获取CPU使用率信息

第一种： 

#define _WIN32_WINNT 0x0501    //使用GetSystemTimes需要定义该变量值大于等于0x0501,详看MSDN

 

__int64 CompareFileTime ( FILETIME time1, FILETIME time2 )

{

__int64 a = time1.dwHighDateTime << 32 | time1.dwLowDateTime ;

__int64 b = time2.dwHighDateTime << 32 | time2.dwLowDateTime ;

return (b - a);

}

 

//获取CPU利用率

int GetCpuUsage()

{

BOOL res ;

FILETIME preidleTime;

FILETIME prekernelTime;

FILETIME preuserTime;

FILETIME idleTime;

FILETIME kernelTime;

FILETIME userTime;

res = GetSystemTimes(&idleTime, &kernelTime, &userTime);

preidleTime = idleTime;

prekernelTime = kernelTime;

preuserTime = userTime ;

::Sleep(1000);

res = GetSystemTimes( &idleTime, &kernelTime, &userTime );

int idle = CompareFileTime( preidleTime,idleTime);

int kernel = CompareFileTime( prekernelTime, kernelTime);

int user = CompareFileTime(preuserTime, userTime);

int cpu = (kernel +user - idle) *100/(kernel+user);

int cpuidle = ( idle) *100/(kernel+user);

preidleTime = idleTime;

prekernelTime = kernelTime;

preuserTime = userTime ;

return cpu;

} 

 

第二种：使用NtQuerySystemInformation 

#include <windows.h>

#include <conio.h>

#include <stdio.h>

#define SystemBasicInformation     0

#define SystemPerformanceInformation 2

#define SystemTimeInformation     3 

 #define Li2Double(x) ((double)((x).HighPart) * 4.294967296E9 + (double)((x).LowPart))

 

typedef struct

{

DWORD   dwUnknown1;

ULONG   uKeMaximumIncrement;

ULONG   uPageSize;

ULONG   uMmNumberOfPhysicalPages;

ULONG   uMmLowestPhysicalPage;

ULONG   uMmHighestPhysicalPage;

ULONG   uAllocationGranularity;

PVOID   pLowestUserAddress;

PVOID   pMmHighestUserAddress;

ULONG   uKeActiveProcessors;

BYTE   bKeNumberProcessors;

BYTE   bUnknown2;

WORD   wUnknown3;

} SYSTEM_BASIC_INFORMATION;

typedef struct

{

LARGE_INTEGER   liIdleTime;

DWORD       dwSpare[76];

} SYSTEM_PERFORMANCE_INFORMATION;

typedef struct

{

LARGE_INTEGER liKeBootTime;

LARGE_INTEGER liKeSystemTime;

LARGE_INTEGER liExpTimeZoneBias;

ULONG       uCurrentTimeZoneId;

DWORD       dwReserved;

} SYSTEM_TIME_INFORMATION; 

 

///////////get cpu usage//////////////////

////2k,xp//////据资料说NtQuerySystemInformation 函数在win7下不好使，没验证

SYSTEM_PERFORMANCE_INFORMATION SysPerfInfo;

SYSTEM_TIME_INFORMATION     SysTimeInfo;

SYSTEM_BASIC_INFORMATION     SysBaseInfo;

double                 dbIdleTime;

double                 dbSystemTime;

LONG                   status;

LARGE_INTEGER             liOldIdleTime = {0,0};

LARGE_INTEGER             liOldSystemTime = {0,0};

NtQuerySystemInformation = (PROCNTQSI)GetProcAddress(

GetModuleHandle("ntdll"),

"NtQuerySystemInformation"

);

if (!NtQuerySystemInformation)

return -1;

// get number of processors in the system

status = NtQuerySystemInformation(SystemBasicInformation,&SysBaseInfo,sizeof(SysBaseInfo),NULL);

if (status != NO_ERROR)

return -1;

printf("/nCPU Usage (press any key to exit):   ");

while(!_kbhit())

{

// get new system time

status = NtQuerySystemInformation(SystemTimeInformation,&SysTimeInfo,sizeof(SysTimeInfo),0);

if (status!=NO_ERROR)

return -1;

// get new CPU's idle time

status = NtQuerySystemInformation(SystemPerformanceInformation,&SysPerfInfo,sizeof(SysPerfInfo),NULL);

if (status != NO_ERROR)

return -1;

// if it's a first call - skip it

if (liOldIdleTime.QuadPart != 0)

{

// CurrentValue = NewValue - OldValue

dbIdleTime = Li2Double(SysPerfInfo.liIdleTime) - Li2Double(liOldIdleTime);

dbSystemTime = Li2Double(SysTimeInfo.liKeSystemTime) - Li2Double(liOldSystemTime);

// CurrentCpuIdle = IdleTime / SystemTime

dbIdleTime = dbIdleTime / dbSystemTime;

// CurrentCpuUsage% = 100 - (CurrentCpuIdle * 100) / NumberOfProcessors

dbIdleTime = 100.0 - dbIdleTime * 100.0 / (double)SysBaseInfo.bKeNumberProcessors + 0.5;

printf("/b/b/b/b%3d%%",(UINT)dbIdleTime);

}

// store new CPU's idle and system time

liOldIdleTime = SysPerfInfo.liIdleTime;

liOldSystemTime = SysTimeInfo.liKeSystemTime;

// wait one second

Sleep(1000);

}

printf("/n");

     

    ////////2k,xp//////////

///9x  can not used in xp ////

     HKEY hkey;

DWORD dwDataSize;

DWORD dwType;

DWORD dwCpuUsage;

// starting the counter

if ( RegOpenKeyEx( HKEY_DYN_DATA,

             "PerfStats\\StartStat",

             0,KEY_ALL_ACCESS,

             &hkey ) != ERROR_SUCCESS)

{

printf("openkeyex start stat");

return -1;

}

dwDataSize=sizeof(DWORD);

RegQueryValueEx( hkey,

"KERNEL\\CPUUsage",

NULL,&dwType,

(LPBYTE)&dwCpuUsage,

&dwDataSize );

RegCloseKey(hkey);

// geting current counter's value

if ( RegOpenKeyEx( HKEY_DYN_DATA,

"PerfStats\\StatData",

0,KEY_READ,

&hkey ) != ERROR_SUCCESS)

{

printf("openkeyex statdata");

return -1;

}

printf("\nCPU Usage (press any key to exit):  ");

while(!_kbhit())

{

dwDataSize=sizeof(DWORD);

RegQueryValueEx( hkey,

"KERNEL\\CPUUsage",

NULL,&dwType,

(LPBYTE)&dwCpuUsage,

&dwDataSize );

Sleep(500);

printf("\b\b\b\b%3d%%",dwCpuUsage);

}

printf("\n");

RegCloseKey(hkey);

// stoping the counter

if( RegOpenKeyEx( HKEY_DYN_DATA,

"PerfStats\\StopStat",

0,KEY_ALL_ACCESS,

&hkey ) != ERROR_SUCCESS)

{

printf("open stopstat");

return -1;

}

dwDataSize=sizeof(DWORD);

RegQueryValueEx( hkey,

"KERNEL\\CPUUsage",

NULL,&dwType,

(LPBYTE)&dwCpuUsage,

&dwDataSize );

RegCloseKey(hkey);

 

///9x....////