[HBASE-7434] Use generics appropriately in RPCEngine and reduce casts, with fixing a related bug of breaking thread-safety in HConnectionManager

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.95.1
• Assignee: Hiroshi Ikeda
• Reporter: Hiroshi Ikeda
• Created: 25/Dec/12 05:48
• Updated: 23/Sep/13 19:08
• Resolved: 24/Apr/13 05:11

Description

In RpcEngine,

  VersionedProtocol getProxy(Class<? extends VersionedProtocol> protocol, ...)

should be

  <T extends VersionedProtocol> T getProxy(Class<T> protocol, ...)

Also, while removing casts I encountered a bug of the method HConnectionManager.HConnectionImplementation.getProtocol() using broken logic just like double-checked locking for HashMap.