var(
   //併發任務同步
   _syncGp sync.WaitGroup
   //載入一次
   _syncOnce sync.Once
   //sync.Map
   _syncMap sync.Map
   //互斥鎖
    _lock sync.Mutex
   //讀寫互斥鎖
   _rdLock sync.RWMutex
)

func main(){
   var x int
   _syncGp.Add(1)
   //互斥鎖
   go func() {
      for j:=0;j<100;j++ {
         _lock.Lock()
         x =  x + 1
         _lock.Unlock()
      }
      _syncGp.Done()
   }()

   _syncGp.Add(3)
   var y int64
   //讀寫互斥
   go func() {
      for i :=0 ;i<100;i++ {
         _rdLock.Lock()
         y = y + 1
         _rdLock.Unlock()
      }
      _syncGp.Done()
   }()
    //讀鎖
   go func() {
      _rdLock.RLock()
      fmt.Println("讀取y=",y)
      _rdLock.RUnlock()
      _syncGp.Done()
   }()

   //原子鎖
   go func() {
      atomic.AddInt64(&y,1)
      _syncGp.Done()
   }()

   //執行一次
   _syncOnce.Do(func() {
      fmt.Println("載入一次")
   })

   _syncGp.Add(1)
   //sync.Map
   go func() {
      for i:=0;i<5;i++{
         _syncGp.Add(1)
         go func(j int) {
            key := strconv.Itoa(j)
            _syncMap.Store(key,j)
            data,_ := _syncMap.Load(key)
            fmt.Printf("k=:%v,v:=%v\n", key, data)
            _syncGp.Done()
         }(i)
      }
      _syncGp.Done()
   }()

   _syncGp.Wait()
   fmt.Println("x=",x)
    fmt.Println("yy=",y)
}