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, 15 insertions, 15 deletions

diff --git a/src/init.cpp b/src/init.cpp
index bb93f5c79..633dd8cef 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -187,7 +187,7 @@ void Shutdown(NodeContext& node)
     /// Be sure that anything that writes files or flushes caches only does this if the respective
     /// module was initialized.
     util::ThreadRename("shutoff");
-    mempool.AddTransactionsUpdated(1);
+    if (node.mempool) node.mempool->AddTransactionsUpdated(1);
 
     StopHTTPRPC();
     StopREST();
@@ -231,8 +231,8 @@ void Shutdown(NodeContext& node)
     node.connman.reset();
     node.banman.reset();
 
-    if (::mempool.IsLoaded() && node.args->GetArg("-persistmempool", DEFAULT_PERSIST_MEMPOOL)) {
-        DumpMempool(::mempool);
+    if (node.mempool && node.mempool->IsLoaded() && node.args->GetArg("-persistmempool", DEFAULT_PERSIST_MEMPOOL)) {
+        DumpMempool(*node.mempool);
     }
 
     if (fFeeEstimatesInitialized)
@@ -302,7 +302,7 @@ void Shutdown(NodeContext& node)
     GetMainSignals().UnregisterBackgroundSignalScheduler();
     globalVerifyHandle.reset();
     ECC_Stop();
-    node.mempool = nullptr;
+    node.mempool.reset();
     node.chainman = nullptr;
     node.scheduler.reset();
 
@@ -738,10 +738,7 @@ static void ThreadImport(ChainstateManager& chainman, std::vector<fs::path> vImp
         return;
     }
     } // End scope of CImportingNow
-    if (args.GetArg("-persistmempool", DEFAULT_PERSIST_MEMPOOL)) {
-        LoadMempool(::mempool);
-    }
-    ::mempool.SetIsLoaded(!ShutdownRequested());
+    chainman.ActiveChainstate().LoadMempool(args);
 }
 
 /** Sanity checks
@@ -1054,11 +1051,6 @@ bool AppInitParameterInteraction(const ArgsManager& args)
         }
     }
 
-    // Checkmempool and checkblockindex default to true in regtest mode
-    int ratio = std::min<int>(std::max<int>(args.GetArg("-checkmempool", chainparams.DefaultConsistencyChecks() ? 1 : 0), 0), 1000000);
-    if (ratio != 0) {
-        mempool.setSanityCheck(1.0 / ratio);
-    }
     fCheckBlockIndex = args.GetBoolArg("-checkblockindex", chainparams.DefaultConsistencyChecks());
     fCheckpointsEnabled = args.GetBoolArg("-checkpoints", DEFAULT_CHECKPOINTS_ENABLED);
 
@@ -1368,10 +1360,18 @@ bool AppInitMain(const util::Ref& context, NodeContext& node, interfaces::BlockA
     node.banman = MakeUnique<BanMan>(GetDataDir() / "banlist.dat", &uiInterface, args.GetArg("-bantime", DEFAULT_MISBEHAVING_BANTIME));
     assert(!node.connman);
     node.connman = MakeUnique<CConnman>(GetRand(std::numeric_limits<uint64_t>::max()), GetRand(std::numeric_limits<uint64_t>::max()), args.GetBoolArg("-networkactive", true));
+
     // Make mempool generally available in the node context. For example the connection manager, wallet, or RPC threads,
     // which are all started after this, may use it from the node context.
     assert(!node.mempool);
-    node.mempool = &::mempool;
+    node.mempool = MakeUnique<CTxMemPool>(&::feeEstimator);
+    if (node.mempool) {
+        int ratio = std::min<int>(std::max<int>(args.GetArg("-checkmempool", chainparams.DefaultConsistencyChecks() ? 1 : 0), 0), 1000000);
+        if (ratio != 0) {
+            node.mempool->setSanityCheck(1.0 / ratio);
+        }
+    }
+
     assert(!node.chainman);
     node.chainman = &g_chainman;
     ChainstateManager& chainman = *Assert(node.chainman);
@@ -1559,7 +1559,7 @@ bool AppInitMain(const util::Ref& context, NodeContext& node, interfaces::BlockA
                 chainman.m_total_coinstip_cache = nCoinCacheUsage;
                 chainman.m_total_coinsdb_cache = nCoinDBCache;
 
-                UnloadBlockIndex(node.mempool);
+                UnloadBlockIndex(node.mempool.get());
 
                 // new CBlockTreeDB tries to delete the existing file, which
                 // fails if it's still open from the previous loop. Close it first: