ladybird/Kernel/Syscalls/alarm.cpp
Tom 12cf6f8650 Kernel: Add CLOCK_REALTIME support to the TimerQueue
This allows us to use blocking timeouts with either monotonic or
real time for all blockers. Which means that clock_nanosleep()
now also supports CLOCK_REALTIME.

Also, switch alarm() to use CLOCK_REALTIME as per specification.
2020-12-02 13:02:04 +01:00

59 lines
2.5 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <Kernel/Process.h>
#include <Kernel/Time/TimeManagement.h>
namespace Kernel {
unsigned Process::sys$alarm(unsigned seconds)
{
REQUIRE_PROMISE(stdio);
unsigned previous_alarm_remaining = 0;
if (auto alarm_timer = move(m_alarm_timer)) {
if (TimerQueue::the().cancel_timer(*alarm_timer)) {
// The timer hasn't fired. Round up the remaining time (if any)
timespec remaining;
timespec_add(alarm_timer->remaining(), { 0, 1000000000 - 1 }, remaining);
previous_alarm_remaining = remaining.tv_sec;
}
// We had an existing alarm, must return a non-zero value here!
if (previous_alarm_remaining == 0)
previous_alarm_remaining = 1;
}
if (seconds > 0) {
auto deadline = TimeManagement::the().current_time(CLOCK_REALTIME).value();
timespec_add(deadline, { seconds, 0 }, deadline);
m_alarm_timer = TimerQueue::the().add_timer_without_id(CLOCK_REALTIME, deadline, [this]() {
(void)send_signal(SIGALRM, nullptr);
});
}
return previous_alarm_remaining;
}
}