用哪个函数得到机器的cpu使用率,内存占用率,进程的使用率和占用率?

Question

用哪个函数得到机器的cpu使用率,内存占用率,进程的使用率和占用率?

Answer 1

NtQuerySystemInformation
例子：bool      CanGetCPUUsage()  
{  
           //os  version  information  structure  
           OSVERSIONINFO  OsVersionInfo;  
           OsVersionInfo.dwOSVersionInfoSize=  sizeof(OSVERSIONINFO);  
           //get  os  version  
           GetVersionEx(&OsVersionInfo);  
           //only  run  in  win2000/nt  OS  
           if(OsVersionInfo.dwPlatformId  ==  VER_PLATFORM_WIN32_WINDOWS  )  
           {  
//                        MessageBox("Only  run  in  Win2K/NT,\\nYour  OS  is  not  Win2000/NT!","prompt:");  
                       return  false;  
           }  
 
           //Get  NtQuerySystemInformation  Address  from  ntdll.dll  
       NtQuerySystemInformation  =(NTQSI)GetProcAddress(  
                                                                                               GetModuleHandle("ntdll.dll"),  
                                                                                       "NtQuerySystemInformation"  );  
 
       if  (!NtQuerySystemInformation)  
                       {  
//                                    MessageBox("no  this  function");  
                                   return  false;  
                       }  
 
       //  get  num  of  processors  
       status  =  NtQuerySystemInformation(0,&SysBaseInfo,sizeof(SysBaseInfo),NULL);  
       if  (status  !=  NO_ERROR)  
       {  
//              MessageBox("failed  to  query  basic  info(num  of  processors)");  
             return  false;  
       }  
       return  true;  
}  
double      GetCPUUsage()  
{  
       //  get  system  time  
       status  =  NtQuerySystemInformation(3,&SysTimeInfo,sizeof(SysTimeInfo),0);  
       if  (status!=NO_ERROR)  
           {  
//                        MessageBox("failed  to  get  system  time!");  
                               return  ret_error;  
           }  
 
       //  get  cpu  idle  time  
       status  =  NtQuerySystemInformation(2,&SysPerfInfo,sizeof(SysPerfInfo),NULL);  
       if  (status  !=  NO_ERROR)  
           {  
//                        MessageBox("failed  to  get  cpu  time");  
                               return  ret_error;  
           }  
           if  (liOldIdleTime.QuadPart  !=  0)  
           {  
               //  new  cpu  Time  =  NewTime  -  OldTime  
               dbCpuIdleTime  =LI64ToDouble(SysPerfInfo.liIdleTime)-LI64ToDouble(liOldIdleTime);  
               dbSysTime  =LI64ToDouble(SysTimeInfo.liKeSystemTime)-LI64ToDouble(liOldSysTime);  
 
               //get  cpu  usage  
                       unCpuUsage=100  -  100*(dbCpuIdleTime/dbSysTime)/(double)SysBaseInfo.bKeNumberProcessors+0.5;  
           }  
 
       //  store  new  cpu  idle  and  system  time  
       liOldIdleTime  =  SysPerfInfo.liIdleTime;  
       liOldSysTime  =  SysTimeInfo.liKeSystemTime;  
 
               return  unCpuUsage;  
}  
 
---------------------------------------------------------------  
 
GetProcessUse(PROCESS_INFORMATION  proc,_JOBOBJECT_BASIC_ACCOUNTING_INFORMAT  Info)  
{  
 
Handle  hJob=CreateJobOjbect(NULL,NULL);  
AssignProcessToJobObject(hjob,proc.hProcess,NULL,0,0);  
QueryInformationJobOjbect(hJob,Info)  
closeHandle(hjob);  
}  
 
typedef  struct  _JOBOBJECT_BASIC_ACCOUNTING_INFORMATION  
{  
LARGE_INTEGER    TotalUserTime;    
LARGE_INTEGER    TotalKernelTime;  
LARGE_INTEGER    ThisPeriodTotalUerTime  
LARGE_INTEGER    thisPeriodTotalKernelTime;  
DWORD  TotalPageFaultCount  
DWORD  TotalProcess  
DWORD  ActiveProcesses    
DWORD  TotalTerminatedProcesses;  
}_JOBOBJECT_BASIC_ACCOUNTING_INFORMATION,*_JOBOBJECT_BASIC_ACCOUNTING_INFORMATION