2020-12-22 06:21:58 +00:00
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/*
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2021-04-28 20:46:44 +00:00
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* Copyright (c) 2020, the SerenityOS developers.
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2020-12-22 06:21:58 +00:00
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*
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2021-04-22 08:24:48 +00:00
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* SPDX-License-Identifier: BSD-2-Clause
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2020-12-22 06:21:58 +00:00
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*/
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#pragma once
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#include <AK/Atomic.h>
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#include <AK/RefCounted.h>
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2021-07-18 07:15:52 +00:00
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#include <Kernel/Locking/SpinLock.h>
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2021-08-06 08:45:34 +00:00
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#include <Kernel/Memory/VMObject.h>
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2020-12-22 06:21:58 +00:00
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#include <Kernel/Thread.h>
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namespace Kernel {
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class FutexQueue : public Thread::BlockCondition
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, public RefCounted<FutexQueue>
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2021-08-06 11:49:36 +00:00
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, public Memory::VMObjectDeletedHandler {
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2020-12-22 06:21:58 +00:00
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public:
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2021-08-06 11:49:36 +00:00
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FutexQueue(FlatPtr user_address_or_offset, Memory::VMObject* vmobject = nullptr);
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2020-12-22 06:21:58 +00:00
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virtual ~FutexQueue();
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u32 wake_n_requeue(u32, const Function<FutexQueue*()>&, u32, bool&, bool&);
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u32 wake_n(u32, const Optional<u32>&, bool&);
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u32 wake_all(bool&);
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template<class... Args>
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Thread::BlockResult wait_on(const Thread::BlockTimeout& timeout, Args&&... args)
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{
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return Thread::current()->block<Thread::FutexBlocker>(timeout, *this, forward<Args>(args)...);
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}
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2021-08-06 11:49:36 +00:00
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virtual void vmobject_deleted(Memory::VMObject&) override;
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2020-12-22 06:21:58 +00:00
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2021-07-06 18:48:48 +00:00
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bool queue_imminent_wait();
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void did_remove();
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bool try_remove();
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bool is_empty_and_no_imminent_waits()
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{
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ScopedSpinLock lock(m_lock);
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return is_empty_and_no_imminent_waits_locked();
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}
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bool is_empty_and_no_imminent_waits_locked();
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2020-12-22 06:21:58 +00:00
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protected:
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virtual bool should_add_blocker(Thread::Blocker& b, void* data) override;
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private:
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// For private futexes we just use the user space address.
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// But for global futexes we use the offset into the VMObject
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const FlatPtr m_user_address_or_offset;
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2021-08-06 11:49:36 +00:00
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WeakPtr<Memory::VMObject> m_vmobject;
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2020-12-22 06:21:58 +00:00
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const bool m_is_global;
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2021-07-06 18:48:48 +00:00
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size_t m_imminent_waits { 1 }; // We only create this object if we're going to be waiting, so start out with 1
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bool m_was_removed { false };
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2020-12-22 06:21:58 +00:00
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};
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}
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