Use tokio runtime handle instead of TaskExecutor abstraction (#9737)

* Use tokio runtime handle instead of TaskExecutor abstraction

Before this pr we had the `TaskExecutor` abstraction which theoretically
allowed that any futures executor could have been used. However, this
was never tested and is currently not really required. Anyone running a
node currently only used tokio and nothing else (because this was hard
coded in CLI). So, this pr removes the `TaskExecutor` abstraction and
relies directly on the tokio runtime handle.

Besides this changes, this pr also makes sure that the http and ws rpc
server use the same tokio runtime. This fixes a panic that occurred when
you drop the rpc servers inside an async function (tokio doesn't like
that a tokio runtime is dropped in the async context of another tokio
runtime).

As we don't use any custom runtime in the http rpc server anymore, this
pr also removes the `rpc-http-threads` cli argument. If external parties
complain that there aren't enough threads for the rpc server, we could
bring support for increasing the thread count of the tokio runtime.

* FMT

* Fix try runtime

* Fix integration tests and some other optimizations

* Remove warnings

substrate/bin/node/cli/tests/running_the_node_and_interrupt.rs

@@ -16,23 +16,30 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
+#![cfg(unix)]
+
 use assert_cmd::cargo::cargo_bin;
-use std::{convert::TryInto, process::Command, thread, time::Duration};
+use nix::{
+	sys::signal::{
+		kill,
+		Signal::{self, SIGINT, SIGTERM},
+	},
+	unistd::Pid,
+};
+use sc_service::Deref;
+use std::{
+	convert::TryInto,
+	ops::DerefMut,
+	process::{Child, Command},
+	thread,
+	time::Duration,
+};
 use tempfile::tempdir;
 
 pub mod common;
 
 #[test]
-#[cfg(unix)]
 fn running_the_node_works_and_can_be_interrupted() {
-	use nix::{
-		sys::signal::{
-			kill,
-			Signal::{self, SIGINT, SIGTERM},
-		},
-		unistd::Pid,
-	};
-
 	fn run_command_and_kill(signal: Signal) {
 		let base_path = tempdir().expect("could not create a temp dir");
 		let mut cmd = Command::new(cargo_bin("substrate"))
@@ -55,3 +62,57 @@ fn running_the_node_works_and_can_be_interrupted() {
 	run_command_and_kill(SIGINT);
 	run_command_and_kill(SIGTERM);
 }
+
+struct KillChildOnDrop(Child);
+
+impl Drop for KillChildOnDrop {
+	fn drop(&mut self) {
+		let _ = self.0.kill();
+	}
+}
+
+impl Deref for KillChildOnDrop {
+	type Target = Child;
+
+	fn deref(&self) -> &Self::Target {
+		&self.0
+	}
+}
+
+impl DerefMut for KillChildOnDrop {
+	fn deref_mut(&mut self) -> &mut Self::Target {
+		&mut self.0
+	}
+}
+
+#[test]
+fn running_two_nodes_with_the_same_ws_port_should_work() {
+	fn start_node() -> Child {
+		Command::new(cargo_bin("substrate"))
+			.args(&["--dev", "--tmp", "--ws-port=45789"])
+			.spawn()
+			.unwrap()
+	}
+
+	let mut first_node = KillChildOnDrop(start_node());
+	let mut second_node = KillChildOnDrop(start_node());
+
+	thread::sleep(Duration::from_secs(30));
+
+	assert!(first_node.try_wait().unwrap().is_none(), "The first node should still be running");
+	assert!(second_node.try_wait().unwrap().is_none(), "The second node should still be running");
+
+	kill(Pid::from_raw(first_node.id().try_into().unwrap()), SIGINT).unwrap();
+	kill(Pid::from_raw(second_node.id().try_into().unwrap()), SIGINT).unwrap();
+
+	assert_eq!(
+		common::wait_for(&mut first_node, 30).map(|x| x.success()),
+		Some(true),
+		"The first node must exit gracefully",
+	);
+	assert_eq!(
+		common::wait_for(&mut second_node, 30).map(|x| x.success()),
+		Some(true),
+		"The second node must exit gracefully",
+	);
+}