/**************************************************************************** * libnx/nxmu/nx_block.c * * Copyright (C) 2012-2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include /**************************************************************************** * 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. * * 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_FEATURES 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; }