[heap] Remove shared heap barrier for code

The barrier is currently not thread-safe but may be executed via
concurrent Sparkplug compilation. Remove the actual barrier code as
the remembered set is anyways not used yet.

Bug: v8:13018, chromium:1336850, chromium:1333414
Change-Id: I9287516d559cc3b10d170fa0fda36b26ca487a15
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3734809
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81438}

src/heap/heap-write-barrier-inl.h

@@ -32,9 +32,6 @@ V8_EXPORT_PRIVATE void Heap_WriteBarrierForCodeSlow(Code host);
 V8_EXPORT_PRIVATE void Heap_GenerationalBarrierForCodeSlow(Code host,
                                                            RelocInfo* rinfo,
                                                            HeapObject object);
-V8_EXPORT_PRIVATE void Heap_SharedHeapBarrierForCodeSlow(Code host,
-                                                         RelocInfo* rinfo,
-                                                         HeapObject object);
 
 V8_EXPORT_PRIVATE void Heap_GenerationalEphemeronKeyBarrierSlow(
     Heap* heap, HeapObject table, Address slot);
@@ -210,10 +207,13 @@ inline void GenerationalBarrierForCode(Code host, RelocInfo* rinfo,
 inline void SharedHeapBarrierForCode(Code host, RelocInfo* rinfo,
                                      HeapObject object) {
   if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL) return;
+
   heap_internals::MemoryChunk* object_chunk =
       heap_internals::MemoryChunk::FromHeapObject(object);
   if (!object_chunk->InSharedHeap()) return;
-  Heap_SharedHeapBarrierForCodeSlow(host, rinfo, object);
+
+  // TODO(v8:11708): Implement a thread-safe shared heap barrier. The barrier is
+  // executed from the main thread as well from concurrent compilation threads.
 }
 
 inline WriteBarrierMode GetWriteBarrierModeForObject(

src/heap/heap.cc

@@ -152,11 +152,6 @@ void Heap_GenerationalBarrierForCodeSlow(Code host, RelocInfo* rinfo,
   Heap::GenerationalBarrierForCodeSlow(host, rinfo, object);
 }
 
-void Heap_SharedHeapBarrierForCodeSlow(Code host, RelocInfo* rinfo,
-                                       HeapObject object) {
-  Heap::SharedHeapBarrierForCodeSlow(host, rinfo, object);
-}
-
 void Heap::SetConstructStubCreateDeoptPCOffset(int pc_offset) {
   DCHECK_EQ(Smi::zero(), construct_stub_create_deopt_pc_offset());
   set_construct_stub_create_deopt_pc_offset(Smi::FromInt(pc_offset));
@@ -7456,16 +7451,6 @@ void Heap::GenerationalBarrierForCodeSlow(Code host, RelocInfo* rinfo,
                                          info.offset);
 }
 
-void Heap::SharedHeapBarrierForCodeSlow(Code host, RelocInfo* rinfo,
-                                        HeapObject object) {
-  DCHECK(object.InSharedHeap());
-  const MarkCompactCollector::RecordRelocSlotInfo info =
-      MarkCompactCollector::ProcessRelocInfo(host, rinfo, object);
-
-  RememberedSet<OLD_TO_SHARED>::InsertTyped(info.memory_chunk, info.slot_type,
-                                            info.offset);
-}
-
 bool Heap::PageFlagsAreConsistent(HeapObject object) {
   if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL) {
     return true;

src/heap/heap.h

@@ -513,9 +513,6 @@ class Heap {
       Address raw_object, Address address, Isolate* isolate);
   V8_EXPORT_PRIVATE static void GenerationalBarrierForCodeSlow(
       Code host, RelocInfo* rinfo, HeapObject value);
-  V8_EXPORT_PRIVATE static void SharedHeapBarrierForCodeSlow(Code host,
-                                                             RelocInfo* rinfo,
-                                                             HeapObject value);
   V8_EXPORT_PRIVATE static bool PageFlagsAreConsistent(HeapObject object);
 
   // Notifies the heap that is ok to start marking or other activities that