Improve tokio task execution (#1181)

* Add logging on shutdown

* Replace tokio::spawn with handle.spawn

* Upgrade tokio

* Add a task executor

* Beacon chain tasks use task executor

* Validator client tasks use task executor

* Rename runtime_handle to executor

* Add duration histograms; minor fixes

* Cleanup

* Fix logs

* Fix tests

* Remove random file

* Get enr dependency instead of libp2p

* Address some review comments

* Libp2p takes a TaskExecutor

* Ugly fix libp2p tests

* Move TaskExecutor to own file

* Upgrade Dockerfile rust version

* Minor fixes

* Revert "Ugly fix libp2p tests"

This reverts commit 58d4bb690f52de28d893943b7504d2d0c6621429.

* Pretty fix libp2p tests

* Add spawn_without_exit; change Counter to Gauge

* Tidy

* Move log from RuntimeContext to TaskExecutor

* Fix errors

* Replace histogram with int_gauge for async tasks

* Fix todo

* Fix memory leak in test by exiting all spawned tasks at the end

Cargo.lock

@@ -1161,7 +1161,10 @@ dependencies = [
  "env_logger",
  "eth2_config",
  "eth2_testnet_config",
+ "exit-future",
  "futures 0.3.5",
+ "lazy_static",
+ "lighthouse_metrics",
  "logging",
  "parking_lot 0.10.2",
  "slog",
@@ -1231,10 +1234,12 @@ dependencies = [
  "base64 0.12.1",
  "dirs",
  "discv5",
+ "environment",
  "error-chain",
  "eth2_ssz",
  "eth2_ssz_derive",
  "eth2_ssz_types",
+ "exit-future",
  "fnv",
  "futures 0.3.5",
  "hashset_delay",
@@ -1365,7 +1370,7 @@ dependencies = [
 name = "eth2_testnet_config"
 version = "0.2.0"
 dependencies = [
- "eth2-libp2p",
+ "enr",
  "eth2_ssz",
  "reqwest",
  "serde",
@@ -2932,9 +2937,11 @@ name = "network"
 version = "0.1.2"
 dependencies = [
  "beacon_chain",
+ "environment",
  "error-chain",
  "eth2-libp2p",
  "eth2_ssz",
+ "exit-future",
  "fnv",
  "futures 0.3.5",
  "genesis",
@@ -3808,6 +3815,7 @@ dependencies = [
  "assert_matches",
  "beacon_chain",
  "bls",
+ "environment",
  "eth2-libp2p",
  "eth2_config",
  "eth2_ssz",
@@ -4853,6 +4861,7 @@ name = "timer"
 version = "0.1.2"
 dependencies = [
  "beacon_chain",
+ "environment",
  "futures 0.3.5",
  "parking_lot 0.10.2",
  "slog",
@@ -5823,6 +5832,7 @@ dependencies = [
 name = "websocket_server"
 version = "0.1.2"
 dependencies = [
+ "environment",
  "futures 0.3.5",
  "serde",
  "serde_derive",

account_manager/Cargo.toml

@@ -31,5 +31,5 @@ eth2_wallet = { path = "../crypto/eth2_wallet" }
 eth2_wallet_manager = { path = "../common/eth2_wallet_manager" }
 rand = "0.7.2"
 validator_dir = { path = "../common/validator_dir", features = ["unencrypted_keys"] }
-tokio = {version = "0.2.20", features = ["full"]}
+tokio = { version = "0.2.21", features = ["full"] }
 eth2_keystore = { path = "../crypto/eth2_keystore" }

account_manager/src/validator/deposit.rs

@@ -83,7 +83,7 @@ pub fn cli_run<T: EthSpec>(
     matches: &ArgMatches<'_>,
     mut env: Environment<T>,
 ) -> Result<(), String> {
-    let log = env.core_context().log;
+    let log = env.core_context().log().clone();
 
     let data_dir = clap_utils::parse_path_with_default_in_home_dir(
         matches,

beacon_node/Cargo.toml

@@ -27,7 +27,7 @@ slog = { version = "2.5.2", features = ["max_level_trace", "release_max_level_tr
 slog-term = "2.5.0"
 slog-async = "2.5.0"
 ctrlc = { version = "3.1.4", features = ["termination"] }
-tokio = {version = "0.2.20", features = ["time"] }
+tokio = { version = "0.2.21", features = ["time"] }
 exit-future = "0.2.0"
 env_logger = "0.7.1"
 dirs = "2.0.2"

beacon_node/beacon_chain/Cargo.toml

@@ -33,7 +33,7 @@ eth2_ssz_derive = "0.1.0"
 state_processing = { path = "../../consensus/state_processing" }
 tree_hash = "0.1.0"
 types = { path = "../../consensus/types" }
-tokio = "0.2.20"
+tokio = "0.2.21"
 eth1 = { path = "../eth1" }
 websocket_server = { path = "../websocket_server" }
 futures = "0.3.5"
@@ -46,7 +46,8 @@ tempfile = "3.1.0"
 bitvec = "0.17.4"
 bls = { path = "../../crypto/bls" }
 safe_arith = { path = "../../consensus/safe_arith" }
+environment = { path = "../../lighthouse/environment" }
 
 [dev-dependencies]
 lazy_static = "1.4.0"
-environment = { path = "../../lighthouse/environment" }
+

beacon_node/beacon_chain/src/eth1_chain.rs

@@ -1,4 +1,5 @@
 use crate::metrics;
+use environment::TaskExecutor;
 use eth1::{Config as Eth1Config, Eth1Block, Service as HttpService};
 use eth2_hashing::hash;
 use slog::{debug, error, trace, Logger};
@@ -285,10 +286,8 @@ impl<T: EthSpec, S: Store<T>> CachingEth1Backend<T, S> {
     }
 
     /// Starts the routine which connects to the external eth1 node and updates the caches.
-    pub fn start(&self, exit: tokio::sync::oneshot::Receiver<()>) {
+    pub fn start(&self, handle: TaskExecutor) {
-        // don't need to spawn as a task is being spawned in auto_update
+        HttpService::auto_update(self.core.clone(), handle);
-        // TODO: check if this is correct
-        HttpService::auto_update(self.core.clone(), exit);
     }
 
     /// Instantiates `self` from an existing service.

beacon_node/client/Cargo.toml

@@ -28,7 +28,7 @@ error-chain = "0.12.2"
 serde_yaml = "0.8.11"
 slog = { version = "2.5.2", features = ["max_level_trace"] }
 slog-async = "2.5.0"
-tokio = "0.2.20"
+tokio = "0.2.21"
 dirs = "2.0.2"
 futures = "0.3.5"
 reqwest = "0.10.4"

beacon_node/client/src/builder.rs

@@ -21,6 +21,7 @@ use std::net::SocketAddr;
 use std::path::Path;
 use std::sync::Arc;
 use std::time::Duration;
+use timer::spawn_timer;
 use tokio::sync::mpsc::UnboundedSender;
 use types::{test_utils::generate_deterministic_keypairs, BeaconState, ChainSpec, EthSpec};
 use websocket_server::{Config as WebSocketConfig, WebSocketSender};
@@ -50,7 +51,6 @@ pub struct ClientBuilder<T: BeaconChainTypes> {
     beacon_chain_builder: Option<BeaconChainBuilder<T>>,
     beacon_chain: Option<Arc<BeaconChain<T>>>,
     eth1_service: Option<Eth1Service>,
-    exit_channels: Vec<tokio::sync::oneshot::Sender<()>>,
     event_handler: Option<T::EventHandler>,
     network_globals: Option<Arc<NetworkGlobals<T::EthSpec>>>,
     network_send: Option<UnboundedSender<NetworkMessage<T::EthSpec>>>,
@@ -84,7 +84,6 @@ where
             beacon_chain_builder: None,
             beacon_chain: None,
             eth1_service: None,
-            exit_channels: vec![],
             event_handler: None,
             network_globals: None,
             network_send: None,
@@ -132,7 +131,7 @@ where
             .ok_or_else(|| "beacon_chain_start_method requires a chain spec".to_string())?;
 
         let builder = BeaconChainBuilder::new(eth_spec_instance)
-            .logger(context.log.clone())
+            .logger(context.log().clone())
             .store(store)
             .store_migrator(store_migrator)
             .data_dir(data_dir)
@@ -150,7 +149,7 @@ where
         // Alternatively, if there's a beacon chain in the database then always resume
         // using it.
         let client_genesis = if client_genesis == ClientGenesis::FromStore && !chain_exists {
-            info!(context.log, "Defaulting to deposit contract genesis");
+            info!(context.log(), "Defaulting to deposit contract genesis");
 
             ClientGenesis::DepositContract
         } else if chain_exists {
@@ -172,7 +171,7 @@ where
                 genesis_state_bytes,
             } => {
                 info!(
-                    context.log,
+                    context.log(),
                     "Starting from known genesis state";
                 );
 
@@ -183,14 +182,14 @@ where
             }
             ClientGenesis::DepositContract => {
                 info!(
-                    context.log,
+                    context.log(),
                     "Waiting for eth2 genesis from eth1";
                     "eth1_endpoint" => &config.eth1.endpoint,
                     "contract_deploy_block" => config.eth1.deposit_contract_deploy_block,
                     "deposit_contract" => &config.eth1.deposit_contract_address
                 );
 
-                let genesis_service = Eth1GenesisService::new(config.eth1, context.log.clone());
+                let genesis_service = Eth1GenesisService::new(config.eth1, context.log().clone());
 
                 let genesis_state = genesis_service
                     .wait_for_genesis_state(
@@ -223,19 +222,18 @@ where
             .ok_or_else(|| "network requires a runtime_context")?
             .clone();
 
-        let (network_globals, network_send, network_exit) =
+        let (network_globals, network_send) =
-            NetworkService::start(beacon_chain, config, &context.runtime_handle, context.log)
+            NetworkService::start(beacon_chain, config, context.executor)
                 .map_err(|e| format!("Failed to start network: {:?}", e))?;
 
         self.network_globals = Some(network_globals);
         self.network_send = Some(network_send);
-        self.exit_channels.push(network_exit);
 
         Ok(self)
     }
 
     /// Immediately starts the timer service.
-    fn timer(mut self) -> Result<Self, String> {
+    fn timer(self) -> Result<Self, String> {
         let context = self
             .runtime_context
             .as_ref()
@@ -251,13 +249,9 @@ where
             .ok_or_else(|| "node timer requires a chain spec".to_string())?
             .milliseconds_per_slot;
 
-        let timer_exit = context
+        spawn_timer(context.executor, beacon_chain, milliseconds_per_slot)
-            .runtime_handle
-            .enter(|| timer::spawn(beacon_chain, milliseconds_per_slot))
             .map_err(|e| format!("Unable to start node timer: {}", e))?;
 
-        self.exit_channels.push(timer_exit);
-
         Ok(self)
     }
 
@@ -290,32 +284,28 @@ where
             network_chan: network_send,
         };
 
