Difference between revisions of "QueryPerformanceCounter"
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+ | {{QueryPerformanceCounter}} | ||
+ | |||
Maybe the one microsecond timestamp is too long for your program. | Maybe the one microsecond timestamp is too long for your program. | ||
You can access the Windows API Performance Counter using code such as shown below. | You can access the Windows API Performance Counter using code such as shown below. | ||
Note that this API may not be as reliable as you might hope. For more information see http://www.virtualdub.org/blog/pivot/entry.php?id=106 | Note that this API may not be as reliable as you might hope. For more information see http://www.virtualdub.org/blog/pivot/entry.php?id=106 | ||
− | + | <syntaxhighlight lang=pascal> | |
− | + | unit Unit1; | |
− | + | {$mode objfpc}{$H+} | |
− | + | interface | |
+ | |||
+ | uses | ||
Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs, | Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs, | ||
StdCtrls, Windows; | StdCtrls, Windows; | ||
− | + | ||
+ | type | ||
{ TForm1 } | { TForm1 } | ||
TForm1 = class(TForm) | TForm1 = class(TForm) | ||
Line 20: | Line 25: | ||
var | var | ||
Form1: TForm1; | Form1: TForm1; | ||
− | + | implementation | |
− | + | ||
− | + | { TForm1 } | |
− | + | ||
+ | procedure TForm1.FormClick(Sender: TObject); | ||
+ | var | ||
PerformanceCounter: int64; | PerformanceCounter: int64; | ||
PerformanceFrequency: int64; | PerformanceFrequency: int64; | ||
− | + | begin | |
if QueryPerformanceFrequency(PerformanceFrequency) | if QueryPerformanceFrequency(PerformanceFrequency) | ||
− | + | and QueryPerformanceCounter(PerformanceCounter) | |
− | then ShowMessage( | + | then ShowMessage('Freq:' + IntToStr(PerformanceFrequency) |
− | + | + ', Counter:' + IntToStr(PerformanceCounter)) | |
− | |||
− | |||
else ShowMessage('Sorry, performance counters not supported.'); | else ShowMessage('Sorry, performance counters not supported.'); | ||
− | + | end; | |
− | + | ||
− | + | initialization | |
− | + | ||
+ | {$I unit1.lrs} | ||
+ | |||
+ | end. | ||
+ | </syntaxhighlight> |
Latest revision as of 00:15, 24 February 2020
This article applies to Windows only.
See also: Multiplatform Programming Guide
│
English (en) │
Maybe the one microsecond timestamp is too long for your program. You can access the Windows API Performance Counter using code such as shown below. Note that this API may not be as reliable as you might hope. For more information see http://www.virtualdub.org/blog/pivot/entry.php?id=106
unit Unit1;
{$mode objfpc}{$H+}
interface
uses
Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
StdCtrls, Windows;
type
{ TForm1 }
TForm1 = class(TForm)
procedure FormClick(Sender: TObject);
private
{ private declarations }
public
{ public declarations }
end;
var
Form1: TForm1;
implementation
{ TForm1 }
procedure TForm1.FormClick(Sender: TObject);
var
PerformanceCounter: int64;
PerformanceFrequency: int64;
begin
if QueryPerformanceFrequency(PerformanceFrequency)
and QueryPerformanceCounter(PerformanceCounter)
then ShowMessage('Freq:' + IntToStr(PerformanceFrequency)
+ ', Counter:' + IntToStr(PerformanceCounter))
else ShowMessage('Sorry, performance counters not supported.');
end;
initialization
{$I unit1.lrs}
end.