One sender thread per client. Requires loads of resources. Kind of hacked, because the internal dependencies are very ugly now. Requires loads of testing. A problem might be the last packet sent by the server to a specific client before closing the connection, for example an error message. It might never even reach the client, because the sender thread is terminated before. I have not yet found a good way to fix this.

src/net/common/sessiondata.cpp

@@ -18,15 +18,20 @@
  ***************************************************************************/
 
 #include <net/sessiondata.h>
+#include <net/senderthread.h>
 
-SessionData::SessionData(SOCKET sockfd, SessionId id)
+SessionData::SessionData(SOCKET sockfd, SessionId id, SenderCallback &cb)
 : m_sockfd(sockfd), m_id(id), m_state(SessionData::Init), m_readyFlag(false),
   m_wantsLobbyMsg(true), m_activityTimeoutNoticeSent(false)
 {
+	m_sender.reset(new SenderThread(cb));
+	m_sender->Start();
 }
 
 SessionData::~SessionData()
 {
+	m_sender->SignalStop();
+	m_sender->WaitStop();
 	if (m_sockfd != INVALID_SOCKET)
 		CLOSESOCKET(m_sockfd);
 }
@@ -122,6 +127,12 @@ SessionData::GetReceiveBuffer()
 	return m_receiveBuffer;
 }
 
+SenderInterface &
+SessionData::GetSender()
+{
+	return *m_sender;
+}
+
 void
 SessionData::ResetActivityTimer()
 {