savi-lang/tcp

TCP networking implementation for the Savi standard library.

TCP

TCP networking implementation for the Savi standard library.

tcp's Issues

Add assertions and async fulfillment to TCP specs.

At the time the specs were written, the Spec library had no way to asynchronously assert nor even to have an example that ran past its initial synchronous execution. As a result, the specs we have now just print some output about what happens with the sockets asynchronously, but a human actually has to read the output to know if something went wrong or not.

As of savi-lang/Spec#5 the Spec library now has these asynchronous features, so we can update our specs to actually assert things.

HTTPServer infinite loop on "too many open files"

On Linux, when using the examples/http server and testing it with a large number of simultaneous connections, I commonly see one thread get stuck in an infinite loop, and the server fails to accept more connections.

After stepping through the issue in lldb, I can see that the TCPListener actor gets stuck in an infinite loop when it tries to run pony_os_accept to accept a connection and that call fails with EMFILE ("too many open files") as the errno. The TCPListener is currently written to naively assume that any failure can be considered spurious, and it tries again to accept a connection. In this failure mode, trying again to accept a new connection will not help - it will always fail. Hence, it gets stuck in an infinite retry loop.