top.c

手机嵌入式Linux下可用的busybox源码

/*
 * A tiny 'top' utility.
 *
 * This is written specifically for the linux /proc/<PID>/stat(m)
 * files format.

 * This reads the PIDs of all processes and their status and shows
 * the status of processes (first ones that fit to screen) at given
 * intervals.
 * 
 * NOTES:
 * - At startup this changes to /proc, all the reads are then
 *   relative to that.
 * 
 * (C) Eero Tamminen <oak at welho dot com>
 *
 * Rewroted by Vladimir Oleynik (C) 2002 <[e-mail]>
 */

/* Original code Copyrights */
/*
 * Copyright (c) 1992 Branko Lankester
 * Copyright (c) 1992 Roger Binns
 * Copyright (C) 1994-1996 Charles L. Blake.
 * Copyright (C) 1992-1998 Michael K. Johnson
 * May be distributed under the conditions of the
 * GNU Library General Public License
 */

#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
/* get page info */
#include <asm/page.h>
#include "busybox.h"

#define FEATURE_CPU_USAGE_PERCENTAGE  /* + 2k */

#ifdef FEATURE_CPU_USAGE_PERCENTAGE
#include <time.h>
#include <sys/time.h>
#include <fcntl.h>
#include <netinet/in.h>  /* htons */
#endif


typedef struct {
	int pid;
	char user[9];
	char state[4];
	unsigned long rss;
	int ppid;
#ifdef FEATURE_CPU_USAGE_PERCENTAGE
	unsigned pcpu;
	unsigned long stime, utime;
#endif
	char *cmd;

	/* basename of executable file in call to exec(2),
		size from kernel headers */
	char short_cmd[16];
} status_t;

typedef int (*cmp_t)(status_t *P, status_t *Q);

static status_t *top;   /* Hehe */
static int ntop;


static int pid_sort (status_t *P, status_t *Q)
{
    int p = P->pid;
    int q = Q->pid;

    if( p < q ) return -1;
    if( p > q ) return  1;
    return 0;
}

static int mem_sort (status_t *P, status_t *Q)
{
    long p = P->rss;
    long q = Q->rss;

    if( p > q ) return -1;
    if( p < q ) return  1;
    return 0;
}

#ifdef FEATURE_CPU_USAGE_PERCENTAGE

#define sort_depth 3
static cmp_t sort_function[sort_depth];

static int pcpu_sort (status_t *P, status_t *Q)
{
    int p = P->pcpu;
    int q = Q->pcpu;

    if( p > q ) return -1;
    if( p < q ) return  1;
    return 0;
}

static int time_sort (status_t *P, status_t *Q)
{
    long p = P->stime;
    long q = Q->stime;

    p += P->utime;
    q += Q->utime;
    if( p > q ) return -1;
    if( p < q ) return  1;
    return 0;
}

int mult_lvl_cmp(void* a, void* b) {
    int i, cmp_val;

    for(i = 0; i < sort_depth; i++) {
	cmp_val = (*sort_function[i])(a, b);
	if (cmp_val != 0)
	    return cmp_val;
    }
    return 0;
}

/* This structure stores some critical information from one frame to
   the next. mostly used for sorting. Added cumulative and resident fields. */
struct save_hist {
    int ticks;
    int pid;
    int utime;
    int stime;
};

/*
 * Calculates percent cpu usage for each task.
 */

static struct save_hist *save_history;

static unsigned long Hertz;

