Dead lock in goroutines

Question

can someone give me some insight about this code, Why this get deadlock error in for x:=range c

func main() {
    c:=make(chan int,10)

    for i:=0;i<5;i++{
        go func(chanel chan int,i int){
            println("i",i)
            chanel <- 1
        }(c,i)
    }

    for x:=range c {
        println(x)
    }
    println("Done!")
}

Answer 1

Because this:

    for x:=range c {
        println(x)
    }

will loop until the channel c closes, which is never done here.

Here is one way you can fix it, using a WaitGroup:

package main

import "sync"

func main() {
    var wg sync.WaitGroup
    c := make(chan int, 10)

    for i := 0; i < 5; i++ {
        wg.Add(1)
        go func(chanel chan int, i int) {
            defer wg.Done()
            println("i", i)
            chanel <- 1
        }(c, i)
    }

    go func() {
        wg.Wait()
        close(c)
    }()

    for x := range c {
        println(x)
    }
    println("Done!")
}

Try it on Go Playground