src/miner.cpp

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2014 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #include "miner.h"
   7 #ifdef ENABLE_MINING
   8 #include "pow/tromp/equi_miner.h"
   9 #endif
  10
  11 #include "amount.h"
  12 #include "base58.h"
  13 #include "chainparams.h"
  14 #include "consensus/consensus.h"
  15 #include "consensus/upgrades.h"
  16 #include "consensus/validation.h"
  17 #ifdef ENABLE_MINING
  18 #include "crypto/equihash.h"
  19 #endif
  20 #include "hash.h"
  21 #include "main.h"
  22 #include "metrics.h"
  23 #include "net.h"
  24 #include "pow.h"
  25 #include "primitives/transaction.h"
  26 #include "random.h"
  27 #include "timedata.h"
  28 #include "ui_interface.h"
  29 #include "util.h"
  30 #include "utilmoneystr.h"
  31 #ifdef ENABLE_WALLET
  32 #include "wallet/wallet.h"
  33 #endif
  34
  35 #include "sodium.h"
  36
  37 #include <boost/thread.hpp>
  38 #include <boost/tuple/tuple.hpp>
  39 #ifdef ENABLE_MINING
  40 #include <functional>
  41 #endif
  42 #include <mutex>
  43
  44 using namespace std;
  45
  46 //////////////////////////////////////////////////////////////////////////////
  47 //
  48 // BitcoinMiner
  49 //
  50
  51 //
  52 // Unconfirmed transactions in the memory pool often depend on other
  53 // transactions in the memory pool. When we select transactions from the
  54 // pool, we select by highest priority or fee rate, so we might consider
  55 // transactions that depend on transactions that aren't yet in the block.
  56 // The COrphan class keeps track of these 'temporary orphans' while
  57 // CreateBlock is figuring out which transactions to include.
  58 //
  59 class COrphan
  60 {
  61 public:
  62     const CTransaction* ptx;
  63     set<uint256> setDependsOn;
  64     CFeeRate feeRate;
  65     double dPriority;
  66
  67     COrphan(const CTransaction* ptxIn) : ptx(ptxIn), feeRate(0), dPriority(0)
  68     {
  69     }
  70 };
  71
  72 uint64_t nLastBlockTx = 0;
  73 uint64_t nLastBlockSize = 0;
  74
  75 // We want to sort transactions by priority and fee rate, so:
  76 typedef boost::tuple<double, CFeeRate, const CTransaction*> TxPriority;
  77 class TxPriorityCompare
  78 {
  79     bool byFee;
  80
  81 public:
  82     TxPriorityCompare(bool _byFee) : byFee(_byFee) { }
  83
  84     bool operator()(const TxPriority& a, const TxPriority& b)
  85     {
  86         if (byFee)
  87         {
  88             if (a.get<1>() == b.get<1>())
  89                 return a.get<0>() < b.get<0>();
  90             return a.get<1>() < b.get<1>();
  91         }
  92         else
  93         {
  94             if (a.get<0>() == b.get<0>())
  95                 return a.get<1>() < b.get<1>();
  96             return a.get<0>() < b.get<0>();
  97         }
  98     }
  99 };
 100
 101 void UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev)
 102 {
 103     pblock->nTime = std::max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
 104 }
 105
 106 CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
 107 {
 108     const CChainParams& chainparams = Params();
 109     // Create new block
 110     std::unique_ptr<CBlockTemplate> pblocktemplate(new CBlockTemplate());
 111     if(!pblocktemplate.get())
 112         return NULL;
 113     CBlock *pblock = &pblocktemplate->block; // pointer for convenience
 114
 115     // -regtest only: allow overriding block.nVersion with
 116     // -blockversion=N to test forking scenarios
