mirror of
https://github.com/DrKLO/Telegram.git
synced 2024-12-23 15:00:50 +01:00
250 lines
12 KiB
C++
250 lines
12 KiB
C++
// Copyright 2019 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_THREAD_POOL_H_
|
|
#define BASE_TASK_THREAD_POOL_H_
|
|
|
|
#include <memory>
|
|
#include <utility>
|
|
|
|
namespace base {
|
|
// TODO(gab): thread_pool.h should include task_traits.h but it can't during the
|
|
// migration because task_traits.h has to include thread_pool.h to get the old
|
|
// base::ThreadPool() trait constructor and that would create a circular
|
|
// dependency. Some of the includes below result in an extended version of this
|
|
// circular dependency. These forward-declarations are temporarily required for
|
|
// the duration of the migration.
|
|
enum class TaskPriority : uint8_t;
|
|
enum class TaskShutdownBehavior : uint8_t;
|
|
enum class ThreadPolicy : uint8_t;
|
|
struct MayBlock;
|
|
struct WithBaseSyncPrimitives;
|
|
class TaskTraits;
|
|
// UpdateableSequencedTaskRunner is part of this dance too because
|
|
// updateable_sequenced_task_runner.h includes task_traits.h
|
|
class UpdateableSequencedTaskRunner;
|
|
} // namespace base
|
|
|
|
#include "base/base_export.h"
|
|
#include "base/bind.h"
|
|
#include "base/callback.h"
|
|
#include "base/callback_helpers.h"
|
|
#include "base/location.h"
|
|
#include "base/memory/scoped_refptr.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/single_thread_task_runner_thread_mode.h"
|
|
#include "base/task_runner.h"
|
|
#include "base/time/time.h"
|
|
#include "build/build_config.h"
|
|
|
|
namespace base {
|
|
|
|
// This is the interface to post tasks to base's thread pool.
|
|
//
|
|
// To post a simple one-off task with default traits:
|
|
// base::ThreadPool::PostTask(FROM_HERE, base::BindOnce(...));
|
|
//
|
|
// To post a high priority one-off task to respond to a user interaction:
|
|
// base::ThreadPool::PostTask(
|
|
// FROM_HERE,
|
|
// {base::TaskPriority::USER_BLOCKING},
|
|
// base::BindOnce(...));
|
|
//
|
|
// To post tasks that must run in sequence with default traits:
|
|
// scoped_refptr<SequencedTaskRunner> task_runner =
|
|
// base::ThreadPool::CreateSequencedTaskRunner();
|
|
// task_runner->PostTask(FROM_HERE, base::BindOnce(...));
|
|
// task_runner->PostTask(FROM_HERE, base::BindOnce(...));
|
|
//
|
|
// To post tasks that may block, must run in sequence and can be skipped on
|
|
// shutdown:
|
|
// scoped_refptr<SequencedTaskRunner> task_runner =
|
|
// base::ThreadPool::CreateSequencedTaskRunner(
|
|
// {MayBlock(), TaskShutdownBehavior::SKIP_ON_SHUTDOWN});
|
|
// task_runner->PostTask(FROM_HERE, base::BindOnce(...));
|
|
// task_runner->PostTask(FROM_HERE, base::BindOnce(...));
|
|
//
|
|
// The default traits apply to tasks that:
|
|
// (1) don't block (ref. MayBlock() and WithBaseSyncPrimitives()),
|
|
// (2) prefer inheriting the current priority to specifying their own, and
|
|
// (3) can either block shutdown or be skipped on shutdown
|
|
// (implementation is free to choose a fitting default).
|
|
// Explicit traits must be specified for tasks for which these loose
|
|
// requirements are not sufficient.
|
|
//
|
|
// Prerequisite: A ThreadPoolInstance must have been registered for the current
|
|
// process via ThreadPoolInstance::Set() before the API below can be invoked.
|
|
// This is typically done during the initialization phase in each process. If
|
|
// your code is not running in that phase, you most likely don't have to worry
|
|
// about this. You will encounter DCHECKs or nullptr dereferences if this is
|
|
// violated. For tests, use base::test::TaskEnvironment.
|
|
class BASE_EXPORT ThreadPool {
|
|
public:
|
|
// base::ThreadPool is meant to be a static API. Do not use this constructor
|
|
// in new code! It is a temporary hack to support the old base::ThreadPool()
|
|
// trait during the migration to static base::ThreadPool:: APIs.
|
|
// Tasks and task runners with this trait will run in the thread pool,
|
|
// concurrently with tasks on other task runners. If you need mutual exclusion
|
|
// between tasks, see base::ThreadPool::CreateSequencedTaskRunner.
|
|
ThreadPool() = default;
|
|
|
|
// Equivalent to calling PostTask with default TaskTraits.
|
|
static bool PostTask(const Location& from_here, OnceClosure task);
|
|
inline static bool PostTask(OnceClosure task,
|
|
const Location& from_here = Location::Current()) {
|
|
return PostTask(from_here, std::move(task));
|
|
}
|
|
|
|
// Equivalent to calling PostDelayedTask with default TaskTraits.
|
|
//
|
|
// Use PostDelayedTask to specify a BEST_EFFORT priority if the task doesn't
|
|
// have to run as soon as |delay| expires.
|
|
static bool PostDelayedTask(const Location& from_here,
|
|
OnceClosure task,
|
|
TimeDelta delay);
|
|
|
|
// Equivalent to calling PostTaskAndReply with default TaskTraits.
|
|
static bool PostTaskAndReply(const Location& from_here,
|
|
OnceClosure task,
|
|
OnceClosure reply);
|
|
|
|
// Equivalent to calling PostTaskAndReplyWithResult with default TaskTraits.
|
|
//
|
|
// Though RepeatingCallback is convertible to OnceCallback, we need a
|
|
// CallbackType template since we can not use template deduction and object
|
|
// conversion at once on the overload resolution.
|
|
// TODO(crbug.com/714018): Update all callers of the RepeatingCallback version
|
|
// to use OnceCallback and remove the CallbackType template.
|
|
template <template <typename> class CallbackType,
|
|
typename TaskReturnType,
|
|
typename ReplyArgType,
|
|
typename = EnableIfIsBaseCallback<CallbackType>>
|
|
static bool PostTaskAndReplyWithResult(
|
|
const Location& from_here,
|
|
CallbackType<TaskReturnType()> task,
|
|
CallbackType<void(ReplyArgType)> reply) {
|
|
return ThreadPool::PostTaskAndReplyWithResult(from_here, std::move(task),
|
|
std::move(reply));
|
|
}
|
|
|
|
// Posts |task| with specific |traits|. Returns false if the task definitely
|
|
// won't run because of current shutdown state.
|
|
static bool PostTask(const Location& from_here,
|
|
const TaskTraits& traits,
|
|
OnceClosure task);
|
|
|
|
// Posts |task| with specific |traits|. |task| will not run before |delay|
|
|
// expires. Returns false if the task definitely won't run because of current
|
|
// shutdown state.
|
|
//
|
|
// Specify a BEST_EFFORT priority via |traits| if the task doesn't have to run
|
|
// as soon as |delay| expires.
|
|
static bool PostDelayedTask(const Location& from_here,
|
|
const TaskTraits& traits,
|
|
OnceClosure task,
|
|
TimeDelta delay);
|
|
|
|
// Posts |task| with specific |traits| and posts |reply| on the caller's
|
|
// execution context (i.e. same sequence or thread and same TaskTraits if
|
|
// applicable) when |task| completes. Returns false if the task definitely
|
|
// won't run because of current shutdown state. Can only be called when
|
|
// SequencedTaskRunnerHandle::IsSet().
|
|
static bool PostTaskAndReply(const Location& from_here,
|
|
const TaskTraits& traits,
|
|
OnceClosure task,
|
|
OnceClosure reply);
|
|
|
|
// Posts |task| with specific |traits| 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. Returns
|
|
// false if the task definitely won't run because of current shutdown state.
|
|
// Can only be called when SequencedTaskRunnerHandle::IsSet().
|
|
//
|
|
// Though RepeatingCallback is convertible to OnceCallback, we need a
|
|
// CallbackType template since we can not use template deduction and object
|
|
// conversion at once on the overload resolution.
