Major Description
if you obtain the NativeFSLock and try to obtain it again in the same JVM and close if if it fails another process will be able to obtain it. This is pretty trappy though. If you execute the main class twice the problem becomes pretty obvious.
import org.apache.lucene.store.Lock;
import org.apache.lucene.store.NativeFSLockFactory;
import java.io.File;
import java.io.IOException;
public class TestLock {
public static void main(String[] foo) throws IOException, InterruptedException {
NativeFSLockFactory lockFactory = new NativeFSLockFactory(new File("/tmp"));
Lock lock = lockFactory.makeLock("LOCK");
if (lock.obtain()) {
System.out.println("OBTAINED");
} else {
lock.close();
System.out.println("FAILED");
}
// try it again and close it if it fails
lock = lockFactory.makeLock("LOCK"); // <<<<==== this is a new lock
if (lock.obtain()) {
System.out.println("OBTAINED AGAIN");
} else {
lock.close(); // <<<<==== this releases the lock we obtained
System.out.println("FAILED on Second");
}
Thread.sleep(Integer.MAX_VALUE);
}
}