go-channel通道死锁
防止通道死锁
如果在一个通道设置接收指定大小的数据, 那么当通道数据满了, 就无法继续接收数据, 将会报出如下错误提示! fatal error: all goroutines are asleep - deadlock!
源代码如下：
package main
import (
"fmt"
"sync"
"time"
)
func acceptChan() {
channel := make(chan string, 2)
fmt.Println("first")
channel <- "write one"
fmt.Println("seccond")
channel <- "write two"
fmt.Println("third")
channel <- "write three"
message := <-channel
fmt.Println(message)
}
func main() {
acceptChan()
}
上面的代码执行结果得到的报错信息如下：
fatal error: all goroutines are asleep - deadlock!
goroutine 1 [chan send]:
main.acceptChan()
D:/company/learning/development/GolandProjects/main.go:54 +0x129
main.main()
D:/company/learning/development/GolandProjects/main.go:64 +0x2a
exit status 2
如果要避免上面的代码执行导致错误的结果, 可以在通道接收数据过程中用 select 处理. 最后把通道的数据传给变量赋值, 使用 select 改进之后代码如下：
package main
import (
"fmt"
"sync"
"time"
)
func acceptChan() {
channel := make(chan string, 2)
fmt.Println("first")
channel <- "write one"
fmt.Println("seccond")
channel <- "write two"
fmt.Println("third")
select {
case channel <- "write three":
fmt.Println("ok")
default:
fmt.Println("final")
}
message := <-channel
fmt.Println("结果：", message)
}
func main() {
acceptChan()
}
最后执行看到结果如下：
first
seccond
third
final
结果： write one