create ?message path tries to create a file at path containing the text message, pid if none provided. It returns true on success, false on failure. Note: there is no way to release the lock or the fd created inside! It will only be released when the process dies.

create_exn ?message path is like create except that it throws an exception on failure instead of returning a boolean value.

waiting_create path repeatedly tries to lock path, becoming determined when path is locked or raising when abort becomes determined. Similar to Lock_file_blocking.create.

is_locked path returns true when the file at path exists and is locked, false otherwise.

Nfs has analogs of functions in Lock_file_blocking.Nfs; see there for documentation. In addition to adding Deferred's, blocking_create was renamed waiting_create to avoid the impression that it blocks Async.