1682204 - arena_t::mId is uninitialised in the constructor

Status: RESOLVED FIXED

(Core :: Memory Allocator, task)

Description

[Paul Bone [:pbone]]

This is benign because mId is filled in during CreateArena after the constructor is called. But we can patch it to make Covertly happy anyway.

New defect(s) Reported-by: Coverity Scan
Showing 1 of 1 defect(s)

** CID 1470619: Uninitialized members (UNINIT_CTOR)
/memory/build/mozjemalloc.cpp: 3565 in arena_t::arena_t(arena_params_s *,
bool)()

---

+________________________
*** CID 1470619: Uninitialized members (UNINIT_CTOR)
/memory/build/mozjemalloc.cpp: 3565 in arena_t::arena_t(arena_params_s *,
bool)()
3559 }
3560 MOZ_ASSERT(i == NUM_SMALL_CLASSES - 1);
3561 3562 #if defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED)
3563 mMagic = ARENA_MAGIC;
3564 #endif

CID 1470619: Uninitialized members (UNINIT_CTOR)
Non-static class member "mId" is not initialized in this
constructor nor in any functions that it calls.
3565 }
3566 3567 arena_t::~arena_t() {
3568 size_t i;
3569 MutexAutoLock lock(mLock);
3570 MOZ_RELEASE_ASSERT(!mLink.Left() && !mLink.Right(),

Comment 1

[Paul Bone [:pbone]]

Hi Glandium.

I see this comment here:
https://searchfox.org/mozilla-central/source/memory/build/mozjemalloc.cpp#890

But I'm not sure what it means when we clear mId in the destructor:
https://searchfox.org/mozilla-central/source/memory/build/mozjemalloc.cpp#3589

Maybe it's referring to TypedBaseAlloc<arena_t>'s destructor, but that makes less sense. Should I delete this line of this comment as it seems to not match the code?

Comment 2

[Paul Bone [:pbone]]

Attachment: Bug 1682204 - Clear arena_t::mId in the constructor r=glandium

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c0446a031b8e
Clear arena_t::mId in the constructor r=glandium

Comment 4

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/c0446a031b8e