4 files changed, 182 insertions, 208 deletions

diff --git a/src/OSSupport/Socket.cpp b/src/OSSupport/Socket.cpp
index 8ea5d8320..d80c9bb3d 100644
--- a/src/OSSupport/Socket.cpp
+++ b/src/OSSupport/Socket.cpp
@@ -87,6 +87,25 @@ void cSocket::CloseSocket()
 
 
 
+void cSocket::ShutdownReadWrite(void)
+{
+	#ifdef _WIN32
+		int res = shutdown(m_Socket, SD_BOTH);
+	#else
+		int res = shutdown(m_Socket, SHUT_RDWR);
+	#endif
+	if (res != 0)
+	{
+		LOGWARN("%s: Error shutting down socket %d (%s): %d (%s)",
+			__FUNCTION__, m_Socket, m_IPString.c_str(), this->GetLastError(), GetLastErrorString().c_str()
+		);
+	}
+}
+
+
+
+
+
 AString cSocket::GetErrorString( int a_ErrNo )
 {
 	char buffer[ 1024 ];
diff --git a/src/OSSupport/Socket.h b/src/OSSupport/Socket.h
index b86560de8..91c9ca5fd 100644
--- a/src/OSSupport/Socket.h
+++ b/src/OSSupport/Socket.h
@@ -39,7 +39,11 @@ public:
 
 	bool IsValid(void) const { return IsValidSocket(m_Socket); }
 	void CloseSocket(void);
-
+	
+	/** Notifies the socket that we don't expect any more reads nor writes on it.
+	Most TCPIP implementations use this to send the FIN flag in a packet */
+	void ShutdownReadWrite(void);
+	
 	operator xSocket(void) const;
 	xSocket GetSocket(void) const;
 	
diff --git a/src/OSSupport/SocketThreads.cpp b/src/OSSupport/SocketThreads.cpp
index 3e505616c..b8069cf00 100644
--- a/src/OSSupport/SocketThreads.cpp
+++ b/src/OSSupport/SocketThreads.cpp
@@ -71,29 +71,6 @@ bool cSocketThreads::AddClient(const cSocket & a_Socket, cCallback * a_Client)
 
 
 
-/*
-void cSocketThreads::RemoveClient(const cSocket * a_Socket)
-{
-	// Remove the socket (and associated client) from processing
-
-	cCSLock Lock(m_CS);
-	for (cSocketThreadList::iterator itr = m_Threads.begin(); itr != m_Threads.end(); ++itr)
-	{
-		if ((*itr)->RemoveSocket(a_Socket))
-		{
-			return;
-		}
-	}  // for itr - m_Threads[]
-	
-	// Cannot assert here, this may actually happen legally, since cClientHandle has to clean up the socket and it may have already closed in the meantime
-	// ASSERT(!"Removing an unknown socket");
-}
-*/
-
-
-
-
-
 void cSocketThreads::RemoveClient(const cCallback * a_Client)
 {
 	// Remove the associated socket and the client from processing
@@ -155,47 +132,6 @@ void cSocketThreads::Write(const cCallback * a_Client, const AString & a_Data)
 
 
 
-/// Stops reading from the socket - when this call returns, no more calls to the callbacks are made
-void cSocketThreads::StopReading(const cCallback * a_Client)
-{
-	cCSLock Lock(m_CS);
-	for (cSocketThreadList::iterator itr = m_Threads.begin(); itr != m_Threads.end(); ++itr)
-	{
-		if ((*itr)->StopReading(a_Client))
-		{
-			return;
-		}
-	}  // for itr - m_Threads[]
-	
-	// Cannot assert, this normally happens if the socket is closed before the client deinitializes
-	// ASSERT(!"Stopping reading on an unknown client");
-}
-
-
-
-
-
-/// Queues the socket for closing, as soon as its outgoing data is sent
-void cSocketThreads::QueueClose(const cCallback * a_Client)
-{
-	LOGD("QueueClose(client %p)", a_Client);
-	
-	cCSLock Lock(m_CS);
-	for (cSocketThreadList::iterator itr = m_Threads.begin(); itr != m_Threads.end(); ++itr)
-	{
-		if ((*itr)->QueueClose(a_Client))
-		{
-			return;
-		}
-	}  // for itr - m_Threads[]
-	
-	ASSERT(!"Queueing close of an unknown client");
-}
-
-
-
-
-
 ////////////////////////////////////////////////////////////////////////////////
 // cSocketThreads::cSocketThread:
 
