shared_fd.h

Go to the documentation of this file.

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2019, Google Inc.
 *
 * File descriptor wrapper with shared ownership
 */

#pragma once

#include <memory>

namespace libcamera {

class UniqueFD;

class SharedFD final
{
public:
    explicit SharedFD(const int &fd = -1);
    explicit SharedFD(int &&fd);
    explicit SharedFD(UniqueFD fd);
    SharedFD(const SharedFD &other);
    SharedFD(SharedFD &&other);
    ~SharedFD();

    SharedFD &operator=(const SharedFD &other);
    SharedFD &operator=(SharedFD &&other);

    bool isValid() const { return fd_ != nullptr; }
    int get() const { return fd_ ? fd_->fd() : -1; }
    UniqueFD dup() const;

private:
    class Descriptor
    {
    public:
        Descriptor(int fd, bool duplicate);
        ~Descriptor();

        int fd() const { return fd_; }

    private:
        int fd_;
    };

    std::shared_ptr<Descriptor> fd_;
};

static inline bool operator==(const SharedFD &lhs, const SharedFD &rhs)
{
    return lhs.get() == rhs.get();
}

static inline bool operator!=(const SharedFD &lhs, const SharedFD &rhs)
{
    return !(lhs == rhs);
}

} /* namespace libcamera */