloc */
724
#define M_KEEP    4    /* UNUSED in this malloc */
725
 
726
#endif
727
 
728
/* mallopt options that actually do something */
729
 
730
#define M_TRIM_THRESHOLD    -1
731
#define M_TOP_PAD           -2
732
#define M_MMAP_THRESHOLD    -3
733
#define M_MMAP_MAX          -4
734
 
735
 
736
 
737
#ifndef DEFAULT_TRIM_THRESHOLD
738
#define DEFAULT_TRIM_THRESHOLD (128L * 1024L)
739
#endif
740
 
741
/*
742
    M_TRIM_THRESHOLD is the maximum amount of unused top-most memory
743
      to keep before releasing via malloc_trim in free().
744
 
745
      Automatic trimming is mainly useful in long-lived programs.
746
      Because trimming via sbrk can be slow on some systems, and can
747
      sometimes be wasteful (in cases where programs immediately
748
      afterward allocate more large chunks) the value should be high
749
      enough so that your overall system performance would improve by
750
      releasing.
751
 
752
      The trim threshold and the mmap control parameters (see below)
753
      can be traded off with one another. Trimming and mmapping are
754
      two different ways of releasing unused memory back to the
755
      system. Between these two, it is often possible to keep
756
      system-level demands of a long-lived program down to a bare
757
      minimum. For example, in one test suite of sessions measuring
758
      the XF86 X server on Linux, using a trim threshold of 128K and a
759
      mmap threshold of 192K led to near-minimal long term resource
760
      consumption.
761
 
762
      If you are using this malloc in a long-lived program, it should
763
      pay to experiment with these values.  As a rough guide, you
764
      might set to a value close to the average size of a process
765
      (program) running on your system.  Releasing this much memory
766
      would allow such a process to run in memory.  Generally, it's
767
      worth it to tune for trimming rather tham memory mapping when a
768
      program undergoes phases where several large chunks are
769
      allocated and released in ways that can reuse each other's
770
      storage, perhaps mixed with phases where there are no such
771
      chunks at all.  And in well-behaved long-lived programs,
772
      controlling release of large blocks via trimming versus mapping
773
      is usually faster.
774
 
775
      However, in most programs, these parameters serve mainly as
776
      protection against the system-level effects of carrying around
777
      massive amounts of unneeded memory. Since frequent calls to
778
      sbrk, mmap, and munmap otherwise degrade performance, the default
779
      parameters are set to relatively high values that serve only as
780
      safeguards.
781
 
782
      The default trim value is high enough to cause trimming only in
783
      fairly extreme (by current memory consumption standards) cases.
784
      It must be greater than page size to have any useful effect.  To
785
      disable trimming completely, you can set to (unsigned long)(-1);
786
 
787
 
788
*/
789
 
790
 
791
#ifndef DEFAULT_TOP_PAD
792
#define DEFAULT_TOP_PAD        (0)
793
#endif
794
 
795
/*
796
    M_TOP_PAD is the amount of extra `padding' space to allocate or
797
      retain whenever sbrk is called. It is used in two ways internally:
798
 
799
      * When sbrk is called to extend the top of the arena to satisfy
800
        a new malloc request, this much padding is added to the sbrk
801
        request.
802
 
803
      * When malloc_trim is called automatically from free(),
804
        it is used as the `pad' argument.
805
 
806
      In both cases, the actual amount of padding is rounded
807
      so that the end of the arena is always a system page boundary.
808
 
809
      The main reason for using padding is to avoid calling sbrk so
810
      often. Having even a small pad greatly reduces the likelihood
811
      that nearly every malloc request during program start-up (or
812
      after trimming) will invoke sbrk, which needlessly wastes
813
      time.
814
 
815
      Automatic rounding-up to page-size units is normally sufficient
816
      to avoid measurable overhead, so the default is 0.  However, in
817
      systems where sbrk is relatively slow, it can pay to increase
818
      this value, at the expense of carrying around more memory than
819
      the program needs.
820
 
821
*/
822
 
823
 
824
#ifndef DEFAULT_MMAP_THRESHOLD
825
#define DEFAULT_MMAP_THRESHOLD (128 * 1024)
826
#endif
827
 
828
/*
829
 
830
    M_MMAP_THRESHOLD is the request size threshold for using mmap()
831
      to service a request. Requests of at least this size that cannot
832
      be allocated using already-existing space will be serviced via mmap.
833
      (If enough normal freed space already exists it is used instead.)
834
 
835
      Using mmap segregates relatively large chunks of memory so that
836
      they can be individually obtained and released from the host
837
      system. A request serviced through mmap is never reused by any
838
      other request (at least not directly; the system may just so
839
      happen to remap successive requests to the same locations).
840
 
841
      Segregating space in this way has the benefit that mmapped space
842
      can ALWAYS be individually released back to the system, which
843
      helps keep the system level memory demands of a long-lived
844
      program low. Mapped memory can never become `locked' between
845
      other chunks, as can happen with normally allocated chunks, which
846
      menas that even trimming via malloc_trim would not release them.
847
 
848
      However, it has the disadvantages that:
849
 
850
         1. The space cannot be reclaimed, consolidated, and then
851
            used to service later requests, as happens with normal chunks.
852
         2. It can lead to more wastage because of mmap page alignment
853
            requirements
854
         3. It causes malloc performance to be more dependent on host
855
            system memory management support routines which may vary in
856
            implementation quality and may impose arbitrary
857
            limitations. Generally, servicing a request via normal
858
            malloc steps is faster than going through a system's mmap.
859
 
860
      All together, these considerations should lead you to use mmap
861
      only for relatively large requests.
862
 
863
 
864
*/
865
 
866
 
867
 
868
#ifndef DEFAULT_MMAP_MAX
869
#if HAVE_MMAP
870
#define DEFAULT_MMAP_MAX       (64)
871
#else
872
#define DEFAULT_MMAP_MAX       (0)
873
#endif
874
#endif
875
 
876
/*
877
    M_MMAP_MAX is the maximum number of requests to simultaneously
878
      service using mmap. This parameter exists because:
879
 
880
         1. Some systems have a limited number of internal tables for
881
            use by mmap.
882
         2. In most systems, overreliance on mmap can degrade overall
883
            performance.
884
         3. If a program allocates many large regions, it is probably
885
            better off using normal sbrk-based allocation routines that
886
            can reclaim and reallocate normal heap memory. Using a
887
            small value allows transition into this mode after the
888
            first few allocations.
889
 
890
      Setting to 0 disables all use of mmap.  If HAVE_MMAP is not set,
891
      the default value is 0, and attempts to set it to non-zero values
892
      in mallopt will fail.
893
*/
894
 
895
 
896
 
897
 
898
/*
899
 
900
  Special defines for linux libc
901
 
902
  Except when compiled using these special defines for Linux libc
903
  using weak aliases, this malloc is NOT designed to work in
904
  multithreaded applications.  No semaphores or other concurrency
905
  control are provided to ensure that multiple malloc or free calls
906
  don't run at the same time, which could be disasterous. A single
907
  semaphore could be used across malloc, realloc, and free (which is
908
  essentially the effect of the linux weak alias approach). It would
909
  be hard to obtain finer granularity.
910
 
911
*/
912
 
913
 
914
#ifdef INTERNAL_LINUX_C_LIB
915
 
916
#if __STD_C
917
 
918
Void_t * __default_morecore_init (ptrdiff_t);
919
Void_t *(*__morecore)(ptrdiff_t) = __default_morecore_init;
920
 
921
#else
922
 
923
Void_t * __default_morecore_init ();
924
Void_t *(*__morecore)() = __default_morecore_init;
925
 
926
#endif
927
 
928
#define MORECORE (*__morecore)
929
#define MORECORE_FAILURE 0
930
#define MORECORE_CLEARS 1 
931
 
932
#else /* INTERNAL_LINUX_C_LIB */
933
 
934
#ifndef INTERNAL_NEWLIB
935
#if __STD_C
936
extern Void_t*     sbrk(ptrdiff_t);
937
#else
938
extern Void_t*     sbrk();
939
#endif
940
#endif
941
 
942
#ifndef MORECORE
943
#define MORECORE sbrk
944
#endif
945
 
946
#ifndef MORECORE_FAILURE
947
#define MORECORE_FAILURE -1
948
#endif
949
 
950
#ifndef MORECORE_CLEARS
951
#define MORECORE_CLEARS 1
952
#endif
953
 
954
#endif /* INTERNAL_LINUX_C_LIB */
955
 
956
#if defined(INTERNAL_LINUX_C_LIB) && defined(__ELF__)
957
 
958
#define cALLOc          __libc_calloc
959
#define fREe            __libc_free
960
#define mALLOc          __libc_malloc
961
#define mEMALIGn        __libc_memalign
962
#define rEALLOc         __libc_realloc
963
#define vALLOc          __libc_valloc
964
#define pvALLOc         __libc_pvalloc
965
#define mALLINFo        __libc_mallinfo
966
#define mALLOPt         __libc_mallopt
967
 
968
#pragma weak calloc = __libc_calloc
969
#pragma weak free = __libc_free
970
#pragma weak cfree = __libc_free
971
#pragma weak malloc = __libc_malloc
972
#pragma weak memalign = __libc_memalign
973
#pragma weak realloc = __libc_realloc
974
#pragma weak valloc = __libc_valloc
975
#pragma weak pvalloc = __libc_pvalloc
976
#pragma weak mallinfo = __libc_mallinfo
977
#pragma weak mallopt = __libc_mallopt
978
 
979
#else
980
 
981
#ifdef INTERNAL_NEWLIB
982
 
983
#define cALLOc          _calloc_r
984
#define fREe            _free_r
985
#define mALLOc          _malloc_r
986
#define mEMALIGn        _memalign_r
987
#define rEALLOc         _realloc_r
988
#define vALLOc          _valloc_r
989
#define pvALLOc         _pvalloc_r
990
#define mALLINFo        _mallinfo_r
991
#define mALLOPt         _mallopt_r
992
 
993
#define malloc_stats                    _malloc_stats_r
994
#define malloc_trim                     _malloc_trim_r
995
#define malloc_usable_size              _malloc_usable_size_r
996
 
997
#define malloc_update_mallinfo          __malloc_update_mallinfo
998
 
999
#define malloc_av_                      __malloc_av_
1000
#define malloc_current_mallinfo         __malloc_current_mallinfo
1001
#define malloc_max_sbrked_mem           __malloc_max_sbrked_mem
1002
#define malloc_max_total_mem            __malloc_max_total_mem
1003
#define malloc_sbrk_base                __malloc_sbrk_base
1004
#define malloc_top_pad                  __malloc_top_pad
1005
#define malloc_trim_threshold           __malloc_trim_threshold
1006
 
1007
#else /* ! INTERNAL_NEWLIB */
1008
 
1009
#define cALLOc          calloc
1010
#define fREe            free
1011
#define mALLOc          malloc
1012
#define mEMALIGn        memalign
1013
#define rEALLOc         realloc
1014
#define vALLOc          valloc
1015
#define pvALLOc         pvalloc
1016
#define mALLINFo        mallinfo
1017
#define mALLOPt         mallopt
1018
 
1019
#endif /* ! INTERNAL_NEWLIB */
1020
#endif
1021
 
1022
/* Public routines */
1023
 
1024
#if __STD_C
1025
 
1026
Void_t* mALLOc(RARG size_t);
1027
void    fREe(RARG Void_t*);
1028
Void_t* rEALLOc(RARG Void_t*, size_t);
1029
Void_t* mEMALIGn(RARG size_t, size_t);
1030
Void_t* vALLOc(RARG size_t);
1031
Void_t* pvALLOc(RARG size_t);
1032
Void_t* cALLOc(RARG size_t, size_t);
1033
void    cfree(Void_t*);
1034
int     malloc_trim(RARG size_t);
1035
size_t  malloc_usable_size(RARG Void_t*);
1036
void    malloc_stats(RONEARG);
1037
int     mALLOPt(RARG int, int);
1038
struct mallinfo mALLINFo(RONEARG);
1039
#else
1040
Void_t* mALLOc();
1041
void    fREe();
1042
Void_t* rEALLOc();
1043
Void_t* mEMALIGn();
1044
Void_t* vALLOc();
1045
Void_t* pvALLOc();
1046
Void_t* cALLOc();
1047
void    cfree();
1048
int     malloc_trim();
1049
size_t  malloc_usable_size();
1050
void    malloc_stats();
1051
int     mALLOPt();
1052
struct mallinfo mALLINFo();
1053
#endif
1054
 
1055
 
1056
#ifdef __cplusplus
1057
};  /* end of extern "C" */
1058
#endif
1059
 
1060
/* ---------- To make a malloc.h, end cutting here ------------ */
1061
 
1062
 
1063
/*
1064
  Emulation of sbrk for WIN32
1065
  All code within the ifdef WIN32 is untested by me.
1066
*/
1067
 
1068
 
1069
#ifdef WIN32
1070
 
1071
#define AlignPage(add) (((add) + (malloc_getpagesize-1)) &
1072
~(malloc_getpagesize-1))
1073
 
1074
/* resrve 64MB to insure large contiguous space */
1075
#define RESERVED_SIZE (1024*1024*64)
1076
#define NEXT_SIZE (2048*1024)
1077
#define TOP_MEMORY ((unsigned long)2*1024*1024*1024)
1078
 
1079
struct GmListElement;
1080
typedef struct GmListElement GmListElement;
1081
 
1082
struct GmListElement
1083
{
1084
        GmListElement* next;
1085
        void* base;
1086
};
1087
 
1088
static GmListElement* head = 0;
1089
static unsigned int gNextAddress = 0;
1090
static unsigned int gAddressBase = 0;
1091
static unsigned int gAllocatedSize = 0;
1092
 
1093
static
1094
GmListElement* makeGmListElement (void* bas)
1095
{
1096
        GmListElement* this;
1097
        this = (GmListElement*)(void*)LocalAlloc (0, sizeof (GmListElement));
1098
        ASSERT (this);
1099
        if (this)
1100
        {
1101
                this->base = bas;
1102
                this->next = head;
1103
                head = this;
1104
        }
1105
        return this;
1106
}
1107
 
