static CLOSING_BLOCKS: LazyLock<RwLock<HashMap<String, Sender<bool>>>>Expand description
Blocks whose pane is being closed. Between stopping a block’s
controller and deleting its record, a resync_controller (frontend
ControllerResync, agent.open, …) would otherwise find the block
still present and spawn a fresh process for it — an orphan the close
never sees. See docs/specs/SPEC_AGENT_PANE_CLOSE_GRACEFUL_SHUTDOWN_2026_09_18.md
§4.2 step 1.
Each entry also carries a completion signal (true once the block’s
process has exited), so a reopen racing the close can wait for the old
process instead of starting a second --resume on the same session
(spec §9.6).