poll.h 2.5 KB

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  1. /* Compatibility definitions for System V `poll' interface.
  2. Copyright (C) 1994-2021 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 _SYS_POLL_H
  16. #define _SYS_POLL_H 1
  17. #include <features.h>
  18. /* Get the platform dependent bits of `poll'. */
  19. #include <bits/poll.h>
  20. #ifdef __USE_GNU
  21. # include <bits/types/__sigset_t.h>
  22. # include <bits/types/struct_timespec.h>
  23. #endif
  24. /* Type used for the number of file descriptors. */
  25. typedef unsigned long int nfds_t;
  26. /* Data structure describing a polling request. */
  27. struct pollfd
  28. {
  29. int fd; /* File descriptor to poll. */
  30. short int events; /* Types of events poller cares about. */
  31. short int revents; /* Types of events that actually occurred. */
  32. };
  33. __BEGIN_DECLS
  34. /* Poll the file descriptors described by the NFDS structures starting at
  35. FDS. If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
  36. an event to occur; if TIMEOUT is -1, block until an event occurs.
  37. Returns the number of file descriptors with events, zero if timed out,
  38. or -1 for errors.
  39. This function is a cancellation point and therefore not marked with
  40. __THROW. */
  41. extern int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout);
  42. #ifdef __USE_GNU
  43. /* Like poll, but before waiting the threads signal mask is replaced
  44. with that specified in the fourth parameter. For better usability,
  45. the timeout value is specified using a TIMESPEC object.
  46. This function is a cancellation point and therefore not marked with
  47. __THROW. */
  48. extern int ppoll (struct pollfd *__fds, nfds_t __nfds,
  49. const struct timespec *__timeout,
  50. const __sigset_t *__ss);
  51. #endif
  52. __END_DECLS
  53. /* Define some inlines helping to catch common problems. */
  54. #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
  55. # include <bits/poll2.h>
  56. #endif
  57. #endif /* sys/poll.h */