Also note that you probably do want to use atomic operations to read and write to the shared memory, even if you're using JS on one thread and Wasm on another. If you don't use atomics, there's no guarantee that the values written on one thread will actually become visible on the other thread when you expect them to.
On Fri, Mar 4, 2022 at 11:49 AM 'Sam Clegg' via emscripten-discuss < [email protected]> wrote: > Historically the `-pthead` flag (or `-s USE_PTHREADS`) is the way to get > shared memory. Is there some reason you have not wanted to use that > flag? (is it code size > of the resulting JS.. if so we are working on reducing that). > > As it happens we just today landed a new `-s SHARED_MEMORY` flag I think > gives you exactly what you want without the overhead of the pthread JS > library code: https://github.com/emscripten-core/emscripten/pull/16419. > > cheers, > sam > > On Fri, Mar 4, 2022 at 10:29 AM Александр Гурьянов <[email protected]> > wrote: > >> https://github.com/WebAssembly/binaryen/pull/4525 >> >> >> пт, 4 мар. 2022 г. в 15:43, Александр Гурьянов <[email protected]>: >> >>> Hi, I want to use shared memory for my WebAssembly module. It's needed >>> for js-dos. Currently emulation works in worker and frame updates are send >>> using postMessage. I want to use SharedArrayBuffer to avoid copying/sending >>> big rgba data. >>> >>> I dont' need to use pthread or threading, I just want to share memory >>> between worker and main process. How I can say emscripten to generate >>> "shared" memory imort. >>> >>> I found similar question here: >>> https://github.com/emscripten-core/emscripten/issues/12098 >>> As suggested I tried wasm2wat and then wat2wasm, but it not working for >>> me. Looks like it affects -s INVOKE_RUN=0, because after wasm2wat my >>> module immediately starts and I can't provide own memory. >>> >>> Without wasm2wat I have this error: >>> >>> LinkError: WebAssembly.instantiate(): mismatch in shared state of >>> memory, declared = *0*, imported = *1* >>> >>> After wasm2wat this: >>> >>> LinkError: WebAssembly.instantiate(): mismatch in shared state of >>> memory, declared = *1*, imported = *0* >>> >>> Can we add some pass to binaryen for turning non-shared memory into >>> shared? >>> >> -- >> 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/CAKOm%3DVE24Q4%2Bewi5QBSdmuuRf7F-FCk_1TM7tZxexwrMOzXdqw%40mail.gmail.com >> <https://groups.google.com/d/msgid/emscripten-discuss/CAKOm%3DVE24Q4%2Bewi5QBSdmuuRf7F-FCk_1TM7tZxexwrMOzXdqw%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- > 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_UWBhM-2yOG_6aUDPa_%3DX%3DmDJOxaC00Bo8CbQa6cDbYw%40mail.gmail.com > <https://groups.google.com/d/msgid/emscripten-discuss/CAL_va2_UWBhM-2yOG_6aUDPa_%3DX%3DmDJOxaC00Bo8CbQa6cDbYw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- 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/CAJZD_EWNu%3Di0%3DACiKbuPyTOUAckT1SDceosApBvJj6VCo8-WYQ%40mail.gmail.com.
