lib/libc/gmon/gmon.c

   1 /*-
   2  * Copyright (c) 1983, 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)gmon.c   8.1 (Berkeley) 6/4/93
  30  * $FreeBSD: src/lib/libc/gmon/gmon.c,v 1.22 2007/01/09 00:27:58 imp Exp $
  31  * $DragonFly: src/lib/libc/gmon/gmon.c,v 1.8 2005/11/13 01:18:20 swildner Exp $
  32  */
  33
  34 #include "namespace.h"
  35 #include <sys/param.h>
  36 #include <sys/time.h>
  37 #include <sys/gmon.h>
  38 #include <sys/sysctl.h>
  39
  40 #include <err.h>
  41 #include <fcntl.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <unistd.h>
  46 #include "un-namespace.h"
  47
  48 #include "libc_private.h"
  49
  50 #if defined(__i386__) || defined(__sparc64__) || defined(__x86_64__) || defined(__powerpc__)
  51 extern char *minbrk __asm (".minbrk");
  52 #else
  53 extern char *minbrk __asm ("minbrk");
  54 #endif
  55
  56 struct gmonparam _gmonparam = { GMON_PROF_OFF };
  57
  58 static int      s_scale;
  59 /* see profil(2) where this is describe (incorrectly) */
  60 #define         SCALE_1_TO_1    0x10000L
  61
  62 #define ERR(s) _write(2, s, sizeof(s))
  63
  64 void    moncontrol(int);
  65 static int hertz(void);
  66
  67 void
  68 monstartup(u_long lowpc, u_long highpc)
  69 {
  70         int o;
  71         char *cp;
  72         struct gmonparam *p = &_gmonparam;
  73
  74         /*
  75          * round lowpc and highpc to multiples of the density we're using
  76          * so the rest of the scaling (here and in gprof) stays in ints.
  77          */
  78         p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
  79         p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
  80         p->textsize = p->highpc - p->lowpc;
  81         p->kcountsize = p->textsize / HISTFRACTION;
  82         p->hashfraction = HASHFRACTION;
  83         p->fromssize = p->textsize / HASHFRACTION;
  84         p->tolimit = p->textsize * ARCDENSITY / 100;
  85         if (p->tolimit < MINARCS)
  86                 p->tolimit = MINARCS;
  87         else if (p->tolimit > MAXARCS)
  88                 p->tolimit = MAXARCS;
  89         p->tossize = p->tolimit * sizeof(struct tostruct);
  90
  91         cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
  92         if (cp == (char *)-1) {
  93                 ERR("monstartup: out of memory\n");
  94                 return;
  95         }
  96 #ifdef notdef
  97         bzero(cp, p->kcountsize + p->fromssize + p->tossize);
  98 #endif
  99         p->tos = (struct tostruct *)cp;
 100         cp += p->tossize;
 101         p->kcount = (u_short *)cp;
 102         cp += p->kcountsize;
 103         p->froms = (u_short *)cp;
 104
 105         minbrk = sbrk(0);
 106         p->tos[0].link = 0;
 107
 108         o = p->highpc - p->lowpc;
 109         if (p->kcountsize < o) {
 110 #ifndef hp300
 111                 s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
 112 #else /* avoid floating point */
 113                 int quot = o / p->kcountsize;
 114
 115                 if (quot >= 0x10000)
 116                         s_scale = 1;
 117                 else if (quot >= 0x100)
 118                         s_scale = 0x10000 / quot;
 119                 else if (o >= 0x800000)
 120                         s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
 121                 else
 122                         s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
 123 #endif
 124         } else
 125                 s_scale = SCALE_1_TO_1;
 126
 127         moncontrol(1);
 128 }
 129
 130 void
 131 _mcleanup(void)
 132 {
 133         int fd;
 134         int fromindex;
 135         int endfrom;
 136         u_long frompc;
 137         int toindex;
 138         struct rawarc rawarc;
 139         struct gmonparam *p = &_gmonparam;
 140         struct gmonhdr gmonhdr, *hdr;
 141         struct clockinfo clockinfo;
 142         char outname[128];
 143         int mib[2];
 144         size_t size;
 145 #ifdef DEBUG
 146         int log, len;
 147         char buf[200];
 148 #endif
 149
 150         if (p->state == GMON_PROF_ERROR)
