From 2924d8833943e24d9ef673dd52b847ee58a4bcac Mon Sep 17 00:00:00 2001
From: Roman Krasiuk <rokrassyuk@gmail.com>
Date: Thu, 19 Sep 2024 11:52:10 +0200
Subject: [PATCH] chore(engine): disable parallel state root (#11024)

---
 crates/engine/tree/src/tree/mod.rs | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/crates/engine/tree/src/tree/mod.rs b/crates/engine/tree/src/tree/mod.rs
index 025575eaa064..922ab89f325f 100644
--- a/crates/engine/tree/src/tree/mod.rs
+++ b/crates/engine/tree/src/tree/mod.rs
@@ -491,10 +491,12 @@ pub struct EngineApiTreeHandler<P, E, T: EngineTypes> {
     payload_builder: PayloadBuilderHandle<T>,
     /// Configuration settings.
     config: TreeConfig,
-    /// Metrics for the engine api.
-    metrics: EngineApiMetrics,
     /// An invalid block hook.
     invalid_block_hook: Box<dyn InvalidBlockHook>,
+    /// Temporary flag to disable parallel state root.
+    parallel_state_root_enabled: bool,
+    /// Metrics for the engine api.
+    metrics: EngineApiMetrics,
 }
 
 impl<P: Debug, E: Debug, T: EngineTypes + Debug> std::fmt::Debug for EngineApiTreeHandler<P, E, T> {
@@ -512,8 +514,9 @@ impl<P: Debug, E: Debug, T: EngineTypes + Debug> std::fmt::Debug for EngineApiTr
             .field("canonical_in_memory_state", &self.canonical_in_memory_state)
             .field("payload_builder", &self.payload_builder)
             .field("config", &self.config)
-            .field("metrics", &self.metrics)
             .field("invalid_block_hook", &format!("{:p}", self.invalid_block_hook))
+            .field("parallel_state_root_enabled", &self.parallel_state_root_enabled)
+            .field("metrics", &self.metrics)
             .finish()
     }
 }
@@ -555,9 +558,10 @@ where
             canonical_in_memory_state,
             payload_builder,
             config,
-            metrics: Default::default(),
             incoming_tx,
             invalid_block_hook: Box::new(NoopInvalidBlockHook),
+            parallel_state_root_enabled: false,
+            metrics: Default::default(),
         }
     }
 
@@ -2178,7 +2182,7 @@ where
         // we are computing in parallel, because we initialize a different database transaction
         // per thread and it might end up with a different view of the database.
         let persistence_in_progress = self.persistence_state.in_progress();
-        if !persistence_in_progress {
+        if self.parallel_state_root_enabled && !persistence_in_progress {
             state_root_result = match self
                 .compute_state_root_in_parallel(block.parent_hash, &hashed_state)
             {