From a09b82261af6ad21d48444d07e70c44785265cf2 Mon Sep 17 00:00:00 2001
From: Guilherme Lawless <guilherme@nano.org>
Date: Mon, 22 Jun 2020 09:05:29 +0100
Subject: [PATCH] Pre-sample block rate for bootstrap connections (#2823)

This solves a Debug assert on msvc: strict weak ordering not being satisfied in `bootstrap_connections::populate_connections` due to `block_rate_cmp`
---
 nano/node/bootstrap/bootstrap_connections.cpp | 11 ++++++-----
 nano/node/bootstrap/bootstrap_connections.hpp |  3 ++-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/nano/node/bootstrap/bootstrap_connections.cpp b/nano/node/bootstrap/bootstrap_connections.cpp
index 53724f02..c8448131 100644
--- a/nano/node/bootstrap/bootstrap_connections.cpp
+++ b/nano/node/bootstrap/bootstrap_connections.cpp
@@ -30,10 +30,11 @@ nano::bootstrap_client::~bootstrap_client ()
 	--connections->connections_count;
 }
 
-double nano::bootstrap_client::block_rate () const
+double nano::bootstrap_client::sample_block_rate ()
 {
 	auto elapsed = std::max (elapsed_seconds (), nano::bootstrap_limits::bootstrap_minimum_elapsed_seconds_blockrate);
-	return static_cast<double> (block_count.load () / elapsed);
+	block_rate = static_cast<double> (block_count.load ()) / elapsed;
+	return block_rate;
 }
 
 void nano::bootstrap_client::set_start_time (std::chrono::steady_clock::time_point start_time_a)
@@ -201,7 +202,7 @@ struct block_rate_cmp
 {
 	bool operator() (const std::shared_ptr<nano::bootstrap_client> & lhs, const std::shared_ptr<nano::bootstrap_client> & rhs) const
 	{
-		return lhs->block_rate () > rhs->block_rate ();
+		return lhs->block_rate > rhs->block_rate;
 	}
 };
 
@@ -225,7 +226,7 @@ void nano::bootstrap_connections::populate_connections (bool repeat)
 					new_clients.push_back (client);
 					endpoints.insert (socket_l->remote_endpoint ());
 					double elapsed_sec = client->elapsed_seconds ();
-					auto blocks_per_sec = client->block_rate ();
+					auto blocks_per_sec = client->sample_block_rate ();
 					rate_sum += blocks_per_sec;
 					if (client->elapsed_seconds () > nano::bootstrap_limits::bootstrap_connection_warmup_time_sec && client->block_count > 0)
 					{
@@ -270,7 +271,7 @@ void nano::bootstrap_connections::populate_connections (bool repeat)
 
 			if (node.config.logging.bulk_pull_logging ())
 			{
-				node.logger.try_log (boost::str (boost::format ("Dropping peer with block rate %1%, block count %2% (%3%) ") % client->block_rate () % client->block_count % client->channel->to_string ()));
+				node.logger.try_log (boost::str (boost::format ("Dropping peer with block rate %1%, block count %2% (%3%) ") % client->block_rate % client->block_count % client->channel->to_string ()));
 			}
 
 			client->stop (false);
diff --git a/nano/node/bootstrap/bootstrap_connections.hpp b/nano/node/bootstrap/bootstrap_connections.hpp
index 85ef479a..d83f4f0f 100644
--- a/nano/node/bootstrap/bootstrap_connections.hpp
+++ b/nano/node/bootstrap/bootstrap_connections.hpp
@@ -24,7 +24,7 @@ public:
 	~bootstrap_client ();
 	std::shared_ptr<nano::bootstrap_client> shared ();
 	void stop (bool force);
-	double block_rate () const;
+	double sample_block_rate ();
 	double elapsed_seconds () const;
 	void set_start_time (std::chrono::steady_clock::time_point start_time_a);
 	std::shared_ptr<nano::node> node;
@@ -33,6 +33,7 @@ public:
 	std::shared_ptr<nano::socket> socket;
 	std::shared_ptr<std::vector<uint8_t>> receive_buffer;
 	std::atomic<uint64_t> block_count{ 0 };
+	std::atomic<double> block_rate{ 0 };
 	std::atomic<bool> pending_stop{ false };
 	std::atomic<bool> hard_stop{ false };