//...header
#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;
typedef LONG (
WINAPI *PROCNTQSI)(UINT,PVOID,ULONG,PULONG);
PROCNTQSI NtQuerySystemInformation;
//GetCPUUsage() gives the information about the system
//it is called and used by another class
double GetCPUUsage()
{
SYSTEM_PERFORMANCE_INFORMATION SysPerfInfo;
SYSTEM_TIME_INFORMATION SysTimeInfo;
SYSTEM_BASIC_INFORMATION SysBaseInfo;
double dbIdleTime;
double dbSystemTime;
static LARGE_INTEGER liOldIdleTime = {0,0};
static LARGE_INTEGER liOldSystemTime = {0,0};
NtQuerySystemInformation = (PROCNTQSI)GetProcAddress(
GetModuleHandle("ntdll"),
"NtQuerySystemInformation");
NtQuerySystemInformation(SystemBasicInformation,&SysBaseInfo,sizeof(SysBaseI
nfo),NULL);
NtQuerySystemInformation(SystemTimeInformation,&SysTimeInfo,sizeof(SysTimeIn
fo),0);
NtQuerySystemInformation(SystemPerformanceInformation,&SysPerfInfo,sizeof(Sy
sPerfInfo),NULL);
if (liOldIdleTime.QuadPart != 0)
{ // if it's a first call - skip it
// CurrentValue = NewValue - OldValue
dbIdleTime = Li2Double(SysPerfInfo.liIdleTime) -
Li2Double(liOldIdleTime);
dbSystemTime = Li2Double(SysTimeInfo.liKeSystemTime) -
Li2Double(liOldSystemTime);
// CurrentCpuIdle = IdleTime / SystemTime
dbIdleTime = dbIdleTime / dbSystemTime;
dbIdleTime = 100.0 - dbIdleTime * 100.0 /
(double)SysBaseInfo.bKeNumberProcessors + 0.5;
}
liOldIdleTime = SysPerfInfo.liIdleTime;
liOldSystemTime = SysTimeInfo.liKeSystemTime;
return dbIdleTime;
}
//----------------------------------