- Ensure that HandleScope is initialized with a thread. (Remove

runtime/vm/debugger_api_impl.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_tools_api.h"
 
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"
 #include "vm/debugger.h"
 #include "vm/isolate.h"
 #include "vm/object_store.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
+// Facilitate quick access to the current zone once we have the curren thread.
+#define Z (T->zone())
+
+
 #define UNWRAP_AND_CHECK_PARAM(type, var, param)                               \
   type& var = type::Handle();                                                  \
   do {                                                                         \
     const Object& tmp = Object::Handle(Api::UnwrapHandle(param));              \
     if (tmp.IsNull()) {                                                        \
       return Api::NewError("%s expects argument '%s' to be non-null.",         \
                            CURRENT_FUNC, #param);                              \
     } else if (tmp.IsApiError()) {                                             \
       return param;                                                            \
     } else if (!tmp.Is##type()) {                                              \
@@ skipping 16 matching lines @@
 
 
 #define CHECK_NOT_NULL(param)                                                  \
   if (param == NULL) {                                                         \
     return Api::NewError("%s expects argument '%s' to be non-null.",           \
                          CURRENT_FUNC, #param);                                \
   }
 
 
 DART_EXPORT intptr_t Dart_CacheObject(Dart_Handle object_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  const Object& obj = Object::Handle(Api::UnwrapHandle(object_in));
+  DARTSCOPE(Thread::Current());
+  const Object& obj = Object::Handle(Z, Api::UnwrapHandle(object_in));
   if (obj.IsApiError()) {
     return -1;
   }
-  return isolate->debugger()->CacheObject(obj);
+  return I->debugger()->CacheObject(obj);
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetCachedObject(intptr_t obj_id) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  if (!isolate->debugger()->IsValidObjectId(obj_id)) {
+  DARTSCOPE(Thread::Current());
+  if (!I->debugger()->IsValidObjectId(obj_id)) {
     return Api::NewError("%s: object id %" Pd " is invalid",
                          CURRENT_FUNC, obj_id);
   }
-  return Api::NewHandle(isolate, isolate->debugger()->GetCachedObject(obj_id));
+  return Api::NewHandle(I, I->debugger()->GetCachedObject(obj_id));
 }
 
 
 DART_EXPORT Dart_Handle Dart_StackTraceLength(
                             Dart_StackTrace trace,
                             intptr_t* length) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   CHECK_NOT_NULL(length);
   CHECK_AND_CAST(DebuggerStackTrace, stack_trace, trace);
   *length = stack_trace->Length();
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetActivationFrame(
                             Dart_StackTrace trace,
                             int frame_index,
                             Dart_ActivationFrame* frame) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   CHECK_NOT_NULL(frame);
   CHECK_AND_CAST(DebuggerStackTrace, stack_trace, trace);
   if ((frame_index < 0) || (frame_index >= stack_trace->Length())) {
     return Api::NewError("argument 'frame_index' is out of range for %s",
                          CURRENT_FUNC);
   }
   *frame = reinterpret_cast<Dart_ActivationFrame>(
        stack_trace->FrameAt(frame_index));
   return Api::Success();
 }
@@ skipping 86 matching lines @@
 
 
 DART_EXPORT void Dart_SetIsolateEventHandler(Dart_IsolateEventHandler handler) {
   isolate_event_handler = handler;
   Debugger::SetEventHandler(DebuggerEventHandler);
 }
 
 
 DART_EXPORT Dart_Handle Dart_SetExceptionPauseInfo(
                             Dart_ExceptionPauseInfo pause_info) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  isolate->debugger()->SetExceptionPauseInfo(pause_info);
+  DARTSCOPE(Thread::Current());
+  I->debugger()->SetExceptionPauseInfo(pause_info);
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_ExceptionPauseInfo Dart_GetExceptionPauseInfo() {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  return isolate->debugger()->GetExceptionPauseInfo();
+  DARTSCOPE(Thread::Current());
+  return I->debugger()->GetExceptionPauseInfo();
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetStackTrace(Dart_StackTrace* trace) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   CHECK_NOT_NULL(trace);
   *trace = reinterpret_cast<Dart_StackTrace>(
-      isolate->debugger()->CurrentStackTrace());
+      I->debugger()->CurrentStackTrace());
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetStackTraceFromError(Dart_Handle handle,
                                                     Dart_StackTrace* trace) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   CHECK_NOT_NULL(trace);
-  const Object& obj = Object::Handle(isolate, Api::UnwrapHandle(handle));
+  const Object& obj = Object::Handle(Z, Api::UnwrapHandle(handle));
   if (obj.IsUnhandledException()) {
     const UnhandledException& error = UnhandledException::Cast(obj);
-    Stacktrace& dart_stacktrace = Stacktrace::Handle(isolate);
+    Stacktrace& dart_stacktrace = Stacktrace::Handle(Z);
     dart_stacktrace ^= error.stacktrace();
     if (dart_stacktrace.IsNull()) {
       *trace = NULL;
     } else {
       *trace = reinterpret_cast<Dart_StackTrace>(
-        isolate->debugger()->StackTraceFrom(dart_stacktrace));
+        I->debugger()->StackTraceFrom(dart_stacktrace));
     }
     return Api::Success();
   } else {
     return Api::NewError("Can only get stacktraces from error handles or "
                          "instances of Error.");
   }
 }
 
