Merge pull request #2098 from tnull/2023-03-add-channel-pending-event
[rust-lightning] / lightning-background-processor / src / lib.rs
index 1d0d787388e43d8e5d2564cd54f16ebff4b127c7..541813c7e42c72f68568ec1c397fc531156d158c 100644 (file)
@@ -7,7 +7,7 @@
 #![deny(private_intra_doc_links)]
 
 #![deny(missing_docs)]
-#![deny(unsafe_code)]
+#![cfg_attr(not(feature = "futures"), deny(unsafe_code))]
 
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
 
@@ -26,6 +26,9 @@ use lightning::chain;
 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use lightning::chain::chainmonitor::{ChainMonitor, Persist};
 use lightning::chain::keysinterface::{EntropySource, NodeSigner, SignerProvider};
+use lightning::events::{Event, PathFailure};
+#[cfg(feature = "std")]
+use lightning::events::{EventHandler, EventsProvider};
 use lightning::ln::channelmanager::ChannelManager;
 use lightning::ln::msgs::{ChannelMessageHandler, OnionMessageHandler, RoutingMessageHandler};
 use lightning::ln::peer_handler::{CustomMessageHandler, PeerManager, SocketDescriptor};
@@ -33,9 +36,6 @@ use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
 use lightning::routing::utxo::UtxoLookup;
 use lightning::routing::router::Router;
 use lightning::routing::scoring::{Score, WriteableScore};
-use lightning::util::events::{Event, PathFailure};
-#[cfg(feature = "std")]
-use lightning::util::events::{EventHandler, EventsProvider};
 use lightning::util::logger::Logger;
 use lightning::util::persist::Persister;
 use lightning_rapid_gossip_sync::RapidGossipSync;
@@ -52,8 +52,6 @@ use std::thread::{self, JoinHandle};
 #[cfg(feature = "std")]
 use std::time::Instant;
 
-#[cfg(feature = "futures")]
-use futures_util::{select_biased, future::FutureExt, task};
 #[cfg(not(feature = "std"))]
 use alloc::vec::Vec;
 
@@ -80,7 +78,7 @@ use alloc::vec::Vec;
 /// unilateral chain closure fees are at risk.
 ///
 /// [`ChannelMonitor`]: lightning::chain::channelmonitor::ChannelMonitor
-/// [`Event`]: lightning::util::events::Event
+/// [`Event`]: lightning::events::Event
 #[cfg(feature = "std")]
 #[must_use = "BackgroundProcessor will immediately stop on drop. It should be stored until shutdown."]
 pub struct BackgroundProcessor {
@@ -384,6 +382,50 @@ macro_rules! define_run_body {
        } }
 }
 
