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//

// ActiveMethod.h

//

// $Id: //poco/1.3/Foundation/include/Poco/ActiveMethod.h#3 $

//

// Library: Foundation

// Package: Threading

// Module:  ActiveObjects

//

// Definition of the ActiveMethod class.

//

// Copyright (c) 2004-2007, Applied Informatics Software Engineering GmbH.

// and Contributors.

//

// Permission is hereby granted, free of charge, to any person or organization

// obtaining a copy of the software and accompanying documentation covered by

// this license (the "Software") to use, reproduce, display, distribute,

// execute, and transmit the Software, and to prepare derivative works of the

// Software, and to permit third-parties to whom the Software is furnished to

// do so, all subject to the following:

// 

// The copyright notices in the Software and this entire statement, including

// the above license grant, this restriction and the following disclaimer,

// must be included in all copies of the Software, in whole or in part, and

// all derivative works of the Software, unless such copies or derivative

// works are solely in the form of machine-executable object code generated by

// a source language processor.

// 

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT

// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE

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// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

// DEALINGS IN THE SOFTWARE.

//

#ifndef Foundation_ActiveMethod_INCLUDED

#define Foundation_ActiveMethod_INCLUDED

#include "Poco/Foundation.h"

#include "Poco/ActiveResult.h"

#include "Poco/ActiveRunnable.h"

#include "Poco/ActiveStarter.h"

#include "Poco/AutoPtr.h"

namespace Poco {

template <class ResultType, class ArgType, class OwnerType, class StarterType = ActiveStarter<OwnerType> >

class ActiveMethod

        /// An active method is a method that, when called, executes

        /// in its own thread. ActiveMethod's take exactly one

        /// argument and can return a value. To pass more than one

        /// argument to the method, use a struct.

        /// The following example shows how to add an ActiveMethod

        /// to a class:

        ///

        ///     class ActiveObject

        ///     {

        ///     public:

        ///         ActiveObject():

        ///             exampleActiveMethod(this, &ActiveObject::exampleActiveMethodImpl)

        ///         {

        ///         }

        ///

        ///         ActiveMethod<std::string, std::string, ActiveObject> exampleActiveMethod;

        ///

        ///     protected:

        ///         std::string exampleActiveMethodImpl(const std::string& arg)

        ///         {

        ///             ...

        ///         }

        ///     };

        ///

        /// And following is an example that shows how to invoke an ActiveMethod.

        ///

        ///     ActiveObject myActiveObject;

        ///     ActiveResult<std::string> result = myActiveObject.exampleActiveMethod("foo");

        ///     ...

        ///     result.wait();

        ///     std::cout << result.data() << std::endl;

        ///

        /// The way an ActiveMethod is started can be changed by passing a StarterType

        /// template argument with a corresponding class. The default ActiveStarter

        /// starts the method in its own thread, obtained from a thread pool.

        ///

        /// For an alternative implementation of StarterType, see ActiveDispatcher.

        ///

        /// For methods that do not require an argument or a return value, the Void

        /// class can be used.

{

public:

        typedef ResultType (OwnerType::*Callback)(const ArgType&);

        typedef ActiveResult<ResultType> ActiveResultType;

        typedef ActiveRunnable<ResultType, ArgType, OwnerType> ActiveRunnableType;

        ActiveMethod(OwnerType* pOwner, Callback method):

                _pOwner(pOwner),

                _method(method)

                /// Creates an ActiveMethod object.

        {

                poco_check_ptr (pOwner);

        }

        ActiveResultType operator () (const ArgType& arg)

                /// Invokes the ActiveMethod.

        {

                ActiveResultType result(new ActiveResultHolder<ResultType>());

                ActiveRunnableBase::Ptr pRunnable(new ActiveRunnableType(_pOwner, _method, arg, result));

                StarterType::start(_pOwner, pRunnable);

                return result;

        }

        ActiveMethod(const ActiveMethod& other):

                _pOwner(other._pOwner),

                _method(other._method)

        {

        }

        ActiveMethod& operator = (const ActiveMethod& other)

        {

                ActiveMethod tmp(other);

                swap(tmp);

                return *this;

        }

        void swap(ActiveMethod& other)

        {

                std::swap(_pOwner, other._pOwner);

                std::swap(_method, other._method);

        }

private:

        ActiveMethod();

        OwnerType* _pOwner;

        Callback   _method;

};

template <class ResultType, class OwnerType, class StarterType>

class ActiveMethod <ResultType, void, OwnerType, StarterType>

        /// An active method is a method that, when called, executes

        /// in its own thread. ActiveMethod's take exactly one

        /// argument and can return a value. To pass more than one

        /// argument to the method, use a struct.

        /// The following example shows how to add an ActiveMethod

        /// to a class:

        ///

        ///     class ActiveObject

        ///     {

        ///     public:

        ///         ActiveObject():

        ///             exampleActiveMethod(this, &ActiveObject::exampleActiveMethodImpl)

        ///         {

        ///         }

        ///

        ///         ActiveMethod<std::string, std::string, ActiveObject> exampleActiveMethod;

        ///

        ///     protected:

        ///         std::string exampleActiveMethodImpl(const std::string& arg)

        ///         {

        ///             ...

        ///         }

        ///     };

        ///

        /// And following is an example that shows how to invoke an ActiveMethod.

        ///

        ///     ActiveObject myActiveObject;

        ///     ActiveResult<std::string> result = myActiveObject.exampleActiveMethod("foo");

        ///     ...

        ///     result.wait();

        ///     std::cout << result.data() << std::endl;

        ///

        /// The way an ActiveMethod is started can be changed by passing a StarterType

        /// template argument with a corresponding class. The default ActiveStarter

        /// starts the method in its own thread, obtained from a thread pool.

        ///

        /// For an alternative implementation of StarterType, see ActiveDispatcher.

        ///

        /// For methods that do not require an argument or a return value, simply use void.

{

public:

        typedef ResultType (OwnerType::*Callback)(void);

        typedef ActiveResult<ResultType> ActiveResultType;

        typedef ActiveRunnable<ResultType, void, OwnerType> ActiveRunnableType;

        ActiveMethod(OwnerType* pOwner, Callback method):

                _pOwner(pOwner),

                _method(method)

                /// Creates an ActiveMethod object.

        {

                poco_check_ptr (pOwner);

        }

        ActiveResultType operator () (void)

                /// Invokes the ActiveMethod.

        {

                ActiveResultType result(new ActiveResultHolder<ResultType>());

                ActiveRunnableBase::Ptr pRunnable(new ActiveRunnableType(_pOwner, _method, result));

                StarterType::start(_pOwner, pRunnable);

                return result;

        }

        ActiveMethod(const ActiveMethod& other):

                _pOwner(other._pOwner),

                _method(other._method)

        {

        }

        ActiveMethod& operator = (const ActiveMethod& other)

        {

                ActiveMethod tmp(other);

                swap(tmp);

                return *this;

        }

        void swap(ActiveMethod& other)

        {

                std::swap(_pOwner, other._pOwner);

                std::swap(_method, other._method);

        }

private:

        ActiveMethod();

        OwnerType* _pOwner;

        Callback   _method;

};

} // namespace Poco

#endif // Foundation_ActiveMethod_INCLUDED