media/base/pipeline.h - Issue 10837206: Rewrite media::Pipeline state transition machinery and simplify shutdown.

Unified Diff: media/base/pipeline.h

Issue 10837206: Rewrite media::Pipeline state transition machinery and simplify shutdown. (Closed) Base URL: svn://chrome-svn/chrome/trunk/src

Patch Set: nits Created 8 years, 3 months ago

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Index: media/base/pipeline.h

diff --git a/media/base/pipeline.h b/media/base/pipeline.h

index 9325f1ab5c199a7ac6985c87d28cc205a64b5729..e023e87224a4214539497055380e1c3fc2553c35 100644

--- a/media/base/pipeline.h

+++ b/media/base/pipeline.h

@@ -10,6 +10,7 @@

#include "base/gtest_prod_util.h"

#include "base/synchronization/condition_variable.h"

#include "base/synchronization/lock.h"

+#include "base/threading/thread_checker.h"

#include "media/base/audio_renderer.h"

#include "media/base/demuxer.h"

#include "media/base/media_export.h"

@@ -66,22 +67,20 @@ class MEDIA_EXPORT PipelineStatusNotification {

// Here's a state diagram that describes the lifetime of this object.

-// [ *Created ] [ Stopped ]

-// | Start() ^

-// V SetError() |

-// [ InitXXX (for each filter) ] -------->[ Stopping (for each filter) ]

-// | ^

-// V | if Stop

-// [ Seeking (for each filter) ] <--------[ Flushing (for each filter) ]

-// | if Seek ^

-// V |

-// [ Starting (for each filter) ] |

-// | |

-// V Seek()/Stop() |

-// [ Started ] -------------------------> [ Pausing (for each filter) ]

-// ^ SetError()

-// |

-// [ Any State Other Than InitXXX ]

+// [ *Created ] [ Any State ]

+// | Start() | Stop() / SetError()

+// V V

+// [ InitXXX (for each filter) ] [ Stopping ]

+// | |

+// V V

+// [ InitPreroll ] [ Stopped ]

+// |

+// V

+// [ Starting ] <-- [ Seeking ]

+// | ^

+// V |

+// [ Started ] ----------'

+// Seek()

// Initialization is a series of state transitions from "Created" through each

// filter initialization state. When all filter initialization states have

@@ -119,6 +118,10 @@ class MEDIA_EXPORT Pipeline

// Build a pipeline to using the given filter collection to construct a filter

// chain, executing |seek_cb| when the initial seek/preroll has completed.

+ // |filter_collection| must be a complete collection containing a demuxer,

+ // audio/video decoders, and audio/video renderers. Failing to do so will

+ // result in a crash.

+ //

// The following permanent callbacks will be executed as follows up until

// Stop() has completed:

// |ended_cb| will be executed whenever the media reaches the end.

@@ -232,9 +235,8 @@ class MEDIA_EXPORT Pipeline

kInitAudioDecoder,

kInitAudioRenderer,

kInitVideoRenderer,

- kPausing,

+ kInitPrerolling,

kSeeking,

- kFlushing,

kStarting,

kStarted,

kStopping,

@@ -244,23 +246,13 @@ class MEDIA_EXPORT Pipeline

// 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 in transition to seek state.

- bool IsPipelineSeeking();

+ static const char* GetStateString(State state);

+ State GetNextState() const;

// Helper method that runs & resets |seek_cb_| and resets |seek_timestamp_|

// and |seek_pending_|.

void FinishSeek();

- // Returns true if the given state is one that transitions to a new state

- // after iterating through each filter.

- static bool TransientState(State state);

- // Given the current state, returns the next state.

- State FindNextState(State current);

// DataSourceHost (by way of DemuxerHost) implementation.

virtual void SetTotalBytes(int64 total_bytes) OVERRIDE;

virtual void AddBufferedByteRange(int64 start, int64 end) OVERRIDE;

@@ -283,16 +275,6 @@ class MEDIA_EXPORT Pipeline

void OnAudioRendererEnded();

void OnVideoRendererEnded();

- // Callbacks executed by filters upon completing initialization.

