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gmon.c revision 1.15
      1 /*	$NetBSD: gmon.c,v 1.15 1999/01/14 22:48:19 kleink 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 1.15 1999/01/14 22:48:19 kleink 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 #include "extern.h"
     58 
     59 struct gmonparam _gmonparam = { GMON_PROF_OFF };
     60 
     61 static u_int	s_scale;
     62 /* see profil(2) where this is describe (incorrectly) */
     63 #define		SCALE_1_TO_1	0x10000L
     64 
     65 #define ERR(s) write(STDERR_FILENO, s, sizeof(s))
     66 
     67 void	moncontrol __P((int));
     68 void	monstartup __P((u_long, u_long));
     69 void	_mcleanup __P((void));
     70 static int hertz __P((void));
     71 
     72 void
     73 monstartup(lowpc, highpc)
     74 	u_long lowpc;
     75 	u_long highpc;
     76 {
     77 	long o;
     78 	char *cp;
     79 	struct gmonparam *p = &_gmonparam;
     80 
     81 	/*
     82 	 * round lowpc and highpc to multiples of the density we're using
     83 	 * so the rest of the scaling (here and in gprof) stays in ints.
     84 	 */
     85 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
     86 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
     87 	p->textsize = p->highpc - p->lowpc;
     88 	p->kcountsize = p->textsize / HISTFRACTION;
     89 	p->hashfraction = HASHFRACTION;
     90 	p->fromssize = p->textsize / p->hashfraction;
     91 	p->tolimit = p->textsize * ARCDENSITY / 100;
     92 	if (p->tolimit < MINARCS)
     93 		p->tolimit = MINARCS;
     94 	else if (p->tolimit > MAXARCS)
     95 		p->tolimit = MAXARCS;
     96 	p->tossize = p->tolimit * sizeof(struct tostruct);
     97 
     98 	cp = sbrk((int)(p->kcountsize + p->fromssize + p->tossize));
     99 	if (cp == (char *)-1) {
    100 		ERR("monstartup: out of memory\n");
    101 		return;
    102 	}
    103 #ifdef notdef
    104 	memset(cp, 0, p->kcountsize + p->fromssize + p->tossize);
    105 #endif
    106 	p->tos = (struct tostruct *)(void *)cp;
    107 	cp += (size_t)p->tossize;
    108 	p->kcount = (u_short *)(void *)cp;
    109 	cp += (size_t)p->kcountsize;
    110 	p->froms = (u_short *)(void *)cp;
    111 
    112 	__minbrk = sbrk(0);
    113 	p->tos[0].link = 0;
    114 
    115 	o = p->highpc - p->lowpc;
    116 	if (p->kcountsize < o) {
    117 #ifndef notdef
    118 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
    119 #else /* avoid floating point */
    120 		int quot = o / p->kcountsize;
    121 
    122 		if (quot >= 0x10000)
    123 			s_scale = 1;
    124 		else if (quot >= 0x100)
    125 			s_scale = 0x10000 / quot;
    126 		else if (o >= 0x800000)
    127 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
    128 		else
    129 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
    130 #endif
    131 	} else
    132 		s_scale = SCALE_1_TO_1;
    133 
    134 	moncontrol(1);
    135 }
    136 
    137 void
    138 _mcleanup()
    139 {
    140 	int fd;
    141 	int fromindex;
    142 	int endfrom;
    143 	u_long frompc;
    144 	int toindex;
    145 	struct rawarc rawarc;
    146 	struct gmonparam *p = &_gmonparam;
    147 	struct gmonhdr gmonhdr, *hdr;
    148 	struct clockinfo clockinfo;
    149 	int mib[2];
    150 	size_t size;
    151 	char *profdir;
    152 	char *proffile;
    153 	char  buf[PATH_MAX];
    154 	int len = sizeof(buf) - 1;
    155 #ifdef DEBUG
    156 	int log, len;
    157 	char buf2[200];
    158 #endif
    159 
    160 	if (p->state == GMON_PROF_ERROR)
    161 		ERR("_mcleanup: tos overflow\n");
    162 
    163 	size = sizeof(clockinfo);
    164 	mib[0] = CTL_KERN;
    165 	mib[1] = KERN_CLOCKRATE;
    166 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
    167 		/*
    168 		 * Best guess
    169 		 */
    170 		clockinfo.profhz = hertz();
    171 	} else if (clockinfo.profhz == 0) {
    172 		if (clockinfo.hz != 0)
    173 			clockinfo.profhz = clockinfo.hz;
    174 		else
    175 			clockinfo.profhz = hertz();
    176 	}
    177 
    178 	moncontrol(0);
    179 
    180 	if ((profdir = getenv("PROFDIR")) != NULL) {
    181 		extern char *__progname;
    182 		char *s, *t;
    183 		pid_t pid;
    184 		long divisor;
    185 
    186 		/* If PROFDIR contains a null value, no profiling
    187 		   output is produced */
    188 		if (*profdir == '\0') {
    189 			return;
    190 		}
    191 
    192 		t = buf;
    193 		s = profdir;
    194 		while ((*t = *s) != '\0') {
    195 			if (len-- == 0) {
    196 				warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
    197 				return;
    198 			}
    199 			t++;
    200 			s++;
    201 		}
    202 		*t++ = '/';
    203 
    204 		/*
    205 		 * Copy and convert pid from a pid_t to a string.  For
    206 		 * best performance, divisor should be initialized to
    207 		 * the largest power of 10 less than PID_MAX.
