[refactor] Cleanup BlockAssembler mempool usage

The `addPackageTxs` method of the `BlockAssembler` currently has access
to two mempool variables, as an argument and as a member. Clean this up
and clarify that they both are the same mempool instance by removing the
argument and instead only using the member variable in the method.

Co-Authored-By: Anthony Towns <[email protected]>
Co-authored-by: stickies-v <[email protected]>

Author: 3 people

src/node/miner.cpp

@@ -142,8 +142,7 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
     int nPackagesSelected = 0;
     int nDescendantsUpdated = 0;
     if (m_mempool) {
-        LOCK(m_mempool->cs);
-        addPackageTxs(*m_mempool, nPackagesSelected, nDescendantsUpdated);
+        addPackageTxs(nPackagesSelected, nDescendantsUpdated);
     }
 
     const auto time_1{SteadyClock::now()};
@@ -292,9 +291,10 @@ 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(const CTxMemPool& mempool, int& nPackagesSelected, int& nDescendantsUpdated)
+void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpdated)
 {
-    AssertLockHeld(mempool.cs);
+    const auto& mempool{*Assert(m_mempool)};
+    LOCK(mempool.cs);
 
     // mapModifiedTx will store sorted packages after they are modified
     // because some of their txs are already in the block

src/node/miner.h

@@ -187,8 +187,11 @@ class BlockAssembler
     // Methods for how to add transactions to a block.
     /** Add transactions based on feerate including unconfirmed ancestors
       * Increments nPackagesSelected / nDescendantsUpdated with corresponding
-      * statistics from the package selection (for logging statistics). */
-    void addPackageTxs(const CTxMemPool& mempool, int& nPackagesSelected, int& nDescendantsUpdated) EXCLUSIVE_LOCKS_REQUIRED(mempool.cs);
+      * statistics from the package selection (for logging statistics).
+      *
+      * @pre BlockAssembler::m_mempool must not be nullptr
+    */
+    void addPackageTxs(int& nPackagesSelected, int& nDescendantsUpdated) EXCLUSIVE_LOCKS_REQUIRED(!m_mempool->cs);
 
     // helper functions for addPackageTxs()
     /** Remove confirmed (inBlock) entries from given set */