Difference between revisions of "EpikTimer"
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===Download=== | ===Download=== | ||
The latest stable release can be found on the [http://sourceforge.net/project/showfiles.php?group_id=92177 Lazarus CCR Files page]. | The latest stable release can be found on the [http://sourceforge.net/project/showfiles.php?group_id=92177 Lazarus CCR Files page]. | ||
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+ | Status: Production/Stable | ||
===Change Log=== | ===Change Log=== | ||
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* Nanosecond resolution is supported on Intel Pentium versions with a Timestamp Counter. | * Nanosecond resolution is supported on Intel Pentium versions with a Timestamp Counter. | ||
* Microsecond system clock is the default timebase. | * Microsecond system clock is the default timebase. | ||
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Tested on: | Tested on: |
Revision as of 10:54, 10 December 2005
About
EpikTimer is a programmer's stopwatch that is capable of measuring very short events with traceably high precision over long periods of time. It's simple to use, consumes virtually no CPU and requires only 25 bytes of ram to implement a timer instance. The component provides a single internal timer... but unlimited numbers can be declared externally and linked to a single EpikTimer component on the form.
The download contains the component, an installation package and a demo application, that illustrates the features of the component along with some instrumentation for evaluating the clock sources on a given system.
This component was designed for cross-platform applications and was written specifically for the Lazarus IDE and Free Pascal Compiler and includes a demo application.
Author
Contributors
License
LGPL (please contact the author if the LGPL doesn't work with your project licensing)
Download
The latest stable release can be found on the Lazarus CCR Files page.
Status: Production/Stable
Change Log
- Initially written on 24-06-2003 TL
- Pre-release 30-06-2003 TL - Needs testing on the BSD's and Win32
- Version 0.1 1-7-2003 TL
- initial beta release
- Version 0.2 3-7-2003 TL
- Revised logic around hardware detection to prevent executing extended instructions if the HasCapabilityData call returns false.
- Removed exposed low level diagnositic functions from unit interface.
- Revised demo.
- Version 0.3 15-11-2005
- Updated 0.2 version to make it compile on the latest Lazarus (0.9.10).
- Added LCL to the required packages.
- Changed mode to Delphi in order to compile.
- Changed windows timebase to use QueryPerformanceCounter, because has a much greater precision then GetSystemTime.
- Added changes to ensure the component compiles on Delphi 7.0
- Made tests on Windows and Linux
- Small changes to the demo to make it compile
Getting the latest source from CVS
cvs -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/lazarus login cvs -z3 -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/lazarus co epiktimer
Dependencies / System Requirements
- Nanosecond resolution is supported on Intel Pentium versions with a Timestamp Counter.
- Microsecond system clock is the default timebase.
Tested on:
- Pentium IV 3,2Mhz on Windows and Linux with great precision (~ 3,220,000,000 ticks per second)
- Pentium 233Mhz with Damn Small Linux. Works great with hardware clock.
Issues: Needs testing on FreeBSD and older machines that lack TSC hardware.
Installation
- In Components/Open Package File, open etpackage.lpk.
- Compile the component to verify that everything is there.
- Install and let Lazarus rebuild
- Component will be in the System Palette (stopwatch-ruler icon)
Usage
Drop the component on a form. The component contains a single timer instance and parameterless calls to start, stop, elapsed and clear will implicitly reference it.
If the timer is named ET
Procedure InstrumentedCall; Begin ET.Clear; // optional... timer is cleared at creation ET.Start; ExecuteFirstTimedSection; ET.Stop; // the timer is actually paused and can be restarted later TimedSection1:=ET.Elapsed; // store the elapsed in a global MakeAnUntimedOverheadCall; // not counted in the timer ET.Start; //resume the timer... continue accumulating ticks CallTimedSection2; TimedSection2:=ET.Elapsed; //timer keeps running... we've just sample it. CallTimedSection3; CallSomethingElse; TimedSection3:=ET.Elapsed; //keep counting... tap the elapsed CallTimedSection4; TimedSection4:=ET.Elapsed; //keep counting... tap the elapsed ET.clear // done... timer is stopped and zeroed end;
You can also create any number of timers from a single component on the form by declaring a TimerData record and passing it as a parameter to start, stop, elapsed and clear using the overloaded methods in the component. An example would be:
Function TimedExecution:Extended; Var DiskAccessTime:TimerData; Begin ET.Clear(DiskAccessTimer); // Declared timers *must* be cleared before use. ET.Start(DiskAccessTimer); ExecuteTheTimedSection; Result:=ET.Elapsed(DiskAccessTimer); // the timer keeps running... etc...
One particular use for EpikTimer is checking is a given amount of time has elapsed before continuing with a task or to another iteration of the same task.
DelayInSeconds := 8; // or any value OldTime := ET.Elapse; while ((1000000.0 * (ET.Elapsed - OldTime) < DelayInSeconds)) do begin ET.SystemSleep(0); end; // DelayInSeconds has elapsed and now you can continue executing the code
See etdemo.pas for additional examples of component usage
The ETDemo Application
The ETDemo application does not require EpikTimer to be installed in order to compile and operate. I never liked having to install a palette full of components only to find out that I didn't like any of them! :)
Installation
- Open etdemo.lpi
- compile
- run
Orginal contributors
This page has been converted from epikwiki. Original content by Tom Lisjac.