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gmon.c revision 1.9
      1 /*	$NetBSD: gmon.c,v 1.9 1997/04/22 11:17:58 mrg 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 #if !defined(lint) && defined(LIBC_SCCS)
     37 #if 0
     38 static char sccsid[] = "@(#)gmon.c	8.1 (Berkeley) 6/4/93";
     39 #else
     40 static char rcsid[] = "$NetBSD: gmon.c,v 1.9 1997/04/22 11:17:58 mrg Exp $";
     41 #endif
     42 #endif
     43 
     44 #include <sys/param.h>
     45 #include <sys/time.h>
     46 #include <sys/gmon.h>
     47 #include <sys/sysctl.h>
     48 
     49 #include <stdio.h>
     50 #include <stdlib.h>
     51 #include <fcntl.h>
     52 #include <limits.h>
     53 #include <unistd.h>
     54 
     55 extern char *minbrk __asm ("minbrk");
     56 
     57 struct gmonparam _gmonparam = { GMON_PROF_OFF };
     58 
     59 static int	s_scale;
     60 /* see profil(2) where this is describe (incorrectly) */
     61 #define		SCALE_1_TO_1	0x10000L
     62 
     63 #define ERR(s) write(2, s, sizeof(s))
     64 
     65 void	moncontrol __P((int));
     66 static int hertz __P((void));
     67 
     68 void
     69 monstartup(lowpc, highpc)
     70 	u_long lowpc;
     71 	u_long highpc;
     72 {
     73 	register int o;
     74 	char *cp;
     75 	struct gmonparam *p = &_gmonparam;
     76 
     77 	/*
     78 	 * round lowpc and highpc to multiples of the density we're using
     79 	 * so the rest of the scaling (here and in gprof) stays in ints.
     80 	 */
     81 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
     82 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
     83 	p->textsize = p->highpc - p->lowpc;
     84 	p->kcountsize = p->textsize / HISTFRACTION;
     85 	p->hashfraction = HASHFRACTION;
     86 	p->fromssize = p->textsize / p->hashfraction;
     87 	p->tolimit = p->textsize * ARCDENSITY / 100;
     88 	if (p->tolimit < MINARCS)
     89 		p->tolimit = MINARCS;
     90 	else if (p->tolimit > MAXARCS)
     91 		p->tolimit = MAXARCS;
     92 	p->tossize = p->tolimit * sizeof(struct tostruct);
     93 
     94 	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
     95 	if (cp == (char *)-1) {
     96 		ERR("monstartup: out of memory\n");
     97 		return;
     98 	}
     99 #ifdef notdef
    100 	bzero(cp, p->kcountsize + p->fromssize + p->tossize);
    101 #endif
    102 	p->tos = (struct tostruct *)cp;
    103 	cp += p->tossize;
    104 	p->kcount = (u_short *)cp;
    105 	cp += p->kcountsize;
    106 	p->froms = (u_short *)cp;
    107 
    108 	minbrk = sbrk(0);
    109 	p->tos[0].link = 0;
    110 
    111 	o = p->highpc - p->lowpc;
    112 	if (p->kcountsize < o) {
    113 #ifndef notdef
    114 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
    115 #else /* avoid floating point */
    116 		int quot = o / p->kcountsize;
    117 
    118 		if (quot >= 0x10000)
    119 			s_scale = 1;
    120 		else if (quot >= 0x100)
    121 			s_scale = 0x10000 / quot;
    122 		else if (o >= 0x800000)
    123 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
    124 		else
    125 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
    126 #endif
    127 	} else
    128 		s_scale = SCALE_1_TO_1;
    129 
    130 	moncontrol(1);
    131 }
    132 
    133 void
    134 _mcleanup()
    135 {
    136 	int fd;
    137 	int fromindex;
    138 	int endfrom;
    139 	u_long frompc;
    140 	int toindex;
    141 	struct rawarc rawarc;
    142 	struct gmonparam *p = &_gmonparam;
    143 	struct gmonhdr gmonhdr, *hdr;
    144 	struct clockinfo clockinfo;
    145 	int mib[2];
    146 	size_t size;
    147 	char *profdir;
    148 	char *proffile;
    149 	char  buf[PATH_MAX];
    150 	int len = sizeof(buf) - 1;
    151 #ifdef DEBUG
    152 	int log, len;
    153 	char buf2[200];
    154 #endif
    155 
    156 	if (p->state == GMON_PROF_ERROR)
    157 		ERR("_mcleanup: tos overflow\n");
    158 
    159 	size = sizeof(clockinfo);
    160 	mib[0] = CTL_KERN;
    161 	mib[1] = KERN_CLOCKRATE;
    162 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
    163 		/*
    164 		 * Best guess
    165 		 */
    166 		clockinfo.profhz = hertz();
    167 	} else if (clockinfo.profhz == 0) {
    168 		if (clockinfo.hz != 0)
    169 			clockinfo.profhz = clockinfo.hz;
    170 		else
    171 			clockinfo.profhz = hertz();
    172 	}
    173 
    174 	moncontrol(0);
    175 
    176 	if ((profdir = getenv("PROFDIR")) != NULL) {
    177 		extern char *__progname;
    178 		char *s, *t;
    179 		pid_t pid;
    180 		long divisor;
    181 
    182 		/* If PROFDIR contains a null value, no profiling
    183 		   output is produced */
    184 		if (*profdir == '\0') {
    185 			return;
    186 		}
    187 
    188 		t = buf;
    189 		s = profdir;
    190 		while ((*t = *s) != '\0') {
    191 			if (len-- == 0) {
    192 				warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
    193 				return;
    194 			}
    195 			t++;
    196 			s++;
    197 		}
    198 		*t++ = '/';
    199 
    200 		/*
    201 		 * Copy and convert pid from a pid_t to a string.  For
    202 		 * best performance, divisor should be initialized to
    203 		 * the largest power of 10 less than PID_MAX.
