mempool: Pass in -maxmempool instead of referencing gArgs

- Store the mempool size limit (-maxmempool) in CTxMemPool as a member.

- Remove the requirement to explicitly specify a mempool size limit for
  CTxMemPool::GetMinFee(...) and LimitMempoolSize(...), just use the
  stored mempool size limit where possible.

- Remove all now-unnecessary instances of:
    gArgs.GetIntArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE_MB) * 1000000

The code change in CChainState::GetCoinsCacheSizeState() is correct
since the coinscache should not repurpose "extra" mempool memory
headroom for itself if the mempool doesn't even exist.

1 files changed, 5 insertions, 7 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index 4252914353..a14f82106f 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -255,7 +255,7 @@ bool CheckSequenceLocksAtTip(CBlockIndex* tip,
 // Returns the script flags which should be checked for a given block
 static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman);
 
-static void LimitMempoolSize(CTxMemPool& pool, CCoinsViewCache& coins_cache, size_t limit, std::chrono::seconds age)
+static void LimitMempoolSize(CTxMemPool& pool, CCoinsViewCache& coins_cache, std::chrono::seconds age)
     EXCLUSIVE_LOCKS_REQUIRED(::cs_main, pool.cs)
 {
     AssertLockHeld(::cs_main);
@@ -266,7 +266,7 @@ static void LimitMempoolSize(CTxMemPool& pool, CCoinsViewCache& coins_cache, siz
     }
 
     std::vector<COutPoint> vNoSpendsRemaining;
-    pool.TrimToSize(limit, &vNoSpendsRemaining);
+    pool.TrimToSize(pool.m_max_size_bytes, &vNoSpendsRemaining);
     for (const COutPoint& removed : vNoSpendsRemaining)
         coins_cache.Uncache(removed);
 }
@@ -377,7 +377,6 @@ void CChainState::MaybeUpdateMempoolForReorg(
     LimitMempoolSize(
         *m_mempool,
         this->CoinsTip(),
-        gArgs.GetIntArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE_MB) * 1000000,
         std::chrono::hours{gArgs.GetIntArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY)});
 }
 
@@ -644,7 +643,7 @@ private:
     {
         AssertLockHeld(::cs_main);
         AssertLockHeld(m_pool.cs);
-        CAmount mempoolRejectFee = m_pool.GetMinFee(gArgs.GetIntArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE_MB) * 1000000).GetFee(package_size);
+        CAmount mempoolRejectFee = m_pool.GetMinFee().GetFee(package_size);
         if (mempoolRejectFee > 0 && package_fee < mempoolRejectFee) {
             return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool min fee not met", strprintf("%d < %d", package_fee, mempoolRejectFee));
         }
@@ -1082,7 +1081,7 @@ bool MemPoolAccept::Finalize(const ATMPArgs& args, Workspace& ws)
     // in the package. LimitMempoolSize() should be called at the very end to make sure the mempool
     // is still within limits and package submission happens atomically.
     if (!args.m_package_submission && !bypass_limits) {
-        LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip(), gArgs.GetIntArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE_MB) * 1000000, std::chrono::hours{gArgs.GetIntArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY)});
+        LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip(), std::chrono::hours{gArgs.GetIntArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY)});
         if (!m_pool.exists(GenTxid::Txid(hash)))
             return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "mempool full");
     }
@@ -1148,7 +1147,6 @@ bool MemPoolAccept::SubmitPackage(const ATMPArgs& args, std::vector<Workspace>&
     // It may or may not be the case that all the transactions made it into the mempool. Regardless,
     // make sure we haven't exceeded max mempool size.
     LimitMempoolSize(m_pool, m_active_chainstate.CoinsTip(),
-                     gArgs.GetIntArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE_MB) * 1000000,
                      std::chrono::hours{gArgs.GetIntArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY)});
 
     // Find the wtxids of the transactions that made it into the mempool. Allow partial submission,
@@ -2292,7 +2290,7 @@ CoinsCacheSizeState CChainState::GetCoinsCacheSizeState()
     AssertLockHeld(::cs_main);
     return this->GetCoinsCacheSizeState(
         m_coinstip_cache_size_bytes,
-        gArgs.GetIntArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE_MB) * 1000000);
+        m_mempool ? m_mempool->m_max_size_bytes : 0);
 }
 
 CoinsCacheSizeState CChainState::GetCoinsCacheSizeState(