用adCpuUsage读取CPU使用率为什么会读出负数？(200分)

younghat · 2006-04-14

我使用adCpuUsage.pas来读取CPU的使用率，发现在单CPU的机器上一切正常，可是在多CPU的机器上经常会读出负数来，这是怎么回事？该怎么处理？ 请使用过adCpuUsage的DFW不吝赐教，谢谢。

younghat · 2006-04-14

在此附上adCpuUsage.pas源代码，请有条件的帮我分析一下问题出在哪里，不胜感激。 unit adCpuUsage; {* USAGE: 1. Include this unit into project. 2. Call GetCPUCount to obtain the numbr of processors in the system 3. Each time you need to know the value of CPU usage call the CollectCPUData   to refresh the CPU usage information. Then call the GetCPUUsage to obtain   the CPU usage for given processor. Note that succesive calls of GetCPUUsage   without calling CollectCPUData will return the same CPU usage value. Example: procedure TTestForm.TimerTimer(Sender: TObject); var i: Integer; begin    CollectCPUData; // Get the data for all processors    for i:=0 to GetCPUCount-1 do // Show data for each processor        MInfo.Lines:=Format('CPU #%d - %5.2f%%',[i,GetCPUUsage(i)*100]); end; *} interface uses    Windows, SysUtils; // Call CollectCPUData to refresh information about CPU usage procedure CollectCPUData; // Call it to obtain the number of CPU's in the system function _GetCPUCount: Integer; // Call it to obtain the % of usage for given CPU function _GetCPUUsage(Index: Integer): Double; // For Win9x only: call it to stop CPU usage monitoring and free system resources procedure ReleaseCPUData; implementation {$ifndef ver110}    {$ifndef ver90}    {$ifndef ver100}    {$define UseInt64}    {$endif}    {$endif}    {$ifdef UseInt64}    type TInt64 = Int64;    {$else}    type TInt64 = Comp;    {$endif} {$else}    type TInt64 = TLargeInteger; {$endif} type    PInt64 = ^TInt64; type    TPERF_DATA_BLOCK = record        Signature : array[0..4 - 1] of WCHAR;        LittleEndian : DWORD;        Version : DWORD;        Revision : DWORD;        TotalByteLength : DWORD;        HeaderLength : DWORD;        NumObjectTypes : DWORD;        DefaultObject : Longint;        SystemTime : TSystemTime;        Reserved: DWORD;        PerfTime : TInt64;        PerfFreq : TInt64;        PerfTime100nSec : TInt64;        SystemNameLength : DWORD;        SystemNameOffset : DWORD;    end;    PPERF_DATA_BLOCK = ^TPERF_DATA_BLOCK;    TPERF_OBJECT_TYPE = record        TotalByteLength : DWORD;        DefinitionLength : DWORD;        HeaderLength : DWORD;        ObjectNameTitleIndex : DWORD;        ObjectNameTitle : LPWSTR;        ObjectHelpTitleIndex : DWORD;        ObjectHelpTitle : LPWSTR;        DetailLevel : DWORD;        NumCounters : DWORD;        DefaultCounter : Longint;        NumInstances : Longint;        CodePage : DWORD;        PerfTime : TInt64;        PerfFreq : TInt64;    end;    PPERF_OBJECT_TYPE = ^TPERF_OBJECT_TYPE; type    TPERF_COUNTER_DEFINITION = record        ByteLength : DWORD;        CounterNameTitleIndex : DWORD;        CounterNameTitle : LPWSTR;        CounterHelpTitleIndex : DWORD;        CounterHelpTitle : LPWSTR;        DefaultScale : Longint;        DetailLevel : DWORD;        CounterType : DWORD;        CounterSize : DWORD;        CounterOffset : DWORD;    end;    PPERF_COUNTER_DEFINITION = ^TPERF_COUNTER_DEFINITION;    TPERF_COUNTER_BLOCK = record        ByteLength : DWORD;    end;    PPERF_COUNTER_BLOCK = ^TPERF_COUNTER_BLOCK;    TPERF_INSTANCE_DEFINITION = record        ByteLength : DWORD;        ParentObjectTitleIndex : DWORD;        ParentObjectInstance : DWORD;        UniqueID : Longint;        NameOffset : DWORD;        NameLength : DWORD;    end;    PPERF_INSTANCE_DEFINITION = ^TPERF_INSTANCE_DEFINITION; //------------------------------------------------------------------------------ {$ifdef ver130} {$L-}         // The L+ causes internal error in Delphi 5 compiler {$O-}         // The O+ causes internal error in Delphi 5 compiler {$Y-}         // The Y+ causes internal error in Delphi 5 compiler {$endif} {$ifndef ver110} type    TInt64F = TInt64; {$else} type    TInt64F = Extended; {$endif} {$ifdef ver110} function FInt64(Value: TInt64): TInt64F; function Int64D(Value: DWORD): TInt64; {$else} type    FInt64 = TInt64F;    Int64D = TInt64; {$endif} {$ifdef ver110} function FInt64(Value: TInt64): TInt64F; var V: TInt64; begin    if (Value.HighPart and $80000000) = 0 then // positive value    begin        result:=Value.HighPart;        result:=result*$10000*$10000;        result:=result+Value.LowPart;    end else    begin        V.HighPart:=Value.HighPart xor $FFFFFFFF;        V.LowPart:=Value.LowPart xor $FFFFFFFF;        result:= -1 - FInt64(V);    end; end; function Int64D(Value: DWORD): TInt64; begin    result.LowPart:=Value;    result.HighPart := 0; // positive only end; {$endif} //------------------------------------------------------------------------------ const    Processor_IDX_Str = '238';    Processor_IDX = 238;    CPUUsageIDX = 6; type    AInt64F = array[0..$FFFF] of TInt64F;    PAInt64F = ^AInt64F; var    _PerfData : PPERF_DATA_BLOCK;    _BufferSize: Integer;    _POT : PPERF_OBJECT_TYPE;    _PCD: PPerf_Counter_Definition;    _ProcessorsCount: Integer;    _Counters: PAInt64F;    _PrevCounters: PAInt64F;    _SysTime: TInt64F;    _PrevSysTime: TInt64F;    _IsWinNT: Boolean;    _W9xCollecting: Boolean;    _W9xCpuUsage: DWORD;    _W9xCpuKey: HKEY; //------------------------------------------------------------------------------ function _GetCPUCount: Integer; begin    if _IsWinNT then    begin        if _ProcessorsCount < 0 then CollectCPUData;        result:=_ProcessorsCount;    end else    begin        result:=1;    end; end; //------------------------------------------------------------------------------ procedure ReleaseCPUData; var H: HKEY;    R: DWORD;    dwDataSize, dwType: DWORD; begin    if _IsWinNT then exit;    if not _W9xCollecting then exit;    _W9xCollecting:=False;    RegCloseKey(_W9xCpuKey);    R:=RegOpenKeyEx( HKEY_DYN_DATA, 'PerfStats/StopStat', 0, KEY_ALL_ACCESS, H );    if R <> ERROR_SUCCESS then exit;    dwDataSize:=sizeof(DWORD);    RegQueryValueEx ( H, 'KERNEL/CPUUsage', nil, @dwType, PBYTE(@_W9xCpuUsage), @dwDataSize);    RegCloseKey(H); end; //------------------------------------------------------------------------------ function _GetCPUUsage(Index: Integer): Double; begin    if _IsWinNT then    begin        if _ProcessorsCount < 0 then CollectCPUData;        if (Index >= _ProcessorsCount) or (Index < 0) then            raise Exception.Create('CPU index out of bounds');        if _PrevSysTime = _SysTime then result:=0 else        result:=1-(_Counters[index] - _PrevCounters[index])/(_SysTime-_PrevSysTime);    end else    begin        if Index <> 0 then            raise Exception.Create('CPU index out of bounds');        if not _W9xCollecting then CollectCPUData;        result:=_W9xCpuUsage / 100;    end; end; var VI: TOSVERSIONINFO; //------------------------------------------------------------------------------ procedure CollectCPUData; var BS: integer;    i: Integer;    _PCB_Instance: PPERF_COUNTER_BLOCK;    _PID_Instance: PPERF_INSTANCE_DEFINITION;    ST: TFileTime; var H: HKEY;    R: DWORD;    dwDataSize, dwType: DWORD; begin    if _IsWinNT then    begin        BS:=_BufferSize;        while RegQueryValueEx( HKEY_PERFORMANCE_DATA, Processor_IDX_Str, nil, nil,                PByte(_PerfData), @BS ) = ERROR_MORE_DATA do        begin            // Get a buffer that is big enough.            