Methods and apparatus for distributed locking interfaces are disclosed. A state manager implements programmatic interfaces for distributed locking operations. In response to a queue-for-lock request for a registry element received via an interface, the state manager provides to the requester, a reference to a first asynchronous computation. The first asynchronous computation comprises an insertion of a lock request into a queue of waiters for a lock on the element. In response to a blocking request for a result of the computation, the state manager transmits, after the lock request has been inserted into the queue of waiters, a notification of the insertion of the request. The notification in turn includes a reference to a second asynchronous computation. The second asynchronous computation comprises a grant of the lock on the particular element to the requester.