Makes interrupt-protected context compression cancellable by an explicit
user or lifecycle stop, without weakening protection against ordinary
incoming messages, voice interjections, or active-turn redirects.
Separates explicit hard cancellation from ordinary interrupt/redirect
state with a dedicated threading.Event; introduces
AuxiliaryExplicitCancellation as an attempt-local frozen-cause signal;
isolates the synchronous provider callback in a bounded daemon worker
during protected compression; atomically linearizes Codex timeout
cleanup against explicit cancellation; propagates hard cancellation
through child agents and explicit stop surfaces; serializes hard-cancel
admission against compression commit admission with
CompressionCommitFence; aborts before session rotation or late DB commit,
restores in-place transcript mutations and compressor state, and releases
the heartbeat and compression lease.
Based on #74449 by @suparious. Resolved merge conflicts in
agent/context_compressor.py (feasibility check + try/except) and
tui_gateway/methods_session.py.
Follow-ups on the salvaged #63359:
- _finalize_child_results carries tool_call_history on subagent_stop
(the #62011/#72403 field landed after the PR branched; the shared
pipeline must emit it for both delegate_task and plugin-launched
children). Lifecycle test updated for the new payload field.
- The lifecycle executor uses DaemonThreadPoolExecutor — a wedged or
abandoned child must never block interpreter exit at atexit-join time
(same rationale as _run_single_child's timeout executor and the
async-delegation pool).
- delegate_task's batch path keeps live-transcript wiring while routing
child construction through the shared
_build_child_preserving_parent_tools helper.
Shaun Prince
Teknium
Tony Simons