Currently the setting of PLDHashTable::ops is very haphazard.
- PLDHashTable has no constructor, so it's not auto-nulled, so lots of places
null it themselves.
- In the fallible PLDHashTable::Init() function, if the entry storage
allocation fails we'll be left with a table that has |ops| set -- indicating
it's been initialized -- but has null entry storage. I'm not certain this can
cause problems but it feels unsafe, and some (but not all) callers of Init()
null it on failure.
- PLDHashTable does not null |ops| in Finish(), so some (but not all) callers
do this themselves.
This patch makes things simpler.
- It adds a constructor that zeroes |ops|.
- It modifies Init() so that it only sets |ops| once success is ensured.
- It zeroes |ops| in Finish().
- Finally, it removes all the now-unnecessary |ops| nulling done by the users
of PLDHashTable.
--HG--
extra : rebase_source : bb34979c218d152562a2f9c7e5215256c111cc5b
I noticed the GetRootPresContext call being expensive in a profile that
involved painting in a (non-e10s) window with around 400-500 tabs.
Moving the mIsActive test (most likely to be false) first should fix
that.
I don't have any tests that exercise this code, and I can't even find a
codepath that demonstrates that it's needed, since the lazy
reconstruction that happens during style-triggered frame reconstruction
all appears to go through PostRestyleEvent rather than
MaybeConstructLazily.
But I think we should either do this or add an assertion that it's not
needed, and given that it's one line, it seems like we may as well just
do it. (Note also that we're currently calling CreateNeededFrames at
the start of style reresolution, in
RestyleManager::ProcessPendingRestyles; this adds a call at the end.)
This makes the ReframingStyleContexts live across the lifetime of the
processing of a full queue of posted restyles.
This depends on bug 1115812 to behave sensibly (and not assert) when
rebuilding the rule tree (RebuildAllStyleData, etc.).
This handles the form of lazy frame construction that is done in
nsCSSFrameConstructor::RecreateFramesForContent, which posts a restyle.
Patch 7 handles any use of the lazy frame construction mechanism.
This patch (with patches 4 and 5 under it, but without patches 1-3)
fixes the original testcase in bug 1110277, except for some flashing of
the final position as the transition starts.
Also fixes bug 1111451.
These assertions are as requested in comment 30 in the bug.
(If the first one doesn't fire, it's possible we could even get rid of
the handling of mDoRebuildAllStyleData that it's within.)
If we discover that we've set mDoRebuildAllStyleData in the middle of
ProcessPendingRestyles(), now that ProcessPendingRestyles() fully
handles mDoRebuildAllStyleData, we only need to make a recursive call to
ProcessPendingRestyles, rather than calling RebuildAllStyleData to call
ProcessPendingRestyles.
This fixes another pre-existing bug in the rebuild-all codepath; it
didn't handle the animation-only update correctly, which could have
caused bugs in transitions with OMT animations enabled.
This means that instead of recurring into DoRebuildAllStyleData, we'll
call StartRebuildAllStyleData in the middle of processing the restyle
queue (which is fine). StartRebuildAllStyleData will move the old rule
tree out of the way and immediately do a full-tree restyle, before
returning to any queue processing that might be left (the full-tree
restyle should have consumed all remaining restyle hints, but might have
posted some new ones for handling reframes that require reframing
ancestors). And, more importantly, the EndReconstruct() call to get rid
of the old rule tree won't happen until after we're done processing the
containing RestyleTracker's queue of restyles, which reduces the risk of
having dangling old style contexts and makes it easier (in bug 1110277)
to have a ReframingStyleContexts with the right lifetime.
This changes what was probably a silly design choice when I wrote the
code for 'rem'-basis handling; we shouldn't try continuing through the
rest of RestyleElement() here, but instead repost the hint to the
rebuild-all process.
This switches RebuildAllStyleData() to the normal
ProcessPendingRestyles() manner of restyle processing. This means a
rebuild-all going through this codepath (the main rebuild-all codepath)
only sets up for non-animation restyle processing once rather than doing
it twice (and potentially having reframes posted in
DoRebuildAllStyleData() that don't get processed until
ProcessPendingRestyles(), which causes a variant of bug 1110277 with
transitions on reframed elements failing to start because it doesn't
match the lifetime of the ReframingStyleContexts).
In the new way of doing a rebuild-all, StartRebuildAllStyleData might be
called directly from ProcessPendingRestyles rather than from
RebuildAllStyleData (which null-checks the root frame) or from within
processing restyles (which can only happen when there's a root frame).
This means it needs its own null-check of the root frame.
Here we call StartRebuildAllStyleData from BeginProcessingRestyles (much
like patch 9 and EndProcessingRestyles). But we will later also call it
from the code that handles a root element font size change when we have
'rem' units. That's because it's fine to *start* the rebuild process in
the middle of processing the queue of pending restyles. (We have to end
after the whole process is done, though, in order to avoid wanting to
destroy the old rule tree while we still have style contexts referencing
it.)
We only call StartRebuildAllStyleData in this case when we're processing
our primary restyle queue (mPendingRestyles), not the animation restyles
(to be removed in bug 960465) or the animation-only restyles, since a
rebuild-all should be processed (in terms of animation phases, or in
terms of having an animation-only update before it) like a normal
restyle. (This isn't true for the 'rem' unit restyle, which could
happen during any sort of update.)
