spawn

Starts proc as a new fiber on the current scheduler and returns its handle. It first runs when the calling fiber blocks or yields, and not at all if the scheduler ends first. The new fiber starts with a copy of the caller's context and temporary storage of its own. Fibers share one OS thread, so they can use shared data without locks as long as they do not block in the middle of updating it.

Io :: #import "Extensions/Io";

main :: () {
    Io.io_run(() {
        results := Io.make_channel(int, 1);
        defer Io.free_channel(results);

        Io.spawn((out: *Io.Channel(int)) { Io.send(out, 42); }, results);

        value, error := Io.recv(results); // waits for the spawned fiber
        assert(error == .NONE && value == 42);
    });
}

spawn :: (proc: $P) -> Fiber_Handle

spawn :: (proc: $P, data: $T) -> Fiber_Handle