Comment on attachment 8921265 [details] Bug 1411084 - Use RAII for mutex locking in mozjemalloc. https://reviewboard.mozilla.org/r/192278/#review197450 RAII is good. r=me with the MOZ_GUARD_OBJECT stuff added, as per below. ::: memory/build/mozjemalloc.cpp:527 (Diff revision 1) > inline void Unlock(); > }; > > +struct MOZ_RAII MutexAutoLock > +{ > + explicit MutexAutoLock(Mutex& aMutex) : mMutex(aMutex) { mMutex.Lock(); } Please add the MOZ_GUARD_OBJECT stuff so this can't be mis-constructed. ::: memory/build/mozjemalloc.cpp:1749 (Diff revision 1) > > if (slot) { > ret = *slot; > } > #ifdef MOZ_DEBUG > - mlock.Lock(); > + MutexAutoLock lock(mlock); What/where is `mlock`? I can't find it...

(In reply to Nicholas Nethercote [:njn] from comment #2) > ::: memory/build/mozjemalloc.cpp:1749 > (Diff revision 1) > > > > if (slot) { > > ret = *slot; > > } > > #ifdef MOZ_DEBUG > > - mlock.Lock(); > > + MutexAutoLock lock(mlock); > > What/where is `mlock`? I can't find it... Argh, it's a typo that comes from bug 1406303, and that went undetected because as of bug 1365460, debug stuff is gated on MOZ_DEBUG... which is actually never defined. The actual debug define is DEBUG (which, I agree, is confusing). I'll file a couple followups for that.

Pushed by mh@glandium.org: https://hg.mozilla.org/integration/autoland/rev/25bc10affd99 Use RAII for mutex locking in mozjemalloc. r=njn