top.c

linux下获取一些环境信息的代码

#ifdef CASEUP_SCALE
   static char nextup[] =  { 'K', 'M', 'G', 'T', 0 };
#else
   static char nextup[] =  { 'k', 'm', 'g', 't', 0 };
#endif
   static char buf[TNYBUFSIZ];
   double *dp;
   char *up;

      /* try an unscaled version first... */
   if (width >= snprintf(buf, sizeof(buf), "%lu", num)) return buf;

      /* now try successively higher types until it fits */
   for (up = nextup + type, dp = scale; *dp; ++dp, ++up) {
         /* the most accurate version */
      if (width >= snprintf(buf, sizeof(buf), "%.1f%c", num / *dp, *up))
         return buf;
         /* the integer version */
      if (width >= snprintf(buf, sizeof(buf), "%ld%c", (unsigned long)(num / *dp), *up))
         return buf;
   }
      /* well shoot, this outta' fit... */
   return "?";
}


        /*
         * Do some scaling stuff.
         * format 'tics' to fit 'width'. */
static const char *scale_tics (TIC_t tics, const int width)
{
#ifdef CASEUP_SCALE
#define HH "%uH"
#define DD "%uD"
#define WW "%uW"
#else
#define HH "%uh"
#define DD "%ud"
#define WW "%uw"
#endif
   static char buf[TNYBUFSIZ];
   unsigned long nt;    // narrow time, for speed on 32-bit
   unsigned cc;         // centiseconds
   unsigned nn;         // multi-purpose whatever

   nt  = (tics * 100ull) / Hertz;
   cc  = nt % 100;                              // centiseconds past second
   nt /= 100;                                   // total seconds
   nn  = nt % 60;                               // seconds past the minute
   nt /= 60;                                    // total minutes
   if (width >= snprintf(buf, sizeof(buf), "%lu:%02u.%02u", nt, nn, cc))
      return buf;
   if (width >= snprintf(buf, sizeof buf, "%lu:%02u", nt, nn))
      return buf;
   nn  = nt % 60;                               // minutes past the hour
   nt /= 60;                                    // total hours
   if (width >= snprintf(buf, sizeof buf, "%lu,%02u", nt, nn))
      return buf;
   nn = nt;                                     // now also hours
   if (width >= snprintf(buf, sizeof buf, HH, nn))
      return buf;
   nn /= 24;                                    // now days
   if (width >= snprintf(buf, sizeof buf, DD, nn))
      return buf;
   nn /= 7;                                     // now weeks
   if (width >= snprintf(buf, sizeof buf, WW, nn))
      return buf;
      // well shoot, this outta' fit...
   return "?";

#undef HH
#undef DD
#undef WW
}

#include <pwd.h>

static int selection_type;
static uid_t selection_uid;

// FIXME: this is "temporary" code we hope
static int good_uid(const proc_t *restrict const pp){
   switch(selection_type){
   case 'p':
      return 1;
   case 0:
      return 1;
   case 'U':
      if (pp->ruid == selection_uid) return 1;
      if (pp->suid == selection_uid) return 1;
      if (pp->fuid == selection_uid) return 1;
      // FALLTHROUGH
   case 'u':
      if (pp->euid == selection_uid) return 1;
      // FALLTHROUGH
   default:
      ;  // don't know what it is; find bugs fast
   }
   return 0;
}

// swiped from ps, and ought to be in libproc
static const char *parse_uid(const char *restrict const str, uid_t *restrict const ret){
   struct passwd *passwd_data;
   char *endp;
   unsigned long num;
   static const char uidrange[] = "User ID out of range.";
   static const char uidexist[] = "User name does not exist.";
   num = strtoul(str, &endp, 0);
   if(*endp != '\0'){  /* hmmm, try as login name */
      passwd_data = getpwnam(str);
      if(!passwd_data)    return uidexist;
      num = passwd_data->pw_uid;
   }
   if(num > 0xfffffffeUL) return uidrange;
   *ret = num;
   return 0;
}


/*######  Library Alternatives  ##########################################*/

        /*
         * Handle our own memory stuff without the risk of leaving the
         * user's terminal in an ugly state should things go sour. */

static void *alloc_c (unsigned numb) MALLOC;
static void *alloc_c (unsigned numb)
{
   void * p;

   if (!numb) ++numb;
   if (!(p = calloc(1, numb)))
      std_err("failed memory allocate");
   return p;
}

static void *alloc_r (void *q, unsigned numb) MALLOC;
static void *alloc_r (void *q, unsigned numb)
{
   void *p;

   if (!numb) ++numb;
   if (!(p = realloc(q, numb)))
      std_err("failed memory allocate");
   return p;
}


        /*
         * This guy's modeled on libproc's 'five_cpu_numbers' function except
         * we preserve all cpu data in our CPU_t array which is organized
         * as follows:
         *    cpus[0] thru cpus[n] == tics for each separate cpu
         *    cpus[Cpu_tot]        == tics from the 1st /proc/stat line */
static CPU_t *cpus_refresh (CPU_t *cpus)
{
   static FILE *fp = NULL;
   int i;
   int num;
   // enough for a /proc/stat CPU line (not the intr line)
   char buf[SMLBUFSIZ];

   /* by opening this file once, we'll avoid the hit on minor page faults
      (sorry Linux, but you'll have to close it for us) */
   if (!fp) {
      if (!(fp = fopen("/proc/stat", "r")))
         std_err(fmtmk("Failed /proc/stat open: %s", strerror(errno)));
      /* note: we allocate one more CPU_t than Cpu_tot so that the last slot
               can hold tics representing the /proc/stat cpu summary (the first
               line read) -- that slot supports our View_CPUSUM toggle */
      cpus = alloc_c((1 + Cpu_tot) * sizeof(CPU_t));
   }
   rewind(fp);
   fflush(fp);

   // first value the last slot with the cpu summary line
   if (!fgets(buf, sizeof(buf), fp)) std_err("failed /proc/stat read");
   cpus[Cpu_tot].x = 0;  // FIXME: can't tell by kernel version number
   cpus[Cpu_tot].y = 0;  // FIXME: can't tell by kernel version number
   cpus[Cpu_tot].z = 0;  // FIXME: can't tell by kernel version number
   num = sscanf(buf, "cpu %Lu %Lu %Lu %Lu %Lu %Lu %Lu %Lu",
      &cpus[Cpu_tot].u,
      &cpus[Cpu_tot].n,
      &cpus[Cpu_tot].s,
      &cpus[Cpu_tot].i,
      &cpus[Cpu_tot].w,
      &cpus[Cpu_tot].x,
      &cpus[Cpu_tot].y,
      &cpus[Cpu_tot].z
   );
   if (num < 4)
         std_err("failed /proc/stat read");

   // and just in case we're 2.2.xx compiled without SMP support...
   if (Cpu_tot == 1) {
      cpus[1].id = 0;
      memcpy(cpus, &cpus[1], sizeof(CPU_t));
   }

   // now value each separate cpu's tics
   for (i = 0; 1 < Cpu_tot && i < Cpu_tot; i++) {
      if (!fgets(buf, sizeof(buf), fp)) std_err("failed /proc/stat read");
      cpus[i].x = 0;  // FIXME: can't tell by kernel version number
      cpus[i].y = 0;  // FIXME: can't tell by kernel version number
      cpus[i].z = 0;  // FIXME: can't tell by kernel version number
      num = sscanf(buf, "cpu%u %Lu %Lu %Lu %Lu %Lu %Lu %Lu %Lu",
         &cpus[i].id,
         &cpus[i].u, &cpus[i].n, &cpus[i].s, &cpus[i].i, &cpus[i].w, &cpus[i].x, &cpus[i].y, &cpus[i].z
      );
      if (num < 4)
            std_err("failed /proc/stat read");
   }
   return cpus;
}


        /*
         * Refresh procs *Helper* function to eliminate yet one more need
         * to loop through our darn proc_t table.  He's responsible for:
         *    1) calculating the elapsed time since the previous frame
         *    2) counting the number of tasks in each state (run, sleep, etc)
         *    3) maintaining the HST_t's and priming the proc_t pcpu field
         *    4) establishing the total number tasks for this frame */
static void prochlp (proc_t *this)
{
   static HST_t    *hist_sav = NULL;
   static HST_t    *hist_new = NULL;
   static unsigned  hist_siz = 0;       // number of structs
   static unsigned  maxt_sav;           // prior frame's max tasks
   TIC_t tics;

   if (unlikely(!this)) {
      static struct timeval oldtimev;
      struct timeval timev;
      struct timezone timez;
      HST_t *hist_tmp;
      float et;

      gettimeofday(&timev, &timez);
      et = (timev.tv_sec - oldtimev.tv_sec)
         + (float)(timev.tv_usec - oldtimev.tv_usec) / 1000000.0;
      oldtimev.tv_sec = timev.tv_sec;
      oldtimev.tv_usec = timev.tv_usec;

      // if in Solaris mode, adjust our scaling for all cpus
      Frame_tscale = 100.0f / ((float)Hertz * (float)et * (Rc.mode_irixps ? 1 : Cpu_tot));
      maxt_sav = Frame_maxtask;
      Frame_maxtask = Frame_running = Frame_sleepin = Frame_stopped = Frame_zombied = 0;

      // reuse memory each time around
      hist_tmp = hist_sav;
      hist_sav = hist_new;
      hist_new = hist_tmp;
      // prep for our binary search by sorting the last frame's HST_t's
      qsort(hist_sav, maxt_sav, sizeof(HST_t), (QFP_t)sort_HST_t);
      return;
   }

   switch (this->state) {
      case 'R':
         Frame_running++;
         break;
      case 'S':
      case 'D':
         Frame_sleepin++;
         break;
      case 'T':
         Frame_stopped++;
         break;
      case 'Z':
         Frame_zombied++;
         break;
   }

   if (unlikely(Frame_maxtask+1 >= hist_siz)) {
      hist_siz = hist_siz * 5 / 4 + 100;  // grow by at least 25%
      hist_sav = alloc_r(hist_sav, sizeof(HST_t) * hist_siz);
      hist_new = alloc_r(hist_new, sizeof(HST_t) * hist_siz);
   }
   /* calculate time in this process; the sum of user time (utime) and
      system time (stime) -- but PLEASE dont waste time and effort on
      calcs and saves that go unused, like the old top! */
   hist_new[Frame_maxtask].pid  = this->tid;
   hist_new[Frame_maxtask].tics = tics = (this->utime + this->stime);

#if 0
{  int i;
   int lo = 0;
   int hi = maxt_sav - 1;

   // find matching entry from previous frame and make ticks elapsed
   while (lo <= hi) {
      i = (lo + hi) / 2;
      if (this->tid < hist_sav[i].pid)
         hi = i - 1;
      else if (likely(this->tid > hist_sav[i].pid))
         lo = i + 1;
      else {
         tics -= hist_sav[i].tics;
         break;
      }
   }
}
#else
{
   HST_t tmp;
   const HST_t *ptr;
   tmp.pid = this->tid;
   ptr = bsearch(&tmp, hist_sav, maxt_sav, sizeof tmp, sort_HST_t);
   if(ptr) tics -= ptr->tics;
}
#endif

   // we're just saving elapsed tics, to be converted into %cpu if
   // this task wins it's displayable screen row lottery... */
   this->pcpu = tics;
// if (Frames_maxcmdln) { }
   // shout this to the world with the final call (or us the next time in)
   Frame_maxtask++;
}


        /*
         * This guy's modeled on libproc's 'readproctab' function except
         * we reuse and extend any prior proc_t's.  He's been customized
         * for our specific needs and to avoid the use of <stdarg.h> */
static proc_t **procs_refresh (proc_t **table, int flags)
{
#define PTRsz  sizeof(proc_t *)
#define ENTsz  sizeof(proc_t)
   static unsigned savmax = 0;          // first time, Bypass: (i)
   proc_t *ptsk = (proc_t *)-1;         // first time, Force: (ii)
   unsigned curmax = 0;                 // every time  (jeeze)
   PROCTAB* PT;
   static int show_threads_was_enabled = 0; // optimization

   prochlp(NULL);                       // prep for a new frame
   if (Monpidsidx)
      PT = openproc(flags, Monpids);
   else
      PT = openproc(flags);

   // i) Allocated Chunks:  *Existing* table;  refresh + reuse
   if (!(CHKw(Curwin, Show_THREADS))) {
      while (curmax < savmax) {
         if (table[curmax]->cmdline) {
            unsigned idx;
            // Skip if Show_THREADS was never enabled
            if (show_threads_was_enabled) {
               for (idx = curmax + 1; idx < savmax; idx++) {
                  if (table[idx]->cmdline == table[curmax]->cmdline)
                     table[idx]->cmdline = NULL;
               }
            }
            free(*table[curmax]->cmdline);
            table[curmax]->cmdline = NULL;
         }
         if (unlikely(!(ptsk = readproc(PT, table[curmax])))) break;
         prochlp(ptsk);                    // tally & complete this proc_t
         ++curmax;
      }
   }
   else {                          // show each thread in a process separately
      while (curmax < savmax) {
         proc_t *ttsk;
         if (unlikely(!(ptsk = readproc(PT, NULL)))) break;
         show_threads_was_enabled = 1;
         while (curmax < savmax) {
            unsigned idx;
            if (table[curmax]->cmdline) {
               // threads share the same cmdline storage.  'table' is
               // qsort()ed, so must look through the rest of the table.
               for (idx = curmax + 1; idx < savmax; idx++) {
                  if (table[idx]->cmdline == table[curmax]->cmdline)
                     table[idx]->cmdline = NULL;
               }
               free(*table[curmax]->cmdline);  // only free once