Bug 32103 – Add zombies to JSC

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Oliver Hunt]

While working on GC issues recently I found it useful to implement zombies in JSC.  With a few assertions added it nailed the gc bugs i was hunting fairly quickly so i figure in the interests of saving people time in future it should get placed in trunk.

[Oliver Hunt]

Created attachment 44209 [details]
Patch

[WebKit Review Bot]

style-queue ran check-webkit-style on attachment 44209 [details] without any errors.

[Gavin Barraclough]

Comment on attachment 44209 [details]
Patch

> -#define COLLECT_ON_EVERY_ALLOCATION 0
> +#define COLLECT_ON_EVERY_ALLOCATION 1

Yeah, I don't think you mean that.  I'm only guessing.

> -                        imp->~JSCell();
> +#if ENABLE(JSC_ZOMBIES)
> +                        if (!imp->isZombie()) {
> +                            const ClassInfo* info = imp->classInfo();
> +#endif
> +                            imp->~JSCell();
> +#if ENABLE(JSC_ZOMBIES)
> +                            new (imp) JSZombie(info, JSZombie::leakedZombieStructure());
> +                            heap.numZombies++;
> +                        }
> +#endif

Personally I think this might be a little nicer as:

#if ENABLE(JSC_ZOMBIES)
                        if (!imp->isZombie()) {
                            const ClassInfo* info = imp->classInfo();
                            imp->~JSCell();
                            new (imp) JSZombie(info, JSZombie::leakedZombieStructure());
                            heap.numZombies++;
                        }
#else
                        imp->~JSCell();
#endif


BRRrrrraaaiiiiiinnnnzzzzzzzzzzzzzzzzzzzzz+

[Oliver Hunt]

Committed r51624

[JSC Zombie]

MMmoorrre BRRrrrraaaiiiiiinnnnzzzzzzzzzzzzzzzzzzzzz.

[Geoffrey Garen]

LOL