mirror of
https://sourceware.org/git/glibc.git
synced 2025-10-30 10:45:40 +03:00
51 lines
1.4 KiB
C
51 lines
1.4 KiB
C
/* 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, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#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)
|