Branch data Line data Source code
1 : : // Copyright (c) 2009-2010 Satoshi Nakamoto
2 : : // Copyright (c) 2009-present 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 <node/miner.h>
7 : :
8 : : #include <chain.h>
9 : : #include <chainparams.h>
10 : : #include <common/args.h>
11 : : #include <consensus/amount.h>
12 : : #include <consensus/consensus.h>
13 : : #include <consensus/merkle.h>
14 : : #include <consensus/params.h>
15 : : #include <consensus/tx_verify.h>
16 : : #include <consensus/validation.h>
17 : : #include <interfaces/types.h>
18 : : #include <node/blockstorage.h>
19 : : #include <node/kernel_notifications.h>
20 : : #include <node/mining_args.h>
21 : : #include <node/mining_types.h>
22 : : #include <policy/feerate.h>
23 : : #include <policy/policy.h>
24 : : #include <pow.h>
25 : : #include <primitives/block.h>
26 : : #include <primitives/transaction.h>
27 : : #include <script/script.h>
28 : : #include <sync.h>
29 : : #include <tinyformat.h>
30 : : #include <txgraph.h>
31 : : #include <txmempool.h>
32 : : #include <uint256.h>
33 : : #include <util/check.h>
34 : : #include <util/feefrac.h>
35 : : #include <util/log.h>
36 : : #include <util/result.h>
37 : : #include <util/signalinterrupt.h>
38 : : #include <util/time.h>
39 : : #include <util/translation.h>
40 : : #include <validation.h>
41 : : #include <validationinterface.h>
42 : : #include <versionbits.h>
43 : :
44 : : #include <algorithm>
45 : : #include <compare>
46 : : #include <condition_variable>
47 : : #include <cstddef>
48 : : #include <functional>
49 : : #include <numeric>
50 : : #include <span>
51 : : #include <stdexcept>
52 : : #include <string>
53 : : #include <utility>
54 : :
55 : : namespace node {
56 : :
57 : 362662 : int64_t GetMinimumTime(const CBlockIndex* pindexPrev, const int64_t difficulty_adjustment_interval)
58 : : {
59 : 362662 : int64_t min_time{pindexPrev->GetMedianTimePast() + 1};
60 : : // Height of block to be mined.
61 : 362662 : const int height{pindexPrev->nHeight + 1};
62 : : // Account for BIP94 timewarp rule on all networks. This makes future
63 : : // activation safer.
64 [ + + ]: 362662 : if (height % difficulty_adjustment_interval == 0) {
65 [ + - ]: 3334 : min_time = std::max<int64_t>(min_time, pindexPrev->GetBlockTime() - MAX_TIMEWARP);
66 : : }
67 : 362662 : return min_time;
68 : : }
69 : :
70 : 362662 : int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev)
71 : : {
72 : 362662 : int64_t nOldTime = pblock->nTime;
73 [ + + ]: 362662 : int64_t nNewTime{std::max<int64_t>(GetMinimumTime(pindexPrev, consensusParams.DifficultyAdjustmentInterval()),
74 : 362662 : TicksSinceEpoch<std::chrono::seconds>(NodeClock::now()))};
75 : :
76 [ + + ]: 362662 : if (nOldTime < nNewTime) {
77 : 239167 : pblock->nTime = nNewTime;
78 : : }
79 : :
80 : : // Updating time can change work required on testnet:
81 [ + - ]: 362662 : if (consensusParams.fPowAllowMinDifficultyBlocks) {
82 : 362662 : pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, consensusParams);
83 : : }
84 : :
85 : 362662 : return nNewTime - nOldTime;
86 : : }
87 : :
88 : 112373 : void RegenerateCommitments(CBlock& block, ChainstateManager& chainman)
89 : : {
90 : 112373 : CMutableTransaction tx{*block.vtx.at(0)};
91 : 112373 : tx.vout.erase(tx.vout.begin() + GetWitnessCommitmentIndex(block));
92 [ + - + - : 224746 : block.vtx.at(0) = MakeTransactionRef(tx);
- + ]
93 : :
94 [ + - + - : 337119 : const CBlockIndex* prev_block = WITH_LOCK(::cs_main, return chainman.m_blockman.LookupBlockIndex(block.hashPrevBlock));
+ - ]
95 [ + - ]: 112373 : chainman.GenerateCoinbaseCommitment(block, prev_block);
96 : :
97 [ + - ]: 112373 : block.hashMerkleRoot = BlockMerkleRoot(block);
98 : 112373 : }
99 : :
100 : 362658 : BlockAssembler::BlockAssembler(Chainstate& chainstate,
101 : : const CTxMemPool* mempool,
102 : 362658 : BlockCreateOptions options)
103 [ - + ]: 362658 : : chainparams{chainstate.m_chainman.GetParams()},
104 [ - + ]: 362658 : m_mempool{options.use_mempool ? mempool : nullptr},
105 : 362658 : m_chainstate{chainstate},
106 [ + - ]: 362658 : m_options{[&] {
107 [ + - - + ]: 725316 : if (auto result{CheckMiningOptions(options, /*use_argnames=*/false)}; !result) {
108 [ # # # # ]: 0 : throw std::runtime_error(util::ErrorString(result).original);
109 : 0 : }
110 [ + - ]: 725316 : return FlattenMiningOptions(std::move(options));
111 [ - + ]: 362658 : }()}
112 : : {
113 : 362658 : }
114 : :
115 : 362658 : void BlockAssembler::resetBlock()
116 : : {
117 : : // Reserve space for fixed-size block header, txs count, and coinbase tx.
118 [ - + ]: 362658 : nBlockWeight = *Assert(m_options.block_reserved_weight);
119 : 362658 : nBlockSigOpsCost = m_options.coinbase_output_max_additional_sigops;
120 : :
121 : : // These counters do not include coinbase tx
122 : 362658 : nBlockTx = 0;
123 : 362658 : nFees = 0;
124 : 362658 : }
125 : :
126 : 362658 : std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock()
127 : : {
128 : 362658 : const auto time_start{SteadyClock::now()};
129 : :
130 : 362658 : resetBlock();
131 : :
132 [ - + ]: 362658 : pblocktemplate.reset(new CBlockTemplate());
133 : 362658 : CBlock* const pblock = &pblocktemplate->block; // pointer for convenience
134 : :
135 : : // Add dummy coinbase tx as first transaction. It is skipped by the
136 : : // getblocktemplate RPC and mining interface consumers must not use it.
137 : 362658 : pblock->vtx.emplace_back();
138 : :
139 : 362658 : LOCK(::cs_main);
140 [ - + ]: 362658 : CBlockIndex* pindexPrev = m_chainstate.m_chain.Tip();
141 [ - + ]: 362658 : assert(pindexPrev != nullptr);
142 : 362658 : nHeight = pindexPrev->nHeight + 1;
143 : :
144 [ + - ]: 362658 : pblock->nVersion = m_chainstate.m_chainman.m_versionbitscache.ComputeBlockVersion(pindexPrev, chainparams.GetConsensus());
145 : : // -regtest only: allow overriding block.nVersion with
146 : : // -blockversion=N to test forking scenarios
147 [ + - ]: 362658 : if (chainparams.MineBlocksOnDemand()) {
148 [ + - ]: 725316 : pblock->nVersion = gArgs.GetIntArg("-blockversion", pblock->nVersion);
149 : : }
150 : :
151 : 362658 : pblock->nTime = TicksSinceEpoch<std::chrono::seconds>(NodeClock::now());
152 : 362658 : m_lock_time_cutoff = pindexPrev->GetMedianTimePast();
153 : :
154 [ + - ]: 362658 : if (m_mempool) {
155 [ + - ]: 362658 : LOCK(m_mempool->cs);
156 : 362658 : m_mempool->StartBlockBuilding();
157 [ + - ]: 362658 : addChunks();
158 [ + - ]: 362658 : m_mempool->StopBlockBuilding();
159 : 362658 : }
160 : :
161 : 362658 : const auto time_1{SteadyClock::now()};
162 : :
163 [ + + ]: 362658 : m_last_block_num_txs = nBlockTx;
164 [ + + ]: 362658 : m_last_block_weight = nBlockWeight;
165 : :
166 : : // Create coinbase transaction.
167 [ + - ]: 362658 : CMutableTransaction coinbaseTx;
168 : :
169 : : // Construct coinbase transaction struct in parallel
170 [ + - ]: 362658 : CoinbaseTx& coinbase_tx{pblocktemplate->m_coinbase_tx};
171 : 362658 : coinbase_tx.version = coinbaseTx.version;
172 : :
173 [ + - ]: 362658 : coinbaseTx.vin.resize(1);
174 : 362658 : coinbaseTx.vin[0].prevout.SetNull();
175 [ + - ]: 362658 : coinbaseTx.vin[0].nSequence = CTxIn::MAX_SEQUENCE_NONFINAL; // Make sure timelock is enforced.
