EpikTimer
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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
- Felipe Monteiro de Carvalho
- Marcel Minderhoud
License
LGPL (please contact the author if the LGPL doesn't work with your project licensing)
Subversion
svn co https://lazarus-ccr.svn.sourceforge.net/svnroot/lazarus-ccr/components/epiktimer epiktimer
Download
The latest stable release can be found on the Lazarus CCR Files page or here.
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
- Version 1.0 06-10-2006
- Changes for 64 bits operation
- Added units BaseUnix, Unix and UnixUtil, removed oldlinux (obsolete)
- Gettimeofday -> fpGettimeofday
- Changed systemsleep for 64 bits systems
- Some changes in timeval
- Tested on AMD64 (linux)
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 3,2Ghz 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.
- Mobile AMD 64 Athlon 3200+ on Windows XP Home (32 bit), Lazarus 9.13
- AMD 64 CPU, running 64 bit version of Ubuntu Linux, Lazarus 9.18.
- Intel i7-3770K, running 64-bit version of FreeBSD 9.1, using FPC 2.6.2
- ARM CPU using Raspberry Pi and FPC 2.6.2
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
uses epiktimer;
var
ET: TEpikTimer;
procedure InitTimer;
begin
ET := TEpikTimer.Create(Application);
end;
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 if a given amount of time has elapsed before continuing with a task or to another iteration of the same task.
DelayInSeconds := 8.5; // or any value
OldTime := ET.Elapse;
while ((ET.Elapsed - OldTime) < DelayInSeconds) do
begin
ET.SystemSleep(10);
end;
// DelayInSeconds has elapsed and now you can continue executing the code
See etdemo.pas for additional examples of component usage
EpikTimer as a profiler
EpikTimer can be used to profile the speed of procedures:
uses
{$ifdef PROFILING}epiktimer,{$endif}
...
type
TMyClass = class
private
{$ifdef PROFILING}
profiler: Tepiktimer;
{$endif}
...
end;
implementation
constructor TMyClass.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
...
{$ifdef CARDROOM_PROFILING}
profiler := TEpikTimer.Create(Self)
{$endif}
end;
procedure TMyClass.MethodToBeProfiled;
begin
{$ifdef PROFILING}
profiler.Clear;
profiler.Start;
{$endif}
// do stuff
{$ifdef PROFILING}
OPDebugLn('TMyClass.MethodToBeProfiled ' + FloatToStr(profiler.Elapsed));
{$endif}
end;
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
See also
- to do: insert Links to FPC time/timer functions
- Yet another Running Timer