计算cpu使用率和判断服务器断开

来源：互联网发布：32位单片机有哪些编辑：程序博客网时间：2024/04/29 01:29

一，获得cup使用率的方法如下
1, 取出系统中cpu个数；

2, 取出当前系统时间，减去原来保存的系统时间，得出从上次取值到目前的系统时间差；

3, 取出系统当前空闲时间，减去原来保存的空闲时间，得出这个时间段空闲时间

4, 用这个时间段空闲时间除以系统时间，得出这段时间系统的cpu空闲率

5, 用100-(系统的空闲率)/(cpu个数)所得的值就是cpu占有率

老外的代码：

void CCpuUsgesCtl::GetCpuUsgesNt()
{
SYSTEM_PERFORMANCE_INFORMATION SysPerfInfo;
    SYSTEM_TIME_INFORMATION        SysTimeInfo;
    SYSTEM_BASIC_INFORMATION       SysBaseInfo;
    double                         dbIdleTime;
    double                         dbSystemTime;
    LONG                           status;
    typedef LONG (WINAPI *PROCNTQSI)(UINT,PVOID,ULONG,PULONG);
    PROCNTQSI NtQuerySystemInformation;

    NtQuerySystemInformation = (PROCNTQSI)GetProcAddress(
                                          GetModuleHandle("ntdll"),
                                         "NtQuerySystemInformation"
                                         );

if (!NtQuerySystemInformation)
{
return;
}

    // get number of processors in the system
    status = NtQuerySystemInformation(SystemBasicInformation,
                                &SysBaseInfo,sizeof(SysBaseInfo),NULL);

if (status != NO_ERROR)
{
return;
}

status = NtQuerySystemInformation(SystemTimeInformation,
                                 &SysTimeInfo,sizeof(SysTimeInfo),0);
     if (status!=NO_ERROR)
{
          return;
}

     // get new CPU's idle time
     status = NtQuerySystemInformation(SystemPerformanceInformation,
                                 &SysPerfInfo,sizeof(SysPerfInfo),NULL);

if (status != NO_ERROR)
{
return;
}

     // if it's a first call - skip it
     if (m_liOldIdleTime.QuadPart != 0)
     {
         // CurrentValue = NewValue - OldValue
         dbIdleTime = Li2Double(SysPerfInfo.liIdleTime) - Li2Double(m_liOldIdleTime);
         dbSystemTime = Li2Double(SysTimeInfo.liKeSystemTime) - Li2Double(m_liOldSystemTime);

// CurrentCpuIdle = IdleTime / SystemTime
dbIdleTime = dbIdleTime / dbSystemTime;

// CurrentCpuUsage% = 100 - (CurrentCpuIdle * 100) / NumberOfProcessors
dbIdleTime = 100.0 - dbIdleTime * 100.0 / (double)SysBaseInfo.bKeNumberProcessors + 0.5;

m_fNewUsges = (UINT)dbIdleTime;
}

     // store new CPU's idle and system time
     m_liOldIdleTime = SysPerfInfo.liIdleTime;
     m_liOldSystemTime = SysTimeInfo.liKeSystemTime;

}

二， send和recv的返回值可以判断，返回值小于等于0，则说明连接已经断开或者出现了错误。

代码：
BOOL ClientDlg::Socket_HasConnectDropped(int i_sd)
{
BOOL bConnDropped = FALSE;
INT iRet = 0;
BOOL bOK = TRUE;

if (i_sd == INVALID_SOCKET)
  return TRUE;

struct timeval timeout = { 0, 0 };
fd_set readSocketSet;

FD_ZERO(&readSocketSet);
FD_SET(i_sd, &readSocketSet);

iRet = ::select(0, &readSocketSet, NULL, NULL, &timeout);
bOK = (iRet > 0);

if(bOK)
{
  bOK = FD_ISSET(i_sd, &readSocketSet);
}

if(bOK)
{
  CHAR szBuffer[1] = "";
  iRet = ::recv(i_sd, szBuffer, 1, MSG_PEEK);
  bOK = (iRet > 0);
  if(!bOK)
  {
   INT iError = ::WSAGetLastError();
   bConnDropped = (( iError == WSAENETRESET) ||
    (iError == WSAECONNABORTED) ||
    (iError == WSAECONNRESET) ||
    (iError == WSAEINVAL) ||
    (iRet == 0));
  }
}
    return(bConnDropped);

}

//资源均来自互联网，我只是想让更多人知道。