问为什么我的golang goroutine代码会死锁

EN

package main

import (
    "fmt"
    "sync"
)

var wg sync.WaitGroup

func main() {
    chan1 := make(chan string)
    chan2 := make(chan string)
    chan3 := make(chan string, 2)
    wg.Add(1)
    go makeChanStr("yeye", chan1, chan3)
    wg.Add(1)
    go makeChanStr("okok", chan2, chan3)
    wg.Wait()
    close(chan3)
    println(<-chan1)
    println(<-chan2)
    for chs := range chan3 {
         println(chs)
    }
}

func makeChanStr(s string, c1 chan string, c2 chan string) {
    defer wg.Done()

    c1 <- "get " + s
    c2 <- "same value"
    fmt.Printf("execute ok %s", s)
}