xref: /freebsd/lib/libc/gmon/gmon.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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 <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include "un-namespace.h"
49 
50 #include "libc_private.h"
51 
52 #if defined(__i386__) || defined(__sparc64__) || defined(__amd64__) || defined(__powerpc__)
53 extern char *minbrk __asm (".minbrk");
54 #else
55 extern char *minbrk __asm ("minbrk");
56 #endif
57 
58 struct gmonparam _gmonparam = { GMON_PROF_OFF };
59 
60 static int	s_scale;
61 /* see profil(2) where this is describe (incorrectly) */
62 #define		SCALE_1_TO_1	0x10000L
63 
64 #define ERR(s) _write(2, s, sizeof(s))
65 
66 void	moncontrol(int);
67 static int hertz(void);
68 
69 void
70 monstartup(lowpc, highpc)
71 	u_long lowpc;
72 	u_long highpc;
73 {
74 	int o;
75 	char *cp;
76 	struct gmonparam *p = &_gmonparam;
77 
78 	/*
79 	 * round lowpc and highpc to multiples of the density we're using
80 	 * so the rest of the scaling (here and in gprof) stays in ints.
81 	 */
82 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
83 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
84 	p->textsize = p->highpc - p->lowpc;
85 	p->kcountsize = p->textsize / HISTFRACTION;
86 	p->hashfraction = HASHFRACTION;
87 	p->fromssize = p->textsize / HASHFRACTION;
88 	p->tolimit = p->textsize * ARCDENSITY / 100;
89 	if (p->tolimit < MINARCS)
90 		p->tolimit = MINARCS;
91 	else if (p->tolimit > MAXARCS)
92 		p->tolimit = MAXARCS;
93 	p->tossize = p->tolimit * sizeof(struct tostruct);
94 
95 	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
96 	if (cp == (char *)-1) {
97 		ERR("monstartup: out of memory\n");
98 		return;
99 	}
100 #ifdef notdef
101 	bzero(cp, p->kcountsize + p->fromssize + p->tossize);
102 #endif
103 	p->tos = (struct tostruct *)cp;
104 	cp += p->tossize;
105 	p->kcount = (u_short *)cp;
106 	cp += p->kcountsize;
107 	p->froms = (u_short *)cp;
108 
109 	minbrk = sbrk(0);
110 	p->tos[0].link = 0;
111 
112 	o = p->highpc - p->lowpc;
113 	if (p->kcountsize < o) {
114 #ifndef hp300
115 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
116 #else /* avoid floating point */
117 		int quot = o / p->kcountsize;
118 
119 		if (quot >= 0x10000)
120 			s_scale = 1;
121 		else if (quot >= 0x100)
122 			s_scale = 0x10000 / quot;
123 		else if (o >= 0x800000)
124 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
125 		else
126 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
127 #endif
128 	} else
129 		s_scale = SCALE_1_TO_1;
130 
131 	moncontrol(1);
132 }
133 
134 void
135 _mcleanup()
136 {
137 	int fd;
138 	int fromindex;
139 	int endfrom;
140 	u_long frompc;
141 	int toindex;
142 	struct rawarc rawarc;
143 	struct gmonparam *p = &_gmonparam;
144 	struct gmonhdr gmonhdr, *hdr;
145 	struct clockinfo clockinfo;
146 	char outname[128];
147 	int mib[2];
148 	size_t size;
149 #ifdef DEBUG
150 	int log, len;
151 	char buf[200];
152 #endif
153 
154 	if (p->state == GMON_PROF_ERROR)
155 		ERR("_mcleanup: tos overflow\n");
156 
157 	size = sizeof(clockinfo);
158 	mib[0] = CTL_KERN;
159 	mib[1] = KERN_CLOCKRATE;
160 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
161 		/*
162 		 * Best guess
163 		 */
164 		clockinfo.profhz = hertz();
165 	} else if (clockinfo.profhz == 0) {
166 		if (clockinfo.hz != 0)
167 			clockinfo.profhz = clockinfo.hz;
168 		else
169 			clockinfo.profhz = hertz();
170 	}
171 
172 	moncontrol(0);
173 	snprintf(outname, sizeof(outname), "%s.gmon", _getprogname());
174 	fd = _open(outname, O_CREAT|O_TRUNC|O_WRONLY, 0666);
175 	if (fd < 0) {
176 		_warn("_mcleanup: %s", outname);
177 		return;
178 	}
179 #ifdef DEBUG
180 	log = _open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
181 	if (log < 0) {
182 		_warn("_mcleanup: gmon.log");
183 		return;
184 	}
185 	len = sprintf(buf, "[mcleanup1] kcount 0x%p ssiz %lu\n",
186 	    p->kcount, p->kcountsize);
187 	_write(log, buf, len);
188 #endif
189 	hdr = (struct gmonhdr *)&gmonhdr;
190 	bzero(hdr, sizeof(*hdr));
191 	hdr->lpc = p->lowpc;
192 	hdr->hpc = p->highpc;
193 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
194 	hdr->version = GMONVERSION;
195 	hdr->profrate = clockinfo.profhz;
196 	_write(fd, (char *)hdr, sizeof *hdr);
197 	_write(fd, p->kcount, p->kcountsize);
198 	endfrom = p->fromssize / sizeof(*p->froms);
199 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
200 		if (p->froms[fromindex] == 0)
201 			continue;
202 
203 		frompc = p->lowpc;
204 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
205 		for (toindex = p->froms[fromindex]; toindex != 0;
206 		     toindex = p->tos[toindex].link) {
207 #ifdef DEBUG
208 			len = sprintf(buf,
209 			"[mcleanup2] frompc 0x%lx selfpc 0x%lx count %lu\n" ,
210 				frompc, p->tos[toindex].selfpc,
211 				p->tos[toindex].count);
212 			_write(log, buf, len);
213 #endif
214 			rawarc.raw_frompc = frompc;
215 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
216 			rawarc.raw_count = p->tos[toindex].count;
217 			_write(fd, &rawarc, sizeof rawarc);
218 		}
219 	}
220 	_close(fd);
221 }
222 
223 /*
224  * Control profiling
225  *	profiling is what mcount checks to see if
226  *	all the data structures are ready.
227  */
228 void
229 moncontrol(mode)
230 	int mode;
231 {
232 	struct gmonparam *p = &_gmonparam;
233 
234 	if (mode) {
235 		/* start */
236 		profil((char *)p->kcount, p->kcountsize, p->lowpc, s_scale);
237 		p->state = GMON_PROF_ON;
238 	} else {
239 		/* stop */
240 		profil((char *)0, 0, 0, 0);
241 		p->state = GMON_PROF_OFF;
242 	}
243 }
244 
245 /*
246  * discover the tick frequency of the machine
247  * if something goes wrong, we return 0, an impossible hertz.
248  */
249 static int
250 hertz()
251 {
252 	struct itimerval tim;
253 
254 	tim.it_interval.tv_sec = 0;
255 	tim.it_interval.tv_usec = 1;
256 	tim.it_value.tv_sec = 0;
257 	tim.it_value.tv_usec = 0;
258 	setitimer(ITIMER_REAL, &tim, 0);
259 	setitimer(ITIMER_REAL, 0, &tim);
260 	if (tim.it_interval.tv_usec < 2)
261 		return(0);
262 	return (1000000 / tim.it_interval.tv_usec);
263 }
264