#476 Deadlock at shutdown

[Kelvin Edmison]

The java process is deadlocked in shutdown.

I tried killing it using ctrl-C initially, then proceeded with various other signals to both the davmail.sh process and to the java process.

A thread dump is attached, showing a deadlock between an ImapConnection thread and a Shutdown thread.

This was created on CentOS 6 x86_64, using davmail-linux-x86_64-4.1.0-2042

[Kelvin Edmison]

Thread dump showing deadlock

[Mickael Guessant]

A simple way to avoid this would be to patch MultiThreadedHttpConnectionManager.shutdownAll and synchronize REFERENCE_TO_CONNECTION_SOURCE only locally:

synchronized (REFERENCE_TO_CONNECTION_SOURCE) {
REFERENCE_TO_CONNECTION_SOURCE.clear();
}

[Mickael Guessant]

Another question: is this always reproducible ?

[Mickael Guessant]

Fix available in trunk

[Mickael Guessant]

Released in 4.8.6