130d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun/* 230d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * Copyright 2011 Google Inc. All Rights Reserved. 330d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * 430d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * Licensed under the Apache License, Version 2.0 (the "License"); 530d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * you may not use this file except in compliance with the License. 630d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * You may obtain a copy of the License at 730d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * 830d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * http://www.apache.org/licenses/LICENSE-2.0 930d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * 1030d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * Unless required by applicable law or agreed to in writing, software 1130d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * distributed under the License is distributed on an "AS IS" BASIS, 1230d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1330d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * See the License for the specific language governing permissions and 1430d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun * limitations under the License. 1530d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun */ 1630d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 1730d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#ifndef SFNTLY_CPP_SRC_SFNTLY_PORT_LOCK_H_ 1830d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#define SFNTLY_CPP_SRC_SFNTLY_PORT_LOCK_H_ 1930d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 2030d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#if defined (WIN32) 2130d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#include <windows.h> 2230d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#else // Assume pthread. 2330d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#include <pthread.h> 2430d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#include <errno.h> 2530d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#endif 2630d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 2730d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#include "sfntly/port/type.h" 2830d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 2930d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurunnamespace sfntly { 3030d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 3130d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#if defined (WIN32) 3230d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun typedef CRITICAL_SECTION OSLockType; 3330d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#else // Assume pthread. 3430d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun typedef pthread_mutex_t OSLockType; 3530d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#endif 3630d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 3730d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurunclass Lock { 3830d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun public: 3930d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun Lock(); 4030d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun ~Lock(); 4130d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 4230d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun // If the lock is not held, take it and return true. If the lock is already 4330d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun // held by something else, immediately return false. 4430d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun bool Try(); 4530d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 4630d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun // Take the lock, blocking until it is available if necessary. 4730d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun void Acquire(); 4830d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 4930d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun // Release the lock. This must only be called by the lock's holder: after 5030d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun // a successful call to Try, or a call to Lock. 5130d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun void Unlock(); 5230d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 5330d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun private: 5430d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun OSLockType os_lock_; 5530d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun NO_COPY_AND_ASSIGN(Lock); 5630d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun}; 5730d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 5830d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun// A helper class that acquires the given Lock while the AutoLock is in scope. 5930d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurunclass AutoLock { 6030d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun public: 6130d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun explicit AutoLock(Lock& lock) : lock_(lock) { 6230d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun lock_.Acquire(); 6330d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun } 6430d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 6530d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun ~AutoLock() { 6630d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun lock_.Unlock(); 6730d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun } 6830d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 6930d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun private: 7030d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun Lock& lock_; 7130d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun NO_COPY_AND_ASSIGN(AutoLock); 7230d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun}; 7330d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 7430d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun} // namespace sfntly 7530d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun 7630d4e1f3d81ad9f7a1aa14ce6d2ceb5df56c15cdSelim Gurun#endif // SFNTLY_CPP_SRC_SFNTLY_PORT_LOCK_H_ 77