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. |
5 | * |
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 | * 4. Neither the name of the University nor the names of its contributors |
15 | * may be used to endorse or promote products derived from this software |
16 | * without specific prior written permission. |
17 | * |
18 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
19 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
21 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
22 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
23 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
24 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
25 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
26 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
27 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
28 | * SUCH DAMAGE. |
29 | */ |
30 | |
31 | |
32 | #include <sys/types.h> |
33 | #include <sys/time.h> |
34 | #include <libc-internal.h> |
35 | |
36 | int |
37 | __profile_frequency (void) |
38 | { |
39 | /* |
40 | * Discover the tick frequency of the machine if something goes wrong, |
41 | * we return 0, an impossible hertz. |
42 | */ |
43 | struct itimerval tim; |
44 | |
45 | tim.it_interval.tv_sec = 0; |
46 | tim.it_interval.tv_usec = 1; |
47 | tim.it_value.tv_sec = 0; |
48 | tim.it_value.tv_usec = 0; |
49 | __setitimer(ITIMER_REAL, new: &tim, old: 0); |
50 | __setitimer(ITIMER_REAL, new: 0, old: &tim); |
51 | if (tim.it_interval.tv_usec < 2) |
52 | return 0; |
53 | return (1000000 / tim.it_interval.tv_usec); |
54 | } |
55 | libc_hidden_def (__profile_frequency) |
56 | |