src/3rdparty/ptmalloc/malloc-2.8.3.h
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     1 /*
       
     2   Default header file for malloc-2.8.x, written by Doug Lea
       
     3   and released to the public domain, as explained at
       
     4   http://creativecommons.org/licenses/publicdomain. 
       
     5  
       
     6   last update: Mon Aug 15 08:55:52 2005  Doug Lea  (dl at gee)
       
     7 
       
     8   This header is for ANSI C/C++ only.  You can set any of
       
     9   the following #defines before including:
       
    10 
       
    11   * If USE_DL_PREFIX is defined, it is assumed that malloc.c 
       
    12     was also compiled with this option, so all routines
       
    13     have names starting with "dl".
       
    14 
       
    15   * If HAVE_USR_INCLUDE_MALLOC_H is defined, it is assumed that this
       
    16     file will be #included AFTER <malloc.h>. This is needed only if
       
    17     your system defines a struct mallinfo that is incompatible with the
       
    18     standard one declared here.  Otherwise, you can include this file
       
    19     INSTEAD of your system system <malloc.h>.  At least on ANSI, all
       
    20     declarations should be compatible with system versions
       
    21 
       
    22   * If MSPACES is defined, declarations for mspace versions are included.
       
    23 */
       
    24 
       
    25 #ifndef MALLOC_280_H
       
    26 #define MALLOC_280_H
       
    27 
       
    28 #ifdef __cplusplus
       
    29 extern "C" {
       
    30 #endif
       
    31 
       
    32 #include <stddef.h>   /* for size_t */
       
    33 
       
    34 #if !ONLY_MSPACES
       
    35 
       
    36 #ifndef USE_DL_PREFIX
       
    37 #define dlcalloc               calloc
       
    38 #define dlfree                 free
       
    39 #define dlmalloc               malloc
       
    40 #define dlmemalign             memalign
       
    41 #define dlrealloc              realloc
       
    42 #define dlvalloc               valloc
       
    43 #define dlpvalloc              pvalloc
       
    44 #define dlmallinfo             mallinfo
       
    45 #define dlmallopt              mallopt
       
    46 #define dlmalloc_trim          malloc_trim
       
    47 #define dlmalloc_stats         malloc_stats
       
    48 #define dlmalloc_usable_size   malloc_usable_size
       
    49 #define dlmalloc_footprint     malloc_footprint
       
    50 #define dlindependent_calloc   independent_calloc
       
    51 #define dlindependent_comalloc independent_comalloc
       
    52 #endif /* USE_DL_PREFIX */
       
    53 
       
    54 
       
    55 /*
       
    56   malloc(size_t n)
       
    57   Returns a pointer to a newly allocated chunk of at least n bytes, or
       
    58   null if no space is available, in which case errno is set to ENOMEM
       
    59   on ANSI C systems.
       
    60 
       
    61   If n is zero, malloc returns a minimum-sized chunk. (The minimum
       
    62   size is 16 bytes on most 32bit systems, and 32 bytes on 64bit
       
    63   systems.)  Note that size_t is an unsigned type, so calls with
       
    64   arguments that would be negative if signed are interpreted as
       
    65   requests for huge amounts of space, which will often fail. The
       
    66   maximum supported value of n differs across systems, but is in all
       
    67   cases less than the maximum representable value of a size_t.
       
    68 */
       
    69 void* dlmalloc(size_t);
       
    70 
       
    71 /*
       
    72   free(void* p)
       
    73   Releases the chunk of memory pointed to by p, that had been previously
       
    74   allocated using malloc or a related routine such as realloc.
       
    75   It has no effect if p is null. If p was not malloced or already
       
    76   freed, free(p) will by default cuase the current program to abort.
       
    77 */
       
    78 void  dlfree(void*);
       
    79 
       
    80 /*
       
    81   calloc(size_t n_elements, size_t element_size);
       
    82   Returns a pointer to n_elements * element_size bytes, with all locations
       
    83   set to zero.
       
    84 */
       
    85 void* dlcalloc(size_t, size_t);
       
    86 
       
    87 /*
       
    88   realloc(void* p, size_t n)
       
    89   Returns a pointer to a chunk of size n that contains the same data
       
    90   as does chunk p up to the minimum of (n, p's size) bytes, or null
       
    91   if no space is available.
       
