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https://github.com/RGBCube/serenity
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aee4786d8e
This singleton simplifies many aspects that we struggled with before: 1. There's no need to make derived classes of Device expose the constructor as public anymore. The singleton is a friend of them, so he can call the constructor. This solves the issue with try_create_device helper neatly, hopefully for good. 2. Getting a reference of the NullDevice is now being done from this singleton, which means that NullDevice no longer needs to use its own singleton, and we can apply the try_create_device helper on it too :) 3. We can now defer registration completely after the Device constructor which means the Device constructor is merely assigning the major and minor numbers of the Device, and the try_create_device helper ensures it calls the after_inserting method immediately after construction. This creates a great opportunity to make registration more OOM-safe.
32 lines
925 B
C++
32 lines
925 B
C++
/*
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* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <Kernel/Devices/CharacterDevice.h>
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namespace Kernel {
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class RandomDevice final : public CharacterDevice {
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AK_MAKE_ETERNAL
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friend class DeviceManagement;
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public:
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static NonnullRefPtr<RandomDevice> must_create();
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virtual ~RandomDevice() override;
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private:
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RandomDevice();
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// ^CharacterDevice
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virtual KResultOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override;
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virtual KResultOr<size_t> write(OpenFileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
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virtual bool can_read(const OpenFileDescription&, size_t) const override;
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virtual bool can_write(const OpenFileDescription&, size_t) const override { return true; }
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virtual StringView class_name() const override { return "RandomDevice"; }
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};
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}
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