| /* |
| * Copyright (C) 2007 Apple Inc. All rights reserved. |
| * Copyright (C) 2007 Brent Fulgham |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of |
| * its contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| #include "config.h" |
| #include "Threading.h" |
| |
| namespace WebCore { |
| |
| Mutex::Mutex() |
| { |
| m_mutex.m_recursionCount = 0; |
| ::InitializeCriticalSection(&m_mutex.m_internalMutex); |
| } |
| |
| Mutex::~Mutex() |
| { |
| ::DeleteCriticalSection(&m_mutex.m_internalMutex); |
| } |
| |
| void Mutex::lock() |
| { |
| ::EnterCriticalSection(&m_mutex.m_internalMutex); |
| ++m_mutex.m_recursionCount; |
| } |
| |
| bool Mutex::tryLock() |
| { |
| // This method is modeled after the behavior of pthread_mutex_trylock, |
| // which will return an error if the lock is already owned by the |
| // current thread. Since the primitive Win32 'TryEnterCriticalSection' |
| // treats this as a successful case, it changes the behavior of several |
| // tests in WebKit that check to see if the current thread already |
| // owned this mutex (see e.g., IconDatabase::getOrCreateIconRecord) |
| DWORD result = ::TryEnterCriticalSection(&m_mutex.m_internalMutex); |
| |
| if (result != 0) { // We got the lock |
| // If this thread already had the lock, we must unlock and |
| // return false so that we mimic the behavior of POSIX's |
| // pthread_mutex_trylock: |
| if (m_mutex.m_recursionCount > 0) { |
| ::LeaveCriticalSection(&m_mutex.m_internalMutex); |
| return false; |
| } |
| |
| ++m_mutex.m_recursionCount; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| void Mutex::unlock() |
| { |
| --m_mutex.m_recursionCount; |
| ::LeaveCriticalSection(&m_mutex.m_internalMutex); |
| } |
| |
| } // namespace WebCore |