-        let log = context.log.clone();
+        let listening_addr = rest_api::start_server(
-        let (exit_channel, listening_addr) = context.runtime_handle.enter(|| {
+            context.executor,
-            rest_api::start_server(
+            &client_config.rest_api,
-                &client_config.rest_api,
+            beacon_chain,
-                beacon_chain,
+            network_info,
-                network_info,
+            client_config
-                client_config
+                .create_db_path()
-                    .create_db_path()
+                .map_err(|_| "unable to read data dir")?,
-                    .map_err(|_| "unable to read data dir")?,
+            client_config
-                client_config
+                .create_freezer_db_path()
-                    .create_freezer_db_path()
+                .map_err(|_| "unable to read freezer DB dir")?,
-                    .map_err(|_| "unable to read freezer DB dir")?,
+            eth2_config.clone(),
-                eth2_config.clone(),
+        )
-                log,
+        .map_err(|e| format!("Failed to start HTTP API: {:?}", e))?;
-            )
-            .map_err(|e| format!("Failed to start HTTP API: {:?}", e))
-        })?;
 
-        self.exit_channels.push(exit_channel);
         self.http_listen_addr = Some(listening_addr);
 
         Ok(self)
     }
 
     /// Immediately starts the service that periodically logs information each slot.
-    pub fn notifier(mut self) -> Result<Self, String> {
+    pub fn notifier(self) -> Result<Self, String> {
         let context = self
             .runtime_context
             .as_ref()
@@ -335,19 +325,13 @@ where
             .ok_or_else(|| "slot_notifier requires a chain spec".to_string())?
             .milliseconds_per_slot;
 
-        let exit_channel = context
+        spawn_notifier(
-            .runtime_handle
+            context.executor,
-            .enter(|| {
+            beacon_chain,
-                spawn_notifier(
+            network_globals,
-                    beacon_chain,
+            milliseconds_per_slot,
-                    network_globals,
+        )
-                    milliseconds_per_slot,
+        .map_err(|e| format!("Unable to start slot notifier: {}", e))?;
-                    context.log.clone(),
-                )
-            })
-            .map_err(|e| format!("Unable to start slot notifier: {}", e))?;
-
-        self.exit_channels.push(exit_channel);
 
         Ok(self)
     }
@@ -365,7 +349,6 @@ where
             network_globals: self.network_globals,
             http_listen_addr: self.http_listen_addr,
             websocket_listen_addr: self.websocket_listen_addr,
-            _exit_channels: self.exit_channels,
         }
     }
 }
@@ -436,22 +419,14 @@ where
             .ok_or_else(|| "websocket_event_handler requires a runtime_context")?
             .service_context("ws".into());
 
-        let (sender, exit_channel, listening_addr): (
+        let (sender, listening_addr): (WebSocketSender<TEthSpec>, Option<_>) = if config.enabled {
-            WebSocketSender<TEthSpec>,
+            let (sender, listening_addr) =
-            Option<_>,
+                websocket_server::start_server(context.executor, &config)?;
-            Option<_>,
+            (sender, Some(listening_addr))
-        ) = if config.enabled {
-            let (sender, exit, listening_addr) = context
-                .runtime_handle
-                .enter(|| websocket_server::start_server(&config, &context.log))?;
-            (sender, Some(exit), Some(listening_addr))
         } else {
-            (WebSocketSender::dummy(), None, None)
+            (WebSocketSender::dummy(), None)
         };
 
-        if let Some(channel) = exit_channel {
-            self.exit_channels.push(channel);
-        }
         self.event_handler = Some(sender);
         self.websocket_listen_addr = listening_addr;
 
@@ -494,7 +469,7 @@ where
             .clone()
             .ok_or_else(|| "disk_store requires a chain spec".to_string())?;
 
-        let store = HotColdDB::open(hot_path, cold_path, config, spec, context.log)
+        let store = HotColdDB::open(hot_path, cold_path, config, spec, context.log().clone())
             .map_err(|e| format!("Unable to open database: {:?}", e))?;
         self.store = Some(Arc::new(store));
         Ok(self)
@@ -555,7 +530,7 @@ where
         let store = self.store.clone().ok_or_else(|| {
             "background_migrator requires the store to be initialized".to_string()
         })?;
-        self.store_migrator = Some(BackgroundMigrator::new(store, context.log.clone()));
+        self.store_migrator = Some(BackgroundMigrator::new(store, context.log().clone()));
         Ok(self)
     }
 }
@@ -617,25 +592,23 @@ where
                         &persisted,
                         config.clone(),
                         store.clone(),
-                        &context.log,
+                        &context.log().clone(),
                     )
                     .map(|chain| chain.into_backend())
                 })
                 .unwrap_or_else(|| {
-                    Ok(CachingEth1Backend::new(config, context.log.clone(), store))
+                    Ok(CachingEth1Backend::new(
+                        config,
+                        context.log().clone(),
+                        store,
+                    ))
                 })?
         };
 
         self.eth1_service = None;
 
-        let exit = {
-            let (tx, rx) = tokio::sync::oneshot::channel();
-            self.exit_channels.push(tx);
-            rx
-        };
-
         // Starts the service that connects to an eth1 node and periodically updates caches.
-        context.runtime_handle.enter(|| backend.start(exit));
+        backend.start(context.executor);
 
         self.beacon_chain_builder = Some(beacon_chain_builder.eth1_backend(Some(backend)));
 

beacon_node/client/src/lib.rs

@@ -25,8 +25,6 @@ pub struct Client<T: BeaconChainTypes> {
     network_globals: Option<Arc<NetworkGlobals<T::EthSpec>>>,
     http_listen_addr: Option<SocketAddr>,
     websocket_listen_addr: Option<SocketAddr>,
-    /// Exit channels will complete/error when dropped, causing each service to exit gracefully.
-    _exit_channels: Vec<tokio::sync::oneshot::Sender<()>>,
 }
 
 impl<T: BeaconChainTypes> Client<T> {

beacon_node/client/src/notifier.rs

@@ -23,11 +23,11 @@ const SPEEDO_OBSERVATIONS: usize = 4;
 
 /// Spawns a notifier service which periodically logs information about the node.
 pub fn spawn_notifier<T: BeaconChainTypes>(
+    executor: environment::TaskExecutor,
     beacon_chain: Arc<BeaconChain<T>>,
     network: Arc<NetworkGlobals<T::EthSpec>>,
     milliseconds_per_slot: u64,
-    log: slog::Logger,
+) -> Result<(), String> {
-) -> Result<tokio::sync::oneshot::Sender<()>, String> {
     let slot_duration = Duration::from_millis(milliseconds_per_slot);
     let duration_to_next_slot = beacon_chain
         .slot_clock
@@ -41,6 +41,7 @@ pub fn spawn_notifier<T: BeaconChainTypes>(
     let interval_duration = slot_duration;
 
     let speedo = Mutex::new(Speedo::default());
+    let log = executor.log().clone();
     let mut interval = tokio::time::interval_at(start_instant, interval_duration);
 
     let interval_future = async move {
@@ -163,12 +164,10 @@ pub fn spawn_notifier<T: BeaconChainTypes>(
         Ok::<(), ()>(())
     };
 
-    let (exit_signal, exit) = tokio::sync::oneshot::channel();
-
     // run the notifier on the current executor
-    tokio::spawn(futures::future::select(Box::pin(interval_future), exit));
+    executor.spawn(interval_future.unwrap_or_else(|_| ()), "notifier");
 
-    Ok(exit_signal)
+    Ok(())
 }
 
 /// Returns the peer count, returning something helpful if it's `usize::max_value` (effectively a

beacon_node/eth1/Cargo.toml

@@ -6,7 +6,6 @@ edition = "2018"
 
 [dev-dependencies]
 eth1_test_rig = { path = "../../testing/eth1_test_rig" }
-environment = { path = "../../lighthouse/environment" }
 toml = "0.5.6"
 web3 = "0.11.0"
 sloggers = "1.0.0"
@@ -25,8 +24,9 @@ tree_hash = "0.1.0"
 eth2_hashing = "0.1.0"
 parking_lot = "0.10.2"
 slog = "2.5.2"
-tokio = { version = "0.2.20", features = ["full"] }
+tokio = { version = "0.2.21", features = ["full"] }
 state_processing = { path = "../../consensus/state_processing" }
 libflate = "1.0.0"
 lighthouse_metrics = { path = "../../common/lighthouse_metrics"}
 lazy_static = "1.4.0"
+environment = { path = "../../lighthouse/environment" }

beacon_node/eth1/src/service.rs

@@ -290,7 +290,7 @@ impl Service {
     /// - Err(_) if there is an error.
     ///
     /// Emits logs for debugging and errors.
-    pub fn auto_update(service: Self, exit: tokio::sync::oneshot::Receiver<()>) {
+    pub fn auto_update(service: Self, handle: environment::TaskExecutor) {
         let update_interval = Duration::from_millis(service.config().auto_update_interval_millis);
 
         let mut interval = interval_at(Instant::now(), update_interval);
@@ -303,9 +303,7 @@ impl Service {
             }
         };
 
-        let future = futures::future::select(Box::pin(update_future), exit);
+        handle.spawn(update_future, "eth1");
-
-        tokio::task::spawn(future);
     }
 
     async fn do_update(service: Self, update_interval: Duration) -> Result<(), ()> {

beacon_node/eth2-libp2p/Cargo.toml

@@ -35,6 +35,7 @@ tokio-util = { version = "0.3.1", features = ["codec", "compat"] }
 # Patched for quick updates
 discv5 = { git = "https://github.com/sigp/discv5", rev = "7b3bd40591b62b8c002ffdb85de008aa9f82e2e5" }
 tiny-keccak = "2.0.2"
+environment = { path = "../../lighthouse/environment" }
 libp2p-tcp = { version = "0.19.1", default-features = false, features = ["tokio"] }
 
 [dependencies.libp2p]
@@ -49,3 +50,4 @@ slog-stdlog = "4.0.0"
 slog-term = "2.5.0"
 slog-async = "2.5.0"
 tempdir = "0.3.7"
+exit-future = "0.2.0"

beacon_node/eth2-libp2p/src/service.rs

@@ -84,6 +84,7 @@ pub struct Service<TSpec: EthSpec> {
 
 impl<TSpec: EthSpec> Service<TSpec> {
     pub fn new(
+        executor: environment::TaskExecutor,
         config: &NetworkConfig,
         enr_fork_id: EnrForkId,
         log: &slog::Logger,
@@ -122,15 +123,15 @@ impl<TSpec: EthSpec> Service<TSpec> {
             let behaviour = Behaviour::new(&local_keypair, config, network_globals.clone(), &log)?;
 
