On 05/02/14 21:19, Jean-Marc Vanel wrote:
In fact, isInTransaction() returns false
( because ThreadLocal returns setInitialValue() ) ,
so there must be something broken in the TDB dataset .
isInTransaction returning true means that the current thread is in a
transaction, not that there is some other somewhere else in a
transaction on the same dataset.
TDB is single writer AND multiple reader. writers get queued on the
lock you are seeing so my best guess is that another thread has started
a write transaction and not committed or aborted it (hence the resources
style suggestion in the API documentation using finally)
Andy
2014-05-02 21:26 GMT+02:00 Andy Seaborne <a...@apache.org>:
On 02/05/14 18:48, Jean-Marc Vanel wrote:
Yes , it can be the case that another thread is accessing the dataset.
From what you write, and the doc.:
https://jena.apache.org/documentation/tdb/tdb_transactions.html
I understand that the kind of access that can be the cause of this
transaction not opening is
a write transaction not closed in another thread.
Yes - it's waiting on the writer transaction lock.
I have a suspect in my app code,
but is there a way to know at runtime the status of a dataset regarding
transactions ?
with more detail like the thread than :
public boolean isInTransaction() ;
There isn't another way but isInTransaction() is backed by a ThreadLocal
so it does tell you the state from the thread viewpoint.
Andy
2014-05-02 18:20 GMT+02:00 Andy Seaborne <a...@apache.org>:
Hi,
Do you have a complete, minimal example?
I built a test from the details below and it works so maybe it something
related but not shown here.
The other thing to consider is whether any other thread is accessing the
dataset.
Andy
On 02/05/14 14:15, Jean-Marc Vanel wrote:
Hi
I'm trying to delete a whole named graph.
The code:
try {
Dataset dataset = TDBFactory.createDataset(
directory.getAbsolutePath());
UpdateProcessor qexec = UpdateExecutionFactory.create(request,
GraphStoreFactory.create( dataset ) );
dataset.begin( ReadWrite.WRITE ); // frozen here !!!!!!
qexec.execute();
dataset.commit();
}
The SPARQL :
WITH <file:/home/jmv/ontologies/unspsc84-title.rdfs.n3>
DELETE { ?subject ?property ?value }
WHERE { ?subject ?property ?value }
The stack when suspending in debugger:
Daemon Thread [SwingWorker-pool-4-thread-1] (Suspended)
Unsafe.park(boolean, long) line: not available [native method]
LockSupport.park(Object) line: 186
Semaphore$FairSync(AbstractQueuedSynchronizer).parkAndCheckInterrupt()
line: 834
Semaphore$FairSync(AbstractQueuedSynchronizer).
doAcquireSharedInterruptibly(int)
line: 994
Semaphore$FairSync(AbstractQueuedSynchronizer).
acquireSharedInterruptibly(int)
line: 1303
Semaphore.acquire() line: 317
TransactionManager.begin(ReadWrite, String) line: 306
TransactionManager.begin(ReadWrite) line: 287
StoreConnection.begin(ReadWrite) line: 103
DatasetGraphTransaction._begin(ReadWrite) line: 155
DatasetGraphTransaction(DatasetGraphTrackActive).begin(ReadWrite) line:
42
DatasetImpl.begin(ReadWrite) line: 125
Jena:
<dependency>
<groupId>org.apache.jena</groupId>
<artifactId>apache-jena-libs</artifactId><version>2.11.1</
version>
<type>pom</type>
</dependency>
The system:
% uname -a
Linux oem-laptop 3.11.0-20-generic #34-Ubuntu SMP Tue Apr 1 20:40:25 UTC
2014 x86_64 x86_64 x86_64 GNU/Linux
% java -version
java version "1.7.0_51"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode)
For more details, I'll be on IRC #jena .
