Go并发缓冲channel

无缓存

ch := make (chan int) 等价于 ch := make (chan int, 0)

无缓存的channel，如果想要写入值，但没有人读的话，写的值会一直写不进去（阻塞在写入处）。直到有人读取，才会写入，并传递到读出的数那里。

package main

import (
	"fmt"
	"time"
)

var ch chan int

// 写chan
func writech(){
	ch <- 1
	fmt.Println("writech end")
}

func main(){
	ch = make (chan int, 0)

	go writech()
	time.Sleep(2 * time.Second)

	// 读chan
	fmt.Println("start to read chan")
	<-ch

	time.Sleep(time.Second)
	fmt.Println("end main")
}

有缓存

缓冲满了之后阻塞，除非有人对它操作（读）

package main

import (
	"fmt"
	"time"
)

var ch chan int

// 写chan
func writech(){
	ch <- 1
	fmt.Println("writech 1")
	ch <- 2
	fmt.Println("writech 2")
	ch <- 3
	fmt.Println("writech 3, end")
}

func main(){
	ch = make (chan int, 2)

	go writech()
	time.Sleep(2 * time.Second)

	// 读chan
	fmt.Println("start to read chan")
	<-ch
	fmt.Println("chan read end")

	time.Sleep(time.Second)
	fmt.Println("end main")
}