1 files changed, 675 insertions, 0 deletions

diff --git a/src/OSSupport/SocketThreads.cpp b/src/OSSupport/SocketThreads.cpp
new file mode 100644
index 000000000..3e505616c
--- /dev/null
+++ b/src/OSSupport/SocketThreads.cpp
@@ -0,0 +1,675 @@
+
+// cSocketThreads.cpp
+
+// Implements the cSocketThreads class representing the heart of MCS's client networking.
+// This object takes care of network communication, groups sockets into threads and uses as little threads as possible for full read / write support
+// For more detail, see http://forum.mc-server.org/showthread.php?tid=327
+
+#include "Globals.h"
+#include "SocketThreads.h"
+
+
+
+
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// cSocketThreads:
+
+cSocketThreads::cSocketThreads(void)
+{
+}
+
+
+
+
+
+cSocketThreads::~cSocketThreads()
+{
+	for (cSocketThreadList::iterator itr = m_Threads.begin(); itr != m_Threads.end(); ++itr)
+	{
+		delete *itr;
+	}  // for itr - m_Threads[]
+	m_Threads.clear();
+}
+
+
+
+
+
+
+bool cSocketThreads::AddClient(const cSocket & a_Socket, cCallback * a_Client)
+{
+	// Add a (socket, client) pair for processing, data from a_Socket is to be sent to a_Client
+	
+	// Try to add to existing threads:
+	cCSLock Lock(m_CS);
+	for (cSocketThreadList::iterator itr = m_Threads.begin(); itr != m_Threads.end(); ++itr)
+	{
+		if ((*itr)->IsValid() && (*itr)->HasEmptySlot())
+		{
+			(*itr)->AddClient(a_Socket, a_Client);
+			return true;
+		}
+	}
+	
+	// No thread has free space, create a new one:
+	LOGD("Creating a new cSocketThread (currently have %d)", m_Threads.size());
+	cSocketThread * Thread = new cSocketThread(this);
+	if (!Thread->Start())
+	{
+		// There was an error launching the thread (but it was already logged along with the reason)
+		LOGERROR("A new cSocketThread failed to start");
+		delete Thread;
+		return false;
+	}
+	Thread->AddClient(a_Socket, a_Client);
+	m_Threads.push_back(Thread);
+	return true;
+}
+
+
+
+
+
+/*
+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
+
+	cCSLock Lock(m_CS);
+	for (cSocketThreadList::iterator itr = m_Threads.begin(); itr != m_Threads.end(); ++itr)
+	{
+		if ((*itr)->RemoveClient(a_Client))
+		{
+			return;
+		}
+	}  // for itr - m_Threads[]
+
+	ASSERT(!"Removing an unknown client");
+}
+
+
+
+
+
+void cSocketThreads::NotifyWrite(const cCallback * a_Client)
+{
+	// Notifies the thread responsible for a_Client that the client has something to write
+
+	cCSLock Lock(m_CS);
+	for (cSocketThreadList::iterator itr = m_Threads.begin(); itr != m_Threads.end(); ++itr)
+	{
+		if ((*itr)->NotifyWrite(a_Client))
+		{
+			return;
+		}
+	}  // for itr - m_Threads[]
+	
+	// Cannot assert - this normally happens if a client disconnects and has pending packets, the cServer::cNotifyWriteThread will call this on invalid clients too
+	// ASSERT(!"Notifying write to an unknown client");
+}
+
+
+
+
+
+void cSocketThreads::Write(const cCallback * a_Client, const AString & a_Data)
+{
+	// Puts a_Data into outgoing data queue for a_Client
+	cCSLock Lock(m_CS);
+	for (cSocketThreadList::iterator itr = m_Threads.begin(); itr != m_Threads.end(); ++itr)
+	{
+		if ((*itr)->Write(a_Client, a_Data))
+		{
+			return;
+		}
+	}  // for itr - m_Threads[]
+	
+	// This may be perfectly legal, if the socket has been destroyed and the client is finishing up
+	// ASSERT(!"Writing to an unknown socket");
+}
+
+
+
+
+
+/// 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:
+
+cSocketThreads::cSocketThread::cSocketThread(cSocketThreads * a_Parent) :
+	cIsThread("cSocketThread"),
+	m_Parent(a_Parent),
+	m_NumSlots(0)
+{
+	// Nothing needed yet
+}
+
+
+
+
+
+cSocketThreads::cSocketThread::~cSocketThread()
+{
+	m_ShouldTerminate = true;
+
+	// Notify the thread:
+	ASSERT(m_ControlSocket2.IsValid());
+	m_ControlSocket2.Send("a", 1);
+
+	// Wait for the thread to finish:
+	Wait();
+	
+	// Close the control sockets:
+	m_ControlSocket1.CloseSocket();
