Fix for 3303 MultithreadedParallelIsolates has a race condition.

src/assembler.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 706 matching lines @@
   rinfo_.pc_ = code->instruction_start();
   rinfo_.data_ = 0;
   // Relocation info is read backwards.
   pos_ = code->relocation_start() + code->relocation_size();
   end_ = code->relocation_start();
   done_ = false;
   mode_mask_ = mode_mask;
   last_id_ = 0;
   last_position_ = 0;
   byte* sequence = code->FindCodeAgeSequence();
-  if (sequence != NULL && !Code::IsYoungSequence(sequence)) {
+  // We get the isolate from the map, because at serialization time
+  // the code pointer has been cloned and isn't really in heap space.
+  Isolate* isolate = code->map()->GetIsolate();
+  if (sequence != NULL && !Code::IsYoungSequence(isolate, sequence)) {
     code_age_sequence_ = sequence;
   } else {
     code_age_sequence_ = NULL;
   }
   if (mode_mask_ == 0) pos_ = end_;
   next();
 }
 
 
 RelocIterator::RelocIterator(const CodeDesc& desc, int mode_mask) {
@@ skipping 111 matching lines @@
       PrintF(out, "  (deoptimization bailout %d)", id);
     }
   }
 
   PrintF(out, "\n");
 }
 #endif  // ENABLE_DISASSEMBLER
 
 
 #ifdef VERIFY_HEAP
-void RelocInfo::Verify() {
+void RelocInfo::Verify(Isolate* isolate) {
   switch (rmode_) {
     case EMBEDDED_OBJECT:
       Object::VerifyPointer(target_object());
       break;
     case CELL:
       Object::VerifyPointer(target_cell());
       break;
     case DEBUG_BREAK:
     case CONSTRUCT_CALL:
     case CODE_TARGET_WITH_ID:
     case CODE_TARGET: {
       // convert inline target address to code object
       Address addr = target_address();
       CHECK(addr != NULL);
       // Check that we can find the right code object.
       Code* code = Code::GetCodeFromTargetAddress(addr);
-      Object* found = code->GetIsolate()->FindCodeObject(addr);
+      Object* found = isolate->FindCodeObject(addr);
       CHECK(found->IsCode());
       CHECK(code->address() == HeapObject::cast(found)->address());
       break;
     }
     case RUNTIME_ENTRY:
     case JS_RETURN:
     case COMMENT:
     case POSITION:
     case STATEMENT_POSITION:
     case EXTERNAL_REFERENCE:
     case INTERNAL_REFERENCE:
     case CONST_POOL:
     case VENEER_POOL:
     case DEBUG_BREAK_SLOT:
     case NONE32:
     case NONE64:
       break;
     case NUMBER_OF_MODES:
       UNREACHABLE();
       break;
     case CODE_AGE_SEQUENCE:
-      ASSERT(Code::IsYoungSequence(pc_) || code_age_stub()->IsCode());
+      ASSERT(Code::IsYoungSequence(isolate, pc_) || code_age_stub()->IsCode());
       break;
   }
 }
 #endif  // VERIFY_HEAP
 
 
 // -----------------------------------------------------------------------------
 // Implementation of ExternalReference
 
 void ExternalReference::SetUp() {
@@ skipping 730 matching lines @@
       r2 = r2 - ad;
     }
     delta = ad - r2;
   } while (q1 < delta || (q1 == delta && r1 == 0));
   int32_t mul = static_cast<int32_t>(q2 + 1);
   multiplier_ = (d < 0) ? -mul : mul;
   shift_ = p - 32;
 }
 
 } }  // namespace v8::internal