如何确定goroutine是否已完成而没有阻塞？

Question

All the examples I've seen so far involve blocking to get the result (via the <-chan operator).

My current approach involves passing a pointer to a struct:

type goresult struct {
    result resultType;
    finished bool;
}

which the goroutine writes upon completion. Then it's a simple matter of checking finished whenever convenient. Do you have better alternatives?

What I'm really aiming for is a Qt-style signal-slot system. I have a hunch the solution will look almost trivial (chans have lots of unexplored potential), but I'm not yet familiar enough with the language to figure it out.

Answer 1

You can use the "comma, ok" pattern (see their page on "effective go"):

foo     := <- ch; // This blocks.
foo, ok := <- ch; // This returns immediately.