stopwatch

问题 Given that the Stopwatch class in C# can use something like three different timers underneath e.g. System timer e.g. precision of approx +-10 ms depending on timer resolution that can be set with timeBeginPeriod it can be approx +-1 ms . Time Stamp Counter (TSC) e.g. with a tick frequency of 2.5MHz or 1 tick = 400 ns so ideally a precision of that. High Precision Event Timer (HPET) e.g. with a tick frequency of 25MHz or 1 tick = 40 ns so ideally a precision of that. how can we measure the

问题 Coming from my "answer" to question "Stopwatch in a Task seems to be additive across all tasks, want to measure just task interval" What are the possible differences between creating a new Stopwatch instance as: Stopwatch timer = System.Diagnostics.Stopwatch.StartNew(); with Stopwatch timer = new Stopwatch(); timer.Start(); Implied subquestion: Why was StartNew() method provided? 回答1: StartNew , create new instance of the stop watch and starts it as well. Simple new is Stopwatch instantiation

问题 I wanted to create a stopwatch program in ruby so I googled it and found this SO Q. But over there, the author calls the tick function with 1000xxx.times . I wanted to know how I can do it using something like (every second).times or for each increment of second do call the tick function. 回答1: Thread.new do while true do puts Time.now # or call tick function sleep 1 end end 回答2: This function: def every_so_many_seconds(seconds) last_tick = Time.now loop do sleep 0.1 if Time.now - last_tick >=

问题 I am trying to implement a time service that will report time with greater accuracy than 1ms. I thought an easy solution would be to take an initial measurement and use StopWatch to add a delta to it. The problem is that this method seems to diverge extremely fast from wall time. For example, the following code attempts to measure the divergence between Wall Time and my High Resolution Clock: public static void Main(string[] args) { System.Diagnostics.Stopwatch s = new System.Diagnostics

问题 Can I get the elapsed time since I have called Start on a stopwatch using ElapsedMilliseconds without calling Stop ? I have searched a lot round the internet but only saw examples where ElapsedMilliseconds is called after Stop . Is this value filled on a call to Stop or is it always correct? 回答1: You can query the properties Elapsed, ElapsedMilliseconds, and ElapsedTicks while the Stopwatch instance is running or stopped. The elapsed time properties steadily increase while the Stopwatch is

问题 Debug.WriteLine("Timer is high-resolution: {0}", Stopwatch.IsHighResolution); Debug.WriteLine("Timer frequency: {0}", Stopwatch.Frequency); Result: Timer is high-resolution: True Timer frequency: 2597705 This article (from 2005!) mentions a Frequency of 3579545, a million more than mine. This blog post mentions a Frequency of 3,325,040,000, which is insane. Why is my Frequency so much comparatively lower? I'm on an i7 920 machine, so shouldn't it be faster? 回答1: 3,579,545 is the magic number.

问题 I have datagridview whose datasource is datatable. I have two columns in datagridview: NAME, IN TIME After the datagridview is loaded, I want to add a new column called DURATION which is a timer column i.e. based on the IN TIME, DURATION column should display a stopwatch with the timespan interval of CURRENT TIME-IN TIME. How do I make the DURATION column stopwatch to continue the timer for every seconds like digital clock? 回答1: You can add a string column to DataTable and use it as duration

问题 I find that the System.Diagnostics.Stopwatch class has what seems to be measurable inaccuracy, even over a short time period (i.e. 20 seconds). My process is showing an elapsed time of 20.3+ seconds for a process coded to run 20 seconds: $elapsed = [System.Diagnostics.Stopwatch]::StartNew() write-host "Started at $(get-date)" for ($t=1; $t -le 20; $t++) { Write-Host "Elapsed Time: $($elapsed.Elapsed.ToString())" sleep 1 } write-host "Ended at $(get-date)" write-host "Total Elapsed Time: $(

问题 I'm doing a project that involves comparing programming languages. I'm computing the Ackermann function. I tested Java, Python, and Ruby, and got responses between 10 and 30 milliseconds. But C++ seems to take 125 milliseconds. Is this normal, or is it a problem with the gettimeofday() ? Gettimeofday() is in time.h. I'm testing on a (virtual) Ubuntu Natty Narwhal 32-bit. I'm not short processing power (Quad-core 2.13 GHz Intel Xeon). My code is here: #include <iostream> #include <sys/time.h>

问题 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