Changed windows timebase to use queryperformancecounter, because has. Solarwinds recently acquired vividcortex, a top saasdelivered solution for cloud andor onpremises environments, supporting postgresql, mongodb, amazon aurora, redis, and mysql. Nov 28, 2014 handmade hero why start from scratch vs using an engine. It is a system independent c function declared in time. The current logic, that seems proven stable, is using a faultspertoleranceinterval algorithm, introduced in bug 836869 make queryperformancecounter. A more accurate means of timing code is to use the high resolution timers provided by windows queryperformancecounter and queryperformancefrequency. It doesnt show you the real time of your code execution, because of the thread switching. Fink mac os x, all 32bit ms windows 9598nt2000xp vista7, macosx, posix linux,bsd,solaris etc, bsd, freebsd, netbsd. Simple example of queryperformancecounter usage github. Muss noch unter freebsd sowie alteren rechnern ohne tschardware getestet werden.
Handmade hero why start from scratch vs using an engine. Lazarus lcl, however, still does not provide easy means for highdpi scenarios or custom control sizing. Queryperformancecounter it tells that you can get different results if it executes on different processors. Queryperformancecounter uses the pcs clock counter just as gettickcount, but it reads the current value of the countdown register in the timer chip to gain more accuracy down to 1. As you know, using queryperformancecounter you measure how much time passed at all. Sep 18, 2016 free pascal lazarus project synced with lazarus subversion trunk every 15 minutes alrieckertlazarus. Apr 18, 2018 a program that uses the queryperformancecounter function to query system time may perform poorly. Unlike windows, queryperformancecounter is also supported on cpus which do not have a clock counter register.
That algorithm is now obsolete and we have a better one. When you use the ping command to send internet control message protocol icmp packets to a remote computer, the reply may show negative response times. Dllcall queryperformancecounter, int64, counterbefore sleep dllcall queryperformancecounter, int64, counteraf. Eventually, it becomes more regular, and ultimately establishes a reliable 10minute period. One way to overcome this is to specify a specific processor by setting a thread affinity so this always executes on the same processor. Handmade hero day 010 queryperformancecounter and rdtsc. The queryperformancecounter is the most precise time stamp counter on windows systems its useful e. Lazarus linux i386 deb 32 bits lazarus linux amd64 deb 64 bits. A program that uses the queryperformancecounter function to query system time may perform poorly.
Apparently virtualbox uses standard hpet frequency of 3. Example for queryperformancecounter to get current time in. And if queryperformancefrequency function return zero, means your machine not support high resolution performance counter. Running time calculation using queryperformancecounter. Then you can call queryperformancecounter as many times as you wish. Microsoft recommend that we use queryperformancecounter for highperformance, highaccuracy timers on windows. The lazarus ide is a stable and feature rich visual programming environment for the freepascal compiler. Queryperformancecounter intel trace analyzer and collector. If youre on modern hardware, this generally works well except current bugs on some athlon x2 systems. Get full visibility with a solution crossplatform teams including development, devops, and dbas can use.
The highperformance timer is a counter that the system increments many times a second. Amd 64 cpu, running 64 bit version of ubuntu linux, lazarus 9. For example, you retrieve the value of the counter at the beginning and the end of a piece of code you want to time, and if you subtract the former from the latter value you get the number of ticks elapsed in the meantime. So wanted to know if there are better ways to implement queryperformancecounter for linux. Free pascal lazarus project synced with lazarus subversion trunk every 15 minutes alrieckertlazarus. For example, the following ping command may generate the following replies. Queryperformancecounter vs gettickcount toradex community. It also comes with a full custom drawn drawer, games and more. Oct 07, 2000 then you can call queryperformancecounter as many times as you wish. Simply go to the github epiktimer url and click the download zip button on. To find out how quickly the timer is incremented, use queryperformancefrequency. Dllcallqueryperformancecounter, int64, counterbefore sleep dllcallqueryperformancecounter, int64, counteraf.
Hi, actually you have to call queryperformancefrequency first. Now, i am getting an uptime of 1 hour 20minutes and change, even though system has been up for over three days both systeminfo and net statistics workstation correctly identify that system. Queryperformancecounter obtains the current reading of the systems highperformance timer. The time stamp counter is a 64bit counter that was added to most x86 cpus starting around the pentium era, and which counts up at the clock rate of the cpu. Queryperformancecounter example suggestions autohotkey. In one of my older posts im describing how the mozilla platform decides on whether this high precision timer function is behaving properly or not. Queryperformancecounter calls ftreadtime which relies on the high resolution timer driver. The often used windows api method gettickcount retrieves the number of milliseconds that have elapsed since the system was started, but the gettickcount function only archieve resolutions of 1ms and on the other side they are very imprecise. Stopped then throw new applicationexceptioncant start, already started end if state timestate. Queryperformancecounter starttime end sub public function stop as double queryperformancecounter endtime if state timestate. It includes custom buttons, labels, panels, progress bars, and others.
Bgra controls is a set open source ui components for lazarus ide. For mips, the resolution is about twice the clock speed of the processor. Queryperformancecounter retrieves the current value of the highresolution performance counter. Queryperformancecounter calibration with gettickcount. What is free pascals equivalent of delphis tstopwatch.
If you know its frequency, you can use the highperformance timer to measure small. Beware of queryperformancecounter when it comes to highprecision timing on windows, many have gotten used to using the cpus time stamp counter tsc. Queryperformancecounterstarttime end sub public function stop as double queryperformancecounterendtime if state timestate. So i implemented my queryperformancecounter and it seems very ugly. The value of queryperformancefrequency never changes, while a system is running. Virtualbox sometimes doesnt increment the upper 32 bits when the lower 32 bits overflow, which makes queryperformancecounter jump back by 20 minutes. It needs jujibo component to provide coloured buttons, thats just a download but other than that it was written using laz 1. Problem with queryperformancecounter solutions experts. Highprecision timing with the queryperformancecounter api. Virtualbox sometimes doesnt increment the upper 32 bits when the lower 32 bits overflow, which makes. In some applications exact time measurement methods are very important. Pointer to a variable that receives the current performancecounter value, in counts.
Pentium iv 3,2ghz on windows and linux with great precision 3,220,000,000 ticks per second pentium 233mhz with damn small linux. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Queryperformancecounter returns the resolution of a high resolution performance counter if the hardware supports one. It supports the creation of selfstanding graphical and console applications and runs on linux, freebsd, macosx and windows. The function queryperformancefrequencyvar lpfrequency int64 returns 0 if the system does not support a high resolution timer.
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