Add support for simultaneously using dynamic linking + pthreads.

[juj]

Current pthreads implementation has a limitation that the dynamic linking feature cannot be used with it. Investigate what is needed to enable this.

[kripken]

I would hope that this would just work. Did you see a problem when trying it?

[juj]

I did not try, this was motivated by your comment in the pull, will need a bit of an audit and testing.

[stale]

This issue has been automatically marked as stale because there has been no activity in the past 2 years. It will be closed automatically if no further activity occurs in the next 7 days. Feel free to re-open at any time if this issue is still relevant.

[jbkempf]

Any update on this?

[kripken]

I don't believe anyone is working on it. It would require some design thinking, as say dlopen on one thread would require adding to the Table on all other threads. However, non-dlopen dynamic linking may be a lot easier.

[jbkempf]

What about dlopening all from the "main-thread"?

[jbkempf]

However, non-dlopen dynamic linking may be a lot easier.

That would mean to have all the .so (is it really .so?) modules loaded all the time, no?

[msabwat]

@sbc100 talked about a shared table instead, would it be feasible? the SIDE_MODULE would still expose its native table to JS (like a normal wasm module does). I don't see how emscripten reads the native table? is it here?

For now, "agressively" disabling the errors when we USE_PTHREADS+SIDE_MODULE lands into a wasm-ld assert:

/b/s/w/ir/cache/builder/emscripten-releases/llvm-project/lld/wasm/Writer.cpp:715: void lld::wasm::(anonymous namespace)::Writer::createInitMemoryFunction(): Assertion `WasmSym::initMemoryFlag' failed.

Makes me think there's another write. Is it like that? :

1. We extract the symbols from the binary. (with llvm-nm)
2. We write them into a JS Table object.
3. We give that table to wasm-ld to have the final .wasm binary.

Dynamic linking in our case would be to be able to feed the JS table from SIDE_MODULES and read from it from the MAIN_MODULE.