source: XMLIO_V2/external/include/Poco/ActiveMethod.h @ 80

//
// 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
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// 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