Resolution for issue #5092: Unit test handle checks consider dangling handles to be valid.

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 516 matching lines @@
 
 Dart_Handle Api::AcquiredError(Isolate* isolate) {
   ASSERT(isolate != NULL);
   ApiState* state = isolate->api_state();
   ASSERT(state != NULL);
   PersistentHandle* acquired_error_handle = state->AcquiredError();
   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) ||
+         isolate->api_state()->IsActivePersistentHandle(

[bkonyi, 2017/01/20 23:07:11]

I added IsActive(Weak)PersistentHandle to check if the handle is valid and is
not part of the free list.

+             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) {
   ASSERT(thread != NULL);
   ApiLocalScope* scope = thread->api_top_scope();
   ASSERT(scope != NULL);
   return scope;
 }
 
 
 void Api::InitOnce() {
   ASSERT(api_native_key_ == kUnsetThreadLocalKey);
@@ skipping 6250 matching lines @@
 }
 
 
 DART_EXPORT void Dart_DumpNativeStackTrace(void* context) {
 #ifndef PRODUCT
   Profiler::DumpStackTrace(context);
 #endif
 }
 
 }  // namespace dart