🏄 [heap] Add page evacuation mode for new->old

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 6201 matching lines @@
 
 void KeyedLookupCache::Clear() {
   for (int index = 0; index < kLength; index++) keys_[index].map = NULL;
 }
 
 
 void DescriptorLookupCache::Clear() {
   for (int index = 0; index < kLength; index++) keys_[index].source = NULL;
 }
 
-
+template <Heap::ExternalStringTable::CleanupMode mode>
 void Heap::ExternalStringTable::CleanUp() {
   int last = 0;
   for (int i = 0; i < new_space_strings_.length(); ++i) {
     if (new_space_strings_[i] == heap_->the_hole_value()) {
       continue;
     }
     DCHECK(new_space_strings_[i]->IsExternalString());
     if (heap_->InNewSpace(new_space_strings_[i])) {
       new_space_strings_[last++] = new_space_strings_[i];
     } else {
       old_space_strings_.Add(new_space_strings_[i]);
     }
   }
   new_space_strings_.Rewind(last);
   new_space_strings_.Trim();
 
-  last = 0;
-  for (int i = 0; i < old_space_strings_.length(); ++i) {
-    if (old_space_strings_[i] == heap_->the_hole_value()) {
-      continue;
+  if (mode == CleanupMode::kFull) {
+    last = 0;
+    for (int i = 0; i < old_space_strings_.length(); ++i) {
+      if (old_space_strings_[i] == heap_->the_hole_value()) {
+        continue;
+      }
+      DCHECK(old_space_strings_[i]->IsExternalString());
+      DCHECK(!heap_->InNewSpace(old_space_strings_[i]));
+      old_space_strings_[last++] = old_space_strings_[i];
     }
-    DCHECK(old_space_strings_[i]->IsExternalString());
-    DCHECK(!heap_->InNewSpace(old_space_strings_[i]));
-    old_space_strings_[last++] = old_space_strings_[i];
+    old_space_strings_.Rewind(last);
+    old_space_strings_.Trim();
   }
-  old_space_strings_.Rewind(last);
-  old_space_strings_.Trim();
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) {
     Verify();
   }
 #endif
 }
 
+template void Heap::ExternalStringTable::CleanUp<
+    Heap::ExternalStringTable::CleanupMode::kFull>();
+template void Heap::ExternalStringTable::CleanUp<
+    Heap::ExternalStringTable::CleanupMode::kPromoteOnly>();
 
 void Heap::ExternalStringTable::TearDown() {
   for (int i = 0; i < new_space_strings_.length(); ++i) {
     heap_->FinalizeExternalString(ExternalString::cast(new_space_strings_[i]));
   }
   new_space_strings_.Free();
   for (int i = 0; i < old_space_strings_.length(); ++i) {
     heap_->FinalizeExternalString(ExternalString::cast(old_space_strings_[i]));
   }
   old_space_strings_.Free();
@@ skipping 169 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8