sys::syscall(3pm) [debian man page]
Sys::Syscall(3pm) User Contributed Perl Documentation Sys::Syscall(3pm) NAME
Sys::Syscall - access system calls that Perl doesn't normally provide access to SYNOPSIS
use Sys::Syscall; DESCRIPTION
Use epoll, sendfile, from Perl. Mostly Linux-only support now, but more syscalls/OSes planned for future. Exports Nothing by default. May export: sendfile epoll_ctl epoll_create epoll_wait EPOLLIN EPOLLOUT EPOLLERR EPOLLHUP EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD Export tags: :epoll and :sendfile Functions epoll support $ok = epoll_defined() Returns true if epoll might be available. (caller must still test with epoll_create) $epfd = epoll_create([ $start_size ]) Create a new epoll filedescriptor. Returns -1 if epoll isn't available. $rv = epoll_ctl($epfd, $op, $fd, $events) See manpage for epoll_ctl $count = epoll_wait($epfd, $max_events, $timeout, $arrayref) See manpage for epoll_wait. $arrayref is an arrayref to be modified with the items returned. The values put into $arrayref are arrayrefs of [$fd, $state]. sendfile support $ok = sendfile_defined() Returns true if sendfile should work on this operating system. $sent = sendfile($sock_fd, $file_fd, $max_send) Sends up to $max_send bytes from $file_fd to $sock_fd. Returns bytes actually sent, or -1 on error. COPYRIGHT
This module is Copyright (c) 2005, 2006 Six Apart, Ltd. All rights reserved. You may distribute under the terms of either the GNU General Public License or the Artistic License, as specified in the Perl README file. If you need more liberal licensing terms, please contact the maintainer. Contributing Want to contribute? See: L<http://contributing.appspot.com/sys-syscall> WARRANTY
This is free software. IT COMES WITHOUT WARRANTY OF ANY KIND. AUTHORS
Brad Fitzpatrick <brad@danga.com> perl v5.10.1 2010-04-19 Sys::Syscall(3pm)
Check Out this Related Man Page
EPOLL_CTL(2) Linux Programmer's Manual EPOLL_CTL(2) NAME
epoll_ctl - control interface for an epoll descriptor SYNOPSIS
#include <sys/epoll.h> int epoll_ctl(int epfd, int op, int fd, struct epoll_event *event); DESCRIPTION
This system call performs control operations on the epoll instance referred to by the file descriptor epfd. It requests that the operation op be performed for the target file descriptor, fd. Valid values for the op argument are : EPOLL_CTL_ADD Register the target file descriptor fd on the epoll instance referred to by the file descriptor epfd and associate the event event with the internal file linked to fd. EPOLL_CTL_MOD Change the event event associated with the target file descriptor fd. EPOLL_CTL_DEL Remove (deregister) the target file descriptor fd from the epoll instance referred to by epfd. The event is ignored and can be NULL (but see BUGS below). The event argument describes the object linked to the file descriptor fd. The struct epoll_event is defined as : typedef union epoll_data { void *ptr; int fd; uint32_t u32; uint64_t u64; } epoll_data_t; struct epoll_event { uint32_t events; /* Epoll events */ epoll_data_t data; /* User data variable */ }; The events member is a bit set composed using the following available event types: EPOLLIN The associated file is available for read(2) operations. EPOLLOUT The associated file is available for write(2) operations. EPOLLRDHUP (since Linux 2.6.17) Stream socket peer closed connection, or shut down writing half of connection. (This flag is especially useful for writing simple code to detect peer shutdown when using Edge Triggered monitoring.) EPOLLPRI There is urgent data available for read(2) operations. EPOLLERR Error condition happened on the associated file descriptor. epoll_wait(2) will always wait for this event; it is not necessary to set it in events. EPOLLHUP Hang up happened on the associated file descriptor. epoll_wait(2) will always wait for this event; it is not necessary to set it in events. EPOLLET Sets the Edge Triggered behavior for the associated file descriptor. The default behavior for epoll is Level Triggered. See epoll(7) for more detailed information about Edge and Level Triggered event distribution architectures. EPOLLONESHOT (since Linux 2.6.2) Sets the one-shot behavior for the associated file descriptor. This means that after an event is pulled out with epoll_wait(2) the associated file descriptor is internally disabled and no other events will be reported by the epoll interface. The user must call epoll_ctl() with EPOLL_CTL_MOD to rearm the file descriptor with a new event mask. RETURN VALUE
When successful, epoll_ctl() returns zero. When an error occurs, epoll_ctl() returns -1 and errno is set appropriately. ERRORS
EBADF epfd or fd is not a valid file descriptor. EEXIST op was EPOLL_CTL_ADD, and the supplied file descriptor fd is already registered with this epoll instance. EINVAL epfd is not an epoll file descriptor, or fd is the same as epfd, or the requested operation op is not supported by this interface. ENOENT op was EPOLL_CTL_MOD or EPOLL_CTL_DEL, and fd is not registered with this epoll instance. ENOMEM There was insufficient memory to handle the requested op control operation. ENOSPC The limit imposed by /proc/sys/fs/epoll/max_user_watches was encountered while trying to register (EPOLL_CTL_ADD) a new file descriptor on an epoll instance. See epoll(7) for further details. EPERM The target file fd does not support epoll. CONFORMING TO
epoll_ctl() is Linux-specific, and was introduced in kernel 2.5.44. NOTES
The epoll interface supports all file descriptors that support poll(2). BUGS
In kernel versions before 2.6.9, the EPOLL_CTL_DEL operation required a non-NULL pointer in event, even though this argument is ignored. Since Linux 2.6.9, event can be specified as NULL when using EPOLL_CTL_DEL. Applications that need to be portable to kernels before 2.6.9 should specify a non-NULL pointer in event. SEE ALSO
epoll_create(2), epoll_wait(2), poll(2), epoll(7) COLOPHON
This page is part of release 3.27 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 2010-08-29 EPOLL_CTL(2)