Unbuffered channel with two selects, one sending and one receiving

[Inchs Nicodi]

Two goroutines are using the same unbuffered channel.

One sends on it inside a select with a default clause.

The other receives from it inside a select with a default clause.

goroutine 1:

for {

    select {

    case obj <- ch:

    default:

    }

    ....

}

goroutine 2:

for {

    select {

    case ch <- obj:

    default:

    }

    ....

}

The channel is unbuffered.

Can these two goroutines ever communicate with each other?

It's a difficult thing to test if they never meet except once in a billion attempts.

I've looked at runtime/chan.go but I'm not sure if this depends on what the compiler generates for those select statements.

[tapi...@gmail.com]

By the current official implementation, communicate will never happen.

Because the send and receive goroutines are never put into the wait queues.