fix(gateway): force exit after graceful shutdown

Co-Authored-By: Paperclip <noreply@paperclip.ing>

gateway/run.py

@@ -18689,11 +18689,21 @@ def main():
             data = yaml.safe_load(f) or {}
             config = GatewayConfig.from_dict(data)
     
-    # Run the gateway - exit with code 1 if no platforms connected,
-    # so systemd Restart=on-failure will retry on transient errors (e.g. DNS)
+    # start_gateway() already performs graceful teardown before returning.
+    # Force-exit afterwards so a wedged non-daemon worker thread cannot block
+    # interpreter finalization and strand the gateway half-shut down.
     success = asyncio.run(start_gateway(config))
-    if not success:
-        sys.exit(1)
+    _exit_after_graceful_shutdown(success)
+
+
+def _exit_after_graceful_shutdown(success: bool) -> None:
+    """Flush stdio and terminate immediately after graceful shutdown."""
+    for stream in (sys.stdout, sys.stderr):
+        try:
+            stream.flush()
+        except Exception:
+            pass
+    os._exit(0 if success else 1)
 
 
 if __name__ == "__main__":

tests/gateway/test_gateway_process_exit.py

@@ -0,0 +1,58 @@
+from types import SimpleNamespace
+from unittest.mock import Mock
+
+import pytest
+
+import gateway.run as gateway_run
+
+
+class _ExitCalled(Exception):
+    def __init__(self, code: int):
+        super().__init__(code)
+        self.code = code
+
+
+def _raise_exit(code: int) -> None:
+    raise _ExitCalled(code)
+
+
+def test_main_force_exits_zero_after_clean_shutdown(monkeypatch):
+    async def fake_start_gateway(config=None):
+        return True
+
+    stdout = SimpleNamespace(flush=Mock())
+    stderr = SimpleNamespace(flush=Mock())
+
+    monkeypatch.setattr(gateway_run, "start_gateway", fake_start_gateway)
+    monkeypatch.setattr(gateway_run.os, "_exit", _raise_exit)
+    monkeypatch.setattr(gateway_run.sys, "argv", ["gateway.run"])
+    monkeypatch.setattr(gateway_run.sys, "stdout", stdout)
+    monkeypatch.setattr(gateway_run.sys, "stderr", stderr)
+
+    with pytest.raises(_ExitCalled) as exc_info:
+        gateway_run.main()
+
+    assert exc_info.value.code == 0
+    stdout.flush.assert_called_once_with()
+    stderr.flush.assert_called_once_with()
+
+
+def test_main_force_exits_one_after_failed_shutdown(monkeypatch):
+    async def fake_start_gateway(config=None):
+        return False
+
+    stdout = SimpleNamespace(flush=Mock())
+    stderr = SimpleNamespace(flush=Mock())
+
+    monkeypatch.setattr(gateway_run, "start_gateway", fake_start_gateway)
+    monkeypatch.setattr(gateway_run.os, "_exit", _raise_exit)
+    monkeypatch.setattr(gateway_run.sys, "argv", ["gateway.run"])
+    monkeypatch.setattr(gateway_run.sys, "stdout", stdout)
+    monkeypatch.setattr(gateway_run.sys, "stderr", stderr)
+
+    with pytest.raises(_ExitCalled) as exc_info:
+        gateway_run.main()
+
+    assert exc_info.value.code == 1
+    stdout.flush.assert_called_once_with()
+    stderr.flush.assert_called_once_with()