Process cpu, gpu, memory, network

Under linux, it is actually calculated by calling the system api under windows by reading and parsing the corresponding field value of the process virtual file in the /proc directory .

cpu memory

#include <iostream>
#include <thread>
#include <chrono>
#include <string.h>

#ifdef WIN32
#include <windows.h>  
#include <psapi.h>  
//#include <tlhelp32.h>
#include <direct.h>
#include <process.h>
#else
#include <sys/stat.h>
#include <sys/sysinfo.h>
#include <sys/time.h>
#include <unistd.h>
#endif

// get current process pid
inline int GetCurrentPid()
{
    
    
    return getpid();
}

// get specific process cpu occupation ratio by pid
#ifdef WIN32
// 
static uint64_t convert_time_format(const FILETIME* ftime)
{
    
    
    LARGE_INTEGER li;

    li.LowPart = ftime->dwLowDateTime;
    li.HighPart = ftime->dwHighDateTime;
    return li.QuadPart;
}
#else
// FIXME: can also get cpu and mem status from popen cmd
// the info line num in /proc/{pid}/status file
#define VMRSS_LINE 22
#define PROCESS_ITEM 14

static const char* get_items(const char* buffer, unsigned int item)
{
    
    
    // read from buffer by offset
    const char* p = buffer;

    int len = strlen(buffer);
    int count = 0;

    for (int i = 0; i < len; i++)
    {
    
    
        if (' ' == *p)
        {
    
    
            count++;
            if (count == item - 1)
            {
    
    
                p++;
                break;
            }
        }
        p++;
    }

    return p;
}

static inline unsigned long get_cpu_total_occupy()
{
    
    
    // get total cpu use time

    // different mode cpu occupy time
    unsigned long user_time;
    unsigned long nice_time;
    unsigned long system_time;
    unsigned long idle_time;

    FILE* fd;
    char buff[1024] = {
    
     0 };

    fd = fopen("/proc/stat", "r");
    if (nullptr == fd)
        return 0;

    fgets(buff, sizeof(buff), fd);
    char name[64] = {
    
     0 };
    sscanf(buff, "%s %ld %ld %ld %ld", name, &user_time, &nice_time, &system_time, &idle_time);
    fclose(fd);

    return (user_time + nice_time + system_time + idle_time);
}

static inline unsigned long get_cpu_proc_occupy(int pid)
{
    
    
    // get specific pid cpu use time
    unsigned int tmp_pid;
    unsigned long utime;  // user time
    unsigned long stime;  // kernel time
    unsigned long cutime; // all user time
    unsigned long cstime; // all dead time

    char file_name[64] = {
    
     0 };
    FILE* fd;
    char line_buff[1024] = {
    
     0 };
    sprintf(file_name, "/proc/%d/stat", pid);

    fd = fopen(file_name, "r");
    if (nullptr == fd)
        return 0;

    fgets(line_buff, sizeof(line_buff), fd);

    sscanf(line_buff, "%u", &tmp_pid);
    const char* q = get_items(line_buff, PROCESS_ITEM);
    sscanf(q, "%ld %ld %ld %ld", &utime, &stime, &cutime, &cstime);
    fclose(fd);

    return (utime + stime + cutime + cstime);
}
#endif

inline float GetCpuUsageRatio(int pid)
{
    
    
#ifdef WIN32
    static int64_t last_time = 0;
    static int64_t last_system_time = 0;

    FILETIME now;
    FILETIME creation_time;
    FILETIME exit_time;
    FILETIME kernel_time;
    FILETIME user_time;
    int64_t system_time;
    int64_t time;
    int64_t system_time_delta;
    int64_t time_delta;

    // get cpu num
    SYSTEM_INFO info;
    GetSystemInfo(&info);
    int cpu_num = info.dwNumberOfProcessors;

    float cpu_ratio = 0.0;

    // get process hanlde by pid
    HANDLE process = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid);
    // use GetCurrentProcess() can get current process and no need to close handle

    // get now time
    GetSystemTimeAsFileTime(&now);

    if (!GetProcessTimes(process, &creation_time, &exit_time, &kernel_time, &user_time))
    {
    
    
        // We don't assert here because in some cases (such as in the Task Manager)  
        // we may call this function on a process that has just exited but we have  
        // not yet received the notification.  
        printf("GetCpuUsageRatio GetProcessTimes failed\n");
        return 0.0;
    }

