Made some tweaks to help properly stop the JobRunner

SessionUtilitiesKit/JobRunner/JobRunner.swift

@@ -111,6 +111,7 @@ public final class JobRunner {
     fileprivate static var perSessionJobsCompleted: Atomic<Set<Int64>> = Atomic([])
     private static var hasCompletedInitialBecomeActive: Atomic<Bool> = Atomic(false)
     private static var shutdownBackgroundTask: Atomic<OWSBackgroundTask?> = Atomic(nil)
+    fileprivate static var canStartQueues: Atomic<Bool> = Atomic(false)
     
     // MARK: - Configuration
     
@@ -161,6 +162,9 @@ public final class JobRunner {
         
         queues.wrappedValue[job.variant]?.upsert(job, canStartJob: canStartJob)
         
+        // Don't start the queue if the job can't be started
+        guard canStartJob else { return }
+        
         // Start the job runner if needed
         db.afterNextTransaction { _ in
             queues.wrappedValue[job.variant]?.start()
@@ -188,15 +192,13 @@ public final class JobRunner {
         
         queues.wrappedValue[updatedJob.variant]?.insert(updatedJob, before: otherJob)
         
-        // Start the job runner if needed
-        db.afterNextTransaction { _ in
-            queues.wrappedValue[updatedJob.variant]?.start()
-        }
-        
         return (jobId, updatedJob)
     }
     
     public static func appDidFinishLaunching() {
+        // Flag that the JobRunner can start it's queues
+        JobRunner.canStartQueues.mutate { $0 = true }
+        
         // Note: 'appDidBecomeActive' will run on first launch anyway so we can
         // leave those jobs out and can wait until then to start the JobRunner
         let jobsToRun: (blocking: [Job], nonBlocking: [Job]) = Storage.shared
@@ -242,6 +244,9 @@ public final class JobRunner {
     }
     
     public static func appDidBecomeActive() {
+        // Flag that the JobRunner can start it's queues
+        JobRunner.canStartQueues.mutate { $0 = true }
+        
         // If we have a running "sutdownBackgroundTask" then we want to cancel it as otherwise it
         // can result in the database being suspended and us being unable to interact with it at all
         shutdownBackgroundTask.mutate {
@@ -291,6 +296,11 @@ public final class JobRunner {
         exceptForVariant: Job.Variant? = nil,
         onComplete: (() -> ())? = nil
     ) {
+        // Inform the JobRunner that it can't start any queues (this is to prevent queues from
+        // rescheduling themselves while in the background, when the app restarts or becomes active
+        // the JobRunenr will update this flag)
+        JobRunner.canStartQueues.mutate { $0 = false }
+        
         // Stop all queues except for the one containing the `exceptForVariant`
         queues.wrappedValue
             .values
@@ -632,6 +642,7 @@ private final class JobQueue {
     fileprivate func start(force: Bool = false) {
         // We only want the JobRunner to run in the main app
         guard CurrentAppContext().isMainApp else { return }
+        guard JobRunner.canStartQueues.wrappedValue else { return }
         guard force || !isRunning.wrappedValue else { return }
         
         // The JobRunner runs synchronously we need to ensure this doesn't start
@@ -852,8 +863,9 @@ private final class JobQueue {
                 .fetchOne(db)
         }
         
-        // If there are no remaining jobs the trigger the 'onQueueDrained' callback and stop
-        guard let nextJobTimestamp: TimeInterval = nextJobTimestamp else {
+        // If there are no remaining jobs or the JobRunner isn't allowed to start any queues then trigger
+        // the 'onQueueDrained' callback and stop
+        guard let nextJobTimestamp: TimeInterval = nextJobTimestamp, JobRunner.canStartQueues.wrappedValue else {
             if executionType != .concurrent || jobsCurrentlyRunning.wrappedValue.isEmpty {
                 self.onQueueDrained?()
             }
@@ -1064,6 +1076,8 @@ private final class JobQueue {
                         queue = queue.filter { !dependantJobIds.contains($0.id ?? -1) }
                     }
                 }
+                
+                performCleanUp(for: job, result: .failed)
                 return
             }
             
@@ -1082,7 +1096,7 @@ private final class JobQueue {
             try job.dependantJobs
                 .updateAll(
                     db,
-                    Job.Columns.failureCount.set(to: job.failureCount),
+                    Job.Columns.failureCount.set(to: (job.failureCount + 1)),
                     Job.Columns.nextRunTimestamp.set(to: (nextRunTimestamp + (1 / 1000)))
                 )