Avoid throwing out potentially good blocks.

libethereum/BlockQueue.cpp

@@ -111,10 +111,22 @@ void BlockQueue::verifierBody()
 			{
 				// we're next!
 				m_verifying.pop_front();
-				m_verified.push_back(move(res));
+				if (m_knownBad.count(res.verified.info.hash()))
+				{
+					m_readySet.erase(res.verified.info.hash());
+					m_knownBad.insert(res.verified.info.hash());
+				}
+				else
+					m_verified.push_back(move(res));
 				while (m_verifying.size() && !m_verifying.front().blockData.empty())
 				{
-					m_verified.push_back(move(m_verifying.front()));
+					if (m_knownBad.count(m_verifying.front().verified.info.hash()))
+					{
+						m_readySet.erase(m_verifying.front().verified.info.hash());
+						m_knownBad.insert(res.verified.info.hash());
+					}
+					else
+						m_verified.push_back(move(m_verifying.front()));
 					m_verifying.pop_front();
 				}
 				ready = true;
@@ -229,8 +241,24 @@ bool BlockQueue::doneDrain(h256s const& _bad)
 	DEV_INVARIANT_CHECK;
 	m_drainingSet.clear();
 	if (_bad.size())
-		// one of them was bad. since they all rely on their parent, all following are bad.
+	{
+		// at least one of them was bad.
+		m_knownBad += _bad;
 		DEV_GUARDED(m_verification)
+		{
+			std::vector<VerifiedBlock> oldVerified;
+			swap(m_verified, oldVerified);
+			for (auto& b: oldVerified)
+				if (m_knownBad.count(b.verified.info.parentHash))
+				{
+					m_knownBad.insert(b.verified.info.hash());
+					m_readySet.erase(b.verified.info.hash());
+				}
+				else
+					m_verified.push_back(std::move(b));
+		}
+	}
+/*		DEV_GUARDED(m_verification)
 		{
 			m_knownBad += _bad;
 			m_knownBad += m_readySet;
@@ -238,7 +266,7 @@ bool BlockQueue::doneDrain(h256s const& _bad)
 			m_verified.clear();
 			m_verifying.clear();
 			m_unverified.clear();
-		}
+		}*/
 	return !m_readySet.empty();
 }
 

libethereum/BlockQueue.h

@@ -132,8 +132,8 @@ private:
 
 	mutable Mutex m_verification;										///< Mutex that allows writing to m_verified, m_verifying and m_unverified.
 	std::condition_variable m_moreToVerify;								///< Signaled when m_unverified has a new entry.
-	std::vector<VerifiedBlock> m_verified;				///< List of blocks, in correct order, verified and ready for chain-import.
+	std::vector<VerifiedBlock> m_verified;								///< List of blocks, in correct order, verified and ready for chain-import.
-	std::deque<VerifiedBlock> m_verifying;				///< List of blocks being verified; as long as the second component (bytes) is empty, it's not finished.
+	std::deque<VerifiedBlock> m_verifying;								///< List of blocks being verified; as long as the second component (bytes) is empty, it's not finished.
 	std::deque<std::pair<h256, bytes>> m_unverified;					///< List of blocks, in correct order, ready for verification.
 
 	std::vector<std::thread> m_verifiers;								///< Threads who only verify.