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Diffstat (limited to 'src/libcamera/base/file_descriptor.cpp')
| -rw-r--r-- | src/libcamera/base/file_descriptor.cpp | 266 |
1 files changed, 0 insertions, 266 deletions
diff --git a/src/libcamera/base/file_descriptor.cpp b/src/libcamera/base/file_descriptor.cpp deleted file mode 100644 index 8e181abc..00000000 --- a/src/libcamera/base/file_descriptor.cpp +++ /dev/null @@ -1,266 +0,0 @@ -/* SPDX-License-Identifier: LGPL-2.1-or-later */ -/* - * Copyright (C) 2019, Google Inc. - * - * file_descriptor.cpp - File descriptor wrapper - */ - -#include <libcamera/base/file_descriptor.h> - -#include <string.h> -#include <sys/types.h> -#include <unistd.h> -#include <utility> - -#include <libcamera/base/log.h> -#include <libcamera/base/unique_fd.h> - -/** - * \file base/file_descriptor.h - * \brief File descriptor wrapper - */ - -namespace libcamera { - -LOG_DEFINE_CATEGORY(FileDescriptor) - -/** - * \class FileDescriptor - * \brief RAII-style wrapper for file descriptors - * - * The FileDescriptor class provides RAII-style lifetime management of file - * descriptors with an efficient mechanism for ownership sharing. At its core, - * an internal Descriptor object wraps a file descriptor (expressed as a signed - * integer) with an RAII-style interface. The Descriptor is then implicitly - * shared with all FileDescriptor instances constructed as copies. - * - * When constructed from a numerical file descriptor, the FileDescriptor - * instance either duplicates or takes over the file descriptor: - * - * - The FileDescriptor(const int &) constructor duplicates the numerical file - * descriptor and wraps the duplicate in a Descriptor. The caller is - * responsible for closing the original file descriptor, and the value - * returned by fd() will be different from the value passed to the - * constructor. - * - * - The FileDescriptor(int &&) constructor takes over the numerical file - * descriptor and wraps it in a Descriptor. The caller shall not touch the - * original file descriptor once the function returns, and the value returned - * by fd() will be identical to the value passed to the constructor. - * - * The copy constructor and assignment operator create copies that share the - * Descriptor, while the move versions of those functions additionally make the - * other FileDescriptor invalid. When the last FileDescriptor that references a - * Descriptor is destroyed, the file descriptor is closed. - * - * The numerical file descriptor is available through the fd() function. All - * FileDescriptor instances created as copies of a FileDescriptor will report - * the same fd() value. Callers can perform operations on the fd(), but shall - * never close it manually. - */ - -/** - * \brief Create a FileDescriptor copying a given \a fd - * \param[in] fd File descriptor - * - * Construct a FileDescriptor from a numerical file descriptor by duplicating - * the \a fd, and take ownership of the copy. The original \a fd is left - * untouched, and the caller is responsible for closing it when appropriate. - * The duplicated file descriptor will be closed automatically when all - * FileDescriptor instances that reference it are destroyed. - * - * If the \a fd is negative, the FileDescriptor is constructed as invalid and - * the fd() function will return -1. - */ -FileDescriptor::FileDescriptor(const int &fd) -{ - if (fd < 0) - return; - - fd_ = std::make_shared<Descriptor>(fd, true); - if (fd_->fd() < 0) - fd_.reset(); -} - -/** - * \brief Create a FileDescriptor taking ownership of a given \a fd - * \param[in] fd File descriptor - * - * Construct a FileDescriptor from a numerical file descriptor by taking - * ownership of the \a fd. The original \a fd is set to -1 and shall not be - * touched by the caller anymore. In particular, the caller shall not close the - * original \a fd manually. The duplicated file descriptor will be closed - * automatically when all FileDescriptor instances that reference it are - * destroyed. - * - * If the \a fd is negative, the FileDescriptor is constructed as invalid and - * the fd() function will return -1. - */ -FileDescriptor::FileDescriptor(int &&fd) -{ - if (fd < 0) - return; - - fd_ = std::make_shared<Descriptor>(fd, false); - /* - * The Descriptor constructor can't have failed here, as it took over - * the fd without duplicating it. Just set the original fd to -1 to - * implement move semantics. - */ - fd = -1; -} - -/** - * \brief Create a FileDescriptor taking ownership of a given UniqueFD \a fd - * \param[in] fd UniqueFD - * - * Construct a FileDescriptor from