+	m_ControlSocket2.CloseSocket();
+}
+
+
+
+
+
+void cSocketThreads::cSocketThread::AddClient(const cSocket & a_Socket, cCallback * a_Client)
+{
+	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_NumSlots++;
+	
+	// Notify the thread of the change:
+	ASSERT(m_ControlSocket2.IsValid());
+	m_ControlSocket2.Send("a", 1);
+}
+
+
+
+
+
+bool cSocketThreads::cSocketThread::RemoveClient(const cCallback * a_Client)
+{
+	// Returns true if removed, false if not found
+	
+	if (m_NumSlots == 0)
+	{
+		return false;
+	}
+	
+	for (int i = m_NumSlots - 1; i >= 0 ; --i)
+	{
+		if (m_Slots[i].m_Client != 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)
+		{
+			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::HasClient(const cCallback * a_Client) const
+{
+	for (int i = m_NumSlots - 1; i >= 0; --i)
+	{
+		if (m_Slots[i].m_Client == a_Client)
+		{
+			return true;
+		}
+	}  // for i - m_Slots[]
+	return false;
+}
+
+
+
+
+
+bool cSocketThreads::cSocketThread::HasSocket(const cSocket * a_Socket) const
+{
+	for (int i = m_NumSlots - 1; i >= 0; --i)
+	{
+		if (m_Slots[i].m_Socket == *a_Socket)
+		{
+			return true;
+		}
+	}  // for i - m_Slots[]
+	return false;
+}
+
+
+
+
+
+bool cSocketThreads::cSocketThread::NotifyWrite(const cCallback * a_Client)
+{
+	if (HasClient(a_Client))
+	{
+		// Notify the thread that there's another packet in the queue:
+		ASSERT(m_ControlSocket2.IsValid());
+		m_ControlSocket2.Send("q", 1);
+		return true;
+	}
+	return false;
+}
+
+
+
+
+
+bool cSocketThreads::cSocketThread::Write(const cCallback * a_Client, const AString & a_Data)
+{
+	// 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_Outgoing.append(a_Data);
+			
+			// Notify the thread that there's data in the queue:
+			ASSERT(m_ControlSocket2.IsValid());
+			m_ControlSocket2.Send("q", 1);
+			
+			return true;
+		}
+	}  // for i - m_Slots[]
+	return false;
+}
+
+
+
+
+
+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
+	m_ControlSocket2 = cSocket::CreateSocket(cSocket::IPv4);
+	if (!m_ControlSocket2.IsValid())
+	{
+		LOGERROR("Cannot create a Control socket for a cSocketThread (\"%s\"); continuing, but server may be unreachable from now on.", cSocket::GetLastErrorString().c_str());
+		return false;
+	}
+	if (!m_ControlSocket2.BindToLocalhostIPv4(cSocket::ANY_PORT))
+	{
+		LOGERROR("Cannot bind a Control socket for a cSocketThread (\"%s\"); continuing, but server may be unreachable from now on.", cSocket::GetLastErrorString().c_str());
+		m_ControlSocket2.CloseSocket();
+		return false;
+	}
+	if (!m_ControlSocket2.Listen(1))
+	{
+		LOGERROR("Cannot listen on a Control socket for a cSocketThread (\"%s\"); continuing, but server may be unreachable from now on.", cSocket::GetLastErrorString().c_str());
+		m_ControlSocket2.CloseSocket();
+		return false;
+	}
+	if (m_ControlSocket2.GetPort() == 0)
+	{
+		LOGERROR("Cannot determine Control socket port (\"%s\"); conitnuing, but the server may be unreachable from now on.", cSocket::GetLastErrorString().c_str());
+		m_ControlSocket2.CloseSocket();
+		return false;
+	}
+
+	// Start the thread
+	if (!super::Start())
+	{
+		LOGERROR("Cannot start new cSocketThread");
+		m_ControlSocket2.CloseSocket();
+		return false;
+	}
+	
+	// Finish connecting the control socket by accepting connection from the thread's socket
+	cSocket tmp = m_ControlSocket2.AcceptIPv4();
+	if (!tmp.IsValid())
+	{
+		LOGERROR("Cannot link Control sockets for a cSocketThread (\"%s\"); continuing, but server may be unreachable from now on.", cSocket::GetLastErrorString().c_str());
+		m_ControlSocket2.CloseSocket();
+		return false;
+	}
+	m_ControlSocket2.CloseSocket();
+	m_ControlSocket2 = tmp;
+	
+	return true;
+}
+
+
+
+
+
+void cSocketThreads::cSocketThread::Execute(void)
+{
+	// Connect the "client" part of the Control socket:
+	m_ControlSocket1 = cSocket::CreateSocket(cSocket::IPv4);
