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{
;
}
}
