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Kumar Gala81673e92008-05-13 19:01:54 -05001#include <common.h>
2
wdenk217c9da2002-10-25 20:35:49 +00003#if 0 /* Moved to malloc.h */
4/* ---------- To make a malloc.h, start cutting here ------------ */
5
6/*
7 A version of malloc/free/realloc written by Doug Lea and released to the
8 public domain. Send questions/comments/complaints/performance data
9 to dl@cs.oswego.edu
10
11* VERSION 2.6.6 Sun Mar 5 19:10:03 2000 Doug Lea (dl at gee)
12
13 Note: There may be an updated version of this malloc obtainable at
wdenk8bde7f72003-06-27 21:31:46 +000014 ftp://g.oswego.edu/pub/misc/malloc.c
15 Check before installing!
wdenk217c9da2002-10-25 20:35:49 +000016
17* Why use this malloc?
18
19 This is not the fastest, most space-conserving, most portable, or
20 most tunable malloc ever written. However it is among the fastest
21 while also being among the most space-conserving, portable and tunable.
22 Consistent balance across these factors results in a good general-purpose
23 allocator. For a high-level description, see
24 http://g.oswego.edu/dl/html/malloc.html
25
26* Synopsis of public routines
27
28 (Much fuller descriptions are contained in the program documentation below.)
29
30 malloc(size_t n);
31 Return a pointer to a newly allocated chunk of at least n bytes, or null
32 if no space is available.
33 free(Void_t* p);
34 Release the chunk of memory pointed to by p, or no effect if p is null.
35 realloc(Void_t* p, size_t n);
36 Return a pointer to a chunk of size n that contains the same data
37 as does chunk p up to the minimum of (n, p's size) bytes, or null
38 if no space is available. The returned pointer may or may not be
39 the same as p. If p is null, equivalent to malloc. Unless the
40 #define REALLOC_ZERO_BYTES_FREES below is set, realloc with a
41 size argument of zero (re)allocates a minimum-sized chunk.
42 memalign(size_t alignment, size_t n);
43 Return a pointer to a newly allocated chunk of n bytes, aligned
44 in accord with the alignment argument, which must be a power of
45 two.
46 valloc(size_t n);
47 Equivalent to memalign(pagesize, n), where pagesize is the page
48 size of the system (or as near to this as can be figured out from
49 all the includes/defines below.)
50 pvalloc(size_t n);
51 Equivalent to valloc(minimum-page-that-holds(n)), that is,
52 round up n to nearest pagesize.
53 calloc(size_t unit, size_t quantity);
54 Returns a pointer to quantity * unit bytes, with all locations
55 set to zero.
56 cfree(Void_t* p);
57 Equivalent to free(p).
58 malloc_trim(size_t pad);
59 Release all but pad bytes of freed top-most memory back
60 to the system. Return 1 if successful, else 0.
61 malloc_usable_size(Void_t* p);
62 Report the number usable allocated bytes associated with allocated
63 chunk p. This may or may not report more bytes than were requested,
64 due to alignment and minimum size constraints.
65 malloc_stats();
66 Prints brief summary statistics.
67 mallinfo()
68 Returns (by copy) a struct containing various summary statistics.
69 mallopt(int parameter_number, int parameter_value)
70 Changes one of the tunable parameters described below. Returns
71 1 if successful in changing the parameter, else 0.
72
73* Vital statistics:
74
75 Alignment: 8-byte
76 8 byte alignment is currently hardwired into the design. This
77 seems to suffice for all current machines and C compilers.
78
79 Assumed pointer representation: 4 or 8 bytes
80 Code for 8-byte pointers is untested by me but has worked
81 reliably by Wolfram Gloger, who contributed most of the
82 changes supporting this.
83
84 Assumed size_t representation: 4 or 8 bytes
85 Note that size_t is allowed to be 4 bytes even if pointers are 8.
86
87 Minimum overhead per allocated chunk: 4 or 8 bytes
88 Each malloced chunk has a hidden overhead of 4 bytes holding size
89 and status information.
90
91 Minimum allocated size: 4-byte ptrs: 16 bytes (including 4 overhead)
wdenk8bde7f72003-06-27 21:31:46 +000092 8-byte ptrs: 24/32 bytes (including, 4/8 overhead)
wdenk217c9da2002-10-25 20:35:49 +000093
94 When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte
95 ptrs but 4 byte size) or 24 (for 8/8) additional bytes are
96 needed; 4 (8) for a trailing size field
97 and 8 (16) bytes for free list pointers. Thus, the minimum
98 allocatable size is 16/24/32 bytes.
99
100 Even a request for zero bytes (i.e., malloc(0)) returns a
101 pointer to something of the minimum allocatable size.
102
103 Maximum allocated size: 4-byte size_t: 2^31 - 8 bytes
wdenk8bde7f72003-06-27 21:31:46 +0000104 8-byte size_t: 2^63 - 16 bytes
wdenk217c9da2002-10-25 20:35:49 +0000105
106 It is assumed that (possibly signed) size_t bit values suffice to
107 represent chunk sizes. `Possibly signed' is due to the fact
108 that `size_t' may be defined on a system as either a signed or
109 an unsigned type. To be conservative, values that would appear
110 as negative numbers are avoided.
111 Requests for sizes with a negative sign bit when the request
112 size is treaded as a long will return null.
113
114 Maximum overhead wastage per allocated chunk: normally 15 bytes
115
116 Alignnment demands, plus the minimum allocatable size restriction
117 make the normal worst-case wastage 15 bytes (i.e., up to 15
118 more bytes will be allocated than were requested in malloc), with
119 two exceptions:
wdenk8bde7f72003-06-27 21:31:46 +0000120 1. Because requests for zero bytes allocate non-zero space,
121 the worst case wastage for a request of zero bytes is 24 bytes.
122 2. For requests >= mmap_threshold that are serviced via
123 mmap(), the worst case wastage is 8 bytes plus the remainder
124 from a system page (the minimal mmap unit); typically 4096 bytes.
wdenk217c9da2002-10-25 20:35:49 +0000125
126* Limitations
127
128 Here are some features that are NOT currently supported
129
130 * No user-definable hooks for callbacks and the like.
131 * No automated mechanism for fully checking that all accesses
132 to malloced memory stay within their bounds.
133 * No support for compaction.
134
135* Synopsis of compile-time options:
136
137 People have reported using previous versions of this malloc on all
138 versions of Unix, sometimes by tweaking some of the defines
139 below. It has been tested most extensively on Solaris and
140 Linux. It is also reported to work on WIN32 platforms.
141 People have also reported adapting this malloc for use in
142 stand-alone embedded systems.
143
144 The implementation is in straight, hand-tuned ANSI C. Among other
145 consequences, it uses a lot of macros. Because of this, to be at
146 all usable, this code should be compiled using an optimizing compiler
147 (for example gcc -O2) that can simplify expressions and control
148 paths.
149
150 __STD_C (default: derived from C compiler defines)
151 Nonzero if using ANSI-standard C compiler, a C++ compiler, or
152 a C compiler sufficiently close to ANSI to get away with it.
153 DEBUG (default: NOT defined)
154 Define to enable debugging. Adds fairly extensive assertion-based
155 checking to help track down memory errors, but noticeably slows down
156 execution.
157 REALLOC_ZERO_BYTES_FREES (default: NOT defined)
158 Define this if you think that realloc(p, 0) should be equivalent
159 to free(p). Otherwise, since malloc returns a unique pointer for
160 malloc(0), so does realloc(p, 0).
161 HAVE_MEMCPY (default: defined)
162 Define if you are not otherwise using ANSI STD C, but still
163 have memcpy and memset in your C library and want to use them.
164 Otherwise, simple internal versions are supplied.
165 USE_MEMCPY (default: 1 if HAVE_MEMCPY is defined, 0 otherwise)
166 Define as 1 if you want the C library versions of memset and
167 memcpy called in realloc and calloc (otherwise macro versions are used).
168 At least on some platforms, the simple macro versions usually
169 outperform libc versions.
170 HAVE_MMAP (default: defined as 1)
171 Define to non-zero to optionally make malloc() use mmap() to
172 allocate very large blocks.
173 HAVE_MREMAP (default: defined as 0 unless Linux libc set)
174 Define to non-zero to optionally make realloc() use mremap() to
175 reallocate very large blocks.
176 malloc_getpagesize (default: derived from system #includes)
177 Either a constant or routine call returning the system page size.
178 HAVE_USR_INCLUDE_MALLOC_H (default: NOT defined)
179 Optionally define if you are on a system with a /usr/include/malloc.h
180 that declares struct mallinfo. It is not at all necessary to
181 define this even if you do, but will ensure consistency.
182 INTERNAL_SIZE_T (default: size_t)
183 Define to a 32-bit type (probably `unsigned int') if you are on a
184 64-bit machine, yet do not want or need to allow malloc requests of
185 greater than 2^31 to be handled. This saves space, especially for
186 very small chunks.
187 INTERNAL_LINUX_C_LIB (default: NOT defined)
188 Defined only when compiled as part of Linux libc.
189 Also note that there is some odd internal name-mangling via defines
190 (for example, internally, `malloc' is named `mALLOc') needed
191 when compiling in this case. These look funny but don't otherwise
192 affect anything.
193 WIN32 (default: undefined)
194 Define this on MS win (95, nt) platforms to compile in sbrk emulation.
195 LACKS_UNISTD_H (default: undefined if not WIN32)
196 Define this if your system does not have a <unistd.h>.
197 LACKS_SYS_PARAM_H (default: undefined if not WIN32)
198 Define this if your system does not have a <sys/param.h>.
199 MORECORE (default: sbrk)
200 The name of the routine to call to obtain more memory from the system.
201 MORECORE_FAILURE (default: -1)
202 The value returned upon failure of MORECORE.
203 MORECORE_CLEARS (default 1)
York Sun472d5462013-04-01 11:29:11 -0700204 true (1) if the routine mapped to MORECORE zeroes out memory (which
wdenk217c9da2002-10-25 20:35:49 +0000205 holds for sbrk).
206 DEFAULT_TRIM_THRESHOLD
207 DEFAULT_TOP_PAD
208 DEFAULT_MMAP_THRESHOLD
209 DEFAULT_MMAP_MAX
210 Default values of tunable parameters (described in detail below)
211 controlling interaction with host system routines (sbrk, mmap, etc).
212 These values may also be changed dynamically via mallopt(). The
213 preset defaults are those that give best performance for typical
214 programs/systems.
215 USE_DL_PREFIX (default: undefined)
216 Prefix all public routines with the string 'dl'. Useful to
217 quickly avoid procedure declaration conflicts and linker symbol
218 conflicts with existing memory allocation routines.
219
220
221*/
222
223
224
wdenk217c9da2002-10-25 20:35:49 +0000225/* Preliminaries */
226
227#ifndef __STD_C
228#ifdef __STDC__
229#define __STD_C 1
230#else
231#if __cplusplus
232#define __STD_C 1
233#else
234#define __STD_C 0
235#endif /*__cplusplus*/
236#endif /*__STDC__*/
237#endif /*__STD_C*/
238
239#ifndef Void_t
240#if (__STD_C || defined(WIN32))
241#define Void_t void
242#else
243#define Void_t char
244#endif
245#endif /*Void_t*/
246
247#if __STD_C
248#include <stddef.h> /* for size_t */
249#else
250#include <sys/types.h>
251#endif
252
253#ifdef __cplusplus
254extern "C" {
255#endif
256
257#include <stdio.h> /* needed for malloc_stats */
258
259
260/*
261 Compile-time options
262*/
263
264
265/*
266 Debugging:
267
268 Because freed chunks may be overwritten with link fields, this
269 malloc will often die when freed memory is overwritten by user
270 programs. This can be very effective (albeit in an annoying way)
271 in helping track down dangling pointers.
272
273 If you compile with -DDEBUG, a number of assertion checks are
274 enabled that will catch more memory errors. You probably won't be
275 able to make much sense of the actual assertion errors, but they
276 should help you locate incorrectly overwritten memory. The
277 checking is fairly extensive, and will slow down execution
278 noticeably. Calling malloc_stats or mallinfo with DEBUG set will
279 attempt to check every non-mmapped allocated and free chunk in the
280 course of computing the summmaries. (By nature, mmapped regions
281 cannot be checked very much automatically.)
282
283 Setting DEBUG may also be helpful if you are trying to modify
284 this code. The assertions in the check routines spell out in more
285 detail the assumptions and invariants underlying the algorithms.
286
287*/
288
wdenk217c9da2002-10-25 20:35:49 +0000289/*
290 INTERNAL_SIZE_T is the word-size used for internal bookkeeping
291 of chunk sizes. On a 64-bit machine, you can reduce malloc
292 overhead by defining INTERNAL_SIZE_T to be a 32 bit `unsigned int'
293 at the expense of not being able to handle requests greater than
294 2^31. This limitation is hardly ever a concern; you are encouraged
295 to set this. However, the default version is the same as size_t.
296*/
297
298#ifndef INTERNAL_SIZE_T
299#define INTERNAL_SIZE_T size_t
300#endif
301
302/*
303 REALLOC_ZERO_BYTES_FREES should be set if a call to
304 realloc with zero bytes should be the same as a call to free.
305 Some people think it should. Otherwise, since this malloc
306 returns a unique pointer for malloc(0), so does realloc(p, 0).
307*/
308
309
310/* #define REALLOC_ZERO_BYTES_FREES */
311
312
313/*
314 WIN32 causes an emulation of sbrk to be compiled in
315 mmap-based options are not currently supported in WIN32.
316*/
317
318/* #define WIN32 */
319#ifdef WIN32
320#define MORECORE wsbrk
321#define HAVE_MMAP 0
322
323#define LACKS_UNISTD_H
324#define LACKS_SYS_PARAM_H
325
326/*
327 Include 'windows.h' to get the necessary declarations for the
328 Microsoft Visual C++ data structures and routines used in the 'sbrk'
329 emulation.
330
331 Define WIN32_LEAN_AND_MEAN so that only the essential Microsoft
332 Visual C++ header files are included.
333*/
334#define WIN32_LEAN_AND_MEAN
335#include <windows.h>
336#endif
337
338
339/*
340 HAVE_MEMCPY should be defined if you are not otherwise using
341 ANSI STD C, but still have memcpy and memset in your C library
342 and want to use them in calloc and realloc. Otherwise simple
343 macro versions are defined here.
344
345 USE_MEMCPY should be defined as 1 if you actually want to
346 have memset and memcpy called. People report that the macro
347 versions are often enough faster than libc versions on many
348 systems that it is better to use them.
