Reduce locking in overuse frame detector now that (as of r9508) the observer_ and options_ can only

webrtc/video_engine/overuse_frame_detector.h

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 103 matching lines @@
   class EncodeTimeAvg;
   class SendProcessingUsage;
   class FrameQueue;
 
   void UpdateCpuOveruseMetrics() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // TODO(asapersson): This method is only used on one thread, so it shouldn't
   // need a guard.
   void AddProcessingTime(int elapsed_ms) EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
-  // TODO(asapersson): This method is always called on the processing thread.
-  // If locking is required, consider doing that locking inside the
-  // implementation and reduce scope as much as possible.  We should also
-  // see if we can avoid calling out to other methods while holding the lock.
-  bool IsOverusing() EXCLUSIVE_LOCKS_REQUIRED(crit_);
-  bool IsUnderusing(int64_t time_now) EXCLUSIVE_LOCKS_REQUIRED(crit_);
+  // Only called on the processing thread.
+  bool IsOverusing(const CpuOveruseMetrics& metrics);
+  bool IsUnderusing(const CpuOveruseMetrics& metrics, int64_t time_now);
 
   bool FrameTimeoutDetected(int64_t now) const EXCLUSIVE_LOCKS_REQUIRED(crit_);
   bool FrameSizeChanged(int num_pixels) const EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   void ResetAll(int num_pixels) EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Protecting all members except const and those that are only accessed on the
   // processing thread.
   // TODO(asapersson): See if we can reduce locking.  As is, video frame
   // processing contends with reading stats and the processing thread.
   mutable rtc::CriticalSection crit_;
 
   const CpuOveruseOptions options_;
 
   // Observer getting overuse reports.
   CpuOveruseObserver* const observer_;
 
   // Stats metrics.
   CpuOveruseMetricsObserver* const metrics_observer_;
   CpuOveruseMetrics metrics_ GUARDED_BY(crit_);
 
   Clock* const clock_;
-  int64_t next_process_time_;  // Only accessed on the processing thread.
   int64_t num_process_times_ GUARDED_BY(crit_);
 
   int64_t last_capture_time_ GUARDED_BY(crit_);
 
-  // These six members are only accessed on the processing thread.
+  // Number of pixels of last captured frame.
+  int num_pixels_ GUARDED_BY(crit_);
+
+  // These seven members are only accessed on the processing thread.
+  int64_t next_process_time_;
   int64_t last_overuse_time_;
   int checks_above_threshold_;
   int num_overuse_detections_;
-
   int64_t last_rampup_time_;
   bool in_quick_rampup_;
   int current_rampup_delay_ms_;
 
-  // Number of pixels of last captured frame.
-  int num_pixels_ GUARDED_BY(crit_);
-
   int64_t last_encode_sample_ms_;  // Only accessed by one thread.
+  int64_t last_sample_time_ms_;    // Only accessed by one thread.
 
   // TODO(asapersson): Can these be regular members (avoid separate heap
   // allocs)?
   const rtc::scoped_ptr<EncodeTimeAvg> encode_time_ GUARDED_BY(crit_);
   const rtc::scoped_ptr<SendProcessingUsage> usage_ GUARDED_BY(crit_);
   const rtc::scoped_ptr<FrameQueue> frame_queue_ GUARDED_BY(crit_);
 
-  int64_t last_sample_time_ms_;  // Only accessed by one thread.
-
   rtc::ThreadChecker processing_thread_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(OveruseFrameDetector);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_ENGINE_OVERUSE_FRAME_DETECTOR_H_