Struct DemandPagingManager 

pub struct DemandPagingManager {
    pub cow_table: CowTable,
    /* private fields */
}

Manages lazy mappings and COW state.

The manager does NOT directly modify page tables. Instead, its methods return allocation results (frame number + flags) that the caller uses to install the actual mapping via the VAS / page table infrastructure.

Fields

cow_table: CowTable

COW-shared frame tracking.

Implementations

impl DemandPagingManager

pub fn new() -> Self

Create a new demand paging manager.

pub fn register_lazy( &mut self, start_vaddr: usize, size: usize, flags: PageFlags, backing: BackingType, )

Register a lazy mapping. No physical memory is allocated.

pub fn try_demand_page( &mut self, vaddr: usize, ) -> Result<(FrameNumber, PageFlags), KernelError>

Try to resolve a demand-page fault at vaddr.

If the address falls within a registered lazy mapping that has not yet been faulted in, allocates a physical frame and returns Ok((frame, flags)). The caller is responsible for installing the mapping in the page table.

pub fn handle_cow_fault(&self, vaddr: usize) -> Result<FrameNumber, KernelError>

Handle a COW fault at vaddr.

Allocates a new frame, copies the contents from the old shared frame, decrements the COW ref count, and returns the new frame.

pub fn unregister_lazy(&mut self, start_vaddr: usize)

Remove a lazy mapping.

pub fn mark_cow_range(&mut self, base: usize, pages: &[(usize, FrameNumber)])

Mark a range of pages as COW-shared.

pub fn add_cow_entry(&mut self, vaddr: usize, frame: FrameNumber)

Add a single COW entry (used by cow_fork).

Trait Implementations

impl Default for DemandPagingManager

Available on crate feature alloc only.

fn default() -> Self

Returns the “default value” for a type.