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gmon.c revision 1.16
      1 /*	$NetBSD: gmon.c,v 1.16 2000/12/20 20:55:23 christos 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 1.16 2000/12/20 20:55:23 christos 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 extern char *__progname;
     60 
     61 struct gmonparam _gmonparam = { GMON_PROF_OFF };
     62 
     63 static u_int	s_scale;
     64 /* see profil(2) where this is describe (incorrectly) */
     65 #define		SCALE_1_TO_1	0x10000L
     66 
     67 #define ERR(s) write(STDERR_FILENO, s, sizeof(s))
     68 
     69 void	moncontrol __P((int));
     70 void	monstartup __P((u_long, u_long));
     71 void	_mcleanup __P((void));
     72 static int hertz __P((void));
     73 
     74 
     75 void
     76 monstartup(lowpc, highpc)
     77 	u_long lowpc;
     78 	u_long highpc;
     79 {
     80 	long o;
     81 	char *cp;
     82 	struct gmonparam *p = &_gmonparam;
     83 
     84 	/*
     85 	 * round lowpc and highpc to multiples of the density we're using
     86 	 * so the rest of the scaling (here and in gprof) stays in ints.
     87 	 */
     88 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
     89 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
     90 	p->textsize = p->highpc - p->lowpc;
     91 	p->kcountsize = p->textsize / HISTFRACTION;
     92 	p->hashfraction = HASHFRACTION;
     93 	p->fromssize = p->textsize / p->hashfraction;
     94 	p->tolimit = p->textsize * ARCDENSITY / 100;
     95 	if (p->tolimit < MINARCS)
     96 		p->tolimit = MINARCS;
     97 	else if (p->tolimit > MAXARCS)
     98 		p->tolimit = MAXARCS;
     99 	p->tossize = p->tolimit * sizeof(struct tostruct);
    100 
    101 	cp = sbrk((intptr_t)(p->kcountsize + p->fromssize + p->tossize));
    102 	if (cp == (char *)-1) {
    103 		ERR("monstartup: out of memory\n");
    104 		return;
    105 	}
    106 #ifdef notdef
    107 	memset(cp, 0, p->kcountsize + p->fromssize + p->tossize);
    108 #endif
    109 	p->tos = (struct tostruct *)(void *)cp;
    110 	cp += (size_t)p->tossize;
    111 	p->kcount = (u_short *)(void *)cp;
    112 	cp += (size_t)p->kcountsize;
    113 	p->froms = (u_short *)(void *)cp;
    114 
    115 	__minbrk = sbrk((intptr_t)0);
    116 	p->tos[0].link = 0;
    117 
    118 	o = p->highpc - p->lowpc;
    119 	if (p->kcountsize < o) {
    120 #ifndef notdef
    121 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
    122 #else /* avoid floating point */
    123 		int quot = o / p->kcountsize;
    124 
    125 		if (quot >= 0x10000)
    126 			s_scale = 1;
    127 		else if (quot >= 0x100)
    128 			s_scale = 0x10000 / quot;
    129 		else if (o >= 0x800000)
    130 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
    131 		else
    132 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
    133 #endif
    134 	} else
    135 		s_scale = SCALE_1_TO_1;
    136 
    137 	moncontrol(1);
    138 }
    139 
    140 void
    141 _mcleanup()
    142 {
    143 	int fd;
    144 	int fromindex;
    145 	int endfrom;
    146 	u_long frompc;
    147 	int toindex;
    148 	struct rawarc rawarc;
    149 	struct gmonparam *p = &_gmonparam;
    150 	struct gmonhdr gmonhdr, *hdr;
    151 	struct clockinfo clockinfo;
    152 	int mib[2];
    153 	size_t size;
    154 	char *profdir;
    155 	char *proffile;
    156 	char  buf[PATH_MAX];
    157 	int len = sizeof(buf) - 1;
    158 #ifdef DEBUG
    159 	int log, len;
    160 	char buf2[200];
    161 #endif
    162 
    163 	if (p->state == GMON_PROF_ERROR)
    164 		ERR("_mcleanup: tos overflow\n");
    165 
    166 	size = sizeof(clockinfo);
    167 	mib[0] = CTL_KERN;
    168 	mib[1] = KERN_CLOCKRATE;
    169 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
    170 		/*
    171 		 * Best guess
    172 		 */
    173 		clockinfo.profhz = hertz();
    174 	} else if (clockinfo.profhz == 0) {
    175 		if (clockinfo.hz != 0)
    176 			clockinfo.profhz = clockinfo.hz;
    177 		else
    178 			clockinfo.profhz = hertz();
    179 	}
    180 
    181 	moncontrol(0);
    182 
    183 	if ((profdir = getenv("PROFDIR")) != NULL) {
    184 		char *s, *t;
    185 		pid_t pid;
    186 		long divisor;
    187 
    188 		/* If PROFDIR contains a null value, no profiling
    189 		   output is produced */
    190 		if (*profdir == '\0') {
    191 			return;
    192 		}
    193 
    194 		t = buf;
    195 		s = profdir;
    196 		while ((*t = *s) != '\0') {
    197 			if (len-- == 0) {
    198 				warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
    199 				return;
    200 			}
    201 			t++;
    202 			s++;
    203 		}
    204 		*t++ = '/';
    205 
    206 		/*
    207 		 * Copy and convert pid from a pid_t to a string.  For
    208 		 * best performance, divisor should be initialized to
    209 		 * the largest power of 10 less than PID_MAX.