    92 
       
    93   The returned pointer may or may not be the same as p. The algorithm
       
    94   prefers extending p in most cases when possible, otherwise it
       
    95   employs the equivalent of a malloc-copy-free sequence.
       
    96 
       
    97   If p is null, realloc is equivalent to malloc.
       
    98 
       
    99   If space is not available, realloc returns null, errno is set (if on
       
   100   ANSI) and p is NOT freed.
       
   101 
       
   102   if n is for fewer bytes than already held by p, the newly unused
       
   103   space is lopped off and freed if possible.  realloc with a size
       
   104   argument of zero (re)allocates a minimum-sized chunk.
       
   105 
       
   106   The old unix realloc convention of allowing the last-free'd chunk
       
   107   to be used as an argument to realloc is not supported.
       
   108 */
       
   109 
       
   110 void* dlrealloc(void*, size_t);
       
   111 
       
   112 /*
       
   113   memalign(size_t alignment, size_t n);
       
   114   Returns a pointer to a newly allocated chunk of n bytes, aligned
       
   115   in accord with the alignment argument.
       
   116 
       
   117   The alignment argument should be a power of two. If the argument is
       
   118   not a power of two, the nearest greater power is used.
       
   119   8-byte alignment is guaranteed by normal malloc calls, so don't
       
   120   bother calling memalign with an argument of 8 or less.
       
   121 
       
   122   Overreliance on memalign is a sure way to fragment space.
       
   123 */
       
   124 void* dlmemalign(size_t, size_t);
       
   125 
       
   126 /*
       
   127   valloc(size_t n);
       
   128   Equivalent to memalign(pagesize, n), where pagesize is the page
       
   129   size of the system. If the pagesize is unknown, 4096 is used.
       
   130 */
       
   131 void* dlvalloc(size_t);
       
   132 
       
   133 /*
       
   134   mallopt(int parameter_number, int parameter_value)
       
   135   Sets tunable parameters The format is to provide a
       
   136   (parameter-number, parameter-value) pair.  mallopt then sets the
       
   137   corresponding parameter to the argument value if it can (i.e., so
       
   138   long as the value is meaningful), and returns 1 if successful else
       
   139   0.  SVID/XPG/ANSI defines four standard param numbers for mallopt,
       
   140   normally defined in malloc.h.  None of these are use in this malloc,
       
   141   so setting them has no effect. But this malloc also supports other
       
   142   options in mallopt:
       
   143 
       
   144   Symbol            param #  default    allowed param values
       
   145   M_TRIM_THRESHOLD     -1   2*1024*1024   any   (-1U disables trimming)
       
   146   M_GRANULARITY        -2     page size   any power of 2 >= page size
       
   147   M_MMAP_THRESHOLD     -3      256*1024   any   (or 0 if no MMAP support)
       
   148 */
       
   149 int dlmallopt(int, int);
       
   150 
       
   151 #define M_TRIM_THRESHOLD     (-1)
       
   152 #define M_GRANULARITY        (-2)
       
   153 #define M_MMAP_THRESHOLD     (-3)
       
   154 
       
   155 
       
   156 /*
       
   157   malloc_footprint();
       
   158   Returns the number of bytes obtained from the system.  The total
       
   159   number of bytes allocated by malloc, realloc etc., is less than this
       
   160   value. Unlike mallinfo, this function returns only a precomputed
       
   161   result, so can be called frequently to monitor memory consumption.
       
   162   Even if locks are otherwise defined, this function does not use them,
       
   163   so results might not be up to date.
       
   164 */
       
   165 size_t dlmalloc_footprint(void);
       
   166 
       
   167 #if !NO_MALLINFO
       
   168 /*
       
   169   mallinfo()
       
   170   Returns (by copy) a struct containing various summary statistics:
       
   171 
       
   172   arena:     current total non-mmapped bytes allocated from system
       
   173   ordblks:   the number of free chunks
       
   174   smblks:    always zero.
       