 
 DART_EXPORT Dart_Handle Dart_ActivationFrameInfo(
                             Dart_ActivationFrame activation_frame,
                             Dart_Handle* function_name,
                             Dart_Handle* script_url,
                             intptr_t* line_number,
                             intptr_t* column_number) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   CHECK_AND_CAST(ActivationFrame, frame, activation_frame);
   if (function_name != NULL) {
-    *function_name = Api::NewHandle(isolate, frame->QualifiedFunctionName());
+    *function_name = Api::NewHandle(I, frame->QualifiedFunctionName());
   }
   if (script_url != NULL) {
-    *script_url = Api::NewHandle(isolate, frame->SourceUrl());
+    *script_url = Api::NewHandle(I, frame->SourceUrl());
   }
   if (line_number != NULL) {
     *line_number = frame->LineNumber();
   }
   if (column_number != NULL) {
     *column_number = frame->ColumnNumber();
   }
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_ActivationFrameGetLocation(
                             Dart_ActivationFrame activation_frame,
                             Dart_Handle* function_name,
                             Dart_Handle* function,
                             Dart_CodeLocation* location) {
   // TODO(hausner): Implement a way to recognize when there
   // is no source code for the code in the frame.
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   CHECK_AND_CAST(ActivationFrame, frame, activation_frame);
   if (function_name != NULL) {
-    *function_name = Api::NewHandle(isolate, frame->QualifiedFunctionName());
+    *function_name = Api::NewHandle(I, frame->QualifiedFunctionName());
   }
   if (function != NULL) {
-    *function = Api::NewHandle(isolate, frame->function().raw());
+    *function = Api::NewHandle(I, frame->function().raw());
   }
 
   if (location != NULL) {
-    location->script_url = Api::NewHandle(isolate, frame->SourceUrl());
-    const Library& lib = Library::Handle(frame->Library());
+    location->script_url = Api::NewHandle(I, frame->SourceUrl());
+    const Library& lib = Library::Handle(Z, frame->Library());
     location->library_id = lib.index();
     location->token_pos = frame->TokenPos();
   }
   return Api::Success();
 }
 
 DART_EXPORT Dart_Handle Dart_ActivationFrameGetFramePointer(
                             Dart_ActivationFrame activation_frame,
                             uintptr_t* frame_pointer) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   CHECK_AND_CAST(ActivationFrame, frame, activation_frame);
 
   if (frame_pointer != NULL) {
     *frame_pointer = static_cast<uintptr_t>(frame->fp());
   }
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetFunctionOrigin(Dart_Handle function_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   UNWRAP_AND_CHECK_PARAM(Function, function, function_in);
 
-  const Class& cls = Class::Handle(function.origin());
+  const Class& cls = Class::Handle(Z, function.origin());
   if (!cls.IsTopLevel()) {
     return Dart_NewInteger(cls.id());
   }
   return Api::Null();
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetLocalVariables(
                             Dart_ActivationFrame activation_frame) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   CHECK_AND_CAST(ActivationFrame, frame, activation_frame);
-  return Api::NewHandle(isolate, frame->GetLocalVariables());
+  return Api::NewHandle(I, frame->GetLocalVariables());
 }
 
 
 DART_EXPORT Dart_Handle Dart_SetBreakpoint(
                             Dart_Handle script_url_in,
                             intptr_t line_number) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   UNWRAP_AND_CHECK_PARAM(String, script_url, script_url_in);
 
-  Debugger* debugger = isolate->debugger();
+  Debugger* debugger = I->debugger();
   Breakpoint* bpt =
       debugger->SetBreakpointAtLine(script_url, line_number);
   if (bpt == NULL) {
     return Api::NewError("%s: could not set breakpoint at line %" Pd " in '%s'",
                          CURRENT_FUNC, line_number, script_url.ToCString());
   }
   return Dart_NewInteger(bpt->id());
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetBreakpointURL(intptr_t bp_id) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  Debugger* debugger = isolate->debugger();
+  DARTSCOPE(Thread::Current());
+  Debugger* debugger = I->debugger();
 
