#typescript/src/effects_exec

#typescript/src/effects_exec

Synchronous execution primitives for the two effect methods Node cannot perform synchronously on the main thread: spawn (a concurrent child whose exit status must be readable later, synchronously, through Spawned.wait()) and http.

The effects API is synchronous by contract (§2.5.6 pins ctx.effects.run(argv, opts?) => Completed, not a Promise), because a forwarded carrier has to arrive at a later effect's parameter as a value, not as a pending promise. run gets that for free from spawnSync; these two do not, and each uses the smallest mechanism that gives it:

• spawn: a worker thread starts the child and signals the main thread

through a SharedArrayBuffer flag (pid on start, exit code on close). The main thread blocks with Atomics.wait, which is permitted on Node's main thread, and drains the payload with receiveMessageOnPort.

• http: a short-lived child node process performs the fetch and writes a

JSON envelope to stdout. No worker machinery is needed for a single request/response round trip, and a child process cannot leak a live handle back into the parent's event loop.

Neither mechanism degrades: a failure to start is thrown, never swallowed.

#SpawnedChild

export interface SpawnedChild

A started child whose exit status can be awaited synchronously later.

#spawnConcurrent

export function spawnConcurrent(

Starts a child concurrently and returns a handle whose wait() blocks the main thread synchronously. Throws if the child cannot be started.

#HttpResult

export interface HttpResult

A performed HTTP request's raw result.

#httpSync

export function httpSync(

Performs an HTTP request synchronously. Throws when the request fails.