From ce205f382cb1f2964f1edcbbb08e43e93bd200c9 Mon Sep 17 00:00:00 2001
From: Gav Wood <i@gavwood.com>
Date: Tue, 19 May 2015 23:22:44 +0200
Subject: [PATCH] Remote mining fixes.

---
 alethzero/MainWin.cpp    | 2 +-
 ethminer/MinerAux.h      | 2 ++
 libethereum/BlockQueue.h | 2 +-
 libethereum/Client.cpp   | 8 +++++++-
 libethereum/Client.h     | 3 +++
 5 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/alethzero/MainWin.cpp b/alethzero/MainWin.cpp
index 076e9d547..4f236b3e8 100644
--- a/alethzero/MainWin.cpp
+++ b/alethzero/MainWin.cpp
@@ -1166,7 +1166,7 @@ void Main::on_turboMining_triggered()
 
 void Main::refreshBlockChain()
 {
-	if (!ui->blocks->isVisible() || !isVisible())
+	if (!ui->blocks->isVisible() && isVisible())
 		return;
 
 	DEV_TIMED_FUNCTION_ABOVE(500);
diff --git a/ethminer/MinerAux.h b/ethminer/MinerAux.h
index 53a5fa7e4..d99e36976 100644
--- a/ethminer/MinerAux.h
+++ b/ethminer/MinerAux.h
@@ -419,6 +419,8 @@ private:
 					Json::Value v = rpc.eth_getWork();
 					h256 hh(v[0].asString());
 					h256 newSeedHash(v[1].asString());
+					if (current.seedHash != newSeedHash)
+						cnote << "Grabbing DAG for" << newSeedHash;
 					if (!(dag = EthashAux::full(newSeedHash, true, [&](unsigned _pc){ cout << "\rCreating DAG. " << _pc << "% done..." << flush; return 0; })))
 						BOOST_THROW_EXCEPTION(DAGCreationFailure());
 					if (hh != current.headerHash)
diff --git a/libethereum/BlockQueue.h b/libethereum/BlockQueue.h
index c865bac32..d0437739d 100644
--- a/libethereum/BlockQueue.h
+++ b/libethereum/BlockQueue.h
@@ -94,7 +94,7 @@ public:
 	void retryAllUnknown();
 
 	/// Get information on the items queued.
-	std::pair<unsigned, unsigned> items() const { ReadGuard l(m_lock); return std::make_pair(m_verified.size(), m_unknown.size()); }
+	std::pair<unsigned, unsigned> items() const { ReadGuard l(m_lock); return std::make_pair(m_readySet.size(), m_unknownSet.size()); }
 
 	/// Clear everything.
 	void clear() { WriteGuard l(m_lock); DEV_INVARIANT_CHECK; Guard l2(m_verification); m_readySet.clear(); m_drainingSet.clear(); m_verified.clear(); m_unverified.clear(); m_unknownSet.clear(); m_unknown.clear(); m_future.clear(); }
diff --git a/libethereum/Client.cpp b/libethereum/Client.cpp
index e39126713..0fd27520d 100644
--- a/libethereum/Client.cpp
+++ b/libethereum/Client.cpp
@@ -455,8 +455,13 @@ ProofOfWork::WorkPackage Client::getWork()
 {
 	// lock the work so a later submission isn't invalidated by processing a transaction elsewhere.
 	// this will be reset as soon as a new block arrives, allowing more transactions to be processed.
+	bool oldShould = shouldServeWork();
 	m_lastGetWork = chrono::system_clock::now();
 	m_remoteWorking = true;
+
+	// if this request has made us bother to serve work, prep it now.
+	if (!oldShould && shouldServeWork())
+		onPostStateChanged();
 	return ProofOfWork::package(m_miningInfo);
 }
 
@@ -612,7 +617,8 @@ bool Client::remoteActive() const
 void Client::onPostStateChanged()
 {
 	cnote << "Post state changed";
-	if (isMining() || remoteActive())
+
+	if (m_bq.items().first == 0 && (isMining() || remoteActive()))
 	{
 		cnote << "Restarting mining...";
 		DEV_WRITE_GUARDED(x_working)
diff --git a/libethereum/Client.h b/libethereum/Client.h
index 4fa6da8b1..c77cb6034 100644
--- a/libethereum/Client.h
+++ b/libethereum/Client.h
@@ -274,6 +274,9 @@ private:
 	/// Ticks various system-level objects.
 	void tick();
 
+	/// @returns true only if it's worth bothering to prep the mining block.
+	bool shouldServeWork() const { return m_bq.items().first == 0 && (isMining() || remoteActive()); }
+
 	VersionChecker m_vc;					///< Dummy object to check & update the protocol version.
 	CanonBlockChain m_bc;					///< Maintains block database.
 	BlockQueue m_bq;						///< Maintains a list of incoming blocks not yet on the blockchain (to be imported).