performance - Multicore and thread aware.Net stopwatch.

Posted by 2018  •  article

The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object .)

To view the .NET Framework source code for this type, see the Reference Source . You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see instructions .

I need an accurate timer, and DateTime.Now seems not accurate enough. From the descriptions I read, System.Diagnostics.Stopwatch seems to be exactly what I want.

But I have a phobia. I'm nervous about using anything from System.Diagnostics in actual production code. (I use it extensively for debugging with Asserts and PrintLns etc, but never yet for production stuff.) I'm not merely trying to use a timer to benchmark my functions - my app needs an actual timer. I've read on another forum that System.Diagnostics.StopWatch is only for benchmarking, and shouldn't be used in retail code, though there was no reason given. Is this correct, or am I (and whoever posted that advice) being too closed minded about System.Diagnostics? ie, is it ok to use System.Diagnostics.Stopwatch in production code? Thanks Adrian

Under the hood, pretty much all Stopwatch does is wrap QueryPerformanceCounter . As I understand it, Stopwatch is there to provide access to the high-resolution timer - if you need this resolution in production code I don't see anything wrong with using it.

The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object .)

To view the .NET Framework source code for this type, see the Reference Source . You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see instructions .

I need an accurate timer, and DateTime.Now seems not accurate enough. From the descriptions I read, System.Diagnostics.Stopwatch seems to be exactly what I want.

But I have a phobia. I'm nervous about using anything from System.Diagnostics in actual production code. (I use it extensively for debugging with Asserts and PrintLns etc, but never yet for production stuff.) I'm not merely trying to use a timer to benchmark my functions - my app needs an actual timer. I've read on another forum that System.Diagnostics.StopWatch is only for benchmarking, and shouldn't be used in retail code, though there was no reason given. Is this correct, or am I (and whoever posted that advice) being too closed minded about System.Diagnostics? ie, is it ok to use System.Diagnostics.Stopwatch in production code? Thanks Adrian

Under the hood, pretty much all Stopwatch does is wrap QueryPerformanceCounter . As I understand it, Stopwatch is there to provide access to the high-resolution timer - if you need this resolution in production code I don't see anything wrong with using it.


Disclamer: This site is in no way affiliated with Microsoft. Our content is created solely from promotional material and own creations. Supported by Triagis Wordpress Security and Webmaster.Net

A System.Diagnostics.Stopwatch instance can measure elapsed time for one interval, or the total of elapsed time across multiple intervals. In a typical System.Diagnostics.Stopwatch scenario, you call the Stopwatch.Start method, then eventually call the Stopwatch.Stop method, and then you check elapsed time using the Stopwatch.Elapsed property.

A System.Diagnostics.Stopwatch instance is either running or stopped; use Stopwatch.IsRunning to determine the current state of a System.Diagnostics.Stopwatch . Use Stopwatch.Start to begin measuring elapsed time; use Stopwatch.Stop to stop measuring elapsed time. Query the elapsed time value through the properties Stopwatch.Elapsed , Stopwatch.ElapsedMilliseconds , or Stopwatch.ElapsedTicks . You can query the elapsed time properties while the instance is running or stopped. The elapsed time properties steadily increase while the System.Diagnostics.Stopwatch is running; they remain constant when the instance is stopped.

By default, the elapsed time value of a System.Diagnostics.Stopwatch instance equals the total of all measured time intervals. Each call to Stopwatch.Start begins counting at the cumulative elapsed time; each call to Stopwatch.Stop ends the current interval measurement and freezes the cumulative elapsed time value. Use the Stopwatch.Reset method to clear the cumulative elapsed time in an existing System.Diagnostics.Stopwatch instance.

The Time Stamp Counter ( TSC ) is a 64-bit register present on all x86 processors since the Pentium . It counts the number of cycles since reset. The instruction RDTSC returns the TSC in EDX:EAX. In x86-64 mode, RDTSC also clears the higher 32 bits of RAX and RDX . Its opcode is 0F 31 . [1] Pentium competitors such as the Cyrix 6x86 did not always have a TSC and may consider RDTSC an illegal instruction. Cyrix included a Time Stamp Counter in their MII .

Relying on the TSC also reduces portability, as other processors may not have a similar feature. Recent Intel processors include a constant rate TSC (identified by the kern.timecounter.invariant_tsc sysctl on FreeBSD or by the " constant_tsc " flag in Linux's /proc/cpuinfo ). With these processors, the TSC ticks at the processor's nominal frequency, regardless of the actual CPU clock frequency due to turbo or power saving states. Hence TSC ticks are counting the passage of time, not the number of CPU clock cycles elapsed.