176 : 362658 : coinbase_tx.sequence = coinbaseTx.vin[0].nSequence;
177 : :
178 : : // Add an output that spends the full coinbase reward.
179 [ + - ]: 362658 : coinbaseTx.vout.resize(1);
180 : 362658 : coinbaseTx.vout[0].scriptPubKey = m_options.coinbase_output_script;
181 : : // Block subsidy + fees
182 [ + - ]: 362658 : const CAmount block_reward{nFees + GetBlockSubsidy(nHeight, chainparams.GetConsensus())};
183 [ + - ]: 362658 : coinbaseTx.vout[0].nValue = block_reward;
184 : 362658 : coinbase_tx.block_reward_remaining = block_reward;
185 : :
186 : : // Start the coinbase scriptSig with the block height as required by BIP34.
187 : : // Mining clients are expected to append extra data to this prefix, so
188 : : // increasing its length would reduce the space they can use and may break
189 : : // existing clients.
190 [ + - ]: 362658 : coinbaseTx.vin[0].scriptSig = CScript() << nHeight;
191 : : // Set script_sig_prefix here, so IPC mining clients are not affected by
192 : : // the optional scriptSig padding below. They provide their own extraNonce,
193 : : // and in a typical setup a pool name or realistic extraNonce already makes
194 : : // the scriptSig long enough.
195 : 362658 : coinbase_tx.script_sig_prefix = coinbaseTx.vin[0].scriptSig;
196 [ + + ]: 362658 : if (nHeight <= 16) {
197 : : // For blocks at heights <= 16, the BIP34-encoded height alone is only
198 : : // one byte. Consensus requires coinbase scriptSigs to be at least two
199 : : // bytes long (bad-cb-length), so an OP_0 is always appended at those
200 : : // heights.
201 [ + - ]: 54057 : coinbaseTx.vin[0].scriptSig << OP_0;
202 : : }
203 [ - + ]: 362658 : Assert(nHeight > 0);
204 : 362658 : coinbaseTx.nLockTime = static_cast<uint32_t>(nHeight - 1);
205 : 362658 : coinbase_tx.lock_time = coinbaseTx.nLockTime;
206 : :
207 [ + - - + ]: 725316 : pblock->vtx[0] = MakeTransactionRef(std::move(coinbaseTx));
208 [ + - ]: 362658 : m_chainstate.m_chainman.GenerateCoinbaseCommitment(*pblock, pindexPrev);
209 : :
210 [ + - ]: 362658 : const CTransactionRef& final_coinbase{pblock->vtx[0]};
211 [ + - ]: 362658 : if (final_coinbase->HasWitness()) {
212 [ - + ]: 362658 : const auto& witness_stack{final_coinbase->vin[0].scriptWitness.stack};
213 : : // Consensus requires the coinbase witness stack to have exactly one
214 : : // element of 32 bytes.
215 [ - + + - : 362658 : Assert(witness_stack.size() == 1 && witness_stack[0].size() == 32);
- + - + -
+ ]
216 [ - + - + ]: 362658 : coinbase_tx.witness = uint256(witness_stack[0]);
217 : : }
218 [ + - ]: 362658 : if (const int witness_index = GetWitnessCommitmentIndex(*pblock); witness_index != NO_WITNESS_COMMITMENT) {
219 [ + - - + : 362658 : Assert(witness_index >= 0 && static_cast<size_t>(witness_index) < final_coinbase->vout.size());
- + - + ]
220 [ + - ]: 362658 : coinbase_tx.required_outputs.push_back(final_coinbase->vout[witness_index]);
221 : : }
222 : :
223 [ + - ]: 362658 : LogInfo("CreateNewBlock(): block weight: %u txs: %u fees: %ld sigops %d\n", GetBlockWeight(*pblock), nBlockTx, nFees, nBlockSigOpsCost);
224 : :
225 : : // Fill in header
226 : 362658 : pblock->hashPrevBlock = pindexPrev->GetBlockHash();
227 [ + - ]: 362658 : UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev);
228 [ + - ]: 362658 : pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, chainparams.GetConsensus());
229 : 362658 : pblock->nNonce = 0;
230 : :
231 [ + - ]: 362658 : if (m_options.test_block_validity) {
232 [ + - - + ]: 362658 : if (BlockValidationState state{TestBlockValidity(m_chainstate, *pblock, /*check_pow=*/false, /*check_merkle_root=*/false)}; !state.IsValid()) {
233 [ # # # # : 0 : throw std::runtime_error(strprintf("TestBlockValidity failed: %s", state.ToString()));
# # ]
234 : 362658 : }
235 : : }
236 : 362658 : const auto time_2{SteadyClock::now()};
237 : :
238 [ + - + + : 362658 : LogDebug(BCLog::BENCH, "CreateNewBlock() chunks: %.2fms, validity: %.2fms (total %.2fms)\n",
+ - ]
239 : : Ticks<MillisecondsDouble>(time_1 - time_start),
240 : : Ticks<MillisecondsDouble>(time_2 - time_1),
241 : : Ticks<MillisecondsDouble>(time_2 - time_start));
242 : :
243 : 362658 : return std::move(pblocktemplate);
244 [ + - ]: 725316 : }
245 : :
246 : 64765 : bool BlockAssembler::TestChunkBlockLimits(FeePerWeight chunk_feerate, int64_t chunk_sigops_cost) const
247 : : {
248 : : // block_max_weight has been flattened before block assembly limit checks.
249 [ - + ]: 64765 : Assert(m_options.block_max_weight);
250 [ + + ]: 64765 : if (nBlockWeight + chunk_feerate.size >= *m_options.block_max_weight) {
251 : : return false;
252 : : }
253 [ - + ]: 43768 : if (nBlockSigOpsCost + chunk_sigops_cost >= MAX_BLOCK_SIGOPS_COST) {
254 : 0 : return false;
255 : : }
256 : : return true;
257 : : }
258 : :
259 : : // Perform transaction-level checks before adding to block:
260 : : // - transaction finality (locktime)
261 : 43768 : bool BlockAssembler::TestChunkTransactions(const std::vector<CTxMemPoolEntryRef>& txs) const
262 : : {
263 [ + + ]: 92183 : for (const auto tx : txs) {
264 [ + - ]: 48415 : if (!IsFinalTx(tx.get().GetTx(), nHeight, m_lock_time_cutoff)) {
265 : : return false;
266 : : }
267 : : }
268 : : return true;
269 : : }
270 : :
271 : 48415 : void BlockAssembler::AddToBlock(const CTxMemPoolEntry& entry)
272 : : {
273 [ + - + - ]: 96830 : pblocktemplate->block.vtx.emplace_back(entry.GetSharedTx());
274 : 48415 : pblocktemplate->vTxFees.push_back(entry.GetFee());
275 : 48415 : pblocktemplate->vTxSigOpsCost.push_back(entry.GetSigOpCost());
276 [ - + ]: 48415 : nBlockWeight += entry.GetTxWeight();
277 : 48415 : ++nBlockTx;
278 [ - + ]: 48415 : nBlockSigOpsCost += entry.GetSigOpCost();
279 : 48415 : nFees += entry.GetFee();
280 : :
281 [ - + ]: 48415 : if (*m_options.print_modified_fee) {
282 [ # # # # : 0 : LogInfo("fee rate %s txid %s\n",
# # # # ]
283 : : CFeeRate(entry.GetModifiedFee(), entry.GetTxSize()).ToString(),
284 : : entry.GetTx().GetHash().ToString());
285 : : }
286 : 48415 : }
287 : :
288 : 362658 : void BlockAssembler::addChunks()
289 : : {
290 : : // Limit the number of attempts to add transactions to the block when it is
291 : : // close to full; this is just a simple heuristic to finish quickly if the
292 : : // mempool has a lot of entries.
293 : 362658 : const int64_t MAX_CONSECUTIVE_FAILURES = 1000;
294 : 362658 : constexpr int32_t BLOCK_FULL_ENOUGH_WEIGHT_DELTA = 4000;
295 : 362658 : int64_t nConsecutiveFailed = 0;
296 : :
297 : 362658 : std::vector<CTxMemPoolEntry::CTxMemPoolEntryRef> selected_transactions;
298 [ + - ]: 362658 : selected_transactions.reserve(MAX_CLUSTER_COUNT_LIMIT);
299 : 362658 : FeePerWeight chunk_feerate;
300 : :
301 : : // This fills selected_transactions
302 [ + - ]: 362658 : chunk_feerate = m_mempool->GetBlockBuilderChunk(selected_transactions);
303 : 362658 : FeePerVSize chunk_feerate_vsize = ToFeePerVSize(chunk_feerate);
304 : :
305 [ - + + + ]: 427423 : while (selected_transactions.size() > 0) {
306 : : // Check to see if min fee rate is still respected.
307 [ + + ]: 66552 : if (ByRatio{chunk_feerate_vsize} < ByRatio{m_options.block_min_fee_rate->GetFeePerVSize()}) {
308 : : // Everything else we might consider has a lower feerate
309 : : return;
310 : : }
311 : :
312 : 64765 : int64_t chunk_sig_ops = 0;
313 [ + + ]: 136399 : for (const auto& tx : selected_transactions) {
314 : 71634 : chunk_sig_ops += tx.get().GetSigOpCost();
315 : : }
316 : :
317 : : // Check to see if this chunk will fit.
318 [ + - + + : 64765 : if (!TestChunkBlockLimits(chunk_feerate, chunk_sig_ops) || !TestChunkTransactions(selected_transactions)) {
+ - - + ]
319 : : // This chunk won't fit, so we skip it and will try the next best one.
320 : 20997 : m_mempool->SkipBuilderChunk();
321 : 20997 : ++nConsecutiveFailed;
322 : :
323 : : // block_max_weight has been flattened before block assembly limit checks.
324 [ - + ]: 20997 : Assert(m_options.block_max_weight);
325 [ - + ]: 20997 : if (nConsecutiveFailed > MAX_CONSECUTIVE_FAILURES && nBlockWeight +
326 [ # # ]: 0 : BLOCK_FULL_ENOUGH_WEIGHT_DELTA > *m_options.block_max_weight) {
327 : : // Give up if we're close to full and haven't succeeded in a while
328 : : return;
329 : : }
330 : : } else {
331 : 43768 : m_mempool->IncludeBuilderChunk();
332 : :
333 : : // This chunk will fit, so add it to the block.
334 : 43768 : nConsecutiveFailed = 0;
335 [ + + ]: 92183 : for (const auto& tx : selected_transactions) {
336 [ + - ]: 48415 : AddToBlock(tx);
337 : : }
338 [ + - ]: 43768 : pblocktemplate->m_package_feerates.emplace_back(chunk_feerate_vsize);
339 : : }
340 : :
341 [ + - ]: 64765 : selected_transactions.clear();
342 [ + - ]: 64765 : chunk_feerate = m_mempool->GetBlockBuilderChunk(selected_transactions);
343 : 64765 : chunk_feerate_vsize = ToFeePerVSize(chunk_feerate);
344 : : }
345 : 362658 : }
346 : :
347 : 0 : void AddMerkleRootAndCoinbase(CBlock& block, CTransactionRef coinbase, uint32_t version, uint32_t timestamp, uint32_t nonce)
348 : : {
349 [ # # # # ]: 0 : if (block.vtx.size() == 0) {
350 : 0 : block.vtx.emplace_back(coinbase);
351 : : } else {
352 : 0 : block.vtx[0] = coinbase;
353 : : }
354 : 0 : block.nVersion = version;
355 : 0 : block.nTime = timestamp;
356 : 0 : block.nNonce = nonce;
357 : 0 : block.hashMerkleRoot = BlockMerkleRoot(block);
358 : :
359 : : // Reset cached checks
360 : 0 : block.m_checked_witness_commitment = false;
361 : 0 : block.m_checked_merkle_root = false;
362 : 0 : block.fChecked = false;
363 : 0 : }
364 : :
365 : : namespace {
366 : : class SubmitBlockStateCatcher final : public CValidationInterface
367 : : {
368 : : public:
369 : : uint256 m_hash;
370 : : bool m_found{false};
371 : : BlockValidationState m_state;
372 : :
373 : 0 : explicit SubmitBlockStateCatcher(const uint256& hash) : m_hash{hash} {}
374 : :
375 : : protected:
376 : 0 : void BlockChecked(const std::shared_ptr<const CBlock>& block, const BlockValidationState& state) override
377 : : {
378 [ # # ]: 0 : if (block->GetHash() != m_hash) return;
379 : : // ProcessNewBlock emits BlockChecked synchronously while holding cs_main,
380 : : // so SubmitBlock can read these fields after ProcessNewBlock returns
381 : : // without extra synchronization.
