1 files changed, 81 insertions, 0 deletions
diff --git a/gfx/layers/ipc/CompositorThread.h b/gfx/layers/ipc/CompositorThread.h
new file mode 100644
index 0000000000..3352889982
--- /dev/null
+++ b/gfx/layers/ipc/CompositorThread.h
@@ -0,0 +1,81 @@
+/* -*- 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_layers_CompositorThread_h
+#define mozilla_layers_CompositorThread_h
+
+#include "nsISupportsImpl.h"
+#include "nsIThread.h"
+
+namespace mozilla::baseprofiler {
+class BaseProfilerThreadId;
+}
+using ProfilerThreadId = mozilla::baseprofiler::BaseProfilerThreadId;
+class nsIThread;
+
+namespace mozilla {
+namespace layers {
+
+class CompositorThreadHolder final {
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DELETE_ON_MAIN_THREAD(
+      CompositorThreadHolder)
+
+ public:
+  CompositorThreadHolder();
+
+  nsIThread* GetCompositorThread() const { return mCompositorThread; }
+
+  /**
+   * Returns true if the calling thread is the compositor thread. This works
+   * even if the CompositorThread has begun to shutdown.
+   */
+  bool IsInThread() {
+    bool rv = false;
+    MOZ_ALWAYS_TRUE(NS_SUCCEEDED(mCompositorThread->IsOnCurrentThread(&rv)));
+    return rv;
+  }
+
+  nsresult Dispatch(already_AddRefed<nsIRunnable> event,
+                    uint32_t flags = nsIEventTarget::DISPATCH_NORMAL) {
+    return mCompositorThread->Dispatch(std::move(event), flags);
+  }
+
+  static CompositorThreadHolder* GetSingleton();
+
+  static bool IsActive() { return !!GetSingleton(); }
+
+  /**
+   * Creates the compositor thread and the global compositor map.
+   */
+  static void Start();
+
+  /*
+   * Waits for all [CrossProcess]CompositorBridgeParents to shutdown and
+   * releases compositor-thread owned resources.
+   */
+  static void Shutdown();
+
+  // Returns true if the calling thread is the compositor thread.
+  static bool IsInCompositorThread();
+
+  // Thread id to use as a MarkerThreadId option for profiler markers.
+  static ProfilerThreadId GetThreadId();
+
+ private:
+  ~CompositorThreadHolder();
+
+  const nsCOMPtr<nsIThread> mCompositorThread;
+
+  static already_AddRefed<nsIThread> CreateCompositorThread();
+
+  friend class CompositorBridgeParent;
+};
+
+nsIThread* CompositorThread();
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif  // mozilla_layers_CompositorThread_h