Line data    Source code

       1             : // Copyright 2015 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #include "src/address-map.h"
       6             : #include "src/heap/heap.h"
       7             : #include "src/isolate.h"
       8             : #include "src/objects-inl.h"
       9             : #include "src/objects/heap-object-inl.h"
      10             : 
      11             : namespace v8 {
      12             : namespace internal {
      13             : 
      14      669012 : RootIndexMap::RootIndexMap(Isolate* isolate) {
      15      669012 :   map_ = isolate->root_index_map();
      16      669012 :   if (map_ != nullptr) return;
      17       34451 :   map_ = new HeapObjectToIndexHashMap();
      18             :   for (RootIndex root_index = RootIndex::kFirstStrongOrReadOnlyRoot;
      19    10171744 :        root_index <= RootIndex::kLastStrongOrReadOnlyRoot; ++root_index) {
      20             :     Object root = isolate->root(root_index);
      21    10154530 :     if (!root->IsHeapObject()) continue;
      22             :     // Omit root entries that can be written after initialization. They must
      23             :     // not be referenced through the root list in the snapshot.
      24             :     // Since we map the raw address of an root item to its root list index, the
      25             :     // raw address must be constant, i.e. the object must be immovable.
      26    10154544 :     if (RootsTable::IsImmortalImmovable(root_index)) {
      27             :       HeapObject heap_object = HeapObject::cast(root);
      28     9827472 :       Maybe<uint32_t> maybe_index = map_->Get(heap_object);
      29     9827493 :       uint32_t index = static_cast<uint32_t>(root_index);
      30     9827493 :       if (maybe_index.IsJust()) {
      31             :         // Some are initialized to a previous value in the root list.
      32             :         DCHECK_LT(maybe_index.FromJust(), index);
      33             :       } else {
      34     9827414 :         map_->Set(heap_object, index);
      35             :       }
      36             :     }
      37             :   }
      38       17214 :   isolate->set_root_index_map(map_);
      39             : }
      40             : 
      41   242656783 : bool RootIndexMap::Lookup(Address obj, RootIndex* out_root_list) const {
      42   242656783 :   return Lookup(HeapObject::cast(Object(obj)), out_root_list);
      43             : }
      44             : 
      45             : }  // namespace internal
      46      122004 : }  // namespace v8