Bug report, Beta 2.12 Standard Edition

Question

Bug report: redundant, confusing, and apparently erroneous calls to
jdoPreClear
and jdoPostLoad. Note in output the null name in the third iteration.
Hi,
A lot of information being sent. Sorry, but I think you'll find it
helpful. I expected the exact same sequence of calls to jdoPreClear
and jdoPostLoad on the 2nd and third iteration. In fact, since,
retain values is true, and no changes are being made, I expected that
jdoPreClear and jdoPostLoad would not be called at all on the 2nd and
3rd iteration.
David Ezzio
Using 2.12 Beta, standard edition
Business method uses one PM. Configured to datastore transaction,
retainValues == true, non-TR == false, and non-TW == false.
The business methods open a transaction and leave it open.
The client calls commitTransaction() to close the open
transaction.
Two persistent objects, Widget and Box. Each implement
InstanceCallbacks and put out a message in jdoPreClear ("will be
made hollow") and in jdoPostLoad ("has been made persistent-clean").
The Widget has a reference to its Box. The number in parenthesis
is the sequence number obtained from the object ID.
Business methods implementation:
public ArrayList getWidgetsByName(String name)
Transaction trans = pm.currentTransaction();
if (!trans.isActive())
trans.begin();
Collection c = (Collection) widgetsByOneName.execute(name);
ArrayList aList = new ArrayList(c);
widgetsByOneName.close(c);
return aList;
public void commitTransaction()
Transaction trans = pm.currentTransaction();
if (trans.isActive())
trans.commit();
Output: from three loops that:
call findWidgetsByName("Maxi-Widget")
list the widgets returned
call commitTransaction()
finding Maxi-Widgets ...
Widget Maxi-Widget (650) has been made persistent-clean
Box Large (652) has been made persistent-clean
Widget Maxi-Widget (650): Box Large (652) at location Top Shelf
Widget Maxi-Widget (709) has been made persistent-clean
Box Large (710) has been made persistent-clean
Widget Maxi-Widget (709): Box Large (710) at location Middle Shelf
Widget Maxi-Widget (708) has been made persistent-clean
Box Large (713) has been made persistent-clean
Widget Maxi-Widget (708): Box Large (713) at location Top Shelf
Widget Maxi-Widget (700) has been made persistent-clean
Box Large (717) has been made persistent-clean
Widget Maxi-Widget (700): Box Large (717) at location Top Shelf
Widget Maxi-Widget (707) has been made persistent-clean
Box Large (716) has been made persistent-clean
Widget Maxi-Widget (707): Box Large (716) at location Top Shelf
Finding them again
finding Maxi-Widgets ...
Widget Maxi-Widget (650) will be made hollow
Widget Maxi-Widget (650): Box Large (652) at location Top Shelf
Widget Maxi-Widget (709) will be made hollow
Widget Maxi-Widget (709): Box Large (710) at location Middle Shelf
Widget Maxi-Widget (708) will be made hollow
Widget Maxi-Widget (708): Box Large (713) at location Top Shelf
Widget Maxi-Widget (700) will be made hollow
Widget Maxi-Widget (700): Box Large (717) at location Top Shelf
Widget Maxi-Widget (707) will be made hollow
Widget Maxi-Widget (707): Box Large (716) at location Top Shelf
Finding them yet again
finding Maxi-Widgets ...
Widget null (650) will be made hollow
Widget Maxi-Widget (650) has been made persistent-clean
Widget Maxi-Widget (650): Box Large (652) at location Top Shelf
Widget null (709) will be made hollow
Widget Maxi-Widget (709) has been made persistent-clean
Widget Maxi-Widget (709): Box Large (710) at location Middle Shelf
Widget null (708) will be made hollow
Widget Maxi-Widget (708) has been made persistent-clean
Widget Maxi-Widget (708): Box Large (713) at location Top Shelf
Widget null (700) will be made hollow
Widget Maxi-Widget (700) has been made persistent-clean
Widget Maxi-Widget (700): Box Large (717) at location Top Shelf
Widget null (707) will be made hollow
Widget Maxi-Widget (707) has been made persistent-clean
Widget Maxi-Widget (707): Box Large (716) at location Top Shelf
-- All done!

Answer 1

Due to better understanding on my part, and the fixes in Beta 2.2, the
issues raised in this thread are put to rest.
Abe White wrote:
>
We'll investigate further. Stay tuned...
"David Ezzio" <[email protected]> wrote in message
news:[email protected]..
Abe,
Actually, it doesn't make sense. The first iteration shows
jdoPostLoad is called just prior to using the fields of Widget and Box.
After the commit, the instances are not cleared. So far, so good.
In the second iteration, we see that jdoPreClear is called, but
jdoPostLoad is not called. Yet the values are there for use during the
call to Widget.toString() and Box.toString() within the iteration. How
did that happen?
On the third iteration, now the value of name is null, but last we
looked it was available in the second iteration. Other than that, I
agree that the third iteration looks ok, since it is being cleared and
loaded prior to use. But in the jdoPreClear, the values should be there
since the values were used in the previous iteration and are not cleared
at transaction commit due to retainValues == true.
David
Abe White wrote:
David --
I believe the behavior you are seeing to be correct. Section 5.6.1 of
the
JDO spec outlines the behavior of persistent-nontransactional instancesused
with data store transactions. As you can see, persistentnon-transactional
instances are cleared when they enter a transaction; thus the calls to
jdoPreClear. When the default fetch group is loaded again (like whenyou
access the name of the widget) a call to jdoPostLoad is made.
You are seeing the name of one instance as 'null' in the third iterationof
your loop because the instance has been cleared in the second iteration,and
the jdoPreClear method is not modified by the enhancer (see section10.3).
Make sense?