epoll_create, epoll_create1 — open an epoll file descriptor
#include <sys/epoll.h>
int
epoll_create( |
int | size) ; |
int
epoll_create1( |
int | flags) ; |
epoll_create
() opens an
epoll
file
descriptor by requesting the kernel to allocate an event
backing store dimensioned for size
descriptors. The
size
is not the
maximum size of the backing store but just a hint to the
kernel about how to dimension internal structures. (Nowadays,
size
is ignored; see
NOTES below.)
The returned file descriptor is used for all the
subsequent calls to the epoll
interface. The file
descriptor returned by epoll_create
() must be closed by using
close(2).
If flags
is 0,
then, other than the fact that the obsolete flags
argument is dropped,
epoll_create1
() is the same as
epoll_create
(). The following
value can be included in flags
to obtain different
behavior:
EPOLL_CLOEXEC
Set the close-on-exec (FD_CLOEXEC
) flag on the new file
descriptor. See the description of the O_CLOEXEC
flag in open(2) for reasons
why this may be useful.
On success, these system calls return a non-negative file
descriptor. On error, −1 is returned, and errno
is set to indicate the error.
size
is not
positive.
(epoll_create1
())
Invalid value specified in flags
.
The system limit on the total number of open files has been reached.
There was insufficient memory to create the kernel object.
Since Linux 2.6.8, the size
argument is unused. (The
kernel dynamically sizes the required data structures without
needing this initial hint.)
This page is part of release 3.16 of the Linux man-pages
project. A
description of the project, and information about reporting
bugs, can be found at
http://www.kernel.org/doc/man-pages/.
epoll by Davide Libenzi ( efficient event notification retrieval ) Copyright (C) 2003 Davide Libenzi This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Davide Libenzi <davidelxmailserver.org> Modified 2004-06-17 by Michael Kerrisk <mtk.manpagesgmail.com> Modified 2005-04-04 by Marko Kohtala <marko.kohtalagmail.com> 2008-10-10, mtk: add description of epoll_create1() |