gecko-dev/image/ProgressTracker.cpp
Andreas Farre f2fa2e633c Bug 1620594 - Part 5: Use GetMainThreadSerialEventTarget instead of SystemGroup::EventTargetFor. r=nika
This patch also tries to remove the event target entirely if it would
default to the main thread on a null event target.

Depends on D67634

Differential Revision: https://phabricator.services.mozilla.com/D67635

--HG--
extra : moz-landing-system : lando
2020-04-07 15:17:07 +00:00

557 lines
18 KiB
C++

/* -*- 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 "ImageLogging.h"
#include "ProgressTracker.h"
#include "imgINotificationObserver.h"
#include "imgIRequest.h"
#include "Image.h"
#include "nsNetUtil.h"
#include "nsIObserverService.h"
#include "mozilla/Assertions.h"
#include "mozilla/Services.h"
using mozilla::WeakPtr;
namespace mozilla {
namespace image {
static void CheckProgressConsistency(Progress aOldProgress,
Progress aNewProgress, bool aIsMultipart) {
// Check preconditions for every progress bit.
// Error's do not get propagated from the tracker for each image part to the
// tracker for the multipart image because we don't want one bad part to
// prevent the remaining parts from showing. So we need to consider whether
// this is a tracker for a multipart image for these assertions to work.
if (aNewProgress & FLAG_SIZE_AVAILABLE) {
// No preconditions.
}
if (aNewProgress & FLAG_DECODE_COMPLETE) {
MOZ_ASSERT(aNewProgress & FLAG_SIZE_AVAILABLE);
MOZ_ASSERT(aIsMultipart ||
aNewProgress & (FLAG_FRAME_COMPLETE | FLAG_HAS_ERROR));
}
if (aNewProgress & FLAG_FRAME_COMPLETE) {
MOZ_ASSERT(aNewProgress & FLAG_SIZE_AVAILABLE);
}
if (aNewProgress & FLAG_LOAD_COMPLETE) {
MOZ_ASSERT(aIsMultipart ||
aNewProgress & (FLAG_SIZE_AVAILABLE | FLAG_HAS_ERROR));
}
if (aNewProgress & FLAG_IS_ANIMATED) {
// No preconditions; like FLAG_HAS_TRANSPARENCY, we should normally never
// discover this *after* FLAG_SIZE_AVAILABLE, but unfortunately some corrupt
// GIFs may fool us.
}
if (aNewProgress & FLAG_HAS_TRANSPARENCY) {
// XXX We'd like to assert that transparency is only set during metadata
// decode but we don't have any way to assert that until bug 1254892 is
// fixed.
}
if (aNewProgress & FLAG_LAST_PART_COMPLETE) {
MOZ_ASSERT(aNewProgress & FLAG_LOAD_COMPLETE);
}
if (aNewProgress & FLAG_HAS_ERROR) {
// No preconditions.
}
}
ProgressTracker::ProgressTracker()
: mMutex("ProgressTracker::mMutex"),
mImage(nullptr),
mEventTarget(WrapNotNull(
nsCOMPtr<nsIEventTarget>(GetMainThreadSerialEventTarget()))),
mObserversWithTargets(0),
mObservers(new ObserverTable),
mProgress(NoProgress),
mIsMultipart(false) {}
void ProgressTracker::SetImage(Image* aImage) {
MutexAutoLock lock(mMutex);
MOZ_ASSERT(aImage, "Setting null image");
MOZ_ASSERT(!mImage, "Setting image when we already have one");
mImage = aImage;
}
void ProgressTracker::ResetImage() {
MutexAutoLock lock(mMutex);
MOZ_ASSERT(mImage, "Resetting image when it's already null!");
mImage = nullptr;
}
uint32_t ProgressTracker::GetImageStatus() const {
uint32_t status = imgIRequest::STATUS_NONE;
// Translate our current state to a set of imgIRequest::STATE_* flags.
