-module(albedo_settings_lock).
-export([with_lock/3]).
%% One daemon owns each home. This lock serializes its settings mutations,
%% including credential updates. It is not a lock shared with CLI processes.
%% Nested operations in the same process retain the outer lock until it exits.
with_lock(Home, Run, Busy) ->
Directory = unicode:characters_to_binary(filename:absname(Home)),
Key = {?MODULE, Directory},
case get(Key) of
held -> Run();
_ ->
Locked = fun() ->
put(Key, held),
try Run() after erase(Key) end
end,
case global:trans({Key, self()}, Locked, [node()], 8) of
aborted -> Busy();
Result -> Result
end
end.