How to know a buffered channel is full

Question

How to know a buffered channel is full? I don\'t know to be blocked when the buffered channel is full, instead I choose to drop the item sent to the buffered channel.

Answer 1

I use this code to remove one item if the channel was full. For channels with only one sending go routine it's enough to ensure that sending to ch will work afterwards.

// Remove one item from chan if full
if len(ch) == cap(ch) {
    // Channel was full, but might not be by now
    select {
    case _ := <-ch:
    // Discard one item
    default:
        // Maybe it was empty already
    }
}

// Now we can send to channel