From d586af007403c678185e2dbcff23f0f3017341f6 Mon Sep 17 00:00:00 2001
From: Robert O'Callahan <rocallahan@google.com>
Date: Tue, 7 Apr 2026 23:21:17 +0000
Subject: [PATCH] Fix data race in ParallelDispatchThreadPool destruction

---
 kernel/threading.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/threading.h b/kernel/threading.h
index a041def2c..1aded4931 100644
--- a/kernel/threading.h
+++ b/kernel/threading.h
@@ -232,7 +232,6 @@ private:
 	}
 	void run_worker(int thread_num);
 
-	std::unique_ptr<ThreadPool> thread_pool;
 	std::function<void(const RunCtx &)> *current_work = nullptr;
 	// Keeps a correct count even when threads are exiting.
 	int num_worker_threads_;
@@ -291,6 +290,10 @@ private:
 		done_workers.store(0, std::memory_order_relaxed);
 	}
 #endif
+	// Ensure `thread_pool` is destroyed before any other members,
+	// forcing all threads to be joined before destroying the
+	// members (e.g. workers_to_main_signal_mutex) they might be using.
+	std::unique_ptr<ThreadPool> thread_pool;
 };
 
 template <class T>