Normally, the pattern I use is to create a separate class that
implements Runnable or Callable. Not sure if your use of an inline
anonymous class inside the WOComponent has anything to do with your
problem.... I just don't know since I don't use that pattern for
threads. Might be worth refactoring the threaded code into a separate
class...
On Aug 4, 2008, at 9:53 PM, Jeff Schmitz wrote:
Sure, here's how the thread is kicked off. updateResultsThread and
updateResults are both functions in the Component class.
public void updateResultsThread(final int winCmd) {
t = new Thread("updateResults") {
public void run() {
updateResults(winCmd);
}
};
t.start();
}
and here is everything in the updateResults function that occurs up
to the exception occuring:
public void updateResults(int winCmd) {
/* Provide the thread with its own access layer stack. */
EOObjectStoreCoordinator parentObjectStore = new
EOObjectStoreCoordinator();
EOEditingContext threadEditingContext = new
EOEditingContext(parentObjectStore);
//EOObjectStoreCoordinator rootObjectStore =
(EOObjectStoreCoordinator
)Session().defaultEditingContext().rootObjectStore();
try {
threadEditingContext.lock();
NSArray <Pool> pools =
Pool.fetchStandardPoolsByName(threadEditingContext);
There is a ton of other stuff that occurs after this point, but the
execution never gets that far.
Thanks!
Jeff
On Aug 4, 2008, at 6:20 AM, Kieran Kelleher wrote:
This may be just a trivial coding sequence problem Jeff.
Why not post your whole Runnable (or Callable) class so we can see
what you are doing ?
On Aug 4, 2008, at 12:01 AM, Jeff Schmitz wrote:
Hello,
Continuing on with trying to access EOs in a background thread,
I'm trying to give the background thread its own
EOObjectStoreCoordinator. To create a new
EOObjectStoreCoordinator, I'm using the following code:
EOObjectStoreCoordinator parentObjectStore = new
EOObjectStoreCoordinator();
EOEditingContext threadEditingContext = new
EOEditingContext(parentObjectStore);
However, when I try to fetch something into the
threadEditingContext using one of the static "fetch" functions, I
get an error:
INFO er.transaction.adaptor.Exceptions - Database Exception
occured: java.lang.IllegalStateException: Attempt to access an EO
that has either not been inserted into any EOEditingContext or its
EOEditingContext has already been disposed
Exception in thread "updateResults"
java.lang.IllegalStateException: Attempt to access an EO that has
either not been inserted into any EOEditingContext or its
EOEditingContext has already been disposed
at
com
.webobjects.eocontrol.EOCustomObject.willRead(EOCustomObject.java:
1158)
I kind of thought the static fetch operations were a way to insert
objects into EC's in the first place, so I'm a little confused
about the error. Is there something extra I need to do because
its not the default editing context?
below is more info on the fetch call I'm making if you'd want to
take a look. This is what I do after creating the
threadEditingContext...
try {
threadEditingContext.lock();
EOQualifier poolQual = Pool.POOL_TYPE.eq(Constants.FULLPOOL);
NSArray<EOSortOrdering> poolOrder = new NSArray<EOSortOrdering>(
new EOSortOrdering(Pool.NAME_KEY,
EOSortOrdering.CompareAscending)); // Sort
return Pool.fetchPools(threadEditingContext, poolQual, poolOrder);
// Below is the fetchPools function generated by the EOGenerator:
public static NSArray<Pool> fetchPools(EOEditingContext
editingContext, EOQualifier qualifier, NSArray<EOSortOrdering>
sortOrderings) {
EOFetchSpecification fetchSpec = new
EOFetchSpecification(_Pool.ENTITY_NAME, qualifier, sortOrderings);
fetchSpec.setIsDeep(true);
NSArray<Pool> eoObjects =
(NSArray
<Pool>)editingContext.objectsWithFetchSpecification(fetchSpec);
return eoObjects;
}
The error actually occurs on:
NSArray<Pool> eoObjects =
(NSArray
<Pool>)editingContext.objectsWithFetchSpecification(fetchSpec);
On Jul 30, 2008, at 8:25 AM, Kieran Kelleher wrote:
I have an app that does very long tasks like this a few times a
week. The tasks I have a *very* EOF intensive, as in hammering
the database usually for a very long time (4 to 24 hours)
Here is approach I use:
Create a Callable (or Runnable) class for the task.
Create setters/getters for any initial variables you need to pass
in. For EnterpriseObjects, just pass in the EOGlobalIDs, not the
objects themselves.
In the task method itself:
- Create a new ObjectStoreCoordinator (use Wonder OSC
synchronization if you want changes to propogate)
- Create any editing contexts using that single task OSC as a
parent
- lock and unlock your ec's manually when working with them
- depending on how much EO's you are fiddling with, memory
management can be challenging, so recycling ec's, and, dare I say
it, resorting to checking available memory and forcing garbage
collection when memory almost exhausted (some will cringe at
this, but extreme EOF just sucks memory and does not let go fast
enough ... depending on the conditions)
Tips
- Surround the task with a try/catch to get any errors
- Send an email to the user (if user initiated), or admin (if
necessary) notifying them of success, failure or error when task
is done (or error is thrown).
- Using log4j smtp appender for ERROR level is good too to
ensure errors in anonymous tasks are alerted to admin/devs
promptly.
On Jul 30, 2008, at 12:23 AM, Jeff Schmitz wrote:
Hello,
I have the need to kick off a VERY long (i.e. possibly up to
8-10 hour) background task that before it's through fetches most
of the contents of the database (via EO's of course) and
performs calculations on the data and saves the calculated
values back to the EOs many times during the process. And oh,
I'd like to have the results available to the rest of my app as
they are saved by the background task.
Currently btw, I do this with a java thread and don't really use
EOs, and I just return a page immediately after the thread is
kicked off, i.e. I don't really care about a status page
reloading for 8 hours as I'm the only user that actually kicks
off this process.
My first question is, now that I'm using EOs throughout my app
(including the background process) is there any reason to use
the WOLongResponsePage if I still don't care about the status
page? If so, there seems to be a dearth of information on
exactly how to use such a component. All I can really find is a
very terse API doc, and a few mentions of its existance on the
wiki. Any examples out there anywhere?
I'll save my context locking and memory flushing questions until
after I've researched the subject a little more. From what I
can tell though, I'll want to create a new editing context for
the background thread (not sure about needing an independent
Object store coordinator for the background process, but I don't
think so), so that's a start.
Finally, anything in project Wonder that can help me? I did run
across this:
http://webobjects.mdimension.com/wonder/api/er/extensions/concurrency/class-use/ERXLongResponseTask.html#er.extensions.concurrency
but again, very terse docs.
Thanks,
Jeff
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