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

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, 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 "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "lib/stacktrace.h"
@@ skipping 522 matching lines @@
   return reinterpret_cast<Dart_Handle>(acquired_error_handle);
 }
 
 
 bool Api::IsValid(Dart_Handle handle) {
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
 
   // Check against all of the handles in the current isolate as well as the
   // read-only handles.
-  return isolate->thread_registry()->IsValidHandle(handle) ||
+  return Thread::Current()->IsValidHandle(handle) ||

[bkonyi, 2017/02/02 22:22:34]

I wasn't able to reproduce the issue described in #28606, but I'm fairly certain
that this should resolve the crash caused by the race.

          isolate->api_state()->IsActivePersistentHandle(
              reinterpret_cast<Dart_PersistentHandle>(handle)) ||
          isolate->api_state()->IsActiveWeakPersistentHandle(
              reinterpret_cast<Dart_WeakPersistentHandle>(handle)) ||
          Dart::IsReadOnlyApiHandle(handle) ||
          Dart::IsReadOnlyHandle(reinterpret_cast<uword>(handle));
 }
 
 
 ApiLocalScope* Api::TopScope(Thread* thread) {
@@ skipping 6265 matching lines @@
 }
 
 
 DART_EXPORT void Dart_DumpNativeStackTrace(void* context) {
 #ifndef PRODUCT
   Profiler::DumpStackTrace(context);
 #endif
 }
 
 }  // namespace dart