lnworker: add own taskgroup (run in daemon.taskgroup)

electrum/lnpeer.py

@@ -238,7 +238,7 @@ class Peer(Logger):
                 self.close_and_cleanup()
         return wrapper_func
 
-    @ignore_exceptions  # do not kill main_taskgroup
+    @ignore_exceptions  # do not kill outer taskgroup
     @log_exceptions
     @handle_disconnect
     async def main_loop(self):

electrum/lnworker.py

@@ -32,7 +32,7 @@ from .transaction import Transaction
 from .crypto import sha256
 from .bip32 import BIP32Node
 from .util import bh2u, bfh, InvoiceError, resolve_dns_srv, is_ip_address, log_exceptions
-from .util import ignore_exceptions, make_aiohttp_session
+from .util import ignore_exceptions, make_aiohttp_session, SilentTaskGroup
 from .util import timestamp_to_datetime
 from .util import MyEncoder
 from .logging import Logger
@@ -126,6 +126,7 @@ class LNWorker(Logger):
         Logger.__init__(self)
         self.node_keypair = generate_keypair(BIP32Node.from_xkey(xprv), LnKeyFamily.NODE_KEY)
         self.peers = {}  # type: Dict[bytes, Peer]  # pubkey -> Peer
+        self.taskgroup = SilentTaskGroup()
         # set some feature flags as baseline for both LNWallet and LNGossip
         # note that e.g. DATA_LOSS_PROTECT is needed for LNGossip as many peers require it
         self.localfeatures = LnLocalFeatures(0)
@@ -136,6 +137,7 @@ class LNWorker(Logger):
         return {}
 
     async def maybe_listen(self):
+        # FIXME: only one LNWorker can listen at a time (single port)
         listen_addr = self.config.get('lightning_listen')
         if listen_addr:
             addr, port = listen_addr.rsplit(':', 2)
@@ -151,11 +153,21 @@ class LNWorker(Logger):
                     return
                 peer = Peer(self, node_id, transport)
                 self.peers[node_id] = peer
-                await self.network.main_taskgroup.spawn(peer.main_loop())
+                await self.taskgroup.spawn(peer.main_loop())
-            await asyncio.start_server(cb, addr, int(port))
+            try:
+                await asyncio.start_server(cb, addr, int(port))
+            except OSError as e:
+                self.logger.error(f"cannot listen for lightning p2p. error: {e!r}")
 
-    @log_exceptions
+    @ignore_exceptions  # don't kill outer taskgroup
     async def main_loop(self):
+        try:
+            async with self.taskgroup as group:
+                await group.spawn(self._maintain_connectivity())
+        except Exception as e:
+            self.logger.exception("taskgroup died.")
+
+    async def _maintain_connectivity(self):
         while True:
             await asyncio.sleep(1)
             now = time.time()
@@ -176,7 +188,7 @@ class LNWorker(Logger):
         self._last_tried_peer[peer_addr] = time.time()
         self.logger.info(f"adding peer {peer_addr}")
         peer = Peer(self, node_id, transport)
-        await self.network.main_taskgroup.spawn(peer.main_loop())
+        await self.taskgroup.spawn(peer.main_loop())
         self.peers[node_id] = peer
         return peer
 
@@ -328,7 +340,7 @@ class LNGossip(LNWorker):
     def start_network(self, network: 'Network'):
         assert network
         super().start_network(network)
-        asyncio.run_coroutine_threadsafe(network.daemon.taskgroup.spawn(self.maintain_db()), self.network.asyncio_loop)
+        asyncio.run_coroutine_threadsafe(self.taskgroup.spawn(self.maintain_db()), self.network.asyncio_loop)
 
     async def maintain_db(self):
         await self.channel_db.load_data()
@@ -429,7 +441,6 @@ class LNWallet(LNWorker):
         self.lnwatcher = LNWalletWatcher(self, network)
         self.lnwatcher.start_network(network)
         self.network = network
-        daemon = network.daemon
         for chan_id, chan in self.channels.items():
             self.lnwatcher.add_channel(chan.funding_outpoint.to_str(), chan.get_funding_address())
 
@@ -441,8 +452,8 @@ class LNWallet(LNWorker):
                 self.sync_with_local_watchtower(),
                 self.sync_with_remote_watchtower(),
         ]:
-            # FIXME: exceptions in those coroutines will cancel daemon.taskgroup
+            tg_coro = self.taskgroup.spawn(coro)
-            asyncio.run_coroutine_threadsafe(daemon.taskgroup.spawn(coro), self.network.asyncio_loop)
+            asyncio.run_coroutine_threadsafe(tg_coro, self.network.asyncio_loop)
 
     def peer_closed(self, peer):
         for chan in self.channels_for_peer(peer.pubkey).values():
@@ -1285,8 +1296,7 @@ class LNWallet(LNWorker):
                 if peer:
                     await peer.group.spawn(peer.reestablish_channel(chan))
                 else:
-                    await self.network.main_taskgroup.spawn(
+                    await self.taskgroup.spawn(self.reestablish_peer_for_given_channel(chan))
-                        self.reestablish_peer_for_given_channel(chan))
 
     def current_feerate_per_kw(self):
         from .simple_config import FEE_LN_ETA_TARGET, FEERATE_FALLBACK_STATIC_FEE, FEERATE_REGTEST_HARDCODED