miner: Make mempool optional for BlockAssembler

...also adjust callers

Changes:

- In BlockAssembler::CreateNewBlock, we now only lock m_mempool->cs and
  call addPackageTxs if m_mempool is not nullptr
- BlockAssembler::addPackageTxs now takes in a mempool reference, and is
  annotated to require that mempool's lock.
- In TestChain100Setup::CreateBlock and generateblock, don't construct
  an empty mempool, just pass in a nullptr for mempool

1 files changed, 18 insertions, 15 deletions

diff --git a/src/node/miner.cpp b/src/node/miner.cpp
index 167499ee41..9db10feae4 100644
--- a/src/node/miner.cpp
+++ b/src/node/miner.cpp
@@ -62,7 +62,7 @@ BlockAssembler::Options::Options()
     nBlockMaxWeight = DEFAULT_BLOCK_MAX_WEIGHT;
 }
 
-BlockAssembler::BlockAssembler(CChainState& chainstate, const CTxMemPool& mempool, const Options& options)
+BlockAssembler::BlockAssembler(CChainState& chainstate, const CTxMemPool* mempool, const Options& options)
     : chainparams{chainstate.m_chainman.GetParams()},
       m_mempool(mempool),
       m_chainstate(chainstate)
@@ -87,7 +87,7 @@ static BlockAssembler::Options DefaultOptions()
     return options;
 }
 
-BlockAssembler::BlockAssembler(CChainState& chainstate, const CTxMemPool& mempool)
+BlockAssembler::BlockAssembler(CChainState& chainstate, const CTxMemPool* mempool)
     : BlockAssembler(chainstate, mempool, DefaultOptions()) {}
 
 void BlockAssembler::resetBlock()
@@ -121,7 +121,7 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
     pblocktemplate->vTxFees.push_back(-1); // updated at end
     pblocktemplate->vTxSigOpsCost.push_back(-1); // updated at end
 
-    LOCK2(cs_main, m_mempool.cs);
+    LOCK(::cs_main);
     CBlockIndex* pindexPrev = m_chainstate.m_chain.Tip();
     assert(pindexPrev != nullptr);
     nHeight = pindexPrev->nHeight + 1;
@@ -138,7 +138,10 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
 
     int nPackagesSelected = 0;
     int nDescendantsUpdated = 0;
-    addPackageTxs(nPackagesSelected, nDescendantsUpdated);
+    if (m_mempool) {
+        LOCK(m_mempool->cs);
+        addPackageTxs(*m_mempool, nPackagesSelected, nDescendantsUpdated);
+    }
 
     int64_t nTime1 = GetTimeMicros();
 
@@ -287,9 +290,9 @@ void BlockAssembler::SortForBlock(const CTxMemPool::setEntries& package, std::ve
 // Each time through the loop, we compare the best transaction in
 // mapModifiedTxs with the next transaction in the mempool to decide what
 // transaction package to work on next.
-void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpdated)
+void BlockAssembler::addPackageTxs(const CTxMemPool& mempool, int& nPackagesSelected, int& nDescendantsUpdated)
 {
-    AssertLockHeld(m_mempool.cs);
+    AssertLockHeld(mempool.cs);
 
     // mapModifiedTx will store sorted packages after they are modified
     // because some of their txs are already in the block
@@ -297,7 +300,7 @@ void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpda
     // Keep track of entries that failed inclusion, to avoid duplicate work
     CTxMemPool::setEntries failedTx;
 
-    CTxMemPool::indexed_transaction_set::index<ancestor_score>::type::iterator mi = m_mempool.mapTx.get<ancestor_score>().begin();
+    CTxMemPool::indexed_transaction_set::index<ancestor_score>::type::iterator mi = mempool.mapTx.get<ancestor_score>().begin();
     CTxMemPool::txiter iter;
 
     // Limit the number of attempts to add transactions to the block when it is
@@ -306,7 +309,7 @@ void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpda
     const int64_t MAX_CONSECUTIVE_FAILURES = 1000;
     int64_t nConsecutiveFailed = 0;
 
-    while (mi != m_mempool.mapTx.get<ancestor_score>().end() || !mapModifiedTx.empty()) {
+    while (mi != mempool.mapTx.get<ancestor_score>().end() || !mapModifiedTx.empty()) {
         // First try to find a new transaction in mapTx to evaluate.
         //
         // Skip entries in mapTx that are already in a block or are present
@@ -320,9 +323,9 @@ void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpda
         // cached size/sigops/fee values that are not actually correct.
         /** Return true if given transaction from mapTx has already been evaluated,
          * or if the transaction's cached data in mapTx is incorrect. */
-        if (mi != m_mempool.mapTx.get<ancestor_score>().end()) {
-            auto it = m_mempool.mapTx.project<0>(mi);
-            assert(it != m_mempool.mapTx.end());
+        if (mi != mempool.mapTx.get<ancestor_score>().end()) {
+            auto it = mempool.mapTx.project<0>(mi);
+            assert(it != mempool.mapTx.end());
             if (mapModifiedTx.count(it) || inBlock.count(it) || failedTx.count(it)) {
                 ++mi;
                 continue;
@@ -334,13 +337,13 @@ void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpda
         bool fUsingModified = false;
 
         modtxscoreiter modit = mapModifiedTx.get<ancestor_score>().begin();
-        if (mi == m_mempool.mapTx.get<ancestor_score>().end()) {
+        if (mi == mempool.mapTx.get<ancestor_score>().end()) {
             // We're out of entries in mapTx; use the entry from mapModifiedTx
             iter = modit->iter;
             fUsingModified = true;
         } else {
             // Try to compare the mapTx entry to the mapModifiedTx entry
-            iter = m_mempool.mapTx.project<0>(mi);
+            iter = mempool.mapTx.project<0>(mi);
             if (modit != mapModifiedTx.get<ancestor_score>().end() &&
                     CompareTxMemPoolEntryByAncestorFee()(*modit, CTxMemPoolModifiedEntry(iter))) {
                 // The best entry in mapModifiedTx has higher score
@@ -395,7 +398,7 @@ void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpda
         CTxMemPool::setEntries ancestors;
         uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
         std::string dummy;
-        m_mempool.CalculateMemPoolAncestors(*iter, ancestors, nNoLimit, nNoLimit, nNoLimit, nNoLimit, dummy, false);
+        mempool.CalculateMemPoolAncestors(*iter, ancestors, nNoLimit, nNoLimit, nNoLimit, nNoLimit, dummy, false);
 
         onlyUnconfirmed(ancestors);
         ancestors.insert(iter);
@@ -425,7 +428,7 @@ void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpda
         ++nPackagesSelected;
 
         // Update transactions that depend on each of these
-        nDescendantsUpdated += UpdatePackagesForAdded(m_mempool, ancestors, mapModifiedTx);
+        nDescendantsUpdated += UpdatePackagesForAdded(mempool, ancestors, mapModifiedTx);
     }
 }
 } // namespace node