349
350*/
351
352#define HAVE_MEMCPY
353
354#ifndef USE_MEMCPY
355#ifdef HAVE_MEMCPY
356#define USE_MEMCPY 1
357#else
358#define USE_MEMCPY 0
359#endif
360#endif
361
362#if (__STD_C || defined(HAVE_MEMCPY))
363
364#if __STD_C
365void* memset(void*, int, size_t);
366void* memcpy(void*, const void*, size_t);
367#else
368#ifdef WIN32
wdenk8bde7f72003-06-27 21:31:46 +0000369/* On Win32 platforms, 'memset()' and 'memcpy()' are already declared in */
370/* 'windows.h' */
wdenk217c9da2002-10-25 20:35:49 +0000371#else
372Void_t* memset();
373Void_t* memcpy();
374#endif
375#endif
376#endif
377
378#if USE_MEMCPY
379
380/* The following macros are only invoked with (2n+1)-multiples of
381 INTERNAL_SIZE_T units, with a positive integer n. This is exploited
382 for fast inline execution when n is small. */
383
384#define MALLOC_ZERO(charp, nbytes) \
385do { \
386 INTERNAL_SIZE_T mzsz = (nbytes); \
387 if(mzsz <= 9*sizeof(mzsz)) { \
388 INTERNAL_SIZE_T* mz = (INTERNAL_SIZE_T*) (charp); \
389 if(mzsz >= 5*sizeof(mzsz)) { *mz++ = 0; \
wdenk8bde7f72003-06-27 21:31:46 +0000390 *mz++ = 0; \
wdenk217c9da2002-10-25 20:35:49 +0000391 if(mzsz >= 7*sizeof(mzsz)) { *mz++ = 0; \
wdenk8bde7f72003-06-27 21:31:46 +0000392 *mz++ = 0; \
393 if(mzsz >= 9*sizeof(mzsz)) { *mz++ = 0; \
394 *mz++ = 0; }}} \
395 *mz++ = 0; \
396 *mz++ = 0; \
397 *mz = 0; \
wdenk217c9da2002-10-25 20:35:49 +0000398 } else memset((charp), 0, mzsz); \
399} while(0)
400
401#define MALLOC_COPY(dest,src,nbytes) \
402do { \
403 INTERNAL_SIZE_T mcsz = (nbytes); \
404 if(mcsz <= 9*sizeof(mcsz)) { \
405 INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) (src); \
406 INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) (dest); \
407 if(mcsz >= 5*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \
wdenk8bde7f72003-06-27 21:31:46 +0000408 *mcdst++ = *mcsrc++; \
wdenk217c9da2002-10-25 20:35:49 +0000409 if(mcsz >= 7*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \
wdenk8bde7f72003-06-27 21:31:46 +0000410 *mcdst++ = *mcsrc++; \
411 if(mcsz >= 9*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \
412 *mcdst++ = *mcsrc++; }}} \
413 *mcdst++ = *mcsrc++; \
414 *mcdst++ = *mcsrc++; \
415 *mcdst = *mcsrc ; \
wdenk217c9da2002-10-25 20:35:49 +0000416 } else memcpy(dest, src, mcsz); \
417} while(0)
418
419#else /* !USE_MEMCPY */
420
421/* Use Duff's device for good zeroing/copying performance. */
422
423#define MALLOC_ZERO(charp, nbytes) \
424do { \
425 INTERNAL_SIZE_T* mzp = (INTERNAL_SIZE_T*)(charp); \
426 long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \
427 if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \
428 switch (mctmp) { \
429 case 0: for(;;) { *mzp++ = 0; \
430 case 7: *mzp++ = 0; \
431 case 6: *mzp++ = 0; \
432 case 5: *mzp++ = 0; \
433 case 4: *mzp++ = 0; \
434 case 3: *mzp++ = 0; \
435 case 2: *mzp++ = 0; \
436 case 1: *mzp++ = 0; if(mcn <= 0) break; mcn--; } \
437 } \
438} while(0)
439
440#define MALLOC_COPY(dest,src,nbytes) \
441do { \
442 INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) src; \
443 INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) dest; \
444 long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \
445 if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \
446 switch (mctmp) { \
447 case 0: for(;;) { *mcdst++ = *mcsrc++; \
448 case 7: *mcdst++ = *mcsrc++; \
449 case 6: *mcdst++ = *mcsrc++; \
450 case 5: *mcdst++ = *mcsrc++; \
451 case 4: *mcdst++ = *mcsrc++; \
452 case 3: *mcdst++ = *mcsrc++; \
453 case 2: *mcdst++ = *mcsrc++; \
454 case 1: *mcdst++ = *mcsrc++; if(mcn <= 0) break; mcn--; } \
455 } \
456} while(0)
457
458#endif
459
460
461/*
462 Define HAVE_MMAP to optionally make malloc() use mmap() to
463 allocate very large blocks. These will be returned to the
464 operating system immediately after a free().
465*/
466
467#ifndef HAVE_MMAP
468#define HAVE_MMAP 1
469#endif
470
471/*
472 Define HAVE_MREMAP to make realloc() use mremap() to re-allocate
473 large blocks. This is currently only possible on Linux with
474 kernel versions newer than 1.3.77.
475*/
476
477#ifndef HAVE_MREMAP
478#ifdef INTERNAL_LINUX_C_LIB
479#define HAVE_MREMAP 1
480#else
481#define HAVE_MREMAP 0
482#endif
483#endif
484
485#if HAVE_MMAP
486
487#include <unistd.h>
488#include <fcntl.h>
489#include <sys/mman.h>
490
491#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
492#define MAP_ANONYMOUS MAP_ANON
493#endif
494
495#endif /* HAVE_MMAP */
496
497/*
498 Access to system page size. To the extent possible, this malloc
499 manages memory from the system in page-size units.
500
501 The following mechanics for getpagesize were adapted from
502 bsd/gnu getpagesize.h
503*/
504
505#ifndef LACKS_UNISTD_H
506# include <unistd.h>
507#endif
508
509#ifndef malloc_getpagesize
510# ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */
511# ifndef _SC_PAGE_SIZE
512# define _SC_PAGE_SIZE _SC_PAGESIZE
513# endif
514# endif
515# ifdef _SC_PAGE_SIZE
516# define malloc_getpagesize sysconf(_SC_PAGE_SIZE)
517# else
518# if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE)
519 extern size_t getpagesize();
520# define malloc_getpagesize getpagesize()
521# else
522# ifdef WIN32
523# define malloc_getpagesize (4096) /* TBD: Use 'GetSystemInfo' instead */
524# else
525# ifndef LACKS_SYS_PARAM_H
526# include <sys/param.h>
527# endif
528# ifdef EXEC_PAGESIZE
529# define malloc_getpagesize EXEC_PAGESIZE
530# else
531# ifdef NBPG
532# ifndef CLSIZE
533# define malloc_getpagesize NBPG
534# else
535# define malloc_getpagesize (NBPG * CLSIZE)
536# endif
537# else
538# ifdef NBPC
539# define malloc_getpagesize NBPC
540# else
541# ifdef PAGESIZE
542# define malloc_getpagesize PAGESIZE
543# else
544# define malloc_getpagesize (4096) /* just guess */
545# endif
546# endif
547# endif
548# endif
549# endif
550# endif
551# endif
552#endif
553
554
wdenk217c9da2002-10-25 20:35:49 +0000555/*
556
557 This version of malloc supports the standard SVID/XPG mallinfo
558 routine that returns a struct containing the same kind of
559 information you can get from malloc_stats. It should work on
560 any SVID/XPG compliant system that has a /usr/include/malloc.h
561 defining struct mallinfo. (If you'd like to install such a thing
562 yourself, cut out the preliminary declarations as described above
563 and below and save them in a malloc.h file. But there's no
564 compelling reason to bother to do this.)
565
566 The main declaration needed is the mallinfo struct that is returned
567 (by-copy) by mallinfo(). The SVID/XPG malloinfo struct contains a
568 bunch of fields, most of which are not even meaningful in this
569 version of malloc. Some of these fields are are instead filled by
570 mallinfo() with other numbers that might possibly be of interest.
571
572 HAVE_USR_INCLUDE_MALLOC_H should be set if you have a
573 /usr/include/malloc.h file that includes a declaration of struct
574 mallinfo. If so, it is included; else an SVID2/XPG2 compliant
575 version is declared below. These must be precisely the same for
576 mallinfo() to work.
577
578*/
579
580/* #define HAVE_USR_INCLUDE_MALLOC_H */
581
582#if HAVE_USR_INCLUDE_MALLOC_H
583#include "/usr/include/malloc.h"
584#else
585
586/* SVID2/XPG mallinfo structure */
587
588struct mallinfo {
589 int arena; /* total space allocated from system */
590 int ordblks; /* number of non-inuse chunks */
591 int smblks; /* unused -- always zero */
592 int hblks; /* number of mmapped regions */
593 int hblkhd; /* total space in mmapped regions */
594 int usmblks; /* unused -- always zero */
595 int fsmblks; /* unused -- always zero */
596 int uordblks; /* total allocated space */
597 int fordblks; /* total non-inuse space */
598 int keepcost; /* top-most, releasable (via malloc_trim) space */
599};
600
601/* SVID2/XPG mallopt options */
602
603#define M_MXFAST 1 /* UNUSED in this malloc */
604#define M_NLBLKS 2 /* UNUSED in this malloc */
605#define M_GRAIN 3 /* UNUSED in this malloc */
606#define M_KEEP 4 /* UNUSED in this malloc */
607
608#endif
609
610/* mallopt options that actually do something */
611
612#define M_TRIM_THRESHOLD -1
613#define M_TOP_PAD -2
614#define M_MMAP_THRESHOLD -3
615#define M_MMAP_MAX -4
616
617
wdenk217c9da2002-10-25 20:35:49 +0000618#ifndef DEFAULT_TRIM_THRESHOLD
619#define DEFAULT_TRIM_THRESHOLD (128 * 1024)
620#endif
621
622/*
623 M_TRIM_THRESHOLD is the maximum amount of unused top-most memory
624 to keep before releasing via malloc_trim in free().
625
626 Automatic trimming is mainly useful in long-lived programs.
627 Because trimming via sbrk can be slow on some systems, and can
628 sometimes be wasteful (in cases where programs immediately
629 afterward allocate more large chunks) the value should be high
630 enough so that your overall system performance would improve by
631 releasing.
632
633 The trim threshold and the mmap control parameters (see below)
634 can be traded off with one another. Trimming and mmapping are
635 two different ways of releasing unused memory back to the
636 system. Between these two, it is often possible to keep
637 system-level demands of a long-lived program down to a bare
638 minimum. For example, in one test suite of sessions measuring
639 the XF86 X server on Linux, using a trim threshold of 128K and a
640 mmap threshold of 192K led to near-minimal long term resource
641 consumption.
642
643 If you are using this malloc in a long-lived program, it should
644 pay to experiment with these values. As a rough guide, you
645 might set to a value close to the average size of a process
646 (program) running on your system. Releasing this much memory
647 would allow such a process to run in memory. Generally, it's
648 worth it to tune for trimming rather tham memory mapping when a
649 program undergoes phases where several large chunks are
650 allocated and released in ways that can reuse each other's
651 storage, perhaps mixed with phases where there are no such
652 chunks at all. And in well-behaved long-lived programs,
653 controlling release of large blocks via trimming versus mapping
654 is usually faster.
655
656 However, in most programs, these parameters serve mainly as
657 protection against the system-level effects of carrying around
658 massive amounts of unneeded memory. Since frequent calls to
659 sbrk, mmap, and munmap otherwise degrade performance, the default
660 parameters are set to relatively high values that serve only as
661 safeguards.
662
663 The default trim value is high enough to cause trimming only in
664 fairly extreme (by current memory consumption standards) cases.
665 It must be greater than page size to have any useful effect. To
666 disable trimming completely, you can set to (unsigned long)(-1);
667
668
669*/
670
671
672#ifndef DEFAULT_TOP_PAD
673#define DEFAULT_TOP_PAD (0)
674#endif
675
676/*
677 M_TOP_PAD is the amount of extra `padding' space to allocate or
678 retain whenever sbrk is called. It is used in two ways internally:
679
680 * When sbrk is called to extend the top of the arena to satisfy
wdenk8bde7f72003-06-27 21:31:46 +0000681 a new malloc request, this much padding is added to the sbrk
682 request.
wdenk217c9da2002-10-25 20:35:49 +0000683
684 * When malloc_trim is called automatically from free(),
wdenk8bde7f72003-06-27 21:31:46 +0000685 it is used as the `pad' argument.
wdenk217c9da2002-10-25 20:35:49 +0000686
687 In both cases, the actual amount of padding is rounded
688 so that the end of the arena is always a system page boundary.
689
690 The main reason for using padding is to avoid calling sbrk so
691 often. Having even a small pad greatly reduces the likelihood
692 that nearly every malloc request during program start-up (or
693 after trimming) will invoke sbrk, which needlessly wastes
694 time.
695
696 Automatic rounding-up to page-size units is normally sufficient
697 to avoid measurable overhead, so the default is 0. However, in
698 systems where sbrk is relatively slow, it can pay to increase
699 this value, at the expense of carrying around more memory than
700 the program needs.
701
702*/
703
704
705#ifndef DEFAULT_MMAP_THRESHOLD
706#define DEFAULT_MMAP_THRESHOLD (128 * 1024)
707#endif
708
709/*
710
711 M_MMAP_THRESHOLD is the request size threshold for using mmap()
712 to service a request. Requests of at least this size that cannot
713 be allocated using already-existing space will be serviced via mmap.
714 (If enough normal freed space already exists it is used instead.)
715
716 Using mmap segregates relatively large chunks of memory so that
717 they can be individually obtained and released from the host
718 system. A request serviced through mmap is never reused by any
719 other request (at least not directly; the system may just so
720 happen to remap successive requests to the same locations).
721
722 Segregating space in this way has the benefit that mmapped space
723 can ALWAYS be individually released back to the system, which
724 helps keep the system level memory demands of a long-lived
725 program low. Mapped memory can never become `locked' between
726 other chunks, as can happen with normally allocated chunks, which
727 menas that even trimming via malloc_trim would not release them.
728
729 However, it has the disadvantages that:
730
wdenk8bde7f72003-06-27 21:31:46 +0000731 1. The space cannot be reclaimed, consolidated, and then
732 used to service later requests, as happens with normal chunks.
733 2. It can lead to more wastage because of mmap page alignment
734 requirements
735 3. It causes malloc performance to be more dependent on host
736 system memory management support routines which may vary in
737 implementation quality and may impose arbitrary
738 limitations. Generally, servicing a request via normal
739 malloc steps is faster than going through a system's mmap.
wdenk217c9da2002-10-25 20:35:49 +0000740
741 All together, these considerations should lead you to use mmap
742 only for relatively large requests.
743
744
745*/
746
747
wdenk217c9da2002-10-25 20:35:49 +0000748#ifndef DEFAULT_MMAP_MAX
749#if HAVE_MMAP
750#define DEFAULT_MMAP_MAX (64)
751#else
752#define DEFAULT_MMAP_MAX (0)
753#endif
754#endif
755
756/*
757 M_MMAP_MAX is the maximum number of requests to simultaneously
758 service using mmap. This parameter exists because:
759
wdenk8bde7f72003-06-27 21:31:46 +0000760 1. Some systems have a limited number of internal tables for
761 use by mmap.
762 2. In most systems, overreliance on mmap can degrade overall
763 performance.
764 3. If a program allocates many large regions, it is probably
765 better off using normal sbrk-based allocation routines that
766 can reclaim and reallocate normal heap memory. Using a
767 small value allows transition into this mode after the
768 first few allocations.
wdenk217c9da2002-10-25 20:35:49 +0000769
770 Setting to 0 disables all use of mmap. If HAVE_MMAP is not set,
771 the default value is 0, and attempts to set it to non-zero values
772 in mallopt will fail.
773*/
774
775
wdenk217c9da2002-10-25 20:35:49 +0000776/*
777 USE_DL_PREFIX will prefix all public routines with the string 'dl'.
778 Useful to quickly avoid procedure declaration conflicts and linker
779 symbol conflicts with existing memory allocation routines.
780
781*/
782
783/* #define USE_DL_PREFIX */
784
785
wdenk217c9da2002-10-25 20:35:49 +0000786/*
787
788 Special defines for linux libc
789
790 Except when compiled using these special defines for Linux libc
791 using weak aliases, this malloc is NOT designed to work in
792 multithreaded applications. No semaphores or other concurrency
793 control are provided to ensure that multiple malloc or free calls
794 don't run at the same time, which could be disasterous. A single
795 semaphore could be used across malloc, realloc, and free (which is
796 essentially the effect of the linux weak alias approach). It would
797 be hard to obtain finer granularity.
