xref: /freebsd/lib/libc/gmon/gmon.c (revision e627b39baccd1ec9129690167cf5e6d860509655)
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)
35 static char sccsid[] = "@(#)gmon.c	8.1 (Berkeley) 6/4/93";
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 <fcntl.h>
45 #include <unistd.h>
46 
47 #if defined(__ELF__)
48 extern char *minbrk asm (".minbrk");
49 #else
50 extern char *minbrk asm ("minbrk");
51 #endif
52 
53 struct gmonparam _gmonparam = { GMON_PROF_OFF };
54 
55 static int	s_scale;
56 /* see profil(2) where this is describe (incorrectly) */
57 #define		SCALE_1_TO_1	0x10000L
58 
59 #define ERR(s) write(2, s, sizeof(s))
60 
61 void	moncontrol __P((int));
62 static int hertz __P((void));
63 
64 void
65 monstartup(lowpc, highpc)
66 	u_long lowpc;
67 	u_long highpc;
68 {
69 	register int o;
70 	char *cp;
71 	struct gmonparam *p = &_gmonparam;
72 
73 	/*
74 	 * round lowpc and highpc to multiples of the density we're using
75 	 * so the rest of the scaling (here and in gprof) stays in ints.
76 	 */
77 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
78 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
79 	p->textsize = p->highpc - p->lowpc;
80 	p->kcountsize = p->textsize / HISTFRACTION;
81 	p->hashfraction = HASHFRACTION;
82 	p->fromssize = p->textsize / HASHFRACTION;
83 	p->tolimit = p->textsize * ARCDENSITY / 100;
84 	if (p->tolimit < MINARCS)
85 		p->tolimit = MINARCS;
86 	else if (p->tolimit > MAXARCS)
87 		p->tolimit = MAXARCS;
88 	p->tossize = p->tolimit * sizeof(struct tostruct);
89 
90 	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
91 	if (cp == (char *)-1) {
92 		ERR("monstartup: out of memory\n");
93 		return;
94 	}
95 #ifdef notdef
96 	bzero(cp, p->kcountsize + p->fromssize + p->tossize);
97 #endif
98 	p->tos = (struct tostruct *)cp;
99 	cp += p->tossize;
100 	p->kcount = (u_short *)cp;
101 	cp += p->kcountsize;
102 	p->froms = (u_short *)cp;
103 
104 	minbrk = sbrk(0);
105 	p->tos[0].link = 0;
106 
107 	o = p->highpc - p->lowpc;
108 	if (p->kcountsize < o) {
109 #ifndef hp300
110 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
111 #else /* avoid floating point */
112 		int quot = o / p->kcountsize;
113 
114 		if (quot >= 0x10000)
115 			s_scale = 1;
116 		else if (quot >= 0x100)
117 			s_scale = 0x10000 / quot;
118 		else if (o >= 0x800000)
119 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
120 		else
121 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
122 #endif
123 	} else
124 		s_scale = SCALE_1_TO_1;
125 
126 	moncontrol(1);
127 }
128 
129 void
130 _mcleanup()
131 {
132 	int fd;
133 	int fromindex;
134 	int endfrom;
135 	u_long frompc;
136 	int toindex;
137 	struct rawarc rawarc;
138 	struct gmonparam *p = &_gmonparam;
139 	struct gmonhdr gmonhdr, *hdr;
140 	struct clockinfo clockinfo;
141 	int mib[2];
142 	size_t size;
143 #ifdef DEBUG
144 	int log, len;
145 	char buf[200];
146 #endif
147 
148 	if (p->state == GMON_PROF_ERROR)
149 		ERR("_mcleanup: tos overflow\n");
150 
151 	size = sizeof(clockinfo);
152 	mib[0] = CTL_KERN;
153 	mib[1] = KERN_CLOCKRATE;
154 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
155 		/*
156 		 * Best guess
157 		 */
158 		clockinfo.profhz = hertz();
159 	} else if (clockinfo.profhz == 0) {
160 		if (clockinfo.hz != 0)
161 			clockinfo.profhz = clockinfo.hz;
162 		else
163 			clockinfo.profhz = hertz();
164 	}
165 
166 	moncontrol(0);
167 	fd = open("gmon.out", O_CREAT|O_TRUNC|O_WRONLY, 0666);
168 	if (fd < 0) {
169 		perror("mcount: gmon.out");
170 		return;
171 	}
172 #ifdef DEBUG
173 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
174 	if (log < 0) {
175 		perror("mcount: gmon.log");
176 		return;
177 	}
178 	len = sprintf(buf, "[mcleanup1] kcount 0x%x ssiz %d\n",
179 	    p->kcount, p->kcountsize);
180 	write(log, buf, len);
181 #endif
182 	hdr = (struct gmonhdr *)&gmonhdr;
183 	hdr->lpc = p->lowpc;
184 	hdr->hpc = p->highpc;
185 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
186 	hdr->version = GMONVERSION;
187 	hdr->profrate = clockinfo.profhz;
188 	write(fd, (char *)hdr, sizeof *hdr);
189 	write(fd, p->kcount, p->kcountsize);
190 	endfrom = p->fromssize / sizeof(*p->froms);
191 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
192 		if (p->froms[fromindex] == 0)
193 			continue;
194 
195 		frompc = p->lowpc;
196 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
197 		for (toindex = p->froms[fromindex]; toindex != 0;
198 		     toindex = p->tos[toindex].link) {
199 #ifdef DEBUG
200 			len = sprintf(buf,
201 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
202 				frompc, p->tos[toindex].selfpc,
203 				p->tos[toindex].count);
204 			write(log, buf, len);
205 #endif
206 			rawarc.raw_frompc = frompc;
207 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
208 			rawarc.raw_count = p->tos[toindex].count;
209 			write(fd, &rawarc, sizeof rawarc);
210 		}
211 	}
212 	close(fd);
213 }
214 
215 /*
216  * Control profiling
217  *	profiling is what mcount checks to see if
218  *	all the data structures are ready.
219  */
220 void
221 moncontrol(mode)
222 	int mode;
223 {
224 	struct gmonparam *p = &_gmonparam;
225 
226 	if (mode) {
227 		/* start */
228 		profil((char *)p->kcount, p->kcountsize, (int)p->lowpc,
229 		    s_scale);
230 		p->state = GMON_PROF_ON;
231 	} else {
232 		/* stop */
233 		profil((char *)0, 0, 0, 0);
234 		p->state = GMON_PROF_OFF;
235 	}
236 }
237 
238 /*
239  * discover the tick frequency of the machine
240  * if something goes wrong, we return 0, an impossible hertz.
241  */
242 static int
243 hertz()
244 {
245 	struct itimerval tim;
246 
247 	tim.it_interval.tv_sec = 0;
248 	tim.it_interval.tv_usec = 1;
249 	tim.it_value.tv_sec = 0;
250 	tim.it_value.tv_usec = 0;
251 	setitimer(ITIMER_REAL, &tim, 0);
252 	setitimer(ITIMER_REAL, 0, &tim);
253 	if (tim.it_interval.tv_usec < 2)
254 		return(0);
255 	return (1000000 / tim.it_interval.tv_usec);
256 }
257 
258 
259