xref: /freebsd/lib/libc/gmon/gmon.c (revision afe61c15161c324a7af299a9b8457aba5afc92db)
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 extern char *minbrk asm ("minbrk");
48 
49 struct gmonparam _gmonparam = { GMON_PROF_OFF };
50 
51 static int	s_scale;
52 /* see profil(2) where this is describe (incorrectly) */
53 #define		SCALE_1_TO_1	0x10000L
54 
55 #define ERR(s) write(2, s, sizeof(s))
56 
57 void	moncontrol __P((int));
58 static int hertz __P((void));
59 
60 void
61 monstartup(lowpc, highpc)
62 	u_long lowpc;
63 	u_long highpc;
64 {
65 	register int o;
66 	char *cp;
67 	struct gmonparam *p = &_gmonparam;
68 
69 	/*
70 	 * round lowpc and highpc to multiples of the density we're using
71 	 * so the rest of the scaling (here and in gprof) stays in ints.
72 	 */
73 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
74 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
75 	p->textsize = p->highpc - p->lowpc;
76 	p->kcountsize = p->textsize / HISTFRACTION;
77 	p->hashfraction = HASHFRACTION;
78 	p->fromssize = p->textsize / HASHFRACTION;
79 	p->tolimit = p->textsize * ARCDENSITY / 100;
80 	if (p->tolimit < MINARCS)
81 		p->tolimit = MINARCS;
82 	else if (p->tolimit > MAXARCS)
83 		p->tolimit = MAXARCS;
84 	p->tossize = p->tolimit * sizeof(struct tostruct);
85 
86 	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
87 	if (cp == (char *)-1) {
88 		ERR("monstartup: out of memory\n");
89 		return;
90 	}
91 #ifdef notdef
92 	bzero(cp, p->kcountsize + p->fromssize + p->tossize);
93 #endif
94 	p->tos = (struct tostruct *)cp;
95 	cp += p->tossize;
96 	p->kcount = (u_short *)cp;
97 	cp += p->kcountsize;
98 	p->froms = (u_short *)cp;
99 
100 	minbrk = sbrk(0);
101 	p->tos[0].link = 0;
102 
103 	o = p->highpc - p->lowpc;
104 	if (p->kcountsize < o) {
105 #ifndef hp300
106 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
107 #else /* avoid floating point */
108 		int quot = o / p->kcountsize;
109 
110 		if (quot >= 0x10000)
111 			s_scale = 1;
112 		else if (quot >= 0x100)
113 			s_scale = 0x10000 / quot;
114 		else if (o >= 0x800000)
115 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
116 		else
117 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
118 #endif
119 	} else
120 		s_scale = SCALE_1_TO_1;
121 
122 	moncontrol(1);
123 }
124 
125 void
126 _mcleanup()
127 {
128 	int fd;
129 	int fromindex;
130 	int endfrom;
131 	u_long frompc;
132 	int toindex;
133 	struct rawarc rawarc;
134 	struct gmonparam *p = &_gmonparam;
135 	struct gmonhdr gmonhdr, *hdr;
136 	struct clockinfo clockinfo;
137 	int mib[2];
138 	size_t size;
139 #ifdef DEBUG
140 	int log, len;
141 	char buf[200];
142 #endif
143 
144 	if (p->state == GMON_PROF_ERROR)
145 		ERR("_mcleanup: tos overflow\n");
146 
147 	size = sizeof(clockinfo);
148 	mib[0] = CTL_KERN;
149 	mib[1] = KERN_CLOCKRATE;
150 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
151 		/*
152 		 * Best guess
153 		 */
154 		clockinfo.profhz = hertz();
155 	} else if (clockinfo.profhz == 0) {
156 		if (clockinfo.hz != 0)
157 			clockinfo.profhz = clockinfo.hz;
158 		else
159 			clockinfo.profhz = hertz();
160 	}
161 
162 	moncontrol(0);
163 	fd = open("gmon.out", O_CREAT|O_TRUNC|O_WRONLY, 0666);
164 	if (fd < 0) {
165 		perror("mcount: gmon.out");
166 		return;
167 	}
168 #ifdef DEBUG
169 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
170 	if (log < 0) {
171 		perror("mcount: gmon.log");
172 		return;
173 	}
174 	len = sprintf(buf, "[mcleanup1] kcount 0x%x ssiz %d\n",
175 	    p->kcount, p->kcountsize);
176 	write(log, buf, len);
177 #endif
178 	hdr = (struct gmonhdr *)&gmonhdr;
179 	hdr->lpc = p->lowpc;
180 	hdr->hpc = p->highpc;
181 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
182 	hdr->version = GMONVERSION;
183 	hdr->profrate = clockinfo.profhz;
184 	write(fd, (char *)hdr, sizeof *hdr);
185 	write(fd, p->kcount, p->kcountsize);
186 	endfrom = p->fromssize / sizeof(*p->froms);
187 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
188 		if (p->froms[fromindex] == 0)
189 			continue;
190 
191 		frompc = p->lowpc;
192 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
193 		for (toindex = p->froms[fromindex]; toindex != 0;
194 		     toindex = p->tos[toindex].link) {
195 #ifdef DEBUG
196 			len = sprintf(buf,
197 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
198 				frompc, p->tos[toindex].selfpc,
199 				p->tos[toindex].count);
200 			write(log, buf, len);
201 #endif
202 			rawarc.raw_frompc = frompc;
203 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
204 			rawarc.raw_count = p->tos[toindex].count;
205 			write(fd, &rawarc, sizeof rawarc);
206 		}
207 	}
208 	close(fd);
209 }
210 
211 /*
212  * Control profiling
213  *	profiling is what mcount checks to see if
214  *	all the data structures are ready.
215  */
216 void
217 moncontrol(mode)
218 	int mode;
219 {
220 	struct gmonparam *p = &_gmonparam;
221 
222 	if (mode) {
223 		/* start */
224 		profil((char *)p->kcount, p->kcountsize, (int)p->lowpc,
225 		    s_scale);
226 		p->state = GMON_PROF_ON;
227 	} else {
228 		/* stop */
229 		profil((char *)0, 0, 0, 0);
230 		p->state = GMON_PROF_OFF;
231 	}
232 }
233 
234 /*
235  * discover the tick frequency of the machine
236  * if something goes wrong, we return 0, an impossible hertz.
237  */
238 static int
239 hertz()
240 {
241 	struct itimerval tim;
242 
243 	tim.it_interval.tv_sec = 0;
244 	tim.it_interval.tv_usec = 1;
245 	tim.it_value.tv_sec = 0;
246 	tim.it_value.tv_usec = 0;
247 	setitimer(ITIMER_REAL, &tim, 0);
248 	setitimer(ITIMER_REAL, 0, &tim);
249 	if (tim.it_interval.tv_usec < 2)
250 		return(0);
251 	return (1000000 / tim.it_interval.tv_usec);
252 }
253 
254 
255