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gmon.c revision 1.2
      1 /*-
      2  * Copyright (c) 1983, 1992, 1993
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #if !defined(lint) && defined(LIBC_SCCS)
     35 /* from: static char sccsid[] = "@(#)gmon.c	8.1 (Berkeley) 6/4/93"; */
     36 static char *rcsid = "$Id: gmon.c,v 1.2 1994/05/14 06:31:15 cgd Exp $";
     37 #endif
     38 
     39 #include <sys/param.h>
     40 #include <sys/time.h>
     41 #include <sys/gmon.h>
     42 #include <sys/sysctl.h>
     43 
     44 #include <stdio.h>
     45 #include <fcntl.h>
     46 #include <unistd.h>
     47 
     48 extern char *minbrk asm ("minbrk");
     49 
     50 struct gmonparam _gmonparam = { GMON_PROF_OFF };
     51 
     52 static int	s_scale;
     53 /* see profil(2) where this is describe (incorrectly) */
     54 #define		SCALE_1_TO_1	0x10000L
     55 
     56 #define ERR(s) write(2, s, sizeof(s))
     57 
     58 void	moncontrol __P((int));
     59 static int hertz __P((void));
     60 
     61 void
     62 monstartup(lowpc, highpc)
     63 	u_long lowpc;
     64 	u_long highpc;
     65 {
     66 	register int o;
     67 	char *cp;
     68 	struct gmonparam *p = &_gmonparam;
     69 
     70 	/*
     71 	 * round lowpc and highpc to multiples of the density we're using
     72 	 * so the rest of the scaling (here and in gprof) stays in ints.
     73 	 */
     74 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
     75 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
     76 	p->textsize = p->highpc - p->lowpc;
     77 	p->kcountsize = p->textsize / HISTFRACTION;
     78 	p->hashfraction = HASHFRACTION;
     79 	p->fromssize = p->textsize / HASHFRACTION;
     80 	p->tolimit = p->textsize * ARCDENSITY / 100;
     81 	if (p->tolimit < MINARCS)
     82 		p->tolimit = MINARCS;
     83 	else if (p->tolimit > MAXARCS)
     84 		p->tolimit = MAXARCS;
     85 	p->tossize = p->tolimit * sizeof(struct tostruct);
     86 
     87 	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
     88 	if (cp == (char *)-1) {
     89 		ERR("monstartup: out of memory\n");
     90 		return;
     91 	}
     92 #ifdef notdef
     93 	bzero(cp, p->kcountsize + p->fromssize + p->tossize);
     94 #endif
     95 	p->tos = (struct tostruct *)cp;
     96 	cp += p->tossize;
     97 	p->kcount = (u_short *)cp;
     98 	cp += p->kcountsize;
     99 	p->froms = (u_short *)cp;
    100 
    101 	minbrk = sbrk(0);
    102 	p->tos[0].link = 0;
    103 
    104 	o = p->highpc - p->lowpc;
    105 	if (p->kcountsize < o) {
    106 #ifndef notdef
    107 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
    108 #else /* avoid floating point */
    109 		int quot = o / p->kcountsize;
    110 
    111 		if (quot >= 0x10000)
    112 			s_scale = 1;
    113 		else if (quot >= 0x100)
    114 			s_scale = 0x10000 / quot;
    115 		else if (o >= 0x800000)
    116 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
    117 		else
    118 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
    119 #endif
    120 	} else
    121 		s_scale = SCALE_1_TO_1;
    122 
    123 	moncontrol(1);
    124 }
    125 
    126 void
    127 _mcleanup()
    128 {
    129 	int fd;
    130 	int fromindex;
    131 	int endfrom;
    132 	u_long frompc;
    133 	int toindex;
    134 	struct rawarc rawarc;
    135 	struct gmonparam *p = &_gmonparam;
    136 	struct gmonhdr gmonhdr, *hdr;
    137 	struct clockinfo clockinfo;
    138 	int mib[2];
    139 	size_t size;
    140 #ifdef DEBUG
    141 	int log, len;
    142 	char buf[200];
    143 #endif
    144 
    145 	if (p->state == GMON_PROF_ERROR)
    146 		ERR("_mcleanup: tos overflow\n");
    147 
    148 	size = sizeof(clockinfo);
    149 	mib[0] = CTL_KERN;
    150 	mib[1] = KERN_CLOCKRATE;
    151 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
    152 		/*
    153 		 * Best guess
    154 		 */
    155 		clockinfo.profhz = hertz();
    156 	} else if (clockinfo.profhz == 0) {
    157 		if (clockinfo.hz != 0)
    158 			clockinfo.profhz = clockinfo.hz;
    159 		else
    160 			clockinfo.profhz = hertz();
    161 	}
    162 
    163 	moncontrol(0);
    164 	fd = open("gmon.out", O_CREAT|O_TRUNC|O_WRONLY, 0666);
    165 	if (fd < 0) {
    166 		perror("mcount: gmon.out");
    167 		return;
    168 	}
    169 #ifdef DEBUG
    170 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
    171 	if (log < 0) {
    172 		perror("mcount: gmon.log");
    173 		return;
    174 	}
    175 	len = sprintf(buf, "[mcleanup1] kcount 0x%x ssiz %d\n",
    176 	    p->kcount, p->kcountsize);
    177 	write(log, buf, len);
    178 #endif
    179 	hdr = (struct gmonhdr *)&gmonhdr;
    180 	hdr->lpc = p->lowpc;
    181 	hdr->hpc = p->highpc;
    182 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
    183 	hdr->version = GMONVERSION;
    184 	hdr->profrate = clockinfo.profhz;
    185 	write(fd, (char *)hdr, sizeof *hdr);
    186 	write(fd, p->kcount, p->kcountsize);
    187 	endfrom = p->fromssize / sizeof(*p->froms);
    188 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
    189 		if (p->froms[fromindex] == 0)
    190 			continue;
    191 
    192 		frompc = p->lowpc;
    193 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
    194 		for (toindex = p->froms[fromindex]; toindex != 0;
    195 		     toindex = p->tos[toindex].link) {
    196 #ifdef DEBUG
    197 			len = sprintf(buf,
    198 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
    199 				frompc, p->tos[toindex].selfpc,
    200 				p->tos[toindex].count);
    201 			write(log, buf, len);
    202 #endif
    203 			rawarc.raw_frompc = frompc;
    204 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
    205 			rawarc.raw_count = p->tos[toindex].count;
    206 			write(fd, &rawarc, sizeof rawarc);
    207 		}
    208 	}
    209 	close(fd);
    210 }
    211 
    212 /*
    213  * Control profiling
    214  *	profiling is what mcount checks to see if
    215  *	all the data structures are ready.
    216  */
    217 void
    218 moncontrol(mode)
    219 	int mode;
    220 {
    221 	struct gmonparam *p = &_gmonparam;
    222 
    223 	if (mode) {
    224 		/* start */
    225 		profil((char *)p->kcount, p->kcountsize, (int)p->lowpc,
    226 		    s_scale);
    227 		p->state = GMON_PROF_ON;
    228 	} else {
    229 		/* stop */
    230 		profil((char *)0, 0, 0, 0);
    231 		p->state = GMON_PROF_OFF;
    232 	}
    233 }
    234 
    235 /*
    236  * discover the tick frequency of the machine
    237  * if something goes wrong, we return 0, an impossible hertz.
    238  */
    239 static int
    240 hertz()
    241 {
    242 	struct itimerval tim;
    243 
    244 	tim.it_interval.tv_sec = 0;
    245 	tim.it_interval.tv_usec = 1;
    246 	tim.it_value.tv_sec = 0;
    247 	tim.it_value.tv_usec = 0;
    248 	setitimer(ITIMER_REAL, &tim, 0);
    249 	setitimer(ITIMER_REAL, 0, &tim);
    250 	if (tim.it_interval.tv_usec < 2)
    251 		return(0);
    252 	return (1000000 / tim.it_interval.tv_usec);
    253 }
    254 
    255 
    256