ports/sysdeps/tile/nptl/pthread_spin_unlock.c

   1 /* pthread_spin_unlock -- unlock a spin lock.  Tile version.
   2    Copyright (C) 2012-2014 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 #include "pthreadP.h"
  20 #include <atomic.h>
  21
  22 int
  23 pthread_spin_unlock (pthread_spinlock_t *lock)
  24 {
  25 #ifdef __tilegx__
  26   /* Use exchange() to bypass the write buffer. */
  27   atomic_exchange_rel (lock, 0);
  28 #else
  29   atomic_full_barrier ();
  30   *lock = 0;
  31 #endif
  32   return 0;
  33 }