             // use the executor for libp2p
-            struct Executor(tokio::runtime::Handle);
+            struct Executor(environment::TaskExecutor);
             impl libp2p::core::Executor for Executor {
                 fn exec(&self, f: Pin<Box<dyn Future<Output = ()> + Send>>) {
-                    self.0.spawn(f);
+                    self.0.spawn(f, "libp2p");
                 }
             }
             SwarmBuilder::new(transport, behaviour, local_peer_id.clone())
                 .peer_connection_limit(MAX_CONNECTIONS_PER_PEER)
-                .executor(Box::new(Executor(tokio::runtime::Handle::current())))
+                .executor(Box::new(Executor(executor)))
                 .build()
         };
 

beacon_node/eth2-libp2p/tests/common/mod.rs

@@ -12,6 +12,21 @@ use types::{EnrForkId, MinimalEthSpec};
 type E = MinimalEthSpec;
 use tempdir::TempDir;
 
+pub struct Libp2pInstance(LibP2PService<E>, exit_future::Signal);
+
+impl std::ops::Deref for Libp2pInstance {
+    type Target = LibP2PService<E>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl std::ops::DerefMut for Libp2pInstance {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
 pub fn build_log(level: slog::Level, enabled: bool) -> slog::Logger {
     let decorator = slog_term::TermDecorator::new().build();
     let drain = slog_term::FullFormat::new(decorator).build().fuse();
@@ -82,13 +97,20 @@ pub fn build_libp2p_instance(
     boot_nodes: Vec<Enr>,
     secret_key: Option<String>,
     log: slog::Logger,
-) -> LibP2PService<E> {
+) -> Libp2pInstance {
     let port = unused_port("tcp").unwrap();
     let config = build_config(port, boot_nodes, secret_key);
     // launch libp2p service
-    LibP2PService::new(&config, EnrForkId::default(), &log)
+
-        .expect("should build libp2p instance")
+    let (signal, exit) = exit_future::signal();
-        .1
+    let executor =
+        environment::TaskExecutor::new(tokio::runtime::Handle::current(), exit, log.clone());
+    Libp2pInstance(
+        LibP2PService::new(executor, &config, EnrForkId::default(), &log)
+            .expect("should build libp2p instance")
+            .1,
+        signal,
+    )
 }
 
 #[allow(dead_code)]
@@ -99,8 +121,8 @@ pub fn get_enr(node: &LibP2PService<E>) -> Enr {
 
 // Returns `n` libp2p peers in fully connected topology.
 #[allow(dead_code)]
-pub fn build_full_mesh(log: slog::Logger, n: usize) -> Vec<LibP2PService<E>> {
+pub fn build_full_mesh(log: slog::Logger, n: usize) -> Vec<Libp2pInstance> {
-    let mut nodes: Vec<LibP2PService<E>> = (0..n)
+    let mut nodes: Vec<_> = (0..n)
         .map(|_| build_libp2p_instance(vec![], None, log.clone()))
         .collect();
     let multiaddrs: Vec<Multiaddr> = nodes
@@ -124,7 +146,7 @@ pub fn build_full_mesh(log: slog::Logger, n: usize) -> Vec<LibP2PService<E>> {
 // Constructs a pair of nodes with separate loggers. The sender dials the receiver.
 // This returns a (sender, receiver) pair.
 #[allow(dead_code)]
-pub async fn build_node_pair(log: &slog::Logger) -> (LibP2PService<E>, LibP2PService<E>) {
+pub async fn build_node_pair(log: &slog::Logger) -> (Libp2pInstance, Libp2pInstance) {
     let sender_log = log.new(o!("who" => "sender"));
     let receiver_log = log.new(o!("who" => "receiver"));
 
@@ -168,8 +190,8 @@ pub async fn build_node_pair(log: &slog::Logger) -> (LibP2PService<E>, LibP2PSer
 
 // Returns `n` peers in a linear topology
 #[allow(dead_code)]
-pub fn build_linear(log: slog::Logger, n: usize) -> Vec<LibP2PService<E>> {
+pub fn build_linear(log: slog::Logger, n: usize) -> Vec<Libp2pInstance> {
-    let mut nodes: Vec<LibP2PService<E>> = (0..n)
+    let mut nodes: Vec<_> = (0..n)
         .map(|_| build_libp2p_instance(vec![], None, log.clone()))
         .collect();
     let multiaddrs: Vec<Multiaddr> = nodes

beacon_node/eth2-libp2p/tests/noise.rs

@@ -136,7 +136,10 @@ async fn test_secio_noise_fallback() {
 
     let port = common::unused_port("tcp").unwrap();
     let noisy_config = common::build_config(port, vec![], None);
-    let mut noisy_node = Service::new(&noisy_config, EnrForkId::default(), &log)
+    let (_signal, exit) = exit_future::signal();
+    let executor =
+        environment::TaskExecutor::new(tokio::runtime::Handle::current(), exit, log.clone());
+    let mut noisy_node = Service::new(executor, &noisy_config, EnrForkId::default(), &log)
         .expect("should build a libp2p instance")
         .1;
 

beacon_node/genesis/Cargo.toml

@@ -18,7 +18,7 @@ merkle_proof = { path = "../../consensus/merkle_proof" }
 eth2_ssz = "0.1.2"
 eth2_hashing = "0.1.0"
 tree_hash = "0.1.0"
-tokio = { version = "0.2.20", features = ["full"] }
+tokio = { version = "0.2.21", features = ["full"] }
 parking_lot = "0.10.2"
 slog = "2.5.2"
 exit-future = "0.2.0"

beacon_node/genesis/tests/tests.rs

@@ -24,7 +24,7 @@ pub fn new_env() -> Environment<MinimalEthSpec> {
 #[test]
 fn basic() {
     let mut env = new_env();
-    let log = env.core_context().log.clone();
+    let log = env.core_context().log().clone();
     let mut spec = env.eth2_config().spec.clone();
 
     env.runtime().block_on(async {

beacon_node/network/Cargo.toml

@@ -10,6 +10,7 @@ genesis = { path = "../genesis" }
 lazy_static = "1.4.0"
 matches = "0.1.8"
 tempfile = "3.1.0"
+exit-future = "0.2.0"
 
 [dependencies]
 beacon_chain =  { path = "../beacon_chain" }
@@ -25,7 +26,7 @@ eth2_ssz = "0.1.2"
 tree_hash = "0.1.0"
 futures = "0.3.5"
 error-chain = "0.12.2"
-tokio = { version = "0.2.20", features = ["full"] }
+tokio = { version = "0.2.21", features = ["full"] }
 parking_lot = "0.10.2"
 smallvec = "1.4.0"
 # TODO: Remove rand crate for mainnet
@@ -34,3 +35,4 @@ fnv = "1.0.6"
 rlp = "0.4.5"
 lazy_static = "1.4.0"
 lighthouse_metrics = { path = "../../common/lighthouse_metrics" }
+environment = { path = "../../lighthouse/environment" }

beacon_node/network/src/router/mod.rs

@@ -58,7 +58,7 @@ impl<T: BeaconChainTypes> Router<T> {
         beacon_chain: Arc<BeaconChain<T>>,
         network_globals: Arc<NetworkGlobals<T::EthSpec>>,
         network_send: mpsc::UnboundedSender<NetworkMessage<T::EthSpec>>,
-        runtime_handle: &tokio::runtime::Handle,
+        executor: environment::TaskExecutor,
         log: slog::Logger,
     ) -> error::Result<mpsc::UnboundedSender<RouterMessage<T::EthSpec>>> {
         let message_handler_log = log.new(o!("service"=> "router"));
@@ -68,7 +68,7 @@ impl<T: BeaconChainTypes> Router<T> {
 
         // Initialise a message instance, which itself spawns the syncing thread.
         let processor = Processor::new(
-            runtime_handle,
+            executor.clone(),
             beacon_chain,
             network_globals.clone(),
             network_send.clone(),
@@ -84,12 +84,15 @@ impl<T: BeaconChainTypes> Router<T> {
         };
 
         // spawn handler task and move the message handler instance into the spawned thread
-        runtime_handle.spawn(async move {
+        executor.spawn(
-            handler_recv
+            async move {
-                .for_each(move |msg| future::ready(handler.handle_message(msg)))
+                debug!(log, "Network message router started");
-                .await;
+                handler_recv
-            debug!(log, "Network message handler terminated.");
+                    .for_each(move |msg| future::ready(handler.handle_message(msg)))
-        });
+                    .await;
+            },
+            "router",
+        );
 
         Ok(handler_send)
     }

beacon_node/network/src/router/processor.rs

@@ -14,7 +14,7 @@ use slog::{debug, error, o, trace, warn};
 use ssz::Encode;
 use std::sync::Arc;
 use store::Store;
-use tokio::sync::{mpsc, oneshot};
+use tokio::sync::mpsc;
 use types::{
     Attestation, ChainSpec, Epoch, EthSpec, Hash256, SignedAggregateAndProof, SignedBeaconBlock,
     Slot,
@@ -33,8 +33,6 @@ pub struct Processor<T: BeaconChainTypes> {
     chain: Arc<BeaconChain<T>>,
     /// A channel to the syncing thread.
     sync_send: mpsc::UnboundedSender<SyncMessage<T::EthSpec>>,
-    /// A oneshot channel for destroying the sync thread.
-    _sync_exit: oneshot::Sender<()>,
     /// A network context to return and handle RPC requests.
     network: HandlerNetworkContext<T::EthSpec>,
     /// The `RPCHandler` logger.
@@ -44,7 +42,7 @@ pub struct Processor<T: BeaconChainTypes> {
 impl<T: BeaconChainTypes> Processor<T> {
     /// Instantiate a `Processor` instance
     pub fn new(
-        runtime_handle: &tokio::runtime::Handle,
+        executor: environment::TaskExecutor,
         beacon_chain: Arc<BeaconChain<T>>,
         network_globals: Arc<NetworkGlobals<T::EthSpec>>,
         network_send: mpsc::UnboundedSender<NetworkMessage<T::EthSpec>>,
@@ -53,8 +51,8 @@ impl<T: BeaconChainTypes> Processor<T> {
         let sync_logger = log.new(o!("service"=> "sync"));
 
         // spawn the sync thread
-        let (sync_send, _sync_exit) = crate::sync::manager::spawn(
+        let sync_send = crate::sync::manager::spawn(
-            runtime_handle,
+            executor,
             beacon_chain.clone(),
             network_globals,
             network_send.clone(),
@@ -64,7 +62,6 @@ impl<T: BeaconChainTypes> Processor<T> {
         Processor {
             chain: beacon_chain,
             sync_send,
-            _sync_exit,
             network: HandlerNetworkContext::new(network_send, log.clone()),
             log: log.clone(),
         }

beacon_node/network/src/service.rs

@@ -14,8 +14,7 @@ use rest_types::ValidatorSubscription;
 use slog::{debug, error, info, o, trace};
 use std::sync::Arc;
 use std::time::Duration;
-use tokio::runtime::Handle;
+use tokio::sync::mpsc;
-use tokio::sync::{mpsc, oneshot};
 use tokio::time::Delay;
 use types::EthSpec;
 
