/* Copyright (C) 1997-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #ifndef _SYS_POLL_H # error "Never use directly; include instead." #endif /* Event types that can be polled for. These bits may be set in `events' to indicate the interesting event types; they will appear in `revents' to indicate the status of the file descriptor. */ #define POLLIN 0x001 /* There is data to read. */ #define POLLPRI 0x002 /* There is urgent data to read. */ #define POLLOUT 0x004 /* Writing now will not block. */ #if defined __USE_XOPEN || defined __USE_XOPEN2K8 /* These values are defined in XPG4.2. */ # define POLLRDNORM 0x040 /* Normal data may be read. */ # define POLLRDBAND 0x080 /* Priority data may be read. */ # define POLLWRNORM 0x100 /* Writing now will not block. */ # define POLLWRBAND 0x200 /* Priority data may be written. */ #endif #ifdef __USE_GNU /* These are extensions for Linux. */ # define POLLMSG 0x400 # define POLLREMOVE 0x1000 # define POLLRDHUP 0x2000 #endif /* Event types always implicitly polled for. These bits need not be set in `events', but they will appear in `revents' to indicate the status of the file descriptor. */ #define POLLERR 0x008 /* Error condition. */ #define POLLHUP 0x010 /* Hung up. */ #define POLLNVAL 0x020 /* Invalid polling request. */