798
799*/
800
801
802#ifdef INTERNAL_LINUX_C_LIB
803
804#if __STD_C
805
806Void_t * __default_morecore_init (ptrdiff_t);
807Void_t *(*__morecore)(ptrdiff_t) = __default_morecore_init;
808
809#else
810
811Void_t * __default_morecore_init ();
812Void_t *(*__morecore)() = __default_morecore_init;
813
814#endif
815
816#define MORECORE (*__morecore)
817#define MORECORE_FAILURE 0
818#define MORECORE_CLEARS 1
819
820#else /* INTERNAL_LINUX_C_LIB */
821
822#if __STD_C
823extern Void_t* sbrk(ptrdiff_t);
824#else
825extern Void_t* sbrk();
826#endif
827
828#ifndef MORECORE
829#define MORECORE sbrk
830#endif
831
832#ifndef MORECORE_FAILURE
833#define MORECORE_FAILURE -1
834#endif
835
836#ifndef MORECORE_CLEARS
837#define MORECORE_CLEARS 1
838#endif
839
840#endif /* INTERNAL_LINUX_C_LIB */
841
842#if defined(INTERNAL_LINUX_C_LIB) && defined(__ELF__)
843
844#define cALLOc __libc_calloc
845#define fREe __libc_free
846#define mALLOc __libc_malloc
847#define mEMALIGn __libc_memalign
848#define rEALLOc __libc_realloc
849#define vALLOc __libc_valloc
850#define pvALLOc __libc_pvalloc
851#define mALLINFo __libc_mallinfo
852#define mALLOPt __libc_mallopt
853
854#pragma weak calloc = __libc_calloc
855#pragma weak free = __libc_free
856#pragma weak cfree = __libc_free
857#pragma weak malloc = __libc_malloc
858#pragma weak memalign = __libc_memalign
859#pragma weak realloc = __libc_realloc
860#pragma weak valloc = __libc_valloc
861#pragma weak pvalloc = __libc_pvalloc
862#pragma weak mallinfo = __libc_mallinfo
863#pragma weak mallopt = __libc_mallopt
864
865#else
866
867#ifdef USE_DL_PREFIX
868#define cALLOc dlcalloc
869#define fREe dlfree
870#define mALLOc dlmalloc
871#define mEMALIGn dlmemalign
872#define rEALLOc dlrealloc
873#define vALLOc dlvalloc
874#define pvALLOc dlpvalloc
875#define mALLINFo dlmallinfo
876#define mALLOPt dlmallopt
877#else /* USE_DL_PREFIX */
878#define cALLOc calloc
879#define fREe free
880#define mALLOc malloc
881#define mEMALIGn memalign
882#define rEALLOc realloc
883#define vALLOc valloc
884#define pvALLOc pvalloc
885#define mALLINFo mallinfo
886#define mALLOPt mallopt
887#endif /* USE_DL_PREFIX */
888
889#endif
890
891/* Public routines */
892
893#if __STD_C
894
895Void_t* mALLOc(size_t);
896void fREe(Void_t*);
897Void_t* rEALLOc(Void_t*, size_t);
898Void_t* mEMALIGn(size_t, size_t);
899Void_t* vALLOc(size_t);
900Void_t* pvALLOc(size_t);
901Void_t* cALLOc(size_t, size_t);
902void cfree(Void_t*);
903int malloc_trim(size_t);
904size_t malloc_usable_size(Void_t*);
905void malloc_stats();
906int mALLOPt(int, int);
907struct mallinfo mALLINFo(void);
908#else
909Void_t* mALLOc();
910void fREe();
911Void_t* rEALLOc();
912Void_t* mEMALIGn();
913Void_t* vALLOc();
914Void_t* pvALLOc();
915Void_t* cALLOc();
916void cfree();
917int malloc_trim();
918size_t malloc_usable_size();
919void malloc_stats();
920int mALLOPt();
921struct mallinfo mALLINFo();
922#endif
923
924
925#ifdef __cplusplus
926}; /* end of extern "C" */
927#endif
928
929/* ---------- To make a malloc.h, end cutting here ------------ */
Wolfgang Denkea882ba2010-06-20 23:33:59 +0200930#endif /* 0 */ /* Moved to malloc.h */
wdenk217c9da2002-10-25 20:35:49 +0000931
932#include <malloc.h>
Wolfgang Denkea882ba2010-06-20 23:33:59 +0200933#ifdef DEBUG
wdenk217c9da2002-10-25 20:35:49 +0000934#if __STD_C
935static void malloc_update_mallinfo (void);
936void malloc_stats (void);
937#else
938static void malloc_update_mallinfo ();
939void malloc_stats();
940#endif
Wolfgang Denkea882ba2010-06-20 23:33:59 +0200941#endif /* DEBUG */
wdenk217c9da2002-10-25 20:35:49 +0000942
Wolfgang Denkd87080b2006-03-31 18:32:53 +0200943DECLARE_GLOBAL_DATA_PTR;
944
wdenk217c9da2002-10-25 20:35:49 +0000945/*
946 Emulation of sbrk for WIN32
947 All code within the ifdef WIN32 is untested by me.
948
949 Thanks to Martin Fong and others for supplying this.
950*/
951
952
953#ifdef WIN32
954
955#define AlignPage(add) (((add) + (malloc_getpagesize-1)) & \
956~(malloc_getpagesize-1))
957#define AlignPage64K(add) (((add) + (0x10000 - 1)) & ~(0x10000 - 1))
958
959/* resrve 64MB to insure large contiguous space */
960#define RESERVED_SIZE (1024*1024*64)
961#define NEXT_SIZE (2048*1024)
962#define TOP_MEMORY ((unsigned long)2*1024*1024*1024)
963
964struct GmListElement;
965typedef struct GmListElement GmListElement;
966
967struct GmListElement
968{
969 GmListElement* next;
970 void* base;
971};
972
973static GmListElement* head = 0;
974static unsigned int gNextAddress = 0;
975static unsigned int gAddressBase = 0;
976static unsigned int gAllocatedSize = 0;
977
978static
979GmListElement* makeGmListElement (void* bas)
980{
981 GmListElement* this;
982 this = (GmListElement*)(void*)LocalAlloc (0, sizeof (GmListElement));
983 assert (this);
984 if (this)
985 {
986 this->base = bas;
987 this->next = head;
988 head = this;
989 }
990 return this;
991}
992
993void gcleanup ()
994{
995 BOOL rval;
996 assert ( (head == NULL) || (head->base == (void*)gAddressBase));
997 if (gAddressBase && (gNextAddress - gAddressBase))
998 {
999 rval = VirtualFree ((void*)gAddressBase,
1000 gNextAddress - gAddressBase,
1001 MEM_DECOMMIT);
wdenk8bde7f72003-06-27 21:31:46 +00001002 assert (rval);
wdenk217c9da2002-10-25 20:35:49 +00001003 }
1004 while (head)
1005 {
1006 GmListElement* next = head->next;
1007 rval = VirtualFree (head->base, 0, MEM_RELEASE);
1008 assert (rval);
1009 LocalFree (head);
1010 head = next;
1011 }
1012}
1013
1014static
1015void* findRegion (void* start_address, unsigned long size)
1016{
1017 MEMORY_BASIC_INFORMATION info;
1018 if (size >= TOP_MEMORY) return NULL;
1019
1020 while ((unsigned long)start_address + size < TOP_MEMORY)
1021 {
1022 VirtualQuery (start_address, &info, sizeof (info));
1023 if ((info.State == MEM_FREE) && (info.RegionSize >= size))
1024 return start_address;
1025 else
1026 {
wdenk8bde7f72003-06-27 21:31:46 +00001027 /* Requested region is not available so see if the */
1028 /* next region is available. Set 'start_address' */
1029 /* to the next region and call 'VirtualQuery()' */
1030 /* again. */
wdenk217c9da2002-10-25 20:35:49 +00001031
1032 start_address = (char*)info.BaseAddress + info.RegionSize;
1033
wdenk8bde7f72003-06-27 21:31:46 +00001034 /* Make sure we start looking for the next region */
1035 /* on the *next* 64K boundary. Otherwise, even if */
1036 /* the new region is free according to */
1037 /* 'VirtualQuery()', the subsequent call to */
1038 /* 'VirtualAlloc()' (which follows the call to */
1039 /* this routine in 'wsbrk()') will round *down* */
1040 /* the requested address to a 64K boundary which */
1041 /* we already know is an address in the */
1042 /* unavailable region. Thus, the subsequent call */
1043 /* to 'VirtualAlloc()' will fail and bring us back */
1044 /* here, causing us to go into an infinite loop. */
wdenk217c9da2002-10-25 20:35:49 +00001045
1046 start_address =
1047 (void *) AlignPage64K((unsigned long) start_address);
1048 }
1049 }
1050 return NULL;
1051
1052}
1053
1054
1055void* wsbrk (long size)
1056{
1057 void* tmp;
1058 if (size > 0)
1059 {
1060 if (gAddressBase == 0)
1061 {
1062 gAllocatedSize = max (RESERVED_SIZE, AlignPage (size));
1063 gNextAddress = gAddressBase =
1064 (unsigned int)VirtualAlloc (NULL, gAllocatedSize,
1065 MEM_RESERVE, PAGE_NOACCESS);
1066 } else if (AlignPage (gNextAddress + size) > (gAddressBase +
1067gAllocatedSize))
1068 {
1069 long new_size = max (NEXT_SIZE, AlignPage (size));
1070 void* new_address = (void*)(gAddressBase+gAllocatedSize);
1071 do
1072 {
1073 new_address = findRegion (new_address, new_size);
1074
1075 if (new_address == 0)
1076 return (void*)-1;
1077
1078 gAddressBase = gNextAddress =
1079 (unsigned int)VirtualAlloc (new_address, new_size,
1080 MEM_RESERVE, PAGE_NOACCESS);
wdenk8bde7f72003-06-27 21:31:46 +00001081 /* repeat in case of race condition */
1082 /* The region that we found has been snagged */
1083 /* by another thread */
wdenk217c9da2002-10-25 20:35:49 +00001084 }
1085 while (gAddressBase == 0);
1086
1087 assert (new_address == (void*)gAddressBase);
1088
1089 gAllocatedSize = new_size;
1090
1091 if (!makeGmListElement ((void*)gAddressBase))
1092 return (void*)-1;
1093 }
1094 if ((size + gNextAddress) > AlignPage (gNextAddress))
1095 {
1096 void* res;
1097 res = VirtualAlloc ((void*)AlignPage (gNextAddress),
1098 (size + gNextAddress -
1099 AlignPage (gNextAddress)),
1100 MEM_COMMIT, PAGE_READWRITE);
1101 if (res == 0)
1102 return (void*)-1;
1103 }
1104 tmp = (void*)gNextAddress;
1105 gNextAddress = (unsigned int)tmp + size;
1106 return tmp;
1107 }
1108 else if (size < 0)
1109 {
1110 unsigned int alignedGoal = AlignPage (gNextAddress + size);
1111 /* Trim by releasing the virtual memory */
1112 if (alignedGoal >= gAddressBase)
1113 {
1114 VirtualFree ((void*)alignedGoal, gNextAddress - alignedGoal,
1115 MEM_DECOMMIT);
1116 gNextAddress = gNextAddress + size;
1117 return (void*)gNextAddress;
1118 }
1119 else
1120 {
1121 VirtualFree ((void*)gAddressBase, gNextAddress - gAddressBase,
1122 MEM_DECOMMIT);
1123 gNextAddress = gAddressBase;
1124 return (void*)-1;
1125 }
1126 }
1127 else
1128 {
1129 return (void*)gNextAddress;
1130 }
1131}
1132
1133#endif
1134
1135
1136
1137/*
1138 Type declarations
1139*/
1140
1141
1142struct malloc_chunk
1143{
1144 INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */
1145 INTERNAL_SIZE_T size; /* Size in bytes, including overhead. */
1146 struct malloc_chunk* fd; /* double links -- used only if free. */
1147 struct malloc_chunk* bk;
Joakim Tjernlund1ba91ba2010-10-14 08:51:34 +02001148} __attribute__((__may_alias__)) ;
wdenk217c9da2002-10-25 20:35:49 +00001149
1150typedef struct malloc_chunk* mchunkptr;
1151
1152/*
1153
1154 malloc_chunk details:
1155
1156 (The following includes lightly edited explanations by Colin Plumb.)
1157
1158 Chunks of memory are maintained using a `boundary tag' method as
1159 described in e.g., Knuth or Standish. (See the paper by Paul
1160 Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a
1161 survey of such techniques.) Sizes of free chunks are stored both
1162 in the front of each chunk and at the end. This makes
1163 consolidating fragmented chunks into bigger chunks very fast. The
1164 size fields also hold bits representing whether chunks are free or
1165 in use.
1166
1167 An allocated chunk looks like this:
1168
1169
1170 chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
wdenk8bde7f72003-06-27 21:31:46 +00001171 | Size of previous chunk, if allocated | |
1172 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1173 | Size of chunk, in bytes |P|
wdenk217c9da2002-10-25 20:35:49 +00001174 mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
wdenk8bde7f72003-06-27 21:31:46 +00001175 | User data starts here... .
1176 . .
1177 . (malloc_usable_space() bytes) .
1178 . |
wdenk217c9da2002-10-25 20:35:49 +00001179nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
wdenk8bde7f72003-06-27 21:31:46 +00001180 | Size of chunk |
1181 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
wdenk217c9da2002-10-25 20:35:49 +00001182
1183
1184 Where "chunk" is the front of the chunk for the purpose of most of
1185 the malloc code, but "mem" is the pointer that is returned to the
1186 user. "Nextchunk" is the beginning of the next contiguous chunk.
1187
1188 Chunks always begin on even word boundries, so the mem portion
1189 (which is returned to the user) is also on an even word boundary, and
1190 thus double-word aligned.
1191
1192 Free chunks are stored in circular doubly-linked lists, and look like this:
1193
1194 chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
wdenk8bde7f72003-06-27 21:31:46 +00001195 | Size of previous chunk |
1196 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
wdenk217c9da2002-10-25 20:35:49 +00001197 `head:' | Size of chunk, in bytes |P|
1198 mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
wdenk8bde7f72003-06-27 21:31:46 +00001199 | Forward pointer to next chunk in list |
1200 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1201 | Back pointer to previous chunk in list |
1202 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1203 | Unused space (may be 0 bytes long) .
1204 . .
1205 . |
wdenk217c9da2002-10-25 20:35:49 +00001206nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1207 `foot:' | Size of chunk, in bytes |
wdenk8bde7f72003-06-27 21:31:46 +00001208 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
wdenk217c9da2002-10-25 20:35:49 +00001209
1210 The P (PREV_INUSE) bit, stored in the unused low-order bit of the
1211 chunk size (which is always a multiple of two words), is an in-use
1212 bit for the *previous* chunk. If that bit is *clear*, then the
1213 word before the current chunk size contains the previous chunk
1214 size, and can be used to find the front of the previous chunk.
1215 (The very first chunk allocated always has this bit set,
1216 preventing access to non-existent (or non-owned) memory.)
1217
1218 Note that the `foot' of the current chunk is actually represented
1219 as the prev_size of the NEXT chunk. (This makes it easier to
1220 deal with alignments etc).
1221
1222 The two exceptions to all this are
1223
1224 1. The special chunk `top', which doesn't bother using the
wdenk8bde7f72003-06-27 21:31:46 +00001225 trailing size field since there is no
1226 next contiguous chunk that would have to index off it. (After
1227 initialization, `top' is forced to always exist. If it would
1228 become less than MINSIZE bytes long, it is replenished via
1229 malloc_extend_top.)
wdenk217c9da2002-10-25 20:35:49 +00001230
1231 2. Chunks allocated via mmap, which have the second-lowest-order
wdenk8bde7f72003-06-27 21:31:46 +00001232 bit (IS_MMAPPED) set in their size fields. Because they are
1233 never merged or traversed from any other chunk, they have no
1234 foot size or inuse information.
wdenk217c9da2002-10-25 20:35:49 +00001235
1236 Available chunks are kept in any of several places (all declared below):
1237
1238 * `av': An array of chunks serving as bin headers for consolidated
1239 chunks. Each bin is doubly linked. The bins are approximately
1240 proportionally (log) spaced. There are a lot of these bins
1241 (128). This may look excessive, but works very well in
1242 practice. All procedures maintain the invariant that no
1243 consolidated chunk physically borders another one. Chunks in
1244 bins are kept in size order, with ties going to the
1245 approximately least recently used chunk.
1246
1247 The chunks in each bin are maintained in decreasing sorted order by
1248 size. This is irrelevant for the small bins, which all contain
1249 the same-sized chunks, but facilitates best-fit allocation for
1250 larger chunks. (These lists are just sequential. Keeping them in
1251 order almost never requires enough traversal to warrant using
1252 fancier ordered data structures.) Chunks of the same size are
1253 linked with the most recently freed at the front, and allocations
1254 are taken from the back. This results in LRU or FIFO allocation
1255 order, which tends to give each chunk an equal opportunity to be
1256 consolidated with adjacent freed chunks, resulting in larger free
1257 chunks and less fragmentation.
1258
1259 * `top': The top-most available chunk (i.e., the one bordering the
1260 end of available memory) is treated specially. It is never
1261 included in any bin, is used only if no other chunk is
1262 available, and is released back to the system if it is very
1263 large (see M_TRIM_THRESHOLD).
1264
1265 * `last_remainder': A bin holding only the remainder of the
1266 most recently split (non-top) chunk. This bin is checked
1267 before other non-fitting chunks, so as to provide better
1268 locality for runs of sequentially allocated chunks.
1269
1270 * Implicitly, through the host system's memory mapping tables.
1271 If supported, requests greater than a threshold are usually
1272 serviced via calls to mmap, and then later released via munmap.
