gmon.c revision 1.6 
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)
35static char rcsid[] = "$OpenBSD: gmon.c,v 1.6 1996/09/05 12:29:12 deraadt Exp $";
36#endif
37
38#include <sys/param.h>
39#include <sys/time.h>
40#include <sys/gmon.h>
41#include <sys/sysctl.h>
42
43#include <stdio.h>
44#include <stdlib.h>
45#include <fcntl.h>
46#include <limits.h>
47#include <unistd.h>
48
49extern char *minbrk __asm ("minbrk");
50
51struct gmonparam _gmonparam = { GMON_PROF_OFF };
52
53static int	s_scale;
54/* see profil(2) where this is describe (incorrectly) */
55#define		SCALE_1_TO_1	0x10000L
56
57#define ERR(s) write(2, s, sizeof(s))
58
59void	moncontrol __P((int));
60static int hertz __P((void));
61
62void
63monstartup(lowpc, highpc)
64	u_long lowpc;
65	u_long highpc;
66{
67	register int o;
68	char *cp;
69	struct gmonparam *p = &_gmonparam;
70
71	/*
72	 * round lowpc and highpc to multiples of the density we're using
73	 * so the rest of the scaling (here and in gprof) stays in ints.
74	 */
75	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
76	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
77	p->textsize = p->highpc - p->lowpc;
78	p->kcountsize = p->textsize / HISTFRACTION;
79	p->hashfraction = HASHFRACTION;
80	p->fromssize = p->textsize / p->hashfraction;
81	p->tolimit = p->textsize * ARCDENSITY / 100;
82	if (p->tolimit < MINARCS)
83		p->tolimit = MINARCS;
84	else if (p->tolimit > MAXARCS)
85		p->tolimit = MAXARCS;
86	p->tossize = p->tolimit * sizeof(struct tostruct);
87
88	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
89	if (cp == (char *)-1) {
90		ERR("monstartup: out of memory\n");
91		return;
92	}
93#ifdef notdef
94	bzero(cp, p->kcountsize + p->fromssize + p->tossize);
95#endif
96	p->tos = (struct tostruct *)cp;
97	cp += p->tossize;
98	p->kcount = (u_short *)cp;
99	cp += p->kcountsize;
100	p->froms = (u_short *)cp;
101
102	minbrk = sbrk(0);
103	p->tos[0].link = 0;
104
105	o = p->highpc - p->lowpc;
106	if (p->kcountsize < o) {
107#ifndef notdef
108		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
109#else /* avoid floating point */
110		int quot = o / p->kcountsize;
111
112		if (quot >= 0x10000)
113			s_scale = 1;
114		else if (quot >= 0x100)
115			s_scale = 0x10000 / quot;
116		else if (o >= 0x800000)
117			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
118		else
119			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
120#endif
121	} else
122		s_scale = SCALE_1_TO_1;
123
124	moncontrol(1);
125}
126
127void
128_mcleanup()
129{
130	int fd;
131	int fromindex;
132	int endfrom;
133	u_long frompc;
134	int toindex;
135	struct rawarc rawarc;
136	struct gmonparam *p = &_gmonparam;
137	struct gmonhdr gmonhdr, *hdr;
138	struct clockinfo clockinfo;
139	int mib[2];
140	size_t size;
141	char *profdir;
142	char *proffile;
143	char  buf[PATH_MAX];
144#ifdef DEBUG
145	int log, len;
146	char dbuf[200];
147#endif
148
149	if (p->state == GMON_PROF_ERROR)
150		ERR("_mcleanup: tos overflow\n");
151
152	size = sizeof(clockinfo);
153	mib[0] = CTL_KERN;
154	mib[1] = KERN_CLOCKRATE;
155	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
156		/*
157		 * Best guess
158		 */
159		clockinfo.profhz = hertz();
160	} else if (clockinfo.profhz == 0) {
161		if (clockinfo.hz != 0)
162			clockinfo.profhz = clockinfo.hz;
163		else
164			clockinfo.profhz = hertz();
165	}
166
167	moncontrol(0);
168
169	if (issetugid() == 0 && (profdir = getenv("PROFDIR")) != NULL) {
170		extern char *__progname;
171		char *s, *t, *limit;
172		pid_t pid;
173		long divisor;
174
175		/* If PROFDIR contains a null value, no profiling
176		   output is produced */
177		if (*profdir == '\0') {
178			return;
179		}
180
181		limit = buf + sizeof buf - 1 - 10 - 1 -
182		    strlen(__progname) - 1;
183		t = buf;
184		s = profdir;
185		while((*t = *s) != '\0' && t < limit) {
186			t++;
187			s++;
188		}
189		*t++ = '/';
190
191		/*
192		 * Copy and convert pid from a pid_t to a string.  For
193		 * best performance, divisor should be initialized to
194		 * the largest power of 10 less than PID_MAX.
195		 */
196		pid = getpid();
197		divisor=10000;
198		while (divisor > pid) divisor /= 10;	/* skip leading zeros */
199		do {
200			*t++ = (pid/divisor) + '0';
201			pid %= divisor;
202		} while (divisor /= 10);
203		*t++ = '.';
204
205		s = __progname;
206		while ((*t++ = *s++) != '\0')
207			;
208
209		proffile = buf;
210	} else {
211		proffile = "gmon.out";
212	}
213
214	fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
215	if (fd < 0) {
216		perror( proffile );
217		return;
218	}
219#ifdef DEBUG
220	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
221	if (log < 0) {
222		perror("mcount: gmon.log");
223		return;
224	}
225	len = sprintf(dbuf, "[mcleanup1] kcount 0x%x ssiz %d\n",
226	    p->kcount, p->kcountsize);
227	write(log, dbuf, len);
228#endif
229	hdr = (struct gmonhdr *)&gmonhdr;
230	hdr->lpc = p->lowpc;
231	hdr->hpc = p->highpc;
232	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
233	hdr->version = GMONVERSION;
234	hdr->profrate = clockinfo.profhz;
235	write(fd, (char *)hdr, sizeof *hdr);
236	write(fd, p->kcount, p->kcountsize);
237	endfrom = p->fromssize / sizeof(*p->froms);
238	for (fromindex = 0; fromindex < endfrom; fromindex++) {
239		if (p->froms[fromindex] == 0)
240			continue;
241
242		frompc = p->lowpc;
243		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
244		for (toindex = p->froms[fromindex]; toindex != 0;
245		     toindex = p->tos[toindex].link) {
246#ifdef DEBUG
247			len = sprintf(dbuf,
248			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
249				frompc, p->tos[toindex].selfpc,
250				p->tos[toindex].count);
251			write(log, dbuf, len);
252#endif
253			rawarc.raw_frompc = frompc;
254			rawarc.raw_selfpc = p->tos[toindex].selfpc;
255			rawarc.raw_count = p->tos[toindex].count;
256			write(fd, &rawarc, sizeof rawarc);
257		}
258	}
259	close(fd);
260}
261
262/*
263 * Control profiling
264 *	profiling is what mcount checks to see if
265 *	all the data structures are ready.
266 */
267void
268moncontrol(mode)
269	int mode;
270{
271	struct gmonparam *p = &_gmonparam;
272
273	if (mode) {
274		/* start */
275		profil((char *)p->kcount, p->kcountsize, p->lowpc,
276		    s_scale);
277		p->state = GMON_PROF_ON;
278	} else {
279		/* stop */
280		profil((char *)0, 0, 0, 0);
281		p->state = GMON_PROF_OFF;
282	}
283}
284
285/*
286 * discover the tick frequency of the machine
287 * if something goes wrong, we return 0, an impossible hertz.
288 */
289static int
290hertz()
291{
292	struct itimerval tim;
293
294	tim.it_interval.tv_sec = 0;
295	tim.it_interval.tv_usec = 1;
296	tim.it_value.tv_sec = 0;
297	tim.it_value.tv_usec = 0;
298	setitimer(ITIMER_REAL, &tim, 0);
299	setitimer(ITIMER_REAL, 0, &tim);
300	if (tim.it_interval.tv_usec < 2)
301		return(0);
302	return (1000000 / tim.it_interval.tv_usec);
303}
304
305
306