Implemented the NET_WM_SYNC protocol on X11.

Done with Thorbjørn Lindeijer

Task-number: 220550
Reviewed-by: Thorbjørn Lindeijer
Reviewed-by: mae

4 files changed, 127 insertions, 2 deletions

diff --git a/src/gui/kernel/qapplication_x11.cpp b/src/gui/kernel/qapplication_x11.cpp
index 1473421..8ebea19 100644
--- a/src/gui/kernel/qapplication_x11.cpp
+++ b/src/gui/kernel/qapplication_x11.cpp
@@ -157,6 +157,8 @@ static const char * x11_atomnames = {
     "WM_TAKE_FOCUS\0"
     "_NET_WM_PING\0"
     "_NET_WM_CONTEXT_HELP\0"
+    "_NET_WM_SYNC_REQUEST\0"
+    "_NET_WM_SYNC_REQUEST_COUNTER\0"
 
     // ICCCM window state
     "WM_STATE\0"
@@ -508,6 +510,7 @@ static Bool qt_xfixes_scanner(Display*, XEvent *event, XPointer arg)
 class QETWidget : public QWidget                // event translator widget
 {
 public:
+    QWidgetPrivate* d_func() { return QWidget::d_func(); }
     bool translateMouseEvent(const XEvent *);
     void translatePaintEvent(const XEvent *);
     bool translateConfigEvent(const XEvent *);
@@ -718,6 +721,44 @@ static int qt_xio_errhandler(Display *)
 }
 #endif
 
+#ifndef QT_NO_XSYNC
+struct qt_sync_request_event_data
+{
+    WId window;
+};
+
+#if defined(Q_C_CALLBACKS)
+extern "C" {
+#endif
+
+static Bool qt_sync_request_scanner(Display*, XEvent *event, XPointer arg)
+{
+    qt_sync_request_event_data *data =
+        reinterpret_cast<qt_sync_request_event_data*>(arg);
+    if (event->type == ClientMessage &&
+        event->xany.window == data->window &&
+        event->xclient.message_type == ATOM(WM_PROTOCOLS) &&
+        (Atom)event->xclient.data.l[0] == ATOM(_NET_WM_SYNC_REQUEST)) {
+        QWidget *w = QWidget::find(event->xany.window);
+        if (QTLWExtra *tlw = ((QETWidget*)w)->d_func()->maybeTopData()) {
+            const ulong timestamp = (const ulong) event->xclient.data.l[1];
+            if (timestamp > X11->time)
+                X11->time = timestamp;
+            if (timestamp == CurrentTime || timestamp > tlw->syncRequestTimestamp) {
+                tlw->syncRequestTimestamp = timestamp;
+                tlw->newCounterValueLo = event->xclient.data.l[2];
+                tlw->newCounterValueHi = event->xclient.data.l[3];
+            }
+        }
+        return true;
+    }
+    return false;
+}
+
+#if defined(Q_C_CALLBACKS)
+}
+#endif
+#endif // QT_NO_XSYNC
 
 static void qt_x11_create_intern_atoms()
 {
@@ -2090,6 +2131,13 @@ void qt_init(QApplicationPrivate *priv, int,
 #endif // QT_RUNTIME_XCURSOR
 #endif // QT_NO_XCURSOR
 