1273
1274*/
wdenk217c9da2002-10-25 20:35:49 +00001275
wdenk217c9da2002-10-25 20:35:49 +00001276/* sizes, alignments */
1277
1278#define SIZE_SZ (sizeof(INTERNAL_SIZE_T))
1279#define MALLOC_ALIGNMENT (SIZE_SZ + SIZE_SZ)
1280#define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1)
1281#define MINSIZE (sizeof(struct malloc_chunk))
1282
1283/* conversion from malloc headers to user pointers, and back */
1284
1285#define chunk2mem(p) ((Void_t*)((char*)(p) + 2*SIZE_SZ))
1286#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ))
1287
1288/* pad request bytes into a usable size */
1289
1290#define request2size(req) \
1291 (((long)((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) < \
1292 (long)(MINSIZE + MALLOC_ALIGN_MASK)) ? MINSIZE : \
1293 (((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) & ~(MALLOC_ALIGN_MASK)))
1294
1295/* Check if m has acceptable alignment */
1296
1297#define aligned_OK(m) (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0)
1298
1299
1300
1301
1302/*
1303 Physical chunk operations
1304*/
1305
1306
1307/* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */
1308
1309#define PREV_INUSE 0x1
1310
1311/* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */
1312
1313#define IS_MMAPPED 0x2
1314
1315/* Bits to mask off when extracting size */
1316
1317#define SIZE_BITS (PREV_INUSE|IS_MMAPPED)
1318
1319
1320/* Ptr to next physical malloc_chunk. */
1321
1322#define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->size & ~PREV_INUSE) ))
1323
1324/* Ptr to previous physical malloc_chunk */
1325
1326#define prev_chunk(p)\
1327 ((mchunkptr)( ((char*)(p)) - ((p)->prev_size) ))
1328
1329
1330/* Treat space at ptr + offset as a chunk */
1331
1332#define chunk_at_offset(p, s) ((mchunkptr)(((char*)(p)) + (s)))
1333
1334
1335
1336
1337/*
1338 Dealing with use bits
1339*/
1340
1341/* extract p's inuse bit */
1342
1343#define inuse(p)\
1344((((mchunkptr)(((char*)(p))+((p)->size & ~PREV_INUSE)))->size) & PREV_INUSE)
1345
1346/* extract inuse bit of previous chunk */
1347
1348#define prev_inuse(p) ((p)->size & PREV_INUSE)
1349
1350/* check for mmap()'ed chunk */
1351
1352#define chunk_is_mmapped(p) ((p)->size & IS_MMAPPED)
1353
1354/* set/clear chunk as in use without otherwise disturbing */
1355
1356#define set_inuse(p)\
1357((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size |= PREV_INUSE
1358
1359#define clear_inuse(p)\
1360((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size &= ~(PREV_INUSE)
1361
1362/* check/set/clear inuse bits in known places */
1363
1364#define inuse_bit_at_offset(p, s)\
1365 (((mchunkptr)(((char*)(p)) + (s)))->size & PREV_INUSE)
1366
1367#define set_inuse_bit_at_offset(p, s)\
1368 (((mchunkptr)(((char*)(p)) + (s)))->size |= PREV_INUSE)
1369
1370#define clear_inuse_bit_at_offset(p, s)\
1371 (((mchunkptr)(((char*)(p)) + (s)))->size &= ~(PREV_INUSE))
1372
1373
1374
1375
1376/*
1377 Dealing with size fields
1378*/
1379
1380/* Get size, ignoring use bits */
1381
1382#define chunksize(p) ((p)->size & ~(SIZE_BITS))
1383
1384/* Set size at head, without disturbing its use bit */
1385
1386#define set_head_size(p, s) ((p)->size = (((p)->size & PREV_INUSE) | (s)))
1387
1388/* Set size/use ignoring previous bits in header */
1389
1390#define set_head(p, s) ((p)->size = (s))
1391
1392/* Set size at footer (only when chunk is not in use) */
1393
1394#define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_size = (s))
1395
1396
1397
1398
1399
1400/*
1401 Bins
1402
1403 The bins, `av_' are an array of pairs of pointers serving as the
1404 heads of (initially empty) doubly-linked lists of chunks, laid out
1405 in a way so that each pair can be treated as if it were in a
1406 malloc_chunk. (This way, the fd/bk offsets for linking bin heads
1407 and chunks are the same).
1408
1409 Bins for sizes < 512 bytes contain chunks of all the same size, spaced
1410 8 bytes apart. Larger bins are approximately logarithmically
1411 spaced. (See the table below.) The `av_' array is never mentioned
1412 directly in the code, but instead via bin access macros.
1413
1414 Bin layout:
1415
1416 64 bins of size 8
1417 32 bins of size 64
1418 16 bins of size 512
1419 8 bins of size 4096
1420 4 bins of size 32768
1421 2 bins of size 262144
1422 1 bin of size what's left
1423
1424 There is actually a little bit of slop in the numbers in bin_index
1425 for the sake of speed. This makes no difference elsewhere.
1426
1427 The special chunks `top' and `last_remainder' get their own bins,
1428 (this is implemented via yet more trickery with the av_ array),
1429 although `top' is never properly linked to its bin since it is
1430 always handled specially.
1431
1432*/
1433
1434#define NAV 128 /* number of bins */
1435
1436typedef struct malloc_chunk* mbinptr;
1437
1438/* access macros */
1439
1440#define bin_at(i) ((mbinptr)((char*)&(av_[2*(i) + 2]) - 2*SIZE_SZ))
1441#define next_bin(b) ((mbinptr)((char*)(b) + 2 * sizeof(mbinptr)))
1442#define prev_bin(b) ((mbinptr)((char*)(b) - 2 * sizeof(mbinptr)))
1443
1444/*
1445 The first 2 bins are never indexed. The corresponding av_ cells are instead
1446 used for bookkeeping. This is not to save space, but to simplify
1447 indexing, maintain locality, and avoid some initialization tests.
1448*/
1449
Stefan Roesef2302d42008-08-06 14:05:38 +02001450#define top (av_[2]) /* The topmost chunk */
wdenk217c9da2002-10-25 20:35:49 +00001451#define last_remainder (bin_at(1)) /* remainder from last split */
1452
1453
1454/*
1455 Because top initially points to its own bin with initial
1456 zero size, thus forcing extension on the first malloc request,
1457 we avoid having any special code in malloc to check whether
1458 it even exists yet. But we still need to in malloc_extend_top.
1459*/
1460
1461#define initial_top ((mchunkptr)(bin_at(0)))
1462
1463/* Helper macro to initialize bins */
1464
1465#define IAV(i) bin_at(i), bin_at(i)
1466
1467static mbinptr av_[NAV * 2 + 2] = {
Kim Phillips199adb62012-10-29 13:34:32 +00001468 NULL, NULL,
wdenk217c9da2002-10-25 20:35:49 +00001469 IAV(0), IAV(1), IAV(2), IAV(3), IAV(4), IAV(5), IAV(6), IAV(7),
1470 IAV(8), IAV(9), IAV(10), IAV(11), IAV(12), IAV(13), IAV(14), IAV(15),
1471 IAV(16), IAV(17), IAV(18), IAV(19), IAV(20), IAV(21), IAV(22), IAV(23),
1472 IAV(24), IAV(25), IAV(26), IAV(27), IAV(28), IAV(29), IAV(30), IAV(31),
1473 IAV(32), IAV(33), IAV(34), IAV(35), IAV(36), IAV(37), IAV(38), IAV(39),
1474 IAV(40), IAV(41), IAV(42), IAV(43), IAV(44), IAV(45), IAV(46), IAV(47),
1475 IAV(48), IAV(49), IAV(50), IAV(51), IAV(52), IAV(53), IAV(54), IAV(55),
1476 IAV(56), IAV(57), IAV(58), IAV(59), IAV(60), IAV(61), IAV(62), IAV(63),
1477 IAV(64), IAV(65), IAV(66), IAV(67), IAV(68), IAV(69), IAV(70), IAV(71),
1478 IAV(72), IAV(73), IAV(74), IAV(75), IAV(76), IAV(77), IAV(78), IAV(79),
1479 IAV(80), IAV(81), IAV(82), IAV(83), IAV(84), IAV(85), IAV(86), IAV(87),
1480 IAV(88), IAV(89), IAV(90), IAV(91), IAV(92), IAV(93), IAV(94), IAV(95),
1481 IAV(96), IAV(97), IAV(98), IAV(99), IAV(100), IAV(101), IAV(102), IAV(103),
1482 IAV(104), IAV(105), IAV(106), IAV(107), IAV(108), IAV(109), IAV(110), IAV(111),
1483 IAV(112), IAV(113), IAV(114), IAV(115), IAV(116), IAV(117), IAV(118), IAV(119),
1484 IAV(120), IAV(121), IAV(122), IAV(123), IAV(124), IAV(125), IAV(126), IAV(127)
1485};
1486
Wolfgang Denk2e5167c2010-10-28 20:00:11 +02001487#ifdef CONFIG_NEEDS_MANUAL_RELOC
Gabor Juhos7b395232013-01-21 21:10:38 +00001488static void malloc_bin_reloc(void)
wdenk217c9da2002-10-25 20:35:49 +00001489{
Simon Glass93691842012-09-04 11:31:07 +00001490 mbinptr *p = &av_[2];
1491 size_t i;
1492
1493 for (i = 2; i < ARRAY_SIZE(av_); ++i, ++p)
1494 *p = (mbinptr)((ulong)*p + gd->reloc_off);
wdenk217c9da2002-10-25 20:35:49 +00001495}
Gabor Juhos7b395232013-01-21 21:10:38 +00001496#else
1497static inline void malloc_bin_reloc(void) {}
Peter Tyser521af042009-09-21 11:20:36 -05001498#endif
Peter Tyser5e93bd12009-08-21 23:05:19 -05001499
1500ulong mem_malloc_start = 0;
1501ulong mem_malloc_end = 0;
1502ulong mem_malloc_brk = 0;
1503
1504void *sbrk(ptrdiff_t increment)
1505{
1506 ulong old = mem_malloc_brk;
1507 ulong new = old + increment;
1508
Kumar Gala6163f5b2010-11-15 18:41:43 -06001509 /*
1510 * if we are giving memory back make sure we clear it out since
1511 * we set MORECORE_CLEARS to 1
1512 */
1513 if (increment < 0)
1514 memset((void *)new, 0, -increment);
1515
Peter Tyser5e93bd12009-08-21 23:05:19 -05001516 if ((new < mem_malloc_start) || (new > mem_malloc_end))
karl.beldan@gmail.comae30b8c2010-04-06 22:18:08 +02001517 return (void *)MORECORE_FAILURE;
Peter Tyser5e93bd12009-08-21 23:05:19 -05001518
1519 mem_malloc_brk = new;
1520
1521 return (void *)old;
1522}
wdenk217c9da2002-10-25 20:35:49 +00001523
Peter Tyserd4e8ada2009-08-21 23:05:21 -05001524void mem_malloc_init(ulong start, ulong size)
1525{
1526 mem_malloc_start = start;
1527 mem_malloc_end = start + size;
1528 mem_malloc_brk = start;
1529
1530 memset((void *)mem_malloc_start, 0, size);
Gabor Juhos7b395232013-01-21 21:10:38 +00001531
1532 malloc_bin_reloc();
Peter Tyserd4e8ada2009-08-21 23:05:21 -05001533}
Peter Tyserd4e8ada2009-08-21 23:05:21 -05001534
wdenk217c9da2002-10-25 20:35:49 +00001535/* field-extraction macros */
1536
1537#define first(b) ((b)->fd)
1538#define last(b) ((b)->bk)
1539
1540/*
1541 Indexing into bins
1542*/
1543
1544#define bin_index(sz) \
1545(((((unsigned long)(sz)) >> 9) == 0) ? (((unsigned long)(sz)) >> 3): \
1546 ((((unsigned long)(sz)) >> 9) <= 4) ? 56 + (((unsigned long)(sz)) >> 6): \
1547 ((((unsigned long)(sz)) >> 9) <= 20) ? 91 + (((unsigned long)(sz)) >> 9): \
1548 ((((unsigned long)(sz)) >> 9) <= 84) ? 110 + (((unsigned long)(sz)) >> 12): \
1549 ((((unsigned long)(sz)) >> 9) <= 340) ? 119 + (((unsigned long)(sz)) >> 15): \
1550 ((((unsigned long)(sz)) >> 9) <= 1364) ? 124 + (((unsigned long)(sz)) >> 18): \
wdenk8bde7f72003-06-27 21:31:46 +00001551 126)
wdenk217c9da2002-10-25 20:35:49 +00001552/*
1553 bins for chunks < 512 are all spaced 8 bytes apart, and hold
1554 identically sized chunks. This is exploited in malloc.
1555*/
1556
1557#define MAX_SMALLBIN 63
1558#define MAX_SMALLBIN_SIZE 512
1559#define SMALLBIN_WIDTH 8
1560
1561#define smallbin_index(sz) (((unsigned long)(sz)) >> 3)
1562
1563/*
1564 Requests are `small' if both the corresponding and the next bin are small
1565*/
1566
1567#define is_small_request(nb) (nb < MAX_SMALLBIN_SIZE - SMALLBIN_WIDTH)
1568
1569
1570
1571/*
1572 To help compensate for the large number of bins, a one-level index
1573 structure is used for bin-by-bin searching. `binblocks' is a
1574 one-word bitvector recording whether groups of BINBLOCKWIDTH bins
1575 have any (possibly) non-empty bins, so they can be skipped over
1576 all at once during during traversals. The bits are NOT always
1577 cleared as soon as all bins in a block are empty, but instead only
1578 when all are noticed to be empty during traversal in malloc.
1579*/
1580
1581#define BINBLOCKWIDTH 4 /* bins per block */
1582
Stefan Roesef2302d42008-08-06 14:05:38 +02001583#define binblocks_r ((INTERNAL_SIZE_T)av_[1]) /* bitvector of nonempty blocks */
1584#define binblocks_w (av_[1])
wdenk217c9da2002-10-25 20:35:49 +00001585
1586/* bin<->block macros */
1587
1588#define idx2binblock(ix) ((unsigned)1 << (ix / BINBLOCKWIDTH))
Stefan Roesef2302d42008-08-06 14:05:38 +02001589#define mark_binblock(ii) (binblocks_w = (mbinptr)(binblocks_r | idx2binblock(ii)))
1590#define clear_binblock(ii) (binblocks_w = (mbinptr)(binblocks_r & ~(idx2binblock(ii))))
wdenk217c9da2002-10-25 20:35:49 +00001591
1592
1593
1594
1595
1596/* Other static bookkeeping data */
1597
1598/* variables holding tunable values */
1599
1600static unsigned long trim_threshold = DEFAULT_TRIM_THRESHOLD;
1601static unsigned long top_pad = DEFAULT_TOP_PAD;
1602static unsigned int n_mmaps_max = DEFAULT_MMAP_MAX;
1603static unsigned long mmap_threshold = DEFAULT_MMAP_THRESHOLD;
1604
1605/* The first value returned from sbrk */
1606static char* sbrk_base = (char*)(-1);
1607
1608/* The maximum memory obtained from system via sbrk */
1609static unsigned long max_sbrked_mem = 0;
1610
1611/* The maximum via either sbrk or mmap */
1612static unsigned long max_total_mem = 0;
1613
1614/* internal working copy of mallinfo */
1615static struct mallinfo current_mallinfo = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
1616
1617/* The total memory obtained from system via sbrk */
1618#define sbrked_mem (current_mallinfo.arena)
1619
1620/* Tracking mmaps */
1621
Wolfgang Denkea882ba2010-06-20 23:33:59 +02001622#ifdef DEBUG
wdenk217c9da2002-10-25 20:35:49 +00001623static unsigned int n_mmaps = 0;
Wolfgang Denkea882ba2010-06-20 23:33:59 +02001624#endif /* DEBUG */
wdenk217c9da2002-10-25 20:35:49 +00001625static unsigned long mmapped_mem = 0;
1626#if HAVE_MMAP
1627static unsigned int max_n_mmaps = 0;
1628static unsigned long max_mmapped_mem = 0;
1629#endif
1630
1631
1632
1633/*
1634 Debugging support
1635*/
1636
1637#ifdef DEBUG
1638
1639
1640/*
1641 These routines make a number of assertions about the states
1642 of data structures that should be true at all times. If any
1643 are not true, it's very likely that a user program has somehow
1644 trashed memory. (It's also possible that there is a coding error
1645 in malloc. In which case, please report it!)
