Regardless of the size of an encoded image, SourceBuffer::Compact would
try to consolidate all of the chunks into a single chunk. If an image is
quite large, it can be actively harmful to do this, because we want a
very large contiguous chunk of memory for no real reason, and spend
extra time on the main thread doing the memcpy/consolidation.
Instead we now cap out the chunk size at 20MB. If we start allocating
chunks of this size, we will not perform compacting when we have
received all of the data. (Save for realloc'ing the last chunk since it
probably isn't full.)
On a related note, if we hit an out-of-memory condition in the middle of
appending data to the SourceBuffer, we would swallow the error. This is
because nsIInputStream::ReadSegments will succeed if any data was
written. This leaves the SourceBuffer out of sync. We now propogate this
error up properly to the higher levels.
fixup
All animated images on a page are currently registered with the refresh
driver and advance with the tick refresh. These animations may not even
be in view, and if they are large and thus cause redecoding, cause a
marked increase in CPU usage for no benefit to the user.
This patch adds an additional flag, mCompositedFrameRequested, to the
AnimationState used by FrameAnimator. It is set to true each time the
current animated image frame is requested via
FrameAnimator::GetCompositedFrame. It is set to false each time the
frame is advanced in FrameAnimator::AdvanceFrame (via
FrameAnimator::RequestRefresh). If it is true when
FrameAnimator::RequestRefresh is called, then it will advance the
animation according to the normal rules. If it is false, then it will
set the current animation time to the current time instead of advancing.
This should not cause the animation to fall behind anymore or skip
frames more than it does today. This is because if
FrameAnimator::GetCompositedFrame is not called, then the internal state
of the animation is advancing ahead of what the user sees. Once it is
called, the new frame is far ahead of the previously displayed frame.
The only difference now is that we will display the previous frame for
slightly longer until the next refresh tick.
Note that if an animated image is layerized (should not happen today) or
otherwise uses an ImageContainer, this optimization fails. While we know
whether or not we have an image container, we do not know if anything is
actively using it.
We can discard frames from an animated image if the memory footprint
exceeds the threshold. This will cause us to redecode frames on demand
instead. However decoders can fail to produce the same results on
subsequent runs due to differences in memory pressure, etc. If this
happens our state can get inconsistent. In particular, if we keep
failing on the first frame, we end up in an infinite loop on the decoder
thread.
Since we don't have the owning image to signal, as we had to release our
reference to it after the first pass, we can do little but stop decoding.
From the user's perspective, the animation will come to a stop.
If an imgCacheValidator object is destroyed without calling
imgCacheValidator::OnStartRequest, or imgRequest::Init fails in
OnStartRequest, we left the bound proxies hanging on an update. Now we
cancel the new request, and bind the validating proxies to said request
to ensure their listeners fail gracefully.
We can discard frames from an animated image if the memory footprint
exceeds the threshold. This will cause us to redecode frames on demand
instead. However decoders can fail to produce the same results on
subsequent runs due to differences in memory pressure, etc. If this
happens our state can get inconsistent. In particular, if we keep
failing on the first frame, we end up in an infinite loop on the decoder
thread.
Since we don't have the owning image to signal, as we had to release our
reference to it after the first pass, we can do little but stop decoding.
From the user's perspective, the animation will come to a stop.
Many of these could probably be fuzzed but in the interests of getting
the reftest suite turned on sooner I'm doing a blanket fails-if. This
covers all the reftests where there is more fuzz with webrender on
windows than any of existing annotations account for. In some cases the
fuzz is only a few pixels more than the equivalent Linux fuzz already
annotated, but I'll clean that up in a future bug.
MozReview-Commit-ID: IaKarbnL46d
--HG--
extra : rebase_source : 71889340305b0b12fa8eace722e42bb3faf14419
NullPrincipal::Create() (will null OA) may cause an OriginAttributes bypass.
We change Create() so OriginAttributes is no longer optional, and rename
Create() with no arguments to make it more explicit about what the caller is doing.
MozReview-Commit-ID: 7DQGlgh1tgJ
When we shutdown the decode pool threads, it does not do a simple join
with the main thread. It will actually process the main thread event
loop, which can cause a bad series of events. The refresh tick could
still be running and advancing our animated images, causing the animated
decoders to continue running, which in turn prevents the decoder threads
from finishing shutting down, and the main thread from joining them.
Now we check on each frame whether or not the decoder should just stop
decoding more frames because the decode pool has started shutdown. If it
has, it will stop immediately.
We should only attempt to discard animation image frames after passing
the frame threshold on the very first pass on the animation. Redecodes
are already in the correct state, as it will discard frames as it
advances the animation. This patch makes it clear what it should be
doing when, but there should be no functional change.
* Deserialization now only happens via a mutator
* The CID for URI implementations actually returns the nsIURIMutator for each class
* The QueryInterface of mutators implementing nsISerializable will now act as a finalizer if passed the IID of an interface implemented by the URI it holds
MozReview-Commit-ID: H5MUJOEkpia
--HG--
extra : rebase_source : 01c8d16f7d31977eda6ca061e7889cedbf6940c2
* Deserialization now only happens via a mutator
* The CID for URI implementations actually returns the nsIURIMutator for each class
* The QueryInterface of mutators implementing nsISerializable will now act as a finalizer if passed the IID of an interface implemented by the URI it holds
MozReview-Commit-ID: H5MUJOEkpia
--HG--
extra : rebase_source : 8ebb459445cab23288a6c4c86e4e00c6ee611e34
After decoding the first frame we allocate the second frame, but before it finishes we encounter an error, Decoder::PostError is called it aborts the second frame and decrements the frame count. But AnimationSurfaceProvider::CheckForFrameAtTerminalState just asks for the current frame ref from the decoder (which it never cleared) and inserts that.
The condition that we use from the decoder to decide to report a new frame is mFinishedNewFrame (via TakeCompleteFrameCount), however this doesn't directly correspond to mFrameCount. So we create a new bool on the Decoder to track when there is a frame that we can take.
This didn't cause any problems before but now we have tighter coupling between the list of frames the AnimationSurfaceProvider has and what FrameAnimator expects.
Another possible fix would be to clear the current frame ref in PostError, but the only place we clear the current frame is when we allocate the new frame and we have the mImageData pointer still around that decoders could theorhetically use to do final processing on the last partial frame.
These threads should not have deep stacks, and as we can have a number
of them running simultaneously, it's beneficial to set the stack size to
something reasonably low.
When cloning an animated image decoder, we asserted that
Decoder::HasAnimation was true. This is incorrect because if the decoder
has yet to complete the metadata decoding, or it has but only finds out
the image is animated when it discovers the second frame, then we will
try to clone a valid animated image decoder, but fail the assertion.
Instead, this patch verifies the image type supports animations.
With the previous parts, for large animated images, we will now discard
previous frames after we reach the threshold. This mochitest configures
a very low threshold, such that it will trigger on a small animated
image. It then verifies that we are already to loop the animation a
couple of times.
Andrew Osmond
Chris Peterson
shindli
Emilio Cobos Álvarez
Kartikaya Gupta
Boris Zbarsky
Jeff Muizelaar
Cosmin Sabou
Sebastian Hengst
Tristan Bourvon
Ciure Andrei
Nika Layzell
Christoph Kerschbaumer
Tom Ritter
Xidorn Quan
Miko Mynttinen
Valentin Gosu
Andreea Pavel
Lee Salzman
Timothy Nikkel
Nathan Froyd