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

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index aa851bfed4250cc6e7bd8dbb0b0b2c01f73a28ac..7360f82346e21de1cd626554c5af8d5c5a150f59 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -2091,6 +2091,14 @@ void Isolate::PrintJSON(JSONStream* stream, bool ref) {
     }
   }
 }
+
+
+void Isolate::PrintThreadsInfoToJSONObject(JSONObject* obj) {
+  obj->AddPropertyF("isolate_address", "0x%" Px "",
+                    reinterpret_cast<uword>(this));

[siva, 2016/12/07 22:12:52]

Can we use isolate id instead of isolate address here. I think the service
protocol uses isolate ids to track isolates.

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

Yes, I've gone ahead and switched from addresses to ids for isolates and
threads.

+  ASSERT(thread_registry_ != NULL);
+  thread_registry_->PrintToJSONObjectLocked(obj);
+}
 #endif
 
 
@@ -2488,6 +2496,20 @@ void Isolate::RemoveIsolateFromList(Isolate* isolate) {
 }
 
 
+#ifndef RELEASE
+void Isolate::PrintAllIsolatesMemoryInfoToJSONLocked(JSONStream* stream) {

[Cutch, 2016/12/06 19:11:14]

The suffix of 'Locked' is usually applied to functions which assume the lock is
already taken. I would recommend dropping the 'Locked' suffix.

[bkonyi, 2016/12/08 18:04:13]

Done.

+  MonitorLocker ml(isolates_list_monitor_);
+  JSONArray arr(stream);
+  Isolate* current = isolates_list_head_;
+  while (current != NULL) {

[Cutch, 2016/12/06 19:11:14]

Please use Isolates::VisitIsolates instead of walking the list yourself.  It
also takes care of the locking too.

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

Done.

+    JSONObject isolate_obj(&arr);
+    current->PrintThreadsInfoToJSONObject(&isolate_obj);
+    current = current->next_;
+  }
+}
+#endif
+
+
 void Isolate::DisableIsolateCreation() {
   MonitorLocker ml(isolates_list_monitor_);
   creation_enabled_ = false;