- Add and enable concurrent sweeper.

runtime/vm/metrics.cc

 // Copyright (c) 2014, 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 "vm/metrics.h"
 
 #include "vm/isolate.h"
 #include "vm/json_stream.h"
 #include "vm/native_entry.h"
 #include "vm/runtime_entry.h"
@@ skipping 33 matching lines @@
   ASSERT(next_ == NULL);
   ASSERT(name != NULL);
   name_ = name;
   description_ = description;
   unit_ = unit;
   RegisterWithVM();
 }
 
 
 Metric::~Metric() {
-  if (isolate_ == NULL) {
-    DeregisterWithVM();
-  } else {
-    DeregisterWithIsolate();
+  // Only deregister metrics which had been registered. Metrics without a name
+  // are from shallow copy isolates.
+  if (name_ != NULL) {
+    if (isolate_ == NULL) {
+      DeregisterWithVM();
+    } else {
+      DeregisterWithIsolate();
+    }
   }
 }
 
 
 static const char* UnitString(intptr_t unit) {
   switch (unit) {
     case Metric::kCounter: return "counter";
     case Metric::kByte: return "byte";
     default:
       UNREACHABLE();
@@ skipping 165 matching lines @@
 
 
 void Metric::InitOnce() {
 #define VM_METRIC_INIT(type, variable, name, unit)                             \
   vm_metric_##variable##_.Init(name, NULL, Metric::unit);
   VM_METRIC_LIST(VM_METRIC_INIT);
 #undef VM_METRIC_INIT
 }
 
 }  // namespace dart