Created methods to surface zone memory information for each isolate and thread in JSON.

runtime/vm/thread_registry.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_REGISTRY_H_
 #define RUNTIME_VM_THREAD_REGISTRY_H_
 
 #include "vm/globals.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
 #include "vm/lockers.h"
 #include "vm/stack_frame.h"
 #include "vm/thread.h"
 
+#ifndef RELEASE

[Cutch, 2016/12/06 19:11:15]

here too.

We typically write:

#if DEFINED(DEBUG)
#endif

or 

#ifndef PRODUCT
#endif

[bkonyi, 2016/12/08 18:04:14]

Done.

+class JSONObject;
+class JSONArray;
+#endif
+
 namespace dart {
 
 // Unordered collection of threads relating to a particular isolate.
 class ThreadRegistry {
  public:
   ThreadRegistry()
       : threads_lock_(new Monitor()),
         active_list_(NULL),
         free_list_(NULL),
         mutator_thread_(NULL) {}
   ~ThreadRegistry();
 
   void VisitObjectPointers(ObjectPointerVisitor* visitor, bool validate_frames);
   void PrepareForGC();
   Thread* mutator_thread() const { return mutator_thread_; }
 
+#ifndef RELEASE
+  void PrintToJSONObjectLocked(JSONObject* obj);
+#endif
+
  private:
   Thread* active_list() const { return active_list_; }
   Monitor* threads_lock() const { return threads_lock_; }
 
   Thread* GetFreeThreadLocked(Isolate* isolate, bool is_mutator);
   void ReturnThreadLocked(bool is_mutator, Thread* thread);
   void AddToActiveListLocked(Thread* thread);
   void RemoveFromActiveListLocked(Thread* thread);
   Thread* GetFromFreelistLocked(Isolate* isolate);
   void ReturnToFreelistLocked(Thread* thread);
 
+#ifndef RELEASE
+  void PrintToJSONObjectHelper(JSONArray* arr, Thread* thread);
+#endif
+
   // This monitor protects the threads list for an isolate, it is used whenever
   // we need to iterate over threads (both active and free) in an isolate.
   Monitor* threads_lock_;
   Thread* active_list_;  // List of active threads in the isolate.
   Thread* free_list_;    // Free list of Thread objects that can be reused.
 
   // TODO(asiva): Currently we treat a mutator thread as a special thread
   // and always schedule execution of Dart code on the same mutator thread
   // object. The ApiLocalScope has been made thread specific but we still
   // have scenarios where we do a temporary exit of an Isolate with live
   // zones/handles in the API scope :
   // - Dart_RunLoop()
   // - IsolateSaver in Dart_NewNativePort
   // - Isolate spawn (function/uri) under FLAG_i_like_slow_isolate_spawn
   // We probably need a mechanism to return to the specific thread only
   // for these specific cases. We should also determine if the embedder
   // should allow exiting an isolate with live state in zones/handles in
   // which case a new API for returning to the specific thread needs to be
   // added.
   Thread* mutator_thread_;
 
   friend class Isolate;
   friend class SafepointHandler;
   DISALLOW_COPY_AND_ASSIGN(ThreadRegistry);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_THREAD_REGISTRY_H_