man2/epoll_create.2

   1 .\"
   2 .\"  epoll by Davide Libenzi ( efficient event notification retrieval )
   3 .\"  Copyright (C) 2003  Davide Libenzi
   4 .\"
   5 .\"  This program is free software; you can redistribute it and/or modify
   6 .\"  it under the terms of the GNU General Public License as published by
   7 .\"  the Free Software Foundation; either version 2 of the License, or
   8 .\"  (at your option) any later version.
   9 .\"
  10 .\"  This program is distributed in the hope that it will be useful,
  11 .\"  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 .\"  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 .\"  GNU General Public License for more details.
  14 .\"
  15 .\"  You should have received a copy of the GNU General Public License
  16 .\"  along with this program; if not, write to the Free Software
  17 .\"  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 .\"
  19 .\"  Davide Libenzi <davidel@xmailserver.org>
  20 .\"
  21 .\" Modified 2004-06-17 by Michael Kerrisk <mtk.manpages@gmail.com>
  22 .\" Modified 2005-04-04 by Marko Kohtala <marko.kohtala@gmail.com>
  23 .\"
  24 .TH EPOLL_CREATE 2 2008-05-29 "Linux" "Linux Programmer's Manual"
  25 .SH NAME
  26 epoll_create \- open an epoll file descriptor
  27 .SH SYNOPSIS
  28 .B #include <sys/epoll.h>
  29 .sp
  30 .BI "int epoll_create(int " size );
  31 .SH DESCRIPTION
  32 Open an
  33 .B epoll
  34 file descriptor by requesting the kernel to allocate
  35 an event backing store dimensioned for
  36 .I size
  37 descriptors.
  38 The
  39 .I size
  40 is not the maximum size of the backing store but
  41 just a hint to the kernel about how to dimension internal structures.
  42 The returned file descriptor will be used for all the subsequent calls to the
  43 .B epoll
  44 interface.
  45 The file descriptor returned by
  46 .BR epoll_create ()
  47 must be closed by using
  48 .BR close (2).
  49 .SH "RETURN VALUE"
  50 When successful,
  51 .BR epoll_create ()
  52 returns a non-negative integer identifying the descriptor.
  53 When an error occurs,
  54 .BR epoll_create ()
  55 returns \-1 and
  56 .I errno
  57 is set appropriately.
  58 .SH ERRORS
  59 .TP
  60 .B EINVAL
  61 .I size
  62 is not positive.
  63 .TP
  64 .B ENFILE
  65 The system limit on the total number of open files has been reached.
  66 .TP
  67 .B ENOMEM
  68 There was insufficient memory to create the kernel object.
  69 .SH CONFORMING TO
  70 .BR epoll_create ()
  71 is Linux-specific, and was introduced in kernel 2.5.44.
  72 .\" The interface should be finalized by Linux kernel 2.5.66.
  73 .SH NOTES
  74 Since Linux 2.6.8, the
  75 .I size
  76 argument is unused.
  77 .SH "SEE ALSO"
  78 .BR close (2),
  79 .BR epoll_ctl (2),
  80 .BR epoll_wait (2),
  81 .BR epoll (7)