xref: /netbsd-src/lib/libc/gmon/gmon.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
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