From 1ebcec3ce25e30a3afa07bc778f7caaef6e77f6a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Piotr=20W=C3=B3jcik?=
 <3044353+pwojcikdev@users.noreply.github.com>
Date: Thu, 21 Mar 2024 17:55:22 +0100
Subject: [PATCH] Config option for disabling hinted scheduler (#4512)

---
 nano/core_test/toml.cpp            | 3 +++
 nano/node/scheduler/hinted.cpp     | 7 +++++++
 nano/node/scheduler/hinted.hpp     | 1 +
 nano/node/scheduler/optimistic.cpp | 4 ++--
 4 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/nano/core_test/toml.cpp b/nano/core_test/toml.cpp
index 9e2a5cbe..b29519ba 100644
--- a/nano/core_test/toml.cpp
+++ b/nano/core_test/toml.cpp
@@ -245,6 +245,7 @@ TEST (toml, daemon_config_deserialize_defaults)
 	ASSERT_EQ (conf.node.optimistic_scheduler.gap_threshold, defaults.node.optimistic_scheduler.gap_threshold);
 	ASSERT_EQ (conf.node.optimistic_scheduler.max_size, defaults.node.optimistic_scheduler.max_size);
 
+	ASSERT_EQ (conf.node.hinted_scheduler.enabled, defaults.node.hinted_scheduler.enabled);
 	ASSERT_EQ (conf.node.hinted_scheduler.hinting_threshold_percent, defaults.node.hinted_scheduler.hinting_threshold_percent);
 	ASSERT_EQ (conf.node.hinted_scheduler.check_interval.count (), defaults.node.hinted_scheduler.check_interval.count ());
 	ASSERT_EQ (conf.node.hinted_scheduler.block_cooldown.count (), defaults.node.hinted_scheduler.block_cooldown.count ());
@@ -516,6 +517,7 @@ TEST (toml, daemon_config_deserialize_no_defaults)
 	max_size = 999
 
 	[node.hinted_scheduler]
+	enabled = false
 	hinting_threshold = 99
 	check_interval = 999
 	block_cooldown = 999
@@ -667,6 +669,7 @@ TEST (toml, daemon_config_deserialize_no_defaults)
 	ASSERT_NE (conf.node.optimistic_scheduler.gap_threshold, defaults.node.optimistic_scheduler.gap_threshold);
 	ASSERT_NE (conf.node.optimistic_scheduler.max_size, defaults.node.optimistic_scheduler.max_size);
 
+	ASSERT_NE (conf.node.hinted_scheduler.enabled, defaults.node.hinted_scheduler.enabled);
 	ASSERT_NE (conf.node.hinted_scheduler.hinting_threshold_percent, defaults.node.hinted_scheduler.hinting_threshold_percent);
 	ASSERT_NE (conf.node.hinted_scheduler.check_interval.count (), defaults.node.hinted_scheduler.check_interval.count ());
 	ASSERT_NE (conf.node.hinted_scheduler.block_cooldown.count (), defaults.node.hinted_scheduler.block_cooldown.count ());
diff --git a/nano/node/scheduler/hinted.cpp b/nano/node/scheduler/hinted.cpp
index a6f97686..0d971aa1 100644
--- a/nano/node/scheduler/hinted.cpp
+++ b/nano/node/scheduler/hinted.cpp
@@ -30,6 +30,11 @@ void nano::scheduler::hinted::start ()
 {
 	debug_assert (!thread.joinable ());
 
+	if (!config.enabled)
+	{
+		return;
+	}
+
 	thread = std::thread{ [this] () {
 		nano::thread_role::set (nano::thread_role::name::scheduler_hinted);
 		run ();
@@ -254,6 +259,7 @@ nano::scheduler::hinted_config::hinted_config (nano::network_constants const & n
 
 nano::error nano::scheduler::hinted_config::serialize (nano::tomlconfig & toml) const
 {
+	toml.put ("enable", enabled, "Enable or disable hinted elections\ntype:bool");
 	toml.put ("hinting_threshold", hinting_threshold_percent, "Percentage of online weight needed to start a hinted election. \ntype:uint32,[0,100]");
 	toml.put ("check_interval", check_interval.count (), "Interval between scans of the vote cache for possible hinted elections. \ntype:milliseconds");
 	toml.put ("block_cooldown", block_cooldown.count (), "Cooldown period for blocks that failed to start an election. \ntype:milliseconds");
@@ -264,6 +270,7 @@ nano::error nano::scheduler::hinted_config::serialize (nano::tomlconfig & toml)
 
 nano::error nano::scheduler::hinted_config::deserialize (nano::tomlconfig & toml)
 {
+	toml.get ("enabled", enabled);
 	toml.get ("hinting_threshold", hinting_threshold_percent);
 
 	auto check_interval_l = check_interval.count ();
diff --git a/nano/node/scheduler/hinted.hpp b/nano/node/scheduler/hinted.hpp
index 4bb30cd9..9e8fd425 100644
--- a/nano/node/scheduler/hinted.hpp
+++ b/nano/node/scheduler/hinted.hpp
@@ -36,6 +36,7 @@ public:
 	nano::error serialize (nano::tomlconfig & toml) const;
 
 public:
+	bool enabled{ true };
 	std::chrono::milliseconds check_interval{ 1000 };
 	std::chrono::milliseconds block_cooldown{ 10000 };
 	unsigned hinting_threshold_percent{ 10 };
diff --git a/nano/node/scheduler/optimistic.cpp b/nano/node/scheduler/optimistic.cpp
index a11e1540..cda28666 100644
--- a/nano/node/scheduler/optimistic.cpp
+++ b/nano/node/scheduler/optimistic.cpp
@@ -25,13 +25,13 @@ nano::scheduler::optimistic::~optimistic ()
 
 void nano::scheduler::optimistic::start ()
 {
+	debug_assert (!thread.joinable ());
+
 	if (!config.enabled)
 	{
 		return;
 	}
 
-	debug_assert (!thread.joinable ());
-
 	thread = std::thread{ [this] () {
 		nano::thread_role::set (nano::thread_role::name::scheduler_optimistic);
 		run ();