   Breakpoint* bpt = debugger->GetBreakpointById(bp_id);
   if (bpt == NULL) {
     return Api::NewError("%s: breakpoint with id %" Pd " does not exist",
                            CURRENT_FUNC, bp_id);
   }
-  return Api::NewHandle(isolate, bpt->bpt_location()->url());
+  return Api::NewHandle(I, bpt->bpt_location()->url());
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetBreakpointLine(intptr_t bp_id) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  Debugger* debugger = isolate->debugger();
+  DARTSCOPE(Thread::Current());
+  Debugger* debugger = I->debugger();
 
   Breakpoint* bpt = debugger->GetBreakpointById(bp_id);
   if (bpt == NULL) {
     return Api::NewError("%s: breakpoint with id %" Pd " does not exist",
                          CURRENT_FUNC, bp_id);
   }
   return Dart_NewInteger(bpt->bpt_location()->LineNumber());
 }
 
 
 DART_EXPORT Dart_Handle Dart_SetBreakpointAtEntry(
                             Dart_Handle library_in,
                             Dart_Handle class_name_in,
                             Dart_Handle function_name_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   UNWRAP_AND_CHECK_PARAM(Library, library, library_in);
   UNWRAP_AND_CHECK_PARAM(String, class_name, class_name_in);
   UNWRAP_AND_CHECK_PARAM(String, function_name, function_name_in);
 
   // Ensure that the library is loaded.
   if (!library.Loaded()) {
     return Api::NewError(
         "%s expects library argument 'library_in' to be loaded.",
         CURRENT_FUNC);
   }
 
   // Resolve the breakpoint target function.
-  Debugger* debugger = isolate->debugger();
+  Debugger* debugger = I->debugger();
   const Function& bp_target = Function::Handle(
       debugger->ResolveFunction(library, class_name, function_name));
   if (bp_target.IsNull()) {
     const bool toplevel = class_name.Length() == 0;
     return Api::NewError("%s: could not find function '%s%s%s'",
                          CURRENT_FUNC,
                          toplevel ? "" : class_name.ToCString(),
                          toplevel ? "" : ".",
                          function_name.ToCString());
   }
 
   Breakpoint* bpt = debugger->SetBreakpointAtEntry(bp_target, false);
   if (bpt == NULL) {
     const char* target_name = Debugger::QualifiedFunctionName(bp_target);
     return Api::NewError("%s: no breakpoint location found in '%s'",
                          CURRENT_FUNC, target_name);
   }
   return Dart_NewInteger(bpt->id());
 }
 
 
 DART_EXPORT Dart_Handle Dart_OneTimeBreakAtEntry(
                             Dart_Handle library_in,
                             Dart_Handle class_name_in,
                             Dart_Handle function_name_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   UNWRAP_AND_CHECK_PARAM(Library, library, library_in);
   UNWRAP_AND_CHECK_PARAM(String, class_name, class_name_in);
   UNWRAP_AND_CHECK_PARAM(String, function_name, function_name_in);
 
   // Ensure that the library is loaded.
   if (!library.Loaded()) {
     return Api::NewError(
         "%s expects library argument 'library_in' to be loaded.",
         CURRENT_FUNC);
   }
 
   // Resolve the breakpoint target function.
-  Debugger* debugger = isolate->debugger();
+  Debugger* debugger = I->debugger();
   const Function& bp_target = Function::Handle(
       debugger->ResolveFunction(library, class_name, function_name));
   if (bp_target.IsNull()) {
     const bool toplevel = class_name.Length() == 0;
     return Api::NewError("%s: could not find function '%s%s%s'",
                          CURRENT_FUNC,
                          toplevel ? "" : class_name.ToCString(),
                          toplevel ? "" : ".",
                          function_name.ToCString());
   }
 
