Fix to ethash seedHash caching.

alethzero/Main.ui

@@ -180,6 +180,7 @@
     <addaction name="separator"/>
     <addaction name="usePrivate"/>
     <addaction name="jitvm"/>
+    <addaction name="retryUnknown"/>
    </widget>
    <widget class="QMenu" name="menu_View">
     <property name="title">
@@ -1679,6 +1680,11 @@ font-size: 14pt</string>
     <string>&amp;GPU Mining</string>
    </property>
   </action>
+  <action name="retryUnknown">
+   <property name="text">
+    <string>Retry Unknown Parent Blocks</string>
+   </property>
+  </action>
  </widget>
  <layoutdefault spacing="6" margin="11"/>
  <customwidgets>

alethzero/MainWin.cpp

@@ -1752,6 +1752,11 @@ void Main::on_clearPending_triggered()
 	refreshAll();
 }
 
+void Main::on_retryUnknown_triggered()
+{
+	ethereum()->retryUnkonwn();
+}
+
 void Main::on_killBlockchain_triggered()
 {
 	writeSettings();

alethzero/MainWin.h

@@ -163,6 +163,7 @@ private slots:
 	void on_usePrivate_triggered();
 	void on_turboMining_triggered();
 	void on_jitvm_triggered();
+	void on_retryUnknown_triggered();
 
 	// Debugger
 	void on_debugCurrent_triggered();

eth/main.cpp

@@ -32,11 +32,12 @@
 #include <libdevcrypto/FileSystem.h>
 #include <libevmcore/Instruction.h>
 #include <libdevcore/StructuredLogger.h>
+#include <libethcore/ProofOfWork.h>
+#include <libethcore/EthashAux.h>
 #include <libevm/VM.h>
 #include <libevm/VMFactory.h>
 #include <libethereum/All.h>
 #include <libwebthree/WebThree.h>
-#include <libethcore/ProofOfWork.h>
 #if ETH_READLINE
 #include <readline/readline.h>
 #include <readline/history.h>
@@ -111,6 +112,7 @@ void help()
 		<< "    -b,--bootstrap  Connect to the default Ethereum peerserver." << endl
 		<< "    -B,--block-fees <n>  Set the block fee profit in the reference unit e.g. ¢ (Default: 15)." << endl
 		<< "    -c,--client-name <name>  Add a name to your client's version string (default: blank)." << endl
+		<< "    -C,--check-pow <headerHash> <seedHash> <difficulty> <nonce>  Check PoW credentials for validity." << endl
 		<< "    -d,--db-path <path>  Load database from path (default:  ~/.ethereum " << endl
 		<< "                         <APPDATA>/Etherum or Library/Application Support/Ethereum)." << endl
 		<< "    -D,--create-dag <this/next/number>  Create the DAG in preparation for mining on given block and exit." << endl
@@ -401,6 +403,43 @@ int main(int argc, char** argv)
 					return -1;
 				}
 		}
+		else if ((arg == "-C" || arg == "--check-pow") && i + 4 < argc)
+		{
+			string m;
+			try
+			{
+				BlockInfo bi;
+				m = boost::to_lower_copy(string(argv[++i]));
+				h256 powHash(m);
+				m = boost::to_lower_copy(string(argv[++i]));
+				h256 seedHash;
+				if (m.size() == 64 || m.size() == 66)
+					seedHash = h256(m);
+				else
+					seedHash = EthashAux::seedHash(stol(m));
+				m = boost::to_lower_copy(string(argv[++i]));
+				bi.difficulty = u256(m);
+				auto boundary = bi.boundary();
+				m = boost::to_lower_copy(string(argv[++i]));
+				bi.nonce = h64(m);
+				auto r = EthashAux::eval(seedHash, powHash, bi.nonce);
+				bool valid = r.value < boundary;
+				cout << (valid ? "VALID :-)" : "INVALID :-(") << endl;
+				cout << r.value << (valid ? " < " : " >= ") << boundary << endl;
+				cout << "  where " << boundary << " = 2^256 / " << bi.difficulty << endl;
+				cout << "  and " << r.value << " = ethash(" << powHash << ", " << bi.nonce << ")" << endl;
+				cout << "  with seed as " << seedHash << endl;
+				if (valid)
+					cout << "(mixHash = " << r.mixHash << ")" << endl;
+				cout << "SHA3( light(seed) ) = " << sha3(bytesConstRef((byte const*)EthashAux::light(seedHash), EthashAux::params(seedHash).cache_size)) << endl;
+				exit(0);
+			}
+			catch (...)
+			{
+				cerr << "Bad " << arg << " option: " << m << endl;
+				return -1;
+			}
+		}
 		else if ((arg == "-B" || arg == "--block-fees") && i + 1 < argc)
 		{
 			try

libdevcore/Guards.h

@@ -38,4 +38,75 @@ using UpgradableGuard = boost::upgrade_lock<boost::shared_mutex>;
 using UpgradeGuard = boost::upgrade_to_unique_lock<boost::shared_mutex>;
 using WriteGuard = boost::unique_lock<boost::shared_mutex>;
 
