1 files changed, 73 insertions, 0 deletions
diff --git a/dom/base/GlobalTeardownObserver.cpp b/dom/base/GlobalTeardownObserver.cpp
new file mode 100644
index 0000000000..9f9ac39b47
--- /dev/null
+++ b/dom/base/GlobalTeardownObserver.cpp
@@ -0,0 +1,73 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GlobalTeardownObserver.h"
+#include "mozilla/Sprintf.h"
+#include "mozilla/dom/Document.h"
+
+namespace mozilla {
+
+GlobalTeardownObserver::GlobalTeardownObserver() = default;
+GlobalTeardownObserver::GlobalTeardownObserver(nsIGlobalObject* aGlobalObject,
+                                               bool aHasOrHasHadOwnerWindow)
+    : mHasOrHasHadOwnerWindow(aHasOrHasHadOwnerWindow) {
+  BindToOwner(aGlobalObject);
+}
+
+GlobalTeardownObserver::~GlobalTeardownObserver() {
+  if (mParentObject) {
+    mParentObject->RemoveGlobalTeardownObserver(this);
+  }
+}
+
+void GlobalTeardownObserver::BindToOwner(nsIGlobalObject* aOwner) {
+  MOZ_ASSERT(!mParentObject);
+
+  if (aOwner) {
+    mParentObject = aOwner;
+    aOwner->AddGlobalTeardownObserver(this);
+    // Let's cache the result of this QI for fast access and off main thread
+    // usage
+    mOwnerWindow =
+        nsCOMPtr<nsPIDOMWindowInner>(do_QueryInterface(aOwner)).get();
+    if (mOwnerWindow) {
+      mHasOrHasHadOwnerWindow = true;
+    }
+  }
+}
+
+void GlobalTeardownObserver::DisconnectFromOwner() {
+  if (mParentObject) {
+    mParentObject->RemoveGlobalTeardownObserver(this);
+  }
+  mOwnerWindow = nullptr;
+  mParentObject = nullptr;
+}
+
+nsresult GlobalTeardownObserver::CheckCurrentGlobalCorrectness() const {
+  NS_ENSURE_STATE(!mHasOrHasHadOwnerWindow || mOwnerWindow);
+
+  // Main-thread.
+  if (mOwnerWindow && !mOwnerWindow->IsCurrentInnerWindow()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (NS_IsMainThread()) {
+    return NS_OK;
+  }
+
+  if (!mParentObject) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (mParentObject->IsDying()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+};  // namespace mozilla