lib/allocator.h

   1 /* Memory allocators such as malloc+free.
   2
   3    Copyright (C) 2011-2024 Free Software Foundation, Inc.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Written by Paul Eggert.  */
  19
  20 #ifndef _GL_ALLOCATOR_H
  21 #define _GL_ALLOCATOR_H
  22
  23 #include <stddef.h>
  24
  25 #ifdef __cplusplus
  26 extern "C" {
  27 #endif
  28
  29
  30 /* An object describing a memory allocator family.  */
  31
  32 struct allocator
  33 {
  34   /* Do not use GCC attributes such as __attribute__ ((malloc)) with
  35      the function types pointed at by these members, because these
  36      attributes do not work with pointers to functions.  See
  37      <https://lists.gnu.org/r/bug-gnulib/2011-04/msg00007.html>.  */
  38
  39   /* Call ALLOCATE to allocate memory, like 'malloc'.  On failure ALLOCATE
  40      should return NULL, though not necessarily set errno.  When given
  41      a zero size it may return NULL even if successful.  */
  42   void *(*allocate) (size_t);
  43
  44   /* If nonnull, call REALLOCATE to reallocate memory, like 'realloc'.
  45      On failure REALLOCATE should return NULL, though not necessarily set
  46      errno.  When given a zero size it may return NULL even if
  47      successful.  */
  48   void *(*reallocate) (void *, size_t);
  49
  50   /* Call FREE to free memory, like 'free'.  */
  51   void (*free) (void *);
  52
  53   /* If nonnull, call DIE (SIZE) if MALLOC (SIZE) or REALLOC (...,
  54      SIZE) fails.  DIE should not return.  SIZE should equal SIZE_MAX
  55      if size_t overflow was detected while calculating sizes to be
  56      passed to MALLOC or REALLOC.  */
  57   void (*die) (size_t);
  58 };
  59
  60 /* An allocator using the stdlib functions and a null DIE function.  */
  61 extern struct allocator const stdlib_allocator;
  62
  63
  64 #ifdef __cplusplus
  65 }
  66 #endif
  67
  68 #endif /* _GL_ALLOCATOR_H */