 117     if (Params().MineBlocksOnDemand())
 118         pblock->nVersion = GetArg("-blockversion", pblock->nVersion);
 119
 120     // Add dummy coinbase tx as first transaction
 121     pblock->vtx.push_back(CTransaction());
 122     pblocktemplate->vTxFees.push_back(-1); // updated at end
 123     pblocktemplate->vTxSigOps.push_back(-1); // updated at end
 124
 125     // Largest block you're willing to create:
 126     unsigned int nBlockMaxSize = GetArg("-blockmaxsize", DEFAULT_BLOCK_MAX_SIZE);
 127     // Limit to betweeen 1K and MAX_BLOCK_SIZE-1K for sanity:
 128     nBlockMaxSize = std::max((unsigned int)1000, std::min((unsigned int)(MAX_BLOCK_SIZE-1000), nBlockMaxSize));
 129
 130     // How much of the block should be dedicated to high-priority transactions,
 131     // included regardless of the fees they pay
 132     unsigned int nBlockPrioritySize = GetArg("-blockprioritysize", DEFAULT_BLOCK_PRIORITY_SIZE);
 133     nBlockPrioritySize = std::min(nBlockMaxSize, nBlockPrioritySize);
 134
 135     // Minimum block size you want to create; block will be filled with free transactions
 136     // until there are no more or the block reaches this size:
 137     unsigned int nBlockMinSize = GetArg("-blockminsize", DEFAULT_BLOCK_MIN_SIZE);
 138     nBlockMinSize = std::min(nBlockMaxSize, nBlockMinSize);
 139
 140     // Collect memory pool transactions into the block
 141     CAmount nFees = 0;
 142
 143     {
 144         LOCK2(cs_main, mempool.cs);
 145         CBlockIndex* pindexPrev = chainActive.Tip();
 146         const int nHeight = pindexPrev->nHeight + 1;
 147         uint32_t consensusBranchId = CurrentEpochBranchId(nHeight, chainparams.GetConsensus());
 148         pblock->nTime = GetAdjustedTime();
 149         const int64_t nMedianTimePast = pindexPrev->GetMedianTimePast();
 150         CCoinsViewCache view(pcoinsTip);
 151
 152         // Priority order to process transactions
 153         list<COrphan> vOrphan; // list memory doesn't move
 154         map<uint256, vector<COrphan*> > mapDependers;
 155         bool fPrintPriority = GetBoolArg("-printpriority", false);
 156
 157         // This vector will be sorted into a priority queue:
 158         vector<TxPriority> vecPriority;
 159         vecPriority.reserve(mempool.mapTx.size());
 160         for (CTxMemPool::indexed_transaction_set::iterator mi = mempool.mapTx.begin();
 161              mi != mempool.mapTx.end(); ++mi)
 162         {
 163             const CTransaction& tx = mi->GetTx();
 164
 165             int64_t nLockTimeCutoff = (STANDARD_LOCKTIME_VERIFY_FLAGS & LOCKTIME_MEDIAN_TIME_PAST)
 166                                     ? nMedianTimePast
 167                                     : pblock->GetBlockTime();
 168
 169             if (tx.IsCoinBase() || !IsFinalTx(tx, nHeight, nLockTimeCutoff) || IsExpiredTx(tx, nHeight))
 170                 continue;
 171
 172             COrphan* porphan = NULL;
 173             double dPriority = 0;
 174             CAmount nTotalIn = 0;
 175             bool fMissingInputs = false;
 176             BOOST_FOREACH(const CTxIn& txin, tx.vin)
 177             {
 178                 // Read prev transaction
 179                 if (!view.HaveCoins(txin.prevout.hash))
 180                 {
 181                     // This should never happen; all transactions in the memory
 182                     // pool should connect to either transactions in the chain
 183                     // or other transactions in the memory pool.
 184                     if (!mempool.mapTx.count(txin.prevout.hash))
 185                     {
 186                         LogPrintf("ERROR: mempool transaction missing input\n");
 187                         if (fDebug) assert("mempool transaction missing input" == 0);
 188                         fMissingInputs = true;
 189                         if (porphan)
 190                             vOrphan.pop_back();
 191                         break;
 192                     }
 193
 194                     // Has to wait for dependencies
 195                     if (!porphan)
 196                     {
 197                         // Use list for automatic deletion
 198                         vOrphan.push_back(COrphan(&tx));
 199                         porphan = &vOrphan.back();
 200                     }
 201                     mapDependers[txin.prevout.hash].push_back(porphan);
 202                     porphan->setDependsOn.insert(txin.prevout.hash);
 203                     nTotalIn += mempool.mapTx.find(txin.prevout.hash)->GetTx().vout[txin.prevout.n].nValue;
 204                     continue;
 205                 }
 206                 const CCoins* coins = view.AccessCoins(txin.prevout.hash);
 207                 assert(coins);
 208
 209                 CAmount nValueIn = coins->vout[txin.prevout.n].nValue;
 210                 nTotalIn += nValueIn;
 211
 212                 int nConf = nHeight - coins->nHeight;
 213
 214                 dPriority += (double)nValueIn * nConf;
 215             }
 216             nTotalIn += tx.GetJoinSplitValueIn();
 217
 218             if (fMissingInputs) continue;
 219
 220             // Priority is sum(valuein * age) / modified_txsize
 221             unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
 222             dPriority = tx.ComputePriority(dPriority, nTxSize);
 223
 224             uint256 hash = tx.GetHash();
 225             mempool.ApplyDeltas(hash, dPriority, nTotalIn);
 226
 227             CFeeRate feeRate(nTotalIn-tx.GetValueOut(), nTxSize);
 228
 229             if (porphan)
 230             {
 231                 porphan->dPriority = dPriority;
 232                 porphan->feeRate = feeRate;
 233             }
 234             else
 235                 vecPriority.push_back(TxPriority(dPriority, feeRate, &(mi->GetTx())));
 236         }
 237
 238         // Collect transactions into block
 239         uint64_t nBlockSize = 1000;
 240         uint64_t nBlockTx = 0;
 241         int nBlockSigOps = 100;
 242         bool fSortedByFee = (nBlockPrioritySize <= 0);
 243
 244         TxPriorityCompare comparer(fSortedByFee);
 245         std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
 246
 247         while (!vecPriority.empty())
 248         {
 249             // Take highest priority transaction off the priority queue:
 250             double dPriority = vecPriority.front().get<0>();
 251             CFeeRate feeRate = vecPriority.front().get<1>();
 252             const CTransaction& tx = *(vecPriority.front().get<2>());
 253
 254             std::pop_heap(vecPriority.begin(), vecPriority.end(), comparer);
 255             vecPriority.pop_back();
 256
 257             // Size limits
 258             unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
 259             if (nBlockSize + nTxSize >= nBlockMaxSize)
 260                 continue;
 261
 262             // Legacy limits on sigOps:
 263             unsigned int nTxSigOps = GetLegacySigOpCount(tx);
 264             if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
 265                 continue;
 266
 267             // Skip free transactions if we're past the minimum block size:
 268             const uint256& hash = tx.GetHash();
 269             double dPriorityDelta = 0;
 270             CAmount nFeeDelta = 0;
 271             mempool.ApplyDeltas(hash, dPriorityDelta, nFeeDelta);
 272             if (fSortedByFee && (dPriorityDelta <= 0) && (nFeeDelta <= 0) && (feeRate < ::minRelayTxFee) && (nBlockSize + nTxSize >= nBlockMinSize))
 273                 continue;
 274
 275             // Prioritise by fee once past the priority size or we run out of high-priority
 276             // transactions:
 277             if (!fSortedByFee &&
 278                 ((nBlockSize + nTxSize >= nBlockPrioritySize) || !AllowFree(dPriority)))
 279             {
 280                 fSortedByFee = true;
 281                 comparer = TxPriorityCompare(fSortedByFee);
 282                 std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
 283             }
 284
 285             if (!view.HaveInputs(tx))
 286                 continue;
 287
 288             CAmount nTxFees = view.GetValueIn(tx)-tx.GetValueOut();
 289
 290             nTxSigOps += GetP2SHSigOpCount(tx, view);
 291             if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
 292                 continue;
 293
 294             // Note that flags: we don't want to set mempool/IsStandard()
 295             // policy here, but we still have to ensure that the block we
 296             // create only contains transactions that are valid in new blocks.
