gmon.c revision 1.15 
1/*	$NetBSD: gmon.c,v 1.15 1999/01/14 22:48:19 kleink 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 1.15 1999/01/14 22:48:19 kleink 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
59struct gmonparam _gmonparam = { GMON_PROF_OFF };
60
61static u_int	s_scale;
62/* see profil(2) where this is describe (incorrectly) */
63#define		SCALE_1_TO_1	0x10000L
64
65#define ERR(s) write(STDERR_FILENO, s, sizeof(s))
66
67void	moncontrol __P((int));
68void	monstartup __P((u_long, u_long));
69void	_mcleanup __P((void));
70static int hertz __P((void));
71
72void
73monstartup(lowpc, highpc)
74	u_long lowpc;
75	u_long highpc;
76{
77	long o;
78	char *cp;
79	struct gmonparam *p = &_gmonparam;
80
81	/*
82	 * round lowpc and highpc to multiples of the density we're using
83	 * so the rest of the scaling (here and in gprof) stays in ints.
84	 */
85	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
86	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
87	p->textsize = p->highpc - p->lowpc;
88	p->kcountsize = p->textsize / HISTFRACTION;
89	p->hashfraction = HASHFRACTION;
90	p->fromssize = p->textsize / p->hashfraction;
91	p->tolimit = p->textsize * ARCDENSITY / 100;
92	if (p->tolimit < MINARCS)
93		p->tolimit = MINARCS;
94	else if (p->tolimit > MAXARCS)
95		p->tolimit = MAXARCS;
96	p->tossize = p->tolimit * sizeof(struct tostruct);
97
98	cp = sbrk((int)(p->kcountsize + p->fromssize + p->tossize));
99	if (cp == (char *)-1) {
100		ERR("monstartup: out of memory\n");
101		return;
102	}
103#ifdef notdef
104	memset(cp, 0, p->kcountsize + p->fromssize + p->tossize);
105#endif
106	p->tos = (struct tostruct *)(void *)cp;
107	cp += (size_t)p->tossize;
108	p->kcount = (u_short *)(void *)cp;
109	cp += (size_t)p->kcountsize;
110	p->froms = (u_short *)(void *)cp;
111
112	__minbrk = sbrk(0);
113	p->tos[0].link = 0;
114
115	o = p->highpc - p->lowpc;
116	if (p->kcountsize < o) {
117#ifndef notdef
118		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
119#else /* avoid floating point */
120		int quot = o / p->kcountsize;
121
122		if (quot >= 0x10000)
123			s_scale = 1;
124		else if (quot >= 0x100)
125			s_scale = 0x10000 / quot;
126		else if (o >= 0x800000)
127			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
128		else
129			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
130#endif
131	} else
132		s_scale = SCALE_1_TO_1;
133
134	moncontrol(1);
135}
136
137void
138_mcleanup()
139{
140	int fd;
141	int fromindex;
142	int endfrom;
143	u_long frompc;
144	int toindex;
145	struct rawarc rawarc;
146	struct gmonparam *p = &_gmonparam;
147	struct gmonhdr gmonhdr, *hdr;
148	struct clockinfo clockinfo;
149	int mib[2];
150	size_t size;
151	char *profdir;
152	char *proffile;
153	char  buf[PATH_MAX];
154	int len = sizeof(buf) - 1;
155#ifdef DEBUG
156	int log, len;
157	char buf2[200];
158#endif
159
160	if (p->state == GMON_PROF_ERROR)
161		ERR("_mcleanup: tos overflow\n");
162
163	size = sizeof(clockinfo);
164	mib[0] = CTL_KERN;
165	mib[1] = KERN_CLOCKRATE;
166	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
167		/*
168		 * Best guess
169		 */
170		clockinfo.profhz = hertz();
171	} else if (clockinfo.profhz == 0) {
172		if (clockinfo.hz != 0)
173			clockinfo.profhz = clockinfo.hz;
174		else
175			clockinfo.profhz = hertz();
176	}
177
178	moncontrol(0);
179
180	if ((profdir = getenv("PROFDIR")) != NULL) {
181		extern char *__progname;
182		char *s, *t;
183		pid_t pid;
184		long divisor;
185
186		/* If PROFDIR contains a null value, no profiling
187		   output is produced */
188		if (*profdir == '\0') {
189			return;
190		}
191
192		t = buf;
193		s = profdir;
194		while ((*t = *s) != '\0') {
195			if (len-- == 0) {
196				warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
197				return;
198			}
199			t++;
200			s++;
201		}
202		*t++ = '/';
203
204		/*
205		 * Copy and convert pid from a pid_t to a string.  For
206		 * best performance, divisor should be initialized to
207		 * the largest power of 10 less than PID_MAX.