+#[cfg(feature = "futures")]
+pub(crate) mod futures_util {
+       use core::future::Future;
+       use core::task::{Poll, Waker, RawWaker, RawWakerVTable};
+       use core::pin::Pin;
+       use core::marker::Unpin;
+       pub(crate) struct Selector<A: Future<Output=()> + Unpin, B: Future<Output=bool> + Unpin> {
+               pub a: A,
+               pub b: B,
+       }
+       pub(crate) enum SelectorOutput {
+               A, B(bool),
+       }
+
+       impl<A: Future<Output=()> + Unpin, B: Future<Output=bool> + Unpin> Future for Selector<A, B> {
+               type Output = SelectorOutput;
+               fn poll(mut self: Pin<&mut Self>, ctx: &mut core::task::Context<'_>) -> Poll<SelectorOutput> {
+                       match Pin::new(&mut self.a).poll(ctx) {
+                               Poll::Ready(()) => { return Poll::Ready(SelectorOutput::A); },
+                               Poll::Pending => {},
+                       }
+                       match Pin::new(&mut self.b).poll(ctx) {
+                               Poll::Ready(res) => { return Poll::Ready(SelectorOutput::B(res)); },
+                               Poll::Pending => {},
+                       }
+                       Poll::Pending
+               }
+       }
+
+       // If we want to poll a future without an async context to figure out if it has completed or
+       // not without awaiting, we need a Waker, which needs a vtable...we fill it with dummy values
+       // but sadly there's a good bit of boilerplate here.
+       fn dummy_waker_clone(_: *const ()) -> RawWaker { RawWaker::new(core::ptr::null(), &DUMMY_WAKER_VTABLE) }
+       fn dummy_waker_action(_: *const ()) { }
+
+       const DUMMY_WAKER_VTABLE: RawWakerVTable = RawWakerVTable::new(
+               dummy_waker_clone, dummy_waker_action, dummy_waker_action, dummy_waker_action);
+       pub(crate) fn dummy_waker() -> Waker { unsafe { Waker::from_raw(RawWaker::new(core::ptr::null(), &DUMMY_WAKER_VTABLE)) } }
+}
+#[cfg(feature = "futures")]
+use futures_util::{Selector, SelectorOutput, dummy_waker};
+#[cfg(feature = "futures")]
+use core::task;
+
 /// Processes background events in a future.
 ///
 /// `sleeper` should return a future which completes in the given amount of time and returns a
@@ -470,16 +512,20 @@ where
                chain_monitor, chain_monitor.process_pending_events_async(async_event_handler).await,
                channel_manager, channel_manager.process_pending_events_async(async_event_handler).await,
                gossip_sync, peer_manager, logger, scorer, should_break, {
-                       select_biased! {
-                               _ = channel_manager.get_persistable_update_future().fuse() => true,
-                               exit = sleeper(Duration::from_millis(100)).fuse() => {
+                       let fut = Selector {
+                               a: channel_manager.get_persistable_update_future(),
+                               b: sleeper(Duration::from_millis(100)),
+                       };
+                       match fut.await {
+                               SelectorOutput::A => true,
+                               SelectorOutput::B(exit) => {
                                        should_break = exit;
                                        false
                                }
                        }
                }, |t| sleeper(Duration::from_secs(t)),
                |fut: &mut SleepFuture, _| {
-                       let mut waker = task::noop_waker();
+                       let mut waker = dummy_waker();
                        let mut ctx = task::Context::from_waker(&mut waker);
                        core::pin::Pin::new(fut).poll(&mut ctx).is_ready()
                })
@@ -663,7 +709,8 @@ mod tests {
        use lightning::chain::channelmonitor::ANTI_REORG_DELAY;
        use lightning::chain::keysinterface::{InMemorySigner, KeysManager};
        use lightning::chain::transaction::OutPoint;
-       use lightning::get_event_msg;
+       use lightning::events::{Event, PathFailure, MessageSendEventsProvider, MessageSendEvent};
+       use lightning::{get_event_msg, get_event};
        use lightning::ln::PaymentHash;
        use lightning::ln::channelmanager;
        use lightning::ln::channelmanager::{BREAKDOWN_TIMEOUT, ChainParameters, MIN_CLTV_EXPIRY_DELTA, PaymentId};
@@ -674,7 +721,6 @@ mod tests {
        use lightning::routing::router::{DefaultRouter, RouteHop};
        use lightning::routing::scoring::{ChannelUsage, Score};
        use lightning::util::config::UserConfig;
-       use lightning::util::events::{Event, PathFailure, MessageSendEventsProvider, MessageSendEvent};
        use lightning::util::ser::Writeable;
        use lightning::util::test_utils;
        use lightning::util::persist::KVStorePersister;
@@ -1012,7 +1058,10 @@ mod tests {
                ($node_a: expr, $node_b: expr, $temporary_channel_id: expr, $tx: expr) => {{
                        $node_a.node.funding_transaction_generated(&$temporary_channel_id, &$node_b.node.get_our_node_id(), $tx.clone()).unwrap();
                        $node_b.node.handle_funding_created(&$node_a.node.get_our_node_id(), &get_event_msg!($node_a, MessageSendEvent::SendFundingCreated, $node_b.node.get_our_node_id()));
+                       get_event!($node_b, Event::ChannelPending);
+
                        $node_a.node.handle_funding_signed(&$node_b.node.get_our_node_id(), &get_event_msg!($node_b, MessageSendEvent::SendFundingSigned, $node_a.node.get_our_node_id()));
+                       get_event!($node_a, Event::ChannelPending);
                }}
        }