|
|
// TODO(crbug.com/714018): Update all callers of the RepeatingCallback version
|
|
// to use OnceCallback and remove the CallbackType template.
|
|
template <template <typename> class CallbackType,
|
|
typename TaskReturnType,
|
|
typename ReplyArgType,
|
|
typename = EnableIfIsBaseCallback<CallbackType>>
|
|
static bool PostTaskAndReplyWithResult(
|
|
const Location& from_here,
|
|
const TaskTraits& traits,
|
|
CallbackType<TaskReturnType()> task,
|
|
CallbackType<void(ReplyArgType)> reply) {
|
|
auto* result = new std::unique_ptr<TaskReturnType>();
|
|
return PostTaskAndReply(
|
|
from_here, traits,
|
|
BindOnce(&internal::ReturnAsParamAdapter<TaskReturnType>,
|
|
std::move(task), result),
|
|
BindOnce(&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.
|
|
static scoped_refptr<TaskRunner> CreateTaskRunner(const TaskTraits& traits);
|
|
|
|
// Returns a SequencedTaskRunner whose PostTask invocations result in
|
|
// scheduling tasks using |traits|. Tasks run one at a time in posting order.
|
|
static scoped_refptr<SequencedTaskRunner> CreateSequencedTaskRunner(
|
|
const TaskTraits& traits);
|
|
|
|
// Returns a task runner whose PostTask invocations result in scheduling tasks
|
|
// using |traits|. The priority in |traits| can be updated at any time via
|
|
// UpdateableSequencedTaskRunner::UpdatePriority(). An update affects all
|
|
// tasks posted to the task runner that aren't running yet. Tasks run one at a
|
|
// time in posting order.
|
|
//
|
|
// |traits| requirements:
|
|
// - base::ThreadPolicy must be specified if the priority of the task runner
|
|
// will ever be increased from BEST_EFFORT.
|
|
static scoped_refptr<UpdateableSequencedTaskRunner>
|
|
CreateUpdateableSequencedTaskRunner(const TaskTraits& traits);
|
|
|
|
// Returns a SingleThreadTaskRunner whose PostTask invocations result in
|
|
// scheduling tasks using |traits| on a thread determined by |thread_mode|.
|
|
// See base/task/single_thread_task_runner_thread_mode.h for |thread_mode|
|
|
// details. If |traits| identifies an existing thread,
|
|
// SingleThreadTaskRunnerThreadMode::SHARED must be used. 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
|
|
// CreateSequencedTaskRunner(). 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.
|
|
static scoped_refptr<SingleThreadTaskRunner> CreateSingleThreadTaskRunner(
|
|
const TaskTraits& traits,
|
|
SingleThreadTaskRunnerThreadMode thread_mode =
|
|
SingleThreadTaskRunnerThreadMode::SHARED);
|
|
|
|
#if defined(OS_WIN)
|
|
// Returns a SingleThreadTaskRunner whose PostTask invocations result in
|
|
// scheduling tasks using |traits| in a COM Single-Threaded Apartment on a
|
|
// thread determined by |thread_mode|. See
|
|
// base/task/single_thread_task_runner_thread_mode.h for |thread_mode|
|
|
// details. If |traits| identifies an existing thread,
|
|
// SingleThreadTaskRunnerThreadMode::SHARED must be used. Tasks run in the
|
|
// same Single-Threaded Apartment in posting order for the returned
|
|
// SingleThreadTaskRunner. There is not necessarily a one-to-one
|
|
// correspondence between SingleThreadTaskRunners and Single-Threaded
|
|
// Apartments. The implementation is free to share apartments or create new
|
|
// apartments as necessary. In either case, care should be taken to make sure
|
|
// COM pointers are not smuggled across apartments.
|
|
static scoped_refptr<SingleThreadTaskRunner> CreateCOMSTATaskRunner(
|
|
const TaskTraits& traits,
|
|
SingleThreadTaskRunnerThreadMode thread_mode =
|
|
SingleThreadTaskRunnerThreadMode::SHARED);
|
|
#endif // defined(OS_WIN)
|
|
};
|
|
|
|
} // namespace base
|
|
|
|
#endif // BASE_TASK_THREAD_POOL_H_
|