lnworker: clear paysessions dict

electrum/lnworker.py

@@ -693,6 +693,7 @@ class PaySession(Logger):
 
         self._amount_inflight = 0  # what we sent in htlcs (that receiver gets, without fees)
         self._nhtlcs_inflight = 0
+        self.is_active = True
 
     def diagnostic_name(self):
         pkey = sha256(self.payment_key)
@@ -779,6 +780,14 @@ class PaySession(Logger):
     def get_outstanding_amount_to_send(self) -> int:
         return self.amount_to_pay - self._amount_inflight
 
+    def can_be_deleted(self) -> bool:
+        if self.is_active:
+            return False
+        # note: no one is consuming from sent_htlcs_q anymore
+        nhtlcs_resolved = self.sent_htlcs_q.qsize()
+        assert nhtlcs_resolved <= self._nhtlcs_inflight
+        return nhtlcs_resolved == self._nhtlcs_inflight
+
 
 class LNWallet(LNWorker):
 
@@ -1412,7 +1421,7 @@ class LNWallet(LNWorker):
                 raise OnionRoutingFailure(code=OnionFailureCode.TRAMPOLINE_EXPIRY_TOO_SOON, data=b'')
 
         payment_key = payment_hash + payment_secret
-        #assert payment_key not in self._paysessions  # FIXME
+        assert payment_key not in self._paysessions
         self._paysessions[payment_key] = paysession = PaySession(
             payment_hash=payment_hash,
             payment_secret=payment_secret,
@@ -1429,6 +1438,7 @@ class LNWallet(LNWorker):
         # when encountering trampoline forwarding difficulties in the legacy case, we
         # sometimes need to fall back to a single trampoline forwarder, at the expense
         # of privacy
+        try:
             while True:
                 if (amount_to_send := paysession.get_outstanding_amount_to_send()) > 0:
                     # 1. create a set of routes for remaining amount.
@@ -1488,6 +1498,10 @@ class LNWallet(LNWorker):
                 else:
                     self.handle_error_code_from_failed_htlc(
                         route=route, sender_idx=sender_idx, failure_msg=failure_msg, amount=htlc_log.amount_msat)
+        finally:
+            paysession.is_active = False
+            if paysession.can_be_deleted():
+                self._paysessions.pop(payment_key)
 
     async def pay_to_route(
             self, *,
@@ -2225,6 +2239,8 @@ class LNWallet(LNWorker):
                 amount_msat=shi.amount_receiver_msat,
                 trampoline_fee_level=shi.trampoline_fee_level)
             q.put_nowait(htlc_log)
+            if paysession.can_be_deleted():
+                self._paysessions.pop(payment_key)
         else:
             key = payment_hash.hex()
             self.set_invoice_status(key, PR_PAID)
@@ -2278,6 +2294,8 @@ class LNWallet(LNWorker):
                 sender_idx=sender_idx,
                 trampoline_fee_level=shi.trampoline_fee_level)
             q.put_nowait(htlc_log)
+            if paysession.can_be_deleted():
+                self._paysessions.pop(payment_okey)
         else:
             self.logger.info(f"received unknown htlc_failed, probably from previous session")
             key = payment_hash.hex()