From 7289258a751269de15f7e69d32a10f6b4ca6ab58 Mon Sep 17 00:00:00 2001
From: tearshark <tearshark@163.com>
Date: Sun, 16 Feb 2020 10:27:00 +0800
Subject: [PATCH] =?UTF-8?q?=E5=87=86=E5=A4=87=E6=94=AF=E6=8C=81=E8=B0=83?=
 =?UTF-8?q?=E5=BA=A6generator?=
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---
 librf/src/def.h                      |  9 +++
 librf/src/generator.h                | 52 ++++++++--------
 librf/src/promise.inl                |  4 +-
 librf/src/scheduler.cpp              |  9 ++-
 librf/src/scheduler.h                |  6 +-
 librf/src/state.cpp                  | 37 +++++++++++-
 librf/src/state.h                    | 90 +++++++++++++---------------
 librf/src/state.inl                  | 10 ++--
 tutorial/test_async_yield_return.cpp |  2 +-
 vs_proj/librf.vcxproj                |  6 +-
 vs_proj/librf.vcxproj.filters        |  3 +
 11 files changed, 133 insertions(+), 95 deletions(-)

diff --git a/librf/src/def.h b/librf/src/def.h
index 1747e03..dc6241d 100644
--- a/librf/src/def.h
+++ b/librf/src/def.h
@@ -67,6 +67,8 @@ namespace resumef
 
 	template<typename _PromiseT = void>
 	using coroutine_handle = std::experimental::coroutine_handle<_PromiseT>;
+	template <typename _Ty, typename _Alloc = std::allocator<char>>
+	using generator_t = std::experimental::generator<_Ty, _Alloc>;
 
 	enum struct error_code
 	{
@@ -151,6 +153,13 @@ namespace resumef
 	template<class _Ty>
 	_INLINE_VAR constexpr bool is_future_v = is_future<std::remove_cvref_t<_Ty>>::value;
 
+	template<class _G>
+	struct is_generator : std::false_type {};
+	template <typename _Ty, typename _Alloc>
+	struct is_generator<generator_t<_Ty, _Alloc>> : std::true_type {};
+	template<class _Ty>
+	_INLINE_VAR constexpr bool is_generator_v = is_generator<std::remove_cvref_t<_Ty>>::value;
+
 	//获得当前线程下的调度器
 	scheduler_t* this_scheduler();
 }
diff --git a/librf/src/generator.h b/librf/src/generator.h
index 1a8bbfa..08f15cb 100644
--- a/librf/src/generator.h
+++ b/librf/src/generator.h
@@ -20,7 +20,10 @@
 
 #include <experimental/resumable>
 
-#pragma pack(push, _CRT_PACKING)
+#pragma pack(push,_CRT_PACKING)
+#pragma warning(push,_STL_WARNING_LEVEL)
+#pragma warning(disable: _STL_DISABLED_WARNINGS)
+_STL_DISABLE_CLANG_WARNINGS
 #pragma push_macro("new")
 #undef new
 
@@ -49,23 +52,18 @@ namespace experimental {
 
 		generator_iterator &operator++()
 		{
+			_Coro.resume();
 			if (_Coro.done())
 				_Coro = nullptr;
-			else
-				_Coro.resume();
 			return *this;
 		}
 
-		generator_iterator operator++(int) = delete;
-		// generator iterator current_value
-		// is a reference to a temporary on the coroutine frame
-		// implementing postincrement will require storing a copy
-		// of the value in the iterator.
-		//{
-		//	auto _Result = *this;
-		//	++(*this);
-		//	return _Result;
-		//}
+		void operator++(int)
+		{
+			// This postincrement operator meets the requirements of the Ranges TS
+			// InputIterator concept, but not those of Standard C++ InputIterator.
+			++* this;
+		}
 
 		bool operator==(generator_iterator const &right_) const
 		{
@@ -92,6 +90,10 @@ namespace experimental {
 	template <typename _Ty, typename promise_type>
 	struct generator_iterator : public generator_iterator<void, promise_type>
 	{
+		using value_type = _Ty;
+		using reference = _Ty const&;
+		using pointer = _Ty const*;
+
 		generator_iterator(nullptr_t) : generator_iterator<void, promise_type>(nullptr)
 		{
 		}
@@ -99,14 +101,14 @@ namespace experimental {
 		{
 		}
 