    // should handle the multiple cpu num
    system_time = (convert_time_format(&kernel_time) + convert_time_format(&user_time)) / cpu_num;
    time = convert_time_format(&now);

    if ((last_system_time == 0) || (last_time == 0))
    {
    
    
        // First call, just set the last values.  
        last_system_time = system_time;
        last_time = time;
        return 0.0;
    }

    system_time_delta = system_time - last_system_time;
    time_delta = time - last_time;

    CloseHandle(process);

    if (time_delta == 0)
    {
    
    
        printf("GetCpuUsageRatio time_delta is 0, error\n");
        return 0.0;
    }

    // We add time_delta / 2 so the result is rounded.  
    cpu_ratio = (int)((system_time_delta * 100 + time_delta / 2) / time_delta); // the % unit
    last_system_time = system_time;
    last_time = time;

    cpu_ratio /= 100.0; // convert to float number

    return cpu_ratio;
#else
    unsigned long totalcputime1, totalcputime2;
    unsigned long procputime1, procputime2;

    totalcputime1 = get_cpu_total_occupy();
    procputime1 = get_cpu_proc_occupy(pid);

    // FIXME: the 200ms is a magic number, works well
    usleep(200000); // sleep 200ms to fetch two time point cpu usage snapshots sample for later calculation

    totalcputime2 = get_cpu_total_occupy();
    procputime2 = get_cpu_proc_occupy(pid);

    float pcpu = 0.0;
    if (0 != totalcputime2 - totalcputime1)
        pcpu = (procputime2 - procputime1) / float(totalcputime2 - totalcputime1); // float number

    int cpu_num = get_nprocs();
    pcpu *= cpu_num; // should multiply cpu num in multiple cpu machine

    return pcpu;
#endif
}

// get specific process physical memeory occupation size by pid (MB)
inline float GetMemoryUsage(int pid)
{
    
    
#ifdef WIN32
    uint64_t mem = 0, vmem = 0;
    PROCESS_MEMORY_COUNTERS pmc;

    // get process hanlde by pid
    HANDLE process = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid);
    if (GetProcessMemoryInfo(process, &pmc, sizeof(pmc)))
    {
    
    
        mem = pmc.WorkingSetSize;
        vmem = pmc.PagefileUsage;
    }
    CloseHandle(process);

    // use GetCurrentProcess() can get current process and no need to close handle

    // convert mem from B to MB
    return mem / 1024.0 / 1024.0;

#else
    char file_name[64] = {
    
     0 };
    FILE* fd;
    char line_buff[512] = {
    
     0 };
    sprintf(file_name, "/proc/%d/status", pid);

    fd = fopen(file_name, "r");
    if (nullptr == fd)
        return 0;

    char name[64];
    int vmrss = 0;
    for (int i = 0; i < VMRSS_LINE - 1; i++)
        fgets(line_buff, sizeof(line_buff), fd);

    fgets(line_buff, sizeof(line_buff), fd);
    sscanf(line_buff, "%s %d", name, &vmrss);
    fclose(fd);

    // cnvert VmRSS from KB to MB
    return vmrss / 1024.0;
#endif
}

int main()
{
    
    
    // launch some task to occupy cpu and memory
    for (int i = 0; i < 5; i++)
        std::thread([]
            {
    
    
                std::this_thread::sleep_for(std::chrono::milliseconds(10));
            }).detach();

    int current_pid = GetCurrentPid(); // or you can set a outside program pid
    float cpu_usage_ratio = GetCpuUsageRatio(current_pid);
    float memory_usage = GetMemoryUsage(current_pid);

    while (true)
    {
    
    
        std::cout << "current pid: " << current_pid << std::endl;
        std::cout << "cpu usage ratio: " << cpu_usage_ratio * 100 << "%" << std::endl;
        std::cout << "memory usage: " << memory_usage << "MB" << std::endl;

        std::this_thread::sleep_for(std::chrono::milliseconds(1000));
    }

    return 0;
}

network

The network is more troublesome. If it is your own process, you can capture all traffic values ​​in the process. In addition, the main way to use the bypass is to use pcap to bypass the packet capture. nethogs is already used The pcap method bypasses statistics to capture packets, you can use this directly.
$ yum -y install libpcap-devel ncurses-devel
$ tar zxvf nethogs-0.8.0.tar.gz
$ cd nethogs
$ make && make install
$ nethogs eth0

The nethelp function can be used on windows

gpu

This occupation is more troublesome, I will talk about it next time.