HandlerFactory fails with multithreaded implementation
------------------------------------------------------
Key: DROIDS-68
URL: https://issues.apache.org/jira/browse/DROIDS-68
Project: Droids
Issue Type: Bug
Components: core
Environment: Ubuntu 9.04 i386
Java Runtime 1.6_16
Reporter: Javier Puerto
Priority: Critical
Hi, I'm working with Droids and made some URL crawlers to save a lot of web
pages in disk. In JUnit test, I run a little http server and crawl 20 pages,
the most times everything works ok but in rare cases I get an error. I found
the problem in the HandlerFactory implementation, in the example the call to
handlers is like this:
protected void handle(ContentEntity entity, Link link)
throws DroidsException, IOException
{
droid.getHandlerFactory().handle(link.getURI(), entity);
}
If two or more workers is trying to handle at same time, the HandlerFactory
will handle with the same instance. The solution could be saving memory or
improving performance.
The first solution could be implemented adding a "synchronized" to
HandlerFactory.handle like this.
public synchronized boolean handle(URI uri, ContentEntity entity)
throws DroidsException, IOException {
for (Handler handler : getMap().values()) {
handler.handle(uri, entity);
}
return true;
}
This solution works but it is a workaround.
The real solution was discussed in the dev list and it was make the Droid and
the GenericFactory abstractions clonable and invoking the clone method in the
Worker's constructor.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
