activemethod.h

This software aims to create an applet and panel tools to manage a wireless interface card, such as

//
// ActiveMethod.h
//
// $Id: //poco/Main/Foundation/include/Foundation/ActiveMethod.h#5 $
//
// Definition of the ActiveMethod class.
//
// Copyright (c) 2004, Guenter Obiltschnig/Applied Informatics.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//
// 2. 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.
//
// 3. Redistributions in any form must be accompanied by information on
//    how to obtain complete source code for this software and any
//    accompanying software that uses this software.  The source code
//    must either be included in the distribution or be available for no
//    more than the cost of distribution plus a nominal fee, and must be
//    freely redistributable under reasonable conditions.  For an
//    executable file, complete source code means the source code for all
//    modules it contains.  It does not include source code for modules or
//    files that typically accompany the major components of the operating
//    system on which the executable file runs.
//
// 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 OWNER 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.
//


#ifndef Foundation_ActiveMethod_INCLUDED
#define Foundation_ActiveMethod_INCLUDED


#ifndef Foundation_Foundation_INCLUDED
#include "Foundation/Foundation.h"
#endif
#ifndef Foundation_ActiveResult_INCLUDED
#include "Foundation/ActiveResult.h"
#endif
#ifndef Foundation_Runnable_INCLUDED
#include "Foundation/Runnable.h"
#endif
#ifndef Foundation_ThreadPool_INCLUDED
#include "Foundation/ThreadPool.h"
#endif
#ifndef Foundation_Exception_INCLUDED
#include "Foundation/Exception.h"
#endif


Foundation_BEGIN


template <class ResultType, class ArgType, class OwnerType>
class ActiveRunnable: public Runnable
	/// This class is used by ActiveMethod.
	/// See the ActiveMethod class for more information.
{
public:
	typedef ResultType (OwnerType::*Callback)(const ArgType&);
	typedef ActiveResult<ResultType> ActiveResultType;

	ActiveRunnable(OwnerType* pOwner, Callback method, const ArgType& arg, const ActiveResultType& result):
		_pOwner(pOwner),
		_method(method),
		_arg(arg),
		_result(result)
	{
		poco_check_ptr (pOwner);
	}

	void run()
	{
		try
		{
			_result.data() = (_pOwner->*_method)(_arg);
		}
		catch (Exception& e)
		{
			_result.error(e.message());
		}
		catch (std::exception& e)
		{
			_result.error(e.what());
		}
		catch (...)
		{
			_result.error("unknown exception");
		}
		_result.notify();
		delete this;
	}

private:
	OwnerType* _pOwner;
	Callback   _method;
	ArgType    _arg;
	ActiveResultType _result;
};


template <class ResultType, class ArgType, class 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::exampleActiveMethodImp)
	///         {
	///         }
	///
	///         ActiveMethod<std::string, std::string, ActiveObject> exampleActiveMethod;
	///
	///     protected:
	///         std::string exampleActiveMethodImp(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;
{
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>());
		ActiveRunnableType* pRunnable = new ActiveRunnableType(_pOwner, _method, arg, result);
		ThreadPool::defaultPool().start(*pRunnable);
		return result;
	}
		
private:
	ActiveMethod();
	ActiveMethod(const ActiveMethod&);
	ActiveMethod& operator = (const ActiveMethod&);

	OwnerType* _pOwner;
	Callback   _method;
};


Foundation_END


#endif // Foundation_ActiveMethod_INCLUDED