Understanding Persistent vs. Transient

The words Persistent and Transient appear frequently throughout the documentation for wRTOS Monitor and its related APIs. It is important to understand the meaning of these words in the context of wRTOS monitoring.

Persistent refers to something that affects the global monitoring environment. A persistent change is saved and applied to all other future sessions.
Transient refers to something that only affects the current monitor session. A transient change is not saved and does not persist to future sessions.

In the wRTOS monitoring environment, these concepts typically apply in reference to monitoring event sets and product components.

Persistent vs. Transient Event Sets

Monitor events belong to two distinct sets; the Persistent Event Set and the Transient Event Set:

The Persistent Event Set is the set of enabled/disabled monitoring events persisted in the Registry. This set is configured using the wRTOS Settings. Each time the wRTOS Subsystem starts, the Persistent Event Set becomes the set of enabled monitoring events.
The Transient Event Set only exists when monitoring is enabled. When the Transient Event Set exists, it controls which monitoring events are enabled/disabled. At the time monitoring is enabled, the Transient Event Set is initialized from the Persistent Event Set. The Transient Event Set is modified using wRTOS Monitor. Changes to the Transient Event Set do not affect the Persistent Event Set. When monitoring is disabled, the Transient Event Set is destroyed.

Persistent vs. Transient Product Components

You can enable/disable event collection for individual wRTOS product components persistently through wRTOS Settings or programmatically, using the APIs referenced below. Depending on the APIs you use, changes to component event collection will either be persistent or transient.

API	Description
Real-Time API RT_MONITOR_COMPONENT	An enumeration that represents wRTOS product components that can have their monitoring event generation enabled/disabled transiently.
Managed Code Framework API Subsystem.MonitorComponent Enumeration	An enumeration that represents the product components that can have monitor event generation enabled/disabled transiently or persistently.