+template <class GuardType, class MutexType>
+struct GenericGuardBool: GuardType
+{
+	GenericGuardBool(MutexType& _m): GuardType(_m) {}
+	bool b = true;
+};
+template <class MutexType>
+struct GenericUnguardBool
+{
+	GenericUnguardBool(MutexType& _m): m(_m) { m.unlock(); }
+	~GenericUnguardBool() { m.lock(); }
+	bool b = true;
+	MutexType& m;
+};
+template <class MutexType>
+struct GenericUnguardSharedBool
+{
+	GenericUnguardSharedBool(MutexType& _m): m(_m) { m.unlock_shared(); }
+	~GenericUnguardSharedBool() { m.lock_shared(); }
+	bool b = true;
+	MutexType& m;
+};
+
+/** @brief Simple block guard.
+ * The expression/block following is guarded though the given mutex.
+ * Usage:
+ * @code
+ * Mutex m;
+ * unsigned d;
+ * ...
+ * ETH_GUARDED(m) d = 1;
+ * ...
+ * ETH_GUARDED(m) { for (auto d = 10; d > 0; --d) foo(d); d = 0; }
+ * @endcode
+ *
+ * There are several variants of this basic mechanism for different Mutex types and Guards.
+ *
+ * There is also the UNGUARD variant which allows an unguarded expression/block to exist within a
+ * guarded expression. eg:
+ *
+ * @code
+ * Mutex m;
+ * int d;
+ * ...
+ * ETH_GUARDED(m)
+ * {
+ *   for (auto d = 50; d > 25; --d)
+ *     foo(d);
+ *   ETH_UNGUARDED(m)
+ *     bar();
+ *   for (; d > 0; --d)
+ *     foo(d);
+ * }
+ * @endcode
+ */
+
+#define ETH_GUARDED(MUTEX) \
+	for (GenericGuardBool<Guard, Mutex> __eth_l(MUTEX); __eth_l.b; __eth_l.b = false)
+#define ETH_READ_GUARDED(MUTEX) \
+	for (GenericGuardBool<ReadGuard, SharedMutex> __eth_l(MUTEX); __eth_l.b; __eth_l.b = false)
+#define ETH_WRITE_GUARDED(MUTEX) \
+	for (GenericGuardBool<WriteGuard, SharedMutex> __eth_l(MUTEX); __eth_l.b; __eth_l.b = false)
+#define ETH_RECURSIVE_GUARDED(MUTEX) \
+	for (GenericGuardBool<RecursiveGuard, RecursiveMutex> __eth_l(MUTEX); __eth_l.b; __eth_l.b = false)
+#define ETH_UNGUARDED(MUTEX) \
+	for (GenericUnguardBool<Mutex> __eth_l(MUTEX); __eth_l.b; __eth_l.b = false)
+#define ETH_READ_UNGUARDED(MUTEX) \
+	for (GenericUnguardSharedBool<SharedMutex> __eth_l(MUTEX); __eth_l.b; __eth_l.b = false)
+#define ETH_WRITE_UNGUARDED(MUTEX) \
+	for (GenericUnguardBool<SharedMutex> __eth_l(MUTEX); __eth_l.b; __eth_l.b = false)
+
 }

libethcore/EthashAux.cpp

@@ -67,19 +67,24 @@ h256 EthashAux::seedHash(unsigned _number)
 {
 	unsigned epoch = _number / ETHASH_EPOCH_LENGTH;
 	RecursiveGuard l(get()->x_this);
-	if (_number < get()->m_seedHashes.size())
-		return get()->m_seedHashes[_number];
-	h256 ret;
-	unsigned n = 0;
-	if (!get()->m_seedHashes.empty())
+	if (epoch >= get()->m_seedHashes.size())
 	{
-		ret = get()->m_seedHashes.back();
-		n = get()->m_seedHashes.size() - 1;
+		h256 ret;
+		unsigned n = 0;
+		if (!get()->m_seedHashes.empty())
+		{
+			ret = get()->m_seedHashes.back();
+			n = get()->m_seedHashes.size() - 1;
+		}
+		get()->m_seedHashes.resize(epoch + 1);
+		cdebug << "Searching for seedHash of epoch " << epoch;
+		for (; n <= epoch; ++n, ret = sha3(ret))
+		{
+			get()->m_seedHashes[n] = ret;
+			cdebug << "Epoch" << n << "is" << ret.abridged();
+		}
 	}
-	cdebug << "Searching for seedHash of epoch " << epoch;
-	for (; n < epoch; ++n, ret = sha3(ret))
-		cdebug << "Epoch" << n << "is" << ret.abridged();
-	return ret;
+	return get()->m_seedHashes[epoch];
 }
 