    208 		 */
    209 		pid = getpid();
    210 		divisor=10000;
    211 		while (divisor > pid) divisor /= 10;	/* skip leading zeros */
    212 		do {
    213 			*t++ = (char)((pid/divisor) + '0');
    214 			pid %= (pid_t)divisor;
    215 		} while (divisor /= 10);
    216 		*t++ = '.';
    217 
    218 		s = __progname;
    219 		while ((*t++ = *s++) != '\0')
    220 			;
    221 
    222 		proffile = buf;
    223 	} else {
    224 		proffile = "gmon.out";
    225 	}
    226 
    227 	fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
    228 	if (fd < 0) {
    229 		warn("mcount: Cannot open `%s'", proffile);
    230 		return;
    231 	}
    232 #ifdef DEBUG
    233 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
    234 	if (log < 0) {
    235 		warn("mcount: Cannot open `gmon.log'");
    236 		return;
    237 	}
    238 	len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
    239 	    p->kcount, p->kcountsize);
    240 	write(log, buf2, len);
    241 #endif
    242 	hdr = (struct gmonhdr *)&gmonhdr;
    243 	hdr->lpc = p->lowpc;
    244 	hdr->hpc = p->highpc;
    245 	hdr->ncnt = (int)(p->kcountsize + sizeof(gmonhdr));
    246 	hdr->version = GMONVERSION;
    247 	hdr->profrate = clockinfo.profhz;
    248 	(void)write(fd, hdr, sizeof *hdr);
    249 	(void)write(fd, p->kcount, (size_t)p->kcountsize);
    250 	endfrom = (int)(p->fromssize / sizeof(*p->froms));
    251 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
    252 		if (p->froms[fromindex] == 0)
    253 			continue;
    254 
    255 		frompc = p->lowpc;
    256 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
    257 		for (toindex = p->froms[fromindex]; toindex != 0;
    258 		     toindex = p->tos[toindex].link) {
    259 #ifdef DEBUG
    260 			len = snprintf(buf2, sizeof buf2,
    261 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
    262 				frompc, p->tos[toindex].selfpc,
    263 				p->tos[toindex].count);
    264 			write(log, buf2, len);
    265 #endif
    266 			rawarc.raw_frompc = frompc;
    267 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
    268 			rawarc.raw_count = p->tos[toindex].count;
    269 			write(fd, &rawarc, sizeof rawarc);
    270 		}
    271 	}
    272 	close(fd);
    273 }
    274 
    275 /*
    276  * Control profiling
    277  *	profiling is what mcount checks to see if
    278  *	all the data structures are ready.
    279  */
    280 void
    281 moncontrol(mode)
    282 	int mode;
    283 {
    284 	struct gmonparam *p = &_gmonparam;
    285 
    286 	if (mode) {
    287 		/* start */
    288 		profil((char *)(void *)p->kcount, (size_t)p->kcountsize,
    289 		    p->lowpc, s_scale);
    290 		p->state = GMON_PROF_ON;
    291 	} else {
    292 		/* stop */
    293 		profil(NULL, 0, (u_long)0, 0);
    294 		p->state = GMON_PROF_OFF;
    295 	}
    296 }
    297 
    298 /*
    299  * discover the tick frequency of the machine
    300  * if something goes wrong, we return 0, an impossible hertz.
    301  */
    302 static int
    303 hertz()
    304 {
    305 	struct itimerval tim;
    306 
    307 	tim.it_interval.tv_sec = 0;
    308 	tim.it_interval.tv_usec = 1;
    309 	tim.it_value.tv_sec = 0;
    310 	tim.it_value.tv_usec = 0;
    311 	setitimer(ITIMER_REAL, &tim, 0);
    312 	setitimer(ITIMER_REAL, 0, &tim);
    313 	if (tim.it_interval.tv_usec < 2)
    314 		return(0);
    315 	return (int)(1000000 / tim.it_interval.tv_usec);
    316 }
    317