+#ifndef QT_NO_XSYNC
+        int xsync_evbase, xsync_errbase;
+        int major, minor;
+        if (XSyncQueryExtension(X11->display, &xsync_evbase, &xsync_errbase))
+            XSyncInitialize(X11->display, &major, &minor);
+#endif // QT_NO_XSYNC
+
 #ifndef QT_NO_XINERAMA
 #ifdef QT_RUNTIME_XINERAMA
         X11->ptrXineramaQueryExtension = 0;
@@ -3116,6 +3164,19 @@ int QApplication::x11ClientMessage(QWidget* w, XEvent* event, bool passive_only)
                     XSendEvent(event->xclient.display, event->xclient.window,
                                 False, SubstructureNotifyMask|SubstructureRedirectMask, event);
                 }
+#ifndef QT_NO_XSYNC
+            } else if (a == ATOM(_NET_WM_SYNC_REQUEST)) {
+                const ulong timestamp = (const ulong) event->xclient.data.l[1];
+                if (timestamp > X11->time)
+                    X11->time = timestamp;
+                if (QTLWExtra *tlw = w->d_func()->maybeTopData()) {
+                    if (timestamp == CurrentTime || timestamp > tlw->syncRequestTimestamp) {
+                        tlw->syncRequestTimestamp = timestamp;
+                        tlw->newCounterValueLo = event->xclient.data.l[2];
+                        tlw->newCounterValueHi = event->xclient.data.l[3];
+                    }
+                }
+#endif
             }
         } else if (event->xclient.message_type == ATOM(_QT_SCROLL_DONE)) {
             widget->translateScrollDoneEvent(event);
@@ -4144,7 +4205,9 @@ bool QETWidget::translateMouseEvent(const XEvent *event)
                 || ((nextEvent.type == EnterNotify || nextEvent.type == LeaveNotify)
                     && qt_button_down == this)
                 || (nextEvent.type == ClientMessage
-                    && nextEvent.xclient.message_type == ATOM(_QT_SCROLL_DONE))) {
+                    && (nextEvent.xclient.message_type == ATOM(_QT_SCROLL_DONE) ||
+                    (nextEvent.xclient.message_type == ATOM(WM_PROTOCOLS) &&
+                     (Atom)nextEvent.xclient.data.l[0] == ATOM(_NET_WM_SYNC_REQUEST))))) {
                 qApp->x11ProcessEvent(&nextEvent);
                 continue;
             } else if (nextEvent.type != MotionNotify ||
@@ -5200,6 +5263,14 @@ bool QETWidget::translateConfigEvent(const XEvent *event)
                                    otherEvent.xconfigure.border_width;
                 }
             }
+#ifndef QT_NO_XSYNC
+            qt_sync_request_event_data sync_event;
+            sync_event.window = internalWinId();
+            for (XEvent ev;;) {
+                if (!XCheckIfEvent(X11->display, &ev, &qt_sync_request_scanner, (XPointer)&sync_event))
+                    break;
+            }
+#endif // QT_NO_XSYNC
         }
 
         QRect cr (geometry());
@@ -5285,6 +5356,20 @@ bool QETWidget::translateConfigEvent(const XEvent *event)
         if (d->extra && d->extra->topextra)
             d->extra->topextra->inTopLevelResize = false;
     }
+#ifndef QT_NO_XSYNC
+    if (QTLWExtra *tlwExtra = d->maybeTopData()) {
+        if (tlwExtra->newCounterValueLo != 0 || tlwExtra->newCounterValueHi != 0) {
+            XSyncValue value;
+            XSyncIntsToValue(&value,
+                             tlwExtra->newCounterValueLo,
+                             tlwExtra->newCounterValueHi);
+
+            XSyncSetCounter(X11->display, tlwExtra->syncUpdateCounter, value);
+            tlwExtra->newCounterValueHi = 0;
+            tlwExtra->newCounterValueLo = 0;
+        }
+    }
+#endif
     return true;
 }
 
diff --git a/src/gui/kernel/qt_x11_p.h b/src/gui/kernel/qt_x11_p.h
index b9ace9d..21bb550 100644
--- a/src/gui/kernel/qt_x11_p.h
+++ b/src/gui/kernel/qt_x11_p.h
@@ -154,6 +154,10 @@ extern "C" {
 #  include <X11/extensions/Xrender.h>
 #endif // QT_NO_XRENDER
 
+#ifndef QT_NO_XSYNC
+#  include "X11/extensions/sync.h"
+#endif
+
 // #define QT_NO_XKB
 #ifndef QT_NO_XKB
 #  include <X11/XKBlib.h>
@@ -514,6 +518,8 @@ struct QX11Data
         WM_TAKE_FOCUS,
         _NET_WM_PING,
         _NET_WM_CONTEXT_HELP,
+        _NET_WM_SYNC_REQUEST,
+        _NET_WM_SYNC_REQUEST_COUNTER,
 
