1 files changed, 85 insertions, 0 deletions
diff --git a/gfx/ipc/CanvasRenderThread.h b/gfx/ipc/CanvasRenderThread.h
new file mode 100644
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+++ b/gfx/ipc/CanvasRenderThread.h
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+/* -*- 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 _include_gfx_ipc_CanvasRenderThread_h__
+#define _include_gfx_ipc_CanvasRenderThread_h__
+
+#include "mozilla/AlreadyAddRefed.h"
+#include "mozilla/Mutex.h"
+#include "nsCOMPtr.h"
+#include "nsISupportsImpl.h"
+#include "nsTArray.h"
+
+class nsIRunnable;
+class nsIThread;
+class nsIThreadPool;
+
+namespace mozilla {
+class TaskQueue;
+
+namespace gfx {
+
+/**
+ * This class represents the virtual thread for canvas rendering. Depending on
+ * platform requirements and user configuration, canvas rendering may happen on
+ * the Compositor thread, Render thread or the CanvasRender thread.
+ */
+class CanvasRenderThread final {
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DELETE_ON_MAIN_THREAD(
+      CanvasRenderThread)
+
+ public:
+  /// Can only be called from the main thread, expected to be called at most
+  /// once during a process' lifetime. Must be called after the Compositor and
+  /// Render threads are initialized.
+  static void Start();
+
+  /// Can only be called from the main thread. Must be called before the
+  /// Compositor and Render threads are shutdown.
+  static void Shutdown();
+
+  /// Can be called from any thread.
+  static bool IsInCanvasRenderThread();
+
+  /// Can be called from any thread.
+  static bool IsInCanvasWorkerThread();
+
+  /// Can be called from any thread.
+  static bool IsInCanvasRenderOrWorkerThread();
+
+  /// Can be called from any thread, may return nullptr late in shutdown.
+  static already_AddRefed<nsIThread> GetCanvasRenderThread();
+
+  static already_AddRefed<TaskQueue> CreateWorkerTaskQueue();
+
+  static void ShutdownWorkerTaskQueue(TaskQueue* aTaskQueue);
+
+  static void FinishShutdownWorkerTaskQueue(TaskQueue* aTaskQueue);
+
+  static void Dispatch(already_AddRefed<nsIRunnable> aRunnable);
+
+ private:
+  CanvasRenderThread(nsCOMPtr<nsIThread>&& aThread,
+                     nsCOMPtr<nsIThreadPool>&& aWorkers, bool aCreatedThread);
+  ~CanvasRenderThread();
+
+  Mutex mMutex;
+
+  nsCOMPtr<nsIThread> const mThread;
+
+  nsCOMPtr<nsIThreadPool> const mWorkers;
+
+  nsTArray<RefPtr<TaskQueue>> mPendingShutdownTaskQueues MOZ_GUARDED_BY(mMutex);
+
+  // True if mThread points to CanvasRender thread, false if mThread points to
+  // Compositor/Render thread.
+  const bool mCreatedThread;
+};
+
+}  // namespace gfx
+}  // namespace mozilla
+
+#endif  // _include_gfx_ipc_CanvasRenderThread_h__