if (mProgress & FLAG_SIZE_AVAILABLE) {
status |= imgIRequest::STATUS_SIZE_AVAILABLE;
}
if (mProgress & FLAG_DECODE_COMPLETE) {
status |= imgIRequest::STATUS_DECODE_COMPLETE;
}
if (mProgress & FLAG_FRAME_COMPLETE) {
status |= imgIRequest::STATUS_FRAME_COMPLETE;
}
if (mProgress & FLAG_LOAD_COMPLETE) {
status |= imgIRequest::STATUS_LOAD_COMPLETE;
}
if (mProgress & FLAG_IS_ANIMATED) {
status |= imgIRequest::STATUS_IS_ANIMATED;
}
if (mProgress & FLAG_HAS_TRANSPARENCY) {
status |= imgIRequest::STATUS_HAS_TRANSPARENCY;
}
if (mProgress & FLAG_HAS_ERROR) {
status |= imgIRequest::STATUS_ERROR;
}
return status;
}
// A helper class to allow us to call SyncNotify asynchronously.
class AsyncNotifyRunnable : public Runnable {
public:
AsyncNotifyRunnable(ProgressTracker* aTracker, IProgressObserver* aObserver)
: Runnable("ProgressTracker::AsyncNotifyRunnable"), mTracker(aTracker) {
MOZ_ASSERT(NS_IsMainThread(), "Should be created on the main thread");
MOZ_ASSERT(aTracker, "aTracker should not be null");
MOZ_ASSERT(aObserver, "aObserver should not be null");
mObservers.AppendElement(aObserver);
}
NS_IMETHOD Run() override {
MOZ_ASSERT(NS_IsMainThread(), "Should be running on the main thread");
MOZ_ASSERT(mTracker, "mTracker should not be null");
for (uint32_t i = 0; i < mObservers.Length(); ++i) {
mObservers[i]->ClearPendingNotify();
mTracker->SyncNotify(mObservers[i]);
}
mTracker->mRunnable = nullptr;
return NS_OK;
}
void AddObserver(IProgressObserver* aObserver) {
mObservers.AppendElement(aObserver);
}
void RemoveObserver(IProgressObserver* aObserver) {
mObservers.RemoveElement(aObserver);
}
private:
friend class ProgressTracker;
RefPtr<ProgressTracker> mTracker;
nsTArray<RefPtr<IProgressObserver>> mObservers;
};
ProgressTracker::MediumHighRunnable::MediumHighRunnable(
already_AddRefed<AsyncNotifyRunnable>&& aEvent)
: PrioritizableRunnable(std::move(aEvent),
nsIRunnablePriority::PRIORITY_MEDIUMHIGH) {}
void ProgressTracker::MediumHighRunnable::AddObserver(
IProgressObserver* aObserver) {
static_cast<AsyncNotifyRunnable*>(mRunnable.get())->AddObserver(aObserver);
}
void ProgressTracker::MediumHighRunnable::RemoveObserver(
IProgressObserver* aObserver) {
static_cast<AsyncNotifyRunnable*>(mRunnable.get())->RemoveObserver(aObserver);
}
/* static */
already_AddRefed<ProgressTracker::MediumHighRunnable>
ProgressTracker::MediumHighRunnable::Create(
already_AddRefed<AsyncNotifyRunnable>&& aEvent) {
MOZ_ASSERT(NS_IsMainThread());
RefPtr<ProgressTracker::MediumHighRunnable> event(
new ProgressTracker::MediumHighRunnable(std::move(aEvent)));
return event.forget();
}
void ProgressTracker::Notify(IProgressObserver* aObserver) {
MOZ_ASSERT(NS_IsMainThread());
if (aObserver->NotificationsDeferred()) {
// There is a pending notification, or the observer isn't ready yet.
return;
}
if (MOZ_LOG_TEST(gImgLog, LogLevel::Debug)) {
RefPtr<Image> image = GetImage();
LOG_FUNC_WITH_PARAM(gImgLog, "ProgressTracker::Notify async", "uri", image);
}
aObserver->MarkPendingNotify();
// If we have an existing runnable that we can use, we just append this
// observer to its list of observers to be notified. This ensures we don't
// unnecessarily delay onload.
if (mRunnable) {
mRunnable->AddObserver(aObserver);
} else {
RefPtr<AsyncNotifyRunnable> ev = new AsyncNotifyRunnable(this, aObserver);
mRunnable = ProgressTracker::MediumHighRunnable::Create(ev.forget());
mEventTarget->Dispatch(mRunnable, NS_DISPATCH_NORMAL);
}
}
// A helper class to allow us to call SyncNotify asynchronously for a given,
// fixed, state.
