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超难：如何控制CPU使用率，大家一起讨论；如可解决，可以加分到300～1000

楼主minimu（minimu）2004-12-03 09:45:27 在 Delphi / Windows SDK/API 提问

RT，我在一款电视卡的软件（具体记不清了，老外的东西，国内的没有见过，以前想看加密电视的时候用的）里面有设置，如果设置CPU不是full占用的话，那么最多占用70～80％的CPU资源

是如何实现的？小弟才菜了，一直没有头绪，欢迎高手指点，也希望大家一起讨论

如果问题能够解决的话，散分至少300，讨论得多还可以多散分哈，绝不食言问题点数：0、回复次数：23Top

1 楼aiirii（ari-http://spaces.msn.com/members/aiirii/）回复于 2004-12-03 09:48:56 得分 0

>>如何控制CPU使用率
找找 win jobs 相關的幫助提示!

當然, 你也可設置相應的線程的優先級.

如果在你自己的程序中, 你也可多用sleep, application.processMessage 之類來釋放占有的CPU時間

正常, 如果不是在服務器的東西, 我覺得還是小心用這種控制Top

2 楼meiqingsong（阿飛）回复于 2004-12-03 09:50:26 得分 0

http://community.csdn.net/Expert/topic/3456/3456772.xml?temp=.6938593Top

3 楼extcsdn（Studing VB now）回复于 2004-12-03 09:52:38 得分 0

关注Top

4 楼Tensionli（）回复于 2004-12-03 09:52:48 得分 0

关注，帮顶Top

5 楼minimu（minimu）回复于 2004-12-03 09:56:17 得分 0

谢谢，其实就是想作一个控制程序，比如要用程序控制或者启动A、B、C三个任务
但是这三个任务默认都会使用100％的CPU资源，而且有优先级，如A>B=C
如果我先启动B或（和）C，那么A的一些请求就可能被延迟，但是使用中这是不允许的
所以我想可以设定CPU的使用，如B和C分别最多占用40％的资源，那么A任何时间启动都至少有20％的资源可以利用啊Top

6 楼minimu（minimu）回复于 2004-12-08 16:31:59 得分 0

没有什么进展，win jobs 的帮助在哪儿呀？

我没有找到

Top

7 楼ZengMuAnSha（曾牧暗鲨）回复于 2004-12-08 18:33:33 得分 0

设置他们的优先级为IDLETop

8 楼minimu（minimu）回复于 2004-12-10 10:11:10 得分 0

继续问Top

9 楼wfhlxl（光明正大地偷......学）回复于 2004-12-10 10:41:16 得分 0

in 98 is dificullt,
in win 2000 xp ,you can read registryTop

10 楼minimu（minimu）回复于 2004-12-10 13:41:23 得分 0

不是读取CPU使用率
而是控制，这个读取注册表是没有用处的Top

11 楼minimu（minimu）回复于 2004-12-13 16:28:36 得分 0

uPTop

12 楼ZengMuAnSha（曾牧暗鲨）回复于 2004-12-13 17:38:50 得分 0

Do.....
Application->ProcessMessage();
Sleep(10);
Do....Top

13 楼minimu（minimu）回复于 2004-12-14 08:36:22 得分 0

To ZengMuAnSha(曾牧暗鲨)：这样这是等待，没有办法比较准确的控制的Top

14 楼shangxuesong（幻影）回复于 2004-12-17 08:42:00 得分 0

你可以使用进程的方式，在该进程中运行一个循环，一定的间隔时间sleep()一下，我做的在cpu1.8G的情况下可以控制cpu的使用率在80%左右，但是cpu使用率肯定是有抖动的。不知道是否满足你的要求。Top

15 楼ygflydream（飞飞）回复于 2004-12-17 08:46:10 得分 0

顶！Top

16 楼princesd（中原）回复于 2004-12-17 08:47:58 得分 0

资源分配当然是OS的事.OS会自动按优先级分配给每个进程的.你不想让操作系统给那么多的话,让自己的进程优先级低些就是了.
Top

17 楼zglwxb（假钞换贞操）回复于 2004-12-17 08:50:06 得分 0

找了个VC的程序，转成D，N多问题，但CB却没事。

CB程序的正常，但一转成Delphi的就很多问题，那位有空改改，
如果成功了，多谢了告诉一声。各位老大帮俺试试

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls;

type
TForm1 = class(TForm)
Memo1: TMemo;
Timer1: TTimer;
Button1: TButton;
procedure Timer1Timer(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

const
MAX_RAW_VALUES = 20;

{$A-}
type
THandle = Pointer;
PHandle = ^THandle;

PPDH_RAW_COUNTER = ^TPDH_RAW_COUNTER;
_PDH_RAW_COUNTER = record
CStatus: DWORD;
TimeStamp: TFileTime;
FirstValue: Int64;
SecondValue: Int64;
MultiCount: DWORD;
end;
TPDH_RAW_COUNTER = _PDH_RAW_COUNTER;

PPDHCounterStruct = ^TPDHCounterStruct;
_tag_PDHCounterStruct = record
hCounter: THandle; // Handle to the counter - given to use by PDH Library
hNextIndex: Integer;
nOldestIndex: Integer;
nRawCount: Integer;
RawValue: array [0..MAX_RAW_VALUES - 1] of TPDH_RAW_COUNTER;
end;
TPDHCounterStruct = _tag_PDHCounterStruct;

PPDH_FMT_CouterValue = ^TPDH_FMT_CouterValue;
_PDH_FMT_COUNTERVALUE = record
CStatus: DWORD;
case Integer of
0: (longValue: DWORD);
1: (doubleValue: Double);
2: (largeValue: Int64);
3: (AnsiStringValue: PChar);
4: (WideStringValue: PWideChar);
end;
TPDH_FMT_CouterValue = _PDH_FMT_COUNTERVALUE;

const
Pdh = 'Pdh.dll';

function PdhOpenQuery(szDataSource: PChar; dwUserData: DWORD;
phQuery: PHandle): DWORD; stdcall; external Pdh name 'PdhOpenQueryA';

function PdhAddCounter(hQuery: THandle; const szFullCounterPath: PChar;
dwUserData: DWORD; phCounter: PHandle):
DWORD; stdcall; external Pdh name 'PdhAddCounterA';

function PdhCollectQueryData(hQuery: THandle): DWORD; stdcall; external Pdh name 'PdhCollectQueryData';
function PdhCloseQuery(hQuery: THandle): DWORD; stdcall; external Pdh name 'PdhCloseQuery';

function PdhGetFormattedCounterValue(hCounter: THandle; dwFormat: DWORD;
lpdwType: PDWORD; pValue: PPDH_FMT_CouterValue):
DWORD; stdcall; external Pdh name 'PdhGetFormattedCounterValue';

const
CounterPath: PChar = '\Processor(_Total)\% Processor Time';

type
TCpuUsage = class
private
FHandle: THandle;
FCounter: TPDHCounterStruct;
function InitUsage: Boolean;
public
constructor Create;
destructor Destroy; override;
function GetUsage: Integer;
end;

{ TCpuUsage }

constructor TCpuUsage.Create;
begin
inherited Create;
FHandle := nil;
FillChar(FCounter, Sizeof(FCounter), 0);
if not InitUsage then
raise Exception.Create(SysErrorMessage(GetLastError));
end;

destructor TCpuUsage.Destroy;
begin
if FHandle <> nil then
PdhCloseQuery(FHandle);
inherited Destroy;
end;

function TCpuUsage.GetUsage: Integer;
const
PDH_FMT_LONG = $100;
var
Formatted: TPDH_FMT_CouterValue;
begin
if ERROR_SUCCESS <> PdhCollectQueryData(FHandle) then
raise Exception.Create(SysErrorMessage(GetLastError));
if PdhGetFormattedCounterValue(FCounter.hCounter, PDH_FMT_LONG,
nil, @Formatted) = ERROR_SUCCESS then
Result := Formatted.longValue
else
Result := 0;
end;

function TCpuUsage.InitUsage: Boolean;
begin
Result := FHandle <> nil;
if Result then Exit;
Result := PdhOpenQuery(nil, 1, @FHandle) = ERROR_SUCCESS;
if not Result then Exit;
Result := PdhAddCounter(FHandle, CounterPath,
DWORD(@FCounter), @FCounter.hCounter) = ERROR_SUCCESS;
end;

var
Usage: TCpuUsage = nil;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
Memo1.Lines.Add(Format('CPU Usage: %d', [Usage.GetUsage]))
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
Usage := TCpuU
end;

end.

上面的程序是取CPU的使用频率的，但转成D老是有问题，但在CB中却是正常，请教了N人，
我的结果是：准备做成C的DLL。没办法了。

Top

18 楼muroachanf（阿远之哈儿）回复于 2004-12-17 08:58:04 得分 0

如果你把线程的优先级设置得高点，并且使用死循环的话，就会导致你的程序始终占用资源，如果你中途使用WaitForSingleObject,Sleep等等函数来等待或者暂缓线程的执行，则会释放资源，如果希望准确控制某线程在某时刻占用多少资源，应该说是没有这种可能的，WINDOWS是一个抢先任务式的操作系统，系统会随时在任意线程之间切换，唯一可以控制的，高优先级的线程优先执行。Top

19 楼ghchen（）回复于 2004-12-17 08:59:52 得分 0

学习Top

20 楼aiirii（ari-http://spaces.msn.com/members/aiirii/）回复于 2004-12-17 09:07:15 得分 0

http://community.csdn.net/Expert/topicview.asp?id=3456772Top

21 楼muroachanf（阿远之哈儿）回复于 2004-12-17 09:35:08 得分 0

已修改
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
Memo1: TMemo;
Timer1: TTimer;
procedure Timer1Timer(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
//procedure FormClose(Sender: TObject; var Action: TCloseAction);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

const
MAX_RAW_VALUES = 20;

{$A-}
type
PHandle = ^THandle;

PPDH_RAW_COUNTER = ^TPDH_RAW_COUNTER;
_PDH_RAW_COUNTER = record
CStatus: DWORD;
TimeStamp: TFileTime;
FirstValue: Int64;
SecondValue: Int64;
MultiCount: DWORD;
end;
TPDH_RAW_COUNTER = _PDH_RAW_COUNTER;

PPDHCounterStruct = ^TPDHCounterStruct;
_tag_PDHCounterStruct = record
hCounter: THandle; // Handle to the counter - given to use by PDH Library
hNextIndex: Integer;
nOldestIndex: Integer;
nRawCount: Integer;
RawValue: array [0..MAX_RAW_VALUES - 1] of TPDH_RAW_COUNTER;
end;
TPDHCounterStruct = _tag_PDHCounterStruct;

PPDH_FMT_CouterValue = ^TPDH_FMT_CouterValue;
_PDH_FMT_COUNTERVALUE = record
CStatus: DWORD;
case Integer of
0: (longValue: DWORD);
1: (doubleValue: Double);
2: (largeValue: Int64);
3: (AnsiStringValue: PChar);
4: (WideStringValue: PWideChar);
end;
TPDH_FMT_CouterValue = _PDH_FMT_COUNTERVALUE;

const
Pdh = 'Pdh.dll';

function PdhOpenQuery(szDataSource: PChar; dwUserData: DWORD;
phQuery: PHandle): DWORD; stdcall; external Pdh name 'PdhOpenQueryA';

function PdhAddCounter(hQuery: THandle; const szFullCounterPath: PChar;
dwUserData: DWORD; phCounter: PHandle):
DWORD; stdcall; external Pdh name 'PdhAddCounterA';

function PdhCollectQueryData(hQuery: THandle): DWORD; stdcall; external Pdh name 'PdhCollectQueryData';
function PdhCloseQuery(hQuery: THandle): DWORD; stdcall; external Pdh name 'PdhCloseQuery';

function PdhGetFormattedCounterValue(hCounter: THandle; dwFormat: DWORD;
lpdwType: PDWORD; pValue: PPDH_FMT_CouterValue):
DWORD; stdcall; external Pdh name 'PdhGetFormattedCounterValue';

var
CounterPath: array [1..MAX_PATH] of char;

type
TCpuUsage = class
private
FHandle: THandle;
FCounter: TPDHCounterStruct;
function InitUsage: Boolean;
public
constructor Create;
destructor Destroy; override;
function GetUsage: Integer;
end;

{ TCpuUsage }

constructor TCpuUsage.Create;
begin
inherited Create;
FHandle := 0;
FillChar(FCounter, Sizeof(FCounter), 0);
if not InitUsage then
raise Exception.Create(SysErrorMessage(GetLastError));
end;

destructor TCpuUsage.Destroy;
begin
if FHandle <> 0 then
PdhCloseQuery(FHandle);
inherited Destroy;
end;

function TCpuUsage.GetUsage: Integer;
const
PDH_FMT_LONG = $100;
var
Formatted: TPDH_FMT_CouterValue;
begin
if ERROR_SUCCESS <> PdhCollectQueryData(FHandle) then
raise Exception.Create(SysErrorMessage(GetLastError));
if PdhGetFormattedCounterValue(FCounter.hCounter, PDH_FMT_LONG,
nil, @Formatted) = ERROR_SUCCESS then
Result := Formatted.longValue
else
Result := 0;
end;

function TCpuUsage.InitUsage: Boolean;
begin
Result := FHandle <> 0;
if Result then Exit;
Result := PdhOpenQuery(nil, 0, @FHandle) = ERROR_SUCCESS;
if not Result then Exit;
lstrcpy(@CounterPath[1], '\Processor(_Total)\% Processor Time');
Result := PdhAddCounter(FHandle, @CounterPath[1],
0, @FCounter.hCounter) = ERROR_SUCCESS;
end;

var
Usage: TCpuUsage = nil;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
Memo1.Lines.Add(Format('CPU Usage: %d', [Usage.GetUsage]))
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
Usage := TCpuUsage.Create
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
Timer1.Enabled := true;
end;

end.Top

22 楼Kshape（C/C++初学者~~~~）回复于 2004-12-31 17:08:49 得分 0

学习中Top

23 楼minimu（minimu）回复于 2005-01-04 09:13:02 得分 0

学习中

大家继续讨论，有好的结果另外开帖散分Top