Add registration checks.

src/syn_backbone.erl

@@ -66,16 +66,21 @@ find_by_pid(Pid) ->
         _ -> undefined
     end.
 
--spec register(Key :: any(), Pid :: pid()) -> ok | {error, key_taken}.
+-spec register(Key :: any(), Pid :: pid()) -> ok | {error, already_taken}.
 register(Key, Pid) ->
-    %% add to table
-    mnesia:dirty_write(#syn_processes_table{
-        key = Key,
-        pid = Pid,
-        node = node()
-    }),
-    %% link
-    gen_server:call(?MODULE, {link_process, Pid}).
+    case find_by_key(Key) of
+        undefined ->
+            %% add to table
+            mnesia:dirty_write(#syn_processes_table{
+                key = Key,
+                pid = Pid,
+                node = node()
+            }),
+            %% link
+            gen_server:call(?MODULE, {link_process, Pid});
+        _ ->
+            {error, already_taken}
+    end.
 
 %% ===================================================================
 %% Callbacks

test/syn_create_mnesia_SUITE.erl

@@ -144,11 +144,11 @@ end_per_group(two_nodes_mnesia_creation, Config) ->
     %% get slave node name
     SlaveNodeName = proplists:get_value(slave_node_name, Config),
     %% clean
-    clean_after_test(SlaveNodeName),
+    syn_test_suite_helper:clean_after_test(SlaveNodeName),
     %% stop slave
     syn_test_suite_helper:stop_slave(SlaveNodeName);
 end_per_group(_GroupName, _Config) ->
-    clean_after_test().
+    syn_test_suite_helper:clean_after_test().
 
 %% ===================================================================
 %% Tests
@@ -198,6 +198,7 @@ two_nodes_when_mnesia_is_ram(Config) ->
     %% start
     ok = syn:start(),
     ok = rpc:call(SlaveNodeName, syn, start, []),
+    timer:sleep(100),
     %% check table exists on local
     true = lists:member(syn_processes_table, mnesia:system_info(tables)),
     %% check table exists on remote
@@ -213,6 +214,7 @@ two_nodes_when_mnesia_is_opt_disc_no_schema_exists(Config) ->
     %% start
     ok = syn:start(),
     ok = rpc:call(SlaveNodeName, syn, start, []),
+    timer:sleep(100),
     %% check table exists on local
     true = lists:member(syn_processes_table, mnesia:system_info(tables)),
     %% check table exists on remote
@@ -230,6 +232,7 @@ two_nodes_when_mnesia_is_opt_disc_schema_exists(Config) ->
     %% start
     ok = syn:start(),
     ok = rpc:call(SlaveNodeName, syn, start, []),
+    timer:sleep(100),
     %% check table exists on local
     true = lists:member(syn_processes_table, mnesia:system_info(tables)),
     %% check table exists on remote
@@ -247,28 +250,9 @@ two_nodes_when_mnesia_is_disc(Config) ->
     %% start
     ok = syn:start(),
     ok = rpc:call(SlaveNodeName, syn, start, []),
+    timer:sleep(100),
     %% check table exists on local
     true = lists:member(syn_processes_table, mnesia:system_info(tables)),
     %% check table exists on remote
     SlaveNodeMnesiaSystemInfo = rpc:call(SlaveNodeName, mnesia, system_info, [tables]),
     true = rpc:call(SlaveNodeName, lists, member, [syn_processes_table, SlaveNodeMnesiaSystemInfo]).
-
-%% ===================================================================
-%% Internal
-%% ===================================================================
-clean_after_test() ->
-    %% stop mnesia
-    mnesia:stop(),
-    %% delete schema
-    mnesia:delete_schema([node()]),
-    %% stop syn
-    syn:stop().
-
-clean_after_test(SlaveNodeName) ->
-    clean_after_test(),
-    %% stop mnesia
-    rpc:call(SlaveNodeName, mnesia, stop, []),
-    %% delete schema
-    rpc:call(SlaveNodeName, mnesia, delete_schema, [SlaveNodeName]),
-    %% stop syn
-    rpc:call(SlaveNodeName, syn, stop, []).

test/syn_register_processes_SUITE.erl

@@ -33,10 +33,19 @@
 -export([init_per_suite/1, end_per_suite/1]).
 -export([groups/0, init_per_group/2, end_per_group/2]).
 
