Update.
[glibc.git] / sysdeps / generic / prof-freq.c
blob2755c1f9a20a1cd0205eae46a32bc98fc507d3d8
1 /* Return frequency of ticks reported by profil. Generic version. */
2 /*-
3 * Copyright (c) 1983, 1992, 1993
4 * The Regents of the University of California. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by the University of
17 * California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
36 #include <sys/types.h>
37 #include <sys/time.h>
39 int
40 __profile_frequency (void)
43 * Discover the tick frequency of the machine if something goes wrong,
44 * we return 0, an impossible hertz.
46 struct itimerval tim;
48 tim.it_interval.tv_sec = 0;
49 tim.it_interval.tv_usec = 1;
50 tim.it_value.tv_sec = 0;
51 tim.it_value.tv_usec = 0;
52 __setitimer(ITIMER_REAL, &tim, 0);
53 __setitimer(ITIMER_REAL, 0, &tim);
54 if (tim.it_interval.tv_usec < 2)
55 return 0;
56 return (1000000 / tim.it_interval.tv_usec);