Make creating sockets with an explicit network session thread safe

Added a mutex to QNetworkSessionPrivate
Lock the mutex in the symbian bearer plugin for functions that change
    the validity of the RConnection.
Added factory functions to open an RSocket or RHostResolver, which lock
    the mutex before the esock function calls. If there is no RConnection,
    then KErrNotReady is returned (the same as when there is an RConnection
    but it has not been started).

Task-number: QTBUG-18143
Reviewed-by: Markus Goetz

3 files changed, 43 insertions, 11 deletions

diff --git a/src/network/bearer/qnetworksession.cpp b/src/network/bearer/qnetworksession.cpp
index 6106550..21e64d9 100644
--- a/src/network/bearer/qnetworksession.cpp
+++ b/src/network/bearer/qnetworksession.cpp
@@ -44,10 +44,16 @@
 
 #include <QEventLoop>
 #include <QTimer>
+#include <QThread>
 
 #include "qnetworkconfigmanager_p.h"
 #include "qnetworksession_p.h"
 
+#ifdef Q_OS_SYMBIAN
+#include <es_sock.h>
+#include <private/qcore_symbian_p.h>
+#endif
+
 #ifndef QT_NO_BEARERMANAGEMENT
 
 QT_BEGIN_NAMESPACE
@@ -710,8 +716,33 @@ RConnection* QNetworkSessionPrivate::nativeSession(QNetworkSession &s)
 {
     if (!s.d)
         return 0;
+    if (s.thread() != QThread::currentThread())
+        qWarning("QNetworkSessionPrivate::nativeSession called in wrong thread");
     return s.d->nativeSession();
 }
+
+TInt QNetworkSessionPrivate::nativeOpenSocket(QNetworkSession& s, RSocket& sock, TUint family, TUint type, TUint protocol)
+{
+    if (!s.d)
+        return 0;
+    QMutexLocker lock(&(s.d->mutex));
+    RConnection *con = s.d->nativeSession();
+    if (!con || !con->SubSessionHandle())
+        return KErrNotReady;
+    return sock.Open(qt_symbianGetSocketServer(), family, type, protocol, *con);
+}
+
+TInt QNetworkSessionPrivate::nativeOpenHostResolver(QNetworkSession& s, RHostResolver& resolver, TUint family, TUint protocol)
+{
+    if (!s.d)
+        return 0;
+    QMutexLocker lock(&(s.d->mutex));
+    RConnection *con = s.d->nativeSession();
+    if (!con || !con->SubSessionHandle())
+        return KErrNotReady;
+    return resolver.Open(qt_symbianGetSocketServer(), family, protocol, *con);
+}
+
 #endif
 
 #include "moc_qnetworksession.cpp"
diff --git a/src/network/bearer/qnetworksession_p.h b/src/network/bearer/qnetworksession_p.h
index e2fcfe6..b359f80 100644
--- a/src/network/bearer/qnetworksession_p.h
+++ b/src/network/bearer/qnetworksession_p.h
@@ -61,6 +61,8 @@
 
 #ifdef Q_OS_SYMBIAN
 class RConnection;
+class RSocket;
+class RHostResolver;
 #endif
 
 QT_BEGIN_NAMESPACE
@@ -108,8 +110,13 @@ public:
     virtual quint64 activeTime() const = 0;
 
 #ifdef Q_OS_SYMBIAN
+    // get internal RConnection (not thread safe, call only from thread that owns the QNetworkSession)
     static RConnection* nativeSession(QNetworkSession&);
     virtual RConnection* nativeSession() = 0;
+    // open socket using the internal RConnection (thread safe)
+    static TInt nativeOpenSocket(QNetworkSession& session, RSocket& socket, TUint family, TUint type, TUint protocol);
+    // open host resolver using the internal RConnection (thread safe)
+    static TInt nativeOpenHostResolver(QNetworkSession& session, RHostResolver& resolver, TUint family, TUint protocol);
 #endif
 protected:
     inline QNetworkConfigurationPrivatePointer privateConfiguration(const QNetworkConfiguration &config) const
@@ -150,6 +157,8 @@ protected:
 
     QNetworkSession::State state;
     bool isOpen;
+
+    QMutex mutex;
 };
 
 QT_END_NAMESPACE
diff --git a/src/network/socket/qsymbiansocketengine.cpp b/src/network/socket/qsymbiansocketengine.cpp
index be04b56..688f724 100644
--- a/src/network/socket/qsymbiansocketengine.cpp
+++ b/src/network/socket/qsymbiansocketengine.cpp
@@ -189,21 +189,13 @@ bool QSymbianSocketEnginePrivate::createNewSocket(QAbstractSocket::SocketType so
     //Check if there is a user specified session
     RConnection *connection = 0;
     QVariant v(q->property("_q_networksession"));
+    TInt err;
     if (v.isValid()) {
         QSharedPointer<QNetworkSession> s = qvariant_cast<QSharedPointer<QNetworkSession> >(v);
-        connection = QNetworkSessionPrivate::nativeSession(*s);
+        err = QNetworkSessionPrivate::nativeOpenSocket(*s, nativeSocket, family, type, protocol);
 #ifdef QNATIVESOCKETENGINE_DEBUG
-        qDebug() << "QSymbianSocketEnginePrivate::createNewSocket - _q_networksession was set" << connection;
+        qDebug() << "QSymbianSocketEnginePrivate::createNewSocket - _q_networksession was set" << err;
 #endif
-    }
-    TInt err;
-    if (connection) {
-        if (connection->SubSessionHandle())
-            err = nativeSocket.Open(socketServer, family, type, protocol, *connection);
-        else {
-            setError(QAbstractSocket::NetworkError, SessionNotOpenErrorString);
-            return false;
-        }
     } else
         err = nativeSocket.Open(socketServer, family, type, protocol); //TODO: FIXME - deprecated API, make sure we always have a connection instead