A simple TCP server class, which should learn its know-how in the derived classes. More...

#include <TcpServer.h>

Inheritance diagram for tcp::Server:

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Collaboration diagram for tcp::Server:

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Classes
class	ServerReceiverTransmitter
	Tuple of socket Receiver and Transmitter for the Server. More...

Public Member Functions
	Server (unsigned int uiPort, int iAdressFamily, int iSocketType, int iProtocol, unsigned int uiDataSize, unsigned long ulMaxClients, int iSecTimeOut)

virtual	~Server ()

virtual void	cancel () override

int	acceptClientMessage (AbstractMessage *pTcpMessage)

Public Member Functions inherited from tcp::TcpMain
	TcpMain (unsigned int uiPort, int iAdressFamily, int iSocketType, int iProtocol, int iSecTimeOut)

	TcpMain (unsigned int uiPort, int iAdressFamily, int iSocketType, int iProtocol, unsigned int uiDataSize, int iSecTimeOut)

virtual	~TcpMain ()

unsigned int	getPortNum () const

virtual void	setDataSize (unsigned int uiDataSize)

unsigned int	getDataSize () const

SOCKET	getMainSocket () const

void	setTimeOutSec (int iSecTimeOut)

int	TimeOutSec ()

Public Member Functions inherited from eut::RepeatingThread
	RepeatingThread ()

virtual	~RepeatingThread ()

virtual int	start ()

bool	testCancel ()

RepeatingThread::STATUS	status () const

bool	isInExclusiveAccess () const

void	setExclusiveAccess ()

void	unsetExclusiveAccess ()

int	getBreakCounter ()

virtual void	takeABreak ()

virtual void	finishBreak ()

void	waitForInput ()

void	signalInput ()

Protected Member Functions
	Server ()

	Server (unsigned int, int, int, int, int)

	Server (unsigned int, int, int, int, unsigned int, int)

virtual void	work () override

virtual void	insertNewClient (Server::ServerReceiverTransmitter *pNewServerReceiverTransmitter)

Server::ServerReceiverTransmitter *	getClient (SOCKET Socket)

virtual int	removeClient (SOCKET Socket)

virtual Server::ServerReceiverTransmitter *	generateNewServerReceiverTransmitter (Server *pParent, SOCKET Socket, unsigned int iDataSize) const

void	setClientMapReceiverValid (bool bValid)

void	clearClientMap ()

unsigned long	getMaxClients () const

virtual void	processClientMessage (AbstractMessage *pTcpMessage)

virtual int	send (SOCKET ClientSocket, char *pszRawMsg, unsigned int uiRawMsgSize, unsigned int uiMessageID=0, int iActionCode=0, const std::string &rstrInfo="")

virtual int	send (Message *pTcpMessage) override

Protected Member Functions inherited from tcp::TcpMain
	TcpMain ()

void	setWSACleanup () const

int	startWinsock () const

Protected Member Functions inherited from eut::RepeatingThread
void	threadWork ()

void	setStatus (STATUS eStatus)

STATUS	getStatus ()

void	toOrder (ORDER eOrder)

ORDER	getOrder ()

Protected Attributes
ServerAcceptReceiver *	m_pAcceptReceiver

std::map< SOCKET, ServerReceiverTransmitter *, std::less< SOCKET > >	m_ClientMap

Protected Attributes inherited from tcp::TcpMain
int	m_iSecTimeOut

unsigned int	m_uiServerPort

unsigned int	m_uiDataSize

int	m_iAdressFamily

int	m_iSocketType

int	m_iProtocol

SOCKET	m_MainSocket

Private Member Functions
	Server (const Server &rT)

void	init ()

Server &	operator= (const Server &)

Private Attributes
unsigned long	m_ulMaxClients

std::queue< AbstractMessage * >	m_MsgQueue

Additional Inherited Members
Public Types inherited from eut::RepeatingThread
enum	EuTHREADERROR { EuTHREAD_ERR_NO_THREAD = -10301 , EuTHREAD_ERR_THREAD_ALREADY_WORKING = -10302 , EuTHREAD_ERR_THREAD_BREAK_COUNT_LESS_THAN_ZERO = -10303 , EuTHREAD_ERR_UNKNOWN = -10400 }
	Error range = -10301 to -10400 More...

enum	STATUS { eAT_THE_START , eWORKING , ePAUSING , eENDING , eCOMPLETED }

enum	ORDER { eUNDEFINED , eDO_WORK , eEXIT }

Detailed Description

A simple TCP server class, which should learn its know-how in the derived classes.

