QAbstractSocket: insert timer to prevent timeout

This fixes a timeout that occurred on Mac with the gui event dispatcher:
we were waiting for a write notification, but timed out when we were in
closing state and still waiting for the socket engine to complete
writing.
Now we close the socket anyway after 2 seconds.

Reviewed-by: Thiago Macieira

3 files changed, 30 insertions, 2 deletions

diff --git a/src/network/socket/qabstractsocket.cpp b/src/network/socket/qabstractsocket.cpp
index 955fee0..89a6e91 100644
--- a/src/network/socket/qabstractsocket.cpp
+++ b/src/network/socket/qabstractsocket.cpp
@@ -462,6 +462,7 @@ QAbstractSocketPrivate::QAbstractSocketPrivate()
       isBuffered(false),
       blockingTimeout(30000),
       connectTimer(0),
+      disconnectTimer(0),
       connectTimeElapsed(0),
       hostLookupId(-1),
       socketType(QAbstractSocket::UnknownSocketType),
@@ -497,9 +498,10 @@ void QAbstractSocketPrivate::resetSocketLayer()
         socketEngine = 0;
         cachedSocketDescriptor = -1;
     }
-    if (connectTimer) {
+    if (connectTimer)
         connectTimer->stop();
-    }
+    if (disconnectTimer)
+        disconnectTimer->stop();
 }
 
 /*! \internal
@@ -1094,6 +1096,15 @@ void QAbstractSocketPrivate::_q_abortConnectionAttempt()
     }
 }
 
+void QAbstractSocketPrivate::_q_forceDisconnect()
+{
+    Q_Q(QAbstractSocket);
+    if (socketEngine && socketEngine->isValid() && state == QAbstractSocket::ClosingState) {
+        socketEngine->close();
+        q->disconnectFromHost();
+    }
+}
+
 /*! \internal
 
     Reads data from the socket layer into the read buffer. Returns
@@ -2356,6 +2367,20 @@ void QAbstractSocket::disconnectFromHostImplementation()
         // Wait for pending data to be written.
         if (d->socketEngine && d->socketEngine->isValid() && (d->writeBuffer.size() > 0
             || d->socketEngine->bytesToWrite() > 0)) {
+            // hack: when we are waiting for the socket engine to write bytes (only
+            // possible when using Socks5 or HTTP socket engine), then close
+            // anyway after 2 seconds. This is to prevent a timeout on Mac, where we
+            // sometimes just did not get the write notifier from the underlying
+            // CFSocket and no progress was made.
+            if (d->writeBuffer.size() == 0 && d->socketEngine->bytesToWrite() > 0) {
+                if (!d->disconnectTimer) {
+                    d->disconnectTimer = new QTimer(this);
+                    connect(d->disconnectTimer, SIGNAL(timeout()), this,
+                            SLOT(_q_forceDisconnect()), Qt::DirectConnection);
+                }
+                if (!d->disconnectTimer->isActive())
+                    d->disconnectTimer->start(2000);
+            }
             d->socketEngine->setWriteNotificationEnabled(true);
 
 #if defined(QABSTRACTSOCKET_DEBUG)
diff --git a/src/network/socket/qabstractsocket.h b/src/network/socket/qabstractsocket.h
index 5d94a01..5cfae17 100644
--- a/src/network/socket/qabstractsocket.h
+++ b/src/network/socket/qabstractsocket.h
@@ -216,6 +216,7 @@ private:
     Q_PRIVATE_SLOT(d_func(), void _q_startConnecting(const QHostInfo &))
     Q_PRIVATE_SLOT(d_func(), void _q_abortConnectionAttempt())
     Q_PRIVATE_SLOT(d_func(), void _q_testConnection())
+    Q_PRIVATE_SLOT(d_func(), void _q_forceDisconnect())
 
 #ifdef QT3_SUPPORT
 public:
diff --git a/src/network/socket/qabstractsocket_p.h b/src/network/socket/qabstractsocket_p.h
index 8ccddd3..acf82bf 100644
--- a/src/network/socket/qabstractsocket_p.h
+++ b/src/network/socket/qabstractsocket_p.h
@@ -93,6 +93,7 @@ public:
     void _q_startConnecting(const QHostInfo &hostInfo);
     void _q_testConnection();
     void _q_abortConnectionAttempt();
+    void _q_forceDisconnect();
 
     bool readSocketNotifierCalled;
     bool readSocketNotifierState;
@@ -148,6 +149,7 @@ public:
     int blockingTimeout;
 
     QTimer *connectTimer;
+    QTimer *disconnectTimer;
     int connectTimeElapsed;
 
     int hostLookupId;