@@ -233,13 +169,13 @@ cSocketThreads::cSocketThread::~cSocketThread()
 
 void cSocketThreads::cSocketThread::AddClient(const cSocket & a_Socket, cCallback * a_Client)
 {
+	ASSERT(m_Parent->m_CS.IsLockedByCurrentThread());
 	ASSERT(m_NumSlots < MAX_SLOTS);  // Use HasEmptySlot() to check before adding
 	
 	m_Slots[m_NumSlots].m_Client = a_Client;
 	m_Slots[m_NumSlots].m_Socket = a_Socket;
 	m_Slots[m_NumSlots].m_Outgoing.clear();
-	m_Slots[m_NumSlots].m_ShouldClose = false;
-	m_Slots[m_NumSlots].m_ShouldCallClient = true;
+	m_Slots[m_NumSlots].m_State = sSlot::ssNormal;
 	m_NumSlots++;
 	
 	// Notify the thread of the change:
@@ -253,7 +189,7 @@ void cSocketThreads::cSocketThread::AddClient(const cSocket & a_Socket, cCallbac
 
 bool cSocketThreads::cSocketThread::RemoveClient(const cCallback * a_Client)
 {
-	// Returns true if removed, false if not found
+	ASSERT(m_Parent->m_CS.IsLockedByCurrentThread());
 	
 	if (m_NumSlots == 0)
 	{
@@ -267,36 +203,29 @@ bool cSocketThreads::cSocketThread::RemoveClient(const cCallback * a_Client)
 			continue;
 		}
 		
-		// Found, remove it:
-		m_Slots[i] = m_Slots[--m_NumSlots];
-		
-		// Notify the thread of the change:
-		ASSERT(m_ControlSocket2.IsValid());
-		m_ControlSocket2.Send("r", 1);
-		return true;
-	}  // for i - m_Slots[]
-	
-	// Not found
-	return false;
-}
-
-
-
-
-
-bool cSocketThreads::cSocketThread::RemoveSocket(const cSocket * a_Socket)
-{
-	// Returns true if removed, false if not found
-
-	for (int i = m_NumSlots - 1; i >= 0 ; --i)
-	{
-		if (m_Slots[i].m_Socket != *a_Socket)
+		// Found the slot:
+		if (m_Slots[i].m_State == sSlot::ssRemoteClosed)
 		{
-			continue;
+			// The remote has already closed the socket, remove the slot altogether:
+			m_Slots[i] = m_Slots[--m_NumSlots];
+		}
+		else
+		{
+			// Query and queue the last batch of outgoing data:
+			m_Slots[i].m_Client->GetOutgoingData(m_Slots[i].m_Outgoing);
+			if (m_Slots[i].m_Outgoing.empty())
+			{
+				// No more outgoing data, shut the socket down immediately:
+				m_Slots[i].m_Socket.ShutdownReadWrite();
+				m_Slots[i].m_State = sSlot::ssShuttingDown;
+			}
+			else
+			{
+				// More data to send, shut down reading and wait for the rest to get sent:
+				m_Slots[i].m_State = sSlot::ssWritingRestOut;
+			}
+			m_Slots[i].m_Client = NULL;
 		}
-		
-		// Found, remove it:
-		m_Slots[i] = m_Slots[--m_NumSlots];
 		
