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/* Determine realtime clock frequency.
Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sys/time.h>
#include <libc-internal.h>
#include <kernel-features.h>
#include <ldsodefs.h>
int
__profile_frequency (void)
{
#ifdef __ASSUME_AT_CLKTCK
return GLRO(dl_clktck);
#else
if (GLRO(dl_clktck) != 0)
return GLRO(dl_clktck);
struct itimerval tim;
tim.it_interval.tv_sec = 0;
tim.it_interval.tv_usec = 1;
tim.it_value.tv_sec = 0;
tim.it_value.tv_usec = 0;
__setitimer (ITIMER_REAL, &tim, 0);
__setitimer (ITIMER_REAL, 0, &tim);
if (tim.it_interval.tv_usec < 2)
return 0;
return 1000000 / tim.it_interval.tv_usec;
#endif
}
libc_hidden_def (__profile_frequency)
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