include/barrett/thread/null_mutex.h

/*
 * null_mutex.h
 *
 *  Created on: Dec 15, 2009
 *      Author: dc
 */

#ifndef BARRETT_THREAD_NULL_MUTEX_H_
#define BARRETT_THREAD_NULL_MUTEX_H_


#include <barrett/detail/ca_macro.h>
#include <barrett/thread/abstract/mutex.h>


namespace barrett {
namespace thread {


// provides no synchronization or mutual exclusion
class NullMutex : public Mutex {
public:
        // since all NullMutex's are the same, feel free to give out references to this object if you just need to return a NullMutex...
        static NullMutex aNullMutex;

        NullMutex() {}
        virtual ~NullMutex() {}

        virtual void lock() {}
        virtual bool try_lock() {  return true;  }
        virtual void unlock() {}

        virtual int fullUnlock() { return 0; }
        virtual void relock(int lc) {}

private:
        DISALLOW_COPY_AND_ASSIGN(NullMutex);
};


}
}


#endif /* BARRETT_THREAD_NULL_MUTEX_H_ */