From 7834662ca35aeb202d177fde1044add611240ecd Mon Sep 17 00:00:00 2001
From: Thomas Schatzl <tschatzl@openjdk.org>
Date: Tue, 17 Sep 2024 08:11:22 +0000
Subject: [PATCH] 8340119: Remove oopDesc::size_might_change()

Reviewed-by: stefank, iwalulya
---
 src/hotspot/share/oops/oop.cpp        | 11 -----------
 src/hotspot/share/oops/oop.hpp        |  2 --
 src/hotspot/share/oops/oop.inline.hpp |  2 +-
 3 files changed, 1 insertion(+), 14 deletions(-)

diff --git a/src/hotspot/share/oops/oop.cpp b/src/hotspot/share/oops/oop.cpp
index fde91969ea5..38dee491a10 100644
--- a/src/hotspot/share/oops/oop.cpp
+++ b/src/hotspot/share/oops/oop.cpp
@@ -218,14 +218,3 @@ void oopDesc::release_float_field_put(int offset, jfloat value)       { Atomic::
 
 jdouble oopDesc::double_field_acquire(int offset) const               { return Atomic::load_acquire(field_addr<jdouble>(offset)); }
 void oopDesc::release_double_field_put(int offset, jdouble value)     { Atomic::release_store(field_addr<jdouble>(offset), value); }
-
-#ifdef ASSERT
-bool oopDesc::size_might_change() {
-  // UseParallelGC and UseG1GC can change the length field
-  // of an "old copy" of an object array in the young gen so it indicates
-  // the grey portion of an already copied array. This will cause the first
-  // disjunct below to fail if the two comparands are computed across such
-  // a concurrent change.
-  return Universe::heap()->is_stw_gc_active() && is_objArray() && is_forwarded() && (UseParallelGC || UseG1GC);
-}
-#endif
diff --git a/src/hotspot/share/oops/oop.hpp b/src/hotspot/share/oops/oop.hpp
index 2d827699b41..a330b3df529 100644
--- a/src/hotspot/share/oops/oop.hpp
+++ b/src/hotspot/share/oops/oop.hpp
@@ -319,8 +319,6 @@ class oopDesc {
 
   // for error reporting
   static void* load_oop_raw(oop obj, int offset);
-
-  DEBUG_ONLY(bool size_might_change();)
 };
 
 // An oopDesc is not initialized via a constructor.  Space is allocated in
diff --git a/src/hotspot/share/oops/oop.inline.hpp b/src/hotspot/share/oops/oop.inline.hpp
index ffcc9af24c3..95b99b215fa 100644
--- a/src/hotspot/share/oops/oop.inline.hpp
+++ b/src/hotspot/share/oops/oop.inline.hpp
@@ -190,7 +190,7 @@ size_t oopDesc::size_given_klass(Klass* klass)  {
       // skipping the intermediate round to HeapWordSize.
       s = align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize;
 
-      assert(s == klass->oop_size(this) || size_might_change(), "wrong array object size");
+      assert(s == klass->oop_size(this), "wrong array object size");
     } else {
       // Must be zero, so bite the bullet and take the virtual call.
       s = klass->oop_size(this);