   175   hblks:     current number of mmapped regions
       
   176   hblkhd:    total bytes held in mmapped regions
       
   177   usmblks:   the maximum total allocated space. This will be greater
       
   178                 than current total if trimming has occurred.
       
   179   fsmblks:   always zero
       
   180   uordblks:  current total allocated space (normal or mmapped)
       
   181   fordblks:  total free space
       
   182   keepcost:  the maximum number of bytes that could ideally be released
       
   183                back to system via malloc_trim. ("ideally" means that
       
   184                it ignores page restrictions etc.)
       
   185 
       
   186   Because these fields are ints, but internal bookkeeping may
       
   187   be kept as longs, the reported values may wrap around zero and
       
   188   thus be inaccurate.
       
   189 */
       
   190 #ifndef HAVE_USR_INCLUDE_MALLOC_H
       
   191 #ifndef _MALLOC_H
       
   192 #ifndef MALLINFO_FIELD_TYPE
       
   193 #define MALLINFO_FIELD_TYPE size_t
       
   194 #endif /* MALLINFO_FIELD_TYPE */
       
   195 struct mallinfo {
       
   196   MALLINFO_FIELD_TYPE arena;    /* non-mmapped space allocated from system */
       
   197   MALLINFO_FIELD_TYPE ordblks;  /* number of free chunks */
       
   198   MALLINFO_FIELD_TYPE smblks;   /* always 0 */
       
   199   MALLINFO_FIELD_TYPE hblks;    /* always 0 */
       
   200   MALLINFO_FIELD_TYPE hblkhd;   /* space in mmapped regions */
       
   201   MALLINFO_FIELD_TYPE usmblks;  /* maximum total allocated space */
       
   202   MALLINFO_FIELD_TYPE fsmblks;  /* always 0 */
       
   203   MALLINFO_FIELD_TYPE uordblks; /* total allocated space */
       
   204   MALLINFO_FIELD_TYPE fordblks; /* total free space */
       
   205   MALLINFO_FIELD_TYPE keepcost; /* releasable (via malloc_trim) space */
       
   206 };
       
   207 #endif  /* _MALLOC_H */
       
   208 #endif  /* HAVE_USR_INCLUDE_MALLOC_H */
       
   209 
       
   210 struct mallinfo dlmallinfo(void);
       
   211 #endif  /* NO_MALLINFO */
       
   212 
       
   213 /*
       
   214   independent_calloc(size_t n_elements, size_t element_size, void* chunks[]);
       
   215 
       
   216   independent_calloc is similar to calloc, but instead of returning a
       
   217   single cleared space, it returns an array of pointers to n_elements
       
   218   independent elements that can hold contents of size elem_size, each
       
   219   of which starts out cleared, and can be independently freed,
       
   220   realloc'ed etc. The elements are guaranteed to be adjacently
       
   221   allocated (this is not guaranteed to occur with multiple callocs or
       
   222   mallocs), which may also improve cache locality in some
       
   223   applications.
       
   224 
       
   225   The "chunks" argument is optional (i.e., may be null, which is
       
   226   probably the most typical usage). If it is null, the returned array
       
   227   is itself dynamically allocated and should also be freed when it is
       
   228   no longer needed. Otherwise, the chunks array must be of at least
       
   229   n_elements in length. It is filled in with the pointers to the
       
   230   chunks.
       
   231 
       
   232   In either case, independent_calloc returns this pointer array, or
       
   233   null if the allocation failed.  If n_elements is zero and "chunks"
       
   234   is null, it returns a chunk representing an array with zero elements
       
   235   (which should be freed if not wanted).
       
   236 
       
   237   Each element must be individually freed when it is no longer
       
   238   needed. If you'd like to instead be able to free all at once, you
       
   239   should instead use regular calloc and assign pointers into this
       
   240   space to represent elements.  (In this case though, you cannot
       
   241   independently free elements.)
       
