linuxthreads/spinlock.h

   1 /* Linuxthreads - a simple clone()-based implementation of Posix        */
   2 /* threads for Linux.                                                   */
   3 /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) and          */
   4 /* Richard Henderson (rth@tamu.edu)                                     */
   5 /*                                                                      */
   6 /* This program is free software; you can redistribute it and/or        */
   7 /* modify it under the terms of the GNU Library General Public License  */
   8 /* as published by the Free Software Foundation; either version 2       */
   9 /* of the License, or (at your option) any later version.               */
  10 /*                                                                      */
  11 /* This program is distributed in the hope that it will be useful,      */
  12 /* but WITHOUT ANY WARRANTY; without even the implied warranty of       */
  13 /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        */
  14 /* GNU Library General Public License for more details.                 */
  15
  16 /* Spin locks */
  17
  18 extern void __pthread_acquire(int * spinlock);
  19
  20 static inline void acquire(int * spinlock)
  21 {
  22   if (testandset(spinlock)) __pthread_acquire(spinlock);
  23 }
  24
  25 static inline void release(int * spinlock)
  26 {
  27 #ifndef RELEASE
  28   *spinlock = 0;
  29 #else
  30   RELEASE(spinlock);
  31 #endif
  32 }