Add native C++ and Python implementations

.dockerignore

@@ -6,9 +6,22 @@ artifacts/
 BenchmarkDotNet.Artifacts/
 bin/
 obj/
+build/
+out/
 TestResults/
 coverage/
 node_modules/
+__pycache__/
+*.py[cod]
+.venv/
+venv/
+dist/
+*.egg-info/
+*.o
+*.so
+*.a
+*.dll
+*.exe
 *.log
 *.log.*
 *.trx

.gitattributes

@@ -0,0 +1 @@
+protocol/fixtures/v1.2/*.snapshot.json text eol=lf

.github/workflows/ci.yml

@@ -25,10 +25,10 @@ jobs:
 
     steps:
       - name: Check out source
-        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Set up .NET 10
-        uses: actions/setup-dotnet@67a3573c9a986a3f9c594539f4ab511d57bb3ce9 # v4
+        uses: actions/setup-dotnet@c2fa09f4bde5ebb9d1777cf28262a3eb3db3ced7 # v5.2.0
         with:
           dotnet-version: 10.0.x
 
@@ -62,13 +62,88 @@ jobs:
 
     steps:
       - name: Check out source
-        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Set up .NET 10
-        uses: actions/setup-dotnet@67a3573c9a986a3f9c594539f4ab511d57bb3ce9 # v4
+        uses: actions/setup-dotnet@c2fa09f4bde5ebb9d1777cf28262a3eb3db3ced7 # v5.2.0
         with:
           dotnet-version: 10.0.x
 
       - name: Validate Docker sharing
         shell: pwsh
         run: ./scripts/validate-docker-shared-memory.ps1 -Configuration Release
+
+  native:
+    name: Native (${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 30
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+
+    steps:
+      - name: Check out source
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Validate CMake build, tests, install, and clean consumer
+        shell: pwsh
+        run: ./scripts/validate-native.ps1 -Configuration Release
+
+  python:
+    name: Python (${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 30
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+
+    steps:
+      - name: Check out source
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Set up Python 3.12
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+        with:
+          python-version: '3.12'
+
+      - name: Install Python build frontend
+        run: python -m pip install --upgrade build
+
+      - name: Validate source tests, wheel contents, and clean installation
+        shell: pwsh
+        run: ./scripts/validate-python.ps1 -Configuration Release
+
+  interoperability:
+    name: Interoperability (${{ matrix.os }})
+    needs: [native, python]
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 60
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+
+    steps:
+      - name: Check out source
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Set up .NET 10
+        uses: actions/setup-dotnet@c2fa09f4bde5ebb9d1777cf28262a3eb3db3ced7 # v5.2.0
+        with:
+          dotnet-version: 10.0.x
+
+      - name: Set up Python 3.12
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+        with:
+          python-version: '3.12'
+
+      - name: Validate all ordered runtime pairs and stress lifecycles
+        shell: pwsh
+        run: >-
+          ./scripts/validate-interoperability.ps1
+          -Configuration Release
+          -Stress
+          -StressValueCount 1000
+          -StressLifecycleCycleCount 10000

.gitignore

@@ -1,8 +1,21 @@
 bin/
 obj/
+build/
+out/
 artifacts/
 TestResults/
 BenchmarkDotNet.Artifacts/
+__pycache__/
+*.py[cod]
+.venv/
+venv/
+dist/
+*.egg-info/
+*.o
+*.so
+*.a
+*.dll
+*.exe
 *.log
 *.trx
 *.tmp

.specify/feature.json

@@ -1,3 +1,3 @@
 {
-  "feature_directory": "specs/007-linux-windows-support"
+  "feature_directory": "specs/008-cpp-python-implementations"
 }

AGENTS.md

@@ -1,5 +1,5 @@
 <!-- SPECKIT START -->
 For additional context about technologies to be used, project structure,
 shell commands, and other important information, read the current plan
-at specs/007-linux-windows-support/plan.md
+at specs/008-cpp-python-implementations/plan.md
 <!-- SPECKIT END -->

CHANGELOG.md

@@ -3,6 +3,47 @@
 All notable package and documentation changes are recorded in reverse
 chronological order.
 
