Refactor AudioInputController and related interfaces.

media/audio/audio_input_controller.h

Index: media/audio/audio_input_controller.h
diff --git a/media/audio/audio_input_controller.h b/media/audio/audio_input_controller.h
index ef691f1cf13679192e4deaca17c644ba5f7843ee..cfd65926cd61c85e95599696bf0fd3708d05b8ae 100644
--- a/media/audio/audio_input_controller.h
+++ b/media/audio/audio_input_controller.h
@@ -11,15 +11,8 @@
 #include <memory>
 #include <string>
 
-#include "base/atomicops.h"
-#include "base/callback.h"
 #include "base/files/file.h"
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/synchronization/lock.h"
-#include "base/synchronization/waitable_event.h"
-#include "base/threading/thread.h"
-#include "build/build_config.h"
+#include "base/memory/weak_ptr.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_manager_base.h"
 #include "media/base/audio_bus.h"
@@ -55,14 +48,11 @@
 //                        AudioInputStream::Open()
 //                                  .- - - - - - - - - - - - ->   OnError()
 //                                  .------------------------->  OnCreated()
-//                               kCreated
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 // Record() ==>                 DoRecord()
 //                      AudioInputStream::Start()
-//                              kRecording
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 // Close() ==>                  DoClose()
-//                           state_ = kClosed
 //                        AudioInputStream::Stop()
 //                        AudioInputStream::Close()
 //                          SyncWriter::Close()
@@ -85,8 +75,7 @@ class AudioFileWriter;
 class UserInputMonitor;
 
 class MEDIA_EXPORT AudioInputController
-    : public base::RefCountedThreadSafe<AudioInputController>,
-      public AudioInputStream::AudioInputCallback {
+    : public base::RefCountedThreadSafe<AudioInputController> {
  public:
   // Error codes to make native logging more clear. These error codes are added
   // to generic error strings to provide a higher degree of details.
@@ -114,8 +103,6 @@ class MEDIA_EXPORT AudioInputController
     virtual void OnCreated(AudioInputController* controller) = 0;
     virtual void OnError(AudioInputController* controller,
                          ErrorCode error_code) = 0;
-    virtual void OnData(AudioInputController* controller,
-                        const AudioBus* data) = 0;
     virtual void OnLog(AudioInputController* controller,
                        const std::string& message) = 0;
 
@@ -164,6 +151,7 @@ class MEDIA_EXPORT AudioInputController
   static scoped_refptr<AudioInputController> Create(
       AudioManager* audio_manager,
       EventHandler* event_handler,
+      SyncWriter* sync_writer,
       const AudioParameters& params,
       const std::string& device_id,
       UserInputMonitor* user_input_monitor);
@@ -221,16 +209,6 @@ class MEDIA_EXPORT AudioInputController
   // to muted and 1.0 to maximum volume.
   virtual void SetVolume(double volume);
 
-  // AudioInputCallback implementation. Threading details depends on the
-  // device-specific implementation.
-  void OnData(AudioInputStream* stream,
-              const AudioBus* source,
-              uint32_t hardware_delay_bytes,
-              double volume) override;
-  void OnError(AudioInputStream* stream) override;
-
-  bool SharedMemoryAndSyncSocketMode() const { return sync_writer_ != NULL; }
-
   // Enable debug recording of audio input.
   virtual void EnableDebugRecording(const base::FilePath& file_name);
 
@@ -260,13 +238,6 @@ class MEDIA_EXPORT AudioInputController
     CAPTURE_STARTUP_RESULT_MAX = CAPTURE_STARTUP_NEVER_GOT_DATA
   };
 
-  // Internal state of the source.
-  enum State {
-    CREATED,
-    RECORDING,
-    CLOSED
-  };
-
 #if defined(AUDIO_POWER_MONITORING)
   // Used to log a silence report (see OnData).
   // Elements in this enum should not be deleted or rearranged; the only
@@ -287,13 +258,22 @@ class MEDIA_EXPORT AudioInputController
   };
 #endif
 
-  AudioInputController(EventHandler* handler,
+  AudioInputController(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+                       EventHandler* handler,
                        SyncWriter* sync_writer,
                        std::unique_ptr<AudioFileWriter> debug_writer,
                        UserInputMonitor* user_input_monitor,
                        const bool agc_is_enabled);
-  ~AudioInputController() override;
+  virtual ~AudioInputController();
+
+  const scoped_refptr<base::SingleThreadTaskRunner>& GetTaskRunnerForTesting()
+      const {
+    return task_runner_;
+  }
 
