Made DataFrame edit overlay thread safe

Author: vincentlaucsb

.github/workflows/README.md

@@ -12,14 +12,18 @@ This directory contains GitHub Actions workflows for comprehensive memory and th
 - **UndefinedBehaviorSanitizer (UBSan)** - Catches undefined behavior: signed overflow, type mismatches
 
 **Config:**
-- Runs on Ubuntu with GCC
-- Tests C++17 and C++20 standards
+- Runs Linux sanitizer coverage on Ubuntu with GCC
+- Adds a dedicated Windows/MSVC AddressSanitizer leg on C++20
 - Debug builds for better diagnostics
 - Timeout: 20 minutes per configuration
 - Artifacts: Upload logs on failure
 
 **Key Features:**
-- Matrix testing: 3 sanitizers × 2 C++ standards = 6 parallel jobs
+- Linux matrix testing:
+  - ASan on C++20
+  - TSan on C++20
+  - UBSan on C++17
+- Dedicated Windows/MSVC ASan coverage for AVX2- and codegen-sensitive issues
 - Fail-fast disabled to see all results
 - Environment variables configured for halt-on-error behavior
 
@@ -54,6 +58,16 @@ cmake -B build/asan -DCMAKE_BUILD_TYPE=Debug \
   -DCMAKE_CXX_FLAGS="-fsanitize=address -fno-omit-frame-pointer -g"
 cmake --build build/asan
 cd build/asan && ctest --output-on-failure && cd ../..
+
+# Windows / MSVC AddressSanitizer
+cmake -S . -B build/msvc-asan ^
+  -DCSV_CXX_STANDARD=20 ^
+  -DCMAKE_BUILD_TYPE=RelWithDebInfo ^
+  -DCMAKE_CXX_FLAGS="/fsanitize=address /Zi" ^
+  -DCMAKE_C_FLAGS="/fsanitize=address /Zi" ^
+  -DCMAKE_EXE_LINKER_FLAGS="/INCREMENTAL:NO"
+cmake --build build/msvc-asan --config RelWithDebInfo
+ctest --test-dir build/msvc-asan --build-config RelWithDebInfo --output-on-failure
 ```
 
 ### CI/CD Pipeline Order
@@ -75,6 +89,7 @@ cd build/asan && ctest --output-on-failure && cd ../..
 - **Why Important:** Catches CSVFieldList memory issues like issue #278
 - Cannot run simultaneously with TSan (different memory models)
 - Better performance than TSan for memory safety
+- The MSVC C++20 ASan leg is especially useful for AVX2- and codegen-sensitive regressions
 
 ### Valgrind
 - Slower than sanitizers but more mature tool

.github/workflows/sanitizers.yml

@@ -10,22 +10,23 @@ permissions:
   contents: read
 
 jobs:
-  sanitizers:
+  linux-sanitizers:
     runs-on: ubuntu-latest
 
     strategy:
       fail-fast: false
       matrix:
-        sanitizer: [address, thread, undefined]
-        cxx_standard: [17, 20]
         include:
           - sanitizer: address
+            cxx_standard: 20
             flag: "-fsanitize=address -fno-omit-frame-pointer"
             name: "AddressSanitizer"
           - sanitizer: thread
+            cxx_standard: 20
             flag: "-fsanitize=thread"
             name: "ThreadSanitizer"
           - sanitizer: undefined
+            cxx_standard: 17
             flag: "-fsanitize=undefined -fno-omit-frame-pointer"
             name: "UndefinedBehaviorSanitizer"
 
@@ -69,9 +70,52 @@ jobs:
       if: failure()
       uses: actions/upload-artifact@v4
       with:
-        name: sanitizer-logs-${{ matrix.sanitizer }}-std${{ matrix.cxx_standard }}
+        name: linux-sanitizer-logs-${{ matrix.sanitizer }}-std${{ matrix.cxx_standard }}
         path: build/Testing/
 
+  windows-asan-msvc:
+    name: MSVC AddressSanitizer (C++20)
+    runs-on: windows-latest
+
+    env:
+      ASAN_OPTIONS: "halt_on_error=1"
+
+    steps:
+    - name: Checkout repository and submodules
+      uses: actions/checkout@v5
+      with:
+        submodules: recursive
+
+    - name: Set up MSVC developer command prompt
+      uses: ilammy/msvc-dev-cmd@v1
+
+    - name: Configure CMake with MSVC AddressSanitizer
+      shell: cmd
+      run: >
+        cmake -S %GITHUB_WORKSPACE%
+        -B %GITHUB_WORKSPACE%\build\msvc-asan
+        -DCSV_CXX_STANDARD=20
+        -DCMAKE_BUILD_TYPE=RelWithDebInfo
+        -DCMAKE_CXX_FLAGS="/fsanitize=address /Zi"
+        -DCMAKE_C_FLAGS="/fsanitize=address /Zi"
+        -DCMAKE_EXE_LINKER_FLAGS="/INCREMENTAL:NO"
+        -DCMAKE_SHARED_LINKER_FLAGS="/INCREMENTAL:NO"
+
+    - name: Build with MSVC AddressSanitizer
+      run: cmake --build ${{ github.workspace }}/build/msvc-asan --config RelWithDebInfo
+
+    - name: Test with MSVC AddressSanitizer
+      working-directory: ${{ github.workspace }}/build/msvc-asan
+      run: ctest --build-config RelWithDebInfo --output-on-failure -V
+      timeout-minutes: 20
+
+    - name: Upload MSVC AddressSanitizer logs
+      if: failure()
+      uses: actions/upload-artifact@v4
+      with:
+        name: windows-msvc-asan-logs-std20
+        path: build/msvc-asan/Testing/
+
   valgrind:
     runs-on: ubuntu-latest