DClockPolicy (simulator 3.1.5 API)

java.lang.Object
- com.github.benmanes.caffeine.cache.simulator.policy.irr.DClockPolicy

All Implemented Interfaces:

Policy, Policy.KeyOnlyPolicy
```
public final class DClockPolicy
extends Object
implements Policy.KeyOnlyPolicy
```
Double Clock algorithm. This algorithm organizes blocks by their reuse distance and partitions the cache into an active and inactive space. A new arrival enters the inactive space and on a subsequent hit is promoted to the active space, which may cause the oldest active entry to be demoted to be inactive. An eviction discards the oldest inactive entry which becomes a shadow (non-resident) node and is stamped with its refault distance. If on a cache miss the shadow entry exists and has a refault distance that is less than the active space's size, then it is optimistically promoted on insert.
The algorithm is explained by the authors in linux/mm/workingset.c. The target size of the active and inactive list is calculated in linux/mm/vmscan.c.

Nested Class Summary
- Nested classes/interfaces inherited from interface com.github.benmanes.caffeine.cache.simulator.policy.Policy
  Policy.Characteristic, Policy.KeyOnlyPolicy, Policy.PolicySpec

Constructor Summary

Constructors
Constructor Description

DClockPolicy(com.github.benmanes.caffeine.cache.simulator.policy.irr.DClockPolicy.DClockSettings settings, double percentActive)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`finished()`	Indicates that the recording has completed.
`static Set<Policy>`	`policies(Config config)`	Returns all variations of this policy based on the configuration parameters.
`void`	`record(long key)`
`PolicyStats`	`stats()`	Returns the cache efficiency statistics.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.github.benmanes.caffeine.cache.simulator.policy.Policy
name

Methods inherited from interface com.github.benmanes.caffeine.cache.simulator.policy.Policy.KeyOnlyPolicy
record

- Constructor Detail
  - DClockPolicy
```
public DClockPolicy(com.github.benmanes.caffeine.cache.simulator.policy.irr.DClockPolicy.DClockSettings settings,
                    double percentActive)
```
- Method Detail
  - policies
```
public static Set<Policy> policies(Config config)
```
    Returns all variations of this policy based on the configuration parameters.
  - record
```
public void record(long key)
```
    Specified by:
    
    record in interface Policy.KeyOnlyPolicy
  - stats
```
public PolicyStats stats()
```
    Description copied from interface: Policy
    
    Returns the cache efficiency statistics.
    
    Specified by:
    
    stats in interface Policy
  - finished
```
public void finished()
```
    Description copied from interface: Policy
    
    Indicates that the recording has completed.
    
    Specified by:
    
    finished in interface Policy