golang读写锁简单例子

package main

import (
	"fmt"
	"math/rand"
	"sync"
)

var count int           		// 全局变量count
var rwlock sync.RWMutex       	// 全局读写锁 rwlock

func read(n int)  {
	rwlock.RLock()
	fmt.Printf("读 goroutine %d 正在读取数据...\n", n)
	num := count
	fmt.Printf("读 goroutine %d 读取数据结束，读到 %d\n", n, num)
	defer rwlock.RUnlock()
}
func write(n int)  {
	rwlock.Lock()
	fmt.Printf("写 goroutine %d 正在写数据...\n", n)
	num := rand.Intn(1000)
	count = num
	fmt.Printf("写 goroutine %d 写数据结束，写入新值 %d\n", n, num)
	defer rwlock.Unlock()
}
func main()  {

    for i:=0;i<5;i++{
    	go read(i+1)
	}

	for i:=0;i<5;i++{
		go write(i+1)
	}


for{
	;
}
}