gecko-dev/image/Image.cpp
Nika Layzell f07fc1f61f Bug 1687391 - Avoid using a spinlock in ThreadSafeWeakReference, r=glandium,mccr8,Gankra,sg
This new approach to weak references is roughly modeled after the approach used
by Rust's Arc<T>, and uses an atomic compare-and-swap loop to perform weak to
strong reference upgrades. This approach ends up moving the strong reference
count out of the tracked object and into the weak reference object, as the
strong reference count atomic needs to outlife the object itself.

Rust's Arc Weak::upgrade implementation:
d98d2f57d9/library/alloc/src/sync.rs (L1806-L1837)

Differential Revision: https://phabricator.services.mozilla.com/D102245
2021-02-03 17:00:04 +00:00

475 lines
16 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 "Image.h"
#include "imgRequest.h"
#include "Layers.h" // for LayerManager
#include "nsIObserverService.h"
#include "nsRefreshDriver.h"
#include "nsContentUtils.h"
#include "mozilla/gfx/Point.h"
#include "mozilla/gfx/Rect.h"
#include "mozilla/Services.h"
#include "mozilla/SizeOfState.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/Tuple.h" // for Tie
#include "mozilla/layers/SharedSurfacesChild.h"
namespace mozilla {
namespace image {
///////////////////////////////////////////////////////////////////////////////
// Memory Reporting
///////////////////////////////////////////////////////////////////////////////
ImageMemoryCounter::ImageMemoryCounter(imgRequest* aRequest,
SizeOfState& aState, bool aIsUsed)
: mProgress(UINT32_MAX),
mType(UINT16_MAX),
mIsUsed(aIsUsed),
mHasError(false),
mValidating(false) {
MOZ_ASSERT(aRequest);
// We don't have the image object yet, but we can get some information.
nsCOMPtr<nsIURI> imageURL;
nsresult rv = aRequest->GetURI(getter_AddRefs(imageURL));
if (NS_SUCCEEDED(rv) && imageURL) {
imageURL->GetSpec(mURI);
}
mType = imgIContainer::TYPE_REQUEST;
mHasError = NS_FAILED(aRequest->GetImageErrorCode());
mValidating = !!aRequest->GetValidator();
RefPtr<ProgressTracker> tracker = aRequest->GetProgressTracker();
if (tracker) {
mProgress = tracker->GetProgress();
}
}
ImageMemoryCounter::ImageMemoryCounter(imgRequest* aRequest, Image* aImage,
SizeOfState& aState, bool aIsUsed)
: mProgress(UINT32_MAX),
mType(UINT16_MAX),
mIsUsed(aIsUsed),
mHasError(false),
mValidating(false) {
MOZ_ASSERT(aRequest);
MOZ_ASSERT(aImage);
// Extract metadata about the image.
nsCOMPtr<nsIURI> imageURL(aImage->GetURI());
if (imageURL) {
imageURL->GetSpec(mURI);
}
int32_t width = 0;
int32_t height = 0;
aImage->GetWidth(&width);
aImage->GetHeight(&height);
mIntrinsicSize.SizeTo(width, height);
mType = aImage->GetType();
mHasError = aImage->HasError();
mValidating = !!aRequest->GetValidator();
RefPtr<ProgressTracker> tracker = aImage->GetProgressTracker();
if (tracker) {
mProgress = tracker->GetProgress();
}
// Populate memory counters for source and decoded data.
mValues.SetSource(aImage->SizeOfSourceWithComputedFallback(aState));
aImage->CollectSizeOfSurfaces(mSurfaces, aState.mMallocSizeOf);
// Compute totals.
for (const SurfaceMemoryCounter& surfaceCounter : mSurfaces) {
mValues += surfaceCounter.Values();
}
}
///////////////////////////////////////////////////////////////////////////////
// Image Base Types
///////////////////////////////////////////////////////////////////////////////
bool ImageResource::GetSpecTruncatedTo1k(nsCString& aSpec) const {
static const size_t sMaxTruncatedLength = 1024;
mURI->GetSpec(aSpec);
if (sMaxTruncatedLength >= aSpec.Length()) {
return true;
}
aSpec.Truncate(sMaxTruncatedLength);
return false;
}
void ImageResource::SetCurrentImage(layers::ImageContainer* aContainer,
gfx::SourceSurface* aSurface,
const Maybe<gfx::IntRect>& aDirtyRect) {
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(aContainer);
if (!aSurface) {
// The OS threw out some or all of our buffer. We'll need to wait for the
// redecode (which was automatically triggered by GetFrame) to complete.
return;
}
// |image| holds a reference to a SourceSurface which in turn holds a lock on
// the current frame's data buffer, ensuring that it doesn't get freed as
// long as the layer system keeps this ImageContainer alive.
