Struct InstanceAllocator

pub struct InstanceAllocator { /* private fields */ }

This is an intermediate type that manages the raw allocation and metadata when creating an [Instance].

This type will free the allocated memory if it’s dropped before being used.

It is important to remind that [Instance] is dynamically-sized based on VMOffsets: The Instance.vmctx field represents a dynamically-sized array that extends beyond the nominal end of the type. So in order to create an instance of it, we must:

1. Define the correct layout for Instance (size and alignment),
2. Allocate it properly.

The InstanceAllocator::instance_layout computes the correct layout to represent the wanted [Instance].

Then we use this layout to allocate an empty Instance properly.

Implementations

impl InstanceAllocator

pub fn new( module: &ModuleInfo, ) -> (Self, Vec<NonNull<VMMemoryDefinition>>, Vec<NonNull<VMTableDefinition>>)

Allocates instance data for use with VMInstance::new.

Returns a wrapper type around the allocation and 2 vectors of pointers into the allocated buffer. These lists of pointers correspond to the location in memory for the local memories and tables respectively. These pointers should be written to before calling VMInstance::new.

Trait Implementations

impl Drop for InstanceAllocator

fn drop(&mut self)

Executes the destructor for this type.