Cache WeakCell for optimized code.

src/objects.cc

 // Copyright 2013 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 <sstream>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/allocation-site-scopes.h"
@@ skipping 11015 matching lines @@
 #define CASE(name) case name: return #name;
     CODE_KIND_LIST(CASE)
 #undef CASE
     case NUMBER_OF_KINDS: break;
   }
   UNREACHABLE();
   return NULL;
 }
 
 
+Handle<WeakCell> Code::WeakCellFor(Handle<Code> code) {
+  DCHECK(code->kind() == OPTIMIZED_FUNCTION);
+  WeakCell* raw_cell = code->CachedWeakCell();
+  if (raw_cell != NULL) return Handle<WeakCell>(raw_cell);

[Yang, 2015/01/26 14:55:23]

Suggestion: add an assertion that the cached code is indeed the code we expect.

[ulan, 2015/01/26 15:00:07]

Done. Added check in Code::CachedWeakCell

+  Handle<WeakCell> cell = code->GetIsolate()->factory()->NewWeakCell(code);
+  DeoptimizationInputData::cast(code->deoptimization_data())
+      ->SetWeakCellCache(*cell);
+  return cell;
+}
+
+
+WeakCell* Code::CachedWeakCell() {
+  DCHECK(kind() == OPTIMIZED_FUNCTION);
+  Object* weak_cell_cache =
+      DeoptimizationInputData::cast(deoptimization_data())->WeakCellCache();
+  if (weak_cell_cache->IsWeakCell()) return WeakCell::cast(weak_cell_cache);
+  return NULL;
+}
+
+
 #ifdef ENABLE_DISASSEMBLER
 
 void DeoptimizationInputData::DeoptimizationInputDataPrint(
     std::ostream& os) {  // NOLINT
   disasm::NameConverter converter;
   int deopt_count = DeoptCount();
   os << "Deoptimization Input Data (deopt points = " << deopt_count << ")\n";
   if (0 != deopt_count) {
     os << " index  ast id    argc     pc";
     if (FLAG_print_code_verbose) os << "  commands";
@@ skipping 5792 matching lines @@
   Handle<DependentCode> codes =
       DependentCode::Insert(handle(cell->dependent_code(), info->isolate()),
                             DependentCode::kPropertyCellChangedGroup,
                             info->object_wrapper());
   if (*codes != cell->dependent_code()) cell->set_dependent_code(*codes);
   info->dependencies(DependentCode::kPropertyCellChangedGroup)->Add(
       cell, info->zone());
 }
 
 } }  // namespace v8::internal