| 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 10.0 |