xref: /freebsd/lib/libc/gmon/gmon.c (revision 2e1417489338b971e5fd599ff48b5f65df9e8d3b)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)gmon.c	8.1 (Berkeley) 6/4/93";
32 #endif
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include "namespace.h"
37 #include <sys/param.h>
38 #include <sys/time.h>
39 #include <sys/gmon.h>
40 #include <sys/sysctl.h>
41 
42 #include <err.h>
43 #include <fcntl.h>
44 #include <inttypes.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 #include "un-namespace.h"
50 
51 #include "libc_private.h"
52 
53 #if defined(__i386__) || defined(__sparc64__) || defined(__amd64__) || (defined(__powerpc__) && !defined(__powerpc64__))
54 extern char *minbrk __asm (".minbrk");
55 #elif defined(__powerpc64__)
56 extern char *minbrk __asm ("_minbrk");
57 #else
58 extern char *minbrk __asm ("minbrk");
59 #endif
60 
61 struct gmonparam _gmonparam = { GMON_PROF_OFF };
62 
63 static int	s_scale;
64 /* See profil(2) where this is described (incorrectly). */
65 #define	SCALE_SHIFT	16
66 
67 #define ERR(s) _write(2, s, sizeof(s))
68 
69 void	moncontrol(int);
70 static int hertz(void);
71 
72 void
73 monstartup(lowpc, highpc)
74 	u_long lowpc;
75 	u_long highpc;
76 {
77 	int 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 / 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(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 	bzero(cp, p->kcountsize + p->fromssize + p->tossize);
105 #endif
106 	p->tos = (struct tostruct *)cp;
107 	cp += p->tossize;
108 	p->kcount = (u_short *)cp;
109 	cp += p->kcountsize;
110 	p->froms = (u_short *)cp;
111 
112 	minbrk = sbrk(0);
113 	p->tos[0].link = 0;
114 
115 	o = p->highpc - p->lowpc;
116 	s_scale = (p->kcountsize < o) ?
117 	    ((uintmax_t)p->kcountsize << SCALE_SHIFT) / o : (1 << SCALE_SHIFT);
118 	moncontrol(1);
119 }
120 
121 void
122 _mcleanup(void)
123 {
124 	int fd;
125 	int fromindex;
126 	int endfrom;
127 	u_long frompc;
128 	int toindex;
129 	struct rawarc rawarc;
130 	struct gmonparam *p = &_gmonparam;
131 	struct gmonhdr gmonhdr, *hdr;
132 	struct clockinfo clockinfo;
133 	char outname[128];
134 	int mib[2];
135 	size_t size;
136 #ifdef DEBUG
137 	int log, len;
138 	char buf[200];
139 #endif
140 
141 	if (p->state == GMON_PROF_ERROR)
142 		ERR("_mcleanup: tos overflow\n");
143 
144 	size = sizeof(clockinfo);
145 	mib[0] = CTL_KERN;
146 	mib[1] = KERN_CLOCKRATE;
147 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
148 		/*
149 		 * Best guess
150 		 */
151 		clockinfo.profhz = hertz();
152 	} else if (clockinfo.profhz == 0) {
153 		if (clockinfo.hz != 0)
154 			clockinfo.profhz = clockinfo.hz;
155 		else
156 			clockinfo.profhz = hertz();
157 	}
158 
159 	moncontrol(0);
160 	snprintf(outname, sizeof(outname), "%s.gmon", _getprogname());
161 	fd = _open(outname, O_CREAT|O_TRUNC|O_WRONLY, 0666);
162 	if (fd < 0) {
163 		_warn("_mcleanup: %s", outname);
164 		return;
165 	}
166 #ifdef DEBUG
167 	log = _open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
168 	if (log < 0) {
169 		_warn("_mcleanup: gmon.log");
170 		return;
171 	}
172 	len = sprintf(buf, "[mcleanup1] kcount 0x%p ssiz %lu\n",
173 	    p->kcount, p->kcountsize);
174 	_write(log, buf, len);
175 #endif
176 	hdr = (struct gmonhdr *)&gmonhdr;
177 	bzero(hdr, sizeof(*hdr));
178 	hdr->lpc = p->lowpc;
179 	hdr->hpc = p->highpc;
180 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
181 	hdr->version = GMONVERSION;
182 	hdr->profrate = clockinfo.profhz;
183 	_write(fd, (char *)hdr, sizeof *hdr);
184 	_write(fd, p->kcount, p->kcountsize);
185 	endfrom = p->fromssize / sizeof(*p->froms);
186 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
187 		if (p->froms[fromindex] == 0)
188 			continue;
189 
190 		frompc = p->lowpc;
191 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
192 		for (toindex = p->froms[fromindex]; toindex != 0;
193 		     toindex = p->tos[toindex].link) {
194 #ifdef DEBUG
195 			len = sprintf(buf,
196 			"[mcleanup2] frompc 0x%lx selfpc 0x%lx count %lu\n" ,
197 				frompc, p->tos[toindex].selfpc,
198 				p->tos[toindex].count);
199 			_write(log, buf, len);
200 #endif
201 			rawarc.raw_frompc = frompc;
202 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
203 			rawarc.raw_count = p->tos[toindex].count;
204 			_write(fd, &rawarc, sizeof rawarc);
205 		}
206 	}
207 	_close(fd);
208 }
209 
210 /*
211  * Control profiling
212  *	profiling is what mcount checks to see if
213  *	all the data structures are ready.
214  */
215 void
216 moncontrol(mode)
217 	int mode;
218 {
219 	struct gmonparam *p = &_gmonparam;
220 
221 	if (mode) {
222 		/* start */
223 		profil((char *)p->kcount, p->kcountsize, p->lowpc, s_scale);
224 		p->state = GMON_PROF_ON;
225 	} else {
226 		/* stop */
227 		profil((char *)0, 0, 0, 0);
228 		p->state = GMON_PROF_OFF;
229 	}
230 }
231 
232 /*
233  * discover the tick frequency of the machine
234  * if something goes wrong, we return 0, an impossible hertz.
235  */
236 static int
237 hertz()
238 {
239 	struct itimerval tim;
240 
241 	tim.it_interval.tv_sec = 0;
242 	tim.it_interval.tv_usec = 1;
243 	tim.it_value.tv_sec = 0;
244 	tim.it_value.tv_usec = 0;
245 	setitimer(ITIMER_REAL, &tim, 0);
246 	setitimer(ITIMER_REAL, 0, &tim);
247 	if (tim.it_interval.tv_usec < 2)
248 		return(0);
249 	return (1000000 / tim.it_interval.tv_usec);
250 }
251