    210 		 */
    211 		pid = getpid();
    212 		divisor=10000;
    213 		while (divisor > pid) divisor /= 10;	/* skip leading zeros */
    214 		do {
    215 			*t++ = (char)((pid/divisor) + '0');
    216 			pid %= (pid_t)divisor;
    217 		} while (divisor /= 10);
    218 		*t++ = '.';
    219 
    220 		s = __progname;
    221 		while ((*t++ = *s++) != '\0')
    222 			;
    223 
    224 		proffile = buf;
    225 	} else {
    226 		proffile = "gmon.out";
    227 	}
    228 
    229 	fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
    230 	if (fd < 0) {
    231 		warn("mcount: Cannot open `%s'", proffile);
    232 		return;
    233 	}
    234 #ifdef DEBUG
    235 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
    236 	if (log < 0) {
    237 		warn("mcount: Cannot open `gmon.log'");
    238 		return;
    239 	}
    240 	len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
    241 	    p->kcount, p->kcountsize);
    242 	write(log, buf2, len);
    243 #endif
    244 	hdr = (struct gmonhdr *)&gmonhdr;
    245 	hdr->lpc = p->lowpc;
    246 	hdr->hpc = p->highpc;
    247 	hdr->ncnt = (int)(p->kcountsize + sizeof(gmonhdr));
    248 	hdr->version = GMONVERSION;
    249 	hdr->profrate = clockinfo.profhz;
    250 	(void)write(fd, hdr, sizeof *hdr);
    251 	(void)write(fd, p->kcount, (size_t)p->kcountsize);
    252 	endfrom = (int)(p->fromssize / sizeof(*p->froms));
    253 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
    254 		if (p->froms[fromindex] == 0)
    255 			continue;
    256 
    257 		frompc = p->lowpc;
    258 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
    259 		for (toindex = p->froms[fromindex]; toindex != 0;
    260 		     toindex = p->tos[toindex].link) {
    261 #ifdef DEBUG
    262 			len = snprintf(buf2, sizeof buf2,
    263 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
    264 				frompc, p->tos[toindex].selfpc,
    265 				p->tos[toindex].count);
    266 			write(log, buf2, len);
    267 #endif
    268 			rawarc.raw_frompc = frompc;
    269 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
    270 			rawarc.raw_count = p->tos[toindex].count;
    271 			write(fd, &rawarc, sizeof rawarc);
    272 		}
    273 	}
    274 	close(fd);
    275 }
    276 
    277 /*
    278  * Control profiling
    279  *	profiling is what mcount checks to see if
    280  *	all the data structures are ready.
    281  */
    282 void
    283 moncontrol(mode)
    284 	int mode;
    285 {
    286 	struct gmonparam *p = &_gmonparam;
    287 
    288 	if (mode) {
    289 		/* start */
    290 		profil((char *)(void *)p->kcount, (size_t)p->kcountsize,
    291 		    p->lowpc, s_scale);
    292 		p->state = GMON_PROF_ON;
    293 	} else {
    294 		/* stop */
    295 		profil(NULL, 0, (u_long)0, 0);
    296 		p->state = GMON_PROF_OFF;
    297 	}
    298 }
    299 
    300 /*
    301  * discover the tick frequency of the machine
    302  * if something goes wrong, we return 0, an impossible hertz.
    303  */
    304 static int
    305 hertz()
    306 {
    307 	struct itimerval tim;
    308 
    309 	tim.it_interval.tv_sec = 0;
    310 	tim.it_interval.tv_usec = 1;
    311 	tim.it_value.tv_sec = 0;
    312 	tim.it_value.tv_usec = 0;
    313 	setitimer(ITIMER_REAL, &tim, 0);
    314 	setitimer(ITIMER_REAL, 0, &tim);
    315 	if (tim.it_interval.tv_usec < 2)
    316 		return(0);
    317 	return (int)(1000000 / tim.it_interval.tv_usec);
    318 }
    319