class AsyncNotifyCurrentStateRunnable : public Runnable {
public:
AsyncNotifyCurrentStateRunnable(ProgressTracker* aProgressTracker,
IProgressObserver* aObserver)
: Runnable("image::AsyncNotifyCurrentStateRunnable"),
mProgressTracker(aProgressTracker),
mObserver(aObserver) {
MOZ_ASSERT(NS_IsMainThread(), "Should be created on the main thread");
MOZ_ASSERT(mProgressTracker, "mProgressTracker should not be null");
MOZ_ASSERT(mObserver, "mObserver should not be null");
mImage = mProgressTracker->GetImage();
}
NS_IMETHOD Run() override {
MOZ_ASSERT(NS_IsMainThread(), "Should be running on the main thread");
mObserver->ClearPendingNotify();
mProgressTracker->SyncNotify(mObserver);
return NS_OK;
}
private:
RefPtr<ProgressTracker> mProgressTracker;
RefPtr<IProgressObserver> mObserver;
// We have to hold on to a reference to the tracker's image, just in case
// it goes away while we're in the event queue.
RefPtr<Image> mImage;
};
void ProgressTracker::NotifyCurrentState(IProgressObserver* aObserver) {
MOZ_ASSERT(NS_IsMainThread());
if (aObserver->NotificationsDeferred()) {
// There is a pending notification, or the observer isn't ready yet.
return;
}
if (MOZ_LOG_TEST(gImgLog, LogLevel::Debug)) {
RefPtr<Image> image = GetImage();
LOG_FUNC_WITH_PARAM(gImgLog, "ProgressTracker::NotifyCurrentState", "uri",
image);
}
aObserver->MarkPendingNotify();
nsCOMPtr<nsIRunnable> ev =
new AsyncNotifyCurrentStateRunnable(this, aObserver);
mEventTarget->Dispatch(ev.forget(), NS_DISPATCH_NORMAL);
}
/**
* ImageObserverNotifier is a helper type that abstracts over the difference
* between sending notifications to all of the observers in an ObserverTable,
* and sending them to a single observer. This allows the same notification code
* to be used for both cases.
*/
template <typename T>
struct ImageObserverNotifier;
template <>
struct MOZ_STACK_CLASS ImageObserverNotifier<const ObserverTable*> {
explicit ImageObserverNotifier(const ObserverTable* aObservers,
bool aIgnoreDeferral = false)
: mObservers(aObservers), mIgnoreDeferral(aIgnoreDeferral) {}
template <typename Lambda>
void operator()(Lambda aFunc) {
for (auto iter = mObservers->ConstIter(); !iter.Done(); iter.Next()) {
RefPtr<IProgressObserver> observer = iter.Data().get();
if (observer && (mIgnoreDeferral || !observer->NotificationsDeferred())) {
aFunc(observer);
}
}
}
private:
const ObserverTable* mObservers;
const bool mIgnoreDeferral;
};
template <>
struct MOZ_STACK_CLASS ImageObserverNotifier<IProgressObserver*> {
explicit ImageObserverNotifier(IProgressObserver* aObserver)
: mObserver(aObserver) {}
template <typename Lambda>
void operator()(Lambda aFunc) {
if (mObserver && !mObserver->NotificationsDeferred()) {
aFunc(mObserver);
}
}
private:
IProgressObserver* mObserver;
};
template <typename T>
void SyncNotifyInternal(const T& aObservers, bool aHasImage, Progress aProgress,
const nsIntRect& aDirtyRect) {
MOZ_ASSERT(NS_IsMainThread());
typedef imgINotificationObserver I;
ImageObserverNotifier<T> notify(aObservers);
if (aProgress & FLAG_SIZE_AVAILABLE) {
notify([](IProgressObserver* aObs) { aObs->Notify(I::SIZE_AVAILABLE); });
}
if (aHasImage) {
// OnFrameUpdate
// If there's any content in this frame at all (always true for
// vector images, true for raster images that have decoded at
// least one frame) then send OnFrameUpdate.
