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.
Currently imagelib's DecodePool spawns the maximum number of threads
during startup, based on the number of processors. This patch changes it
to spawn a single thread on startup (which cannot fail), and more up to
the maximum as jobs are added to the queue. A thread will only be
spawned if there is a backlog present when a new job is added. This
typically results in fewer threads allocated in the parent process, as
well as deferred spawning in the content processes.
Currently imagelib's DecodePool spawns the maximum number of threads
during startup, based on the number of processors. This patch changes it
to spawn a single thread on startup (which cannot fail), and more up to
the maximum as jobs are added to the queue. A thread will only be
spawned if there is a backlog present when a new job is added. This
typically results in fewer threads allocated in the parent process, as
well as deferred spawning in the content processes.
This patch makes the following changes to the macros.
- Removes PROFILER_LABEL_FUNC. It's only suitable for use in functions outside
classes, due to PROFILER_FUNCTION_NAME not getting class names, and it was
mostly misused.
- Removes PROFILER_FUNCTION_NAME. It's no longer used, and __func__ is
universally available now anyway.
- Combines the first two string literal arguments of PROFILER_LABEL and
PROFILER_LABEL_DYNAMIC into a single argument. There was no good reason for
them to be separate, and it forced a '::' in the label, which isn't always
appropriate. Also, the meaning of the "name_space" argument was interpreted
in an interesting variety of ways.
- Adds an "AUTO_" prefix to PROFILER_LABEL and PROFILER_LABEL_DYNAMIC, to make
it clearer they construct RAII objects rather than just being function calls.
(I myself have screwed up the scoping because of this in the past.)
- Fills in the 'js::ProfileEntry::Category::' qualifier within the macro, so
the caller doesn't need to. This makes a *lot* more of the uses fit onto a
single line.
The patch also makes the following changes to the macro uses (beyond those
required by the changes described above).
- Fixes a bunch of labels that had gotten out of sync with the name of the
class and/or function that encloses them.
- Removes a useless PROFILER_LABEL use within a trivial scope in
EventStateManager::DispatchMouseOrPointerEvent(). It clearly wasn't serving
any useful purpose. It also serves as extra evidence that the AUTO_ prefix is
a good idea.
- Tweaks DecodePool::SyncRunIf{Preferred,Possible} so that the labelling is
done within them, instead of at their callsites, because that's a more
standard way of doing things.
--HG--
extra : rebase_source : 318d1bc6fc1425a94aacbf489dd46e4f83211de4
The Decode call may result in synchronously creating the surface, but we only check again if the surface is there for FLAG_SYNC_DECODE, not FLAG_SYNC_DECODE_IF_FAST.
All of the decoding we do during painting is of the type FLAG_SYNC_DECODE_IF_FAST, which means it would be useless to do that decoding synchronously during painting because the paint doesn't benefit from the result of that decoding.
Looking at the history of this code it looks like https://hg.mozilla.org/mozilla-central/rev/435df926eb10 (part 6 of bug 1119774) was where this bug was introduced. Before that changeset we always did another LookupFrameInternal call after the Decode (called WantDecodedFrames back then). But that changeset changed it to only be done for standard sync decodes, not "sync decode if fast".
The decoding loop in Decoder::Decode only pauses to report progress when it runs out of bytes to decode. So for long animated images where the network is keeping up with decoding it will be a relatively long time until we deliver the first frame complete notification and corresponding invalidation. In most cases this shouldn't be too expensive as it is just dispatching a runnable to the main thread from the decoding thread.
The decoding loop in Decoder::Decode only pauses to report progress when it runs out of bytes to decode. So for long animated images where the network is keeping up with decoding it will be a relatively long time until we deliver the first frame complete notification and corresponding invalidation. In most cases this shouldn't be too expensive as it is just dispatching a runnable to the main thread from the decoding thread.
The bulk of this commit was generated with a script, executed at the top
level of a typical source code checkout. The only non-machine-generated
part was modifying MFBT's moz.build to reflect the new naming.
CLOSED TREE makes big refactorings like this a piece of cake.
# The main substitution.
find . -name '*.cpp' -o -name '*.cc' -o -name '*.h' -o -name '*.mm' -o -name '*.idl'| \
xargs perl -p -i -e '
s/nsRefPtr\.h/RefPtr\.h/g; # handle includes
s/nsRefPtr ?</RefPtr</g; # handle declarations and variables
'
# Handle a special friend declaration in gfx/layers/AtomicRefCountedWithFinalize.h.
perl -p -i -e 's/::nsRefPtr;/::RefPtr;/' gfx/layers/AtomicRefCountedWithFinalize.h
# Handle nsRefPtr.h itself, a couple places that define constructors
# from nsRefPtr, and code generators specially. We do this here, rather
# than indiscriminantly s/nsRefPtr/RefPtr/, because that would rename
# things like nsRefPtrHashtable.
perl -p -i -e 's/nsRefPtr/RefPtr/g' \
mfbt/nsRefPtr.h \
xpcom/glue/nsCOMPtr.h \
xpcom/base/OwningNonNull.h \
ipc/ipdl/ipdl/lower.py \
ipc/ipdl/ipdl/builtin.py \
dom/bindings/Codegen.py \
python/lldbutils/lldbutils/utils.py
# In our indiscriminate substitution above, we renamed
# nsRefPtrGetterAddRefs, the class behind getter_AddRefs. Fix that up.
find . -name '*.cpp' -o -name '*.h' -o -name '*.idl' | \
xargs perl -p -i -e 's/nsRefPtrGetterAddRefs/RefPtrGetterAddRefs/g'
if [ -d .git ]; then
git mv mfbt/nsRefPtr.h mfbt/RefPtr.h
else
hg mv mfbt/nsRefPtr.h mfbt/RefPtr.h
fi
--HG--
rename : mfbt/nsRefPtr.h => mfbt/RefPtr.h
Bas Schouten
Sylvestre Ledru
Andrew Osmond
Margareta Eliza Balazs
Nicholas Nethercote
Timothy Nikkel
Seth Fowler
Sebastian Hengst
Aryeh Gregor
Nathan Froyd
Bobby Holley
Birunthan Mohanathas