# AdaptiveLruPage

from pandac.PandaModules import AdaptiveLruPage

Class : AdaptiveLruPage
Description : One atomic piece that may be managed by a AdaptiveLru chain. To use this class, inherit from it and override evict_lru().
This class multiply inherits from two classes which in turn both inherit from LinkedListNode. This is just a sneaky C++ trick to allow this class to inherit from LinkedListNode twice, so that pages can be stored on two different linked lists simultaneously. The AdaptiveLru class depends on this; it maintains its pages in two different lists, one grouped by priority, and one in order by next partial update needs.

## Inheritance:

AdaptiveLruPage: AdaptiveLruPageDynamicList AdaptiveLruPageStaticList
AdaptiveLruPageDynamicList:
AdaptiveLruPageStaticList:

## Methods of AdaptiveLruPage:

AdaptiveLruPage (Constructor)
dequeueLru
enqueueLru
evictLru
getLru
getLruSize
getNumFrames
getNumInactiveFrames
markUsedLru
operator =
output
setLruSize
write

AdaptiveLruPage AdaptiveLruPage::AdaptiveLruPage(unsigned int lru_size); Description:

dequeueLru void AdaptiveLruPage::dequeue_lru(void); Description: Removes the page from its AdaptiveLru.

enqueueLru void AdaptiveLruPage::enqueue_lru(AdaptiveLru *lru); Description: Adds the page to the LRU for the first time, or marks it recently-accessed if it has already been added. If lru is NULL, it means to remove this page from its LRU.

evictLru virtual void AdaptiveLruPage::evict_lru(void); Description: Evicts the page from the LRU. Called internally when the LRU determines that it is full. May also be called externally when necessary to explicitly evict the page. It is legal for this method to either evict the page as requested, do nothing (in which case the eviction will be requested again at the next epoch), or requeue itself on the tail of the queue (in which case the eviction will be requested again much later).

getLru AdaptiveLru *AdaptiveLruPage::get_lru(void) const; Description: Returns the LRU that manages this page, or NULL if it is not currently managed by any LRU.

getLruSize unsigned int AdaptiveLruPage::get_lru_size(void) const; Description: Returns the size of this page as reported to the LRU, presumably in bytes.

getNumFrames unsigned int AdaptiveLruPage::get_num_frames(void) const; Not defined in SimpleLruPage. Description: Returns the number of frames since the page was first added to its LRU. Returns 0 if it does not have an LRU.

getNumInactiveFrames unsigned int AdaptiveLruPage::get_num_inactive_frames(void) const; Not defined in SimpleLruPage. Description: Returns the number of frames since the page was last accessed on its LRU. Returns 0 if it does not have an LRU.

markUsedLru void AdaptiveLruPage::mark_used_lru(void) const; Description: To be called when the page is used; this will move it to the tail of the AdaptiveLru queue it is already on. This method is const because it's not technically modifying the contents of the page itself. Description: To be called when the page is used; this will move it to the tail of the specified AdaptiveLru queue.

operator = void AdaptiveLruPage::operator =(AdaptiveLruPage const &copy); Description:

output virtual void AdaptiveLruPage::output(ostream &out) const; Description:

setLruSize void AdaptiveLruPage::set_lru_size(unsigned int lru_size); Description: Specifies the size of this page, presumably in bytes, although any unit is possible.

write virtual void AdaptiveLruPage::write(ostream &out, int indent_level) const; Description: