ladybird/Kernel/WaitQueue.h
Tom 41d2a0e9f7 Kernel: Dequeue dying threads from WaitQueue
If a thread is waiting but getting killed, we need to dequeue
the thread from the WaitQueue so that a potential wake before
finalization doesn't happen.
2020-08-06 10:02:55 +02:00

57 lines
2.0 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.
*/
#pragma once
#include <AK/Atomic.h>
#include <AK/SinglyLinkedList.h>
#include <Kernel/SpinLock.h>
#include <Kernel/Thread.h>
namespace Kernel {
class WaitQueue {
public:
WaitQueue();
~WaitQueue();
SpinLock<u32>& get_lock() { return m_lock; }
bool enqueue(Thread&);
bool dequeue(Thread&);
void wake_one(Atomic<bool>* lock = nullptr);
void wake_n(u32 wake_count);
void wake_all();
void clear();
private:
typedef IntrusiveList<Thread, &Thread::m_wait_queue_node> ThreadList;
ThreadList m_threads;
SpinLock<u32> m_lock;
bool m_wake_requested { false };
};
}