Services¶
Managing the Lifecycle¶
<a name=”state-changes-and-causes”></a>State Changes and Causes¶
The following table summarises the changes of state and cause, depending on the old state and the call made. If any call is made that does not appear in these tables, or listed under Ignored Calls, an exception is thrown.
No errors during call¶
This table assumes no errors occur during the call
| old state | full call | short call | new state & cause |
|---|---|---|---|
| INITIAL | start(STARTED) | start() | RUNNING, STARTED |
| RUNNING | stop(STOPPED) | stop() | STOPPED, STOPPED |
| RUNNING | stop(FAILED) | fail() | FAILED, FAILED |
| RUNNING | stop(DEPENDENCY_S TOPPED) | dependencyStop() | STOPPED, DEPENDENCY_STOPPE D |
| RUNNING | stop(DEPENDENCY_F AILED) | dependencyFail() | STOPPED, DEPENDENCY_FAILED |
| STOPPED | start(STARTED) | start() | RUNNING, STARTED |
| FAILED | reset() | INITIAL, RESET |
Error occurs during call¶
This table assumes that an error occurs during the call
| old state | full call | short call | new state & cause |
|---|---|---|---|
| INITIAL | start(STARTED) | start() | FAILED, FAILED_TO_START* |
| STOPPED | start(STARTED) | start() | FAILED, FAILED_TO_START* |
| INITIAL | start(STARTED) | start() | INITIAL, DEPENDENCY_FAILED ** |
| STOPPED | start(STARTED) | start() | STOPPED, DEPENDENCY_FAILED ** |
| RUNNING | stop(STOPPED) | stop() | FAILED, FAILED_TO_STOP |
| RUNNING | stop(FAILED) | fail() | FAILED, FAILED |
| RUNNING | stop(DEPENDENCY_S TOPPED) | dependencyStop() | FAILED, FAILED_TO_STOP |
| RUNNING | stop(DEPENDENCY_F AILED) | dependencyFail() | FAILED, FAILED_TO_STOP |
| FAILED | reset() | FAILED, FAILED_TO_RESET |
- Error in the Service that was called<br>
- Error in a dependency of the Service that was called
Ignored Calls¶
A call to start() when the state is STARTING or RUNNING is ignored A call to stop(), fail(), dependencyStop(), dependencyFail() when the state is INITIAL, RESETTING, STOPPED or FAILED is ignored A call to reset() when the state is INITIAL or RESETTING is ignored
Service Instantiation¶
When a Service is instantiated through Guice, AOP in the ServicesModule calls ServicesModel.addService, which also creates all its dependencies from the ‘template’ provided by the ServicesModel.classGraph
This means that the instanceGraph should always have a complete set of dependencies for any Service instantiated through Guice.