if (!aDirtyRect.IsEmpty()) {
notify([&](IProgressObserver* aObs) {
aObs->Notify(I::FRAME_UPDATE, &aDirtyRect);
});
}
if (aProgress & FLAG_FRAME_COMPLETE) {
notify([](IProgressObserver* aObs) { aObs->Notify(I::FRAME_COMPLETE); });
}
if (aProgress & FLAG_HAS_TRANSPARENCY) {
notify(
[](IProgressObserver* aObs) { aObs->Notify(I::HAS_TRANSPARENCY); });
}
if (aProgress & FLAG_IS_ANIMATED) {
notify([](IProgressObserver* aObs) { aObs->Notify(I::IS_ANIMATED); });
}
}
if (aProgress & FLAG_DECODE_COMPLETE) {
MOZ_ASSERT(aHasImage, "Stopped decoding without ever having an image?");
notify([](IProgressObserver* aObs) { aObs->Notify(I::DECODE_COMPLETE); });
}
if (aProgress & FLAG_LOAD_COMPLETE) {
notify([=](IProgressObserver* aObs) {
aObs->OnLoadComplete(aProgress & FLAG_LAST_PART_COMPLETE);
});
}
}
void ProgressTracker::SyncNotifyProgress(Progress aProgress,
const nsIntRect& aInvalidRect
/* = nsIntRect() */) {
MOZ_ASSERT(NS_IsMainThread(), "Use mObservers on main thread only");
Progress progress = Difference(aProgress);
CheckProgressConsistency(mProgress, mProgress | progress, mIsMultipart);
// Apply the changes.
mProgress |= progress;
// Send notifications.
mObservers.Read([&](const ObserverTable* aTable) {
SyncNotifyInternal(aTable, HasImage(), progress, aInvalidRect);
});
if (progress & FLAG_HAS_ERROR) {
FireFailureNotification();
}
}
void ProgressTracker::SyncNotify(IProgressObserver* aObserver) {
MOZ_ASSERT(NS_IsMainThread());
RefPtr<Image> image = GetImage();
LOG_SCOPE_WITH_PARAM(gImgLog, "ProgressTracker::SyncNotify", "uri", image);
nsIntRect rect;
if (image) {
int32_t width, height;
if (NS_FAILED(image->GetWidth(&width)) ||
NS_FAILED(image->GetHeight(&height))) {
// Either the image has no intrinsic size, or it has an error.
rect = GetMaxSizedIntRect();
} else {
rect.SizeTo(width, height);
}
}
SyncNotifyInternal(aObserver, !!image, mProgress, rect);
}
void ProgressTracker::EmulateRequestFinished(IProgressObserver* aObserver) {
MOZ_ASSERT(NS_IsMainThread(),
"SyncNotifyState and mObservers are not threadsafe");
RefPtr<IProgressObserver> kungFuDeathGrip(aObserver);
if (!(mProgress & FLAG_LOAD_COMPLETE)) {
aObserver->OnLoadComplete(true);
}
}
already_AddRefed<nsIEventTarget> ProgressTracker::GetEventTarget() const {
MutexAutoLock lock(mMutex);
nsCOMPtr<nsIEventTarget> target = mEventTarget;
return target.forget();
}
void ProgressTracker::AddObserver(IProgressObserver* aObserver) {
MOZ_ASSERT(NS_IsMainThread());
RefPtr<IProgressObserver> observer = aObserver;
nsCOMPtr<nsIEventTarget> target = observer->GetEventTarget();
if (target) {
if (mObserversWithTargets == 0) {
// On the first observer with a target (i.e. listener), always accept its
// event target; this may be for a specific DocGroup, or it may be the
// unlabelled main thread target.
MutexAutoLock lock(mMutex);
mEventTarget = WrapNotNull(target);
} else if (mEventTarget.get() != target.get()) {
// If a subsequent observer comes in with a different target, we need to
// switch to use the unlabelled main thread target, if we haven't already.