 297             CValidationState state;
 298             PrecomputedTransactionData txdata(tx);
 299             if (!ContextualCheckInputs(tx, state, view, true, MANDATORY_SCRIPT_VERIFY_FLAGS, true, txdata, Params().GetConsensus(), consensusBranchId))
 300                 continue;
 301
 302             UpdateCoins(tx, view, nHeight);
 303
 304             // Added
 305             pblock->vtx.push_back(tx);
 306             pblocktemplate->vTxFees.push_back(nTxFees);
 307             pblocktemplate->vTxSigOps.push_back(nTxSigOps);
 308             nBlockSize += nTxSize;
 309             ++nBlockTx;
 310             nBlockSigOps += nTxSigOps;
 311             nFees += nTxFees;
 312
 313             if (fPrintPriority)
 314             {
 315                 LogPrintf("priority %.1f fee %s txid %s\n",
 316                     dPriority, feeRate.ToString(), tx.GetHash().ToString());
 317             }
 318
 319             // Add transactions that depend on this one to the priority queue
 320             if (mapDependers.count(hash))
 321             {
 322                 BOOST_FOREACH(COrphan* porphan, mapDependers[hash])
 323                 {
 324                     if (!porphan->setDependsOn.empty())
 325                     {
 326                         porphan->setDependsOn.erase(hash);
 327                         if (porphan->setDependsOn.empty())
 328                         {
 329                             vecPriority.push_back(TxPriority(porphan->dPriority, porphan->feeRate, porphan->ptx));
 330                             std::push_heap(vecPriority.begin(), vecPriority.end(), comparer);
 331                         }
 332                     }
 333                 }
 334             }
 335         }
 336
 337         nLastBlockTx = nBlockTx;
 338         nLastBlockSize = nBlockSize;
 339         LogPrintf("CreateNewBlock(): total size %u\n", nBlockSize);
 340
 341         // Create coinbase tx
 342         CMutableTransaction txNew = CreateNewContextualCMutableTransaction(chainparams.GetConsensus(), nHeight);
 343         txNew.vin.resize(1);
 344         txNew.vin[0].prevout.SetNull();
 345         txNew.vout.resize(1);
 346         txNew.vout[0].scriptPubKey = scriptPubKeyIn;
 347         txNew.vout[0].nValue = GetBlockSubsidy(nHeight, chainparams.GetConsensus());
 348         // Set to 0 so expiry height does not apply to coinbase txs
 349         txNew.nExpiryHeight = 0;
 350
 351         if ((nHeight > 0) && (nHeight <= chainparams.GetConsensus().GetLastFoundersRewardBlockHeight())) {
 352             // Founders reward is 20% of the block subsidy
 353             auto vFoundersReward = txNew.vout[0].nValue / 5;
 354             // Take some reward away from us
 355             txNew.vout[0].nValue -= vFoundersReward;
 356
 357             // And give it to the founders
 358             txNew.vout.push_back(CTxOut(vFoundersReward, chainparams.GetFoundersRewardScriptAtHeight(nHeight)));
 359         }
 360
 361         // Add fees
 362         txNew.vout[0].nValue += nFees;
 363         txNew.vin[0].scriptSig = CScript() << nHeight << OP_0;
 364
 365         pblock->vtx[0] = txNew;
 366         pblocktemplate->vTxFees[0] = -nFees;
 367
 368         // Randomise nonce
 369         arith_uint256 nonce = UintToArith256(GetRandHash());
 370         // Clear the top and bottom 16 bits (for local use as thread flags and counters)
 371         nonce <<= 32;
 372         nonce >>= 16;
 373         pblock->nNonce = ArithToUint256(nonce);
 374
 375         // Fill in header
 376         pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
 377         pblock->hashFinalSaplingRoot   = uint256(); // TODO
 378         UpdateTime(pblock, Params().GetConsensus(), pindexPrev);
 379         pblock->nBits          = GetNextWorkRequired(pindexPrev, pblock, Params().GetConsensus());
 380         pblock->nSolution.clear();
 381         pblocktemplate->vTxSigOps[0] = GetLegacySigOpCount(pblock->vtx[0]);
 382
 383         CValidationState state;
 384         if (!TestBlockValidity(state, *pblock, pindexPrev, false, false))
 385             throw std::runtime_error("CreateNewBlock(): TestBlockValidity failed");
 386     }
 387
 388     return pblocktemplate.release();
 389 }
 390
 391 #ifdef ENABLE_WALLET
 392 boost::optional<CScript> GetMinerScriptPubKey(CReserveKey& reservekey)
 393 #else
 394 boost::optional<CScript> GetMinerScriptPubKey()
 395 #endif
 396 {
 397     CKeyID keyID;
 398     CTxDestination addr = DecodeDestination(GetArg("-mineraddress", ""));
 399     if (IsValidDestination(addr)) {
 400         keyID = boost::get<CKeyID>(addr);
 401     } else {
 402 #ifdef ENABLE_WALLET
 403         CPubKey pubkey;
 404         if (!reservekey.GetReservedKey(pubkey)) {
 405             return boost::optional<CScript>();
 406         }
 407         keyID = pubkey.GetID();
 408 #else
 409         return boost::optional<CScript>();
 410 #endif
 411     }
 412
 413     CScript scriptPubKey = CScript() << OP_DUP << OP_HASH160 << ToByteVector(keyID) << OP_EQUALVERIFY << OP_CHECKSIG;
 414     return scriptPubKey;
 415 }
 416
 417 #ifdef ENABLE_WALLET
 418 CBlockTemplate* CreateNewBlockWithKey(CReserveKey& reservekey)
 419 {
 420     boost::optional<CScript> scriptPubKey = GetMinerScriptPubKey(reservekey);
 421 #else
 422 CBlockTemplate* CreateNewBlockWithKey()
 423 {
 424     boost::optional<CScript> scriptPubKey = GetMinerScriptPubKey();
 425 #endif
 426
 427     if (!scriptPubKey) {
 428         return NULL;
 429     }
 430     return CreateNewBlock(*scriptPubKey);
 431 }
 432
 433 //////////////////////////////////////////////////////////////////////////////
 434 //
 435 // Internal miner
 436 //
 437
 438 #ifdef ENABLE_MINING
 439
 440 void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int& nExtraNonce)
 441 {
 442     // Update nExtraNonce
 443     static uint256 hashPrevBlock;
 444     if (hashPrevBlock != pblock->hashPrevBlock)
 445     {
 446         nExtraNonce = 0;
 447         hashPrevBlock = pblock->hashPrevBlock;
 448     }
 449     ++nExtraNonce;
 450     unsigned int nHeight = pindexPrev->nHeight+1; // Height first in coinbase required for block.version=2
 451     CMutableTransaction txCoinbase(pblock->vtx[0]);
 452     txCoinbase.vin[0].scriptSig = (CScript() << nHeight << CScriptNum(nExtraNonce)) + COINBASE_FLAGS;
 453     assert(txCoinbase.vin[0].scriptSig.size() <= 100);
 454
 455     pblock->vtx[0] = txCoinbase;
 456     pblock->hashMerkleRoot = pblock->BuildMerkleTree();
 457 }
 458
 459 #ifdef ENABLE_WALLET
 460 static bool ProcessBlockFound(CBlock* pblock, CWallet& wallet, CReserveKey& reservekey)
 461 #else
 462 static bool ProcessBlockFound(CBlock* pblock)
 463 #endif // ENABLE_WALLET
 464 {
 465     LogPrintf("%s\n", pblock->ToString());
 466     LogPrintf("generated %s\n", FormatMoney(pblock->vtx[0].vout[0].nValue));
 467
 468     // Found a solution
 469     {
 470         LOCK(cs_main);
 471         if (pblock->hashPrevBlock != chainActive.Tip()->GetBlockHash())
 472             return error("ZcashMiner: generated block is stale");
 473     }
 474
 475 #ifdef ENABLE_WALLET
 476     if (GetArg("-mineraddress", "").empty()) {
 477         // Remove key from key pool
 478         reservekey.KeepKey();
 479     }
 480
 481     // Track how many getdata requests this block gets
 482     {
 483         LOCK(wallet.cs_wallet);
 484         wallet.mapRequestCount[pblock->GetHash()] = 0;
 485     }
 486 #endif
 487
 488     // Process this block the same as if we had received it from another node
 489     CValidationState state;
 490     if (!ProcessNewBlock(state, NULL, pblock, true, NULL))
 491         return error("ZcashMiner: ProcessNewBlock, block not accepted");
 492
 493     TrackMinedBlock(pblock->GetHash());
 494
 495     return true;
 496 }
 497
 498 #ifdef ENABLE_WALLET
 499 void static BitcoinMiner(CWallet *pwallet)
 500 #else
 501 void static BitcoinMiner()
 502 #endif
 503 {
 504     LogPrintf("ZcashMiner started\n");
 505     SetThreadPriority(THREAD_PRIORITY_LOWEST);
 506     RenameThread("zcash-miner");
 507     const CChainParams& chainparams = Params();
 508
 509 #ifdef ENABLE_WALLET
 510     // Each thread has its own key
 511     CReserveKey reservekey(pwallet);
 512 #endif
 513
 514     // Each thread has its own counter
 515     unsigned int nExtraNonce = 0;
 516
 517     unsigned int n = chainparams.EquihashN();
 518     unsigned int k = chainparams.EquihashK();
 519
 520     std::string solver = GetArg("-equihashsolver", "default");
 521     assert(solver == "tromp" || solver == "default");
 522     LogPrint("pow", "Using Equihash solver \"%s\" with n = %u, k = %u\n", solver, n, k);
 523
 524     std::mutex m_cs;
 525     bool cancelSolver = false;
 526     boost::signals2::connection c = uiInterface.NotifyBlockTip.connect(
 527         [&m_cs, &cancelSolver](const uint256& hashNewTip) mutable {
 528             std::lock_guard<std::mutex> lock{m_cs};
 529             cancelSolver = true;
 530         }
 531     );
 532     miningTimer.start();
 533
 534     try {
 535         while (true) {
 536             if (chainparams.MiningRequiresPeers()) {
 537                 // Busy-wait for the network to come online so we don't waste time mining
 538                 // on an obsolete chain. In regtest mode we expect to fly solo.
 539                 miningTimer.stop();
 540                 do {
 541                     bool fvNodesEmpty;
 542                     {
 543                         LOCK(cs_vNodes);
 544                         fvNodesEmpty = vNodes.empty();
 545                     }
 546                     if (!fvNodesEmpty && !IsInitialBlockDownload())
 547                         break;
 548                     MilliSleep(1000);
 549                 } while (true);
 550                 miningTimer.start();
 551             }
 552
 553             //
 554             // Create new block
 555             //
 556             unsigned int nTransactionsUpdatedLast = mempool.GetTransactionsUpdated();
 557             CBlockIndex* pindexPrev = chainActive.Tip();
 558
 559 #ifdef ENABLE_WALLET
 560             unique_ptr<CBlockTemplate> pblocktemplate(CreateNewBlockWithKey(reservekey));
 561 #else
 562             unique_ptr<CBlockTemplate> pblocktemplate(CreateNewBlockWithKey());
 563 #endif
 564             if (!pblocktemplate.get())
 565             {
 566                 if (GetArg("-mineraddress", "").empty()) {
 567                     LogPrintf("Error in ZcashMiner: Keypool ran out, please call keypoolrefill before restarting the mining thread\n");
 568                 } else {
 569                     // Should never reach here, because -mineraddress validity is checked in init.cpp
 570                     LogPrintf("Error in ZcashMiner: Invalid -mineraddress\n");
 571                 }
 572                 return;
 573             }
 574             CBlock *pblock = &pblocktemplate->block;
 575             IncrementExtraNonce(pblock, pindexPrev, nExtraNonce);
 576
 577             LogPrintf("Running ZcashMiner with %u transactions in block (%u bytes)\n", pblock->vtx.size(),
 578                 ::GetSerializeSize(*pblock, SER_NETWORK, PROTOCOL_VERSION));
 579
 580             //
 581             // Search
 582             //
 583             int64_t nStart = GetTime();
 584             arith_uint256 hashTarget = arith_uint256().SetCompact(pblock->nBits);
 585
 586             while (true) {
 587                 // Hash state
 588                 crypto_generichash_blake2b_state state;
 589                 EhInitialiseState(n, k, state);
 590
 591                 // I = the block header minus nonce and solution.
