stopwatch

I'm running in a loop and kicking off tasks in the following manner: var iResult = new List<Task>(); foreach(var i in myCollection) { var task = Task.Factory.StartNew(() => DoSomething(), TaskCreationOptions.LongRunning); task.ContinueWith(m => myResponseHandler(m.Result)); iResult.Add(task); } Within my DoSomething() method, I have a timer: public static myMsg DoSomething() { var timer = System.Diagnostics.Stopwatch.StartNew(); DoLongRunningTask(); //If it matters this hits a REST endpoint (https) timer.Stop(); return new myMsg(timer.ElaspedMilliseconds); } When I iterate through my list of

As we all know the stopwatch might have issues in a multi-threaded async application that will be running on all cores. On a multiprocessor computer, it does not matter which processor the thread runs on. However, because of bugs in the BIOS or the Hardware Abstraction Layer (HAL), you can get different timing results on different processors. To specify processor affinity for a thread, use the ProcessThread.ProcessorAffinity method. Are there any way for me to get some reliable tick/timestamp like values that has high resolution/accuracy as well is consistent across cpu cores? If not possible

For example foo() //Some operation bound by an external resource. db,I/O, whatever. vs. var watch = new Stopwatch(); watch.Start(); foo() var time = watch.ElapsedMilliseconds watch.Stop(); I believe Stopwatch is built on top of QueryPerformanceCounter, so each call results in a kernel transition. If foo() is very brief, the QPC overhead will dwarf it. If you're using Stopwatch to measure short tasks, you should run foo() many times (like thousands), and use Stopwatch around the whole batch. Divide the total time by the number of runs to get average time for the task. This sounds like a

概述 Spring Boot框架带来一个Web应用启动的重大变化。 Java的Web应用部署都是通过容器，如：Tomcat、JBoss、Weblogic、Undertow等，一般都是将Java的Web应用构建成war、ear包再部署到相关的容器中。 Spring Boot带来了另外一种方式，就是可以将Web应用构建Jar包直接通过java命令启动，简化了应用的部署启动。这种启动方式底层技术并没有实际的变化，而是通过内嵌容器的方式取代外部容器，比如：spring-boot-starter-web默认使用Tomcat内嵌容器，你也可以选择使用其他内嵌容器。 在这篇文章里面主要是之前阅读了一些Spring Boot的启动源码，对Spring Boot启动流程作了一些简单的梳理。 Spring Boot应用启动方式 上文说到，Spring Boot的Web应用可以构建Jar包直接启动，即Spring Boot应用可以通过main方法直接启动，应用启动入口代码如下： /** * @author: cent * @email: 292462859@qq.com * @date: 2019/2/9. * @description: */ @SpringBootApplication public class Application { public static void main(String

上篇《 Spring Boot 2.x 启动全过程源码分析（一）入口类剖析 》我们分析了 Spring Boot 入口类 SpringApplication 的源码，并知道了其构造原理，这篇我们继续往下面分析其核心 run 方法。 [toc] SpringApplication 实例 run 方法运行过程 上面分析了 SpringApplication 实例对象构造方法初始化过程，下面继续来看下这个 SpringApplication 对象的 run 方法的源码和运行流程。 public ConfigurableApplicationContext run(String... args) { // 1、创建并启动计时监控类 StopWatch stopWatch = new StopWatch(); stopWatch.start(); // 2、初始化应用上下文和异常报告集合 ConfigurableApplicationContext context = null; Collection<SpringBootExceptionReporter> exceptionReporters = new ArrayList<>(); // 3、设置系统属性 `java.awt.headless` 的值，默认值为：true configureHeadlessProperty(); // 4

I have an app using an NSTimer at centisecond (0.01 second) update intervals to display a running stopwatch in String Format as 00:00.00 (mm:ss.SS). (Basically cloning the iOS built-in stopwatch to integrate into realtime sports timing math problems, possibly needing millisecond accuracy in the future) I use (misuse?) the NSTimer to force-update the UILabel. If the user presses Start, this is the NSTimer code used to start repeating the function: displayOnlyTimer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: Selector("display"), userInfo: nil, repeats: true) And here

I used to think that Stopwatch.ElapsedTicks was equal to Stopwatch.Elapsed.Ticks . But it isn't. While the latter is a number of 100 nanoseconds periods, the former use a mysterious unit called timer ticks . I wonder what those are, and why are they different from the usual unit of measurement? From the docs : The Stopwatch measures elapsed time by counting timer ticks in the underlying timer mechanism. If the installed hardware and operating system support a high-resolution performance counter, then the Stopwatch class uses that counter to measure elapsed time. Otherwise, the Stopwatch class