fix(realtime): await cancelled background tasks in _cleanup()

[devteamaegis]

Summary

Fixes #3334 — RealtimeSession._cleanup() now awaits cancelled guardrail and tool-call tasks before closing the model, so their finally-blocks always complete.

Root cause

_cleanup_guardrail_tasks() and _cleanup_tool_call_tasks() called task.cancel() and immediately cleared the tracking sets, never awaiting the cancelled coroutines:

def _cleanup_guardrail_tasks(self) -> None:   # before
    for task in self._guardrail_tasks:
        if not task.done():
            task.cancel()
    self._guardrail_tasks.clear()             # tasks discarded, not awaited

Because task.cancel() only schedules a CancelledError injection, the tasks' finally-blocks run asynchronously after _cleanup() had already returned. Cancellation exceptions and callbacks could fire after the session had moved on to model.close().

Fix

Both helpers now return the list of pending tasks. _cleanup() gathers them before touching the model:

pending_tasks = (
    self._cleanup_guardrail_tasks() + self._cleanup_tool_call_tasks()
)
if pending_tasks:
    await asyncio.gather(*pending_tasks, return_exceptions=True)
# model.remove_listener / model.close() follow here

return_exceptions=True prevents CancelledError from propagating out of _cleanup() while ensuring every task fully drains.

Tests

tests/realtime/test_realtime_cleanup.py — 4 tests:

• test_cleanup_awaits_guardrail_task_finally_block — finally-block of a cancelled guardrail task runs before _cleanup() returns
• test_cleanup_awaits_tool_call_task_finally_block — same for tool-call tasks
• test_cleanup_awaits_both_task_types_before_model_close — both finally-blocks precede model.close()
• test_cleanup_idempotent_when_no_pending_tasks — no error when task sets are empty

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Avoid awaiting the cleanup caller task

If cleanup is initiated from one of these background tasks, for example an async tool or guardrail that calls await session.close(), the task set still contains asyncio.current_task(), so this gather() attempts to await the task that is currently executing after cancelling it. That can deadlock or recurse through cancellation and prevents the model from being closed; filter the current task out of pending_tasks before awaiting the rest.

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