//
// TCPServer.h
//
// $Id: //poco/1.3/Net/include/Poco/Net/TCPServer.h#2 $
//
// Library: Net
// Package: TCPServer
// Module:  TCPServer
//
// Definition of the TCPServer class.
//
// Copyright (c) 2005-2006, 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 Net_TCPServer_INCLUDED
#define Net_TCPServer_INCLUDED


#include "Poco/Net/Net.h"
#include "Poco/Net/ServerSocket.h"
#include "Poco/Runnable.h"
#include "Poco/Thread.h"
#include "Poco/ThreadPool.h"


namespace Poco {
namespace Net {


class TCPServerParams;
class TCPServerDispatcher;
class TCPServerConnectionFactory;


class Net_API TCPServer: public Poco::Runnable
	/// This class implements a multithreaded TCP server.
	///
	/// The server uses a ServerSocket to listen for incoming
	/// connections. The ServerSocket must have been bound to
	/// an address before it is passed to the TCPServer constructor.
	/// Additionally, the ServerSocket must be put into listening
	/// state before the TCPServer is started by calling the start()
	/// method.
	///
	/// The server uses a thread pool to assign threads to incoming
	/// connections. Before incoming connections are assigned to
	/// a connection thread, they are put into a queue.
	/// Connection threads fetch new connections from the queue as soon
	/// as they become free. Thus, a connection thread may serve more
	/// than one connection.
	///
	/// As soon as a connection thread fetches the next connection from
	/// the queue, it creates a TCPServerConnection object for it
	/// (using the TCPServerConnectionFactory passed to the constructor)
	/// and calls the TCPServerConnection's start() method. When the
	/// start() method returns, the connection object is deleted.
	///
	/// The number of connection threads is adjusted dynamically, depending
	/// on the number of connections waiting to be served.
	///
	/// It is possible to specify a maximum number of queued connections.
	/// This prevents the connection queue from overflowing in the 
	/// case of an extreme server load. In such a case, connections that
	/// cannot be queued are silently and immediately closed.
	///
	/// TCPServer uses a separate thread to accept incoming connections.
	/// Thus, the call to start() returns immediately, and the server
	/// continues to run in the background.
	///
	/// To stop the server from accepting new connections, call stop().
	///
	/// After calling stop(), no new connections will be accepted and
	/// all queued connections will be discarded.
	/// Already served connections, however, will continue being served.
{
public:
	TCPServer(TCPServerConnectionFactory* pFactory, const ServerSocket& socket, TCPServerParams* pParams = 0);
		/// Creates the TCPServer, using the given ServerSocket.
		///
		/// The server takes ownership of the TCPServerConnectionFactory
		/// and deletes it when it's no longer needed.
		///
		/// The server also takes ownership of the TCPServerParams object.
		/// If no TCPServerParams object is given, the server's TCPServerDispatcher
		/// creates its own one.
		///
		/// News threads are taken from the default thread pool.

	TCPServer(TCPServerConnectionFactory* pFactory, Poco::ThreadPool& threadPool, const ServerSocket& socket, TCPServerParams* pParams = 0);
		/// Creates the TCPServer, using the given ServerSocket.
		///
		/// The server takes ownership of the TCPServerConnectionFactory
		/// and deletes it when it's no longer needed.
		///
		/// The server also takes ownership of the TCPServerParams object.
		/// If no TCPServerParams object is given, the server's TCPServerDispatcher
		/// creates its own one.
		///
		/// News threads are taken from the given thread pool.

	virtual ~TCPServer();
		/// Destroys the TCPServer and its TCPServerConnectionFactory.
				
	const TCPServerParams& params() const;
		/// Returns a const reference to the TCPServerParam object
		/// used by the server's TCPServerDispatcher.	
				
	void start();
		/// Starts the server. A new thread will be
		/// created that waits for and accepts incoming
		/// connections.
		///
		/// Before start() is called, the ServerSocket passed to
		/// TCPServer must have been bound and put into listening state.
		
	void stop();
		/// Stops the server.
		///
		/// No new connections will be accepted.
		/// Already handled connections will continue to be served.
		///
		/// Once the server is stopped, it cannot be restarted.
		
	int currentThreads() const;
		/// Returns the number of currently used connection threads.

	int totalConnections() const;
		/// Returns the total number of handled connections.
		
	int currentConnections() const;
		/// Returns the number of currently handled connections.

	int maxConcurrentConnections() const;
		/// Returns the maximum number of concurrently handled connections.	
		
	int queuedConnections() const;
		/// Returns the number of queued connections.

	int refusedConnections() const;
		/// Returns the number of refused connections.

	Poco::UInt16 port() const;
		/// Returns the port the server socket listens to

protected:
	void run();
		/// Runs the server. The server will run until
		/// the stop() method is called, or the server
		/// object is destroyed, which implicitly calls
		/// the stop() method.

	static std::string threadName(const ServerSocket& socket);
		/// Returns a thread name for the server thread.

private:
	TCPServer();
	TCPServer(const TCPServer&);
	TCPServer& operator = (const TCPServer&);
	
	ServerSocket         _socket;
	TCPServerDispatcher* _pDispatcher;
	Poco::Thread         _thread;
	bool                 _stopped;
};


inline Poco::UInt16 TCPServer::port() const
{
	return _socket.address().port();
}


} } // namespace Poco::Net


#endif // Net_TCPServer_INCLUDED