sysdeps/unix/sysv/linux/sys/epoll.h

   1 /* Copyright (C) 2002-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   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
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _SYS_EPOLL_H
  19 #define _SYS_EPOLL_H    1
  20
  21 #include <stdint.h>
  22 #include <sys/types.h>
  23
  24 #include <bits/types/sigset_t.h>
  25 #include <bits/types/struct_timespec.h>
  26
  27 /* Get the platform-dependent flags.  */
  28 #include <bits/epoll.h>
  29
  30 #ifndef __EPOLL_PACKED
  31 # define __EPOLL_PACKED
  32 #endif
  33
  34
  35 enum EPOLL_EVENTS
  36   {
  37     EPOLLIN = 0x001,
  38 #define EPOLLIN EPOLLIN
  39     EPOLLPRI = 0x002,
  40 #define EPOLLPRI EPOLLPRI
  41     EPOLLOUT = 0x004,
  42 #define EPOLLOUT EPOLLOUT
  43     EPOLLRDNORM = 0x040,
  44 #define EPOLLRDNORM EPOLLRDNORM
  45     EPOLLRDBAND = 0x080,
  46 #define EPOLLRDBAND EPOLLRDBAND
  47     EPOLLWRNORM = 0x100,
  48 #define EPOLLWRNORM EPOLLWRNORM
  49     EPOLLWRBAND = 0x200,
  50 #define EPOLLWRBAND EPOLLWRBAND
  51     EPOLLMSG = 0x400,
  52 #define EPOLLMSG EPOLLMSG
  53     EPOLLERR = 0x008,
  54 #define EPOLLERR EPOLLERR
  55     EPOLLHUP = 0x010,
  56 #define EPOLLHUP EPOLLHUP
  57     EPOLLRDHUP = 0x2000,
  58 #define EPOLLRDHUP EPOLLRDHUP
  59     EPOLLEXCLUSIVE = 1u << 28,
  60 #define EPOLLEXCLUSIVE EPOLLEXCLUSIVE
  61     EPOLLWAKEUP = 1u << 29,
  62 #define EPOLLWAKEUP EPOLLWAKEUP
  63     EPOLLONESHOT = 1u << 30,
  64 #define EPOLLONESHOT EPOLLONESHOT
  65     EPOLLET = 1u << 31
  66 #define EPOLLET EPOLLET
  67   };
  68
  69
  70 /* Valid opcodes ( "op" parameter ) to issue to epoll_ctl().  */
  71 #define EPOLL_CTL_ADD 1 /* Add a file descriptor to the interface.  */
  72 #define EPOLL_CTL_DEL 2 /* Remove a file descriptor from the interface.  */
  73 #define EPOLL_CTL_MOD 3 /* Change file descriptor epoll_event structure.  */
  74
  75
  76 typedef union epoll_data
  77 {
  78   void *ptr;
  79   int fd;
  80   uint32_t u32;
  81   uint64_t u64;
  82 } epoll_data_t;
  83
  84 struct epoll_event
  85 {
  86   uint32_t events;      /* Epoll events */
  87   epoll_data_t data;    /* User data variable */
  88 } __EPOLL_PACKED;
  89
  90
  91 __BEGIN_DECLS
  92
  93 /* Creates an epoll instance.  Returns an fd for the new instance.
  94    The "size" parameter is a hint specifying the number of file
  95    descriptors to be associated with the new instance.  The fd
  96    returned by epoll_create() should be closed with close().  */
  97 extern int epoll_create (int __size) __THROW;
  98
  99 /* Same as epoll_create but with an FLAGS parameter.  The unused SIZE
 100    parameter has been dropped.  */
 101 extern int epoll_create1 (int __flags) __THROW;
 102
 103
 104 /* Manipulate an epoll instance "epfd". Returns 0 in case of success,
 105    -1 in case of error ( the "errno" variable will contain the
 106    specific error code ) The "op" parameter is one of the EPOLL_CTL_*
 107    constants defined above. The "fd" parameter is the target of the
 108    operation. The "event" parameter describes which events the caller
 109    is interested in and any associated user data.  */
 110 extern int epoll_ctl (int __epfd, int __op, int __fd,
 111                       struct epoll_event *__event) __THROW;
 112
 113
 114 /* Wait for events on an epoll instance "epfd". Returns the number of
 115    triggered events returned in "events" buffer. Or -1 in case of
 116    error with the "errno" variable set to the specific error code. The
 117    "events" parameter is a buffer that will contain triggered
 118    events. The "maxevents" is the maximum number of events to be
 119    returned ( usually size of "events" ). The "timeout" parameter
 120    specifies the maximum wait time in milliseconds (-1 == infinite).
 121
 122    This function is a cancellation point and therefore not marked with
 123    __THROW.  */
 124 extern int epoll_wait (int __epfd, struct epoll_event *__events,
 125                        int __maxevents, int __timeout)
 126         __attr_access ((__write_only__, 2, 3)) __nonnull ((2));
 127
 128
 129 /* Same as epoll_wait, but the thread's signal mask is temporarily
 130    and atomically replaced with the one provided as parameter.
 131
 132    This function is a cancellation point and therefore not marked with
 133    __THROW.  */
 134 extern int epoll_pwait (int __epfd, struct epoll_event *__events,
 135                         int __maxevents, int __timeout,
 136                         const __sigset_t *__ss)
 137         __attr_access ((__write_only__, 2, 3)) __nonnull ((2));
 138
 139 /* Same as epoll_pwait, but the timeout as a timespec.
 140
 141    This function is a cancellation point and therefore not marked with
 142    __THROW.  */
 143 #ifndef __USE_TIME64_REDIRECTS
 144 extern int epoll_pwait2 (int __epfd, struct epoll_event *__events,
 145                          int __maxevents, const struct timespec *__timeout,
 146                          const __sigset_t *__ss)
 147         __attr_access ((__write_only__, 2, 3)) __nonnull ((2));
 148 #else
 149 # ifdef __REDIRECT
 150 extern int __REDIRECT (epoll_pwait2, (int __epfd, struct epoll_event *__ev,
 151                                       int __maxevs,
 152                                       const struct timespec *__timeout,
 153                                       const __sigset_t *__ss),
 154                        __epoll_pwait2_time64)
 155         __attr_access ((__write_only__, 2, 3)) __nonnull ((2));
 156 # else
 157 #  define epoll_pwait2 __epoll_pwait2_time64
 158 # endif
 159 #endif
 160
 161 __END_DECLS
 162
 163 #endif /* sys/epoll.h */