serenity/Kernel/Devices/Generic/NullDevice.h

37 lines
1 KiB
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();
// ^Device
virtual bool is_openable_by_jailed_processes() const override { return true; }
// ^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; }
};
}