1/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*- 2 * 3 * Copyright (c) 2004-2012 Apple Inc. All rights reserved. 4 * 5 * @APPLE_LICENSE_HEADER_START@ 6 * 7 * This file contains Original Code and/or Modifications of Original Code 8 * as defined in and that are subject to the Apple Public Source License 9 * Version 2.0 (the 'License'). You may not use this file except in 10 * compliance with the License. Please obtain a copy of the License at 11 * http://www.opensource.apple.com/apsl/ and read it before using this 12 * file. 13 * 14 * The Original Code and all software distributed under the License are 15 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 16 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 17 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 19 * Please see the License for the specific language governing rights and 20 * limitations under the License. 21 * 22 * @APPLE_LICENSE_HEADER_END@ 23 */ 24 25 26#ifndef __DYLDLOCK__ 27#define __DYLDLOCK__ 28 29// 30// This file contains the synchronization utilities used to make dyld APIs be thread safe. 31// 32// The implementation of all dyld API's must hold acquire global lock (in libSystem) 33// before calling into dyld proper, and release the lock after returning from dyld. 34// This is done using the macros DYLD_LOCK_THIS_BLOCK. 35// Example: 36// 37// void dyld_api() { 38// DYLD_LOCK_THIS_BLOCK; 39// // free to do stuff here 40// // that accesses dyld internal data structures 41// } 42// 43// void dyld_api_state_free() { 44// DYLD_NO_LOCK_THIS_BLOCK 45// // can only do stuff here 46// // that does not require locking 47// } 48// 49 50#define DYLD_LOCK_THIS_BLOCK LockHelper _dyld_lock; 51#define DYLD_NO_LOCK_THIS_BLOCK 52 53// used by dyld wrapper functions in libSystem 54class __attribute__((visibility("hidden"))) LockHelper 55{ 56public: 57 LockHelper(); 58 ~LockHelper(); 59}; 60 61 62// to initialize 63extern void dyldGlobalLockInitialize() __attribute__((visibility("hidden"))); 64extern void dyldGlobalLockAcquire() __attribute__((visibility("hidden"))); 65extern void dyldGlobalLockRelease() __attribute__((visibility("hidden"))); 66 67#endif // __DYLDLOCK__ 68 69