 ethash_params EthashAux::params(h256 const& _seedHash)
@@ -93,17 +98,13 @@ ethash_params EthashAux::params(h256 const& _seedHash)
 	catch (...)
 	{
 		cdebug << "Searching for seedHash " << _seedHash.abridged();
-		for (h256 h; h != _seedHash && epoch < 2048; ++epoch, h = sha3(h))
-		{
-			cdebug << "Epoch" << epoch << "is" << h.abridged();
-		}
+		for (h256 h; h != _seedHash && epoch < 2048; ++epoch, h = sha3(h), get()->m_epochs[h] = epoch) {}
 		if (epoch == 2048)
 		{
 			std::ostringstream error;
 			error << "apparent block number for " << _seedHash.abridged() << " is too high; max is " << (ETHASH_EPOCH_LENGTH * 2048);
 			throw std::invalid_argument(error.str());
 		}
-		get()->m_epochs[_seedHash] = epoch;
 	}
 	return params(epoch * ETHASH_EPOCH_LENGTH);
 }

libethcore/EthashAux.h

@@ -41,7 +41,7 @@ public:
 	static ethash_params params(h256 const& _seedHash);
 	static ethash_params params(unsigned _n);
 	static LightType light(BlockInfo const& _header);
-	static LightType light(h256 const& _header);
+	static LightType light(h256 const& _seedHash);
 	static bytesConstRef full(BlockInfo const& _header, bytesRef _dest = bytesRef());
 	static bytesConstRef full(h256 const& _header, bytesRef _dest = bytesRef());
 

libethcore/Params.cpp

@@ -30,7 +30,6 @@ namespace eth
 //--- BEGIN: AUTOGENERATED FROM github.com/ethereum/common/params.json
 u256 const c_genesisDifficulty = 131072;
 u256 const c_maximumExtraDataSize = 1024;
-u256 const c_epochDuration = 30000;
 u256 const c_genesisGasLimit = 3141592;
 u256 const c_minGasLimit = 125000;
 u256 const c_gasLimitBoundDivisor = 1024;

libethcore/Params.h

@@ -37,7 +37,6 @@ extern u256 const c_minimumDifficulty;
 extern u256 const c_difficultyBoundDivisor;
 extern u256 const c_durationLimit;
 extern u256 const c_maximumExtraDataSize;
-extern u256 const c_epochDuration;
 extern u256 const c_stackLimit;
 
 extern u256 const c_tierStepGas[8];			///< Once per operation, for a selection of them.

libethereum/BlockQueue.cpp

@@ -183,3 +183,15 @@ void BlockQueue::noteReadyWithoutWriteGuard(h256 _good)
 		m_unknown.erase(r.first, r.second);
 	}
 }
+
+void BlockQueue::retryAllUnknown()
+{
+	for (auto it = m_unknown.begin(); it != m_unknown.end(); ++it)
+	{
+		m_ready.push_back(it->second.second);
+		auto newReady = it->second.first;
+		m_unknownSet.erase(newReady);
+		m_readySet.insert(newReady);
+	}
+	m_unknown.clear();
+}

libethereum/BlockQueue.h

@@ -71,6 +71,9 @@ public:
 	/// Notify the queue that the chain has changed and a new block has attained 'ready' status (i.e. is in the chain).
 	void noteReady(h256 _b) { WriteGuard l(m_lock); noteReadyWithoutWriteGuard(_b); }
 
+	/// Force a retry of all the blocks with unknown parents.
+	void retryAllUnknown();
+
 	/// Get information on the items queued.
 	std::pair<unsigned, unsigned> items() const { ReadGuard l(m_lock); return std::make_pair(m_ready.size(), m_unknown.size()); }
 

libethereum/Client.cpp

@@ -436,15 +436,12 @@ void Client::syncBlockQueue()
 {
 	ImportRoute ir;
 
