text: //
  // ActiveMethod.h
  //
  // $Id: //poco/1.4/Foundation/include/Poco/ActiveMethod.h#1 $
  //
  // 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 "Foundation.h"
  #include "ActiveResult.h"
  #include "ActiveRunnable.h"
  #include "ActiveStarter.h"
  #include "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
  