- void OnFilterInitialize(PipelineStatus status);

- // Callback executed by filters upon completing Play(), Pause(), Flush(),

- // Seek() or Stop().

- void OnFilterStateTransition(PipelineStatus status);

- // Callback executed by filters when completing teardown operations.

- void OnTeardownStateTransition(PipelineStatus status);

// Callback executed by filters to update statistics.

void OnUpdateStatistics(const PipelineStatistics& stats);

@@ -314,13 +296,6 @@ class MEDIA_EXPORT Pipeline

const PipelineStatusCB& seek_cb,

const BufferingStateCB& buffering_state_cb);

- // InitializeTask() performs initialization in multiple passes. It is executed

- // 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);

@@ -345,38 +320,12 @@ class MEDIA_EXPORT Pipeline

// Carries out disabling the audio renderer.

void AudioDisabledTask();

- // Carries out advancing to the next filter during Play()/Pause()/Seek().

- void FilterStateTransitionTask();

- // Carries out advancing to the next teardown operation.

- void TeardownStateTransitionTask();

- // Carries out stopping filter threads, deleting filters, running

- // appropriate callbacks, and setting the appropriate pipeline state

- // depending on whether we performing Stop() or SetError().

- // Called after all filters have been stopped.

- void FinishDestroyingFiltersTask();

- // Internal methods used in the implementation of the pipeline thread. All

- // of these methods are only called on the pipeline thread.

- // The following initialize methods are used to select a specific type of

- // object from FilterCollection and initialize it asynchronously.

- void InitializeDemuxer();

- void OnDemuxerInitialized(PipelineStatus status);

- // Returns true if the asynchronous action of creating decoder has started.

- // Returns false if this method did nothing because the corresponding

- // audio stream does not exist.

- bool InitializeAudioDecoder(const scoped_refptr<Demuxer>& demuxer);

- // Initializes a renderer and connects it with decoder. Returns true if the

- // asynchronous action of creating renderer has started. Returns

- // false if this method did nothing because the corresponding audio/video

- // stream does not exist.

- bool InitializeAudioRenderer(const scoped_refptr<AudioDecoder>& decoder);

- bool InitializeVideoRenderer(

- const scoped_refptr<DemuxerStream>& stream);

+ // Kicks off initialization for each media object, executing |done_cb| with

+ // the result when completed.

+ void InitializeDemuxer(const PipelineStatusCB& done_cb);

+ void InitializeAudioDecoder(const PipelineStatusCB& done_cb);

+ void InitializeAudioRenderer(const PipelineStatusCB& done_cb);

+ void InitializeVideoRenderer(const PipelineStatusCB& done_cb);

// Kicks off destroying filters. Called by StopTask() and ErrorChangedTask().

// When we start to tear down the pipeline, we will consider two cases:

@@ -390,30 +339,34 @@ class MEDIA_EXPORT Pipeline

// Compute the time corresponding to a byte offset.

base::TimeDelta TimeForByteOffset_Locked(int64 byte_offset) const;

- // Initiates an asynchronous Pause/Seek/Play/Stop() call sequence executing

- // |done_cb| when completed.

- void DoPause(const PipelineStatusCB& done_cb);

- void DoFlush(const PipelineStatusCB& done_cb);

- void DoPlay(const PipelineStatusCB& done_cb);

- void DoStop(const PipelineStatusCB& done_cb);

+ void OnStateTransition(PipelineStatus status);

+ void StateTransitionTask(PipelineStatus status);

- // Initiates an asynchronous Seek() and preroll call sequence executing

- // |done_cb| with the final status when completed. If |skip_demuxer_seek| is

- // true then only renderers will attempt to preroll.

