Process Host

A process.host runs Lua and WebAssembly processes on a work-stealing scheduler. This page is a configuration and lifecycle reference; the YAML block is an entry fragment.

Each host schedules processes independently. Load is not distributed between hosts automatically.

Entry Kind

Kind	Description
`process.host`	Process execution host with scheduler

Configuration

- name: main_host
  kind: process.host
  host:
    workers: 8
    queue_size: 1024
    local_queue_size: 256
  lifecycle:
    auto_start: true

Field	Type	Default	Description
`workers`	int	NumCPU	Worker goroutines
`queue_size`	int	1024	Initial global queue capacity
`local_queue_size`	int	256	Initial per-worker local deque capacity

Both queues grow when their initial capacity is exhausted. Values must be positive after defaults are applied. The global queue clamps its effective initial capacity to at least 16; each local deque rounds its capacity up to a power of two.

Lifecycle

A process host is a supervisor-managed service. lifecycle.auto_start defaults to false; a host that has not started rejects process spawns. The standard lifecycle fields also apply, including requires, startup, start_timeout, stop_timeout, stable_threshold, restart, and security.

Stopping a host is terminal for that host instance. The scheduler sends a cancellation event to each process, waits for them to drain until the stop context expires, then cancels and closes any remaining processes.

Live updates may resize host.workers. Changes to queue sizes or lifecycle configuration are rejected and require replacing the host. When CPU affinity manages the worker set, the worker count cannot be changed live either.

Scheduler

The scheduler uses work-stealing: each worker has a local deque, and idle workers steal from the global queue or other workers. This balances load automatically.

Workers execute processes concurrently.
Global queue holds pending processes when all workers are busy.
Local queues reduce contention by keeping work close to workers.

Process Types

Process hosts execute entries of these kinds:

Kind	Description
`process.lua`	Source-based Lua process
`process.lua.bc`	Precompiled Lua bytecode
`process.wasm`	WebAssembly process (experimental)

Processes run independently with their own frame context and communicate via messages. Security configured on the process entry is applied to that process frame before execution. Monitors, links, and application supervisors can react to failure; the process host does not automatically restart every failed process.