LUMIERA.clone/src/vault/real-clock.cpp

68 lines
2.3 KiB
C++

/*
RealClock - convenience front-end to access the system clock
Copyright (C) Lumiera.org
2012, Hermann Vosseler <Ichthyostega@web.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* *****************************************************/
/** @file real-clock.cpp
** Implementation of simplified access to the current wall clock time.
**
** @todo just a rough draft as of 2012 / 2017
** @todo the idea was that the vault has elaborate knowledge about
** timings and time progression; upper layers should thus be able
** to fulfil their timing needs by querying the vault layer
*/
#include "vault/real-clock.hpp"
#include <ctime>
using lib::time::FSecs;
namespace vault {
#define MICRO_TICS_PER_NANOSECOND (1000*1000*1000 / TimeValue::SCALE)
/** events during the last ms are considered "recent" for the purpose of testing */
const Offset RealClock::CONSIDERED_RECENT{FSecs {1,1000}};
TimeValue
RealClock::_readSystemTime()
{
timespec now;
clock_gettime(CLOCK_REALTIME, &now);
////////////////////////////////////////////TODO shouldn't that be CLOCK_MONOTONIC ?
////////////////////////////////////////////TODO (what happens on ntp adjustments?)
////////////////////////////////////////////TICKET #886
gavl_time_t ticksSince1970 = now.tv_sec * TimeValue::SCALE
+ now.tv_nsec / MICRO_TICS_PER_NANOSECOND;
ENSURE (ticksSince1970 == _raw(TimeValue{ticksSince1970}));
return TimeValue::buildRaw_(ticksSince1970); // bypassing the limit check
}
} // namespace vault