@edu.umd.cs.findbugs.annotations.SuppressWarnings(value = "IS2_INCONSISTENT_SYNC",
      justification = "Presume the lock on processing request held by caller is protection enough")
  @Override
  public void done() {
    super.done();
    this.getConnection().decRpcCount(); // Say that we're done with this call.
  }
Call is done. Execution happened and we returned results to client. It is now safe to cleanup.
hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/SimpleServerCall.java