+## Unreleased
+
+### Added
+
+- Added an independently versioned CMake `SharedMemoryStore` `0.1.0`
+  distribution with a C++20 protocol core, Windows and Linux adapters,
+  fixed-width C ABI `1.0`, move-only C++ RAII wrappers, dependency-free native
+  tests, install/export rules, clean-consumer project, and basic sample.
+- Added the Python `shared-memory-store` `0.1.0` source and wheel configuration
+  for Python 3.10 or newer. Its standard-library `ctypes` API packages and
+  validates the native library beside the Python modules and exposes
+  context-managed stores, leases, reservations, recovery, waits, and
+  diagnostics.
+- Added the canonical language-neutral protocol boundary for layout `1.2`,
+  resource naming `1`, exact conformance fixtures, compatibility metadata, and
+  test-only .NET, C++, and Python JSON-lines participants.
+- Added an ordered 3x3 core exchange harness plus native and Python contract,
+  lifecycle, ABI, diagnostics, and package tests.
+
+### Security
+
+- Preserved the trusted same-host participant boundary across all three
+  distributions. Native and Python callers receive lifecycle and layout
+  validation, but no implementation claims protection from a malicious writer
+  that already has legitimate access to the shared resources.
+- Restricted Python native loading to the library packaged beside its modules;
+  it does not search the current directory, `PATH`, or system library paths.
+
+### Compatibility
+
+- NuGet `SharedMemoryStore` remains `1.0.1`; its public managed API, status
+  numbers, BCL-only runtime dependency surface, and layout `1.2` behavior are
+  unchanged. The native and Python artifacts are sibling distributions and are
+  not included in the NuGet package.
+- NuGet, CMake, and Python versions advance independently. Cross-runtime
+  compatibility is declared through layout `1.2`, resource naming `1`, and C
+  ABI `1.0` where applicable.
+- The native and Python `0.1.0` lines are alpha. Registry publication and full
+  Windows/Linux ordered-pair release evidence remain explicit publication
+  gates rather than claims made by this entry.
+
 ## 1.0.1 - 2026-07-10
 
 ### Packaging

CMakeLists.txt

@@ -0,0 +1,82 @@
+cmake_minimum_required(VERSION 3.20)
+
+project(
+    SharedMemoryStore
+    VERSION 0.1.0
+    DESCRIPTION "Cross-process shared memory value store"
+    LANGUAGES CXX)
+
+include(GNUInstallDirs)
+include(CMakePackageConfigHelpers)
+find_package(Threads REQUIRED)
+
+option(SMS_BUILD_TESTS "Build the dependency-free native test suite" OFF)
+option(SMS_BUILD_SAMPLES "Build native usage samples" OFF)
+option(SMS_BUILD_STATIC "Build the optional static native library" OFF)
+
+set(_sms_install_default ON)
+if(NOT CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
+    set(_sms_install_default OFF)
+endif()
+option(SMS_INSTALL "Generate native install and CMake package rules"
+       "${_sms_install_default}")
+unset(_sms_install_default)
+set(
+    SMS_PYTHON_INSTALL_DIR
+    ""
+    CACHE STRING
+          "Optional wheel-relative directory for the Python native library")
+
+add_subdirectory(src/cpp)
+
+if(SMS_INSTALL AND NOT SMS_PYTHON_INSTALL_DIR STREQUAL "")
+    install(
+        FILES
+            "${CMAKE_CURRENT_SOURCE_DIR}/src/python/shared_memory_store/__init__.py"
+            "${CMAKE_CURRENT_SOURCE_DIR}/src/python/shared_memory_store/_native.py"
+            "${CMAKE_CURRENT_SOURCE_DIR}/src/python/shared_memory_store/enums.py"
+            "${CMAKE_CURRENT_SOURCE_DIR}/src/python/shared_memory_store/store.py"
+        DESTINATION "${SMS_PYTHON_INSTALL_DIR}"
+        COMPONENT Python)
+endif()
+
+if(SMS_BUILD_TESTS)
+    include(CTest)
+    enable_testing()
+    add_subdirectory(tests/cpp)
+endif()
+
+if(SMS_BUILD_SAMPLES)
+    add_subdirectory(samples/CppBasicUsage)
+endif()
+
+if(SMS_INSTALL)
+    set(
+        SMS_INSTALL_CMAKEDIR
+        "${CMAKE_INSTALL_LIBDIR}/cmake/SharedMemoryStore"
+        CACHE STRING "Directory used to install the CMake package files")
+
+    configure_package_config_file(
+        "${CMAKE_CURRENT_SOURCE_DIR}/cmake/SharedMemoryStoreConfig.cmake.in"
+        "${CMAKE_CURRENT_BINARY_DIR}/SharedMemoryStoreConfig.cmake"
+        INSTALL_DESTINATION "${SMS_INSTALL_CMAKEDIR}")
+
+    write_basic_package_version_file(
+        "${CMAKE_CURRENT_BINARY_DIR}/SharedMemoryStoreConfigVersion.cmake"
+        VERSION "${PROJECT_VERSION}"
+        COMPATIBILITY SameMajorVersion)
+
+    install(
+        EXPORT SharedMemoryStoreTargets
+        FILE SharedMemoryStoreTargets.cmake
+        NAMESPACE SharedMemoryStore::
+        DESTINATION "${SMS_INSTALL_CMAKEDIR}"
+        COMPONENT Development)
+
+    install(
+        FILES
+            "${CMAKE_CURRENT_BINARY_DIR}/SharedMemoryStoreConfig.cmake"
+            "${CMAKE_CURRENT_BINARY_DIR}/SharedMemoryStoreConfigVersion.cmake"
+        DESTINATION "${SMS_INSTALL_CMAKEDIR}"
+        COMPONENT Development)
+endif()