nptl/pthread_spin_trylock.c

   1 /* pthread_spin_trylock -- trylock a spin lock.  Generic version.
   2    Copyright (C) 2012-2016 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 <errno.h>
  20 #include <atomic.h>
  21 #include "pthreadP.h"
  22
  23 int
  24 pthread_spin_trylock (pthread_spinlock_t *lock)
  25 {
  26   return atomic_exchange_acq (lock, 1) ? EBUSY : 0;
  27 }