[SSHD-123] TcpipForward race condition & deadlock on client disconnect.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.3.0, 0.5.0, 0.6.0
• Fix Version/s: 0.7.0
• Environment: I am able to reproduce this every single time on my quad core windows 7 machine.
• Assignee: Guillaume Nodet
• Reporter: Bill Kuker
• Created: 21/Apr/11 13:03
• Updated: 21/May/12 14:09
• Resolved: 21/May/12 14:09

Description

If a client with an active remote port forward disconnects at about the same time a new connection comes in to that port forward two NioProcessor threads end up deadlocked in TcpipForwardSupport, at the following spots:

NioProcessor-14 stuck at org.apache.sshd.server.session.TcpipForwardSupport.sessionCreated(...):
OpenFuture future = channel.open().await();

NioProcessor-2 stuck at org.apache.sshd.server.session.TcpipForwardSupport.close():
acceptor.dispose();

It appears that the new connection to the port forward is trying to create a new channel over a session that is currently trying to close. Both threads end up waiting on different objects, and are never notified.