Merge pull request adafruit#22 from dhalbert/cleanup-on-exit

disconnect connections on ctrl-c

_bleio/adapter_.py

@@ -31,6 +31,7 @@
 from typing import Iterable, Optional, Union
 
 import asyncio
+import atexit
 import platform
 import threading
 import time
@@ -84,6 +85,18 @@ def __init__(self):
         # device scanning.
         self._cached_devices = {}
 
+        # Clean up connections, etc. when exiting (even by KeyboardInterrupt)
+        atexit.register(self._cleanup)
+
+    def _cleanup(self):
+        """Clean up connections, so that the underlying OS software does not
+        leave them open.
+        """
+        # Use a copy of the list because each connection will be deleted
+        # on disconnect().
+        for connection in self._connections.copy():
+            connection.disconnect()
+
     @property
     def _use_hcitool(self):
         if self._hcitool_is_usable is None:
@@ -367,7 +380,6 @@ async def _connect_async(self, address: Address, *, timeout: float) -> None:
         client = BleakClient(device if device else address._bleak_address)
         # connect() takes a timeout, but it's a timeout to do a
         # discover() scan, not an actual connect timeout.
-        # TODO: avoid the second discovery.
         try:
             await client.connect(timeout=timeout)
             # This does not seem to connect reliably.