Merge pull request #1826 from ericniebler/std-this_thread-sync_wait

define types directly in namespaces specified by the standard

Author: ericniebler

examples/nvexec/launch.cu

@@ -23,8 +23,8 @@
 
 #include <thrust/device_vector.h>
 
-constexpr std::size_t N = 2 * 1024;
-constexpr std::size_t THREAD_BLOCK_SIZE = 128u;
+constexpr std::size_t N = 2ul * 1024ul;
+constexpr std::size_t THREAD_BLOCK_SIZE = 128ul;
 constexpr std::size_t NUM_BLOCKS = (N + THREAD_BLOCK_SIZE - 1) / THREAD_BLOCK_SIZE;
 
 enum {
@@ -46,12 +46,13 @@ auto main() -> int {
 
   nvexec::stream_context stream{};
 
-  auto snd = stdexec::transfer_just(stream.get_scheduler(), first, last)
+  auto snd = stdexec::just(first, last) //
+           | stdexec::continues_on(stream.get_scheduler())
            | nvexec::launch(
                {.grid_size = NUM_BLOCKS, .block_size = THREAD_BLOCK_SIZE},
                [](cudaStream_t, int* first, int* last) {
                  assert(nvexec::is_on_gpu());
-                 int32_t idx = blockIdx.x * blockDim.x + threadIdx.x;
+                 ptrdiff_t idx = blockIdx.x * blockDim.x + threadIdx.x;
                  if (idx < (last - first)) {
                    first[idx] *= scaling;
                  }

examples/nvexec/reduce.cu

@@ -19,7 +19,7 @@
 
 #include <thrust/device_vector.h>
 
-#include <cstdio>
+#include <iostream>
 #include <span>
 
 namespace ex = stdexec;
@@ -32,7 +32,8 @@ auto main() -> int {
 
   nvexec::stream_context stream_ctx{};
 
-  auto snd = ex::transfer_just(stream_ctx.get_scheduler(), std::span{first, last})
+  auto snd = ex::just(std::span{first, last})             //
+           | ex::continues_on(stream_ctx.get_scheduler()) //
            | nvexec::reduce(42.0f);
 
   auto [result] = stdexec::sync_wait(std::move(snd)).value();

examples/server_theme/let_value.cpp

@@ -24,21 +24,20 @@
  *    - optional GPU context that may be used on some types of servers
  *
  * Specific problem description:
- * - we are looking at the flow of processing an HTTP request and sending back
- * the response
- * - show how one can break the (slightly complex) flow into steps with let_*
- * functions
- * - different phases of processing HTTP requests are broken down into separate
- * concerns
- * - each part of the processing might use different execution contexts (details
- * not shown in this example)
- * - error handling is generic, regardless which component fails; we always send
- * the right response to the clients
+ *
+ * - we are looking at the flow of processing an HTTP request and sending back the
+ *   response
+ * - show how one can break the (slightly complex) flow into steps with let_* functions
+ * - different phases of processing HTTP requests are broken down into separate concerns
+ * - each part of the processing might use different execution contexts (details not shown
+ *   in this example)
+ * - error handling is generic, regardless which component fails; we always send the right
+ *   response to the clients
  *
  * Example goals:
  * - show how one can break more complex flows into steps with let_* functions
- * - exemplify the use of let_value, let_error, let_stopped, transfer_just and just
- * algorithms
+ * - exemplify the use of let_value, let_error, let_stopped, continues_on and just
+ *   algorithms
  */
 
 #include <iostream>
@@ -77,7 +76,7 @@ auto schedule_request_start(S sched, int idx) -> ex::sender auto {
   std::cout << "HTTP request " << idx << " arrived\n";
 
   // Return a sender for the incoming http_request
-  return ex::transfer_just(std::forward<S>(sched), std::move(req));
+  return ex::just(std::move(req)) | ex::continues_on(std::forward<S>(sched));
 }
 
 // Sends a response back to the client; yields a void signal on success

include/exec/any_sender_of.hpp

@@ -855,7 +855,7 @@ namespace exec {
       STDEXEC::inplace_stop_source __stop_source_{};
       using __stop_callback = typename STDEXEC::stop_token_of_t<
         STDEXEC::env_of_t<_Receiver>
-      >::template callback_type<__forward_stop_request>;
+      >::template callback_type<STDEXEC::__forward_stop_request>;
       std::optional<__stop_callback> __on_stop_{};
     };
 

include/exec/env.hpp

@@ -33,10 +33,10 @@ namespace exec {
     };
 
     template <class _Env, class _Query>
-    struct __without : STDEXEC::__env::__env_base_t<_Env> {
+    struct __without : STDEXEC::__env_base_t<_Env> {
       static_assert(STDEXEC::__nothrow_move_constructible<_Env>);
 
