What is channel buffer size?

Question

I\'m trying to create an asynchronous channel and I\'ve been looking at http://golang.org/ref/spec#Making_slices_maps_and_channels.

c := make(chan int, 10)          


        

Answer 1

package main

import (
    "fmt"
    "time"
)

func receiver(ch <-chan int) {
    time.Sleep(500 * time.Millisecond)
    msg := <-ch
    fmt.Printf("receive messages  %d from the channel\n", msg)
}

func main() {
    start := time.Now()
    zero_buffer_ch := make(chan int, 0)
    go receiver(zero_buffer_ch)
    zero_buffer_ch <- 444
    elapsed := time.Since(start)    
    fmt.Printf("Elapsed using zero_buffer channel: %v\n", elapsed)

    restart := time.Now()
    non_zero_buffer_ch := make(chan int, 1)
    go receiver(non_zero_buffer_ch)
    non_zero_buffer_ch <- 4444
    reelapsed := time.Since(restart)
    fmt.Printf("Elapsed using non zero_buffer channel: %v\n", reelapsed)
}

result:

receive messages 444 from the channel

Elapsed using zero_buffer channel: 505.6729ms

Elapsed using non zero_buffer channel: 0s