ladybird/Kernel/WaitQueue.cpp
Brian Gianforcaro 1f64e3eb16 Kernel: Implement FUTEX_WAKE of arbitrary count.
Previously we just woke all waiters no matter how many were
requested. Fix this by implementing WaitQueue::wake_n(..).
2020-04-26 12:35:35 +02:00

89 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/Thread.h>
#include <Kernel/WaitQueue.h>
namespace Kernel {
WaitQueue::WaitQueue()
{
}
WaitQueue::~WaitQueue()
{
}
void WaitQueue::enqueue(Thread& thread)
{
InterruptDisabler disabler;
m_threads.append(thread);
}
void WaitQueue::wake_one(Atomic<bool>* lock)
{
InterruptDisabler disabler;
if (lock)
*lock = false;
if (m_threads.is_empty())
return;
if (auto* thread = m_threads.take_first())
thread->wake_from_queue();
Scheduler::stop_idling();
}
void WaitQueue::wake_n(i32 wake_count)
{
InterruptDisabler disabler;
if (m_threads.is_empty())
return;
for (i32 i = 0; i < wake_count; ++i) {
Thread* thread = m_threads.take_first();
if (!thread)
break;
thread->wake_from_queue();
}
Scheduler::stop_idling();
}
void WaitQueue::wake_all()
{
InterruptDisabler disabler;
if (m_threads.is_empty())
return;
while (!m_threads.is_empty())
m_threads.take_first()->wake_from_queue();
Scheduler::stop_idling();
}
void WaitQueue::clear()
{
InterruptDisabler disabler;
m_threads.clear();
}
}