Module mmtk::vm[−][src]

MMTk-to-VM interface: the VMBinding trait.

This module provides VM-specific traits that serve as MMTK-to-VM interfaces. Each VM binding needs to provide an implementation for each of the traits. MMTk requires the interfaces to be efficient, as some of the methods are called frequently during collection (e.g. the methods for ObjectModel). We rely on cross-crate link-time-optimization to remove the overhead of MMTk invoking methods on those traits.

It is recommended for a VM binding that uses mmtk-core to do the following to ensure LTO is enabled for performance.

  1. Add the following section in the manifest file of a VM binding (Cargo.toml). This enables LTO for the release build: 
    [profile.release]
lto = true
  2. Make sure that the crate type for a VM binding supports LTO. To our knowledge, staticlib and cdylib support LTO, and rlib does not support LTO.

Traits

ActivePlan

VM-specific methods for the current plan.

Collection

VM-specific methods for garbage collection.

ObjectModel

VM-specific methods for object model.

ReferenceGlue

VM-specific methods for reference processing.

Scanning

VM-specific methods for scanning roots/objects.

VMBinding

The VMBinding trait associates with each trait, and provides VM-specific constants.