Accumulates the time in between running unlabeled runnables in a histogram. This
measurement will be useful to see how much of a win the cooperative scheduler
will be, assuming we label no more runnables.
MozReview-Commit-ID: 9lgoGJcXLP9
This function is arguably nicer than calling NS_ProcessNextEvent
manually, is slightly more efficient, and will enable better auditing
for NS_ProcessNextEvent when we do Quantum DOM scheduling changes.
NS_SetCurrentThreadName() is added as an alternative to PR_SetCurrentThreadName()
inside libxul. The thread names are collected in the form of crash annotation to
be processed on socorro.
MozReview-Commit-ID: 4RpAWzTuvPs
There's an antipattern where nsLiteralString is used as an unnecessary intermediary in converting from CharT* to CharT*,
e.g. CallAFunctionThatTakesACharPointer(NS_LITERAL_CSTRING("foo").get());
or
NS_NAMED_LITERAL_STRING(foo, "abc");
CallAFunctionThatTakesACharPointer(foo.get());
This patch rewrites the callsites that can be trivially changed to use char*/char16_t*.
I'd somewhat like to remove nsTLiteralString::get() altogether, but in code that's less straightforward than these examples, get() is useful enough to keep.
MozReview-Commit-ID: Kh1rUziVllo
--HG--
extra : rebase_source : c21a65694d6e1c42fd88f73632f7ac8f38d005ae
There's an antipattern where nsLiteralString is used as an unnecessary intermediary in converting from CharT* to CharT*,
e.g. CallAFunctionThatTakesACharPointer(NS_LITERAL_CSTRING("foo").get());
or
NS_NAMED_LITERAL_STRING(foo, "abc");
CallAFunctionThatTakesACharPointer(foo.get());
This patch rewrites the callsites that can be trivially changed to use char*/char16_t*.
I'd somewhat like to remove nsTLiteralString::get() altogether, but in code that's less straightforward than these examples, get() is useful enough to keep.
MozReview-Commit-ID: Kh1rUziVllo
--HG--
extra : rebase_source : c21a65694d6e1c42fd88f73632f7ac8f38d005ae
The point of this exercise is to make the thread name available in the thread
func of the thread, so that we can register the thread with the profiler from
the very start of its lifetime, and so that registration and unregistration
can be inside the same function.
MozReview-Commit-ID: DiiMKUQVr55
--HG--
extra : rebase_source : 24b15d56315ad49e72b3e9b76db7fb634f3bfe01
Rewrite VsyncRefreshDriverTimer::GetTimerRate to always use the cached
value of the vsync rate in VsyncChild to avoid processing events on
the main thread.
Since VsyncChild::GetTimerRate is called in VsyncRefreshDriverTimer's
constructor, that cached value is bound to be set soon. This should
make the period of time we need to guess in
VsyncRefreshDriverTimer::GetTimerRate very short.
MozReview-Commit-ID: 1bnHNXAP8jY
--HG--
extra : rebase_source : 5a731962d417c4b3352970b2adb92b5d31de021c
The intent of idleDispatch is the possibility to have a runnable
executed when the thread is idle. This is accomplished by adding an
event queue for idle tasks that will only be considered when the main
event queue is empty and the caller of ProcessNextEvent doesn't
require that we wait until there is an event on the main event queue.
MozReview-Commit-ID: IDWQfzZqWpZ
--HG--
extra : rebase_source : 0d5bfeebd08e01597c2cd8b76e8e848d9f9c58f0
The intent of idleDispatch is the possibility to have a runnable
executed when the thread is idle. This is accomplished by adding an
event queue for idle tasks that will only be considered when the main
event queue is empty and the caller of ProcessNextEvent doesn't
require that we wait until there is an event on the main event queue.
MozReview-Commit-ID: IDWQfzZqWpZ
--HG--
extra : rebase_source : b16ff65d7a9b2fa16216a9ce8756358014d7ad96
The new name makes the sense of the condition much clearer. E.g. compare:
NS_WARN_IF_FALSE(!rv.Failed());
with:
NS_WARNING_ASSERTION(!rv.Failed());
The new name also makes it clearer that it only has effect in debug builds,
because that's standard for assertions.
--HG--
extra : rebase_source : 886e57a9e433e0cb6ed635cc075b34b7ebf81853
nsThreadManager::get() can return a reference. This lets us remove some
redundant assertions.
nsThreadArray elements can be NotNull<>s.
