mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-01 06:35:42 +00:00
124 lines
4.7 KiB
C
124 lines
4.7 KiB
C
/* -*- 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 "prlock.h"
|
|
#include "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___ */
|