I have a question about threads in UIMA. My application ("Main thread") starts
an UIMA Collection Processing Engine (CPE), which contains a Collection-Reader
and several Annotators. Here is my code for starting the CPE:
public class UimaRunCPE extends Thread {
/**
* The CPE instance.
*/
private CollectionProcessingEngine mCPE;
public void runCPE() throws Exception {
// parse CPE descriptor
CpeDescription cpeDesc = UIMAFramework.getXMLParser().parseCpeDescription(
new XMLInputSource(pathToDescriptor));
// instantiate CPE
mCPE = UIMAFramework.produceCollectionProcessingEngine(cpeDesc);
// Create and register a Status Callback Listener
mCPE.addStatusCallbackListener(new StatusCallbackListenerImpl());
// Start Processing
mCPE.process();
System.out.println("CPE ended\n");
}
}
As I understand it (I stepped thru it in debug-mode in Eclipse), the CPE works
like this -
--
1. all the Annotator.initialize()'s are done in "Main thread"
2. when mCPE.process() is called, these threads are created---
BaseCPMImpl-Thread
CPMEngine Thread
Processing Pipeline#1 Thread
3. the Collection-Reader runs in its own thread
4. the Annotator.process() methods run in the Processing Pipeline#1 Thread
5. when all Annotators are done, Processing Pipeline#1 Thread and CPMEngine
Thread go away. Control goes to
BaseCPMImpl-Thread.collectionProcessComplete(). When that's done, all
processing is over.
My problem is this: in Main-thread, mCPE.process() returns right away; it does
not wait around to make sure that the CPE finished OK. I need a way to do
that. It would work if Main-thread could do a join() on BaseCPMImpl-Thread,
but I don't see any way to do that.
Any ideas?
