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 50PR_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 */ 65typedef void PRLock; 66#else 67typedef 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***********************************************************************/ 85NSPR_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***********************************************************************/ 96NSPR_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***********************************************************************/ 107NSPR_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***********************************************************************/ 119NSPR_API(PRStatus) PR_Unlock(PRLock *lock); 120 121PR_END_EXTERN_C 122 123#endif /* prlock_h___ */ 124