[Research] std::execution support

.github/workflows/ci-latest-kernel.yml

@@ -72,6 +72,7 @@ jobs:
               -DBUILD_EXAMPLES=ON \
               -DBUILD_BENCHMARKS=ON \
               -DBUILD_TESTS=ON \
+              -DENABLE_STDEXEC=ON \
               -DCMAKE_C_COMPILER=clang \
               -DCMAKE_CXX_COMPILER=clang++ \
               -DCMAKE_BUILD_TYPE=Release \

.github/workflows/ci-main.yml

@@ -65,6 +65,7 @@ jobs:
               -DBUILD_EXAMPLES=ON \
               -DBUILD_BENCHMARKS=ON \
               -DBUILD_TESTS=ON \
+              -DENABLE_STDEXEC=ON \
               $SANITIZER_FLAG \
               -DCMAKE_C_COMPILER=${{matrix.compiler.cc}} \
               -DCMAKE_CXX_COMPILER=${{matrix.compiler.cxx}} \

.github/workflows/ci-static-check.yml

@@ -45,6 +45,7 @@ jobs:
               -DBUILD_EXAMPLES=ON \
               -DBUILD_BENCHMARKS=ON \
               -DBUILD_TESTS=ON \
+              -DENABLE_STDEXEC=ON \
               -DCMAKE_C_COMPILER=clang \
               -DCMAKE_CXX_COMPILER=clang++ \
               -DCMAKE_BUILD_TYPE=Debug \

.github/workflows/ci-toolchain.yml

@@ -46,6 +46,7 @@ jobs:
               -DBUILD_EXAMPLES=ON \
               -DBUILD_BENCHMARKS=ON \
               -DBUILD_TESTS=ON \
+              -DENABLE_STDEXEC=ON \
               -DCMAKE_C_COMPILER=${{ matrix.compiler.cc }} \
               -DCMAKE_CXX_COMPILER=${{ matrix.compiler.cxx }} \
               -DCMAKE_BUILD_TYPE=Debug
@@ -61,8 +62,10 @@ jobs:
       - name: Build module-hello
         # liburing < 2.13 exposes TU-local entities that break GCC modules
         # https://github.com/axboe/liburing/issues/1457
+        # stdexec uses TU-local entities incompatible with GCC C++20 modules
         if: >
           matrix.generator == 'Ninja'
+          && matrix.compiler.cc != 'gcc'
           && !(matrix.compiler.cc == 'gcc' && matrix.liburing-version == '2.3')
         run: |
           cmake -B ${{github.workspace}}/build_module -G Ninja \
@@ -75,5 +78,6 @@ jobs:
       - name: Run module-hello
         if: >
           matrix.generator == 'Ninja'
+          && matrix.compiler.cc != 'gcc'
           && !(matrix.compiler.cc == 'gcc' && matrix.liburing-version == '2.3')
         run: ${{github.workspace}}/build_module/examples/module-hello

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "third_party/doxygen-awesome-css"]
 	path = third_party/doxygen-awesome-css
 	url = https://github.com/jothepro/doxygen-awesome-css.git
+[submodule "third_party/stdexec"]
+	path = third_party/stdexec
+	url = https://github.com/NVIDIA/stdexec.git

CMakeLists.txt

@@ -11,6 +11,7 @@ option(TESTS_STATIC_LINK "Use static linking for tests" OFF)
 option(TESTS_TSAN "Enable thread sanitizer for tests" OFF)
 option(TESTS_ASAN "Enable address and undefined behavior sanitizers for tests" OFF)
 option(LINK_LIBURING "Use liburing from third_party and link it to condy" ON)
+option(ENABLE_STDEXEC "Enable stdexec execution integration" ON)
 
 if (ENABLE_CLANG_TIDY)
     find_program(CLANG_TIDY_EXE NAMES "clang-tidy")
@@ -55,6 +56,12 @@ if(BUILD_EXAMPLES OR BUILD_BENCHMARKS OR BUILD_TESTS OR LINK_LIBURING OR BUILD_M
     set_target_properties(uring PROPERTIES IMPORTED_LOCATION ${LIBURING_SOURCE_DIR}/src/liburing.a)
     target_include_directories(uring INTERFACE ${LIBURING_SOURCE_DIR}/src/include)
     add_dependencies(uring liburing_ext)
+
+    if(ENABLE_STDEXEC)
+        # stdexec
+        add_library(stdexec INTERFACE)
+        target_include_directories(stdexec SYSTEM INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/third_party/stdexec/include)
+    endif()
 endif()
 
 if(LINK_LIBURING)
@@ -67,6 +74,11 @@ if(BUILD_MODULE)
     add_subdirectory(module)
 endif()
 
