1 files changed, 58 insertions, 0 deletions
diff --git a/dom/fs/shared/TargetPtrHolder.h b/dom/fs/shared/TargetPtrHolder.h
new file mode 100644
index 0000000000..952fc075b9
--- /dev/null
+++ b/dom/fs/shared/TargetPtrHolder.h
@@ -0,0 +1,58 @@
+/* -*- 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/. */
+
+#ifndef DOM_FS_SHARED_TARGETPTRHOLDER_H_
+#define DOM_FS_SHARED_TARGETPTRHOLDER_H_
+
+#include "mozilla/RefPtr.h"
+#include "nsCOMPtr.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla::dom::fs {
+
+// TODO: Remove this ad hoc class when bug 1805830 is fixed.
+template <typename T>
+class TargetPtrHolder {
+ public:
+  MOZ_IMPLICIT TargetPtrHolder(T* aRawPtr)
+      : mTarget(GetCurrentSerialEventTarget()), mPtr(aRawPtr) {
+    MOZ_ASSERT(mPtr);
+  }
+
+  TargetPtrHolder(const TargetPtrHolder&) = default;
+
+  TargetPtrHolder& operator=(const TargetPtrHolder&) = default;
+
+  TargetPtrHolder(TargetPtrHolder&&) = default;
+
+  TargetPtrHolder& operator=(TargetPtrHolder&&) = default;
+
+  ~TargetPtrHolder() {
+    if (!mPtr) {
+      return;
+    }
+
+    NS_ProxyRelease("TargetPtrHolder::mPtr", mTarget, mPtr.forget());
+  }
+
+  T* get() const {
+    MOZ_ASSERT(mPtr);
+
+    return mPtr.get();
+  }
+
+  T* operator->() const MOZ_NO_ADDREF_RELEASE_ON_RETURN { return get(); }
+
+  bool operator!() { return !mPtr.get(); }
+
+ private:
+  nsCOMPtr<nsISerialEventTarget> mTarget;
+  RefPtr<T> mPtr;
+};
+
+}  // namespace mozilla::dom::fs
+
+#endif  // DOM_FS_SHARED_TARGETPTRHOLDER_H_