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       1             : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* This Source Code Form is subject to the terms of the Mozilla Public
       3             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       4             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       5             : 
       6             : /*
       7             : ** File:                prrwlock.h
       8             : ** Description: API to basic reader-writer lock functions of NSPR.
       9             : **
      10             : **/
      11             : 
      12             : #ifndef prrwlock_h___
      13             : #define prrwlock_h___
      14             : 
      15             : #include "prtypes.h"
      16             : 
      17             : PR_BEGIN_EXTERN_C
      18             : 
      19             : /*
      20             :  * PRRWLock --
      21             :  *
      22             :  *      The reader writer lock, PRRWLock, is an opaque object to the clients
      23             :  *      of NSPR.  All routines operate on a pointer to this opaque entity.
      24             :  */
      25             : 
      26             : 
      27             : typedef struct PRRWLock PRRWLock;
      28             : 
      29             : #define PR_RWLOCK_RANK_NONE     0
      30             : 
      31             : 
      32             : /***********************************************************************
      33             : ** FUNCTION:    PR_NewRWLock
      34             : ** DESCRIPTION:
      35             : **  Returns a pointer to a newly created reader-writer lock object.
      36             : ** INPUTS:      Lock rank
      37             : **                              Lock name
      38             : ** OUTPUTS:     void
      39             : ** RETURN:      PRRWLock*
      40             : **   If the lock cannot be created because of resource constraints, NULL
      41             : **   is returned.
      42             : **  
      43             : ***********************************************************************/
      44           0 : NSPR_API(PRRWLock*) PR_NewRWLock(PRUint32 lock_rank, const char *lock_name);
      45             : 
      46             : /***********************************************************************
      47             : ** FUNCTION:    PR_DestroyRWLock
      48             : ** DESCRIPTION:
      49             : **  Destroys a given RW lock object.
      50             : ** INPUTS:      PRRWLock *lock - Lock to be freed.
      51             : ** OUTPUTS:     void
      52             : ** RETURN:      None
      53             : ***********************************************************************/
      54           0 : NSPR_API(void) PR_DestroyRWLock(PRRWLock *lock);
      55             : 
      56             : /***********************************************************************
      57             : ** FUNCTION:    PR_RWLock_Rlock
      58             : ** DESCRIPTION:
      59             : **  Apply a read lock (non-exclusive) on a RWLock
      60             : ** INPUTS:      PRRWLock *lock - Lock to be read-locked.
      61             : ** OUTPUTS:     void
      62             : ** RETURN:      None
      63             : ***********************************************************************/
      64           0 : NSPR_API(void) PR_RWLock_Rlock(PRRWLock *lock);
      65             : 
      66             : /***********************************************************************
      67             : ** FUNCTION:    PR_RWLock_Wlock
      68             : ** DESCRIPTION:
      69             : **  Apply a write lock (exclusive) on a RWLock
      70             : ** INPUTS:      PRRWLock *lock - Lock to write-locked.
      71             : ** OUTPUTS:     void
      72             : ** RETURN:      None
      73             : ***********************************************************************/
      74           0 : NSPR_API(void) PR_RWLock_Wlock(PRRWLock *lock);
      75             : 
      76             : /***********************************************************************
      77             : ** FUNCTION:    PR_RWLock_Unlock
      78             : ** DESCRIPTION:
      79             : **  Release a RW lock. Unlocking an unlocked lock has undefined results.
      80             : ** INPUTS:      PRRWLock *lock - Lock to unlocked.
      81             : ** OUTPUTS:     void
      82             : ** RETURN:      void
      83             : ***********************************************************************/
      84           0 : NSPR_API(void) PR_RWLock_Unlock(PRRWLock *lock);
      85             : 
      86             : PR_END_EXTERN_C
      87             : 
      88             : #endif /* prrwlock_h___ */