Make authorship soft deadline configurable. (#10125)

* Make soft deadline configurable.

* cargo +nightly fmt --all

* Move setter where it belongs.

client/basic-authorship/src/basic_authorship.rs

@@ -42,7 +42,7 @@ use sp_inherents::InherentData;
 use sp_runtime::{
 	generic::BlockId,
 	traits::{BlakeTwo256, Block as BlockT, Hash as HashT, Header as HeaderT},
-	Digest,
+	Digest, Percent, SaturatedConversion,
 };
 use std::{marker::PhantomData, pin::Pin, sync::Arc, time};
 
@@ -58,6 +58,8 @@ use sc_proposer_metrics::MetricsLink as PrometheusMetrics;
 /// transferred to other nodes.
 pub const DEFAULT_BLOCK_SIZE_LIMIT: usize = 4 * 1024 * 1024 + 512;
 
+const DEFAULT_SOFT_DEADLINE_PERCENT: Percent = Percent::from_percent(50);
+
 /// [`Proposer`] factory.
 pub struct ProposerFactory<A, B, C, PR> {
 	spawn_handle: Box<dyn SpawnNamed>,
@@ -72,6 +74,14 @@ pub struct ProposerFactory<A, B, C, PR> {
 	/// If no `block_size_limit` is passed to [`sp_consensus::Proposer::propose`], this block size
 	/// limit will be used.
 	default_block_size_limit: usize,
+	/// Soft deadline percentage of hard deadline.
+	///
+	/// The value is used to compute soft deadline during block production.
+	/// The soft deadline indicates where we should stop attempting to add transactions
+	/// to the block, which exhaust resources. After soft deadline is reached,
+	/// we switch to a fixed-amount mode, in which after we see `MAX_SKIPPED_TRANSACTIONS`
+	/// transactions which exhaust resrouces, we will conclude that the block is full.
+	soft_deadline_percent: Percent,
 	telemetry: Option<TelemetryHandle>,
 	/// When estimating the block size, should the proof be included?
 	include_proof_in_block_size_estimation: bool,
@@ -96,6 +106,7 @@ impl<A, B, C> ProposerFactory<A, B, C, DisableProofRecording> {
 			transaction_pool,
 			metrics: PrometheusMetrics::new(prometheus),
 			default_block_size_limit: DEFAULT_BLOCK_SIZE_LIMIT,
+			soft_deadline_percent: DEFAULT_SOFT_DEADLINE_PERCENT,
 			telemetry,
 			client,
 			include_proof_in_block_size_estimation: false,
@@ -124,6 +135,7 @@ impl<A, B, C> ProposerFactory<A, B, C, EnableProofRecording> {
 			transaction_pool,
 			metrics: PrometheusMetrics::new(prometheus),
 			default_block_size_limit: DEFAULT_BLOCK_SIZE_LIMIT,
+			soft_deadline_percent: DEFAULT_SOFT_DEADLINE_PERCENT,
 			telemetry,
 			include_proof_in_block_size_estimation: true,
 			_phantom: PhantomData,
@@ -147,6 +159,22 @@ impl<A, B, C, PR> ProposerFactory<A, B, C, PR> {
 	pub fn set_default_block_size_limit(&mut self, limit: usize) {
 		self.default_block_size_limit = limit;
 	}
+
+	/// Set soft deadline percentage.
+	///
+	/// The value is used to compute soft deadline during block production.
+	/// The soft deadline indicates where we should stop attempting to add transactions
+	/// to the block, which exhaust resources. After soft deadline is reached,
+	/// we switch to a fixed-amount mode, in which after we see `MAX_SKIPPED_TRANSACTIONS`
+	/// transactions which exhaust resrouces, we will conclude that the block is full.
+	///
+	/// Setting the value too low will significantly limit the amount of transactions
+	/// we try in case they exhaust resources. Setting the value too high can
+	/// potentially open a DoS vector, where many "exhaust resources" transactions
+	/// are being tried with no success, hence block producer ends up creating an empty block.
+	pub fn set_soft_deadline(&mut self, percent: Percent) {
+		self.soft_deadline_percent = percent;
+	}
 }
 
 impl<B, Block, C, A, PR> ProposerFactory<A, B, C, PR>
@@ -184,6 +212,7 @@ where
 			now,
 			metrics: self.metrics.clone(),
 			default_block_size_limit: self.default_block_size_limit,
+			soft_deadline_percent: self.soft_deadline_percent,
 			telemetry: self.telemetry.clone(),
 			_phantom: PhantomData,
 			include_proof_in_block_size_estimation: self.include_proof_in_block_size_estimation,
@@ -229,6 +258,7 @@ pub struct Proposer<B, Block: BlockT, C, A: TransactionPool, PR> {
 	metrics: PrometheusMetrics,
 	default_block_size_limit: usize,
 	include_proof_in_block_size_estimation: bool,
+	soft_deadline_percent: Percent,
 	telemetry: Option<TelemetryHandle>,
 	_phantom: PhantomData<(B, PR)>,
 }
@@ -340,7 +370,10 @@ where
 		// proceed with transactions
 		// We calculate soft deadline used only in case we start skipping transactions.
 		let now = (self.now)();
-		let soft_deadline = now + deadline.saturating_duration_since(now) / 2;
+		let left = deadline.saturating_duration_since(now);
+		let left_micros: u64 = left.as_micros().saturated_into();
+		let soft_deadline =
+			now + time::Duration::from_micros(self.soft_deadline_percent.mul_floor(left_micros));
 		let block_timer = time::Instant::now();
 		let mut skipped = 0;
 		let mut unqueue_invalid = Vec::new();