382 : 0 : m_found = true;
383 : 0 : m_state = state;
384 : : }
385 : : };
386 : : } // namespace
387 : :
388 : 0 : bool SubmitBlock(ChainstateManager& chainman, const std::shared_ptr<const CBlock>& block, bool* new_block, std::string& reason, std::string& debug)
389 : : {
390 : 0 : reason.clear();
391 : 0 : debug.clear();
392 : :
393 : : // This follows the submitblock RPC's validation-state capture pattern, but
394 : : // is intentionally kept separate from the RPC implementation. The RPC entry
395 : : // point decodes hex, formats BIP22/JSONRPC results, and calls
396 : : // UpdateUncommittedBlockStructures() for legacy witness handling. IPC
397 : : // callers submit already-formed blocks and need bool + reason/debug
398 : : // results, while submitSolution() preserves its duplicate-as-success
399 : : // behavior.
400 : 0 : auto sc = std::make_shared<SubmitBlockStateCatcher>(block->GetHash());
401 [ # # # # : 0 : CHECK_NONFATAL(chainman.m_options.signals)->RegisterSharedValidationInterface(sc);
# # ]
402 [ # # ]: 0 : bool accepted = chainman.ProcessNewBlock(block, /*force_processing=*/true, /*min_pow_checked=*/true, /*new_block=*/new_block);
403 [ # # # # : 0 : CHECK_NONFATAL(chainman.m_options.signals)->UnregisterSharedValidationInterface(sc);
# # ]
404 : :
405 [ # # # # : 0 : if (new_block && !*new_block && accepted) {
# # ]
406 [ # # ]: 0 : reason = "duplicate";
407 [ # # ]: 0 : } else if (!sc->m_found) {
408 : : // A block can be accepted and stored without being connected, for
409 : : // example if it does not have more work than the current tip. In that
410 : : // case no BlockChecked callback is emitted, so the validation result is
411 : : // inconclusive. Mining::submitBlock treats this as an error for mining
412 : : // clients, but it does not mean the block is invalid.
413 [ # # ]: 0 : reason = "inconclusive";
414 [ # # ]: 0 : } else if (!sc->m_state.IsValid()) {
415 [ # # ]: 0 : reason = sc->m_state.GetRejectReason();
416 [ # # ]: 0 : debug = sc->m_state.GetDebugMessage();
417 : : }
418 [ # # ]: 0 : return accepted;
419 : 0 : }
420 : :
421 : 0 : void InterruptWait(KernelNotifications& kernel_notifications, bool& interrupt_wait)
422 : : {
423 : 0 : LOCK(kernel_notifications.m_tip_block_mutex);
424 : 0 : interrupt_wait = true;
425 [ # # ]: 0 : kernel_notifications.m_tip_block_cv.notify_all();
426 : 0 : }
427 : :
428 : 0 : std::unique_ptr<CBlockTemplate> WaitAndCreateNewBlock(ChainstateManager& chainman,
429 : : KernelNotifications& kernel_notifications,
430 : : CTxMemPool* mempool,
431 : : const std::unique_ptr<CBlockTemplate>& block_template,
432 : : const BlockWaitOptions& wait_options,
433 : : const BlockCreateOptions& create_options,
434 : : bool& interrupt_wait)
435 : : {
436 : : // Delay calculating the current template fees, just in case a new block
437 : : // comes in before the next tick.
438 : 0 : CAmount current_fees = -1;
439 : :
440 : : // Alternate waiting for a new tip and checking if fees have risen.
441 : : // The latter check is expensive so we only run it once per second.
442 : 0 : auto now{NodeClock::now()};
443 : 0 : const auto deadline = now + wait_options.timeout;
444 : 0 : const MillisecondsDouble tick{1000};
445 : 0 : const bool allow_min_difficulty{chainman.GetParams().GetConsensus().fPowAllowMinDifficultyBlocks};
446 : :
447 : 0 : do {
448 : 0 : bool tip_changed{false};
449 : 0 : {
450 : 0 : WAIT_LOCK(kernel_notifications.m_tip_block_mutex, lock);
451 : : // Note that wait_until() checks the predicate before waiting
452 [ # # ]: 0 : kernel_notifications.m_tip_block_cv.wait_until(lock, std::min(now + tick, deadline), [&]() EXCLUSIVE_LOCKS_REQUIRED(kernel_notifications.m_tip_block_mutex) {
453 : 0 : AssertLockHeld(kernel_notifications.m_tip_block_mutex);
454 : 0 : const auto tip_block{kernel_notifications.TipBlock()};
455 : : // We assume tip_block is set, because this is an instance
456 : : // method on BlockTemplate and no template could have been
457 : : // generated before a tip exists.
458 [ # # # # : 0 : tip_changed = Assume(tip_block) && tip_block != block_template->block.hashPrevBlock;
# # ]
459 [ # # # # : 0 : return tip_changed || chainman.m_interrupt || interrupt_wait;
# # ]
460 : : });
461 [ # # ]: 0 : if (interrupt_wait) {
462 : 0 : interrupt_wait = false;
463 [ # # ]: 0 : return nullptr;
464 : : }
465 : 0 : }
466 : :
467 [ # # ]: 0 : if (chainman.m_interrupt) return nullptr;
468 : : // At this point the tip changed, a full tick went by or we reached
469 : : // the deadline.
470 : :
471 : : // Must release m_tip_block_mutex before locking cs_main, to avoid deadlocks.
472 : 0 : LOCK(::cs_main);
473 : :
474 : : // On test networks return a minimum difficulty block after 20 minutes
475 [ # # # # ]: 0 : if (!tip_changed && allow_min_difficulty) {
476 [ # # # # ]: 0 : const NodeClock::time_point tip_time{std::chrono::seconds{chainman.ActiveChain().Tip()->GetBlockTime()}};
477 [ # # ]: 0 : if (now > tip_time + 20min) {
478 : 0 : tip_changed = true;
479 : : }
480 : : }
481 : :
482 : : /**
483 : : * We determine if fees increased compared to the previous template by generating
484 : : * a fresh template. There may be more efficient ways to determine how much
485 : : * (approximate) fees for the next block increased, perhaps more so after
486 : : * Cluster Mempool.
487 : : *
488 : : * We'll also create a new template if the tip changed during this iteration.
489 : : */
490 [ # # # # ]: 0 : if (wait_options.fee_threshold < MAX_MONEY || tip_changed) {
491 : 0 : auto new_tmpl{BlockAssembler{
492 : : chainman.ActiveChainstate(),
493 : : mempool,
494 : : create_options
495 [ # # # # : 0 : }.CreateNewBlock()};
# # ]
496 : :
497 : : // If the tip changed, return the new template regardless of its fees.
498 [ # # ]: 0 : if (tip_changed) return new_tmpl;
499 : :
500 : : // Calculate the original template total fees if we haven't already
501 [ # # ]: 0 : if (current_fees == -1) {
502 : 0 : current_fees = std::accumulate(block_template->vTxFees.begin(), block_template->vTxFees.end(), CAmount{0});
503 : : }
504 : :
505 : : // Check if fees increased enough to return the new template
506 : 0 : const CAmount new_fees = std::accumulate(new_tmpl->vTxFees.begin(), new_tmpl->vTxFees.end(), CAmount{0});
507 [ # # ]: 0 : Assume(wait_options.fee_threshold != MAX_MONEY);
508 [ # # ]: 0 : if (new_fees >= current_fees + wait_options.fee_threshold) return new_tmpl;
509 [ # # ]: 0 : }
510 : :
511 [ # # ]: 0 : now = NodeClock::now();
512 [ # # ]: 0 : } while (now < deadline);
513 : :
514 : 0 : return nullptr;
515 : : }
516 : :
517 : 352483 : std::optional<BlockRef> GetTip(ChainstateManager& chainman)
518 : : {
519 : 352483 : LOCK(::cs_main);
520 [ + - - + ]: 352483 : CBlockIndex* tip{chainman.ActiveChain().Tip()};
521 [ - + ]: 352483 : if (!tip) return {};
522 : 352483 : return BlockRef{tip->GetBlockHash(), tip->nHeight};
523 : 352483 : }
524 : :
525 : 0 : bool CooldownIfHeadersAhead(ChainstateManager& chainman, KernelNotifications& kernel_notifications, const BlockRef& last_tip, bool& interrupt_mining)
526 : : {
527 : 0 : uint256 last_tip_hash{last_tip.hash};
528 : :
529 [ # # ]: 0 : while (const std::optional<int> remaining = chainman.BlocksAheadOfTip()) {
530 [ # # ]: 0 : const int cooldown_seconds = std::clamp(*remaining, 3, 20);
531 : 0 : const auto cooldown_deadline{MockableSteadyClock::now() + std::chrono::seconds{cooldown_seconds}};