   242 
       
   243   independent_calloc simplifies and speeds up implementations of many
       
   244   kinds of pools.  It may also be useful when constructing large data
       
   245   structures that initially have a fixed number of fixed-sized nodes,
       
   246   but the number is not known at compile time, and some of the nodes
       
   247   may later need to be freed. For example:
       
   248 
       
   249   struct Node { int item; struct Node* next; };
       
   250 
       
   251   struct Node* build_list() {
       
   252     struct Node** pool;
       
   253     int n = read_number_of_nodes_needed();
       
   254     if (n <= 0) return 0;
       
   255     pool = (struct Node**)(independent_calloc(n, sizeof(struct Node), 0);
       
   256     if (pool == 0) die();
       
   257     // organize into a linked list...
       
   258     struct Node* first = pool[0];
       
   259     for (i = 0; i < n-1; ++i)
       
   260       pool[i]->next = pool[i+1];
       
   261     free(pool);     // Can now free the array (or not, if it is needed later)
       
   262     return first;
       
   263   }
       
   264 */
       
   265 void** dlindependent_calloc(size_t, size_t, void**);
       
   266 
       
   267 /*
       
   268   independent_comalloc(size_t n_elements, size_t sizes[], void* chunks[]);
       
   269 
       
   270   independent_comalloc allocates, all at once, a set of n_elements
       
   271   chunks with sizes indicated in the "sizes" array.    It returns
       
   272   an array of pointers to these elements, each of which can be
       
   273   independently freed, realloc'ed etc. The elements are guaranteed to
       
   274   be adjacently allocated (this is not guaranteed to occur with
       
   275   multiple callocs or mallocs), which may also improve cache locality
       
   276   in some applications.
       
   277 
       
   278   The "chunks" argument is optional (i.e., may be null). If it is null
       
   279   the returned array is itself dynamically allocated and should also
       
   280   be freed when it is no longer needed. Otherwise, the chunks array
       
   281   must be of at least n_elements in length. It is filled in with the
       
   282   pointers to the chunks.
       
   283 
       
   284   In either case, independent_comalloc returns this pointer array, or
       
   285   null if the allocation failed.  If n_elements is zero and chunks is
       
   286   null, it returns a chunk representing an array with zero elements
       
   287   (which should be freed if not wanted).
       
   288 
       
   289   Each element must be individually freed when it is no longer
       
   290   needed. If you'd like to instead be able to free all at once, you
       
   291   should instead use a single regular malloc, and assign pointers at
       
   292   particular offsets in the aggregate space. (In this case though, you
       
   293   cannot independently free elements.)
       
   294 
       
   295   independent_comallac differs from independent_calloc in that each
       
   296   element may have a different size, and also that it does not
       
   297   automatically clear elements.
       
   298 
       
   299   independent_comalloc can be used to speed up allocation in cases
       
   300   where several structs or objects must always be allocated at the
       
   301   same time.  For example:
       
   302 
       
   303   struct Head { ... }
       
   304   struct Foot { ... }
       
   305 
       
   306   void send_message(char* msg) {
       
   307     int msglen = strlen(msg);
       
   308     size_t sizes[3] = { sizeof(struct Head), msglen, sizeof(struct Foot) };
       
   309     void* chunks[3];
       
   310     if (independent_comalloc(3, sizes, chunks) == 0)
       
   311       die();
       
   312     struct Head* head = (struct Head*)(chunks[0]);
       
   313     char*        body = (char*)(chunks[1]);
       
   314     struct Foot* foot = (struct Foot*)(chunks[2]);
       
   315     // ...
       
   316   }
       
   317 
       
   318   In general though, independent_comalloc is worth using only for
       
   319   larger values of n_elements. For small values, you probably won't
       
   320   detect enough difference from series of malloc calls to bother.
       
   321 
       
   322   Overuse of independent_comalloc can increase overall memory usage,
       
   323   since it cannot reuse existing noncontiguous small chunks that
       
   324   might be available for some of the elements.
       
   325 */
       
   326 void** dlindependent_comalloc(size_t, size_t*, void**);
       
   327 
       
   328 
       
   329 /*
       
   330   pvalloc(size_t n);
       
   331   Equivalent to valloc(minimum-page-that-holds(n)), that is,
       
   332   round up n to nearest pagesize.
       
