creates an epoll "instance",
requesting the kernel to allocate an event backing store dimensioned for
is not the maximum size of the backing store but
just a hint to the kernel about how to dimension internal structures.
is ignored; see NOTES below.)
returns a file descriptor referring to the new epoll instance.
This file descriptor is used for all the subsequent calls to the
When no longer required, the file descriptor returned by
should be closed by using
When all file descriptors referring to an epoll instance have been closed,
the kernel destroys the instance
and releases the associated resources for reuse.
is 0, then, other than the fact that the obsolete
argument is dropped,
is the same as
The following value can be included in
to obtain different behavior:
Set the close-on-exec
flag on the new file descriptor.
See the description of the
for reasons why this may be useful.
these system calls
return a nonnegative file descriptor.
On error, -1 is returned, and
is set to indicate the error.
is not positive.
Invalid value specified in
The per-user limit on the number of epoll instances imposed by
for further details.
The system limit on the total number of open files has been reached.
There was insufficient memory to create the kernel object.
is Linux-specific, and was introduced in kernel 2.5.44.
Since Linux 2.6.8, the
argument is unused.
(The kernel dynamically sizes the required data structures
without needing this initial hint.)