Move internal miner/block creation to separate miner.cpp module.

Public functions referenced elsewhere are added to miner.h.

1 files changed, 663 insertions, 0 deletions

diff --git a/src/miner.cpp b/src/miner.cpp
new file mode 100644
index 0000000000..e50c0b576d
--- /dev/null
+++ b/src/miner.cpp
@@ -0,0 +1,663 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2012 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "core.h"
+#include "wallet.h"
+#include "miner.h"
+#include "main.h"
+
+
+
+
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// BitcoinMiner
+//
+
+int static FormatHashBlocks(void* pbuffer, unsigned int len)
+{
+    unsigned char* pdata = (unsigned char*)pbuffer;
+    unsigned int blocks = 1 + ((len + 8) / 64);
+    unsigned char* pend = pdata + 64 * blocks;
+    memset(pdata + len, 0, 64 * blocks - len);
+    pdata[len] = 0x80;
+    unsigned int bits = len * 8;
+    pend[-1] = (bits >> 0) & 0xff;
+    pend[-2] = (bits >> 8) & 0xff;
+    pend[-3] = (bits >> 16) & 0xff;
+    pend[-4] = (bits >> 24) & 0xff;
+    return blocks;
+}
+
+static const unsigned int pSHA256InitState[8] =
+{0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};
+
+void SHA256Transform(void* pstate, void* pinput, const void* pinit)
+{
+    SHA256_CTX ctx;
+    unsigned char data[64];
+
+    SHA256_Init(&ctx);
+
+    for (int i = 0; i < 16; i++)
+        ((uint32_t*)data)[i] = ByteReverse(((uint32_t*)pinput)[i]);
+
+    for (int i = 0; i < 8; i++)
+        ctx.h[i] = ((uint32_t*)pinit)[i];
+
+    SHA256_Update(&ctx, data, sizeof(data));
+    for (int i = 0; i < 8; i++)
+        ((uint32_t*)pstate)[i] = ctx.h[i];
+}
+
+//
+// ScanHash scans nonces looking for a hash with at least some zero bits.
+// It operates on big endian data.  Caller does the byte reversing.
+// All input buffers are 16-byte aligned.  nNonce is usually preserved
+// between calls, but periodically or if nNonce is 0xffff0000 or above,
+// the block is rebuilt and nNonce starts over at zero.
+//
+unsigned int static ScanHash_CryptoPP(char* pmidstate, char* pdata, char* phash1, char* phash, unsigned int& nHashesDone)
+{
+    unsigned int& nNonce = *(unsigned int*)(pdata + 12);
+    for (;;)
+    {
+        // Crypto++ SHA256
+        // Hash pdata using pmidstate as the starting state into
+        // pre-formatted buffer phash1, then hash phash1 into phash
+        nNonce++;
+        SHA256Transform(phash1, pdata, pmidstate);
+        SHA256Transform(phash, phash1, pSHA256InitState);
+
+        // Return the nonce if the hash has at least some zero bits,
+        // caller will check if it has enough to reach the target
+        if (((unsigned short*)phash)[14] == 0)
+            return nNonce;
+
+        // If nothing found after trying for a while, return -1
+        if ((nNonce & 0xffff) == 0)
+        {
+            nHashesDone = 0xffff+1;
+            return (unsigned int) -1;
+        }
+        if ((nNonce & 0xfff) == 0)
+            boost::this_thread::interruption_point();
+    }
+}
+
+// Some explaining would be appreciated
+class COrphan
+{
+public:
+    CTransaction* ptx;
+    set<uint256> setDependsOn;
+    double dPriority;
+    double dFeePerKb;
+
+    COrphan(CTransaction* ptxIn)
+    {
+        ptx = ptxIn;
+        dPriority = dFeePerKb = 0;
+    }
+
+    void print() const
+    {
+        printf("COrphan(hash=%s, dPriority=%.1f, dFeePerKb=%.1f)\n",
+               ptx->GetHash().ToString().c_str(), dPriority, dFeePerKb);
+        BOOST_FOREACH(uint256 hash, setDependsOn)
+            printf("   setDependsOn %s\n", hash.ToString().c_str());
+    }
+};
+
+
+uint64 nLastBlockTx = 0;
+uint64 nLastBlockSize = 0;
+
+// We want to sort transactions by priority and fee, so:
+typedef boost::tuple<double, double, CTransaction*> TxPriority;
+class TxPriorityCompare
+{
+    bool byFee;
+public:
+    TxPriorityCompare(bool _byFee) : byFee(_byFee) { }
+    bool operator()(const TxPriority& a, const TxPriority& b)
+    {
+        if (byFee)
+        {
+            if (a.get<1>() == b.get<1>())
+                return a.get<0>() < b.get<0>();
+            return a.get<1>() < b.get<1>();
+        }
+        else
+        {
+            if (a.get<0>() == b.get<0>())
+                return a.get<1>() < b.get<1>();
+            return a.get<0>() < b.get<0>();
+        }
+    }
+};
+
+CBlockTemplate* CreateNewBlock(CReserveKey& reservekey)
+{
+    // Create new block
+    auto_ptr<CBlockTemplate> pblocktemplate(new CBlockTemplate());
+    if(!pblocktemplate.get())
+        return NULL;
+    CBlock *pblock = &pblocktemplate->block; // pointer for convenience
+
+    // Create coinbase tx
+    CTransaction txNew;
+    txNew.vin.resize(1);
+    txNew.vin[0].prevout.SetNull();
+    txNew.vout.resize(1);
+    CPubKey pubkey;
+    if (!reservekey.GetReservedKey(pubkey))
+        return NULL;
+    txNew.vout[0].scriptPubKey << pubkey << OP_CHECKSIG;
+
+    // Add our coinbase tx as first transaction
+    pblock->vtx.push_back(txNew);
+    pblocktemplate->vTxFees.push_back(-1); // updated at end
+    pblocktemplate->vTxSigOps.push_back(-1); // updated at end
+
+    // Largest block you're willing to create:
+    unsigned int nBlockMaxSize = GetArg("-blockmaxsize", MAX_BLOCK_SIZE_GEN/2);
+    // Limit to betweeen 1K and MAX_BLOCK_SIZE-1K for sanity:
+    nBlockMaxSize = std::max((unsigned int)1000, std::min((unsigned int)(MAX_BLOCK_SIZE-1000), nBlockMaxSize));
+
+    // How much of the block should be dedicated to high-priority transactions,
+    // included regardless of the fees they pay
+    unsigned int nBlockPrioritySize = GetArg("-blockprioritysize", DEFAULT_BLOCK_PRIORITY_SIZE);
+    nBlockPrioritySize = std::min(nBlockMaxSize, nBlockPrioritySize);
+
+    // Minimum block size you want to create; block will be filled with free transactions
+    // until there are no more or the block reaches this size:
+    unsigned int nBlockMinSize = GetArg("-blockminsize", 0);
+    nBlockMinSize = std::min(nBlockMaxSize, nBlockMinSize);
+
+    // Collect memory pool transactions into the block
+    int64 nFees = 0;
+    {
+        LOCK2(cs_main, mempool.cs);
+        CBlockIndex* pindexPrev = pindexBest;
+        CCoinsViewCache view(*pcoinsTip, true);
+
+        // Priority order to process transactions
+        list<COrphan> vOrphan; // list memory doesn't move
+        map<uint256, vector<COrphan*> > mapDependers;
+        bool fPrintPriority = GetBoolArg("-printpriority", false);
+
+        // This vector will be sorted into a priority queue:
+        vector<TxPriority> vecPriority;
+        vecPriority.reserve(mempool.mapTx.size());
+        for (map<uint256, CTransaction>::iterator mi = mempool.mapTx.begin(); mi != mempool.mapTx.end(); ++mi)
+        {
+            CTransaction& tx = (*mi).second;
+            if (tx.IsCoinBase() || !IsFinalTx(tx))
+                continue;
+
+            COrphan* porphan = NULL;
+            double dPriority = 0;
+            int64 nTotalIn = 0;
+            bool fMissingInputs = false;
+            BOOST_FOREACH(const CTxIn& txin, tx.vin)
+            {
+                // Read prev transaction
+                if (!view.HaveCoins(txin.prevout.hash))
+                {
+                    // This should never happen; all transactions in the memory
+                    // pool should connect to either transactions in the chain
+                    // or other transactions in the memory pool.
+                    if (!mempool.mapTx.count(txin.prevout.hash))
+                    {
+                        printf("ERROR: mempool transaction missing input\n");
+                        if (fDebug) assert("mempool transaction missing input" == 0);
+                        fMissingInputs = true;
+                        if (porphan)
+                            vOrphan.pop_back();
+                        break;
+                    }
+
+                    // Has to wait for dependencies
+                    if (!porphan)
+                    {
+                        // Use list for automatic deletion
+                        vOrphan.push_back(COrphan(&tx));
+                        porphan = &vOrphan.back();
+                    }
+                    mapDependers[txin.prevout.hash].push_back(porphan);
+                    porphan->setDependsOn.insert(txin.prevout.hash);
+                    nTotalIn += mempool.mapTx[txin.prevout.hash].vout[txin.prevout.n].nValue;
+                    continue;
+                }
+                const CCoins &coins = view.GetCoins(txin.prevout.hash);
+
+                int64 nValueIn = coins.vout[txin.prevout.n].nValue;
+                nTotalIn += nValueIn;
+
+                int nConf = pindexPrev->nHeight - coins.nHeight + 1;
+
+                dPriority += (double)nValueIn * nConf;
+            }
+            if (fMissingInputs) continue;
+
+            // Priority is sum(valuein * age) / txsize
+            unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
+            dPriority /= nTxSize;
+
+            // This is a more accurate fee-per-kilobyte than is used by the client code, because the
+            // client code rounds up the size to the nearest 1K. That's good, because it gives an
+            // incentive to create smaller transactions.
+            double dFeePerKb =  double(nTotalIn-GetValueOut(tx)) / (double(nTxSize)/1000.0);
+
+            if (porphan)
+            {
+                porphan->dPriority = dPriority;
+                porphan->dFeePerKb = dFeePerKb;
+            }
+            else
+                vecPriority.push_back(TxPriority(dPriority, dFeePerKb, &(*mi).second));
+        }
+
+        // Collect transactions into block
+        uint64 nBlockSize = 1000;
+        uint64 nBlockTx = 0;
+        int nBlockSigOps = 100;
+        bool fSortedByFee = (nBlockPrioritySize <= 0);
+
+        TxPriorityCompare comparer(fSortedByFee);
+        std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
+
+        while (!vecPriority.empty())
+        {
+            // Take highest priority transaction off the priority queue:
+            double dPriority = vecPriority.front().get<0>();
+            double dFeePerKb = vecPriority.front().get<1>();
+            CTransaction& tx = *(vecPriority.front().get<2>());
+
+            std::pop_heap(vecPriority.begin(), vecPriority.end(), comparer);
+            vecPriority.pop_back();
+
+            // Size limits
+            unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
+            if (nBlockSize + nTxSize >= nBlockMaxSize)
+                continue;
+
+            // Legacy limits on sigOps:
+            unsigned int nTxSigOps = GetLegacySigOpCount(tx);
+            if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
+                continue;
+
+            // Skip free transactions if we're past the minimum block size:
+            if (fSortedByFee && (dFeePerKb < CTransaction::nMinTxFee) && (nBlockSize + nTxSize >= nBlockMinSize))
+                continue;
+
+            // Prioritize by fee once past the priority size or we run out of high-priority
+            // transactions:
+            if (!fSortedByFee &&
+                ((nBlockSize + nTxSize >= nBlockPrioritySize) || !AllowFree(dPriority)))
+            {
+                fSortedByFee = true;
+                comparer = TxPriorityCompare(fSortedByFee);
+                std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
+            }
+
+            if (!view.HaveInputs(tx))
+                continue;
+
+            int64 nTxFees = view.GetValueIn(tx)-GetValueOut(tx);
+
+            nTxSigOps += GetP2SHSigOpCount(tx, view);
+            if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
+                continue;
+
+            CValidationState state;
+            if (!CheckInputs(tx, state, view, true, SCRIPT_VERIFY_P2SH))
+                continue;
+
+            CTxUndo txundo;
+            uint256 hash = tx.GetHash();
+            UpdateCoins(tx, state, view, txundo, pindexPrev->nHeight+1, hash);
+
+            // Added
+            pblock->vtx.push_back(tx);
+            pblocktemplate->vTxFees.push_back(nTxFees);
+            pblocktemplate->vTxSigOps.push_back(nTxSigOps);
+            nBlockSize += nTxSize;
+            ++nBlockTx;
+            nBlockSigOps += nTxSigOps;
+            nFees += nTxFees;
+
+            if (fPrintPriority)
+            {
+                printf("priority %.1f feeperkb %.1f txid %s\n",
+                       dPriority, dFeePerKb, tx.GetHash().ToString().c_str());
+            }
+
+            // Add transactions that depend on this one to the priority queue
+            if (mapDependers.count(hash))
+            {
+                BOOST_FOREACH(COrphan* porphan, mapDependers[hash])
+                {
+                    if (!porphan->setDependsOn.empty())
+                    {
+                        porphan->setDependsOn.erase(hash);
+                        if (porphan->setDependsOn.empty())
+                        {
+                            vecPriority.push_back(TxPriority(porphan->dPriority, porphan->dFeePerKb, porphan->ptx));
+                            std::push_heap(vecPriority.begin(), vecPriority.end(), comparer);
+                        }
+                    }
+                }
+            }
+        }
+
+        nLastBlockTx = nBlockTx;
+        nLastBlockSize = nBlockSize;
+        printf("CreateNewBlock(): total size %"PRI64u"\n", nBlockSize);
+
+        pblock->vtx[0].vout[0].nValue = GetBlockValue(pindexPrev->nHeight+1, nFees);
+        pblocktemplate->vTxFees[0] = -nFees;
+
+        // Fill in header
+        pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
+        UpdateTime(*pblock, pindexPrev);
+        pblock->nBits          = GetNextWorkRequired(pindexPrev, pblock);
+        pblock->nNonce         = 0;
+        pblock->vtx[0].vin[0].scriptSig = CScript() << OP_0 << OP_0;
+        pblocktemplate->vTxSigOps[0] = GetLegacySigOpCount(pblock->vtx[0]);
+
+        CBlockIndex indexDummy(*pblock);
+        indexDummy.pprev = pindexPrev;
+        indexDummy.nHeight = pindexPrev->nHeight + 1;
+        CCoinsViewCache viewNew(*pcoinsTip, true);
+        CValidationState state;
+        if (!ConnectBlock(*pblock, state, &indexDummy, viewNew, true))
+            throw std::runtime_error("CreateNewBlock() : ConnectBlock failed");
+    }
+
+    return pblocktemplate.release();
+}
+
+
+void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int& nExtraNonce)
+{
+    // Update nExtraNonce
+    static uint256 hashPrevBlock;
+    if (hashPrevBlock != pblock->hashPrevBlock)
+    {
+        nExtraNonce = 0;
+        hashPrevBlock = pblock->hashPrevBlock;
+    }
+    ++nExtraNonce;
+    unsigned int nHeight = pindexPrev->nHeight+1; // Height first in coinbase required for block.version=2
+    pblock->vtx[0].vin[0].scriptSig = (CScript() << nHeight << CBigNum(nExtraNonce)) + COINBASE_FLAGS;
+    assert(pblock->vtx[0].vin[0].scriptSig.size() <= 100);
+
+    pblock->hashMerkleRoot = pblock->BuildMerkleTree();
+}
+
+
+void FormatHashBuffers(CBlock* pblock, char* pmidstate, char* pdata, char* phash1)
+{
+    //
+    // Pre-build hash buffers
+    //
+    struct
+    {
+        struct unnamed2
+        {
+            int nVersion;
+            uint256 hashPrevBlock;
+            uint256 hashMerkleRoot;
+            unsigned int nTime;
+            unsigned int nBits;
+            unsigned int nNonce;
+        }
+        block;
+        unsigned char pchPadding0[64];
+        uint256 hash1;
+        unsigned char pchPadding1[64];
+    }
+    tmp;
+    memset(&tmp, 0, sizeof(tmp));
+
+    tmp.block.nVersion       = pblock->nVersion;
+    tmp.block.hashPrevBlock  = pblock->hashPrevBlock;
+    tmp.block.hashMerkleRoot = pblock->hashMerkleRoot;
+    tmp.block.nTime          = pblock->nTime;
+    tmp.block.nBits          = pblock->nBits;
+    tmp.block.nNonce         = pblock->nNonce;
+
+    FormatHashBlocks(&tmp.block, sizeof(tmp.block));
+    FormatHashBlocks(&tmp.hash1, sizeof(tmp.hash1));
+
+    // Byte swap all the input buffer
+    for (unsigned int i = 0; i < sizeof(tmp)/4; i++)
+        ((unsigned int*)&tmp)[i] = ByteReverse(((unsigned int*)&tmp)[i]);
+
+    // Precalc the first half of the first hash, which stays constant
+    SHA256Transform(pmidstate, &tmp.block, pSHA256InitState);
+
+    memcpy(pdata, &tmp.block, 128);
+    memcpy(phash1, &tmp.hash1, 64);
+}
+
+
+bool CheckWork(CBlock* pblock, CWallet& wallet, CReserveKey& reservekey)
+{
+    uint256 hash = pblock->GetHash();
+    uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
+
+    if (hash > hashTarget)
+        return false;
+
+    //// debug print
+    printf("BitcoinMiner:\n");
+    printf("proof-of-work found  \n  hash: %s  \ntarget: %s\n", hash.GetHex().c_str(), hashTarget.GetHex().c_str());
+    pblock->print();
+    printf("generated %s\n", FormatMoney(pblock->vtx[0].vout[0].nValue).c_str());
+
+    // Found a solution
+    {
+        LOCK(cs_main);
+        if (pblock->hashPrevBlock != hashBestChain)
+            return error("BitcoinMiner : generated block is stale");
+
+        // Remove key from key pool
+        reservekey.KeepKey();
+
+        // Track how many getdata requests this block gets
+        {
+            LOCK(wallet.cs_wallet);
+            wallet.mapRequestCount[pblock->GetHash()] = 0;
+        }
+
+        // Process this block the same as if we had received it from another node
+        CValidationState state;
+        if (!ProcessBlock(state, NULL, pblock))
+            return error("BitcoinMiner : ProcessBlock, block not accepted");
+    }
+
+    return true;
+}
+
+void static BitcoinMiner(CWallet *pwallet)
+{
+    printf("BitcoinMiner started\n");
+    SetThreadPriority(THREAD_PRIORITY_LOWEST);
+    RenameThread("bitcoin-miner");
+
+    // Each thread has its own key and counter
+    CReserveKey reservekey(pwallet);
+    unsigned int nExtraNonce = 0;
+
+    try { while (true) {
+        if (Params().NetworkID() != CChainParams::REGTEST) {
+            // Busy-wait for the network to come online so we don't waste time mining
+            // on an obsolete chain. In regtest mode we expect to fly solo.
+            while (vNodes.empty())
+                MilliSleep(1000);
+        }
+
+        //
+        // Create new block
+        //
+        unsigned int nTransactionsUpdatedLast = nTransactionsUpdated;
+        CBlockIndex* pindexPrev = pindexBest;
+
+        auto_ptr<CBlockTemplate> pblocktemplate(CreateNewBlock(reservekey));
+        if (!pblocktemplate.get())
+            return;
+        CBlock *pblock = &pblocktemplate->block;
+        IncrementExtraNonce(pblock, pindexPrev, nExtraNonce);
+
+        printf("Running BitcoinMiner with %"PRIszu" transactions in block (%u bytes)\n", pblock->vtx.size(),
+               ::GetSerializeSize(*pblock, SER_NETWORK, PROTOCOL_VERSION));
+
+        //
+        // Pre-build hash buffers
+        //
+        char pmidstatebuf[32+16]; char* pmidstate = alignup<16>(pmidstatebuf);
+        char pdatabuf[128+16];    char* pdata     = alignup<16>(pdatabuf);
+        char phash1buf[64+16];    char* phash1    = alignup<16>(phash1buf);
+
+        FormatHashBuffers(pblock, 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);
+
+
+        //
+        // Search
+        //
+        int64 nStart = GetTime();
+        uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
+        uint256 hashbuf[2];
+        uint256& hash = *alignup<16>(hashbuf);
+        while (true)
+        {
+            unsigned int nHashesDone = 0;
+            unsigned int nNonceFound;
+
+            // Crypto++ SHA256
+            nNonceFound = ScanHash_CryptoPP(pmidstate, pdata + 64, phash1,
+                                            (char*)&hash, nHashesDone);
+
+            // Check if something found
+            if (nNonceFound != (unsigned int) -1)
+            {
+                for (unsigned int i = 0; i < sizeof(hash)/4; i++)
+                    ((unsigned int*)&hash)[i] = ByteReverse(((unsigned int*)&hash)[i]);
+
+                if (hash <= hashTarget)
+                {
+                    // Found a solution
+                    pblock->nNonce = ByteReverse(nNonceFound);
+                    assert(hash == pblock->GetHash());
+
+                    SetThreadPriority(THREAD_PRIORITY_NORMAL);
+                    CheckWork(pblock, *pwallet, reservekey);
+                    SetThreadPriority(THREAD_PRIORITY_LOWEST);
+
+                    // In regression test mode, stop mining after a block is found. This
+                    // allows developers to controllably generate a block on demand.
