add total_diff to ping/pong msgs (#350)

* add total_diff to ping/pong msgs
debug log for total_diff on each ping/pong

* expose peer addr to the handle_payload fn
so we know where it came from

* fix p2p tests for ping

* default to 0 if we cannot read total_difficulty

* updating a connected peer in place

* actually update peer info diff

* fixup p2p tests

api/src/handlers.rs

@@ -247,6 +247,7 @@ impl Handler for PeersConnectedHandler {
 	fn handle(&self, _req: &mut Request) -> IronResult<Response> {
 		let mut peers = vec![];
 		for p in &self.p2p_server.all_peers() {
+			let p = p.read().unwrap();
 			let peer_info = p.info.clone();
 			peers.push(peer_info);
 		}

grin/src/adapters.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::collections::HashMap;
 use std::net::SocketAddr;
 use std::sync::{Arc, RwLock};
 use std::thread;
@@ -21,7 +22,7 @@ use core::core::{self, Output};
 use core::core::block::BlockHeader;
 use core::core::hash::{Hash, Hashed};
 use core::core::target::Difficulty;
-use p2p::{self, NetAdapter, PeerData, PeerStore, Server, State};
+use p2p::{self, NetAdapter, Peer, PeerData, PeerStore, Server, State};
 use pool;
 use util::secp::pedersen::Commitment;
 use util::OneTime;
@@ -35,8 +36,8 @@ use util::LOGGER;
 pub struct NetToChainAdapter {
 	chain: Arc<chain::Chain>,
 	peer_store: Arc<PeerStore>,
+	connected_peers: Arc<RwLock<HashMap<SocketAddr, Arc<RwLock<Peer>>>>>,
 	tx_pool: Arc<RwLock<pool::TransactionPool<PoolToChainAdapter>>>,
-
 	syncer: OneTime<Arc<sync::Syncer>>,
 }
 
@@ -247,6 +248,24 @@ impl NetAdapter for NetToChainAdapter {
 			error!(LOGGER, "Could not save connected peer: {:?}", e);
 		}
 	}
+
+	fn peer_difficulty(&self, addr: SocketAddr, diff: Difficulty) {
+		debug!(
+			LOGGER,
+			"peer total_diff (ping/pong): {}, {} vs us {}",
+			addr,
+			diff,
+			self.total_difficulty(),
+		);
+
+		if diff.into_num() > 0 {
+			let peers = self.connected_peers.write().unwrap();
+			if let Some(peer) = peers.get(&addr) {
+				let mut peer = peer.write().unwrap();
+				peer.info.total_difficulty = diff;
+			}
+		}
+	}
 }
 
 impl NetToChainAdapter {
@@ -254,10 +273,12 @@ impl NetToChainAdapter {
 		chain_ref: Arc<chain::Chain>,
 		tx_pool: Arc<RwLock<pool::TransactionPool<PoolToChainAdapter>>>,
 		peer_store: Arc<PeerStore>,
+		connected_peers: Arc<RwLock<HashMap<SocketAddr, Arc<RwLock<Peer>>>>>,
 	) -> NetToChainAdapter {
 		NetToChainAdapter {
 			chain: chain_ref,
 			peer_store: peer_store,
+			connected_peers: connected_peers,
 			tx_pool: tx_pool,
 			syncer: OneTime::new(),
 		}

grin/src/seed.rs

@@ -96,6 +96,7 @@ impl Seeder {
 				// if needed
 				let disconnected = p2p_server.clean_peers();
 				for p in disconnected {
+					let p = p.read().unwrap();
 					if p.is_banned() {
 						debug!(LOGGER, "Marking peer {} as banned.", p.info.addr);
 						let update_result =
@@ -282,6 +283,7 @@ fn connect_and_req(
 	let fut = timeout.then(move |p| {
 		match p {
 			Ok(Some(p)) => {
+				let p = p.read().unwrap();
 				let peer_result = p.send_peer_request(capab);
 				match peer_result {
 					Ok(()) => {}

grin/src/server.rs

@@ -16,6 +16,7 @@
 //! the peer-to-peer server, the blockchain and the transaction pool) and acts
 //! as a facade.
 
+use std::collections::HashMap;
 use std::net::SocketAddr;
 use std::sync::{Arc, RwLock};
 use std::thread;
@@ -108,16 +109,21 @@ impl Server {
 
 		pool_adapter.set_chain(shared_chain.clone());
 
+		// Currently connected peers. Used by both the net_adapter and the p2p_server.
+		let connected_peers = Arc::new(RwLock::new(HashMap::new()));
+
 		let peer_store = Arc::new(p2p::PeerStore::new(config.db_root.clone())?);
 		let net_adapter = Arc::new(NetToChainAdapter::new(
 			shared_chain.clone(),
 			tx_pool.clone(),
 			peer_store.clone(),
+			connected_peers.clone(),
 		));
 
 		let p2p_server = Arc::new(p2p::Server::new(
 			config.capabilities,
 			config.p2p_config.unwrap(),
+			connected_peers.clone(),
 			net_adapter.clone(),
 			genesis.hash(),
 		));

grin/src/sync.rs

@@ -107,6 +107,7 @@ impl Syncer {
 
 			// TODO do something better (like trying to get more) if we lose peers
 			let peer = self.p2p.most_work_peer().expect("No peers available for sync.");
+			let peer = peer.read().unwrap();
 			debug!(
 				LOGGER,
 				"Sync: peer {} vs us {}",
@@ -245,6 +246,7 @@ impl Syncer {
 		let peer = self.p2p.most_work_peer();
 		let locator = self.get_locator(&tip)?;
 		if let Some(p) = peer {
+			let p = p.read().unwrap();
 			debug!(
 				LOGGER,
 				"Asking peer {} for more block headers, locator: {:?}",
@@ -313,6 +315,7 @@ impl Syncer {
 	/// Pick a random peer and ask for a block by hash
 	fn request_block(&self, h: Hash) {
 		let peer = self.p2p.random_peer().unwrap();
+		let peer = peer.read().unwrap();
 		let send_result = peer.send_block_request(h);
 		if let Err(e) = send_result {
 			debug!(LOGGER, "Error requesting block: {:?}", e);

p2p/src/msg.rs

@@ -475,18 +475,50 @@ impl Readable for Headers {
 	}
 }
 
-/// Placeholder for messages like Ping and Pong that don't send anything but
+pub struct Ping {
-/// the header.
+	/// total difficulty accumulated by the sender, used to check whether sync
-pub struct Empty {}
+	/// may be needed
+	pub total_difficulty: Difficulty,
+}
 
-impl Writeable for Empty {
+impl Writeable for Ping {
-	fn write<W: Writer>(&self, _: &mut W) -> Result<(), ser::Error> {
+	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ser::Error> {
+		self.total_difficulty.write(writer).unwrap();
 		Ok(())
 	}
 }
 
-impl Readable for Empty {
+impl Readable for Ping {
-	fn read(_: &mut Reader) -> Result<Empty, ser::Error> {
+	fn read(reader: &mut Reader) -> Result<Ping, ser::Error> {
-		Ok(Empty {})
+		// TODO - once everyone is sending total_difficulty we can clean this up
+		let total_difficulty = match Difficulty::read(reader) {
+			Ok(diff) => diff,
+			Err(_) => Difficulty::zero(),
+		};
+		Ok(Ping { total_difficulty })
+	}
+}
+
+pub struct Pong {
+	/// total difficulty accumulated by the sender, used to check whether sync
+	/// may be needed
+	pub total_difficulty: Difficulty,
+}
+
+impl Writeable for Pong {
+	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ser::Error> {
+		self.total_difficulty.write(writer).unwrap();
+		Ok(())
+	}
+}
+
+impl Readable for Pong {
+	fn read(reader: &mut Reader) -> Result<Pong, ser::Error> {
+		// TODO - once everyone is sending total_difficulty we can clean this up
+		let total_difficulty = match Difficulty::read(reader) {
+			Ok(diff) => diff,
+			Err(_) => Difficulty::zero(),
+		};
+		Ok(Pong { total_difficulty })
 	}
 }

p2p/src/peer.rs

@@ -94,7 +94,7 @@ impl Peer {
 		let state = self.state.clone();
 		let adapter = Arc::new(self.tracking_adapter.clone());
 
-		Box::new(self.proto.handle(conn, adapter).then(move |res| {
+		Box::new(self.proto.handle(conn, adapter, addr).then(move |res| {
 			// handle disconnection, standard disconnections aren't considered an error
 			let mut state = state.write().unwrap();
 			match res {
@@ -134,8 +134,8 @@ impl Peer {
 		self.proto.transmitted_bytes()
 	}
 
