You will have to wait for the JS stack to be idle for events to get dispatched... even promises are only dispatched from an idle state in the JS stack (where it has returned fully).
You can call any JS functions in the initialization callback - but you cannot use the isolate or make a handle scope in not the right thread... so you have to wait for the uv_async_init'ed callback to be triggered before doing queued work. If this isn't sufficient and you really need parallel or injected execution - for node there's a worker-thread module ; but the eventual results have to be dispatched at the idle level still... https://github.com/laverdet/isolated-vm for example... (this is also a C++ thread that deals directly with allocating and managing isolates) you use `uv_async_init` once, which initialized a uv_async_t handle to be associated with a loop. You then use uv_async_send( handle ); which triggers dispatching to that routine; you will have to create a handle scope in that callback before doing JS functions. The handle can only be closed in the main thread also. The work can be queued to internal tracking, and when the async callback runs, it just checks for outstanding work, and calls appropriate JS callbacks. On Mon, Apr 21, 2025 at 9:51 AM jmr <audrius.butkevic...@gmail.com> wrote: > Ok, seems that I CAN call js functions from within RequestInterrupt, > things seem to work. > > I guess I'm confused what this means in that case: "Registered |callback| > must not reenter interrupted Isolate." > > > > On Monday, 21 April 2025 at 17:41:21 UTC+1 jmr wrote: > >> I'm porting an application that is using SpiderMonkey for embedding, and >> I have a few questions. >> >> One of the things my application does is, it allows user (in javascript) >> to register for events: >> >> func handler(...) { {} >> registerEventHandler("evetName", handler); >> >> In C++, I then store these handlers to be called later once the event >> arrives. >> >> Once the event arrives (different thread than isolate is running on), I >> store it in a pending event list for the runtime (isolate), I then >> call JS_RequestInterruptCallback which interrupts the execution of the >> runtime (isolate), and drops into my C++ interrupt callback. >> >> From my C++ callback, I check for pending events, and call the user >> provided functions (re-entering the isolate) delivering the events, and >> resume execution to the user. >> >> Seems that with v8, I can get quite close to this, except >> isolate->RequestInterrupt does not allow re-entering the isolate/calling >> user code, making this not work. >> >> I tried using EnqueueMicrotask but seems those are never delivered >> automatically unless the script stops, or I call PerformMicrotaskCheckpoint >> (which then ends up on the wrong, calling thread) >> >> I tried posting a task to the platform >> (platform->GetForegroundTaskRunner(isolate)->PostTask), but given the >> script is long lived, I don't think this ever gets delivered. >> >> I tried using Locker(isolate) + Isolate::Scope(isolate) >> + isolate->GetCurrentContext() from the event thread, and then calling the >> callbacks, but this crashes non-deterministically, sometimes with "Invoke >> in DisallowJavascriptExecutionScope". >> >> Any guidance is appreciated. >> Thanks. >> >> -- > -- > v8-users mailing list > v8-users@googlegroups.com > http://groups.google.com/group/v8-users > --- > You received this message because you are subscribed to the Google Groups > "v8-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-users+unsubscr...@googlegroups.com. > To view this discussion visit > https://groups.google.com/d/msgid/v8-users/12e0876e-96b5-451f-8c88-11b4c4d8efd3n%40googlegroups.com > <https://groups.google.com/d/msgid/v8-users/12e0876e-96b5-451f-8c88-11b4c4d8efd3n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/v8-users/CAA2GJqXPFoBhCfLdnsjGNfeG3yfWTn5qLZd%2BF0jBHZrEKoxo7g%40mail.gmail.com.