Server is a thread that allows Tcp Client's to connect to it.

TcpServers have as superclass attributes the port, the data size which is sent, the address family, the socket type, the protocol type and a main socket (here AcceptSocket).

In addition, the following attributes are available here: a ServerAcceptReceiver, which processes the new requests as a thread, a MsgQueue, which records the individual messages of the individual ClientSockets, a counter that contains the maximum number of clients and a ClientMap with the individual ServerReceiverTransmitter objects.

For each accepted client, an object of the embedded class ServerReceiverTransmitter is instantiated, which has a Transmitter and a Receiver, and stored in the ClientMap. Transmitter and Receiver are also threads.

Starting the server:

During instantiation with transfer of port, address family, socket type, protocol, data size and maximum number of clients, the own thread and the ServerAcceptReceiver is initialized (with the calling server as parent object and the main socket) and also started as a thread. This always blocks until a client logs on.

New client wants to connect:

When a client logs on to the ServerAcceptReceiver, a new ServerAcceptMessage instantiated (with the new SOCKET of the client as parameter) and to the server via Server::acceptClientMessage(AbstractMessage *) passed on.

In Server::acceptClientMessage(AbstractMessage *) the passed ServerAcceptMessage is appended to the MsgQueue. When the MsgQueue is processed in Server::work(), the ServerAcceptMessage is found.

If the maximum number of clients is exceeded, the client is informed and the client socket is closed.

If the client socket is not closed, a ServerReceiverTransmitter is instantiated using a virtual method Server::generateNewServerReceiverTransmitter (...). The server is passed as the parent object for the ServerReceiver that is still to be instantiated, the new socket and the data size. A Transmitter (which sends data to the new client) and a ServerReceiver (which receives data from the new client) are instantiated for the ServerReceiverTransmitter. It is possible to establish a derived ServerReceiverTransmitter with derived Transmitter or ServerReceiver.

The new ServerReceiverTransmitter is inserted into the ClientMap.

Now the server method Server::processClientMessage(AbstractMessage *) is called, in which further processing can be carried out in subclasses. Among other things, the ServerAcceptMessage is removed from the memory.

The new ServerReceiverTransmitter or its ServerReceiver in the ClientMap is now responsible for further messages from the client.

Processing data from the client:

The ServerReceiver waits in its thread method ServerReceiver::work() for messages from the connected client. If the client sends (abort or data), the ServerReceiver creates a new ServerMessage using the method ServerReceiver::generateNewTcpMessage (... ) (can be overwritten in subclasses to return derived message types) and forwarded to the parent server Server::acceptClientMessage(AbstractMessage *) using the method ServerReceiver::acceptMessage(AbstractMessage *).

In subclasses, a derived ServerReceiver can take over processing in the overwritten ServerReceiver::acceptMessage(AbstractMessage *) and/or the derived Server can take over processing in the overwritten Server::acceptClientMessage(AbstractMessage *).

In the method Server::acceptClientMessage(AbstractMessage *), the transferred ServerMessage is appended to the MsgQueue. When the MsgQueue is processed, the ServerMessage is found and forwarded to Server::processClientMessage(AbstractMessage *). If the client has broken the connection, the message is modified and the client is removed using Server::removeClient(SOCKET Socket)).

In Server::processClientMessage(AbstractMessage *), as mentioned above, special processing can be performed in subclasses; only the ServerAcceptMessage is removed from memory here.

Sending to the client:

Must be worked out in subclasses of Server or subclasses of ServerReceiverTransmitter or otherwise. At least all classes have access to the socket.

Exit from Server:

First the server thread is stopped, then the ServerAcceptReceiver is removed from memory. Finally, all TcpServerReceivers are removed from the ClientMap and memory.

Copyright: © 2010 Helmut Jakoby

Author: Helmut Jakoby

Constructor & Destructor Documentation

◆ Server() [1/5]

tcp::Server::Server ( )

protected

This constructor is not available.

◆ Server() [2/5]

tcp::Server::Server	(	unsigned int	,
		int	,
		int	,
		int	,
		int	)

protected

This constructor is not available.

