Moves the top_ and end_ words of the Scavenger into mutator thread.

runtime/vm/thread.h

 // Copyright (c) 2015, 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.
 
 #ifndef RUNTIME_VM_THREAD_H_
 #define RUNTIME_VM_THREAD_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/atomic.h"
@@ skipping 346 matching lines @@
   }
 
   StackResource* top_resource() const { return top_resource_; }
   void set_top_resource(StackResource* value) { top_resource_ = value; }
   static intptr_t top_resource_offset() {
     return OFFSET_OF(Thread, top_resource_);
   }
 
   // Heap of the isolate that this thread is operating on.
   Heap* heap() const { return heap_; }
   static intptr_t heap_offset() { return OFFSET_OF(Thread, heap_); }

[rmacnak, 2017/07/05 17:39:53]

It should be possible to remove this now, right?

[danunez, 2017/07/05 18:12:56]

Looks like it, according to a grep. Consider it gone.

 
+  void set_top_offset(uword value) {

[rmacnak, 2017/07/05 17:39:53]

set_top

[danunez, 2017/07/05 18:12:56]

Done.

+    ASSERT(heap_ != NULL);
+    top_ = value;
+  }
+  void set_end_offset(uword value) {

[rmacnak, 2017/07/05 17:39:53]

set_end

[danunez, 2017/07/05 18:12:56]

Done.

+    ASSERT(heap_ != NULL);
+    end_ = value;
+  }
+
+  uword top() { return top_; }
+  uword end() { return end_; }
+
+  static intptr_t top_offset() { return OFFSET_OF(Thread, top_); }
+  static intptr_t end_offset() { return OFFSET_OF(Thread, end_); }
+
   int32_t no_handle_scope_depth() const {
 #if defined(DEBUG)
     return no_handle_scope_depth_;
 #else
     return 0;
 #endif
   }
 
   void IncrementNoHandleScopeDepth() {
 #if defined(DEBUG)
@@ skipping 366 matching lines @@
 
   // JumpToExceptionHandler state:
   RawObject* active_exception_;
   RawObject* active_stacktrace_;
   uword resume_pc_;
 
   RawError* sticky_error_;
 
   CompilerStats* compiler_stats_;
 
+  uword top_;

[rmacnak, 2017/07/05 17:39:53]

These should move up to where heap_ is. See comment about fields accessed from
generated code.

[danunez, 2017/07/05 18:12:56]

I placed these down here after I encountered an error during testing about bad
offsets. I will try again and see if I encounter it.

+  uword end_;
+
 // Reusable handles support.
 #define REUSABLE_HANDLE_FIELDS(object) object* object##_handle_;
   REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_FIELDS)
 #undef REUSABLE_HANDLE_FIELDS
 
 #if defined(DEBUG)
 #define REUSABLE_HANDLE_SCOPE_VARIABLE(object)                                 \
   bool reusable_##object##_handle_scope_active_;
   REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_SCOPE_VARIABLE);
 #undef REUSABLE_HANDLE_SCOPE_VARIABLE
@@ skipping 53 matching lines @@
 // Disable thread interrupts.
 class DisableThreadInterruptsScope : public StackResource {
  public:
   explicit DisableThreadInterruptsScope(Thread* thread);
   ~DisableThreadInterruptsScope();
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_THREAD_H_