Introduce new property to OutboundV1Channel

- This property keep track of if the OutboundV1Channel is accepted by
  the peer.

Author: shaavan

lightning/src/ln/channel.rs

@@ -633,6 +633,10 @@ pub(crate) const DISCONNECT_PEER_AWAITING_RESPONSE_TICKS: usize = 2;
 /// exceeding this age limit will be force-closed and purged from memory.
 pub(crate) const UNFUNDED_CHANNEL_AGE_LIMIT_TICKS: usize = 60;
 
+/// The number of ticks that may elapse while we're waiting for an outbound channel to be accepted by peer.
+/// An unaccepted channel exceeding this age limit will be force-closed and purged from memory.
+pub(crate) const UNACCEPTED_CHANNEL_AGE_LIMIT_TICKS: usize = 2;
+
 /// Number of blocks needed for an output from a coinbase transaction to be spendable.
 pub(crate) const COINBASE_MATURITY: u32 = 100;
 
@@ -673,6 +677,34 @@ impl<'a, SP: Deref> ChannelPhase<SP> where
 	}
 }
 
+pub(super) struct UnacceptedChannelContext {
+	/// A counter tracking how many ticks have elapsed since this unaccepted channel was
+	/// created. If this unaccepted channel reaches peer has yet to respond after reaching
+	/// `UNACCEPTED_CHANNEL_AGE_LIMIT_TICKS`, it will be force-closed and purged from memory.
+	///
+	/// This is so that we don't keep outbound request around which have not been accepted
+	/// in a timely manner
+	unaccepted_channel_age_ticks: usize,
+	is_channel_accepted: bool,
+}
+
+impl UnacceptedChannelContext {
+	/// Determines whether we should force-close and purge this unfunded channel from memory due to it
+	/// having reached the unfunded channel age limit.
+	///
+	/// This should be called on every [`super::channelmanager::ChannelManager::timer_tick_occurred`].
+	pub fn should_expire_unaccepted_channel(&mut self) -> bool {
+		if self.is_channel_accepted { return false; }
+		self.unaccepted_channel_age_ticks += 1;
+		self.unaccepted_channel_age_ticks >= UNACCEPTED_CHANNEL_AGE_LIMIT_TICKS
+	}
+
+	/// Set channel status to accepted
+	pub fn channel_accepted(&mut self) {
+		self.is_channel_accepted = true;
+	}
+}
+
 /// Contains all state common to unfunded inbound/outbound channels.
 pub(super) struct UnfundedChannelContext {
 	/// A counter tracking how many ticks have elapsed since this unfunded channel was
@@ -5948,6 +5980,7 @@ impl<SP: Deref> Channel<SP> where
 pub(super) struct OutboundV1Channel<SP: Deref> where SP::Target: SignerProvider {
 	pub context: ChannelContext<SP>,
 	pub unfunded_context: UnfundedChannelContext,
+	pub unaccepted_context: UnacceptedChannelContext,
 }
 
 impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
@@ -6152,7 +6185,8 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 
 				blocked_monitor_updates: Vec::new(),
 			},
-			unfunded_context: UnfundedChannelContext { unfunded_channel_age_ticks: 0 }
+			unfunded_context: UnfundedChannelContext { unfunded_channel_age_ticks: 0 },
+			unaccepted_context: UnacceptedChannelContext { unaccepted_channel_age_ticks: 0, is_channel_accepted: false }
 		})
 	}