INC(_BufferSize,$1000);            BS:=_BufferSize;            ReallocMem( _PerfData, _BufferSize );        end;        // Locate the performance object        _POT := PPERF_OBJECT_TYPE(DWORD(_PerfData) + _PerfData.HeaderLength);        for i := 1 to _PerfData.NumObjectTypes do        begin            if _POT.ObjectNameTitleIndex = Processor_IDX then Break;            _POT := PPERF_OBJECT_TYPE(DWORD(_POT) + _POT.TotalByteLength);        end;        // Check for success        if _POT.ObjectNameTitleIndex <> Processor_IDX then            raise Exception.Create('Unable to locate the "Processor" performance object');        if _ProcessorsCount < 0 then        begin            _ProcessorsCount:=_POT.NumInstances;            GetMem(_Counters,_ProcessorsCount*SizeOf(TInt64));            GetMem(_PrevCounters,_ProcessorsCount*SizeOf(TInt64));        end;        // Locate the "% CPU usage" counter definition        _PCD := PPERF_Counter_DEFINITION(DWORD(_POT) + _POT.HeaderLength);        for i := 1 to _POT.NumCounters do        begin            if _PCD.CounterNameTitleIndex = CPUUsageIDX then break;            _PCD := PPERF_COUNTER_DEFINITION(DWORD(_PCD) + _PCD.ByteLength);        end;        // Check for success        if _PCD.CounterNameTitleIndex <> CPUUsageIDX then            raise Exception.Create('Unable to locate the "% of CPU usage" performance counter');        // Collecting coutners        _PID_Instance := PPERF_INSTANCE_DEFINITION(DWORD(_POT) + _POT.DefinitionLength);        for i := 0 to _ProcessorsCount-1 do        begin            _PCB_Instance := PPERF_COUNTER_BLOCK(DWORD(_PID_Instance) + _PID_Instance.ByteLength );            _PrevCounters:=_Counters;            _Counters:=FInt64(PInt64(DWORD(_PCB_Instance) + _PCD.CounterOffset)^);            _PID_Instance := PPERF_INSTANCE_DEFINITION(DWORD(_PCB_Instance) + _PCB_Instance.ByteLength);        end;        _PrevSysTime:=_SysTime;        SystemTimeToFileTime(_PerfData.SystemTime, ST);        _SysTime:=FInt64(TInt64(ST));    end else    begin        if not _W9xCollecting then        begin            R:=RegOpenKeyEx( HKEY_DYN_DATA, 'PerfStats/StartStat', 0, KEY_ALL_ACCESS, H );            if R <> ERROR_SUCCESS then                raise Exception.Create('Unable to start performance monitoring');            dwDataSize:=sizeof(DWORD);            RegQueryValueEx( H, 'KERNEL/CPUUsage', nil, @dwType, PBYTE(@_W9xCpuUsage), @dwDataSize );            RegCloseKey(H);            R:=RegOpenKeyEx( HKEY_DYN_DATA, 'PerfStats/StatData', 0,KEY_READ, _W9xCpuKey );            if R <> ERROR_SUCCESS then                raise Exception.Create('Unable to read performance data');            _W9xCollecting:=True;        end;        dwDataSize:=sizeof(DWORD);        RegQueryValueEx( _W9xCpuKey, 'KERNEL/CPUUsage', nil,@dwType, PBYTE(@_W9xCpuUsage), @dwDataSize );    end; end; initialization    _ProcessorsCount:= -1;    _BufferSize:= $2000;    _PerfData := AllocMem(_BufferSize);    VI.dwOSVersionInfoSize:=SizeOf(VI);    if not GetVersionEx(VI) then raise Exception.Create('Can''t get the Windows version');    _IsWinNT := VI.dwPlatformId = VER_PLATFORM_WIN32_NT; finalization    ReleaseCPUData;    FreeMem(_PerfData); end.

用adCpuUsage读取CPU使用率为什么会读出负数？(200分)

younghat

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younghat

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