Loading file from inside worker marked as (pending)

[michaelkremenetsky]

So I am creating a thread in c++ using std::thread and then in that I call a js function added via js-library. I need to import a script in the js function but when I do there is no console output from the script and when I look in the network tab I see its trying to load it but its marked as (pending) and stuck on that. Any idea what the issue might be? I tried running both async and sync and I get the same thing. I can't tell if this is a CORS issue or something else.

mergeInto(LibraryManager.library, {
  run_script_example: function (js_path_c, argv_ptr, envp_ptr) {
import("http://localhost:3000/need_to_runt_this_script.js")
      .then((m) => console.log("imported", m))
      .catch((err) => console.error("failed", err));
},
})

Web server I'm running it with:

#!/usr/bin/env python3
from http import server # Python 3

class TheHandler(server.SimpleHTTPRequestHandler):
    def end_headers(self):
        self.send_my_headers()
        server.SimpleHTTPRequestHandler.end_headers(self)

    def send_my_headers(self):
        self.send_header("Cross-Origin-Embedder-Policy", "require-corp")
        self.send_header("Cross-Origin-Opener-Policy", "same-origin")
        # Needed so module worker dynamic import() passes COEP checks
        self.send_header("Cross-Origin-Resource-Policy", "same-origin")


server.test(HandlerClass=TheHandler, port=3000)

[sbc100]

Can you set a break point or add some console logging, so make sure you are hitting the function?

Are you sure the thread is actually running? e.g. can see logging coming from the thread entry point?

[sbc100]

Oh sorry, I didn't read that you are seeing the request marked as pending.

One issue here is that you will need to allow the thread to continue and run its event loop. To do this you would need do something like emscripten_runtime_keepalive_push before returning from thread entry point. If you don't do this the thread will exit before the request is done.

[michaelkremenetsky]

Thanks for the Tip! I'm doing this and dosen't seem to be calling the script. It prints Called Script Example so the function is being called but the example_script.js is not being called. Dosen't show anything at all in the network tab. Don't see [wb] imported. Any ideas?

EM_JS(void, run_script_example,
      (), {
  if (typeof runtimeKeepalivePush === 'function') runtimeKeepalivePush();
  let popped = false;
  const pop = () => {
    if (!popped && typeof runtimeKeepalivePop === 'function') {
      runtimeKeepalivePop();
      popped = true;
    }
  };
  
 console.log("Called Script Example"):

  import('http://localhost:3000/example_script.js)')
    .then(mod => {
      console.log('[wb] imported', mod);
      if (mod && typeof mod.default === 'function') mod.default();
    })
    .catch(err => console.error('[wb] import failed', err))
    .finally(pop);
});

[sbc100]

You could try adding -sPTHREADS_DEBUG to see information about the state of the thread.