Allow SyncPointQueue to be cancelled

Change-Id: Idbf6ee7a5d9721681811189fca4190e7a0286c83

packager/app/job_manager.cc

@@ -7,6 +7,7 @@
 #include "packager/app/job_manager.h"
 
 #include "packager/app/libcrypto_threading.h"
+#include "packager/media/chunking/sync_point_queue.h"
 #include "packager/media/origin/origin_handler.h"
 
 namespace shaka {
@@ -29,6 +30,9 @@ void Job::Run() {
   wait_.Signal();
 }
 
+JobManager::JobManager(std::unique_ptr<SyncPointQueue> sync_points)
+    : sync_points_(std::move(sync_points)) {}
+
 void JobManager::Add(const std::string& name,
                      std::shared_ptr<OriginHandler> handler) {
   // Stores Job entries for delayed construction of Job objects, to avoid
@@ -87,6 +91,8 @@ Status JobManager::RunJobs() {
 
   // If the main loop has exited and there are still jobs running,
   // we need to cancel them and clean-up.
+  if (sync_points_)
+    sync_points_->Cancel();
   for (auto& job : active_jobs) {
     job->Cancel();
   }
@@ -99,6 +105,8 @@ Status JobManager::RunJobs() {
 }
 
 void JobManager::CancelJobs() {
+  if (sync_points_)
+    sync_points_->Cancel();
   for (auto& job : jobs_) {
     job->Cancel();
   }

packager/app/job_manager.h

@@ -17,6 +17,7 @@ namespace shaka {
 namespace media {
 
 class OriginHandler;
+class SyncPointQueue;
 
 // A job is a single line of work that is expected to run in parallel with
 // other jobs.
@@ -54,7 +55,10 @@ class Job : public base::SimpleThread {
 // jobs.
 class JobManager {
  public:
-  JobManager() = default;
+  // @param sync_points is an optional SyncPointQueue used to synchronize and
+  //        align cue points. JobManager cancels @a sync_points when any job
+  //        fails or is cancelled. It can be NULL.
+  explicit JobManager(std::unique_ptr<SyncPointQueue> sync_points);
 
   // Create a new job entry by specifying the origin handler at the top of the
   // chain and a name for the thread. This will only register the job. To start
@@ -75,6 +79,8 @@ class JobManager {
   // unblock a call to |RunJobs|.
   void CancelJobs();
 
+  SyncPointQueue* sync_points() { return sync_points_.get(); }
+
  private:
   JobManager(const JobManager&) = delete;
   JobManager& operator=(const JobManager&) = delete;
@@ -86,6 +92,9 @@ class JobManager {
   // Stores Job entries for delayed construction of Job object.
   std::vector<JobEntry> job_entries_;
   std::vector<std::unique_ptr<Job>> jobs_;
+  // Stored in JobManager so JobManager can cancel |sync_points| when any job
+  // fails or is cancelled.
+  std::unique_ptr<SyncPointQueue> sync_points_;
 };
 
 }  // namespace media

packager/media/chunking/cue_alignment_handler.cc

@@ -170,7 +170,10 @@ Status CueAlignmentHandler::OnSample(std::unique_ptr<StreamData> sample) {
 
     std::shared_ptr<const CueEvent> next_sync =
         sync_points_->GetNext(next_cue_hint);
-    DCHECK(next_sync);
+    if (!next_sync) {
+      // This happens only if the job is cancelled.
+      return Status(error::CANCELLED, "SyncPointQueue is cancelled.");
+    }
 
     Status status = UseNewSyncPoint(next_sync);
     if (!status.ok()) {

packager/media/chunking/sync_point_queue.cc

@@ -27,6 +27,14 @@ void SyncPointQueue::AddThread() {
   thread_count_++;
 }
 
+void SyncPointQueue::Cancel() {
+  {
+    base::AutoLock auto_lock(lock_);
+    cancelled_ = true;
+  }
+  sync_condition_.Broadcast();
+}
+
 double SyncPointQueue::GetHint(double time_in_seconds) {
   base::AutoLock auto_lock(lock_);
 
