Copyright (C) 2003 Davide Libenzi Davide Libenzi <firstname.lastname@example.org> %%%LICENSE_START(GPLv2+_SW_3_PARA) 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 MERCHANT...
NAMEepoll_create, epoll_create1 - open an epoll file descriptor
#include <sys/epoll.h> int epoll_create(int size); int epoll_create1(int flags);
DESCRIPTIONepoll_create() creates an epoll(7) instance. Since Linux 2.6.8, the size argument is ignored, but must be greater than zero; see NOTES below.
epoll_create() returns a file descriptor referring to the new epoll instance. This file descriptor is used for all the subsequent calls to the epoll interface. When no longer required, the file descriptor returned by epoll_create() should be closed by using close(2). When all file descriptors referring to an epoll instance have been closed, the kernel destroys the instance and releases the associated resources for reuse.
epoll_create1()If flags is 0, then, other than the fact that the obsolete size argument is dropped, epoll_create1() is the same as epoll_create(). The following value can be included in flags to obtain different behavior:
- 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.
RETURN VALUEOn success, these system calls return a nonnegative 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 per-user limit on the number of epoll instances imposed by /proc/sys/fs/epoll/max_user_instances was encountered. See epoll(7) for further details.
- The per-process limit on the number of open file descriptors has been reached.
- The system-wide limit on the total number of open files has been reached.
- There was insufficient memory to create the kernel object.
VERSIONSepoll_create() was added to the kernel in version 2.6. Library support is provided in glibc starting with version 2.3.2.
epoll_create1() was added to the kernel in version 2.6.27. Library support is provided in glibc starting with version 2.9.