gmon.c revision 1.16 
1/*	$NetBSD: gmon.c,v 1.16 2000/12/20 20:55:23 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
39static char sccsid[] = "@(#)gmon.c	8.1 (Berkeley) 6/4/93";
40#else
41__RCSID("$NetBSD: gmon.c,v 1.16 2000/12/20 20:55:23 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#include "extern.h"
58
59extern char *__progname;
60
61struct gmonparam _gmonparam = { GMON_PROF_OFF };
62
63static u_int	s_scale;
64/* see profil(2) where this is describe (incorrectly) */
65#define		SCALE_1_TO_1	0x10000L
66
67#define ERR(s) write(STDERR_FILENO, s, sizeof(s))
68
69void	moncontrol __P((int));
70void	monstartup __P((u_long, u_long));
71void	_mcleanup __P((void));
72static int hertz __P((void));
73
74
75void
76monstartup(lowpc, highpc)
77	u_long lowpc;
78	u_long highpc;
79{
80	long o;
81	char *cp;
82	struct gmonparam *p = &_gmonparam;
83
84	/*
85	 * round lowpc and highpc to multiples of the density we're using
86	 * so the rest of the scaling (here and in gprof) stays in ints.
87	 */
88	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
89	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
90	p->textsize = p->highpc - p->lowpc;
91	p->kcountsize = p->textsize / HISTFRACTION;
92	p->hashfraction = HASHFRACTION;
93	p->fromssize = p->textsize / p->hashfraction;
94	p->tolimit = p->textsize * ARCDENSITY / 100;
95	if (p->tolimit < MINARCS)
96		p->tolimit = MINARCS;
97	else if (p->tolimit > MAXARCS)
98		p->tolimit = MAXARCS;
99	p->tossize = p->tolimit * sizeof(struct tostruct);
100
101	cp = sbrk((intptr_t)(p->kcountsize + p->fromssize + p->tossize));
102	if (cp == (char *)-1) {
103		ERR("monstartup: out of memory\n");
104		return;
105	}
106#ifdef notdef
107	memset(cp, 0, p->kcountsize + p->fromssize + p->tossize);
108#endif
109	p->tos = (struct tostruct *)(void *)cp;
110	cp += (size_t)p->tossize;
111	p->kcount = (u_short *)(void *)cp;
112	cp += (size_t)p->kcountsize;
113	p->froms = (u_short *)(void *)cp;
114
115	__minbrk = sbrk((intptr_t)0);
116	p->tos[0].link = 0;
117
118	o = p->highpc - p->lowpc;
119	if (p->kcountsize < o) {
120#ifndef notdef
121		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
122#else /* avoid floating point */
123		int quot = o / p->kcountsize;
124
125		if (quot >= 0x10000)
126			s_scale = 1;
127		else if (quot >= 0x100)
128			s_scale = 0x10000 / quot;
129		else if (o >= 0x800000)
130			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
131		else
132			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
133#endif
134	} else
135		s_scale = SCALE_1_TO_1;
136
137	moncontrol(1);
138}
139
140void
141_mcleanup()
142{
143	int fd;
144	int fromindex;
145	int endfrom;
146	u_long frompc;
147	int toindex;
148	struct rawarc rawarc;
149	struct gmonparam *p = &_gmonparam;
150	struct gmonhdr gmonhdr, *hdr;
151	struct clockinfo clockinfo;
152	int mib[2];
153	size_t size;
154	char *profdir;
155	char *proffile;
156	char  buf[PATH_MAX];
157	int len = sizeof(buf) - 1;
158#ifdef DEBUG
159	int log, len;
160	char buf2[200];
161#endif
162
163	if (p->state == GMON_PROF_ERROR)
164		ERR("_mcleanup: tos overflow\n");
165
166	size = sizeof(clockinfo);
167	mib[0] = CTL_KERN;
168	mib[1] = KERN_CLOCKRATE;
169	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
170		/*
171		 * Best guess
172		 */
173		clockinfo.profhz = hertz();
174	} else if (clockinfo.profhz == 0) {
175		if (clockinfo.hz != 0)
176			clockinfo.profhz = clockinfo.hz;
177		else
178			clockinfo.profhz = hertz();
179	}
180
181	moncontrol(0);
182
183	if ((profdir = getenv("PROFDIR")) != NULL) {
184		char *s, *t;
185		pid_t pid;
186		long divisor;
187
188		/* If PROFDIR contains a null value, no profiling
189		   output is produced */
190		if (*profdir == '\0') {
191			return;
192		}
193
194		t = buf;
195		s = profdir;
196		while ((*t = *s) != '\0') {
197			if (len-- == 0) {
198				warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
199				return;
200			}
201			t++;
202			s++;
203		}
204		*t++ = '/';
205
206		/*
207		 * Copy and convert pid from a pid_t to a string.  For
208		 * best performance, divisor should be initialized to
209		 * the largest power of 10 less than PID_MAX.
