1 files changed, 97 insertions, 0 deletions
diff --git a/ipc/glue/TaskFactory.h b/ipc/glue/TaskFactory.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 mozilla_plugins_TaskFactory_h
+#define mozilla_plugins_TaskFactory_h
+
+#include <base/task.h>
+
+#include <utility>
+
+/*
+ * This is based on the ScopedRunnableMethodFactory from
+ * ipc/chromium/src/base/task.h Chromium's factories assert if tasks are created
+ * and run on different threads, which is something we need to do in
+ * PluginModuleParent (hang UI vs. main thread). TaskFactory just provides
+ * cancellable tasks that don't assert this. This version also allows both
+ * ScopedMethod and regular Tasks to be generated by the same Factory object.
+ */
+
+namespace mozilla {
+namespace ipc {
+
+template <class T>
+class TaskFactory : public RevocableStore {
+ private:
+  template <class TaskType>
+  class TaskWrapper : public TaskType {
+   public:
+    template <typename... Args>
+    explicit TaskWrapper(RevocableStore* store, Args&&... args)
+        : TaskType(std::forward<Args>(args)...), revocable_(store) {}
+
+    NS_IMETHOD Run() override {
+      if (!revocable_.revoked()) TaskType::Run();
+      return NS_OK;
+    }
+
+   private:
+    Revocable revocable_;
+  };
+
+ public:
+  explicit TaskFactory(T* object) : object_(object) {}
+
+  template <typename TaskParamType, typename... Args>
+  inline already_AddRefed<TaskParamType> NewTask(Args&&... args) {
+    typedef TaskWrapper<TaskParamType> TaskWrapper;
+    RefPtr<TaskWrapper> task =
+        new TaskWrapper(this, std::forward<Args>(args)...);
+    return task.forget();
+  }
+
+  template <class Method, typename... Args>
+  inline already_AddRefed<Runnable> NewRunnableMethod(Method method,
+                                                      Args&&... args) {
+    typedef decltype(base::MakeTuple(std::forward<Args>(args)...)) ArgTuple;
+    typedef RunnableMethod<Method, ArgTuple> RunnableMethod;
+    typedef TaskWrapper<RunnableMethod> TaskWrapper;
+
+    RefPtr<TaskWrapper> task = new TaskWrapper(
+        this, object_, method, base::MakeTuple(std::forward<Args>(args)...));
+
+    return task.forget();
+  }
+
+ protected:
+  template <class Method, class Params>
+  class RunnableMethod : public Runnable {
+   public:
+    RunnableMethod(T* obj, Method meth, const Params& params)
+        : Runnable("ipc::TaskFactory::RunnableMethod"),
+          obj_(obj),
+          meth_(meth),
+          params_(params) {}
+
+    NS_IMETHOD Run() override {
+      DispatchToMethod(obj_, meth_, params_);
+      return NS_OK;
+    }
+
+   private:
+    T* obj_;
+    Method meth_;
+    Params params_;
+  };
+
+ private:
+  T* object_;
+};
+
+}  // namespace ipc
+}  // namespace mozilla
+
+#endif  // mozilla_plugins_TaskFactory_h