Fix QTimer overflow with interval > 35 minutes on symbian

For long intervals, restart the system timer every 2000 seconds
New autotest to verify long timers don't crash or complete immediately

Task-number: QT-651
Reviewed-by: axis

2 files changed, 30 insertions, 5 deletions

diff --git a/src/corelib/kernel/qeventdispatcher_symbian.cpp b/src/corelib/kernel/qeventdispatcher_symbian.cpp
index b1c8734..11a0da6 100644
--- a/src/corelib/kernel/qeventdispatcher_symbian.cpp
+++ b/src/corelib/kernel/qeventdispatcher_symbian.cpp
@@ -231,15 +231,39 @@ void QTimerActiveObject::RunL()
     }
 }
 
+#define MAX_SYMBIAN_TIMEOUT_MS 2000000
+void QTimerActiveObject::StartTimer()
+{
+    if (m_timerInfo->msLeft > MAX_SYMBIAN_TIMEOUT_MS) {
+        //There is loss of accuracy anyway due to needing to restart the timer every 33 minutes,
+        //so the 1/64s res of After() is acceptable for these very long timers.
+        m_rTimer.After(iStatus, MAX_SYMBIAN_TIMEOUT_MS * 1000);
+        m_timerInfo->msLeft -= MAX_SYMBIAN_TIMEOUT_MS;
+    } else {
+        //HighRes gives the 1ms accuracy expected by Qt, the +1 is to ensure that
+        //"Timers will never time out earlier than the specified timeout value"
+        //condition is always met.
+        m_rTimer.HighRes(iStatus, (m_timerInfo->msLeft + 1) * 1000);
+        m_timerInfo->msLeft = 0;
+    }
+    SetActive();
+}
+
 void QTimerActiveObject::Run()
 {
+    //restart timer immediately, if the timeout has been split because it overflows max for platform.
+    if (m_timerInfo->msLeft > 0) {
+        StartTimer();
+        return;
+    }
+
     if (!okToRun())
         return;
 
     if (m_timerInfo->interval > 0) {
         // Start a new timer immediately so that we don't lose time.
-        SetActive();
-        m_rTimer.After(iStatus, m_timerInfo->interval*1000);
+        m_timerInfo->msLeft = m_timerInfo->interval;
+        StartTimer();
 
         m_timerInfo->dispatcher->timerFired(m_timerInfo->timerId);
     } else {
@@ -261,11 +285,10 @@ void QTimerActiveObject::Run()
 void QTimerActiveObject::Start()
 {
     CActiveScheduler::Add(this);
+    m_timerInfo->msLeft = m_timerInfo->interval;
     if (m_timerInfo->interval > 0) {
         m_rTimer.CreateLocal();
-        iStatus = KRequestPending;
-        SetActive();
-        m_rTimer.After(iStatus, m_timerInfo->interval*1000);
+        StartTimer();
     } else {
         iStatus = KRequestPending;
         SetActive();
diff --git a/src/corelib/kernel/qeventdispatcher_symbian_p.h b/src/corelib/kernel/qeventdispatcher_symbian_p.h
index 53f92a9..fd0350d 100644
--- a/src/corelib/kernel/qeventdispatcher_symbian_p.h
+++ b/src/corelib/kernel/qeventdispatcher_symbian_p.h
@@ -117,6 +117,7 @@ struct SymbianTimerInfo : public QSharedData
 
     int timerId;
     int interval;
+    int msLeft;
     bool inTimerEvent;
     QObject *receiver;
     QTimerActiveObject *timerAO;
@@ -140,6 +141,7 @@ protected:
 
 private:
     void Run();
+    void StartTimer();
 
 private:
     SymbianTimerInfo *m_timerInfo;