1646*/
1647
1648#if __STD_C
1649static void do_check_chunk(mchunkptr p)
1650#else
1651static void do_check_chunk(p) mchunkptr p;
1652#endif
1653{
wdenk217c9da2002-10-25 20:35:49 +00001654 INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
wdenk217c9da2002-10-25 20:35:49 +00001655
1656 /* No checkable chunk is mmapped */
1657 assert(!chunk_is_mmapped(p));
1658
1659 /* Check for legal address ... */
1660 assert((char*)p >= sbrk_base);
1661 if (p != top)
1662 assert((char*)p + sz <= (char*)top);
1663 else
1664 assert((char*)p + sz <= sbrk_base + sbrked_mem);
1665
1666}
1667
1668
1669#if __STD_C
1670static void do_check_free_chunk(mchunkptr p)
1671#else
1672static void do_check_free_chunk(p) mchunkptr p;
1673#endif
1674{
1675 INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
wdenk217c9da2002-10-25 20:35:49 +00001676 mchunkptr next = chunk_at_offset(p, sz);
wdenk217c9da2002-10-25 20:35:49 +00001677
1678 do_check_chunk(p);
1679
1680 /* Check whether it claims to be free ... */
1681 assert(!inuse(p));
1682
1683 /* Unless a special marker, must have OK fields */
1684 if ((long)sz >= (long)MINSIZE)
1685 {
1686 assert((sz & MALLOC_ALIGN_MASK) == 0);
1687 assert(aligned_OK(chunk2mem(p)));
1688 /* ... matching footer field */
1689 assert(next->prev_size == sz);
1690 /* ... and is fully consolidated */
1691 assert(prev_inuse(p));
1692 assert (next == top || inuse(next));
1693
1694 /* ... and has minimally sane links */
1695 assert(p->fd->bk == p);
1696 assert(p->bk->fd == p);
1697 }
1698 else /* markers are always of size SIZE_SZ */
1699 assert(sz == SIZE_SZ);
1700}
1701
1702#if __STD_C
1703static void do_check_inuse_chunk(mchunkptr p)
1704#else
1705static void do_check_inuse_chunk(p) mchunkptr p;
1706#endif
1707{
1708 mchunkptr next = next_chunk(p);
1709 do_check_chunk(p);
1710
1711 /* Check whether it claims to be in use ... */
1712 assert(inuse(p));
1713
1714 /* ... and is surrounded by OK chunks.
1715 Since more things can be checked with free chunks than inuse ones,
1716 if an inuse chunk borders them and debug is on, it's worth doing them.
1717 */
1718 if (!prev_inuse(p))
1719 {
1720 mchunkptr prv = prev_chunk(p);
1721 assert(next_chunk(prv) == p);
1722 do_check_free_chunk(prv);
1723 }
1724 if (next == top)
1725 {
1726 assert(prev_inuse(next));
1727 assert(chunksize(next) >= MINSIZE);
1728 }
1729 else if (!inuse(next))
1730 do_check_free_chunk(next);
1731
1732}
1733
1734#if __STD_C
1735static void do_check_malloced_chunk(mchunkptr p, INTERNAL_SIZE_T s)
1736#else
1737static void do_check_malloced_chunk(p, s) mchunkptr p; INTERNAL_SIZE_T s;
1738#endif
1739{
wdenk217c9da2002-10-25 20:35:49 +00001740 INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
1741 long room = sz - s;
wdenk217c9da2002-10-25 20:35:49 +00001742
1743 do_check_inuse_chunk(p);
1744
1745 /* Legal size ... */
1746 assert((long)sz >= (long)MINSIZE);
1747 assert((sz & MALLOC_ALIGN_MASK) == 0);
1748 assert(room >= 0);
1749 assert(room < (long)MINSIZE);
1750
1751 /* ... and alignment */
1752 assert(aligned_OK(chunk2mem(p)));
1753
1754
1755 /* ... and was allocated at front of an available chunk */
1756 assert(prev_inuse(p));
1757
1758}
1759
1760
1761#define check_free_chunk(P) do_check_free_chunk(P)
1762#define check_inuse_chunk(P) do_check_inuse_chunk(P)
1763#define check_chunk(P) do_check_chunk(P)
1764#define check_malloced_chunk(P,N) do_check_malloced_chunk(P,N)
1765#else
1766#define check_free_chunk(P)
1767#define check_inuse_chunk(P)
1768#define check_chunk(P)
1769#define check_malloced_chunk(P,N)
1770#endif
1771
1772
1773
1774/*
1775 Macro-based internal utilities
1776*/
1777
1778
1779/*
1780 Linking chunks in bin lists.
1781 Call these only with variables, not arbitrary expressions, as arguments.
1782*/
1783
1784/*
1785 Place chunk p of size s in its bin, in size order,
1786 putting it ahead of others of same size.
1787*/
1788
1789
1790#define frontlink(P, S, IDX, BK, FD) \
1791{ \
1792 if (S < MAX_SMALLBIN_SIZE) \
1793 { \
1794 IDX = smallbin_index(S); \
1795 mark_binblock(IDX); \
1796 BK = bin_at(IDX); \
1797 FD = BK->fd; \
1798 P->bk = BK; \
1799 P->fd = FD; \
1800 FD->bk = BK->fd = P; \
1801 } \
1802 else \
1803 { \
1804 IDX = bin_index(S); \
1805 BK = bin_at(IDX); \
1806 FD = BK->fd; \
1807 if (FD == BK) mark_binblock(IDX); \
1808 else \
1809 { \
1810 while (FD != BK && S < chunksize(FD)) FD = FD->fd; \
1811 BK = FD->bk; \
1812 } \
1813 P->bk = BK; \
1814 P->fd = FD; \
1815 FD->bk = BK->fd = P; \
1816 } \
1817}
1818
1819
1820/* take a chunk off a list */
1821
1822#define unlink(P, BK, FD) \
1823{ \
1824 BK = P->bk; \
1825 FD = P->fd; \
1826 FD->bk = BK; \
1827 BK->fd = FD; \
1828} \
1829
1830/* Place p as the last remainder */
1831
1832#define link_last_remainder(P) \
1833{ \
1834 last_remainder->fd = last_remainder->bk = P; \
1835 P->fd = P->bk = last_remainder; \
1836}
1837
1838/* Clear the last_remainder bin */
1839
1840#define clear_last_remainder \
1841 (last_remainder->fd = last_remainder->bk = last_remainder)
1842
1843
wdenk217c9da2002-10-25 20:35:49 +00001844
1845
1846
1847/* Routines dealing with mmap(). */
1848
1849#if HAVE_MMAP
1850
1851#if __STD_C
1852static mchunkptr mmap_chunk(size_t size)
1853#else
1854static mchunkptr mmap_chunk(size) size_t size;
1855#endif
1856{
1857 size_t page_mask = malloc_getpagesize - 1;
1858 mchunkptr p;
1859
1860#ifndef MAP_ANONYMOUS
1861 static int fd = -1;
1862#endif
1863
1864 if(n_mmaps >= n_mmaps_max) return 0; /* too many regions */
1865
1866 /* For mmapped chunks, the overhead is one SIZE_SZ unit larger, because
1867 * there is no following chunk whose prev_size field could be used.
1868 */
1869 size = (size + SIZE_SZ + page_mask) & ~page_mask;
1870
1871#ifdef MAP_ANONYMOUS
1872 p = (mchunkptr)mmap(0, size, PROT_READ|PROT_WRITE,
1873 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
1874#else /* !MAP_ANONYMOUS */
1875 if (fd < 0)
1876 {
1877 fd = open("/dev/zero", O_RDWR);
1878 if(fd < 0) return 0;
1879 }
1880 p = (mchunkptr)mmap(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
1881#endif
1882
1883 if(p == (mchunkptr)-1) return 0;
1884
1885 n_mmaps++;
1886 if (n_mmaps > max_n_mmaps) max_n_mmaps = n_mmaps;
1887
1888 /* We demand that eight bytes into a page must be 8-byte aligned. */
1889 assert(aligned_OK(chunk2mem(p)));
1890
1891 /* The offset to the start of the mmapped region is stored
1892 * in the prev_size field of the chunk; normally it is zero,
1893 * but that can be changed in memalign().
1894 */
1895 p->prev_size = 0;
1896 set_head(p, size|IS_MMAPPED);
1897
1898 mmapped_mem += size;
1899 if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem)
1900 max_mmapped_mem = mmapped_mem;
1901 if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
1902 max_total_mem = mmapped_mem + sbrked_mem;
1903 return p;
1904}
1905
1906#if __STD_C
1907static void munmap_chunk(mchunkptr p)
1908#else
1909static void munmap_chunk(p) mchunkptr p;
1910#endif
1911{
1912 INTERNAL_SIZE_T size = chunksize(p);
1913 int ret;
1914
1915 assert (chunk_is_mmapped(p));
1916 assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem));
1917 assert((n_mmaps > 0));
1918 assert(((p->prev_size + size) & (malloc_getpagesize-1)) == 0);
1919
1920 n_mmaps--;
1921 mmapped_mem -= (size + p->prev_size);
1922
1923 ret = munmap((char *)p - p->prev_size, size + p->prev_size);
1924
1925 /* munmap returns non-zero on failure */
1926 assert(ret == 0);
1927}
1928
1929#if HAVE_MREMAP
1930
1931#if __STD_C
1932static mchunkptr mremap_chunk(mchunkptr p, size_t new_size)
1933#else
1934static mchunkptr mremap_chunk(p, new_size) mchunkptr p; size_t new_size;
1935#endif
1936{
1937 size_t page_mask = malloc_getpagesize - 1;
1938 INTERNAL_SIZE_T offset = p->prev_size;
1939 INTERNAL_SIZE_T size = chunksize(p);
1940 char *cp;
1941
1942 assert (chunk_is_mmapped(p));
1943 assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem));
1944 assert((n_mmaps > 0));
1945 assert(((size + offset) & (malloc_getpagesize-1)) == 0);
1946
1947 /* Note the extra SIZE_SZ overhead as in mmap_chunk(). */
1948 new_size = (new_size + offset + SIZE_SZ + page_mask) & ~page_mask;
1949
1950 cp = (char *)mremap((char *)p - offset, size + offset, new_size, 1);
1951
1952 if (cp == (char *)-1) return 0;
1953
1954 p = (mchunkptr)(cp + offset);
1955
1956 assert(aligned_OK(chunk2mem(p)));
1957
1958 assert((p->prev_size == offset));
1959 set_head(p, (new_size - offset)|IS_MMAPPED);
1960
1961 mmapped_mem -= size + offset;
1962 mmapped_mem += new_size;
1963 if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem)
1964 max_mmapped_mem = mmapped_mem;
1965 if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
1966 max_total_mem = mmapped_mem + sbrked_mem;
1967 return p;
1968}
1969
1970#endif /* HAVE_MREMAP */
1971
1972#endif /* HAVE_MMAP */
1973
1974
1975
1976
1977/*
1978 Extend the top-most chunk by obtaining memory from system.
1979 Main interface to sbrk (but see also malloc_trim).
1980*/
1981
1982#if __STD_C
1983static void malloc_extend_top(INTERNAL_SIZE_T nb)
1984#else
1985static void malloc_extend_top(nb) INTERNAL_SIZE_T nb;
1986#endif
1987{
1988 char* brk; /* return value from sbrk */
1989 INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of sbrked space */
1990 INTERNAL_SIZE_T correction; /* bytes for 2nd sbrk call */
1991 char* new_brk; /* return of 2nd sbrk call */
1992 INTERNAL_SIZE_T top_size; /* new size of top chunk */
1993
1994 mchunkptr old_top = top; /* Record state of old top */
1995 INTERNAL_SIZE_T old_top_size = chunksize(old_top);
1996 char* old_end = (char*)(chunk_at_offset(old_top, old_top_size));
1997
1998 /* Pad request with top_pad plus minimal overhead */
1999
2000 INTERNAL_SIZE_T sbrk_size = nb + top_pad + MINSIZE;
2001 unsigned long pagesz = malloc_getpagesize;
2002
2003 /* If not the first time through, round to preserve page boundary */
2004 /* Otherwise, we need to correct to a page size below anyway. */
2005 /* (We also correct below if an intervening foreign sbrk call.) */
2006
2007 if (sbrk_base != (char*)(-1))
2008 sbrk_size = (sbrk_size + (pagesz - 1)) & ~(pagesz - 1);
2009
2010 brk = (char*)(MORECORE (sbrk_size));
2011
2012 /* Fail if sbrk failed or if a foreign sbrk call killed our space */
2013 if (brk == (char*)(MORECORE_FAILURE) ||
2014 (brk < old_end && old_top != initial_top))
2015 return;
2016
2017 sbrked_mem += sbrk_size;
2018
2019 if (brk == old_end) /* can just add bytes to current top */
2020 {
2021 top_size = sbrk_size + old_top_size;
2022 set_head(top, top_size | PREV_INUSE);
2023 }
2024 else
2025 {
2026 if (sbrk_base == (char*)(-1)) /* First time through. Record base */
2027 sbrk_base = brk;
2028 else /* Someone else called sbrk(). Count those bytes as sbrked_mem. */
2029 sbrked_mem += brk - (char*)old_end;
2030
2031 /* Guarantee alignment of first new chunk made from this space */
2032 front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK;
2033 if (front_misalign > 0)
2034 {
2035 correction = (MALLOC_ALIGNMENT) - front_misalign;
2036 brk += correction;
2037 }
2038 else
2039 correction = 0;
2040
2041 /* Guarantee the next brk will be at a page boundary */
2042
2043 correction += ((((unsigned long)(brk + sbrk_size))+(pagesz-1)) &
wdenk8bde7f72003-06-27 21:31:46 +00002044 ~(pagesz - 1)) - ((unsigned long)(brk + sbrk_size));
wdenk217c9da2002-10-25 20:35:49 +00002045
2046 /* Allocate correction */
2047 new_brk = (char*)(MORECORE (correction));
2048 if (new_brk == (char*)(MORECORE_FAILURE)) return;
2049
2050 sbrked_mem += correction;
2051
2052 top = (mchunkptr)brk;
2053 top_size = new_brk - brk + correction;
2054 set_head(top, top_size | PREV_INUSE);
2055
2056 if (old_top != initial_top)
2057 {
2058
2059 /* There must have been an intervening foreign sbrk call. */
2060 /* A double fencepost is necessary to prevent consolidation */
2061
2062 /* If not enough space to do this, then user did something very wrong */
2063 if (old_top_size < MINSIZE)
2064 {
wdenk8bde7f72003-06-27 21:31:46 +00002065 set_head(top, PREV_INUSE); /* will force null return from malloc */
2066 return;
wdenk217c9da2002-10-25 20:35:49 +00002067 }
2068
2069 /* Also keep size a multiple of MALLOC_ALIGNMENT */
2070 old_top_size = (old_top_size - 3*SIZE_SZ) & ~MALLOC_ALIGN_MASK;
2071 set_head_size(old_top, old_top_size);
2072 chunk_at_offset(old_top, old_top_size )->size =
wdenk8bde7f72003-06-27 21:31:46 +00002073 SIZE_SZ|PREV_INUSE;
wdenk217c9da2002-10-25 20:35:49 +00002074 chunk_at_offset(old_top, old_top_size + SIZE_SZ)->size =
wdenk8bde7f72003-06-27 21:31:46 +00002075 SIZE_SZ|PREV_INUSE;
wdenk217c9da2002-10-25 20:35:49 +00002076 /* If possible, release the rest. */
2077 if (old_top_size >= MINSIZE)
wdenk8bde7f72003-06-27 21:31:46 +00002078 fREe(chunk2mem(old_top));
wdenk217c9da2002-10-25 20:35:49 +00002079 }
2080 }
2081
2082 if ((unsigned long)sbrked_mem > (unsigned long)max_sbrked_mem)
2083 max_sbrked_mem = sbrked_mem;
2084 if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
2085 max_total_mem = mmapped_mem + sbrked_mem;
2086
2087 /* We always land on a page boundary */
2088 assert(((unsigned long)((char*)top + top_size) & (pagesz - 1)) == 0);
2089}
2090
2091
2092
2093
2094/* Main public routines */
2095
2096
2097/*
2098 Malloc Algorthim:
2099
2100 The requested size is first converted into a usable form, `nb'.
2101 This currently means to add 4 bytes overhead plus possibly more to
2102 obtain 8-byte alignment and/or to obtain a size of at least
2103 MINSIZE (currently 16 bytes), the smallest allocatable size.
2104 (All fits are considered `exact' if they are within MINSIZE bytes.)
