stage_left

0.1-dev @jtenner

An experimental actor-style process model for Core WebAssembly with isolated instances, links, signals, typed messages, and explicit lifecycle rules.

stage_left

stage_left is an experimental process specification for Core WebAssembly. It adds actor-style process concepts without turning the interface into a container or resource-configuration API.

The repository is not public yet. This page describes the current 0.1 design.

Process model

One Stage Left process is one isolated WebAssembly instance.

A process can spawn another process. The spawn operation includes one Boolean value that decides whether the parent and child are linked.

A link connects process lifecycle events. It does not share mutable WebAssembly state.

Signals and termination

Stage Left separates normal messages from process signals.

Important operations include:

• process_link and process_unlink;
• process_kill for forced external termination;
• process_trap_signals for signal handling;
• signal_receive for queued terminal signals.

There is no Stage Left panic instruction. An unhandled WebAssembly trap is the process panic outcome.

Messages

Messages use explicit typed transactions. A sender prepares a message, writes typed values, and then commits or aborts the message.

Committed messages keep first-in, first-out ordering.

WebAssembly GC arrays are copied as values when they cross a process boundary. Mutable GC references are not shared between processes.

Isolation and policy

Locally defined mutable WebAssembly state is private to each process. Imported mutable state must also be process-private or the runtime must reject the process image.

The runtime or embedder controls resource limits. Stage Left does not give a guest direct control over process quotas, memory budgets, or scheduler budgets.

Status

The current specification is 0.1-dev. The base process, message, signal, lifecycle, and portability design has no known high-priority design blocker.

Implementation and conformance work can still find problems before the first 0.1.0 freeze.