chore(p2p): Add stop to delayed calls

hathor/conf/settings.py

@@ -392,6 +392,9 @@ def MAXIMUM_NUMBER_OF_HALVINGS(self) -> int:
     # All settings related to Feature Activation
     FEATURE_ACTIVATION: FeatureActivationSettings = FeatureActivationSettings()
 
+    # Maximum number of GET_TIPS delayed calls while running sync.
+    MAX_GET_TIPS_DELAYED_CALLS: int = 5
+
     @classmethod
     def from_yaml(cls, *, filepath: str) -> 'HathorSettings':
         """Takes a filepath to a yaml file and returns a validated HathorSettings instance."""

hathor/p2p/node_sync.py

@@ -623,6 +623,11 @@ def send_tips(self, timestamp: Optional[int] = None, include_hashes: bool = Fals
         """Try to send a TIPS message. If rate limit has been reached, it schedules to send it later."""
         if not self.global_rate_limiter.add_hit(self.GlobalRateLimiter.SEND_TIPS):
             self.log.debug('send_tips throttled')
+            if len(self._send_tips_call_later) > settings.MAX_GET_TIPS_DELAYED_CALLS:
+                self.protocol.send_error_and_close_connection(
+                    'Too many GET_TIPS message'
+                )
+                return
             self._send_tips_call_later.append(
                 self.reactor.callLater(
                     1, self.send_tips, timestamp, include_hashes, offset