ReplacementPolicy.Callback (Apache Derby V10.14 Internals)

All Known Implementing Classes:

ClockPolicy.Holder

Enclosing interface:

ReplacementPolicy
```
public static interface ReplacementPolicy.Callback
```
The interface for the callback objects that ConcurrentCache uses to notify the replacement algorithm about events such as look-ups and removals. Each Callback object is associated with a single entry in the cache.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`access()`	Notify the replacement algorithm that the cache entry has been accessed.
`void`	`free()`	Notify the replacement algorithm that the entry associated with this callback object has been removed, and the callback object and the `Cacheable` can be reused.

- Method Detail
  - access
```
void access()
```
    Notify the replacement algorithm that the cache entry has been accessed. The replacement algorithm can use this information to collect statistics about access frequency which can be used to determine the order of evictions.
    The entry associated with the callback object must be locked by the current thread.
  - free
```
void free()
```
    Notify the replacement algorithm that the entry associated with this callback object has been removed, and the callback object and the Cacheable can be reused.
    The entry associated with the callback object must be locked by the current thread.