m_sco.c

unix系统下top命令的源代码

        struct system_info *si;
        struct process_select *sel;
        int (*compare)();
{
register int i;
register int total_procs;
register int active_procs;
register struct proc **prefp;
register struct proc *pp;

/* set up flags of what we are going to select */
/* these are copied out of sel for simplicity */
int show_idle = sel->idle;
int show_system = sel->system;
int show_uid = sel->uid != -1;
int show_command = sel->command != NULL;

   /* read all the proc structures in one fell swoop */
   (void) getkval(proca, (int *)pbase, bytes, "proc array");

   /* get a pointer to the states summary array */
   si->procstates = process_states;

   /* count up process states and get pointers to interesting procs */
   total_procs = active_procs = 0;
   memset((char *)process_states, 0, sizeof(process_states));
   prefp = pref;
   for (pp = pbase, i = 0; i < v.v_proc; pp++, i++) {
      /*
       * Place pointers to each valid proc structure in pref[].
       * Process slots that are actually in use have a non-zero
       * status field. Processes with SSYS set are system processes --
       * these are ignored unless show_system is set.
       */
      if (pp->p_stat && (show_system || ((pp->p_flag & SSYS) == 0))) {
         total_procs++;
         process_states[pp->p_stat]++;
	 if ((pp->p_stat != SZOMB) &&
	     (show_idle || (pp->p_stat == SRUN) || (pp->p_stat == SONPROC)) &&
	     (!show_uid || pp->p_uid == (ushort)sel->uid)) {
		*prefp++ = pp;
		active_procs++;
	 }
      }
   }

   /* if requested, sort the "interesting" processes */
   if (compare)
      qsort((char *)pref, active_procs, sizeof(struct proc *), compare);

   /* remember active and total counts */
   si->p_total = total_procs;
   si->p_active = pref_len = active_procs;

   /* pass back a handle */
   handle.next_proc = pref;
   handle.remaining = active_procs;
   return((caddr_t)&handle);
}

char fmt[128];		/* static area where result is built */

char *format_next_process(handle, get_userid)
      caddr_t handle;
      char *(*get_userid)();
{
register struct proc *pp;
register time_t cputime;
register double pct;
int where;
struct user u;
struct handle *hp;
char command[29];

   /* find and remember the next proc structure */
   hp = (struct handle *)handle;
   pp = *(hp->next_proc++);
   hp->remaining--;

   /* get the process's user struct and set cputime */
   if ((where = sysi86(RDUBLK, pp->p_pid, &u, sizeof(struct user))) != -1)
      where = (pp->p_flag & SLOAD) ? 0 : 1;
   if (where == -1) {
      strcpy(command, "<swapped>");
      cputime = 0;
   } else {
      /* set u_comm for system processes */
      if (u.u_comm[0] == '\0') {
	 if (pp->p_pid == 0)
	    strcpy(command, "Swapper");
	 else if (pp->p_pid == 2)
	    strcpy(command, "Pager");
	 else if (pp->p_pid == 3)
	    strcpy(command, "Sync'er");
      } else if (where == 1) {
	 /* print swapped processes as <pname> */
	 register char *s1;

	 u.u_psargs[28 - 3] = '\0';
	 strcpy(command, "<");
	 strcat(command, strtok(u.u_psargs, " "));
	 strcat(command, ">");
	 while (s1 = (char *)strtok(NULL, " "))
	    strcat(command, s1);
      } else {
	 sprintf(command, "%s", u.u_psargs);
      }
      cputime = u.u_utime + u.u_stime;
   }
   /* calculate the base for cpu percentages */
   pct = pctdouble(pp->p_cpu);

   /* format this entry */
   sprintf(fmt,
	   Proc_format,
	   pp->p_pid,
	   (*get_userid)(pp->p_uid),
	   pp->p_pri - PZERO,
	   pp->p_nice - NZERO,
	   format_k(PROCSIZE(&u)),
	   0,
	   state_abbrev[pp->p_stat],
	   format_time(cputime / Hz),
	   printable(command));

   return(fmt);
}

/*
 * Checks the nlist to see if any symbols were not found.
 * For every symbol that was not found, a one-line message
 * is printed to stderr. The routine returns the number of
 * symbols NOT founded.
 */

int check_nlist(nlst)
    register struct nlist *nlst;
{
register int i = 0;

   while (nlst->n_name) {
      if (nlst->n_type == 0) {
	 fprintf(stderr, "kernel: no symbol named `%s'\n", nlst->n_name);
	 i++;
      }
      nlst++;
   }
   return i;
}

