Enum mmtk::util::heap::layout::mmapper::MapState

#[repr(u8)]
pub(super) enum MapState {
    Unmapped = 0,
    Quarantined = 1,
    Mapped = 2,
    Protected = 3,
}

The mmap state of a mmap chunk.

Variants

Unmapped = 0

The chunk is unmapped and not managed by MMTk.

Quarantined = 1

The chunk is reserved for future use. MMTk reserved the address range but hasn’t used it yet. We have reserved the addresss range with mmap_noreserve with PROT_NONE.

Mapped = 2

The chunk is mapped by MMTk and is in use.

Protected = 3

The chunk is mapped and is also protected by MMTk.

Implementations

impl MapState

pub(super) fn transition_to_mapped( state: &Atomic<MapState>, mmap_start: Address, strategy: MmapStrategy ) -> Result<()>

Check the current MapState of the chunk, and transition the chunk to MapState::Mapped. The caller should hold a lock before invoking this method.

pub(super) fn transition_to_quarantined( state: &Atomic<MapState>, mmap_start: Address, strategy: MmapStrategy ) -> Result<()>

Check the current MapState of the chunk, and transition the chunk to MapState::Quarantined. The caller should hold a lock before invoking this method.

pub(super) fn bulk_transition_to_quarantined( state_slices: &[&[Atomic<MapState>]], mmap_start: Address, strategy: MmapStrategy ) -> Result<()>

Equivalent to calling transition_to_quarantined on each element of states, but faster. The caller should hold a lock before invoking this method.

The memory region to transition starts from mmap_start. The size is the chunk size multiplied by the total number of Atomic<MapState> in the nested slice of slices.

This function is introduced to speed up initialization of MMTk. MMTk tries to quarantine very large amount of memory during start-up. If we quarantine one chunk at a time, it will require thousands of mmap calls to cover gigabytes of quarantined memory, introducing a noticeable delay.

Arguments:

• state_slices: A slice of slices. Each inner slice is a part of a Slab.
• mmap_start: The start of the region to transition.

pub(super) fn transition_to_protected( state: &Atomic<MapState>, mmap_start: Address ) -> Result<()>

Check the current MapState of the chunk, and transition the chunk to MapState::Protected. The caller should hold a lock before invoking this method.

Trait Implementations

impl Clone for MapState

fn clone(&self) -> MapState

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MapState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for MapState

fn eq(&self, other: &MapState) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for MapState

impl Eq for MapState

impl NoUninit for MapState

impl StructuralPartialEq for MapState