libpthread/nptl/sysdeps/riscv64/pthread_spin_trylock.c

   1 /* pthread_spin_trylock -- trylock a spin lock.  Generic version.
   2    Copyright (C) 2012-2016 Free Software Foundation, Inc.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <atomic.h>
  20 #include "pthreadP.h"
  21
  22 int
  23 pthread_spin_trylock (pthread_spinlock_t *lock)
  24 {
  25   return atomic_exchange_acq (lock, 1) ? EBUSY : 0;
  26 }