KNOTE(9) | Kernel Developer's Manual | KNOTE(9) |
knote
, KNOTE
—
#include <sys/event.h>
void
knote
(struct
klist *list, long
hint);
KNOTE
(struct
klist *list, long
hint);
knote
() function provides a hook into the kqueue
kernel event notification mechanism to allow sections of the kernel to raise a
kernel event in the form of a ‘knote’, which is a
struct knote as defined in
<sys/event.h>
.
knote
() takes a singly linked
list of knotes, along with a
hint (which is passed to the appropriate filter
routine). knote
() then walks the
list making calls to the filter routine for each
knote. As each knote contains a reference to the data structure that it is
attached to, the filter may choose to examine the data structure in deciding
whether an event should be reported. The hint is used
to pass in additional information, which may not be present in the data
structure that the filter examines.
If the filter decides that the event should be returned, it
returns a non-zero value and knote
() links the knote
onto the tail end of the active list in the corresponding kqueue for the
application to retrieve. If the knote is already on the active list, no
action is taken, but the call to the filter occurs in order to provide an
opportunity for the filter to record the activity.
knote
() must not be called from interrupt
contexts running at an interrupt priority level higher than
splsched(9).
KNOTE
() is a macro that calls
knote
(list,
hint) if list is not empty.
knote
() and KNOTE
()
functions first appeared in FreeBSD 4.1, and then in
NetBSD 2.0.
February 18, 2004 | NetBSD 9.2 |