From 8d8c4d2ba9e928eec67f2814e39cec7dc3f078e1 Mon Sep 17 00:00:00 2001
From: gop <gameofpointers@proton.me>
Date: Mon, 11 Sep 2023 18:01:59 -0500
Subject: [PATCH] bugfix: Added lock around block writes to reduce memory
 pressure

Since downloader insert is an asynchronous process, writing thousands of
large blocks into the DB at the same time is very memory intensive.
Adding this lock will make sure that only one block is written at a time
and from the testing in the garden environment this has shown improved
performance in memory use while syncing
---
 core/core.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/core/core.go b/core/core.go
index 25a50c190c..cb3d5b3864 100644
--- a/core/core.go
+++ b/core/core.go
@@ -53,6 +53,8 @@ type Core struct {
 	appendQueue     *lru.Cache
 	processingCache *lru.Cache
 
+	writeBlockLock sync.RWMutex
+
 	quit chan struct{} // core quit channel
 }
 
@@ -352,6 +354,9 @@ func (c *Core) Stop() {
 
 // WriteBlock write the block to the bodydb database
 func (c *Core) WriteBlock(block *types.Block) {
+	c.writeBlockLock.Lock()
+	defer c.writeBlockLock.Unlock()
+
 	if c.sl.IsBlockHashABadHash(block.Hash()) {
 		return
 	}