Android Live Wallpaper: waitForCondition(ReallocateCondition)

Question

I've been developing a live wallpaper using GLWallpaperService, and have gotten good results overall. It runs rock-solid in the emulator and looks good. I've dealt with OpenGL many times before so have a solid command of how to do things... unfortunately I'm having a hell of a time getting this to actually be stable on the actual hardware.

The basic symption occurs when you slide the physical keyboard on a Motorola Droid in and out a few times. This causes the wallpaper to get destroyed/recreated several times in quick succession -- which would be fine, as I have my assets clearing in onDestroy and reloading in onSurfaceChanged. The problem is after a few iterations of this, (four or five, maybe) the calls to onSurfaceChanged completely stop, and i get an endless string of this printed to the log:

04-02 00:53:18.088: WARN/SharedBufferStack(1032): waitForCondition(ReallocateCondition) timed out (identity=337, status=0). CPU may be pegged. trying again.

Is there something I should be implementing here aside from the Android-typical onSurfaceCreated/onSurfaceChanged/onSurfaceDestroyed triumvirate? Browsing through the WallpaperService and WallpaperRenderer classes doesn't pop up anything obvious to me.

Answer 1

I had a similar problem. The error was that I needed to call to "unlockCanvasAndPost":

        Canvas c = null;
    **try {**
            c = holder.lockCanvas(null);
            synchronized (holder) {
                instance.doDraw(c);
            }
        **} finally {
            // do this in a finally so that if an exception is thrown
            // during the above, we don't leave the Surface in an
            // inconsistent state
            if (c != null) {
                holder.unlockCanvasAndPost(c);
            }
        }**