UniqueFD by taking ownership of the \a fd. - * The original \a fd becomes invalid. - */ -FileDescriptor::FileDescriptor(UniqueFD fd) - : FileDescriptor(fd.release()) -{ -} - -/** - * \brief Copy constructor, create a FileDescriptor from a copy of \a other - * \param[in] other The other FileDescriptor - * - * Copying a FileDescriptor implicitly shares ownership of the wrapped file - * descriptor. The original FileDescriptor is left untouched, and the caller is - * responsible for destroying it when appropriate. The wrapped file descriptor - * will be closed automatically when all FileDescriptor instances that - * reference it are destroyed. - */ -FileDescriptor::FileDescriptor(const FileDescriptor &other) - : fd_(other.fd_) -{ -} - -/** - * \brief Move constructor, create a FileDescriptor by taking over \a other - * \param[in] other The other FileDescriptor - * - * Moving a FileDescriptor moves the reference to the wrapped descriptor owned - * by \a other to the new FileDescriptor. The \a other FileDescriptor is - * invalidated and its fd() function will return -1. The wrapped file descriptor - * will be closed automatically when all FileDescriptor instances that - * reference it are destroyed. - */ -FileDescriptor::FileDescriptor(FileDescriptor &&other) - : fd_(std::move(other.fd_)) -{ -} - -/** - * \brief Destroy the FileDescriptor instance - * - * Destroying a FileDescriptor instance releases its reference to the wrapped - * descriptor, if any. When the last instance that references a wrapped - * descriptor is destroyed, the file descriptor is automatically closed. - */ -FileDescriptor::~FileDescriptor() -{ -} - -/** - * \brief Copy assignment operator, replace the wrapped file descriptor with a - * copy of \a other - * \param[in] other The other FileDescriptor - * - * Copying a FileDescriptor creates a new reference to the wrapped file - * descriptor owner by \a other. If \a other is invalid, *this will also be - * invalid. The original FileDescriptor is left untouched, and the caller is - * responsible for destroying it when appropriate. The wrapped file descriptor - * will be closed automatically when all FileDescriptor instances that - * reference it are destroyed. - * - * \return A reference to this FileDescriptor - */ -FileDescriptor &FileDescriptor::operator=(const FileDescriptor &other) -{ - fd_ = other.fd_; - - return *this; -} - -/** - * \brief Move assignment operator, replace the wrapped file descriptor by - * taking over \a other - * \param[in] other The other FileDescriptor - * - * Moving a FileDescriptor moves the reference to the wrapped descriptor owned - * by \a other to the new FileDescriptor. If \a other is invalid, *this will - * also be invalid. The \a other FileDescriptor is invalidated and its fd() - * function will return -1. The wrapped file descriptor will be closed - * automatically when all FileDescriptor instances that reference it are - * destroyed. - * - * \return A reference to this FileDescriptor - */ -FileDescriptor &FileDescriptor::operator=(FileDescriptor &&other) -{ - fd_ = std::move(other.fd_); - - return *this; -} - -/** - * \fn FileDescriptor::isValid() - * \brief Check if the FileDescriptor instance is valid - * \return True if the FileDescriptor is valid, false otherwise - */ - -/** - * \fn FileDescriptor::fd() - * \brief Retrieve the numerical file descriptor - * \return The numerical file descriptor, which may be -1 if the FileDescriptor - * instance is invalid - */ - -/** - * \brief Duplicate a FileDescriptor - * - * Duplicating a FileDescriptor creates a duplicate of the wrapped file - * descriptor and returns a UniqueFD that owns the duplicate. The fd() function - * of the original and the get() function of the duplicate will return different - * values. The duplicate instance will not be affected by destruction of the - * original instance or its copies. - * - * \return A UniqueFD owning a duplicate of the original file descriptor - */ -UniqueFD FileDescriptor::dup() const -{ - UniqueFD dupFd(::dup(fd())); - if (!dupFd.isValid()) { - int ret = -errno; - LOG(FileDescriptor, Error) - << "Failed to dup() fd: " << strerror(-ret); - } - - return dupFd; -} - -FileDescriptor::Descriptor::Descriptor(int fd, bool duplicate) -{ - if (!duplicate) { - fd_ = fd; - return; - } - - /* Failing to dup() a fd should not happen and is fatal. */ - fd_ = ::dup(fd); - if (fd_ == -1) { - int ret = -errno; - LOG(FileDescriptor, Fatal) - << "Failed to dup() fd: " << strerror(-ret); - } -} - -FileDescriptor::Descriptor::~Descriptor() -{ - if (fd_ != -1) - close(fd_); -} - -} /* namespace libcamera */ |