1108
void gcleanup ()
1109
{
1110
        BOOL rval;
1111
        ASSERT ( (head == NULL) || (head->base == (void*)gAddressBase));
1112
        if (gAddressBase && (gNextAddress - gAddressBase))
1113
        {
1114
                rval = VirtualFree ((void*)gAddressBase,
1115
                                                        gNextAddress - gAddressBase,
1116
                                                        MEM_DECOMMIT);
1117
        ASSERT (rval);
1118
        }
1119
        while (head)
1120
        {
1121
                GmListElement* next = head->next;
1122
                rval = VirtualFree (head->base, 0, MEM_RELEASE);
1123
                ASSERT (rval);
1124
                LocalFree (head);
1125
                head = next;
1126
        }
1127
}
1128
 
1129
static
1130
void* findRegion (void* start_address, unsigned long size)
1131
{
1132
        MEMORY_BASIC_INFORMATION info;
1133
        while ((unsigned long)start_address < TOP_MEMORY)
1134
        {
1135
                VirtualQuery (start_address, &info, sizeof (info));
1136
                if (info.State != MEM_FREE)
1137
                        start_address = (char*)info.BaseAddress + info.RegionSize;
1138
                else if (info.RegionSize >= size)
1139
                        return start_address;
1140
                else
1141
                        start_address = (char*)info.BaseAddress + info.RegionSize;
1142
        }
1143
        return NULL;
1144
 
1145
}
1146
 
1147
 
1148
void* wsbrk (long size)
1149
{
1150
        void* tmp;
1151
        if (size > 0)
1152
        {
1153
                if (gAddressBase == 0)
1154
                {
1155
                        gAllocatedSize = max (RESERVED_SIZE, AlignPage (size));
1156
                        gNextAddress = gAddressBase =
1157
                                (unsigned int)VirtualAlloc (NULL, gAllocatedSize,
1158
                                                                                        MEM_RESERVE, PAGE_NOACCESS);
1159
                } else if (AlignPage (gNextAddress + size) > (gAddressBase +
1160
gAllocatedSize))
1161
                {
1162
                        long new_size = max (NEXT_SIZE, AlignPage (size));
1163
                        void* new_address = (void*)(gAddressBase+gAllocatedSize);
1164
                        do
1165
                        {
1166
                                new_address = findRegion (new_address, new_size);
1167
 
1168
                                if (new_address == 0)
1169
                                        return (void*)-1;
1170
 
1171
                                gAddressBase = gNextAddress =
1172
                                        (unsigned int)VirtualAlloc (new_address, new_size,
1173
                                                                                                MEM_RESERVE, PAGE_NOACCESS);
1174
                                // repeat in case of race condition
1175
                                // The region that we found has been snagged 
1176
                                // by another thread
1177
                        }
1178
                        while (gAddressBase == 0);
1179
 
1180
                        ASSERT (new_address == (void*)gAddressBase);
1181
 
1182
                        gAllocatedSize = new_size;
1183
 
1184
                        if (!makeGmListElement ((void*)gAddressBase))
1185
                                return (void*)-1;
1186
                }
1187
                if ((size + gNextAddress) > AlignPage (gNextAddress))
1188
                {
1189
                        void* res;
1190
                        res = VirtualAlloc ((void*)AlignPage (gNextAddress),
1191
                                                                (size + gNextAddress -
1192
                                                                 AlignPage (gNextAddress)),
1193
                                                                MEM_COMMIT, PAGE_READWRITE);
1194
                        if (res == 0)
1195
                                return (void*)-1;
1196
                }
1197
                tmp = (void*)gNextAddress;
1198
                gNextAddress = (unsigned int)tmp + size;
1199
                return tmp;
1200
        }
1201
        else if (size < 0)
1202
        {
1203
                unsigned int alignedGoal = AlignPage (gNextAddress + size);
1204
                /* Trim by releasing the virtual memory */
1205
                if (alignedGoal >= gAddressBase)
1206
                {
1207
                        VirtualFree ((void*)alignedGoal, gNextAddress - alignedGoal,
1208
                                                 MEM_DECOMMIT);
1209
                        gNextAddress = gNextAddress + size;
1210
                        return (void*)gNextAddress;
1211
                }
1212
                else
1213
                {
1214
                        VirtualFree ((void*)gAddressBase, gNextAddress - gAddressBase,
1215
                                                 MEM_DECOMMIT);
1216
                        gNextAddress = gAddressBase;
1217
                        return (void*)-1;
1218
                }
1219
        }
1220
        else
1221
        {
1222
                return (void*)gNextAddress;
1223
        }
1224
}
1225
 
1226
#endif
1227
 
1228
 
1229
 
1230
/*
1231
  Type declarations
1232
*/
1233
 
1234
 
1235
struct malloc_chunk
1236
{
1237
  INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */
1238
  INTERNAL_SIZE_T size;      /* Size in bytes, including overhead. */
1239
  struct malloc_chunk* fd;   /* double links -- used only if free. */
1240
  struct malloc_chunk* bk;
1241
};
1242
 
1243
typedef struct malloc_chunk* mchunkptr;
1244
 
1245
/*
1246
 
1247
   malloc_chunk details:
1248
 
1249
    (The following includes lightly edited explanations by Colin Plumb.)
1250
 
1251
    Chunks of memory are maintained using a `boundary tag' method as
1252
    described in e.g., Knuth or Standish.  (See the paper by Paul
1253
    Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a
1254
    survey of such techniques.)  Sizes of free chunks are stored both
1255
    in the front of each chunk and at the end.  This makes
1256
    consolidating fragmented chunks into bigger chunks very fast.  The
1257
    size fields also hold bits representing whether chunks are free or
1258
    in use.
1259
 
1260
    An allocated chunk looks like this:
1261
 
1262
 
1263
    chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1264
            |             Size of previous chunk, if allocated            | |
1265
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1266
            |             Size of chunk, in bytes                         |P|
1267
      mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1268
            |             User data starts here...                          .
1269
            .                                                               .
1270
            .             (malloc_usable_space() bytes)                     .
1271
            .                                                               |
1272
nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1273
            |             Size of chunk                                     |
1274
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1275
 
1276
 
1277
    Where "chunk" is the front of the chunk for the purpose of most of
1278
    the malloc code, but "mem" is the pointer that is returned to the
1279
    user.  "Nextchunk" is the beginning of the next contiguous chunk.
1280
 
1281
    Chunks always begin on even word boundries, so the mem portion
1282
    (which is returned to the user) is also on an even word boundary, and
1283
    thus double-word aligned.
1284
 
1285
    Free chunks are stored in circular doubly-linked lists, and look like this:
1286
 
1287
    chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1288
            |             Size of previous chunk                            |
1289
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1290
    `head:' |             Size of chunk, in bytes                         |P|
1291
      mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1292
            |             Forward pointer to next chunk in list             |
1293
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1294
            |             Back pointer to previous chunk in list            |
1295
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1296
            |             Unused space (may be 0 bytes long)                .
1297
            .                                                               .
1298
            .                                                               |
1299
nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1300
    `foot:' |             Size of chunk, in bytes                           |
1301
            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1302
 
1303
    The P (PREV_INUSE) bit, stored in the unused low-order bit of the
1304
    chunk size (which is always a multiple of two words), is an in-use
1305
    bit for the *previous* chunk.  If that bit is *clear*, then the
1306
    word before the current chunk size contains the previous chunk
1307
    size, and can be used to find the front of the previous chunk.
1308
    (The very first chunk allocated always has this bit set,
1309
    preventing access to non-existent (or non-owned) memory.)
1310
 
1311
    Note that the `foot' of the current chunk is actually represented
1312
    as the prev_size of the NEXT chunk. (This makes it easier to
1313
    deal with alignments etc).
1314
 
1315
    The two exceptions to all this are
1316
 
1317
     1. The special chunk `top', which doesn't bother using the
1318
        trailing size field since there is no
1319
        next contiguous chunk that would have to index off it. (After
1320
        initialization, `top' is forced to always exist.  If it would
1321
        become less than MINSIZE bytes long, it is replenished via
1322
        malloc_extend_top.)
1323
 
1324
     2. Chunks allocated via mmap, which have the second-lowest-order
1325
        bit (IS_MMAPPED) set in their size fields.  Because they are
1326
        never merged or traversed from any other chunk, they have no
1327
        foot size or inuse information.
1328
 
1329
    Available chunks are kept in any of several places (all declared below):
1330
 
1331
    * `av': An array of chunks serving as bin headers for consolidated
1332
       chunks. Each bin is doubly linked.  The bins are approximately
1333
       proportionally (log) spaced.  There are a lot of these bins
1334
       (128). This may look excessive, but works very well in
1335
       practice.  All procedures maintain the invariant that no
1336
       consolidated chunk physically borders another one. Chunks in
1337
       bins are kept in size order, with ties going to the
1338
       approximately least recently used chunk.
1339
 
1340
       The chunks in each bin are maintained in decreasing sorted order by
1341
       size.  This is irrelevant for the small bins, which all contain
1342
       the same-sized chunks, but facilitates best-fit allocation for
1343
       larger chunks. (These lists are just sequential. Keeping them in
1344
       order almost never requires enough traversal to warrant using
1345
       fancier ordered data structures.)  Chunks of the same size are
1346
       linked with the most recently freed at the front, and allocations
1347
       are taken from the back.  This results in LRU or FIFO allocation
1348
       order, which tends to give each chunk an equal opportunity to be
1349
       consolidated with adjacent freed chunks, resulting in larger free
1350
       chunks and less fragmentation.
1351
 
1352
    * `top': The top-most available chunk (i.e., the one bordering the
1353
       end of available memory) is treated specially. It is never
1354
       included in any bin, is used only if no other chunk is
1355
       available, and is released back to the system if it is very
1356
       large (see M_TRIM_THRESHOLD).
1357
 
1358
    * `last_remainder': A bin holding only the remainder of the
1359
       most recently split (non-top) chunk. This bin is checked
1360
       before other non-fitting chunks, so as to provide better
1361
       locality for runs of sequentially allocated chunks.
1362
 
1363
    *  Implicitly, through the host system's memory mapping tables.
1364
       If supported, requests greater than a threshold are usually
1365
       serviced via calls to mmap, and then later released via munmap.
1366
 
1367
*/
1368
 
1369
 
1370
 
1371
 
1372
 
1373
 
1374
/*  sizes, alignments */
1375
 
1376
#define SIZE_SZ                (sizeof(INTERNAL_SIZE_T))
1377
#ifndef MALLOC_ALIGNMENT
1378
#define MALLOC_ALIGN           8
1379
#define MALLOC_ALIGNMENT       (SIZE_SZ + SIZE_SZ)
1380
#else
1381
#define MALLOC_ALIGN           MALLOC_ALIGNMENT
1382
#endif
1383
#define MALLOC_ALIGN_MASK      (MALLOC_ALIGNMENT - 1)
1384
#define MINSIZE                (sizeof(struct malloc_chunk))
1385
 
1386
/* conversion from malloc headers to user pointers, and back */
1387
 
1388
#define chunk2mem(p)   ((Void_t*)((char*)(p) + 2*SIZE_SZ))
1389
#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ))
1390
 
1391
/* pad request bytes into a usable size */
1392
 
1393
#define request2size(req) \
1394
 (((long)((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) < \
1395
  (long)(MINSIZE + MALLOC_ALIGN_MASK)) ? ((MINSIZE + MALLOC_ALIGN_MASK) & ~(MALLOC_ALIGN_MASK)) : \
1396
   (((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) & ~(MALLOC_ALIGN_MASK)))
1397
 
1398
/* Check if m has acceptable alignment */
1399
 
1400
#define aligned_OK(m)    (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0)
1401
 
1402
 
1403
 
1404
 
1405
/*
1406
  Physical chunk operations
1407
*/
1408
 
1409
 
1410
/* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */
1411
 
1412
#define PREV_INUSE 0x1 
1413
 
1414
/* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */
1415
 
1416
#define IS_MMAPPED 0x2
1417
 
1418
/* Bits to mask off when extracting size */
1419
 
1420
#define SIZE_BITS (PREV_INUSE|IS_MMAPPED)
1421
 
1422
 
1423
/* Ptr to next physical malloc_chunk. */
1424
 
1425
#define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->size & ~PREV_INUSE) ))
1426
 
1427
/* Ptr to previous physical malloc_chunk */
1428
 
1429
#define prev_chunk(p)\
1430
   ((mchunkptr)( ((char*)(p)) - ((p)->prev_size) ))
1431
 
1432
 
1433
/* Treat space at ptr + offset as a chunk */
1434
 
1435
#define chunk_at_offset(p, s)  ((mchunkptr)(((char*)(p)) + (s)))
1436
 
1437
 
1438
 
1439
 
1440
/*
1441
  Dealing with use bits
1442
*/
1443
 
1444
/* extract p's inuse bit */
1445
 
1446
#define inuse(p)\
1447
((((mchunkptr)(((char*)(p))+((p)->size & ~PREV_INUSE)))->size) & PREV_INUSE)
1448
 
1449
/* extract inuse bit of previous chunk */
1450
 
1451
#define prev_inuse(p)  ((p)->size & PREV_INUSE)
1452
 
1453
/* check for mmap()'ed chunk */
1454
 
1455
#define chunk_is_mmapped(p) ((p)->size & IS_MMAPPED)
1456
 
1457
/* set/clear chunk as in use without otherwise disturbing */
1458
 
1459
#define set_inuse(p)\
1460
((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size |= PREV_INUSE
1461
 
1462
#define clear_inuse(p)\
1463
((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size &= ~(PREV_INUSE)
1464
 
1465
/* check/set/clear inuse bits in known places */
1466
 
1467
#define inuse_bit_at_offset(p, s)\
1468
 (((mchunkptr)(((char*)(p)) + (s)))->size & PREV_INUSE)
1469
 
1470
#define set_inuse_bit_at_offset(p, s)\
1471
 (((mchunkptr)(((char*)(p)) + (s)))->size |= PREV_INUSE)
1472
 
1473
#define clear_inuse_bit_at_offset(p, s)\
1474
 (((mchunkptr)(((char*)(p)) + (s)))->size &= ~(PREV_INUSE))
1475
 
1476
 
1477
 
1478
 
1479
/*
1480
  Dealing with size fields
1481
*/
1482
 
1483
/* Get size, ignoring use bits */
1484
 
1485
#define chunksize(p)          ((p)->size & ~(SIZE_BITS))
1486
 
1487
/* Set size at head, without disturbing its use bit */
1488
 
1489
#define set_head_size(p, s)   ((p)->size = (((p)->size & PREV_INUSE) | (s)))
1490
 
1491
/* Set size/use ignoring previous bits in header */
1492
 
1493
#define set_head(p, s)        ((p)->size = (s))
1494
 
1495
/* Set size at footer (only when chunk is not in use) */
1496
 
1497
#define set_foot(p, s)   (((mchunkptr)((char*)(p) + (s)))->prev_size = (s))
1498
 
1499
 
1500
 
1501
 
1502
 
1503
/*
1504
   Bins
1505
 
1506
    The bins, `av_' are an array of pairs of pointers serving as the
1507
    heads of (initially empty) doubly-linked lists of chunks, laid out
1508
    in a way so that each pair can be treated as if it were in a
1509
    malloc_chunk. (This way, the fd/bk offsets for linking bin heads
1510
    and chunks are the same).
1511
 
1512
    Bins for sizes < 512 bytes contain chunks of all the same size, spaced
1513
    8 bytes apart. Larger bins are approximately logarithmically
1514
    spaced. (See the table below.) The `av_' array is never mentioned
1515
    directly in the code, but instead via bin access macros.
1516
 
1517
    Bin layout:
1518
 
1519
    64 bins of size       8
1520
    32 bins of size      64
1521
    16 bins of size     512
1522
     8 bins of size    4096
1523
     4 bins of size   32768
1524
     2 bins of size  262144
1525
     1 bin  of size what's left
1526
 
1527
    There is actually a little bit of slop in the numbers in bin_index
1528
    for the sake of speed. This makes no difference elsewhere.
1529
 
1530
    The special chunks `top' and `last_remainder' get their own bins,
1531
    (this is implemented via yet more trickery with the av_ array),
1532
    although `top' is never properly linked to its bin since it is
1533
    always handled specially.
1534
 
1535
*/
1536
 
1537
#ifdef SEPARATE_OBJECTS
1538
#define av_ malloc_av_
1539
#endif
1540
 
1541
#define NAV             128   /* number of bins */
1542
 
1543
typedef struct malloc_chunk* mbinptr;
1544
 
1545
/* access macros */
1546
 
1547
#define bin_at(i)      ((mbinptr)((char*)&(av_[2*(i) + 2]) - 2*SIZE_SZ))
1548
#define next_bin(b)    ((mbinptr)((char*)(b) + 2 * sizeof(mbinptr)))
1549
#define prev_bin(b)    ((mbinptr)((char*)(b) - 2 * sizeof(mbinptr)))
1550
 
1551
/*
1552
   The first 2 bins are never indexed. The corresponding av_ cells are instead
1553
   used for bookkeeping. This is not to save space, but to simplify
1554
   indexing, maintain locality, and avoid some initialization tests.
1555
*/
1556
 
1557
#define top            (bin_at(0)->fd)   /* The topmost chunk */
1558
#define last_remainder (bin_at(1))       /* remainder from last split */
1559
 
1560
 
1561
/*
1562
   Because top initially points to its own bin with initial
1563
   zero size, thus forcing extension on the first malloc request,
1564
   we avoid having any special code in malloc to check whether
1565
   it even exists yet. But we still need to in malloc_extend_top.
1566
*/
1567
 
1568
#define initial_top    ((mchunkptr)(bin_at(0)))
1569
 
1570
/* Helper macro to initialize bins */
1571
 
1572
#define IAV(i)  bin_at(i), bin_at(i)
1573
 
1574
#ifdef DEFINE_MALLOC
1575
STATIC mbinptr av_[NAV * 2 + 2] = {
1576
 0, 0,
1577
 IAV(0),   IAV(1),   IAV(2),   IAV(3),   IAV(4),   IAV(5),   IAV(6),   IAV(7),
1578
 IAV(8),   IAV(9),   IAV(10),  IAV(11),  IAV(12),  IAV(13),  IAV(14),  IAV(15),
1579
 IAV(16),  IAV(17),  IAV(18),  IAV(19),  IAV(20),  IAV(21),  IAV(22),  IAV(23),
1580
 IAV(24),  IAV(25),  IAV(26),  IAV(27),  IAV(28),  IAV(29),  IAV(30),  IAV(31),
1581
 IAV(32),  IAV(33),  IAV(34),  IAV(35),  IAV(36),  IAV(37),  IAV(38),  IAV(39),
1582
 IAV(40),  IAV(41),  IAV(42),  IAV(43),  IAV(44),  IAV(45),  IAV(46),  IAV(47),
1583
 IAV(48),  IAV(49),  IAV(50),  IAV(51),  IAV(52),  IAV(53),  IAV(54),  IAV(55),
1584
 IAV(56),  IAV(57),  IAV(58),  IAV(59),  IAV(60),  IAV(61),  IAV(62),  IAV(63),
1585
 IAV(64),  IAV(65),  IAV(66),  IAV(67),  IAV(68),  IAV(69),  IAV(70),  IAV(71),
1586
 IAV(72),  IAV(73),  IAV(74),  IAV(75),  IAV(76),  IAV(77),  IAV(78),  IAV(79),
1587
 IAV(80),  IAV(81),  IAV(82),  IAV(83),  IAV(84),  IAV(85),  IAV(86),  IAV(87),
1588
 IAV(88),  IAV(89),  IAV(90),  IAV(91),  IAV(92),  IAV(93),  IAV(94),  IAV(95),
1589
 IAV(96),  IAV(97),  IAV(98),  IAV(99),  IAV(100), IAV(101), IAV(102), IAV(103),
1590
 IAV(104), IAV(105), IAV(106), IAV(107), IAV(108), IAV(109), IAV(110), IAV(111),
1591
 IAV(112), IAV(113), IAV(114), IAV(115), IAV(116), IAV(117), IAV(118), IAV(119),
1592
 IAV(120), IAV(121), IAV(122), IAV(123), IAV(124), IAV(125), IAV(126), IAV(127)
1593
};
1594
#else
1595
extern mbinptr av_[NAV * 2 + 2];
1596
#endif
1597
 
1598
 
1599
 
1600
/* field-extraction macros */
1601
 
1602
#define first(b) ((b)->fd)
1603
#define last(b)  ((b)->bk)
1604
 
1605
/*
1606
  Indexing into bins
1607
*/
1608
 
1609
#define bin_index(sz)                                                          \
1610
(((((unsigned long)(sz)) >> 9) ==    0) ?       (((unsigned long)(sz)) >>  3): \
1611
 ((((unsigned long)(sz)) >> 9) <=    4) ?  56 + (((unsigned long)(sz)) >>  6): \
1612
 ((((unsigned long)(sz)) >> 9) <=   20) ?  91 + (((unsigned long)(sz)) >>  9): \
1613
 ((((unsigned long)(sz)) >> 9) <=   84) ? 110 + (((unsigned long)(sz)) >> 12): \
1614
 ((((unsigned long)(sz)) >> 9) <=  340) ? 119 + (((unsigned long)(sz)) >> 15): \
1615
 ((((unsigned long)(sz)) >> 9) <= 1364) ? 124 + (((unsigned long)(sz)) >> 18): \
1616
                                          126)
1617
/*
1618
  bins for chunks < 512 are all spaced SMALLBIN_WIDTH bytes apart, and hold
1619
  identically sized chunks. This is exploited in malloc.
1620
*/
1621
 
1622
#define MAX_SMALLBIN_SIZE   512
1623
#define SMALLBIN_WIDTH        8
1624
#define SMALLBIN_WIDTH_BITS   3
1625
#define MAX_SMALLBIN        (MAX_SMALLBIN_SIZE / SMALLBIN_WIDTH) - 1
1626
 
1627
#define smallbin_index(sz)  (((unsigned long)(sz)) >> SMALLBIN_WIDTH_BITS)
1628
 
1629
/*
1630
   Requests are `small' if both the corresponding and the next bin are small
1631
*/
1632
 
1633
#define is_small_request(nb) (nb < MAX_SMALLBIN_SIZE - SMALLBIN_WIDTH)
1634
 
1635
 
1636
 
1637
/*
1638
    To help compensate for the large number of bins, a one-level index
1639
    structure is used for bin-by-bin searching.  `binblocks' is a
1640
    one-word bitvector recording whether groups of BINBLOCKWIDTH bins
1641
    have any (possibly) non-empty bins, so they can be skipped over
1642
    all at once during during traversals. The bits are NOT always
1643
    cleared as soon as all bins in a block are empty, but instead only
1644
    when all are noticed to be empty during traversal in malloc.
1645
*/
1646
 
1647
#define BINBLOCKWIDTH     4   /* bins per block */
1648
 
1649
#define binblocks      (bin_at(0)->size) /* bitvector of nonempty blocks */
1650
 
1651
/* bin<->block macros */
1652
 
1653
#define idx2binblock(ix)    ((unsigned long)1 << (ix / BINBLOCKWIDTH))
1654
#define mark_binblock(ii)   (binblocks |= idx2binblock(ii))
1655
#define clear_binblock(ii)  (binblocks &= ~(idx2binblock(ii)))
1656
 
1657
 
1658
 
1659
 
1660
 
1661
/*  Other static bookkeeping data */
1662
 
1663
#ifdef SEPARATE_OBJECTS
1664
#define trim_threshold          malloc_trim_threshold
1665
#define top_pad                 malloc_top_pad
1666
#define n_mmaps_max             malloc_n_mmaps_max
1667
#define mmap_threshold          malloc_mmap_threshold
1668
#define sbrk_base               malloc_sbrk_base
1669
#define max_sbrked_mem          malloc_max_sbrked_mem
1670
#define max_total_mem           malloc_max_total_mem
1671
#define current_mallinfo        malloc_current_mallinfo
1672
#define n_mmaps                 malloc_n_mmaps
1673
#define max_n_mmaps             malloc_max_n_mmaps
1674
#define mmapped_mem             malloc_mmapped_mem
1675
#define max_mmapped_mem         malloc_max_mmapped_mem
1676
#endif
1677
 
1678
/* variables holding tunable values */
1679
 
1680
#ifdef DEFINE_MALLOC
1681
 
1682
STATIC unsigned long trim_threshold   = DEFAULT_TRIM_THRESHOLD;
1683
STATIC unsigned long top_pad          = DEFAULT_TOP_PAD;
1684
#if HAVE_MMAP
1685
STATIC unsigned int  n_mmaps_max      = DEFAULT_MMAP_MAX;
1686
STATIC unsigned long mmap_threshold   = DEFAULT_MMAP_THRESHOLD;
1687
#endif
1688
 
1689
/* The first value returned from sbrk */
1690
STATIC char* sbrk_base = (char*)(-1);
1691
 
1692
/* The maximum memory obtained from system via sbrk */
1693
STATIC unsigned long max_sbrked_mem = 0;
1694
 
1695
/* The maximum via either sbrk or mmap */
1696
STATIC unsigned long max_total_mem = 0;
1697
 
1698
/* internal working copy of mallinfo */
1699
STATIC struct mallinfo current_mallinfo = {  0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
1700
 
1701
#if HAVE_MMAP
1702
 
1703
/* Tracking mmaps */
1704
 
1705
STATIC unsigned int n_mmaps = 0;
1706
STATIC unsigned int max_n_mmaps = 0;
1707
STATIC unsigned long mmapped_mem = 0;
1708
STATIC unsigned long max_mmapped_mem = 0;
1709
 
1710
#endif
1711
 
1712
#else /* ! DEFINE_MALLOC */
1713
 
1714
extern unsigned long trim_threshold;
1715
extern unsigned long top_pad;
1716
#if HAVE_MMAP
1717
extern unsigned int  n_mmaps_max;
1718
extern unsigned long mmap_threshold;
1719
#endif
1720
extern char* sbrk_base;
1721
extern unsigned long max_sbrked_mem;
1722
extern unsigned long max_total_mem;
1723
extern struct mallinfo current_mallinfo;
1724
#if HAVE_MMAP
1725
extern unsigned int n_mmaps;
1726
extern unsigned int max_n_mmaps;
1727
extern unsigned long mmapped_mem;
1728
extern unsigned long max_mmapped_mem;
1729
#endif
1730
 
1731
#endif /* ! DEFINE_MALLOC */
1732
 
1733
/* The total memory obtained from system via sbrk */
1734
#define sbrked_mem  (current_mallinfo.arena)
1735
 
1736
 
1737
 
1738
/*
1739
  Debugging support
1740
*/
1741
 
1742
#if DEBUG
1743
 
1744
 
1745
/*
1746
  These routines make a number of assertions about the states
1747
  of data structures that should be true at all times. If any
1748
  are not true, it's very likely that a user program has somehow
1749
  trashed memory. (It's also possible that there is a coding error
1750
  in malloc. In which case, please report it!)
1751
*/
1752
 
1753
#if __STD_C
1754
static void do_check_chunk(mchunkptr p)
1755
#else
1756
static void do_check_chunk(p) mchunkptr p;
1757
#endif
1758
{
1759
  INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
1760
 
1761
  /* No checkable chunk is mmapped */
1762
  assert(!chunk_is_mmapped(p));
1763
 
1764
  /* Check for legal address ... */
1765
  assert((char*)p >= sbrk_base);
1766
  if (p != top)
1767
    assert((char*)p + sz <= (char*)top);
1768
  else
1769
    assert((char*)p + sz <= sbrk_base + sbrked_mem);
1770
 
