1 /* Determine realtime clock frequency.
2 Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
20 #include <libc-internal.h>
21 #include <kernel-features.h>
26 __profile_frequency (void)
28 #ifdef __ASSUME_AT_CLKTCK
29 return GLRO(dl_clktck
);
31 if (GLRO(dl_clktck
) != 0)
32 return GLRO(dl_clktck
);
36 tim
.it_interval
.tv_sec
= 0;
37 tim
.it_interval
.tv_usec
= 1;
38 tim
.it_value
.tv_sec
= 0;
39 tim
.it_value
.tv_usec
= 0;
41 __setitimer (ITIMER_REAL
, &tim
, 0);
42 __setitimer (ITIMER_REAL
, 0, &tim
);
44 if (tim
.it_interval
.tv_usec
< 2)
47 return 1000000 / tim
.it_interval
.tv_usec
;
50 libc_hidden_def (__profile_frequency
)