Move XCB event reading to a separate thread.

Work-around for bug in XCB which causes a xcb_wait_for_reply to block
if xcb_poll_for_events() is called simultaneously from a different
thread. If the XCB version is too old this work-around causes even
more problems, so we kill two birds with one stone by only using the
work-around if the XCB version has the recent
xcb_poll_for_queue_event() function, which we also need to read
events from a separate thread with reasonable efficiency.

Change-Id: I8a899dad6ded381ce42cba0112e77da3c8aa6887
Reviewed-on: http://codereview.qt.nokia.com/3612
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

2 files changed, 64 insertions, 0 deletions

diff --git a/config.tests/qpa/xcb-poll-for-queued-event/xcb-poll-for-queued-event.cpp b/config.tests/qpa/xcb-poll-for-queued-event/xcb-poll-for-queued-event.cpp
new file mode 100644
index 0000000000..d15e554423
--- /dev/null
+++ b/config.tests/qpa/xcb-poll-for-queued-event/xcb-poll-for-queued-event.cpp
@@ -0,0 +1,59 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the config.tests of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <xcb/xcb.h>
+#include <xcb/xcb_icccm.h>
+#include <xcb/xfixes.h>
+#include <xcb/xcb_image.h>
+#include <xcb/xcb_keysyms.h>
+#include <xcb/sync.h>
+#include <xcb/shm.h>
+
+int main(int, char **)
+{
+    int primaryScreen = 0;
+
+    xcb_connection_t *connection = xcb_connect("", &primaryScreen);
+
+    xcb_generic_event_t *event = xcb_poll_for_queued_event(connection);
+
+    return 0;
+}
diff --git a/config.tests/qpa/xcb-poll-for-queued-event/xcb-poll-for-queued-event.pro b/config.tests/qpa/xcb-poll-for-queued-event/xcb-poll-for-queued-event.pro
new file mode 100644
index 0000000000..6075c55c49
--- /dev/null
+++ b/config.tests/qpa/xcb-poll-for-queued-event/xcb-poll-for-queued-event.pro
@@ -0,0 +1,5 @@
+SOURCES = xcb-poll-for-queued-event.cpp
+CONFIG -= qt
+
+LIBS += -lxcb -lxcb-image -lxcb-keysyms -lxcb-icccm -lxcb-sync -lxcb-xfixes
+