+  EventHandler* GetHandlerForTesting() const { return handler_; }
+
+ private:
   // Methods called on the audio thread (owned by the AudioManager).
   void DoCreate(AudioManager* audio_manager,
                 const AudioParameters& params,
@@ -306,12 +286,8 @@ class MEDIA_EXPORT AudioInputController
   void DoClose();
   void DoReportError();
   void DoSetVolume(double volume);
-  void DoOnData(std::unique_ptr<AudioBus> data);
   void DoLogAudioLevels(float level_dbfs, int microphone_volume_percent);
 
-  // Helper method that stops, closes, and NULL:s |*stream_|.
-  void DoStopCloseAndClearStream();
-
 #if defined(AUDIO_POWER_MONITORING)
   // Updates the silence state, see enum SilenceState above for state
   // transitions.
@@ -336,44 +312,49 @@ class MEDIA_EXPORT AudioInputController
   // Called by the stream with log messages.
   void LogMessage(const std::string& message);
 
+  // Called on the hw callback thread. Checks for keyboard input if
+  // user_input_monitor_ is set otherwise returns false.
+  bool CheckForKeyboardInput();
+
+  // Does power monitoring on supported platforms.
+  // Called on the hw callback thread.
+  // Returns true iff average power and mic volume was returned and should
+  // be posted to DoLogAudioLevels on the audio thread.
+  // Returns false if either power measurements are disabled or aren't needed
+  // right now (they're done periodically).
+  bool CheckAudioPower(const AudioBus* source,
+                       double volume,
+                       float* average_power_dbfs,
+                       int* mic_volume_percent);
+
   // Gives access to the task runner of the creating thread.
-  scoped_refptr<base::SingleThreadTaskRunner> creator_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> const creator_task_runner_;
 
   // The task runner of audio-manager thread that this object runs on.
-  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> const task_runner_;
 
   // Contains the AudioInputController::EventHandler which receives state
   // notifications from this class.
-  EventHandler* handler_;
+  EventHandler* const handler_;
 
   // Pointer to the audio input stream object.
+  // Only used on the audio thread.
   AudioInputStream* stream_;
 
-  // Flag for whether CaptureStartupResults shall be reported.
-  // A value of 1 means that stats shall be reported,
-  // any other value means that stats have already been reported.
-  base::AtomicRefCount should_report_stats;
-
-  // |state_| is written on the audio thread and is read on the hardware audio
-  // thread. These operations need to be locked. But lock is not required for
-  // reading on the audio input controller thread.
-  State state_;
-
-  base::Lock lock_;
-
   // SyncWriter is used only in low-latency mode for synchronous writing.
-  SyncWriter* sync_writer_;
+  SyncWriter* const sync_writer_;
 
   static Factory* factory_;
 
   double max_volume_;
 
-  UserInputMonitor* user_input_monitor_;
+  UserInputMonitor* const user_input_monitor_;
 
   const bool agc_is_enabled_;
 
 #if defined(AUDIO_POWER_MONITORING)
-  // Enabled in DoCrete() but not in DoCreateForStream().
+  // Will be set to true if an AGC is supported and enabled (see DoCreate and
+  // DoCreateForStream). By default set to false.
   bool power_measurement_is_enabled_;
 
   // Updated each time a power measurement is performed.
@@ -394,7 +375,29 @@ class MEDIA_EXPORT AudioInputController
   // Used for audio debug recordings. Accessed on audio thread.
   const std::unique_ptr<AudioFileWriter> debug_writer_;
 
- private:
+  class AudioCallback;
+  // Holds a pointer to the callback object that receives audio data from
+  // the lower audio layer. Valid only while 'recording' (between calls to
+  // stream_->Start() and stream_->Stop()).
+  // The value of this pointer is only set and read on the audio thread while
+  // the callbacks themselves occur on the hw callback thread. More details
+  // in the AudioCallback class in the cc file.
+  std::unique_ptr<AudioCallback> audio_callback_;
+
+  // A weak pointer factory that we use when posting tasks to the audio thread
+  // that we want to be automatically discarded after Close() has been called
+  // and that we do not want to keep the AudioInputController instance alive
+  // beyond what is desired by the user of the instance (e.g.
+  // AudioInputRendererHost). An example of where this is important is when
+  // we fire error notifications from the hw callback thread, post them to
+  // the audio thread. In that case, we do not want the error notification to
+  // keep the AudioInputController alive for as long as the error notification
+  // is pending and then make a callback from an AudioInputController that has
+  // already been closed.
+  // The weak_ptr_factory_ and all outstanding weak pointers, are invalidated
+  // at the end of DoClose.
+  base::WeakPtrFactory<AudioInputController> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioInputController);
 };