Thread safety for QFontEngineS60

On symbian, creating fonts requires a connection to the window server.
Window server sessions are not sharable across threads.
To avoid QFont crashing when used outside the GUI thread, we construct a
private session to the window server when the shared CONE session is not
available.
(CCoeEnv::Static() uses TLS, so it returns null outside of GUI thread)

The private session and screen device are stored in QThreadStorage, so
they are automatically deleted when the QThread exits.

Task-number: QTBUG-8874
Reviewed-by: mread

1 files changed, 25 insertions, 0 deletions

diff --git a/src/gui/kernel/qapplication_s60.cpp b/src/gui/kernel/qapplication_s60.cpp
index 78027b2..f39b462 100644
--- a/src/gui/kernel/qapplication_s60.cpp
+++ b/src/gui/kernel/qapplication_s60.cpp
@@ -2046,4 +2046,29 @@ void QApplication::restoreOverrideCursor()
 
 #endif // QT_NO_CURSOR
 
+QS60ThreadLocalData::QS60ThreadLocalData()
+{
+    CCoeEnv *env = CCoeEnv::Static();
+    if (env) {
+        //if this is the UI thread, share objects owned by CONE
+        usingCONEinstances = true;
+        wsSession = env->WsSession();
+        screenDevice = env->ScreenDevice();
+    }
+    else {
+        usingCONEinstances = false;
+        qt_symbian_throwIfError(wsSession.Connect(qt_s60GetRFs()));
+        screenDevice = new CWsScreenDevice(wsSession);
+        screenDevice->Construct();
+    }
+}
+
+QS60ThreadLocalData::~QS60ThreadLocalData()
+{
+    if (!usingCONEinstances) {
+        delete screenDevice;
+        wsSession.Close();
+    }
+}
+
 QT_END_NAMESPACE