@@ -53,13 +52,12 @@ impl<T: BeaconChainTypes> NetworkService<T> {
     pub fn start(
         beacon_chain: Arc<BeaconChain<T>>,
         config: &NetworkConfig,
-        runtime_handle: &Handle,
+        executor: environment::TaskExecutor,
-        network_log: slog::Logger,
     ) -> error::Result<(
         Arc<NetworkGlobals<T::EthSpec>>,
         mpsc::UnboundedSender<NetworkMessage<T::EthSpec>>,
-        oneshot::Sender<()>,
     )> {
+        let network_log = executor.log().clone();
         // build the network channel
         let (network_send, network_recv) = mpsc::unbounded_channel::<NetworkMessage<T::EthSpec>>();
         // get a reference to the beacon chain store
@@ -75,7 +73,7 @@ impl<T: BeaconChainTypes> NetworkService<T> {
 
         // launch libp2p service
         let (network_globals, mut libp2p) =
-            runtime_handle.enter(|| LibP2PService::new(config, enr_fork_id, &network_log))?;
+            LibP2PService::new(executor.clone(), config, enr_fork_id, &network_log)?;
 
         for enr in load_dht::<T::Store, T::EthSpec>(store.clone()) {
             libp2p.swarm.add_enr(enr);
@@ -88,7 +86,7 @@ impl<T: BeaconChainTypes> NetworkService<T> {
             beacon_chain.clone(),
             network_globals.clone(),
             network_send.clone(),
-            runtime_handle,
+            executor.clone(),
             network_log.clone(),
         )?;
 
@@ -111,19 +109,20 @@ impl<T: BeaconChainTypes> NetworkService<T> {
             propagation_percentage,
         };
 
-        let network_exit = runtime_handle.enter(|| spawn_service(network_service))?;
+        spawn_service(executor, network_service)?;
 
-        Ok((network_globals, network_send, network_exit))
+        Ok((network_globals, network_send))
     }
 }
 
 fn spawn_service<T: BeaconChainTypes>(
+    executor: environment::TaskExecutor,
     mut service: NetworkService<T>,
-) -> error::Result<tokio::sync::oneshot::Sender<()>> {
+) -> error::Result<()> {
-    let (network_exit, mut exit_rx) = tokio::sync::oneshot::channel();
+    let mut exit_rx = executor.exit();
 
     // spawn on the current executor
-    tokio::spawn(async move {
+    executor.spawn_without_exit(async move {
         loop {
             // build the futures to check simultaneously
             tokio::select! {
@@ -361,9 +360,9 @@ fn spawn_service<T: BeaconChainTypes>(
                 }
             }
         }
-    });
+    }, "network");
 
-    Ok(network_exit)
+    Ok(())
 }
 
 /// Returns a `Delay` that triggers shortly after the next change in the beacon chain fork version.

beacon_node/network/src/service/tests.rs

@@ -32,7 +32,9 @@ mod tests {
         let enrs = vec![enr1, enr2];
 
         let runtime = Runtime::new().unwrap();
-        let handle = runtime.handle().clone();
+
+        let (signal, exit) = exit_future::signal();
+        let executor = environment::TaskExecutor::new(runtime.handle().clone(), exit, log.clone());
 
         let mut config = NetworkConfig::default();
         config.libp2p_port = 21212;
@@ -42,8 +44,8 @@ mod tests {
             // Create a new network service which implicitly gets dropped at the
             // end of the block.
 
-            let _ =
+            let _ = NetworkService::start(beacon_chain.clone(), &config, executor).unwrap();
-                NetworkService::start(beacon_chain.clone(), &config, &handle, log.clone()).unwrap();
+            drop(signal);
         });
         runtime.shutdown_timeout(tokio::time::Duration::from_millis(300));
 

beacon_node/network/src/sync/manager.rs

@@ -48,7 +48,7 @@ use smallvec::SmallVec;
 use std::boxed::Box;
 use std::ops::Sub;
 use std::sync::Arc;
-use tokio::sync::{mpsc, oneshot};
+use tokio::sync::mpsc;
 use types::{EthSpec, Hash256, SignedBeaconBlock, Slot};
 
 /// The number of slots ahead of us that is allowed before requesting a long-range (batch)  Sync
@@ -181,17 +181,12 @@ impl SingleBlockRequest {
 /// chain. This allows the chain to be
 /// dropped during the syncing process which will gracefully end the `SyncManager`.
 pub fn spawn<T: BeaconChainTypes>(
-    runtime_handle: &tokio::runtime::Handle,
+    executor: environment::TaskExecutor,
     beacon_chain: Arc<BeaconChain<T>>,
     network_globals: Arc<NetworkGlobals<T::EthSpec>>,
     network_send: mpsc::UnboundedSender<NetworkMessage<T::EthSpec>>,
     log: slog::Logger,
-) -> (
+) -> mpsc::UnboundedSender<SyncMessage<T::EthSpec>> {
-    mpsc::UnboundedSender<SyncMessage<T::EthSpec>>,
-    oneshot::Sender<()>,
-) {
-    // generate the exit channel
-    let (sync_exit, exit_rx) = tokio::sync::oneshot::channel();
     // generate the message channel
     let (sync_send, sync_recv) = mpsc::unbounded_channel::<SyncMessage<T::EthSpec>>();
 
@@ -215,11 +210,8 @@ pub fn spawn<T: BeaconChainTypes>(
 
     // spawn the sync manager thread
     debug!(log, "Sync Manager started");
-    runtime_handle.spawn(async move {
+    executor.spawn(async move { Box::pin(sync_manager.main()).await }, "sync");
-        futures::future::select(Box::pin(sync_manager.main()), exit_rx).await;
+    sync_send
-        info!(log.clone(), "Sync Manager shutdown");
-    });
-    (sync_send, sync_exit)
 }
 
 impl<T: BeaconChainTypes> SyncManager<T> {

beacon_node/rest_api/Cargo.toml

@@ -25,7 +25,7 @@ state_processing = { path = "../../consensus/state_processing" }
 types = { path = "../../consensus/types" }
 http = "0.2.1"
 hyper = "0.13.5"
-tokio = { version = "0.2", features = ["sync"] }
+tokio = { version = "0.2.21", features = ["sync"] }
 url = "2.1.1"
 lazy_static = "1.4.0"
 eth2_config = { path = "../../common/eth2_config" }
@@ -36,6 +36,7 @@ parking_lot = "0.10.2"
 futures = "0.3.5"
 operation_pool = { path = "../operation_pool" }
 rayon = "1.3.0"
+environment = { path = "../../lighthouse/environment" }
 
 [dev-dependencies]
 assert_matches = "1.3.0"

beacon_node/rest_api/src/lib.rs

@@ -35,7 +35,7 @@ use std::net::SocketAddr;
 use std::ops::Deref;
 use std::path::PathBuf;
 use std::sync::Arc;
-use tokio::sync::{mpsc, oneshot};
+use tokio::sync::mpsc;
 use url_query::UrlQuery;
 
 pub use crate::helpers::parse_pubkey_bytes;
@@ -51,14 +51,15 @@ pub struct NetworkInfo<T: BeaconChainTypes> {
 // Allowing more than 7 arguments.
 #[allow(clippy::too_many_arguments)]
 pub fn start_server<T: BeaconChainTypes>(
+    executor: environment::TaskExecutor,
     config: &Config,
     beacon_chain: Arc<BeaconChain<T>>,
     network_info: NetworkInfo<T>,
     db_path: PathBuf,
     freezer_db_path: PathBuf,
     eth2_config: Eth2Config,
-    log: slog::Logger,
+) -> Result<SocketAddr, hyper::Error> {
-) -> Result<(oneshot::Sender<()>, SocketAddr), hyper::Error> {
+    let log = executor.log();
     let inner_log = log.clone();
     let eth2_config = Arc::new(eth2_config);
 
@@ -98,7 +99,7 @@ pub fn start_server<T: BeaconChainTypes>(
     let actual_listen_addr = server.local_addr();
 
     // Build a channel to kill the HTTP server.
-    let (exit_signal, exit) = oneshot::channel::<()>();
+    let exit = executor.exit();
     let inner_log = log.clone();
     let server_exit = async move {
         let _ = exit.await;
@@ -116,7 +117,8 @@ pub fn start_server<T: BeaconChainTypes>(
             inner_log,
             "HTTP server failed to start, Unable to bind"; "address" => format!("{:?}", e)
             )
-        });
+        })
+        .unwrap_or_else(|_| ());
 
     info!(
         log,
@@ -125,9 +127,9 @@ pub fn start_server<T: BeaconChainTypes>(
         "port" => actual_listen_addr.port(),
     );
 
-    tokio::spawn(server_future);
+    executor.spawn_without_exit(server_future, "http");
 
-    Ok((exit_signal, actual_listen_addr))
+    Ok(actual_listen_addr)
 }
 
 #[derive(Clone)]

beacon_node/src/lib.rs

@@ -58,7 +58,7 @@ impl<E: EthSpec> ProductionBeaconNode<E> {
             &matches,
             &context.eth2_config.spec_constants,
             &context.eth2_config().spec,
-            context.log.clone(),
+            context.log().clone(),
         )?;
         Self::new(context, client_config).await
     }
@@ -75,7 +75,7 @@ impl<E: EthSpec> ProductionBeaconNode<E> {
         let client_config_1 = client_config.clone();
         let client_genesis = client_config.genesis.clone();
         let store_config = client_config.store.clone();
-        let log = context.log.clone();
+        let log = context.log().clone();
 
         let db_path = client_config.create_db_path()?;
         let freezer_db_path_res = client_config.create_freezer_db_path();

beacon_node/tests/test.rs

@@ -51,4 +51,5 @@ fn http_server_genesis_state() {
         api_state, db_state,
         "genesis state from api should match that from the DB"
     );
+    env.fire_signal();
 }

beacon_node/timer/Cargo.toml

@@ -8,7 +8,8 @@ edition = "2018"
 beacon_chain =  { path = "../beacon_chain" }
 types = { path = "../../consensus/types" }
 slot_clock = { path = "../../common/slot_clock" }
-tokio = { version = "0.2.20", features = ["full"] }
+tokio = { version = "0.2.21", features = ["full"] }
 slog = "2.5.2"
 parking_lot = "0.10.2"
 futures = "0.3.5"
+environment = { path = "../../lighthouse/environment" }

beacon_node/timer/src/lib.rs

@@ -3,23 +3,20 @@
 //! This service allows task execution on the beacon node for various functionality.
 
 use beacon_chain::{BeaconChain, BeaconChainTypes};
-use futures::future;
 use futures::stream::StreamExt;
+use slog::info;
 use slot_clock::SlotClock;
 use std::sync::Arc;
 use std::time::Duration;
 use tokio::time::{interval_at, Instant};
 
