libpthread/nptl/sysdeps/sparc/sparc64/pthread_spin_trylock.c

   1 /* Copyright (C) 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
   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 "pthreadP.h"
  21
  22 int
  23 pthread_spin_trylock (pthread_spinlock_t *lock)
  24 {
  25   int res;
  26   __asm__ __volatile__
  27     ("ldstub [%1], %0\n"
  28      "membar #StoreLoad | #StoreStore"
  29      : "=r" (res)
  30      : "r" (lock)
  31      : "memory");
  32   return res == 0 ? 0 : EBUSY;
  33 }