-	pub fn send_ping(&self) -> Result<(), Error> {
+	pub fn send_ping(&self, total_difficulty: Difficulty) -> Result<(), Error> {
-		self.proto.send_ping()
+		self.proto.send_ping(total_difficulty)
 	}
 
 	/// Sends the provided block to the remote peer. The request may be dropped
@@ -252,4 +252,8 @@ impl NetAdapter for TrackingAdapter {
 	fn peer_connected(&self, pi: &PeerInfo) {
 		self.adapter.peer_connected(pi)
 	}
+
+	fn peer_difficulty(&self, addr: SocketAddr, diff: Difficulty) {
+		self.adapter.peer_difficulty(addr, diff)
+	}
 }

p2p/src/protocol.rs

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 use std::sync::Arc;
+use std::net::SocketAddr;
 
 use futures::Future;
 use futures::sync::mpsc::UnboundedSender;
@@ -20,6 +21,7 @@ use tokio_core::net::TcpStream;
 
 use core::core;
 use core::core::hash::Hash;
+use core::core::target::Difficulty;
 use core::ser;
 use conn::TimeoutConnection;
 use msg::*;
@@ -46,10 +48,11 @@ impl Protocol for ProtocolV1 {
 		&self,
 		conn: TcpStream,
 		adapter: Arc<NetAdapter>,
+		addr: SocketAddr,
 	) -> Box<Future<Item = (), Error = Error>> {
 		let (conn, listener) = TimeoutConnection::listen(conn, move |sender, header, data| {
 			let adapt = adapter.as_ref();
-			handle_payload(adapt, sender, header, data)
+			handle_payload(adapt, sender, header, data, addr)
 		});
 
 		self.conn.init(conn);
@@ -64,8 +67,13 @@ impl Protocol for ProtocolV1 {
 
 	/// Sends a ping message to the remote peer. Will panic if handle has never
 	/// been called on this protocol.
-	fn send_ping(&self) -> Result<(), Error> {
+	fn send_ping(&self, total_difficulty: Difficulty) -> Result<(), Error> {
-		self.send_request(Type::Ping, Type::Pong, &Empty {}, None)
+		self.send_request(
+			Type::Ping,
+			Type::Pong,
+			&Ping { total_difficulty },
+			None,
+		)
 	}
 
 	/// Serializes and sends a block to our remote peer
@@ -129,14 +137,29 @@ fn handle_payload(
 	sender: UnboundedSender<Vec<u8>>,
 	header: MsgHeader,
 	buf: Vec<u8>,
+	addr: SocketAddr,
 ) -> Result<Option<Hash>, ser::Error> {
 	match header.msg_type {
 		Type::Ping => {
-			let data = ser::ser_vec(&MsgHeader::new(Type::Pong, 0))?;
+			let ping = ser::deserialize::<Ping>(&mut &buf[..])?;
+			adapter.peer_difficulty(addr, ping.total_difficulty);
+			let pong = Pong { total_difficulty: adapter.total_difficulty() };
+			let mut body_data = vec![];
+			try!(ser::serialize(&mut body_data, &pong));
+			let mut data = vec![];
+			try!(ser::serialize(
+				&mut data,
+				&MsgHeader::new(Type::Pong, body_data.len() as u64),
+			));
+			data.append(&mut body_data);
 			sender.unbounded_send(data).unwrap();
 			Ok(None)
 		}
-		Type::Pong => Ok(None),
+		Type::Pong => {
+			let pong = ser::deserialize::<Pong>(&mut &buf[..])?;
+			adapter.peer_difficulty(addr, pong.total_difficulty);
+			Ok(None)
+		},
 		Type::Transaction => {
 			let tx = ser::deserialize::<core::Transaction>(&mut &buf[..])?;
 			adapter.transaction_received(tx);

p2p/src/server.rs

@@ -18,7 +18,6 @@
 use std::cell::RefCell;
 use std::collections::HashMap;
 use std::net::SocketAddr;
-use std::ops::Deref;
 use std::sync::{Arc, RwLock};
 use std::time::Duration;
 
@@ -58,6 +57,7 @@ impl NetAdapter for DummyAdapter {
 	}
 	fn peer_addrs_received(&self, _: Vec<SocketAddr>) {}
 	fn peer_connected(&self, _: &PeerInfo) {}
+	fn peer_difficulty(&self, _: SocketAddr, _: Difficulty) {}
 }
 
