Synchronize ab test event reporting to prevent duplicate reports

astrid/src/com/todoroo/astrid/service/abtesting/ABTestEventReportingService.java

@@ -61,15 +61,13 @@ public final class ABTestEventReportingService {
     }
 
     private void pushAllUnreportedABTestEvents() {
+        synchronized(ABTestEventReportingService.class) {
             if (StatisticsService.dontCollectStatistics())
                 return;
             final TodorooCursor<ABTestEvent> unreported = abTestEventDao.query(Query.select(ABTestEvent.PROPERTIES)
                     .where(ABTestEvent.REPORTED.eq(0))
                     .orderBy(Order.asc(ABTestEvent.TEST_NAME), Order.asc(ABTestEvent.TIME_INTERVAL)));
             if (unreported.getCount() > 0) {
-            new Thread(new Runnable() {
-                @Override
-                public void run() {
                 try {
                     JSONArray payload = jsonArrayFromABTestEvents(unreported);
                     abTestInvoker.post(payload);
@@ -87,7 +85,6 @@ public final class ABTestEventReportingService {
                     unreported.close();
                 }
             }
-            }).start();
         }
     }