Reproduces a deadlock in oc_bifrost's update_acl stored proc.

update_acl_deadlock_shell.erl

% Run this in an oc_bifrost console to reproduce the deadlocks. 
% Don't run this in a production DB as it doesn't clean up after itself. 

MakeID = fun() ->
    Raw = crypto:rand_bytes(16),
    <<Guid:128>> = Raw,
    iolist_to_binary(io_lib:format("~32.16.0b", [Guid])) end.

ActorIds = [ MakeID() || X <- lists:seq(1,5) ].
[ bifrost_db:create(actor, Id, undefined) || Id <- ActorIds ].

GroupIds = [ MakeID() || X <- lists:seq(1,5) ].
[ bifrost_db:create(group, Id, undefined) || Id <- GroupIds].

ObjectId =  MakeID().
bifrost_db:create(object, ObjectId, undefined).

LockUp = fun(Num) -> R = bifrost_db:update_acl(object, ObjectId, "create", ActorIds, GroupIds), io:fwrite("~p: ~p ~n", [Num, R]) end.
[spawn(fun() -> LockUp(X)) end  || X <- lists:seq(1,100)].