source: branches/home/psmith/restructure/src/event/kqueue.lisp

#|
Copyright (c) 2006 Risto Laakso
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.
3. The name of the author may not be used to endorse or promote products
   derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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.
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THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|#
(in-package :event-notification)

#+(or darwin macosx freebsd)
(progn

  (defun make-event-queue ()
    (%kqueue))

  (defun ev-set (kevent ident filter flags fflags data udata)
    (setf (foreign-slot-value kevent 'kevent 'ident) ident
          (foreign-slot-value kevent 'kevent 'filter) filter
          (foreign-slot-value kevent 'kevent 'flags) flags
          (foreign-slot-value kevent 'kevent 'fflags) fflags
          (foreign-slot-value kevent 'kevent 'data) data
          (foreign-slot-value kevent 'kevent 'udata) udata))


  (defun add-fd (event-queue fd mode &optional (trigger :edge))
    "Add FD to EVENT-QUEUE in MODE (or :read :write)."
    (with-foreign-object (ke 'kevent)
      (ev-set ke fd
              (ecase mode (:read +evfilt-read+) (:write +evfilt-write+))
              (logior +ev-add+ (if (eql :edge trigger) +ev-clear+ 0)) 
              0 0 (null-pointer))
      (%kevent event-queue ke 1 (null-pointer) 0 (null-pointer)))
    )

  (defun remove-fd (event-queue fd mode)
    "Remove FD from EVENT-QUEUE in MODE (or :read :write)."
    (with-foreign-object (ke 'kevent)
      (ev-set ke fd
              (ecase mode (:read +evfilt-read+) (:write +evfilt-write+))
              +ev-delete+ 0 0 (null-pointer))
      (%kevent event-queue ke 1 (null-pointer) 0 (null-pointer))))



  (define-condition poll-error (error) ())

  (defun poll-events (event-queue)

    (with-foreign-object (ke 'kevent 10)
      (memzero ke (* +kevent-size+ 10))
      (loop for res = (%kevent event-queue (null-pointer) 0 ke 10 (null-pointer)) do
           (case res
             (-1 (error 'poll-error))
             (0 nil)
             (t 
              (let ((idents nil))
                (loop for i from 0 below res do
                     (push (foreign-slot-value (mem-aref ke 'kevent i) 'kevent 'ident) idents))
                (return idents)))))))

  )