个人物流网站建设方案,网站投稿系统怎么做,大连网络建站模板,手机免费制作logo目录
一、物理内存和虚拟内存使用#xff08;Recorder 类#xff09;
二、 对比 string的“”操作与stringbuilder 操作 的处理效率#xff0c;内存消耗情况#xff0c;
三、异步运行任务、三种启动任务方法、将上一任务方法处理结果作为参数传给下一任务方法
四、嵌套…目录
一、物理内存和虚拟内存使用Recorder 类
二、 对比 string的“”操作与stringbuilder 操作 的处理效率内存消耗情况
三、异步运行任务、三种启动任务方法、将上一任务方法处理结果作为参数传给下一任务方法
四、嵌套子任务
五、同步访问共享资源 Monitor.TryEnter、Monitor.Exit、 原子操作 Interlocked.Increment
六、理解async 和 await :改进控制台响应。 Main方法async Task
七、支持多任务的普通类型 八、异步流 返回类型IEnumerable 一、物理内存和虚拟内存使用Recorder 类
using System;
using System.Diagnostics;
using static System.Console;
using static System.Diagnostics.Process;namespace Packt.Shared
{public static class Recorder{static Stopwatch timer new Stopwatch();static long bytesPhysicalBefore 0;static long bytesVirtualBefore 0;public static void Start(){// force two garbage collections to release memory that is no// longer referenced but has not been released yet// // 强制两次垃圾回收释放不再被引用但尚未释放的内存GC.Collect();GC.WaitForPendingFinalizers();//挂起当前线程直到正在处理终结器队列的线程清空该队列。GC.Collect();//强制立即对所有代进行垃圾回收。//存储当前物理和虚拟内存使用 store the current physical and virtual memory usebytesPhysicalBefore GetCurrentProcess().WorkingSet64;bytesVirtualBefore GetCurrentProcess().VirtualMemorySize64;timer.Restart();}public static void Stop(){timer.Stop();long bytesPhysicalAfter GetCurrentProcess().WorkingSet64;//计时停止时的 物理内存和虚拟内存使用long bytesVirtualAfter GetCurrentProcess().VirtualMemorySize64;WriteLine({0:N0} physical bytes used.,bytesPhysicalAfter - bytesPhysicalBefore);WriteLine({0:N0} virtual bytes used.,bytesVirtualAfter - bytesVirtualBefore);WriteLine({0} time span ellapsed., timer.Elapsed);WriteLine({0:N0} total milliseconds ellapsed.,timer.ElapsedMilliseconds);//获取当前实例测量的总运行时间以毫秒为单位。}}
}
二、 对比 string的“”操作与stringbuilder 操作 的处理效率内存消耗情况
using System;
using System.Linq;
using Packt.Shared;
using static System.Console;namespace MonitoringApp
{class Program{static void Main(string[] args){/*WriteLine(Processing. Please wait...);Recorder.Start();// simulate a process that requires some memory resources...int[] largeArrayOfInts Enumerable.Range(1, 10_000).ToArray();// ...and takes some time to completeSystem.Threading.Thread.Sleep(new Random().Next(5, 10) * 1000);Recorder.Stop();*/int[] numbers Enumerable.Range(1, 50_000).ToArray();//生成指定范围内的整数序列。WriteLine(Using string with );Recorder.Start();string s ;for (int i 0; i numbers.Length; i){s numbers[i] , ;}Recorder.Stop();/*Using string with 35,196,928 physical bytes used.6,291,456 virtual bytes used.00:00:04.0648349 time span ellapsed.4,064 total milliseconds ellapsed.Using StringBuilder0 physical bytes used.0 virtual bytes used.00:00:00.0018665 time span ellapsed.1 total milliseconds ellapsed.*/WriteLine(Using StringBuilder);Recorder.Start();var builder new System.Text.StringBuilder();for (int i 0; i numbers.Length; i){builder.Append(numbers[i]); builder.Append(, );}Recorder.Stop();ReadLine();}}
}
三、异步运行任务、三种启动任务方法、将上一任务方法处理结果作为参数传给下一任务方法
using System;
using System.Threading;
using System.Threading.Tasks;
using System.Diagnostics;
using static System.Console;namespace WorkingWithTasks
{class Program{static void MethodA(){WriteLine(Starting Method A...);Thread.Sleep(3000); // simulate three seconds of work WriteLine(Finished Method A.);}static void MethodB(){WriteLine(Starting Method B...);Thread.Sleep(2000); // simulate two seconds of work WriteLine(Finished Method B.);}static void MethodC(){WriteLine(Starting Method C...);Thread.Sleep(1000); // simulate one second of work WriteLine(Finished Method C.);}static decimal CallWebService(){WriteLine(Starting call to web service...);Thread.Sleep((new Random()).Next(2000, 4000));WriteLine(Finished call to web service.);return 89.99M;}static string CallStoredProcedure(decimal amount){WriteLine(Starting call to stored procedure...);Thread.Sleep((new Random()).Next(2000, 4000));WriteLine(Finished call to stored procedure.);return $12 products cost more than {amount:C}.;}static void Main(string[] args){var timer