// © 2016 and later: Unicode, Inc. and others.

// License & terms of use: http://www.unicode.org/copyright.html

/*

******************************************************************************

*

*   Copyright (C) 1997-2013, International Business Machines

*   Corporation and others.  All Rights Reserved.

*

******************************************************************************

*/

//----------------------------------------------------------------------------

// File:     mutex.h

//

// Lightweight C++ wrapper for umtx_ C mutex functions

//

// Author:   Alan Liu  1/31/97

// History:

// 06/04/97   helena         Updated setImplementation as per feedback from 5/21 drop.

// 04/07/1999  srl               refocused as a thin wrapper

//

//----------------------------------------------------------------------------

#ifndef MUTEX_H

#define MUTEX_H

#include "unicode/utypes.h"

#include "unicode/uobject.h"

#include "umutex.h"

U_NAMESPACE_BEGIN

/**

  * Mutex is a helper class for convenient locking and unlocking of a UMutex.

  *

  * Creating a local scope Mutex will lock a UMutex, holding the lock until the Mutex

  * goes out of scope.

  *

  *  If no UMutex is specified, the ICU global mutex is implied.

  *

  *  For example:

  *

  *  static UMutex myMutex;

  *

  *  void Function(int arg1, int arg2)

  *  {

  *     static Object* foo;      // Shared read-write object

  *     Mutex mutex(&myMutex);   // or no args for the global lock

  *     foo->Method();

  *     // When 'mutex' goes out of scope and gets destroyed here, the lock is released

  *  }

  *

  *  Note:  Do NOT use the form 'Mutex mutex();' as that merely forward-declares a function

  *         returning a Mutex. This is a common mistake which silently slips through the

  *         compiler!!

  */

class U_COMMON_API Mutex : public UMemory {

public:

    Mutex(UMutex *mutex = nullptr) : fMutex(mutex) {

        umtx_lock(fMutex);

    }

    ~Mutex() {

        umtx_unlock(fMutex);

    }

    Mutex(const Mutex &other) = delete; // forbid assigning of this class

    Mutex &operator=(const Mutex &other) = delete; // forbid copying of this class

    void *operator new(size_t s) = delete;  // forbid heap allocation. Locals only.

private:

    UMutex   *fMutex;

};

U_NAMESPACE_END

#endif //_MUTEX_

//eof