Lock for read only when possible

From benchmarking I've established that surface->Lock(DSLF_READ) is
faster than surface->Lock(DSLF_WRITE) which is faster than
surface->Lock(DSLF_READ|DSLF_WRITE).

This patch will make us Lock for read only, when possible.

Reviewed-by: Donald <qt-info@nokia.com>

9 files changed, 40 insertions, 25 deletions

diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.cpp
index 924090c..9796280 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.cpp
@@ -56,15 +56,20 @@ IDirectFBSurface *QDirectFBPaintDevice::directFBSurface() const
 }
 
 
-void QDirectFBPaintDevice::lockDirectFB()
+void QDirectFBPaintDevice::lockDirectFB(uint flags)
 {
-    if (lockedImage)
-        return; // Already locked
-
-    if (uchar *mem = QDirectFBScreen::lockSurface(dfbSurface, DSLF_WRITE, &bpl)) {
+    if (lockedImage) {
+        if (lockFlags & flags)
+            return;
+        unlockDirectFB();
+    }
+    if (uchar *mem = QDirectFBScreen::lockSurface(dfbSurface, flags, &bpl)) {
         const QSize s = size();
         lockedImage = new QImage(mem, s.width(), s.height(), bpl,
                                  QDirectFBScreen::getImageFormat(dfbSurface));
+        lockFlags = flags;
+    } else {
+        lockFlags = 0;
     }
 }
 
@@ -80,10 +85,10 @@ void QDirectFBPaintDevice::unlockDirectFB()
 }
 
 
-void* QDirectFBPaintDevice::memory() const
+void *QDirectFBPaintDevice::memory() const
 {
     QDirectFBPaintDevice* that = const_cast<QDirectFBPaintDevice*>(this);
-    that->lockDirectFB();
+    that->lockDirectFB(DSLF_READ|DSLF_WRITE);
     Q_ASSERT(that->lockedImage);
     return that->lockedImage->bits();
 }
@@ -101,7 +106,7 @@ int QDirectFBPaintDevice::bytesPerLine() const
         // Can only get the stride when we lock the surface
         Q_ASSERT(!lockedImage);
         QDirectFBPaintDevice* that = const_cast<QDirectFBPaintDevice*>(this);
-        that->lockDirectFB();
+        that->lockDirectFB(DSLF_READ);
         Q_ASSERT(bpl != -1);
     }
     return bpl;
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.h b/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.h
index a11064b..1709d69 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.h
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpaintdevice.h
@@ -58,7 +58,7 @@ public:
 
     IDirectFBSurface *directFBSurface() const;
 
-    void lockDirectFB();
+    void lockDirectFB(uint flags);
     void unlockDirectFB();
 
     inline bool forceRasterPrimitives() const { return forceRaster; }
@@ -76,7 +76,9 @@ protected:
           dfbSurface(0),
           lockedImage(0),
           screen(scr),
-          forceRaster(false) {}
+          forceRaster(false),
+          lockFlags(0)
+    {}
 
     inline int dotsPerMeterX() const
     {
@@ -92,6 +94,7 @@ protected:
     QDirectFBScreen *screen;
     int bpl;
     bool forceRaster;
+    uint lockFlags;
 private:
     Q_DISABLE_COPY(QDirectFBPaintDevice)
 };
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
index 14d2146..e9e2b1f 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
@@ -1040,7 +1040,7 @@ void QDirectFBPaintEngine::drawPixmap(const QRectF &r, const QPixmap &pixmap,
         QRasterPaintEngine::drawPixmap(r, pixmap, sr);
     } else if (!d->dfbCanHandleClip(r) || d->matrixRotShear) {
         RASTERFALLBACK(DRAW_PIXMAP, r, pixmap.size(), sr);
-        const QImage *img = static_cast<QDirectFBPixmapData*>(pixmap.pixmapData())->buffer();
+        const QImage *img = static_cast<QDirectFBPixmapData*>(pixmap.pixmapData())->buffer(DSLF_READ);
         d->lock();
         QRasterPaintEngine::drawImage(r, *img, sr);
     } else {
@@ -1066,7 +1066,7 @@ void QDirectFBPaintEngine::drawTiledPixmap(const QRectF &r,
         QRasterPaintEngine::drawTiledPixmap(r, pixmap, sp);
     } else if (!d->dfbCanHandleClip(r) || d->matrixRotShear || !sp.isNull()) {
         RASTERFALLBACK(DRAW_TILED_PIXMAP, r, pixmap.size(), sp);
-        const QImage *img = static_cast<QDirectFBPixmapData*>(pixmap.pixmapData())->buffer();
+        const QImage *img = static_cast<QDirectFBPixmapData*>(pixmap.pixmapData())->buffer(DSLF_READ);
         d->lock();
         QRasterPixmapData *data = new QRasterPixmapData(QPixmapData::PixmapType);
         data->fromImage(*img, Qt::AutoColor);
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp
index ea9bb3a..f7c428b 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp
@@ -357,7 +357,7 @@ QImage QDirectFBPixmapData::toImage() const
     return img->copy();
 }
 
-QPaintEngine* QDirectFBPixmapData::paintEngine() const
+QPaintEngine *QDirectFBPixmapData::paintEngine() const
 {
     if (!engine) {
         // QDirectFBPixmapData is also a QCustomRasterPaintDevice, so pass
@@ -368,10 +368,15 @@ QPaintEngine* QDirectFBPixmapData::paintEngine() const
     return engine;
 }
 
+QImage *QDirectFBPixmapData::buffer()
+{
+    lockDirectFB(DSLF_READ|DSLF_WRITE);
+    return lockedImage;
+}
 
-QImage* QDirectFBPixmapData::buffer()
+QImage * QDirectFBPixmapData::buffer(uint lockFlags)
 {
-    lockDirectFB();
+    lockDirectFB(lockFlags);
     return lockedImage;
 }
 
@@ -381,3 +386,4 @@ void QDirectFBPixmapData::invalidate()
     alpha = false;
     format = QImage::Format_Invalid;
 }
+
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.h b/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.h
index 6cfafcd..697e5ce 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.h
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.h
@@ -69,7 +69,8 @@ public:
                         Qt::TransformationMode mode) const;
     QImage toImage() const;
     QPaintEngine* paintEngine() const;
-    QImage *buffer();
+    virtual QImage *buffer();
+    QImage *buffer(uint lockFlags);
 
     // Pure virtual in QPixmapData, so re-implement here and delegate to QDirectFBPaintDevice
     int metric(QPaintDevice::PaintDeviceMetric m) const {return QDirectFBPaintDevice::metric(m);}
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp
index c1b75c5..9ec5f5f 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.cpp
@@ -1336,12 +1336,12 @@ bool QDirectFBScreen::initSurfaceDescriptionPixelFormat(DFBSurfaceDescription *d
     return true;
 }
 
-uchar *QDirectFBScreen::lockSurface(IDirectFBSurface *surface, DFBSurfaceLockFlags flags, int *bpl)
+uchar *QDirectFBScreen::lockSurface(IDirectFBSurface *surface, uint flags, int *bpl)
 {
     void *mem;
-    const DFBResult result = surface->Lock(surface, flags, static_cast<void**>(&mem), bpl);
+    const DFBResult result = surface->Lock(surface, static_cast<DFBSurfaceLockFlags>(flags), static_cast<void**>(&mem), bpl);
     if (result != DFB_OK) {
-        DirectFBError("QDirectFBPixmapData::lockSurface()", result);
+        DirectFBError("QDirectFBScreen::lockSurface()", result);
     }
 
     return reinterpret_cast<uchar*>(mem);
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h
index 42d0ebe..e91a06b 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbscreen.h
@@ -137,7 +137,7 @@ public:
                                      const QImage &image);
 #endif
 
-    static uchar *lockSurface(IDirectFBSurface *surface, DFBSurfaceLockFlags flags, int *bpl = 0);
+    static uchar *lockSurface(IDirectFBSurface *surface, uint flags, int *bpl = 0);
 
 private:
     void compose(const QRegion &r);
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbsurface.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbsurface.cpp
index beb9b5f..827e10d 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbsurface.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbsurface.cpp
@@ -423,7 +423,7 @@ void QDirectFBSurface::endPaint(const QRegion &)
 }
 
 
-QImage* QDirectFBSurface::buffer(const QWidget *widget)
+QImage *QDirectFBSurface::buffer(const QWidget *widget)
 {
     if (!lockedImage)
         return 0;
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbsurface.h b/src/plugins/gfxdrivers/directfb/qdirectfbsurface.h
index 54c14a5..c554096 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbsurface.h
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbsurface.h
@@ -58,7 +58,7 @@ QT_BEGIN_HEADER
 
 QT_MODULE(Gui)
 
-class QDirectFBSurface: public QWSWindowSurface, public QDirectFBPaintDevice
+class QDirectFBSurface : public QWSWindowSurface, public QDirectFBPaintDevice
 {
 public:
     QDirectFBSurface(DFBSurfaceFlipFlags flipFlags, QDirectFBScreen* scr);
@@ -79,15 +79,15 @@ public:
     QRegion move(const QPoint &offset, const QRegion &newClip);
 
     QImage image() const { return QImage(); }
-    QPaintDevice* paintDevice() { return this; }
-    QPaintEngine* paintEngine() const;
+    QPaintDevice *paintDevice() { return this; }
+    QPaintEngine *paintEngine() const;
 
     void flush(QWidget *widget, const QRegion &region, const QPoint &offset);
 
     void beginPaint(const QRegion &);
     void endPaint(const QRegion &);
 
-    QImage* buffer(const QWidget *widget);
+    QImage *buffer(const QWidget *widget);
 
 private:
 #ifndef QT_NO_DIRECTFB_WM