I think MAIN_THREAD_ASYNC_EM_ASM is what you want. malloc and free work both in C++ and in JS just the same and across threads just fine.
Alternatively you could call the C++ function on the main thread using `emscripten_async_run_in_main_runtime_thread` and then once that function is running on the main thread call out ot EM_ASM or other JS library function as needed. On Thu, Dec 31, 2020 at 4:21 AM Hanns Holger Rutz <[email protected]> wrote: > Hi there, > > I wonder what is the best way to pass a byte array from non-main-thread > C++ to main-thread JS. I'm hesitating to call MAIN_THREAD_SYNC_EM_ASM > because I don't want to block the C++ thread. So the next two options > are EM_ASM and MAIN_THREAD_ASYNC_EM_ASM. In the asynchronous case, > obviously I would have to malloc in C++ and free in JS. Is that > possible? In the EM_ASM case, JS doesn't have access to any regular > objects from the main JS environment. So I would have to copy the data > and defer to the main JS thread? I suppose there is one worker.js that I > would have to listen to from main, and use postMessage from within EM_ASM? > > Also the data is bounded by 8K, could I perhaps use a different > approach, like use a constant size array direct passing somehow? > > best, .h.h. > > -- > You received this message because you are subscribed to the Google Groups > "emscripten-discuss" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/emscripten-discuss/52f2a4ac-2baa-8d90-1486-c5adc57873f4%40sciss.de > . > -- You received this message because you are subscribed to the Google Groups "emscripten-discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/emscripten-discuss/CAL_va2-SE0rq8c5Sok4T6VPiohczkJ%3D4%3DOwoQfqkqskZOVj%3Dmw%40mail.gmail.com.