-		_Ty const &operator*() const
+		reference operator*() const
 		{
-			return *this->_Coro.promise()._CurrentValue;
+			return *_Coro.promise()._CurrentValue;
 		}
 
-		_Ty const *operator->() const
+		pointer operator->() const
 		{
-			return _STD addressof(operator*());
+			return _Coro.promise()._CurrentValue;
 		}
 	};
 
@@ -156,9 +158,11 @@ namespace experimental {
 				return _STD forward<_Uty>(_Whatever);
 			}
 
-			using _Alloc_traits = allocator_traits<_Alloc>;
-			using _Alloc_of_char_type =
-				typename _Alloc_traits::template rebind_alloc<char>;
+			using _Alloc_char = _Rebind_alloc_t<_Alloc, char>;
+			static_assert(is_same_v<char*, typename allocator_traits<_Alloc_char>::pointer>,
+				"generator does not support allocators with fancy pointer types");
+			static_assert(allocator_traits<_Alloc_char>::is_always_equal::value,
+				"generator only supports stateless allocators");
 
 			void *operator new(size_t _Size)
 			{
@@ -179,10 +183,9 @@ namespace experimental {
 		{
 			if (_Coro)
 			{
+				_Coro.resume();
 				if (_Coro.done())
 					return{ nullptr };
-
-				_Coro.resume();
 			}
 			return { _Coro };
 		}
@@ -193,8 +196,7 @@ namespace experimental {
 		}
 
 		explicit generator(promise_type &_Prom)
-			: _Coro(coroutine_handle<promise_type>::from_promise(
-				_Prom))
+			: _Coro(coroutine_handle<promise_type>::from_promise(_Prom))
 		{
 		}
 
@@ -212,7 +214,7 @@ namespace experimental {
 
 		generator &operator=(generator &&right_) noexcept
 		{
-			if (&right_ != this) {
+			if (this != _STD addressof(right_)) {
 				_Coro = right_._Coro;
 				right_._Coro = nullptr;
 			}
diff --git a/librf/src/promise.inl b/librf/src/promise.inl
index fd03223..80d5a6c 100644
--- a/librf/src/promise.inl
+++ b/librf/src/promise.inl
@@ -7,7 +7,7 @@ namespace resumef
 {
 	struct suspend_on_initial
 	{
-		state_base_t* _state;
+		state_future_t* _state;
 
 		inline bool await_ready() noexcept
 		{
@@ -25,7 +25,7 @@ namespace resumef
 	};
 	struct suspend_on_final
 	{
-		state_base_t* _state;
+		state_future_t* _state;
 
 		inline bool await_ready() noexcept
 		{
diff --git a/librf/src/scheduler.cpp b/librf/src/scheduler.cpp
index 76fa7e2..a75e4c7 100644
--- a/librf/src/scheduler.cpp
+++ b/librf/src/scheduler.cpp
@@ -113,7 +113,6 @@ namespace resumef
 
 	void scheduler_t::add_ready(state_base_t* sptr)
 	{
-		assert(sptr->get_scheduler() == this);
 		assert(sptr->is_ready());
 
 		if (sptr->has_handler())
@@ -123,10 +122,14 @@ namespace resumef
 		}
 	}
 
+	void scheduler_t::add_generator(state_base_t* sptr)
+	{
+		scoped_lock<lock_type> __guard(_lock_running);
+		_runing_states.emplace_back(sptr);
+	}
+
 	void scheduler_t::del_final(state_base_t* sptr)
 	{
-		assert(sptr->get_scheduler() == this);
-
 		{
 			scoped_lock<spinlock> __guard(_lock_ready);
 			this->_ready_task.erase(sptr);
diff --git a/librf/src/scheduler.h b/librf/src/scheduler.h
index 267d0a2..a68e91f 100644
--- a/librf/src/scheduler.h
+++ b/librf/src/scheduler.h
@@ -49,11 +49,6 @@ namespace resumef
 				new_task(new ctx_task_t<_Ty>(std::forward<_Ty>(t_)));
 		}
 
