golang sync.RWMutex

sync.RWMutex

package main

import (
    "fmt"
    "runtime"
    "sync"
)

func clickWithMutex(total *int, m *sync.RWMutex, ch chan int) {
    for i := 0; i < 1000; i++ {
        m.Lock()
        *total += 1
        m.Unlock()
        //这里是写 下面是读，外层还有线程的竞争
        if i == 500 {
            m.RLock()
            fmt.Println(*total)
            m.RUnlock()
        }
    }
    ch <- 1
}

func main() {

    runtime.GOMAXPROCS(4) //使用多个处理器，不然都是顺序执行。

    m := new(sync.RWMutex)
    count := 0

    ch := make(chan int, 10) //保证输出时count完了

    for i := 0; i < 10; i++ {
        go clickWithMutex(&count, m, ch)
    }

    for i := 0; i < 10; i++ {
        <-ch
    }

    fmt.Printf("count:%d\n", count)
}