OSX/libsecurity_asn1/security_asn1/prlock.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/
   7  *
   8  * Software distributed under the License is distributed on an "AS
   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.
  19  *
  20  * Contributor(s):
  21  *
  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
  25  * instead of those above.  If you wish to allow use of your
  26  * version of this file only under the terms of the GPL and not to
  27  * allow others to use your version of this file under the MPL,
  28  * indicate your decision by deleting the provisions above and
  29  * replace them with the notice and other provisions required by
  30  * the GPL.  If you do not delete the provisions above, a recipient
  31  * may use your version of this file under either the MPL or the
  32  * GPL.
  33  */
  34
  35 /*
  36 ** File:                prlock.h
  37 ** Description: API to basic locking functions of NSPR.
  38 **
  39 **
  40 ** NSPR provides basic locking mechanisms for thread synchronization.  Locks
  41 ** are lightweight resource contention controls that prevent multiple threads
  42 ** from accessing something (code/data) simultaneously.
  43 **/
  44
  45 #ifndef prlock_h___
  46 #define prlock_h___
  47
  48 #include <security_asn1/prtypes.h>
  49
  50 PR_BEGIN_EXTERN_C
  51
  52 /**********************************************************************/
  53 /************************* TYPES AND CONSTANTS ************************/
  54 /**********************************************************************/
  55
  56 /*
  57  * PRLock --
  58  *
  59  *     NSPR represents the lock as an opaque entity to the client of the
  60  *         API.  All routines operate on a pointer to this opaque entity.
  61  */
  62
  63 #if defined(__APPLE_) & defined(__GNUC__)
  64 /* dmitch - actually a pthread_mutex_t */
  65 typedef void PRLock;
  66 #else
  67 typedef struct PRLock PRLock;
  68 #endif
  69
  70 /**********************************************************************/
  71 /****************************** FUNCTIONS *****************************/
  72 /**********************************************************************/
  73
  74 /***********************************************************************
  75 ** FUNCTION:    PR_NewLock
  76 ** DESCRIPTION:
  77 **  Returns a pointer to a newly created opaque lock object.
  78 ** INPUTS:      void
  79 ** OUTPUTS:     void
  80 ** RETURN:      PRLock*
  81 **   If the lock can not be created because of resource constraints, NULL
  82 **   is returned.
  83 **
  84 ***********************************************************************/
  85 NSPR_API(PRLock*) PR_NewLock(void);
  86
  87 /***********************************************************************
  88 ** FUNCTION:    PR_DestroyLock
  89 ** DESCRIPTION:
  90 **  Destroys a given opaque lock object.
  91 ** INPUTS:      PRLock *lock
  92 **              Lock to be freed.
  93 ** OUTPUTS:     void
  94 ** RETURN:      None
  95 ***********************************************************************/
  96 NSPR_API(void) PR_DestroyLock(PRLock *lock);
  97
  98 /***********************************************************************
  99 ** FUNCTION:    PR_Lock
 100 ** DESCRIPTION:
 101 **  Lock a lock.
 102 ** INPUTS:      PRLock *lock
 103 **              Lock to locked.
 104 ** OUTPUTS:     void
 105 ** RETURN:      None
 106 ***********************************************************************/
 107 NSPR_API(void) PR_Lock(PRLock *lock);
 108
 109 /***********************************************************************
 110 ** FUNCTION:    PR_Unlock
 111 ** DESCRIPTION:
 112 **  Unlock a lock.  Unlocking an unlocked lock has undefined results.
 113 ** INPUTS:      PRLock *lock
 114 **              Lock to unlocked.
 115 ** OUTPUTS:     void
 116 ** RETURN:      PR_STATUS
 117 **              Returns PR_FAILURE if the caller does not own the lock.
 118 ***********************************************************************/
 119 NSPR_API(PRStatus) PR_Unlock(PRLock *lock);
 120
 121 PR_END_EXTERN_C
 122
 123 #endif /* prlock_h___ */