Crate wasmtime_runtime

Runtime library support for Wasmtime.

Modules

libcalls

Runtime library calls.

Structs

Backtrace

Representation of an owned and self-contained backtrace.

CompiledModuleId

A unique identifier (within an engine or similar) for a compiled module.

CompiledModuleIdAllocator

An allocator for compiled module IDs.

DefaultMemoryCreator

A default memory allocator used by Wasmtime

ExportFunction

A function export value.

ExportGlobal

A global export value.

ExportMemory

A memory export value.

ExportTable

A table export value.

GdbJitImageRegistration

Registeration for JIT image

Imports

Resolved import pointers.

InstanceAllocationRequest

Represents a request for a new runtime instance.

InstanceHandle

A handle holding an Instance of a WebAssembly module.

InstanceLimits

Represents the limits placed on instances by the pooling instance allocator.

LinkError

An link error while instantiating a module.

Memory

Representation of a runtime wasm linear memory.

MemoryImage

One backing image for one memory.

MemoryImageSlot

A single slot handled by the copy-on-write memory initialization mechanism.

Mmap

A simple struct consisting of a page-aligned pointer to page-aligned and initially-zeroed memory and a length.

MmapVec

A type akin to Vec<u8>, but backed by mmap and able to be split.

ModuleMemoryImages

Backing images for memories in a module.

OnDemandInstanceAllocator

Represents the on-demand instance allocator.

PoolingInstanceAllocator

Implements the pooling instance allocator.

StorePtr

A pointer to a Store. This Option<*mut dyn Store> is wrapped in a struct so that the function to create a &mut dyn Store is a method on a member of InstanceAllocationRequest, rather than on a &mut InstanceAllocationRequest itself, because several use-sites require a split mut borrow on the InstanceAllocationRequest.

TlsRestore

Opaque state used to help control TLS state across stack switches for async support.

VMCallerCheckedAnyfunc

The VM caller-checked “anyfunc” record, for caller-side signature checking. It consists of the actual function pointer and a signature id to be checked by the caller.

VMContext

The VM “context”, which is pointed to by the vmctx arg in Cranelift. This has information about globals, memories, tables, and other runtime state associated with the current instance.

VMExternRef

An external reference to some opaque data.

VMExternRefActivationsTable

A table that over-approximizes the set of VMExternRefs that any Wasm activation on this thread is currently using.

VMFunctionBody

A placeholder byte-sized type which is just used to provide some amount of type safety when dealing with pointers to JIT-compiled function bodies. Note that it’s deliberately not Copy, as we shouldn’t be carelessly copying function body bytes around.

VMFunctionImport

An imported function.

VMGlobalDefinition

The storage for a WebAssembly global defined within the instance.

VMGlobalImport

The fields compiled code needs to access to utilize a WebAssembly global variable imported from another instance.

VMInvokeArgument

The storage for a WebAssembly invocation argument

VMMemoryDefinition

The fields compiled code needs to access to utilize a WebAssembly linear memory defined within the instance, namely the start address and the size in bytes.

VMMemoryImport

The fields compiled code needs to access to utilize a WebAssembly linear memory imported from another instance.

VMOpaqueContext

An “opaque” version of VMContext which must be explicitly casted to a target context.

VMRuntimeLimits

Structure used to control interrupting wasm code.

VMSharedSignatureIndex

An index into the shared signature registry, usable for checking signatures at indirect calls.

VMTableDefinition

The fields compiled code needs to access to utilize a WebAssembly table defined within the instance.

VMTableImport

The fields compiled code needs to access to utilize a WebAssembly table imported from another instance.

Enums

Export

The value of an export passed from one instance to another.

InstantiationError

An error while instantiating a module.

PoolingAllocationStrategy

The allocation strategy to use for the pooling instance allocator.

Table

Represents an instance’s table.

TableElement

An element going into or coming out of a table.

Trap

Stores trace message with backtrace.

Constants

VERSION

Version number of this crate.

Traits

InstanceAllocator

Represents a runtime instance allocator.

ModuleInfo

Used by the runtime to query module information.

ModuleInfoLookup

Used by the runtime to lookup information about a module given a program counter value.

ModuleRuntimeInfo

Functionality required by this crate for a particular module. This is chiefly needed for lazy initialization of various bits of instance state.

RuntimeLinearMemory

A linear memory

RuntimeMemoryCreator

A memory allocator

Store

Dynamic runtime functionality needed by this crate throughout the execution of a wasm instance.

Functions

catch_traps^⚠

Catches any wasm traps that happen within the execution of closure, returning them as a Result.

gc^⚠

Perform garbage collection of VMExternRefs.

init_traps

This function is required to be called before any WebAssembly is entered. This will configure global state such as signal handlers to prepare the process to receive wasm traps.

raise_lib_trap^⚠

Raises a trap from inside library code immediately.

raise_user_trap^⚠

Raises a user-defined trap immediately.

resume_panic^⚠

Carries a Rust panic across wasm code and resumes the panic on the other side.

tls_eager_initialize

Eagerly initialize thread-local runtime functionality. This will be performed lazily by the runtime if users do not perform it eagerly.

Type Definitions

SignalHandler

Function which may handle custom signals while processing traps.

VMTrampoline

Type definition of the trampoline used to enter WebAssembly from the host.

Unions

ValRaw

A “raw” and unsafe representation of a WebAssembly value.