From f391a0873f4fee61b39e24ce96337296f82045b0 Mon Sep 17 00:00:00 2001
From: antonl <anton.ljungdahl@gmail.com>
Date: Thu, 5 Feb 2026 09:17:53 +0100
Subject: [PATCH] working mpi link in the commlibrary

---
 build.bat        | 14 ++++++++++----
 src/commlayer.cu | 23 +++++++++++++++++++++++
 src/main.cu      |  2 --
 3 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/build.bat b/build.bat
index 133e8cc..c39e0c0 100644
--- a/build.bat
+++ b/build.bat
@@ -1,4 +1,4 @@
-@echo off
+@rem @echo off
 setlocal
 
 @rem I rely on environment variables here.
@@ -8,19 +8,24 @@ setlocal
 set nvccArch=sm_120
 set commLayerSource=commlayer
 set mainSource=main
+
 set CommonXCompFlags=/W3 /O2 /EHsc
 set DllXcompilerFlags="%CommonXCompFlags% /MD"
 set ExeXcompilerFlags="%CommonXCompFlags% /MT"
 set IgnoreWarnings=-Wno-deprecated-gpu-targets
 
+set MPIIncludes=-I"%MSMPI_INC%\"
+set MPILibPath=-L"%MSMPI_LIB64%\"
 set CudaIncludes=-I"%CUDA_PATH%\include" -I"%CUDSS_PATH%\include"
 set OtherIncludes=-Iinclude
 set CudaLibPaths=-L"%CUDA_PATH%\lib\x64" -L"%CUDSS_PATH%\lib\12"
 
-nvcc -c -o build/%commLayerSource%.obj src/%commLayerSource%.cu ^
+set LibraryLinks=-lcudss -lcudart
+
+nvcc -v -c -o build/%commLayerSource%.obj src/%commLayerSource%.cu ^
     -arch=%nvccArch% ^
-     %CudaIncludes% %OtherIncludes% %CudaLibPaths% ^
-    -lcudss -lcudart ^
+     %CudaIncludes% %OtherIncludes% %MPIIncludes% %CudaLibPaths% %MPILibPath% ^
+    %LibraryLinks% ^
     %IgnoreWarnings% ^
     -Xcompiler %DllXcompilerFlags%
 
@@ -32,6 +37,7 @@ if %ERRORLEVEL% NEQ 0 (
 nvcc -shared -o build/%commLayerSource%.dll build/%commLayerSource%.obj ^
     -arch=%nvccArch% ^
     %IgnoreWarnings% ^
+    %MPILibPath% -lmsmpi ^
     -Xcompiler %DllXcompilerFlags% ^
     -Xlinker "/NODEFAULTLIB:LIBCMT"
 
diff --git a/src/commlayer.cu b/src/commlayer.cu
index 7448a77..882b74c 100644
--- a/src/commlayer.cu
+++ b/src/commlayer.cu
@@ -1,14 +1,37 @@
 #include <cuda_runtime.h>
 #include <iostream>
 
+#include <mpi.h>
+
 #define __CSCUDSS_EXPORT extern "C" __declspec(dllexport)
 
 
+__CSCUDSS_EXPORT int cudssCommRank(void *comm, int *rank) {
+  int result = MPI_Comm_rank((*(MPI_Comm*)comm), rank);
+  return result;
+}
+
+__CSCUDSS_EXPORT int cudssCommSize(void *comm, int *size) {
+  int result = MPI_Comm_size((*(MPI_Comm*)comm), size);
+  return result;
+}
+
+
+
 __CSCUDSS_EXPORT int libraryMain() {
 
+  MPI_Init(0,0);
   std::cout << "HELLO LIBRARY" << std::endl;
+  
+  int rank;
+  int size;
+  int Comm = MPI_COMM_WORLD;
+  cudssCommRank(&Comm, &rank);
+  cudssCommSize(&Comm, &size);
 
+  std::cout << "Rank: " << rank << ", size: " << size << std::endl;
 
+  MPI_Finalize();
   return 0;
 
 }
diff --git a/src/main.cu b/src/main.cu
index f31393d..b5d461c 100644
--- a/src/main.cu
+++ b/src/main.cu
@@ -8,8 +8,6 @@
 
 #include "util.h"
 
-
-
 /* ============================================================================
  * Version Information
  * ============================================================================ */