package main

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

func main() {
	runtime.GOMAXPROCS(1)
	var wg sync.WaitGroup
	startTime := time.Now()

	// 4个CPU密集型任务（不释放P）
	for i := 0; i < 4; i++ {
		wg.Add(1)
		go func(id int) {
			defer wg.Done()
			taskStart := time.Now()
			// 模拟1秒CPU密集型计算（不释放P）
			end := time.Now().Add(1 * time.Second)
			for time.Now().Before(end) {
				// 空循环，持续占用CPU
			}
			taskDuration := time.Since(taskStart)
			fmt.Printf("任务%d：自身耗时：%v，完成时间：%v\n",
				id, taskDuration, time.Since(startTime))
		}(i)
	}

	wg.Wait()
	fmt.Printf("总耗时：%v\n", time.Since(startTime))
}