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Async call to node api #1
Description
All uv_run calls for the event loop of nodeJS from either idle handles of Julia event loop or scheduled tasks (e.g. by @async) raises RangeError: Maximum call stack size exceeded.
For example,
using NodeCall
import NodeCall: UvRunMode, UV_RUN_NOWAIT
function sometask()
node"setTimeout(() => console.log('Done'), 2000)"
loop = node_uvloop()
@async let ret = 1
while ret != 0
sleep(0.5) # or `yeild()` to make the task not blocking
ret = @ccall :libjlnode.uv_run(loop::Ptr{Cvoid}, UV_RUN_NOWAIT::UvRunMode)::Cint
end
end
end
p = sometask()
wait(p)throws
undefined:0
RangeError: Maximum call stack size exceeded
Thrown at:
No matter which UvRunMode is used.
Activity
[-]Promises[/-][+]Async call to livnode.uv_run[/+][-]Async call to livnode.uv_run[/-][+]Async call to libnode.uv_run[/+][-]Async call to libnode.uv_run[/-][+]Async call to node api[/+]sunoru commentedon Jul 20, 2021
Actually, any async functions that invoke any node-API would throw this. It is because the API must be used in the main thread.
Even showing js values in REPL will throw this error:
sunoru commentedon Aug 7, 2021
Try using N-API's async APIs.sunoru commentedon Aug 10, 2021
https://nodejs.org/docs/latest-v14.x/api/n-api.html#n_api_asynchronous_thread_safe_function_calls
We probably have to invoke by
napi_threadsafe_function.Maybe it's not worth supporting
@async, since we can always use@node_asyncto let NodeJS control the event loop.Perhaps a function can be provided to wrap a
Taskwith an async context?I'm still not sure how the other
napi_functions should be used in an async environment.Will test later.sunoru commentedon Aug 11, 2021
Instead of wrapping
Tasks, we can directly modifynapi_callto invokenapi_create_threadsafe_functionifcurrent_task() != global_task().See thethreadingbranch and https://github.com/sunoru/jlnode/tree/threading