A callback for operation state changes
Cancel the operation. Beware! This will not necessarily cancel the * execution of the operation on the server side. However it will make * sure that the callback associated with this operation will not be * called anymore, effectively disabling the operation from the client * side's view.
Return the current status of the operation
Increase the reference count by one
Set the callback function that is called when the operation state * changes. Usually this is not necessary, since the functions that * create pa_operation objects already take a callback that is called * when the operation finishes. Registering a state change callback is * mainly useful, if you want to get called back also if the operation * gets cancelled. \since 4.0
Decrease the reference count by one
An asynchronous operation object