go channel例子

package main
 
import "fmt"
import "time"
 
func main() {
c := make(chan int) //初始化一个管道
go func() { //会开启一个协程，并往管道c写入数据
time.Sleep(2 * time.Second)
fmt.Println("all ready")
c <- 3 + 4
close(c)
}()
i := <-c // 将管道c的内容输出赋值到i，在c还没有内容的时候，会一直阻塞在这里。
fmt.Println(i) //打印i的值
c <- 8 //由于c已经在协程里面被关闭，这句将引起run-time panic
 
}
输出结果如下：
[root@localhost hello]# go run channel.go
all ready
7
panic: send on closed channel
 
goroutine 1 [running]:
main.main()
/mnt/hgfs/share/eclipse/testgo/src/hello/channel.go:16 +0x125
exit status 2

func main() {
go func() {
time.Sleep(1 * time.Hour)
}()
c := make(chan int)
go func() {
for i := 0; i < 10; i = i + 1 {
c <- i
}
close(c) //如果将此句注释掉，那么下面的for range在打印完管道的内容后会一直阻塞。
}()
for i := range c {
fmt.Println(i)
}
fmt.Println("Finished")
}

package main
 
import (
"fmt"
)
 
func fab(c, quit chan int) {
x, y := 0, 1
 
for {
select {
case c <- x:
x, y = y, x+y
case <-quit:
return
}
}
 
}
 
func main() {
c := make(chan int)
quit := make(chan int)
 
go func() {
for i := 0; i < 10; i++ {
fmt.Println(<-c)
}
quit <- 0
}()
 
fab(c, quit)
 
}
 
[root@localhost hello]# go run channel.go
0
1
1
2
3
5
8
13
21
34

package main
 
import (
"fmt"
"time"
)
 
func main() {
 
c := make(chan string)
 
go func() {
time.Sleep(30 * time.Second)
c <- "Hello World"
}()
 
select {
case res := <-c:
fmt.Println(res)
case <-time.After(2 * time.Second):
fmt.Println("timeout")
}
 
}
[root@localhost hello]# go run channel.go
timeout