Removing usage of block_processor::flush from bootstrap_legacy and re…

…moving bootstrap_processor::flush.

nano/node/blockprocessor.cpp

@@ -37,17 +37,6 @@ void nano::block_processor::stop ()
 	nano::join_or_pass (processing_thread);
 }
 
-void nano::block_processor::flush ()
-{
-	flushing = true;
-	nano::unique_lock<nano::mutex> lock{ mutex };
-	while (!stopped && (have_blocks () || active))
-	{
-		condition.wait (lock);
-	}
-	flushing = false;
-}
-
 std::size_t nano::block_processor::size ()
 {
 	nano::unique_lock<nano::mutex> lock{ mutex };

nano/node/blockprocessor.hpp

@@ -29,7 +29,6 @@ class block_processor final
 public:
 	explicit block_processor (nano::node &, nano::write_database_queue &);
 	void stop ();
-	void flush ();
 	std::size_t size ();
 	bool full ();
 	bool half_full ();

nano/node/bootstrap/bootstrap_legacy.cpp

@@ -223,10 +223,12 @@ void nano::bootstrap_attempt_legacy::run ()
 			condition.wait (lock, [&stopped = stopped, &pulling = pulling] { return stopped || pulling == 0; });
 		}
 
-		// Flushing may resolve forks which can add more pulls
-		lock.unlock ();
-		node->block_processor.flush ();
-		lock.lock ();
+		// TODO: This check / wait is a heuristic and should be improved.
+		auto wait_start = std::chrono::steady_clock::now ();
+		while (!stopped && node->block_processor.size () != 0 && ((std::chrono::steady_clock::now () - wait_start) < std::chrono::seconds{ 10 }))
+		{
+			condition.wait_for (lock, std::chrono::milliseconds{ 100 }, [this, node] { return stopped || node->block_processor.size () == 0; });
+		}
 
 		if (start_account.number () != std::numeric_limits<nano::uint256_t>::max ())
 		{