 		// Notify the thread of the change:
 		ASSERT(m_ControlSocket2.IsValid());
@@ -314,6 +243,8 @@ bool cSocketThreads::cSocketThread::RemoveSocket(const cSocket * a_Socket)
 
 bool cSocketThreads::cSocketThread::HasClient(const cCallback * a_Client) const
 {
+	ASSERT(m_Parent->m_CS.IsLockedByCurrentThread());
+
 	for (int i = m_NumSlots - 1; i >= 0; --i)
 	{
 		if (m_Slots[i].m_Client == a_Client)
@@ -346,6 +277,8 @@ bool cSocketThreads::cSocketThread::HasSocket(const cSocket * a_Socket) const
 
 bool cSocketThreads::cSocketThread::NotifyWrite(const cCallback * a_Client)
 {
+	ASSERT(m_Parent->m_CS.IsLockedByCurrentThread());
+
 	if (HasClient(a_Client))
 	{
 		// Notify the thread that there's another packet in the queue:
@@ -362,7 +295,7 @@ bool cSocketThreads::cSocketThread::NotifyWrite(const cCallback * a_Client)
 
 bool cSocketThreads::cSocketThread::Write(const cCallback * a_Client, const AString & a_Data)
 {
-	// Returns true if socket handled by this thread
+	ASSERT(m_Parent->m_CS.IsLockedByCurrentThread());
 	for (int i = m_NumSlots - 1; i >= 0; --i)
 	{
 		if (m_Slots[i].m_Client == a_Client)
@@ -383,47 +316,6 @@ bool cSocketThreads::cSocketThread::Write(const cCallback * a_Client, const AStr
 
 
 
-bool cSocketThreads::cSocketThread::StopReading (const cCallback * a_Client)
-{
-	// Returns true if client handled by this thread
-	for (int i = m_NumSlots - 1; i >= 0; --i)
-	{
-		if (m_Slots[i].m_Client == a_Client)
-		{
-			m_Slots[i].m_ShouldCallClient = false;
-			return true;
-		}
-	}  // for i - m_Slots[]
-	return false;
-}
-
-
-
-
-
-bool cSocketThreads::cSocketThread::QueueClose(const cCallback * a_Client)
-{
-	// Returns true if socket handled by this thread
-	for (int i = m_NumSlots - 1; i >= 0; --i)
-	{
-		if (m_Slots[i].m_Client == a_Client)
-		{
-			m_Slots[i].m_ShouldClose = true;
-
-			// Notify the thread that there's a close queued (in case its conditions are already met):
-			ASSERT(m_ControlSocket2.IsValid());
-			m_ControlSocket2.Send("c", 1);
-			
-			return true;
-		}
-	}  // for i - m_Slots[]
-	return false;
-}
-
-
-
-
-
 bool cSocketThreads::cSocketThread::Start(void)
 {
 	// Create the control socket listener
@@ -497,10 +389,13 @@ void cSocketThreads::cSocketThread::Execute(void)
 		fd_set fdRead;
 		cSocket::xSocket Highest = m_ControlSocket1.GetSocket();
 		
-		PrepareSet(&fdRead, Highest);
+		PrepareSet(&fdRead, Highest, false);
 		
 		// Wait for the sockets:
-		if (select(Highest + 1, &fdRead, NULL, NULL, NULL) == -1)
+		timeval Timeout;
+		Timeout.tv_sec = 5;
+		Timeout.tv_usec = 0;
+		if (select(Highest + 1, &fdRead, NULL, NULL, &Timeout) == -1)
 		{
 			LOG("select(R) call failed in cSocketThread: \"%s\"", cSocket::GetLastErrorString().c_str());
 			continue;
@@ -511,8 +406,7 @@ void cSocketThreads::cSocketThread::Execute(void)
 		// Test sockets for writing:
 		fd_set fdWrite;
 		Highest = m_ControlSocket1.GetSocket();
-		PrepareSet(&fdWrite, Highest);		
-		timeval Timeout;
+		PrepareSet(&fdWrite, Highest, true);
 		Timeout.tv_sec = 0;
 		Timeout.tv_usec = 0;
 		if (select(Highest + 1, NULL, &fdWrite, NULL, &Timeout) == -1)
@@ -522,6 +416,8 @@ void cSocketThreads::cSocketThread::Execute(void)
 		}
 		