--HG--
extra : rebase_source : fd49010167101bc15f7f6d01bf95fd63b81d60fb
The patch is generated from following command:
rgrep -l unused.h|xargs sed -i -e s,mozilla/unused.h,mozilla/Unused.h,
MozReview-Commit-ID: AtLcWApZfES
--HG--
rename : mfbt/unused.h => mfbt/Unused.h
This patch makes most Run() declarations in subclasses of nsIRunnable have the
same form: |NS_IMETHOD Run() override|.
As a result of these changes, I had to add |override| to a couple of other
functions to satisfy clang's -Winconsistent-missing-override warning.
--HG--
extra : rebase_source : 815d0018b0b13329bb5698c410f500dddcc3ee12
In two places we fail to check if we successful obtained the crash reporter
before we use it.
--HG--
extra : rebase_source : f757b8320788220b5a4d5242a0264d577d92f15e
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
This class can be used instead of raw pointer for a sound leaking-by-default
behavior. Also it could take advantage of move semantic check in the future.
--HG--
extra : source : 6bf72b4eaa92b13d42b547d8aeee677489a4d3e2
This class can be used instead of raw pointer for a sound leaking-by-default
behavior. Also it could take advantage of move semantic check in the future.
--HG--
extra : source : 47cd2c22bafc8d4bb1c7e1dce3b45517aaec199f
This class can be used instead of raw pointer for a sound leaking-by-default
behavior. Also it could take advantage of move semantic check in the future.
--HG--
extra : source : 3dbd000739dc0ea214a2292e3983469e41e99686
We want to ensure that nsThread's use of nsEventQueue uses locking done
in nsThread instead of nsEventQueue, for efficiency's sake: we only need
to lock once in nsThread, rather than the current situation of locking
in nsThread and additionally in nsEventQueue. With the current
structure of nsEventQueue, that would mean that nsThread should be using
a Monitor internally, rather than a Mutex.
Which would be well and good, except that DOM workers use nsThread's
mutex to protect their own, internal CondVar. Switching nsThread to use
a Monitor would mean that either:
- DOM workers drop their internal CondVar in favor of nsThread's
Monitor-owned CondVar. This change seems unlikely to work out well,
because now the Monitor-owned CondVar is performing double duty:
tracking availability of events in nsThread's event queue and
additionally whatever DOM workers were using a CondVar for. Having a
single CondVar track two things in such a fashion is for Experts Only.
- DOM workers grow their own Mutex to protect their own CondVar. Adding
a mutex like this would change locking in subtle ways and seems
unlikely to lead to success.
Using a Monitor in nsThread is therefore untenable, and we would like to
retain the current Mutex that lives in nsThread. Therefore, we need to
have nsEventQueue manage its own condition variable and push the
required (Mutex) locking to the client of nsEventQueue. This scheme
also seems more fitting: external clients merely need synchronized
access to the event queue; the details of managing notifications about
events in the event queue should be left up to the event queue itself.
Doing so also forces us to merge nsEventQueueBase and nsEventQueue:
there's no way to have nsEventQueueBase require an externally-defined
Mutex and then have nsEventQueue subclass nsEventQueueBase and provide
its own Mutex to the superclass. C++ initialization rules (and the way
things like CondVar are constructed) simply forbid it. But that's OK,
because we want a world where nsEventQueue is externally locked anyway,
so there's no reason to have separate classes here.
One casualty of this work is removing ChaosMode support from
nsEventQueue. nsEventQueue had support to delay placing events into the
queue, theoretically giving other threads the chance to put events there
first. Unfortunately, since the thread would have been holding a lock
(as is evident from the MutexAutoLock& parameter required), sleeping in
PutEvent accomplishes nothing but delaying the thread from getting
useful work done. We should support this, but it's complicated to
figure out how to reasonably support this right now.
A wrinkle in this overall pleasant refactoring is that nsThreadPool's
threads wait for limited amounts of time for new events to be placed in
the event queue, so that they can shut themselves down if no new events
are appearing. Setting limits on the number of threads also needs to be
able to wake up all threads, so threads can shut themselves down if
necessary.
Unfortunately, with the transition to nsEventQueue managing its own
condition variable, there's no way for nsThreadPool to perform these
functions, since there's no Monitor to wait on. Therefore, we add a
private API for accessing the condition variable and performing the
tasks nsThreadPool needs.