/***********************************************************************
 * Some values in /proc are expressed in units of 1/HZ seconds, where HZ
 * is the kernel clock tick rate. One of these units is called a jiffy.
 * The HZ value used in the kernel may vary according to hacker desire.
 * According to Linus Torvalds, this is not true. He considers the values
 * in /proc as being in architecture-dependant units that have no relation
 * to the kernel clock tick rate. Examination of the kernel source code
 * reveals that opinion as wishful thinking.
 *
 * In any case, we need the HZ constant as used in /proc. (the real HZ value
 * may differ, but we don't care) There are several ways we could get HZ:
 *
 * 1. Include the kernel header file. If it changes, recompile this library.
 * 2. Use the sysconf() function. When HZ changes, recompile the C library!
 * 3. Ask the kernel. This is obviously correct...
 *
 * Linus Torvalds won't let us ask the kernel, because he thinks we should
 * not know the HZ value. Oh well, we don't have to listen to him.
 * Someone smuggled out the HZ value. :-)
 *
 * This code should work fine, even if Linus fixes the kernel to match his
 * stated behavior. The code only fails in case of a partial conversion.
 *
 */

#define FILE_TO_BUF(filename, fd) do{                           \
    if (fd == -1 && (fd = open(filename, O_RDONLY)) == -1) {    \
	perror_msg_and_die("/proc not be mounted?");            \
    }                                                           \
    lseek(fd, 0L, SEEK_SET);                                    \
    if ((local_n = read(fd, buf, sizeof buf - 1)) < 0) {        \
	perror_msg_and_die("%s", filename);                     \
    }                                                           \
    buf[local_n] = '\0';                                        \
}while(0)

#define FILE_TO_BUF2(filename, fd) do{                          \
    lseek(fd, 0L, SEEK_SET);                                    \
    if ((local_n = read(fd, buf, sizeof buf - 1)) < 0) {        \
	perror_msg_and_die("%s", filename);                     \
    }                                                           \
    buf[local_n] = '\0';                                        \
}while(0)

static void init_Hertz_value(void) {
  unsigned long user_j, nice_j, sys_j, other_j;  /* jiffies (clock ticks) */
  double up_1, up_2, seconds;
  unsigned long jiffies, h;
  char buf[80];
  int uptime_fd = -1;
  int stat_fd = -1;

  long smp_num_cpus = sysconf(_SC_NPROCESSORS_CONF);

  if(smp_num_cpus<1) smp_num_cpus=1;
  do {
    int local_n;

    FILE_TO_BUF("uptime", uptime_fd);
    up_1 = strtod(buf, 0);
    FILE_TO_BUF("stat", stat_fd);
    sscanf(buf, "cpu %lu %lu %lu %lu", &user_j, &nice_j, &sys_j, &other_j);
    FILE_TO_BUF2("uptime", uptime_fd);
    up_2 = strtod(buf, 0);
  } while((long)( (up_2-up_1)*1000.0/up_1 )); /* want under 0.1% error */

  close(uptime_fd);
  close(stat_fd);

  jiffies = user_j + nice_j + sys_j + other_j;
  seconds = (up_1 + up_2) / 2;
  h = (unsigned long)( (double)jiffies/seconds/smp_num_cpus );
  /* actual values used by 2.4 kernels: 32 64 100 128 1000 1024 1200 */
  switch(h){
  case   30 ...   34 :  Hertz =   32; break; /* ia64 emulator */
  case   48 ...   52 :  Hertz =   50; break;
  case   58 ...   62 :  Hertz =   60; break;
  case   63 ...   65 :  Hertz =   64; break; /* StrongARM /Shark */
  case   95 ...  105 :  Hertz =  100; break; /* normal Linux */
  case  124 ...  132 :  Hertz =  128; break; /* MIPS, ARM */
  case  195 ...  204 :  Hertz =  200; break; /* normal << 1 */
  case  253 ...  260 :  Hertz =  256; break;
  case  295 ...  304 :  Hertz =  300; break; /* 3 cpus */
  case  393 ...  408 :  Hertz =  400; break; /* normal << 2 */
  case  495 ...  504 :  Hertz =  500; break; /* 5 cpus */
  case  595 ...  604 :  Hertz =  600; break; /* 6 cpus */
  case  695 ...  704 :  Hertz =  700; break; /* 7 cpus */
  case  790 ...  808 :  Hertz =  800; break; /* normal << 3 */
  case  895 ...  904 :  Hertz =  900; break; /* 9 cpus */
  case  990 ... 1010 :  Hertz = 1000; break; /* ARM */
  case 1015 ... 1035 :  Hertz = 1024; break; /* Alpha, ia64 */
  case 1095 ... 1104 :  Hertz = 1100; break; /* 11 cpus */
  case 1180 ... 1220 :  Hertz = 1200; break; /* Alpha */
  default:
    /* If 32-bit or big-endian (not Alpha or ia64), assume HZ is 100. */
    Hertz = (sizeof(long)==sizeof(int) || htons(999)==999) ? 100UL : 1024UL;
  }
}

