在Go語言中，沒有內置的讀寫鎖支持超時功能。但是，你可以使用time.After函數和select語句來實現一個帶有超時的讀寫鎖。下面是一個簡單的示例：

package main

import (
	"fmt"
	"sync"
	"time"
)

type TimeoutReadWriteLock struct {
	mu        sync.RWMutex
	cond      *sync.Cond
	timeout   time.Duration
}

func NewTimeoutReadWriteLock(timeout time.Duration) *TimeoutReadWriteLock {
	return &TimeoutReadWriteLock{
		cond: sync.NewCond(&sync.Mutex{}),
		timeout: timeout,
	}
}

func (l *TimeoutReadWriteLock) ReadLock() {
	l.mu.RLock()
	defer l.mu.RUnlock()

	select {
	case <-time.After(l.timeout):
		return fmt.Errorf("read lock timeout")
	default:
		return nil
	}
}

func (l *TimeoutReadWriteLock) ReadUnlock() {
	l.mu.RUnlock()
}

func (l *TimeoutReadWriteLock) WriteLock() {
	l.mu.Lock()
	defer l.mu.Unlock()

	select {
	case <-time.After(l.timeout):
		return fmt.Errorf("write lock timeout")
	default:
		return nil
	}
}

func (l *TimeoutReadWriteLock) WriteUnlock() {
	l.mu.Unlock()
}

func main() {
	lock := NewTimeoutReadWriteLock(2 * time.Second)

	go func() {
		time.Sleep(1 * time.Second)
		lock.WriteLock()
		fmt.Println("Write lock acquired")
		time.Sleep(3 * time.Second)
		lock.WriteUnlock()
		fmt.Println("Write lock released")
	}()

	go func() {
		time.Sleep(500 * time.Millisecond)
		err := lock.ReadLock()
		if err != nil {
			fmt.Println("Read lock error:", err)
		} else {
			fmt.Println("Read lock acquired")
			time.Sleep(2 * time.Second)
			lock.ReadUnlock()
			fmt.Println("Read lock released")
		}
	}()

	time.Sleep(10 * time.Second)
}

在這個示例中，我們創建了一個TimeoutReadWriteLock結構體，它包含一個讀寫鎖、一個條件變量和一個超時時間。ReadLock和WriteLock方法使用select語句來檢查是否已經超過了超時時間。如果超過了超時時間，它們將返回一個錯誤；否則，它們將繼續執行讀寫鎖操作。