| /* -*- 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: prrwlock.h |
| ** Description: API to basic reader-writer lock functions of NSPR. |
| ** |
| **/ |
| |
| #ifndef prrwlock_h___ |
| #define prrwlock_h___ |
| |
| #include "prtypes.h" |
| |
| PR_BEGIN_EXTERN_C |
| |
| /* |
| * PRRWLock -- |
| * |
| * The reader writer lock, PRRWLock, is an opaque object to the clients |
| * of NSPR. All routines operate on a pointer to this opaque entity. |
| */ |
| |
| |
| typedef struct PRRWLock PRRWLock; |
| |
| #define PR_RWLOCK_RANK_NONE 0 |
| |
| |
| /*********************************************************************** |
| ** FUNCTION: PR_NewRWLock |
| ** DESCRIPTION: |
| ** Returns a pointer to a newly created reader-writer lock object. |
| ** INPUTS: Lock rank |
| ** Lock name |
| ** OUTPUTS: void |
| ** RETURN: PRRWLock* |
| ** If the lock cannot be created because of resource constraints, NULL |
| ** is returned. |
| ** |
| ***********************************************************************/ |
| NSPR_API(PRRWLock*) PR_NewRWLock(PRUint32 lock_rank, const char *lock_name); |
| |
| /*********************************************************************** |
| ** FUNCTION: PR_DestroyRWLock |
| ** DESCRIPTION: |
| ** Destroys a given RW lock object. |
| ** INPUTS: PRRWLock *lock - Lock to be freed. |
| ** OUTPUTS: void |
| ** RETURN: None |
| ***********************************************************************/ |
| NSPR_API(void) PR_DestroyRWLock(PRRWLock *lock); |
| |
| /*********************************************************************** |
| ** FUNCTION: PR_RWLock_Rlock |
| ** DESCRIPTION: |
| ** Apply a read lock (non-exclusive) on a RWLock |
| ** INPUTS: PRRWLock *lock - Lock to be read-locked. |
| ** OUTPUTS: void |
| ** RETURN: None |
| ***********************************************************************/ |
| NSPR_API(void) PR_RWLock_Rlock(PRRWLock *lock); |
| |
| /*********************************************************************** |
| ** FUNCTION: PR_RWLock_Wlock |
| ** DESCRIPTION: |
| ** Apply a write lock (exclusive) on a RWLock |
| ** INPUTS: PRRWLock *lock - Lock to write-locked. |
| ** OUTPUTS: void |
| ** RETURN: None |
| ***********************************************************************/ |
| NSPR_API(void) PR_RWLock_Wlock(PRRWLock *lock); |
| |
| /*********************************************************************** |
| ** FUNCTION: PR_RWLock_Unlock |
| ** DESCRIPTION: |
| ** Release a RW lock. Unlocking an unlocked lock has undefined results. |
| ** INPUTS: PRRWLock *lock - Lock to unlocked. |
| ** OUTPUTS: void |
| ** RETURN: void |
| ***********************************************************************/ |
| NSPR_API(void) PR_RWLock_Unlock(PRRWLock *lock); |
| |
| PR_END_EXTERN_C |
| |
| #endif /* prrwlock_h___ */ |