RefPtr<layers::Image> image = new layers::SourceSurfaceImage(aSurface);
// We can share the producer ID with other containers because it is only
// used internally to validate the frames given to a particular container
// so that another object cannot add its own. Similarly the frame ID is
// only used internally to ensure it is always increasing, and skipping
// IDs from an individual container's perspective is acceptable.
AutoTArray<layers::ImageContainer::NonOwningImage, 1> imageList;
imageList.AppendElement(layers::ImageContainer::NonOwningImage(
image, TimeStamp(), mLastFrameID++, mImageProducerID));
if (aDirtyRect) {
aContainer->SetCurrentImagesInTransaction(imageList);
} else {
aContainer->SetCurrentImages(imageList);
}
// If we are animated, then we should request that the image container be
// treated as such, to avoid display list rebuilding to update frames for
// WebRender.
if (mProgressTracker->GetProgress() & FLAG_IS_ANIMATED) {
if (aDirtyRect) {
layers::SharedSurfacesChild::UpdateAnimation(aContainer, aSurface,
aDirtyRect.ref());
} else {
gfx::IntRect dirtyRect(gfx::IntPoint(0, 0), aSurface->GetSize());
layers::SharedSurfacesChild::UpdateAnimation(aContainer, aSurface,
dirtyRect);
}
}
}
ImgDrawResult ImageResource::GetImageContainerImpl(
layers::LayerManager* aManager, const gfx::IntSize& aSize,
const Maybe<SVGImageContext>& aSVGContext, uint32_t aFlags,
layers::ImageContainer** aOutContainer) {
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(aManager);
MOZ_ASSERT(
(aFlags & ~(FLAG_SYNC_DECODE | FLAG_SYNC_DECODE_IF_FAST |
FLAG_ASYNC_NOTIFY | FLAG_HIGH_QUALITY_SCALING)) == FLAG_NONE,
"Unsupported flag passed to GetImageContainer");
ImgDrawResult drawResult;
gfx::IntSize size;
Tie(drawResult, size) = GetImageContainerSize(aManager, aSize, aFlags);
if (drawResult != ImgDrawResult::SUCCESS) {
return drawResult;
}
MOZ_ASSERT(!size.IsEmpty());
if (mAnimationConsumers == 0) {
SendOnUnlockedDraw(aFlags);
}
uint32_t flags = (aFlags & ~(FLAG_SYNC_DECODE | FLAG_SYNC_DECODE_IF_FAST)) |
FLAG_ASYNC_NOTIFY;
RefPtr<layers::ImageContainer> container;
ImageContainerEntry* entry = nullptr;
int i = mImageContainers.Length() - 1;
for (; i >= 0; --i) {
entry = &mImageContainers[i];
if (size == entry->mSize && flags == entry->mFlags &&
aSVGContext == entry->mSVGContext) {
// Lack of a container is handled below.
container = RefPtr<layers::ImageContainer>(entry->mContainer);
break;
} else if (entry->mContainer.IsDead()) {
// Stop tracking if our weak pointer to the image container was freed.
mImageContainers.RemoveElementAt(i);
}
}
if (container) {
switch (entry->mLastDrawResult) {
case ImgDrawResult::SUCCESS:
case ImgDrawResult::BAD_IMAGE:
case ImgDrawResult::BAD_ARGS:
case ImgDrawResult::NOT_SUPPORTED:
container.forget(aOutContainer);
return entry->mLastDrawResult;
case ImgDrawResult::NOT_READY:
case ImgDrawResult::INCOMPLETE:
case ImgDrawResult::TEMPORARY_ERROR:
// Temporary conditions where we need to rerequest the frame to recover.
