Add nx_eventnotify.c

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1349 42af7a65-404d-4744-a932-0658087f49c3

graphics/nxmu/Make.defs

@@ -35,7 +35,7 @@
 
 NX_ASRCS	=
 NXAPI_CSRCS	= nx_bitmap.c nx_closewindow.c nx_connect.c nx_disconnect.c \
-		  nx_eventhandler.c nx_fill.c nx_filltrapezoid.c \
+		  nx_eventhandler.c nx_eventnotify.c nx_fill.c nx_filltrapezoid.c \
 		  nx_getposition.c nx_kbdchin.c nx_kbdin.c nx_lower.c \
 		  nx_mousein.c nx_move.c nx_openwindow.c nx_raise.c \
 		  nx_releasebkgd.c nx_requestbkgd.c nx_setsize.c \

graphics/nxmu/nx_eventnotify.c

@@ -0,0 +1,109 @@
+/****************************************************************************
+ * graphics/nxmu/nx_eventnotify.c
+ *
+ *   Copyright (C) 2008 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 <sys/types.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.
+ *
+ * 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 */

include/nuttx/nx.h

@@ -321,24 +321,56 @@ EXTERN void nx_close(NXHANDLE handle);
  * Description:
  *   The client code must call this function periodically to process
  *   incoming messages from the server.  If CONFIG_NX_BLOCKING is defined,
- *   then this function will never return until the host is disconnected.
+ *   then this function not return until a server message is received.
+ *
+ *   When CONFIG_NX_BLOCKING is not defined, the client must exercise
+ *   caution in the looping to assure that it does not eat up all of
+ *   the CPU bandwidth calling nx_eventhandler repeatedly.  nx_eventnotify
+ *   may be called to get a signal event whenever a new incoming server
+ *   event is avaiable.
  *
  * Input Parameters:
  *   handle - the handle returned by nx_connect
  *
  * Return:
- *   >0: The length of the message received in msgbuffer
- *    0: No message was received
- *   <0: An error occurred and errno has been set appropriately
- *
- *   Of particular interest, it will return errno == EHOSTDOWN when the
- *   server is disconnected.  After that event, the handle can not longer
- *   be used.
+ *     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.  Of
+ *         particular interest, it will return errno == EHOSTDOWN when the
+ *         server is disconnected.  After that event, the handle can no
+ *         longer be used.
  *
  ****************************************************************************/
 
 #ifdef CONFIG_NX_MULTIUSER
 EXTERN int nx_eventhandler(NXHANDLE handle);
+#else
+#  define nx_eventhandler(handle) (OK)
+#endif
+
+/****************************************************************************
+ * 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.
+ *
+ * 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
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NX_MULTIUSER) && !defined(CONFIG_DISABLE_SIGNALS)
+EXTERN int nx_eventnotify(NXHANDLE handle, int signo);
+#else
+#  define nx_eventnotify(handle, signo) (OK)
 #endif
 
 /****************************************************************************