unistd_ext.h 2.0 KB

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