Custodians

A WorkingSetMachine has a boolean state indicating whether or not it is a custodian.

This state determines whether ROD objects are sent eagerly or lazily by its peers. Lazily means that the objects are sent on demand. A non-custodian needs to send a message to a custodian to request ROD objects.

To determine whether a WorkingSetMachine is a custodian the function IsCustodian can be called (it must be called inside a CSpace transaction). It has the following signature:

bool IsCustodian(const WorkingSetMachine* wsm);

This happens implicitly on non-custodians when AsyncGet() is called on a pref/cref which references a ROD object which isn't currently present in its WorkingSet.

By default a WorkingSetMachine is a custodian. This can be changed by calling the SetIsCustodian function. This must be called inside a CSpace transaction.

void SetIsCustodian(WorkingSetMachine* wsm, bool isCustodian);

The peers of a custodian send ROD objects eagerly (albeit asynchronously) - the idea being for a custodean to eventually get its own copy of all the ROD objects in the working set.

The peers of a non-custodean send ROD objects lazily.

It doesn't make sense for non-custodeans to connect to each other directly because neither will tend to be able to service the requests for ROD objects because they tend not to have them all.