nptl/sysdeps/unix/sysv/linux/rtld-lowlevel.h

   1 /* Defintions for lowlevel handling in ld.so.
   2    Copyright (C) 2006-2013 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _RTLD_LOWLEVEL_H
  20 #define  _RTLD_LOWLEVEL_H 1
  21
  22 #include <atomic.h>
  23 #include <lowlevellock.h>
  24
  25
  26 /* Function to wait for variable become zero.  Used in ld.so for
  27    reference counters.  */
  28 #define __rtld_waitzero(word) \
  29   do {                                                                        \
  30     while (1)                                                                 \
  31       {                                                                       \
  32         int val = word;                                                       \
  33         if (val == 0)                                                         \
  34           break;                                                              \
  35         lll_futex_wait (&(word), val, LLL_PRIVATE);                           \
  36       }                                                                       \
  37   } while (0)
  38
  39
  40 #define __rtld_notify(word) \
  41   lll_futex_wake (&(word), 1, LLL_PRIVATE)
  42
  43 #endif