Fix thread starvation when processEvents() is called in a tight loop

One of the qftp test cases calls processEvents() in a tight loop instead
of using an event loop. This was causing the application to hang on symbian
as it blocked a lower priority system thread and the WLAN connection
never completed.
Although calling processEvents in a tight loop is bad practice, it works
on other OS where thread priorities are dynamic.

Reviewed-by: mread

1 files changed, 8 insertions, 0 deletions

diff --git a/src/corelib/kernel/qeventdispatcher_symbian.cpp b/src/corelib/kernel/qeventdispatcher_symbian.cpp
index b3a3d4d..0b7682c 100644
--- a/src/corelib/kernel/qeventdispatcher_symbian.cpp
+++ b/src/corelib/kernel/qeventdispatcher_symbian.cpp
@@ -818,6 +818,14 @@ bool QEventDispatcherSymbian::processEvents ( QEventLoop::ProcessEventsFlags fla
                 CActiveScheduler::Current()->WaitForAnyRequest();
             } else {
                 if (thread.RequestCount() == 0) {
+#ifdef QT_SYMBIAN_PRIORITY_DROP
+                    if (idleDetectorThread()->hasRun()) {
+                        m_lastIdleRequestTimer.start();
+                        idleDetectorThread()->kick();
+                    } else if (m_lastIdleRequestTimer.elapsed() > maxBusyTime) {
+                        User::AfterHighRes(m_delay);
+                    }
+#endif
                     break;
                 }
                 // This one should return without delay.