On Windows platforms, Microsoft strongly discourages using the TSC for high-resolution timing for exactly these reasons, providing instead the Windows APIs QueryPerformanceCounter and QueryPerformanceFrequency . [2] On POSIX systems, a program can get similar function by reading the value of CLOCK_MONOTONIC clock using the clock_gettime function. [3]

The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object .)

To view the .NET Framework source code for this type, see the Reference Source . You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see instructions .

I need an accurate timer, and DateTime.Now seems not accurate enough. From the descriptions I read, System.Diagnostics.Stopwatch seems to be exactly what I want.

But I have a phobia. I'm nervous about using anything from System.Diagnostics in actual production code. (I use it extensively for debugging with Asserts and PrintLns etc, but never yet for production stuff.) I'm not merely trying to use a timer to benchmark my functions - my app needs an actual timer. I've read on another forum that System.Diagnostics.StopWatch is only for benchmarking, and shouldn't be used in retail code, though there was no reason given. Is this correct, or am I (and whoever posted that advice) being too closed minded about System.Diagnostics? ie, is it ok to use System.Diagnostics.Stopwatch in production code? Thanks Adrian

Under the hood, pretty much all Stopwatch does is wrap QueryPerformanceCounter . As I understand it, Stopwatch is there to provide access to the high-resolution timer - if you need this resolution in production code I don't see anything wrong with using it.


Disclamer: This site is in no way affiliated with Microsoft. Our content is created solely from promotional material and own creations. Supported by Triagis Wordpress Security and Webmaster.Net

A System.Diagnostics.Stopwatch instance can measure elapsed time for one interval, or the total of elapsed time across multiple intervals. In a typical System.Diagnostics.Stopwatch scenario, you call the Stopwatch.Start method, then eventually call the Stopwatch.Stop method, and then you check elapsed time using the Stopwatch.Elapsed property.

A System.Diagnostics.Stopwatch instance is either running or stopped; use Stopwatch.IsRunning to determine the current state of a System.Diagnostics.Stopwatch . Use Stopwatch.Start to begin measuring elapsed time; use Stopwatch.Stop to stop measuring elapsed time. Query the elapsed time value through the properties Stopwatch.Elapsed , Stopwatch.ElapsedMilliseconds , or Stopwatch.ElapsedTicks . You can query the elapsed time properties while the instance is running or stopped. The elapsed time properties steadily increase while the System.Diagnostics.Stopwatch is running; they remain constant when the instance is stopped.

By default, the elapsed time value of a System.Diagnostics.Stopwatch instance equals the total of all measured time intervals. Each call to Stopwatch.Start begins counting at the cumulative elapsed time; each call to Stopwatch.Stop ends the current interval measurement and freezes the cumulative elapsed time value. Use the Stopwatch.Reset method to clear the cumulative elapsed time in an existing System.Diagnostics.Stopwatch instance.

The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object .)

To view the .NET Framework source code for this type, see the Reference Source . You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see instructions .

I need an accurate timer, and DateTime.Now seems not accurate enough. From the descriptions I read, System.Diagnostics.Stopwatch seems to be exactly what I want.

But I have a phobia. I'm nervous about using anything from System.Diagnostics in actual production code. (I use it extensively for debugging with Asserts and PrintLns etc, but never yet for production stuff.) I'm not merely trying to use a timer to benchmark my functions - my app needs an actual timer. I've read on another forum that System.Diagnostics.StopWatch is only for benchmarking, and shouldn't be used in retail code, though there was no reason given. Is this correct, or am I (and whoever posted that advice) being too closed minded about System.Diagnostics? ie, is it ok to use System.Diagnostics.Stopwatch in production code? Thanks Adrian

Under the hood, pretty much all Stopwatch does is wrap QueryPerformanceCounter . As I understand it, Stopwatch is there to provide access to the high-resolution timer - if you need this resolution in production code I don't see anything wrong with using it.


Disclamer: This site is in no way affiliated with Microsoft. Our content is created solely from promotional material and own creations. Supported by Triagis Wordpress Security and Webmaster.Net

The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object .)

To view the .NET Framework source code for this type, see the Reference Source . You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see instructions .


need help w/ multi-threaded, multi-CPU tick count.

Posted by 2018  •  article

 
 

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