 		WriteToSockets(&fdWrite);
+		
+		CleanUpShutSockets();
 	}  // while (!mShouldTerminate)
 }
 
@@ -529,7 +425,7 @@ void cSocketThreads::cSocketThread::Execute(void)
 
 
 
-void cSocketThreads::cSocketThread::PrepareSet(fd_set * a_Set, cSocket::xSocket & a_Highest)
+void cSocketThreads::cSocketThread::PrepareSet(fd_set * a_Set, cSocket::xSocket & a_Highest, bool a_IsForWriting)
 {
 	FD_ZERO(a_Set);
 	FD_SET(m_ControlSocket1.GetSocket(), a_Set);
@@ -541,6 +437,11 @@ void cSocketThreads::cSocketThread::PrepareSet(fd_set * a_Set, cSocket::xSocket
 		{
 			continue;
 		}
+		if (m_Slots[i].m_State == sSlot::ssRemoteClosed)
+		{
+			// This socket won't provide nor consume any data anymore, don't put it in the Set
+			continue;
+		}
 		cSocket::xSocket s = m_Slots[i].m_Socket.GetSocket();
 		FD_SET(s, a_Set);
 		if (s > a_Highest)
@@ -576,29 +477,42 @@ void cSocketThreads::cSocketThread::ReadFromSockets(fd_set * a_Read)
 		}
 		char Buffer[1024];
 		int Received = m_Slots[i].m_Socket.Receive(Buffer, ARRAYCOUNT(Buffer), 0);
-		if (Received == 0)
-		{
-			// The socket has been closed by the remote party, close our socket and let it be removed after we process all reading
-			m_Slots[i].m_Socket.CloseSocket();
-			if (m_Slots[i].m_ShouldCallClient)
-			{
-				m_Slots[i].m_Client->SocketClosed();
-			}
-		}
-		else if (Received > 0)
+		if (Received <= 0)
 		{
-			if (m_Slots[i].m_ShouldCallClient)
+			// The socket has been closed by the remote party
+			switch (m_Slots[i].m_State)
 			{
-				m_Slots[i].m_Client->DataReceived(Buffer, Received);
-			}
+				case sSlot::ssNormal:
+				{
+					// Notify the callback that the remote has closed the socket; keep the slot
+					m_Slots[i].m_Client->SocketClosed();
+					m_Slots[i].m_State = sSlot::ssRemoteClosed;
+					break;
+				}
+				case sSlot::ssWritingRestOut:
+				case sSlot::ssShuttingDown:
+				case sSlot::ssShuttingDown2:
+				{
+					// Force-close the socket and remove the slot:
+					m_Slots[i].m_Socket.CloseSocket();
+					m_Slots[i] = m_Slots[--m_NumSlots];
+					break;
+				}
+				default:
+				{
+					LOG("%s: Unexpected socket state: %d (%s)",
+						__FUNCTION__, m_Slots[i].m_Socket.GetSocket(), m_Slots[i].m_Socket.GetIPString().c_str()
+					);
+					ASSERT(!"Unexpected socket state");
+					break;
+				}
+			}  // switch (m_Slots[i].m_State)
 		}
 		else
 		{
-			// The socket has encountered an error, close it and let it be removed after we process all reading
-			m_Slots[i].m_Socket.CloseSocket();
-			if (m_Slots[i].m_ShouldCallClient)
+			if (m_Slots[i].m_Client != NULL)
 			{
-				m_Slots[i].m_Client->SocketClosed();
+				m_Slots[i].m_Client->DataReceived(Buffer, Received);
 			}
 		}
 	}  // for i - m_Slots[]
@@ -622,22 +536,17 @@ void cSocketThreads::cSocketThread::WriteToSockets(fd_set * a_Write)
 		if (m_Slots[i].m_Outgoing.empty())
 		{
 			// Request another chunk of outgoing data:
-			if (m_Slots[i].m_ShouldCallClient)
+			if (m_Slots[i].m_Client != NULL)
 			{
 				m_Slots[i].m_Client->GetOutgoingData(m_Slots[i].m_Outgoing);
 			}
 			if (m_Slots[i].m_Outgoing.empty())
 			{
-				// Nothing ready
-				if (m_Slots[i].m_ShouldClose)
+				// No outgoing data is ready
+				if (m_Slots[i].m_State == sSlot::ssWritingRestOut)
 				{
-					// Socket was queued for closing and there's no more data to send, close it now:
-					
-					// DEBUG
-					LOGD("Socket was queued for closing, closing now. Slot %d, client %p, socket %d", i, m_Slots[i].m_Client, m_Slots[i].m_Socket.GetSocket());
-					
-					m_Slots[i].m_Socket.CloseSocket();
-					// The slot must be freed actively by the client, using RemoveClient()
+					m_Slots[i].m_State = sSlot::ssShuttingDown;
+					m_Slots[i].m_Socket.ShutdownReadWrite();
 				}
 				continue;
 			}
@@ -649,7 +558,7 @@ void cSocketThreads::cSocketThread::WriteToSockets(fd_set * a_Write)
 			int Err = cSocket::GetLastError();
 			LOGWARNING("Error %d while writing to client \"%s\", disconnecting. \"%s\"", Err, m_Slots[i].m_Socket.GetIPString().c_str(), cSocket::GetErrorString(Err).c_str());
 			m_Slots[i].m_Socket.CloseSocket();
-			if (m_Slots[i].m_ShouldCallClient)
+			if (m_Slots[i].m_Client != NULL)
 			{
 				m_Slots[i].m_Client->SocketClosed();
 			}
@@ -657,6 +566,12 @@ void cSocketThreads::cSocketThread::WriteToSockets(fd_set * a_Write)
 		}
 		m_Slots[i].m_Outgoing.erase(0, Sent);
 		
