m_bsd44.c

unix系统下top命令的源代码

static struct handle handle;

caddr_t get_process_info(si, sel, compare)

struct system_info *si;
struct process_select *sel;
int (*compare)();

{
    register int i;
    register int total_procs;
    register int active_procs;
    register struct kinfo_proc **prefp;
    register struct kinfo_proc *pp;

    /* these are copied out of sel for speed */
    int show_idle;
    int show_system;
    int show_uid;
    int show_command;

    
    pbase = kvm_getprocs(kd, KERN_PROC_ALL, 0, &nproc);
    if (nproc > onproc)
	pref = (struct kinfo_proc **) realloc(pref, sizeof(struct kinfo_proc *)
		* (onproc = nproc));
    if (pref == NULL || pbase == NULL) {
	(void) fprintf(stderr, "top: Out of memory.\n");
	quit(23);
    }
    /* get a pointer to the states summary array */
    si->procstates = process_states;

    /* set up flags which define what we are going to select */
    show_idle = sel->idle;
    show_system = sel->system;
    show_uid = sel->uid != -1;
    show_command = sel->command != NULL;

    /* count up process states and get pointers to interesting procs */
    total_procs = 0;
    active_procs = 0;
    memset((char *)process_states, 0, sizeof(process_states));
    prefp = pref;
    for (pp = pbase, i = 0; i < nproc; 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 get ignored unless show_sysprocs is set.
	 */
	if (PP(pp, p_stat) != 0 &&
	    (show_system || ((PP(pp, p_flag) & SSYS) == 0)))
	{
	    total_procs++;
	    process_states[(unsigned char) PP(pp, p_stat)]++;
	    if ((PP(pp, p_stat) != SZOMB) &&
		(show_idle || (PP(pp, p_pctcpu) != 0) || 
		 (PP(pp, p_stat) == SRUN)) &&
		(!show_uid || EP(pp, e_pcred.p_ruid) == (uid_t)sel->uid))
	    {
		*prefp++ = pp;
		active_procs++;
	    }
	}
    }

    /* if requested, sort the "interesting" processes */
    if (compare != NULL)
    {
	qsort((char *)pref, active_procs, sizeof(struct kinfo_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[MAX_COLS];		/* static area where result is built */

char *format_next_process(handle, get_userid)

caddr_t handle;
char *(*get_userid)();

{
    register struct kinfo_proc *pp;
    register long cputime;
    register double pct;
    struct handle *hp;

    /* 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 ((PP(pp, p_flag) & SLOAD) == 0) {
	/*
	 * Print swapped processes as <pname>
	 */
	char *comm = PP(pp, p_comm);
#define COMSIZ sizeof(PP(pp, p_comm))
	char buf[COMSIZ];
	(void) strncpy(buf, comm, COMSIZ);
	comm[0] = '<';
	(void) strncpy(&comm[1], buf, COMSIZ - 2);
	comm[COMSIZ - 2] = '\0';
	(void) strncat(comm, ">", COMSIZ - 1);
	comm[COMSIZ - 1] = '\0';
    }

#if 0
    /* This does not produce the correct results */
    cputime = PP(pp, p_uticks) + PP(pp, p_sticks) + PP(pp, p_iticks);
#endif
    cputime = PP(pp, p_rtime).tv_sec;	/* This does not count interrupts */

    /* calculate the base for cpu percentages */
    pct = pctdouble(PP(pp, p_pctcpu));

    /* format this entry */
    sprintf(fmt,
	    Proc_format,
	    PP(pp, p_pid),
	    (*get_userid)(EP(pp, e_pcred.p_ruid)),
	    PP(pp, p_pri) - PZERO,
	    PP(pp, p_nice) - NZERO,
	    format_k(pagetok(PROCSIZE(pp))),
	    format_k(pagetok(VP(pp, vm_rssize))),
	    state_abbrev[(unsigned char) PP(pp, p_stat)],
	    format_time(cputime),
	    100.0 * weighted_cpu(pct, pp),
	    100.0 * pct,
	    printable(PP(pp, p_comm)));

    /* return the result */
    return(fmt);
}


/*
 * check_nlist(nlst) - 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 found.
 */

static int check_nlist(nlst)

register struct nlist *nlst;

{
    register int i;

    /* check to see if we got ALL the symbols we requested */
    /* this will write one line to stderr for every symbol not found */

    i = 0;
    while (nlst->n_name != NULL)
    {
	if (nlst->n_type == 0)
	{
	    /* this one wasn't found */
	    (void) fprintf(stderr, "kernel: no symbol named `%s'\n",
			   nlst->n_name);
	    i = 1;
	}
	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).
 *  	
 */

static int getkval(offset, ptr, size, refstr)

unsigned long offset;
int *ptr;
int size;
char *refstr;

{
    if (kvm_read(kd, offset, (char *) ptr, size) != size)
    {
	if (*refstr == '!')
	{
	    return(0);
	}
	else
	{
	    fprintf(stderr, "top: kvm_read for %s: %s\n",
		refstr, strerror(errno));
	    quit(23);
	}
    }
    return(1);
}
    
/* comparison routine for qsort */

/*
 *  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		*/
    3,	/* sleep		*/
    1,	/* ABANDONED (WAIT)	*/
    6,	/* run			*/
    5,	/* start		*/
    2,	/* zombie		*/
    4	/* stop			*/
};
 
int
proc_compare(pp1, pp2)

struct proc **pp1;
struct proc **pp2;

{
    register struct kinfo_proc *p1;
    register struct kinfo_proc *p2;
    register int result;
    register pctcpu lresult;

    /* remove one level of indirection */
    p1 = *(struct kinfo_proc **) pp1;
    p2 = *(struct kinfo_proc **) pp2;

    /* compare percent cpu (pctcpu) */
    if ((lresult = PP(p2, p_pctcpu) - PP(p1, p_pctcpu)) == 0)
    {
	/* use cpticks to break the tie */
	if ((result = PP(p2, p_cpticks) - PP(p1, p_cpticks)) == 0)
	{
	    /* use process state to break the tie */
	    if ((result = sorted_state[(unsigned char) PP(p2, p_stat)] -
			  sorted_state[(unsigned char) PP(p1, p_stat)])  == 0)
	    {
		/* use priority to break the tie */
		if ((result = PP(p2, p_pri) - PP(p1, p_pri)) == 0)
		{
		    /* use resident set size (rssize) to break the tie */
		    if ((result = VP(p2, vm_rssize) - VP(p1, vm_rssize)) == 0)
		    {
			/* use total memory to break the tie */
			result = PROCSIZE(p2) - PROCSIZE(p1);
		    }
		}
	    }
	}
    }
    else
    {
	result = lresult < 0 ? -1 : 1;
    }

    return(result);
}


/*
 * proc_owner(pid) - returns the uid that owns process "pid", or -1 if
 *		the process does not exist.
 *		It is EXTREMLY IMPORTANT that this function work correctly.
 *		If top runs setuid root (as in SVR4), then this function
 *		is the only thing that stands in the way of a serious
 *		security problem.  It validates requests for the "kill"
 *		and "renice" commands.
 */

int proc_owner(pid)

int pid;

{
    register int cnt;
    register struct kinfo_proc **prefp;
    register struct kinfo_proc *pp;

    prefp = pref;
    cnt = pref_len;
    while (--cnt >= 0)
    {
	pp = *prefp++;	
	if (PP(pp, p_pid) == (pid_t)pid)
	{
	    return((int)EP(pp, e_pcred.p_ruid));
	}
    }
    return(-1);
}