[wasm] Managed<T> ensures T's lifetime does not leak past Isolate's

test/cctest/test-managed.cc

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "src/managed.h"
+
+#include "src/objects-inl.h"
+#include "test/cctest/cctest.h"
+
+using namespace v8::base;
+using namespace v8::internal;
+
+class DeleteRecorder {
+ public:
+  explicit DeleteRecorder(bool* deleted) : deleted_(deleted) {
+    *deleted_ = false;
+  }
+  ~DeleteRecorder() { *deleted_ = true; }
+  static void Deleter(void* value) {
+    delete reinterpret_cast<DeleteRecorder*>(value);
+  }
+
+ private:
+  bool* deleted_;
+};
+
+TEST(ManagedCollect) {
+  Isolate* isolate = CcTest::InitIsolateOnce();
+  bool deleted1 = false;
+  bool deleted2 = false;
+  DeleteRecorder* d1 = new DeleteRecorder(&deleted1);
+  DeleteRecorder* d2 = new DeleteRecorder(&deleted2);
+  Isolate::ManagedObjectFinalizer* finalizer =
+      isolate->RegisterForReleaseAtTeardown(d2, DeleteRecorder::Deleter);
+  {
+    HandleScope scope(isolate);
+    auto handle = Managed<DeleteRecorder>::New(isolate, d1);
+    USE(handle);
+  }
+
+  CcTest::CollectAllAvailableGarbage();
+
+  CHECK(deleted1);
+  CHECK(!deleted2);
+  isolate->UnregisterFromReleaseAtTeardown(&finalizer);
+  CHECK_NULL(finalizer);
+  delete d2;
+  CHECK(deleted2);
+}
+
+TEST(DisposeCollect) {
+  v8::Isolate::CreateParams create_params;
+  create_params.array_buffer_allocator =
+      CcTest::InitIsolateOnce()->array_buffer_allocator();
+
+  v8::Isolate* isolate = v8::Isolate::New(create_params);
+  isolate->Enter();
+  Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  bool deleted1 = false;
+  bool deleted2 = false;
+  DeleteRecorder* d1 = new DeleteRecorder(&deleted1);
+  DeleteRecorder* d2 = new DeleteRecorder(&deleted2);
+  {
+    HandleScope scope(i_isolate);
+    auto handle = Managed<DeleteRecorder>::New(i_isolate, d1);
+    USE(handle);
+  }
+  i_isolate->RegisterForReleaseAtTeardown(d2, DeleteRecorder::Deleter);
+
+  isolate->Exit();
+  isolate->Dispose();
+  CHECK(deleted1);
+  CHECK(deleted2);
+}