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/*============================================================================
* This file defines an interface that can be implemented to provide a page
* replacement policy in the virtual memory system.
*
* We don't mind if policies use malloc() and free(), just because it keeps
* things simpler.
*/
#ifndef VMPOLICY_H
#define VMPOLICY_H
#include "virtualmem.h"
/* Called by vmem_init() to initialize the page replacement policy. The
* function should return nonzero for successful initialization, 0 otherwise.
*/
int policy_init(int max_resident);
/* Called by vmem_cleanup() to release any resources used by the policy. */
void policy_cleanup(void);
/* Called by the virtual memory system to inform the policy that a page has been
* mapped into virtual memory.
*/
void policy_page_mapped(page_t page);
/* Called by the virtual memory system when a SIGALRM signal is fired, so
* that timer-based policies can update their internal state.
*/
void policy_timer_tick(void);
/* Called by map_page() when space needs to be made for another virtual page
* to be mapped, by evicting a currently mapped page. Note that this function
* both chooses a page to evict, and records in the paging policy that the page
* is now evicted. The virtual memory system will also carry through its own
* tasks for evicting the page.
*/
page_t choose_and_evict_victim_page(void);
#endif /* VMPOLICY_H */