Prior to all the previous patches, placing items in an nsThread's event
queue required three lock/unlock pairs: one for nsThread's Mutex, one to
enter nsEventQueue's ReentrantMonitor, and one to exit nsEventQueue's
ReentrantMonitor. The upshot of all this work is that we now only
require one lock/unlock pair in nsThread itself, as things should be.
This patch is a no-op in terms of functionality. It ensures that we're
always holding nsThread's mutex when we touch mEvents, as dictated by
the comments. Putting this addition into its own patch will help make
the change to having nsEventQueue by guarded by a Mutex, rather than a
Monitor, somewhat clearer.
This is another case of an access to mEvents not being protected by
mLock. Future patches will make this locking requirement explicit in
nsChainedEventQueue, so we won't have problems like this. (Since
nsEventQueue has its own locking at this point, this omission didn't
matter much, but the omission will most certainly matter later.)
GetEvent was only called from one place, so it wasn't terribly useful as
an abstraction. It also broke the invariant that we protect accesses to
mEvents with mLock, as documented in nsThread.h. While upcoming patches
could have just updated GetEvent to do the necessary locking on its own,
it seemed just as easy to make the locking requirements at the callsite,
as will be done for other accesses to mEvents.
nsEventQueue's HasPending event is defined to simply:
return GetEvent(false, nullptr);
So we can substitute HasPendingEvent for this particular GetEvent call
to make the code clearer.
This is motivated by three separate but related problems:
1. Our concept of recursion depth is broken for things that run from AfterProcessNextEvent observers (e.g. Promises). We decrement the recursionDepth counter before firing observers, so a Promise callback running at the lowest event loop depth has a recursion depth of 0 (whereas a regular nsIRunnable would be 1). This is a problem because it's impossible to distinguish a Promise running after a sync XHR's onreadystatechange handler from a top-level event (since the former runs with depth 2 - 1 = 1, and the latter runs with just 1).
2. The nsIThreadObserver mechanism that is used by a lot of code to run "after" the current event is a poor fit for anything that runs script. First, the order the observers fire in is the order they were added, not anything fixed by spec. Additionally, running script can cause the event loop to spin, which is a big source of pain here (bholley has some nasty bug caused by this).
3. We run Promises from different points in the code for workers and main thread. The latter runs from XPConnect's nsIThreadObserver callbacks, while the former runs from a hardcoded call to run Promises in the worker event loop. What workers do is particularly problematic because it means we can't get the right recursion depth no matter what we do to nsThread.
The solve this, this patch does the following:
1. Consolidate some handling of microtasks and all handling of stable state from appshell and WorkerPrivate into CycleCollectedJSRuntime.
2. Make the recursionDepth counter only available to CycleCollectedJSRuntime (and its consumers) and remove it from the nsIThreadInternal and nsIThreadObserver APIs.
3. Adjust the recursionDepth counter so that microtasks run with the recursionDepth of the task they are associated with.
4. Introduce the concept of metastable state to replace appshell's RunBeforeNextEvent. Metastable state is reached after every microtask or task is completed. This provides the semantics that bent and I want for IndexedDB, where transactions autocommit at the end of a microtask and do not "spill" from one microtask into a subsequent microtask. This differs from appshell's RunBeforeNextEvent in two ways:
a) It fires between microtasks, which was the motivation for starting this.
b) It no longer ensures that we're at the same event loop depth in the native event queue. bent decided we don't care about this.
5. Reorder stable state to happen after microtasks such as Promises, per HTML. Right now we call the regular thread observers, including appshell, before the main thread observer (XPConnect), so stable state tasks happen before microtasks.
Andreas Farre
Bill McCloskey
Nathan Froyd
Cervantes Yu
Michael Layzell
Sebastian Hengst
Carsten "Tomcat" Book
Eric Rahm
David Major
Iris Hsiao
Blake Kaplan
Wes Kocher
Markus Stange
Olli Pettay
Eric Faust
Jan de Mooij
Ben Kelly
Phil Ringnalda
Nicholas Nethercote
Kan-Ru Chen
Alexandre Lissy
Julian Seward
Boris Zbarsky
Kirk Steuber
Xidorn Quan
Kyle Huey
Randell Jesup
Xidorn Quan
Chris Peterson
Benoit Girard
Juan Gomez