获取进程CPU占用率

获取进程CPU占用率

// 时间转换

static __int64 file_time_2_utc(const FILETIME* ftime)

{

    LARGE_INTEGER li;

    li.LowPart = ftime->dwLowDateTime;

    li.HighPart = ftime->dwHighDateTime;

    return li.QuadPart;

}

// 获得CPU的核数

static int get_processor_number()

{

    SYSTEM_INFO info;

    GetSystemInfo(&info);

    return (int)info.dwNumberOfProcessors;

}

// 获取进程CPU占用

int get_cpu_usage(int pid)

{

    //cpu数量

    static int processor_count_ = -1;

    //上一次的时间

    static __int64 last_time_ = 0;

    static __int64 last_system_time_ = 0;

    FILETIME now;

    FILETIME creation_time;

    FILETIME exit_time;

    FILETIME kernel_time;

    FILETIME user_time;

    __int64 system_time;

    __int64 time;

    __int64 system_time_delta;

    __int64 time_delta;

    int cpu = -1;

    if(processor_count_ == -1)

    {

        processor_count_ = get_processor_number();

    }

    GetSystemTimeAsFileTime(&now);

    HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, false, pid);

    if (!GetProcessTimes(hProcess, &creation_time, &exit_time, &kernel_time, &user_time))

    {

        return -1;

    }

    system_time = (file_time_2_utc(&kernel_time) + file_time_2_utc(&user_time)) / processor_count_;

    time = file_time_2_utc(&now);

    if ((last_system_time_ == 0) || (last_time_ == 0))

    {

        last_system_time_ = system_time;

        last_time_ = time;

        return -1;

    }

    system_time_delta = system_time - last_system_time_;

    time_delta = time - last_time_;

    if (time_delta == 0)

        return -1;

    cpu = (int)((system_time_delta * 100 + time_delta / 2) / time_delta);

    last_system_time_ = system_time;

    last_time_ = time;

    return cpu;

}