mmtk 0.3.2

MMTk is a framework for the design and implementation of high-performance and portable memory managers.
Documentation 
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use crate::mmtk::MMTK;
use crate::plan::global::BasePlan;
use crate::plan::global::CommonPlan;
use crate::plan::global::GcStatus;
use crate::plan::global::NoCopy;
use crate::plan::marksweep::gc_work::MSProcessEdges;
use crate::plan::marksweep::mutator::ALLOCATOR_MAPPING;
use crate::plan::AllocationSemantics;
use crate::plan::Plan;
use crate::plan::PlanConstraints;
use crate::policy::mallocspace::MallocSpace;
use crate::policy::space::Space;
use crate::scheduler::gc_work::*;
use crate::scheduler::*;
use crate::util::alloc::allocators::AllocatorSelector;
use crate::util::heap::layout::heap_layout::Mmapper;
use crate::util::heap::layout::heap_layout::VMMap;
use crate::util::heap::layout::vm_layout_constants::{HEAP_END, HEAP_START};
use crate::util::heap::HeapMeta;
use crate::util::options::UnsafeOptionsWrapper;
#[cfg(feature = "sanity")]
use crate::util::sanity::sanity_checker::*;
use crate::util::OpaquePointer;
use crate::vm::VMBinding;
use std::sync::Arc;

use enum_map::EnumMap;

pub struct MarkSweep<VM: VMBinding> {
    common: CommonPlan<VM>,
    ms: MallocSpace<VM>,
}

unsafe impl<VM: VMBinding> Sync for MarkSweep<VM> {}

pub const MS_CONSTRAINTS: PlanConstraints = PlanConstraints {
    moves_objects: false,
    gc_header_bits: 2,
    gc_header_words: 0,
    num_specialized_scans: 1,
    ..PlanConstraints::default()
};

impl<VM: VMBinding> Plan for MarkSweep<VM> {
    type VM = VM;

    fn gc_init(
        &mut self,
        heap_size: usize,
        vm_map: &'static VMMap,
        scheduler: &Arc<MMTkScheduler<VM>>,
    ) {
        self.common.gc_init(heap_size, vm_map, scheduler);
    }

    fn schedule_collection(&'static self, scheduler: &MMTkScheduler<VM>) {
        self.base().set_collection_kind();
        self.base().set_gc_status(GcStatus::GcPrepare);
        // Stop & scan mutators (mutator scanning can happen before STW)
        scheduler.work_buckets[WorkBucketStage::Unconstrained]
            .add(StopMutators::<MSProcessEdges<VM>>::new());
        // Prepare global/collectors/mutators
        scheduler.work_buckets[WorkBucketStage::Prepare]
            .add(Prepare::<Self, NoCopy<VM>>::new(self));
        // Release global/collectors/mutators
        scheduler.work_buckets[WorkBucketStage::Release]
            .add(Release::<Self, NoCopy<VM>>::new(self));
        // Resume mutators
        #[cfg(feature = "sanity")]
        scheduler.work_buckets[WorkBucketStage::Final]
            .add(ScheduleSanityGC::<Self, NoCopy<VM>>::new());
        scheduler.set_finalizer(Some(EndOfGC));
    }

    fn get_allocator_mapping(&self) -> &'static EnumMap<AllocationSemantics, AllocatorSelector> {
        &*ALLOCATOR_MAPPING
    }

    fn prepare(&self, tls: OpaquePointer) {
        self.common.prepare(tls, true);
        // Dont need to prepare for MallocSpace
    }

    fn release(&self, tls: OpaquePointer) {
        trace!("Marksweep: Release");
        self.common.release(tls, true);
        unsafe { self.ms.release_all_chunks() };
    }

    fn get_collection_reserve(&self) -> usize {
        0
    }

    fn get_pages_used(&self) -> usize {
        self.common.get_pages_used() + self.ms.reserved_pages()
    }

    fn base(&self) -> &BasePlan<VM> {
        &self.common.base
    }

    fn common(&self) -> &CommonPlan<VM> {
        &self.common
    }

    fn constraints(&self) -> &'static PlanConstraints {
        &MS_CONSTRAINTS
    }

    fn create_worker_local(
        &self,
        tls: OpaquePointer,
        mmtk: &'static MMTK<Self::VM>,
    ) -> GCWorkerLocalPtr {
        let mut c = NoCopy::new(mmtk);
        c.init(tls);
        GCWorkerLocalPtr::new(c)
    }
}

impl<VM: VMBinding> MarkSweep<VM> {
    pub fn new(
        vm_map: &'static VMMap,
        mmapper: &'static Mmapper,
        options: Arc<UnsafeOptionsWrapper>,
        _scheduler: &'static MMTkScheduler<VM>,
    ) -> Self {
        let heap = HeapMeta::new(HEAP_START, HEAP_END);
        MarkSweep {
            common: CommonPlan::new(vm_map, mmapper, options, heap, &MS_CONSTRAINTS, &[]),
            ms: MallocSpace::new(),
        }
    }

    pub fn ms_space(&self) -> &MallocSpace<VM> {
        &self.ms
    }
}