android - Does startService() create a new Service instance or using the existing one?

Question

Does startService() create a new Service instance or using the existing one? For example, in the following code, does it create two UpdateService instances or just one UpdateService instance? Thanks.

    int[] appWidgetIds = new int[] {1, 2};  
    for (int appWidgetId : appWidgetIds) {
        Intent intent = new Intent(context, UpdateService.class);
        intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
        context.startService(intent);
    }

Answer 1

If the service is already started, it does not start as second copy, but onStart() is still called on the existing instance. Services are natural singletons -- there is exactly 0 or 1 copy of the service in operation.