Stopwatch.StartNew();// WriteLine(Running methods synchronously on one thread.);// MethodA();// MethodB();// MethodC();/* //开启任务的三种方法WriteLine(Running methods asynchronously on multiple threads.);Task taskA new Task(MethodA);taskA.Start();Task taskB Task.Factory.StartNew(MethodB);Task taskC Task.Run(new Action(MethodC));Task[] tasks { taskA, taskB, taskC };Task.WaitAll(tasks);*/WriteLine(Passing the result of one task as an input into another.);//将CallWebService的结果作为输入传给CallStoredProcedure任务var taskCallWebServiceAndThenStoredProcedure Task.Factory.StartNew(CallWebService).ContinueWith(previousTask CallStoredProcedure(previousTask.Result));WriteLine($Result: {taskCallWebServiceAndThenStoredProcedure.Result});WriteLine(${timer.ElapsedMilliseconds:#,##0}ms elapsed.);ReadLine();}}
}
四、嵌套子任务
using System;
using System.Threading;
using System.Threading.Tasks;
using System.Diagnostics;
using static System.Console;namespace NestedAndChildTasks
{class Program{static void OuterMethod(){WriteLine(Outer method starting...);var inner Task.Factory.StartNew(InnerMethod,TaskCreationOptions.AttachedToParent);//开启嵌套任务WriteLine(Outer method finished.);}static void InnerMethod()//嵌套子任务方法{WriteLine(Inner method starting...);Thread.Sleep(2000);WriteLine(Inner method finished.);}static void Main(string[] args){var outer Task.Factory.StartNew(OuterMethod);outer.Wait();//等待嵌套子任务完成后才继续WriteLine(Console app is stopping.);}}
}
五、同步访问共享资源 Monitor.TryEnter、Monitor.Exit、 原子操作 Interlocked.Increment
using System;
using System.Threading;
using System.Threading.Tasks;
using System.Diagnostics;
using static System.Console;namespace SynchronizingResourceAccess
{class Program{static Random r new Random();static string Message; // 一个共享资源static int Counter; //另一共享资源static object conch new object();//互斥锁static void MethodA(){try{ //在指定的时间内尝试获取指定对象的独占锁。if (Monitor.TryEnter(conch, TimeSpan.FromSeconds(15))){for (int i 0; i 5; i){Thread.Sleep(r.Next(2000));Message A;Interlocked.Increment(ref Counter);//递增指定变量并将结果存储为原子操作。Write(.);}}else{WriteLine(Method A failed to enter a monitor lock.);}}finally{Monitor.Exit(conch);//释放指定对象上的独占锁。}}static void MethodB(){try{if (Monitor.TryEnter(conch, TimeSpan.FromSeconds(15))){for (int i 0; i 5; i){Thread.Sleep(r.Next(2000));Message B;Interlocked.Increment(ref Counter);Write(.);}}else{WriteLine(Method B failed to enter a monitor lock.);}}finally{Monitor.Exit(conch);}}/*Please wait for the tasks to complete...........Results: AAAAABBBBB.9,083 elapsed milliseconds.10 string modifications.*/static void Main(string[] args){WriteLine(Please wait for the tasks to complete.);Stopwatch watch Stopwatch.StartNew();Task a Task.Factory.StartNew(MethodA);Task b Task.Factory.StartNew(MethodB);Task.WaitAll(new Task[] { a, b });WriteLine();WriteLine($Results: {Message}.);WriteLine(${watch.ElapsedMilliseconds:#,##0} elapsed milliseconds.);WriteLine(${Counter} string modifications.);ReadLine();}}
} 六、理解async 和 await :改进控制台响应。 Main方法async Task 从C#6开始可以在try\catch块中使用await
using System;
using System.Net.Http;
using System.Threading.Tasks;
using static System.Console;namespace AsyncConsole
{class Program{static async Task Main(string[] args){var client new HttpClient();HttpResponseMessage response await client.GetAsync(http://www.apple.com/);WriteLine(Apples home page has {0:N0} bytes.,response.Content.Headers.ContentLength);}}
}
七、支持多任务的普通类型 八、异步流 返回类型IEnumerable using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using static System.Console;namespace AsyncEnumerable
{class Program{async static IAsyncEnumerableint GetNumbers(){var r new Random();// simulate workawait Task.Run(() Task.Delay(r.Next(1500, 3000)));yield return r.Next(0, 1001);await Task.Run(() Task.Delay(r.Next(1500, 3000)));yield return r.Next(0, 1001);await Task.Run(() Task.Delay(r.Next(1500, 3000)));yield return r.Next(0, 1001);}static async Task Main(string[] args){await foreach (int number in GetNumbers()){WriteLine($Number: {number});}}}
}