static void do_stats(void)
{
    struct timeval t;
    static struct timeval oldtime;
    struct timezone timez;
    float elapsed_time;

    status_t *cur;
    int total_time, i, n;
    static int prev_count;
    int systime, usrtime, pid;

    struct save_hist *New_save_hist;

    /*
     * Finds the current time (in microseconds) and calculates the time
     * elapsed since the last update.
     */
    gettimeofday(&t, &timez);
    elapsed_time = (t.tv_sec - oldtime.tv_sec)
	+ (float) (t.tv_usec - oldtime.tv_usec) / 1000000.0;
    oldtime.tv_sec  = t.tv_sec;
    oldtime.tv_usec = t.tv_usec;

    New_save_hist  = alloca(sizeof(struct save_hist)*ntop);
    /*
     * Make a pass through the data to get stats.
     */
    for(n = 0; n < ntop; n++) {
	cur = top + n;

	/*
	 * Calculate time in cur process.  Time is sum of user time
	 * (usrtime) plus system time (systime).
	 */
	systime = cur->stime;
	usrtime = cur->utime;
	pid = cur->pid;
	total_time = systime + usrtime;
	New_save_hist[n].ticks = total_time;
	New_save_hist[n].pid = pid;
	New_save_hist[n].stime = systime;
	New_save_hist[n].utime = usrtime;

	/* find matching entry from previous pass */
	for (i = 0; i < prev_count; i++) {
	    if (save_history[i].pid == pid) {
		total_time -= save_history[i].ticks;
		systime -= save_history[i].stime;
		usrtime -= save_history[i].utime;
		break;
	    }
	}

	/*
	 * Calculate percent cpu time for cur task.
	 */
	i = (total_time * 10 * 100/Hertz) / elapsed_time;
	if (i > 999)
	    i = 999;
	cur->pcpu = i;

    }

    /*
     * Save cur frame's information.
     */
    free(save_history);
    save_history = memcpy(xmalloc(sizeof(struct save_hist)*n), New_save_hist,
						sizeof(struct save_hist)*n);
    prev_count = n;
    qsort(top, n, sizeof(status_t), (void*)mult_lvl_cmp);
}
#else
static cmp_t sort_function;
#endif /* FEATURE_CPU_USAGE_PERCENTAGE */

/* display generic info (meminfo / loadavg) */
static unsigned long display_generic(void)
{
	FILE *fp;
	char buf[80];
	float avg1, avg2, avg3;
	unsigned long total, used, mfree, shared, buffers, cached;

	/* read memory info */
	fp = xfopen("meminfo", "r");
	fgets(buf, sizeof(buf), fp);	/* skip first line */

	if (fscanf(fp, "Mem: %lu %lu %lu %lu %lu %lu",
		   &total, &used, &mfree, &shared, &buffers, &cached) != 6) {
		error_msg_and_die("failed to read '%s'", "meminfo");
	}
	fclose(fp);
	
	/* read load average */
	fp = xfopen("loadavg", "r");
	if (fscanf(fp, "%f %f %f", &avg1, &avg2, &avg3) != 3) {
		error_msg_and_die("failed to read '%s'", "loadavg");
	}
	fclose(fp);

	/* convert to kilobytes */
	used /= 1024;