+		if (m_Slots[i].m_Outgoing.empty() && (m_Slots[i].m_State == sSlot::ssWritingRestOut))
+		{
+			m_Slots[i].m_State = sSlot::ssShuttingDown;
+			m_Slots[i].m_Socket.ShutdownReadWrite();
+		}
+
 		// _X: If there's data left, it means the client is not reading fast enough, the server would unnecessarily spin in the main loop with zero actions taken; so signalling is disabled
 		// This means that if there's data left, it will be sent only when there's incoming data or someone queues another packet (for any socket handled by this thread)
 		/*
@@ -673,3 +588,31 @@ void cSocketThreads::cSocketThread::WriteToSockets(fd_set * a_Write)
 
 
 
+
+void cSocketThreads::cSocketThread::CleanUpShutSockets(void)
+{
+	for (int i = m_NumSlots - 1; i >= 0; i--)
+	{
+		switch (m_Slots[i].m_State)
+		{
+			case sSlot::ssShuttingDown2:
+			{
+				// The socket has reached the shutdown timeout, close it and clear its slot:
+				m_Slots[i].m_Socket.CloseSocket();
+				m_Slots[i] = m_Slots[--m_NumSlots];
+				break;
+			}
+			case sSlot::ssShuttingDown:
+			{
+				// The socket has been shut down for a single thread loop, let it loop once more before closing:
+				m_Slots[i].m_State = sSlot::ssShuttingDown2;
+				break;
+			}
+			default: break;
+		}
+	}  // for i - m_Slots[]
+}
+
+
+
+
diff --git a/src/OSSupport/SocketThreads.h b/src/OSSupport/SocketThreads.h
index 858729c49..9e1947ab6 100644
--- a/src/OSSupport/SocketThreads.h
+++ b/src/OSSupport/SocketThreads.h
@@ -7,19 +7,20 @@
 
