Handle SIGHUP on Windows (#53)

* python on windows does not have SIGHUP - do not use lamba to not repeat the same def multiple times

* check all signals

* changelog

Author: Edoardo Gallo

CHANGELOG.md

@@ -7,6 +7,9 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Added
 - Call `disconnect()` method.
 
+### Fixed
+- Check signals supported by the environment. On Windows there is no `SIGHUP`.
+
 ## [2.0.0rc1] - 2019-10-28
 ### Added
 - Support for Calling `tap`, `tap_async` methods.

signalwire/relay/client.py

@@ -112,9 +112,15 @@ async def cancel_pending_tasks(self):
     [task.cancel() for task in tasks]
     await asyncio.gather(*tasks, return_exceptions=True)
 
+  def handle_signal(self):
+    asyncio.create_task(self.disconnect())
+
   def attach_signals(self):
-    for s in (signal.SIGHUP, signal.SIGTERM, signal.SIGINT):
-      self.loop.add_signal_handler(s, lambda: asyncio.create_task(self.disconnect()))
+    for s in ('SIGHUP', 'SIGTERM', 'SIGINT'):
+      try:
+        self.loop.add_signal_handler(getattr(signal, s), self.handle_signal)
+      except:
+        pass
 
   async def on_socket_open(self):
     try: