If unlocking the acceptor during AprEndpoint shutdown fails, it enters an infinite loop, printing endpoint.warn.unlockAcceptorFailed message (Acceptor thread [{0}] failed to unlock. Forcing hard socket shutdown.) It was reported on users@ mailing lists, http://tomcat.markmail.org/thread/xo2jolyr44ijuu34 It might be caused by a firewall preventing Tomcat from connecting to its own HTTP port. I can reproduce it if I turn the unlockAccept() method in endpoint into an noop (e.g. by adding "if(true){ return; }"), both in 6.0 and in trunk. In 6.0 this bug was introduced in r1065945 and affects 6.0.32 and 6.0.33.
Fixed in trunk and 7.0, will be in 7.0.23. Proposed for 6.0.
Fixed in 6.0.x and will be included in 6.0.34 onwards (r1186001).