 /// Spawns a timer service which periodically executes tasks for the beacon chain
-/// TODO: We might not need a `Handle` to the runtime since this function should be
+pub fn spawn_timer<T: BeaconChainTypes>(
-/// called from the context of a runtime and we can simply spawn using task::spawn.
+    executor: environment::TaskExecutor,
-/// Check for issues without the Handle.
-pub fn spawn<T: BeaconChainTypes>(
     beacon_chain: Arc<BeaconChain<T>>,
     milliseconds_per_slot: u64,
-) -> Result<tokio::sync::oneshot::Sender<()>, &'static str> {
+) -> Result<(), &'static str> {
-    let (exit_signal, exit) = tokio::sync::oneshot::channel();
+    let log = executor.log();
-
     let start_instant = Instant::now()
         + beacon_chain
             .slot_clock
@@ -27,14 +24,15 @@ pub fn spawn<T: BeaconChainTypes>(
             .ok_or_else(|| "slot_notifier unable to determine time to next slot")?;
 
     // Warning: `interval_at` panics if `milliseconds_per_slot` = 0.
-    let timer_future = interval_at(start_instant, Duration::from_millis(milliseconds_per_slot))
+    let mut interval = interval_at(start_instant, Duration::from_millis(milliseconds_per_slot));
-        .for_each(move |_| {
+    let timer_future = async move {
+        while interval.next().await.is_some() {
             beacon_chain.per_slot_task();
-            future::ready(())
+        }
-        });
+    };
 
-    let future = futures::future::select(timer_future, exit);
+    executor.spawn(timer_future, "timer");
-    tokio::spawn(future);
+    info!(log, "Timer service started");
 
-    Ok(exit_signal)
+    Ok(())
 }

beacon_node/websocket_server/Cargo.toml

@@ -12,6 +12,7 @@ serde = "1.0.110"
 serde_derive = "1.0.110"
 serde_json = "1.0.52"
 slog = "2.5.2"
-tokio = { version = "0.2.20", features = ["full"] }
+tokio = { version = "0.2.21", features = ["full"] }
 types = { path = "../../consensus/types" }
 ws = "0.9.1"
+environment = { path = "../../lighthouse/environment" }

beacon_node/websocket_server/src/lib.rs

@@ -1,4 +1,4 @@
-use slog::{debug, error, info, warn, Logger};
+use slog::{debug, error, info, warn};
 use std::marker::PhantomData;
 use std::net::SocketAddr;
 use types::EthSpec;
@@ -34,16 +34,10 @@ impl<T: EthSpec> WebSocketSender<T> {
 }
 
 pub fn start_server<T: EthSpec>(
+    executor: environment::TaskExecutor,
     config: &Config,
-    log: &Logger,
+) -> Result<(WebSocketSender<T>, SocketAddr), String> {
-) -> Result<
+    let log = executor.log();
-    (
-        WebSocketSender<T>,
-        tokio::sync::oneshot::Sender<()>,
-        SocketAddr,
-    ),
-    String,
-> {
     let server_string = format!("{}:{}", config.listen_address, config.port);
 
     // Create a server that simply ignores any incoming messages.
@@ -67,31 +61,26 @@ pub fn start_server<T: EthSpec>(
     let broadcaster = server.broadcaster();
 
     // Produce a signal/channel that can gracefully shutdown the websocket server.
-    let exit_channel = {
+    let exit = executor.exit();
-        let (exit_channel, exit) = tokio::sync::oneshot::channel();
+    let log_inner = log.clone();
-
+    let broadcaster_inner = server.broadcaster();
-        let log_inner = log.clone();
+    let exit_future = async move {
-        let broadcaster_inner = server.broadcaster();
+        let _ = exit.await;
-        let exit_future = async move {
+        if let Err(e) = broadcaster_inner.shutdown() {
-            let _ = exit.await;
+            warn!(
-            if let Err(e) = broadcaster_inner.shutdown() {
+                log_inner,
-                warn!(
+                "Websocket server errored on shutdown";
-                    log_inner,
+                "error" => format!("{:?}", e)
-                    "Websocket server errored on shutdown";
+            );
-                    "error" => format!("{:?}", e)
+        } else {
-                );
+            info!(log_inner, "Websocket server shutdown");
-            } else {
+        }
-                info!(log_inner, "Websocket server shutdown");
-            }
-        };
-
-        // Place a future on the handle that will shutdown the websocket server when the
-        // application exits.
-        tokio::spawn(exit_future);
-
-        exit_channel
     };
 
+    // Place a future on the handle that will shutdown the websocket server when the
+    // application exits.
+    executor.runtime_handle().spawn(exit_future);
+
     let log_inner = log.clone();
 
     let _ = std::thread::spawn(move || match server.run() {
@@ -122,7 +111,6 @@ pub fn start_server<T: EthSpec>(
             sender: Some(broadcaster),
             _phantom: PhantomData,
         },
-        exit_channel,
         actual_listen_addr,
     ))
 }

common/eth2_testnet_config/Cargo.toml

@@ -16,5 +16,5 @@ tempdir = "0.3.7"
 serde = "1.0.110"
 serde_yaml = "0.8.11"
 types = { path = "../../consensus/types"}
-eth2-libp2p = { path = "../../beacon_node/eth2-libp2p"}
+enr = { version = "0.1.0", features = ["libsecp256k1", "ed25519"] }
 eth2_ssz = "0.1.2"

common/eth2_testnet_config/src/lib.rs

@@ -7,7 +7,7 @@
 //!
 //! https://github.com/sigp/lighthouse/pull/605
 
-use eth2_libp2p::Enr;
+use enr::{CombinedKey, Enr};
 use ssz::{Decode, Encode};
 use std::fs::{create_dir_all, File};
 use std::io::{Read, Write};
@@ -36,7 +36,7 @@ pub const HARDCODED_BOOT_ENR: &[u8] = include_bytes!("../witti-v0-11-3/boot_enr.
 pub struct Eth2TestnetConfig<E: EthSpec> {
     pub deposit_contract_address: String,
     pub deposit_contract_deploy_block: u64,
-    pub boot_enr: Option<Vec<Enr>>,
+    pub boot_enr: Option<Vec<Enr<CombinedKey>>>,
     pub genesis_state: Option<BeaconState<E>>,
     pub yaml_config: Option<YamlConfig>,
 }
@@ -239,7 +239,7 @@ mod tests {
     }
 
     fn do_test<E: EthSpec>(
-        boot_enr: Option<Vec<Enr>>,
+        boot_enr: Option<Vec<Enr<CombinedKey>>>,
         genesis_state: Option<BeaconState<E>>,
         yaml_config: Option<YamlConfig>,
     ) {

common/hashset_delay/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2018"
 
 [dependencies]
 futures = "0.3.5"
-tokio = { version = "0.2.20", features = ["time"] }
+tokio = { version = "0.2.21", features = ["time"] }
 
 [dev-dependencies]
-tokio = { version = "0.2.20", features = ["time", "rt-threaded", "macros"] }
+tokio = { version = "0.2.21", features = ["time", "rt-threaded", "macros"] }

common/lighthouse_metrics/src/lib.rs

@@ -56,7 +56,9 @@
 
 use prometheus::{HistogramOpts, HistogramTimer, Opts};
 
-pub use prometheus::{Encoder, Gauge, Histogram, IntCounter, IntGauge, Result, TextEncoder};
+pub use prometheus::{
+    Encoder, Gauge, Histogram, HistogramVec, IntCounter, IntGauge, IntGaugeVec, Result, TextEncoder,
+};
 
 /// Collect all the metrics for reporting.
 pub fn gather() -> Vec<prometheus::proto::MetricFamily> {
@@ -99,6 +101,48 @@ pub fn try_create_histogram(name: &str, help: &str) -> Result<Histogram> {
     Ok(histogram)
 }
 
+/// Attempts to crate a `HistogramVec`, returning `Err` if the registry does not accept the counter
+/// (potentially due to naming conflict).
+pub fn try_create_histogram_vec(
+    name: &str,
+    help: &str,
+    label_names: &[&str],
+) -> Result<HistogramVec> {
+    let opts = HistogramOpts::new(name, help);
+    let histogram_vec = HistogramVec::new(opts, label_names)?;
+    prometheus::register(Box::new(histogram_vec.clone()))?;
+    Ok(histogram_vec)
+}
+
+/// Attempts to crate a `IntGaugeVec`, returning `Err` if the registry does not accept the gauge
+/// (potentially due to naming conflict).
+pub fn try_create_int_gauge_vec(
+    name: &str,
+    help: &str,
+    label_names: &[&str],
+) -> Result<IntGaugeVec> {
+    let opts = Opts::new(name, help);
+    let counter_vec = IntGaugeVec::new(opts, label_names)?;
+    prometheus::register(Box::new(counter_vec.clone()))?;
+    Ok(counter_vec)
+}
+
+pub fn get_int_gauge(int_gauge_vec: &Result<IntGaugeVec>, name: &[&str]) -> Option<IntGauge> {
+    if let Ok(int_gauge_vec) = int_gauge_vec {
+        Some(int_gauge_vec.get_metric_with_label_values(name).ok()?)
+    } else {
+        None
+    }
+}
+
+pub fn get_histogram(histogram_vec: &Result<HistogramVec>, name: &[&str]) -> Option<Histogram> {
+    if let Ok(histogram_vec) = histogram_vec {
+        Some(histogram_vec.get_metric_with_label_values(name).ok()?)
+    } else {
+        None
+    }
+}
+
 /// Starts a timer for the given `Histogram`, stopping when it gets dropped or given to `stop_timer(..)`.
 pub fn start_timer(histogram: &Result<Histogram>) -> Option<HistogramTimer> {
     if let Ok(histogram) = histogram {
@@ -133,6 +177,18 @@ pub fn set_gauge(gauge: &Result<IntGauge>, value: i64) {
     }
 }
 
+pub fn inc_gauge(gauge: &Result<IntGauge>) {
+    if let Ok(gauge) = gauge {
+        gauge.inc();
+    }
+}
+
+pub fn dec_gauge(gauge: &Result<IntGauge>) {
+    if let Ok(gauge) = gauge {
+        gauge.dec();
+    }
+}
+
 pub fn maybe_set_gauge(gauge: &Result<IntGauge>, value_opt: Option<i64>) {
     if let Some(value) = value_opt {
         set_gauge(gauge, value)

lcli/Cargo.toml

@@ -27,7 +27,7 @@ dirs = "2.0.2"
 genesis = { path = "../beacon_node/genesis" }
 deposit_contract = { path = "../common/deposit_contract" }
 tree_hash = "0.1.0"
-tokio = { version = "0.2.20", features = ["full"] }
+tokio = { version = "0.2.21", features = ["full"] }
 clap_utils = { path = "../common/clap_utils" }
 eth2-libp2p = { path = "../beacon_node/eth2-libp2p" }
 validator_dir = { path = "../common/validator_dir", features = ["insecure_keys"] }

lcli/src/eth1_genesis.rs

@@ -46,7 +46,7 @@ pub fn run<T: EthSpec>(mut env: Environment<T>, matches: &ArgMatches<'_>) -> Res
     config.lowest_cached_block_number = eth2_testnet_config.deposit_contract_deploy_block;
     config.follow_distance = spec.eth1_follow_distance / 2;
 
