On Windows and Unix, Factor implements blocking file and network streams on top of a non-blocking I/O substrate, ensuring that Factor threads will yield when performing I/O. This substrate is implemented in the io.ports vocabulary.

A port is a stream using non-blocking I/O substrate:

port

<port> ( handle class -- port )

<buffered-port> ( handle class -- port )

Input ports:

input-port

<input-port> ( handle -- input-port )

Output ports:

output-port

<output-port> ( handle -- output-port )

Global native I/O protocol:

io-backend

init-io ( -- )

init-stdio ( -- )

io-multiplex ( nanos -- )

Per-port native I/O protocol:

(wait-to-read) ( port -- )

(wait-to-write) ( port -- )

Additionally, the I/O backend must provide an implementation of the dispose generic word.