   333  */
       
   334 void*  dlpvalloc(size_t);
       
   335 
       
   336 /*
       
   337   malloc_trim(size_t pad);
       
   338 
       
   339   If possible, gives memory back to the system (via negative arguments
       
   340   to sbrk) if there is unused memory at the `high' end of the malloc
       
   341   pool or in unused MMAP segments. You can call this after freeing
       
   342   large blocks of memory to potentially reduce the system-level memory
       
   343   requirements of a program. However, it cannot guarantee to reduce
       
   344   memory. Under some allocation patterns, some large free blocks of
       
   345   memory will be locked between two used chunks, so they cannot be
       
   346   given back to the system.
       
   347 
       
   348   The `pad' argument to malloc_trim represents the amount of free
       
   349   trailing space to leave untrimmed. If this argument is zero, only
       
   350   the minimum amount of memory to maintain internal data structures
       
   351   will be left. Non-zero arguments can be supplied to maintain enough
       
   352   trailing space to service future expected allocations without having
       
   353   to re-obtain memory from the system.
       
   354 
       
   355   Malloc_trim returns 1 if it actually released any memory, else 0.
       
   356 */
       
   357 int  dlmalloc_trim(size_t);
       
   358 
       
   359 /*
       
   360   malloc_usable_size(void* p);
       
   361 
       
   362   Returns the number of bytes you can actually use in
       
   363   an allocated chunk, which may be more than you requested (although
       
   364   often not) due to alignment and minimum size constraints.
       
   365   You can use this many bytes without worrying about
       
   366   overwriting other allocated objects. This is not a particularly great
       
   367   programming practice. malloc_usable_size can be more useful in
       
   368   debugging and assertions, for example:
       
   369 
       
   370   p = malloc(n);
       
   371   assert(malloc_usable_size(p) >= 256);
       
   372 */
       
   373 size_t dlmalloc_usable_size(void*);
       
   374 
       
   375 /*
       
   376   malloc_stats();
       
   377   Prints on stderr the amount of space obtained from the system (both
       
   378   via sbrk and mmap), the maximum amount (which may be more than
       
   379   current if malloc_trim and/or munmap got called), and the current
       
   380   number of bytes allocated via malloc (or realloc, etc) but not yet
       
   381   freed. Note that this is the number of bytes allocated, not the
       
   382   number requested. It will be larger than the number requested
       
   383   because of alignment and bookkeeping overhead. Because it includes
       
   384   alignment wastage as being in use, this figure may be greater than
       
   385   zero even when no user-level chunks are allocated.
       
   386 
       
   387   The reported current and maximum system memory can be inaccurate if
       
   388   a program makes other calls to system memory allocation functions
       
   389   (normally sbrk) outside of malloc.
       
   390 
       
   391   malloc_stats prints only the most commonly interesting statistics.
       
   392   More information can be obtained by calling mallinfo.
       
   393 */
       
   394 void  dlmalloc_stats(void);
       
   395 
       
   396 #endif /* !ONLY_MSPACES */
       
   397 
       
   398 #if MSPACES
       
   399 
       
   400 /*
       
   401   mspace is an opaque type representing an independent
       
   402   region of space that supports mspace_malloc, etc.
       
   403 */
       
   404 typedef void* mspace;
       
   405 
       
   406 /*
       
   407   create_mspace creates and returns a new independent space with the
       
   408   given initial capacity, or, if 0, the default granularity size.  It
       
   409   returns null if there is no system memory available to create the
       
   410   space.  If argument locked is non-zero, the space uses a separate
       
   411   lock to control access. The capacity of the space will grow
       
   412   dynamically as needed to service mspace_malloc requests.  You can
       
   413   control the sizes of incremental increases of this space by
       
   414   compiling with a different DEFAULT_GRANULARITY or dynamically
       
   415   setting with mallopt(M_GRANULARITY, value).
       
   416 */
       
   417 mspace create_mspace(size_t capacity, int locked);
       
   418 
       
   419 /*
       
   420   destroy_mspace destroys the given space, and attempts to return all
       
   421   of its memory back to the system, returning the total number of
       
   422   bytes freed. After destruction, the results of access to all memory
       
   423   used by the space become undefined.
       
   424 */
       
   425 size_t destroy_mspace(mspace msp);
       
   426 
       
   427 /*
       
   428   create_mspace_with_base uses the memory supplied as the initial base
       
   429   of a new mspace. Part (less than 128*sizeof(size_t) bytes) of this
       
   430   space is used for bookkeeping, so the capacity must be at least this
       
   431   large. (Otherwise 0 is returned.) When this initial space is
       
   432   exhausted, additional memory will be obtained from the system.
       
   433   Destroying this space will deallocate all additionally allocated
       
   434   space (if possible) but not the initial base.
       
   435 */
       
   436 mspace create_mspace_with_base(void* base, size_t capacity, int locked);
       
   437 
       
   438 /*
       
   439   mspace_malloc behaves as malloc, but operates within
       
   440   the given space.
       
   441 */
       
   442 void* mspace_malloc(mspace msp, size_t bytes);
       
   443 
       
   444 /*
       
   445   mspace_free behaves as free, but operates within
       
   446   the given space.
       
   447 
       
   448   If compiled with FOOTERS==1, mspace_free is not actually needed.
       
   449   free may be called instead of mspace_free because freed chunks from
       
   450   any space are handled by their originating spaces.
       
   451 */
       
   452 void mspace_free(mspace msp, void* mem);
       
   453 
       
   454 /*
       
   455   mspace_realloc behaves as realloc, but operates within
       
   456   the given space.
       
   457 
       
   458   If compiled with FOOTERS==1, mspace_realloc is not actually
       
   459   needed.  realloc may be called instead of mspace_realloc because
       
   460   realloced chunks from any space are handled by their originating
       
   461   spaces.
       
   462 */
       
   463 void* mspace_realloc(mspace msp, void* mem, size_t newsize);
       
   464 
       
   465 /*
       
   466   mspace_calloc behaves as calloc, but operates within
       
   467   the given space.
       
   468 */
       
   469 void* mspace_calloc(mspace msp, size_t n_elements, size_t elem_size);
       
   470 
       
   471 /*
       
   472   mspace_memalign behaves as memalign, but operates within
       
   473   the given space.
       
   474 */
       
   475 void* mspace_memalign(mspace msp, size_t alignment, size_t bytes);
       
   476 
       
   477 /*
       
   478   mspace_independent_calloc behaves as independent_calloc, but
       
   479   operates within the given space.
       
   480 */
       
   481 void** mspace_independent_calloc(mspace msp, size_t n_elements,
       
   482                                  size_t elem_size, void* chunks[]);
       
   483 
       
   484 /*
       
   485   mspace_independent_comalloc behaves as independent_comalloc, but
       
   486   operates within the given space.
       
   487 */
       
   488 void** mspace_independent_comalloc(mspace msp, size_t n_elements,
       
   489                                    size_t sizes[], void* chunks[]);
       
   490 
       
   491 /*
       
   492   mspace_footprint() returns the number of bytes obtained from the
       
   493   system for this space.
       
   494 */
       
   495 size_t mspace_footprint(mspace msp);
       
   496 
       
   497 
       
   498 #if !NO_MALLINFO
       
   499 /*
       
   500   mspace_mallinfo behaves as mallinfo, but reports properties of
       
   501   the given space.
       
   502 */
       
   503 struct mallinfo mspace_mallinfo(mspace msp);
       
   504 #endif /* NO_MALLINFO */
       
   505 
       
   506 /*
       
   507   mspace_malloc_stats behaves as malloc_stats, but reports
       
   508   properties of the given space.
       
   509 */
       
   510 void mspace_malloc_stats(mspace msp);
       
   511 
       
   512 /*
       
   513   mspace_trim behaves as malloc_trim, but
       
   514   operates within the given space.
       
   515 */
       
   516 int mspace_trim(mspace msp, size_t pad);
       
   517 
       
   518 /*
       
   519   An alias for malloc_usable_size.
       
   520 */
       
   521 size_t mspace_usable_size(void *mem);
       
   522 
       
   523 /*
       
   524   An alias for mallopt.
       
   525 */
       
   526 int mspace_mallopt(int, int);
       
   527 
       
   528 #endif  /* MSPACES */
       
   529 
       
   530 #ifdef __cplusplus
       
   531 };  /* end of extern "C" */
       
   532 #endif
       
   533 
       
   534 #endif /* MALLOC_280_H */