libraries/source/spidermonkey/include-win32-release/nspr/prrwlock.h

   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 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 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 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 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 NSPR_API(void) PR_RWLock_Unlock(PRRWLock *lock);
  85
  86 PR_END_EXTERN_C
  87
  88 #endif /* prrwlock_h___ */