-  const Error& error =
-      Error::Handle(isolate, debugger->OneTimeBreakAtEntry(bp_target));
+  const Error& error = Error::Handle(Z,
+      debugger->OneTimeBreakAtEntry(bp_target));
   if (!error.IsNull()) {
-    return Api::NewHandle(isolate, error.raw());
+    return Api::NewHandle(I, error.raw());
   }
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_RemoveBreakpoint(intptr_t bp_id) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  isolate->debugger()->RemoveBreakpoint(bp_id);
+  DARTSCOPE(Thread::Current());
+  I->debugger()->RemoveBreakpoint(bp_id);
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_SetStepOver() {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  isolate->debugger()->SetStepOver();
+  DARTSCOPE(Thread::Current());
+  I->debugger()->SetStepOver();
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_SetStepInto() {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  isolate->debugger()->SetSingleStep();
+  DARTSCOPE(Thread::Current());
+  I->debugger()->SetSingleStep();
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_SetStepOut() {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  isolate->debugger()->SetStepOut();
+  DARTSCOPE(Thread::Current());
+  I->debugger()->SetStepOut();
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetInstanceFields(Dart_Handle object_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   UNWRAP_AND_CHECK_PARAM(Instance, obj, object_in);
-  return Api::NewHandle(isolate, isolate->debugger()->GetInstanceFields(obj));
+  return Api::NewHandle(I, I->debugger()->GetInstanceFields(obj));
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetStaticFields(Dart_Handle target) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  const Type& type_obj = Api::UnwrapTypeHandle(isolate, target);
+  DARTSCOPE(Thread::Current());
+  const Type& type_obj = Api::UnwrapTypeHandle(I, target);
   if (type_obj.IsNull()) {
     return Api::NewError("%s expects argument 'target' to be a type",
                          CURRENT_FUNC);
   }
-  const Class& cls = Class::Handle(isolate, type_obj.type_class());
-  return Api::NewHandle(isolate, isolate->debugger()->GetStaticFields(cls));
+  const Class& cls = Class::Handle(Z, type_obj.type_class());
+  return Api::NewHandle(I, I->debugger()->GetStaticFields(cls));
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetLibraryFields(intptr_t library_id) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   const Library& lib =
-      Library::Handle(isolate, Library::GetLibrary(library_id));
+      Library::Handle(Z, Library::GetLibrary(library_id));
   if (lib.IsNull()) {
     return Api::NewError("%s: %" Pd " is not a valid library id",
                          CURRENT_FUNC, library_id);
   }
-  return Api::NewHandle(isolate, isolate->debugger()->GetLibraryFields(lib));
+  return Api::NewHandle(I, I->debugger()->GetLibraryFields(lib));
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetGlobalVariables(intptr_t library_id) {
-  Isolate* isolate = Isolate::Current();
-  ASSERT(isolate != NULL);
-  DARTSCOPE(isolate);
-  const Library& lib = Library::Handle(Library::GetLibrary(library_id));
+  DARTSCOPE(Thread::Current());
+
+  const Library& lib = Library::Handle(Z, Library::GetLibrary(library_id));
   if (lib.IsNull()) {
     return Api::NewError("%s: %" Pd " is not a valid library id",
                          CURRENT_FUNC, library_id);
   }
-  return Api::NewHandle(isolate, isolate->debugger()->GetGlobalFields(lib));
+  return Api::NewHandle(I, I->debugger()->GetGlobalFields(lib));
 }
 
 
 DART_EXPORT Dart_Handle Dart_ActivationFrameEvaluate(
                             Dart_ActivationFrame activation_frame,
                             Dart_Handle expr_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   CHECK_AND_CAST(ActivationFrame, frame, activation_frame);
   UNWRAP_AND_CHECK_PARAM(String, expr, expr_in);
-  return Api::NewHandle(isolate, frame->Evaluate(expr));
+  return Api::NewHandle(I, frame->Evaluate(expr));
 }
 
 
 DART_EXPORT Dart_Handle Dart_EvaluateExpr(Dart_Handle target_in,
                                           Dart_Handle expr_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
 
-  const Object& target = Object::Handle(isolate, Api::UnwrapHandle(target_in));
+  const Object& target = Object::Handle(Z, Api::UnwrapHandle(target_in));
   if (target.IsError()) return target_in;
   if (target.IsNull()) {
     return Api::NewError("%s expects argument 'target' to be non-null",
                          CURRENT_FUNC);
   }
   UNWRAP_AND_CHECK_PARAM(String, expr, expr_in);
   // Type extends Instance, must check first.
   if (target.IsType()) {
-    const Class& cls = Class::Handle(isolate, Type::Cast(target).type_class());
-    return Api::NewHandle(isolate, cls.Evaluate(expr,
-                                                Array::empty_array(),
-                                                Array::empty_array()));
+    const Class& cls = Class::Handle(Z, Type::Cast(target).type_class());
+    return Api::NewHandle(I, cls.Evaluate(expr,
+                                          Array::empty_array(),
+                                          Array::empty_array()));
   } else if (target.IsInstance()) {
     const Instance& inst = Instance::Cast(target);
-    return Api::NewHandle(isolate, inst.Evaluate(expr,
-                                                 Array::empty_array(),
-                                                 Array::empty_array()));
+    return Api::NewHandle(I, inst.Evaluate(expr,
+                                           Array::empty_array(),
+                                           Array::empty_array()));
   } else if (target.IsLibrary()) {
     const Library& lib = Library::Cast(target);
-    return Api::NewHandle(isolate, lib.Evaluate(expr,
-                                                Array::empty_array(),
-                                                Array::empty_array()));
+    return Api::NewHandle(I, lib.Evaluate(expr,
+                                          Array::empty_array(),
+                                          Array::empty_array()));
   } else if (target.IsClass()) {
     const Class& cls = Class::Cast(target);
-    return Api::NewHandle(isolate, cls.Evaluate(expr,
-                                                Array::empty_array(),
-                                                Array::empty_array()));
+    return Api::NewHandle(I, cls.Evaluate(expr,
+                                          Array::empty_array(),
+                                          Array::empty_array()));
   }
   return Api::NewError("%s: unsupported target type", CURRENT_FUNC);
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetObjClass(Dart_Handle object_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   UNWRAP_AND_CHECK_PARAM(Instance, obj, object_in);
-  return Api::NewHandle(isolate, obj.GetType());
+  return Api::NewHandle(I, obj.GetType());
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetObjClassId(Dart_Handle object_in,
                                            intptr_t* class_id) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   UNWRAP_AND_CHECK_PARAM(Instance, obj, object_in);
   CHECK_NOT_NULL(class_id);
   *class_id = obj.GetClassId();
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetClassFromId(intptr_t class_id) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  if (!isolate->class_table()->IsValidIndex(class_id)) {
+  DARTSCOPE(Thread::Current());
+  if (!I->class_table()->IsValidIndex(class_id)) {
     return Api::NewError("%s: %" Pd " is not a valid class id",
                          CURRENT_FUNC, class_id);
   }
-  return Api::NewHandle(isolate, isolate->class_table()->At(class_id));
+  return Api::NewHandle(I, I->class_table()->At(class_id));
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetSupertype(Dart_Handle type_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
 
   UNWRAP_AND_CHECK_PARAM(Type, type, type_in);
   if (!type.IsFinalized()) {
     return Api::NewError("%s: type in 'type_in' is not a finalized type",
                          CURRENT_FUNC);
   }
   if (!type.IsInstantiated()) {
     return Api::NewError("%s: type in 'type_in' is not an instantiated type",
                          CURRENT_FUNC);
   }
   const Class& cls = Class::Handle(type.type_class());
   if (cls.NumTypeParameters() == 0) {
     // The super type has no type parameters or it is already instantiated
     // just return it.
     const AbstractType& type = AbstractType::Handle(cls.super_type());
     if (type.IsNull()) {
       return Dart_Null();
     }
-    return Api::NewHandle(isolate, type.Canonicalize());
+    return Api::NewHandle(I, type.Canonicalize());
   }
   // Set up the type arguments array for the super class type.
   const Class& super_cls = Class::Handle(cls.SuperClass());
   intptr_t num_expected_type_arguments = super_cls.NumTypeArguments();
   TypeArguments& super_type_args_array = TypeArguments::Handle();
   const TypeArguments& type_args_array =
       TypeArguments::Handle(type.arguments());
   if (!type_args_array.IsNull() && (num_expected_type_arguments > 0)) {
     super_type_args_array = TypeArguments::New(num_expected_type_arguments);
     AbstractType& type_arg = AbstractType::Handle();
     for (intptr_t i = 0; i < num_expected_type_arguments; i++) {
       type_arg ^= type_args_array.TypeAt(i);
       super_type_args_array.SetTypeAt(i, type_arg);
     }
   }
 
   // Construct the super type object, canonicalize it and return.
   Type& instantiated_type = Type::Handle(
       Type::New(super_cls, super_type_args_array, Scanner::kNoSourcePos));
   ASSERT(!instantiated_type.IsNull());
   instantiated_type.SetIsFinalized();
-  return Api::NewHandle(isolate, instantiated_type.Canonicalize());
+  return Api::NewHandle(I, instantiated_type.Canonicalize());
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetClosureInfo(
                             Dart_Handle closure,
                             Dart_Handle* name,
                             Dart_Handle* signature,
                             Dart_CodeLocation* location) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   UNWRAP_AND_CHECK_PARAM(Instance, instance, closure);
   CHECK_NOT_NULL(location);
 