 592                 CEquihashInput I{*pblock};
 593                 CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
 594                 ss << I;
 595
 596                 // H(I||...
 597                 crypto_generichash_blake2b_update(&state, (unsigned char*)&ss[0], ss.size());
 598
 599                 // H(I||V||...
 600                 crypto_generichash_blake2b_state curr_state;
 601                 curr_state = state;
 602                 crypto_generichash_blake2b_update(&curr_state,
 603                                                   pblock->nNonce.begin(),
 604                                                   pblock->nNonce.size());
 605
 606                 // (x_1, x_2, ...) = A(I, V, n, k)
 607                 LogPrint("pow", "Running Equihash solver \"%s\" with nNonce = %s\n",
 608                          solver, pblock->nNonce.ToString());
 609
 610                 std::function<bool(std::vector<unsigned char>)> validBlock =
 611 #ifdef ENABLE_WALLET
 612                         [&pblock, &hashTarget, &pwallet, &reservekey, &m_cs, &cancelSolver, &chainparams]
 613 #else
 614                         [&pblock, &hashTarget, &m_cs, &cancelSolver, &chainparams]
 615 #endif
 616                         (std::vector<unsigned char> soln) {
 617                     // Write the solution to the hash and compute the result.
 618                     LogPrint("pow", "- Checking solution against target\n");
 619                     pblock->nSolution = soln;
 620                     solutionTargetChecks.increment();
 621
 622                     if (UintToArith256(pblock->GetHash()) > hashTarget) {
 623                         return false;
 624                     }
 625
 626                     // Found a solution
 627                     SetThreadPriority(THREAD_PRIORITY_NORMAL);
 628                     LogPrintf("ZcashMiner:\n");
 629                     LogPrintf("proof-of-work found  \n  hash: %s  \ntarget: %s\n", pblock->GetHash().GetHex(), hashTarget.GetHex());
 630 #ifdef ENABLE_WALLET
 631                     if (ProcessBlockFound(pblock, *pwallet, reservekey)) {
 632 #else
 633                     if (ProcessBlockFound(pblock)) {
 634 #endif
 635                         // Ignore chain updates caused by us
 636                         std::lock_guard<std::mutex> lock{m_cs};
 637                         cancelSolver = false;
 638                     }
 639                     SetThreadPriority(THREAD_PRIORITY_LOWEST);
 640
 641                     // In regression test mode, stop mining after a block is found.
 642                     if (chainparams.MineBlocksOnDemand()) {
 643                         // Increment here because throwing skips the call below
 644                         ehSolverRuns.increment();
 645                         throw boost::thread_interrupted();
 646                     }
 647
 648                     return true;
 649                 };
 650                 std::function<bool(EhSolverCancelCheck)> cancelled = [&m_cs, &cancelSolver](EhSolverCancelCheck pos) {
 651                     std::lock_guard<std::mutex> lock{m_cs};
 652                     return cancelSolver;
 653                 };
 654
 655                 // TODO: factor this out into a function with the same API for each solver.
 656                 if (solver == "tromp") {
 657                     // Create solver and initialize it.
 658                     equi eq(1);
 659                     eq.setstate(&curr_state);
 660
 661                     // Initialization done, start algo driver.