 /*
 Additional details:
-When a client is terminating a connection:
-- they call the StopReading() method to disable callbacks for the incoming data
-- they call the Write() method to queue any outstanding outgoing data
-- they call the QueueClose() method to queue the socket to close after outgoing data has been sent.
-When a socket slot is marked as having no callback, it is kept alive until its outgoing data queue is empty and its m_ShouldClose flag is set.
-This means that the socket can be written to several times before finally closing it via QueueClose()
+When a client wants to terminate the connection, they call the RemoveClient() function. This calls the
+callback one last time to read all the available outgoing data, putting it in the slot's m_OutgoingData
+buffer. Then it marks the slot as having no callback. The socket is kept alive until its outgoing data
+queue is empty, then shutdown is called on it and finally the socket is closed after a timeout.
+If at any time within this the remote end closes the socket, then the socket is closed directly.
+As soon as the socket is closed, the slot is finally removed from the SocketThread.
+The graph in $/docs/SocketThreads States.gv shows the state-machine transitions of the slot.
 */
 
 
 
 
 
-/// How many clients should one thread handle? (must be less than FD_SETSIZE for your platform)
+/** How many clients should one thread handle? (must be less than FD_SETSIZE for your platform) */
 #define MAX_SLOTS 63
 
 
@@ -27,8 +28,6 @@ This means that the socket can be written to several times before finally closin
 
 
 #pragma once
-#ifndef CSOCKETTHREADS_H_INCLUDED
-#define CSOCKETTHREADS_H_INCLUDED
 
 #include "Socket.h"
 #include "IsThread.h"
@@ -64,13 +63,13 @@ public:
 		// Force a virtual destructor in all subclasses:
 		virtual ~cCallback() {}
 		
-		/// Called when data is received from the remote party
+		/** Called when data is received from the remote party */
 		virtual void DataReceived(const char * a_Data, int a_Size) = 0;
 		
-		/// Called when data can be sent to remote party; the function is supposed to append outgoing data to a_Data
+		/** Called when data can be sent to remote party; the function is supposed to *append* outgoing data to a_Data */
 		virtual void GetOutgoingData(AString & a_Data) = 0;
 		
-		/// Called when the socket has been closed for any reason
+		/** Called when the socket has been closed for any reason */
 		virtual void SocketClosed(void) = 0;
 	} ;
 
@@ -78,24 +77,21 @@ public:
 	cSocketThreads(void);
 	~cSocketThreads();
 	
-	/// Add a (socket, client) pair for processing, data from a_Socket is to be sent to a_Client; returns true if successful
+	/** Add a (socket, client) pair for processing, data from a_Socket is to be sent to a_Client; returns true if successful */
 	bool AddClient(const cSocket & a_Socket, cCallback * a_Client);
 	
-	/// Remove the associated socket and the client from processing. The socket is left to send its data and is removed only after all its m_OutgoingData is sent
+	/** Remove the associated socket and the client from processing.
+	The socket is left to send its last outgoing data and is removed only after all its m_Outgoing is sent
+	and after the socket is properly shutdown (unless the remote disconnects before that)
+	*/
 	void RemoveClient(const cCallback * a_Client);
 	
-	/// Notify the thread responsible for a_Client that the client has something to write
+	/** Notify the thread responsible for a_Client that the client has something to write */
 	void NotifyWrite(const cCallback * a_Client);
 	
-	/// Puts a_Data into outgoing data queue for a_Client
+	/** Puts a_Data into outgoing data queue for a_Client */
 	void Write(const cCallback * a_Client, const AString & a_Data);
 	
