Upgrade to tokio 0.3 (#1839)

## Description

This PR updates Lighthouse to tokio 0.3. It includes a number of dependency updates and some structural changes as to how we create and spawn tasks.

This also brings with it a number of various improvements:

- Discv5 update
- Libp2p update
- Fix for recompilation issues
- Improved UPnP port mapping handling
- Futures dependency update
- Log downgrade to traces for rejecting peers when we've reached our max



Co-authored-by: blacktemplar <blacktemplar@a1.net>

beacon_node/client/Cargo.toml

@@ -27,9 +27,9 @@ error-chain = "0.12.4"
 serde_yaml = "0.8.13"
 slog = { version = "2.5.2", features = ["max_level_trace"] }
 slog-async = "2.5.0"
-tokio = "0.2.22"
+tokio = "0.3.2"
 dirs = "3.0.1"
-futures = "0.3.5"
+futures = "0.3.7"
 reqwest = { version = "0.10.8", features = ["native-tls-vendored"] }
 url = "2.1.1"
 eth1 = { path = "../eth1" }

beacon_node/client/src/builder.rs

@@ -254,10 +254,16 @@ where
                     let (listen_addr, server) = http_api::serve(ctx, exit_future)
                         .map_err(|e| format!("Unable to start HTTP API server: {:?}", e))?;
 
+                    let log_clone = context.log().clone();
+                    let http_api_task = async move {
+                        server.await;
+                        debug!(log_clone, "HTTP API server task ended");
+                    };
+
                     context
                         .clone()
                         .executor
-                        .spawn_without_exit(async move { server.await }, "http-api");
+                        .spawn_without_exit(http_api_task, "http-api");
 
                     Some(listen_addr)
                 } else {
@@ -283,7 +289,7 @@ where
                             "Waiting for HTTP server port to open";
                             "port" => http_listen
                         );
-                        tokio::time::delay_for(Duration::from_secs(1)).await;
+                        tokio::time::sleep(Duration::from_secs(1)).await;
                     }
                 }
 
@@ -442,10 +448,16 @@ where
             let (listen_addr, server) = http_api::serve(ctx, exit)
                 .map_err(|e| format!("Unable to start HTTP API server: {:?}", e))?;
 
+            let http_log = runtime_context.log().clone();
+            let http_api_task = async move {
+                server.await;
+                debug!(http_log, "HTTP API server task ended");
+            };
+
             runtime_context
                 .clone()
                 .executor
-                .spawn_without_exit(async move { server.await }, "http-api");
+                .spawn_without_exit(http_api_task, "http-api");
 
             Some(listen_addr)
         } else {

beacon_node/client/src/notifier.rs

@@ -7,7 +7,7 @@ use slog::{debug, error, info, warn};
 use slot_clock::SlotClock;
 use std::sync::Arc;
 use std::time::{Duration, Instant};
-use tokio::time::delay_for;
+use tokio::time::sleep;
 use types::{EthSpec, Slot};
 
 /// Create a warning log whenever the peer count is at or below this value.
@@ -56,7 +56,7 @@ pub fn spawn_notifier<T: BeaconChainTypes>(
                         "peers" => peer_count_pretty(network.connected_peers()),
                         "wait_time" => estimated_time_pretty(Some(next_slot.as_secs() as f64)),
                     );
-                    delay_for(slot_duration).await;
+                    sleep(slot_duration).await;
                 }
                 _ => break,
             }