--- /dev/null
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is the Netscape Portable Runtime (NSPR).
+ *
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation. Portions created by Netscape are
+ * Copyright (C) 1998-2000 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the
+ * terms of the GNU General Public License Version 2 or later (the
+ * "GPL"), in which case the provisions of the GPL are applicable
+ * instead of those above. If you wish to allow use of your
+ * version of this file only under the terms of the GPL and not to
+ * allow others to use your version of this file under the MPL,
+ * indicate your decision by deleting the provisions above and
+ * replace them with the notice and other provisions required by
+ * the GPL. If you do not delete the provisions above, a recipient
+ * may use your version of this file under either the MPL or the
+ * GPL.
+ */
+
+#ifndef prcvar_h___
+#define prcvar_h___
+
+#include <security_asn1/prlock.h>
+#include <security_asn1/prinrval.h>
+
+PR_BEGIN_EXTERN_C
+
+typedef struct PRCondVar PRCondVar;
+
+/*
+** Create a new condition variable.
+**
+** "lock" is the lock used to protect the condition variable.
+**
+** Condition variables are synchronization objects that threads can use
+** to wait for some condition to occur.
+**
+** This may fail if memory is tight or if some operating system resource
+** is low. In such cases, a NULL will be returned.
+*/
+NSPR_API(PRCondVar*) PR_NewCondVar(PRLock *lock);
+
+/*
+** Destroy a condition variable. There must be no thread
+** waiting on the condvar. The caller is responsible for guaranteeing
+** that the condvar is no longer in use.
+**
+*/
+NSPR_API(void) PR_DestroyCondVar(PRCondVar *cvar);
+
+/*
+** The thread that waits on a condition is blocked in a "waiting on
+** condition" state until another thread notifies the condition or a
+** caller specified amount of time expires. The lock associated with
+** the condition variable will be released, which must have be held
+** prior to the call to wait.
+**
+** Logically a notified thread is moved from the "waiting on condition"
+** state and made "ready." When scheduled, it will attempt to reacquire
+** the lock that it held when wait was called.
+**
+** The timeout has two well known values, PR_INTERVAL_NO_TIMEOUT and
+** PR_INTERVAL_NO_WAIT. The former value requires that a condition be
+** notified (or the thread interrupted) before it will resume from the
+** wait. If the timeout has a value of PR_INTERVAL_NO_WAIT, the effect
+** is to release the lock, possibly causing a rescheduling within the
+** runtime, then immediately attempting to reacquire the lock and resume.
+**
+** Any other value for timeout will cause the thread to be rescheduled
+** either due to explicit notification or an expired interval. The latter
+** must be determined by treating time as one part of the monitored data
+** being protected by the lock and tested explicitly for an expired
+** interval.
+**
+** Returns PR_FAILURE if the caller has not locked the lock associated
+** with the condition variable or the thread was interrupted (PR_Interrupt()).
+** The particular reason can be extracted with PR_GetError().
+*/
+NSPR_API(PRStatus) PR_WaitCondVar(PRCondVar *cvar, PRIntervalTime timeout);
+
+/*
+** Notify ONE thread that is currently waiting on 'cvar'. Which thread is
+** dependent on the implementation of the runtime. Common sense would dictate
+** that all threads waiting on a single condition have identical semantics,
+** therefore which one gets notified is not significant.
+**
+** The calling thead must hold the lock that protects the condition, as
+** well as the invariants that are tightly bound to the condition, when
+** notify is called.
+**
+** Returns PR_FAILURE if the caller has not locked the lock associated
+** with the condition variable.
+*/
+NSPR_API(PRStatus) PR_NotifyCondVar(PRCondVar *cvar);
+
+/*
+** Notify all of the threads waiting on the condition variable. The order
+** that the threads are notified is indeterminant. The lock that protects
+** the condition must be held.
+**
+** Returns PR_FAILURE if the caller has not locked the lock associated
+** with the condition variable.
+*/
+NSPR_API(PRStatus) PR_NotifyAllCondVar(PRCondVar *cvar);
+
+PR_END_EXTERN_C
+
+#endif /* prcvar_h___ */
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