-    let genesis_service = Eth1GenesisService::new(config, env.core_context().log.clone());
+    let genesis_service = Eth1GenesisService::new(config, env.core_context().log().clone());
 
     env.runtime().block_on(async {
         let _ = genesis_service

lighthouse/Cargo.toml

@@ -9,7 +9,7 @@ write_ssz_files = ["beacon_node/write_ssz_files"]  # Writes debugging .ssz files
 
 [dependencies]
 beacon_node = { "path" = "../beacon_node" }
-tokio = "0.2.20"
+tokio = "0.2.21"
 slog = { version = "2.5.2", features = ["max_level_trace"] }
 sloggers = "1.0.0"
 types = { "path" = "../consensus/types" }

lighthouse/environment/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2018"
 
 [dependencies]
 clap = "2.33.0"
-tokio = "0.2.20"
+tokio = "0.2.21"
 slog = { version = "2.5.2", features = ["max_level_trace"] }
 sloggers = "1.0.0"
 types = { "path" = "../../consensus/types" }
@@ -20,6 +20,9 @@ ctrlc = { version = "3.1.4", features = ["termination"] }
 futures = "0.3.5"
 parking_lot = "0.10.2"
 slog-json = "2.3.0"
+exit-future = "0.2.0"
+lazy_static = "1.4.0"
+lighthouse_metrics = { path = "../../common/lighthouse_metrics" }
 
 [dev-dependencies]
 beacon_node = { path = "../../beacon_node" }

lighthouse/environment/src/executor.rs

@@ -0,0 +1,128 @@
+use crate::metrics;
+use futures::prelude::*;
+use slog::{debug, trace};
+use tokio::runtime::Handle;
+
+/// A wrapper over a runtime handle which can spawn async and blocking tasks.
+#[derive(Clone)]
+pub struct TaskExecutor {
+    /// The handle to the runtime on which tasks are spawned
+    pub(crate) handle: Handle,
+    /// The receiver exit future which on receiving shuts down the task
+    pub(crate) exit: exit_future::Exit,
+    pub(crate) log: slog::Logger,
+}
+
+impl TaskExecutor {
+    /// Create a new task executor.
+    ///
+    /// Note: this function is mainly useful in tests. A `TaskExecutor` should be normally obtained from
+    /// a [`RuntimeContext`](struct.RuntimeContext.html)
+    pub fn new(handle: Handle, exit: exit_future::Exit, log: slog::Logger) -> Self {
+        Self { handle, exit, log }
+    }
+
+    /// Spawn a future on the tokio runtime wrapped in an `exit_future::Exit`. The task is canceled
+    /// when the corresponding exit_future `Signal` is fired/dropped.
+    ///
+    /// This function generates prometheus metrics on number of tasks and task duration.
+    pub fn spawn(&self, task: impl Future<Output = ()> + Send + 'static, name: &'static str) {
+        let exit = self.exit.clone();
+        let log = self.log.clone();
+
+        if let Some(int_gauge) = metrics::get_int_gauge(&metrics::ASYNC_TASKS_COUNT, &[name]) {
+            // Task is shutdown before it completes if `exit` receives
+            let int_gauge_1 = int_gauge.clone();
+            let future = future::select(Box::pin(task), exit).then(move |either| {
+                match either {
+                    future::Either::Left(_) => trace!(log, "Async task completed"; "task" => name),
+                    future::Either::Right(_) => {
+                        debug!(log, "Async task shutdown, exit received"; "task" => name)
+                    }
+                }
+                int_gauge_1.dec();
+                futures::future::ready(())
+            });
+
+            int_gauge.inc();
+            self.handle.spawn(future);
+        }
+    }
+
+    /// Spawn a future on the tokio runtime. This function does not wrap the task in an `exit_future::Exit`
+    /// like [spawn](#method.spawn).
+    /// The caller of this function is responsible for wrapping up the task with an `exit_future::Exit` to  
+    /// ensure that the task gets canceled appropriately.
+    /// This function generates prometheus metrics on number of tasks and task duration.
+    ///
+    /// This is useful in cases where the future to be spawned needs to do additional cleanup work when
+    /// the task is completed/canceled (e.g. writing local variables to disk) or the task is created from
+    /// some framework which does its own cleanup (e.g. a hyper server).
+    pub fn spawn_without_exit(
+        &self,
+        task: impl Future<Output = ()> + Send + 'static,
+        name: &'static str,
+    ) {
+        if let Some(int_gauge) = metrics::get_int_gauge(&metrics::ASYNC_TASKS_COUNT, &[name]) {
+            let int_gauge_1 = int_gauge.clone();
+            let future = task.then(move |_| {
+                int_gauge_1.dec();
+                futures::future::ready(())
+            });
+
+            int_gauge.inc();
+            self.handle.spawn(future);
+        }
+    }
+
+    /// Spawn a blocking task on a dedicated tokio thread pool wrapped in an exit future.
+    /// This function generates prometheus metrics on number of tasks and task duration.
+    pub fn spawn_blocking<F>(&self, task: F, name: &'static str)
+    where
+        F: FnOnce() -> () + Send + 'static,
+    {
+        let exit = self.exit.clone();
+        let log = self.log.clone();
+
+        if let Some(metric) = metrics::get_histogram(&metrics::BLOCKING_TASKS_HISTOGRAM, &[name]) {
+            if let Some(int_gauge) = metrics::get_int_gauge(&metrics::BLOCKING_TASKS_COUNT, &[name])
+            {
+                let int_gauge_1 = int_gauge.clone();
+                let timer = metric.start_timer();
+                let join_handle = self.handle.spawn_blocking(task);
+
+                let future = future::select(join_handle, exit).then(move |either| {
+                    match either {
+                        future::Either::Left(_) => {
+                            trace!(log, "Blocking task completed"; "task" => name)
+                        }
+                        future::Either::Right(_) => {
+                            debug!(log, "Blocking task shutdown, exit received"; "task" => name)
+                        }
+                    }
+                    timer.observe_duration();
+                    int_gauge_1.dec();
+                    futures::future::ready(())
+                });
+
+                int_gauge.inc();
+                self.handle.spawn(future);
+            }
+        }
+    }
+
+    /// Returns the underlying runtime handle.
+    pub fn runtime_handle(&self) -> Handle {
+        self.handle.clone()
+    }
+
+    /// Returns a copy of the `exit_future::Exit`.
+    pub fn exit(&self) -> exit_future::Exit {
+        self.exit.clone()
+    }
+
+    /// Returns a reference to the logger.
+    pub fn log(&self) -> &slog::Logger {
+        &self.log
+    }
+}

lighthouse/environment/src/lib.rs

@@ -10,6 +10,8 @@
 use eth2_config::Eth2Config;
 use eth2_testnet_config::Eth2TestnetConfig;
 use futures::channel::oneshot;
+
+pub use executor::TaskExecutor;
 use slog::{info, o, Drain, Level, Logger};
 use sloggers::{null::NullLoggerBuilder, Build};
 use std::cell::RefCell;
@@ -17,8 +19,10 @@ use std::ffi::OsStr;
 use std::fs::{rename as FsRename, OpenOptions};
 use std::path::PathBuf;
 use std::time::{SystemTime, UNIX_EPOCH};
-use tokio::runtime::{Builder as RuntimeBuilder, Handle, Runtime};
+use tokio::runtime::{Builder as RuntimeBuilder, Runtime};
 use types::{EthSpec, InteropEthSpec, MainnetEthSpec, MinimalEthSpec};
+mod executor;
+mod metrics;
 
 pub const ETH2_CONFIG_FILENAME: &str = "eth2-spec.toml";
 
@@ -172,10 +176,13 @@ impl<E: EthSpec> EnvironmentBuilder<E> {
 
     /// Consumes the builder, returning an `Environment`.
     pub fn build(self) -> Result<Environment<E>, String> {
+        let (signal, exit) = exit_future::signal();
         Ok(Environment {
             runtime: self
                 .runtime
                 .ok_or_else(|| "Cannot build environment without runtime".to_string())?,
+            signal: Some(signal),
+            exit,
             log: self
                 .log
                 .ok_or_else(|| "Cannot build environment without log".to_string())?,
@@ -192,8 +199,7 @@ impl<E: EthSpec> EnvironmentBuilder<E> {
 /// `Runtime`, instead it only has access to a `Runtime`.
 #[derive(Clone)]
 pub struct RuntimeContext<E: EthSpec> {
-    pub runtime_handle: Handle,
+    pub executor: TaskExecutor,
-    pub log: Logger,
     pub eth_spec_instance: E,
     pub eth2_config: Eth2Config,
 }
@@ -204,8 +210,11 @@ impl<E: EthSpec> RuntimeContext<E> {
     /// The generated service will have the `service_name` in all it's logs.
     pub fn service_context(&self, service_name: String) -> Self {
         Self {
-            runtime_handle: self.runtime_handle.clone(),
+            executor: TaskExecutor {
-            log: self.log.new(o!("service" => service_name)),
+                handle: self.executor.handle.clone(),
+                exit: self.executor.exit.clone(),
+                log: self.executor.log.new(o!("service" => service_name)),
+            },
             eth_spec_instance: self.eth_spec_instance.clone(),
             eth2_config: self.eth2_config.clone(),
         }
@@ -215,12 +224,19 @@ impl<E: EthSpec> RuntimeContext<E> {
     pub fn eth2_config(&self) -> &Eth2Config {
         &self.eth2_config
     }
+
+    /// Returns a reference to the logger for this service.
+    pub fn log(&self) -> &slog::Logger {
+        self.executor.log()
+    }
 }
 
 /// An environment where Lighthouse services can run. Used to start a production beacon node or
 /// validator client, or to run tests that involve logging and async task execution.
 pub struct Environment<E: EthSpec> {
     runtime: Runtime,
+    signal: Option<exit_future::Signal>,
+    exit: exit_future::Exit,
     log: Logger,
     eth_spec_instance: E,
     pub eth2_config: Eth2Config,
@@ -239,8 +255,11 @@ impl<E: EthSpec> Environment<E> {
     /// Returns a `Context` where no "service" has been added to the logger output.
     pub fn core_context(&mut self) -> RuntimeContext<E> {
         RuntimeContext {
-            runtime_handle: self.runtime.handle().clone(),
+            executor: TaskExecutor {
-            log: self.log.clone(),
+                exit: self.exit.clone(),
+                handle: self.runtime().handle().clone(),
+                log: self.log.clone(),
+            },
             eth_spec_instance: self.eth_spec_instance.clone(),
             eth2_config: self.eth2_config.clone(),
         }
@@ -249,8 +268,11 @@ impl<E: EthSpec> Environment<E> {
     /// Returns a `Context` where the `service_name` is added to the logger output.
     pub fn service_context(&mut self, service_name: String) -> RuntimeContext<E> {
         RuntimeContext {
-            runtime_handle: self.runtime.handle().clone(),
+            executor: TaskExecutor {
-            log: self.log.new(o!("service" => service_name)),
+                exit: self.exit.clone(),
+                handle: self.runtime().handle().clone(),
+                log: self.log.new(o!("service" => service_name.clone())),
+            },
             eth_spec_instance: self.eth_spec_instance.clone(),
             eth2_config: self.eth2_config.clone(),
         }
@@ -279,6 +301,13 @@ impl<E: EthSpec> Environment<E> {
             .shutdown_timeout(std::time::Duration::from_secs(2))
     }
 
+    /// Fire exit signal which shuts down all spawned services
+    pub fn fire_signal(&mut self) {
+        if let Some(signal) = self.signal.take() {
+            let _ = signal.fire();
+        }
+    }
+
     /// Sets the logger (and all child loggers) to log to a file.
     pub fn log_to_json_file(
         &mut self,

lighthouse/environment/src/metrics.rs

@@ -0,0 +1,21 @@
+/// Handles async task metrics
+use lazy_static::lazy_static;
+pub use lighthouse_metrics::*;
+
+lazy_static! {
+    pub static ref ASYNC_TASKS_COUNT: Result<IntGaugeVec> = try_create_int_gauge_vec(
+        "async_tasks_count",
+        "Total number of async tasks spawned using spawn",
+        &["async_task_count"]
+    );
+    pub static ref BLOCKING_TASKS_COUNT: Result<IntGaugeVec> = try_create_int_gauge_vec(
+        "blocking_tasks_count",
+        "Total number of async tasks spawned using spawn_blocking",
+        &["blocking_task_count"]
+    );
+    pub static ref BLOCKING_TASKS_HISTOGRAM: Result<HistogramVec> = try_create_histogram_vec(
+        "blocking_tasks_histogram",
+        "Time taken by blocking tasks",
+        &["blocking_task_hist"]
+    );
+}

lighthouse/src/main.rs

@@ -141,7 +141,7 @@ fn run<E: EthSpec>(
         .eth2_testnet_config(eth2_testnet_config)?
         .build()?;
 
-    let log = environment.core_context().log;
+    let log = environment.core_context().log().clone();
 
     if let Some(log_path) = matches.value_of("logfile") {
         let path = log_path
@@ -216,11 +216,15 @@ fn run<E: EthSpec>(
             ))
             .map_err(|e| format!("Failed to init validator client: {}", e))?;
 
-        environment.core_context().runtime_handle.enter(|| {
+        environment
-            validator
+            .core_context()
-                .start_service()
+            .executor
-                .map_err(|e| format!("Failed to start validator client service: {}", e))
+            .runtime_handle()
-        })?;
+            .enter(|| {
+                validator
+                    .start_service()
+                    .map_err(|e| format!("Failed to start validator client service: {}", e))
+            })?;
 
         Some(validator)
     } else {
@@ -234,9 +238,9 @@ fn run<E: EthSpec>(
 
     // Block this thread until Crtl+C is pressed.
     environment.block_until_ctrl_c()?;
-
     info!(log, "Shutting down..");
 
+    environment.fire_signal();
     drop(beacon_node);
     drop(validator_client);
 

testing/eth1_test_rig/Cargo.toml

@@ -5,8 +5,8 @@ authors = ["Paul Hauner <paul@paulhauner.com>"]
 edition = "2018"
 
 [dependencies]
+tokio = { version = "0.2.21", features = ["time"] }
 web3 = "0.11.0"
-tokio = { version = "0.2.20", features = ["time"] }
 futures = { version = "0.3.5", features = ["compat"] }
 types = { path = "../../consensus/types"}
 serde_json = "1.0.52"

testing/simulator/Cargo.toml

@@ -12,7 +12,7 @@ types = { path = "../../consensus/types" }
 validator_client = { path = "../../validator_client" }
 parking_lot = "0.10.2"
 futures = "0.3.5"
-tokio = "0.2.20"
+tokio = "0.2.21"
 eth1_test_rig = { path = "../eth1_test_rig" }
 env_logger = "0.7.1"
 clap = "2.33.0"

validator_client/Cargo.toml

@@ -9,7 +9,7 @@ name = "validator_client"
 path = "src/lib.rs"
 
 [dev-dependencies]
-tokio = {version = "0.2.20", features = ["time", "rt-threaded", "macros"]}
+tokio = { version = "0.2.21", features = ["time", "rt-threaded", "macros"] }
 
 [dependencies]
 eth2_ssz = "0.1.2"
@@ -27,7 +27,7 @@ serde_json = "1.0.52"
 slog = { version = "2.5.2", features = ["max_level_trace", "release_max_level_trace"] }
 slog-async = "2.5.0"
 slog-term = "2.5.0"
-tokio = {version = "0.2.20", features = ["time"]}
+tokio = { version = "0.2.21", features = ["time"] }
 error-chain = "0.12.2"
 bincode = "1.2.1"
 futures = { version = "0.3.5", features = ["compat"] }

validator_client/src/attestation_service.rs

@@ -3,8 +3,7 @@ use crate::{
     validator_store::ValidatorStore,
 };
 use environment::RuntimeContext;
-use exit_future::Signal;
+use futures::StreamExt;
-use futures::{FutureExt, StreamExt};
 use remote_beacon_node::{PublishStatus, RemoteBeaconNode};
 use slog::{crit, debug, info, trace};
 use slot_clock::SlotClock;
@@ -118,8 +117,8 @@ impl<T, E: EthSpec> Deref for AttestationService<T, E> {
 
 impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
     /// Starts the service which periodically produces attestations.
-    pub fn start_update_service(self, spec: &ChainSpec) -> Result<Signal, String> {
+    pub fn start_update_service(self, spec: &ChainSpec) -> Result<(), String> {
-        let log = self.context.log.clone();
+        let log = self.context.log().clone();
 
         let slot_duration = Duration::from_millis(spec.milliseconds_per_slot);
         let duration_to_next_slot = self
@@ -141,13 +140,11 @@ impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
             )
         };
 
-        let (exit_signal, exit_fut) = exit_future::signal();
+        let executor = self.context.executor.clone();
-
-        let runtime_handle = self.context.runtime_handle.clone();
 
         let interval_fut = async move {
             while interval.next().await.is_some() {
-                let log = &self.context.log;
+                let log = self.context.log();
 
                 if let Err(e) = self.spawn_attestation_tasks(slot_duration) {
                     crit!(
@@ -164,13 +161,8 @@ impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
             }
         };
 
-        let future = futures::future::select(
+        executor.spawn(interval_fut, "attestation_service");
-            Box::pin(interval_fut),
+        Ok(())
-            exit_fut.map(move |_| info!(log, "Shutdown complete")),
-        );
-        runtime_handle.spawn(future);
-
-        Ok(exit_signal)
     }
 
     /// For each each required attestation, spawn a new task that downloads, signs and uploads the
@@ -214,7 +206,7 @@ impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
             .into_iter()
             .for_each(|(committee_index, validator_duties)| {
                 // Spawn a separate task for each attestation.
-                self.inner.context.runtime_handle.spawn(
+                self.inner.context.executor.runtime_handle().spawn(
                     self.clone().publish_attestations_and_aggregates(
                         slot,
                         committee_index,
@@ -243,7 +235,7 @@ impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
         validator_duties: Vec<DutyAndProof>,
         aggregate_production_instant: Instant,
     ) -> Result<(), ()> {
-        let log = &self.context.log;
+        let log = self.context.log();
 
         // There's not need to produce `Attestation` or `SignedAggregateAndProof` if we do not have
         // any validators for the given `slot` and `committee_index`.
@@ -314,7 +306,7 @@ impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
         committee_index: CommitteeIndex,
         validator_duties: &[DutyAndProof],
     ) -> Result<Option<Attestation<E>>, String> {
-        let log = &self.context.log;
+        let log = self.context.log();
 
         if validator_duties.is_empty() {
             return Ok(None);
@@ -448,7 +440,7 @@ impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
         attestation: Attestation<E>,
         validator_duties: &[DutyAndProof],
     ) -> Result<(), String> {
-        let log = &self.context.log;
+        let log = self.context.log();
 
         let aggregated_attestation = self
             .beacon_node
@@ -548,6 +540,7 @@ impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use futures::future::FutureExt;
     use parking_lot::RwLock;
 
     /// This test is to ensure that a `tokio_timer::Delay` with an instant in the past will still

validator_client/src/block_service.rs

@@ -1,7 +1,6 @@
 use crate::{duties_service::DutiesService, validator_store::ValidatorStore};
 use environment::RuntimeContext;
-use exit_future::Signal;
+use futures::{StreamExt, TryFutureExt};
-use futures::{FutureExt, StreamExt, TryFutureExt};
 use remote_beacon_node::{PublishStatus, RemoteBeaconNode};
 use slog::{crit, error, info, trace};
 use slot_clock::SlotClock;
@@ -113,8 +112,8 @@ impl<T, E: EthSpec> Deref for BlockService<T, E> {
 
 impl<T: SlotClock + 'static, E: EthSpec> BlockService<T, E> {
     /// Starts the service that periodically attempts to produce blocks.
-    pub fn start_update_service(self, spec: &ChainSpec) -> Result<Signal, String> {
+    pub fn start_update_service(self, spec: &ChainSpec) -> Result<(), String> {
-        let log = self.context.log.clone();
+        let log = self.context.log().clone();
 
         let duration_to_next_slot = self
             .slot_clock
@@ -136,7 +135,7 @@ impl<T: SlotClock + 'static, E: EthSpec> BlockService<T, E> {
             )
         };
 
-        let runtime_handle = self.inner.context.runtime_handle.clone();
+        let executor = self.inner.context.executor.clone();
 
         let interval_fut = async move {
             while interval.next().await.is_some() {
@@ -144,20 +143,14 @@ impl<T: SlotClock + 'static, E: EthSpec> BlockService<T, E> {
             }
         };
 
-        let (exit_signal, exit_fut) = exit_future::signal();
+        executor.spawn(interval_fut, "block_service");
 
-        let future = futures::future::select(
+        Ok(())
-            Box::pin(interval_fut),
-            exit_fut.map(move |_| info!(log, "Shutdown complete")),
-        );
-        runtime_handle.spawn(future);
-
-        Ok(exit_signal)
     }
 
     /// Attempt to produce a block for any block producers in the `ValidatorStore`.
     async fn do_update(&self) -> Result<(), ()> {
-        let log = &self.context.log;
+        let log = self.context.log();
 
         let slot = self.slot_clock.now().ok_or_else(move || {
             crit!(log, "Duties manager failed to read slot clock");
@@ -190,7 +183,7 @@ impl<T: SlotClock + 'static, E: EthSpec> BlockService<T, E> {
         iter.for_each(|validator_pubkey| {
             let service = self.clone();
             let log = log.clone();
-            self.inner.context.runtime_handle.spawn(
+            self.inner.context.executor.runtime_handle().spawn(
                 service
                     .publish_block(slot, validator_pubkey)
                     .map_err(move |e| {
@@ -208,7 +201,7 @@ impl<T: SlotClock + 'static, E: EthSpec> BlockService<T, E> {
 
