malloc/set-freeres.c

   1 /* Copyright (C) 1997-2019 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <atomic.h>
  19 #include <stdlib.h>
  20 #include <set-hooks.h>
  21 #include <libc-internal.h>
  22
  23 #include "../libio/libioP.h"
  24
  25 DEFINE_HOOK (__libc_subfreeres, (void));
  26
  27 symbol_set_define (__libc_freeres_ptrs);
  28
  29 extern __attribute__ ((weak)) void __libdl_freeres (void);
  30
  31 extern __attribute__ ((weak)) void __libpthread_freeres (void);
  32
  33 void __libc_freeres_fn_section
  34 __libc_freeres (void)
  35 {
  36   /* This function might be called from different places.  So better
  37      protect for multiple executions since these are fatal.  */
  38   static long int already_called;
  39
  40   if (!atomic_compare_and_exchange_bool_acq (&already_called, 1, 0))
  41     {
  42       void *const *p;
  43
  44       _IO_cleanup ();
  45
  46       /* We run the resource freeing after IO cleanup.  */
  47       RUN_HOOK (__libc_subfreeres, ());
  48
  49       /* Call the libdl list of cleanup functions
  50          (weak-ref-and-check).  */
  51       if (&__libdl_freeres != NULL)
  52         __libdl_freeres ();
  53
  54       /* Call the libpthread list of cleanup functions
  55          (weak-ref-and-check).  */
  56       if (&__libpthread_freeres != NULL)
  57         __libpthread_freeres ();
  58
  59       for (p = symbol_set_first_element (__libc_freeres_ptrs);
  60            !symbol_set_end_p (__libc_freeres_ptrs, p); ++p)
  61         free (*p);
  62     }
  63 }
  64 libc_hidden_def (__libc_freeres)