Fixed a race condition where multiple syncs could be started simultaneously

api/src/com/todoroo/astrid/sync/SyncBackgroundService.java

@@ -1,5 +1,7 @@
 package com.todoroo.astrid.sync;
 
+import java.util.concurrent.atomic.AtomicBoolean;
+
 import android.app.AlarmManager;
 import android.app.PendingIntent;
 import android.app.Service;
@@ -45,12 +47,15 @@ abstract public class SyncBackgroundService extends Service {
         DependencyInjectionService.getInstance().inject(this);
     }
 
+    private final AtomicBoolean started = new AtomicBoolean(false);
+
     /** Receive the alarm - start the synchronize service! */
     @Override
     public void onStart(Intent intent, int startId) {
         try {
-            if(intent != null)
+            if(intent != null && !started.getAndSet(true)) {
                 startSynchronization(this);
+            }
         } catch (Exception e) {
             exceptionService.reportError(getSyncUtilities().getIdentifier() + "-bg-sync", e); //$NON-NLS-1$
         }
@@ -67,8 +72,6 @@ abstract public class SyncBackgroundService extends Service {
             return;
 
         getSyncProvider().synchronize(context);
-
-        stopSelf();
     }
 
     @Override
@@ -76,6 +79,11 @@ abstract public class SyncBackgroundService extends Service {
         return null;
     }
 
+    public synchronized void stop() {
+        started.set(false);
+        stopSelf();
+    }
+
     // --- alarm management
 
     /**

api/src/com/todoroo/astrid/sync/SyncProvider.java

@@ -11,7 +11,6 @@ import java.util.HashMap;
 
 import android.app.Activity;
 import android.app.Notification;
-import android.app.Service;
 import android.content.Context;
 import android.widget.Toast;
 
@@ -162,7 +161,7 @@ public abstract class SyncProvider<TYPE extends SyncContainer> {
                 });
             }
             initiateManual((Activity)context);
-        } else if(context instanceof Service) {
+        } else if(context instanceof SyncBackgroundService) {
             // display notification
             final int notificationId = updateNotification(context, notification);
             final NotificationManager nm = new NotificationManager.AndroidNotificationManager(context);
@@ -175,6 +174,7 @@ public abstract class SyncProvider<TYPE extends SyncContainer> {
                         initiateBackground();
                     } finally {
                         nm.cancel(notificationId);
+                        ((SyncBackgroundService)context).stop();
                     }
                 }
             }).start();