--- /dev/null
+// Copyright (c) 2011 Google Inc. 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 name Chromium Embedded
+// Framework 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.
+
+// Do not include this header file directly. Use base/cef_lock.h instead.
+
+#ifndef CEF_INCLUDE_BASE_INTERNAL_CEF_LOCK_IMPL_H_
+#define CEF_INCLUDE_BASE_INTERNAL_CEF_LOCK_IMPL_H_
+
+#include "include/base/cef_build.h"
+
+#if defined(OS_WIN)
+#include <windows.h>
+#elif defined(OS_POSIX)
+#include <pthread.h>
+#endif
+
+#include "include/base/cef_macros.h"
+
+namespace base {
+namespace cef_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 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 cef_internal
+} // namespace base
+
+#endif // CEF_INCLUDE_BASE_INTERNAL_CEF_LOCK_IMPL_H_