xref: /original-bsd/lib/libc/gmon/gmon.c (revision 94193b97)
1 /*-
2  * Copyright (c) 1983, 1992 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #if !defined(lint) && defined(LIBC_SCCS)
9 static char sccsid[] = "@(#)gmon.c	5.14 (Berkeley) 04/27/93";
10 #endif
11 
12 #include <sys/param.h>
13 #include <sys/time.h>
14 #include <sys/gmon.h>
15 #include <sys/sysctl.h>
16 
17 #ifdef DEBUG
18 #include <stdio.h>
19 #include <fcntl.h>
20 #endif
21 
22 #include <unistd.h>
23 
24 extern char *minbrk asm ("minbrk");
25 
26 struct gmonparam _gmonparam = { GMON_PROF_OFF };
27 
28 static int	ssiz;
29 static char	*sbuf;
30 static int	s_scale;
31 /* see profil(2) where this is describe (incorrectly) */
32 #define		SCALE_1_TO_1	0x10000L
33 
34 #define ERR(s) write(2, s, sizeof(s))
35 
36 static struct gmonhdr gmonhdr;
37 
38 monstartup(lowpc, highpc)
39 	u_long lowpc;
40 	u_long highpc;
41 {
42 	register int o;
43 	struct clockinfo clockinfo;
44 	int mib[2], tsize, fsize, size;
45 	char *cp;
46 	struct gmonhdr *hdr;
47 	struct gmonparam *p = &_gmonparam;
48 
49 	/*
50 	 * round lowpc and highpc to multiples of the density we're using
51 	 * so the rest of the scaling (here and in gprof) stays in ints.
52 	 */
53 	lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
54 	p->lowpc = lowpc;
55 	highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
56 	p->highpc = highpc;
57 	p->textsize = highpc - lowpc;
58 	ssiz = p->textsize / HISTFRACTION;
59 	fsize = p->textsize / HASHFRACTION;
60 	tsize = p->textsize * ARCDENSITY / 100;
61 	if (tsize < MINARCS)
62 		tsize = MINARCS;
63 	else if (tsize > MAXARCS)
64 		tsize = MAXARCS;
65 	p->tolimit = tsize;
66 	tsize *= sizeof(struct tostruct);
67 
68 	cp = sbrk(ssiz + fsize + tsize);
69 	if (cp == (char *)-1) {
70 		ERR("monstartup: out of memory\n");
71 		return;
72 	}
73 #ifdef notdef
74 	bzero(cp, ssiz + fsize + tsize);
75 #endif
76 	p->tos = (struct tostruct *)cp;
77 	cp += tsize;
78 	sbuf = cp;
79 	cp += ssiz;
80 	p->froms = (u_short *)cp;
81 
82 	minbrk = sbrk(0);
83 	p->tos[0].link = 0;
84 
85 	o = highpc - lowpc;
86 	if (ssiz < o) {
87 #ifndef hp300
88 		s_scale = ((float)ssiz / o ) * SCALE_1_TO_1;
89 #else /* avoid floating point */
90 		int quot = o / ssiz;
91 
92 		if (quot >= 0x10000)
93 			s_scale = 1;
94 		else if (quot >= 0x100)
95 			s_scale = 0x10000 / quot;
96 		else if (o >= 0x800000)
97 			s_scale = 0x1000000 / (o / (ssiz >> 8));
98 		else
99 			s_scale = 0x1000000 / ((o << 8) / ssiz);
100 #endif
101 	} else
102 		s_scale = SCALE_1_TO_1;
103 
104 	moncontrol(1);
105 	size = sizeof(clockinfo);
106 	mib[0] = CTL_KERN;
107 	mib[1] = KERN_CLOCKRATE;
108 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0)
109 		/*
110 		 * Best guess
111 		 */
112 		clockinfo.profhz = hertz();
113 	else if (clockinfo.profhz == 0) {
114 		if (clockinfo.hz != 0)
115 			clockinfo.profhz = clockinfo.hz;
116 		else
117 			clockinfo.profhz = hertz();
118 	}
119 	hdr = (struct gmonhdr *)&gmonhdr;
120 	hdr->lpc = lowpc;
121 	hdr->hpc = highpc;
122 	hdr->ncnt = ssiz + sizeof(gmonhdr);
123 	hdr->version = GMONVERSION;
124 	hdr->profrate = clockinfo.profhz;
125 }
126 
127 _mcleanup()
128 {
129 	int fd;
130 	int fromindex;
131 	int endfrom;
132 	u_long frompc;
133 	int toindex;
134 	struct rawarc rawarc;
135 	struct gmonparam *p = &_gmonparam;
136 	int log, len;
137 	char buf[200];
138 
139 	if (p->state == GMON_PROF_ERROR)
140 		ERR("_mcleanup: tos overflow\n");
141 
142 	moncontrol(0);
143 	fd = creat("gmon.out", 0666);
144 	if (fd < 0) {
145 		perror("mcount: gmon.out");
146 		return;
147 	}
148 #ifdef DEBUG
149 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
150 	if (log < 0) {
151 		perror("mcount: gmon.log");
152 		return;
153 	}
154 	len = sprintf(buf, "[mcleanup1] sbuf 0x%x ssiz %d\n", sbuf, ssiz);
155 	write(log, buf, len);
156 #endif
157 	write(fd, (char *)&gmonhdr, sizeof(gmonhdr));
158 	write(fd, sbuf, ssiz);
159 	endfrom = p->textsize / (HASHFRACTION * sizeof(*p->froms));
160 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
161 		if (p->froms[fromindex] == 0)
162 			continue;
163 
164 		frompc = p->lowpc;
165 		frompc += fromindex * HASHFRACTION * sizeof(*p->froms);
166 		for (toindex = p->froms[fromindex]; toindex != 0;
167 		     toindex = p->tos[toindex].link) {
168 #ifdef DEBUG
169 			len = sprintf(buf,
170 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
171 				frompc, p->tos[toindex].selfpc,
172 				p->tos[toindex].count);
173 			write(log, buf, len);
174 #endif
175 			rawarc.raw_frompc = frompc;
176 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
177 			rawarc.raw_count = p->tos[toindex].count;
178 			write(fd, &rawarc, sizeof rawarc);
179 		}
180 	}
181 	close(fd);
182 }
183 
184 /*
185  * Control profiling
186  *	profiling is what mcount checks to see if
187  *	all the data structures are ready.
188  */
189 moncontrol(mode)
190 	int mode;
191 {
192 	struct gmonparam *p = &_gmonparam;
193 
194 	if (mode) {
195 		/* start */
196 		profil(sbuf, ssiz, (int)p->lowpc, s_scale);
197 		p->state = GMON_PROF_ON;
198 	} else {
199 		/* stop */
200 		profil((char *)0, 0, 0, 0);
201 		p->state = GMON_PROF_OFF;
202 	}
203 }
204 
205 /*
206  * discover the tick frequency of the machine
207  * if something goes wrong, we return 0, an impossible hertz.
208  */
209 hertz()
210 {
211 	struct itimerval tim;
212 
213 	tim.it_interval.tv_sec = 0;
214 	tim.it_interval.tv_usec = 1;
215 	tim.it_value.tv_sec = 0;
216 	tim.it_value.tv_usec = 0;
217 	setitimer(ITIMER_REAL, &tim, 0);
218 	setitimer(ITIMER_REAL, 0, &tim);
219 	if (tim.it_interval.tv_usec < 2)
220 		return(0);
221 	return (1000000 / tim.it_interval.tv_usec);
222 }
223 
224 
225