1771
}
1772
 
1773
 
1774
#if __STD_C
1775
static void do_check_free_chunk(mchunkptr p)
1776
#else
1777
static void do_check_free_chunk(p) mchunkptr p;
1778
#endif
1779
{
1780
  INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
1781
  mchunkptr next = chunk_at_offset(p, sz);
1782
 
1783
  do_check_chunk(p);
1784
 
1785
  /* Check whether it claims to be free ... */
1786
  assert(!inuse(p));
1787
 
1788
  /* Unless a special marker, must have OK fields */
1789
  if ((long)sz >= (long)MINSIZE)
1790
  {
1791
    assert((sz & MALLOC_ALIGN_MASK) == 0);
1792
    assert(aligned_OK(chunk2mem(p)));
1793
    /* ... matching footer field */
1794
    assert(next->prev_size == sz);
1795
    /* ... and is fully consolidated */
1796
    assert(prev_inuse(p));
1797
    assert (next == top || inuse(next));
1798
 
1799
    /* ... and has minimally sane links */
1800
    assert(p->fd->bk == p);
1801
    assert(p->bk->fd == p);
1802
  }
1803
  else /* markers are always of size SIZE_SZ */
1804
    assert(sz == SIZE_SZ);
1805
}
1806
 
1807
#if __STD_C
1808
static void do_check_inuse_chunk(mchunkptr p)
1809
#else
1810
static void do_check_inuse_chunk(p) mchunkptr p;
1811
#endif
1812
{
1813
  mchunkptr next = next_chunk(p);
1814
  do_check_chunk(p);
1815
 
1816
  /* Check whether it claims to be in use ... */
1817
  assert(inuse(p));
1818
 
1819
  /* ... and is surrounded by OK chunks.
1820
    Since more things can be checked with free chunks than inuse ones,
1821
    if an inuse chunk borders them and debug is on, it's worth doing them.
1822
  */
1823
  if (!prev_inuse(p))
1824
  {
1825
    mchunkptr prv = prev_chunk(p);
1826
    assert(next_chunk(prv) == p);
1827
    do_check_free_chunk(prv);
1828
  }
1829
  if (next == top)
1830
  {
1831
    assert(prev_inuse(next));
1832
    assert(chunksize(next) >= MINSIZE);
1833
  }
1834
  else if (!inuse(next))
1835
    do_check_free_chunk(next);
1836
 
1837
}
1838
 
1839
#if __STD_C
1840
static void do_check_malloced_chunk(mchunkptr p, INTERNAL_SIZE_T s)
1841
#else
1842
static void do_check_malloced_chunk(p, s) mchunkptr p; INTERNAL_SIZE_T s;
1843
#endif
1844
{
1845
  INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
1846
  long room = long_sub_size_t(sz, s);
1847
 
1848
  do_check_inuse_chunk(p);
1849
 
1850
  /* Legal size ... */
1851
  assert((long)sz >= (long)MINSIZE);
1852
  assert((sz & MALLOC_ALIGN_MASK) == 0);
1853
  assert(room >= 0);
1854
  assert(room < (long)MINSIZE);
1855
 
1856
  /* ... and alignment */
1857
  assert(aligned_OK(chunk2mem(p)));
1858
 
1859
 
1860
  /* ... and was allocated at front of an available chunk */
1861
  assert(prev_inuse(p));
1862
 
1863
}
1864
 
1865
 
1866
#define check_free_chunk(P)  do_check_free_chunk(P)
1867
#define check_inuse_chunk(P) do_check_inuse_chunk(P)
1868
#define check_chunk(P) do_check_chunk(P)
1869
#define check_malloced_chunk(P,N) do_check_malloced_chunk(P,N)
1870
#else
1871
#define check_free_chunk(P) 
1872
#define check_inuse_chunk(P)
1873
#define check_chunk(P)
1874
#define check_malloced_chunk(P,N)
1875
#endif
1876
 
1877
 
1878
 
1879
/*
1880
  Macro-based internal utilities
1881
*/
1882
 
1883
 
1884
/*
1885
  Linking chunks in bin lists.
1886
  Call these only with variables, not arbitrary expressions, as arguments.
1887
*/
1888
 
1889
/*
1890
  Place chunk p of size s in its bin, in size order,
1891
  putting it ahead of others of same size.
1892
*/
1893
 
1894
 
1895
#define frontlink(P, S, IDX, BK, FD)                                          \
1896
{                                                                             \
1897
  if (S < MAX_SMALLBIN_SIZE)                                                  \
1898
  {                                                                           \
1899
    IDX = smallbin_index(S);                                                  \
1900
    mark_binblock(IDX);                                                       \
1901
    BK = bin_at(IDX);                                                         \
1902
    FD = BK->fd;                                                              \
1903
    P->bk = BK;                                                               \
1904
    P->fd = FD;                                                               \
1905
    FD->bk = BK->fd = P;                                                      \
1906
  }                                                                           \
1907
  else                                                                        \
1908
  {                                                                           \
1909
    IDX = bin_index(S);                                                       \
1910
    BK = bin_at(IDX);                                                         \
1911
    FD = BK->fd;                                                              \
1912
    if (FD == BK) mark_binblock(IDX);                                         \
1913
    else                                                                      \
1914
    {                                                                         \
1915
      while (FD != BK && S < chunksize(FD)) FD = FD->fd;                      \
1916
      BK = FD->bk;                                                            \
1917
    }                                                                         \
1918
    P->bk = BK;                                                               \
1919
    P->fd = FD;                                                               \
1920
    FD->bk = BK->fd = P;                                                      \
1921
  }                                                                           \
1922
}
1923
 
1924
 
1925
/* take a chunk off a list */
1926
 
1927
#define unlink(P, BK, FD)                                                     \
1928
{                                                                             \
1929
  BK = P->bk;                                                                 \
1930
  FD = P->fd;                                                                 \
1931
  FD->bk = BK;                                                                \
1932
  BK->fd = FD;                                                                \
1933
}                                                                             \
1934
 
1935
/* Place p as the last remainder */
1936
 
1937
#define link_last_remainder(P)                                                \
1938
{                                                                             \
1939
  last_remainder->fd = last_remainder->bk =  P;                               \
1940
  P->fd = P->bk = last_remainder;                                             \
1941
}
1942
 
1943
/* Clear the last_remainder bin */
1944
 
1945
#define clear_last_remainder \
1946
  (last_remainder->fd = last_remainder->bk = last_remainder)
1947
 
1948
 
1949
 
1950
 
1951
 
1952
 
1953
/* Routines dealing with mmap(). */
1954
 
1955
#if HAVE_MMAP
1956
 
1957
#ifdef DEFINE_MALLOC
1958
 
1959
#if __STD_C
1960
static mchunkptr mmap_chunk(size_t size)
1961
#else
1962
static mchunkptr mmap_chunk(size) size_t size;
1963
#endif
1964
{
1965
  size_t page_mask = malloc_getpagesize - 1;
1966
  mchunkptr p;
1967
 
1968
#ifndef MAP_ANONYMOUS
1969
  static int fd = -1;
1970
#endif
1971
 
1972
  if(n_mmaps >= n_mmaps_max) return 0; /* too many regions */
1973
 
1974
  /* For mmapped chunks, the overhead is one SIZE_SZ unit larger, because
1975
   * there is no following chunk whose prev_size field could be used.
1976
   */
1977
  size = (size + SIZE_SZ + page_mask) & ~page_mask;
1978
 
1979
#ifdef MAP_ANONYMOUS
1980
  p = (mchunkptr)mmap(0, size, PROT_READ|PROT_WRITE,
1981
                      MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
1982
#else /* !MAP_ANONYMOUS */
1983
  if (fd < 0)
1984
  {
1985
    fd = open("/dev/zero", O_RDWR);
1986
    if(fd < 0) return 0;
1987
  }
1988
  p = (mchunkptr)mmap(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
1989
#endif
1990
 
1991
  if(p == (mchunkptr)-1) return 0;
1992
 
1993
  n_mmaps++;
1994
  if (n_mmaps > max_n_mmaps) max_n_mmaps = n_mmaps;
1995
 
1996
  /* We demand that eight bytes into a page must be 8-byte aligned. */
1997
  assert(aligned_OK(chunk2mem(p)));
1998
 
1999
  /* The offset to the start of the mmapped region is stored
2000
   * in the prev_size field of the chunk; normally it is zero,
2001
   * but that can be changed in memalign().
2002
   */
2003
  p->prev_size = 0;
2004
  set_head(p, size|IS_MMAPPED);
2005
 
2006
  mmapped_mem += size;
2007
  if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem)
2008
    max_mmapped_mem = mmapped_mem;
2009
  if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
2010
    max_total_mem = mmapped_mem + sbrked_mem;
2011
  return p;
2012
}
2013
 
2014
#endif /* DEFINE_MALLOC */
2015
 
2016
#ifdef SEPARATE_OBJECTS
2017
#define munmap_chunk malloc_munmap_chunk
2018
#endif
2019
 
2020
#ifdef DEFINE_FREE
2021
 
2022
#if __STD_C
2023
STATIC void munmap_chunk(mchunkptr p)
2024
#else
2025
STATIC void munmap_chunk(p) mchunkptr p;
2026
#endif
2027
{
2028
  INTERNAL_SIZE_T size = chunksize(p);
2029
  int ret;
2030
 
2031
  assert (chunk_is_mmapped(p));
2032
  assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem));
2033
  assert((n_mmaps > 0));
2034
  assert(((p->prev_size + size) & (malloc_getpagesize-1)) == 0);
2035
 
2036
  n_mmaps--;
2037
  mmapped_mem -= (size + p->prev_size);
2038
 
2039
  ret = munmap((char *)p - p->prev_size, size + p->prev_size);
2040
 
2041
  /* munmap returns non-zero on failure */
2042
  assert(ret == 0);
2043
}
2044
 
2045
#else /* ! DEFINE_FREE */
2046
 
2047
#if __STD_C
2048
extern void munmap_chunk(mchunkptr);
2049
#else
2050
extern void munmap_chunk();
2051
#endif
2052
 
2053
#endif /* ! DEFINE_FREE */
2054
 
2055
#if HAVE_MREMAP
2056
 
2057
#ifdef DEFINE_REALLOC
2058
 
2059
#if __STD_C
2060
static mchunkptr mremap_chunk(mchunkptr p, size_t new_size)
2061
#else
2062
static mchunkptr mremap_chunk(p, new_size) mchunkptr p; size_t new_size;
2063
#endif
2064
{
2065
  size_t page_mask = malloc_getpagesize - 1;
2066
  INTERNAL_SIZE_T offset = p->prev_size;
2067
  INTERNAL_SIZE_T size = chunksize(p);
2068
  char *cp;
2069
 
2070
  assert (chunk_is_mmapped(p));
2071
  assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem));
2072
  assert((n_mmaps > 0));
2073
  assert(((size + offset) & (malloc_getpagesize-1)) == 0);
2074
 
2075
  /* Note the extra SIZE_SZ overhead as in mmap_chunk(). */
2076
  new_size = (new_size + offset + SIZE_SZ + page_mask) & ~page_mask;
2077
 
2078
  cp = (char *)mremap((char *)p - offset, size + offset, new_size, 1);
2079
 
2080
  if (cp == (char *)-1) return 0;
2081
 
2082
  p = (mchunkptr)(cp + offset);
2083
 
2084
  assert(aligned_OK(chunk2mem(p)));
2085
 
2086
  assert((p->prev_size == offset));
2087
  set_head(p, (new_size - offset)|IS_MMAPPED);
2088
 
2089
  mmapped_mem -= size + offset;
2090
  mmapped_mem += new_size;
2091
  if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem)
2092
    max_mmapped_mem = mmapped_mem;
2093
  if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
2094
    max_total_mem = mmapped_mem + sbrked_mem;
2095
  return p;
2096
}
2097
 
2098
#endif /* DEFINE_REALLOC */
2099
 
2100
#endif /* HAVE_MREMAP */
2101
 
2102
#endif /* HAVE_MMAP */
2103
 
2104
 
2105
 
2106
 
2107
#ifdef DEFINE_MALLOC
2108
 
2109
/*
2110
  Extend the top-most chunk by obtaining memory from system.
2111
  Main interface to sbrk (but see also malloc_trim).
2112
*/
2113
 
2114
#if __STD_C
2115
static void malloc_extend_top(RARG INTERNAL_SIZE_T nb)
2116
#else
2117
static void malloc_extend_top(RARG nb) RDECL INTERNAL_SIZE_T nb;
2118
#endif
2119
{
2120
  char*     brk;                  /* return value from sbrk */
2121
  INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of sbrked space */
2122
  INTERNAL_SIZE_T correction;     /* bytes for 2nd sbrk call */
2123
  char*     new_brk;              /* return of 2nd sbrk call */
2124
  INTERNAL_SIZE_T top_size;       /* new size of top chunk */
2125
 
2126
  mchunkptr old_top     = top;  /* Record state of old top */
2127
  INTERNAL_SIZE_T old_top_size = chunksize(old_top);
2128
  char*     old_end      = (char*)(chunk_at_offset(old_top, old_top_size));
2129
 
2130
  /* Pad request with top_pad plus minimal overhead */
2131
 
2132
  INTERNAL_SIZE_T    sbrk_size     = nb + top_pad + MINSIZE;
2133
  unsigned long pagesz    = malloc_getpagesize;
2134
 
2135
  /* If not the first time through, round to preserve page boundary */
2136
  /* Otherwise, we need to correct to a page size below anyway. */
2137
  /* (We also correct below if an intervening foreign sbrk call.) */
2138
 
2139
  if (sbrk_base != (char*)(-1))
2140
    sbrk_size = (sbrk_size + (pagesz - 1)) & ~(pagesz - 1);
2141
 
2142
  brk = (char*)(MORECORE (sbrk_size));
2143
 
2144
  /* Fail if sbrk failed or if a foreign sbrk call killed our space */
2145
  if (brk == (char*)(MORECORE_FAILURE) ||
2146
      (brk < old_end && old_top != initial_top))
2147
    return;
2148
 
