Enum GcStatus 

pub enum GcStatus {
    Uninitialized,
    NotInGC,
    InConcurrentGC,
    InPause,
    PauseRequested,
    Disabled(usize),
}

The status of MMTk’s GC subsystem. This doubles as the “is MMTk initialized” flag (via GcStatus::Uninitialized) and as the state that tracks whether a GC is running and, if so, what phase it is in. See GcStatusWord (the internal atomic encoding of this type) for how this is stored atomically and which transitions between variants are legal.

Variants

Uninitialized

MMTk has not been initialized yet, i.e. initialize_collection() has not been called, so there are no GC worker threads available to run a collection.

NotInGC

MMTk is initialized, and no GC is running, pending, or requested.

InConcurrentGC

A concurrent GC’s background work (e.g. concurrent marking) is running while mutators continue to run normally. See ConcurrentPlan::concurrent_work_in_progress.

InPause

A stop-the-world pause is active: mutators are stopped and GC workers are doing pause work (e.g. tracing).

PauseRequested

A GC pause has been requested (by GcStatusWord::try_request_pause) but mutators have not all stopped yet.

Disabled(usize)

Collection is currently disabled (e.g. by a mutator calling disable_collection()). The usize payload is the non-zero nesting depth of disable calls: each call to disable_collection() increments the depth, and each call to enable_collection() decrements it. When the depth is about to reach zero, the status is transitioned to NoInGC.

Trait Implementations

impl Clone for GcStatus

fn clone(&self) -> GcStatus

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for GcStatus

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

Formats the value using the given formatter.

impl PartialEq for GcStatus

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl Copy for GcStatus

impl StructuralPartialEq for GcStatus