-		inline void push_task_internal(task_base_t * t_)
-		{
-			new_task(t_);
-		}
-
 		inline bool empty() const
 		{
 			scoped_lock<spinlock, lock_type> __guard(_lock_ready, _lock_running);
@@ -68,6 +63,7 @@ namespace resumef
 		void add_initial(state_base_t* sptr);
 		void add_await(state_base_t* sptr);
 		void add_ready(state_base_t* sptr);
+		void add_generator(state_base_t* sptr);
 		void del_final(state_base_t* sptr);
 
 		friend struct task_base;
diff --git a/librf/src/state.cpp b/librf/src/state.cpp
index b6f4f77..d9a26af 100644
--- a/librf/src/state.cpp
+++ b/librf/src/state.cpp
@@ -9,7 +9,29 @@ namespace resumef
 	{
 	}
 
-	void state_base_t::resume()
+	void state_generator_t::resume()
+	{
+		if (_coro != nullptr)
+		{
+			_coro.resume();
+			if (_coro.done())
+				_coro = nullptr;
+			else
+				_scheduler->add_generator(this);
+		}
+	}
+
+	bool state_generator_t::is_ready() const
+	{
+		return _coro != nullptr && !_coro.done();
+	}
+
+	bool state_generator_t::has_handler() const
+	{
+		return _coro != nullptr;
+	}
+
+	void state_future_t::resume()
 	{
 		coroutine_handle<> handler;
 
@@ -28,7 +50,12 @@ namespace resumef
 		}
 	}
 
-	void state_base_t::set_exception(std::exception_ptr e)
+	bool state_future_t::has_handler() const
+	{
+		return _initor != nullptr || _coro != nullptr;
+	}
+
+	void state_future_t::set_exception(std::exception_ptr e)
 	{
 		scoped_lock<lock_type> __guard(this->_mtx);
 
@@ -37,6 +64,12 @@ namespace resumef
 		if (sch != nullptr)
 			sch->add_ready(this);
 	}
+	
+	bool state_t<void>::is_ready() const
+	{
+		scoped_lock<lock_type> __guard(this->_mtx);
+		return _is_awaitor == false || _has_value || _exception != nullptr;
+	}
 
 	void state_t<void>::future_await_resume()
 	{
diff --git a/librf/src/state.h b/librf/src/state.h
index 5076ad7..a8a3b80 100644
--- a/librf/src/state.h
+++ b/librf/src/state.h
@@ -10,25 +10,50 @@ namespace resumef
 {
 	struct state_base_t : public counted_t<state_base_t>
 	{
-		typedef std::recursive_mutex lock_type;
-
+		RF_API virtual ~state_base_t();
 	protected:
-		mutable lock_type _mtx;
 		scheduler_t* _scheduler = nullptr;
-		coroutine_handle<> _initor;
 		//可能来自协程里的promise产生的，则经过co_await操作后，_coro在初始时不会为nullptr。
 		//也可能来自awaitable_t，如果
 		//		一、经过co_await操作后，_coro在初始时不会为nullptr。
 		//		二、没有co_await操作，直接加入到了调度器里，则_coro在初始时为nullptr。调度器需要特殊处理此种情况。
 		coroutine_handle<> _coro;
+	public:
+		virtual void resume() = 0;
+		virtual bool is_ready() const = 0;
+		virtual bool has_handler() const = 0;
+
+		void set_scheduler(scheduler_t* sch)
+		{
+			_scheduler = sch;
+		}
+		coroutine_handle<> get_handler() const
+		{
+			return _coro;
+		}
+	};
+	
+	struct state_generator_t : public state_base_t
+	{
+		virtual void resume() override;
+		virtual bool is_ready() const override;
+		virtual bool has_handler() const override;
+	};
+
+	struct state_future_t : public state_base_t
+	{
+		typedef std::recursive_mutex lock_type;
+	protected:
+		mutable lock_type _mtx;
+		coroutine_handle<> _initor;
 		std::exception_ptr _exception;
-		state_base_t* _parent = nullptr;
+		state_future_t* _parent = nullptr;
 #if RESUMEF_DEBUG_COUNTER
 		intptr_t _id;
 #endif
 		bool _is_awaitor;
 	public:
-		state_base_t(bool awaitor)
+		state_future_t(bool awaitor)
 		{
 #if RESUMEF_DEBUG_COUNTER
 			_id = ++g_resumef_state_id;
@@ -36,41 +61,13 @@ namespace resumef
 			_is_awaitor = awaitor;
 		}
 
-		RF_API virtual ~state_base_t();
-		virtual bool has_value() const = 0;
-		void resume();
-
-		bool is_ready() const
-		{
-			return _is_awaitor == false || has_value() || _exception != nullptr;
-		}
-
-		coroutine_handle<> get_handler() const
-		{
-			return _coro;
-		}
-		bool has_handler() const
-		{
-			return _initor != nullptr || _coro != nullptr;
-		}
+		virtual void resume() override;
+		virtual bool has_handler() const override;
 
 		scheduler_t* get_scheduler() const
 		{
 			return _parent ? _parent->get_scheduler() : _scheduler;
 		}
-		void set_scheduler(scheduler_t* sch)
-		{
-			scoped_lock<lock_type> __guard(_mtx);
-			_scheduler = sch;
-		}
-		void set_scheduler_handler(scheduler_t* sch, coroutine_handle<> handler)
-		{
-			scoped_lock<lock_type> __guard(_mtx);
-			_scheduler = sch;
-
-			assert(_coro == nullptr);
-			_coro = handler;
-		}
 
 		state_base_t * get_parent() const
 		{
@@ -90,18 +87,18 @@ namespace resumef
 	};
 
 	template <typename _Ty>
-	struct state_t : public state_base_t
+	struct state_t : public state_future_t
 	{
-		using state_base_t::state_base_t;
-		using state_base_t::lock_type;
+		using state_future_t::state_future_t;
+		using state_future_t::lock_type;
 		using value_type = _Ty;
 	protected:
 		std::optional<value_type> _value;
 	public:
-		virtual bool has_value() const override
+		virtual bool is_ready() const override
 		{
 			scoped_lock<lock_type> __guard(this->_mtx);
-			return _value.has_value();
+			return _is_awaitor == false || _value.has_value() || _exception != nullptr;
 		}
 
 		bool future_await_ready()
@@ -116,17 +113,14 @@ namespace resumef
 	};
 
 	template<>
-	struct state_t<void> : public state_base_t
+	struct state_t<void> : public state_future_t
 	{
-		using state_base_t::state_base_t;
-		using state_base_t::lock_type;
+		using state_future_t::state_future_t;
+		using state_future_t::lock_type;
 	protected:
 		std::atomic<bool> _has_value{ false };
 	public:
-		virtual bool has_value() const override
-		{
-			return _has_value;
-		}
+		virtual bool is_ready() const override;
 
 		bool future_await_ready()
 		{
diff --git a/librf/src/state.inl b/librf/src/state.inl
index ad282b8..65c1f89 100644
--- a/librf/src/state.inl
+++ b/librf/src/state.inl
@@ -3,7 +3,7 @@
 namespace resumef
 {
 	template<class _PromiseT, typename _Enable>
-	inline void state_base_t::promise_initial_suspend(coroutine_handle<_PromiseT> handler)
+	inline void state_future_t::promise_initial_suspend(coroutine_handle<_PromiseT> handler)
 	{
 		_PromiseT& promise = handler.promise();
 