2149
  sbrked_mem += sbrk_size;
2150
 
2151
  if (brk == old_end) /* can just add bytes to current top */
2152
  {
2153
    top_size = sbrk_size + old_top_size;
2154
    set_head(top, top_size | PREV_INUSE);
2155
  }
2156
  else
2157
  {
2158
    if (sbrk_base == (char*)(-1))  /* First time through. Record base */
2159
      sbrk_base = brk;
2160
    else  /* Someone else called sbrk().  Count those bytes as sbrked_mem. */
2161
      sbrked_mem += brk - (char*)old_end;
2162
 
2163
    /* Guarantee alignment of first new chunk made from this space */
2164
    front_misalign = (POINTER_UINT)chunk2mem(brk) & MALLOC_ALIGN_MASK;
2165
    if (front_misalign > 0)
2166
    {
2167
      correction = (MALLOC_ALIGNMENT) - front_misalign;
2168
      brk += correction;
2169
    }
2170
    else
2171
      correction = 0;
2172
 
2173
    /* Guarantee the next brk will be at a page boundary */
2174
    correction += pagesz - ((POINTER_UINT)(brk + sbrk_size) & (pagesz - 1));
2175
 
2176
    /* Allocate correction */
2177
    new_brk = (char*)(MORECORE (correction));
2178
    if (new_brk == (char*)(MORECORE_FAILURE)) return;
2179
 
2180
    sbrked_mem += correction;
2181
 
2182
    top = (mchunkptr)brk;
2183
    top_size = new_brk - brk + correction;
2184
    set_head(top, top_size | PREV_INUSE);
2185
 
2186
    if (old_top != initial_top)
2187
    {
2188
 
2189
      /* There must have been an intervening foreign sbrk call. */
2190
      /* A double fencepost is necessary to prevent consolidation */
2191
 
2192
      /* If not enough space to do this, then user did something very wrong */
2193
      if (old_top_size < MINSIZE)
2194
      {
2195
        set_head(top, PREV_INUSE); /* will force null return from malloc */
2196
        return;
2197
      }
2198
 
2199
      /* Also keep size a multiple of MALLOC_ALIGNMENT */
2200
      old_top_size = (old_top_size - 3*SIZE_SZ) & ~MALLOC_ALIGN_MASK;
2201
      set_head_size(old_top, old_top_size);
2202
      chunk_at_offset(old_top, old_top_size          )->size =
2203
        SIZE_SZ|PREV_INUSE;
2204
      chunk_at_offset(old_top, old_top_size + SIZE_SZ)->size =
2205
        SIZE_SZ|PREV_INUSE;
2206
      /* If possible, release the rest. */
2207
      if (old_top_size >= MINSIZE)
2208
        fREe(RCALL chunk2mem(old_top));
2209
    }
2210
  }
2211
 
2212
  if ((unsigned long)sbrked_mem > (unsigned long)max_sbrked_mem)
2213
    max_sbrked_mem = sbrked_mem;
2214
#if HAVE_MMAP
2215
  if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
2216
    max_total_mem = mmapped_mem + sbrked_mem;
2217
#else
2218
  if ((unsigned long)(sbrked_mem) > (unsigned long)max_total_mem)
2219
    max_total_mem = sbrked_mem;
2220
#endif
2221
 
2222
  /* We always land on a page boundary */
2223
  assert(((unsigned long)((char*)top + top_size) & (pagesz - 1)) == 0);
2224
}
2225
 
2226
#endif /* DEFINE_MALLOC */
2227
 
2228
 
2229
/* Main public routines */
2230
 
2231
#ifdef DEFINE_MALLOC
2232
 
2233
/*
2234
  Malloc Algorthim:
2235
 
2236
    The requested size is first converted into a usable form, `nb'.
2237
    This currently means to add 4 bytes overhead plus possibly more to
2238
    obtain 8-byte alignment and/or to obtain a size of at least
2239
    MINSIZE (currently 16 bytes), the smallest allocatable size.
2240
    (All fits are considered `exact' if they are within MINSIZE bytes.)
2241
 
2242
    From there, the first successful of the following steps is taken:
2243
 
2244
      1. The bin corresponding to the request size is scanned, and if
2245
         a chunk of exactly the right size is found, it is taken.
2246
 
2247
      2. The most recently remaindered chunk is used if it is big
2248
         enough.  This is a form of (roving) first fit, used only in
2249
         the absence of exact fits. Runs of consecutive requests use
2250
         the remainder of the chunk used for the previous such request
2251
         whenever possible. This limited use of a first-fit style
2252
         allocation strategy tends to give contiguous chunks
2253
         coextensive lifetimes, which improves locality and can reduce
2254
         fragmentation in the long run.
2255
 
2256
      3. Other bins are scanned in increasing size order, using a
2257
         chunk big enough to fulfill the request, and splitting off
2258
         any remainder.  This search is strictly by best-fit; i.e.,
2259
         the smallest (with ties going to approximately the least
2260
         recently used) chunk that fits is selected.
2261
 
2262
      4. If large enough, the chunk bordering the end of memory
2263
         (`top') is split off. (This use of `top' is in accord with
2264
         the best-fit search rule.  In effect, `top' is treated as
2265
         larger (and thus less well fitting) than any other available
2266
         chunk since it can be extended to be as large as necessary
2267
         (up to system limitations).
2268
 
2269
      5. If the request size meets the mmap threshold and the
2270
         system supports mmap, and there are few enough currently
2271
         allocated mmapped regions, and a call to mmap succeeds,
2272
         the request is allocated via direct memory mapping.
2273
 
2274
      6. Otherwise, the top of memory is extended by
2275
         obtaining more space from the system (normally using sbrk,
2276
         but definable to anything else via the MORECORE macro).
2277
         Memory is gathered from the system (in system page-sized
2278
         units) in a way that allows chunks obtained across different
2279
         sbrk calls to be consolidated, but does not require
2280
         contiguous memory. Thus, it should be safe to intersperse
2281
         mallocs with other sbrk calls.
2282
 
2283
 
2284
      All allocations are made from the the `lowest' part of any found
2285
      chunk. (The implementation invariant is that prev_inuse is
2286
      always true of any allocated chunk; i.e., that each allocated
2287
      chunk borders either a previously allocated and still in-use chunk,
2288
      or the base of its memory arena.)
2289
 
2290
*/
2291
 
2292
#if __STD_C
2293
Void_t* mALLOc(RARG size_t bytes)
2294
#else
2295
Void_t* mALLOc(RARG bytes) RDECL size_t bytes;
2296
#endif
2297
{
2298
#ifdef MALLOC_PROVIDED
2299
 
2300
  malloc (bytes);
2301
 
2302
#else
2303
 
2304
  mchunkptr victim;                  /* inspected/selected chunk */
2305
  INTERNAL_SIZE_T victim_size;       /* its size */
2306
  int       idx;                     /* index for bin traversal */
2307
  mbinptr   bin;                     /* associated bin */
2308
  mchunkptr remainder;               /* remainder from a split */
2309
  long      remainder_size;          /* its size */
2310
  int       remainder_index;         /* its bin index */
2311
  unsigned long block;               /* block traverser bit */
2312
  int       startidx;                /* first bin of a traversed block */
2313
  mchunkptr fwd;                     /* misc temp for linking */
2314
  mchunkptr bck;                     /* misc temp for linking */
2315
  mbinptr q;                         /* misc temp */
2316
 
2317
  INTERNAL_SIZE_T nb  = request2size(bytes);  /* padded request size; */
2318
 
2319
  MALLOC_LOCK;
2320
 
2321
  /* Check for exact match in a bin */
2322
 
2323
  if (is_small_request(nb))  /* Faster version for small requests */
2324
  {
2325
    idx = smallbin_index(nb);
2326
 
2327
    /* No traversal or size check necessary for small bins.  */
2328
 
2329
    q = bin_at(idx);
2330
    victim = last(q);
2331
 
2332
#if MALLOC_ALIGN != 16
2333
    /* Also scan the next one, since it would have a remainder < MINSIZE */
2334
    if (victim == q)
2335
    {
2336
      q = next_bin(q);
2337
      victim = last(q);
2338
    }
2339
#endif
2340
    if (victim != q)
2341
    {
2342
      victim_size = chunksize(victim);
2343
      unlink(victim, bck, fwd);
2344
      set_inuse_bit_at_offset(victim, victim_size);
2345
      check_malloced_chunk(victim, nb);
2346
      MALLOC_UNLOCK;
2347
      return chunk2mem(victim);
2348
    }
2349
 
2350
    idx += 2; /* Set for bin scan below. We've already scanned 2 bins. */
2351
 
2352
  }
2353
  else
2354
  {
2355
    idx = bin_index(nb);
2356
    bin = bin_at(idx);
2357
 
2358
    for (victim = last(bin); victim != bin; victim = victim->bk)
2359
    {
2360
      victim_size = chunksize(victim);
2361
      remainder_size = long_sub_size_t(victim_size, nb);
2362
 
2363
      if (remainder_size >= (long)MINSIZE) /* too big */
2364
      {
2365
        --idx; /* adjust to rescan below after checking last remainder */
2366
        break;
2367
      }
2368
 
2369
      else if (remainder_size >= 0) /* exact fit */
2370
      {
2371
        unlink(victim, bck, fwd);
2372
        set_inuse_bit_at_offset(victim, victim_size);
2373
        check_malloced_chunk(victim, nb);
2374
        MALLOC_UNLOCK;
2375
        return chunk2mem(victim);
2376
      }
2377
    }
2378
 
2379
    ++idx;
2380
 
2381
  }
2382
 
2383
  /* Try to use the last split-off remainder */
2384
 
2385
  if ( (victim = last_remainder->fd) != last_remainder)
2386
  {
2387
    victim_size = chunksize(victim);
2388
    remainder_size = long_sub_size_t(victim_size, nb);
2389
 
2390
    if (remainder_size >= (long)MINSIZE) /* re-split */
2391
    {
2392
      remainder = chunk_at_offset(victim, nb);
2393
      set_head(victim, nb | PREV_INUSE);
2394
      link_last_remainder(remainder);
2395
      set_head(remainder, remainder_size | PREV_INUSE);
2396
      set_foot(remainder, remainder_size);
2397
      check_malloced_chunk(victim, nb);
2398
      MALLOC_UNLOCK;
2399
      return chunk2mem(victim);
2400
    }
2401
 
2402
    clear_last_remainder;
2403
 
2404
    if (remainder_size >= 0)  /* exhaust */
2405
    {
2406
      set_inuse_bit_at_offset(victim, victim_size);
2407
      check_malloced_chunk(victim, nb);
2408
      MALLOC_UNLOCK;
2409
      return chunk2mem(victim);
2410
    }
2411
 
2412
    /* Else place in bin */
2413
 
2414
    frontlink(victim, victim_size, remainder_index, bck, fwd);
2415
  }
2416
 
2417
  /*
2418
     If there are any possibly nonempty big-enough blocks,
2419
     search for best fitting chunk by scanning bins in blockwidth units.
2420
  */
2421
 
2422
  if ( (block = idx2binblock(idx)) <= binblocks)
2423
  {
2424
 
2425
    /* Get to the first marked block */
2426
 
2427
    if ( (block & binblocks) == 0)
2428
    {
2429
      /* force to an even block boundary */
2430
      idx = (idx & ~(BINBLOCKWIDTH - 1)) + BINBLOCKWIDTH;
2431
      block <<= 1;
2432
      while ((block & binblocks) == 0)
2433
      {
2434
        idx += BINBLOCKWIDTH;
2435
        block <<= 1;
2436
      }
2437
    }
2438
 
2439
    /* For each possibly nonempty block ... */
2440
    for (;;)
2441
    {
2442
      startidx = idx;          /* (track incomplete blocks) */
2443
      q = bin = bin_at(idx);
2444
 
2445
      /* For each bin in this block ... */
2446
      do
2447
      {
2448
        /* Find and use first big enough chunk ... */
2449
 
2450
        for (victim = last(bin); victim != bin; victim = victim->bk)
2451
        {
2452
          victim_size = chunksize(victim);
2453
          remainder_size = long_sub_size_t(victim_size, nb);
2454
 
2455
          if (remainder_size >= (long)MINSIZE) /* split */
2456
          {
2457
            remainder = chunk_at_offset(victim, nb);
2458
            set_head(victim, nb | PREV_INUSE);
2459
            unlink(victim, bck, fwd);
2460
            link_last_remainder(remainder);
2461
            set_head(remainder, remainder_size | PREV_INUSE);
2462
            set_foot(remainder, remainder_size);
2463
            check_malloced_chunk(victim, nb);
2464
            MALLOC_UNLOCK;
2465
            return chunk2mem(victim);
2466
          }
2467
 
2468
          else if (remainder_size >= 0)  /* take */
2469
          {
2470
            set_inuse_bit_at_offset(victim, victim_size);
2471
            unlink(victim, bck, fwd);
2472
            check_malloced_chunk(victim, nb);
2473
            MALLOC_UNLOCK;
2474
            return chunk2mem(victim);
2475
          }
2476
 
2477
        }
2478
 
2479
       bin = next_bin(bin);
2480
 
2481
#if MALLOC_ALIGN == 16
2482
       if (idx < MAX_SMALLBIN)
2483
         {
2484
           bin = next_bin(bin);
2485
           ++idx;
2486
         }
2487
#endif
2488
      } while ((++idx & (BINBLOCKWIDTH - 1)) != 0);
2489
 
2490
      /* Clear out the block bit. */
2491
 
2492
      do   /* Possibly backtrack to try to clear a partial block */
2493
      {
2494
        if ((startidx & (BINBLOCKWIDTH - 1)) == 0)
2495
        {
2496
          binblocks &= ~block;
2497
          break;
2498
        }
2499
        --startidx;
2500
       q = prev_bin(q);
2501
      } while (first(q) == q);
2502
 
2503
      /* Get to the next possibly nonempty block */
2504
 
2505
      if ( (block <<= 1) <= binblocks && (block != 0) )
2506
      {
2507
        while ((block & binblocks) == 0)
2508
        {
2509
          idx += BINBLOCKWIDTH;
2510
          block <<= 1;
2511
        }
2512
      }
2513
      else
2514
        break;
2515
    }
2516
  }
2517
 
2518
 
2519
  /* Try to use top chunk */
2520
 
2521
  /* Require that there be a remainder, ensuring top always exists  */
2522
  remainder_size = long_sub_size_t(chunksize(top), nb);
2523
  if (chunksize(top) < nb || remainder_size < (long)MINSIZE)
2524
  {
2525
 
2526
#if HAVE_MMAP
2527
    /* If big and would otherwise need to extend, try to use mmap instead */
2528
    if ((unsigned long)nb >= (unsigned long)mmap_threshold &&
2529
        (victim = mmap_chunk(nb)) != 0)
2530
    {
2531
      MALLOC_UNLOCK;
2532
      return chunk2mem(victim);
2533
    }
2534
#endif
2535
 
2536
    /* Try to extend */
2537
    malloc_extend_top(RCALL nb);
2538
    remainder_size = long_sub_size_t(chunksize(top), nb);
2539
    if (chunksize(top) < nb || remainder_size < (long)MINSIZE)
2540
    {
2541
      MALLOC_UNLOCK;
2542
      return 0; /* propagate failure */
2543
    }
2544
  }
2545
 
2546
  victim = top;
2547
  set_head(victim, nb | PREV_INUSE);
2548
  top = chunk_at_offset(victim, nb);
2549
  set_head(top, remainder_size | PREV_INUSE);
2550
  check_malloced_chunk(victim, nb);
2551
  MALLOC_UNLOCK;
2552
  return chunk2mem(victim);
2553
 
2554
#endif /* MALLOC_PROVIDED */
2555
}
2556
 
2557
#endif /* DEFINE_MALLOC */
2558
 
2559
#ifdef DEFINE_FREE
2560
 
2561
/*
2562
 
2563
  free() algorithm :
2564
 
2565
    cases:
2566
 
2567
       1. free(0) has no effect.
2568
 
2569
       2. If the chunk was allocated via mmap, it is release via munmap().
2570
 
2571
       3. If a returned chunk borders the current high end of memory,
2572
          it is consolidated into the top, and if the total unused
2573
          topmost memory exceeds the trim threshold, malloc_trim is
2574
          called.
2575
 
2576
       4. Other chunks are consolidated as they arrive, and
2577
          placed in corresponding bins. (This includes the case of
2578
          consolidating with the current `last_remainder').
2579
 
2580
*/
2581
 
2582
 
2583
#if __STD_C
2584
void fREe(RARG Void_t* mem)
2585
#else
2586
void fREe(RARG mem) RDECL Void_t* mem;
2587
#endif
2588
{
2589
#ifdef MALLOC_PROVIDED
2590
 
2591
  free (mem);
2592
 
2593
#else
2594
 
2595
  mchunkptr p;         /* chunk corresponding to mem */
2596
  INTERNAL_SIZE_T hd;  /* its head field */
2597
  INTERNAL_SIZE_T sz;  /* its size */
2598
  int       idx;       /* its bin index */
2599
  mchunkptr next;      /* next contiguous chunk */
2600
  INTERNAL_SIZE_T nextsz; /* its size */
2601
  INTERNAL_SIZE_T prevsz; /* size of previous contiguous chunk */
2602
  mchunkptr bck;       /* misc temp for linking */
2603
  mchunkptr fwd;       /* misc temp for linking */
2604
  int       islr;      /* track whether merging with last_remainder */
2605
 
2606
  if (mem == 0)                              /* free(0) has no effect */
2607
    return;
2608
 
2609
  MALLOC_LOCK;
2610
 
2611
  p = mem2chunk(mem);
2612
  hd = p->size;
2613
 
2614
#if HAVE_MMAP
2615
  if (hd & IS_MMAPPED)                       /* release mmapped memory. */
2616
  {
2617
    munmap_chunk(p);
2618
    MALLOC_UNLOCK;
2619
    return;
2620
  }
2621
#endif
2622
 
2623
  check_inuse_chunk(p);
2624
 
2625
  sz = hd & ~PREV_INUSE;
2626
  next = chunk_at_offset(p, sz);
2627
  nextsz = chunksize(next);
2628
 
2629
  if (next == top)                            /* merge with top */
2630
  {
2631
    sz += nextsz;
2632
 
2633
    if (!(hd & PREV_INUSE))                    /* consolidate backward */
2634
    {
2635
      prevsz = p->prev_size;
2636
      p = chunk_at_offset(p, -prevsz);
2637
      sz += prevsz;
2638
      unlink(p, bck, fwd);
2639
    }
2640
 
2641
    set_head(p, sz | PREV_INUSE);
2642
    top = p;
2643
    if ((unsigned long)(sz) >= (unsigned long)trim_threshold)
2644
      malloc_trim(RCALL top_pad);
2645
    MALLOC_UNLOCK;
2646
    return;
2647
  }
2648
 
2649
  set_head(next, nextsz);                    /* clear inuse bit */
2650
 
2651
  islr = 0;
2652
 
2653
  if (!(hd & PREV_INUSE))                    /* consolidate backward */
2654
  {
2655
    prevsz = p->prev_size;
2656
    p = chunk_at_offset(p, -prevsz);
2657
    sz += prevsz;
2658
 
2659
    if (p->fd == last_remainder)             /* keep as last_remainder */
2660
      islr = 1;
2661
    else
2662
      unlink(p, bck, fwd);
2663
  }
2664
 
2665
  if (!(inuse_bit_at_offset(next, nextsz)))   /* consolidate forward */
2666
  {
2667
    sz += nextsz;
2668
 
2669
    if (!islr && next->fd == last_remainder)  /* re-insert last_remainder */
2670
    {
2671
      islr = 1;
2672
      link_last_remainder(p);
2673
    }
2674
    else
2675
      unlink(next, bck, fwd);
2676
  }
2677
 
2678
 
2679
  set_head(p, sz | PREV_INUSE);
2680
  set_foot(p, sz);
2681
  if (!islr)
2682
    frontlink(p, sz, idx, bck, fwd);
2683
 
2684
  MALLOC_UNLOCK;
2685
 
2686
#endif /* MALLOC_PROVIDED */
2687
}
2688
 
2689
#endif /* DEFINE_FREE */
2690
 
2691
#ifdef DEFINE_REALLOC
2692
 
2693
/*
2694
 
2695
  Realloc algorithm:
2696
 
2697
    Chunks that were obtained via mmap cannot be extended or shrunk
2698
    unless HAVE_MREMAP is defined, in which case mremap is used.
2699
    Otherwise, if their reallocation is for additional space, they are
2700
    copied.  If for less, they are just left alone.
2701
 
2702
    Otherwise, if the reallocation is for additional space, and the
2703
    chunk can be extended, it is, else a malloc-copy-free sequence is
2704
    taken.  There are several different ways that a chunk could be
2705
    extended. All are tried:
2706
 
2707
       * Extending forward into following adjacent free chunk.
2708
       * Shifting backwards, joining preceding adjacent space
2709
       * Both shifting backwards and extending forward.
2710
       * Extending into newly sbrked space
2711
 
2712
    Unless the #define REALLOC_ZERO_BYTES_FREES is set, realloc with a
2713
    size argument of zero (re)allocates a minimum-sized chunk.
2714
 
2715
    If the reallocation is for less space, and the new request is for
2716
    a `small' (<512 bytes) size, then the newly unused space is lopped
2717
    off and freed.
2718
 
2719
    The old unix realloc convention of allowing the last-free'd chunk
2720
    to be used as an argument to realloc is no longer supported.
2721
    I don't know of any programs still relying on this feature,
2722
    and allowing it would also allow too many other incorrect
2723
    usages of realloc to be sensible.
2724
 
2725
 
2726
*/
2727
 
2728
 
2729
#if __STD_C
2730
Void_t* rEALLOc(RARG Void_t* oldmem, size_t bytes)
2731
#else
2732
Void_t* rEALLOc(RARG oldmem, bytes) RDECL Void_t* oldmem; size_t bytes;
2733
#endif
2734
{
2735
#ifdef MALLOC_PROVIDED
2736
 
2737
  realloc (oldmem, bytes);
2738
 
2739
#else
2740
 
2741
  INTERNAL_SIZE_T    nb;      /* padded request size */
2742
 
2743
  mchunkptr oldp;             /* chunk corresponding to oldmem */
2744
  INTERNAL_SIZE_T    oldsize; /* its size */
2745
 
2746
  mchunkptr newp;             /* chunk to return */
2747
  INTERNAL_SIZE_T    newsize; /* its size */
2748
  Void_t*   newmem;           /* corresponding user mem */
2749
 
2750
  mchunkptr next;             /* next contiguous chunk after oldp */
2751
  INTERNAL_SIZE_T  nextsize;  /* its size */
2752
 
2753
  mchunkptr prev;             /* previous contiguous chunk before oldp */
2754
  INTERNAL_SIZE_T  prevsize;  /* its size */
2755
 
2756
  mchunkptr remainder;        /* holds split off extra space from newp */
2757
  INTERNAL_SIZE_T  remainder_size;   /* its size */
2758
 
2759
  mchunkptr bck;              /* misc temp for linking */
2760
  mchunkptr fwd;              /* misc temp for linking */
2761
 
2762
#ifdef REALLOC_ZERO_BYTES_FREES
2763
  if (bytes == 0) { fREe(RCALL oldmem); return 0; }
2764
#endif
2765
 
2766
 
2767
  /* realloc of null is supposed to be same as malloc */
2768
  if (oldmem == 0) return mALLOc(RCALL bytes);
2769
 
2770
  MALLOC_LOCK;
2771
 
2772
  newp    = oldp    = mem2chunk(oldmem);
2773
  newsize = oldsize = chunksize(oldp);
2774
 
2775
 
2776
  nb = request2size(bytes);
2777
 
2778
#if HAVE_MMAP
2779
  if (chunk_is_mmapped(oldp))
2780
  {
2781
#if HAVE_MREMAP
2782
    newp = mremap_chunk(oldp, nb);
2783
    if(newp)
2784
    {
2785
      MALLOC_UNLOCK;
2786
      return chunk2mem(newp);
2787
    }
2788
#endif
2789
    /* Note the extra SIZE_SZ overhead. */
2790
    if(oldsize - SIZE_SZ >= nb)
2791
    {
2792
      MALLOC_UNLOCK;
2793
      return oldmem; /* do nothing */
2794
    }
2795
    /* Must alloc, copy, free. */
2796
    newmem = mALLOc(RCALL bytes);
2797
    if (newmem == 0)
2798
    {
2799
      MALLOC_UNLOCK;
2800
      return 0; /* propagate failure */
2801
    }
2802
    MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ);
2803
    munmap_chunk(oldp);
2804
    MALLOC_UNLOCK;
2805
    return newmem;
2806
  }
2807
#endif
2808
 
2809
  check_inuse_chunk(oldp);
2810
 
2811
  if ((long)(oldsize) < (long)(nb))
2812
  {
2813
 
2814
    /* Try expanding forward */
2815
 
2816
    next = chunk_at_offset(oldp, oldsize);
2817
    if (next == top || !inuse(next))
2818
    {
2819
      nextsize = chunksize(next);
2820
 
2821
      /* Forward into top only if a remainder */
2822
      if (next == top)
2823
      {
2824
        if ((long)(nextsize + newsize) >= (long)(nb + MINSIZE))
2825
        {
2826
          newsize += nextsize;
2827
          top = chunk_at_offset(oldp, nb);
2828
          set_head(top, (newsize - nb) | PREV_INUSE);
2829
          set_head_size(oldp, nb);
2830
          MALLOC_UNLOCK;
2831
          return chunk2mem(oldp);
2832
        }
2833
      }
2834
 
2835
      /* Forward into next chunk */
2836
      else if (((long)(nextsize + newsize) >= (long)(nb)))
2837
      {
2838
        unlink(next, bck, fwd);
2839
        newsize  += nextsize;
2840
        goto split;
2841
      }
2842
    }
2843
    else
2844
    {
2845
      next = 0;
2846
      nextsize = 0;
2847
    }
2848
 
2849
    /* Try shifting backwards. */
2850
 
2851
    if (!prev_inuse(oldp))
2852
    {
2853
      prev = prev_chunk(oldp);
2854
      prevsize = chunksize(prev);
2855
 
2856
      /* try forward + backward first to save a later consolidation */
2857
 
2858
      if (next != 0)
2859
      {
2860
        /* into top */
2861
        if (next == top)
2862
        {
2863
          if ((long)(nextsize + prevsize + newsize) >= (long)(nb + MINSIZE))
2864
          {
2865
            unlink(prev, bck, fwd);
2866
            newp = prev;
2867
            newsize += prevsize + nextsize;
2868
            newmem = chunk2mem(newp);
2869
            MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2870
            top = chunk_at_offset(newp, nb);
2871
            set_head(top, (newsize - nb) | PREV_INUSE);
2872
            set_head_size(newp, nb);
2873
            MALLOC_UNLOCK;
2874
            return newmem;
2875
          }
2876
        }
2877
 
2878
        /* into next chunk */
2879
        else if (((long)(nextsize + prevsize + newsize) >= (long)(nb)))
2880
        {
2881
          unlink(next, bck, fwd);
2882
          unlink(prev, bck, fwd);
2883
          newp = prev;
2884
          newsize += nextsize + prevsize;
2885
          newmem = chunk2mem(newp);
2886
          MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2887
          goto split;
2888
        }
2889
      }
2890
 
2891
      /* backward only */
2892
      if (prev != 0 && (long)(prevsize + newsize) >= (long)nb)
2893
      {
2894
        unlink(prev, bck, fwd);
2895
        newp = prev;
2896
        newsize += prevsize;
2897
        newmem = chunk2mem(newp);
2898
        MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2899
        goto split;
2900
      }
2901
    }
2902
 