-	/// Stops reading from the client - when this call returns, no more calls to the callbacks are made
-	void StopReading(const cCallback * a_Client);
-	
-	/// Queues the client for closing, as soon as its outgoing data is sent
-	void QueueClose(const cCallback * a_Client);
-
 private:
 
 	class cSocketThread :
@@ -114,13 +110,10 @@ private:
 
 		void AddClient   (const cSocket &   a_Socket, cCallback * a_Client);  // Takes ownership of the socket
 		bool RemoveClient(const cCallback * a_Client);  // Returns true if removed, false if not found
-		bool RemoveSocket(const cSocket *   a_Socket);  // Returns true if removed, false if not found
 		bool HasClient   (const cCallback * a_Client) const;
 		bool HasSocket   (const cSocket *   a_Socket) const;
 		bool NotifyWrite (const cCallback * a_Client);  // Returns true if client handled by this thread
 		bool Write       (const cCallback * a_Client, const AString & a_Data);  // Returns true if client handled by this thread
-		bool StopReading (const cCallback * a_Client);  // Returns true if client handled by this thread
-		bool QueueClose  (const cCallback * a_Client);  // Returns true if client handled by this thread
 		
 		bool Start(void);  // Hide the cIsThread's Start method, we need to provide our own startup to create the control socket
 		
@@ -134,24 +127,45 @@ private:
 		cSocket m_ControlSocket1;
 		cSocket m_ControlSocket2;
 		
-		// Socket-client-packetqueues triplets.
+		// Socket-client-dataqueues-state quadruplets.
 		// Manipulation with these assumes that the parent's m_CS is locked
 		struct sSlot
 		{
-			cSocket     m_Socket;  // The socket is primarily owned by this
+			/** The socket is primarily owned by this object */
+			cSocket m_Socket;
+			
+			/** The callback to call for events. May be NULL */
 			cCallback * m_Client;
-			AString     m_Outgoing;  // If sending writes only partial data, the rest is stored here for another send
-			bool        m_ShouldClose;  // If true, the socket is to be closed after sending all outgoing data
-			bool        m_ShouldCallClient;  // If true, the client callbacks are called. Set to false in StopReading()
+			
+			/** If sending writes only partial data, the rest is stored here for another send.
+			Also used when the slot is being removed to store the last batch of outgoing data. */
+			AString m_Outgoing;
+			
+			enum eState
+			{
+				ssNormal,          ///< Normal read / write operations
+				ssWritingRestOut,  ///< The client callback was removed, continue to send outgoing data
+				ssShuttingDown,    ///< The last outgoing data has been sent, the socket has called shutdown()
+				ssShuttingDown2,   ///< The shutdown has been done at least 1 thread loop ago (timeout detection)
+				ssRemoteClosed,    ///< The remote end has closed the connection (and we still have a client callback)
+			} m_State;
 		} ;
+		
 		sSlot m_Slots[MAX_SLOTS];
 		int   m_NumSlots;  // Number of slots actually used
 		
 		virtual void Execute(void) override;
 		
-		void PrepareSet     (fd_set * a_Set, cSocket::xSocket & a_Highest);  // Puts all sockets into the set, along with m_ControlSocket1
+		/** Puts all sockets into the set, along with m_ControlSocket1.
+		Only sockets that are able to send and receive data are put in the Set.
+		Is a_IsForWriting is true, the ssWritingRestOut sockets are added as well. */
+		void PrepareSet(fd_set * a_Set, cSocket::xSocket & a_Highest, bool a_IsForWriting);
+		
 		void ReadFromSockets(fd_set * a_Read);  // Reads from sockets indicated in a_Read
 		void WriteToSockets (fd_set * a_Write);  // Writes to sockets indicated in a_Write
+		
+		/** Removes those slots in ssShuttingDown2 state, sets those with ssShuttingDown state to ssShuttingDown2 */
+		void CleanUpShutSockets(void);
 	} ;
 	
 	typedef std::list<cSocketThread *> cSocketThreadList;
@@ -164,9 +178,3 @@ private:
 
 
 
-
-#endif  // CSOCKETTHREADS_H_INCLUDED
-
-
-
-