Differential D4675 Diff 20391 ps/trunk/source/ps/Future.h

Changeset View

Standalone View

ps/trunk/source/ps/Future.h

/* Copyright (C) 2021 Wildfire Games.		/* Copyright (C) 2022 Wildfire Games.
* This file is part of 0 A.D.		* This file is part of 0 A.D.
*		*
* 0 A.D. is free software: you can redistribute it and/or modify		* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by		* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or		* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.		* (at your option) any later version.
*		*
* 0 A.D. is distributed in the hope that it will be useful,		* 0 A.D. is distributed in the hope that it will be useful,
▲ Show 20 Lines • Show All 62 Lines • ▼ Show 20 Lines
* The shared state between futures and packaged state.		* The shared state between futures and packaged state.
* Holds all relevant data.		* Holds all relevant data.
*/		*/
template<typename ResultType>		template<typename ResultType>
class SharedState : public SharedStateResult<ResultType>		class SharedState : public SharedStateResult<ResultType>
{		{
static constexpr bool VoidResult = std::is_same_v<ResultType, void>;		static constexpr bool VoidResult = std::is_same_v<ResultType, void>;
public:		public:
SharedState(std::function<ResultType()>&& func) : m_Func(func) {}		SharedState(std::function<ResultType()>&& func) : m_Func(std::move(func)) {}
~SharedState()		~SharedState()
{		{
// For safety, wait on started task completion, but not on pending ones (auto-cancelled).		// For safety, wait on started task completion, but not on pending ones (auto-cancelled).
if (!Cancel())		if (!Cancel())
{		{
Wait();		Wait();
Cancel();		Cancel();
}		}
▲ Show 20 Lines • Show All 81 Lines • ▼ Show 20 Lines	class Future
template<typename T>		template<typename T>
friend class PackagedTask;		friend class PackagedTask;

static constexpr bool VoidResult = std::is_same_v<ResultType, void>;		static constexpr bool VoidResult = std::is_same_v<ResultType, void>;

using Status = FutureSharedStateDetail::Status;		using Status = FutureSharedStateDetail::Status;
using SharedState = FutureSharedStateDetail::SharedState<ResultType>;		using SharedState = FutureSharedStateDetail::SharedState<ResultType>;
public:		public:
Future() {};		Future() = default;
Future(const Future& o) = delete;		Future(const Future& o) = delete;
Future(Future&&) = default;		Future(Future&&) = default;
Future& operator=(Future&&) = default;		Future& operator=(Future&&) = default;
~Future() {}		~Future() = default;

/**		/**
* Make the future wait for the result of @a func.		* Make the future wait for the result of @a func.
*/		*/
template<typename T>		template<typename T>
PackagedTask<ResultType> Wrap(T&& func);		PackagedTask<ResultType> Wrap(T&& func);

/**		/**
▲ Show 20 Lines • Show All 76 Lines • ▼ Show 20 Lines
* handling the promise & continuation logic.		* handling the promise & continuation logic.
*/		*/
template<typename ResultType>		template<typename ResultType>
class PackagedTask		class PackagedTask
{		{
static constexpr bool VoidResult = std::is_same_v<ResultType, void>;		static constexpr bool VoidResult = std::is_same_v<ResultType, void>;
public:		public:
PackagedTask() = delete;		PackagedTask() = delete;
PackagedTask(const std::shared_ptr<typename Future<ResultType>::SharedState>& ss) : m_SharedState(ss) {}		PackagedTask(std::shared_ptr<typename Future<ResultType>::SharedState> ss) : m_SharedState(std::move(ss)) {}

void operator()()		void operator()()
{		{
typename Future<ResultType>::Status expected = Future<ResultType>::Status::PENDING;		typename Future<ResultType>::Status expected = Future<ResultType>::Status::PENDING;
if (!m_SharedState->m_Status.compare_exchange_strong(expected, Future<ResultType>::Status::STARTED))		if (!m_SharedState->m_Status.compare_exchange_strong(expected, Future<ResultType>::Status::STARTED))
return;		return;

if constexpr (VoidResult)		if constexpr (VoidResult)
▲ Show 20 Lines • Show All 43 Lines • Show Last 20 Lines