nptl/sysdeps/sh/pthread_spin_lock.c

   1 /* Copyright (C) 2003 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include "pthreadP.h"
  20
  21 int
  22 pthread_spin_lock (lock)
  23      pthread_spinlock_t *lock;
  24 {
  25   unsigned int val;
  26
  27   do
  28     asm volatile ("tas.b @%1; movt %0"
  29                   : "=&r" (val)
  30                   : "r" (lock)
  31                   : "memory");
  32   while (val == 0);
  33
  34   return 0;
  35 }