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/client/cli/src/commands/run_cmd.rs

@@ -127,10 +127,6 @@ pub struct RunCmd {
 	#[structopt(long = "ws-max-connections", value_name = "COUNT")]
 	pub ws_max_connections: Option<usize>,
 
-	/// Size of the RPC HTTP server thread pool.
-	#[structopt(long = "rpc-http-threads", value_name = "COUNT")]
-	pub rpc_http_threads: Option<usize>,
-
 	/// Specify browser Origins allowed to access the HTTP & WS RPC servers.
 	///
 	/// A comma-separated list of origins (protocol://domain or special `null`
@@ -381,10 +377,6 @@ impl CliConfiguration for RunCmd {
 		Ok(self.ws_max_connections)
 	}
 
-	fn rpc_http_threads(&self) -> Result<Option<usize>> {
-		Ok(self.rpc_http_threads)
-	}
-
 	fn rpc_cors(&self, is_dev: bool) -> Result<Option<Vec<String>>> {
 		Ok(self
 			.rpc_cors

substrate/client/cli/src/config.rs

@@ -29,7 +29,7 @@ use sc_service::{
 	config::{
 		BasePath, Configuration, DatabaseSource, KeystoreConfig, NetworkConfiguration,
 		NodeKeyConfig, OffchainWorkerConfig, PrometheusConfig, PruningMode, Role, RpcMethods,
-		TaskExecutor, TelemetryEndpoints, TransactionPoolOptions, WasmExecutionMethod,
+		TelemetryEndpoints, TransactionPoolOptions, WasmExecutionMethod,
 	},
 	ChainSpec, KeepBlocks, TracingReceiver, TransactionStorageMode,
 };
@@ -348,13 +348,6 @@ pub trait CliConfiguration<DCV: DefaultConfigurationValues = ()>: Sized {
 		Ok(None)
 	}
 
-	/// Get the RPC HTTP thread pool size (`None` for a default 4-thread pool config).
-	///
-	/// By default this is `None`.
-	fn rpc_http_threads(&self) -> Result<Option<usize>> {
-		Ok(None)
-	}
-
 	/// Get the RPC cors (`None` if disabled)
 	///
 	/// By default this is `Some(Vec::new())`.
@@ -465,7 +458,7 @@ pub trait CliConfiguration<DCV: DefaultConfigurationValues = ()>: Sized {
 	fn create_configuration<C: SubstrateCli>(
 		&self,
 		cli: &C,
-		task_executor: TaskExecutor,
+		tokio_handle: tokio::runtime::Handle,
 	) -> Result<Configuration> {
 		let is_dev = self.is_dev()?;
 		let chain_id = self.chain_id(is_dev)?;
@@ -490,7 +483,7 @@ pub trait CliConfiguration<DCV: DefaultConfigurationValues = ()>: Sized {
 		Ok(Configuration {
 			impl_name: C::impl_name(),
 			impl_version: C::impl_version(),
-			task_executor,
+			tokio_handle,
 			transaction_pool: self.transaction_pool()?,
 			network: self.network_config(
 				&chain_spec,
@@ -518,7 +511,6 @@ pub trait CliConfiguration<DCV: DefaultConfigurationValues = ()>: Sized {
 			rpc_ipc: self.rpc_ipc()?,
 			rpc_methods: self.rpc_methods()?,
 			rpc_ws_max_connections: self.rpc_ws_max_connections()?,
-			rpc_http_threads: self.rpc_http_threads()?,
 			rpc_cors: self.rpc_cors(is_dev)?,
 			rpc_max_payload: self.rpc_max_payload()?,
 			prometheus_config: self.prometheus_config(DCV::prometheus_listen_port())?,

substrate/client/cli/src/lib.rs

@@ -35,8 +35,8 @@ pub use config::*;
 pub use error::*;
 pub use params::*;
 pub use runner::*;
+use sc_service::Configuration;
 pub use sc_service::{ChainSpec, Role};
-use sc_service::{Configuration, TaskExecutor};
 pub use sc_tracing::logging::LoggerBuilder;
 pub use sp_version::RuntimeVersion;
 use std::io::Write;
@@ -216,9 +216,9 @@ pub trait SubstrateCli: Sized {
 	fn create_configuration<T: CliConfiguration<DVC>, DVC: DefaultConfigurationValues>(
 		&self,
 		command: &T,
-		task_executor: TaskExecutor,
+		tokio_handle: tokio::runtime::Handle,
 	) -> error::Result<Configuration> {
-		command.create_configuration(self, task_executor)
+		command.create_configuration(self, tokio_handle)
 	}
 
 	/// Create a runner for the command provided in argument. This will create a Configuration and

substrate/client/cli/src/runner.rs

@@ -20,7 +20,7 @@ use crate::{error::Error as CliError, CliConfiguration, Result, SubstrateCli};
 use chrono::prelude::*;
 use futures::{future, future::FutureExt, pin_mut, select, Future};
 use log::info;
-use sc_service::{Configuration, Error as ServiceError, TaskManager, TaskType};
+use sc_service::{Configuration, Error as ServiceError, TaskManager};
 use sc_utils::metrics::{TOKIO_THREADS_ALIVE, TOKIO_THREADS_TOTAL};
 use std::marker::PhantomData;
 
@@ -116,15 +116,8 @@ impl<C: SubstrateCli> Runner<C> {
 		let tokio_runtime = build_runtime()?;
 		let runtime_handle = tokio_runtime.handle().clone();
 
-		let task_executor = move |fut, task_type| match task_type {
-			TaskType::Async => runtime_handle.spawn(fut).map(drop),
-			TaskType::Blocking => runtime_handle
-				.spawn_blocking(move || futures::executor::block_on(fut))
-				.map(drop),
-		};
-
 		Ok(Runner {
-			config: command.create_configuration(cli, task_executor.into())?,
+			config: command.create_configuration(cli, runtime_handle)?,
 			tokio_runtime,
 			phantom: PhantomData,
 		})