Simplify implementation of Mutex.

src/mutex.cc

+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * 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.
+//     * Neither the name of Google Inc. 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
+// OWNER OR 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 "mutex.h"
+
+#include <errno.h>
+
+#include "checks.h"
+
+namespace v8 {
+namespace internal {
+
+#if V8_OS_UNIX
+
+Mutex::Mutex() {
+  pthread_mutexattr_t attr;
+  int result = pthread_mutexattr_init(&attr);
+  ASSERT_EQ(0, result);
+  result = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+  ASSERT_EQ(0, result);
+  result = pthread_mutex_init(&mutex_, &attr);
+  ASSERT_EQ(0, result);
+  result = pthread_mutexattr_destroy(&attr);
+  ASSERT_EQ(0, result);
+  USE(result);
+}
+
+
+Mutex::~Mutex() {
+  pthread_mutex_destroy(&mutex_);
+}
+
+
+void Mutex::Lock() {
+  int result = pthread_mutex_lock(&mutex_);
+  ASSERT_EQ(0, result);
+  USE(result);
+}
+
+
+void Mutex::Unlock() {
+  int result = pthread_mutex_unlock(&mutex_);
+  ASSERT_EQ(0, result);
+  USE(result);
+}
+
+
+bool Mutex::TryLock() {
+  int result = pthread_mutex_trylock(&mutex_);
+  // Return false if the lock is busy and locking failed.
+  if (result == EBUSY) {
+    return false;
+  }
+  ASSERT_EQ(0, result);
+  return true;
+}
+
+#elif V8_OS_WIN32
+
+Mutex::Mutex() {
+  InitializeCriticalSection(&cs_);
+}
+
+
+Mutex::~Mutex() {
+  DeleteCriticalSection(&cs_);
+}
+
+
+void Mutex::Lock() {
+  EnterCriticalSection(&cs_);
+}
+
+
+void Mutex::Unlock() {
+  LeaveCriticalSection(&cs_);
+}
+
+
+bool Mutex::TryLock() {
+  return TryEnterCriticalSection(&cs_);
+}
+
+#endif  // V8_OS_WIN32
+
+} }  // namespace v8::internal