unistd_ext.h 2.6 KB

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  1. //
  2. // Copyright 2026 Aarav Ravindra Kharade
  3. //
  4. // Licensed under the Apache License, Version 2.0 (the "License");
  5. // you may not use this file except in compliance with the License.
  6. // You may obtain a copy of the License at
  7. //
  8. // http://www.apache.org/licenses/LICENSE-2.0
  9. //
  10. // Unless required by applicable law or agreed to in writing, software
  11. // distributed under the License is distributed on an "AS IS" BASIS,
  12. // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13. // See the License for the specific language governing permissions and
  14. // limitations under the License.
  15. //
  16. /* System-specific extensions of <unistd.h>, Linux version.
  17. Copyright (C) 2019-2026 Free Software Foundation, Inc.
  18. This file is part of the GNU C Library.
  19. The GNU C Library is free software; you can redistribute it and/or
  20. modify it under the terms of the GNU Lesser General Public
  21. License as published by the Free Software Foundation; either
  22. version 2.1 of the License, or (at your option) any later version.
  23. The GNU C Library is distributed in the hope that it will be useful,
  24. but WITHOUT ANY WARRANTY; without even the implied warranty of
  25. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  26. Lesser General Public License for more details.
  27. You should have received a copy of the GNU Lesser General Public
  28. License along with the GNU C Library; if not, see
  29. <https://www.gnu.org/licenses/>. */
  30. #ifndef _UNISTD_H
  31. # error "Never include <bits/unistd_ext.h> directly; use <unistd.h> instead."
  32. #endif
  33. #ifdef __USE_GNU
  34. /* Return the kernel thread ID (TID) of the current thread. The
  35. returned value is not subject to caching. Most Linux system calls
  36. accept a TID in place of a PID. Using the TID to change properties
  37. of a thread that has been created using pthread_create can lead to
  38. undefined behavior (comparable to manipulating file descriptors
  39. directly that have not been created explicitly). Note that a TID
  40. uniquely identifies a thread only while this thread is running; a
  41. TID can be reused once a thread has exited, even if the thread is
  42. not detached and has not been joined. */
  43. extern __pid_t gettid (void) __THROW;
  44. #ifdef __has_include
  45. # if __has_include ("linux/close_range.h")
  46. # include "linux/close_range.h"
  47. # endif
  48. #endif
  49. /* Unshare the file descriptor table before closing file descriptors. */
  50. #ifndef CLOSE_RANGE_UNSHARE
  51. # define CLOSE_RANGE_UNSHARE (1U << 1)
  52. #endif
  53. /* Set the FD_CLOEXEC bit instead of closing the file descriptor. */
  54. #ifndef CLOSE_RANGE_CLOEXEC
  55. # define CLOSE_RANGE_CLOEXEC (1U << 2)
  56. #endif
  57. #endif /* __USE_GNU */