为什么我的goroutine不执行？ [重复]

Question

This question already has an answer here:

• No output from goroutine in Go 3 answers

I'm learning Go and I wanted to try goroutines and channels.

Here's my code:

package main
import "fmt"
func main(){

messages := make(chan string,3)

messages <- "one"
messages <- "two"
messages <- "three"

go func(m *chan string) {
    fmt.Println("Entering the goroutine...")
    for {
        fmt.Println(<- *m)
    }
}(&messages)

fmt.Println("Done!")
}

And here's the result:

Done!

I don't understand why my goroutine is never executed. The "Entering the goroutine" is not printed and I don't have any error message.

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Answer 1

The fact is that your goroutine starts, but is ended before doing anything because your program stop right after printing Done!: execution of goroutines is independant of the main program, but will be stopped at the same than the program. So basically, you need some process to make the program wait for them. It could be another channel waiting for a number of messages, a sync.WaitGroup, or other tricks.

You should read the excellent post about concurrency in go in the golang blog.