Could you post a stack trace that leads to the FATAL()? On Tue, Apr 12, 2016 at 7:27 PM Ben Noordhuis <i...@bnoordhuis.nl> wrote:
> On Tue, Apr 12, 2016 at 7:11 PM, <benjamin.pas...@gmail.com> wrote: > > Hi, > > > > we (Microsoft VS Code team) are tracking down a very weird native crash > in > > our use of node.js (5.10.0, V8 46) that only ever shows up since we > updated > > from node.js 4.x (V8 45). It seems that changes (around the Garbace > > Collector?) in V8 46 have an impact to the crash. > > > > Specifically, we are using the node-weak module > > (https://github.com/TooTallNate/node-weak) to be able to get weak > references > > onto JavaScript objects. This used to work relatively good in node.js > 4.x, > > but with node.js 5.x we suddenly get the entire node.js program to > terminate > > with a fatal crash. > > > > Today we were finally able to track the location of where the crash > > originates and it seems to happen when our application simply calls into > a > > property of the object that is weakly referenced. This call at one point > > reaches the following assertion: > > > > void Object::VerifyApiCallResultType() { > > #if DEBUG > > if (!(IsSmi() || IsString() || IsSymbol() || IsSpecObject() || > > IsHeapNumber() || IsSimd128Value() || IsUndefined() || IsTrue() > || > > IsFalse() || IsNull())) { > > FATAL("API call returned invalid object"); > > } > > #endif // DEBUG > > } > > > > > > The process terminates from the FATAL call, as none of the previous > checks > > in this method hold. > > > > > > Now, the interesting question is: How would it be possible to have a JS > > object where calling properties on it would fail in such a fatal way? It > > seems to us that the object we are calling a property on is a pointer to > a > > location in memory where no V8 object exists anymore. It almost seems > that > > the object was garbage collected (or moved to another address?) without > the > > JS side (or more specifically the node-weak side) getting to know. > > > > > > Since this only reproduces with using node-weak, it seems very likely > that > > there is an issue with either node-weak or NAN. In fact, node-weak is > > calling into SetWeak() > > ( > https://github.com/TooTallNate/node-weak/blob/master/src/weakref.cc#L174) > > and relies on the fact that the callback passed in is triggered and maybe > > this callback is not triggered anymore in a sync fashion but rather > async? > > > > > > I would appreciate some pointers if there is something that could have > > probably changed in V8 46 that could have an impact on this. > > If you have a simple test case (stress on 'simple'), I'll have a look. > > -- > -- > v8-dev mailing list > v8-dev@googlegroups.com > http://groups.google.com/group/v8-dev > --- > You received this message because you are subscribed to the Google Groups > "v8-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-dev+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- -- v8-dev mailing list v8-dev@googlegroups.com http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-dev+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
