Module async_precmd 

async_precmd submodule — run precmd-style hooks on the worker pool so they don’t block prompt rendering (writes into the shared param table). async_precmd hook — run precmd-style functions on a POOL WORKER THREAD so they never block prompt rendering.

zsh’s precmd hooks run synchronously before the prompt paints, so a slow hook stalls the prompt. async_precmd is a new lifecycle hook (no zsh equivalent): its functions run on the shared worker pool AFTER the prompt is built/rendered, writing their results into the shared, RwLock-synchronized global param table. The prompt reads whatever is currently there and never waits — a slow segment simply updates a prompt or two later.

Registration mirrors zsh’s hook arrays:

• a function literally named async_precmd, and/or
• members of the async_precmd_functions array.

Built on the Phase-1 crate::vm_helper::ShellExecutor::new_worker lightweight worker executor. No isolation is needed here: async_precmd WANTS its typeset -g writes to land in the shared table.

Functions

fire_async_precmd

Fire the async_precmd hooks on a worker thread. Called from preprompt() AFTER precmd + prompt render, so the prompt is already on screen. Returns immediately (non-blocking): it submits ONE closure to the shared worker pool and lets it run in the background. Debounced via [RUNNING].

set_session_pool

Publish the session worker pool. Called once from ShellExecutor::new().