◆ Server() [3/5]

tcp::Server::Server	(	unsigned int	,
		int	,
		int	,
		int	,
		unsigned int	,
		int	)

protected

This constructor is not available.

◆ Server() [4/5]

tcp::Server::Server	(	unsigned int	uiPort,
		int	iAdressFamily,
		int	iSocketType,
		int	iProtocol,
		unsigned int	uiDataSize,
		unsigned long	ulMaxClients,
		int	iSecTimeOut )

This constructor starts the server.

Parameters

[in]	uiPort	The port of the server.
[in]	iAdressFamily	The socket address family to instantiate a socket (usually AF_INET).
[in]	iSocketType	The socket type (usually SOCK_STREAM).
[in]	iProtocol	The socket protocol (usually 0).
[in]	uiDataSize	The packet size.
[in]	ulMaxClients	The maximum number of clients allowed to connect.
[in]	iSecTimeOut	The time until waiting for a connection or waiting for data is aborted.

Exceptions

eut::ErrorNException An exception is thrown if an error occurs.

◆ ~Server()

virtual tcp::Server::~Server ( )

virtual

Destructor. It is cleaned up (AcceptReceiver and MsgQueue).

◆ Server() [5/5]

tcp::Server::Server ( const Server & rT )

private

The copy constructor is not available.

Member Function Documentation

◆ acceptClientMessage()

int tcp::Server::acceptClientMessage ( AbstractMessage * pTcpMessage )

The transferred Message is inserted into the MsgQueue by the client via the ServerAcceptReceiver or ServerReceiver and is thus processed.

Parameters

[in] pTcpMessage The received message from the client.

Returns: A return < 0 indicates an error.

◆ cancel()

virtual void tcp::Server::cancel ( )

overridevirtual

When the thread ends, this virtual method is called. The MsgQueue is cleaned up here.

Note: This method only exists when not compiled with POSIX threads (defined (__PTHREADS)).

Reimplemented from eut::RepeatingThread.

◆ clearClientMap()

void tcp::Server::clearClientMap ( )

protected

Removes all ServerReceiverTransmitters from its list of clients and from memory.

◆ generateNewServerReceiverTransmitter()

virtual Server::ServerReceiverTransmitter * tcp::Server::generateNewServerReceiverTransmitter	(	Server *	pParent,
		SOCKET	Socket,
		unsigned int	iDataSize ) const

protectedvirtual

Returns a ServerReceiverTransmitter here; can be overwritten in subclasses to return a derived type. Is called in work() when a new client is added.

Parameters

[in]	pParent	Server or subclass.
[in]	Socket	Socket of the new client.
[in]	iDataSize	The packet size.

Returns: The ServerReceiverTransmitter or derived type required in the subclasses.

◆ getClient()

Server::ServerReceiverTransmitter * tcp::Server::getClient ( SOCKET Socket )

protected

Looks for the ServerReceiverTransmitter corresponding to the 'Socket' parameter in its list of clients and returns a pointer to it, if any.

Parameters

[in] Socket The socket of the ServerReceiverTransmitter being searched for.

Returns: If != 0, then the ServerReceiverTransmitter found.

Attention: The returned object only lives as long as the returning object and must NOT be removed from memory by the calling instance.

◆ getMaxClients()

unsigned long tcp::Server::getMaxClients ( ) const

protected

Returns the maximum number of client connections allowed.

Returns: The maximum number of client connections allowed.

◆ init()

void tcp::Server::init ( )

private

Initializes the socket and instantiates a ServerAcceptReceiver. The own attributes must have meaningful values.

Exceptions

eut::ErrorNException An exception is thrown if an error occurs.

◆ insertNewClient()

virtual void tcp::Server::insertNewClient ( Server::ServerReceiverTransmitter * pNewServerReceiverTransmitter )

protectedvirtual

Adds new client as 'ServerReceiverTransmitter' to its list of clients. This method is virtual, so that subclasses can react to it; e.g. let someone know that a new client has arrived.

Parameters

[in] pNewServerReceiverTransmitter The client is in this object.

◆ operator=()

Server & tcp::Server::operator= ( const Server & )

private

The assignment operator is not available.

