> ### 讀寫鎖 ```go package main import ( "time" "sync" "fmt" ) var number int //同時操作時只能一個G寫或多個G讀) var rwm sync.RWMutex func main() { go func() { for i := 0; i < 3; i++ { rwm.Lock() number++ fmt.Println("G1", number) time.Sleep(time.Second) rwm.Unlock() } }() go func() { for i := 0; i < 3; i++ { rwm.RLock() fmt.Println("G2", number) time.Sleep(time.Second) rwm.RUnlock() } }() go func() { for i := 0; i < 3; i++ { rwm.RLock() fmt.Println("G3", number) time.Sleep(time.Second) rwm.RUnlock() } }() time.Sleep(time.Second * 10) } ``` > ### 相關閱讀 * [鎖及鎖粒度的詳細比喻](https://www.cnblogs.com/nancymake/p/6252536.html)