Atmosphere/libraries/libstratosphere/source/os/impl/os_timer_event_helper.cpp

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2020-04-29 07:41:51 +00:00
/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
*/
#include <stratosphere.hpp>
#include "os_timer_event_helper.hpp"
namespace ams::os::impl {
TimeSpan SaturatedAdd(TimeSpan t1, TimeSpan t2) {
AMS_ASSERT(t1 >= 0);
AMS_ASSERT(t2 >= 0);
const u64 u1 = t1.GetNanoSeconds();
const u64 u2 = t2.GetNanoSeconds();
const u64 sum = u1 + u2;
return TimeSpan::FromNanoSeconds(std::min<u64>(std::numeric_limits<s64>::max(), sum));
}
void StopTimerUnsafe(TimerEventType *event) {
GetReference(event->next_time_to_wakeup) = 0;
event->timer_state = TimerEventType::TimerState_Stop;
}
bool UpdateSignalStateAndRecalculateNextTimeToWakeupUnsafe(TimerEventType *event, TimeSpan cur_time) {
TimeSpan next_time = GetReference(event->next_time_to_wakeup);
switch (event->timer_state) {
case TimerEventType::TimerState_Stop:
break;
case TimerEventType::TimerState_OneShot:
if (next_time < cur_time) {
event->signaled = true;
StopTimerUnsafe(event);
return true;
}
break;
case TimerEventType::TimerState_Periodic:
if (next_time < cur_time) {
event->signaled = true;
next_time = SaturatedAdd(next_time, GetReference(event->interval));
if (next_time < cur_time) {
const u64 elapsed_from_first = (cur_time - GetReference(event->first)).GetNanoSeconds();
const u64 interval = GetReference(event->interval).GetNanoSeconds();
const u64 t = std::min<u64>(std::numeric_limits<s64>::max(), ((elapsed_from_first / interval) + 1) * interval);
next_time = SaturatedAdd(TimeSpan::FromNanoSeconds(t), GetReference(event->first));
}
GetReference(event->next_time_to_wakeup) = next_time;
return true;
}
break;
AMS_UNREACHABLE_DEFAULT_CASE();
}
return false;
}
}