Notification Type

Context

Description

Synchronous

Notification:
Variable handler

Processing:
Variable handler

 

The notification will result in a call of a callback function in charge of the data processing.

 

Asynchronous

Notification:
Variable handler

Processing:
Subscriber recipient

The notification will be sent to a synchronization mechanism (i.e. a protected FIFO). When the data handler is ready to process the notified request, it may use the associated observer providing access to the current value of the variable. The value that will be read during this access is the most recent one.

Asynchronous with copy

Notification:
Variable handler

Processing:
Subscriber recipient

The handling of the notification follows the asynchronous one but the data value that will be read using the observer is the one that resulted in the notification. This gives the warranty that no value is never lost. This also means that if the notification is ignored for a certain amount of time, the value that is read is probably obsolete.