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/* Fallback for fast jitter just return 0.
Copyright (C) 2019-2025 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
<https://www.gnu.org/licenses/>. */
#ifndef _FAST_JITTER_H
# define _FAST_JITTER_H
# include <stdint.h>
# include <hp-timing.h>
/* Baseline just return 0. We could create jitter using a clock or
'random_bits' but that may imply a syscall and the goal of
'get_fast_jitter' is minimal overhead "randomness" when such
randomness helps performance. Adding high overhead the function
defeats the purpose. */
static inline uint32_t
get_fast_jitter (void)
{
# if HP_TIMING_INLINE
hp_timing_t jitter;
HP_TIMING_NOW (jitter);
return (uint32_t) jitter;
# else
return 0;
# endif
}
#endif
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