| // 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_STARBOARD) |
| #include "starboard/mutex.h" |
| #elif defined(__LB_SHELL__) |
| #include "lb_mutex.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 OSLockType; |
| #elif defined(OS_STARBOARD) |
| typedef SbMutex OSLockType; |
| #elif defined(__LB_SHELL__) |
| typedef lb_shell_mutex_t OSLockType; |
| #elif defined(OS_POSIX) |
| typedef pthread_mutex_t OSLockType; |
| #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. |
| OSLockType* os_lock() { return &os_lock_; } |
| |
| private: |
| OSLockType os_lock_; |
| |
| DISALLOW_COPY_AND_ASSIGN(LockImpl); |
| }; |
| |
| } // namespace internal |
| } // namespace base |
| |
| #endif // BASE_SYNCHRONIZATION_LOCK_IMPL_H_ |