2105
2106 From there, the first successful of the following steps is taken:
2107
2108 1. The bin corresponding to the request size is scanned, and if
wdenk8bde7f72003-06-27 21:31:46 +00002109 a chunk of exactly the right size is found, it is taken.
wdenk217c9da2002-10-25 20:35:49 +00002110
2111 2. The most recently remaindered chunk is used if it is big
wdenk8bde7f72003-06-27 21:31:46 +00002112 enough. This is a form of (roving) first fit, used only in
2113 the absence of exact fits. Runs of consecutive requests use
2114 the remainder of the chunk used for the previous such request
2115 whenever possible. This limited use of a first-fit style
2116 allocation strategy tends to give contiguous chunks
2117 coextensive lifetimes, which improves locality and can reduce
2118 fragmentation in the long run.
wdenk217c9da2002-10-25 20:35:49 +00002119
2120 3. Other bins are scanned in increasing size order, using a
wdenk8bde7f72003-06-27 21:31:46 +00002121 chunk big enough to fulfill the request, and splitting off
2122 any remainder. This search is strictly by best-fit; i.e.,
2123 the smallest (with ties going to approximately the least
2124 recently used) chunk that fits is selected.
wdenk217c9da2002-10-25 20:35:49 +00002125
2126 4. If large enough, the chunk bordering the end of memory
wdenk8bde7f72003-06-27 21:31:46 +00002127 (`top') is split off. (This use of `top' is in accord with
2128 the best-fit search rule. In effect, `top' is treated as
2129 larger (and thus less well fitting) than any other available
2130 chunk since it can be extended to be as large as necessary
2131 (up to system limitations).
wdenk217c9da2002-10-25 20:35:49 +00002132
2133 5. If the request size meets the mmap threshold and the
wdenk8bde7f72003-06-27 21:31:46 +00002134 system supports mmap, and there are few enough currently
2135 allocated mmapped regions, and a call to mmap succeeds,
2136 the request is allocated via direct memory mapping.
wdenk217c9da2002-10-25 20:35:49 +00002137
2138 6. Otherwise, the top of memory is extended by
wdenk8bde7f72003-06-27 21:31:46 +00002139 obtaining more space from the system (normally using sbrk,
2140 but definable to anything else via the MORECORE macro).
2141 Memory is gathered from the system (in system page-sized
2142 units) in a way that allows chunks obtained across different
2143 sbrk calls to be consolidated, but does not require
2144 contiguous memory. Thus, it should be safe to intersperse
2145 mallocs with other sbrk calls.
wdenk217c9da2002-10-25 20:35:49 +00002146
2147
2148 All allocations are made from the the `lowest' part of any found
2149 chunk. (The implementation invariant is that prev_inuse is
2150 always true of any allocated chunk; i.e., that each allocated
2151 chunk borders either a previously allocated and still in-use chunk,
2152 or the base of its memory arena.)
2153
2154*/
2155
2156#if __STD_C
2157Void_t* mALLOc(size_t bytes)
2158#else
2159Void_t* mALLOc(bytes) size_t bytes;
2160#endif
2161{
2162 mchunkptr victim; /* inspected/selected chunk */
2163 INTERNAL_SIZE_T victim_size; /* its size */
2164 int idx; /* index for bin traversal */
2165 mbinptr bin; /* associated bin */
2166 mchunkptr remainder; /* remainder from a split */
2167 long remainder_size; /* its size */
2168 int remainder_index; /* its bin index */
2169 unsigned long block; /* block traverser bit */
2170 int startidx; /* first bin of a traversed block */
2171 mchunkptr fwd; /* misc temp for linking */
2172 mchunkptr bck; /* misc temp for linking */
2173 mbinptr q; /* misc temp */
2174
2175 INTERNAL_SIZE_T nb;
2176
Wolfgang Denk27405442010-01-15 11:20:10 +01002177 /* check if mem_malloc_init() was run */
2178 if ((mem_malloc_start == 0) && (mem_malloc_end == 0)) {
2179 /* not initialized yet */
Kim Phillips199adb62012-10-29 13:34:32 +00002180 return NULL;
Wolfgang Denk27405442010-01-15 11:20:10 +01002181 }
2182
Kim Phillips199adb62012-10-29 13:34:32 +00002183 if ((long)bytes < 0) return NULL;
wdenk217c9da2002-10-25 20:35:49 +00002184
2185 nb = request2size(bytes); /* padded request size; */
2186
2187 /* Check for exact match in a bin */
2188
2189 if (is_small_request(nb)) /* Faster version for small requests */
2190 {
2191 idx = smallbin_index(nb);
2192
2193 /* No traversal or size check necessary for small bins. */
2194
2195 q = bin_at(idx);
2196 victim = last(q);
2197
2198 /* Also scan the next one, since it would have a remainder < MINSIZE */
2199 if (victim == q)
2200 {
2201 q = next_bin(q);
2202 victim = last(q);
2203 }
2204 if (victim != q)
2205 {
2206 victim_size = chunksize(victim);
2207 unlink(victim, bck, fwd);
2208 set_inuse_bit_at_offset(victim, victim_size);
2209 check_malloced_chunk(victim, nb);
2210 return chunk2mem(victim);
2211 }
2212
2213 idx += 2; /* Set for bin scan below. We've already scanned 2 bins. */
2214
2215 }
2216 else
2217 {
2218 idx = bin_index(nb);
2219 bin = bin_at(idx);
2220
2221 for (victim = last(bin); victim != bin; victim = victim->bk)
2222 {
2223 victim_size = chunksize(victim);
2224 remainder_size = victim_size - nb;
2225
2226 if (remainder_size >= (long)MINSIZE) /* too big */
2227 {
wdenk8bde7f72003-06-27 21:31:46 +00002228 --idx; /* adjust to rescan below after checking last remainder */
2229 break;
wdenk217c9da2002-10-25 20:35:49 +00002230 }
2231
2232 else if (remainder_size >= 0) /* exact fit */
2233 {
wdenk8bde7f72003-06-27 21:31:46 +00002234 unlink(victim, bck, fwd);
2235 set_inuse_bit_at_offset(victim, victim_size);
2236 check_malloced_chunk(victim, nb);
2237 return chunk2mem(victim);
wdenk217c9da2002-10-25 20:35:49 +00002238 }
2239 }
2240
2241 ++idx;
2242
2243 }
2244
2245 /* Try to use the last split-off remainder */
2246
2247 if ( (victim = last_remainder->fd) != last_remainder)
2248 {
2249 victim_size = chunksize(victim);
2250 remainder_size = victim_size - nb;
2251
2252 if (remainder_size >= (long)MINSIZE) /* re-split */
2253 {
2254 remainder = chunk_at_offset(victim, nb);
2255 set_head(victim, nb | PREV_INUSE);
2256 link_last_remainder(remainder);
2257 set_head(remainder, remainder_size | PREV_INUSE);
2258 set_foot(remainder, remainder_size);
2259 check_malloced_chunk(victim, nb);
2260 return chunk2mem(victim);
2261 }
2262
2263 clear_last_remainder;
2264
2265 if (remainder_size >= 0) /* exhaust */
2266 {
2267 set_inuse_bit_at_offset(victim, victim_size);
2268 check_malloced_chunk(victim, nb);
2269 return chunk2mem(victim);
2270 }
2271
2272 /* Else place in bin */
2273
2274 frontlink(victim, victim_size, remainder_index, bck, fwd);
2275 }
2276
2277 /*
2278 If there are any possibly nonempty big-enough blocks,
2279 search for best fitting chunk by scanning bins in blockwidth units.
2280 */
2281
Stefan Roesef2302d42008-08-06 14:05:38 +02002282 if ( (block = idx2binblock(idx)) <= binblocks_r)
wdenk217c9da2002-10-25 20:35:49 +00002283 {
2284
2285 /* Get to the first marked block */
2286
Stefan Roesef2302d42008-08-06 14:05:38 +02002287 if ( (block & binblocks_r) == 0)
wdenk217c9da2002-10-25 20:35:49 +00002288 {
2289 /* force to an even block boundary */
2290 idx = (idx & ~(BINBLOCKWIDTH - 1)) + BINBLOCKWIDTH;
2291 block <<= 1;
Stefan Roesef2302d42008-08-06 14:05:38 +02002292 while ((block & binblocks_r) == 0)
wdenk217c9da2002-10-25 20:35:49 +00002293 {
wdenk8bde7f72003-06-27 21:31:46 +00002294 idx += BINBLOCKWIDTH;
2295 block <<= 1;
wdenk217c9da2002-10-25 20:35:49 +00002296 }
2297 }
2298
2299 /* For each possibly nonempty block ... */
2300 for (;;)
2301 {
2302 startidx = idx; /* (track incomplete blocks) */
2303 q = bin = bin_at(idx);
2304
2305 /* For each bin in this block ... */
2306 do
2307 {
wdenk8bde7f72003-06-27 21:31:46 +00002308 /* Find and use first big enough chunk ... */
wdenk217c9da2002-10-25 20:35:49 +00002309
wdenk8bde7f72003-06-27 21:31:46 +00002310 for (victim = last(bin); victim != bin; victim = victim->bk)
2311 {
2312 victim_size = chunksize(victim);
2313 remainder_size = victim_size - nb;
wdenk217c9da2002-10-25 20:35:49 +00002314
wdenk8bde7f72003-06-27 21:31:46 +00002315 if (remainder_size >= (long)MINSIZE) /* split */
2316 {
2317 remainder = chunk_at_offset(victim, nb);
2318 set_head(victim, nb | PREV_INUSE);
2319 unlink(victim, bck, fwd);
2320 link_last_remainder(remainder);
2321 set_head(remainder, remainder_size | PREV_INUSE);
2322 set_foot(remainder, remainder_size);
2323 check_malloced_chunk(victim, nb);
2324 return chunk2mem(victim);
2325 }
wdenk217c9da2002-10-25 20:35:49 +00002326
wdenk8bde7f72003-06-27 21:31:46 +00002327 else if (remainder_size >= 0) /* take */
2328 {
2329 set_inuse_bit_at_offset(victim, victim_size);
2330 unlink(victim, bck, fwd);
2331 check_malloced_chunk(victim, nb);
2332 return chunk2mem(victim);
2333 }
wdenk217c9da2002-10-25 20:35:49 +00002334
wdenk8bde7f72003-06-27 21:31:46 +00002335 }
wdenk217c9da2002-10-25 20:35:49 +00002336
2337 bin = next_bin(bin);
2338
2339 } while ((++idx & (BINBLOCKWIDTH - 1)) != 0);
2340
2341 /* Clear out the block bit. */
2342
2343 do /* Possibly backtrack to try to clear a partial block */
2344 {
wdenk8bde7f72003-06-27 21:31:46 +00002345 if ((startidx & (BINBLOCKWIDTH - 1)) == 0)
2346 {
Stefan Roesef2302d42008-08-06 14:05:38 +02002347 av_[1] = (mbinptr)(binblocks_r & ~block);
wdenk8bde7f72003-06-27 21:31:46 +00002348 break;
2349 }
2350 --startidx;
wdenk217c9da2002-10-25 20:35:49 +00002351 q = prev_bin(q);
2352 } while (first(q) == q);
2353
2354 /* Get to the next possibly nonempty block */
2355
Stefan Roesef2302d42008-08-06 14:05:38 +02002356 if ( (block <<= 1) <= binblocks_r && (block != 0) )
wdenk217c9da2002-10-25 20:35:49 +00002357 {
Stefan Roesef2302d42008-08-06 14:05:38 +02002358 while ((block & binblocks_r) == 0)
wdenk8bde7f72003-06-27 21:31:46 +00002359 {
2360 idx += BINBLOCKWIDTH;
2361 block <<= 1;
2362 }
wdenk217c9da2002-10-25 20:35:49 +00002363 }
2364 else
wdenk8bde7f72003-06-27 21:31:46 +00002365 break;
wdenk217c9da2002-10-25 20:35:49 +00002366 }
2367 }
2368
2369
2370 /* Try to use top chunk */
2371
2372 /* Require that there be a remainder, ensuring top always exists */
2373 if ( (remainder_size = chunksize(top) - nb) < (long)MINSIZE)
2374 {
2375
2376#if HAVE_MMAP
2377 /* If big and would otherwise need to extend, try to use mmap instead */
2378 if ((unsigned long)nb >= (unsigned long)mmap_threshold &&
wdenk8bde7f72003-06-27 21:31:46 +00002379 (victim = mmap_chunk(nb)) != 0)
wdenk217c9da2002-10-25 20:35:49 +00002380 return chunk2mem(victim);
2381#endif
2382
2383 /* Try to extend */
2384 malloc_extend_top(nb);
2385 if ( (remainder_size = chunksize(top) - nb) < (long)MINSIZE)
Kim Phillips199adb62012-10-29 13:34:32 +00002386 return NULL; /* propagate failure */
wdenk217c9da2002-10-25 20:35:49 +00002387 }
2388
2389 victim = top;
2390 set_head(victim, nb | PREV_INUSE);
2391 top = chunk_at_offset(victim, nb);
2392 set_head(top, remainder_size | PREV_INUSE);
2393 check_malloced_chunk(victim, nb);
2394 return chunk2mem(victim);
2395
2396}
2397
2398
2399
2400
2401/*
2402
2403 free() algorithm :
2404
2405 cases:
2406
2407 1. free(0) has no effect.
2408
2409 2. If the chunk was allocated via mmap, it is release via munmap().
2410
2411 3. If a returned chunk borders the current high end of memory,
wdenk8bde7f72003-06-27 21:31:46 +00002412 it is consolidated into the top, and if the total unused
2413 topmost memory exceeds the trim threshold, malloc_trim is
2414 called.
wdenk217c9da2002-10-25 20:35:49 +00002415
2416 4. Other chunks are consolidated as they arrive, and
wdenk8bde7f72003-06-27 21:31:46 +00002417 placed in corresponding bins. (This includes the case of
2418 consolidating with the current `last_remainder').
wdenk217c9da2002-10-25 20:35:49 +00002419
2420*/
2421
2422
2423#if __STD_C
2424void fREe(Void_t* mem)
2425#else
2426void fREe(mem) Void_t* mem;
2427#endif
2428{
2429 mchunkptr p; /* chunk corresponding to mem */
2430 INTERNAL_SIZE_T hd; /* its head field */
2431 INTERNAL_SIZE_T sz; /* its size */
2432 int idx; /* its bin index */
2433 mchunkptr next; /* next contiguous chunk */
2434 INTERNAL_SIZE_T nextsz; /* its size */
2435 INTERNAL_SIZE_T prevsz; /* size of previous contiguous chunk */
2436 mchunkptr bck; /* misc temp for linking */
2437 mchunkptr fwd; /* misc temp for linking */
2438 int islr; /* track whether merging with last_remainder */
2439
Kim Phillips199adb62012-10-29 13:34:32 +00002440 if (mem == NULL) /* free(0) has no effect */
wdenk217c9da2002-10-25 20:35:49 +00002441 return;
2442
2443 p = mem2chunk(mem);
2444 hd = p->size;
2445
2446#if HAVE_MMAP
2447 if (hd & IS_MMAPPED) /* release mmapped memory. */
2448 {
2449 munmap_chunk(p);
2450 return;
2451 }
2452#endif
2453
2454 check_inuse_chunk(p);
2455
2456 sz = hd & ~PREV_INUSE;
2457 next = chunk_at_offset(p, sz);
2458 nextsz = chunksize(next);
2459
2460 if (next == top) /* merge with top */
2461 {
2462 sz += nextsz;
2463
2464 if (!(hd & PREV_INUSE)) /* consolidate backward */
2465 {
2466 prevsz = p->prev_size;
2467 p = chunk_at_offset(p, -((long) prevsz));
2468 sz += prevsz;
2469 unlink(p, bck, fwd);
2470 }
2471
2472 set_head(p, sz | PREV_INUSE);
2473 top = p;
2474 if ((unsigned long)(sz) >= (unsigned long)trim_threshold)
2475 malloc_trim(top_pad);
2476 return;
2477 }
2478
2479 set_head(next, nextsz); /* clear inuse bit */
2480
2481 islr = 0;
2482
2483 if (!(hd & PREV_INUSE)) /* consolidate backward */
2484 {
2485 prevsz = p->prev_size;
2486 p = chunk_at_offset(p, -((long) prevsz));
2487 sz += prevsz;
2488
2489 if (p->fd == last_remainder) /* keep as last_remainder */
2490 islr = 1;
2491 else
2492 unlink(p, bck, fwd);
2493 }
2494
2495 if (!(inuse_bit_at_offset(next, nextsz))) /* consolidate forward */
2496 {
2497 sz += nextsz;
2498
2499 if (!islr && next->fd == last_remainder) /* re-insert last_remainder */
2500 {
2501 islr = 1;
2502 link_last_remainder(p);
2503 }
2504 else
2505 unlink(next, bck, fwd);
2506 }
2507
2508
2509 set_head(p, sz | PREV_INUSE);
2510 set_foot(p, sz);
2511 if (!islr)
2512 frontlink(p, sz, idx, bck, fwd);
2513}
2514
2515
2516
2517
2518
2519/*
2520
2521 Realloc algorithm:
2522
2523 Chunks that were obtained via mmap cannot be extended or shrunk
2524 unless HAVE_MREMAP is defined, in which case mremap is used.
