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/****************************************************************************
* graphics/nxmu/nx_block.c
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 <errno.h>
#include <debug.h>
#include <nuttx/nx/nx.h>
#include "nxbe.h"
#include "nxfe.h"
/****************************************************************************
* Pre-Processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nx_block
*
* Description:
* This is callback will do to things: (1) any queue a 'blocked' callback
* to the window and then (2) block any further window messaging.
*
* The 'blocked' callback is the response from nx_block (or nxtk_block).
* Those blocking interfaces are used to assure that no further messages are
* are directed to the window. Receipt of the blocked callback signifies
* that (1) there are no further pending callbacks and (2) that the
* window is now 'defunct' and will receive no further callbacks.
*
* This callback supports coordinated destruction of a window in multi-
* user mode. In multi-use mode, the client window logic must stay
* intact until all of the queued callbacks are processed. Then the
* window may be safely closed. Closing the window prior with pending
* callbacks can lead to bad behavior when the callback is executed.
*
* Multiple user mode only!
*
* Input Parameters:
* wnd - The window to be blocked
* arg - An argument that will accompany the block messages (This is arg2
* in the blocked callback).
*
* Return:
* OK on success; ERROR on failure with errno set appropriately
*
****************************************************************************/
int nx_block(NXWINDOW hwnd, FAR void *arg)
{
FAR struct nxbe_window_s *wnd = (FAR struct nxbe_window_s *)hwnd;
struct nxsvrmsg_blocked_s outmsg;
int ret = OK;
#ifdef CONFIG_DEBUG
if (!hwnd)
{
set_errno(EINVAL);
return ERROR;
}
#endif
/* Ignore additional attempts to block messages (no errors reported) */
if (!NXBE_ISBLOCKED(wnd))
{
/* Mark the window as blocked. This will stop all messages to the window
* (EXCEPT the NX_SVRMSG_BLOCKED). Blocking the messages before sending the
* blocked message is awkward but assures that no other messages sneak into
* the message queue before we can set the blocked state.
*/
NXBE_SETBLOCKED(wnd);
/* Send the message inicating that the window is blocked (and because of
* queue also that there are no additional queue messages for the window)
*/
outmsg.msgid = NX_SVRMSG_BLOCKED;
outmsg.wnd = wnd;
outmsg.arg = arg;
/* Send the window message via nxmu_sendserver (vs. nxmu_sendwindow) so
* that it will not be blocked.
*/
ret = nxmu_sendserver(wnd->conn, &outmsg, sizeof(struct nxsvrmsg_blocked_s));
}
return ret;
}
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