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gmon.c revision 1.13
      1 /*	$NetBSD: gmon.c,v 1.13 1998/08/10 02:43:10 perry Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1983, 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #if !defined(lint) && defined(LIBC_SCCS)
     38 #if 0
     39 static char sccsid[] = "@(#)gmon.c	8.1 (Berkeley) 6/4/93";
     40 #else
     41 __RCSID("$NetBSD: gmon.c,v 1.13 1998/08/10 02:43:10 perry Exp $");
     42 #endif
     43 #endif
     44 
     45 #include "namespace.h"
     46 #include <sys/param.h>
     47 #include <sys/time.h>
     48 #include <sys/gmon.h>
     49 #include <sys/sysctl.h>
     50 
     51 #include <stdio.h>
     52 #include <stdlib.h>
     53 #include <fcntl.h>
     54 #include <limits.h>
     55 #include <unistd.h>
     56 #include <err.h>
     57 
     58 extern char *minbrk __asm ("minbrk");
     59 
     60 struct gmonparam _gmonparam = { GMON_PROF_OFF };
     61 
     62 static int	s_scale;
     63 /* see profil(2) where this is describe (incorrectly) */
     64 #define		SCALE_1_TO_1	0x10000L
     65 
     66 #define ERR(s) write(STDERR_FILENO, s, sizeof(s))
     67 
     68 void	moncontrol __P((int));
     69 void	monstartup __P((u_long, u_long));
     70 void	_mcleanup __P((void));
     71 static int hertz __P((void));
     72 
     73 void
     74 monstartup(lowpc, highpc)
     75 	u_long lowpc;
     76 	u_long highpc;
     77 {
     78 	int o;
     79 	char *cp;
     80 	struct gmonparam *p = &_gmonparam;
     81 
     82 	/*
     83 	 * round lowpc and highpc to multiples of the density we're using
     84 	 * so the rest of the scaling (here and in gprof) stays in ints.
     85 	 */
     86 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
     87 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
     88 	p->textsize = p->highpc - p->lowpc;
     89 	p->kcountsize = p->textsize / HISTFRACTION;
     90 	p->hashfraction = HASHFRACTION;
     91 	p->fromssize = p->textsize / p->hashfraction;
     92 	p->tolimit = p->textsize * ARCDENSITY / 100;
     93 	if (p->tolimit < MINARCS)
     94 		p->tolimit = MINARCS;
     95 	else if (p->tolimit > MAXARCS)
     96 		p->tolimit = MAXARCS;
     97 	p->tossize = p->tolimit * sizeof(struct tostruct);
     98 
     99 	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
    100 	if (cp == (char *)-1) {
    101 		ERR("monstartup: out of memory\n");
    102 		return;
    103 	}
    104 #ifdef notdef
    105 	memset(cp, 0, p->kcountsize + p->fromssize + p->tossize);
    106 #endif
    107 	p->tos = (struct tostruct *)cp;
    108 	cp += p->tossize;
    109 	p->kcount = (u_short *)cp;
    110 	cp += p->kcountsize;
    111 	p->froms = (u_short *)cp;
    112 
    113 	minbrk = sbrk(0);
    114 	p->tos[0].link = 0;
    115 
    116 	o = p->highpc - p->lowpc;
    117 	if (p->kcountsize < o) {
    118 #ifndef notdef
    119 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
    120 #else /* avoid floating point */
    121 		int quot = o / p->kcountsize;
    122 
    123 		if (quot >= 0x10000)
    124 			s_scale = 1;
    125 		else if (quot >= 0x100)
    126 			s_scale = 0x10000 / quot;
    127 		else if (o >= 0x800000)
    128 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
    129 		else
    130 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
    131 #endif
    132 	} else
    133 		s_scale = SCALE_1_TO_1;
    134 
    135 	moncontrol(1);
    136 }
    137 
    138 void
    139 _mcleanup()
    140 {
    141 	int fd;
    142 	int fromindex;
    143 	int endfrom;
    144 	u_long frompc;
    145 	int toindex;
    146 	struct rawarc rawarc;
    147 	struct gmonparam *p = &_gmonparam;
    148 	struct gmonhdr gmonhdr, *hdr;
    149 	struct clockinfo clockinfo;
    150 	int mib[2];
    151 	size_t size;
    152 	char *profdir;
    153 	char *proffile;
    154 	char  buf[PATH_MAX];
    155 	int len = sizeof(buf) - 1;
    156 #ifdef DEBUG
    157 	int log, len;
    158 	char buf2[200];
    159 #endif
    160 
    161 	if (p->state == GMON_PROF_ERROR)
    162 		ERR("_mcleanup: tos overflow\n");
    163 
    164 	size = sizeof(clockinfo);
    165 	mib[0] = CTL_KERN;
    166 	mib[1] = KERN_CLOCKRATE;
    167 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
    168 		/*
    169 		 * Best guess
    170 		 */
    171 		clockinfo.profhz = hertz();
    172 	} else if (clockinfo.profhz == 0) {
    173 		if (clockinfo.hz != 0)
    174 			clockinfo.profhz = clockinfo.hz;
    175 		else
    176 			clockinfo.profhz = hertz();
    177 	}
    178 
    179 	moncontrol(0);
    180 
    181 	if ((profdir = getenv("PROFDIR")) != NULL) {
    182 		extern char *__progname;
    183 		char *s, *t;
    184 		pid_t pid;
    185 		long divisor;
    186 
    187 		/* If PROFDIR contains a null value, no profiling
    188 		   output is produced */
    189 		if (*profdir == '\0') {
    190 			return;
    191 		}
    192 
    193 		t = buf;
    194 		s = profdir;
    195 		while ((*t = *s) != '\0') {
    196 			if (len-- == 0) {
    197 				warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
    198 				return;
    199 			}
    200 			t++;
    201 			s++;
    202 		}
    203 		*t++ = '/';
    204 
    205 		/*
    206 		 * Copy and convert pid from a pid_t to a string.  For
    207 		 * best performance, divisor should be initialized to
    208 		 * the largest power of 10 less than PID_MAX.
