xref: /netbsd-src/lib/libc/gmon/gmon.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: gmon.c,v 1.10 1997/07/13 19:53:06 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 1.10 1997/07/13 19:53:06 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 
58 extern char *minbrk __asm ("minbrk");
59 
60 struct gmonparam _gmonparam = { GMON_PROF_OFF };
61 
62 static int	s_scale;
63 /* see profil(2) where this is describe (incorrectly) */
64 #define		SCALE_1_TO_1	0x10000L
65 
66 #define ERR(s) write(2, s, sizeof(s))
67 
68 void	moncontrol __P((int));
69 void	monstartup __P((u_long, u_long));
70 void	_mcleanup __P((void));
71 static int hertz __P((void));
72 
73 void
74 monstartup(lowpc, highpc)
75 	u_long lowpc;
76 	u_long highpc;
77 {
78 	register int o;
79 	char *cp;
80 	struct gmonparam *p = &_gmonparam;
81 
82 	/*
83 	 * round lowpc and highpc to multiples of the density we're using
84 	 * so the rest of the scaling (here and in gprof) stays in ints.
85 	 */
86 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
87 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
88 	p->textsize = p->highpc - p->lowpc;
89 	p->kcountsize = p->textsize / HISTFRACTION;
90 	p->hashfraction = HASHFRACTION;
91 	p->fromssize = p->textsize / p->hashfraction;
92 	p->tolimit = p->textsize * ARCDENSITY / 100;
93 	if (p->tolimit < MINARCS)
94 		p->tolimit = MINARCS;
95 	else if (p->tolimit > MAXARCS)
96 		p->tolimit = MAXARCS;
97 	p->tossize = p->tolimit * sizeof(struct tostruct);
98 
99 	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
100 	if (cp == (char *)-1) {
101 		ERR("monstartup: out of memory\n");
102 		return;
103 	}
104 #ifdef notdef
105 	bzero(cp, p->kcountsize + p->fromssize + p->tossize);
106 #endif
107 	p->tos = (struct tostruct *)cp;
108 	cp += p->tossize;
109 	p->kcount = (u_short *)cp;
110 	cp += p->kcountsize;
111 	p->froms = (u_short *)cp;
112 
113 	minbrk = sbrk(0);
114 	p->tos[0].link = 0;
115 
116 	o = p->highpc - p->lowpc;
117 	if (p->kcountsize < o) {
118 #ifndef notdef
119 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
120 #else /* avoid floating point */
121 		int quot = o / p->kcountsize;
122 
123 		if (quot >= 0x10000)
124 			s_scale = 1;
125 		else if (quot >= 0x100)
126 			s_scale = 0x10000 / quot;
127 		else if (o >= 0x800000)
128 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
129 		else
130 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
131 #endif
132 	} else
133 		s_scale = SCALE_1_TO_1;
134 
135 	moncontrol(1);
136 }
137 
138 void
139 _mcleanup()
140 {
141 	int fd;
142 	int fromindex;
143 	int endfrom;
144 	u_long frompc;
145 	int toindex;
146 	struct rawarc rawarc;
147 	struct gmonparam *p = &_gmonparam;
148 	struct gmonhdr gmonhdr, *hdr;
149 	struct clockinfo clockinfo;
150 	int mib[2];
151 	size_t size;
152 	char *profdir;
153 	char *proffile;
154 	char  buf[PATH_MAX];
155 	int len = sizeof(buf) - 1;
156 #ifdef DEBUG
157 	int log, len;
158 	char buf2[200];
159 #endif
160 
161 	if (p->state == GMON_PROF_ERROR)
162 		ERR("_mcleanup: tos overflow\n");
163 
164 	size = sizeof(clockinfo);
165 	mib[0] = CTL_KERN;
166 	mib[1] = KERN_CLOCKRATE;
167 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
168 		/*
169 		 * Best guess
170 		 */
171 		clockinfo.profhz = hertz();
172 	} else if (clockinfo.profhz == 0) {
173 		if (clockinfo.hz != 0)
174 			clockinfo.profhz = clockinfo.hz;
175 		else
176 			clockinfo.profhz = hertz();
177 	}
178 
179 	moncontrol(0);
180 
181 	if ((profdir = getenv("PROFDIR")) != NULL) {
182 		extern char *__progname;
183 		char *s, *t;
184 		pid_t pid;
185 		long divisor;
186 
187 		/* If PROFDIR contains a null value, no profiling
188 		   output is produced */
189 		if (*profdir == '\0') {
190 			return;
191 		}
192 
193 		t = buf;
194 		s = profdir;
195 		while ((*t = *s) != '\0') {
196 			if (len-- == 0) {
197 				warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
198 				return;
199 			}
200 			t++;
201 			s++;
202 		}
203 		*t++ = '/';
204 
205 		/*
206 		 * Copy and convert pid from a pid_t to a string.  For
207 		 * best performance, divisor should be initialized to
208 		 * the largest power of 10 less than PID_MAX.
209 		 */
210 		pid = getpid();
211 		divisor=10000;
212 		while (divisor > pid) divisor /= 10;	/* skip leading zeros */
213 		do {
214 			*t++ = (pid/divisor) + '0';
215 			pid %= divisor;
216 		} while (divisor /= 10);
217 		*t++ = '.';
218 
219 		s = __progname;
220 		while ((*t++ = *s++) != '\0')
221 			;
222 
223 		proffile = buf;
224 	} else {
225 		proffile = "gmon.out";
226 	}
227 
228 	fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
229 	if (fd < 0) {
230 		warn("mcount: Cannot open `%s'", proffile);
231 		return;
232 	}
233 #ifdef DEBUG
234 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
235 	if (log < 0) {
236 		warn("mcount: Cannot open `gmon.log'");
237 		return;
238 	}
239 	len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
240 	    p->kcount, p->kcountsize);
241 	write(log, buf2, len);
242 #endif
243 	hdr = (struct gmonhdr *)&gmonhdr;
244 	hdr->lpc = p->lowpc;
245 	hdr->hpc = p->highpc;
246 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
247 	hdr->version = GMONVERSION;
248 	hdr->profrate = clockinfo.profhz;
249 	write(fd, (char *)hdr, sizeof *hdr);
250 	write(fd, p->kcount, p->kcountsize);
251 	endfrom = p->fromssize / sizeof(*p->froms);
252 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
253 		if (p->froms[fromindex] == 0)
254 			continue;
255 
256 		frompc = p->lowpc;
257 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
258 		for (toindex = p->froms[fromindex]; toindex != 0;
259 		     toindex = p->tos[toindex].link) {
260 #ifdef DEBUG
261 			len = snprintf(buf2, sizeof buf2,
262 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
263 				frompc, p->tos[toindex].selfpc,
264 				p->tos[toindex].count);
265 			write(log, buf2, len);
266 #endif
267 			rawarc.raw_frompc = frompc;
268 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
269 			rawarc.raw_count = p->tos[toindex].count;
270 			write(fd, &rawarc, sizeof rawarc);
271 		}
272 	}
273 	close(fd);
274 }
275 
276 /*
277  * Control profiling
278  *	profiling is what mcount checks to see if
279  *	all the data structures are ready.
280  */
281 void
282 moncontrol(mode)
283 	int mode;
284 {
285 	struct gmonparam *p = &_gmonparam;
286 
287 	if (mode) {
288 		/* start */
289 		profil((char *)p->kcount, p->kcountsize, p->lowpc,
290 		    s_scale);
291 		p->state = GMON_PROF_ON;
292 	} else {
293 		/* stop */
294 		profil((char *)0, 0, 0, 0);
295 		p->state = GMON_PROF_OFF;
296 	}
297 }
298 
299 /*
300  * discover the tick frequency of the machine
301  * if something goes wrong, we return 0, an impossible hertz.
302  */
303 static int
304 hertz()
305 {
306 	struct itimerval tim;
307 
308 	tim.it_interval.tv_sec = 0;
309 	tim.it_interval.tv_usec = 1;
310 	tim.it_value.tv_sec = 0;
311 	tim.it_value.tv_usec = 0;
312 	setitimer(ITIMER_REAL, &tim, 0);
313 	setitimer(ITIMER_REAL, 0, &tim);
314 	if (tim.it_interval.tv_usec < 2)
315 		return(0);
316 	return (1000000 / tim.it_interval.tv_usec);
317 }
318