ConfigDef.parseType deadlock

hi,
the problem was found, when I restarted ConnectDistributed

I restart ConnectDistributed in the single node for the test, with not delete connectors.
sometimes the process stopped when creating connectors.

I add some logger and found it had a deadlock in `ConfigDef.parseType`.My connectors always have the same transforms. I guess when connector startup (in startAndStopExecutor which default 8 threads) and load the same class file it has something wrong.

I attached the jstack log file.

thanks for any help.