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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 http://mozilla.org/MPL/2.0/. */
#include "IDecodingTask.h"
#include "nsThreadUtils.h"
#include "Decoder.h"
#include "DecodePool.h"
#include "RasterImage.h"
#include "SurfaceCache.h"
namespace mozilla {
using gfx::IntRect;
namespace image {
///////////////////////////////////////////////////////////////////////////////
// Helpers for sending notifications to the image associated with a decoder.
///////////////////////////////////////////////////////////////////////////////
void IDecodingTask::EnsureHasEventTarget(NotNull<RasterImage*> aImage) {
if (!mEventTarget) {
// We determine the event target as late as possible, at the first dispatch
// time, because the observers bound to an imgRequest will affect it.
// We cache it rather than query for the event target each time because the
// event target can change. We don't want to risk events being executed in
// a different order than they are dispatched, which can happen if we
// selected scheduler groups which have no ordering guarantees relative to
// each other (e.g. it moves from scheduler group A for doc group DA to
// scheduler group B for doc group DB due to changing observers -- if we
// dispatched the first event on A, and the second on B, we don't know which
// will execute first.)
RefPtr<ProgressTracker> tracker = aImage->GetProgressTracker();
if (tracker) {
mEventTarget = tracker->GetEventTarget();
} else {
mEventTarget = GetMainThreadSerialEventTarget();
}
}
}
bool IDecodingTask::IsOnEventTarget() const {
// This is essentially equivalent to NS_IsOnMainThread() because all of the
// event targets are for the main thread (although perhaps with a different
// label / scheduler group). The observers in ProgressTracker may have
// different event targets from this, so this is just a best effort guess.
bool current = false;
mEventTarget->IsOnCurrentThread(&current);
return current;
}
void IDecodingTask::NotifyProgress(NotNull<RasterImage*> aImage,
NotNull<Decoder*> aDecoder) {
MOZ_ASSERT(aDecoder->HasProgress() && !aDecoder->IsMetadataDecode());
EnsureHasEventTarget(aImage);
// Capture the decoder's state. If we need to notify asynchronously, it's
// important that we don't wait until the lambda actually runs to capture the
// state that we're going to notify. That would both introduce data races on
// the decoder's state and cause inconsistencies between the NotifyProgress()
// calls we make off-main-thread and the notifications that RasterImage
// actually receives, which would cause bugs.
Progress progress = aDecoder->TakeProgress();
OrientedIntRect invalidRect = aDecoder->TakeInvalidRect();
Maybe<uint32_t> frameCount = aDecoder->TakeCompleteFrameCount();
DecoderFlags decoderFlags = aDecoder->GetDecoderFlags();
SurfaceFlags surfaceFlags = aDecoder->GetSurfaceFlags();
// Synchronously notify if we can.
if (IsOnEventTarget() && !(decoderFlags & DecoderFlags::ASYNC_NOTIFY)) {
aImage->NotifyProgress(progress, invalidRect, frameCount, decoderFlags,
surfaceFlags);
return;
}
// Don't try to dispatch after shutdown, we'll just leak the runnable.
if (gXPCOMThreadsShutDown) {
return;
}
// We're forced to notify asynchronously.
NotNull<RefPtr<RasterImage>> image = aImage;
mEventTarget->Dispatch(CreateRenderBlockingRunnable(NS_NewRunnableFunction(
"IDecodingTask::NotifyProgress",
[=]() -> void {
image->NotifyProgress(progress, invalidRect,
frameCount, decoderFlags,
surfaceFlags);
})),
NS_DISPATCH_NORMAL);
}
void IDecodingTask::NotifyDecodeComplete(NotNull<RasterImage*> aImage,
NotNull<Decoder*> aDecoder) {
MOZ_ASSERT(aDecoder->HasError() || !aDecoder->InFrame(),
"Decode complete in the middle of a frame?");
EnsureHasEventTarget(aImage);
// Capture the decoder's state.
