prlock.h
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- /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
- /* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * 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 the Initial Developer are Copyright (C) 1998-2000
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
- /*
- ** File: prlock.h
- ** Description: API to basic locking functions of NSPR.
- **
- **
- ** NSPR provides basic locking mechanisms for thread synchronization. Locks
- ** are lightweight resource contention controls that prevent multiple threads
- ** from accessing something (code/data) simultaneously.
- **/
- #ifndef prlock_h___
- #define prlock_h___
- #include "prtypes.h"
- PR_BEGIN_EXTERN_C
- /**********************************************************************/
- /************************* TYPES AND CONSTANTS ************************/
- /**********************************************************************/
- /*
- * PRLock --
- *
- * NSPR represents the lock as an opaque entity to the client of the
- * API. All routines operate on a pointer to this opaque entity.
- */
- typedef struct PRLock PRLock;
- /**********************************************************************/
- /****************************** FUNCTIONS *****************************/
- /**********************************************************************/
- /***********************************************************************
- ** FUNCTION: PR_NewLock
- ** DESCRIPTION:
- ** Returns a pointer to a newly created opaque lock object.
- ** INPUTS: void
- ** OUTPUTS: void
- ** RETURN: PRLock*
- ** If the lock can not be created because of resource constraints, NULL
- ** is returned.
- **
- ***********************************************************************/
- NSPR_API(PRLock*) PR_NewLock(void);
- /***********************************************************************
- ** FUNCTION: PR_DestroyLock
- ** DESCRIPTION:
- ** Destroys a given opaque lock object.
- ** INPUTS: PRLock *lock
- ** Lock to be freed.
- ** OUTPUTS: void
- ** RETURN: None
- ***********************************************************************/
- NSPR_API(void) PR_DestroyLock(PRLock *lock);
- /***********************************************************************
- ** FUNCTION: PR_Lock
- ** DESCRIPTION:
- ** Lock a lock.
- ** INPUTS: PRLock *lock
- ** Lock to locked.
- ** OUTPUTS: void
- ** RETURN: None
- ***********************************************************************/
- NSPR_API(void) PR_Lock(PRLock *lock);
- /***********************************************************************
- ** FUNCTION: PR_Unlock
- ** DESCRIPTION:
- ** Unlock a lock. Unlocking an unlocked lock has undefined results.
- ** INPUTS: PRLock *lock
- ** Lock to unlocked.
- ** OUTPUTS: void
- ** RETURN: PR_STATUS
- ** Returns PR_FAILURE if the caller does not own the lock.
- ***********************************************************************/
- NSPR_API(PRStatus) PR_Unlock(PRLock *lock);
- PR_END_EXTERN_C
- #endif /* prlock_h___ */