+ // Initiates an asynchronous preroll call sequence executing |done_cb|

+ // with the final status when completed.

+ void DoInitialPreroll(const PipelineStatusCB& done_cb);

+ // Initiates an asynchronous pause-flush-seek-preroll call sequence

+ // executing |done_cb| with the final status when completed.

// TODO(scherkus): Prerolling should be separate from seeking so we can report

// finer grained ready states (HAVE_CURRENT_DATA vs. HAVE_FUTURE_DATA)

// indepentent from seeking.

- void DoSeek(base::TimeDelta seek_timestamp, bool skip_demuxer_seek,

- const PipelineStatusCB& done_cb);

+ void DoSeek(base::TimeDelta seek_timestamp, const PipelineStatusCB& done_cb);

+ // Updates playback rate and volume and initiates an asynchronous play call

+ // sequence executing |done_cb| with the final status when completed.

+ void DoPlay(const PipelineStatusCB& done_cb);

+ // Initiates an asynchronous pause-flush-stop call sequence executing

+ // |done_cb| when completed.

+ void DoStop(const PipelineStatusCB& done_cb);

+ void OnStopCompleted(PipelineStatus status);

void OnAudioUnderflow();

void StartClockIfWaitingForTimeUpdate_Locked();

- // Report pipeline |status| through |cb| avoiding duplicate error reporting.

- void ReportStatus(const PipelineStatusCB& cb, PipelineStatus status);

// Message loop used to execute pipeline tasks.

scoped_refptr<base::MessageLoopProxy> message_loop_;

@@ -426,15 +379,6 @@ class MEDIA_EXPORT Pipeline

// 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 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_;

@@ -459,9 +403,6 @@ class MEDIA_EXPORT Pipeline

// the filters.

float playback_rate_;

- // Playback rate to set when the current seek has finished.

- float pending_playback_rate_;

// Reference clock. Keeps track of current playback time. Uses system

// clock and linear interpolation, but can have its time manually set

// by filters.

@@ -491,10 +432,6 @@ class MEDIA_EXPORT Pipeline

// Member that tracks the current state.

State state_;

- // For kSeeking we need to remember where we're seeking between filter

- // replies.

- base::TimeDelta seek_timestamp_;

// Whether we've received the audio/video ended events.

bool audio_ended_;

bool video_ended_;

@@ -502,12 +439,15 @@ class MEDIA_EXPORT Pipeline

// Set to true in DisableAudioRendererTask().

bool audio_disabled_;

- // Filter collection as passed in by Start().

scoped_ptr<FilterCollection> filter_collection_;

- // Callbacks for various pipeline operations.

+ // Temporary callback used for Start() and Seek().

PipelineStatusCB seek_cb_;

+ // Temporary callback used for Stop().

base::Closure stop_cb_;

+ // Permanent callbacks passed in via Start().

PipelineStatusCB ended_cb_;

PipelineStatusCB error_cb_;

BufferingStateCB buffering_state_cb_;

@@ -527,19 +467,22 @@ class MEDIA_EXPORT Pipeline

// Demuxer reference used for setting the preload value.

scoped_refptr<Demuxer> demuxer_;

- // Helper class that stores filter references during pipeline

- // initialization.

- struct PipelineInitState;

- scoped_ptr<PipelineInitState> pipeline_init_state_;

+ // Audio decoder reference used during initialization.

+ //

+ // TODO(scherkus): Remove after renderers do initialization, see

+ // http://crbug.com/145635

+ scoped_refptr<AudioDecoder> audio_decoder_;

- // Statistics.

PipelineStatistics statistics_;

// Time of pipeline creation; is non-zero only until the pipeline first

// reaches "kStarted", at which point it is used & zeroed out.

base::Time creation_time_;

scoped_ptr<SerialRunner> pending_callbacks_;

+ base::ThreadChecker thread_checker_;

DISALLOW_COPY_AND_ASSIGN(Pipeline);

};

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