@@ -46,7 +54,7 @@ double SyncPointQueue::GetHint(double time_in_seconds) {
 std::shared_ptr<const CueEvent> SyncPointQueue::GetNext(
     double hint_in_seconds) {
   base::AutoLock auto_lock(lock_);
-  while (true) {
+  while (!cancelled_) {
     // Find the promoted cue that would line up with our hint, which is the
     // first cue that is not less than |hint_in_seconds|.
     auto iter = promoted_.lower_bound(hint_in_seconds);
@@ -70,6 +78,7 @@ std::shared_ptr<const CueEvent> SyncPointQueue::GetNext(
     sync_condition_.Wait();
     waiting_thread_count_--;
   }
+  return nullptr;
 }
 
 std::shared_ptr<const CueEvent> SyncPointQueue::PromoteAt(

packager/media/chunking/sync_point_queue.h

@@ -26,6 +26,9 @@ class SyncPointQueue {
   /// order to keep track of its clients.
   void AddThread();
 
+  /// Cancel the queue and unblock all threads.
+  void Cancel();
+
   /// @return A hint for when the next cue event would be. The returned hint is
   ///         not less than @a time_in_seconds. The actual time for the next cue
   ///         event will not be less than the returned hint, with the exact
@@ -37,7 +40,7 @@ class SyncPointQueue {
   ///         after @a hint_in_seconds has been promoted, this will block until
   ///         either a cue is promoted or all threads are blocked (in which
   ///         case, the unpromoted cue at @a hint_in_seconds will be
-  ///         self-promoted and returned).
+  ///         self-promoted and returned) or Cancel() is called.
   std::shared_ptr<const CueEvent> GetNext(double hint_in_seconds);
 
   /// Promote the first cue that is not greater than @a time_in_seconds. All
@@ -56,6 +59,7 @@ class SyncPointQueue {
   base::ConditionVariable sync_condition_;
   size_t thread_count_ = 0;
   size_t waiting_thread_count_ = 0;
+  bool cancelled_ = false;
 
   std::map<double, std::shared_ptr<CueEvent>> unpromoted_;
   std::map<double, std::shared_ptr<CueEvent>> promoted_;

packager/packager.cc

@@ -54,6 +54,7 @@ namespace shaka {
 
 // TODO(kqyang): Clean up namespaces.
 using media::Demuxer;
+using media::JobManager;
 using media::KeySource;
 using media::MuxerOptions;
 using media::SyncPointQueue;
@@ -797,9 +798,8 @@ struct Packager::PackagerInternal {
   std::unique_ptr<KeySource> encryption_key_source;
   std::unique_ptr<MpdNotifier> mpd_notifier;
   std::unique_ptr<hls::HlsNotifier> hls_notifier;
-  std::unique_ptr<SyncPointQueue> sync_points;
   BufferCallbackParams buffer_callback_params;
-  media::JobManager job_manager;
+  std::unique_ptr<media::JobManager> job_manager;
 };
 
 Packager::Packager() {}
@@ -869,10 +869,12 @@ Status Packager::Initialize(
     internal->hls_notifier.reset(new hls::SimpleHlsNotifier(hls_params));
   }
 
+  std::unique_ptr<SyncPointQueue> sync_points;
   if (!packaging_params.ad_cue_generator_params.cue_points.empty()) {
-    internal->sync_points.reset(
+    sync_points.reset(
         new SyncPointQueue(packaging_params.ad_cue_generator_params));
   }
+  internal->job_manager.reset(new JobManager(std::move(sync_points)));
 
   std::vector<StreamDescriptor> streams_for_jobs;
 
@@ -916,8 +918,9 @@ Status Packager::Initialize(
 
   Status status = media::CreateAllJobs(
       streams_for_jobs, packaging_params, internal->mpd_notifier.get(),
-      internal->encryption_key_source.get(), internal->sync_points.get(),
+      internal->encryption_key_source.get(),
-      &muxer_listener_factory, &muxer_factory, &internal->job_manager);
+      internal->job_manager->sync_points(), &muxer_listener_factory,
+      &muxer_factory, internal->job_manager.get());
 
   if (!status.ok()) {
     return status;
@@ -931,7 +934,7 @@ Status Packager::Run() {
   if (!internal_)
     return Status(error::INVALID_ARGUMENT, "Not yet initialized.");
 
-  Status status = internal_->job_manager.RunJobs();
+  Status status = internal_->job_manager->RunJobs();
   if (!status.ok())
     return status;
 
@@ -951,7 +954,7 @@ void Packager::Cancel() {
     LOG(INFO) << "Not yet initialized. Return directly.";
     return;
   }
-  internal_->job_manager.CancelJobs();
+  internal_->job_manager->CancelJobs();
 }
 
 std::string Packager::GetLibraryVersion() {