ports/sysdeps/hppa/nptl/pthread_spin_trylock.c

   1 /* Copyright (C) 2005 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   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 #if 0
  26   volatile unsigned int *a = __ldcw_align (lock);
  27
  28   return __ldcw (a) ? 0 : EBUSY;
  29 #endif
  30
  31   return atomic_compare_and_exchange_val_acq(lock, 1, 0) ? EBUSY : 0;
  32
  33 }