src/common/file-descriptor.hpp

   1 /*
   2  * Copyright (C) 2023 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #include <common/error.hpp>
   9 #include <common/format.hpp>
  10
  11 #include <algorithm>
  12
  13 #include <unistd.h>
  14
  15 namespace lttng {
  16
  17 /*
  18  * RAII wrapper around a UNIX file descriptor. A file_descriptor's underlying
  19  * file descriptor
  20  */
  21 class file_descriptor {
  22 public:
  23         explicit file_descriptor(int raw_fd) noexcept : _raw_fd{raw_fd}
  24         {
  25                 LTTNG_ASSERT(_is_valid_fd(_raw_fd));
  26         }
  27
  28         file_descriptor(const file_descriptor&) = delete;
  29
  30         file_descriptor(file_descriptor&& other) : _raw_fd{-1}
  31         {
  32                 LTTNG_ASSERT(_is_valid_fd(_raw_fd));
  33                 std::swap(_raw_fd, other._raw_fd);
  34         }
  35
  36         ~file_descriptor()
  37         {
  38                 if (!_is_valid_fd(_raw_fd)) {
  39                         return;
  40                 }
  41
  42                 const auto ret = ::close(_raw_fd);
  43                 if (ret) {
  44                         PERROR("Failed to close file descriptor: fd=%i", _raw_fd);
  45                 }
  46         }
  47
  48         int fd() const noexcept
  49         {
  50                 LTTNG_ASSERT(_is_valid_fd(_raw_fd));
  51                 return _raw_fd;
  52         }
  53
  54 private:
  55         static bool _is_valid_fd(int fd)
  56         {
  57                 return fd >= 0;
  58         }
  59
  60         int _raw_fd;
  61 };
  62
  63 } /* namespace lttng */