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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <Kernel/DoubleBuffer.h>
#include <Kernel/FileSystem/File.h>
#include <Kernel/Lock.h>
#include <Kernel/UnixTypes.h>
#include <Kernel/WaitQueue.h>
namespace Kernel {
class FileDescription;
class FIFO final : public File {
public:
enum class Direction : u8 {
Neither,
Reader,
Writer
};
static NonnullRefPtr<FIFO> create(uid_t);
virtual ~FIFO() override;
uid_t uid() const { return m_uid; }
KResultOr<NonnullRefPtr<FileDescription>> open_direction(Direction);
KResultOr<NonnullRefPtr<FileDescription>> open_direction_blocking(Direction);
void attach(Direction);
void detach(Direction);
private:
// ^File
virtual KResultOr<size_t> write(FileDescription&, size_t, const UserOrKernelBuffer&, size_t) override;
virtual KResultOr<size_t> read(FileDescription&, size_t, UserOrKernelBuffer&, size_t) override;
virtual KResult stat(::stat&) const override;
virtual bool can_read(const FileDescription&, size_t) const override;
virtual bool can_write(const FileDescription&, size_t) const override;
virtual String absolute_path(const FileDescription&) const override;
virtual const char* class_name() const override { return "FIFO"; }
virtual bool is_fifo() const override { return true; }
explicit FIFO(uid_t);
unsigned m_writers { 0 };
unsigned m_readers { 0 };
DoubleBuffer m_buffer;
uid_t m_uid { 0 };
int m_fifo_id { 0 };
WaitQueue m_read_open_queue;
WaitQueue m_write_open_queue;
Lock m_open_lock;
};
}
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