 /// P2P server implementation, handling bootstrapping to find and connect to
@@ -65,7 +65,7 @@ impl NetAdapter for DummyAdapter {
 pub struct Server {
 	config: P2PConfig,
 	capabilities: Capabilities,
-	peers: Arc<RwLock<HashMap<SocketAddr, Arc<Peer>>>>,
+	peers: Arc<RwLock<HashMap<SocketAddr, Arc<RwLock<Peer>>>>>,
 	handshake: Arc<Handshake>,
 	adapter: Arc<NetAdapter>,
 	stop: RefCell<Option<futures::sync::oneshot::Sender<()>>>,
@@ -80,13 +80,14 @@ impl Server {
 	pub fn new(
 		capab: Capabilities,
 		config: P2PConfig,
+		peers: Arc<RwLock<HashMap<SocketAddr, Arc<RwLock<Peer>>>>>,
 		adapter: Arc<NetAdapter>,
 		genesis: Hash,
 	) -> Server {
 		Server {
 			config: config,
 			capabilities: capab,
-			peers: Arc::new(RwLock::new(HashMap::new())),
+			peers: peers,
 			handshake: Arc::new(Handshake::new(genesis)),
 			adapter: adapter,
 			stop: RefCell::new(None),
@@ -108,19 +109,27 @@ impl Server {
 		// main peer acceptance future handling handshake
 		let hp = h.clone();
 		let peers_listen = socket.incoming().map_err(From::from).map(move |(conn, _)| {
-			let adapter = adapter.clone();
-			let total_diff = adapter.total_difficulty();
 			let peers = peers.clone();
+			let total_diff = adapter.total_difficulty();
 
 			// accept the peer and add it to the server map
-			let accept = Peer::accept(conn, capab, total_diff, &handshake.clone(), adapter.clone());
+			let accept = Peer::accept(
-			let added = add_to_peers(peers, adapter, accept);
+				conn,
+				capab,
+				total_diff,
+				&handshake.clone(),
+				adapter.clone(),
+			);
+			let added = add_to_peers(peers, adapter.clone(), accept);
 
 			// wire in a future to timeout the accept after 5 secs
 			let timed_peer = with_timeout(Box::new(added), &hp);
 
 			// run the main peer protocol
-			timed_peer.and_then(move |(conn, peer)| peer.clone().run(conn))
+			timed_peer.and_then(move |(conn, peer)| {
+				let peer = peer.read().unwrap();
+				peer.run(conn)
+			})
 		});
 
 		// spawn each peer future to its own task
@@ -143,12 +152,15 @@ impl Server {
 			*stop_mut = Some(stop);
 		}
 
+
 		// timer to regularly check on our peers by pinging them
+		let adapter = self.adapter.clone();
 		let peers_inner = self.peers.clone();
 		let peers_timer = Timer::default()
 			.interval(Duration::new(20, 0))
 			.fold((), move |_, _| {
-				check_peers(peers_inner.clone());
+				let total_diff = adapter.total_difficulty();
+				check_peers(peers_inner.clone(), total_diff);
 				Ok(())
 			});
 
@@ -172,7 +184,7 @@ impl Server {
 		&self,
 		addr: SocketAddr,
 		h: reactor::Handle,
-	) -> Box<Future<Item = Option<Arc<Peer>>, Error = Error>> {
+	) -> Box<Future<Item = Option<Arc<RwLock<Peer>>>, Error = Error>> {
 		if let Some(p) = self.get_peer(addr) {
 			// if we're already connected to the addr, just return the peer
 			return Box::new(future::ok(Some(p)));
@@ -206,11 +218,12 @@ impl Server {
 				with_timeout(Box::new(added), &h)
 			})
 			.and_then(move |(socket, peer)| {
-				h2.spawn(peer.run(socket).map_err(|e| {
+				let peer_inner = peer.read().unwrap();
+				h2.spawn(peer_inner.run(socket).map_err(|e| {
 					error!(LOGGER, "Peer error: {:?}", e);
 					()
 				}));
-				Ok(Some(peer))
+				Ok(Some(peer.clone()))
 			});
 		Box::new(request)
 	}
@@ -220,32 +233,34 @@ impl Server {
 		self.get_peer(addr).is_some()
 	}
 
-	pub fn all_peers(&self) -> Vec<Arc<Peer>> {
+	pub fn all_peers(&self) -> Vec<Arc<RwLock<Peer>>> {
 		self.peers.read().unwrap().values().map(|p| p.clone()).collect()
 	}
 
