1 files changed, 48 insertions, 0 deletions
diff --git a/dom/workers/WorkerEventTarget.h b/dom/workers/WorkerEventTarget.h
new file mode 100644
index 0000000000..dd9cb61748
--- /dev/null
+++ b/dom/workers/WorkerEventTarget.h
@@ -0,0 +1,48 @@
+/* -*- 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 mozilla_dom_WorkerEventTarget_h
+#define mozilla_dom_WorkerEventTarget_h
+
+#include "nsISerialEventTarget.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/dom/WorkerPrivate.h"
+
+namespace mozilla::dom {
+
+class WorkerEventTarget final : public nsISerialEventTarget {
+ public:
+  // The WorkerEventTarget supports different dispatch behaviors:
+  //
+  // * Hybrid targets will attempt to dispatch as a normal runnable,
+  //   but fallback to a control runnable if that fails.  This is
+  //   often necessary for code that wants normal dispatch order, but
+  //   also needs to execute while the worker is shutting down (possibly
+  //   with a holder in place.)
+  //
+  // * ControlOnly targets will simply dispatch a control runnable.
+  enum class Behavior : uint8_t { Hybrid, ControlOnly };
+
+ private:
+  mozilla::Mutex mMutex;
+  CheckedUnsafePtr<WorkerPrivate> mWorkerPrivate MOZ_GUARDED_BY(mMutex);
+  const Behavior mBehavior MOZ_GUARDED_BY(mMutex);
+
+  ~WorkerEventTarget() = default;
+
+ public:
+  WorkerEventTarget(WorkerPrivate* aWorkerPrivate, Behavior aBehavior);
+
+  void ForgetWorkerPrivate(WorkerPrivate* aWorkerPrivate);
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIEVENTTARGET
+  NS_DECL_NSISERIALEVENTTARGET
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_WorkerEventTarget_h