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- /* $Id: sm_cpu.c,v 1.9 2008/01/30 12:06:50 dijkstra Exp $ */
- /* The author of this code is Willem Dijkstra (wpd@xs4all.nl).
- *
- * The percentages function was written by William LeFebvre and is part
- * of the 'top' utility. His copyright statement is below.
- *
- * Copyright (c) 2001-2008 Willem Dijkstra
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * - Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following
- * disclaimer in the documentation and/or other materials provided
- * with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- */
- /*
- * Top users/processes display for Unix
- * Version 3
- *
- * This program may be freely redistributed,
- * but this entire comment MUST remain intact.
- *
- * Copyright (c) 1984, 1989, William LeFebvre, Rice University
- * Copyright (c) 1989, 1990, 1992, William LeFebvre, Northwestern University
- */
- /*
- * Get current cpu statistics in percentages (total of all counts = 100.0)
- * and returns them in symon_buf as
- *
- * user : nice : system : interrupt : idle
- */
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <fcntl.h>
- #include <ctype.h>
- #include <errno.h>
- #include <stdlib.h>
- #include <string.h>
- #include <strings.h>
- #include <unistd.h>
- #include "conf.h"
- #include "error.h"
- #include "symon.h"
- #include "xmalloc.h"
- __BEGIN_DECLS
- static int percentages(int, int64_t *, int64_t *, int64_t *, int64_t *);
- __END_DECLS
- /* Globals for this module all start with cp_ */
- static void *cp_buf = NULL;
- static int cp_size = 0;
- static int cp_maxsize = 0;
- /*
- * percentages(cnt, out, new, old, diffs) - calculate percentage change
- * between array "old" and "new", putting the percentages i "out".
- * "cnt" is size of each array and "diffs" is used for scratch space.
- * The array "old" is updated on each call.
- * The routine assumes modulo arithmetic. This function is especially
- * useful on BSD mchines for calculating cpu state percentages.
- */
- static int
- percentages(int cnt, int64_t *out, int64_t *new, int64_t *old, int64_t *diffs)
- {
- int64_t change, total_change, *dp, half_total;
- int i;
- /* initialization */
- total_change = 0;
- dp = diffs;
- /* calculate changes for each state and the overall change */
- for (i = 0; i < cnt; i++) {
- if ((change = *new - *old) < 0) {
- /* this only happens when the counter wraps */
- change = (QUAD_MAX - *old) + *new;
- }
- total_change += (*dp++ = change);
- *old++ = *new++;
- }
- /* avoid divide by zero potential */
- if (total_change == 0)
- total_change = 1;
- /* calculate percentages based on overall change, rounding up */
- half_total = total_change / 2l;
- for (i = 0; i < cnt; i++)
- *out++ = ((*diffs++ * 1000 + half_total) / total_change);
- /* return the total in case the caller wants to use it */
- return (total_change);
- }
- void
- init_cpu(struct stream *st)
- {
- char buf[SYMON_MAX_OBJSIZE];
- if (cp_buf == NULL) {
- cp_maxsize = SYMON_MAX_OBJSIZE;
- cp_buf = xmalloc(cp_maxsize);
- }
- if (st->arg != NULL && isdigit(*st->arg)) {
- snprintf(st->parg.cp.name, sizeof(st->parg.cp.name), "cpu%s", st->arg);
- } else {
- snprintf(st->parg.cp.name, sizeof(st->parg.cp.name), "cpu");
- }
- gets_cpu();
- get_cpu(buf, sizeof(buf), st);
- info("started module cpu(%.200s)", st->arg);
- }
- void
- gets_cpu()
- {
- int fd;
- if ((fd = open("/proc/stat", O_RDONLY)) < 0) {
- warning("cannot access /proc/stat: %.200s", strerror(errno));
- return;
- }
- bzero(cp_buf, cp_maxsize);
- cp_size = read(fd, cp_buf, cp_maxsize);
- close(fd);
- if (cp_size == cp_maxsize) {
- /* buffer is too small to hold all interface data */
- cp_maxsize += SYMON_MAX_OBJSIZE;
- if (cp_maxsize > SYMON_MAX_OBJSIZE * SYMON_MAX_DOBJECTS) {
- fatal("%s:%d: dynamic object limit (%d) exceeded for cp data",
- __FILE__, __LINE__, SYMON_MAX_OBJSIZE * SYMON_MAX_DOBJECTS);
- }
- cp_buf = xrealloc(cp_buf, cp_maxsize);
- gets_cpu();
- return;
- }
- if (cp_size == -1) {
- warning("could not read if statistics from /proc/stat: %.200s", strerror(errno));
- }
- }
- int
- get_cpu(char *symon_buf, int maxlen, struct stream *st)
- {
- char *line;
- if (cp_size <= 0) {
- return 0;
- }
- if ((line = strstr(cp_buf, st->parg.cp.name)) == NULL) {
- warning("could not find %s", st->parg.cp.name);
- return 0;
- }
- line += strlen(st->parg.cp.name);
- if (CPUSTATES > sscanf(line, "%llu %llu %llu %llu %llu %llu %llu %llu\n",
- &st->parg.cp.time[CP_USER],
- &st->parg.cp.time[CP_NICE],
- &st->parg.cp.time[CP_SYS],
- &st->parg.cp.time[CP_IDLE],
- &st->parg.cp.time[CP_IOWAIT],
- &st->parg.cp.time[CP_HARDIRQ],
- &st->parg.cp.time[CP_SOFTIRQ],
- &st->parg.cp.time[CP_STEAL])) {
- /* /proc/stat might not support steal */
- st->parg.cp.time[CP_STEAL] = 0;
- if ((CPUSTATES - 1) > sscanf(line, "%llu %llu %llu %llu %llu %llu %llu\n",
- &st->parg.cp.time[CP_USER],
- &st->parg.cp.time[CP_NICE],
- &st->parg.cp.time[CP_SYS],
- &st->parg.cp.time[CP_IDLE],
- &st->parg.cp.time[CP_IOWAIT],
- &st->parg.cp.time[CP_HARDIRQ],
- &st->parg.cp.time[CP_SOFTIRQ])) {
- warning("could not parse cpu statistics for %.200s", &st->parg.cp.name);
- return 0;
- }
- }
- percentages(CPUSTATES, st->parg.cp.states, st->parg.cp.time,
- st->parg.cp.old, st->parg.cp.diff);
- return snpack(symon_buf, maxlen, st->arg, MT_CPU,
- (double) (st->parg.cp.states[CP_USER] / 10.0),
- (double) (st->parg.cp.states[CP_NICE] / 10.0),
- (double) (st->parg.cp.states[CP_SYS] / 10.0),
- (double) (st->parg.cp.states[CP_IOWAIT] +
- st->parg.cp.states[CP_HARDIRQ] +
- st->parg.cp.states[CP_SOFTIRQ] +
- st->parg.cp.states[CP_STEAL]) / 10.0,
- (double) (st->parg.cp.states[CP_IDLE] / 10.0));
- }
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