 	/// Get a peer we're connected to by address.
-	pub fn get_peer(&self, addr: SocketAddr) -> Option<Arc<Peer>> {
+	pub fn get_peer(&self, addr: SocketAddr) -> Option<Arc<RwLock<Peer>>> {
 		self.peers.read().unwrap().get(&addr).map(|p| p.clone())
 	}
 
 	/// Have the server iterate over its peer list and prune all peers we have
 	/// lost connection to or have been deemed problematic. The removed peers
 	/// are returned.
-	pub fn clean_peers(&self) -> Vec<Arc<Peer>> {
+	pub fn clean_peers(&self) -> Vec<Arc<RwLock<Peer>>> {
 		let mut rm = vec![];
 
 		// build a list of peers to be cleaned up
 		for peer in self.all_peers() {
-			if !peer.is_connected() {
+			let peer_inner = peer.read().unwrap();
-				debug!(LOGGER, "cleaning {:?}, not connected", peer.info.addr);
+			if !peer_inner.is_connected() {
-				rm.push(peer);
+				debug!(LOGGER, "cleaning {:?}, not connected", peer_inner.info.addr);
+				rm.push(peer.clone());
 			}
 		}
 
 		// now clean up peer map based on the list to remove
 		let mut peers = self.peers.write().unwrap();
 		for p in rm.clone() {
+			let p = p.read().unwrap();
 			peers.remove(&p.info.addr);
 		}
 
@@ -254,22 +269,21 @@ impl Server {
 
 	/// Returns the peer with the most worked branch, showing the highest total
 	/// difficulty.
-	pub fn most_work_peer(&self) -> Option<Arc<Peer>> {
+	pub fn most_work_peer(&self) -> Option<Arc<RwLock<Peer>>> {
-		let peers = self.all_peers();
+		let mut peers = self.all_peers();
 		if peers.len() == 0 {
 			return None;
 		}
-		let mut res = peers[0].clone();
+		peers.sort_by_key(|p| {
-		for p in peers.deref() {
+			let p = p.read().unwrap();
-			if p.is_connected() && res.info.total_difficulty < p.info.total_difficulty {
+			p.info.total_difficulty.clone()
-				res = (*p).clone();
+		});
-			}
+		let peer = peers.last().unwrap();
-		}
+		Some(peer.clone())
-		Some(res)
 	}
 
 	/// Returns a random peer we're connected to.
-	pub fn random_peer(&self) -> Option<Arc<Peer>> {
+	pub fn random_peer(&self) -> Option<Arc<RwLock<Peer>>> {
 		let peers = self.all_peers();
 		if peers.len() == 0 {
 			None
@@ -285,7 +299,8 @@ impl Server {
 	pub fn broadcast_block(&self, b: &core::Block) {
 		let peers = self.all_peers();
 		let mut count = 0;
-		for p in peers.deref() {
+		for p in peers {
+			let p = p.read().unwrap();
 			if p.is_connected() {
 				if let Err(e) = p.send_block(b) {
 					debug!(LOGGER, "Error sending block to peer: {:?}", e);
@@ -294,7 +309,7 @@ impl Server {
 				}
 			}
 		}
-		debug!(LOGGER, "Bardcasted block {} to {} peers.", b.header.height, count);
+		debug!(LOGGER, "Broadcasted block {} to {} peers.", b.header.height, count);
 	}
 
 	/// Broadcasts the provided transaction to all our peers. A peer
@@ -302,7 +317,8 @@ impl Server {
 	/// remote peer already has the transaction.
 	pub fn broadcast_transaction(&self, tx: &core::Transaction) {
 		let peers = self.all_peers();
-		for p in peers.deref() {
+		for p in peers {
+			let p = p.read().unwrap();
 			if p.is_connected() {
 				if let Err(e) = p.send_transaction(tx) {
 					debug!(LOGGER, "Error sending block to peer: {:?}", e);
@@ -320,7 +336,8 @@ impl Server {
 	pub fn stop(self) {
 		info!(LOGGER, "calling stop on server");
 		let peers = self.all_peers();
-		for p in peers.deref() {
+		for p in peers {
+			let p = p.write().unwrap();
 			p.stop();
 		}
 		self.stop.into_inner().unwrap().send(()).unwrap();
@@ -329,17 +346,17 @@ impl Server {
 
