| /* -*- 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. |
| */ |
| |
| /* |
| ** 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___ */ |