From bc7900f33db3d01fb93dfee7981c01ea495cd42e Mon Sep 17 00:00:00 2001
From: TheCharlatan <seb.kung@gmail.com>
Date: Fri, 13 Sep 2024 10:22:00 +0200
Subject: [PATCH] kernel: Move background load thread to node context

The thread handle is never used by the ChainstateManager, so move it out
and into the node context. Users of the kernel library now no longer
have to manually join the thread when destructing the ChainstateManager.
---
 src/bitcoin-chainstate.cpp | 2 --
 src/init.cpp               | 4 ++--
 src/node/context.h         | 2 ++
 src/validation.h           | 2 --
 4 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/bitcoin-chainstate.cpp b/src/bitcoin-chainstate.cpp
index ebe013b638b8d..9cbafa233dde3 100644
--- a/src/bitcoin-chainstate.cpp
+++ b/src/bitcoin-chainstate.cpp
@@ -283,8 +283,6 @@ int main(int argc, char* argv[])
 epilogue:
     // Without this precise shutdown sequence, there will be a lot of nullptr
     // dereferencing and UB.
-    if (chainman.m_thread_load.joinable()) chainman.m_thread_load.join();
-
     validation_signals.FlushBackgroundCallbacks();
     {
         LOCK(cs_main);
diff --git a/src/init.cpp b/src/init.cpp
index f67835d7da591..da3d99b6bf25d 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -298,7 +298,7 @@ void Shutdown(NodeContext& node)
 
     StopTorControl();
 
-    if (node.chainman && node.chainman->m_thread_load.joinable()) node.chainman->m_thread_load.join();
+    if (node.background_init_thread.joinable()) node.background_init_thread.join();
     // After everything has been shut down, but before things get flushed, stop the
     // the scheduler. After this point, SyncWithValidationInterfaceQueue() should not be called anymore
     // as this would prevent the shutdown from completing.
@@ -1789,7 +1789,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         vImportFiles.push_back(fs::PathFromString(strFile));
     }
 
-    chainman.m_thread_load = std::thread(&util::TraceThread, "initload", [=, &chainman, &args, &node] {
+    node.background_init_thread = std::thread(&util::TraceThread, "initload", [=, &chainman, &args, &node] {
         ScheduleBatchPriority();
         // Import blocks
         ImportBlocks(chainman, vImportFiles);
diff --git a/src/node/context.h b/src/node/context.h
index a664fad80be87..398089ff3c0eb 100644
--- a/src/node/context.h
+++ b/src/node/context.h
@@ -9,6 +9,7 @@
 #include <cstdlib>
 #include <functional>
 #include <memory>
+#include <thread>
 #include <vector>
 
 class ArgsManager;
@@ -86,6 +87,7 @@ struct NodeContext {
     std::atomic<int> exit_status{EXIT_SUCCESS};
     //! Manages all the node warnings
     std::unique_ptr<node::Warnings> warnings;
+    std::thread background_init_thread;
 
     //! Declare default constructor and destructor that are not inline, so code
     //! instantiating the NodeContext struct doesn't need to #include class
diff --git a/src/validation.h b/src/validation.h
index 059ae52bdf4ca..6bc8a14de95a6 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -42,7 +42,6 @@
 #include <span>
 #include <stdint.h>
 #include <string>
-#include <thread>
 #include <type_traits>
 #include <utility>
 #include <vector>
@@ -1008,7 +1007,6 @@ class ChainstateManager
 
     const util::SignalInterrupt& m_interrupt;
     const Options m_options;
-    std::thread m_thread_load;
     //! A single BlockManager instance is shared across each constructed
     //! chainstate to avoid duplicating block metadata.
     node::BlockManager m_blockman;