Merge pull request #948 from sipa/unstuck
[novacoin.git] / src / main.cpp
index f78133b..491044e 100644 (file)
@@ -21,7 +21,7 @@ using namespace boost;
 // Name of client reported in the 'version' message. Report the same name
 // for both bitcoind and bitcoin-qt, to make it harder for attackers to
 // target servers or GUI users specifically.
-const std::string CLIENT_NAME("bitcoin-qt");
+const std::string CLIENT_NAME("Satoshi");
 
 CCriticalSection cs_setpwalletRegistered;
 set<CWallet*> setpwalletRegistered;
@@ -57,22 +57,12 @@ CScript COINBASE_FLAGS;
 
 const string strMessageMagic = "Bitcoin Signed Message:\n";
 
-
 double dHashesPerSec;
 int64 nHPSTimerStart;
 
 // Settings
-int fGenerateBitcoins = false;
 int64 nTransactionFee = 0;
-int fLimitProcessors = false;
-int nLimitProcessors = 1;
-int fMinimizeToTray = true;
-int fMinimizeOnClose = true;
-#if USE_UPNP
-int fUseUPnP = true;
-#else
-int fUseUPnP = false;
-#endif
+
 
 
 //////////////////////////////////////////////////////////////////////////////
@@ -177,13 +167,14 @@ void static ResendWalletTransactions()
 // mapOrphanTransactions
 //
 
-void static AddOrphanTx(const CDataStream& vMsg)
+void AddOrphanTx(const CDataStream& vMsg)
 {
     CTransaction tx;
     CDataStream(vMsg) >> tx;
     uint256 hash = tx.GetHash();
     if (mapOrphanTransactions.count(hash))
         return;
+
     CDataStream* pvMsg = mapOrphanTransactions[hash] = new CDataStream(vMsg);
     BOOST_FOREACH(const CTxIn& txin, tx.vin)
         mapOrphanTransactionsByPrev.insert(make_pair(txin.prevout.hash, pvMsg));
@@ -211,6 +202,23 @@ void static EraseOrphanTx(uint256 hash)
     mapOrphanTransactions.erase(hash);
 }
 
+int LimitOrphanTxSize(int nMaxOrphans)
+{
+    int nEvicted = 0;
+    while (mapOrphanTransactions.size() > nMaxOrphans)
+    {
+        // Evict a random orphan:
+        std::vector<unsigned char> randbytes(32);
+        RAND_bytes(&randbytes[0], 32);
+        uint256 randomhash(randbytes);
+        map<uint256, CDataStream*>::iterator it = mapOrphanTransactions.lower_bound(randomhash);
+        if (it == mapOrphanTransactions.end())
+            it = mapOrphanTransactions.begin();
+        EraseOrphanTx(it->first);
+        ++nEvicted;
+    }
+    return nEvicted;
+}
 
 
 
@@ -618,11 +626,15 @@ bool CTransaction::RemoveFromMemoryPool()
     // Remove transaction from memory pool
     CRITICAL_BLOCK(cs_mapTransactions)
     {
-        BOOST_FOREACH(const CTxIn& txin, vin)
-            mapNextTx.erase(txin.prevout);
-        mapTransactions.erase(GetHash());
-        nTransactionsUpdated++;
-        --nPooledTx;
+        uint256 hash = GetHash();
+        if (mapTransactions.count(hash))
+        {
+            BOOST_FOREACH(const CTxIn& txin, vin)
+                mapNextTx.erase(txin.prevout);
+            mapTransactions.erase(hash);
+            nTransactionsUpdated++;
+            --nPooledTx;
+        }
     }
     return true;
 }
@@ -918,6 +930,15 @@ void static InvalidChainFound(CBlockIndex* pindexNew)
         printf("InvalidChainFound: WARNING: Displayed transactions may not be correct!  You may need to upgrade, or other nodes may need to upgrade.\n");
 }
 
+void CBlock::UpdateTime(const CBlockIndex* pindexPrev)
+{
+    nTime = max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
+
+    // Updating time can change work required on testnet:
+    if (fTestNet)
+        nBits = GetNextWorkRequired(pindexPrev, this);
+}
+
 
 
 
@@ -955,8 +976,10 @@ bool CTransaction::DisconnectInputs(CTxDB& txdb)
     }
 
     // Remove transaction from index
-    if (!txdb.EraseTxIndex(*this))
-        return error("DisconnectInputs() : EraseTxPos failed");
+    // This can fail if a duplicate of this transaction was in a chain that got
+    // reorganized away. This is only possible if this transaction was completely
+    // spent, so erasing it would be a no-op anway.
+    txdb.EraseTxIndex(*this);
 
     return true;
 }
@@ -1125,7 +1148,14 @@ bool CTransaction::ConnectInputs(MapPrevTx inputs,
             {
                 // Verify signature
                 if (!VerifySignature(txPrev, *this, i, fStrictPayToScriptHash, 0))
+                {
+                    // only during transition phase for P2SH: do not invoke anti-DoS code for
+                    // potentially old clients relaying bad P2SH transactions
+                    if (fStrictPayToScriptHash && VerifySignature(txPrev, *this, i, false, 0))
+                        return error("ConnectInputs() : %s P2SH VerifySignature failed", GetHash().ToString().substr(0,10).c_str());
+
                     return DoS(100,error("ConnectInputs() : %s VerifySignature failed", GetHash().ToString().substr(0,10).c_str()));
+                }
             }
 
             // Mark outpoints as spent
@@ -1228,6 +1258,26 @@ bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex)
     if (!CheckBlock())
         return false;
 
+    // Do not allow blocks that contain transactions which 'overwrite' older transactions,
+    // unless those are already completely spent.
+    // If such overwrites are allowed, coinbases and transactions depending upon those
+    // can be duplicated to remove the ability to spend the first instance -- even after
+    // being sent to another address.
+    // See BIP30 and http://r6.ca/blog/20120206T005236Z.html for more information.
+    // This logic is not necessary for memory pool transactions, as AcceptToMemoryPool
+    // already refuses previously-known transaction id's entirely.
+    // This rule applies to all blocks whose timestamp is after March 15, 2012, 0:00 UTC.
+    // On testnet it is enabled as of februari 20, 2012, 0:00 UTC.
+    if (pindex->nTime > 1331769600 || (fTestNet && pindex->nTime > 1329696000))
+        BOOST_FOREACH(CTransaction& tx, vtx)
+        {
+            CTxIndex txindexOld;
+            if (txdb.ReadTxIndex(tx.GetHash(), txindexOld))
+                BOOST_FOREACH(CDiskTxPos &pos, txindexOld.vSpent)
+                    if (pos.IsNull())
+                        return false;
+        }
+
     // To avoid being on the short end of a block-chain split,
     // don't do secondary validation of pay-to-script-hash transactions
     // until blocks with timestamps after paytoscripthashtime (see init.cpp for default).
@@ -1332,6 +1382,9 @@ bool static Reorganize(CTxDB& txdb, CBlockIndex* pindexNew)
         vConnect.push_back(pindex);
     reverse(vConnect.begin(), vConnect.end());
 
+    printf("REORGANIZE: Disconnect %i blocks; %s..%s\n", vDisconnect.size(), pfork->GetBlockHash().ToString().substr(0,20).c_str(), pindexBest->GetBlockHash().ToString().substr(0,20).c_str());
+    printf("REORGANIZE: Connect %i blocks; %s..%s\n", vConnect.size(), pfork->GetBlockHash().ToString().substr(0,20).c_str(), pindexNew->GetBlockHash().ToString().substr(0,20).c_str());
+
     // Disconnect shorter branch
     vector<CTransaction> vResurrect;
     BOOST_FOREACH(CBlockIndex* pindex, vDisconnect)
@@ -1340,7 +1393,7 @@ bool static Reorganize(CTxDB& txdb, CBlockIndex* pindexNew)
         if (!block.ReadFromDisk(pindex))
             return error("Reorganize() : ReadFromDisk for disconnect failed");
         if (!block.DisconnectBlock(txdb, pindex))
-            return error("Reorganize() : DisconnectBlock failed");
+            return error("Reorganize() : DisconnectBlock %s failed", pindex->GetBlockHash().ToString().substr(0,20).c_str());
 
         // Queue memory transactions to resurrect
         BOOST_FOREACH(const CTransaction& tx, block.vtx)
@@ -1360,7 +1413,7 @@ bool static Reorganize(CTxDB& txdb, CBlockIndex* pindexNew)
         {
             // Invalid block
             txdb.TxnAbort();
-            return error("Reorganize() : ConnectBlock failed");
+            return error("Reorganize() : ConnectBlock %s failed", pindex->GetBlockHash().ToString().substr(0,20).c_str());
         }
 
         // Queue memory transactions to delete
@@ -1392,6 +1445,8 @@ bool static Reorganize(CTxDB& txdb, CBlockIndex* pindexNew)
     BOOST_FOREACH(CTransaction& tx, vDelete)
         tx.RemoveFromMemoryPool();
 
+    printf("REORGANIZE: done\n");
+
     return true;
 }
 
@@ -1404,6 +1459,31 @@ runCommand(std::string strCommand)
         printf("runCommand error: system(%s) returned %d\n", strCommand.c_str(), nErr);
 }
 
+// Called from inside SetBestChain: attaches a block to the new best chain being built
+bool CBlock::SetBestChainInner(CTxDB& txdb, CBlockIndex *pindexNew)
+{
+    uint256 hash = GetHash();
+
+    // Adding to current best branch
+    if (!ConnectBlock(txdb, pindexNew) || !txdb.WriteHashBestChain(hash))
+    {
+        txdb.TxnAbort();
+        InvalidChainFound(pindexNew);
+        return false;
+    }
+    if (!txdb.TxnCommit())
+        return error("SetBestChain() : TxnCommit failed");
+
+    // Add to current best branch
+    pindexNew->pprev->pnext = pindexNew;
+
+    // Delete redundant memory transactions
+    BOOST_FOREACH(CTransaction& tx, vtx)
+        tx.RemoveFromMemoryPool();
+
+    return true;
+}
+
 bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
 {
     uint256 hash = GetHash();
@@ -1418,32 +1498,50 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
     }
     else if (hashPrevBlock == hashBestChain)
     {
-        // Adding to current best branch
-        if (!ConnectBlock(txdb, pindexNew) || !txdb.WriteHashBestChain(hash))
+        if (!SetBestChainInner(txdb, pindexNew))
+            return error("SetBestChain() : SetBestChainInner failed");
+    }
+    else
+    {
+        // the first block in the new chain that will cause it to become the new best chain
+        CBlockIndex *pindexIntermediate = pindexNew;
+
+        // list of blocks that need to be connected afterwards
+        std::vector<CBlockIndex*> vpindexSecondary;
+
+        // Reorganize is costly in terms of db load, as it works in a single db transaction.
+        // Try to limit how much needs to be done inside
+        while (pindexIntermediate->pprev && pindexIntermediate->pprev->bnChainWork > pindexBest->bnChainWork)
         {
-            txdb.TxnAbort();
-            InvalidChainFound(pindexNew);
-            return error("SetBestChain() : ConnectBlock failed");
+            vpindexSecondary.push_back(pindexIntermediate);
+            pindexIntermediate = pindexIntermediate->pprev;
         }
-        if (!txdb.TxnCommit())
-            return error("SetBestChain() : TxnCommit failed");
 
-        // Add to current best branch
-        pindexNew->pprev->pnext = pindexNew;
+        if (!vpindexSecondary.empty())
+            printf("Postponing %i reconnects\n", vpindexSecondary.size());
 
-        // Delete redundant memory transactions
-        BOOST_FOREACH(CTransaction& tx, vtx)
-            tx.RemoveFromMemoryPool();
-    }
-    else
-    {
-        // New best branch
-        if (!Reorganize(txdb, pindexNew))
+        // Switch to new best branch
+        if (!Reorganize(txdb, pindexIntermediate))
         {
             txdb.TxnAbort();
             InvalidChainFound(pindexNew);
             return error("SetBestChain() : Reorganize failed");
         }
+
+        // Connect futher blocks
+        BOOST_REVERSE_FOREACH(CBlockIndex *pindex, vpindexSecondary)
+        {
+            CBlock block;
+            if (!block.ReadFromDisk(pindex))
+            {
+                printf("SetBestChain() : ReadFromDisk failed\n");
+                break;
+            }
+            txdb.TxnBegin();
+            // errors now are not fatal, we still did a reorganisation to a new chain in a valid way
+            if (!block.SetBestChainInner(txdb, pindex))
+                break;
+        }
     }
 
     // Update best block in wallet (so we can detect restored wallets)
@@ -1610,10 +1708,11 @@ bool CBlock::AcceptBlock()
         return error("AcceptBlock() : AddToBlockIndex failed");
 
     // Relay inventory, but don't relay old inventory during initial block download
+    int nBlockEstimate = Checkpoints::GetTotalBlocksEstimate();
     if (hashBestChain == hash)
         CRITICAL_BLOCK(cs_vNodes)
             BOOST_FOREACH(CNode* pnode, vNodes)
-                if (nBestHeight > (pnode->nStartingHeight != -1 ? pnode->nStartingHeight - 2000 : 140700))
+                if (nBestHeight > (pnode->nStartingHeight != -1 ? pnode->nStartingHeight - 2000 : nBlockEstimate))
                     pnode->PushInventory(CInv(MSG_BLOCK, hash));
 
     return true;
@@ -1639,7 +1738,8 @@ bool ProcessBlock(CNode* pfrom, CBlock* pblock)
         int64 deltaTime = pblock->GetBlockTime() - pcheckpoint->nTime;
         if (deltaTime < 0)
         {
-            pfrom->Misbehaving(100);
+            if (pfrom)
+                pfrom->Misbehaving(100);
             return error("ProcessBlock() : block with timestamp before last checkpoint");
         }
         CBigNum bnNewBlock;
@@ -1648,7 +1748,8 @@ bool ProcessBlock(CNode* pfrom, CBlock* pblock)
         bnRequired.SetCompact(ComputeMinWork(pcheckpoint->nBits, deltaTime));
         if (bnNewBlock > bnRequired)
         {
-            pfrom->Misbehaving(100);
+            if (pfrom)
+                pfrom->Misbehaving(100);
             return error("ProcessBlock() : block with too little proof-of-work");
         }
     }
@@ -2087,18 +2188,24 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         CAddress addrFrom;
         uint64 nNonce = 1;
         vRecv >> pfrom->nVersion >> pfrom->nServices >> nTime >> addrMe;
+        if (pfrom->nVersion < 209)
+        {
+            // Since February 20, 2012, the protocol is initiated at version 209,
+            // and earlier versions are no longer supported
+            printf("partner %s using obsolete version %i; disconnecting\n", pfrom->addr.ToString().c_str(), pfrom->nVersion);
+            pfrom->fDisconnect = true;
+            return false;
+        }
+
         if (pfrom->nVersion == 10300)
             pfrom->nVersion = 300;
-        if (pfrom->nVersion >= 106 && !vRecv.empty())
+        if (!vRecv.empty())
             vRecv >> addrFrom >> nNonce;
-        if (pfrom->nVersion >= 106 && !vRecv.empty())
+        if (!vRecv.empty())
             vRecv >> pfrom->strSubVer;
-        if (pfrom->nVersion >= 209 && !vRecv.empty())
+        if (!vRecv.empty())
             vRecv >> pfrom->nStartingHeight;
 
-        if (pfrom->nVersion == 0)
-            return false;
-
         // Disconnect if we connected to ourself
         if (nNonce == nLocalHostNonce && nNonce > 1)
         {
@@ -2116,11 +2223,8 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         AddTimeData(pfrom->addr, nTime);
 
         // Change version
-        if (pfrom->nVersion >= 209)
-            pfrom->PushMessage("verack");
+        pfrom->PushMessage("verack");
         pfrom->vSend.SetVersion(min(pfrom->nVersion, PROTOCOL_VERSION));
-        if (pfrom->nVersion < 209)
-            pfrom->vRecv.SetVersion(min(pfrom->nVersion, PROTOCOL_VERSION));
 
         if (!pfrom->fInbound)
         {
@@ -2184,8 +2288,6 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         vRecv >> vAddr;
 
         // Don't want addr from older versions unless seeding
-        if (pfrom->nVersion < 209)
-            return true;
         if (pfrom->nVersion < 31402 && mapAddresses.size() > 1000)
             return true;
         if (vAddr.size() > 1000)
@@ -2257,8 +2359,10 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         }
 
         CTxDB txdb("r");
-        BOOST_FOREACH(const CInv& inv, vInv)
+        for (int nInv = 0; nInv < vInv.size(); nInv++)
         {
+            const CInv &inv = vInv[nInv];
+
             if (fShutdown)
                 return true;
             pfrom->AddInventoryKnown(inv);
@@ -2267,9 +2371,12 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
             if (fDebug)
                 printf("  got inventory: %s  %s\n", inv.ToString().c_str(), fAlreadyHave ? "have" : "new");
 
-            if (!fAlreadyHave)
+            // Always request the last block in an inv bundle (even if we already have it), as it is the
+            // trigger for the other side to send further invs. If we are stuck on a (very long) side chain,
+            // this is necessary to connect earlier received orphan blocks to the chain again.
+            if (!fAlreadyHave || (inv.type == MSG_BLOCK && nInv==vInv.size()-1))
                 pfrom->AskFor(inv);
-            else if (inv.type == MSG_BLOCK && mapOrphanBlocks.count(inv.hash))
+            if (inv.type == MSG_BLOCK && mapOrphanBlocks.count(inv.hash))
                 pfrom->PushGetBlocks(pindexBest, GetOrphanRoot(mapOrphanBlocks[inv.hash]));
 
             // Track requests for our stuff
@@ -2457,6 +2564,11 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         {
             printf("storing orphan tx %s\n", inv.hash.ToString().substr(0,10).c_str());
             AddOrphanTx(vMsg);
+
+            // DoS prevention: do not allow mapOrphanTransactions to grow unbounded
+            int nEvicted = LimitOrphanTxSize(MAX_ORPHAN_TRANSACTIONS);
+            if (nEvicted > 0)
+                printf("mapOrphan overflow, removed %d tx\n", nEvicted);
         }
         if (tx.nDoS) pfrom->Misbehaving(tx.nDoS);
     }
@@ -2647,17 +2759,14 @@ bool ProcessMessages(CNode* pfrom)
         }
 
         // Checksum
-        if (vRecv.GetVersion() >= 209)
+        uint256 hash = Hash(vRecv.begin(), vRecv.begin() + nMessageSize);
+        unsigned int nChecksum = 0;
+        memcpy(&nChecksum, &hash, sizeof(nChecksum));
+        if (nChecksum != hdr.nChecksum)
         {
-            uint256 hash = Hash(vRecv.begin(), vRecv.begin() + nMessageSize);
-            unsigned int nChecksum = 0;
-            memcpy(&nChecksum, &hash, sizeof(nChecksum));
-            if (nChecksum != hdr.nChecksum)
-            {
-                printf("ProcessMessage(%s, %u bytes) : CHECKSUM ERROR nChecksum=%08x hdr.nChecksum=%08x\n",
-                       strCommand.c_str(), nMessageSize, nChecksum, hdr.nChecksum);
-                continue;
-            }
+            printf("ProcessMessage(%s, %u bytes) : CHECKSUM ERROR nChecksum=%08x hdr.nChecksum=%08x\n",
+               strCommand.c_str(), nMessageSize, nChecksum, hdr.nChecksum);
+            continue;
         }
 
         // Copy message to its own buffer
@@ -3164,7 +3273,7 @@ CBlock* CreateNewBlock(CReserveKey& reservekey)
     // Fill in header
     pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
     pblock->hashMerkleRoot = pblock->BuildMerkleTree();
-    pblock->nTime          = max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
+    pblock->UpdateTime(pindexPrev);
     pblock->nBits          = GetNextWorkRequired(pindexPrev, pblock.get());
     pblock->nNonce         = 0;
 
@@ -3273,6 +3382,10 @@ bool CheckWork(CBlock* pblock, CWallet& wallet, CReserveKey& reservekey)
 
 void static ThreadBitcoinMiner(void* parg);
 
+static bool fGenerateBitcoins = false;
+static bool fLimitProcessors = false;
+static int nLimitProcessors = -1;
+
 void static BitcoinMiner(CWallet *pwallet)
 {
     printf("BitcoinMiner started\n");
@@ -3322,6 +3435,7 @@ void static BitcoinMiner(CWallet *pwallet)
         FormatHashBuffers(pblock.get(), pmidstate, pdata, phash1);
 
         unsigned int& nBlockTime = *(unsigned int*)(pdata + 64 + 4);
+        unsigned int& nBlockBits = *(unsigned int*)(pdata + 64 + 8);
         unsigned int& nBlockNonce = *(unsigned int*)(pdata + 64 + 12);
 
