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-rw-r--r--src/OSSupport/SocketThreads.cpp675
1 files changed, 675 insertions, 0 deletions
diff --git a/src/OSSupport/SocketThreads.cpp b/src/OSSupport/SocketThreads.cpp
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index 000000000..3e505616c
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+++ 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]
+}
+
+
+
+
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