Struct mmtk::plan::Mutator

#[repr(C)]
pub struct Mutator<VM: VMBinding> {
    pub barrier: Box<dyn Barrier<VM>>,
    pub mutator_tls: VMMutatorThread,
    /* private fields */
}

A mutator is a per-thread data structure that manages allocations and barriers. It is usually highly coupled with the language VM. It is recommended for MMTk users 1) to have a mutator struct of the same layout in the thread local storage that can be accessed efficiently, and 2) to implement fastpath allocation and barriers for the mutator in the VM side.

Fields

barrier: Box<dyn Barrier<VM>>

Holds some thread-local states for the barrier.

mutator_tls: VMMutatorThread

The mutator thread that is bound with this Mutator struct.

Implementations

impl<VM: VMBinding> Mutator<VM>

pub fn on_destroy(&mut self)

Inform each allocator about destroying. Call allocator-specific on destroy methods.

pub unsafe fn allocator( &self, selector: AllocatorSelector ) -> &dyn Allocator<VM>

Get the allocator for the selector.

Safety

The selector needs to be valid, and points to an allocator that has been initialized. crate::memory_manager::get_allocator_mapping can be used to get a selector.

pub unsafe fn allocator_mut( &mut self, selector: AllocatorSelector ) -> &mut dyn Allocator<VM>

Get the mutable allocator for the selector.

Safety

The selector needs to be valid, and points to an allocator that has been initialized. crate::memory_manager::get_allocator_mapping can be used to get a selector.

pub unsafe fn allocator_impl<T: Allocator<VM>>( &self, selector: AllocatorSelector ) -> &T

Get the allocator of a concrete type for the selector.

Safety

The selector needs to be valid, and points to an allocator that has been initialized. crate::memory_manager::get_allocator_mapping can be used to get a selector.

pub unsafe fn allocator_impl_mut<T: Allocator<VM>>( &mut self, selector: AllocatorSelector ) -> &mut T

Get the mutable allocator of a concrete type for the selector.

Safety

The selector needs to be valid, and points to an allocator that has been initialized. crate::memory_manager::get_allocator_mapping can be used to get a selector.

pub fn get_allocator_base_offset(selector: AllocatorSelector) -> usize

Return the base offset from a mutator pointer to the allocator specified by the selector.

Trait Implementations

impl<VM: VMBinding> MutatorContext<VM> for Mutator<VM>

unsafe fn barrier_impl<B: Barrier<VM>>(&mut self) -> &mut B

Used by specialized barrier slow-path calls to avoid dynamic dispatches.

fn prepare(&mut self, tls: VMWorkerThread)

Do the prepare work for this mutator.

fn release(&mut self, tls: VMWorkerThread)

Do the release work for this mutator.

fn alloc( &mut self, size: usize, align: usize, offset: usize, allocator: AllocationSemantics ) -> Address

Allocate memory for an object.

fn alloc_slow( &mut self, size: usize, align: usize, offset: usize, allocator: AllocationSemantics ) -> Address

The slow path allocation. This is only useful when the binding implements the fast path allocation, and would like to explicitly call the slow path after the fast path allocation fails.

fn post_alloc( &mut self, refer: ObjectReference, _bytes: usize, allocator: AllocationSemantics )

Perform post-allocation actions. For many allocators none are required.

fn get_tls(&self) -> VMMutatorThread

Get the mutator thread for this mutator context. This is the same value as the argument supplied in crate::memory_manager::bind_mutator when this mutator is created.

fn barrier(&mut self) -> &mut dyn Barrier<VM>

Get active barrier trait object

fn flush_remembered_sets(&mut self)

Flush per-mutator remembered sets and create GC work for the remembered sets.

fn flush(&mut self)

Flush the mutator context.