208		 */
209		pid = getpid();
210		divisor=10000;
211		while (divisor > pid) divisor /= 10;	/* skip leading zeros */
212		do {
213			*t++ = (char)((pid/divisor) + '0');
214			pid %= (pid_t)divisor;
215		} while (divisor /= 10);
216		*t++ = '.';
217
218		s = __progname;
219		while ((*t++ = *s++) != '\0')
220			;
221
222		proffile = buf;
223	} else {
224		proffile = "gmon.out";
225	}
226
227	fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
228	if (fd < 0) {
229		warn("mcount: Cannot open `%s'", proffile);
230		return;
231	}
232#ifdef DEBUG
233	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
234	if (log < 0) {
235		warn("mcount: Cannot open `gmon.log'");
236		return;
237	}
238	len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
239	    p->kcount, p->kcountsize);
240	write(log, buf2, len);
241#endif
242	hdr = (struct gmonhdr *)&gmonhdr;
243	hdr->lpc = p->lowpc;
244	hdr->hpc = p->highpc;
245	hdr->ncnt = (int)(p->kcountsize + sizeof(gmonhdr));
246	hdr->version = GMONVERSION;
247	hdr->profrate = clockinfo.profhz;
248	(void)write(fd, hdr, sizeof *hdr);
249	(void)write(fd, p->kcount, (size_t)p->kcountsize);
250	endfrom = (int)(p->fromssize / sizeof(*p->froms));
251	for (fromindex = 0; fromindex < endfrom; fromindex++) {
252		if (p->froms[fromindex] == 0)
253			continue;
254
255		frompc = p->lowpc;
256		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
257		for (toindex = p->froms[fromindex]; toindex != 0;
258		     toindex = p->tos[toindex].link) {
259#ifdef DEBUG
260			len = snprintf(buf2, sizeof buf2,
261			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
262				frompc, p->tos[toindex].selfpc,
263				p->tos[toindex].count);
264			write(log, buf2, len);
265#endif
266			rawarc.raw_frompc = frompc;
267			rawarc.raw_selfpc = p->tos[toindex].selfpc;
268			rawarc.raw_count = p->tos[toindex].count;
269			write(fd, &rawarc, sizeof rawarc);
270		}
271	}
272	close(fd);
273}
274
275/*
276 * Control profiling
277 *	profiling is what mcount checks to see if
278 *	all the data structures are ready.
279 */
280void
281moncontrol(mode)
282	int mode;
283{
284	struct gmonparam *p = &_gmonparam;
285
286	if (mode) {
287		/* start */
288		profil((char *)(void *)p->kcount, (size_t)p->kcountsize,
289		    p->lowpc, s_scale);
290		p->state = GMON_PROF_ON;
291	} else {
292		/* stop */
293		profil(NULL, 0, (u_long)0, 0);
294		p->state = GMON_PROF_OFF;
295	}
296}
297
298/*
299 * discover the tick frequency of the machine
300 * if something goes wrong, we return 0, an impossible hertz.
301 */
302static int
303hertz()
304{
305	struct itimerval tim;
306
307	tim.it_interval.tv_sec = 0;
308	tim.it_interval.tv_usec = 1;
309	tim.it_value.tv_sec = 0;
310	tim.it_value.tv_usec = 0;
311	setitimer(ITIMER_REAL, &tim, 0);
312	setitimer(ITIMER_REAL, 0, &tim);
313	if (tim.it_interval.tv_usec < 2)
314		return(0);
315	return (int)(1000000 / tim.it_interval.tv_usec);
316}
317