* Unit test for BF abort after after_command_before_result()

* Revised logic for handling BF abort around after command operations
* Added lighweight thread class for runtime thread id checking

src/test_utils.hpp

@@ -0,0 +1,29 @@
+//
+// Copyright (C) 2018 Codership Oy <info@codership.com>
+//
+
+// Forward declarations
+namespace wsrep
+{
+    class client_context;
+    class mock_server_context;
+}
+
+#include "wsrep/transaction_context.hpp"
+#include "wsrep/provider.hpp"
+
+//
+// Utility functions
+//
+namespace wsrep_test
+{
+
+    // Simple BF abort method to BF abort unordered transasctions
+    void bf_abort_unordered(wsrep::client_context& cc);
+
+    // BF abort method to abort transactions via provider
+    void bf_abort_provider(wsrep::mock_server_context& sc,
+                           const wsrep::transaction_context& tc,
+                           wsrep::seqno bf_seqno);
+
+}