ladybird/Kernel/FileSystem/FIFO.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

67 lines
1.9 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <Kernel/DoubleBuffer.h>
#include <Kernel/FileSystem/File.h>
#include <Kernel/Locking/Mutex.h>
#include <Kernel/UnixTypes.h>
#include <Kernel/WaitQueue.h>
namespace Kernel {
class OpenFileDescription;
class FIFO final : public File {
public:
enum class Direction : u8 {
Neither,
Reader,
Writer
};
static ErrorOr<NonnullLockRefPtr<FIFO>> try_create(UserID);
virtual ~FIFO() override;
UserID uid() const { return m_uid; }
ErrorOr<NonnullLockRefPtr<OpenFileDescription>> open_direction(Direction);
ErrorOr<NonnullLockRefPtr<OpenFileDescription>> open_direction_blocking(Direction);
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Woverloaded-virtual"
void attach(Direction);
void detach(Direction);
#pragma GCC diagnostic pop
private:
// ^File
virtual ErrorOr<size_t> write(OpenFileDescription&, u64, UserOrKernelBuffer const&, size_t) override;
virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override;
virtual ErrorOr<struct stat> stat() const override;
virtual bool can_read(OpenFileDescription const&, u64) const override;
virtual bool can_write(OpenFileDescription const&, u64) const override;
virtual ErrorOr<NonnullOwnPtr<KString>> pseudo_path(OpenFileDescription const&) const override;
virtual StringView class_name() const override { return "FIFO"sv; }
virtual bool is_fifo() const override { return true; }
explicit FIFO(UserID, NonnullOwnPtr<DoubleBuffer> buffer);
unsigned m_writers { 0 };
unsigned m_readers { 0 };
NonnullOwnPtr<DoubleBuffer> m_buffer;
UserID m_uid { 0 };
int m_fifo_id { 0 };
WaitQueue m_read_open_queue;
WaitQueue m_write_open_queue;
Mutex m_open_lock;
};
}