JobQueue deadlocks

Problem
-------

The JobQueue holds the lock while executing jobs.  A job must be free
to acquire any lock including the JobQueue lock to avoid deadlocks.

Solution
--------

Release the lock before executing jobs.

dds/DCPS/JobQueue.cpp

@@ -27,15 +27,17 @@ int JobQueue::handle_exception(ACE_HANDLE /*fd*/)
   ThreadStatusManager::Event ev(thread_status_manager);
 
   Queue q;
+  {
+    ACE_GUARD_RETURN(ACE_Thread_Mutex, guard, mutex_, -1);
+    q.swap(job_queue_);
+  }
 
-  ACE_Reverse_Lock<ACE_Thread_Mutex> rev_lock(mutex_);
-  ACE_GUARD_RETURN(ACE_Thread_Mutex, guard, mutex_, -1);
-  q.swap(job_queue_);
   for (Queue::const_iterator pos = q.begin(), limit = q.end(); pos != limit; ++pos) {
     ThreadStatusManager::Event event(thread_status_manager);
     (*pos)->execute();
   }
 
+  ACE_GUARD_RETURN(ACE_Thread_Mutex, guard, mutex_, -1);
   if (!job_queue_.empty()) {
     guard.release();
     reactor()->notify(this);