break;
case ImgDrawResult::WRONG_SIZE:
// Unused by GetFrameInternal
default:
MOZ_ASSERT_UNREACHABLE("Unhandled ImgDrawResult type!");
container.forget(aOutContainer);
return entry->mLastDrawResult;
}
}
#ifdef DEBUG
NotifyDrawingObservers();
#endif
gfx::IntSize bestSize;
RefPtr<gfx::SourceSurface> surface;
Tie(drawResult, bestSize, surface) = GetFrameInternal(
size, aSVGContext, FRAME_CURRENT, aFlags | FLAG_ASYNC_NOTIFY);
// The requested size might be refused by the surface cache (i.e. due to
// factor-of-2 mode). In that case we don't want to create an entry for this
// specific size, but rather re-use the entry for the substituted size.
if (bestSize != size) {
MOZ_ASSERT(!bestSize.IsEmpty());
// We can only remove the entry if we no longer have a container, because if
// there are strong references to it remaining, we need to still update it
// in UpdateImageContainer.
if (i >= 0 && !container) {
mImageContainers.RemoveElementAt(i);
}
// Forget about the stale container, if any. This lets the entry creation
// logic do its job below, if it turns out there is no existing best entry
// or the best entry doesn't have a container.
container = nullptr;
// We need to do the entry search again for the new size. We skip pruning
// because we did this above once already, but ImageContainer is threadsafe,
// so there is a remote possibility it got freed.
i = mImageContainers.Length() - 1;
for (; i >= 0; --i) {
entry = &mImageContainers[i];
if (bestSize == entry->mSize && flags == entry->mFlags &&
aSVGContext == entry->mSVGContext) {
container = RefPtr<layers::ImageContainer>(entry->mContainer);
if (container) {
switch (entry->mLastDrawResult) {
case ImgDrawResult::SUCCESS:
case ImgDrawResult::BAD_IMAGE:
case ImgDrawResult::BAD_ARGS:
case ImgDrawResult::NOT_SUPPORTED:
container.forget(aOutContainer);
return entry->mLastDrawResult;
case ImgDrawResult::NOT_READY:
case ImgDrawResult::INCOMPLETE:
case ImgDrawResult::TEMPORARY_ERROR:
// Temporary conditions where we need to rerequest the frame to
// recover. We have already done so!
break;
case ImgDrawResult::WRONG_SIZE:
// Unused by GetFrameInternal
default:
MOZ_ASSERT_UNREACHABLE("Unhandled DrawResult type!");
container.forget(aOutContainer);
return entry->mLastDrawResult;
}
}
break;
}
}
}
if (!container) {
// We need a new ImageContainer, so create one.
container = layers::LayerManager::CreateImageContainer();
if (i >= 0) {
entry->mContainer = container;
} else {
entry = mImageContainers.AppendElement(
ImageContainerEntry(bestSize, aSVGContext, container.get(), flags));
}
}
SetCurrentImage(container, surface, Nothing());
entry->mLastDrawResult = drawResult;
container.forget(aOutContainer);
return drawResult;
}
bool ImageResource::UpdateImageContainer(
const Maybe<gfx::IntRect>& aDirtyRect) {
MOZ_ASSERT(NS_IsMainThread());
for (int i = mImageContainers.Length() - 1; i >= 0; --i) {
ImageContainerEntry& entry = mImageContainers[i];
RefPtr<layers::ImageContainer> container(entry.mContainer);
if (container) {
gfx::IntSize bestSize;
RefPtr<gfx::SourceSurface> surface;
Tie(entry.mLastDrawResult, bestSize, surface) = GetFrameInternal(
entry.mSize, entry.mSVGContext, FRAME_CURRENT, entry.mFlags);
// It is possible that this is a factor-of-2 substitution. Since we
// managed to convert the weak reference into a strong reference, that
// means that an imagelib user still is holding onto the container. thus
// we cannot consolidate and must keep updating the duplicate container.
if (aDirtyRect) {
SetCurrentImage(container, surface, aDirtyRect);
} else {
gfx::IntRect dirtyRect(gfx::IntPoint(0, 0), bestSize);
SetCurrentImage(container, surface, Some(dirtyRect));
}
} else {
// Stop tracking if our weak pointer to the image container was freed.
mImageContainers.RemoveElementAt(i);
}
}
return !mImageContainers.IsEmpty();
}
void ImageResource::ReleaseImageContainer() {
MOZ_ASSERT(NS_IsMainThread());
mImageContainers.Clear();
}
// Constructor
ImageResource::ImageResource(nsIURI* aURI)
: mURI(aURI),
mInnerWindowId(0),
mAnimationConsumers(0),
mAnimationMode(kNormalAnimMode),
mInitialized(false),
mAnimating(false),
mError(false),
mImageProducerID(layers::ImageContainer::AllocateProducerID()),
mLastFrameID(0) {}
ImageResource::~ImageResource() {
// Ask our ProgressTracker to drop its weak reference to us.
