Calling async API from node worker threads results in errors

[devongovett]

Calling e.g. swc.parse from inside a node worker thread results in errors like the following:

FATAL ERROR: HandleScope::HandleScope Entering the V8 API without proper locking in place

This is likely due to calling the callback on the wrong thread, or with the wrong napi environment. I'm not familiar with Rust so I'm not sure where to debug further, but that's been my experience in C++.

[kdy1]

I think neon does not support the case.
I filed an issue on neon.

neon-bindings/neon#489

[dherman]

Is this use case actually using any of the Neon async/threading APIs (including the new experimental one), or is it just simply calling regular Neon functions from within a Node worker that fails? I'm guessing it's the latter, and there may be something straightforward we've got wrong in order to support running Neon code in Node workers. But I want to make sure I know your use case before we fix the wrong thing.

[amilajack]

Hey @devongovett! Would love if you could add a small test case that reproduces this to neon-bindings/neon#489.

[kdy1]

@dherman My usecase includes Task api. Also, although it's not used now, I need to call EventHandler from Task.

I'm not sure about node js worker threads.