google maps - Android 2.1 GoogleMaps ItemizedOverlay ConcurrentModificationException

Question

I cannot figure out the origin of the ConcurrentModificationException. In my activity I'm calling updateMapOverlay(). I'm also calling updateMapOverlay() inside another Thread (a TimerTask) that is invoked on regular intervals. I'm taking the appropriate locks when invoking updateMapOverlay() from both the threads. Is this problem being caused because I'm invoking updateMapOverlay from inside a non-UI thread (i.e., TimerTask). Has anyone else faced a similar issue ?

private void updateMapOverlay() {

    this.itemizedOverlay.refreshItems(createOverlayItemsList());
    List<Overlay> overlays = mapView.getOverlays();
    overlays.clear();
    overlays.add(cotItemizedOverlay);
            this.mapview.invalidate();

}

Thanks.

Exception:

W/dalvikvm(10641): threadid=3: thread exiting with uncaught exception (group=0x4001b180)
E/AndroidRuntime(10641): Uncaught handler: thread main exiting due to uncaught exception
E/AndroidRuntime(10641): java.util.ConcurrentModificationException
E/AndroidRuntime(10641):    at java.util.AbstractList$SimpleListIterator.next(AbstractList.java:64)
E/AndroidRuntime(10641):    at com.google.android.maps.OverlayBundle.draw(OverlayBundle.java:41)
E/AndroidRuntime(10641):    at com.google.android.maps.MapView.onDraw(MapView.java:494)
E/AndroidRuntime(10641):    at android.view.View.draw(View.java:6535)
E/AndroidRuntime(10641):    at android.view.ViewGroup.drawChild(ViewGroup.java:1531)
E/AndroidRuntime(10641):    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
E/AndroidRuntime(10641):    at android.view.ViewGroup.drawChild(ViewGroup.java:1529)
E/AndroidRuntime(10641):    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
E/AndroidRuntime(10641):    at android.view.View.draw(View.java:6538)
E/AndroidRuntime(10641):    at android.widget.FrameLayout.draw(FrameLayout.java:352)
E/AndroidRuntime(10641):    at android.view.ViewGroup.drawChild(ViewGroup.java:1531)
E/AndroidRuntime(10641):    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
E/AndroidRuntime(10641):    at android.view.ViewGroup.drawChild(ViewGroup.java:1529)
E/AndroidRuntime(10641):    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1258)
E/AndroidRuntime(10641):    at android.view.View.draw(View.java:6538)
E/AndroidRuntime(10641):    at android.widget.FrameLayout.draw(FrameLayout.java:352)
E/AndroidRuntime(10641):    at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1830)
E/AndroidRuntime(10641):    at android.view.ViewRoot.draw(ViewRoot.java:1349)
E/AndroidRuntime(10641):    at android.view.ViewRoot.performTraversals(ViewRoot.java:1114)
E/AndroidRuntime(10641):    at android.view.ViewRoot.handleMessage(ViewRoot.java:1633)
E/AndroidRuntime(10641):    at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime(10641):    at android.os.Looper.loop(Looper.java:123)
E/AndroidRuntime(10641):    at android.app.ActivityThread.main(ActivityThread.java:4363)
E/AndroidRuntime(10641):    at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(10641):    at java.lang.reflect.Method.invoke(Method.java:521)
E/AndroidRuntime(10641):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
E/AndroidRuntime(10641):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
E/AndroidRuntime(10641):    at dalvik.system.NativeStart.main(Native Method)
I/Process (   95): Sending signal. PID: 10641 SIG: 3

Answer 1

Is this problem being caused because I'm invoking updateMapOverlay from inside a non-UI thread

Yes.

I'm also calling updateMapOverlay() inside another Thread (a TimerTask) that is invoked on regular intervals.

Why are you removing and adding an overlay constantly? Just update the overlay and invalidate. See here for an example of updating an overlay asynchronously.