-      using STDEXEC::__env::__env_base_t<_Env>::query;
+      using STDEXEC::__env_base_t<_Env>::query;
 
       STDEXEC_ATTRIBUTE(nodiscard, host, device)
       auto query(_Query) const noexcept = delete;
@@ -168,9 +168,9 @@ namespace exec {
   inline constexpr __read_with_default::__read_with_default_t read_with_default{};
 
   [[deprecated("exec::write has been renamed to STDEXEC::write_env")]]
-  inline constexpr STDEXEC::__write::write_env_t write{};
-  [[deprecated("write_env has been moved to the STDEXEC:: namespace")]]
-  inline constexpr STDEXEC::__write::write_env_t write_env{};
+  inline constexpr STDEXEC::__write_env_t write{};
+  [[deprecated("exec::write_env has been moved to the STDEXEC:: namespace")]]
+  inline constexpr STDEXEC::__write_env_t write_env{};
 
   namespace __write_attrs {
     using namespace STDEXEC;

include/exec/start_now.hpp

@@ -188,7 +188,7 @@ namespace exec {
 
     struct start_now_t {
       template <
-        STDEXEC::queryable _Env,
+        STDEXEC::__queryable _Env,
         exec::__scope::__async_scope _AsyncScope,
         STDEXEC::sender... _Sender
       >

include/exec/task.hpp

@@ -334,7 +334,7 @@ namespace exec {
 
      private:
       using __scheduler_t =
-        __query_result_or_t<get_scheduler_t, _Context, STDEXEC::inline_scheduler>;
+        __call_result_or_t<get_scheduler_t, STDEXEC::inline_scheduler, _Context>;
 
       struct __final_awaitable {
         static constexpr auto await_ready() noexcept -> bool {

include/stdexec/__detail/__as_awaitable.hpp

@@ -47,7 +47,7 @@ namespace STDEXEC {
     template <class _Sender, class _Promise>
     using __value_t = __decay_t<
       __value_types_of_t<_Sender, env_of_t<_Promise&>, __q<__single_value>, __msingle_or<void>>
-      >;
+    >;
   } // namespace __detail
 
   /////////////////////////////////////////////////////////////////////////////
@@ -185,61 +185,62 @@ namespace STDEXEC {
       constexpr void return_void() noexcept;
       constexpr auto unhandled_stopped() noexcept -> __std::coroutine_handle<>;
     };
+  } // namespace __as_awaitable
 
-    struct as_awaitable_t {
-      template <class _Tp, class _Promise>
-      static consteval auto __get_declfn() noexcept {
-        if constexpr (__connect_await::__has_as_awaitable_member<_Tp, _Promise>) {
-          using __result_t = decltype(__declval<_Tp>().as_awaitable(__declval<_Promise&>()));
-          constexpr bool __is_nothrow = noexcept(__declval<_Tp>()
-                                                   .as_awaitable(__declval<_Promise&>()));
-          return __declfn<__result_t, __is_nothrow>();
-          // NOLINTNEXTLINE(bugprone-branch-clone)
-        } else if constexpr (__awaitable<_Tp, __unspecified>) { // NOT __awaitable<_Tp, _Promise> !!
-          return __declfn<_Tp&&>();
-        } else if constexpr (__awaitable_sender<_Tp, _Promise>) {
-          using __result_t = __sender_awaitable<_Promise, _Tp>;
-          constexpr bool __is_nothrow =
-            __nothrow_constructible_from<__result_t, _Tp, __std::coroutine_handle<_Promise>>;
-          return __declfn<__result_t, __is_nothrow>();
-        } else {
-          return __declfn<_Tp&&>();
-        }
-      }
-
-      template <class _Tp, class _Promise, auto _DeclFn = __get_declfn<_Tp, _Promise>()>
-        requires __callable<__mtypeof<_DeclFn>>
-      auto operator()(_Tp&& __t, _Promise& __promise) const noexcept(noexcept(_DeclFn()))
-        -> decltype(_DeclFn()) {
-        if constexpr (__connect_await::__has_as_awaitable_member<_Tp, _Promise>) {
-          using __result_t = decltype(static_cast<_Tp&&>(__t).as_awaitable(__promise));
-          static_assert(__awaitable<__result_t, _Promise>);
-          return static_cast<_Tp&&>(__t).as_awaitable(__promise);
-          // NOLINTNEXTLINE(bugprone-branch-clone)
-        } else if constexpr (__awaitable<_Tp, __unspecified>) { // NOT __awaitable<_Tp, _Promise> !!
-          return static_cast<_Tp&&>(__t);
-        } else if constexpr (__awaitable_sender<_Tp, _Promise>) {
-          auto __hcoro = __std::coroutine_handle<_Promise>::from_promise(__promise);
-          return __sender_awaitable<_Promise, _Tp>{static_cast<_Tp&&>(__t), __hcoro};
-        } else {
-          return static_cast<_Tp&&>(__t);
-        }
+  struct as_awaitable_t {
+    template <class _Tp, class _Promise>
+    static consteval auto __get_declfn() noexcept {
+      using __as_awaitable::__unspecified;
+      if constexpr (__connect_await::__has_as_awaitable_member<_Tp, _Promise>) {
+        using __result_t = decltype(__declval<_Tp>().as_awaitable(__declval<_Promise&>()));
+        constexpr bool __is_nothrow = noexcept(__declval<_Tp>()
+                                                 .as_awaitable(__declval<_Promise&>()));
+        return __declfn<__result_t, __is_nothrow>();
+        // NOLINTNEXTLINE(bugprone-branch-clone)
+      } else if constexpr (__awaitable<_Tp, __unspecified>) { // NOT __awaitable<_Tp, _Promise> !!
+        return __declfn<_Tp&&>();
+      } else if constexpr (__as_awaitable::__awaitable_sender<_Tp, _Promise>) {
+        using __result_t = __as_awaitable::__sender_awaitable<_Promise, _Tp>;
+        constexpr bool __is_nothrow =
+          __nothrow_constructible_from<__result_t, _Tp, __std::coroutine_handle<_Promise>>;
+        return __declfn<__result_t, __is_nothrow>();
+      } else {
+        return __declfn<_Tp&&>();
       }
+    }
 
-      template <class _Tp, class _Promise, auto _DeclFn = __get_declfn<_Tp, _Promise>()>
-        requires __callable<__mtypeof<_DeclFn>> || __tag_invocable<as_awaitable_t, _Tp, _Promise&>
-      [[deprecated("the use of tag_invoke for as_awaitable is deprecated")]]
-      auto operator()(_Tp&& __t, _Promise& __promise) const
-        noexcept(__nothrow_tag_invocable<as_awaitable_t, _Tp, _Promise&>)
-          -> __tag_invoke_result_t<as_awaitable_t, _Tp, _Promise&> {
-        using __result_t = __tag_invoke_result_t<as_awaitable_t, _Tp, _Promise&>;
+    template <class _Tp, class _Promise, auto _DeclFn = __get_declfn<_Tp, _Promise>()>
+      requires __callable<__mtypeof<_DeclFn>>
+    auto operator()(_Tp&& __t, _Promise& __promise) const noexcept(noexcept(_DeclFn()))
+      -> decltype(_DeclFn()) {
+      using __as_awaitable::__unspecified;
+      if constexpr (__connect_await::__has_as_awaitable_member<_Tp, _Promise>) {
+        using __result_t = decltype(static_cast<_Tp&&>(__t).as_awaitable(__promise));
         static_assert(__awaitable<__result_t, _Promise>);
-        return __tag_invoke(*this, static_cast<_Tp&&>(__t), __promise);
+        return static_cast<_Tp&&>(__t).as_awaitable(__promise);
+        // NOLINTNEXTLINE(bugprone-branch-clone)
+      } else if constexpr (__awaitable<_Tp, __unspecified>) { // NOT __awaitable<_Tp, _Promise> !!
+        return static_cast<_Tp&&>(__t);
+      } else if constexpr (__as_awaitable::__awaitable_sender<_Tp, _Promise>) {
+        auto __hcoro = __std::coroutine_handle<_Promise>::from_promise(__promise);
+        return __as_awaitable::__sender_awaitable<_Promise, _Tp>{static_cast<_Tp&&>(__t), __hcoro};
+      } else {
+        return static_cast<_Tp&&>(__t);
       }
-    };
-  } // namespace __as_awaitable
+    }
+
+    template <class _Tp, class _Promise, auto _DeclFn = __get_declfn<_Tp, _Promise>()>
+      requires __callable<__mtypeof<_DeclFn>> || __tag_invocable<as_awaitable_t, _Tp, _Promise&>
+    [[deprecated("the use of tag_invoke for as_awaitable is deprecated")]]
+    auto operator()(_Tp&& __t, _Promise& __promise) const
+      noexcept(__nothrow_tag_invocable<as_awaitable_t, _Tp, _Promise&>)
+        -> __tag_invoke_result_t<as_awaitable_t, _Tp, _Promise&> {
+      using __result_t = __tag_invoke_result_t<as_awaitable_t, _Tp, _Promise&>;
+      static_assert(__awaitable<__result_t, _Promise>);
+      return __tag_invoke(*this, static_cast<_Tp&&>(__t), __promise);
+    }
+  };
 
