net.openhft.chronicle.core.io

Interface ReferenceChangeListener

public interface ReferenceChangeListener

Receives callbacks whenever the reference count of a ReferenceCounted changes. Typical uses include tracking resource ownership and diagnosing reference leaks during development.

Callbacks are invoked by ReferenceCounted implementations via ReferenceChangeListenerManager in the order that listeners were registered. Implementations must avoid long or blocking work as callbacks can be triggered while the owning object is holding internal locks, risking deadlock.

Method Summary

Modifier and Type	Method and Description
default void	onReferenceAdded(ReferenceCounted referenceCounted, ReferenceOwner referenceOwner) Invoked immediately after a reservation is made on the supplied ReferenceCounted instance.
default void	onReferenceRemoved(@Nullable ReferenceCounted referenceCounted, ReferenceOwner referenceOwner) Invoked after a reservation is released from the supplied ReferenceCounted instance.
default void	onReferenceTransferred(ReferenceCounted referenceCounted, ReferenceOwner fromOwner, ReferenceOwner toOwner) Invoked after a reservation is moved from one owner to another on the supplied ReferenceCounted instance.

Method Detail

onReferenceAdded

default void onReferenceAdded(ReferenceCounted referenceCounted,
                              ReferenceOwner referenceOwner)

Invoked immediately after a reservation is made on the supplied ReferenceCounted instance.

The call may occur while the owner object is synchronized. Keep the implementation short and non-blocking to avoid deadlock.

Parameters:

referenceCounted - the resource whose reference count increased

referenceOwner - the owner of the new reference

onReferenceRemoved

default void onReferenceRemoved(@Nullable
                                @Nullable ReferenceCounted referenceCounted,
                                ReferenceOwner referenceOwner)

Invoked after a reservation is released from the supplied ReferenceCounted instance.

As above, the call can happen whilst the owner is holding locks, so avoid blocking operations.

Parameters:

referenceCounted - the resource whose reference count decreased

referenceOwner - the owner whose reference was removed or null if unknown

onReferenceTransferred

default void onReferenceTransferred(ReferenceCounted referenceCounted,
                                    ReferenceOwner fromOwner,
                                    ReferenceOwner toOwner)

Invoked after a reservation is moved from one owner to another on the supplied ReferenceCounted instance.

Implementations should again avoid lengthy work as the call may be made within the ReferenceCounted's critical section.

Parameters:

referenceCounted - the resource whose reference was transferred

fromOwner - the previous owner of the reference

toOwner - the new owner of the reference