◆ processClientMessage()

virtual void tcp::Server::processClientMessage ( AbstractMessage * pTcpMessage )

protectedvirtual

Should process the message from the client in subclasses. In the overwritten methods always this method must be called, because among other things the passed Message is removed from the memory here.

Parameters

[in] pTcpMessage The message to be processed by the client.

Reimplemented in MyTestServer.

◆ removeClient()

virtual int tcp::Server::removeClient ( SOCKET Socket )

protectedvirtual

Looks for the ServerReceiverTransmitter corresponding to the 'Socket' parameter in its list of clients and removes it from the list and from memory.

Parameters

[in] Socket The socket to be closed.

Returns: A return value < 0 indicates an error.

◆ send() [1/2]

virtual int tcp::Server::send ( Message * pTcpMessage )

overrideprotectedvirtual

Sends the transferred Message to the client via its Transmitter (Client information is in the ServerMessage).

Parameters

[in] pTcpMessage The message packet to be sent must be a ServerMessage.

Returns: A return < 0 indicates an error.

Attention: The passed Message must not be removed from memory by the calling instance! Since the Message is given to the Transmitter for further processing, and the Transmitter decides when to send. Therefore, the Transmitter will also remove the Message from memory.

Implements tcp::TcpMain.

◆ send() [2/2]

virtual int tcp::Server::send	(	SOCKET	ClientSocket,
		char *	pszRawMsg,
		unsigned int	uiRawMsgSize,
		unsigned int	uiMessageID = 0,
		int	iActionCode = 0,
		const std::string &	rstrInfo = "" )

protectedvirtual

Sends the transferred data in a Message via its Transmitter to the client. A header will be generated.

Parameters

[in]	ClientSocket	The socket of the target client.
[in]	pszRawMsg	Pointer to the data to be sent.
[in]	uiRawMsgSize	The size of the data to be sent.
[in]	uiMessageID	A MessageID can be passed.
[in]	iActionCode	A ActionCode can be passed.
[in]	rstrInfo	A free info can be passed.

Returns: A return value < 0 indicates an error.

Attention: The data in pszRawMsg is internally removed from memory; the calling instance may no longer use the data to be sent or remove it from memory.

◆ setClientMapReceiverValid()

void tcp::Server::setClientMapReceiverValid ( bool bValid )

protected

Sets the Valid flag for all ServerReceiverTransmitters from its list of clients.

Parameters

[in] bValid If false -> no more reception!

◆ work()

virtual void tcp::Server::work ( )

overrideprotectedvirtual

Work of the thread. New clients will be 'accepted' or rejected when the maximum number is reached. Messages from clients are processed.

Implements eut::RepeatingThread.

Member Data Documentation

◆ m_ClientMap

std::map< SOCKET, ServerReceiverTransmitter *, std::less< SOCKET > > tcp::Server::m_ClientMap

protected

All accepted clients in Server::ServerReceiverTransmitter.

◆ m_MsgQueue

std::queue<AbstractMessage *> tcp::Server::m_MsgQueue

private

The queue with the received data from the client.

◆ m_pAcceptReceiver

ServerAcceptReceiver* tcp::Server::m_pAcceptReceiver

protected

The AcceptReceiver accepts new clients.

◆ m_ulMaxClients

unsigned long tcp::Server::m_ulMaxClients

private

The maximum number of clients to accept. If the number is exceeded, no more clients are accepted.

The documentation for this class was generated from the following file:

TcpServer.h

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Starting the server:

New client wants to connect:

Processing data from the client:

Sending to the client:

Exit from Server:

Constructor & Destructor Documentation

◆ Server() [1/5]

◆ Server() [2/5]

◆ Server() [3/5]

◆ Server() [4/5]

◆ ~Server()

◆ Server() [5/5]

Member Function Documentation

◆ acceptClientMessage()

◆ cancel()

◆ clearClientMap()

◆ generateNewServerReceiverTransmitter()

◆ getClient()

◆ getMaxClients()

◆ init()

◆ insertNewClient()

◆ operator=()

◆ processClientMessage()

◆ removeClient()

◆ send() [1/2]

◆ send() [2/2]

◆ setClientMapReceiverValid()

◆ work()

Member Data Documentation

◆ m_ClientMap

◆ m_MsgQueue

◆ m_pAcceptReceiver

◆ m_ulMaxClients