         // ICCCM window state
         WM_STATE,
diff --git a/src/gui/kernel/qwidget_p.h b/src/gui/kernel/qwidget_p.h
index bf4f091..ff194f7 100644
--- a/src/gui/kernel/qwidget_p.h
+++ b/src/gui/kernel/qwidget_p.h
@@ -131,6 +131,10 @@ struct QTLWExtra {
     uint embedded : 1;
 
     // *************************** Platform specific values (bit fields first) **********
+#ifndef QT_NO_XSYNC
+    int newCounterValueHi : 32;
+    uint newCounterValueLo : 32;
+#endif
 #if defined(Q_WS_X11) // <----------------------------------------------------------- X11
     uint spont_unmapped: 1; // window was spontaneously unmapped
     uint dnd : 1; // DND properties installed
@@ -156,6 +160,10 @@ struct QTLWExtra {
     QWSManager *qwsManager;
 #endif
 #endif
+#ifndef QT_NO_XSYNC
+    WId syncUpdateCounter;
+    ulong syncRequestTimestamp;
+#endif
 };
 
 struct QWExtra {
diff --git a/src/gui/kernel/qwidget_x11.cpp b/src/gui/kernel/qwidget_x11.cpp
index 4e34045..8159f8e 100644
--- a/src/gui/kernel/qwidget_x11.cpp
+++ b/src/gui/kernel/qwidget_x11.cpp
@@ -754,11 +754,14 @@ void QWidgetPrivate::create_sys(WId window, bool initializeWindow, bool destroyO
                       qBound(1, data.crect.width(), XCOORD_MAX),
                       qBound(1, data.crect.height(), XCOORD_MAX));
         XStoreName(dpy, id, appName.data());
-        Atom protocols[4];
+        Atom protocols[5];
         int n = 0;
         protocols[n++] = ATOM(WM_DELETE_WINDOW);        // support del window protocol
         protocols[n++] = ATOM(WM_TAKE_FOCUS);                // support take focus window protocol
         protocols[n++] = ATOM(_NET_WM_PING);                // support _NET_WM_PING protocol
+#ifndef QT_NO_XSYNC
+        protocols[n++] = ATOM(_NET_WM_SYNC_REQUEST);        // support _NET_WM_SYNC_REQUEST protocol
+#endif // QT_NO_XSYNC
         if (flags & Qt::WindowContextHelpButtonHint)
             protocols[n++] = ATOM(_NET_WM_CONTEXT_HELP);
         XSetWMProtocols(dpy, id, protocols, n);
@@ -1877,6 +1880,23 @@ void QWidgetPrivate::show_sys()
         if (setUserTime)
             qt_net_update_user_time(q, userTime);
 
+#ifndef QT_NO_XSYNC
+        if (!topData()->syncUpdateCounter) {
+            XSyncValue value;
+            XSyncIntToValue(&value, 0);
+            topData()->syncUpdateCounter = XSyncCreateCounter(X11->display, value);
+
+            XChangeProperty(X11->display, q->internalWinId(),
+                            ATOM(_NET_WM_SYNC_REQUEST_COUNTER),
+                            XA_CARDINAL,
+                            32, PropModeReplace,
+                            (uchar *) &topData()->syncUpdateCounter, 1);
+
+            topData()->newCounterValueHi = 0;
+            topData()->newCounterValueLo = 0;
+        }
+#endif
+
         if (!topData()->embedded
             && (topData()->validWMState || topData()->waitingForMapNotify)
             && !q->isMinimized()) {
@@ -2687,6 +2707,12 @@ void QWidgetPrivate::createTLSysExtra()
     extra->topextra->waitingForMapNotify = 0;
     extra->topextra->parentWinId = 0;
     extra->topextra->userTimeWindow = 0;
+#ifndef QT_NO_XSYNC
+    extra->topextra->syncUpdateCounter = 0;
+    extra->topextra->syncRequestTimestamp = 0;
+    extra->topextra->newCounterValueHi = 0;
+    extra->topextra->newCounterValueLo = 0;
+#endif
 }
 
 void QWidgetPrivate::deleteTLSysExtra()