(fix):potential fix for multi scheduling of event work (#268)

* potential fix for multi scheduling of event work

* add a comment why not restarting in event rescheduler

Author: thomaszurkan-optimizely

event-handler/src/main/java/com/optimizely/ab/android/event_handler/EventRescheduler.java

@@ -101,8 +101,11 @@ void reschedule(@NonNull Context context, @NonNull Intent broadcastIntent, @NonN
                     // with wifi the service will be rescheduled on the interval.
                     // Wifi connection state changes all the time and starting services is expensive
                     // so it's important to only do this if we have stored events.
-                    ServiceScheduler.startService(context, EventIntentService.JOB_ID, eventServiceIntent);
-                    logger.info("Preemptively flushing events since wifi became available");
+                    // In android O and higher, we use a persistent job so we do not need to restart.
+                    if (android.os.Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
+                        ServiceScheduler.startService(context, EventIntentService.JOB_ID, eventServiceIntent);
+                        logger.info("Preemptively flushing events since wifi became available");
+                    }
                 }
         } else {
             logger.warn("Received unsupported broadcast action to event rescheduler");

shared/src/main/java/com/optimizely/ab/android/shared/ServiceScheduler.java

@@ -33,6 +33,8 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.stream.Collectors;
+
 import static android.app.job.JobScheduler.RESULT_SUCCESS;
 
 /**
@@ -273,6 +275,12 @@ public static void startService(Context context, Integer jobId, Intent intent) {
                     .build();
             JobScheduler jobScheduler = (JobScheduler) context.getSystemService(Context.JOB_SCHEDULER_SERVICE);
 
+            if (jobScheduler.getAllPendingJobs().stream().filter(job -> job.getId() == jobId && job.getExtras().equals(intent.getExtras())).count() > 0) {
+                // already pending job. don't run again
+                LoggerFactory.getLogger("ServiceScheduler").info("Job already pending");
+                return;
+            }
+
             JobWorkItem jobWorkItem = new JobWorkItem(intent);
             try {
                 jobScheduler.enqueue(jobInfo, jobWorkItem);