"""Regression: #71671 — gateway must survive faulthandler.enable() with sys.stderr=None."""

from __future__ import annotations

import sys

import pytest




_SIGUSR2_CHILD = """
import os, signal, sys, time
from types import SimpleNamespace
sys.path.insert(0, sys.argv[2])
from gateway.run_startup import GatewayStartupMixin
runner = object.__new__(GatewayStartupMixin)
runner.config = SimpleNamespace(log_dir=sys.argv[1])
runner._start_install_faulthandler()
print("ready", flush=True)
time.sleep(30)
"""


@pytest.mark.skipif(not hasattr(__import__("signal"), "SIGUSR2"), reason="POSIX-only signal")
def test_sigusr2_stack_dump_leaves_the_gateway_running(tmp_path):
    """#110437 — SIGUSR2 must dump stacks to the log and return; chaining to the
    signal's default disposition (terminate) killed the process being inspected."""
    import os
    import signal
    import subprocess
    import time

    repo_root = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
    child = subprocess.Popen(
        [sys.executable, "-c", _SIGUSR2_CHILD, str(tmp_path), repo_root],
        stdin=subprocess.DEVNULL, stdout=subprocess.PIPE, text=True,
    )
    try:
        assert child.stdout.readline().strip() == "ready"
        child.send_signal(signal.SIGUSR2)
        time.sleep(0.5)
        assert child.poll() is None, f"gateway died on SIGUSR2 (rc={child.returncode})"
    finally:
        child.kill()
        child.wait()
    dump = (tmp_path / "gateway_faulthandler.log").read_text(encoding="utf-8")
    assert "Thread 0x" in dump or "Current thread" in dump