Add 3 nodes conflict test.

test/syn_registry_SUITE.erl

@@ -52,7 +52,8 @@
     three_nodes_partial_netsplit_consistency/1,
     three_nodes_full_netsplit_consistency/1,
     three_nodes_start_syn_before_connecting_cluster_with_conflict/1,
-    three_nodes_start_syn_before_connecting_cluster_with_custom_conflict_resolution/1
+    three_nodes_start_syn_before_connecting_cluster_with_custom_conflict_resolution/1,
+    three_nodes_registration_race_condition_custom_conflict_resolution/1
 ]).
 
 %% support
@@ -117,7 +118,8 @@ groups() ->
             three_nodes_partial_netsplit_consistency,
             three_nodes_full_netsplit_consistency,
             three_nodes_start_syn_before_connecting_cluster_with_conflict,
-            three_nodes_start_syn_before_connecting_cluster_with_custom_conflict_resolution
+            three_nodes_start_syn_before_connecting_cluster_with_custom_conflict_resolution,
+            three_nodes_registration_race_condition_custom_conflict_resolution
         ]}
     ].
 %% -------------------------------------------------------------------
@@ -847,6 +849,42 @@ three_nodes_start_syn_before_connecting_cluster_with_custom_conflict_resolution(
     true = rpc:call(SlaveNode1, erlang, is_process_alive, [Pid1]),
     true = rpc:call(SlaveNode2, erlang, is_process_alive, [Pid2]).
 
+three_nodes_registration_race_condition_custom_conflict_resolution(Config) ->
+    ConflictingName = "COMMON",
+    %% get slaves
+    SlaveNode1 = proplists:get_value(slave_node_1, Config),
+    SlaveNode2 = proplists:get_value(slave_node_2, Config),
+    %% use customer handler
+    syn_test_suite_helper:use_custom_handler(),
+    rpc:call(SlaveNode1, syn_test_suite_helper, use_custom_handler, []),
+    rpc:call(SlaveNode2, syn_test_suite_helper, use_custom_handler, []),
+    %% start syn on nodes
+    ok = syn:start(),
+    ok = rpc:call(SlaveNode1, syn, start, []),
+    ok = rpc:call(SlaveNode2, syn, start, []),
+    timer:sleep(500),
+    %% start processes
+    Pid0 = syn_test_suite_helper:start_process(),
+    Pid1 = syn_test_suite_helper:start_process(SlaveNode1),
+    Pid2 = syn_test_suite_helper:start_process(SlaveNode2),
+    %% inject into syn to simulate concurrent registration
+    ok = rpc:call(SlaveNode1, syn_registry, add_to_local_table, [ConflictingName, Pid1, keep_this_one, undefined]),
+    %% register on master node to trigger conflict resolution
+    ok = syn:register(ConflictingName, Pid0, node()),
+    timer:sleep(1000),
+    %% retrieve
+    true = lists:member(syn:whereis(ConflictingName), [Pid0, Pid1, Pid2]),
+    true = lists:member(rpc:call(SlaveNode1, syn, whereis, [ConflictingName]), [Pid0, Pid1, Pid2]),
+    true = lists:member(rpc:call(SlaveNode2, syn, whereis, [ConflictingName]), [Pid0, Pid1, Pid2]),
+    %% check metadata that we kept the correct process on all nodes
+    {Pid1, keep_this_one} = syn:whereis(ConflictingName, with_meta),
+    {Pid1, keep_this_one} = rpc:call(SlaveNode1, syn, whereis, [ConflictingName, with_meta]),
+    {Pid1, keep_this_one} = rpc:call(SlaveNode1, syn, whereis, [ConflictingName, with_meta]),
+    %% check that other processes are still alive because we didn't kill them
+    true = is_process_alive(Pid0),
+    true = rpc:call(SlaveNode1, erlang, is_process_alive, [Pid1]),
+    true = rpc:call(SlaveNode2, erlang, is_process_alive, [Pid2]).
+
 %% ===================================================================
 %% Internal
 %% ===================================================================