Segfaulting Threaded code

[bryaan]

PythonCall

When running the following script you will get a segfault. Please help debug as it seems to be a problem with this lib and async methods. Seems to work when @Spawn is changed to @async but that causes it to execute sequentially, which is another issue.

using PythonCall

Web3 = pyimport("web3")

web3async = Web3.AsyncWeb3(Web3.AsyncHTTPProvider("https://mainnet.infura.io/v3/b048b4d49aad428babc12c0eb65dcdc9"))

while true
    @time for _ in range(1, 10)
        Threads.@spawn begin
            blockCoro = web3async.eth.get_block(17418534)
            # block = asyncio_run(blockCoro)
            # @show block 
        end
    end
    sleep(1)
end

wait()

[73021] signal (11.2): Segmentation fault: 11

[cjdoris]

PythonCall is not thread safe. You can only call Python from the main thread: https://cjdoris.github.io/PythonCall.jl/dev/faq/#Is-PythonCall/JuliaCall-thread-safe?

If you want to use multithreading you have to do that from Python.