Optional io_uring backend

CMakeLists.txt

@@ -44,6 +44,7 @@ option(JOIN_ENABLE_CRYPTO "Enable crypto." ON)
 option(JOIN_ENABLE_DATA "Enable data." ON)
 option(JOIN_ENABLE_FABRIC "Enable fabric." ON)
 option(JOIN_ENABLE_SERVICES "Enable services." ON)
+option(JOIN_ENABLE_IO_URING "Enable io_uring backend." OFF)
 option(JOIN_ENABLE_NUMA "Enable NUMA support." OFF)
 option(JOIN_ENABLE_SAMPLES "Build samples" OFF)
 option(JOIN_ENABLE_TESTS "Enable tests." OFF)

CMakePresets.json

@@ -38,7 +38,8 @@
       "binaryDir": "${sourceDir}/build/gcc/debug",
       "cacheVariables": {
         "CMAKE_BUILD_TYPE": "Debug",
-        "JOIN_ENABLE_COVERAGE": "ON"
+        "JOIN_ENABLE_COVERAGE": "ON",
+        "JOIN_ENABLE_IO_URING": "ON"
       }
     },
     {
@@ -58,7 +59,8 @@
       "binaryDir": "${sourceDir}/build/clang/debug",
       "cacheVariables": {
         "CMAKE_BUILD_TYPE": "Debug",
-        "JOIN_ENABLE_COVERAGE": "ON"
+        "JOIN_ENABLE_COVERAGE": "ON",
+        "JOIN_ENABLE_IO_URING": "ON"
       }
     },
     {
@@ -120,4 +122,4 @@
       }
     }
   ]
-}
+}

README.md

@@ -90,10 +90,12 @@ sudo apt install pkg-config libssl-dev zlib1g-dev libgtest-dev libgmock-dev
 
 | Option | Library | Default | Description |
 | :--- | :--- | :---: | :--- |
+| `JOIN_ENABLE_IO_URING` | `liburing-dev` | `OFF` | Enables the io_uring based proactor backend for async I/O. |
 | `JOIN_ENABLE_NUMA` | `libnuma-dev` | `OFF` | Enables NUMA aware memory binding for `LocalMem` and `ShmMem`. |
 
 Install as needed:
 ```bash
+sudo apt install liburing-dev   # for JOIN_ENABLE_IO_URING
 sudo apt install libnuma-dev    # for JOIN_ENABLE_NUMA
 ```
 
@@ -108,6 +110,7 @@ cmake --build build
 With optional backends:
 ```bash
 cmake -B build -DCMAKE_BUILD_TYPE=Release \
+    -DJOIN_ENABLE_IO_URING=ON \
     -DJOIN_ENABLE_NUMA=ON \
     -DJOIN_ENABLE_TESTS=ON
 cmake --build build
@@ -122,6 +125,7 @@ cmake --build build
 | `JOIN_ENABLE_DATA` | `ON` | Build the data module. |
 | `JOIN_ENABLE_FABRIC` | `ON` | Build the fabric module. |
 | `JOIN_ENABLE_SERVICES` | `ON` | Build the services module (requires crypto, data, fabric). |
+| `JOIN_ENABLE_IO_URING` | `OFF` | Enable io_uring based proactor backend (requires `liburing-dev`). |
 | `JOIN_ENABLE_NUMA` | `OFF` | Enable NUMA support (requires `libnuma-dev`). |
 | `JOIN_ENABLE_SAMPLES` | `OFF` | Build sample programs. |
 | `JOIN_ENABLE_TESTS` | `OFF` | Build the test suite. |

core/CMakeLists.txt

@@ -1,5 +1,9 @@
 cmake_minimum_required(VERSION 3.22.1)
 
+if(JOIN_ENABLE_IO_URING)
+    pkg_check_modules(LIBURING REQUIRED liburing)
+endif()
+
 if(JOIN_ENABLE_NUMA)
     pkg_check_modules(NUMA REQUIRED numa)
 endif()
@@ -12,6 +16,7 @@ set(PUBLIC_HEADERS
     include/join/traits.hpp
     include/join/variant.hpp
     include/join/reactor.hpp
+    include/join/io_operation.hpp
     include/join/proactor.hpp
     include/join/memory.hpp
     include/join/allocator.hpp
@@ -38,10 +43,16 @@ set(PUBLIC_HEADERS
     include/join/statistics.hpp
 )
 
+if(JOIN_ENABLE_IO_URING)
+    list(APPEND PUBLIC_HEADERS include/join/io_policy.hpp include/join/proactor_uring_impl.hpp)
+else()
+    list(APPEND PUBLIC_HEADERS include/join/proactor_epoll_impl.hpp)
+endif()
+
 set(SOURCES
     src/error.cpp
     src/reactor.cpp
-    src/proactor.cpp
+    src/io_operation.cpp
     src/mutex.cpp
     src/condition.cpp
     src/semaphore.cpp
@@ -67,6 +78,7 @@ target_include_directories(${JOIN_CORE}
     PUBLIC
         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
         $<INSTALL_INTERFACE:include>
+        $<$<BOOL:${JOIN_ENABLE_IO_URING}>:${LIBURING_INCLUDE_DIRS}>
         $<$<BOOL:${JOIN_ENABLE_NUMA}>:${NUMA_INCLUDE_DIRS}>
     PRIVATE
         ${CMAKE_CURRENT_SOURCE_DIR}/src
@@ -77,9 +89,14 @@ target_link_libraries(${JOIN_CORE}
         OpenSSL::SSL
         OpenSSL::Crypto
         Threads::Threads
+        $<$<BOOL:${JOIN_ENABLE_IO_URING}>:${LIBURING_LIBRARIES}>
         $<$<BOOL:${JOIN_ENABLE_NUMA}>:${NUMA_LIBRARIES}>
 )
 
+if(JOIN_ENABLE_IO_URING)
+    target_compile_definitions(${JOIN_CORE} PUBLIC JOIN_HAS_IO_URING)
+endif()
+
 if(JOIN_ENABLE_NUMA)
     target_compile_definitions(${JOIN_CORE} PUBLIC JOIN_HAS_NUMA)
 endif()

core/include/join/allocator.hpp

@@ -262,6 +262,26 @@ namespace join
             return ((ptr >= base) && (ptr < end));
         }
 
+        /**
+         * @brief get the index of a chunk in the pool.
+         * @param p pointer to the chunk (must be owned by this pool).
+         * @return index of the chunk.
+         */
+        uint32_t getIndex (void* p) const noexcept
+        {
+            return static_cast<uint32_t> (reinterpret_cast<Chunk*> (p) - _segment->_chunks);
+        }
+
+        /**
+         * @brief get the pointer to a chunk by index.
+         * @param idx index of the chunk (must be in range).
+         * @return pointer to the chunk.
+         */
+        void* getPtr (uint32_t idx) const noexcept
+        {
+            return &_segment->_chunks[idx];
+        }
+
         /// pointer into the mapped region.
         Segment* _segment = nullptr;
     };