Fix for issue #28606. Removed loop which iterated over all threads in the thread registry to check …

runtime/vm/thread_registry.cc

 // 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.
 
 #include "vm/thread_registry.h"
 
 #include "vm/isolate.h"
 #include "vm/json_stream.h"
 #include "vm/lockers.h"
 
@@ skipping 87 matching lines @@
   JSONArray threads(stream);
   Thread* current = active_list_;
   while (current != NULL) {
     threads.AddValue(current);
     current = current->next_;
   }
 }
 #endif
 
 
-bool ThreadRegistry::IsValidHandle(Dart_Handle handle) const {
-  MonitorLocker ml(threads_lock());
-  Thread* current = active_list_;
-  while (current != NULL) {
-    if (current->IsValidHandle(handle)) {
-      return true;
-    }
-    current = current->next_;
-  }
-  return false;
-}
-
-
 intptr_t ThreadRegistry::CountZoneHandles() const {
   MonitorLocker ml(threads_lock());
   intptr_t count = 0;
   Thread* current = active_list_;
   while (current != NULL) {
     count += current->CountZoneHandles();
     current = current->next_;
   }
   return count;
 }
@@ skipping 58 matching lines @@
   ASSERT(thread->os_thread_ == NULL);
   ASSERT(thread->isolate_ == NULL);
   ASSERT(thread->heap_ == NULL);
   ASSERT(threads_lock()->IsOwnedByCurrentThread());
   // Add thread to the free list.
   thread->next_ = free_list_;
   free_list_ = thread;
 }
 
 }  // namespace dart