DecoderFinalStatus finalStatus = aDecoder->FinalStatus();
ImageMetadata metadata = aDecoder->GetImageMetadata();
DecoderTelemetry telemetry = aDecoder->Telemetry();
Progress progress = aDecoder->TakeProgress();
OrientedIntRect invalidRect = aDecoder->TakeInvalidRect();
Maybe<uint32_t> frameCount = aDecoder->TakeCompleteFrameCount();
DecoderFlags decoderFlags = aDecoder->GetDecoderFlags();
SurfaceFlags surfaceFlags = aDecoder->GetSurfaceFlags();
// Synchronously notify if we can.
if (IsOnEventTarget() && !(decoderFlags & DecoderFlags::ASYNC_NOTIFY)) {
aImage->NotifyDecodeComplete(finalStatus, metadata, telemetry, progress,
invalidRect, frameCount, decoderFlags,
surfaceFlags);
return;
}
// Don't try to dispatch after shutdown, we'll just leak the runnable.
if (gXPCOMThreadsShutDown) {
return;
}
// We're forced to notify asynchronously.
NotNull<RefPtr<RasterImage>> image = aImage;
mEventTarget->Dispatch(CreateRenderBlockingRunnable(NS_NewRunnableFunction(
"IDecodingTask::NotifyDecodeComplete",
[=]() -> void {
image->NotifyDecodeComplete(
finalStatus, metadata, telemetry, progress,
invalidRect, frameCount, decoderFlags,
surfaceFlags);
})),
NS_DISPATCH_NORMAL);
}
///////////////////////////////////////////////////////////////////////////////
// IDecodingTask implementation.
///////////////////////////////////////////////////////////////////////////////
void IDecodingTask::Resume() { DecodePool::Singleton()->AsyncRun(this); }
///////////////////////////////////////////////////////////////////////////////
// MetadataDecodingTask implementation.
///////////////////////////////////////////////////////////////////////////////
MetadataDecodingTask::MetadataDecodingTask(NotNull<Decoder*> aDecoder)
: mMutex("mozilla::image::MetadataDecodingTask"), mDecoder(aDecoder) {
MOZ_ASSERT(mDecoder->IsMetadataDecode(),
"Use DecodingTask for non-metadata decodes");
}
void MetadataDecodingTask::Run() {
MutexAutoLock lock(mMutex);
LexerResult result = mDecoder->Decode(WrapNotNull(this));
if (result.is<TerminalState>()) {
NotifyDecodeComplete(mDecoder->GetImage(), mDecoder);
return; // We're done.
}
if (result == LexerResult(Yield::NEED_MORE_DATA)) {
// We can't make any more progress right now. We also don't want to report
// any progress, because it's important that metadata decode results are
// delivered atomically. The decoder itself will ensure that we get
// reenqueued when more data is available; just return for now.
return;
}
MOZ_ASSERT_UNREACHABLE("Metadata decode yielded for an unexpected reason");
}
///////////////////////////////////////////////////////////////////////////////
// AnonymousDecodingTask implementation.
///////////////////////////////////////////////////////////////////////////////
AnonymousDecodingTask::AnonymousDecodingTask(NotNull<Decoder*> aDecoder,
bool aResumable)
: mDecoder(aDecoder), mResumable(aResumable) {}
void AnonymousDecodingTask::Run() {
while (true) {
LexerResult result = mDecoder->Decode(WrapNotNull(this));
if (result.is<TerminalState>()) {
return; // We're done.
}
if (result == LexerResult(Yield::NEED_MORE_DATA)) {
// We can't make any more progress right now. Let the caller decide how to
// handle it.
return;
}
// Right now we don't do anything special for other kinds of yields, so just
// keep working.
MOZ_ASSERT(result.is<Yield>());
}
}
void AnonymousDecodingTask::Resume() {
// Anonymous decoders normally get all their data at once. We have tests
// where they don't; typically in these situations, the test re-runs them
// manually. However some tests want to verify Resume works, so they will
// explicitly request this behaviour.
if (mResumable) {
RefPtr<AnonymousDecodingTask> self(this);
NS_DispatchToMainThread(
NS_NewRunnableFunction("image::AnonymousDecodingTask::Resume",
[self]() -> void { self->Run(); }));
}
}
} // namespace image
} // namespace mozilla