+                    if (Params().NetworkID() == CChainParams::REGTEST)
+                        throw boost::thread_interrupted();
+
+                    break;
+                }
+            }
+
+            // Meter hashes/sec
+            static int64 nHashCounter;
+            if (nHPSTimerStart == 0)
+            {
+                nHPSTimerStart = GetTimeMillis();
+                nHashCounter = 0;
+            }
+            else
+                nHashCounter += nHashesDone;
+            if (GetTimeMillis() - nHPSTimerStart > 4000)
+            {
+                static CCriticalSection cs;
+                {
+                    LOCK(cs);
+                    if (GetTimeMillis() - nHPSTimerStart > 4000)
+                    {
+                        dHashesPerSec = 1000.0 * nHashCounter / (GetTimeMillis() - nHPSTimerStart);
+                        nHPSTimerStart = GetTimeMillis();
+                        nHashCounter = 0;
+                        static int64 nLogTime;
+                        if (GetTime() - nLogTime > 30 * 60)
+                        {
+                            nLogTime = GetTime();
+                            printf("hashmeter %6.0f khash/s\n", dHashesPerSec/1000.0);
+                        }
+                    }
+                }
+            }
+
+            // Check for stop or if block needs to be rebuilt
+            boost::this_thread::interruption_point();
+            if (vNodes.empty() && Params().NetworkID() != CChainParams::REGTEST)
+                break;
+            if (nBlockNonce >= 0xffff0000)
+                break;
+            if (nTransactionsUpdated != nTransactionsUpdatedLast && GetTime() - nStart > 60)
+                break;
+            if (pindexPrev != pindexBest)
+                break;
+
+            // Update nTime every few seconds
+            UpdateTime(*pblock, pindexPrev);
+            nBlockTime = ByteReverse(pblock->nTime);
+            if (TestNet())
+            {
+                // Changing pblock->nTime can change work required on testnet:
+                nBlockBits = ByteReverse(pblock->nBits);
+                hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
+            }
+        }
+    } }
+    catch (boost::thread_interrupted)
+    {
+        printf("BitcoinMiner terminated\n");
+        throw;
+    }
+}
+
+void GenerateBitcoins(bool fGenerate, CWallet* pwallet)
+{
+    static boost::thread_group* minerThreads = NULL;
+
+    int nThreads = GetArg("-genproclimit", -1);
+    if (nThreads < 0) {
+        if (Params().NetworkID() == CChainParams::REGTEST)
+            nThreads = 1;
+        else
+            nThreads = boost::thread::hardware_concurrency();
+    }
+
+    if (minerThreads != NULL)
+    {
+        minerThreads->interrupt_all();
+        delete minerThreads;
+        minerThreads = NULL;
+    }
+
+    if (nThreads == 0 || !fGenerate)
+        return;
+
+    minerThreads = new boost::thread_group();
+    for (int i = 0; i < nThreads; i++)
+        minerThreads->create_thread(boost::bind(&BitcoinMiner, pwallet));
+}
+
+
+