// Copyright (c) 2011 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef BASE_SYNCHRONIZATION_LOCK_IMPL_H_ #define BASE_SYNCHRONIZATION_LOCK_IMPL_H_ #include "build/build_config.h" #if defined(OS_WIN) #include <windows.h> #elif defined(OS_POSIX) #include <pthread.h> #endif #include "base/base_export.h" #include "base/basictypes.h" namespace base { namespace internal { // This class implements the underlying platform-specific spin-lock mechanism // used for the Lock class. Most users should not use LockImpl directly, but // should instead use Lock. class BASE_EXPORT LockImpl { public: #if defined(OS_WIN) typedef CRITICAL_SECTION NativeHandle; #elif defined(OS_POSIX) typedef pthread_mutex_t NativeHandle; #endif LockImpl(); ~LockImpl(); // If the lock is not held, take it and return true. If the lock is already // held by something else, immediately return false. bool Try(); // Take the lock, blocking until it is available if necessary. void Lock(); // Release the lock. This must only be called by the lock's holder: after // a successful call to Try, or a call to Lock. void Unlock(); // Return the native underlying lock. // TODO(awalker): refactor lock and condition variables so that this is // unnecessary. NativeHandle* native_handle() { return &native_handle_; } private: NativeHandle native_handle_; DISALLOW_COPY_AND_ASSIGN(LockImpl); }; } // namespace internal } // namespace base #endif // BASE_SYNCHRONIZATION_LOCK_IMPL_H_