    204 		 */
    205 		pid = getpid();
    206 		divisor=10000;
    207 		while (divisor > pid) divisor /= 10;	/* skip leading zeros */
    208 		do {
    209 			*t++ = (pid/divisor) + '0';
    210 			pid %= divisor;
    211 		} while (divisor /= 10);
    212 		*t++ = '.';
    213 
    214 		s = __progname;
    215 		while ((*t++ = *s++) != '\0')
    216 			;
    217 
    218 		proffile = buf;
    219 	} else {
    220 		proffile = "gmon.out";
    221 	}
    222 
    223 	fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
    224 	if (fd < 0) {
    225 		perror( proffile );
    226 		return;
    227 	}
    228 #ifdef DEBUG
    229 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
    230 	if (log < 0) {
    231 		perror("mcount: gmon.log");
    232 		return;
    233 	}
    234 	len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
    235 	    p->kcount, p->kcountsize);
    236 	write(log, buf2, len);
    237 #endif
    238 	hdr = (struct gmonhdr *)&gmonhdr;
    239 	hdr->lpc = p->lowpc;
    240 	hdr->hpc = p->highpc;
    241 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
    242 	hdr->version = GMONVERSION;
    243 	hdr->profrate = clockinfo.profhz;
    244 	write(fd, (char *)hdr, sizeof *hdr);
    245 	write(fd, p->kcount, p->kcountsize);
    246 	endfrom = p->fromssize / sizeof(*p->froms);
    247 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
    248 		if (p->froms[fromindex] == 0)
    249 			continue;
    250 
    251 		frompc = p->lowpc;
    252 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
    253 		for (toindex = p->froms[fromindex]; toindex != 0;
    254 		     toindex = p->tos[toindex].link) {
    255 #ifdef DEBUG
    256 			len = snprintf(buf2, sizeof buf2,
    257 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
    258 				frompc, p->tos[toindex].selfpc,
    259 				p->tos[toindex].count);
    260 			write(log, buf2, len);
    261 #endif
    262 			rawarc.raw_frompc = frompc;
    263 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
    264 			rawarc.raw_count = p->tos[toindex].count;
    265 			write(fd, &rawarc, sizeof rawarc);
    266 		}
    267 	}
    268 	close(fd);
    269 }
    270 
    271 /*
    272  * Control profiling
    273  *	profiling is what mcount checks to see if
    274  *	all the data structures are ready.
    275  */
    276 void
    277 moncontrol(mode)
    278 	int mode;
    279 {
    280 	struct gmonparam *p = &_gmonparam;
    281 
    282 	if (mode) {
    283 		/* start */
    284 		profil((char *)p->kcount, p->kcountsize, p->lowpc,
    285 		    s_scale);
    286 		p->state = GMON_PROF_ON;
    287 	} else {
    288 		/* stop */
    289 		profil((char *)0, 0, 0, 0);
    290 		p->state = GMON_PROF_OFF;
    291 	}
    292 }
    293 
    294 /*
    295  * discover the tick frequency of the machine
    296  * if something goes wrong, we return 0, an impossible hertz.
    297  */
    298 static int
    299 hertz()
    300 {
    301 	struct itimerval tim;
    302 
    303 	tim.it_interval.tv_sec = 0;
    304 	tim.it_interval.tv_usec = 1;
    305 	tim.it_value.tv_sec = 0;
    306 	tim.it_value.tv_usec = 0;
    307 	setitimer(ITIMER_REAL, &tim, 0);
    308 	setitimer(ITIMER_REAL, 0, &tim);
    309 	if (tim.it_interval.tv_usec < 2)
    310 		return(0);
    311 	return (1000000 / tim.it_interval.tv_usec);
    312 }
    313 
    314 
    315