Disconnect from Bluetooth devices before the server stops

The polling threads are daemon threads, so a stop ended the server in the middle of a Bluetooth read. The read got no disconnect, and the adapter kept an open connection or a scan in progress.

The server now sets the stop event at exit, closes its socket, and waits at most 20 seconds for the polling threads. A Bluetooth read that sees the stop event cancels its current step, disconnects, and returns. A read that waits for the adapter does not connect after a stop.

tests/test_server.py

@@ -25,6 +25,7 @@ def _poll_once(devices, stop, debug=0):
     for device in devices.values():
         device.data = collect_device_data(device, debug)
         device.polled.set()
+    return []
 
 
 # ---------------------------------------------------------------------------
@@ -217,6 +218,39 @@ listener.accept()
         assert result.stderr.strip() == "terminating"
         assert not socket_path.exists()
 
+    def test_sigterm_during_a_bluetooth_read_waits_for_the_disconnect(self, tmp_path):
+        """The server process itself, with a stand-in for the Bluetooth read."""
+        socket_path = tmp_path / "bms.sock"
+        script = """
+import os
+import signal
+import sys
+import threading
+from bmspy import server
+
+def bluetooth_read(config, debug=0, stop=None):
+    if stop.is_set():
+        return False
+    print("read started", flush=True)
+    threading.Timer(0.1, os.kill, args=(os.getpid(), signal.SIGTERM)).start()
+    stop.wait(10)
+    print("disconnected", flush=True)
+    return False
+
+server.ecoflow_collect_data = bluetooth_read
+sys.argv = ["bmspy-server", "--socket", sys.argv[1],
+            "-d", "river@02:00:00:00:00:01/R601TEST00000001/test-user"]
+server.main()
+"""
+        result = subprocess.run(
+            [sys.executable, "-c", script, str(socket_path)],
+            capture_output=True, text=True, timeout=30,
+        )
+        assert result.stdout.splitlines() == ["read started", "disconnected"]
+        assert result.returncode == 1
+        assert result.stderr.strip() == "terminating"
+        assert not socket_path.exists()
+
 
 # ---------------------------------------------------------------------------
 # socket_cleanup
@@ -765,7 +799,7 @@ class TestServerMain:
              patch("bmspy.server.signal.signal"), \
              patch("bmspy.server.atexit.register"), \
              patch("bmspy.server.initialise_serial"), \
-             patch("bmspy.server.start_polling"), \
+             patch("bmspy.server.start_polling", return_value=[]), \
              patch("bmspy.server.os.path.isdir", return_value=True), \
              patch.object(socket_module.socket, "accept", side_effect=KeyboardInterrupt):
             from bmspy.server import main as server_main
@@ -773,6 +807,31 @@ class TestServerMain:
                 server_main()
         assert exit_info.value.code == 1
 
+    def test_exit_closes_the_socket_and_stops_polling(self, tmp_path):
+        sock_path = str(tmp_path / "server_stop.sock")
+        threads = [object()]
+        listeners = []
+        original_listen = socket_module.socket.listen
+
+        def listen(self, backlog=1):
+            listeners.append(self)
+            return original_listen(self, backlog)
+
+        with patch("sys.argv", ["bmspy-server", "--socket", sock_path, "--device", "/dev/ttyUSB0"]), \
+             patch("bmspy.server.signal.signal"), \
+             patch("bmspy.server.atexit.register"), \
+             patch("bmspy.server.initialise_serial"), \
+             patch("bmspy.server.start_polling", return_value=threads) as start, \
+             patch("bmspy.server.stop_polling") as stop_polling, \
+             patch("bmspy.server.os.path.isdir", return_value=True), \
+             patch.object(socket_module.socket, "listen", listen), \
+             patch.object(socket_module.socket, "accept", side_effect=KeyboardInterrupt):
+            from bmspy.server import main as server_main
+            with pytest.raises(SystemExit):
+                server_main()
+        stop_polling.assert_called_once_with(threads, start.call_args.args[1])
+        assert listeners[0].fileno() == -1
+
     def test_socket_read_error_logs_and_continues(self, tmp_path, capsys):
         """Test that read_request errors are caught and logged."""
         sock_path = str(tmp_path / "server_err.sock")
@@ -1098,7 +1157,7 @@ class TestServerMain:
              patch("bmspy.server.signal.signal"), \
              patch("bmspy.server.atexit.register"), \
              patch("bmspy.server.initialise_serial"), \
-             patch("bmspy.server.start_polling"), \
+             patch("bmspy.server.start_polling", return_value=[]), \
              patch("bmspy.server.os.path.isdir", return_value=True), \
              patch.object(socket_module.socket, "accept", side_effect=OSError("accept failed")) as accept:
             from bmspy.server import main as server_main