sync_point_queue.h

// Copyright 2018 Google LLC. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
 
#include <cstddef>
#include <map>
#include <memory>
 
#include <absl/base/thread_annotations.h>
#include <absl/synchronization/mutex.h>
 
#include <packager/ad_cue_generator_params.h>
 
namespace shaka {
namespace media {
 
struct CueEvent;
 
class SyncPointQueue {
 public:
  explicit SyncPointQueue(const AdCueGeneratorParams& params);
  ~SyncPointQueue() = default;
 
  void AddThread();
 
  void Cancel();
 
  double GetHint(double time_in_seconds);
 
  std::shared_ptr<const CueEvent> GetNext(double hint_in_seconds);
 
  std::shared_ptr<const CueEvent> PromoteAt(double time_in_seconds);
 
  bool HasMore(double hint_in_seconds) const;
 
 private:
  SyncPointQueue(const SyncPointQueue&) = delete;
  SyncPointQueue& operator=(const SyncPointQueue&) = delete;
 
  // PromoteAt() without locking. It is called by PromoteAt() and other
  // functions that have locks.
  std::shared_ptr<const CueEvent> PromoteAtNoLocking(double time_in_seconds);
 
  absl::Mutex mutex_;
  absl::CondVar sync_condition_ ABSL_GUARDED_BY(mutex_);
  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_;
};
 
}  // namespace media
}  // namespace shaka