Hi Mario,
Ah, I can see that I was behind a bit in my emails.
The question I still have is why the loops can be null while valid
pipelines are installed?
The SG2D starts life with invalid pipes installed, which means that
*ALL* graphics operations get vectored through a validate process before
any work is done. Since no pipeline operation objects are installed at
that point (i.e. all pipeline fields in SG2D have a reference to an
InvalidPipe instance installed in them), then no references to loops can
occur. When the InvalidPipe methods are invoked it validates the SG2D,
which both installs real pipelines and fills in the loops member, and
then reinvokes on the new pipelines - which should be OK since the loops
field should have been installed by then. So, some other bug must
exist, one of:
- Some validatePipe implementation in some SurfaceData class is
installing a loop-based pipeline without initializing the loops
- Some code is calling a method on a loop-based pipeline that it did not
get from the SG2D itself (i.e. it got it from a different SG2D, but
invoked it on this SG2D - or it had a static reference to a pipeline
object and just invoked it directly rather than invoking the one that
was installed on the SG2D it is using). All calls to pipeline objects
should be using the paradigm of "sg2d.fooPipe.Render(sg2d, ...)".
- A race condition where thread A is validating the pipeline and
installs the pipeline objects but hasn't yet reached the code to install
the loops while thread B starts rendering using that SG2D thus invoking
an operation on a partially initialized pipeline - in this case the NPE
is appropriate and allowed since we don't support multi-threaded use of
the Graphics2D objects.
...jim
Mario Torre wrote:
Il giorno ven, 12/06/2009 alle 18.41 -0700, Phil Race ha scritto:
Mario,
Did you, or can you, share a test case (and any platform specific info
needed) to repro this?
-phil.
Hi Phil!
I think I didn't explained myself very well :)
The purpose of my change is to remove the line of code that initialises
the loops from the constructor:
@@ -254,11 +254,10 @@
font = f;
if (font == null) {
font = defaultFont;
}
- loops = sd.getRenderLoops(this);
setDevClip(sd.getBounds());
invalidatePipe();
}
protected Object clone() {
The reason I want to do this is to avoid a reference to "this"
to be passed to an external class because SG2D may not be fully initialised,
and I would say that this is at least non nice :)
As for the NPE, I was referring to the fact that just removing the call to
sd.getRenderLoops(this) (which is, again, what I want to do), leaves the loops
uninitialised. This happens in the Java2D demo, for example, because validate
is not called in all the cases as the first thing.
A solution could be to put a check for null in checkFontInfo, like Jim
suggested,
because this is called before validate.
I'll prepare a test case for this issue based on the J2D demo,
but of course it's only useful to show the NPE if you remove the
sd.getRenderLoops(this) line from the constructor.
I hope this clarifies a bit my idea.
Cheers,
Mario
