OpenBSD-4.6/lib/libc/gmon/gmon.c
/* $OpenBSD: gmon.c,v 1.20 2005/11/20 17:06:06 millert Exp $ */
/*-
* Copyright (c) 1983, 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#include <sys/param.h>
#include <sys/time.h>
#include <sys/gmon.h>
#include <sys/mman.h>
#include <sys/sysctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <limits.h>
#include <unistd.h>
struct gmonparam _gmonparam = { GMON_PROF_OFF };
static int s_scale;
/* see profil(2) where this is describe (incorrectly) */
#define SCALE_1_TO_1 0x10000L
#define ERR(s) write(STDERR_FILENO, s, sizeof(s))
void moncontrol(int);
static int hertz(void);
void monstartup(u_long lowpc, u_long highpc);
void _mcleanup(void);
void
monstartup(u_long lowpc, u_long highpc)
{
int o;
void *addr;
struct gmonparam *p = &_gmonparam;
/*
* round lowpc and highpc to multiples of the density we're using
* so the rest of the scaling (here and in gprof) stays in ints.
*/
p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
p->textsize = p->highpc - p->lowpc;
p->kcountsize = p->textsize / HISTFRACTION;
p->hashfraction = HASHFRACTION;
p->fromssize = p->textsize / p->hashfraction;
p->tolimit = p->textsize * ARCDENSITY / 100;
if (p->tolimit < MINARCS)
p->tolimit = MINARCS;
else if (p->tolimit > MAXARCS)
p->tolimit = MAXARCS;
p->tossize = p->tolimit * sizeof(struct tostruct);
addr = mmap((void *)0, p->kcountsize, PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, -1, (off_t)0);
if (addr == MAP_FAILED)
goto mapfailed;
p->kcount = addr;
addr = mmap((void *)0, p->fromssize, PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, -1, (off_t)0);
if (addr == MAP_FAILED)
goto mapfailed;
p->froms = addr;
addr = mmap((void *)0, p->tossize, PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, -1, (off_t)0);
if (addr == MAP_FAILED)
goto mapfailed;
p->tos = addr;
p->tos[0].link = 0;
o = p->highpc - p->lowpc;
if (p->kcountsize < o) {
#ifndef notdef
s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
#else /* avoid floating point */
int quot = o / p->kcountsize;
if (quot >= 0x10000)
s_scale = 1;
else if (quot >= 0x100)
s_scale = 0x10000 / quot;
else if (o >= 0x800000)
s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
else
s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
#endif
} else
s_scale = SCALE_1_TO_1;
moncontrol(1);
return;
mapfailed:
if (p->kcount != NULL) {
munmap(p->kcount, p->kcountsize);
p->kcount = NULL;
}
if (p->froms != NULL) {
munmap(p->froms, p->fromssize);
p->froms = NULL;
}
if (p->tos != NULL) {
munmap(p->tos, p->tossize);
p->tos = NULL;
}
ERR("monstartup: out of memory\n");
}
void
_mcleanup(void)
{
int fd;
int fromindex;
int endfrom;
u_long frompc;
int toindex;
struct rawarc rawarc;
struct gmonparam *p = &_gmonparam;
struct gmonhdr gmonhdr, *hdr;
struct clockinfo clockinfo;
int mib[2];
size_t size;
char *profdir;
char *proffile;
char buf[PATH_MAX];
#ifdef DEBUG
int log, len;
char dbuf[200];
#endif
if (p->state == GMON_PROF_ERROR)
ERR("_mcleanup: tos overflow\n");
size = sizeof(clockinfo);
mib[0] = CTL_KERN;
mib[1] = KERN_CLOCKRATE;
if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
/*
* Best guess
*/
clockinfo.profhz = hertz();
} else if (clockinfo.profhz == 0) {
if (clockinfo.hz != 0)
clockinfo.profhz = clockinfo.hz;
else
clockinfo.profhz = hertz();
}
moncontrol(0);
if (issetugid() == 0 && (profdir = getenv("PROFDIR")) != NULL) {
extern char *__progname;
char *s, *t, *limit;
pid_t pid;
long divisor;
/* If PROFDIR contains a null value, no profiling
output is produced */
if (*profdir == '\0') {
return;
}
limit = buf + sizeof buf - 1 - 10 - 1 -
strlen(__progname) - 1;
t = buf;
s = profdir;
while((*t = *s) != '\0' && t < limit) {
t++;
s++;
}
*t++ = '/';
/*
* Copy and convert pid from a pid_t to a string. For
* best performance, divisor should be initialized to
* the largest power of 10 less than PID_MAX.