+%% internal
+-export([process_main/0]).
+
 %% tests
 -export([
     single_node_when_mnesia_is_ram_find_by_key/1,
-    single_node_when_mnesia_is_ram_find_by_pid/1
+    single_node_when_mnesia_is_ram_find_by_pid/1,
+    single_node_when_mnesia_is_ram_re_register_error/1,
+    single_node_when_mnesia_is_disc_find_by_key/1
+]).
+-export([
+    two_nodes_when_mnesia_is_ram_find_by_key/1,
+    two_nodes_when_mnesia_is_disc_find_by_pid/1
 ]).
 
 %% include
@@ -56,7 +65,8 @@
 %% -------------------------------------------------------------------
 all() ->
     [
-        {group, single_node_process_registration}
+        {group, single_node_process_registration},
+        {group, two_nodes_process_registration}
     ].
 
 %% -------------------------------------------------------------------
@@ -75,7 +85,13 @@ groups() ->
     [
         {single_node_process_registration, [shuffle], [
             single_node_when_mnesia_is_ram_find_by_key,
-            single_node_when_mnesia_is_ram_find_by_pid
+            single_node_when_mnesia_is_ram_find_by_pid,
+            single_node_when_mnesia_is_ram_re_register_error,
+            single_node_when_mnesia_is_disc_find_by_key
+        ]},
+        {two_nodes_process_registration, [shuffle], [
+            two_nodes_when_mnesia_is_ram_find_by_key,
+            two_nodes_when_mnesia_is_disc_find_by_pid
         ]}
     ].
 %% -------------------------------------------------------------------
@@ -106,6 +122,15 @@ end_per_suite(_Config) -> ok.
 %% Config0 = Config1 = [tuple()]
 %% Reason = term()
 %% -------------------------------------------------------------------
+init_per_group(two_nodes_process_registration, Config) ->
+    %% get slave node short name
+    SlaveNodeShortName = proplists:get_value(slave_node_short_name, Config),
+    {ok, SlaveNodeName} = syn_test_suite_helper:start_slave(SlaveNodeShortName),
+    %% config
+    [
+        {slave_node_name, SlaveNodeName}
+        | Config
+    ];
 init_per_group(_GroupName, Config) -> Config.
 
 %% -------------------------------------------------------------------
@@ -114,8 +139,15 @@ init_per_group(_GroupName, Config) -> Config.
 %% GroupName = atom()
 %% Config0 = Config1 = [tuple()]
 %% -------------------------------------------------------------------
+end_per_group(two_nodes_mnesia_creation, Config) ->
+    %% get slave node name
+    SlaveNodeName = proplists:get_value(slave_node_name, Config),
+    %% clean
+    syn_test_suite_helper:clean_after_test(SlaveNodeName),
+    %% stop slave
+    syn_test_suite_helper:stop_slave(SlaveNodeName);
 end_per_group(_GroupName, _Config) ->
-    clean_after_test().
+    syn_test_suite_helper:clean_after_test().
 
 %% ===================================================================
 %% Tests
@@ -130,7 +162,7 @@ single_node_when_mnesia_is_ram_find_by_key(_Config) ->
     %% retrieve
     undefined = syn:find_by_key(<<"my proc">>),
     %% register
-    syn:register(<<"my proc">>, Pid),
+    ok = syn:register(<<"my proc">>, Pid),
     %% retrieve
     Pid = syn:find_by_key(<<"my proc">>),
     %% kill process
@@ -147,7 +179,7 @@ single_node_when_mnesia_is_ram_find_by_pid(_Config) ->
     %% start process
     Pid = start_process(),
     %% register
-    syn:register(<<"my proc">>, Pid),
+    ok = syn:register(<<"my proc">>, Pid),
     %% retrieve
     <<"my proc">> = syn:find_by_pid(Pid),
     %% kill process
@@ -156,17 +188,111 @@ single_node_when_mnesia_is_ram_find_by_pid(_Config) ->
     %% retrieve
     undefined = syn:find_by_pid(Pid).
 
