poll.h 2.0 KB

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  1. /* Copyright (C) 1997 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Library General Public License as
  5. published by the Free Software Foundation; either version 2 of the
  6. License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Library General Public License for more details.
  11. You should have received a copy of the GNU Library General Public
  12. License along with the GNU C Library; see the file COPYING.LIB. If not,
  13. write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  14. Boston, MA 02111-1307, USA. */
  15. #ifndef _SYS_POLL_H
  16. # error "Never use <bits/poll.h> directly; include <sys/poll.h> instead."
  17. #endif
  18. /* Event types that can be polled for. These bits may be set in `events'
  19. to indicate the interesting event types; they will appear in `revents'
  20. to indicate the status of the file descriptor. */
  21. #define POLLIN 0x001 /* There is data to read. */
  22. #define POLLPRI 0x002 /* There is urgent data to read. */
  23. #define POLLOUT 0x004 /* Writing now will not block. */
  24. #ifdef __USE_XOPEN
  25. /* These values are defined in XPG4.2. */
  26. # define POLLRDNORM 0x040 /* Normal data may be read. */
  27. # define POLLRDBAND 0x080 /* Priority data may be read. */
  28. # define POLLWRNORM POLLOUT /* Writing now will not block. */
  29. # define POLLWRBAND 0x100 /* Priority data may be written. */
  30. #endif
  31. /* Event types always implicitly polled for. These bits need not be set in
  32. `events', but they will appear in `revents' to indicate the status of
  33. the file descriptor. */
  34. #define POLLERR 0x008 /* Error condition. */
  35. #define POLLHUP 0x010 /* Hung up. */
  36. #define POLLNVAL 0x020 /* Invalid polling request. */
  37. /* Canonical number of polling requests to read in at a time in poll. */
  38. #define NPOLLFILE 30