   if (!instance.IsClosure()) {
     return Api::NewError("%s: parameter 0 is not a closure", CURRENT_FUNC);
   }
   const Function& func = Function::Handle(Closure::function(instance));
   ASSERT(!func.IsNull());
   if (name != NULL) {
-    *name = Api::NewHandle(isolate, func.QualifiedUserVisibleName());
+    *name = Api::NewHandle(I, func.QualifiedUserVisibleName());
   }
   if (signature != NULL) {
-    *signature = Api::NewHandle(isolate, func.UserVisibleSignature());
+    *signature = Api::NewHandle(I, func.UserVisibleSignature());
   }
 
   if (location != NULL) {
     if (func.token_pos() >= 0) {
-      const Class& cls = Class::Handle(func.origin());
+      const Class& cls = Class::Handle(Z, func.origin());
       ASSERT(!cls.IsNull());
-      const Library& lib = Library::Handle(isolate, cls.library());
+      const Library& lib = Library::Handle(Z, cls.library());
       ASSERT(!lib.IsNull());
       // Note func.script() is not the same as cls.script() for eval functions.
-      const Script& script = Script::Handle(func.script());
+      const Script& script = Script::Handle(Z, func.script());
       ASSERT(!script.IsNull());
-      location->script_url = Api::NewHandle(isolate, script.url());
+      location->script_url = Api::NewHandle(I, script.url());
       location->library_id = lib.index();
       location->token_pos = func.token_pos();
     } else {
-      location->script_url = Api::NewHandle(isolate, String::null());
+      location->script_url = Api::NewHandle(I, String::null());
       location->library_id = -1;
       location->token_pos = -1;
     }
   }
   return Api::True();
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetClassInfo(
                             intptr_t cls_id,
                             Dart_Handle* class_name,
                             intptr_t* library_id,
                             intptr_t* super_class_id,
                             Dart_Handle* static_fields) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  if (!isolate->class_table()->IsValidIndex(cls_id)) {
+  DARTSCOPE(Thread::Current());
+  if (!I->class_table()->IsValidIndex(cls_id)) {
     return Api::NewError("%s: %" Pd " is not a valid class id",
                          CURRENT_FUNC, cls_id);
   }
-  Class& cls = Class::Handle(isolate, isolate->class_table()->At(cls_id));
+  Class& cls = Class::Handle(Z, I->class_table()->At(cls_id));
   if (class_name != NULL) {
-    *class_name = Api::NewHandle(isolate, cls.Name());
+    *class_name = Api::NewHandle(I, cls.Name());
   }
   if (library_id != NULL) {
-    const Library& lib = Library::Handle(isolate, cls.library());
+    const Library& lib = Library::Handle(Z, cls.library());
     *library_id = lib.index();
   }
   if (super_class_id != NULL) {
     *super_class_id = 0;
-    Class& super_cls = Class::Handle(isolate, cls.SuperClass());
+    Class& super_cls = Class::Handle(Z, cls.SuperClass());
     if (!super_cls.IsNull()) {
       *super_class_id = super_cls.id();
     }
   }
   if (static_fields != NULL) {
     *static_fields =
-        Api::NewHandle(isolate, isolate->debugger()->GetStaticFields(cls));
+        Api::NewHandle(I, I->debugger()->GetStaticFields(cls));
   }
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_ScriptGetSource(
                             intptr_t library_id,
                             Dart_Handle script_url_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   const Library& lib = Library::Handle(Library::GetLibrary(library_id));
   if (lib.IsNull()) {
     return Api::NewError("%s: %" Pd " is not a valid library id",
                          CURRENT_FUNC, library_id);
   }
   UNWRAP_AND_CHECK_PARAM(String, script_url, script_url_in);
   const Script& script = Script::Handle(lib.LookupScript(script_url));
   if (script.IsNull()) {
     return Api::NewError("%s: script '%s' not found in library '%s'",
                          CURRENT_FUNC, script_url.ToCString(),
                          String::Handle(lib.url()).ToCString());
   }
-  return Api::NewHandle(isolate, script.Source());
+  return Api::NewHandle(I, script.Source());
 }
 
 
 DART_EXPORT Dart_Handle Dart_ScriptGetTokenInfo(
                             intptr_t library_id,
                             Dart_Handle script_url_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   const Library& lib = Library::Handle(Library::GetLibrary(library_id));
   if (lib.IsNull()) {
     return Api::NewError("%s: %" Pd " is not a valid library id",
                          CURRENT_FUNC, library_id);
   }
   UNWRAP_AND_CHECK_PARAM(String, script_url, script_url_in);
   const Script& script = Script::Handle(lib.LookupScript(script_url));
   if (script.IsNull()) {
     return Api::NewError("%s: script '%s' not found in library '%s'",
                          CURRENT_FUNC, script_url.ToCString(),
                          String::Handle(lib.url()).ToCString());
   }
 
   const GrowableObjectArray& info =
       GrowableObjectArray::Handle(script.GenerateLineNumberArray());
-  return Api::NewHandle(isolate, Array::MakeArray(info));
+  return Api::NewHandle(I, Array::MakeArray(info));
 }
 
