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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
#ifndef mozilla_GraphRunner_h
#define mozilla_GraphRunner_h
#include "GraphDriver.h"
#include "MediaSegment.h"
#include "mozilla/Monitor.h"
#include <thread>
struct PRThread;
namespace mozilla {
class AudioMixer;
class MediaTrackGraphImpl;
class GraphRunner final : public Runnable {
using IterationResult = GraphInterface::IterationResult;
public:
static already_AddRefed<GraphRunner> Create(MediaTrackGraphImpl* aGraph);
/**
* Marks us as shut down and signals mThread, so that it runs until the end.
*/
MOZ_CAN_RUN_SCRIPT void Shutdown();
/**
* Signals one iteration of mGraph. Hands state over to mThread and runs
* the iteration there.
*/
IterationResult OneIteration(GraphTime aStateEnd, GraphTime aIterationEnd,
AudioMixer* aMixer);
/**
* Runs mGraph until it shuts down.
*/
NS_IMETHOD Run();
/**
* Returns true if called on mThread.
*/
bool OnThread();
#ifdef DEBUG
/**
* Returns true if called on mThread, and aDriver was the driver that called
* OneIteration() last.
*/
bool InDriverIteration(GraphDriver* aDriver);
#endif
private:
explicit GraphRunner(MediaTrackGraphImpl* aGraph,
already_AddRefed<nsIThread> aThread);
~GraphRunner();
class IterationState {
GraphTime mStateEnd;
GraphTime mIterationEnd;
AudioMixer* MOZ_NON_OWNING_REF mMixer;
public:
IterationState(GraphTime aStateEnd, GraphTime aIterationEnd,
AudioMixer* aMixer)
: mStateEnd(aStateEnd), mIterationEnd(aIterationEnd), mMixer(aMixer) {}
IterationState& operator=(const IterationState& aOther) = default;
GraphTime StateEnd() const { return mStateEnd; }
GraphTime IterationEnd() const { return mIterationEnd; }
AudioMixer* Mixer() const { return mMixer; }
};
// Monitor used for yielding mThread through Wait(), and scheduling mThread
// through Signal() from a GraphDriver.
Monitor mMonitor;
// The MediaTrackGraph we're running. Weakptr beecause this graph owns us and
// guarantees that our lifetime will not go beyond that of itself.
MediaTrackGraphImpl* const mGraph;
// State being handed over to the graph through OneIteration. Protected by
// mMonitor.
Maybe<IterationState> mIterationState;
// Result from mGraph's OneIteration. Protected by mMonitor.
IterationResult mIterationResult;
enum class ThreadState {
Wait, // Waiting for a message. This is the initial state.
// A transition from Run back to Wait occurs on the runner
// thread after it processes as far as mIterationState->mStateEnd
// and sets mIterationResult.
Run, // Set on driver thread after each mIterationState update.
Shutdown, // Set when Shutdown() is called on main thread.
};
// Protected by mMonitor until set to Shutdown, after which this is not
// modified.
ThreadState mThreadState;
// The thread running mGraph. Set on construction, after other members are
// initialized. Cleared at the end of Shutdown().
const nsCOMPtr<nsIThread> mThread;
#ifdef DEBUG
// Set to mGraph's audio callback driver's thread id, if run by an
// AudioCallbackDriver, while OneIteration() is running.
std::thread::id mAudioDriverThreadId = std::thread::id();
// Set to mGraph's system clock driver's thread, if run by a
// SystemClockDriver, while OneIteration() is running.
nsIThread* mClockDriverThread = nullptr;
#endif
};
} // namespace mozilla
#endif