585221 - Figure out why JSOPTION_UNROOTED_GLOBAL flag is lost

Status: RESOLVED WORKSFORME

(Core :: JavaScript Engine, defect)

Description

[Andreas Gal :gal]

I had to add code to manually restore the flag at every cycle collection.

https://bugzilla.mozilla.org/show_bug.cgi?id=584495

An assert in JSAPI could reveal where the flag is lost.

Comment 1

[Brendan Eich [:brendan]]

Not an assertion, that'll just screw users again if you commit it before fixing. Since it seems hard to repro, would a warning suffice?

/be

Comment 2

[Andreas Gal :gal]

I will just tryserver it till kingdom come. Maybe I catch it there.

Comment 3

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

I'm not sure if this is still an issue, but I'm getting an assertion that seems related. It's here:

void XPCJSRuntime::TraceXPConnectRoots(JSTracer *trc)
{ ...
        JS_ASSERT(acx->hasRunOption(JSOPTION_UNROOTED_GLOBAL));
}

The place where the option gets unset is here:
ContextHolder::ContextHolder(JSContext *aOuterCx, JSObject *aSandbox)
{ ...
        JS_SetOptions(mJSContext,
                      JSOPTION_DONT_REPORT_UNCAUGHT |
                      JSOPTION_PRIVATE_IS_NSISUPPORTS);
}

Would it be correct just to add JSOPTION_UNROOTED_GLOBAL to this list?

Note that I'm doing some weird stuff here where I'm calling a non-GC tracer at an unusual time. But it still seems like the code is wrong as it stands. Or else maybe the assertion is wrong?

Comment 4

[André Bargull [:anba]]

JSOPTION_UNROOTED_GLOBAL was removed in https://hg.mozilla.org/mozilla-central/rev/efae8cc0fff8. Resolving as WFM.