Move PostTaskAndReplyWithStatus into task_runner_helpers.h

base/task_runner_util.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_TASK_RUNNER_UTIL_H_
+#define BASE_TASK_RUNNER_UTIL_H_
+#pragma once
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/logging.h"
+#include "base/task_runner.h"
+
+namespace base {
+
+namespace internal {
+
+// Helper class for TaskRunner::PostTaskAndReplyWithResult.
+template <typename ReturnType>
+void ReturnAsParamAdapter(const Callback<ReturnType(void)>& func,
+                          ReturnType* result) {
+  if (!func.is_null())
+    *result = func.Run();
+}
+
+// Helper class for TaskRunner::PostTaskAndReplyWithResult.
+template <typename ReturnType>
+Closure ReturnAsParam(const Callback<ReturnType(void)>& func,
+                      ReturnType* result) {
+  DCHECK(result);
+  return Bind(&ReturnAsParamAdapter<ReturnType>, func, result);
+}
+
+// Helper class for TaskRunner::PostTaskAndReplyWithResult.
+template <typename ReturnType>
+void ReplyAdapter(const Callback<void(ReturnType)>& callback,
+                  ReturnType* result) {
+  DCHECK(result);
+  if(!callback.is_null())
+    callback.Run(*result);
+}
+
+// Helper class for TaskRunner::PostTaskAndReplyWithResult.
+template <typename ReturnType, typename OwnedType>
+Closure ReplyHelper(const Callback<void(ReturnType)>& callback,
+                    OwnedType result) {
+  return Bind(&ReplyAdapter<ReturnType>, callback, result);
+}
+
+}  // namespace internal
+
+// When you have these methods
+//
+//   R DoWorkAndReturn();
+//   void Callback(const R& result);
+//
+// and want to call them in a PostTaskAndReply kind of fashion where the
+// result of DoWorkAndReturn is passed to the Callback, you can use
+// PostTaskAndReplyWithResult as in this example:
+//
+// PostTaskAndReplyWithResult(
+//     target_thread_.message_loop_proxy(),
+//     FROM_HERE,
+//     Bind(&DoWorkAndReturn),
+//     Bind(&Callback));
+template <typename ReturnType>
+bool PostTaskAndReplyWithResult(
+    TaskRunner* task_runner,
+    const tracked_objects::Location& from_here,
+    const Callback<ReturnType(void)>& task,
+    const Callback<void(ReturnType)>& reply) {
+  ReturnType* result = new ReturnType;
+  return task_runner->PostTaskAndReply(
+      from_here,
+      internal::ReturnAsParam<ReturnType>(task, result),
+      internal::ReplyHelper(reply, Owned(result)));
+}
+
+}  // namespace base
+
+#endif  // BASE_TASK_RUNNER_UTIL_H_