Disconnect CoreSession _networks before delete

Explicitly call disconnect for each CoreNetwork, process events, then
wait for each network to disconnect before deleting it.

This overwrides the automatic cleanup in CoreNetwork to handle
shutting down tens of networks at once.  This allows all CoreNetworks
to start disconnecting at once before waiting for each to individually
shut down.

Resolves GH-207.

(cherry picked from commit d414dd5212cc00f1d43615528bb97470a65143b5)

diff --git a/src/core/coresession.cpp b/src/core/coresession.cpp
index 1d0d5c5..a3b38cf 100644 (file)
--- a/src/core/coresession.cpp
+++ b/src/core/coresession.cpp
@@ -137,7 +137,47 @@ CoreSession::CoreSession(UserId uid, bool restoreState, QObject *parent)
 CoreSession::~CoreSession()
 {
     saveSessionState();
+
+    /* Why partially duplicate CoreNetwork destructor?  When each CoreNetwork quits in the
+     * destructor, disconnections are processed in sequence for each object.  For many IRC servers
+     * on a slow network, this could significantly delay core shutdown [msecs wait * network count].
+     *
+     * Here, CoreSession first calls disconnect on all networks, letting them all start
+     * disconnecting before beginning to sequentially wait for each network.  Ideally, after the
+     * first network is disconnected, the other networks will have already closed.  Worst-case may
+     * still wait [msecs wait time * num. of networks], but the risk should be much lower.
+     *
+     * CoreNetwork should still do cleanup in its own destructor in case a network is deleted
+     * outside of deleting the whole CoreSession.
+     *
+     * If this proves to be problematic in the future, there's an alternative Qt signal-based system
+     * implemented in another pull request that guarentees a maximum amount of time to disconnect,
+     * but at the cost of more complex code.
+     *
+     * See https://github.com/quassel/quassel/pull/203
+     */
+
+    foreach(CoreNetwork *net, _networks.values()) {
+        // Request each network properly disconnect, but don't count as user-requested disconnect
+        if (net->socketConnected()) {
+            // Only try if the socket's fully connected (not initializing or disconnecting).
+            // Force an immediate disconnect, jumping the command queue.  Ensures the proper QUIT is
+            // shown even if other messages are queued.
+            net->disconnectFromIrc(false, QString(), false, true);
+        }
+    }
+
+    // Process the putCmd events that trigger the quit.  Without this, shutting down the core
+    // results in abrubtly closing the socket rather than sending the QUIT as expected.
+    QCoreApplication::processEvents();
+
     foreach(CoreNetwork *net, _networks.values()) {
+        // Wait briefly for each network to disconnect.  Sometimes it takes a little while to send.
+        if (!net->forceDisconnect()) {
+            qWarning() << "Timed out quitting network" << net->networkName() <<
+                          "(user ID " << net->userId() << ")";
+        }
+        // Delete the network now that it's closed
         delete net;
     }
 }