"""U11-7: the vLLM rollout worker (own session, serves forever) must not outlive rank 0."""
import importlib.util
import os
import sys

REPO = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))


def _load():
    spec = importlib.util.spec_from_file_location("grpo_under_test", os.path.join(REPO, "scripts", "grpo.py"))
    m = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(m)
    return m


class _Proc:
    pid = 4242


def test_spawn_bounds_worker_lifetime_and_registers_teardown(monkeypatch, tmp_path):
    grpo = _load()
    import align.rollout.client as client

    seen = {}
    monkeypatch.setattr(client, "spawn_worker", lambda *a, **kw: seen.update(kw) or _Proc())
    killed = []
    monkeypatch.setattr(client, "terminate_worker", lambda p, *a, **kw: killed.append(p))
    registered = []
    monkeypatch.setattr(grpo.atexit, "register", lambda fn, *a, **kw: registered.append((fn, a)))

    proc = grpo._spawn_rollout_worker(str(tmp_path / "spool"), 3, str(tmp_path / "w.log"))
    assert proc.pid == 4242
    # not 'serve forever': an orphaned worker (rank 0 SIGKILLed) must exit by itself
    assert seen["idle_exit_s"] > 0
    # an exception anywhere between spawn and the train try/finally still tears it down
    assert len(registered) == 1
    fn, args = registered[0]
    fn(*args)
    assert killed == [proc]