Move the Job#onSubmit call to be outside of the JobController lock.

app/src/main/java/org/thoughtcrime/securesms/jobmanager/JobController.java

@@ -80,7 +80,8 @@ class JobController {
   }
 
   @WorkerThread
-  synchronized void submitNewJobChain(@NonNull List<List<Job>> chain) {
+  void submitNewJobChain(@NonNull List<List<Job>> chain) {
+    synchronized (this) {
       chain = Stream.of(chain).filterNot(List::isEmpty).toList();
 
       if (chain.isEmpty()) {
@@ -96,15 +97,22 @@ class JobController {
       }
 
       insertJobChain(chain);
-    triggerOnSubmit(chain);
-    notifyAll();
       scheduleJobs(chain.get(0));
     }
 
+    // We have no control over what happens in jobs' onSubmit method, so we drop our lock to reduce the possibility of a deadlock
+    triggerOnSubmit(chain);
+
+    synchronized (this) {
+      notifyAll();
+    }
+  }
+
   @WorkerThread
-  synchronized void submitJobWithExistingDependencies(@NonNull Job job, @NonNull Collection<String> dependsOn, @Nullable String dependsOnQueue) {
+  void submitJobWithExistingDependencies(@NonNull Job job, @NonNull Collection<String> dependsOn, @Nullable String dependsOnQueue) {
     List<List<Job>> chain = Collections.singletonList(Collections.singletonList(job));
 
+    synchronized (this) {
       if (chainExceedsMaximumInstances(chain)) {
         jobTracker.onStateChange(job, JobTracker.JobState.IGNORED);
         Log.w(TAG, JobLogger.format(job, "Already at the max instance count. Factory limit: " + job.getParameters().getMaxInstancesForFactory() + ", Queue limit: " + job.getParameters().getMaxInstancesForQueue() + ". Skipping."));
@@ -138,9 +146,15 @@ class JobController {
       jobStorage.insertJobs(Collections.singletonList(fullSpec));
 
       scheduleJobs(Collections.singletonList(job));
+    }
+
+    // We have no control over what happens in jobs' onSubmit method, so we drop our lock to reduce the possibility of a deadlock
     triggerOnSubmit(chain);
+
+    synchronized (this) {
       notifyAll();
     }
+  }
 
   @WorkerThread
   synchronized void cancelJob(@NonNull String id) {