EPOLL_CREATE(2) 					     Linux Programmer's Manual						   EPOLL_CREATE(2)

NAME

       epoll_create, epoll_create1 - open an epoll file descriptor

SYNOPSIS

       #include <sys/epoll.h>

       int epoll_create(int size);
       int epoll_create1(int flags);

DESCRIPTION

       epoll_create() creates an epoll "instance", 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.)

       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.

       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:

       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 rea-
	      sons why this may be useful.

RETURN VALUE

       On success, these system calls return a nonnegative file descriptor.  On error, -1 is returned, and errno is set to indicate the error.

ERRORS

       EINVAL size is not positive.

       EINVAL (epoll_create1()) Invalid value specified in flags.

       EMFILE 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.

       ENFILE The system limit on the total number of open files has been reached.

       ENOMEM There was insufficient memory to create the kernel object.

CONFORMING TO

       epoll_create() is Linux-specific, and was introduced in kernel 2.5.44.

NOTES

       Since  Linux  2.6.8,  the size argument is unused.  (The kernel dynamically sizes the required data structures without needing this initial
       hint.)

SEE ALSO

       close(2), epoll_ctl(2), epoll_wait(2), epoll(7)

COLOPHON

       This page is part of release 3.25 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/.

Linux								    2009-01-17							   EPOLL_CREATE(2)