[codegen] Create PersistentHandles instead of DeferredHandles

As a note, we are not yet passing this to the background so we only
have canonical persistent handles on the main thread.

Bug: v8:7790
Change-Id: I15b264cfacc2d5524a3d13f62574a3576bb7e1a4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2330017
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69176}

src/codegen/compiler.cc

@@ -173,17 +173,19 @@ class CompilerTracer : public AllStatic {
 }  // namespace
 
 // A wrapper around a OptimizedCompilationInfo that detaches the Handles from
-// the underlying DeferredHandleScope and stores them in info_ on
+// the underlying PersistentHandlesScope and stores them in info_ on
 // destruction.
 class CompilationHandleScope final {
  public:
   explicit CompilationHandleScope(Isolate* isolate,
                                   OptimizedCompilationInfo* info)
-      : deferred_(isolate), info_(info) {}
-  ~CompilationHandleScope() { info_->set_deferred_handles(deferred_.Detach()); }
+      : persistent_(isolate), info_(info) {}
+  ~CompilationHandleScope() {
+    info_->set_persistent_handles(persistent_.Detach());
+  }
 
  private:
-  DeferredHandleScope deferred_;
+  PersistentHandlesScope persistent_;
   OptimizedCompilationInfo* info_;
 };
 

src/codegen/optimized-compilation-info.cc

@@ -136,10 +136,10 @@ OptimizedCompilationInfo::~OptimizedCompilationInfo() {
   }
 }
 
-void OptimizedCompilationInfo::set_deferred_handles(
-    std::unique_ptr<DeferredHandles> deferred_handles) {
-  DCHECK_NULL(deferred_handles_);
-  deferred_handles_ = std::move(deferred_handles);
+void OptimizedCompilationInfo::set_persistent_handles(
+    std::unique_ptr<PersistentHandles> persistent_handles) {
+  DCHECK_NULL(persistent_handles_);
+  persistent_handles_ = std::move(persistent_handles);
 }
 
 void OptimizedCompilationInfo::ReopenHandlesInNewHandleScope(Isolate* isolate) {

src/codegen/optimized-compilation-info.h

@@ -159,7 +159,8 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
     osr_frame_ = osr_frame;
   }
 
-  void set_deferred_handles(std::unique_ptr<DeferredHandles> deferred_handles);
+  void set_persistent_handles(
+      std::unique_ptr<PersistentHandles> persistent_handles);
 
   void ReopenHandlesInNewHandleScope(Isolate* isolate);
 
@@ -263,7 +264,7 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
   // OptimizedCompilationInfo allocates.
   Zone* const zone_;
 
-  std::unique_ptr<DeferredHandles> deferred_handles_;
+  std::unique_ptr<PersistentHandles> persistent_handles_;
 
   BailoutReason bailout_reason_ = BailoutReason::kNoReason;
 

src/execution/isolate.cc

@@ -2958,7 +2958,7 @@ Isolate::Isolate(std::unique_ptr<i::IsolateAllocator> isolate_allocator)
       builtins_(this),
       rail_mode_(PERFORMANCE_ANIMATION),
       code_event_dispatcher_(new CodeEventDispatcher()),
-      persistent_handles_list_(new PersistentHandlesList(this)),
+      persistent_handles_list_(new PersistentHandlesList()),
       jitless_(FLAG_jitless),
 #if V8_SFI_HAS_UNIQUE_ID
       next_unique_sfi_id_(0),

src/handles/persistent-handles.cc

@@ -121,12 +121,8 @@ void PersistentHandlesList::Remove(PersistentHandles* persistent_handles) {
     persistent_handles_head_ = persistent_handles->next_;
 }
 
-void PersistentHandlesList::Iterate(RootVisitor* visitor) {
-#if DEBUG
-  DCHECK(isolate_->heap()->safepoint()->IsActive());
-#else
-  USE(isolate_);
-#endif
+void PersistentHandlesList::Iterate(RootVisitor* visitor, Isolate* isolate) {
+  DCHECK_IMPLIES(FLAG_local_heaps, isolate->heap()->safepoint()->IsActive());
   base::MutexGuard guard(&persistent_handles_mutex_);
   for (PersistentHandles* current = persistent_handles_head_; current;
        current = current->next_) {

src/handles/persistent-handles.h

@@ -86,20 +86,16 @@ class PersistentHandles {
 
 class PersistentHandlesList {
  public:
-  explicit PersistentHandlesList(Isolate* isolate)
-      : isolate_(isolate), persistent_handles_head_(nullptr) {}
+  PersistentHandlesList() : persistent_handles_head_(nullptr) {}
 
-  // Iteration is only safe during a safepoint
-  void Iterate(RootVisitor* visitor);
+  void Iterate(RootVisitor* visitor, Isolate* isolate);
 
  private:
   void Add(PersistentHandles* persistent_handles);
   void Remove(PersistentHandles* persistent_handles);
 
-  Isolate* isolate_;
-
   base::Mutex persistent_handles_mutex_;
-  PersistentHandles* persistent_handles_head_ = nullptr;
+  PersistentHandles* persistent_handles_head_;
 
   friend class PersistentHandles;
 };

src/heap/heap.cc

@@ -4588,10 +4588,13 @@ void Heap::IterateRoots(RootVisitor* v, base::EnumSet<SkipRoot> options) {
     if (FLAG_local_heaps) {
       safepoint_->Iterate(&left_trim_visitor);
       safepoint_->Iterate(v);
-      isolate_->persistent_handles_list()->Iterate(&left_trim_visitor);
-      isolate_->persistent_handles_list()->Iterate(v);
     }
 
+    isolate_->persistent_handles_list()->Iterate(&left_trim_visitor, isolate_);
+    isolate_->persistent_handles_list()->Iterate(v, isolate_);
+
+    // TODO(solanes): Delete these two iterations once we delete all
+    // DeferredHandle uses.
     isolate_->IterateDeferredHandles(&left_trim_visitor);
     isolate_->IterateDeferredHandles(v);
     v->Synchronize(VisitorSynchronization::kHandleScope);