2525 Otherwise, if their reallocation is for additional space, they are
2526 copied. If for less, they are just left alone.
2527
2528 Otherwise, if the reallocation is for additional space, and the
2529 chunk can be extended, it is, else a malloc-copy-free sequence is
2530 taken. There are several different ways that a chunk could be
2531 extended. All are tried:
2532
2533 * Extending forward into following adjacent free chunk.
2534 * Shifting backwards, joining preceding adjacent space
2535 * Both shifting backwards and extending forward.
2536 * Extending into newly sbrked space
2537
2538 Unless the #define REALLOC_ZERO_BYTES_FREES is set, realloc with a
2539 size argument of zero (re)allocates a minimum-sized chunk.
2540
2541 If the reallocation is for less space, and the new request is for
2542 a `small' (<512 bytes) size, then the newly unused space is lopped
2543 off and freed.
2544
2545 The old unix realloc convention of allowing the last-free'd chunk
2546 to be used as an argument to realloc is no longer supported.
2547 I don't know of any programs still relying on this feature,
2548 and allowing it would also allow too many other incorrect
2549 usages of realloc to be sensible.
2550
2551
2552*/
2553
2554
2555#if __STD_C
2556Void_t* rEALLOc(Void_t* oldmem, size_t bytes)
2557#else
2558Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
2559#endif
2560{
2561 INTERNAL_SIZE_T nb; /* padded request size */
2562
2563 mchunkptr oldp; /* chunk corresponding to oldmem */
2564 INTERNAL_SIZE_T oldsize; /* its size */
2565
2566 mchunkptr newp; /* chunk to return */
2567 INTERNAL_SIZE_T newsize; /* its size */
2568 Void_t* newmem; /* corresponding user mem */
2569
2570 mchunkptr next; /* next contiguous chunk after oldp */
2571 INTERNAL_SIZE_T nextsize; /* its size */
2572
2573 mchunkptr prev; /* previous contiguous chunk before oldp */
2574 INTERNAL_SIZE_T prevsize; /* its size */
2575
2576 mchunkptr remainder; /* holds split off extra space from newp */
2577 INTERNAL_SIZE_T remainder_size; /* its size */
2578
2579 mchunkptr bck; /* misc temp for linking */
2580 mchunkptr fwd; /* misc temp for linking */
2581
2582#ifdef REALLOC_ZERO_BYTES_FREES
2583 if (bytes == 0) { fREe(oldmem); return 0; }
2584#endif
2585
Kim Phillips199adb62012-10-29 13:34:32 +00002586 if ((long)bytes < 0) return NULL;
wdenk217c9da2002-10-25 20:35:49 +00002587
2588 /* realloc of null is supposed to be same as malloc */
Kim Phillips199adb62012-10-29 13:34:32 +00002589 if (oldmem == NULL) return mALLOc(bytes);
wdenk217c9da2002-10-25 20:35:49 +00002590
2591 newp = oldp = mem2chunk(oldmem);
2592 newsize = oldsize = chunksize(oldp);
2593
2594
2595 nb = request2size(bytes);
2596
2597#if HAVE_MMAP
2598 if (chunk_is_mmapped(oldp))
2599 {
2600#if HAVE_MREMAP
2601 newp = mremap_chunk(oldp, nb);
2602 if(newp) return chunk2mem(newp);
2603#endif
2604 /* Note the extra SIZE_SZ overhead. */
2605 if(oldsize - SIZE_SZ >= nb) return oldmem; /* do nothing */
2606 /* Must alloc, copy, free. */
2607 newmem = mALLOc(bytes);
2608 if (newmem == 0) return 0; /* propagate failure */
2609 MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ);
2610 munmap_chunk(oldp);
2611 return newmem;
2612 }
2613#endif
2614
2615 check_inuse_chunk(oldp);
2616
2617 if ((long)(oldsize) < (long)(nb))
2618 {
2619
2620 /* Try expanding forward */
2621
2622 next = chunk_at_offset(oldp, oldsize);
2623 if (next == top || !inuse(next))
2624 {
2625 nextsize = chunksize(next);
2626
2627 /* Forward into top only if a remainder */
2628 if (next == top)
2629 {
wdenk8bde7f72003-06-27 21:31:46 +00002630 if ((long)(nextsize + newsize) >= (long)(nb + MINSIZE))
2631 {
2632 newsize += nextsize;
2633 top = chunk_at_offset(oldp, nb);
2634 set_head(top, (newsize - nb) | PREV_INUSE);
2635 set_head_size(oldp, nb);
2636 return chunk2mem(oldp);
2637 }
wdenk217c9da2002-10-25 20:35:49 +00002638 }
2639
2640 /* Forward into next chunk */
2641 else if (((long)(nextsize + newsize) >= (long)(nb)))
2642 {
wdenk8bde7f72003-06-27 21:31:46 +00002643 unlink(next, bck, fwd);
2644 newsize += nextsize;
2645 goto split;
wdenk217c9da2002-10-25 20:35:49 +00002646 }
2647 }
2648 else
2649 {
Kim Phillips199adb62012-10-29 13:34:32 +00002650 next = NULL;
wdenk217c9da2002-10-25 20:35:49 +00002651 nextsize = 0;
2652 }
2653
2654 /* Try shifting backwards. */
2655
2656 if (!prev_inuse(oldp))
2657 {
2658 prev = prev_chunk(oldp);
2659 prevsize = chunksize(prev);
2660
2661 /* try forward + backward first to save a later consolidation */
2662
Kim Phillips199adb62012-10-29 13:34:32 +00002663 if (next != NULL)
wdenk217c9da2002-10-25 20:35:49 +00002664 {
wdenk8bde7f72003-06-27 21:31:46 +00002665 /* into top */
2666 if (next == top)
2667 {
2668 if ((long)(nextsize + prevsize + newsize) >= (long)(nb + MINSIZE))
2669 {
2670 unlink(prev, bck, fwd);
2671 newp = prev;
2672 newsize += prevsize + nextsize;
2673 newmem = chunk2mem(newp);
2674 MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2675 top = chunk_at_offset(newp, nb);
2676 set_head(top, (newsize - nb) | PREV_INUSE);
2677 set_head_size(newp, nb);
2678 return newmem;
2679 }
2680 }
wdenk217c9da2002-10-25 20:35:49 +00002681
wdenk8bde7f72003-06-27 21:31:46 +00002682 /* into next chunk */
2683 else if (((long)(nextsize + prevsize + newsize) >= (long)(nb)))
2684 {
2685 unlink(next, bck, fwd);
2686 unlink(prev, bck, fwd);
2687 newp = prev;
2688 newsize += nextsize + prevsize;
2689 newmem = chunk2mem(newp);
2690 MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2691 goto split;
2692 }
wdenk217c9da2002-10-25 20:35:49 +00002693 }
2694
2695 /* backward only */
Kim Phillips199adb62012-10-29 13:34:32 +00002696 if (prev != NULL && (long)(prevsize + newsize) >= (long)nb)
wdenk217c9da2002-10-25 20:35:49 +00002697 {
wdenk8bde7f72003-06-27 21:31:46 +00002698 unlink(prev, bck, fwd);
2699 newp = prev;
2700 newsize += prevsize;
2701 newmem = chunk2mem(newp);
2702 MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2703 goto split;
wdenk217c9da2002-10-25 20:35:49 +00002704 }
2705 }
2706
2707 /* Must allocate */
2708
2709 newmem = mALLOc (bytes);
2710
Kim Phillips199adb62012-10-29 13:34:32 +00002711 if (newmem == NULL) /* propagate failure */
2712 return NULL;
wdenk217c9da2002-10-25 20:35:49 +00002713
2714 /* Avoid copy if newp is next chunk after oldp. */
2715 /* (This can only happen when new chunk is sbrk'ed.) */
2716
2717 if ( (newp = mem2chunk(newmem)) == next_chunk(oldp))
2718 {
2719 newsize += chunksize(newp);
2720 newp = oldp;
2721 goto split;
2722 }
2723
2724 /* Otherwise copy, free, and exit */
2725 MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2726 fREe(oldmem);
2727 return newmem;
2728 }
2729
2730
2731 split: /* split off extra room in old or expanded chunk */
2732
2733 if (newsize - nb >= MINSIZE) /* split off remainder */
2734 {
2735 remainder = chunk_at_offset(newp, nb);
2736 remainder_size = newsize - nb;
2737 set_head_size(newp, nb);
2738 set_head(remainder, remainder_size | PREV_INUSE);
2739 set_inuse_bit_at_offset(remainder, remainder_size);
2740 fREe(chunk2mem(remainder)); /* let free() deal with it */
2741 }
2742 else
2743 {
2744 set_head_size(newp, newsize);
2745 set_inuse_bit_at_offset(newp, newsize);
2746 }
2747
2748 check_inuse_chunk(newp);
2749 return chunk2mem(newp);
2750}
2751
2752
2753
2754
2755/*
2756
2757 memalign algorithm:
2758
2759 memalign requests more than enough space from malloc, finds a spot
2760 within that chunk that meets the alignment request, and then
2761 possibly frees the leading and trailing space.
2762
2763 The alignment argument must be a power of two. This property is not
2764 checked by memalign, so misuse may result in random runtime errors.
2765
2766 8-byte alignment is guaranteed by normal malloc calls, so don't
2767 bother calling memalign with an argument of 8 or less.
2768
2769 Overreliance on memalign is a sure way to fragment space.
2770
2771*/
2772
2773
2774#if __STD_C
2775Void_t* mEMALIGn(size_t alignment, size_t bytes)
2776#else
2777Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes;
2778#endif
2779{
2780 INTERNAL_SIZE_T nb; /* padded request size */
2781 char* m; /* memory returned by malloc call */
2782 mchunkptr p; /* corresponding chunk */
2783 char* brk; /* alignment point within p */
2784 mchunkptr newp; /* chunk to return */
2785 INTERNAL_SIZE_T newsize; /* its size */
2786 INTERNAL_SIZE_T leadsize; /* leading space befor alignment point */
2787 mchunkptr remainder; /* spare room at end to split off */
2788 long remainder_size; /* its size */
2789
Kim Phillips199adb62012-10-29 13:34:32 +00002790 if ((long)bytes < 0) return NULL;
wdenk217c9da2002-10-25 20:35:49 +00002791
2792 /* If need less alignment than we give anyway, just relay to malloc */
2793
2794 if (alignment <= MALLOC_ALIGNMENT) return mALLOc(bytes);
2795
2796 /* Otherwise, ensure that it is at least a minimum chunk size */
2797
2798 if (alignment < MINSIZE) alignment = MINSIZE;
2799
2800 /* Call malloc with worst case padding to hit alignment. */
2801
2802 nb = request2size(bytes);
2803 m = (char*)(mALLOc(nb + alignment + MINSIZE));
2804
Kim Phillips199adb62012-10-29 13:34:32 +00002805 if (m == NULL) return NULL; /* propagate failure */
wdenk217c9da2002-10-25 20:35:49 +00002806
2807 p = mem2chunk(m);
2808
2809 if ((((unsigned long)(m)) % alignment) == 0) /* aligned */
2810 {
2811#if HAVE_MMAP
2812 if(chunk_is_mmapped(p))
2813 return chunk2mem(p); /* nothing more to do */
2814#endif
2815 }
2816 else /* misaligned */
2817 {
2818 /*
2819 Find an aligned spot inside chunk.
2820 Since we need to give back leading space in a chunk of at
2821 least MINSIZE, if the first calculation places us at
2822 a spot with less than MINSIZE leader, we can move to the
2823 next aligned spot -- we've allocated enough total room so that
2824 this is always possible.
2825 */
2826
2827 brk = (char*)mem2chunk(((unsigned long)(m + alignment - 1)) & -((signed) alignment));
2828 if ((long)(brk - (char*)(p)) < MINSIZE) brk = brk + alignment;
2829
2830 newp = (mchunkptr)brk;
2831 leadsize = brk - (char*)(p);
2832 newsize = chunksize(p) - leadsize;
2833
2834#if HAVE_MMAP
2835 if(chunk_is_mmapped(p))
2836 {
2837 newp->prev_size = p->prev_size + leadsize;
2838 set_head(newp, newsize|IS_MMAPPED);
2839 return chunk2mem(newp);
2840 }
2841#endif
2842
2843 /* give back leader, use the rest */
2844
2845 set_head(newp, newsize | PREV_INUSE);
2846 set_inuse_bit_at_offset(newp, newsize);
2847 set_head_size(p, leadsize);
2848 fREe(chunk2mem(p));
2849 p = newp;
2850
2851 assert (newsize >= nb && (((unsigned long)(chunk2mem(p))) % alignment) == 0);
2852 }
2853
2854 /* Also give back spare room at the end */
2855
2856 remainder_size = chunksize(p) - nb;
2857
2858 if (remainder_size >= (long)MINSIZE)
2859 {
2860 remainder = chunk_at_offset(p, nb);
2861 set_head(remainder, remainder_size | PREV_INUSE);
2862 set_head_size(p, nb);
2863 fREe(chunk2mem(remainder));
2864 }
2865
2866 check_inuse_chunk(p);
2867 return chunk2mem(p);
2868
2869}
2870
2871
2872
2873
2874/*
2875 valloc just invokes memalign with alignment argument equal
2876 to the page size of the system (or as near to this as can
2877 be figured out from all the includes/defines above.)
2878*/
2879
2880#if __STD_C
2881Void_t* vALLOc(size_t bytes)
2882#else
2883Void_t* vALLOc(bytes) size_t bytes;
2884#endif
2885{
2886 return mEMALIGn (malloc_getpagesize, bytes);
2887}
2888
2889/*
2890 pvalloc just invokes valloc for the nearest pagesize
2891 that will accommodate request
2892*/
2893
2894
2895#if __STD_C
2896Void_t* pvALLOc(size_t bytes)
2897#else
2898Void_t* pvALLOc(bytes) size_t bytes;
2899#endif
2900{
2901 size_t pagesize = malloc_getpagesize;
2902 return mEMALIGn (pagesize, (bytes + pagesize - 1) & ~(pagesize - 1));
2903}
2904
2905/*
2906
2907 calloc calls malloc, then zeroes out the allocated chunk.
2908
2909*/
2910
2911#if __STD_C
2912Void_t* cALLOc(size_t n, size_t elem_size)
2913#else
2914Void_t* cALLOc(n, elem_size) size_t n; size_t elem_size;
2915#endif
2916{
2917 mchunkptr p;
2918 INTERNAL_SIZE_T csz;
2919
2920 INTERNAL_SIZE_T sz = n * elem_size;
2921
2922
2923 /* check if expand_top called, in which case don't need to clear */
2924#if MORECORE_CLEARS
2925 mchunkptr oldtop = top;
2926 INTERNAL_SIZE_T oldtopsize = chunksize(top);
2927#endif
2928 Void_t* mem = mALLOc (sz);
2929
Kim Phillips199adb62012-10-29 13:34:32 +00002930 if ((long)n < 0) return NULL;
wdenk217c9da2002-10-25 20:35:49 +00002931
Kim Phillips199adb62012-10-29 13:34:32 +00002932 if (mem == NULL)
2933 return NULL;
wdenk217c9da2002-10-25 20:35:49 +00002934 else
2935 {
2936 p = mem2chunk(mem);
2937
2938 /* Two optional cases in which clearing not necessary */
2939
2940
2941#if HAVE_MMAP
2942 if (chunk_is_mmapped(p)) return mem;
2943#endif
2944
2945 csz = chunksize(p);
2946
2947#if MORECORE_CLEARS
2948 if (p == oldtop && csz > oldtopsize)
2949 {
2950 /* clear only the bytes from non-freshly-sbrked memory */
2951 csz = oldtopsize;
2952 }
2953#endif
2954
2955 MALLOC_ZERO(mem, csz - SIZE_SZ);
2956 return mem;
2957 }
2958}
2959
2960/*
2961
2962 cfree just calls free. It is needed/defined on some systems
2963 that pair it with calloc, presumably for odd historical reasons.
