blob: 7ae085b407f02f16b033daf13e6fdd9353e68696 [file] [log] [blame]
// 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_
#include <memory>
#include <utility>
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/callback.h"
#include "base/logging.h"
#include "base/post_task_and_reply_with_result_internal.h"
#include "base/task_runner.h"
namespace base {
// 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_.task_runner(),
// FROM_HERE,
// BindOnce(&DoWorkAndReturn),
// BindOnce(&Callback));
template <typename TaskReturnType, typename ReplyArgType>
bool PostTaskAndReplyWithResult(TaskRunner* task_runner,
const Location& from_here,
OnceCallback<TaskReturnType()> task,
OnceCallback<void(ReplyArgType)> reply) {
DCHECK(task);
DCHECK(reply);
// std::unique_ptr used to avoid the need of a default constructor.
auto* result = new std::unique_ptr<TaskReturnType>();
return task_runner->PostTaskAndReply(
from_here,
BindOnce(&internal::ReturnAsParamAdapter<TaskReturnType>, std::move(task),
result),
BindOnce(&internal::ReplyAdapter<TaskReturnType, ReplyArgType>,
std::move(reply), Owned(result)));
}
// Callback version of PostTaskAndReplyWithResult above.
// Though RepeatingCallback is convertible to OnceCallback, we need this since
// we cannot use template deduction and object conversion at once on the
// overload resolution.
// TODO(crbug.com/714018): Update all callers of the Callback version to use
// OnceCallback.
template <typename TaskReturnType, typename ReplyArgType>
bool PostTaskAndReplyWithResult(TaskRunner* task_runner,
const Location& from_here,
Callback<TaskReturnType()> task,
Callback<void(ReplyArgType)> reply) {
return PostTaskAndReplyWithResult(
task_runner, from_here, OnceCallback<TaskReturnType()>(std::move(task)),
OnceCallback<void(ReplyArgType)>(std::move(reply)));
}
} // namespace base
#endif // BASE_TASK_RUNNER_UTIL_H_