*/
pid = getpid();
divisor=10000;
while (divisor > pid) divisor /= 10; /* skip leading zeros */
do {
*t++ = (pid/divisor) + '0';
pid %= divisor;
} while (divisor /= 10);
*t++ = '.';
s = __progname;
while ((*t++ = *s++) != '\0')
;
proffile = buf;
} else {
proffile = "gmon.out";
}
fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0664);
if (fd < 0) {
perror( proffile );
return;
}
#ifdef DEBUG
log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
if (log < 0) {
perror("mcount: gmon.log");
return;
}
snprintf(dbuf, sizeof dbuf, "[mcleanup1] kcount 0x%x ssiz %d\n",
p->kcount, p->kcountsize);
write(log, dbuf, strlen(dbuf));
#endif
hdr = (struct gmonhdr *)&gmonhdr;
bzero(hdr, sizeof(*hdr));
hdr->lpc = p->lowpc;
hdr->hpc = p->highpc;
hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
hdr->version = GMONVERSION;
hdr->profrate = clockinfo.profhz;
write(fd, (char *)hdr, sizeof *hdr);
write(fd, p->kcount, p->kcountsize);
endfrom = p->fromssize / sizeof(*p->froms);
for (fromindex = 0; fromindex < endfrom; fromindex++) {
if (p->froms[fromindex] == 0)
continue;
frompc = p->lowpc;
frompc += fromindex * p->hashfraction * sizeof(*p->froms);
for (toindex = p->froms[fromindex]; toindex != 0;
toindex = p->tos[toindex].link) {
#ifdef DEBUG
(void) snprintf(dbuf, sizeof dbuf,
"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
frompc, p->tos[toindex].selfpc,
p->tos[toindex].count);
write(log, dbuf, strlen(dbuf));
#endif
rawarc.raw_frompc = frompc;
rawarc.raw_selfpc = p->tos[toindex].selfpc;
rawarc.raw_count = p->tos[toindex].count;
write(fd, &rawarc, sizeof rawarc);
}
}
close(fd);
#ifdef notyet
if (p->kcount != NULL) {
munmap(p->kcount, p->kcountsize);
p->kcount = NULL;
}
if (p->froms != NULL) {
munmap(p->froms, p->fromssize);
p->froms = NULL;
}
if (p->tos != NULL) {
munmap(p->tos, p->tossize);
p->tos = NULL;
}
#endif
}
/*
* Control profiling
* profiling is what mcount checks to see if
* all the data structures are ready.
*/
void
moncontrol(int mode)
{
struct gmonparam *p = &_gmonparam;
if (mode) {
/* start */
profil((char *)p->kcount, p->kcountsize, p->lowpc,
s_scale);
p->state = GMON_PROF_ON;
} else {
/* stop */
profil((char *)0, 0, 0, 0);
p->state = GMON_PROF_OFF;
}
}
/*
* discover the tick frequency of the machine
* if something goes wrong, we return 0, an impossible hertz.
*/
static int
hertz(void)
{
struct itimerval tim;
tim.it_interval.tv_sec = 0;
tim.it_interval.tv_usec = 1;
tim.it_value.tv_sec = 0;
tim.it_value.tv_usec = 0;
setitimer(ITIMER_REAL, &tim, 0);
setitimer(ITIMER_REAL, 0, &tim);
if (tim.it_interval.tv_usec < 2)
return(0);
return (1000000 / tim.it_interval.tv_usec);
}