Finit Services
==============

![The service state machine](svc-machine.png "The service state machine")

State Machine
-------------

A service is bound to a state machine that is in one of six (6) states.
For `run`s and `task`s there is an additional end state called `DONE`,
not shown in the diagram for brevity.  Services start in the `HALTED`
state.

The current state depends on the two following conditions:

* `E`: Service enabled. In order for `E` to be satisfied, the service
  must be allowed to run in the current runlevel and not be stopped.
  
  A service may be stopped, or blocked, for several reasons:

  - The user has manually stopped the service using `initctl stop JOB`
  - The program exits immediately. I.e. keeps crashing (make sure to use
    the 'run this service in the foreground' command line option)
  - The binary is missing in the filesystem

* `C`: Service conditions are satisfied:

  - `on` (+): The condition is asserted.
  - `off` (-): The condition is deasserted.
  - `flux` (~): The condition state is unknown.

For a detailed description of conditions, and how to debug them,
see the [Finit Conditions](conditions.md) document.