1 files changed, 117 insertions, 0 deletions
diff --git a/gfx/layers/apz/util/APZThreadUtils.h b/gfx/layers/apz/util/APZThreadUtils.h
new file mode 100644
index 0000000000..fb03ac10da
--- /dev/null
+++ b/gfx/layers/apz/util/APZThreadUtils.h
@@ -0,0 +1,117 @@
+/* -*- 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_APZThreadUtils_h
+#define mozilla_layers_APZThreadUtils_h
+
+#include "nsINamed.h"
+#include "nsITimer.h"
+#include "nsString.h"
+
+class nsISerialEventTarget;
+
+namespace mozilla {
+
+class Runnable;
+
+namespace layers {
+
+class APZThreadUtils {
+ public:
+  /**
+   * In the gtest environment everything runs on one thread, so we
+   * shouldn't assert that we're on a particular thread. This enables
+   * that behaviour.
+   */
+  static void SetThreadAssertionsEnabled(bool aEnabled);
+  static bool GetThreadAssertionsEnabled();
+
+  /**
+   * Set the controller thread.
+   */
+  static void SetControllerThread(nsISerialEventTarget* aThread);
+
+  /**
+   * This can be used to assert that the current thread is the
+   * controller/UI thread (on which input events are received).
+   * This does nothing if thread assertions are disabled.
+   */
+  static void AssertOnControllerThread();
+
+  /**
+   * Run the given task on the APZ "controller thread" for this platform. If
+   * this function is called from the controller thread itself then the task is
+   * run immediately without getting queued.
+   */
+  static void RunOnControllerThread(RefPtr<Runnable>&& aTask);
+
+  /**
+   * Returns true if currently on APZ "controller thread".
+   */
+  static bool IsControllerThread();
+
+  /**
+   * Returns true if the controller thread is still alive.
+   */
+  static bool IsControllerThreadAlive();
+
+  /**
+   * Schedules a runnable to run on the controller thread at some time
+   * in the future.
+   */
+  static void DelayedDispatch(already_AddRefed<Runnable> aRunnable,
+                              int aDelayMs);
+};
+
+// A base class for GenericNamedTimerCallback<Function>.
+// This is necessary because NS_IMPL_ISUPPORTS doesn't work for a class
+// template.
+class GenericNamedTimerCallbackBase : public nsITimerCallback, public nsINamed {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+ protected:
+  virtual ~GenericNamedTimerCallbackBase() = default;
+};
+
+// An nsITimerCallback implementation with nsINamed that can be used with any
+// function object that's callable with no arguments.
+template <typename Function>
+class GenericNamedTimerCallback final : public GenericNamedTimerCallbackBase {
+ public:
+  GenericNamedTimerCallback(const Function& aFunction, const char* aName)
+      : mFunction(aFunction), mName(aName) {}
+
+  NS_IMETHOD Notify(nsITimer*) override {
+    mFunction();
+    return NS_OK;
+  }
+
+  NS_IMETHOD GetName(nsACString& aName) override {
+    aName = mName;
+    return NS_OK;
+  }
+
+ private:
+  Function mFunction;
+  nsCString mName;
+};
+
+// Convenience function for constructing a GenericNamedTimerCallback.
+// Returns a raw pointer, suitable for passing directly as an argument to
+// nsITimer::InitWithCallback(). The intention is to enable the following
+// terse inline usage:
+//    timer->InitWithCallback(NewNamedTimerCallback([](){ ... }, name), delay);
+template <typename Function>
+GenericNamedTimerCallback<Function>* NewNamedTimerCallback(
+    const Function& aFunction, const char* aName) {
+  return new GenericNamedTimerCallback<Function>(aFunction, aName);
+}
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif /* mozilla_layers_APZThreadUtils_h */