/*
 *  getkval(offset, ptr, size, refstr) - get a value out of the kernel.
 *	"offset" is the byte offset into the kernel for the desired value,
 *  	"ptr" points to a buffer into which the value is retrieved,
 *  	"size" is the size of the buffer (and the object to retrieve),
 *  	"refstr" is a reference string used when printing error meessages,
 *	    if "refstr" starts with a '!', then a failure on read will not
 *  	    be fatal (this may seem like a silly way to do things, but I
 *  	    really didn't want the overhead of another argument).
 *  	
 */

getkval(offset, ptr, size, refstr)
unsigned long offset;
int *ptr;
int size;
char *refstr;
{
   if (lseek(kmem, (long)offset, SEEK_SET) == -1) {
      if (*refstr == '!')
         refstr++;
      fprintf(stderr, "%s: lseek to %s: %s\n", KMEM,
	       refstr, errmsg(errno));
      quit(23);
   }
   if (read(kmem, (char *)ptr, size) == -1) {
      if (*refstr == '!')
         return 0;
      fprintf(stderr, "%s: reading %s: %s\n", KMEM,
	       refstr, errmsg(errno));
      quit(23);
   }
   return(1);
}
    
/* comparison routine for qsort */
/* NOTE: this is specific to the BSD proc structure, but it should
   give you a good place to start. */

/*
 *  proc_compare - comparison function for "qsort"
 *	Compares the resource consumption of two processes using five
 *  	distinct keys.  The keys (in descending order of importance) are:
 *  	percent cpu, cpu ticks, state, resident set size, total virtual
 *  	memory usage.  The process states are ordered as follows (from least
 *  	to most important):  WAIT, zombie, sleep, stop, start, run.  The
 *  	array declaration below maps a process state index into a number
 *  	that reflects this ordering.
 */

static unsigned char sorted_state[] =
{
    0,	/* not used		*/
    5,	/* sleep		*/
    6,	/* run			*/
    2,	/* zombie		*/
    4,	/* stop			*/
    1,	/* start		*/
    7,	/* onpr    		*/
    3,	/* swap            	*/
};
 
proc_compare(pp1, pp2)
struct proc **pp1;
struct proc **pp2;

{
register struct proc *p1;
register struct proc *p2;
register int result;
register ulong lresult;

   /* remove one level of indirection */
   p1 = *pp1;
   p2 = *pp2;

   /* use process state to break the tie */
   if ((result = sorted_state[p2->p_stat] -
		 sorted_state[p1->p_stat])  == 0)
   {
      /* use priority to break the tie */
      if ((result = p2->p_pri - p1->p_pri) == 0)
      {
	 /* use time to break the tie */
	 if ((result = (p2->p_utime + p2->p_stime) -
		       (p1->p_utime + p1->p_stime)) == 0)
	 {
	    /* use resident set size (rssize) to break the tie */
	    if ((result = p2->p_size - p1->p_size) == 0)
	    {
	       result = 0;
	    }
	 }
      }
   }

    return(result);
}

/* returns uid of owner of process pid */
proc_owner(pid)
int pid;
{
register int cnt;
register struct proc **prefp;
register struct proc  *pp;

   prefp = pref;
   cnt = pref_len;
   while (--cnt >= 0) {
      if ((pp = *prefp++)->p_pid == (short)pid)
	 return ((int)pp->p_uid);
   }
   return(-1);
}

int setpriority(int dummy, int who, int nicewal)
{
   errno = 1;
   return -1;
}

/* sigblock is not POSIX conformant */
sigset_t sigblock (sigset_t mask)
{
sigset_t oset;

   sigemptyset(&oset);
   sigprocmask(SIG_BLOCK, &mask, &oset);
   return oset;
}

/* sigsetmask is not POSIX conformant */
sigsetmask(sigset_t mask)
{
sigset_t oset;

   sigemptyset(&oset);
   sigprocmask(SIG_SETMASK, &mask, &oset);
   return oset;
}