532 : :
533 : 0 : {
534 : 0 : WAIT_LOCK(kernel_notifications.m_tip_block_mutex, lock);
535 [ # # ]: 0 : kernel_notifications.m_tip_block_cv.wait_until(lock, cooldown_deadline, [&]() EXCLUSIVE_LOCKS_REQUIRED(kernel_notifications.m_tip_block_mutex) {
536 : 0 : const auto tip_block = kernel_notifications.TipBlock();
537 [ # # # # : 0 : return chainman.m_interrupt || interrupt_mining || (tip_block && *tip_block != last_tip_hash);
# # # # ]
538 : : });
539 [ # # # # : 0 : if (chainman.m_interrupt || interrupt_mining) {
# # ]
540 : 0 : interrupt_mining = false;
541 [ # # ]: 0 : return false;
542 : : }
543 : :
544 : : // If the tip changed during the wait, extend the deadline
545 [ # # ]: 0 : const auto tip_block = kernel_notifications.TipBlock();
546 [ # # # # ]: 0 : if (tip_block && *tip_block != last_tip_hash) {
547 [ # # ]: 0 : last_tip_hash = *tip_block;
548 [ # # ]: 0 : continue;
549 : : }
550 : 0 : }
551 : :
552 : : // No tip change and the cooldown window has expired.
553 [ # # ]: 0 : if (MockableSteadyClock::now() >= cooldown_deadline) break;
554 : : }
555 : :
556 : : return true;
557 : : }
558 : :
559 : 352483 : std::optional<BlockRef> WaitTipChanged(ChainstateManager& chainman, KernelNotifications& kernel_notifications, const uint256& current_tip, MillisecondsDouble& timeout, bool& interrupt)
560 : : {
561 [ - + ]: 352483 : Assume(timeout >= 0ms); // No internal callers should use a negative timeout
562 [ - + ]: 352483 : if (timeout < 0ms) timeout = 0ms;
563 [ + - ]: 352483 : if (timeout > std::chrono::years{100}) timeout = std::chrono::years{100}; // Upper bound to avoid UB in std::chrono
564 : 352483 : auto deadline{std::chrono::steady_clock::now() + timeout};
565 : 352483 : {
566 : 352483 : WAIT_LOCK(kernel_notifications.m_tip_block_mutex, lock);
567 : : // For callers convenience, wait longer than the provided timeout
568 : : // during startup for the tip to be non-null. That way this function
569 : : // always returns valid tip information when possible and only
570 : : // returns null when shutting down, not when timing out.
571 [ + - ]: 352483 : kernel_notifications.m_tip_block_cv.wait(lock, [&]() EXCLUSIVE_LOCKS_REQUIRED(kernel_notifications.m_tip_block_mutex) {
572 [ - + - - : 352483 : return kernel_notifications.TipBlock() || chainman.m_interrupt || interrupt;
- - ]
573 : : });
574 [ + - + - : 352483 : if (chainman.m_interrupt || interrupt) {
+ - ]
575 : 0 : interrupt = false;
576 : 0 : return {};
577 : : }
578 : : // At this point TipBlock is set, so continue to wait until it is
579 : : // different then `current_tip` provided by caller.
580 [ + - ]: 352483 : kernel_notifications.m_tip_block_cv.wait_until(lock, deadline, [&]() EXCLUSIVE_LOCKS_REQUIRED(kernel_notifications.m_tip_block_mutex) {
581 [ - + - + : 352483 : return Assume(kernel_notifications.TipBlock()) != current_tip || chainman.m_interrupt || interrupt;
- - - - ]
582 : : });
583 [ + - + - : 352483 : if (chainman.m_interrupt || interrupt) {
+ - ]
584 : 0 : interrupt = false;
585 : 0 : return {};
586 : : }
587 : 0 : }
588 : :
589 : : // Must release m_tip_block_mutex before getTip() locks cs_main, to
590 : : // avoid deadlocks.
591 : 352483 : return GetTip(chainman);
592 : : }
593 : :
594 : : } // namespace node
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