Collision on concurrent read on buffered channel in golang?

Question

I have a buffered channel that are read by multiple (4 in this example) go routines.

queue := make(chan string, 10000) // a large buffered channel

Each go routine checks the number of elements available in the channel and process them all.

for i :=0; i< 4; i++{ // spun 4 go routines
    go func() {
        for {
            for elem := range queue {
                // do something with the elem from the channel
            }
         }
     }
  }

Will multiple go routines collide on the reads? In other words, could different go routine grab the same elem in the channel, or while one go routine is reading the buffer, the other go routines already read and processed some of the elements? How to block other go routines from reading while one go routine is reading?

Answer 1

Simple answer: no. Elements placed on a Go channel can only be read once, regardless of how many goroutines are trying to read off the channel at the same time, and that applies regardless of whether the channel is buffered or not. There's no possibility that an element will be read by two different goroutines unless that element was sent to the channel more than once. The only thing that buffering does, with regards to channel semantics, is remove the necessity for the read and write to occur synchronously.