Bug 552568

Description Ansgar Radermacher 2019-10-30 11:10:50 EDT

In more complex diagrams with SVG shapes, Eclipse sometimes crashes with the error message.
cairo-surface.c:955: cairo_surface_destroy: Assertion  `CAIRO_REFERENCE_COUNT_HAS_REFERENCE (&surface->ref_count)' failed.

This error has been reported in the context of SWT earlier (see bug 544501), but is probably a GMF-runtime issue.
The class RenderHelper from GMF creates new images via getSWTImage in a rendering thread. The code of this method shown below disposes an eventual existing image - this could only happen, if another thread calls getSWTImage on the same image at the same time - in this case "dispose" could be called twice.

in oe.gmf.runtime.draw2d.ui.render.internal.AbstractRenderedImage:

final public Image getSWTImage() {
    if (img != null)
        return img;

    Image image = renderImage();   [calls SVGImage.renderImage in our case]
    if (img != null && !img.isDisposed()) {
        img.dispose();
     }
     img = image;
     return img;
}

The issue does not happen any more, if the method getSWTImage is tagged as "synchronized" (in this case the 2nd (img != null) check and eventual removal can be removed, as img is always null).