 662                     eq.digit0(0);
 663                     eq.xfull = eq.bfull = eq.hfull = 0;
 664                     eq.showbsizes(0);
 665                     for (u32 r = 1; r < WK; r++) {
 666                         (r&1) ? eq.digitodd(r, 0) : eq.digiteven(r, 0);
 667                         eq.xfull = eq.bfull = eq.hfull = 0;
 668                         eq.showbsizes(r);
 669                     }
 670                     eq.digitK(0);
 671                     ehSolverRuns.increment();
 672
 673                     // Convert solution indices to byte array (decompress) and pass it to validBlock method.
 674                     for (size_t s = 0; s < eq.nsols; s++) {
 675                         LogPrint("pow", "Checking solution %d\n", s+1);
 676                         std::vector<eh_index> index_vector(PROOFSIZE);
 677                         for (size_t i = 0; i < PROOFSIZE; i++) {
 678                             index_vector[i] = eq.sols[s][i];
 679                         }
 680                         std::vector<unsigned char> sol_char = GetMinimalFromIndices(index_vector, DIGITBITS);
 681
 682                         if (validBlock(sol_char)) {
 683                             // If we find a POW solution, do not try other solutions
 684                             // because they become invalid as we created a new block in blockchain.
 685                             break;
 686                         }
 687                     }
 688                 } else {
 689                     try {
 690                         // If we find a valid block, we rebuild
 691                         bool found = EhOptimisedSolve(n, k, curr_state, validBlock, cancelled);
 692                         ehSolverRuns.increment();
 693                         if (found) {
 694                             break;
 695                         }
 696                     } catch (EhSolverCancelledException&) {
 697                         LogPrint("pow", "Equihash solver cancelled\n");
 698                         std::lock_guard<std::mutex> lock{m_cs};
 699                         cancelSolver = false;
 700                     }
 701                 }
 702
 703                 // Check for stop or if block needs to be rebuilt
 704                 boost::this_thread::interruption_point();
 705                 // Regtest mode doesn't require peers
 706                 if (vNodes.empty() && chainparams.MiningRequiresPeers())
 707                     break;
 708                 if ((UintToArith256(pblock->nNonce) & 0xffff) == 0xffff)
 709                     break;
 710                 if (mempool.GetTransactionsUpdated() != nTransactionsUpdatedLast && GetTime() - nStart > 60)
 711                     break;
 712                 if (pindexPrev != chainActive.Tip())
 713                     break;
 714
 715                 // Update nNonce and nTime
 716                 pblock->nNonce = ArithToUint256(UintToArith256(pblock->nNonce) + 1);
 717                 UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev);
 718             }
 719         }
 720     }
 721     catch (const boost::thread_interrupted&)
 722     {
 723         miningTimer.stop();
 724         c.disconnect();
 725         LogPrintf("ZcashMiner terminated\n");
 726         throw;
 727     }
 728     catch (const std::runtime_error &e)
 729     {
 730         miningTimer.stop();
 731         c.disconnect();
 732         LogPrintf("ZcashMiner runtime error: %s\n", e.what());
 733         return;
 734     }
 735     miningTimer.stop();
 736     c.disconnect();
 737 }
 738
 739 #ifdef ENABLE_WALLET
 740 void GenerateBitcoins(bool fGenerate, CWallet* pwallet, int nThreads)
 741 #else
 742 void GenerateBitcoins(bool fGenerate, int nThreads)
 743 #endif
 744 {
 745     static boost::thread_group* minerThreads = NULL;
 746
 747     if (nThreads < 0)
 748         nThreads = GetNumCores();
 749
 750     if (minerThreads != NULL)
 751     {
 752         minerThreads->interrupt_all();
 753         delete minerThreads;
 754         minerThreads = NULL;
 755     }
 756
 757     if (nThreads == 0 || !fGenerate)
 758         return;
 759
 760     minerThreads = new boost::thread_group();
 761     for (int i = 0; i < nThreads; i++) {
 762 #ifdef ENABLE_WALLET
 763         minerThreads->create_thread(boost::bind(&BitcoinMiner, pwallet));
 764 #else
 765         minerThreads->create_thread(&BitcoinMiner);
 766 #endif
 767     }
 768 }
 769
 770 #endif // ENABLE_MINING