Merge #19556: Remove mempool global

fafb381af8279b2d2ca768df0bf68d7eb036a2f9 Remove mempool global (MarcoFalke)
fa0359c5b30730744aa8a7cd9ffab79ded91041f Remove mempool global from p2p (MarcoFalke)
eeee1104d78eb59a582ee1709ff4ac2c33ee1190 Remove mempool global from init (MarcoFalke)

Pull request description:

  This refactor unlocks some nice potential features, such as, but not limited to:
  * Removing the fee estimates global (would avoid slightly fragile workarounds such as #18766)
  * Making the mempool optional for a "blocksonly" operation mode

  Even absent those features, the new code without the global should be easier to maintain, read and write tests for.

ACKs for top commit:
  jnewbery:
    utACK fafb381af8279b2d2ca768df0bf68d7eb036a2f9
  hebasto:
    ACK fafb381af8279b2d2ca768df0bf68d7eb036a2f9, I have reviewed the code and it looks OK, I agree it can be merged.
  darosior:
    ACK fafb381af8279b2d2ca768df0bf68d7eb036a2f9

Tree-SHA512: a2e696dc377e2e81eaf9c389e6d13dde4a48d81f3538df88f4da502d3012dd61078495140ab5a5854f360a06249fe0e1f6a094c4e006d8b5cc2552a946becf26

1 files changed, 8 insertions, 1 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index 58af8744d..bdbae6651 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -148,7 +148,6 @@ arith_uint256 nMinimumChainWork;
 CFeeRate minRelayTxFee = CFeeRate(DEFAULT_MIN_RELAY_TX_FEE);
 
 CBlockPolicyEstimator feeEstimator;
-CTxMemPool mempool(&feeEstimator);
 
 // Internal stuff
 namespace {
@@ -4227,6 +4226,14 @@ bool static LoadBlockIndexDB(ChainstateManager& chainman, const CChainParams& ch
     return true;
 }
 
+void CChainState::LoadMempool(const ArgsManager& args)
+{
+    if (args.GetArg("-persistmempool", DEFAULT_PERSIST_MEMPOOL)) {
+        ::LoadMempool(m_mempool);
+    }
+    m_mempool.SetIsLoaded(!ShutdownRequested());
+}
+
 bool CChainState::LoadChainTip(const CChainParams& chainparams)
 {
     AssertLockHeld(cs_main);