nsprpub/pr/include/prmem.h

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  37
  38 /*
  39 ** File: prmem.h
  40 ** Description: API to NSPR memory management functions
  41 **
  42 */
  43 #ifndef prmem_h___
  44 #define prmem_h___
  45
  46 #include "prtypes.h"
  47 #include <stdlib.h>
  48
  49 PR_BEGIN_EXTERN_C
  50
  51 /*
  52 ** Thread safe memory allocation.
  53 **
  54 ** NOTE: pr wraps up malloc, free, calloc, realloc so they are already
  55 ** thread safe (and are not declared here - look in stdlib.h).
  56 */
  57
  58 /*
  59 ** PR_Malloc, PR_Calloc, PR_Realloc, and PR_Free have the same signatures
  60 ** as their libc equivalent malloc, calloc, realloc, and free, and have
  61 ** the same semantics.  (Note that the argument type size_t is replaced
  62 ** by PRUint32.)  Memory allocated by PR_Malloc, PR_Calloc, or PR_Realloc
  63 ** must be freed by PR_Free.
  64 */
  65
  66 NSPR_API(void *) PR_Malloc(PRUint32 size);
  67
  68 NSPR_API(void *) PR_Calloc(PRUint32 nelem, PRUint32 elsize);
  69
  70 NSPR_API(void *) PR_Realloc(void *ptr, PRUint32 size);
  71
  72 NSPR_API(void) PR_Free(void *ptr);
  73
  74 /*
  75 ** The following are some convenience macros defined in terms of
  76 ** PR_Malloc, PR_Calloc, PR_Realloc, and PR_Free.
  77 */
  78
  79 /***********************************************************************
  80 ** FUNCTION:    PR_MALLOC()
  81 ** DESCRIPTION:
  82 **   PR_NEW() allocates an untyped item of size _size from the heap.
  83 ** INPUTS:  _size: size in bytes of item to be allocated
  84 ** OUTPUTS:     untyped pointer to the node allocated
  85 ** RETURN:      pointer to node or error returned from malloc().
  86 ***********************************************************************/
  87 #define PR_MALLOC(_bytes) (PR_Malloc((_bytes)))
  88
  89 /***********************************************************************
  90 ** FUNCTION:    PR_NEW()
  91 ** DESCRIPTION:
  92 **   PR_NEW() allocates an item of type _struct from the heap.
  93 ** INPUTS:  _struct: a data type
  94 ** OUTPUTS:     pointer to _struct
  95 ** RETURN:      pointer to _struct or error returns from malloc().
  96 ***********************************************************************/
  97 #define PR_NEW(_struct) ((_struct *) PR_MALLOC(sizeof(_struct)))
  98
  99 /***********************************************************************
 100 ** FUNCTION:    PR_REALLOC()
 101 ** DESCRIPTION:
 102 **   PR_REALLOC() re-allocates _ptr bytes from the heap as a _size
 103 **   untyped item.
 104 ** INPUTS:      _ptr: pointer to node to reallocate
 105 **          _size: size of node to allocate
 106 ** OUTPUTS:     pointer to node allocated
 107 ** RETURN:      pointer to node allocated
 108 ***********************************************************************/
 109 #define PR_REALLOC(_ptr, _size) (PR_Realloc((_ptr), (_size)))
 110
 111 /***********************************************************************
 112 ** FUNCTION:    PR_CALLOC()
 113 ** DESCRIPTION:
 114 **   PR_CALLOC() allocates a _size bytes untyped item from the heap
 115 **   and sets the allocated memory to all 0x00.
 116 ** INPUTS:      _size: size of node to allocate
 117 ** OUTPUTS:     pointer to node allocated
 118 ** RETURN:      pointer to node allocated
 119 ***********************************************************************/
 120 #define PR_CALLOC(_size) (PR_Calloc(1, (_size)))
 121
 122 /***********************************************************************
 123 ** FUNCTION:    PR_NEWZAP()
 124 ** DESCRIPTION:
 125 **   PR_NEWZAP() allocates an item of type _struct from the heap
 126 **   and sets the allocated memory to all 0x00.
 127 ** INPUTS:      _struct: a data type
 128 ** OUTPUTS:     pointer to _struct
 129 ** RETURN:      pointer to _struct
 130 ***********************************************************************/
 131 #define PR_NEWZAP(_struct) ((_struct*)PR_Calloc(1, sizeof(_struct)))
 132
 133 /***********************************************************************
 134 ** FUNCTION:    PR_DELETE()
 135 ** DESCRIPTION:
 136 **   PR_DELETE() unallocates an object previosly allocated via PR_NEW()
 137 **   or PR_NEWZAP() to the heap.
 138 ** INPUTS:      pointer to previously allocated object
 139 ** OUTPUTS:     the referenced object is returned to the heap
 140 ** RETURN:      void
 141 ***********************************************************************/
 142 #define PR_DELETE(_ptr) { PR_Free(_ptr); (_ptr) = NULL; }
 143
 144 /***********************************************************************
 145 ** FUNCTION:    PR_FREEIF()
 146 ** DESCRIPTION:
 147 **   PR_FREEIF() conditionally unallocates an object previously allocated
 148 **   vial PR_NEW() or PR_NEWZAP(). If the pointer to the object is
 149 **   equal to zero (0), the object is not released.
 150 ** INPUTS:      pointer to previously allocated object
 151 ** OUTPUTS:     the referenced object is conditionally returned to the heap
 152 ** RETURN:      void
 153 ***********************************************************************/
 154 #define PR_FREEIF(_ptr) if (_ptr) PR_DELETE(_ptr)
 155
 156 PR_END_EXTERN_C
 157
 158 #endif /* prmem_h___ */