There are times where the PTC pluging becomes permanently locked when it will not release the thread, if a server restart happens at the same time.

What we do is if we are polling on the scm, or checking out new files and the server is restarted the Http request might never return, causing that thread to be permanently locked.

Once these threads are locked the can never be killed unless the jenkins server is fully restarted.

A proposed solution would be to add a time out (even if it is 60 minutes) that would allow the sockets to eventually release and allow the server to move along.

If you need more information let me know. I would eb glad to help.