Asynchronous methods

Some API methods are asynchronous, which means that the operation they perform might not be complete when the method returns. Asynchronous methods return a handle that you can query to see the status of the operation; status information for some operations might include a percentage of completion.

When you query an asynchronous operation, its result can be one of the following types:
Note the following points when using asynchronous methods or obtaining the status of a running asynchronous operation: