Public commit record
35/100 · Opaque
What the developer wrote
Authored by f321x
add helper method: run_htlc_switch_iteration
no code modification, indent-only
✓ Descriptive subject! No meaningful explanatory body
What changed, and why it matters
This commit is a pure code restructure: it extracts the inner body of Electrum's Lightning HTLC switching loop into a new private helper method named `_run_htlc_switch_iteration`. The commit message explicitly says 'no code modification, indent-only', and the diff matches that claim. There are no functional changes, no security fixes, and no new behavior introduced.
Recommended action
No security action needed. Treat as a normal refactoring commit.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The change refactors Peer.htlc_switch() in electrum/lnpeer.py by moving the per-iteration HTLC processing logic into a synchronous helper _run_htlc_switch_iteration(). The original loop body is indented one level and wrapped in a method decorated with @util.profiler. A runtime assertion assert not inspect.iscoroutinefunction(self._run_htlc_switch_iteration) is added to preserve the existing no-context-switch invariant. No logic, control flow, or data handling changes are made.
Changed components
electrum/lnpeer.pyLightning HTLC switch loopInspect captured patch +76 / −71
diff --git a/electrum/lnpeer.py b/electrum/lnpeer.py
index 39c6cf9..dc40eb0 100644
--- a/electrum/lnpeer.py
+++ b/electrum/lnpeer.py
@@ -2742,13 +2742,9 @@ class Peer(Logger, EventListener):
return closing_tx.txid()
async def htlc_switch(self):
- # In this loop, an item of chan.unfulfilled_htlcs may go through 4 stages:
- # - 1. not forwarded yet: (None, onion_packet_hex)
- # - 2. forwarded: (forwarding_key, onion_packet_hex)
- # - 3. processed: (forwarding_key, None), not irrevocably removed yet
- # - 4. done: (forwarding_key, None), irrevocably removed
-
await self.initialized
+ # don't context switch in a htlc switch iteration as htlc sets are shared between peers
+ assert not inspect.iscoroutinefunction(self._run_htlc_switch_iteration)
while True:
await self.ping_if_required()
self._htlc_switch_iterdone_event.set()
@@ -2764,75 +2760,84 @@ class Peer(Logger, EventListener):
await group.spawn(self.downstream_htlc_resolved_event.wait())
self._htlc_switch_iterstart_event.set()
self._htlc_switch_iterstart_event.clear()
- self._maybe_cleanup_received_htlcs_pending_removal()
- for chan_id, chan in self.channels.items():
- if not chan.can_update_ctx(proposer=LOCAL):
+ self._run_htlc_switch_iteration()
+
+ @util.profiler(min_threshold=0.02)
+ def _run_htlc_switch_iteration(self):
+ self._maybe_cleanup_received_htlcs_pending_removal()
+ # In this loop, an item of chan.unfulfilled_htlcs may go through 4 stages:
+ # - 1. not forwarded yet: (None, onion_packet_hex)
+ # - 2. forwarded: (forwarding_key, onion_packet_hex)
+ # - 3. processed: (forwarding_key, None), not irrevocably removed yet
+ # - 4. done: (forwarding_key, None), irrevocably removed
+ for chan_id, chan in self.channels.items():
+ if not chan.can_update_ctx(proposer=LOCAL):
+ continue
+ self.maybe_send_commitment(chan)
+ done = set()
+ unfulfilled = chan.unfulfilled_htlcs
+ for htlc_id, (onion_packet_hex, forwarding_key) in unfulfilled.items():
+ if not chan.hm.is_htlc_irrevocably_added_yet(htlc_proposer=REMOTE, htlc_id=htlc_id):
+ continue
+ htlc = chan.hm.get_htlc_by_id(REMOTE, htlc_id)
+ if chan.hm.is_htlc_irrevocably_removed_yet(htlc_proposer=REMOTE, htlc_id=htlc_id):
+ assert onion_packet_hex is None
+ self.lnworker.maybe_cleanup_mpp(chan.get_scid_or_local_alias(), htlc)
+ if forwarding_key:
+ self.lnworker.maybe_cleanup_forwarding(forwarding_key)
+ done.add(htlc_id)
continue
- self.maybe_send_commitment(chan)
- done = set()
- unfulfilled = chan.unfulfilled_htlcs
- for htlc_id, (onion_packet_hex, forwarding_key) in unfulfilled.items():
