about summary refs log tree commit diff
path: root/nptl/pthread_cond_wait.c
diff options
context:
space:
mode:
Diffstat (limited to 'nptl/pthread_cond_wait.c')
-rw-r--r--nptl/pthread_cond_wait.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/nptl/pthread_cond_wait.c b/nptl/pthread_cond_wait.c
new file mode 100644
index 0000000000..37c5ffe846
--- /dev/null
+++ b/nptl/pthread_cond_wait.c
@@ -0,0 +1,66 @@
+/* Copyright (C) 2002 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include "pthreadP.h"
+#include <lowlevellock.h>
+
+
+int
+pthread_cond_wait (cond, mutex)
+     pthread_cond_t *cond;
+     pthread_mutex_t *mutex;
+{
+  int err;
+
+  /* This function is a cancellation point.  Test before we potentially
+     go to sleep.  */
+  CANCELLATION_P (THREAD_SELF);
+
+  /* Make sure the condition is modified atomically.  */
+  lll_mutex_lock (cond->__data.__lock);
+
+  /* Release the mutex.  This might fail.  */
+  err = pthread_mutex_unlock (mutex);
+  if (__builtin_expect (err != 0, 0))
+    {
+      lll_mutex_unlock (cond->__data.__lock);
+      return err;
+    }
+
+  /* One more tread waiting.  */
+  ++cond->__data.__nr_sleepers;
+
+  /* The actual conditional variable implementation.  */
+  lll_cond_wait (cond);
+
+  if (--cond->__data.__nr_sleepers == 0)
+    /* Forget about the current wakeups now that they are done.  */
+    cond->__data.__nr_wakers = 0;
+
+  /* Lose the condvar lock.  */
+  lll_mutex_unlock (cond->__data.__lock);
+
+  /* We have to get the mutex before returning.  */
+  err = pthread_mutex_lock (mutex);
+
+  /* Cancellation handling.  */
+  CANCELLATION_P (THREAD_SELF);
+
+  return err;
+}