sysdeps/nacl/lowlevellock.h

   1 /* Low-level lock implementation.  NaCl version.
   2    Copyright (C) 2015 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 _LOWLEVELLOCK_H
  20
  21 /* Everything except the exit handling is the same as the generic code.  */
  22 # include <sysdeps/nptl/lowlevellock.h>
  23
  24 /* See exit-thread.h for details.  */
  25 # define NACL_EXITING_TID       1
  26
  27 # undef lll_wait_tid
  28 # define lll_wait_tid(tid)                              \
  29   do {                                                  \
  30     __typeof (tid) __tid;                               \
  31     volatile __typeof (tid) *__tidp = &(tid);           \
  32     while ((__tid = atomic_load_relaxed (__tidp)) != 0) \
  33       {                                                 \
  34         if (__tid == NACL_EXITING_TID)                  \
  35           atomic_spin_nop ();                           \
  36         else                                            \
  37           lll_futex_wait (__tidp, __tid, LLL_PRIVATE);  \
  38       }                                                 \
  39   } while (0)
  40
  41 #endif  /* lowlevellock.h */