 // Adds the peer built by the provided future in the peers map
 fn add_to_peers<A>(
-	peers: Arc<RwLock<HashMap<SocketAddr, Arc<Peer>>>>,
+	peers: Arc<RwLock<HashMap<SocketAddr, Arc<RwLock<Peer>>>>>,
 	adapter: Arc<NetAdapter>,
 	peer_fut: A,
-) -> Box<Future<Item = Result<(TcpStream, Arc<Peer>), ()>, Error = Error>>
+) -> Box<Future<Item = Result<(TcpStream, Arc<RwLock<Peer>>), ()>, Error = Error>>
 where
 	A: IntoFuture<Item = (TcpStream, Peer), Error = Error> + 'static,
 {
 	let peer_add = peer_fut.into_future().map(move |(conn, peer)| {
 		adapter.peer_connected(&peer.info);
 		let addr = peer.info.addr.clone();
-		let apeer = Arc::new(peer);
+		let apeer = Arc::new(RwLock::new(peer));
 		let mut peers = peers.write().unwrap();
 		peers.insert(addr, apeer.clone());
 		Ok((conn, apeer))
@@ -349,11 +366,15 @@ where
 
 // Ping all our connected peers. Always automatically expects a pong back or
 // disconnects. This acts as a liveness test.
-fn check_peers(peers: Arc<RwLock<HashMap<SocketAddr, Arc<Peer>>>>) {
+fn check_peers(
+	peers: Arc<RwLock<HashMap<SocketAddr, Arc<RwLock<Peer>>>>>,
+	total_difficulty: Difficulty,
+) {
 	let peers_map = peers.read().unwrap();
 	for p in peers_map.values() {
+		let p = p.read().unwrap();
 		if p.is_connected() {
-			let _ = p.send_ping();
+			let _ = p.send_ping(total_difficulty.clone());
 		}
 	}
 }

p2p/src/types.rs

@@ -126,11 +126,11 @@ pub trait Protocol {
 	/// be  known already, usually passed during construction. Will typically
 	/// block so needs to be called withing a coroutine. Should also be called
 	/// only once.
-	fn handle(&self, conn: TcpStream, na: Arc<NetAdapter>)
+	fn handle(&self, conn: TcpStream, na: Arc<NetAdapter>, addr: SocketAddr)
 		-> Box<Future<Item = (), Error = Error>>;
 
 	/// Sends a ping message to the remote peer.
-	fn send_ping(&self) -> Result<(), Error>;
+	fn send_ping(&self, total_difficulty: Difficulty) -> Result<(), Error>;
 
 	/// Relays a block to the remote peer.
 	fn send_block(&self, b: &core::Block) -> Result<(), Error>;
@@ -189,4 +189,7 @@ pub trait NetAdapter: Sync + Send {
 
 	/// Network successfully connected to a peer.
 	fn peer_connected(&self, &PeerInfo);
+
+	/// Heard total_difficulty from a connected peer (via ping/pong).
+	fn peer_difficulty(&self, SocketAddr, Difficulty);
 }

p2p/tests/peer_handshake.rs

@@ -17,8 +17,9 @@ extern crate grin_core as core;
 extern crate grin_p2p as p2p;
 extern crate tokio_core;
 
+use std::collections::HashMap;
 use std::net::SocketAddr;
-use std::sync::Arc;
+use std::sync::{Arc, RwLock};
 use std::time;
 
 use futures::future::Future;
@@ -37,9 +38,11 @@ fn peer_handshake() {
 	let handle = evtlp.handle();
 	let p2p_conf = p2p::P2PConfig::default();
 	let net_adapter = Arc::new(p2p::DummyAdapter {});
+	let connected_peers = Arc::new(RwLock::new(HashMap::new()));
 	let server = p2p::Server::new(
 		p2p::UNKNOWN,
 		p2p_conf,
+		connected_peers,
 		net_adapter.clone(),
 		Hash::from_vec(vec![]),
 	);
@@ -73,7 +76,7 @@ fn peer_handshake() {
 						rhandle.spawn(peer.run(socket).map_err(|e| {
 							panic!("Client run failed: {:?}", e);
 						}));
-						peer.send_ping().unwrap();
+						peer.send_ping(Difficulty::one()).unwrap();
 						timeout_send.from_err().map(|_| peer)
 					})
 					.and_then(|peer| {