Allow emscripten_atomic_wait_suspending to return synchronously#26947
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Allow emscripten_atomic_wait_suspending to return synchronously#26947sbc100 wants to merge 1 commit into
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I have a nice followup to which I think makes this solution nicer: f5cc8ee |
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Sounds reasonable. |
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@tlively Do you think this approach makes sense then? i.e. the version where we return a promise and only suspend sometimes? If so, are you OK landing this change? (with the "await_unchecked") as a separate followup? |
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Actually maybe lets just land #26954 first |
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This works with ASYNCIFY like the existing `emscripten_promise_await` but is a lot simpler since it only handles the fulfilled case. In this case we can simple return the result directly without needing to allocate a `em_promise_result_t` struct to deal with the out param (i.e. no memory access needed). This can be useful in cases where we don't want to handle the rejections case. Split out from #26947
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OK, this is now rebase on top of #26954. PTAL! |
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Followup to the initial version landed in emscripten-core#26941
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| void _emscripten_thread_notify(pthread_t thread); | ||
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| // Internal promise-returning API used to implement | ||
| // emscripten_atomic_wait_syspending. |
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| // emscripten_atomic_wait_syspending. | |
| // emscripten_atomic_wait_suspending. |
| 'MAX_WEBGL_VERSION': 0, | ||
| 'BUILD_AS_WORKER': 1, | ||
| 'LINK_AS_CXX': 1, | ||
| 'SHARED_MEMORY': 0, |
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Followup to the initial version landed in #26941. This version of the code allows for reporting of synchronous results without actually suspending.
The implementation of
emscripten_atomic_wait_suspendingis not in libc, and it works by first calling a non-JSPI function which can return a promise, or a sync result. Then, only in the case that a promise is returned do we actually need to suspend using a JSPI call.