ladybird/Kernel/Syscalls/alarm.cpp
2021-09-06 13:06:05 +02:00

44 lines
1.5 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Process.h>
#include <Kernel/Time/TimeManagement.h>
namespace Kernel {
KResultOr<FlatPtr> Process::sys$alarm(unsigned seconds)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
REQUIRE_PROMISE(stdio);
unsigned previous_alarm_remaining = 0;
if (m_alarm_timer) {
bool was_in_use = false;
if (TimerQueue::the().cancel_timer(*m_alarm_timer, &was_in_use)) {
// The timer hasn't fired. Round up the remaining time (if any)
Time remaining = m_alarm_timer->remaining() + Time::from_nanoseconds(999'999'999);
previous_alarm_remaining = remaining.to_truncated_seconds();
}
// We had an existing alarm, must return a non-zero value here!
if (was_in_use && previous_alarm_remaining == 0)
previous_alarm_remaining = 1;
}
if (seconds > 0) {
auto deadline = TimeManagement::the().current_time(CLOCK_REALTIME_COARSE);
deadline = deadline + Time::from_seconds(seconds);
if (!m_alarm_timer) {
m_alarm_timer = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) Timer));
}
auto timer_was_added = TimerQueue::the().add_timer_without_id(*m_alarm_timer, CLOCK_REALTIME_COARSE, deadline, [this]() {
[[maybe_unused]] auto rc = send_signal(SIGALRM, nullptr);
});
if (!timer_was_added)
return ENOMEM;
}
return previous_alarm_remaining;
}
}