 
 DART_EXPORT Dart_Handle Dart_GenerateScriptSource(Dart_Handle library_url_in,
                                                   Dart_Handle script_url_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   UNWRAP_AND_CHECK_PARAM(String, library_url, library_url_in);
   UNWRAP_AND_CHECK_PARAM(String, script_url, script_url_in);
 
   const Library& library = Library::Handle(Library::LookupLibrary(library_url));
   if (library.IsNull()) {
     return Api::NewError("%s: library '%s' not found",
                          CURRENT_FUNC, library_url.ToCString());
   }
 
   const Script& script = Script::Handle(library.LookupScript(script_url));
   if (script.IsNull()) {
     return Api::NewError("%s: script '%s' not found in library '%s'",
                          CURRENT_FUNC, script_url.ToCString(),
                          library_url.ToCString());
   }
 
-  return Api::NewHandle(isolate, script.GenerateSource());
+  return Api::NewHandle(I, script.GenerateSource());
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetScriptURLs(Dart_Handle library_url_in) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   UNWRAP_AND_CHECK_PARAM(String, library_url, library_url_in);
 
   const Library& library = Library::Handle(Library::LookupLibrary(library_url));
   if (library.IsNull()) {
     return Api::NewError("%s: library '%s' not found",
                          CURRENT_FUNC, library_url.ToCString());
   }
   const Array& loaded_scripts = Array::Handle(library.LoadedScripts());
   ASSERT(!loaded_scripts.IsNull());
   intptr_t num_scripts = loaded_scripts.Length();
   const Array& script_list = Array::Handle(Array::New(num_scripts));
   Script& script = Script::Handle();
   String& url = String::Handle();
   for (int i = 0; i < num_scripts; i++) {
     script ^= loaded_scripts.At(i);
     url = script.url();
     script_list.SetAt(i, url);
   }
-  return Api::NewHandle(isolate, script_list.raw());
+  return Api::NewHandle(I, script_list.raw());
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetLibraryIds() {
-  Isolate* isolate = Isolate::Current();
-  ASSERT(isolate != NULL);
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
 
   const GrowableObjectArray& libs =
-      GrowableObjectArray::Handle(isolate->object_store()->libraries());
+      GrowableObjectArray::Handle(Z, I->object_store()->libraries());
   int num_libs = libs.Length();
 
   // Create new list and populate with the url of loaded libraries.
   Library &lib = Library::Handle();
-  const Array& library_id_list = Array::Handle(Array::New(num_libs));
+  const Array& library_id_list = Array::Handle(Z, Array::New(num_libs));
   for (int i = 0; i < num_libs; i++) {
     lib ^= libs.At(i);
     ASSERT(!lib.IsNull());
     ASSERT(Smi::IsValid(lib.index()));
     library_id_list.SetAt(i, Smi::Handle(Smi::New(lib.index())));
   }
-  return Api::NewHandle(isolate, library_id_list.raw());
+  return Api::NewHandle(I, library_id_list.raw());
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetLibraryFromId(intptr_t library_id) {
-  Isolate* isolate = Isolate::Current();
-  ASSERT(isolate != NULL);
-  DARTSCOPE(isolate);
-  const Library& lib = Library::Handle(Library::GetLibrary(library_id));
+  DARTSCOPE(Thread::Current());
+  const Library& lib = Library::Handle(Z, Library::GetLibrary(library_id));
   if (lib.IsNull()) {
     return Api::NewError("%s: %" Pd " is not a valid library id",
                          CURRENT_FUNC, library_id);
   }
-  return Api::NewHandle(isolate, lib.raw());
+  return Api::NewHandle(I, lib.raw());
 }
 
