/* Signal a condition. Generic version. Copyright (C) 2000 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include #include static int cond_signal (struct __pthread_cond *cond, int *unblocked) { struct __pthread *wakeup; __pthread_spin_lock (&cond->__lock); wakeup = cond->__queue; if (wakeup) __pthread_dequeue (wakeup); __pthread_spin_unlock (&cond->__lock); if (wakeup) { /* We found a thread waiting for the condition to be signalled. Wake it up! */ __pthread_wakeup (wakeup); *unblocked = 1; } return 0; } /* Unblock at least one of the threads that are blocked on condition variable COND. */ int pthread_cond_signal (pthread_cond_t *cond) { int unblocked = 0; return cond_signal (cond, &unblocked); }