Overseer

overseer implements the Overseer architecture described in the implementers' guide. For the motivations behind implementing the overseer itself you should check out that guide, documentation in this crate will be mostly discussing technical stuff.

An Overseer is something that allows spawning/stopping and overseeing asynchronous tasks as well as establishing a well-defined and easy to use protocol that the tasks can use to communicate with each other. It is desired that this protocol is the only way tasks communicate with each other, however at this moment there are no foolproof guards against other ways of communication.

The Overseer is instantiated with a pre-defined set of Subsystems that share the same behavior from Overseer's point of view.

                             +-----------------------------+
                             |         Overseer            |
                             +-----------------------------+

            ................|  Overseer "holds" these and uses |..............
            .                  them to (re)start things                      .
            .                                                                .
            .  +-------------------+                +---------------------+  .
            .  |   Subsystem1      |                |   Subsystem2        |  .
            .  +-------------------+                +---------------------+  .
            .           |                                       |            .
            ..................................................................
                        |                                       |
                      start()                                 start()
                        V                                       V
            ..................| Overseer "runs" these |.......................
            .  +--------------------+               +---------------------+  .
            .  | SubsystemInstance1 |               | SubsystemInstance2  |  .
            .  +--------------------+               +---------------------+  .
            ..................................................................