-  using __as_awaitable::as_awaitable_t;
   inline constexpr as_awaitable_t as_awaitable{};
 #endif
 } // namespace STDEXEC

include/stdexec/__detail/__basic_sender.hpp

@@ -46,7 +46,7 @@ namespace STDEXEC {
 #else // ^^^ EDG ^^^ / vvv !EDG vvv
 #  define STDEXEC_SEXPR_DESCRIPTOR_FN(_Descriptor) ([] { return _Descriptor(); })
 #  define STDEXEC_SEXPR_DESCRIPTOR(_Tag, _Data, _Child)                                            \
-    STDEXEC::__descriptor_fn_v<STDEXEC::__detail::__desc<_Tag, _Data, _Child>>
+    STDEXEC::__descriptor_fn_v<STDEXEC::__desc<_Tag, _Data, _Child>>
 #endif
 
 #if defined(STDEXEC_DEMANGLE_SENDER_NAMES)
@@ -59,7 +59,7 @@ namespace STDEXEC {
 
   template <class _Tag, class _Data, class... _Child>
   consteval auto __descriptor_fn() noexcept {
-    return __descriptor_fn_v<__detail::__desc<_Tag, _Data, _Child...>>;
+    return __descriptor_fn_v<__desc<_Tag, _Data, _Child...>>;
   }
 
   template <class _Tag>

include/stdexec/__detail/__bulk.hpp

@@ -34,10 +34,6 @@ namespace STDEXEC {
   /////////////////////////////////////////////////////////////////////////////
   // [execution.senders.adaptors.bulk]
   namespace __bulk {
-    struct bulk_t;
-    struct bulk_chunked_t;
-    struct bulk_unchunked_t;
-
     //! Wrapper for a policy object.
     //!
     //! If we wrap a standard execution policy, we don't store anything, as we know the type.
@@ -240,29 +236,6 @@ namespace STDEXEC {
     template <class _Fun>
     STDEXEC_HOST_DEVICE_DEDUCTION_GUIDE __as_bulk_chunked_fn(_Fun) -> __as_bulk_chunked_fn<_Fun>;
 
-    struct bulk_t : __generic_bulk_t<bulk_t> {
-      struct __transform_sender_fn {
-        template <class _Data, class _Child>
-        constexpr auto operator()(__ignore, _Data&& __data, _Child&& __child) const {
-          // Lower `bulk` to `bulk_chunked`. If `bulk_chunked` is customized, we will see the customization.
-          return bulk_chunked(
-            static_cast<_Child&&>(__child),
-            __data.__pol_.__get(),
-            __data.__shape_,
-            __as_bulk_chunked_fn(std::move(__data.__fun_)));
-        }
-      };
-
-      template <class _Sender>
-      static constexpr auto transform_sender(set_value_t, _Sender&& __sndr, __ignore) {
-        return __apply(__transform_sender_fn(), static_cast<_Sender&&>(__sndr));
-      }
-    };
-
-    struct bulk_chunked_t : __generic_bulk_t<bulk_chunked_t> { };
-
-    struct bulk_unchunked_t : __generic_bulk_t<bulk_unchunked_t> { };
-
     template <class _AlgoTag>
     struct __impl_base : __sexpr_defaults {
       template <class _Sender>
@@ -356,9 +329,23 @@ namespace STDEXEC {
     };
   } // namespace __bulk
 
-  using __bulk::bulk_t;
-  using __bulk::bulk_chunked_t;
-  using __bulk::bulk_unchunked_t;
+  struct bulk_t : __bulk::__generic_bulk_t<bulk_t> {
+    template <class _Sender>
+    static constexpr auto transform_sender(set_value_t, _Sender&& __sndr, __ignore) {
+      auto& [__tag, __data, __child] = __sndr;
+      // Lower `bulk` to `bulk_chunked`. If `bulk_chunked` is customized, we will see the customization.
+      return bulk_chunked(
+        STDEXEC::__forward_like<_Sender>(__child),
+        __data.__pol_.__get(),
+        __data.__shape_,
+        __bulk::__as_bulk_chunked_fn(STDEXEC::__forward_like<_Sender>(__data).__fun_));
+    }
+  };
+
+  struct bulk_chunked_t : __bulk::__generic_bulk_t<bulk_chunked_t> { };
+
+  struct bulk_unchunked_t : __bulk::__generic_bulk_t<bulk_unchunked_t> { };
+
   inline constexpr bulk_t bulk{};
   inline constexpr bulk_chunked_t bulk_chunked{};
   inline constexpr bulk_unchunked_t bulk_unchunked{};