Fix timer panics in the wasm light client (#4561)

* Make WASM browser thing compile

* Fix

* updated exit-future (github repo)

* Switch to broadcast crate

* Migrate client/cli

* Switch exit-future to modernize branch

* Small changes

* Switch to cargo version and fix fg tests

* fix basic-authorship

* Fix crash on grafana macro

* Fix grafana macro

* Switch node python version

* Disable record_metrics_slice in grafana macro on wasm

* Update client/grafana-data-source/src/lib.rs

* Revert "Update client/grafana-data-source/src/lib.rs"

This reverts commit 888009a8e0b7051bd4bfbbfdb0448bcf2e2aae93.

* Add wasm support for state machine

* Switch to my own libp2p version

* Revert "Switch to my own libp2p version"

This reverts commit ce613871b59264b3165b45c37943e6560240daa7.

* Revert "Add wasm support for state machine"

This reverts commit de7eaa0694d9534fc3b164621737968e9a6a7c5f.

* Add sc-browser

* Squash

* remove sc-browser

* Fix keystore on wasm

* stubs for removed functions to make env compatible with old runtimes

* Add test (that doesn't work)

* Fix build scripts

* Revert basic-authorship due to no panics

* Revert cli/informant

* Revert consensus

* revert offchain

* Update utils/browser/Cargo.toml

Co-Authored-By: Benjamin Kampmann <ben@gnunicorn.org>

* export console functions

* Add new chainspec

* Fix ws in chain spec

* revert chainspec

* Fix chainspec

* Use an Option<PathBuf> in keystore instead of cfg flags

* Remove crud

* Only use wasm-timer for instant and systemtime

* Remove telemetry changes

* Assuming this is ok

* Add a KeystoreConfig

* Add stubs back in

* Update libp2p

* Revert "Add stubs back in"

This reverts commit 4690cf1882aa0f99f7f00a58c4080c8aa9b77c36.

* Remove commented js again

* Bump kvdb-web version

* Fix cli

* Switch branch on futures-timer

* Fix tests

* Remove sc-client test build in check-web-wasm because there isn't a good way to build futures-timer with wasm-bindgen support in the build

* Remove more things ^^

* Switch branch on futures-timer back

* Put DB io stats behind a cfg flag

* Fix things

* Don't timeout transports on wasm

* Update branch of futures-timer and fix bad merge

* Spawn informant

* Fix network test

* Fix delay resets

* Changes

* Fix tests

* use wasm_timer for transaction pool

* Fixes

* Switch futures-timer to crates

* Only diagnose futures on native

* Fix sc-network-test tests

* Select log level in js

* Fix syncing ;^)

* Allow disabling colours in the informant

* Use OutputFormat enum for informant

* MallocSizeOf impl on transaction pool broke stuff because wasm_timer::Instant doesnt impl it so just revert the transaction pool to master

* Update futures-diagnose

* Revert "MallocSizeOf impl on transaction pool broke stuff because wasm_timer::Instant doesnt impl it so just revert the transaction pool to master"

This reverts commit baa4ffc94fd968b6660a2c17ba8113e06af15548.

* Pass whole chain spec in start_client

* Get Instant::now to work in transaction pool again

* Informant dep reordering

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
Co-authored-by: Svyatoslav Nikolsky <svyatonik@gmail.com>
Co-authored-by: Benjamin Kampmann <ben.kampmann@googlemail.com>
Co-authored-by: Demi Obenour <48690212+DemiMarie-parity@users.noreply.github.com>

substrate/client/finality-grandpa/Cargo.toml

@@ -8,7 +8,7 @@ license = "GPL-3.0"
 [dependencies]
 fork-tree = { version = "2.0.0", path = "../../utils/fork-tree" }
 futures = "0.3.1"
-futures-timer = "2.0.2"
+futures-timer = "3.0.1"
 log = "0.4.8"
 parking_lot = "0.10.0"
 rand = "0.7.2"

substrate/client/finality-grandpa/src/communication/periodic.rs

@@ -19,7 +19,7 @@
 use futures_timer::Delay;
 use futures::{channel::mpsc, future::{FutureExt as _}, prelude::*, ready, stream::Stream};
 use log::debug;
-use std::{pin::Pin, task::{Context, Poll}, time::{Instant, Duration}};
+use std::{pin::Pin, task::{Context, Poll}, time::Duration};
 
 use sc_network::PeerId;
 use sp_runtime::traits::{NumberFor, Block as BlockT};
@@ -28,10 +28,6 @@ use super::gossip::{NeighborPacket, GossipMessage};
 // How often to rebroadcast, in cases where no new packets are created.
 const REBROADCAST_AFTER: Duration = Duration::from_secs(2 * 60);
 
-fn rebroadcast_instant() -> Instant {
-	Instant::now() + REBROADCAST_AFTER
-}
-
 /// A sender used to send neighbor packets to a background job.
 #[derive(Clone)]
 pub(super) struct NeighborPacketSender<B: BlockT>(
@@ -85,7 +81,7 @@ impl <B: BlockT> Stream for NeighborPacketWorker<B> {
 		match this.rx.poll_next_unpin(cx) {
 			Poll::Ready(None) => return Poll::Ready(None),
 			Poll::Ready(Some((to, packet))) => {
-				this.delay.reset(rebroadcast_instant());
+				this.delay.reset(REBROADCAST_AFTER);
 				this.last = Some((to.clone(), packet.clone()));
 
 				return Poll::Ready(Some((to, GossipMessage::<B>::from(packet.clone()))));
@@ -98,7 +94,7 @@ impl <B: BlockT> Stream for NeighborPacketWorker<B> {
 
 		// Getting this far here implies that the timer fired.
 
-		this.delay.reset(rebroadcast_instant());
+		this.delay.reset(REBROADCAST_AFTER);
 
 		// Make sure the underlying task is scheduled for wake-up.
 		//