+	ASSERT(m_ControlSocket2.GetPort() != 0);  // We checked in the Start() method, but let's be sure
+	if (!m_ControlSocket1.ConnectToLocalhostIPv4(m_ControlSocket2.GetPort()))
+	{
+		LOGERROR("Cannot connect Control sockets for a cSocketThread (\"%s\"); continuing, but the server may be unreachable from now on.", cSocket::GetLastErrorString().c_str());
+		m_ControlSocket2.CloseSocket();
+		return;
+	}
+	
+	// The main thread loop:
+	while (!m_ShouldTerminate)
+	{
+		// Put all sockets into the Read set:
+		fd_set fdRead;
+		cSocket::xSocket Highest = m_ControlSocket1.GetSocket();
+		
+		PrepareSet(&fdRead, Highest);
+		
+		// Wait for the sockets:
+		if (select(Highest + 1, &fdRead, NULL, NULL, NULL) == -1)
+		{
+			LOG("select(R) call failed in cSocketThread: \"%s\"", cSocket::GetLastErrorString().c_str());
+			continue;
+		}
+		
+		ReadFromSockets(&fdRead);
+
+		// Test sockets for writing:
+		fd_set fdWrite;
+		Highest = m_ControlSocket1.GetSocket();
+		PrepareSet(&fdWrite, Highest);		
+		timeval Timeout;
+		Timeout.tv_sec = 0;
+		Timeout.tv_usec = 0;
+		if (select(Highest + 1, NULL, &fdWrite, NULL, &Timeout) == -1)
+		{
+			LOG("select(W) call failed in cSocketThread: \"%s\"", cSocket::GetLastErrorString().c_str());
+			continue;
+		}
+		
+		WriteToSockets(&fdWrite);
+	}  // while (!mShouldTerminate)
+}
+
+
+
+
+
+void cSocketThreads::cSocketThread::PrepareSet(fd_set * a_Set, cSocket::xSocket & a_Highest)
+{
+	FD_ZERO(a_Set);
+	FD_SET(m_ControlSocket1.GetSocket(), a_Set);
+
+	cCSLock Lock(m_Parent->m_CS);
+	for (int i = m_NumSlots - 1; i >= 0; --i)
+	{
+		if (!m_Slots[i].m_Socket.IsValid())
+		{
+			continue;
+		}
+		cSocket::xSocket s = m_Slots[i].m_Socket.GetSocket();
+		FD_SET(s, a_Set);
+		if (s > a_Highest)
+		{
+			a_Highest = s;
+		}
+	}  // for i - m_Slots[]
+}
+
+
+
+
+
+void cSocketThreads::cSocketThread::ReadFromSockets(fd_set * a_Read)
+{
+	// Read on available sockets:
+
+	// Reset Control socket state:
+	if (FD_ISSET(m_ControlSocket1.GetSocket(), a_Read))
+	{
+		char Dummy[128];
+		m_ControlSocket1.Receive(Dummy, sizeof(Dummy), 0);
+	}
+
+	// Read from clients:
+	cCSLock Lock(m_Parent->m_CS);
+	for (int i = m_NumSlots - 1; i >= 0; --i)
+	{
+		cSocket::xSocket Socket = m_Slots[i].m_Socket.GetSocket();
+		if (!cSocket::IsValidSocket(Socket) || !FD_ISSET(Socket, a_Read))
+		{
+			continue;
+		}
+		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 (m_Slots[i].m_ShouldCallClient)
+			{
+				m_Slots[i].m_Client->DataReceived(Buffer, Received);
+			}
+		}
+		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)
+			{
+				m_Slots[i].m_Client->SocketClosed();
+			}
+		}
+	}  // for i - m_Slots[]
+}
+
+
+
+
+
+void cSocketThreads::cSocketThread::WriteToSockets(fd_set * a_Write)
+{
+	// Write to available client sockets:
+	cCSLock Lock(m_Parent->m_CS);
+	for (int i = m_NumSlots - 1; i >= 0; --i)
+	{
+		cSocket::xSocket Socket = m_Slots[i].m_Socket.GetSocket();
+		if (!cSocket::IsValidSocket(Socket) || !FD_ISSET(Socket, a_Write))
+		{
+			continue;
+		}
+		if (m_Slots[i].m_Outgoing.empty())
+		{
+			// Request another chunk of outgoing data:
+			if (m_Slots[i].m_ShouldCallClient)
+			{
+				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)
+				{
+					// 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()
+				}
+				continue;
+			}
+		}  // if (outgoing data is empty)
+		
+		int Sent = m_Slots[i].m_Socket.Send(m_Slots[i].m_Outgoing.data(), m_Slots[i].m_Outgoing.size());
+		if (Sent < 0)
+		{
+			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)
+			{
+				m_Slots[i].m_Client->SocketClosed();
+			}
+			return;
+		}
+		m_Slots[i].m_Outgoing.erase(0, Sent);
+		
+		// _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)
+		/*
+		// If there's any data left, signalize the Control socket:
+		if (!m_Slots[i].m_Outgoing.empty())
+		{
+			ASSERT(m_ControlSocket2.IsValid());
+			m_ControlSocket2.Send("q", 1);
+		}
+		*/
+	}  // for i - m_Slots[i]
+}
+
+
+
+