mProgressTracker->ResetImage();
}
void ImageResource::IncrementAnimationConsumers() {
MOZ_ASSERT(NS_IsMainThread(),
"Main thread only to encourage serialization "
"with DecrementAnimationConsumers");
mAnimationConsumers++;
}
void ImageResource::DecrementAnimationConsumers() {
MOZ_ASSERT(NS_IsMainThread(),
"Main thread only to encourage serialization "
"with IncrementAnimationConsumers");
MOZ_ASSERT(mAnimationConsumers >= 1, "Invalid no. of animation consumers!");
mAnimationConsumers--;
}
nsresult ImageResource::GetAnimationModeInternal(uint16_t* aAnimationMode) {
if (mError) {
return NS_ERROR_FAILURE;
}
NS_ENSURE_ARG_POINTER(aAnimationMode);
*aAnimationMode = mAnimationMode;
return NS_OK;
}
nsresult ImageResource::SetAnimationModeInternal(uint16_t aAnimationMode) {
if (mError) {
return NS_ERROR_FAILURE;
}
NS_ASSERTION(aAnimationMode == kNormalAnimMode ||
aAnimationMode == kDontAnimMode ||
aAnimationMode == kLoopOnceAnimMode,
"Wrong Animation Mode is being set!");
mAnimationMode = aAnimationMode;
return NS_OK;
}
bool ImageResource::HadRecentRefresh(const TimeStamp& aTime) {
// Our threshold for "recent" is 1/2 of the default refresh-driver interval.
// This ensures that we allow for frame rates at least as fast as the
// refresh driver's default rate.
static TimeDuration recentThreshold =
TimeDuration::FromMilliseconds(nsRefreshDriver::DefaultInterval() / 2.0);
if (!mLastRefreshTime.IsNull() &&
aTime - mLastRefreshTime < recentThreshold) {
return true;
}
// else, we can proceed with a refresh.
// But first, update our last refresh time:
mLastRefreshTime = aTime;
return false;
}
void ImageResource::EvaluateAnimation() {
if (!mAnimating && ShouldAnimate()) {
nsresult rv = StartAnimation();
mAnimating = NS_SUCCEEDED(rv);
} else if (mAnimating && !ShouldAnimate()) {
StopAnimation();
}
}
void ImageResource::SendOnUnlockedDraw(uint32_t aFlags) {
if (!mProgressTracker) {
return;
}
if (!(aFlags & FLAG_ASYNC_NOTIFY)) {
mProgressTracker->OnUnlockedDraw();
} else {
NotNull<RefPtr<ImageResource>> image = WrapNotNull(this);
nsCOMPtr<nsIEventTarget> eventTarget = mProgressTracker->GetEventTarget();
nsCOMPtr<nsIRunnable> ev = NS_NewRunnableFunction(
"image::ImageResource::SendOnUnlockedDraw", [=]() -> void {
RefPtr<ProgressTracker> tracker = image->GetProgressTracker();
if (tracker) {
tracker->OnUnlockedDraw();
}
});
eventTarget->Dispatch(CreateMediumHighRunnable(ev.forget()),
NS_DISPATCH_NORMAL);
}
}
#ifdef DEBUG
void ImageResource::NotifyDrawingObservers() {
if (!mURI || !NS_IsMainThread()) {
return;
}
if (!mURI->SchemeIs("resource") && !mURI->SchemeIs("chrome")) {
return;
}
// Record the image drawing for startup performance testing.
nsCOMPtr<nsIURI> uri = mURI;
nsContentUtils::AddScriptRunner(NS_NewRunnableFunction(
"image::ImageResource::NotifyDrawingObservers", [uri]() {
nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
NS_WARNING_ASSERTION(obs, "Can't get an observer service handle");
if (obs) {
nsAutoCString spec;
uri->GetSpec(spec);
obs->NotifyObservers(nullptr, "image-drawing",
NS_ConvertUTF8toUTF16(spec).get());
}
}));
}
#endif
} // namespace image
} // namespace mozilla