2903
    /* Must allocate */
2904
 
2905
    newmem = mALLOc (RCALL bytes);
2906
 
2907
    if (newmem == 0)  /* propagate failure */
2908
    {
2909
      MALLOC_UNLOCK;
2910
      return 0;
2911
    }
2912
 
2913
    /* Avoid copy if newp is next chunk after oldp. */
2914
    /* (This can only happen when new chunk is sbrk'ed.) */
2915
 
2916
    if ( (newp = mem2chunk(newmem)) == next_chunk(oldp))
2917
    {
2918
      newsize += chunksize(newp);
2919
      newp = oldp;
2920
      goto split;
2921
    }
2922
 
2923
    /* Otherwise copy, free, and exit */
2924
    MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2925
    fREe(RCALL oldmem);
2926
    MALLOC_UNLOCK;
2927
    return newmem;
2928
  }
2929
 
2930
 
2931
 split:  /* split off extra room in old or expanded chunk */
2932
 
2933
  remainder_size = long_sub_size_t(newsize, nb);
2934
 
2935
  if (remainder_size >= (long)MINSIZE) /* split off remainder */
2936
  {
2937
    remainder = chunk_at_offset(newp, nb);
2938
    set_head_size(newp, nb);
2939
    set_head(remainder, remainder_size | PREV_INUSE);
2940
    set_inuse_bit_at_offset(remainder, remainder_size);
2941
    fREe(RCALL chunk2mem(remainder)); /* let free() deal with it */
2942
  }
2943
  else
2944
  {
2945
    set_head_size(newp, newsize);
2946
    set_inuse_bit_at_offset(newp, newsize);
2947
  }
2948
 
2949
  check_inuse_chunk(newp);
2950
  MALLOC_UNLOCK;
2951
  return chunk2mem(newp);
2952
 
2953
#endif /* MALLOC_PROVIDED */
2954
}
2955
 
2956
#endif /* DEFINE_REALLOC */
2957
 
2958
#ifdef DEFINE_MEMALIGN
2959
 
2960
/*
2961
 
2962
  memalign algorithm:
2963
 
2964
    memalign requests more than enough space from malloc, finds a spot
2965
    within that chunk that meets the alignment request, and then
2966
    possibly frees the leading and trailing space.
2967
 
2968
    The alignment argument must be a power of two. This property is not
2969
    checked by memalign, so misuse may result in random runtime errors.
2970
 
2971
    8-byte alignment is guaranteed by normal malloc calls, so don't
2972
    bother calling memalign with an argument of 8 or less.
2973
 
2974
    Overreliance on memalign is a sure way to fragment space.
2975
 
2976
*/
2977
 
2978
 
2979
#if __STD_C
2980
Void_t* mEMALIGn(RARG size_t alignment, size_t bytes)
2981
#else
2982
Void_t* mEMALIGn(RARG alignment, bytes) RDECL size_t alignment; size_t bytes;
2983
#endif
2984
{
2985
  INTERNAL_SIZE_T    nb;      /* padded  request size */
2986
  char*     m;                /* memory returned by malloc call */
2987
  mchunkptr p;                /* corresponding chunk */
2988
  char*     brk;              /* alignment point within p */
2989
  mchunkptr newp;             /* chunk to return */
2990
  INTERNAL_SIZE_T  newsize;   /* its size */
2991
  INTERNAL_SIZE_T  leadsize;  /* leading space befor alignment point */
2992
  mchunkptr remainder;        /* spare room at end to split off */
2993
  long      remainder_size;   /* its size */
2994
 
2995
  /* If need less alignment than we give anyway, just relay to malloc */
2996
 
2997
  if (alignment <= MALLOC_ALIGNMENT) return mALLOc(RCALL bytes);
2998
 
2999
  /* Otherwise, ensure that it is at least a minimum chunk size */
3000
 
3001
  if (alignment <  MINSIZE) alignment = MINSIZE;
3002
 
3003
  /* Call malloc with worst case padding to hit alignment. */
3004
 
3005
  nb = request2size(bytes);
3006
  m  = (char*)(mALLOc(RCALL nb + alignment + MINSIZE));
3007
 
3008
  if (m == 0) return 0; /* propagate failure */
3009
 
3010
  MALLOC_LOCK;
3011
 
3012
  p = mem2chunk(m);
3013
 
3014
  if ((((unsigned long)(m)) % alignment) == 0) /* aligned */
3015
  {
3016
#if HAVE_MMAP
3017
    if(chunk_is_mmapped(p))
3018
    {
3019
      MALLOC_UNLOCK;
3020
      return chunk2mem(p); /* nothing more to do */
3021
    }
3022
#endif
3023
  }
3024
  else /* misaligned */
3025
  {
3026
    /*
3027
      Find an aligned spot inside chunk.
3028
      Since we need to give back leading space in a chunk of at
3029
      least MINSIZE, if the first calculation places us at
3030
      a spot with less than MINSIZE leader, we can move to the
3031
      next aligned spot -- we've allocated enough total room so that
3032
      this is always possible.
3033
    */
3034
 
3035
    brk = (char*)mem2chunk(((unsigned long)(m + alignment - 1)) & -alignment);
3036
    if ((long)(brk - (char*)(p)) < (long)MINSIZE) brk = brk + alignment;
3037
 
3038
    newp = (mchunkptr)brk;
3039
    leadsize = brk - (char*)(p);
3040
    newsize = chunksize(p) - leadsize;
3041
 
3042
#if HAVE_MMAP
3043
    if(chunk_is_mmapped(p))
3044
    {
3045
      newp->prev_size = p->prev_size + leadsize;
3046
      set_head(newp, newsize|IS_MMAPPED);
3047
      MALLOC_UNLOCK;
3048
      return chunk2mem(newp);
3049
    }
3050
#endif
3051
 
3052
    /* give back leader, use the rest */
3053
 
3054
    set_head(newp, newsize | PREV_INUSE);
3055
    set_inuse_bit_at_offset(newp, newsize);
3056
    set_head_size(p, leadsize);
3057
    fREe(RCALL chunk2mem(p));
3058
    p = newp;
3059
 
3060
    assert (newsize >= nb && (((unsigned long)(chunk2mem(p))) % alignment) == 0);
3061
  }
3062
 
3063
  /* Also give back spare room at the end */
3064
 
3065
  remainder_size = long_sub_size_t(chunksize(p), nb);
3066
 
3067
  if (remainder_size >= (long)MINSIZE)
3068
  {
3069
    remainder = chunk_at_offset(p, nb);
3070
    set_head(remainder, remainder_size | PREV_INUSE);
3071
    set_head_size(p, nb);
3072
    fREe(RCALL chunk2mem(remainder));
3073
  }
3074
 
3075
  check_inuse_chunk(p);
3076
  MALLOC_UNLOCK;
3077
  return chunk2mem(p);
3078
 
3079
}
3080
 
3081
#endif /* DEFINE_MEMALIGN */
3082
 
3083
#ifdef DEFINE_VALLOC
3084
 
3085
/*
3086
    valloc just invokes memalign with alignment argument equal
3087
    to the page size of the system (or as near to this as can
3088
    be figured out from all the includes/defines above.)
3089
*/
3090
 
3091
#if __STD_C
3092
Void_t* vALLOc(RARG size_t bytes)
3093
#else
3094
Void_t* vALLOc(RARG bytes) RDECL size_t bytes;
3095
#endif
3096
{
3097
  return mEMALIGn (RCALL malloc_getpagesize, bytes);
3098
}
3099
 
3100
#endif /* DEFINE_VALLOC */
3101
 
3102
#ifdef DEFINE_PVALLOC
3103
 
3104
/*
3105
  pvalloc just invokes valloc for the nearest pagesize
3106
  that will accommodate request
3107
*/
3108
 
3109
 
3110
#if __STD_C
3111
Void_t* pvALLOc(RARG size_t bytes)
3112
#else
3113
Void_t* pvALLOc(RARG bytes) RDECL size_t bytes;
3114
#endif
3115
{
3116
  size_t pagesize = malloc_getpagesize;
3117
  return mEMALIGn (RCALL pagesize, (bytes + pagesize - 1) & ~(pagesize - 1));
3118
}
3119
 
3120
#endif /* DEFINE_PVALLOC */
3121
 
3122
#ifdef DEFINE_CALLOC
3123
 
3124
/*
3125
 
3126
  calloc calls malloc, then zeroes out the allocated chunk.
3127
 
3128
*/
3129
 
3130
#if __STD_C
3131
Void_t* cALLOc(RARG size_t n, size_t elem_size)
3132
#else
3133
Void_t* cALLOc(RARG n, elem_size) RDECL size_t n; size_t elem_size;
3134
#endif
3135
{
3136
  mchunkptr p;
3137
  INTERNAL_SIZE_T csz;
3138
 
3139
  INTERNAL_SIZE_T sz = n * elem_size;
3140
 
3141
#if MORECORE_CLEARS
3142
  mchunkptr oldtop;
3143
  INTERNAL_SIZE_T oldtopsize;
3144
#endif
3145
  Void_t* mem;
3146
 
3147
  /* check if expand_top called, in which case don't need to clear */
3148
#if MORECORE_CLEARS
3149
  MALLOC_LOCK;
3150
  oldtop = top;
3151
  oldtopsize = chunksize(top);
3152
#endif
3153
 
3154
  mem = mALLOc (RCALL sz);
3155
 
3156
  if (mem == 0)
3157
  {
3158
#if MORECORE_CLEARS
3159
    MALLOC_UNLOCK;
3160
#endif
3161
    return 0;
3162
  }
3163
  else
3164
  {
3165
    p = mem2chunk(mem);
3166
 
3167
    /* Two optional cases in which clearing not necessary */
3168
 
3169
 
3170
#if HAVE_MMAP
3171
    if (chunk_is_mmapped(p))
3172
    {
3173
#if MORECORE_CLEARS
3174
      MALLOC_UNLOCK;
3175
#endif
3176
      return mem;
3177
    }
3178
#endif
3179
 
3180
    csz = chunksize(p);
3181
 
3182
#if MORECORE_CLEARS
3183
    if (p == oldtop && csz > oldtopsize)
3184
    {
3185
      /* clear only the bytes from non-freshly-sbrked memory */
3186
      csz = oldtopsize;
3187
    }
3188
    MALLOC_UNLOCK;
3189
#endif
3190
 
3191
    MALLOC_ZERO(mem, csz - SIZE_SZ);
3192
    return mem;
3193
  }
3194
}
3195
 
3196
#endif /* DEFINE_CALLOC */
3197
 
3198
#ifdef DEFINE_CFREE
3199
 
3200
/*
3201
 
3202
  cfree just calls free. It is needed/defined on some systems
3203
  that pair it with calloc, presumably for odd historical reasons.
3204
 
3205
*/
3206
 
3207
#if !defined(INTERNAL_LINUX_C_LIB) || !defined(__ELF__)
3208
#if !defined(INTERNAL_NEWLIB) || !defined(_REENT_ONLY)
3209
#if __STD_C
3210
void cfree(Void_t *mem)
3211
#else
3212
void cfree(mem) Void_t *mem;
3213
#endif
3214
{
3215
#ifdef INTERNAL_NEWLIB
3216
  fREe(_REENT, mem);
3217
#else
3218
  fREe(mem);
3219
#endif
3220
}
3221
#endif
3222
#endif
3223
 
3224
#endif /* DEFINE_CFREE */
3225
 
3226
#ifdef DEFINE_FREE
3227
 
3228
/*
3229
 
3230
    Malloc_trim gives memory back to the system (via negative
3231
    arguments to sbrk) if there is unused memory at the `high' end of
3232
    the malloc pool. You can call this after freeing large blocks of
3233
    memory to potentially reduce the system-level memory requirements
3234
    of a program. However, it cannot guarantee to reduce memory. Under
3235
    some allocation patterns, some large free blocks of memory will be
3236
    locked between two used chunks, so they cannot be given back to
3237
    the system.
3238
 
3239
    The `pad' argument to malloc_trim represents the amount of free
3240
    trailing space to leave untrimmed. If this argument is zero,
3241
    only the minimum amount of memory to maintain internal data
3242
    structures will be left (one page or less). Non-zero arguments
3243
    can be supplied to maintain enough trailing space to service
3244
    future expected allocations without having to re-obtain memory
3245
    from the system.
3246
 
3247
    Malloc_trim returns 1 if it actually released any memory, else 0.
3248
 
3249
*/
3250
 
3251
#if __STD_C
3252
int malloc_trim(RARG size_t pad)
3253
#else
3254
int malloc_trim(RARG pad) RDECL size_t pad;
3255
#endif
3256
{
3257
  long  top_size;        /* Amount of top-most memory */
3258
  long  extra;           /* Amount to release */
3259
  char* current_brk;     /* address returned by pre-check sbrk call */
3260
  char* new_brk;         /* address returned by negative sbrk call */
3261
 
3262
  unsigned long pagesz = malloc_getpagesize;
3263
 
3264
  MALLOC_LOCK;
3265
 
3266
  top_size = chunksize(top);
3267
  extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz;
3268
 
3269
  if (extra < (long)pagesz)  /* Not enough memory to release */
3270
  {
3271
    MALLOC_UNLOCK;
3272
    return 0;
3273
  }
3274
 
3275
  else
3276
  {
3277
    /* Test to make sure no one else called sbrk */
3278
    current_brk = (char*)(MORECORE (0));
3279
    if (current_brk != (char*)(top) + top_size)
3280
    {
3281
      MALLOC_UNLOCK;
3282
      return 0;     /* Apparently we don't own memory; must fail */
3283
    }
3284
 
3285
    else
3286
    {
3287
      new_brk = (char*)(MORECORE (-extra));
3288
 
3289
      if (new_brk == (char*)(MORECORE_FAILURE)) /* sbrk failed? */
3290
      {
3291
        /* Try to figure out what we have */
3292
        current_brk = (char*)(MORECORE (0));
3293
        top_size = current_brk - (char*)top;
3294
        if (top_size >= (long)MINSIZE) /* if not, we are very very dead! */
3295
        {
3296
          sbrked_mem = current_brk - sbrk_base;
3297
          set_head(top, top_size | PREV_INUSE);
3298
        }
3299
        check_chunk(top);
3300
        MALLOC_UNLOCK;
3301
        return 0;
3302
      }
3303
 
