All MGraphs returned by TcManager are LockableMgraphs, this graphs are
thread-safe independently on whether the underlying provider is
thread-safe or not. Note however that like the synchronized
collections returned by java.util.Collections a
ConcurrentModificationException may occur when the TripleCollection is
modified while iterating over it. To be sure that no other thread may
do any modification while iterating over it, the iterating thread may
acquire a ReadLock using the following construct:
Lock l = mGraph.getLock().readLock();
l.lock();
try {
Iterator<Triple> iter = mGraph.filter(...);
//iterate over triples
} finally {
l.unlock();
}
Note that single method invocations always lock the TripleCollection, but if you need a lock to span multiple method invocation you need to acquire a (read or write) lock as described above.