    209 		 */
    210 		pid = getpid();
    211 		divisor=10000;
    212 		while (divisor > pid) divisor /= 10;	/* skip leading zeros */
    213 		do {
    214 			*t++ = (pid/divisor) + '0';
    215 			pid %= divisor;
    216 		} while (divisor /= 10);
    217 		*t++ = '.';
    218 
    219 		s = __progname;
    220 		while ((*t++ = *s++) != '\0')
    221 			;
    222 
    223 		proffile = buf;
    224 	} else {
    225 		proffile = "gmon.out";
    226 	}
    227 
    228 	fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
    229 	if (fd < 0) {
    230 		warn("mcount: Cannot open `%s'", proffile);
    231 		return;
    232 	}
    233 #ifdef DEBUG
    234 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
    235 	if (log < 0) {
    236 		warn("mcount: Cannot open `gmon.log'");
    237 		return;
    238 	}
    239 	len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
    240 	    p->kcount, p->kcountsize);
    241 	write(log, buf2, len);
    242 #endif
    243 	hdr = (struct gmonhdr *)&gmonhdr;
    244 	hdr->lpc = p->lowpc;
    245 	hdr->hpc = p->highpc;
    246 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
    247 	hdr->version = GMONVERSION;
    248 	hdr->profrate = clockinfo.profhz;
    249 	write(fd, (char *)hdr, sizeof *hdr);
    250 	write(fd, p->kcount, p->kcountsize);
    251 	endfrom = p->fromssize / sizeof(*p->froms);
    252 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
    253 		if (p->froms[fromindex] == 0)
    254 			continue;
    255 
    256 		frompc = p->lowpc;
    257 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
    258 		for (toindex = p->froms[fromindex]; toindex != 0;
    259 		     toindex = p->tos[toindex].link) {
    260 #ifdef DEBUG
    261 			len = snprintf(buf2, sizeof buf2,
    262 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
    263 				frompc, p->tos[toindex].selfpc,
    264 				p->tos[toindex].count);
    265 			write(log, buf2, len);
    266 #endif
    267 			rawarc.raw_frompc = frompc;
    268 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
    269 			rawarc.raw_count = p->tos[toindex].count;
    270 			write(fd, &rawarc, sizeof rawarc);
    271 		}
    272 	}
    273 	close(fd);
    274 }
    275 
    276 /*
    277  * Control profiling
    278  *	profiling is what mcount checks to see if
    279  *	all the data structures are ready.
    280  */
    281 void
    282 moncontrol(mode)
    283 	int mode;
    284 {
    285 	struct gmonparam *p = &_gmonparam;
    286 
    287 	if (mode) {
    288 		/* start */
    289 		profil((char *)p->kcount, p->kcountsize, p->lowpc,
    290 		    s_scale);
    291 		p->state = GMON_PROF_ON;
    292 	} else {
    293 		/* stop */
    294 		profil((char *)0, 0, 0, 0);
    295 		p->state = GMON_PROF_OFF;
    296 	}
    297 }
    298 
    299 /*
    300  * discover the tick frequency of the machine
    301  * if something goes wrong, we return 0, an impossible hertz.
    302  */
    303 static int
    304 hertz()
    305 {
    306 	struct itimerval tim;
    307 
    308 	tim.it_interval.tv_sec = 0;
    309 	tim.it_interval.tv_usec = 1;
    310 	tim.it_value.tv_sec = 0;
    311 	tim.it_value.tv_usec = 0;
    312 	setitimer(ITIMER_REAL, &tim, 0);
    313 	setitimer(ITIMER_REAL, 0, &tim);
    314 	if (tim.it_interval.tv_usec < 2)
    315 		return(0);
    316 	return (1000000 / tim.it_interval.tv_usec);
    317 }
    318