[Digikam-devel] extragear/graphics/digikam/digikam

[Marcel Wiesweg]

SVN commit 567460 by mwiesweg:

Kill the preview ioslave each time properly so that is frees its Shared Memory.

Note: It seems that the usage of Shared Memory is dangerous, 
as the segments are not freed when the application crashes.

BUG: 131277
CCMAIL: digikam-devel at kde.org



 M  +6 -0      imagepreviewjob.cpp  
 M  +19 -5     imagepreviewwidget.cpp  


--- trunk/extragear/graphics/digikam/digikam/imagepreviewjob.cpp #567459:567460
@@ -173,6 +173,12 @@
         stream >> width >> height >> depth;
         preview = QImage(d->shmaddr, width, height, depth,
                          0, 0, QImage::IgnoreEndian);
+
+        // The buffer supplied to the QImage constructor above must remain valid
+        // throughout the lifetime of the object.
+        // This is not true, the shared memory will be freed or reused.
+        // If we pass the object around, we must do a deep copy.
+        preview = preview.copy();
     }
     else
     {
--- trunk/extragear/graphics/digikam/digikam/imagepreviewwidget.cpp #567459:567460
@@ -91,11 +91,11 @@
 
 ImagePreviewWidget::~ImagePreviewWidget()
 {
-    if (!d->previewJob.isNull())
+    if (d->previewJob)
         d->previewJob->kill();
-    
+
     d->blinkPreviewTimer->stop();
-            
+
     delete d;
 }
 
@@ -107,6 +107,9 @@
     d->previewBlink      = false;
     d->blinkPreviewTimer->start(200);
 
+    if (d->previewJob)
+        d->previewJob->kill();
+
     d->previewJob = new ImagePreviewJob(KURL(path), 1024, AlbumSettings::instance()->getExifRotate());
 
     connect(d->previewJob, SIGNAL(signalImagePreview(const KURL&, const QImage&)),
@@ -129,9 +132,16 @@
 void ImagePreviewWidget::slotGotImagePreview(const KURL&, const QImage& preview)
 {
     d->blinkPreviewTimer->stop();
-    d->previewJob = 0;    
     d->preview    = preview;
     d->pixmap     = QPixmap(contentsRect().size());
+
+    // It is very important to kill the thumbnail job properly
+    // so that is frees its shared memory. Otherwise the memory
+    // will _never_ be freed, see b.k.o. #131277
+    if (d->previewJob)
+        d->previewJob->kill();
+    d->previewJob = 0;
+
     updatePixmap();
     repaint(false);
     emit previewComplete();
@@ -140,7 +150,11 @@
 void ImagePreviewWidget::slotFailedImagePreview(const KURL&)
 {
     d->blinkPreviewTimer->stop();
-    d->previewJob = 0;    
+
+    if (d->previewJob)
+        d->previewJob->kill();
+    d->previewJob = 0;
+
     d->preview    = QImage();
     d->pixmap     = QPixmap(contentsRect().size());
     updatePixmap();