if the stage didn't complete yet, the node is active and auto-init is set to true, perform the steps necessary. note, this invocation will be thread safe and only run once however, any implementation needs to be crash resilient, if it didn't complete fully, it might be called again. if this stage does not support auto-init, you must return None the method may throw "PassiveInstanceException" if it becomes passive

given the result of this stage, create the next stage

test whether the stage is completed already through a previous init. if so, return result

can be used to track closeables created with this class that should be cleaned up after this stage

main handler to implement where we attempt to init this stage if we return None, then the init was okay but stopped at this level (waiting for further input)

the attempt and store handler that runs sequential on the init queue it will attempt to create the next stage and store it in the current atomic reference

Removes a shutdown task from the list using a token returned by runOnShutdown

Blocks until all earlier tasks have completed and then prevents further tasks from being run.

if external input is necessary

Check whether we're closing. Susceptible to race conditions; unless you're using using this as a flag to the retry lib or you really know what you're doing, prefer performUnlessClosing and friends.

track running futures on shutdown

set to true to get detailed information about all futures that did not complete during shutdown. if set to false, we don't do anything.

How often to poll to check that all tasks have completed.

Use this method to create a PromiseUnlessShutdown that will automatically be cancelled when the close context is closed. This allows proper clean up of stray promises when the node is transitioning to a passive state.

Note: you should *not* invoke success on the returned promise but rather use trySuccess. The reason is that the call to success may fail in case of shutdown.

Blocks until all earlier tasks have completed and then prevents further tasks from being run.

Performs the task given by f unless a shutdown has been initiated. The shutdown will only begin after f completes, but other tasks may execute concurrently with f, if started using this function, or one of the other variants (performUnlessClosingF and performUnlessClosingEitherT). The tasks are assumed to take less than closingTimeout to complete.

DO NOT CALL this.close as part of f, because it will result in a deadlock.

Performs the EitherT[Future] given by etf unless a shutdown has been initiated, in which case the provided error is returned instead. Both etf and the error are lazy; etf is only evaluated if there is no shutdown, the error only if we're shutting down. The shutdown will only begin after etf completes, but other tasks may execute concurrently with etf, if started using this function, or one of the other variants (performUnlessClosing and performUnlessClosingF). The tasks are assumed to take less than closingTimeout to complete.

DO NOT CALL this.close as part of etf, because it will result in a deadlock.

Performs the Future given by f unless a shutdown has been initiated. The future is lazy and not evaluated during shutdown. The shutdown will only begin after f completes, but other tasks may execute concurrently with f, if started using this function, or one of the other variants (performUnlessClosing and performUnlessClosingEitherT). The tasks are assumed to take less than closingTimeout to complete.

DO NOT CALL this.close as part of f, because it will result in a deadlock.

Same as runOnShutdown_ but returns a token that allows you to remove the task explicitly from being run using cancelShutdownTask

Register a task to run when shutdown is initiated.

You can use this for example to register tasks that cancel long-running computations, whose termination you can then wait for in "closeAsync".

iterative start handler which will attempt to start the stages until we are either up and running or awaiting some init action by the user

if a passive node hits a manual init step, it will return "start" is succeeded and wait in the background for the active node to finish the startup sequence