text: // 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_
  