+single_node_when_mnesia_is_ram_re_register_error(_Config) ->
+    %% set schema location
+    application:set_env(mnesia, schema_location, ram),
+    %% start
+    ok = syn:start(),
+    %% start process
+    Pid = start_process(),
+    Pid2 = start_process(),
+    %% register
+    ok = syn:register(<<"my proc">>, Pid),
+    {error, already_taken} = syn:register(<<"my proc">>, Pid2),
+    %% retrieve
+    Pid = syn:find_by_key(<<"my proc">>),
+    %% kill process
+    kill_process(Pid),
+    timer:sleep(100),
+    %% retrieve
+    undefined = syn:find_by_key(<<"my proc">>),
+    %% reuse
+    ok = syn:register(<<"my proc">>, Pid2),
+    %% retrieve
+    Pid2 = syn:find_by_key(<<"my proc">>),
+    %% kill process
+    kill_process(Pid),
+    timer:sleep(100),
+    %% retrieve
+    undefined = syn:find_by_pid(Pid).
+
+single_node_when_mnesia_is_disc_find_by_key(_Config) ->
+    %% set schema location
+    application:set_env(mnesia, schema_location, disc),
+    %% create schema
+    mnesia:create_schema([node()]),
+    %% start
+    ok = syn:start(),
+    %% start process
+    Pid = start_process(),
+    %% retrieve
+    undefined = syn:find_by_key(<<"my proc">>),
+    %% register
+    ok = syn:register(<<"my proc">>, Pid),
+    %% retrieve
+    Pid = syn:find_by_key(<<"my proc">>),
+    %% kill process
+    kill_process(Pid),
+    timer:sleep(100),
+    %% retrieve
+    undefined = syn:find_by_key(<<"my proc">>).
+
+two_nodes_when_mnesia_is_ram_find_by_key(Config) ->
+    %% get slave
+    SlaveNodeName = proplists:get_value(slave_node_name, Config),
+    %% set schema location
+    application:set_env(mnesia, schema_location, ram),
+    rpc:call(SlaveNodeName, mnesia, schema_location, [ram]),
+    %% start
+    ok = syn:start(),
+    ok = rpc:call(SlaveNodeName, syn, start, []),
+    timer:sleep(100),
+    %% start process
+    Pid = start_process(),
+    %% retrieve
+    undefined = syn:find_by_key(<<"my proc">>),
+    undefined = rpc:call(SlaveNodeName, syn, find_by_key, [<<"my proc">>]),
+    %% register
+    ok = syn:register(<<"my proc">>, Pid),
+    %% retrieve
+    Pid = syn:find_by_key(<<"my proc">>),
+    Pid = rpc:call(SlaveNodeName, syn, find_by_key, [<<"my proc">>]),
+    %% kill process
+    kill_process(Pid),
+    timer:sleep(100),
+    %% retrieve
+    undefined = syn:find_by_key(<<"my proc">>),
+    undefined = rpc:call(SlaveNodeName, syn, find_by_key, [<<"my proc">>]).
+
+two_nodes_when_mnesia_is_disc_find_by_pid(Config) ->
+    %% get slave
+    SlaveNodeName = proplists:get_value(slave_node_name, Config),
+    %% set schema location
+    application:set_env(mnesia, schema_location, disc),
+    rpc:call(SlaveNodeName, mnesia, schema_location, [disc]),
+    %% create schema
+    mnesia:create_schema([node(), SlaveNodeName]),
+    %% start
+    ok = syn:start(),
+    ok = rpc:call(SlaveNodeName, syn, start, []),
+    timer:sleep(100),
+    %% start process
+    Pid = start_process(),
+    %% register
+    ok = syn:register(<<"my proc">>, Pid),
+    %% retrieve
+    <<"my proc">> = syn:find_by_pid(Pid),
+    <<"my proc">> = rpc:call(SlaveNodeName, syn, find_by_pid, [Pid]),
+    %% kill process
+    kill_process(Pid),
+    timer:sleep(100),
+    %% retrieve
+    undefined = syn:find_by_pid(Pid),
+    undefined = rpc:call(SlaveNodeName, syn, find_by_pid, [Pid]).
+
 %% ===================================================================
 %% Internal
 %% ===================================================================
-clean_after_test() ->
-    %% stop mnesia
-    mnesia:stop(),
-    %% delete schema
-    mnesia:delete_schema([node()]),
-    %% stop syn
-    syn:stop().
-
 start_process() ->
     Pid = spawn(?MODULE, process_main, []),
     Pid.

test/syn_test_suite_helper.erl

@@ -30,6 +30,7 @@
 
 %% API
 -export([start_slave/1, stop_slave/1]).
+-export([clean_after_test/0, clean_after_test/1]).
 
 
 %% ===================================================================
@@ -47,3 +48,20 @@ start_slave(NodeShortName) ->
 
 stop_slave(NodeName) ->
     ct_slave:stop(NodeName).
+
+clean_after_test() ->
+    %% stop mnesia
+    mnesia:stop(),
+    %% delete schema
+    mnesia:delete_schema([node()]),
+    %% stop syn
+    syn:stop().
+
+clean_after_test(NodeName) ->
+    clean_after_test(),
+    %% stop mnesia
+    rpc:call(NodeName, mnesia, stop, []),
+    %% delete schema
+    rpc:call(NodeName, mnesia, delete_schema, [NodeName]),
+    %% stop syn
+    rpc:call(NodeName, syn, stop, []).