Allow init_backends to be called multiple times

Mikaka27 · Dec 5, 2024 · 29cb353 · 29cb353
1 parent eb9cbfb
commit 29cb353
Showing 1 changed file with 21 additions and 6 deletions.
diff --git a/lib/mnesia/src/mnesia_schema.erl b/lib/mnesia/src/mnesia_schema.erl
@@ -72,6 +72,8 @@
          info/1,
          init/1,
 	 init_backends/0,
+	 init_backends/1,
+	 get_backends_to_initialize/1,
          insert_cstruct/3,
 	 is_remote_member/1,
          list2cs/1,
@@ -161,13 +163,22 @@ init(IgnoreFallback) ->
     mnesia_controller:add_active_replica(schema, node()),
     init_backends().
 
-
 init_backends() ->
-    Backends = lists:foldl(fun({Alias, Mod}, Acc) ->
-				   orddict:append(Mod, Alias, Acc)
-			   end, orddict:new(), get_ext_types()),
-    [init_backend(Mod, Aliases) || {Mod, Aliases} <- Backends],
-    ok.
+    Backends = get_backends_to_initialize(get_ext_types()),
+    init_backends(Backends).
+init_backends([]) ->
+    ok;
+init_backends([{Mod, Aliases} = Backend | Rest]) ->
+    Mods = mnesia_lib:val(ext_backends),
+    case lists:member(Mod, Mods) of
+        true ->
+            dbg_out("Backend ~p is already initialized~n", [Backend]);
+        false ->
+            init_backend(Mod, Aliases),
+            mnesia_lib:set(ext_backends, [Mod | Mods]),
+            dbg_out("Backend ~p initialized~n", [Backend])
+    end,
+    init_backends(Rest).
 
 init_backend(Mod, [_|_] = Aliases) ->
     case Mod:init_backend() of
@@ -177,6 +188,10 @@ init_backend(Mod, [_|_] = Aliases) ->
 	    mnesia:abort({backend_init_error, Error})
     end.
 
+get_backends_to_initialize(Ext) ->
+    lists:foldl(fun({Alias, Mod}, Acc) ->
+        orddict:append(Mod, Alias, Acc) end, orddict:new(), Ext).
+
 exit_on_error({error, Reason}) ->
     exit(Reason);
 exit_on_error(GoodRes) ->