MuditaOS/module-sys/SystemManager/doc/ServicesSynchronization.md

Services synchronization

If a service has dependencies to other services, it should be started after its dependencies are started.

For example, a ServiceA may be dependent on the ServiceDB. It means that the ServiceA can not be started unless the ServiceDB successfully starts.

It is a part of the Services Synchronization feature to order services based on their dependencies.

Service Manifest

Each service should export its manifest. The manifest may contain the following information:

• dependencies to other services
• start limit
• start timeout
• on failure strategy

The System Manager needs to read the manifests to run the services in the correct order.

Synchronization algorithm

The topological sorting algorithm may be used to build a linear ordering of services that are to be started by the System Manager.

Important note: The Dependency Graph implementation handles Directed Acyclic Graphs only.