210		 */
211		pid = getpid();
212		divisor=10000;
213		while (divisor > pid) divisor /= 10;	/* skip leading zeros */
214		do {
215			*t++ = (char)((pid/divisor) + '0');
216			pid %= (pid_t)divisor;
217		} while (divisor /= 10);
218		*t++ = '.';
219
220		s = __progname;
221		while ((*t++ = *s++) != '\0')
222			;
223
224		proffile = buf;
225	} else {
226		proffile = "gmon.out";
227	}
228
229	fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
230	if (fd < 0) {
231		warn("mcount: Cannot open `%s'", proffile);
232		return;
233	}
234#ifdef DEBUG
235	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
236	if (log < 0) {
237		warn("mcount: Cannot open `gmon.log'");
238		return;
239	}
240	len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
241	    p->kcount, p->kcountsize);
242	write(log, buf2, len);
243#endif
244	hdr = (struct gmonhdr *)&gmonhdr;
245	hdr->lpc = p->lowpc;
246	hdr->hpc = p->highpc;
247	hdr->ncnt = (int)(p->kcountsize + sizeof(gmonhdr));
248	hdr->version = GMONVERSION;
249	hdr->profrate = clockinfo.profhz;
250	(void)write(fd, hdr, sizeof *hdr);
251	(void)write(fd, p->kcount, (size_t)p->kcountsize);
252	endfrom = (int)(p->fromssize / sizeof(*p->froms));
253	for (fromindex = 0; fromindex < endfrom; fromindex++) {
254		if (p->froms[fromindex] == 0)
255			continue;
256
257		frompc = p->lowpc;
258		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
259		for (toindex = p->froms[fromindex]; toindex != 0;
260		     toindex = p->tos[toindex].link) {
261#ifdef DEBUG
262			len = snprintf(buf2, sizeof buf2,
263			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
264				frompc, p->tos[toindex].selfpc,
265				p->tos[toindex].count);
266			write(log, buf2, len);
267#endif
268			rawarc.raw_frompc = frompc;
269			rawarc.raw_selfpc = p->tos[toindex].selfpc;
270			rawarc.raw_count = p->tos[toindex].count;
271			write(fd, &rawarc, sizeof rawarc);
272		}
273	}
274	close(fd);
275}
276
277/*
278 * Control profiling
279 *	profiling is what mcount checks to see if
280 *	all the data structures are ready.
281 */
282void
283moncontrol(mode)
284	int mode;
285{
286	struct gmonparam *p = &_gmonparam;
287
288	if (mode) {
289		/* start */
290		profil((char *)(void *)p->kcount, (size_t)p->kcountsize,
291		    p->lowpc, s_scale);
292		p->state = GMON_PROF_ON;
293	} else {
294		/* stop */
295		profil(NULL, 0, (u_long)0, 0);
296		p->state = GMON_PROF_OFF;
297	}
298}
299
300/*
301 * discover the tick frequency of the machine
302 * if something goes wrong, we return 0, an impossible hertz.
303 */
304static int
305hertz()
306{
307	struct itimerval tim;
308
309	tim.it_interval.tv_sec = 0;
310	tim.it_interval.tv_usec = 1;
311	tim.it_value.tv_sec = 0;
312	tim.it_value.tv_usec = 0;
313	setitimer(ITIMER_REAL, &tim, 0);
314	setitimer(ITIMER_REAL, 0, &tim);
315	if (tim.it_interval.tv_usec < 2)
316		return(0);
317	return (int)(1000000 / tim.it_interval.tv_usec);
318}
319