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-rw-r--r--libpthread/sysdeps/generic/pt-cond-signal.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/libpthread/sysdeps/generic/pt-cond-signal.c b/libpthread/sysdeps/generic/pt-cond-signal.c
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+++ b/libpthread/sysdeps/generic/pt-cond-signal.c
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+/* 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 <pthread.h>
+
+#include <pt-internal.h>
+
+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);
+}