65 lines
2.3 KiB
C
65 lines
2.3 KiB
C
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/**
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* @file clockcheck.h
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* @brief Implements clock sanity checking.
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* @note Copyright (C) 2013 Miroslav Lichvar <mlichvar@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef HAVE_CLOCKCHECK_H
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#define HAVE_CLOCKCHECK_H
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#include <stdint.h>
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/** Opaque type */
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struct clockcheck;
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/**
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* Create a new instance of a clock sanity check.
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* @param freq_limit The maximum allowed frequency offset between uncorrected
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* clock and the system monotonic clock in ppb.
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* @return A pointer to a new clock check on success, NULL otherwise.
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*/
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struct clockcheck *clockcheck_create(int freq_limit);
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/**
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* Perform the sanity check on a time stamp.
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* @param cc Pointer to a clock check obtained via @ref clockcheck_create().
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* @param ts Time stamp made by the clock in nanoseconds.
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* @return Zero if ts passed the check, non-zero otherwise.
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*/
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int clockcheck_sample(struct clockcheck *cc, uint64_t ts);
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/**
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* Inform clock check about changes in current frequency of the clock.
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* @param cc Pointer to a clock check obtained via @ref clockcheck_create().
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* @param freq Frequency correction applied to the clock in ppb.
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*/
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void clockcheck_set_freq(struct clockcheck *cc, int freq);
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/**
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* Inform clock check that the clock was stepped.
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* @param cc Pointer to a clock check obtained via @ref clockcheck_create().
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* @param step Step correction applied to the clock in nanoseconds.
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*/
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void clockcheck_step(struct clockcheck *cc, int64_t step);
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/**
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* Destroy a clock check.
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* @param cc Pointer to a clock check obtained via @ref clockcheck_create().
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*/
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void clockcheck_destroy(struct clockcheck *cc);
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#endif
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