+	cwork << "BQ ==> CHAIN ==> STATE";
 	{
 		WriteGuard l(x_stateDB);
-		cwork << "BQ ==> CHAIN ==> STATE";
 		OverlayDB db = m_stateDB;
-		x_stateDB.unlock();
-
-		tie(ir.first, ir.second, m_syncBlockQueue) = m_bc.sync(m_bq, db, 100);
-
-		x_stateDB.lock();
+		ETH_WRITE_UNGUARDED(x_stateDB)
+			tie(ir.first, ir.second, m_syncBlockQueue) = m_bc.sync(m_bq, db, 100);
 		if (ir.first.empty())
 			return;
 		m_stateDB = db;
@@ -458,7 +455,11 @@ void Client::syncTransactionQueue()
 	cwork << "postSTATE <== TQ";
 
 	h256Set changeds;
-	TransactionReceipts newPendingReceipts = m_postMine.sync(m_bc, m_tq, *m_gp);
+	TransactionReceipts newPendingReceipts;
+
+	ETH_WRITE_GUARDED(x_stateDB)
+		newPendingReceipts = m_postMine.sync(m_bc, m_tq, *m_gp);
+
 	if (newPendingReceipts.size())
 	{
 		for (size_t i = 0; i < newPendingReceipts.size(); i++)
@@ -512,8 +513,7 @@ void Client::onChainChanged(ImportRoute const& _ir)
 	// RESTART MINING
 
 	// LOCKS REALLY NEEDED?
-	{
-		ReadGuard l(x_stateDB);
+	ETH_WRITE_GUARDED(x_stateDB)
 		if (m_preMine.sync(m_bc) || m_postMine.address() != m_preMine.address())
 		{
 			if (isMining())
@@ -522,11 +522,9 @@ void Client::onChainChanged(ImportRoute const& _ir)
 			m_postMine = m_preMine;
 			changeds.insert(PendingChangedFilter);
 
-			x_stateDB.unlock_shared();
-			onPostStateChanged();
-			x_stateDB.lock_shared();
+			ETH_WRITE_UNGUARDED(x_stateDB)
+				onPostStateChanged();
 		}
-	}
 
 	noteChanged(changeds);
 }
@@ -534,17 +532,24 @@ void Client::onChainChanged(ImportRoute const& _ir)
 void Client::onPostStateChanged()
 {
 	cnote << "Post state changed: Restarting mining...";
+	if (isMining())
 	{
-		WriteGuard l(x_stateDB);
-		cdebug << "Pre:" << m_preMine.info();
-		m_postMine.commitToMine(m_bc);
-		m_miningInfo = m_postMine.info();
-		cdebug << "Pre:" << m_preMine.info();
-		cdebug << "Post:" << m_postMine.info();
-		cdebug << "Pre:" << m_preMine.info().headerHash(WithoutNonce) << "; Post:" << m_postMine.info().headerHash(WithoutNonce);
+		{
+			WriteGuard l(x_stateDB);
+			m_postMine.commitToMine(m_bc);
+			m_miningInfo = m_postMine.info();
+		}
+		m_farm.setWork(m_miningInfo);
 	}
+}
 
-	m_farm.setWork(m_miningInfo);
+void Client::startMining()
+{
+	if (m_turboMining)
+		m_farm.startGPU();
+	else
+		m_farm.startCPU();
+	onPostStateChanged();
 }
 
 void Client::noteChanged(h256Set const& _filters)

libethereum/Client.h

@@ -169,7 +169,7 @@ public:
 
 	/// Start mining.
 	/// NOT thread-safe - call it & stopMining only from a single thread
-	void startMining() override { if (m_turboMining) m_farm.startGPU(); else m_farm.startCPU(); onPostStateChanged(); }
+	void startMining() override;
 	/// Stop mining.
 	/// NOT thread-safe
 	void stopMining() override { m_farm.stop(); }
@@ -202,6 +202,8 @@ public:
 	void clearPending();
 	/// Kills the blockchain. Just for debug use.
 	void killChain();
+	/// Retries all blocks with unknown parents.
+	void retryUnkonwn() { m_bq.retryAllUnknown(); }
 
 protected:
 	/// InterfaceStub methods

libethereum/Farm.h

@@ -92,11 +92,12 @@ public:
 		WriteGuard l(x_minerWork);
 		m_miners.clear();
 		m_work.reset();
+		m_isMining = false;
 	}
 
 	bool isMining() const
 	{
-		return !!m_work;
+		return m_isMining;
 	}
 
 	/**
@@ -165,6 +166,7 @@ private:
 			m_miners.push_back(std::shared_ptr<Miner>(new MinerType(std::make_pair(this, i))));
 			m_miners.back()->setWork(m_work);
 		}
+		m_isMining = true;
 		resetTimer();
 		return true;
 	}
@@ -179,6 +181,8 @@ private:
 	WorkPackage m_work;
 	BlockInfo m_header;
 
+	std::atomic<bool> m_isMining = {false};
+
 	mutable SharedMutex x_progress;
 	mutable MiningProgress m_progress;
 	std::chrono::steady_clock::time_point m_lastStart;