nsTimerEvent goes through a multi-step initialization for reasons that
are lost to time. We are also seeing peculiar crashes in
`nsTimerEvent::SetTimer()` that are only explainable by `SetTimer`
finding a non-null pointer where there should have been a null pointer.
The compiler ought to have been able to optimize those bits away, but no
matter: we can do the job ourselves and make the code clearer.
Since we only call `SetTimer` once, we should just move its work into
nsTimerEvent's constructor.
Doing this code movement separately will ideally make the next part of
this work easier to review. The idea is that we want to extract all the
necessary information from `timer` before we pass ownership of it into
the newly-allocated nsTimerEvent.
Unlike many of our uses of `new`, nsTimerEvent has its own definition of
`operator new`, to ensure instances are allocated through
TimerEventAllocator. And allocating with TimerEventAllocator can fail.
Later changes, however, want to assume that constructing an nsTimerEvent
can't fail, which is difficult to guarantee with the current structure.
To make that guarantee, we need to make explicit what calling `new`
does: there's an "allocate memory" step and a "construct the object"
step. The first part can fail, and that's what we care about here.
Once we have a chunk of memory, we can construct the object as normal,
secure in the knowledge that calling (placement) `new` is now guaranteed
to succeed.
Clang format does not always reflow comments correctly to get them
within 80 columns.
The major categories of failures I have noticed in xpcom/ are:
- Comments that are lists. I fixed these by manually getting them so
they'll be within 80 columns after clang-format runs.
- Comments intermixed with lists of things like enums, initializers,
or even fields in a class. It doesn't seem to associate the comment
with the item in the list correctly. The worst cases of these happen
when it changes initializer lists from having commas at the start of
each item to having them at the end. In the initializer comma cases,
I fixed them by making the commas at the end, so clang-format won't
mix things up. For other cases, I often moved the comment for an
item onto its own line, because it was not possible to have both the
comment and the item on the same line and stay within 80 columns.
- One odd case is nsEnumeratorUtils.cpp, where the end of line comment
after a NS_DECL macro confused clang-format and made it stop
realizing that the NS_DECL thing was a complete statement. I also
added a blank line to that file before a declaration because I think
that is better.
Depends on D13183
Differential Revision: https://phabricator.services.mozilla.com/D13184
--HG--
extra : moz-landing-system : lando
We only use nsINamed on runnables for certain kinds of telemetry, and
those kinds of telemetry aren't being gathered on RELEASE_OR_BETA
builds. We effectively make nsINamed::GetName a no-op when we're not
collecting said telemetry. But implementing nsINamed does have a cost:
the vtable of every runnable (and we have hundreds of subclasses of
mozilla::Runnable) will contain pointers for GetName (and extra pointers
for QueryInterface/AddRef/Release), and all those pointers times all
those subclasses adds up quickly. Let's not implement nsINamed when
nsINamed isn't going to be used.
This change saves ~100K of binary size on x86-64 Linux; the savings
should be similar on other 64-bit systems, and ~50K on 32-bit systems.
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
These are generally good practice for reference-counted objects; they
catch cases where these operations are used by accident, breaking
reference-counting.
This doesn't show any existing problems, though.
MozReview-Commit-ID: EvRkNCymOqT