3304
      else
3305
      {
3306
        /* Success. Adjust top accordingly. */
3307
        set_head(top, (top_size - extra) | PREV_INUSE);
3308
        sbrked_mem -= extra;
3309
        check_chunk(top);
3310
        MALLOC_UNLOCK;
3311
        return 1;
3312
      }
3313
    }
3314
  }
3315
}
3316
 
3317
#endif /* DEFINE_FREE */
3318
 
3319
#ifdef DEFINE_MALLOC_USABLE_SIZE
3320
 
3321
/*
3322
  malloc_usable_size:
3323
 
3324
    This routine tells you how many bytes you can actually use in an
3325
    allocated chunk, which may be more than you requested (although
3326
    often not). You can use this many bytes without worrying about
3327
    overwriting other allocated objects. Not a particularly great
3328
    programming practice, but still sometimes useful.
3329
 
3330
*/
3331
 
3332
#if __STD_C
3333
size_t malloc_usable_size(RARG Void_t* mem)
3334
#else
3335
size_t malloc_usable_size(RARG mem) RDECL Void_t* mem;
3336
#endif
3337
{
3338
  mchunkptr p;
3339
  if (mem == 0)
3340
    return 0;
3341
  else
3342
  {
3343
    p = mem2chunk(mem);
3344
    if(!chunk_is_mmapped(p))
3345
    {
3346
      if (!inuse(p)) return 0;
3347
#if DEBUG
3348
      MALLOC_LOCK;
3349
      check_inuse_chunk(p);
3350
      MALLOC_UNLOCK;
3351
#endif
3352
      return chunksize(p) - SIZE_SZ;
3353
    }
3354
    return chunksize(p) - 2*SIZE_SZ;
3355
  }
3356
}
3357
 
3358
#endif /* DEFINE_MALLOC_USABLE_SIZE */
3359
 
3360
#ifdef DEFINE_MALLINFO
3361
 
3362
/* Utility to update current_mallinfo for malloc_stats and mallinfo() */
3363
 
3364
STATIC void malloc_update_mallinfo()
3365
{
3366
  int i;
3367
  mbinptr b;
3368
  mchunkptr p;
3369
#if DEBUG
3370
  mchunkptr q;
3371
#endif
3372
 
3373
  INTERNAL_SIZE_T avail = chunksize(top);
3374
  int   navail = ((long)(avail) >= (long)MINSIZE)? 1 : 0;
3375
 
3376
  for (i = 1; i < NAV; ++i)
3377
  {
3378
    b = bin_at(i);
3379
    for (p = last(b); p != b; p = p->bk)
3380
    {
3381
#if DEBUG
3382
      check_free_chunk(p);
3383
      for (q = next_chunk(p);
3384
           q < top && inuse(q) && (long)(chunksize(q)) >= (long)MINSIZE;
3385
           q = next_chunk(q))
3386
        check_inuse_chunk(q);
3387
#endif
3388
      avail += chunksize(p);
3389
      navail++;
3390
    }
3391
  }
3392
 
3393
  current_mallinfo.ordblks = navail;
3394
  current_mallinfo.uordblks = sbrked_mem - avail;
3395
  current_mallinfo.fordblks = avail;
3396
#if HAVE_MMAP
3397
  current_mallinfo.hblks = n_mmaps;
3398
  current_mallinfo.hblkhd = mmapped_mem;
3399
#endif
3400
  current_mallinfo.keepcost = chunksize(top);
3401
 
3402
}
3403
 
3404
#else /* ! DEFINE_MALLINFO */
3405
 
3406
#if __STD_C
3407
extern void malloc_update_mallinfo(void);
3408
#else
3409
extern void malloc_update_mallinfo();
3410
#endif
3411
 
3412
#endif /* ! DEFINE_MALLINFO */
3413
 
3414
#ifdef DEFINE_MALLOC_STATS
3415
 
3416
/*
3417
 
3418
  malloc_stats:
3419
 
3420
    Prints on stderr the amount of space obtain from the system (both
3421
    via sbrk and mmap), the maximum amount (which may be more than
3422
    current if malloc_trim and/or munmap got called), the maximum
3423
    number of simultaneous mmap regions used, and the current number
3424
    of bytes allocated via malloc (or realloc, etc) but not yet
3425
    freed. (Note that this is the number of bytes allocated, not the
3426
    number requested. It will be larger than the number requested
3427
    because of alignment and bookkeeping overhead.)
3428
 
3429
*/
3430
 
3431
#if __STD_C
3432
void malloc_stats(RONEARG)
3433
#else
3434
void malloc_stats(RONEARG) RDECL
3435
#endif
3436
{
3437
  unsigned long local_max_total_mem;
3438
  int local_sbrked_mem;
3439
  struct mallinfo local_mallinfo;
3440
#if HAVE_MMAP
3441
  unsigned long local_mmapped_mem, local_max_n_mmaps;
3442
#endif
3443
  FILE *fp;
3444
 
3445
  MALLOC_LOCK;
3446
  malloc_update_mallinfo();
3447
  local_max_total_mem = max_total_mem;
3448
  local_sbrked_mem = sbrked_mem;
3449
  local_mallinfo = current_mallinfo;
3450
#if HAVE_MMAP
3451
  local_mmapped_mem = mmapped_mem;
3452
  local_max_n_mmaps = max_n_mmaps;
3453
#endif
3454
  MALLOC_UNLOCK;
3455
 
3456
#ifdef INTERNAL_NEWLIB
3457
  fp = _stderr_r(reent_ptr);
3458
#define fprintf fiprintf
3459
#else
3460
  fp = stderr;
3461
#endif
3462
 
3463
  fprintf(fp, "max system bytes = %10u\n",
3464
          (unsigned int)(local_max_total_mem));
3465
#if HAVE_MMAP
3466
  fprintf(fp, "system bytes     = %10u\n",
3467
          (unsigned int)(local_sbrked_mem + local_mmapped_mem));
3468
  fprintf(fp, "in use bytes     = %10u\n",
3469
          (unsigned int)(local_mallinfo.uordblks + local_mmapped_mem));
3470
#else
3471
  fprintf(fp, "system bytes     = %10u\n",
3472
          (unsigned int)local_sbrked_mem);
3473
  fprintf(fp, "in use bytes     = %10u\n",
3474
          (unsigned int)local_mallinfo.uordblks);
3475
#endif
3476
#if HAVE_MMAP
3477
  fprintf(fp, "max mmap regions = %10u\n",
3478
          (unsigned int)local_max_n_mmaps);
3479
#endif
3480
}
3481
 
3482
#endif /* DEFINE_MALLOC_STATS */
3483
 
3484
#ifdef DEFINE_MALLINFO
3485
 
3486
/*
3487
  mallinfo returns a copy of updated current mallinfo.
3488
*/
3489
 
3490
#if __STD_C
3491
struct mallinfo mALLINFo(RONEARG)
3492
#else
3493
struct mallinfo mALLINFo(RONEARG) RDECL
3494
#endif
3495
{
3496
  struct mallinfo ret;
3497
 
3498
  MALLOC_LOCK;
3499
  malloc_update_mallinfo();
3500
  ret = current_mallinfo;
3501
  MALLOC_UNLOCK;
3502
  return ret;
3503
}
3504
 
3505
#endif /* DEFINE_MALLINFO */
3506
 
3507
#ifdef DEFINE_MALLOPT
3508
 
3509
/*
3510
  mallopt:
3511
 
3512
    mallopt is the general SVID/XPG interface to tunable parameters.
3513
    The format is to provide a (parameter-number, parameter-value) pair.
3514
    mallopt then sets the corresponding parameter to the argument
3515
    value if it can (i.e., so long as the value is meaningful),
3516
    and returns 1 if successful else 0.
3517
 
3518
    See descriptions of tunable parameters above.
3519
 
3520
*/
3521
 
3522
#if __STD_C
3523
int mALLOPt(RARG int param_number, int value)
3524
#else
3525
int mALLOPt(RARG param_number, value) RDECL int param_number; int value;
3526
#endif
3527
{
3528
  MALLOC_LOCK;
3529
  switch(param_number)
3530
  {
3531
    case M_TRIM_THRESHOLD:
3532
      trim_threshold = value; MALLOC_UNLOCK; return 1;
3533
    case M_TOP_PAD:
3534
      top_pad = value; MALLOC_UNLOCK; return 1;
3535
    case M_MMAP_THRESHOLD:
3536
#if HAVE_MMAP
3537
      mmap_threshold = value;
3538
#endif
3539
      MALLOC_UNLOCK;
3540
      return 1;
3541
    case M_MMAP_MAX:
3542
#if HAVE_MMAP
3543
      n_mmaps_max = value; MALLOC_UNLOCK; return 1;
3544
#else
3545
      MALLOC_UNLOCK; return value == 0;
3546
#endif
3547
 
3548
    default:
3549
      MALLOC_UNLOCK;
3550
      return 0;
3551
  }
3552
}
3553
 
3554
#endif /* DEFINE_MALLOPT */
3555
 
3556
/*
3557
 
3558
History:
3559
 
3560
    V2.6.3 Sun May 19 08:17:58 1996  Doug Lea  (dl at gee)
3561
      * Added pvalloc, as recommended by H.J. Liu
3562
      * Added 64bit pointer support mainly from Wolfram Gloger
3563
      * Added anonymously donated WIN32 sbrk emulation
3564
      * Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen
3565
      * malloc_extend_top: fix mask error that caused wastage after
3566
        foreign sbrks
3567
      * Add linux mremap support code from HJ Liu
3568
 
3569
    V2.6.2 Tue Dec  5 06:52:55 1995  Doug Lea  (dl at gee)
3570
      * Integrated most documentation with the code.
3571
      * Add support for mmap, with help from
3572
        Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
3573
      * Use last_remainder in more cases.
3574
      * Pack bins using idea from  colin@nyx10.cs.du.edu
3575
      * Use ordered bins instead of best-fit threshhold
3576
      * Eliminate block-local decls to simplify tracing and debugging.
3577
      * Support another case of realloc via move into top
3578
      * Fix error occuring when initial sbrk_base not word-aligned.
3579
      * Rely on page size for units instead of SBRK_UNIT to
3580
        avoid surprises about sbrk alignment conventions.
3581
      * Add mallinfo, mallopt. Thanks to Raymond Nijssen
3582
        (raymond@es.ele.tue.nl) for the suggestion.
3583
      * Add `pad' argument to malloc_trim and top_pad mallopt parameter.
3584
      * More precautions for cases where other routines call sbrk,
3585
        courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
3586
      * Added macros etc., allowing use in linux libc from
3587
        H.J. Lu (hjl@gnu.ai.mit.edu)
3588
      * Inverted this history list
3589
 
3590
    V2.6.1 Sat Dec  2 14:10:57 1995  Doug Lea  (dl at gee)
3591
      * Re-tuned and fixed to behave more nicely with V2.6.0 changes.
3592
      * Removed all preallocation code since under current scheme
3593
        the work required to undo bad preallocations exceeds
3594
        the work saved in good cases for most test programs.
3595
      * No longer use return list or unconsolidated bins since
3596
        no scheme using them consistently outperforms those that don't
3597
        given above changes.
3598
      * Use best fit for very large chunks to prevent some worst-cases.
3599
      * Added some support for debugging
3600
 
3601
    V2.6.0 Sat Nov  4 07:05:23 1995  Doug Lea  (dl at gee)
3602
      * Removed footers when chunks are in use. Thanks to
3603
        Paul Wilson (wilson@cs.texas.edu) for the suggestion.
3604
 
3605
    V2.5.4 Wed Nov  1 07:54:51 1995  Doug Lea  (dl at gee)
3606
      * Added malloc_trim, with help from Wolfram Gloger
3607
        (wmglo@Dent.MED.Uni-Muenchen.DE).
3608
 
3609
    V2.5.3 Tue Apr 26 10:16:01 1994  Doug Lea  (dl at g)
3610
 
3611
    V2.5.2 Tue Apr  5 16:20:40 1994  Doug Lea  (dl at g)
3612
      * realloc: try to expand in both directions
3613
      * malloc: swap order of clean-bin strategy;
3614
      * realloc: only conditionally expand backwards
3615
      * Try not to scavenge used bins
3616
      * Use bin counts as a guide to preallocation
3617
      * Occasionally bin return list chunks in first scan
3618
      * Add a few optimizations from colin@nyx10.cs.du.edu
3619
 
3620
    V2.5.1 Sat Aug 14 15:40:43 1993  Doug Lea  (dl at g)
3621
      * faster bin computation & slightly different binning
3622
      * merged all consolidations to one part of malloc proper
3623
         (eliminating old malloc_find_space & malloc_clean_bin)
3624
      * Scan 2 returns chunks (not just 1)
3625
      * Propagate failure in realloc if malloc returns 0
3626
      * Add stuff to allow compilation on non-ANSI compilers
3627
          from kpv@research.att.com
3628
 
3629
    V2.5 Sat Aug  7 07:41:59 1993  Doug Lea  (dl at g.oswego.edu)
3630
      * removed potential for odd address access in prev_chunk
3631
      * removed dependency on getpagesize.h
3632
      * misc cosmetics and a bit more internal documentation
3633
      * anticosmetics: mangled names in macros to evade debugger strangeness
3634
      * tested on sparc, hp-700, dec-mips, rs6000
3635
          with gcc & native cc (hp, dec only) allowing
3636
          Detlefs & Zorn comparison study (in SIGPLAN Notices.)
3637
 
3638
    Trial version Fri Aug 28 13:14:29 1992  Doug Lea  (dl at g.oswego.edu)
3639
      * Based loosely on libg++-1.2X malloc. (It retains some of the overall
3640
         structure of old version,  but most details differ.)
3641
 
3642
*/
3643
 

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