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

   1 /* Defintions for lowlevel handling in ld.so.
   2    Copyright (C) 2006, 2007 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _RTLD_LOWLEVEL_H
  21 #define  _RTLD_LOWLEVEL_H 1
  22
  23 #include <atomic.h>
  24 #include <lowlevellock.h>
  25
  26
  27 /* Function to wait for variable become zero.  Used in ld.so for
  28    reference counters.  */
  29 #define __rtld_waitzero(word) \
  30   do {                                                                        \
  31     while (1)                                                                 \
  32       {                                                                       \
  33         int val = word;                                                       \
  34         if (val == 0)                                                         \
  35           break;                                                              \
  36         lll_futex_wait (&(word), val, LLL_PRIVATE);                           \
  37       }                                                                       \
  38   } while (0)
  39
  40
  41 #define __rtld_notify(word) \
  42   lll_futex_wake (&(word), 1, LLL_PRIVATE)
  43
  44 #endif