MutexAutoLock lock(mMutex);
nsCOMPtr<nsIEventTarget> mainTarget(do_GetMainThread());
mEventTarget = WrapNotNull(mainTarget);
}
++mObserversWithTargets;
}
mObservers.Write([=](ObserverTable* aTable) {
MOZ_ASSERT(!aTable->Get(observer, nullptr),
"Adding duplicate entry for image observer");
WeakPtr<IProgressObserver> weakPtr = observer.get();
aTable->Put(observer, weakPtr);
});
MOZ_ASSERT(mObserversWithTargets <= ObserverCount());
}
bool ProgressTracker::RemoveObserver(IProgressObserver* aObserver) {
MOZ_ASSERT(NS_IsMainThread());
RefPtr<IProgressObserver> observer = aObserver;
// Remove the observer from the list.
bool removed = mObservers.Write(
[observer](ObserverTable* aTable) { return aTable->Remove(observer); });
// Sometimes once an image is decoded, and all of its observers removed, a new
// document may request the same image. Thus we need to clear our event target
// state when the last observer is removed, so that we select the most
// appropriate event target when a new observer is added. Since the event
// target may have changed (e.g. due to the scheduler group going away before
// we were removed), so we should be cautious comparing this target against
// anything at this stage.
if (removed) {
nsCOMPtr<nsIEventTarget> target = observer->GetEventTarget();
if (target) {
MOZ_ASSERT(mObserversWithTargets > 0);
--mObserversWithTargets;
// If we've shutdown the main thread there's no need to update
// event targets.
if ((mObserversWithTargets == 0) && !gXPCOMThreadsShutDown) {
MutexAutoLock lock(mMutex);
nsCOMPtr<nsIEventTarget> target(do_GetMainThread());
mEventTarget = WrapNotNull(target);
}
}
MOZ_ASSERT(mObserversWithTargets <= ObserverCount());
}
// Observers can get confused if they don't get all the proper teardown
// notifications. Part ways on good terms.
if (removed && !aObserver->NotificationsDeferred()) {
EmulateRequestFinished(aObserver);
}
// Make sure we don't give callbacks to an observer that isn't interested in
// them any more.
if (aObserver->NotificationsDeferred() && mRunnable) {
mRunnable->RemoveObserver(aObserver);
aObserver->ClearPendingNotify();
}
return removed;
}
uint32_t ProgressTracker::ObserverCount() const {
MOZ_ASSERT(NS_IsMainThread());
return mObservers.Read(
[](const ObserverTable* aTable) { return aTable->Count(); });
}
void ProgressTracker::OnUnlockedDraw() {
MOZ_ASSERT(NS_IsMainThread());
mObservers.Read([](const ObserverTable* aTable) {
ImageObserverNotifier<const ObserverTable*> notify(aTable);
notify([](IProgressObserver* aObs) {
aObs->Notify(imgINotificationObserver::UNLOCKED_DRAW);
});
});
}
void ProgressTracker::ResetForNewRequest() {
MOZ_ASSERT(NS_IsMainThread());
mProgress = NoProgress;
}
void ProgressTracker::OnDiscard() {
MOZ_ASSERT(NS_IsMainThread());
mObservers.Read([](const ObserverTable* aTable) {
ImageObserverNotifier<const ObserverTable*> notify(aTable);
notify([](IProgressObserver* aObs) {
aObs->Notify(imgINotificationObserver::DISCARD);
});
});
}
void ProgressTracker::OnImageAvailable() {
MOZ_ASSERT(NS_IsMainThread());
// Notify any imgRequestProxys that are observing us that we have an Image.
mObservers.Read([](const ObserverTable* aTable) {
ImageObserverNotifier<const ObserverTable*> notify(
aTable, /* aIgnoreDeferral = */ true);
notify([](IProgressObserver* aObs) { aObs->SetHasImage(); });
});
}
void ProgressTracker::FireFailureNotification() {
MOZ_ASSERT(NS_IsMainThread());
// Some kind of problem has happened with image decoding.
// Report the URI to net:failed-to-process-uri-conent observers.
RefPtr<Image> image = GetImage();
if (image) {
// Should be on main thread, so ok to create a new nsIURI.
nsCOMPtr<nsIURI> uri = image->GetURI();
if (uri) {
nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
if (os) {
os->NotifyObservers(uri, "net:failed-to-process-uri-content", nullptr);
}
}
}
}
} // namespace image
} // namespace mozilla