Re-use the same Event Loop for each coroutine

Function asyncio.run creates a new event loop each time it's called and
executes coroutine in that new loop.  However, we want all our coroutines to
be executed from the same event loop, so we acquire a loop when lacre.daemon
starts and then use it to execute them later.

See: Disroot/gpg-lacre#109

lacre/daemon.py

@@ -47,6 +47,9 @@ class MailEncryptionProxy:
         except TypeError as te:
             LOG.exception("Got exception while processing", exc_info=te)
             return RESULT_ERROR
+        except:
+            LOG.exception('Unexpected exception caught, bouncing message')
+            return RESULT_ERROR
 
         ellapsed = (time.process_time() - start) * 1000
         LOG.info(f'Message delivered in {ellapsed:.2f} ms')
@@ -88,7 +91,8 @@ def _main():
     _validate_config()
 
     keyring_path = conf.get_item('gpg', 'keyhome')
-    keyring = kcache.KeyRing(keyring_path)
+    loop = asyncio.get_event_loop()
+    keyring = kcache.KeyRing(keyring_path, loop)
     controller = _init_controller(keyring)
     reloader = _init_reloader(keyring_path, keyring)
 
@@ -99,7 +103,7 @@ def _main():
     controller.start()
 
     try:
-        asyncio.run(_sleep())
+        loop.run_until_complete(_sleep())
     except KeyboardInterrupt:
         LOG.info("Finishing...")
     except:

lacre/keyring.py

@@ -9,7 +9,7 @@ import lacre.config as conf
 import logging
 from os import stat
 from watchdog.events import FileSystemEventHandler, FileSystemEvent
-from asyncio import Semaphore, run
+from asyncio import Semaphore, create_task, get_event_loop
 import copy
 
 import GnuPG
@@ -73,12 +73,13 @@ class KeyRing:
     fingerprint=>email maps.
     """
 
-    def __init__(self, path: str):
+    def __init__(self, path: str, loop=None):
         """Initialise the adapter."""
         self._path = path
         self._keys = self._load_and_sanitize()
         self._sema = Semaphore()
         self._last_mod = None
+        self._loop = loop or get_event_loop()
 
     def _load_and_sanitize(self):
         keys = self._load_keyring_from(self._path)
@@ -96,7 +97,8 @@ class KeyRing:
     def load(self):
         """Load keyring, replacing any previous contents of the cache."""
         LOG.debug('Reloading keys...')
-        run(self._load())
+        tsk = create_task(self._load(), 'LoadTask')
+        self._loop.run_until_complete(tsk)
 
     async def _load(self):
         last_mod = self._read_mod_time()