// Copyright (c) 2011 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. // This file contains the implementation for TaskRunner::PostTaskAndReply. #ifndef BASE_THREADING_POST_TASK_AND_REPLY_IMPL_H_ #define BASE_THREADING_POST_TASK_AND_REPLY_IMPL_H_ #include "base/base_export.h" #include "base/callback.h" #include "base/location.h" namespace base { namespace internal { // Inherit from this in a class that implements PostTask to send a task to a // custom execution context. // // If you're looking for a concrete implementation of PostTaskAndReply, you // probably want a base::TaskRunner (typically obtained from // base/task/thread_pool.h). class BASE_EXPORT PostTaskAndReplyImpl { public: virtual ~PostTaskAndReplyImpl() = default; // Posts |task| by calling PostTask(). On completion, posts |reply| to the // origin sequence. Can only be called when // SequencedTaskRunnerHandle::IsSet(). Each callback is deleted synchronously // after running, or scheduled for asynchronous deletion on the origin // sequence if it can't run (e.g. if a TaskRunner skips it on shutdown). See // SequencedTaskRunner::DeleteSoon() for when objects scheduled for // asynchronous deletion can be leaked. Note: All //base task posting APIs // require callbacks to support deletion on the posting sequence if they can't // be scheduled. bool PostTaskAndReply(const Location& from_here, OnceClosure task, OnceClosure reply); private: virtual bool PostTask(const Location& from_here, OnceClosure task) = 0; }; } // namespace internal } // namespace base #endif // BASE_THREADING_POST_TASK_AND_REPLY_IMPL_H_