別の方法は、一度に1つのゴルーチンのみを実行できる制御チャネルを用意し、各ルーチンがアトミック操作の実行を完了するたびに「制御ロック」に送り返すことです。
package main
import "fmt"
import "time"
func routine(id int, control chan struct{}){
for {
// Get the control
<-control
fmt.Printf("routine %d got control\n", id)
fmt.Printf("A lot of things happen here...")
time.Sleep(1)
fmt.Printf("... but only in routine %d !\n", id)
fmt.Printf("routine %d gives back control\n", id)
// Sending back the control to whichever other routine catches it
control<-struct{}{}
}
}
func main() {
// Control channel is blocking
control := make(chan struct{})
// Start all routines
go routine(0, control)
go routine(1, control)
go routine(2, control)
// Sending control to whichever catches it first
control<-struct{}{}
// Let routines play for some time...
time.Sleep(10)
// Getting control back and terminating
<-control
close(control)
fmt.Println("Finished !")
}
これは印刷します:
routine 0 got control
A lot of things happen here...... but only in routine 0 !
routine 0 gives back control
routine 1 got control
A lot of things happen here...... but only in routine 1 !
routine 1 gives back control
routine 2 got control
A lot of things happen here...... but only in routine 2 !
routine 2 gives back control
routine 0 got control
A lot of things happen here...... but only in routine 0 !
routine 0 gives back control
routine 1 got control
A lot of things happen here...... but only in routine 1 !
routine 1 gives back control
routine 2 got control
A lot of things happen here...... but only in routine 2 !
routine 2 gives back control
routine 0 got control
A lot of things happen here...... but only in routine 0 !
routine 0 gives back control
routine 1 got control
A lot of things happen here...... but only in routine 1 !
routine 1 gives back control
routine 2 got control
A lot of things happen here...... but only in routine 2 !
routine 2 gives back control
routine 0 got control
A lot of things happen here...... but only in routine 0 !
routine 0 gives back control
routine 1 got control
A lot of things happen here...... but only in routine 1 !
routine 1 gives back control
routine 2 got control
A lot of things happen here...... but only in routine 2 !
routine 2 gives back control
Finished !