Go language: A simple goroutine synchronization (Synchronize)

We can use channels to synchronize between multiple goroutine (synchronize), see the example below.
Example 1, use Chan to wait for a goroutine to end.

package mainimport "fmt"import "time"//在这定义一个函数，以goroutine的方式运行。使用done这个chan来通知//其它的函数本函数的工作已成。这个例子是通知main函数。func worker(done chan bool) {    fmt.Print("working...")    for i:=0;i<10;i++ {        time.Sleep(time.Second)        fmt.Print(".")    }    fmt.Println("done")    // 函数结束时，给chan赋值    done <- true}func main() {    // Start a worker goroutine, giving it the channel to    // notify on.    //启动一个goroutine并给传入一个chan    c := make(chan bool, 1)    go worker(c)    // main函数在没有收到chan的值时会一直block.    <-c //如果没有这句， mai函数会立即退出而不会等待worker}

In Example 2, function B runs after function a ends.

package mainimport (  "fmt"  "time")//定义函数A，以goroutine的方式运行func workerA(done chan bool){  fmt.Print("A is running")  for i:=0;i<10;i++{    fmt.Print(".")    time.Sleep(1 * time.Second)  }  fmt.Println("done")  done <- true}//定义函数B，以gortoutine的方式运行func workerB(){  fmt.Print("B is running")  for i:=0;i<10;i++{    fmt.Print(".")    time.Sleep(1 * time.Second)  }  fmt.Println("done")}func main(){  c:= make(chan bool, 1)  //启动A，传入chan c  go workerA(c)      //只有A运行结束时，B才能运行  select {  case <-c:    go workerB()    //fmt.Println("B is done !")  }    // wait for workerB exit.  // 为防止main函数在B之前退出，等待一段时间。  time.Sleep(20*time.Second)}

Go language: A simple goroutine synchronization (Synchronize)