ladybird/Kernel/Devices/NullDevice.h
Andreas Kling 11eee67b85 Kernel: Make self-contained locking smart pointers their own classes
Until now, our kernel has reimplemented a number of AK classes to
provide automatic internal locking:

- RefPtr
- NonnullRefPtr
- WeakPtr
- Weakable

This patch renames the Kernel classes so that they can coexist with
the original AK classes:

- RefPtr => LockRefPtr
- NonnullRefPtr => NonnullLockRefPtr
- WeakPtr => LockWeakPtr
- Weakable => LockWeakable

The goal here is to eventually get rid of the Lock* classes in favor of
using external locking.
2022-08-20 17:20:43 +02:00

33 lines
958 B
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <Kernel/Devices/CharacterDevice.h>
namespace Kernel {
class NullDevice final : public CharacterDevice {
friend class DeviceManagement;
public:
virtual ~NullDevice() override;
static NonnullLockRefPtr<NullDevice> must_initialize();
private:
NullDevice();
// ^CharacterDevice
virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override;
virtual ErrorOr<size_t> write(OpenFileDescription&, u64, UserOrKernelBuffer const&, size_t) override;
virtual bool can_write(OpenFileDescription const&, u64) const override { return true; }
virtual bool can_read(OpenFileDescription const&, u64) const override;
virtual StringView class_name() const override { return "NullDevice"sv; }
virtual bool is_seekable() const override { return true; }
};
}