Add EVFILT_USER to kevents.

Add user events support to kernel events which are not associated with any
kernel mechanism but are triggered by user level code.  This is useful for
adding user level events to an event handler that may also be monitoring
kernel events.

Approved by:	rwatson (co-mentor)

1 files changed, 39 insertions, 1 deletions

diff --git a/lib/libc/sys/kqueue.2 b/lib/libc/sys/kqueue.2
index 119ff79..1e5e2b5 100644
--- a/lib/libc/sys/kqueue.2
+++ b/lib/libc/sys/kqueue.2
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 6, 2007
+.Dd September 15, 2009
 .Dt KQUEUE 2
 .Os
 .Sh NAME
@@ -441,6 +441,44 @@ The link state is invalid.
 On return,
 .Va fflags
 contains the events which triggered the filter.
+.It Dv EVFILT_USER
+Establishes a user event identified by
+.Va ident
+which is not assosicated with any kernel mechanism but is triggered by
+user level code.
+The lower 24 bits of the 
+.Va fflags
+may be used for user defined flags and manipulated using the following:
+.Bl -tag -width XXNOTE_FFLAGSMASK 
+.It Dv NOTE_FFNOP
+Ignore the input
+.Va fflags .
+.It Dv NOTE_FFAND
+Bitwise AND
+.Va fflags .
+.It Dv NOTE_FFOR
+Bitwise OR
+.Va fflags .
+.It Dv NOTE_COPY
+Copy
+.Va fflags .
+.It Dv NOTE_FFCTRLMASK
+Control mask for
+.Va fflags .
+.It Dv NOTE_FFLAGSMASK
+User defined flag mask for
+.Va fflags .
+.El
+.Pp
+A user event is triggered for output with the following:
+.Bl -tag -width XXNOTE_FFLAGSMASK
+.It Dv NOTE_TRIGGER
+Cause the event to be triggered.
+.El
+.Pp
+On return,
+.Va fflags
+contains the users defined flags in the lower 24 bits.
 .El
 .Sh RETURN VALUES
 The