third_party/npapi/npspy/extern/nspr/prrwlock.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /*
   3  * The contents of this file are subject to the Mozilla Public
   4  * License Version 1.1 (the "License"); you may not use this file
   5  * except in compliance with the License. You may obtain a copy of
   6  * the License at http://www.mozilla.org/MPL/
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   9  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
  10  * implied. See the License for the specific language governing
  11  * rights and limitations under the License.
  12  *
  13  * The Original Code is the Netscape Portable Runtime (NSPR).
  14  *
  15  * The Initial Developer of the Original Code is Netscape
  16  * Communications Corporation.  Portions created by Netscape are
  17  * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
  18  * Rights Reserved.
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  22  * Alternatively, the contents of this file may be used under the
  23  * terms of the GNU General Public License Version 2 or later (the
  24  * "GPL"), in which case the provisions of the GPL are applicable
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  26  * version of this file only under the terms of the GPL and not to
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  31  * may use your version of this file under either the MPL or the
  32  * GPL.
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  34
  35 /*
  36 ** File:                prrwlock.h
  37 ** Description: API to basic reader-writer lock functions of NSPR.
  38 **
  39 **/
  40
  41 #ifndef prrwlock_h___
  42 #define prrwlock_h___
  43
  44 #include "prtypes.h"
  45
  46 PR_BEGIN_EXTERN_C
  47
  48 /*
  49  * PRRWLock --
  50  *
  51  *      The reader writer lock, PRRWLock, is an opaque object to the clients
  52  *      of NSPR.  All routines operate on a pointer to this opaque entity.
  53  */
  54
  55
  56 typedef struct PRRWLock PRRWLock;
  57
  58 #define PR_RWLOCK_RANK_NONE     0
  59
  60
  61 /***********************************************************************
  62 ** FUNCTION:    PR_NewRWLock
  63 ** DESCRIPTION:
  64 **  Returns a pointer to a newly created reader-writer lock object.
  65 ** INPUTS:      Lock rank
  66 **                              Lock name
  67 ** OUTPUTS:     void
  68 ** RETURN:      PRRWLock*
  69 **   If the lock cannot be created because of resource constraints, NULL
  70 **   is returned.
  71 **
  72 ***********************************************************************/
  73 NSPR_API(PRRWLock*) PR_NewRWLock(PRUint32 lock_rank, const char *lock_name);
  74
  75 /***********************************************************************
  76 ** FUNCTION:    PR_DestroyRWLock
  77 ** DESCRIPTION:
  78 **  Destroys a given RW lock object.
  79 ** INPUTS:      PRRWLock *lock - Lock to be freed.
  80 ** OUTPUTS:     void
  81 ** RETURN:      None
  82 ***********************************************************************/
  83 NSPR_API(void) PR_DestroyRWLock(PRRWLock *lock);
  84
  85 /***********************************************************************
  86 ** FUNCTION:    PR_RWLock_Rlock
  87 ** DESCRIPTION:
  88 **  Apply a read lock (non-exclusive) on a RWLock
  89 ** INPUTS:      PRRWLock *lock - Lock to be read-locked.
  90 ** OUTPUTS:     void
  91 ** RETURN:      None
  92 ***********************************************************************/
  93 NSPR_API(void) PR_RWLock_Rlock(PRRWLock *lock);
  94
  95 /***********************************************************************
  96 ** FUNCTION:    PR_RWLock_Wlock
  97 ** DESCRIPTION:
  98 **  Apply a write lock (exclusive) on a RWLock
  99 ** INPUTS:      PRRWLock *lock - Lock to write-locked.
 100 ** OUTPUTS:     void
 101 ** RETURN:      None
 102 ***********************************************************************/
 103 NSPR_API(void) PR_RWLock_Wlock(PRRWLock *lock);
 104
 105 /***********************************************************************
 106 ** FUNCTION:    PR_RWLock_Unlock
 107 ** DESCRIPTION:
 108 **  Release a RW lock. Unlocking an unlocked lock has undefined results.
 109 ** INPUTS:      PRRWLock *lock - Lock to unlocked.
 110 ** OUTPUTS:     void
 111 ** RETURN:      void
 112 ***********************************************************************/
 113 NSPR_API(void) PR_RWLock_Unlock(PRRWLock *lock);
 114
 115 PR_END_EXTERN_C
 116
 117 #endif /* prrwlock_h___ */