Pass Callback by value on PostTaskAndReply family

base/task_scheduler/post_task.h

 // Copyright 2016 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_SCHEDULER_POST_TASK_H_
 #define BASE_TASK_SCHEDULER_POST_TASK_H_
 
 #include "base/base_export.h"
 #include "base/bind.h"
-#include "base/callback_forward.h"
+#include "base/callback.h"
 #include "base/location.h"
 #include "base/memory/ref_counted.h"
 #include "base/post_task_and_reply_with_result_internal.h"
 #include "base/sequenced_task_runner.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner.h"
 #include "base/task_scheduler/task_traits.h"
 #include "base/time/time.h"
 
 namespace base {
@@ skipping 53 matching lines @@
 BASE_EXPORT void PostDelayedTask(const tracked_objects::Location& from_here,
                                  const Closure& task,
                                  TimeDelta delay);
 
 // Posts |task| to the TaskScheduler and posts |reply| on the caller's execution
 // context (i.e. same sequence or thread and same TaskTraits if applicable) when
 // |task| completes. Calling this is equivalent to calling
 // PostTaskWithTraitsAndReply with plain TaskTraits. Can only be called when
 // SequencedTaskRunnerHandle::IsSet().
 BASE_EXPORT void PostTaskAndReply(const tracked_objects::Location& from_here,
-                                  const Closure& task,
-                                  const Closure& reply);
+                                  Closure task,
+                                  Closure reply);
 
 // Posts |task| to the TaskScheduler and posts |reply| with the return value of
 // |task| as argument on the caller's execution context (i.e. same sequence or
 // thread and same TaskTraits if applicable) when |task| completes. Calling this
 // is equivalent to calling PostTaskWithTraitsAndReplyWithResult with plain
 // TaskTraits. Can only be called when SequencedTaskRunnerHandle::IsSet().
 template <typename TaskReturnType, typename ReplyArgType>
 void PostTaskAndReplyWithResult(const tracked_objects::Location& from_here,
-                                const Callback<TaskReturnType(void)>& task,
-                                const Callback<void(ReplyArgType)>& reply) {
-  PostTaskWithTraitsAndReplyWithResult(from_here, TaskTraits(), task, reply);
+                                Callback<TaskReturnType(void)> task,
+                                Callback<void(ReplyArgType)> reply) {
+  PostTaskWithTraitsAndReplyWithResult(from_here, TaskTraits(), std::move(task),
+                                       std::move(reply));

[gab, 2017/02/07 15:46:08]

#include <utility>

[tzik, 2017/02/08 01:39:32]

Done.

 }
 
 // Posts |task| with specific |traits| to the TaskScheduler.
 BASE_EXPORT void PostTaskWithTraits(const tracked_objects::Location& from_here,
                                     const TaskTraits& traits,
                                     const Closure& task);
 
 // Posts |task| with specific |traits| to the TaskScheduler. |task| will not run
 // before |delay| expires.
 //
 // Specify a BACKGROUND priority via |traits| if the task doesn't have to run as
 // soon as |delay| expires.
 BASE_EXPORT void PostDelayedTaskWithTraits(
     const tracked_objects::Location& from_here,
     const TaskTraits& traits,
     const Closure& task,
     TimeDelta delay);
 
 // Posts |task| with specific |traits| to the TaskScheduler and posts |reply| on
 // the caller's execution context (i.e. same sequence or thread and same
 // TaskTraits if applicable) when |task| completes. Can only be called when
 // SequencedTaskRunnerHandle::IsSet().
 BASE_EXPORT void PostTaskWithTraitsAndReply(
     const tracked_objects::Location& from_here,
     const TaskTraits& traits,
-    const Closure& task,
-    const Closure& reply);
+    Closure task,
+    Closure reply);
 
 // Posts |task| with specific |traits| to the TaskScheduler and posts |reply|
 // with the return value of |task| as argument on the caller's execution context
 // (i.e. same sequence or thread and same TaskTraits if applicable) when |task|
 // completes. Can only be called when SequencedTaskRunnerHandle::IsSet().
 template <typename TaskReturnType, typename ReplyArgType>
 void PostTaskWithTraitsAndReplyWithResult(
     const tracked_objects::Location& from_here,
     const TaskTraits& traits,
-    const Callback<TaskReturnType(void)>& task,
-    const Callback<void(ReplyArgType)>& reply) {
+    Callback<TaskReturnType()> task,
+    Callback<void(ReplyArgType)> reply) {
   TaskReturnType* result = new TaskReturnType();
   return PostTaskWithTraitsAndReply(
-      from_here, traits,
-      Bind(&internal::ReturnAsParamAdapter<TaskReturnType>, task, result),
-      Bind(&internal::ReplyAdapter<TaskReturnType, ReplyArgType>, reply,
-           Owned(result)));
+      from_here, traits, Bind(&internal::ReturnAsParamAdapter<TaskReturnType>,
+                              std::move(task), result),
+      Bind(&internal::ReplyAdapter<TaskReturnType, ReplyArgType>,
+           std::move(reply), Owned(result)));
 }
 
 // Returns a TaskRunner whose PostTask invocations result in scheduling tasks
 // using |traits|. Tasks may run in any order and in parallel.
 BASE_EXPORT scoped_refptr<TaskRunner> CreateTaskRunnerWithTraits(
     const TaskTraits& traits);
 
 // Returns a SequencedTaskRunner whose PostTask invocations result in scheduling
 // tasks using |traits|. Tasks run one at a time in posting order.
 BASE_EXPORT scoped_refptr<SequencedTaskRunner>
 CreateSequencedTaskRunnerWithTraits(const TaskTraits& traits);
 
 // Returns a SingleThreadTaskRunner whose PostTask invocations result in
 // scheduling tasks using |traits|. Tasks run on a single thread in posting
 // order.
 //
 // If all you need is to make sure that tasks don't run concurrently (e.g.
 // because they access a data structure which is not thread-safe), use
 // CreateSequencedTaskRunnerWithTraits(). Only use this if you rely on a thread-
 // affine API (it might be safer to assume thread-affinity when dealing with
 // under-documented third-party APIs, e.g. other OS') or share data across tasks
 // using thread-local storage.
 BASE_EXPORT scoped_refptr<SingleThreadTaskRunner>
 CreateSingleThreadTaskRunnerWithTraits(const TaskTraits& traits);
 
 }  // namespace base
 
 #endif  // BASE_TASK_SCHEDULER_POST_TASK_H_