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author | jmg <jmg@FreeBSD.org> | 2006-10-04 20:16:23 +0000 |
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committer | jmg <jmg@FreeBSD.org> | 2006-10-04 20:16:23 +0000 |
commit | d5ba3e12e8cc1f0298f4972a2044d05bd25a0425 (patch) | |
tree | e8d5850206cd3d197f897d6ac7ee7d111a7b3c60 /share/man/man9/kqueue.9 | |
parent | 58ae44274d6d518dce53999a796721f8bc131404 (diff) | |
download | FreeBSD-src-d5ba3e12e8cc1f0298f4972a2044d05bd25a0425.zip FreeBSD-src-d5ba3e12e8cc1f0298f4972a2044d05bd25a0425.tar.gz |
add man page talking about how to interface w/ the kqueue system so others
can write additional filters...
mdoc police please!
Diffstat (limited to 'share/man/man9/kqueue.9')
-rw-r--r-- | share/man/man9/kqueue.9 | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/share/man/man9/kqueue.9 b/share/man/man9/kqueue.9 new file mode 100644 index 0000000..a0ad6e0 --- /dev/null +++ b/share/man/man9/kqueue.9 @@ -0,0 +1,338 @@ +.\" Copyright 2004 John-Mark Gurney +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd September 1, 2004 +.Dt KQUEUE 9 +.Os +.Sh NAME +.Nm kqueue_add_filteropts , kqueue_del_filteropts +.Nd "add and remove kqueue event filters" +.Pp +.Nm kqfd_register +.Nd "register a kevent with kqueue by fd" +.Pp +.Nm knote_fdclose +.Nd "deactivate all knotes associated with fd" +.Pp +.Nm knlist_add , knlist_remove , knlist_remove_inevent , knlist_empty , knlist_init , knlist_destroy , knlist_clear , knlist_delete +.Nd "initalize and manipulate lists of knotes" +.Pp +.Nm KNOTE_LOCKED , KNOTE_UNLOCKED +.Nd "activate knotes on a knlist" +.Sh SYNOPSIS +.In sys/event.h +.Ft int +.Fn kqueue_add_filteropts "int filt" "struct filterops *" +.Ft int +.Fn kqueue_del_filteropts "int filt" +.Ft int +.Fn kqfd_register "int fd" "struct kevent *" "struct thread *" "int waitok" +.Ft void +.Fn knote_fdclose "struct thread *" "int fd" +.Ft void +.Fn knlist_add "struct knlist *" "struct knote *" "int islocked" +.Ft void +.Fn knlist_remove "struct knlist *" "struct knote *" "int islocked" +.Ft void +.Fn knlist_remove_inevent "struct knlist *" "struct knote *" +.Ft int +.Fn knlist_empty "struct knlist *" +.Ft void +.Fn knlist_init "struct knlist *" "void *lock" "void (*kl_lock)(void *)" "void (*kl_unlock)(void *) "int (*kl_locked)(void *)" +.Ft void +.Fn knlist_destroy "struct knlist *" +.Ft void +.Fn knlist_clear "struct knlist *" "int islocked" +.Ft void +.Fn knlist_delete "struct knlist *" "struct thread *" "int islocked" +.Ft void +.Fn KNOTE_LOCKED "struct knlist *" "long hint" +.Ft void +.Fn KNOTE_UNLOCKED "struct knlist *" "long hint" +.Sh DESCRIPTION +The functions +.Fn kqueue_add_filteropts +and +.Fn kqueue_del_filteropts +allows the addition and removal of a filter type. +The filter is staticly defined by the +.Dv EVFILT_* +macros. +The function +.Fn kqueue_add_filteropts +will make filt available. The +.Vt "struct filterops" +has the following members: +.Bl -tag -width ".Va f_attach" +.It Va f_isfd +If +.Va f_isfd +is set, +.Va ident +in +.Vt "struct kevent" +is taken to be a file descriptor. +In this case, the knote passed into +.Va f_attach +will have the +.Va kn_fp +member initalized to the +.Vt "struct file *" +that represense the file descriptor. +.It Va f_attach +The +.Va f_attach +member will be called when attaching a +.Vt knote +to the object. +The method should call +.Fn knlist_add +to add the +.Vt knote +to the list that was initalized with +.Fn knlist_init . +The call to +.Fn knlist_add +is only necesary if the object can have multiple knotes associated with it. +If there is no +.Vt knlist +to call +.Fn knlist_add +with, the function +.Va f_attach +must clear the +.Dv KN_DETACHED +bit of +.Va kn_status +in the +.Va knote . +The function shall return 0 on success, or appropriate errno for the failure. +Durning +.Va f_attach +it is valid to change the +.Va kn_fops +pointer to a different pointer. +This will change the +.Va f_event +and +.Va f_detach +members called when processing the knote. +.It Va f_detach +The +.Va f_detach +member will be called to detach the +.Vt knote +if the +.Vt knote +has not already been detached by a call to +.Fn knlist_remove . +.It Va f_event +The +.Va f_event +meber will be called to update the status of the +.Vt knote . +If the function returns 0, it will be assumed that the object is not +ready (or no longer ready) to be woken up. +The hint field will be 0 when called scanning knotes to see which +are available. +Otherwise the hint field will be populated with the value passed to +.Dv KNOTE_LOCKED +or +.Dv KNOTE_UNLOCKED . +The +.Va kn_data +value should be updated as necessary to reflect the current value, such as +number of bytes available for reading, or buffer space available for writing. +If the note needs to be removed, +.Fn knlist_remove_inevent +must be called. +The function +.Fn knlist_remove_inevent +will remove the note from the list, the +.Va f_detach +member will not be called and the +.Va knote +will not be returned as an event. +.El +.Pp +The function +.Fn kqfd_register +will register the +.Vt kevent +on the kqueue file descriptor +.Fa fd . +If it is safe to sleep, waitok should be set. +.Pp +The function +.Fn knote_fdclose +is used to delete all +.Vt knotes +associated with +.Fa fd . +Once returned there will no longer be any +.Vt knotes +associated with the +.Fa fd . +The +.Vt knotes +removed will never be returned from a +.Xr kevent 2 +call, so if userland uses the +.Vt knote +to track resources, they will be leaked. +The +.Fn FILEDESC_LOCK +must be held over the call to +.Fn knote_fdclose +so that file descriptors cannot be added or removed. +.Pp +The +.Fn knlist_* +family of functions are for managing knotes associated with an object. +A +.Va knlist +is not required, but is commonly used. +If used, the +.Vt knlist +must be initalized with the +.Fn knlist_init +function. +If +.Fa lock +is +.Dv NULL , +an internal lock will be used and the remaining arguments will be ignored. +The +.Fa kl_lock , kl_unlock +and +.Fa kl_locked +will be used to manipulate +.Fa lock . +If the argument is +.Dv NULL , +a default routine operating on +.Vt "struct mtx *" +will be used. +The +.Vt knlist +structure may be embeded in your object structure. +The +.Fa lock +will be held over calls to +.Fn f_event . +If +.Dv NULL +is passed for the mutex, a private mutex will be used. +The function +.Fn knlist_empty +requires that +.Fa lock +be held. +The function +.Fn knlist_clear +is used to remove all knotes associated with the list. +The +.Fa islocked +argument declares if you have the +.Fa lock +has been aquired. +All +.Vt knotes +will be marked as detached, and +.Dv EV_ONESHOT +will be set so that the +.Vt knote +will be deleted after the next scan. +The function +.Fn knlist_destroy +is to be used at object destruction time. +There must be no +.Vt knotes +associated with the +.Vt knlist +.Fn ( knlist_clear +be called before or +.Fn knlist_empty +returns true) and no more +.Vt knotes +are able to be attached to the object. +.Pp +.Pp +The functions +.Fn KNOTE_LOCKED +and +.Fn KNOTE_UNLOCKED +are used to notify knotes about events associated with your object. +It will iterated over all +.Vt knotes +on the list calling the +.Va f_event +function associated with the +.Vt knote . +The function +.Fn KNOTE_LOCKED +must be used if the lock associated with the +.Fa knl +passed in is held. +The function +.Fn KNOTE_UNLOCKED +will aquire the lock before iterating over the list of +.Ft knotes . +.Sh RETURN VALUES +The function +.Fn kqueue_add_filteropts +will return zero on success, +.Er EINVAL +in the case of an invalid +.Fa filt +or +.Er EEXIST +if the filter has already been installed. +.Pp +The function +.Fn kqueue_del_filteropts +will return zero on success, +.Er EINVAL +in the case of an invalid +.Fa filt +or +.Er EBUSY +if the filter is still in use. +.Pp +The function +.Fn kqfd_register +will return zero on success, +.Er EBADF +if the file descriptor is not a kqueue or any of the possible values returned +by +.Xr kevent . +.Sh SEE ALSO +.Xr kqueue 2 , +.Xr kevent 2 +.Sh AUTHORS +This +manual page was written by +.An John-Mark Gurney Aq jmg@FreeBSD.org . |