+if(ENABLE_STDEXEC)
+    target_link_libraries(condy INTERFACE stdexec)
+    target_compile_definitions(condy INTERFACE CONDY_HAS_STDEXEC)
+endif()
+
 # Warnings as errors
 add_compile_options(-Wall -Wextra -Werror)
 if(CMAKE_CXX_COMPILER_ID MATCHES "GNU")

include/condy.hpp

@@ -15,6 +15,7 @@
 #include "condy/channel.hpp"            // IWYU pragma: export
 #include "condy/coro.hpp"               // IWYU pragma: export
 #include "condy/cqe_handler.hpp"        // IWYU pragma: export
+#include "condy/execution.hpp"          // IWYU pragma: export
 #include "condy/futex.hpp"              // IWYU pragma: export
 #include "condy/helpers.hpp"            // IWYU pragma: export
 #include "condy/pmr.hpp"                // IWYU pragma: export

include/condy/channel.hpp

@@ -20,6 +20,9 @@
 #include <new>
 #include <optional>
 #include <type_traits>
+#ifdef CONDY_HAS_STDEXEC
+#include "condy/detail/execution.hpp"
+#endif
 
 namespace condy {
 
@@ -52,6 +55,11 @@ template <typename T, size_t N = 2> class Channel {
 
     CONDY_DELETE_COPY_MOVE(Channel);
 
+private:
+    class [[nodiscard]] MovePushSenderImpl;
+    class [[nodiscard]] CopyPushSenderImpl;
+    class [[nodiscard]] PopSenderImpl;
+
 public:
     /**
      * @brief Try to push an item into the channel.
@@ -111,7 +119,11 @@ template <typename T, size_t N = 2> class Channel {
         push_awaiters_.push_back(fake_handle);
     }
 
-    class [[nodiscard]] MovePushSender;
+#ifdef CONDY_HAS_STDEXEC
+    using MovePushSender = detail::StandardSender<MovePushSenderImpl>;
+#else
+    using MovePushSender = MovePushSenderImpl;
+#endif
     /**
      * @brief Push an item into the channel, awaiting if necessary.
      * @param item The item to be pushed into the channel.
@@ -126,7 +138,11 @@ template <typename T, size_t N = 2> class Channel {
      */
     MovePushSender push(T &&item) noexcept { return {*this, std::move(item)}; }
 
-    class [[nodiscard]] CopyPushSender;
+#ifdef CONDY_HAS_STDEXEC
+    using CopyPushSender = detail::StandardSender<CopyPushSenderImpl>;
+#else
+    using CopyPushSender = CopyPushSenderImpl;
+#endif
     /**
      * @brief Push an item into the channel, awaiting if necessary.
      * @param item The item to be pushed into the channel.
@@ -140,7 +156,11 @@ template <typename T, size_t N = 2> class Channel {
         return {*this, item};
     }
 
-    class [[nodiscard]] PopSender;
+#ifdef CONDY_HAS_STDEXEC
+    using PopSender = detail::StandardSender<PopSenderImpl>;
+#else
+    using PopSender = PopSenderImpl;
+#endif
     /**
      * @brief Pop an item from the channel, awaiting if necessary.
      * @return std::pair<int32_t, T> 0 and the popped item if successful; -EPIPE
@@ -529,12 +549,12 @@ class Channel<T, N>::PopFinishHandle
     std::optional<StopCallbackType> stop_callback_;
 };
 
-template <typename T, size_t N> class Channel<T, N>::MovePushSender {
+template <typename T, size_t N> class Channel<T, N>::MovePushSenderImpl {
 public:
     using CondySender = void;
     using ReturnType = int32_t;
 
-    MovePushSender(Channel &channel, T &&item)
+    MovePushSenderImpl(Channel &channel, T &&item)
         : channel_(channel), item_(std::move(item)) {}
 
     template <typename Receiver> auto connect_impl(Receiver receiver) noexcept {
@@ -562,12 +582,12 @@ template <typename T, size_t N> class Channel<T, N>::MovePushSender {
     T &&item_;
 };
 
-template <typename T, size_t N> class Channel<T, N>::CopyPushSender {
+template <typename T, size_t N> class Channel<T, N>::CopyPushSenderImpl {
 public:
     using CondySender = void;
     using ReturnType = int32_t;
 
-    CopyPushSender(Channel &channel, const T &item)
+    CopyPushSenderImpl(Channel &channel, const T &item)
         : channel_(channel), item_(item) {}
 
     template <typename Receiver> auto connect_impl(Receiver receiver) noexcept {
@@ -598,12 +618,12 @@ template <typename T, size_t N> class Channel<T, N>::CopyPushSender {
     const T &item_;
 };
 
-template <typename T, size_t N> class Channel<T, N>::PopSender {
+template <typename T, size_t N> class Channel<T, N>::PopSenderImpl {
 public:
     using CondySender = void;
     using ReturnType = std::pair<int32_t, T>;
 
-    PopSender(Channel &channel) : channel_(channel) {}
+    PopSenderImpl(Channel &channel) : channel_(channel) {}
 
     template <typename Receiver> auto connect_impl(Receiver receiver) noexcept {
         return OperationState<Receiver>(channel_, std::move(receiver));