Google Cloud Platform for Developers

Waiters

Waiters take the form of a key to observe, a timeout, and one or more end conditions. An end condition defines a cardinality (number of values for the observed key) and whether the number signifies a success or failure. Unlike watchers, waiters are implemented as a dedicated API resource type. When a waiter is created, the API request returns immediately and clients must poll the watcher resource to identify changes. Waiters also contain a done property, which signifies whether the waiter's timeout has been reached, as well as an error property, which reports an error message should the waiter fail.