 151                 ERR("_mcleanup: tos overflow\n");
 152
 153         size = sizeof(clockinfo);
 154         mib[0] = CTL_KERN;
 155         mib[1] = KERN_CLOCKRATE;
 156         if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
 157                 /*
 158                  * Best guess
 159                  */
 160                 clockinfo.profhz = hertz();
 161         } else if (clockinfo.profhz == 0) {
 162                 if (clockinfo.hz != 0)
 163                         clockinfo.profhz = clockinfo.hz;
 164                 else
 165                         clockinfo.profhz = hertz();
 166         }
 167
 168         moncontrol(0);
 169         snprintf(outname, sizeof(outname), "%s.gmon", _getprogname());
 170         fd = _open(outname, O_CREAT|O_TRUNC|O_WRONLY, 0666);
 171         if (fd < 0) {
 172                 _warn("_mcleanup: %s", outname);
 173                 return;
 174         }
 175 #ifdef DEBUG
 176         log = _open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
 177         if (log < 0) {
 178                 _warn("_mcleanup: gmon.log");
 179                 return;
 180         }
 181         len = sprintf(buf, "[mcleanup1] kcount 0x%p ssiz %lu\n",
 182             p->kcount, p->kcountsize);
 183         _write(log, buf, len);
 184 #endif
 185         hdr = (struct gmonhdr *)&gmonhdr;
 186         bzero(hdr, sizeof(*hdr));
 187         hdr->lpc = p->lowpc;
 188         hdr->hpc = p->highpc;
 189         hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
 190         hdr->version = GMONVERSION;
 191         hdr->profrate = clockinfo.profhz;
 192         _write(fd, (char *)hdr, sizeof *hdr);
 193         _write(fd, p->kcount, p->kcountsize);
 194         endfrom = p->fromssize / sizeof(*p->froms);
 195         for (fromindex = 0; fromindex < endfrom; fromindex++) {
 196                 if (p->froms[fromindex] == 0)
 197                         continue;
 198
 199                 frompc = p->lowpc;
 200                 frompc += fromindex * p->hashfraction * sizeof(*p->froms);
 201                 for (toindex = p->froms[fromindex]; toindex != 0;
 202                      toindex = p->tos[toindex].link) {
 203 #ifdef DEBUG
 204                         len = sprintf(buf,
 205                         "[mcleanup2] frompc 0x%lx selfpc 0x%lx count %lu\n" ,
 206                                 frompc, p->tos[toindex].selfpc,
 207                                 p->tos[toindex].count);
 208                         _write(log, buf, len);
 209 #endif
 210                         rawarc.raw_frompc = frompc;
 211                         rawarc.raw_selfpc = p->tos[toindex].selfpc;
 212                         rawarc.raw_count = p->tos[toindex].count;
 213                         _write(fd, &rawarc, sizeof rawarc);
 214                 }
 215         }
 216         _close(fd);
 217 }
 218
 219 /*
 220  * Control profiling
 221  *      profiling is what mcount checks to see if
 222  *      all the data structures are ready.
 223  */
 224 void
 225 moncontrol(int mode)
 226 {
 227         struct gmonparam *p = &_gmonparam;
 228
 229         if (mode) {
 230                 /* start */
 231                 profil((char *)p->kcount, p->kcountsize, p->lowpc, s_scale);
 232                 p->state = GMON_PROF_ON;
 233         } else {
 234                 /* stop */
 235                 profil(NULL, 0, 0, 0);
 236                 p->state = GMON_PROF_OFF;
 237         }
 238 }
 239
 240 /*
 241  * discover the tick frequency of the machine
 242  * if something goes wrong, we return 0, an impossible hertz.
 243  */
 244 static int
 245 hertz(void)
 246 {
 247         struct itimerval tim;
 248
 249         tim.it_interval.tv_sec = 0;
 250         tim.it_interval.tv_usec = 1;
 251         tim.it_value.tv_sec = 0;
 252         tim.it_value.tv_usec = 0;
 253         setitimer(ITIMER_REAL, &tim, 0);
 254         setitimer(ITIMER_REAL, 0, &tim);
 255         if (tim.it_interval.tv_usec < 2)
 256                 return(0);
 257         return (1000000 / tim.it_interval.tv_usec);
 258 }