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 /* An object describing a memory allocator family.  */
  26
  27 struct allocator
  28 {
  29   /* Do not use GCC attributes such as __attribute__ ((malloc)) with
  30      the function types pointed at by these members, because these
  31      attributes do not work with pointers to functions.  See
  32      <https://lists.gnu.org/r/bug-gnulib/2011-04/msg00007.html>.  */
  33
  34   /* Call ALLOCATE to allocate memory, like 'malloc'.  On failure ALLOCATE
  35      should return NULL, though not necessarily set errno.  When given
  36      a zero size it may return NULL even if successful.  */
  37   void *(*allocate) (size_t);
  38
  39   /* If nonnull, call REALLOCATE to reallocate memory, like 'realloc'.
  40      On failure REALLOCATE should return NULL, though not necessarily set
  41      errno.  When given a zero size it may return NULL even if
  42      successful.  */
  43   void *(*reallocate) (void *, size_t);
  44
  45   /* Call FREE to free memory, like 'free'.  */
  46   void (*free) (void *);
  47
  48   /* If nonnull, call DIE (SIZE) if MALLOC (SIZE) or REALLOC (...,
  49      SIZE) fails.  DIE should not return.  SIZE should equal SIZE_MAX
  50      if size_t overflow was detected while calculating sizes to be
  51      passed to MALLOC or REALLOC.  */
  52   void (*die) (size_t);
  53 };
  54
  55 /* An allocator using the stdlib functions and a null DIE function.  */
  56 extern struct allocator const stdlib_allocator;
  57
  58 #endif /* _GL_ALLOCATOR_H */