ladybird/Kernel/Syscalls/alarm.cpp
Andreas Kling 11eee67b85 Kernel: Make self-contained locking smart pointers their own classes
Until now, our kernel has reimplemented a number of AK classes to
provide automatic internal locking:

- RefPtr
- NonnullRefPtr
- WeakPtr
- Weakable

This patch renames the Kernel classes so that they can coexist with
the original AK classes:

- RefPtr => LockRefPtr
- NonnullRefPtr => NonnullLockRefPtr
- WeakPtr => LockWeakPtr
- Weakable => LockWeakable

The goal here is to eventually get rid of the Lock* classes in favor of
using external locking.
2022-08-20 17:20:43 +02:00

46 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>
#include <Kernel/TimerQueue.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$alarm(unsigned seconds)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::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_lock_ref_or_enomem(new (nothrow) Timer));
}
auto timer_was_added = TimerQueue::the().add_timer_without_id(*m_alarm_timer, CLOCK_REALTIME_COARSE, deadline, [this]() {
MUST(send_signal(SIGALRM, nullptr));
});
if (!timer_was_added)
return ENOMEM;
}
return previous_alarm_remaining;
}
}