 
@@ -3386,7 +3500,7 @@ void static BitcoinMiner(CWallet *pwallet)
                         {
                             nLogTime = GetTime();
                             printf("%s ", DateTimeStrFormat("%x %H:%M", GetTime()).c_str());
-                            printf("hashmeter %3d CPUs %6.0f khash/s\n", vnThreadsRunning[3], dHashesPerSec/1000.0);
+                            printf("hashmeter %3d CPUs %6.0f khash/s\n", vnThreadsRunning[THREAD_MINER], dHashesPerSec/1000.0);
                         }
                     }
                 }
@@ -3397,7 +3511,7 @@ void static BitcoinMiner(CWallet *pwallet)
                 return;
             if (!fGenerateBitcoins)
                 return;
-            if (fLimitProcessors && vnThreadsRunning[3] > nLimitProcessors)
+            if (fLimitProcessors && vnThreadsRunning[THREAD_MINER] > nLimitProcessors)
                 return;
             if (vNodes.empty())
                 break;
@@ -3409,8 +3523,14 @@ void static BitcoinMiner(CWallet *pwallet)
                 break;
 
             // Update nTime every few seconds
-            pblock->nTime = max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
+            pblock->UpdateTime(pindexPrev);
             nBlockTime = ByteReverse(pblock->nTime);
+            if (fTestNet)
+            {
+                // Changing pblock->nTime can change work required on testnet:
+                nBlockBits = ByteReverse(pblock->nBits);
+                hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
+            }
         }
     }
 }
@@ -3420,34 +3540,34 @@ void static ThreadBitcoinMiner(void* parg)
     CWallet* pwallet = (CWallet*)parg;
     try
     {
-        vnThreadsRunning[3]++;
+        vnThreadsRunning[THREAD_MINER]++;
         BitcoinMiner(pwallet);
-        vnThreadsRunning[3]--;
+        vnThreadsRunning[THREAD_MINER]--;
     }
     catch (std::exception& e) {
-        vnThreadsRunning[3]--;
+        vnThreadsRunning[THREAD_MINER]--;
         PrintException(&e, "ThreadBitcoinMiner()");
     } catch (...) {
-        vnThreadsRunning[3]--;
+        vnThreadsRunning[THREAD_MINER]--;
         PrintException(NULL, "ThreadBitcoinMiner()");
     }
     UIThreadCall(boost::bind(CalledSetStatusBar, "", 0));
     nHPSTimerStart = 0;
-    if (vnThreadsRunning[3] == 0)
+    if (vnThreadsRunning[THREAD_MINER] == 0)
         dHashesPerSec = 0;
-    printf("ThreadBitcoinMiner exiting, %d threads remaining\n", vnThreadsRunning[3]);
+    printf("ThreadBitcoinMiner exiting, %d threads remaining\n", vnThreadsRunning[THREAD_MINER]);
 }
 
 
 void GenerateBitcoins(bool fGenerate, CWallet* pwallet)
 {
-    if (fGenerateBitcoins != fGenerate)
-    {
-        fGenerateBitcoins = fGenerate;
-        WriteSetting("fGenerateBitcoins", fGenerateBitcoins);
-        MainFrameRepaint();
-    }
-    if (fGenerateBitcoins)
+    fGenerateBitcoins = fGenerate;
+    nLimitProcessors = GetArg("-genproclimit", -1);
+    if (nLimitProcessors == 0)
+        fGenerateBitcoins = false;
+    fLimitProcessors = (nLimitProcessors != -1);
+
+    if (fGenerate)
     {
         int nProcessors = boost::thread::hardware_concurrency();
         printf("%d processors\n", nProcessors);
@@ -3455,7 +3575,7 @@ void GenerateBitcoins(bool fGenerate, CWallet* pwallet)
             nProcessors = 1;
         if (fLimitProcessors && nProcessors > nLimitProcessors)
             nProcessors = nLimitProcessors;
-        int nAddThreads = nProcessors - vnThreadsRunning[3];
+        int nAddThreads = nProcessors - vnThreadsRunning[THREAD_MINER];
         printf("Starting %d BitcoinMiner threads\n", nAddThreads);
         for (int i = 0; i < nAddThreads; i++)
         {