text: /* fake_mutex.h                  -*-C++-*-
   *
   *************************************************************************
   *
   * Copyright (C) 2013-2016, Intel Corporation
   * 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 Intel Corporation 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
   * HOLDER 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.
   * 
   * *********************************************************************
   * 
   * PLEASE NOTE: This file is a downstream copy of a file mainitained in
   * a repository at cilkplus.org. Changes made to this file that are not
   * submitted through the contribution process detailed at
   * http://www.cilkplus.org/submit-cilk-contribution will be lost the next
   * time that a new version is released. Changes only submitted to the
   * GNU compiler collection or posted to the git repository at
   * https://bitbucket.org/intelcilkruntime/intel-cilk-runtime.git are
   * not tracked.
   * 
   * We welcome your contributions to this open source project. Thank you
   * for your assistance in helping us improve Cilk Plus.
   *
   **************************************************************************
   *
   * Cilkscreen fake mutexes are provided to indicate to the Cilkscreen race
   * detector that a race should be ignored.
   *
   * NOTE: This class does not provide mutual exclusion.  You should use the
   * mutual exclusion constructs provided by TBB or your operating system to
   * protect against real data races.
   */
  
  #ifndef FAKE_MUTEX_H_INCLUDED
  #define FAKE_MUTEX_H_INCLUDED
  
  #include <cilktools/cilkscreen.h>
  
  namespace cilkscreen
  {
      class fake_mutex
      {
      public:
  	fake_mutex() : locked(false)
  	{
  	}
  
  	~fake_mutex()
  	{
  	    __CILKRTS_ASSERT(! locked);
  	}
  
          // Wait until mutex is available, then enter
          void lock()
          {
              __cilkscreen_acquire_lock(&locked);
  	    __CILKRTS_ASSERT(! locked);
  	    locked = true;
          }
  
          // A fake mutex is always available
          bool try_lock() { lock(); return true; }
  
          // Releases the mutex
          void unlock()
          {
  	    __CILKRTS_ASSERT(locked);
  	    locked = false;
              __cilkscreen_release_lock(&locked);
          }
  
      private:
          bool locked;
      };
  
  } // namespace cilk
  
  #endif  // FAKE_MUTEX_H_INCLUDED
  