peersim.core
Interface Cleanable

All Known Subinterfaces:

Linkable

All Known Implementing Classes:

IdleProtocol, OracleIdleProtocol, SimpleNewscast

public interface Cleanable

This interface must be implemented by protocols that need to release some references when the fail state of their host node is set to Fallible.DEAD. Recall that this fail state means that the node will never get back online. However, other nodes and protocols might still have references to these dead nodes and protocols, and this fact is not always a bug. So implementing this interface allows for removing stuff that we know is no longer necessary. Especially for linkable protocols in the presence of churn, this is essential: they typically have to release their links to other nodes to prevent the formation of trees of removed nodes with a live reference to the root.

Method Summary

void	onKill() Performs cleanup when removed from the network.

Method Detail

onKill

void onKill()

Performs cleanup when removed from the network. This is called by the host node when its fail state is set to Fallible.DEAD. It is very important that after calling this method, NONE of the methods of the implementing object are guaranteed to work any longer. They might throw arbitrary exceptions, etc. The idea is that after calling this, typically no one should access this object. However, as a recommendation, at least toString should be guaranteed to execute normally, to aid debugging.