Golang channel死锁的几种情况小结

func main() {
	// 死锁1
	ch := make(chan int)
	ch <- 100
	num := <-ch
	fmt.Println("num=", num)
}

package main

import (
    "fmt"
    "time"
)

func main() {
    ch1 := make(chan int)
    go fmt.Println(<-ch1)
    ch1 <- 5
    time.Sleep(1 * time.Second)
}

func main()  {
	ch := make(chan int)
	ch <- 100  //此处死锁 优于go程之前使用通道
	go func() {
		num := <-ch
		fmt.Println("num=", num)
	}()
	//ch <- 100  此处不死锁
	time.Sleep(time.Second*3)
	fmt.Println("finish")
} 

// 死锁3
func main()  {
	ch1 := make(chan int )
	ch2 := make(chan int )

	go func() {
		for {
			select {
				case num := <-ch1:
					fmt.Println("num=", num)
					ch2 <- 100
			}
		}
	}()

	for {
		select {
			case num := <-ch2:
				fmt.Println("num=", num)
				ch1 <- 300
		}
	}
}

func main() {
	// 死锁1
	ch := make(chan int)
	//close(ch) 向关闭的channel中读取数据 是该数据的类型的零值
	num := <-ch
	fmt.Println("num=", num)
}

func main() {
	ch := make(chan int, 2)
	ch <- 1
	ch <- 2
	ch <- 3
	num := <-ch
	fmt.Println("num=", num)
}

func main() {
	ch := make(chan int, 2)
	close(ch)
	ch <- 1
	num := <-ch
	fmt.Println("num=", num)
}