nuttx/graphics/nxmu/nx_eventnotify.c

/****************************************************************************
 * graphics/nxmu/nx_eventnotify.c
 *
 *   Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
 *
 * 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. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
 * COPYRIGHT OWNER 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.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <stdlib.h>
#include <mqueue.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>

#include <nuttx/nx.h>
#include "nxfe.h"

#ifndef CONFIG_DISABLE_SIGNALS

/****************************************************************************
 * Pre-Processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Types
 ****************************************************************************/

/****************************************************************************
 * Private Data
 ****************************************************************************/

/****************************************************************************
 * Public Data
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: nx_eventnotify
 *
 * Description:
 *   Rather than calling nx_eventhandler periodically, the client may
 *   register to receive a signal when a server event is available.  The
 *   client can then call nv_eventhandler() only when incoming events are
 *   available.
 *
 *   Only one such event is issued.  Upon receipt of the signal, if the client
 *   wishes further notifications, it must call nx_eventnotify again.
 *
 * Input Parameters:
 *   handle - the handle returned by nx_connect
 *
 * Return:
 *      OK: No errors occurred.  If CONFIG_NX_BLOCKING is defined, then
 *          one or more server message was processed.
 *   ERROR: An error occurred and errno has been set appropriately
 *
 ****************************************************************************/

int nx_eventnotify(NXHANDLE handle, int signo)
{
  FAR struct nxfe_conn_s *conn = (FAR struct nxfe_conn_s *)handle;
  struct sigevent se;

  se.sigev_notify          = SIGEV_SIGNAL;
  se.sigev_signo           = signo;
  se.sigev_value.sival_ptr = (FAR void *)handle;

  return mq_notify(conn->crdmq, &se);
}

#endif /* CONFIG_DISABLE_SIGNALS */