异步任务比同步任务快多少_异步通知和同步通知的时间差-优快云博客

本文通过代码示例对比了异步任务与同步任务在执行效率上的差异，发现异步任务在特定场景下能显著提升性能，尤其是在使用`Task.WaitAll`时。测试结果显示，第一个异步示例的性能大约是其他同步示例的六到七倍。同时，文章也提到了并行处理对于性能的提升，但并行与异步的比较并不直接相关。总结了不同方法的时间消耗，为理解和优化代码执行速度提供了参考。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

using System.Diagnostics;namespace TestStatue{    internal class Program    {        static async Task Main(string[] args)        {            DateTime now = DateTime.Now;            var t1 = new List<Task<HttpResponseMessage>>();            for (int i = 0; i < 100; i++)            {                var resultResponse = new HttpClient().SendAsync(new HttpRequestMessage { RequestUri = new Uri("https://www.baidu.com") });                t1.Add(resultResponse);                // var result = await resultResponse.Content.ReadAsStreamAsync();            }            var t2 = new List<Task<Stream>>();            t1.ForEach(async x =>            {                var res = await x;                t2.Add(res.Content.ReadAsStreamAsync());            });            Task.WaitAll(t2.ToArray());            Console.WriteLine($"运行时间：{DateTime.Now.Subtract(now).TotalMilliseconds}");        }    }}//using System.Diagnostics;//namespace TestStatue//{//    internal class Program//    {//        static async Task Main(string[] args)//        {//            Stopwatch stopwatch = new Stopwatch();//          四川党性培训 www.sdganxun.cn    stopwatch.Start();//            var t2 = new List<Task<Stream>>();//            for (int i = 0; i < 100; i++)//            {//                var resultResponse = await new HttpClient().SendAsync(new HttpRequestMessage { RequestUri = new Uri("https://www.baidu.com") });//                var result = resultResponse.Content.ReadAsStreamAsync();//                t2.Add(result);//            }//            Task.WaitAll(t2.ToArray());//            //Console.WriteLine(result);//            stopwatch.Stop();//            Console.WriteLine($"运行时间：{stopwatch.ElapsedMilliseconds}");//        }//    }//}//using System.Diagnostics;//namespace TestStatue//{//    internal class Program//    {//        static async Task Main(string[] args)//        {//            Stopwatch stopwatch = new Stopwatch();//            stopwatch.Start();//            for (int i = 0; i < 100; i++)//            {//                var resultResponse = await new HttpClient().SendAsync(new HttpRequestMessage { RequestUri = new Uri("https://www.baidu.com") });//                var result = await resultResponse.Content.ReadAsStreamAsync();//            }//            //Console.WriteLine(result);//            stopwatch.Stop();//            Console.WriteLine($"运行时间：{stopwatch.ElapsedMilliseconds}");//        }//    }//}//using System.Diagnostics;//namespace TestStatue//{//    internal class Program//    {//        static void Main(string[] args)//        {//            Stopwatch stopwatch = new Stopwatch();//            stopwatch.Start();//            Parallel.For(0, 10, (i) =>//             {//                 var resultResponse = new HttpClient().Send(new HttpRequestMessage { RequestUri = new Uri("https://www.baidu.com") });//                 var result = resultResponse.Content.ReadAsStream();//             });//            //Console.WriteLine(result);//            stopwatch.Stop();//            Console.WriteLine($"运行时间：{stopwatch.ElapsedMilliseconds}");//        }//    }//}//using System.Diagnostics;//namespace TestStatue//{//    internal class Program//    {//        static void Main(string[] args)//        {//            Stopwatch stopwatch = new Stopwatch();//            stopwatch.Start();//            for (int i = 0; i < 100; i++)//            {//                var resultResponse = new HttpClient().Send(new HttpRequestMessage { RequestUri = new Uri("https://www.baidu.com") });//                var result = resultResponse.Content.ReadAsStream();//            }//            //Console.WriteLine(result);//            stopwatch.Stop();//            Console.WriteLine($"运行时间：{stopwatch.ElapsedMilliseconds}");//        }//    }//}