- if not chan.hm.is_htlc_irrevocably_added_yet(htlc_proposer=REMOTE, htlc_id=htlc_id):
- continue
- htlc = chan.hm.get_htlc_by_id(REMOTE, htlc_id)
- if chan.hm.is_htlc_irrevocably_removed_yet(htlc_proposer=REMOTE, htlc_id=htlc_id):
- assert onion_packet_hex is None
- self.lnworker.maybe_cleanup_mpp(chan.get_scid_or_local_alias(), htlc)
- if forwarding_key:
- self.lnworker.maybe_cleanup_forwarding(forwarding_key)
- done.add(htlc_id)
- continue
- if onion_packet_hex is None:
- # has been processed already
- continue
- error_reason = None # type: Optional[OnionRoutingFailure]
- error_bytes = None # type: Optional[bytes]
- preimage = None
- onion_packet_bytes = bytes.fromhex(onion_packet_hex)
- onion_packet = None
+ if onion_packet_hex is None:
+ # has been processed already
+ continue
+ error_reason = None # type: Optional[OnionRoutingFailure]
+ error_bytes = None # type: Optional[bytes]
+ preimage = None
+ onion_packet_bytes = bytes.fromhex(onion_packet_hex)
+ onion_packet = None
+ try:
+ onion_packet = OnionPacket.from_bytes(onion_packet_bytes)
+ except OnionRoutingFailure as e:
+ error_reason = e
+ else:
try:
- onion_packet = OnionPacket.from_bytes(onion_packet_bytes)
+ preimage, _forwarding_key, error_bytes = self.process_unfulfilled_htlc(
+ chan=chan,
+ htlc=htlc,
+ forwarding_key=forwarding_key,
+ onion_packet_bytes=onion_packet_bytes,
+ onion_packet=onion_packet)
+ if _forwarding_key:
+ assert forwarding_key is None
+ unfulfilled[htlc_id] = onion_packet_hex, _forwarding_key
except OnionRoutingFailure as e:
- error_reason = e
+ error_bytes = construct_onion_error(e, onion_packet.public_key, self.privkey, self.network.get_local_height())
+ if error_bytes:
+ error_bytes = obfuscate_onion_error(error_bytes, onion_packet.public_key, our_onion_private_key=self.privkey)
+
+ if preimage or error_reason or error_bytes:
+ if preimage:
+ self.lnworker.set_request_status(htlc.payment_hash, PR_PAID)
+ if not self.lnworker.enable_htlc_settle:
+ continue
+ self.fulfill_htlc(chan, htlc.htlc_id, preimage)
+ elif error_bytes:
+ self.fail_htlc(
+ chan=chan,
+ htlc_id=htlc.htlc_id,
+ error_bytes=error_bytes)
else:
- try:
- preimage, _forwarding_key, error_bytes = self.process_unfulfilled_htlc(
- chan=chan,
- htlc=htlc,
- forwarding_key=forwarding_key,
- onion_packet_bytes=onion_packet_bytes,
- onion_packet=onion_packet)
- if _forwarding_key:
- assert forwarding_key is None
- unfulfilled[htlc_id] = onion_packet_hex, _forwarding_key
- except OnionRoutingFailure as e:
- error_bytes = construct_onion_error(e, onion_packet.public_key, self.privkey, self.network.get_local_height())
- if error_bytes:
- error_bytes = obfuscate_onion_error(error_bytes, onion_packet.public_key, our_onion_private_key=self.privkey)
-
- if preimage or error_reason or error_bytes:
- if preimage:
- self.lnworker.set_request_status(htlc.payment_hash, PR_PAID)
- if not self.lnworker.enable_htlc_settle:
- continue
- self.fulfill_htlc(chan, htlc.htlc_id, preimage)
- elif error_bytes:
- self.fail_htlc(
- chan=chan,
- htlc_id=htlc.htlc_id,
- error_bytes=error_bytes)
- else:
- self.fail_malformed_htlc(
- chan=chan,
- htlc_id=htlc.htlc_id,
- reason=error_reason)
- # blank onion field to mark it as processed
- unfulfilled[htlc_id] = None, forwarding_key
-
- # cleanup
- for htlc_id in done:
- unfulfilled.pop(htlc_id)
- self.maybe_send_commitment(chan)
+ self.fail_malformed_htlc(
+ chan=chan,
+ htlc_id=htlc.htlc_id,
+ reason=error_reason)
+ # blank onion field to mark it as processed
+ unfulfilled[htlc_id] = None, forwarding_key
+
+ # cleanup
+ for htlc_id in done:
+ unfulfilled.pop(htlc_id)
+ self.maybe_send_commitment(chan)
def _maybe_cleanup_received_htlcs_pending_removal(self) -> None:
done = set()
Risk score
Our methodology →Why this scored 15/100
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