commit 1603204ba5392d375e05ecf2c5b2fea7309f4cf1
author Christopher Tate <ctate@google.com> Fri Oct 05 15:53:50 2018 -0700
committer Christopher Tate <ctate@google.com> Wed Oct 10 13:04:42 2018 -0700
tree 351626e4af56615a80ae2d9dbf8e22ae30be941b
parent e3aece094788d3e21242bb322e31d8687b984f0b

Fix persisted job handling in bad-boot-RTC situations

Persisted jobs were inadvertently being discarded rather than
rescheduled with appropriate time constraints.  The underlying
bug is that the cancel-with-replacement code path was failing
to manage the replacement properly, and the other code path
leading to it was working around the bug by explicitly
rescheduling the job following cancellation.

Test: atest CtsJobSchedulerTestCases
Bug: 114292041
Bug: 117346686
Change-Id: I3a77e8a38c2f7028b61791bafd9c88b7a714ff6d

services/core/java/com/android/server/job/JobSchedulerService.java

diff --git a/services/core/java/com/android/server/job/JobSchedulerService.java b/services/core/java/com/android/server/job/JobSchedulerService.java
index 389782a..dd993b8 100644
--- a/services/core/java/com/android/server/job/JobSchedulerService.java
+++ b/services/core/java/com/android/server/job/JobSchedulerService.java
@@ -877,14 +877,17 @@
             // This may throw a SecurityException.
             jobStatus.prepareLocked(ActivityManager.getService());
 
-            if (toCancel != null) {
-                cancelJobImplLocked(toCancel, jobStatus, "job rescheduled by app");
-            }
             if (work != null) {
                 // If work has been supplied, enqueue it into the new job.
                 jobStatus.enqueueWorkLocked(ActivityManager.getService(), work);
             }
-            startTrackingJobLocked(jobStatus, toCancel);
+
+            if (toCancel != null) {
+                // Implicitly replaces the existing job record with the new instance
+                cancelJobImplLocked(toCancel, jobStatus, "job rescheduled by app");
+            } else {
+                startTrackingJobLocked(jobStatus, null);
+            }
             StatsLog.write_non_chained(StatsLog.SCHEDULED_JOB_STATE_CHANGED,
                     uId, null, jobStatus.getBatteryName(),
                     StatsLog.SCHEDULED_JOB_STATE_CHANGED__STATE__SCHEDULED,
@@ -1013,6 +1016,12 @@
         }
     }
 
+    /**
+     * Cancel the given job, stopping it if it's currently executing.  If {@code incomingJob}
+     * is null, the cancelled job is removed outright from the system.  If
+     * {@code incomingJob} is non-null, it replaces {@code cancelled} in the store of
+     * currently scheduled jobs.
+     */
     private void cancelJobImplLocked(JobStatus cancelled, JobStatus incomingJob, String reason) {
         if (DEBUG) Slog.d(TAG, "CANCEL: " + cancelled.toShortString());
         cancelled.unprepareLocked(ActivityManager.getService());
@@ -1023,6 +1032,11 @@
         }
         // Cancel if running.
         stopJobOnServiceContextLocked(cancelled, JobParameters.REASON_CANCELED, reason);
+        // If this is a replacement, bring in the new version of the job
+        if (incomingJob != null) {
+            if (DEBUG) Slog.i(TAG, "Tracking replacement job " + incomingJob.toShortString());
+            startTrackingJobLocked(incomingJob, cancelled);
+        }
         reportActiveLocked();
     }