xref: /freebsd/lib/libc/gmon/gmon.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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 <err.h>
44 #include <errno.h>
45 #include <stdio.h>
46 #include <fcntl.h>
47 #include <unistd.h>
48 
49 #if defined(__ELF__) && defined(i386)
50 extern char *minbrk asm (".minbrk");
51 #else
52 extern char *minbrk asm ("minbrk");
53 #endif
54 
55 extern char *__progname;
56 
57 struct gmonparam _gmonparam = { GMON_PROF_OFF };
58 
59 static int	s_scale;
60 /* see profil(2) where this is describe (incorrectly) */
61 #define		SCALE_1_TO_1	0x10000L
62 
63 #define ERR(s) write(2, s, sizeof(s))
64 
65 void	moncontrol __P((int));
66 static int hertz __P((void));
67 
68 void
69 monstartup(lowpc, highpc)
70 	u_long lowpc;
71 	u_long highpc;
72 {
73 	register int o;
74 	char *cp;
75 	struct gmonparam *p = &_gmonparam;
76 
77 	/*
78 	 * round lowpc and highpc to multiples of the density we're using
79 	 * so the rest of the scaling (here and in gprof) stays in ints.
80 	 */
81 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
82 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
83 	p->textsize = p->highpc - p->lowpc;
84 	p->kcountsize = p->textsize / HISTFRACTION;
85 	p->hashfraction = HASHFRACTION;
86 	p->fromssize = p->textsize / HASHFRACTION;
87 	p->tolimit = p->textsize * ARCDENSITY / 100;
88 	if (p->tolimit < MINARCS)
89 		p->tolimit = MINARCS;
90 	else if (p->tolimit > MAXARCS)
91 		p->tolimit = MAXARCS;
92 	p->tossize = p->tolimit * sizeof(struct tostruct);
93 
94 	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
95 	if (cp == (char *)-1) {
96 		ERR("monstartup: out of memory\n");
97 		return;
98 	}
99 #ifdef notdef
100 	bzero(cp, p->kcountsize + p->fromssize + p->tossize);
101 #endif
102 	p->tos = (struct tostruct *)cp;
103 	cp += p->tossize;
104 	p->kcount = (u_short *)cp;
105 	cp += p->kcountsize;
106 	p->froms = (u_short *)cp;
107 
108 	minbrk = sbrk(0);
109 	p->tos[0].link = 0;
110 
111 	o = p->highpc - p->lowpc;
112 	if (p->kcountsize < o) {
113 #ifndef hp300
114 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
115 #else /* avoid floating point */
116 		int quot = o / p->kcountsize;
117 
118 		if (quot >= 0x10000)
119 			s_scale = 1;
120 		else if (quot >= 0x100)
121 			s_scale = 0x10000 / quot;
122 		else if (o >= 0x800000)
123 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
124 		else
125 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
126 #endif
127 	} else
128 		s_scale = SCALE_1_TO_1;
129 
130 	moncontrol(1);
131 }
132 
133 void
134 _mcleanup()
135 {
136 	int fd;
137 	int fromindex;
138 	int endfrom;
139 	u_long frompc;
140 	int toindex;
141 	struct rawarc rawarc;
142 	struct gmonparam *p = &_gmonparam;
143 	struct gmonhdr gmonhdr, *hdr;
144 	struct clockinfo clockinfo;
145 	char outname[128];
146 	int mib[2];
147 	size_t size;
148 #ifdef DEBUG
149 	int log, len;
150 	char buf[200];
151 #endif
152 
153 	if (p->state == GMON_PROF_ERROR)
154 		ERR("_mcleanup: tos overflow\n");
155 
156 	size = sizeof(clockinfo);
157 	mib[0] = CTL_KERN;
158 	mib[1] = KERN_CLOCKRATE;
159 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
160 		/*
161 		 * Best guess
162 		 */
163 		clockinfo.profhz = hertz();
164 	} else if (clockinfo.profhz == 0) {
165 		if (clockinfo.hz != 0)
166 			clockinfo.profhz = clockinfo.hz;
167 		else
168 			clockinfo.profhz = hertz();
169 	}
170 
171 	moncontrol(0);
172 	snprintf(outname,sizeof(outname),"%s.gmon",__progname);
173 	fd = open(outname, O_CREAT|O_TRUNC|O_WRONLY, 0666);
174 	if (fd < 0) {
175 		warnx("_mcleanup: %s - %s",outname,strerror(errno));
176 		return;
177 	}
178 #ifdef DEBUG
179 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
180 	if (log < 0) {
181 		perror("_mcleanup: gmon.log");
182 		return;
183 	}
184 	len = sprintf(buf, "[mcleanup1] kcount 0x%x ssiz %d\n",
185 	    p->kcount, p->kcountsize);
186 	write(log, buf, len);
187 #endif
188 	hdr = (struct gmonhdr *)&gmonhdr;
189 	hdr->lpc = p->lowpc;
190 	hdr->hpc = p->highpc;
191 	hdr->ncnt = p->kcountsize + sizeof(gmonhdr);
192 	hdr->version = GMONVERSION;
193 	hdr->profrate = clockinfo.profhz;
194 	write(fd, (char *)hdr, sizeof *hdr);
195 	write(fd, p->kcount, p->kcountsize);
196 	endfrom = p->fromssize / sizeof(*p->froms);
197 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
198 		if (p->froms[fromindex] == 0)
199 			continue;
200 
201 		frompc = p->lowpc;
202 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
203 		for (toindex = p->froms[fromindex]; toindex != 0;
204 		     toindex = p->tos[toindex].link) {
205 #ifdef DEBUG
206 			len = sprintf(buf,
207 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
208 				frompc, p->tos[toindex].selfpc,
209 				p->tos[toindex].count);
210 			write(log, buf, len);
211 #endif
212 			rawarc.raw_frompc = frompc;
213 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
214 			rawarc.raw_count = p->tos[toindex].count;
215 			write(fd, &rawarc, sizeof rawarc);
216 		}
217 	}
218 	close(fd);
219 }
220 
221 /*
222  * Control profiling
223  *	profiling is what mcount checks to see if
224  *	all the data structures are ready.
225  */
226 void
227 moncontrol(mode)
228 	int mode;
229 {
230 	struct gmonparam *p = &_gmonparam;
231 
232 	if (mode) {
233 		/* start */
234 		profil((char *)p->kcount, p->kcountsize, p->lowpc, s_scale);
235 		p->state = GMON_PROF_ON;
236 	} else {
237 		/* stop */
238 		profil((char *)0, 0, 0, 0);
239 		p->state = GMON_PROF_OFF;
240 	}
241 }
242 
243 /*
244  * discover the tick frequency of the machine
245  * if something goes wrong, we return 0, an impossible hertz.
246  */
247 static int
248 hertz()
249 {
250 	struct itimerval tim;
251 
252 	tim.it_interval.tv_sec = 0;
253 	tim.it_interval.tv_usec = 1;
254 	tim.it_value.tv_sec = 0;
255 	tim.it_value.tv_usec = 0;
256 	setitimer(ITIMER_REAL, &tim, 0);
257 	setitimer(ITIMER_REAL, 0, &tim);
258 	if (tim.it_interval.tv_usec < 2)
259 		return(0);
260 	return (1000000 / tim.it_interval.tv_usec);
261 }
262