m_mtxinu.c

unix系统下top命令的源代码

    /* 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 */

/* define what weighted cpu is.  */
#define weighted_cpu(pct, pp) ((pp)->p_time == 0 ? 0.0 : \
			 ((pct) / (1.0 - exp((pp)->p_time * logcpu))))

char *format_next_process(handle, get_userid)

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

{
    register struct proc *pp;
    register double pct;
    struct user u;
    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 (getu(pp, &u) == -1)
    {
	(void) strcpy(u.u_comm, "<swapped>");
    }
    else
    {
	/* set u_comm for system processes */
	if (u.u_comm[0] == '\0')
	{
	    if (pp->p_pid == 0)
	    {
		(void) strcpy(u.u_comm, "Swapper");
	    }
	    else if (pp->p_pid == 2)
	    {
		(void) strcpy(u.u_comm, "Pager");
	    }
	}
    }

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

    /* 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(pagetok(PROCSIZE(pp))),
	    format_k(pagetok(pp->p_rssize)),
	    state_abbrev[pp->p_stat],
	    format_time(PROCTIME(pp)),
	    100.0 * weighted_cpu(pct, pp),
	    100.0 * pct,
	    printable(u.u_comm));

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

/*
 *  getu(p, u) - get the user structure for the process whose proc structure
 *      is pointed to by p.  The user structure is put in the buffer pointed
 *      to by u.  Return 0 if successful, -1 on failure (such as the process
 *      being swapped out).
 */

getu(p, u)

register struct proc *p;
struct user *u;

{
    struct pte uptes[UPAGES];
    register caddr_t upage;
    register struct pte *pte;
    register nbytes, n;

    /*
     *  Check if the process is currently loaded or swapped out.  The way we
     *  get the u area is totally different for the two cases.  For this
     *  application, we just don't bother if the process is swapped out.
     */
    if ((p->p_flag & SLOAD) == 0)
    {
	return(-1);
    }

    /*
     *  Process is currently in memory, we hope!
     */
    if (!getkval((unsigned long)p->p_addr, (int *)uptes, sizeof(uptes),
		"!p->p_addr"))
    {
	/* we can't seem to get to it, so pretend it's swapped out */
	return(-1);
    }
    upage = (caddr_t)u;
    pte = uptes;
    for (nbytes = sizeof(struct user); nbytes > 0; nbytes -= NBPG)
    {
	(void) lseek(mem, (long)(pte++->pg_pfnum * NBPG), 0);
	n = MIN(nbytes, NBPG);
	if (read(mem, upage, n) != n)
	{
	    /* we can't seem to get to it, so pretend it's swapped out */
	    return(-1);
	}
	upage += n;
    }
    return(0);
}

/*
 * 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.
 */

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 */
	    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).
 *
 */

getkval(offset, ptr, size, refstr)

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

{
    if (lseek(kmem, (long)offset, 0) == -1)
    {
	if (*refstr == '!')
	{
	    refstr++;
	}
	fprintf(stderr, "%s: lseek to %s: %s\n",
	    KMEM, refstr, sys_errlist[errno]);
	quit(22);
    }
    if (read(kmem, (char *)ptr, size) == -1)
    {
	if (*refstr == '!')
	{
	    /* we lost the race with the kernel, process isn't in memory */
	    return(0);
	}
	else
	{
	    fprintf(stderr, "%s: reading %s: %s\n",
		KMEM, refstr, sys_errlist[errno]);
	    quit(23);
	}
    }
    return(1);
}

/* comparison routines for qsort */

/*
 * There are currently four possible comparison routines.  main selects
 * one of these by indexing in to the array proc_compares.
 *
 * Possible keys are defined as macros below.  Currently these keys are
 * defined:  percent cpu, cpu ticks, process 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.
 */

/* First, the possible comparison keys.  These are defined in such a way
   that they can be merely listed in the source code to define the actual
   desired ordering.
 */

#define ORDERKEY_PCTCPU  if (lresult = p2->p_pctcpu - p1->p_pctcpu,\
			     (result = lresult < 0 ? -1 : 1) == 0)
#define ORDERKEY_CPTICKS if ((result = PROCTIME(p2) - PROCTIME(p1)) == 0)
#define ORDERKEY_STATE   if ((result = (long) (sorted_state[p2->p_stat] - \
			       sorted_state[p1->p_stat])) == 0)
#define ORDERKEY_PRIO    if ((result = p2->p_pri - p1->p_pri) == 0)
#define ORDERKEY_RSSIZE  if ((result = p2->p_rssize - p1->p_rssize) == 0)
#define ORDERKEY_MEM     if ((result = (PROCSIZE(p2) - PROCSIZE(p1))) == 0)

/* Now the array that maps process state to a weight */

static unsigned char sorted_state[] =
{
    0,  /* not used             */
    3,  /* sleep                */
    1,  /* ABANDONED (WAIT)     */
    6,  /* run                  */
    5,  /* start                */
    2,  /* zombie               */
    4   /* stop                 */
};


/* compare_cpu - the comparison function for sorting by cpu percentage */

compare_cpu(pp1, pp2)

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

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

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

    ORDERKEY_PCTCPU
    ORDERKEY_CPTICKS
    ORDERKEY_STATE
    ORDERKEY_PRIO
    ORDERKEY_RSSIZE
    ORDERKEY_MEM
    ;

    return(result);
}

/* compare_size - the comparison function for sorting by total memory usage */

compare_size(pp1, pp2)

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

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

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

    ORDERKEY_MEM
    ORDERKEY_RSSIZE
    ORDERKEY_PCTCPU
    ORDERKEY_CPTICKS
    ORDERKEY_STATE
    ORDERKEY_PRIO
    ;

    return(result);
}

/* compare_res - the comparison function for sorting by resident set size */

compare_res(pp1, pp2)

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

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

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

    ORDERKEY_RSSIZE
    ORDERKEY_MEM
    ORDERKEY_PCTCPU
    ORDERKEY_CPTICKS
    ORDERKEY_STATE
    ORDERKEY_PRIO
    ;

    return(result);
}

/* compare_time - the comparison function for sorting by total cpu time */

compare_time(pp1, pp2)

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

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

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

    ORDERKEY_CPTICKS
    ORDERKEY_PCTCPU
    ORDERKEY_STATE
    ORDERKEY_PRIO
    ORDERKEY_RSSIZE
    ORDERKEY_MEM
    ;

    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 proc **prefp;
    register struct proc *pp;

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