     /// Produce a block at the given slot for validator_pubkey
     async fn publish_block(self, slot: Slot, validator_pubkey: PublicKey) -> Result<(), String> {
-        let log = &self.context.log;
+        let log = self.context.log();
 
         let current_slot = self
             .slot_clock

validator_client/src/duties_service.rs

@@ -1,11 +1,10 @@
 use crate::{is_synced::is_synced, validator_store::ValidatorStore};
 use environment::RuntimeContext;
-use exit_future::Signal;
+use futures::StreamExt;
-use futures::{FutureExt, StreamExt};
 use parking_lot::RwLock;
 use remote_beacon_node::{PublishStatus, RemoteBeaconNode};
 use rest_types::{ValidatorDuty, ValidatorDutyBytes, ValidatorSubscription};
-use slog::{debug, error, info, trace, warn};
+use slog::{debug, error, trace, warn};
 use slot_clock::SlotClock;
 use std::collections::HashMap;
 use std::convert::TryInto;
@@ -439,9 +438,7 @@ impl<T: SlotClock + 'static, E: EthSpec> DutiesService<T, E> {
     }
 
     /// Start the service that periodically polls the beacon node for validator duties.
-    pub fn start_update_service(self, spec: &ChainSpec) -> Result<Signal, String> {
+    pub fn start_update_service(self, spec: &ChainSpec) -> Result<(), String> {
-        let log = self.context.log.clone();
-
         let duration_to_next_slot = self
             .slot_clock
             .duration_to_next_slot()
@@ -456,15 +453,14 @@ impl<T: SlotClock + 'static, E: EthSpec> DutiesService<T, E> {
             )
         };
 
-        let (exit_signal, exit_fut) = exit_future::signal();
-
         // Run an immediate update before starting the updater service.
         self.inner
             .context
-            .runtime_handle
+            .executor
+            .runtime_handle()
             .spawn(self.clone().do_update());
 
-        let runtime_handle = self.inner.context.runtime_handle.clone();
+        let executor = self.inner.context.executor.clone();
 
         let interval_fut = async move {
             while interval.next().await.is_some() {
@@ -472,18 +468,14 @@ impl<T: SlotClock + 'static, E: EthSpec> DutiesService<T, E> {
             }
         };
 
-        let future = futures::future::select(
+        executor.spawn(interval_fut, "duties_service");
-            Box::pin(interval_fut),
-            exit_fut.map(move |_| info!(log, "Shutdown complete")),
-        );
-        runtime_handle.spawn(future);
 
-        Ok(exit_signal)
+        Ok(())
     }
 
     /// Attempt to download the duties of all managed validators for this epoch and the next.
     async fn do_update(self) -> Result<(), ()> {
-        let log = &self.context.log;
+        let log = self.context.log();
 
         if !is_synced(&self.beacon_node, &self.slot_clock, None).await
             && !self.allow_unsynced_beacon_node
@@ -550,7 +542,7 @@ impl<T: SlotClock + 'static, E: EthSpec> DutiesService<T, E> {
             .await
             .map_err(move |e| format!("Failed to get duties for epoch {}: {:?}", epoch, e))?;
 
-        let log = self.context.log.clone();
+        let log = self.context.log().clone();
 
         let mut new_validator = 0;
         let mut new_epoch = 0;
@@ -652,7 +644,7 @@ impl<T: SlotClock + 'static, E: EthSpec> DutiesService<T, E> {
             )
         }
 
-        let log = self.context.log.clone();
+        let log = self.context.log().clone();
         let count = validator_subscriptions.len();
 
         if count == 0 {

validator_client/src/fork_service.rs

@@ -1,9 +1,8 @@
 use environment::RuntimeContext;
-use exit_future::Signal;
+use futures::StreamExt;
-use futures::{FutureExt, StreamExt};
 use parking_lot::RwLock;
 use remote_beacon_node::RemoteBeaconNode;
-use slog::{debug, info, trace};
+use slog::{debug, trace};
 use slot_clock::SlotClock;
 use std::ops::Deref;
 use std::sync::Arc;
@@ -100,9 +99,7 @@ impl<T: SlotClock + 'static, E: EthSpec> ForkService<T, E> {
     }
 
     /// Starts the service that periodically polls for the `Fork`.
-    pub fn start_update_service(self, spec: &ChainSpec) -> Result<Signal, String> {
+    pub fn start_update_service(self, spec: &ChainSpec) -> Result<(), String> {
-        let log = self.context.log.clone();
-
         let duration_to_next_epoch = self
             .slot_clock
             .duration_to_next_epoch(E::slots_per_epoch())
@@ -117,15 +114,14 @@ impl<T: SlotClock + 'static, E: EthSpec> ForkService<T, E> {
             )
         };
 
-        let (exit_signal, exit_fut) = exit_future::signal();
-
         // Run an immediate update before starting the updater service.
         self.inner
             .context
-            .runtime_handle
+            .executor
+            .runtime_handle()
             .spawn(self.clone().do_update());
 
-        let runtime_handle = self.inner.context.runtime_handle.clone();
+        let executor = self.inner.context.executor.clone();
 
         let interval_fut = async move {
             while interval.next().await.is_some() {
@@ -133,18 +129,14 @@ impl<T: SlotClock + 'static, E: EthSpec> ForkService<T, E> {
             }
         };
 
-        let future = futures::future::select(
+        executor.spawn(interval_fut, "fork_service");
-            Box::pin(interval_fut),
-            exit_fut.map(move |_| info!(log, "Shutdown complete")),
-        );
-        runtime_handle.spawn(future);
 
-        Ok(exit_signal)
+        Ok(())
     }
 
     /// Attempts to download the `Fork` from the server.
     async fn do_update(self) -> Result<(), ()> {
-        let log = &self.context.log;
+        let log = self.context.log();
 
         let fork = self
             .inner

validator_client/src/lib.rs

@@ -17,7 +17,6 @@ use clap::ArgMatches;
 use config::SLASHING_PROTECTION_FILENAME;
 use duties_service::{DutiesService, DutiesServiceBuilder};
 use environment::RuntimeContext;
-use exit_future::Signal;
 use fork_service::{ForkService, ForkServiceBuilder};
 use notifier::spawn_notifier;
 use remote_beacon_node::RemoteBeaconNode;
@@ -41,7 +40,6 @@ pub struct ProductionValidatorClient<T: EthSpec> {
     fork_service: ForkService<SystemTimeSlotClock, T>,
     block_service: BlockService<SystemTimeSlotClock, T>,
     attestation_service: AttestationService<SystemTimeSlotClock, T>,
-    exit_signals: Vec<Signal>,
     config: Config,
 }
 
@@ -60,10 +58,10 @@ impl<T: EthSpec> ProductionValidatorClient<T> {
     /// Instantiates the validator client, _without_ starting the timers to trigger block
     /// and attestation production.
     pub async fn new(mut context: RuntimeContext<T>, config: Config) -> Result<Self, String> {
-        let log_1 = context.log.clone();
+        let log_1 = context.log().clone();
-        let log_2 = context.log.clone();
+        let log_2 = context.log().clone();
-        let log_3 = context.log.clone();
+        let log_3 = context.log().clone();
-        let log_4 = context.log.clone();
+        let log_4 = context.log().clone();
 
         info!(
             log_1,
@@ -217,46 +215,32 @@ impl<T: EthSpec> ProductionValidatorClient<T> {
             fork_service,
             block_service,
             attestation_service,
-            exit_signals: vec![],
             config,
         })
     }
 
     pub fn start_service(&mut self) -> Result<(), String> {
-        let duties_exit = self
+        self.duties_service
-            .duties_service
             .clone()
             .start_update_service(&self.context.eth2_config.spec)
             .map_err(|e| format!("Unable to start duties service: {}", e))?;
 
-        let fork_exit = self
+        self.fork_service
-            .fork_service
             .clone()
             .start_update_service(&self.context.eth2_config.spec)
             .map_err(|e| format!("Unable to start fork service: {}", e))?;
 
-        let block_exit = self
+        self.block_service
-            .block_service
             .clone()
             .start_update_service(&self.context.eth2_config.spec)
             .map_err(|e| format!("Unable to start block service: {}", e))?;
 
-        let attestation_exit = self
+        self.attestation_service
-            .attestation_service
             .clone()
             .start_update_service(&self.context.eth2_config.spec)
             .map_err(|e| format!("Unable to start attestation service: {}", e))?;
 
-        let notifier_exit =
+        spawn_notifier(self).map_err(|e| format!("Failed to start notifier: {}", e))?;
-            spawn_notifier(self).map_err(|e| format!("Failed to start notifier: {}", e))?;
-
-        self.exit_signals = vec![
-            duties_exit,
-            fork_exit,
-            block_exit,
-            attestation_exit,
-            notifier_exit,
-        ];
 
         Ok(())
     }

validator_client/src/notifier.rs

@@ -1,16 +1,14 @@
 use crate::{is_synced::is_synced, ProductionValidatorClient};
-use exit_future::Signal;
+use futures::StreamExt;
-use futures::{FutureExt, StreamExt};
 use slog::{error, info};
 use slot_clock::SlotClock;
 use tokio::time::{interval_at, Duration, Instant};
 use types::EthSpec;
 
 /// Spawns a notifier service which periodically logs information about the node.
-pub fn spawn_notifier<T: EthSpec>(client: &ProductionValidatorClient<T>) -> Result<Signal, String> {
+pub fn spawn_notifier<T: EthSpec>(client: &ProductionValidatorClient<T>) -> Result<(), String> {
     let context = client.context.service_context("notifier".into());
-    let runtime_handle = context.runtime_handle.clone();
+    let executor = context.executor.clone();
-    let log = context.log.clone();
     let duties_service = client.duties_service.clone();
     let allow_unsynced_beacon_node = client.config.allow_unsynced_beacon_node;
 
@@ -25,7 +23,7 @@ pub fn spawn_notifier<T: EthSpec>(client: &ProductionValidatorClient<T>) -> Resu
     let mut interval = interval_at(start_instant, slot_duration);
 
     let interval_fut = async move {
-        let log = &context.log;
+        let log = context.log();
 
         while interval.next().await.is_some() {
             if !is_synced(
@@ -83,12 +81,6 @@ pub fn spawn_notifier<T: EthSpec>(client: &ProductionValidatorClient<T>) -> Resu
         }
     };
 
-    let (exit_signal, exit) = exit_future::signal();
+    executor.spawn(interval_fut, "validator_notifier");
-    let future = futures::future::select(
+    Ok(())
-        Box::pin(interval_fut),
-        exit.map(move |_| info!(log, "Shutdown complete")),
-    );
-    runtime_handle.spawn(future);
-
-    Ok(exit_signal)
 }