[kevingadd]

asm.js doesn't have support for reference types. You can access threads via the HTML5 'Web Worker' feature.

[CmonDev → kevingadd]

So, all the C++ threading code will automatically be converted to 'Web Workers'?

[flohofwoe → CmonDev]

No, but it's not a great deal to write a parallel execution subsystem in C/C++ which abstracts the differences between pthreads and WebWorkers away. Using low-level pthreads primitives directly in high-level code is a bad idea anyway.