Merge Pipeline's kError state with kStopped: a baby step towards bringing sanity to shutdown.

media/base/pipeline.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BASE_PIPELINE_H_
 #define MEDIA_BASE_PIPELINE_H_
 
 #include <string>
 
 #include "base/gtest_prod_util.h"
@@ skipping 98 matching lines @@
   //   |ended_cb| will be executed whenever the media reaches the end.
   //   |error_cb| will be executed whenever an error occurs but hasn't
   //               been reported already through another callback.
   //
   // It is an error to call this method after the pipeline has already started.
   void Start(scoped_ptr<FilterCollection> filter_collection,
              const PipelineStatusCB& ended_cb,
              const PipelineStatusCB& error_cb,
              const PipelineStatusCB& start_cb);
 
-  // Asynchronously stops the pipeline and resets it to an uninitialized state.
+  // Asynchronously stops the pipeline, executing |stop_cb| when the pipeline
+  // teardown has completed.
   //
-  // If provided, |stop_cb| will be executed when the pipeline has been
-  // completely torn down and reset to an uninitialized state.  It is acceptable
-  // to call Start() again once the callback has finished executing.
-  //
-  // Stop() must be called before destroying the pipeline.  Clients can
-  // determine whether Stop() must be called by checking IsRunning().
-  //
-  // It is an error to call this method if the pipeline has not started.
-  //
-  // TODO(scherkus): ideally clients would destroy the pipeline after calling
-  // Stop() and create a new pipeline as needed.
+  // Stop() must complete before destroying the pipeline. It it permissible to
+  // call Stop() multiple times.

[Ami GONE FROM CHROMIUM, 2012/08/09 20:55:41]

why?

[scherkus (not reviewing), 2012/08/09 22:07:49]

gah my wording here was bad -- it's more about being able to call Stop() at any
time after a Pipeline has been created rather than calling Stop() a bunch of
times (this way clients such as WMPI don't need to externally track whether
they've called Start())

   void Stop(const base::Closure& stop_cb);
 
   // Attempt to seek to the position specified by time.  |seek_cb| will be
   // executed when the all filters in the pipeline have processed the seek.
   //
   // Clients are expected to call GetMediaTime() to check whether the seek
   // succeeded.
   //
   // It is an error to call this method if the pipeline has not started.
   void Seek(base::TimeDelta time, const PipelineStatusCB& seek_cb);
@@ skipping 52 matching lines @@
   // be 0.
   void GetNaturalVideoSize(gfx::Size* out_size) const;
 
   // Return true if loading progress has been made since the last time this
   // method was called.
   bool DidLoadingProgress() const;
 
   // Gets the current pipeline statistics.
   PipelineStatistics GetStatistics() const;
 
-  // TODO(scherkus): Remove IsInitializedForTesting() after stop/error teardown
-  // paths are sane, see http://crbug.com/110228
-  bool IsInitializedForTesting();
   void SetClockForTesting(Clock* clock);
   void SetErrorForTesting(PipelineStatus status);
 
  private:
   FRIEND_TEST_ALL_PREFIXES(PipelineTest, GetBufferedTimeRanges);
   FRIEND_TEST_ALL_PREFIXES(PipelineTest, DisableAudioRenderer);
   FRIEND_TEST_ALL_PREFIXES(PipelineTest, DisableAudioRendererDuringInit);
   FRIEND_TEST_ALL_PREFIXES(PipelineTest, EndedCallback);
   FRIEND_TEST_ALL_PREFIXES(PipelineTest, AudioStreamShorterThanVideo);
   friend class MediaLog;
@@ skipping 10 matching lines @@
     kInitAudioRenderer,
     kInitVideoDecoder,
     kInitVideoRenderer,
     kPausing,
     kSeeking,
     kFlushing,
     kStarting,
     kStarted,
     kStopping,
     kStopped,
-    kError,
   };
 
   // Updates |state_|. All state transitions should use this call.
   void SetState(State next_state);
 
   // Simple method used to make sure the pipeline is running normally.
   bool IsPipelineOk();
 
-  // Helper method to tell whether we are stopped or in error.
-  bool IsPipelineStopped();
-
-  // Helper method to tell whether we are in transition to stop state.
-  bool IsPipelineTearingDown();
-
   // Helper method to tell whether we are in transition to seek state.
   bool IsPipelineSeeking();
 
   // Helper method to execute callback from Start() and reset
   // |filter_collection_|. Called when initialization completes
   // normally or when pipeline is stopped or error occurs during
   // initialization.
   void FinishInitialization();
 
   // Returns true if the given state is one that transitions to a new state
@@ skipping 59 matching lines @@
   // as a result of calling Start() or InitializationComplete() that advances
   // initialization to the next state. It works as a hub of state transition for
   // initialization.  One stage communicates its status to the next through
   // |last_stage_status|.
   void InitializeTask(PipelineStatus last_stage_status);
 
   // Stops and destroys all filters, placing the pipeline in the kStopped state.
   void StopTask(const base::Closure& stop_cb);
 
   // Carries out stopping and destroying all filters, placing the pipeline in
-  // the kError state.
+  // the kStopped state.
   void ErrorChangedTask(PipelineStatus error);
 
   // Carries out notifying filters that the playback rate has changed.
   void PlaybackRateChangedTask(float playback_rate);
 
   // Carries out notifying filters that the volume has changed.
   void VolumeChangedTask(float volume);
 
   // Carries out notifying filters that we are seeking to a new timestamp.
   void SeekTask(base::TimeDelta time, const PipelineStatusCB& seek_cb);
@@ skipping 86 matching lines @@
 
   // Whether or not the pipeline is running.
   bool running_;
 
   // Whether or not the pipeline is in transition for a seek operation.
   bool seek_pending_;
 
   // Whether or not the pipeline is perform a stop operation.
   bool tearing_down_;
 
-  // Whether or not an error triggered the teardown.
-  bool error_caused_teardown_;
-
   // Whether or not a playback rate change should be done once seeking is done.
   bool playback_rate_change_pending_;
 
   // Amount of available buffered data.  Set by filters.
   Ranges<int64> buffered_byte_ranges_;
   Ranges<base::TimeDelta> buffered_time_ranges_;
 
   // True when AddBufferedByteRange() has been called more recently than
   // DidLoadingProgress().
   mutable bool did_loading_progress_;
@@ skipping 94 matching lines @@
   base::Time creation_time_;
 
   scoped_ptr<SerialRunner> pending_callbacks_;
 
   DISALLOW_COPY_AND_ASSIGN(Pipeline);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_PIPELINE_H_