From c4fe5bf90c2d368c29714de63a90eca444fb3ece Mon Sep 17 00:00:00 2001
From: Aleksey Shipilev <shade@openjdk.org>
Date: Thu, 2 May 2024 08:26:09 +0000
Subject: [PATCH] 8331405: Shenandoah: Optimize ShenandoahLock with TTAS

Reviewed-by: zgu, ysr
---
 src/hotspot/share/gc/shenandoah/shenandoahLock.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/hotspot/share/gc/shenandoah/shenandoahLock.cpp b/src/hotspot/share/gc/shenandoah/shenandoahLock.cpp
index 39588d68bc8..349f5415cdc 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahLock.cpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahLock.cpp
@@ -54,7 +54,8 @@ template<typename BlockOp>
 void ShenandoahLock::contended_lock_internal(JavaThread* java_thread) {
   int ctr = 0;
   int yields = 0;
-  while (Atomic::cmpxchg(&_state, unlocked, locked) != unlocked) {
+  while (Atomic::load(&_state) == locked ||
+         Atomic::cmpxchg(&_state, unlocked, locked) != unlocked) {
     if ((++ctr & 0xFFF) == 0) {
       BlockOp block(java_thread);
       if (yields > 5) {