package main

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

// 条件变量的基本示例
func basicCondExample() {
	var mu sync.Mutex
	cond := sync.NewCond(&mu)

	var ready bool

	// Goroutine 1: 等待条件成立
	go func() {
		fmt.Println("Goroutine 1: 等待条件")

		mu.Lock()
		for !ready { // 使用for循环而不是if
			fmt.Println("Goroutine 1: 条件不满足，进入等待")
			cond.Wait() // 释放锁并阻塞
			fmt.Println("Goroutine 1: 被唤醒")
		}
		mu.Unlock()

		fmt.Println("Goroutine 1: 条件满足，继续执行")
	}()

	// Goroutine 2: 设置条件
	go func() {
		time.Sleep(2 * time.Second)

		mu.Lock()
		ready = true
		fmt.Println("Goroutine 2: 设置条件为true")
		mu.Unlock()

		cond.Signal() // 唤醒一个等待的goroutine
		fmt.Println("Goroutine 2: 发送信号")
	}()

	time.Sleep(3 * time.Second)
}

func main() {
	fmt.Println("=== 条件变量基本示例 ===")
	basicCondExample()
}