@@ -14,12 +14,12 @@ namespace resumef
 		this->_initor = handler;
 	}
 
-	inline void state_base_t::promise_await_resume()
+	inline void state_future_t::promise_await_resume()
 	{
 	}
 
 	template<class _PromiseT, typename _Enable>
-	inline void state_base_t::promise_final_suspend(coroutine_handle<_PromiseT> handler)
+	inline void state_future_t::promise_final_suspend(coroutine_handle<_PromiseT> handler)
 	{
 		scoped_lock<lock_type> __guard(this->_mtx);
 
@@ -34,13 +34,13 @@ namespace resumef
 	}
 
 	template<class _PromiseT, typename _Enable>
-	inline void state_base_t::future_await_suspend(coroutine_handle<_PromiseT> handler)
+	inline void state_future_t::future_await_suspend(coroutine_handle<_PromiseT> handler)
 	{
 		scoped_lock<lock_type> __guard(this->_mtx);
 
 		_PromiseT& promise = handler.promise();
 
-		state_base_t* parent_state = promise._state.get();
+		auto* parent_state = promise._state.get();
 		scheduler_t* sch = parent_state->get_scheduler();
 		if (this != parent_state)
 		{
diff --git a/tutorial/test_async_yield_return.cpp b/tutorial/test_async_yield_return.cpp
index ca0c3b4..aec2a32 100644
--- a/tutorial/test_async_yield_return.cpp
+++ b/tutorial/test_async_yield_return.cpp
@@ -19,7 +19,7 @@ auto test_yield_int() -> std::experimental::generator<int>
 	std::cout << "3 will yield return" << std::endl;
 	co_yield 3;
 	std::cout << "4 will return" << std::endl;
-	return 4;
+	co_return 4;
 
 	std::cout << "5 will never yield return" << std::endl;
 	co_yield 5;
diff --git a/vs_proj/librf.vcxproj b/vs_proj/librf.vcxproj
index 82e1241..32f3c87 100644
--- a/vs_proj/librf.vcxproj
+++ b/vs_proj/librf.vcxproj
@@ -263,10 +263,7 @@
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
     </ClCompile>
-    <ClCompile Include="..\tutorial\test_async_yield_return.cpp">
-      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
-      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
-    </ClCompile>
+    <ClCompile Include="..\tutorial\test_async_yield_return.cpp" />
     <ClCompile Include="librf.cpp">
       <BasicRuntimeChecks Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">Default</BasicRuntimeChecks>
       <BufferSecurityCheck Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">false</BufferSecurityCheck>
@@ -282,6 +279,7 @@
     <ClInclude Include="..\librf\src\def.h" />
     <ClInclude Include="..\librf\src\event.h" />
     <ClInclude Include="..\librf\src\future.h" />
+    <ClInclude Include="..\librf\src\generator.h" />
     <ClInclude Include="..\librf\src\promise.h" />
     <ClInclude Include="..\librf\src\task_list.h" />
     <ClInclude Include="..\librf\src\mutex.h" />
diff --git a/vs_proj/librf.vcxproj.filters b/vs_proj/librf.vcxproj.filters
index 3327ba3..d654d18 100644
--- a/vs_proj/librf.vcxproj.filters
+++ b/vs_proj/librf.vcxproj.filters
@@ -174,6 +174,9 @@
     <ClInclude Include="..\librf\src\awaitable.h">
       <Filter>librf\src</Filter>
     </ClInclude>
+    <ClInclude Include="..\librf\src\generator.h">
+      <Filter>librf\src</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="..\librf\src\asio_task_1.12.0.inl">