xref: /netbsd-src/lib/libc/gmon/gmon.c (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
1 /*	$NetBSD: gmon.c,v 1.3 1995/02/27 12:54:39 cgd 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 1.3 1995/02/27 12:54:39 cgd 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 <fcntl.h>
51 #include <unistd.h>
52 
53 extern char *minbrk asm ("minbrk");
54 
55 struct gmonparam _gmonparam = { GMON_PROF_OFF };
56 
57 static int	s_scale;
58 /* see profil(2) where this is describe (incorrectly) */
59 #define		SCALE_1_TO_1	0x10000L
60 
61 #define ERR(s) write(2, s, sizeof(s))
62 
63 void	moncontrol __P((int));
64 static int hertz __P((void));
65 
66 void
67 monstartup(lowpc, highpc)
68 	u_long lowpc;
69 	u_long highpc;
70 {
71 	register int o;
72 	char *cp;
73 	struct gmonparam *p = &_gmonparam;
74 
75 	/*
76 	 * round lowpc and highpc to multiples of the density we're using
77 	 * so the rest of the scaling (here and in gprof) stays in ints.
78 	 */
79 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
80 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
81 	p->textsize = p->highpc - p->lowpc;
82 	p->kcountsize = p->textsize / HISTFRACTION;
83 	p->hashfraction = HASHFRACTION;
84 	p->fromssize = p->textsize / HASHFRACTION;
85 	p->tolimit = p->textsize * ARCDENSITY / 100;
86 	if (p->tolimit < MINARCS)
87 		p->tolimit = MINARCS;
88 	else if (p->tolimit > MAXARCS)
89 		p->tolimit = MAXARCS;
90 	p->tossize = p->tolimit * sizeof(struct tostruct);
91 
92 	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
93 	if (cp == (char *)-1) {
94 		ERR("monstartup: out of memory\n");
95 		return;
96 	}
97 #ifdef notdef
98 	bzero(cp, p->kcountsize + p->fromssize + p->tossize);
99 #endif
100 	p->tos = (struct tostruct *)cp;
101 	cp += p->tossize;
102 	p->kcount = (u_short *)cp;
103 	cp += p->kcountsize;
104 	p->froms = (u_short *)cp;
105 
106 	minbrk = sbrk(0);
107 	p->tos[0].link = 0;
108 
109 	o = p->highpc - p->lowpc;
110 	if (p->kcountsize < o) {
111 #ifndef notdef
112 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
113 #else /* avoid floating point */
114 		int quot = o / p->kcountsize;
115 
116 		if (quot >= 0x10000)
117 			s_scale = 1;
118 		else if (quot >= 0x100)
119 			s_scale = 0x10000 / quot;
120 		else if (o >= 0x800000)
121 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
122 		else
123 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
124 #endif
125 	} else
126 		s_scale = SCALE_1_TO_1;
127 
128 	moncontrol(1);
129 }
130 
131 void
132 _mcleanup()
133 {
134 	int fd;
135 	int fromindex;
136 	int endfrom;
137 	u_long frompc;
138 	int toindex;
139 	struct rawarc rawarc;
140 	struct gmonparam *p = &_gmonparam;
141 	struct gmonhdr gmonhdr, *hdr;
142 	struct clockinfo clockinfo;
143 	int mib[2];
144 	size_t size;
145 #ifdef DEBUG
146 	int log, len;
147 	char buf[200];
148 #endif
149 
150 	if (p->state == GMON_PROF_ERROR)
151 		ERR("_mcleanup: tos overflow\n");
152 
153 	size = sizeof(clockinfo);
154 	mib[0] = CTL_KERN;
155 	mib[1] = KERN_CLOCKRATE;
156 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
157 		/*
158 		 * Best guess
159 		 */
160 		clockinfo.profhz = hertz();
161 	} else if (clockinfo.profhz == 0) {
162 		if (clockinfo.hz != 0)
163 			clockinfo.profhz = clockinfo.hz;
164 		else
165 			clockinfo.profhz = hertz();
166 	}
167 
168 	moncontrol(0);
169 	fd = open("gmon.out", O_CREAT|O_TRUNC|O_WRONLY, 0666);
170 	if (fd < 0) {
171 		perror("mcount: gmon.out");
172 		return;
173 	}
174 #ifdef DEBUG
175 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
176 	if (log < 0) {
177 		perror("mcount: gmon.log");
178 		return;
179 	}
180 	len = sprintf(buf, "[mcleanup1] kcount 0x%x ssiz %d\n",
181 	    p->kcount, p->kcountsize);
182 	write(log, buf, len);
183 #endif
184 	hdr = (struct gmonhdr *)&gmonhdr;
185 	hdr->lpc = p->lowpc;
186 	hdr->hpc = p->highpc;
187 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
188 	hdr->version = GMONVERSION;
189 	hdr->profrate = clockinfo.profhz;
190 	write(fd, (char *)hdr, sizeof *hdr);
191 	write(fd, p->kcount, p->kcountsize);
192 	endfrom = p->fromssize / sizeof(*p->froms);
193 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
194 		if (p->froms[fromindex] == 0)
195 			continue;
196 
197 		frompc = p->lowpc;
198 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
199 		for (toindex = p->froms[fromindex]; toindex != 0;
200 		     toindex = p->tos[toindex].link) {
201 #ifdef DEBUG
202 			len = sprintf(buf,
203 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
204 				frompc, p->tos[toindex].selfpc,
205 				p->tos[toindex].count);
206 			write(log, buf, len);
207 #endif
208 			rawarc.raw_frompc = frompc;
209 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
210 			rawarc.raw_count = p->tos[toindex].count;
211 			write(fd, &rawarc, sizeof rawarc);
212 		}
213 	}
214 	close(fd);
215 }
216 
217 /*
218  * Control profiling
219  *	profiling is what mcount checks to see if
220  *	all the data structures are ready.
221  */
222 void
223 moncontrol(mode)
224 	int mode;
225 {
226 	struct gmonparam *p = &_gmonparam;
227 
228 	if (mode) {
229 		/* start */
230 		profil((char *)p->kcount, p->kcountsize, (int)p->lowpc,
231 		    s_scale);
232 		p->state = GMON_PROF_ON;
233 	} else {
234 		/* stop */
235 		profil((char *)0, 0, 0, 0);
236 		p->state = GMON_PROF_OFF;
237 	}
238 }
239 
240 /*
241  * discover the tick frequency of the machine
242  * if something goes wrong, we return 0, an impossible hertz.
243  */
244 static int
245 hertz()
246 {
247 	struct itimerval tim;
248 
249 	tim.it_interval.tv_sec = 0;
250 	tim.it_interval.tv_usec = 1;
251 	tim.it_value.tv_sec = 0;
252 	tim.it_value.tv_usec = 0;
253 	setitimer(ITIMER_REAL, &tim, 0);
254 	setitimer(ITIMER_REAL, 0, &tim);
255 	if (tim.it_interval.tv_usec < 2)
256 		return(0);
257 	return (1000000 / tim.it_interval.tv_usec);
258 }
259 
260 
261