2964
2965*/
2966
2967#if !defined(INTERNAL_LINUX_C_LIB) || !defined(__ELF__)
2968#if __STD_C
2969void cfree(Void_t *mem)
2970#else
2971void cfree(mem) Void_t *mem;
2972#endif
2973{
2974 fREe(mem);
2975}
2976#endif
2977
2978
2979
2980/*
2981
2982 Malloc_trim gives memory back to the system (via negative
2983 arguments to sbrk) if there is unused memory at the `high' end of
2984 the malloc pool. You can call this after freeing large blocks of
2985 memory to potentially reduce the system-level memory requirements
2986 of a program. However, it cannot guarantee to reduce memory. Under
2987 some allocation patterns, some large free blocks of memory will be
2988 locked between two used chunks, so they cannot be given back to
2989 the system.
2990
2991 The `pad' argument to malloc_trim represents the amount of free
2992 trailing space to leave untrimmed. If this argument is zero,
2993 only the minimum amount of memory to maintain internal data
2994 structures will be left (one page or less). Non-zero arguments
2995 can be supplied to maintain enough trailing space to service
2996 future expected allocations without having to re-obtain memory
2997 from the system.
2998
2999 Malloc_trim returns 1 if it actually released any memory, else 0.
3000
3001*/
3002
3003#if __STD_C
3004int malloc_trim(size_t pad)
3005#else
3006int malloc_trim(pad) size_t pad;
3007#endif
3008{
3009 long top_size; /* Amount of top-most memory */
3010 long extra; /* Amount to release */
3011 char* current_brk; /* address returned by pre-check sbrk call */
3012 char* new_brk; /* address returned by negative sbrk call */
3013
3014 unsigned long pagesz = malloc_getpagesize;
3015
3016 top_size = chunksize(top);
3017 extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz;
3018
3019 if (extra < (long)pagesz) /* Not enough memory to release */
3020 return 0;
3021
3022 else
3023 {
3024 /* Test to make sure no one else called sbrk */
3025 current_brk = (char*)(MORECORE (0));
3026 if (current_brk != (char*)(top) + top_size)
3027 return 0; /* Apparently we don't own memory; must fail */
3028
3029 else
3030 {
3031 new_brk = (char*)(MORECORE (-extra));
3032
3033 if (new_brk == (char*)(MORECORE_FAILURE)) /* sbrk failed? */
3034 {
wdenk8bde7f72003-06-27 21:31:46 +00003035 /* Try to figure out what we have */
3036 current_brk = (char*)(MORECORE (0));
3037 top_size = current_brk - (char*)top;
3038 if (top_size >= (long)MINSIZE) /* if not, we are very very dead! */
3039 {
3040 sbrked_mem = current_brk - sbrk_base;
3041 set_head(top, top_size | PREV_INUSE);
3042 }
3043 check_chunk(top);
3044 return 0;
wdenk217c9da2002-10-25 20:35:49 +00003045 }
3046
3047 else
3048 {
wdenk8bde7f72003-06-27 21:31:46 +00003049 /* Success. Adjust top accordingly. */
3050 set_head(top, (top_size - extra) | PREV_INUSE);
3051 sbrked_mem -= extra;
3052 check_chunk(top);
3053 return 1;
wdenk217c9da2002-10-25 20:35:49 +00003054 }
3055 }
3056 }
3057}
3058
3059
3060
3061/*
3062 malloc_usable_size:
3063
3064 This routine tells you how many bytes you can actually use in an
3065 allocated chunk, which may be more than you requested (although
3066 often not). You can use this many bytes without worrying about
3067 overwriting other allocated objects. Not a particularly great
3068 programming practice, but still sometimes useful.
3069
3070*/
3071
3072#if __STD_C
3073size_t malloc_usable_size(Void_t* mem)
3074#else
3075size_t malloc_usable_size(mem) Void_t* mem;
3076#endif
3077{
3078 mchunkptr p;
Kim Phillips199adb62012-10-29 13:34:32 +00003079 if (mem == NULL)
wdenk217c9da2002-10-25 20:35:49 +00003080 return 0;
3081 else
3082 {
3083 p = mem2chunk(mem);
3084 if(!chunk_is_mmapped(p))
3085 {
3086 if (!inuse(p)) return 0;
3087 check_inuse_chunk(p);
3088 return chunksize(p) - SIZE_SZ;
3089 }
3090 return chunksize(p) - 2*SIZE_SZ;
3091 }
3092}
3093
3094
3095
3096
3097/* Utility to update current_mallinfo for malloc_stats and mallinfo() */
3098
Wolfgang Denkea882ba2010-06-20 23:33:59 +02003099#ifdef DEBUG
wdenk217c9da2002-10-25 20:35:49 +00003100static void malloc_update_mallinfo()
3101{
3102 int i;
3103 mbinptr b;
3104 mchunkptr p;
3105#ifdef DEBUG
3106 mchunkptr q;
3107#endif
3108
3109 INTERNAL_SIZE_T avail = chunksize(top);
3110 int navail = ((long)(avail) >= (long)MINSIZE)? 1 : 0;
3111
3112 for (i = 1; i < NAV; ++i)
3113 {
3114 b = bin_at(i);
3115 for (p = last(b); p != b; p = p->bk)
3116 {
3117#ifdef DEBUG
3118 check_free_chunk(p);
3119 for (q = next_chunk(p);
wdenk8bde7f72003-06-27 21:31:46 +00003120 q < top && inuse(q) && (long)(chunksize(q)) >= (long)MINSIZE;
3121 q = next_chunk(q))
3122 check_inuse_chunk(q);
wdenk217c9da2002-10-25 20:35:49 +00003123#endif
3124 avail += chunksize(p);
3125 navail++;
3126 }
3127 }
3128
3129 current_mallinfo.ordblks = navail;
3130 current_mallinfo.uordblks = sbrked_mem - avail;
3131 current_mallinfo.fordblks = avail;
3132 current_mallinfo.hblks = n_mmaps;
3133 current_mallinfo.hblkhd = mmapped_mem;
3134 current_mallinfo.keepcost = chunksize(top);
3135
3136}
Wolfgang Denkea882ba2010-06-20 23:33:59 +02003137#endif /* DEBUG */
wdenk217c9da2002-10-25 20:35:49 +00003138
3139
3140
3141/*
3142
3143 malloc_stats:
3144
3145 Prints on the amount of space obtain from the system (both
3146 via sbrk and mmap), the maximum amount (which may be more than
3147 current if malloc_trim and/or munmap got called), the maximum
3148 number of simultaneous mmap regions used, and the current number
3149 of bytes allocated via malloc (or realloc, etc) but not yet
3150 freed. (Note that this is the number of bytes allocated, not the
3151 number requested. It will be larger than the number requested
3152 because of alignment and bookkeeping overhead.)
3153
3154*/
3155
Wolfgang Denkea882ba2010-06-20 23:33:59 +02003156#ifdef DEBUG
wdenk217c9da2002-10-25 20:35:49 +00003157void malloc_stats()
3158{
3159 malloc_update_mallinfo();
3160 printf("max system bytes = %10u\n",
wdenk8bde7f72003-06-27 21:31:46 +00003161 (unsigned int)(max_total_mem));
wdenk217c9da2002-10-25 20:35:49 +00003162 printf("system bytes = %10u\n",
wdenk8bde7f72003-06-27 21:31:46 +00003163 (unsigned int)(sbrked_mem + mmapped_mem));
wdenk217c9da2002-10-25 20:35:49 +00003164 printf("in use bytes = %10u\n",
wdenk8bde7f72003-06-27 21:31:46 +00003165 (unsigned int)(current_mallinfo.uordblks + mmapped_mem));
wdenk217c9da2002-10-25 20:35:49 +00003166#if HAVE_MMAP
3167 printf("max mmap regions = %10u\n",
wdenk8bde7f72003-06-27 21:31:46 +00003168 (unsigned int)max_n_mmaps);
wdenk217c9da2002-10-25 20:35:49 +00003169#endif
3170}
Wolfgang Denkea882ba2010-06-20 23:33:59 +02003171#endif /* DEBUG */
wdenk217c9da2002-10-25 20:35:49 +00003172
3173/*
3174 mallinfo returns a copy of updated current mallinfo.
3175*/
3176
Wolfgang Denkea882ba2010-06-20 23:33:59 +02003177#ifdef DEBUG
wdenk217c9da2002-10-25 20:35:49 +00003178struct mallinfo mALLINFo()
3179{
3180 malloc_update_mallinfo();
3181 return current_mallinfo;
3182}
Wolfgang Denkea882ba2010-06-20 23:33:59 +02003183#endif /* DEBUG */
wdenk217c9da2002-10-25 20:35:49 +00003184
3185
3186
3187
3188/*
3189 mallopt:
3190
3191 mallopt is the general SVID/XPG interface to tunable parameters.
3192 The format is to provide a (parameter-number, parameter-value) pair.
3193 mallopt then sets the corresponding parameter to the argument
3194 value if it can (i.e., so long as the value is meaningful),
3195 and returns 1 if successful else 0.
3196
3197 See descriptions of tunable parameters above.
3198
3199*/
3200
3201#if __STD_C
3202int mALLOPt(int param_number, int value)
3203#else
3204int mALLOPt(param_number, value) int param_number; int value;
3205#endif
3206{
3207 switch(param_number)
3208 {
3209 case M_TRIM_THRESHOLD:
3210 trim_threshold = value; return 1;
3211 case M_TOP_PAD:
3212 top_pad = value; return 1;
3213 case M_MMAP_THRESHOLD:
3214 mmap_threshold = value; return 1;
3215 case M_MMAP_MAX:
3216#if HAVE_MMAP
3217 n_mmaps_max = value; return 1;
3218#else
3219 if (value != 0) return 0; else n_mmaps_max = value; return 1;
3220#endif
3221
3222 default:
3223 return 0;
3224 }
3225}
3226
3227/*
3228
3229History:
3230
3231 V2.6.6 Sun Dec 5 07:42:19 1999 Doug Lea (dl at gee)
3232 * return null for negative arguments
3233 * Added Several WIN32 cleanups from Martin C. Fong <mcfong@yahoo.com>
wdenk8bde7f72003-06-27 21:31:46 +00003234 * Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h'
3235 (e.g. WIN32 platforms)
3236 * Cleanup up header file inclusion for WIN32 platforms
3237 * Cleanup code to avoid Microsoft Visual C++ compiler complaints
3238 * Add 'USE_DL_PREFIX' to quickly allow co-existence with existing
3239 memory allocation routines
3240 * Set 'malloc_getpagesize' for WIN32 platforms (needs more work)
3241 * Use 'assert' rather than 'ASSERT' in WIN32 code to conform to
wdenk217c9da2002-10-25 20:35:49 +00003242 usage of 'assert' in non-WIN32 code
wdenk8bde7f72003-06-27 21:31:46 +00003243 * Improve WIN32 'sbrk()' emulation's 'findRegion()' routine to
3244 avoid infinite loop
wdenk217c9da2002-10-25 20:35:49 +00003245 * Always call 'fREe()' rather than 'free()'
3246
3247 V2.6.5 Wed Jun 17 15:57:31 1998 Doug Lea (dl at gee)
3248 * Fixed ordering problem with boundary-stamping
3249
3250 V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee)
3251 * Added pvalloc, as recommended by H.J. Liu
3252 * Added 64bit pointer support mainly from Wolfram Gloger
3253 * Added anonymously donated WIN32 sbrk emulation
3254 * Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen
3255 * malloc_extend_top: fix mask error that caused wastage after
wdenk8bde7f72003-06-27 21:31:46 +00003256 foreign sbrks
wdenk217c9da2002-10-25 20:35:49 +00003257 * Add linux mremap support code from HJ Liu
3258
3259 V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee)
3260 * Integrated most documentation with the code.
3261 * Add support for mmap, with help from
wdenk8bde7f72003-06-27 21:31:46 +00003262 Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
wdenk217c9da2002-10-25 20:35:49 +00003263 * Use last_remainder in more cases.
3264 * Pack bins using idea from colin@nyx10.cs.du.edu
3265 * Use ordered bins instead of best-fit threshhold
3266 * Eliminate block-local decls to simplify tracing and debugging.
3267 * Support another case of realloc via move into top
3268 * Fix error occuring when initial sbrk_base not word-aligned.
3269 * Rely on page size for units instead of SBRK_UNIT to
wdenk8bde7f72003-06-27 21:31:46 +00003270 avoid surprises about sbrk alignment conventions.
wdenk217c9da2002-10-25 20:35:49 +00003271 * Add mallinfo, mallopt. Thanks to Raymond Nijssen
wdenk8bde7f72003-06-27 21:31:46 +00003272 (raymond@es.ele.tue.nl) for the suggestion.
wdenk217c9da2002-10-25 20:35:49 +00003273 * Add `pad' argument to malloc_trim and top_pad mallopt parameter.
3274 * More precautions for cases where other routines call sbrk,
wdenk8bde7f72003-06-27 21:31:46 +00003275 courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
wdenk217c9da2002-10-25 20:35:49 +00003276 * Added macros etc., allowing use in linux libc from
wdenk8bde7f72003-06-27 21:31:46 +00003277 H.J. Lu (hjl@gnu.ai.mit.edu)
wdenk217c9da2002-10-25 20:35:49 +00003278 * Inverted this history list
3279
3280 V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee)
3281 * Re-tuned and fixed to behave more nicely with V2.6.0 changes.
3282 * Removed all preallocation code since under current scheme
wdenk8bde7f72003-06-27 21:31:46 +00003283 the work required to undo bad preallocations exceeds
3284 the work saved in good cases for most test programs.
wdenk217c9da2002-10-25 20:35:49 +00003285 * No longer use return list or unconsolidated bins since
wdenk8bde7f72003-06-27 21:31:46 +00003286 no scheme using them consistently outperforms those that don't
3287 given above changes.
wdenk217c9da2002-10-25 20:35:49 +00003288 * Use best fit for very large chunks to prevent some worst-cases.
3289 * Added some support for debugging
3290
3291 V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee)
3292 * Removed footers when chunks are in use. Thanks to
wdenk8bde7f72003-06-27 21:31:46 +00003293 Paul Wilson (wilson@cs.texas.edu) for the suggestion.
wdenk217c9da2002-10-25 20:35:49 +00003294
3295 V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee)
3296 * Added malloc_trim, with help from Wolfram Gloger
wdenk8bde7f72003-06-27 21:31:46 +00003297 (wmglo@Dent.MED.Uni-Muenchen.DE).
wdenk217c9da2002-10-25 20:35:49 +00003298
3299 V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g)
3300
3301 V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g)
3302 * realloc: try to expand in both directions
3303 * malloc: swap order of clean-bin strategy;
3304 * realloc: only conditionally expand backwards
3305 * Try not to scavenge used bins
3306 * Use bin counts as a guide to preallocation
3307 * Occasionally bin return list chunks in first scan
3308 * Add a few optimizations from colin@nyx10.cs.du.edu
3309
3310 V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g)
3311 * faster bin computation & slightly different binning
3312 * merged all consolidations to one part of malloc proper
wdenk8bde7f72003-06-27 21:31:46 +00003313 (eliminating old malloc_find_space & malloc_clean_bin)
wdenk217c9da2002-10-25 20:35:49 +00003314 * Scan 2 returns chunks (not just 1)
3315 * Propagate failure in realloc if malloc returns 0
3316 * Add stuff to allow compilation on non-ANSI compilers
wdenk8bde7f72003-06-27 21:31:46 +00003317 from kpv@research.att.com
wdenk217c9da2002-10-25 20:35:49 +00003318
3319 V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu)
3320 * removed potential for odd address access in prev_chunk
3321 * removed dependency on getpagesize.h
3322 * misc cosmetics and a bit more internal documentation
3323 * anticosmetics: mangled names in macros to evade debugger strangeness
3324 * tested on sparc, hp-700, dec-mips, rs6000
wdenk8bde7f72003-06-27 21:31:46 +00003325 with gcc & native cc (hp, dec only) allowing
3326 Detlefs & Zorn comparison study (in SIGPLAN Notices.)
wdenk217c9da2002-10-25 20:35:49 +00003327
3328 Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu)
3329 * Based loosely on libg++-1.2X malloc. (It retains some of the overall
wdenk8bde7f72003-06-27 21:31:46 +00003330 structure of old version, but most details differ.)
wdenk217c9da2002-10-25 20:35:49 +00003331
3332*/