xref: /freebsd/lib/libc/gmon/gmon.c (revision d056fa046c6a91b90cd98165face0e42a33a5173)
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(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)gmon.c	8.1 (Berkeley) 6/4/93";
36 #endif
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "namespace.h"
41 #include <sys/param.h>
42 #include <sys/time.h>
43 #include <sys/gmon.h>
44 #include <sys/sysctl.h>
45 
46 #include <err.h>
47 #include <fcntl.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include "un-namespace.h"
53 
54 #include "libc_private.h"
55 
56 #if defined(__i386__) || defined(__sparc64__) || defined(__amd64__) || defined(__powerpc__)
57 extern char *minbrk __asm (".minbrk");
58 #else
59 extern char *minbrk __asm ("minbrk");
60 #endif
61 
62 struct gmonparam _gmonparam = { GMON_PROF_OFF };
63 
64 static int	s_scale;
65 /* see profil(2) where this is describe (incorrectly) */
66 #define		SCALE_1_TO_1	0x10000L
67 
68 #define ERR(s) _write(2, s, sizeof(s))
69 
70 void	moncontrol(int);
71 static int hertz(void);
72 
73 void
74 monstartup(lowpc, highpc)
75 	u_long lowpc;
76 	u_long highpc;
77 {
78 	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 / 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 hp300
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 	char outname[128];
151 	int mib[2];
152 	size_t size;
153 #ifdef DEBUG
154 	int log, len;
155 	char buf[200];
156 #endif
157 
158 	if (p->state == GMON_PROF_ERROR)
159 		ERR("_mcleanup: tos overflow\n");
160 
161 	size = sizeof(clockinfo);
162 	mib[0] = CTL_KERN;
163 	mib[1] = KERN_CLOCKRATE;
164 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
165 		/*
166 		 * Best guess
167 		 */
168 		clockinfo.profhz = hertz();
169 	} else if (clockinfo.profhz == 0) {
170 		if (clockinfo.hz != 0)
171 			clockinfo.profhz = clockinfo.hz;
172 		else
173 			clockinfo.profhz = hertz();
174 	}
175 
176 	moncontrol(0);
177 	snprintf(outname, sizeof(outname), "%s.gmon", _getprogname());
178 	fd = _open(outname, O_CREAT|O_TRUNC|O_WRONLY, 0666);
179 	if (fd < 0) {
180 		_warn("_mcleanup: %s", outname);
181 		return;
182 	}
183 #ifdef DEBUG
184 	log = _open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
185 	if (log < 0) {
186 		_warn("_mcleanup: gmon.log");
187 		return;
188 	}
189 	len = sprintf(buf, "[mcleanup1] kcount 0x%p ssiz %lu\n",
190 	    p->kcount, p->kcountsize);
191 	_write(log, buf, len);
192 #endif
193 	hdr = (struct gmonhdr *)&gmonhdr;
194 	bzero(hdr, sizeof(*hdr));
195 	hdr->lpc = p->lowpc;
196 	hdr->hpc = p->highpc;
197 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
198 	hdr->version = GMONVERSION;
199 	hdr->profrate = clockinfo.profhz;
200 	_write(fd, (char *)hdr, sizeof *hdr);
201 	_write(fd, p->kcount, p->kcountsize);
202 	endfrom = p->fromssize / sizeof(*p->froms);
203 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
204 		if (p->froms[fromindex] == 0)
205 			continue;
206 
207 		frompc = p->lowpc;
208 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
209 		for (toindex = p->froms[fromindex]; toindex != 0;
210 		     toindex = p->tos[toindex].link) {
211 #ifdef DEBUG
212 			len = sprintf(buf,
213 			"[mcleanup2] frompc 0x%lx selfpc 0x%lx count %lu\n" ,
214 				frompc, p->tos[toindex].selfpc,
215 				p->tos[toindex].count);
216 			_write(log, buf, len);
217 #endif
218 			rawarc.raw_frompc = frompc;
219 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
220 			rawarc.raw_count = p->tos[toindex].count;
221 			_write(fd, &rawarc, sizeof rawarc);
222 		}
223 	}
224 	_close(fd);
225 }
226 
227 /*
228  * Control profiling
229  *	profiling is what mcount checks to see if
230  *	all the data structures are ready.
231  */
232 void
233 moncontrol(mode)
234 	int mode;
235 {
236 	struct gmonparam *p = &_gmonparam;
237 
238 	if (mode) {
239 		/* start */
240 		profil((char *)p->kcount, p->kcountsize, p->lowpc, s_scale);
241 		p->state = GMON_PROF_ON;
242 	} else {
243 		/* stop */
244 		profil((char *)0, 0, 0, 0);
245 		p->state = GMON_PROF_OFF;
246 	}
247 }
248 
249 /*
250  * discover the tick frequency of the machine
251  * if something goes wrong, we return 0, an impossible hertz.
252  */
253 static int
254 hertz()
255 {
256 	struct itimerval tim;
257 
258 	tim.it_interval.tv_sec = 0;
259 	tim.it_interval.tv_usec = 1;
260 	tim.it_value.tv_sec = 0;
261 	tim.it_value.tv_usec = 0;
262 	setitimer(ITIMER_REAL, &tim, 0);
263 	setitimer(ITIMER_REAL, 0, &tim);
264 	if (tim.it_interval.tv_usec < 2)
265 		return(0);
266 	return (1000000 / tim.it_interval.tv_usec);
267 }
268