 
 DART_EXPORT Dart_Handle Dart_LibraryId(Dart_Handle library,
                                        intptr_t* library_id) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  const Library& lib = Api::UnwrapLibraryHandle(isolate, library);
+  DARTSCOPE(Thread::Current());
+  const Library& lib = Api::UnwrapLibraryHandle(I, library);
   if (lib.IsNull()) {
-    RETURN_TYPE_ERROR(isolate, library, Library);
+    RETURN_TYPE_ERROR(I, library, Library);
   }
   if (library_id == NULL) {
     RETURN_NULL_ERROR(library_id);
   }
   *library_id = lib.index();
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetLibraryImports(intptr_t library_id) {
-  Isolate* isolate = Isolate::Current();
-  ASSERT(isolate != NULL);
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   const Library& lib = Library::Handle(Library::GetLibrary(library_id));
   if (lib.IsNull()) {
     return Api::NewError("%s: %" Pd " is not a valid library id",
                          CURRENT_FUNC, library_id);
   }
   const GrowableObjectArray& import_list =
       GrowableObjectArray::Handle(GrowableObjectArray::New(8));
 
-  String& prefix_name = String::Handle(isolate);
-  Library& imported = Library::Handle(isolate);
+  String& prefix_name = String::Handle(Z);
+  Library& imported = Library::Handle(Z);
   intptr_t num_imports = lib.num_imports();
   for (int i = 0; i < num_imports; i++) {
     import_list.Add(prefix_name);  // Null prefix name means no prefix.
     imported = lib.ImportLibraryAt(i);
     ASSERT(!imported.IsNull());
     ASSERT(Smi::IsValid(imported.index()));
-    import_list.Add(Smi::Handle(Smi::New(imported.index())));
+    import_list.Add(Smi::Handle(Z, Smi::New(imported.index())));
   }
   LibraryPrefixIterator it(lib);
-  LibraryPrefix& prefix = LibraryPrefix::Handle(isolate);
+  LibraryPrefix& prefix = LibraryPrefix::Handle(Z);
   while (it.HasNext()) {
     prefix = it.GetNext();
     prefix_name = prefix.name();
     ASSERT(!prefix_name.IsNull());
     prefix_name = String::Concat(prefix_name, Symbols::Dot());
     for (int32_t i = 0; i < prefix.num_imports(); i++) {
       imported = prefix.GetLibrary(i);
       import_list.Add(prefix_name);
       import_list.Add(Smi::Handle(Smi::New(imported.index())));
     }
   }
-  return Api::NewHandle(isolate, Array::MakeArray(import_list));
+  return Api::NewHandle(I, Array::MakeArray(import_list));
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetLibraryURL(intptr_t library_id) {
-  Isolate* isolate = Isolate::Current();
-  ASSERT(isolate != NULL);
-  DARTSCOPE(isolate);
-  const Library& lib = Library::Handle(Library::GetLibrary(library_id));
+  DARTSCOPE(Thread::Current());
+  const Library& lib = Library::Handle(Z, Library::GetLibrary(library_id));
   if (lib.IsNull()) {
     return Api::NewError("%s: %" Pd " is not a valid library id",
                          CURRENT_FUNC, library_id);
   }
-  return Api::NewHandle(isolate, lib.url());
+  return Api::NewHandle(I, lib.url());
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetLibraryDebuggable(intptr_t library_id,
                                                   bool* is_debuggable) {
-  Isolate* isolate = Isolate::Current();
-  ASSERT(isolate != NULL);
-  DARTSCOPE(isolate);
+  DARTSCOPE(Thread::Current());
   CHECK_NOT_NULL(is_debuggable);
   const Library& lib = Library::Handle(Library::GetLibrary(library_id));
   if (lib.IsNull()) {
     return Api::NewError("%s: %" Pd " is not a valid library id",
                          CURRENT_FUNC, library_id);
   }
   *is_debuggable = lib.IsDebuggable();
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_SetLibraryDebuggable(intptr_t library_id,
                                                   bool is_debuggable) {
-  Isolate* isolate = Isolate::Current();
-  ASSERT(isolate != NULL);
-  DARTSCOPE(isolate);
-  const Library& lib = Library::Handle(Library::GetLibrary(library_id));
+  DARTSCOPE(Thread::Current());
+  const Library& lib = Library::Handle(Z, Library::GetLibrary(library_id));
   if (lib.IsNull()) {
     return Api::NewError("%s: %" Pd " is not a valid library id",
                          CURRENT_FUNC, library_id);
   }
   lib.set_debuggable(is_debuggable);
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Isolate Dart_GetIsolate(Dart_IsolateId isolate_id) {
   Isolate* isolate = PortMap::GetIsolate(isolate_id);
   return Api::CastIsolate(isolate);
 }
 
 
 DART_EXPORT Dart_IsolateId Dart_GetIsolateId(Dart_Isolate dart_isolate) {
   Isolate* isolate = reinterpret_cast<Isolate*>(dart_isolate);
   return isolate->debugger()->GetIsolateId();
 }
 
 }  // namespace dart