Feat: Implement wrappers of the MPI_Sendrecv (#135)

* Feat: Implement wrappers of the MPI_Sendrecv

* Test: if CI passes by commenting out status conversion

Author: adit4443ya

src/mpi.f90

@@ -128,6 +128,10 @@ module mpi
         module procedure MPI_Recv_StatusIgnore_proc    
     end interface
 
+    interface MPI_Sendrecv
+        module procedure MPI_Sendrecv_proc
+    end interface
+
     interface MPI_Waitall
         module procedure MPI_Waitall_proc
     end interface
@@ -668,7 +672,49 @@ subroutine MPI_Irecv_proc(buf, count, datatype, source, tag, comm, request, ierr
                 print *, "MPI_Irecv failed with error code: ", local_ierr
             end if
         end if
-    end subroutine
+    end subroutine MPI_Irecv_proc
+
+    subroutine MPI_Sendrecv_proc (sendbuf, sendcount, sendtype, dest, sendtag, &
+                        recvbuf, recvcount, recvtype, source, recvtag, comm, status, ierror)
+        use iso_c_binding, only: c_int, c_ptr, c_loc
+        use mpi_c_bindings, only: c_mpi_sendrecv, c_mpi_status_c2f
+        real(8), dimension(:,:), target, intent(in) :: sendbuf
+        integer, intent(in) :: sendcount, dest, sendtag
+        real(8), dimension(:,:), target, intent(out) :: recvbuf
+        integer, intent(in) :: recvcount, source, recvtag
+        integer, intent(in) :: comm
+        integer, intent(in) :: sendtype, recvtype
+        integer(kind=MPI_HANDLE_KIND) :: c_comm
+        integer, intent(out) :: status(MPI_STATUS_SIZE)
+        integer, optional, intent(out) :: ierror
+        integer(c_int) :: local_ierr, status_ierr
+        integer(kind=MPI_HANDLE_KIND) :: c_sendtype, c_recvtype
+        type(c_ptr) :: sendbuf_ptr, recvbuf_ptr, c_status
+        integer(c_int), dimension(MPI_STATUS_SIZE), target :: tmp_status
+
+        c_comm = handle_mpi_comm_f2c(comm)
+
+        c_sendtype = handle_mpi_datatype_f2c(sendtype)
+        c_recvtype = handle_mpi_datatype_f2c(recvtype)
+        sendbuf_ptr = c_loc(sendbuf)
+        recvbuf_ptr = c_loc(recvbuf)
+        c_status = c_loc(tmp_status)
+
+        local_ierr = c_mpi_sendrecv(sendbuf_ptr, sendcount, c_sendtype, dest, sendtag, &
+                                    recvbuf_ptr, recvcount, c_recvtype, source, recvtag, &
+                                    c_comm, c_status)
+
+        if (local_ierr == MPI_SUCCESS) then
+        !   status_ierr =  c_mpi_status_c2f(c_status, status)
+        end if
+
+        if (local_ierr /= MPI_SUCCESS) then
+            print *, "MPI_Sendrecv failed with error code: ", local_ierr
+            if (present(ierror)) then
+                ierror = local_ierr
+            end if
+        end if
+    end subroutine MPI_Sendrecv_proc
 
     subroutine MPI_Allreduce_scalar(sendbuf, recvbuf, count, datatype, op, comm, ierror)
         use iso_c_binding, only: c_int, c_ptr, c_loc

src/mpi_c_bindings.f90

@@ -219,6 +219,22 @@ function c_mpi_recv(buf, count, c_dtype, source, tag, c_comm, status) bind(C, na
             integer(c_int) :: c_mpi_recv
         end function c_mpi_recv
 
+        function c_mpi_sendrecv (sendbuf, sendcount, sendtype, dest, sendtag, &
+            recvbuf, recvcount, recvtype, source, recvtag, comm, status) bind(C, name="MPI_Sendrecv")
+            use iso_c_binding, only: c_int, c_ptr
+            type(c_ptr), value :: sendbuf
+            integer(c_int), value :: sendcount
+            integer(kind=MPI_HANDLE_KIND), value :: sendtype
+            integer(c_int), value :: dest, sendtag
+            type(c_ptr), value :: recvbuf
+            integer(c_int), value :: recvcount
+            integer(kind=MPI_HANDLE_KIND), value :: recvtype
+            integer(c_int), value :: source, recvtag
+            integer(kind=MPI_HANDLE_KIND), value :: comm
+            type(c_ptr), value :: status
+            integer(c_int) :: c_mpi_sendrecv
+        end function c_mpi_sendrecv
+
         function c_mpi_waitall(count, requests, statuses) bind(C, name="MPI_Waitall")
             use iso_c_binding, only: c_int, c_ptr
             integer(c_int), value :: count

tests/sendrecv_1.f90

@@ -0,0 +1,52 @@
+program sendrecv_1
+    use mpi
+    implicit none
+    integer :: ierr, rank, size, next, prev
+    real(8), allocatable :: sendbuf(:,:), recvbuf(:,:)
+    integer :: status(MPI_STATUS_SIZE)
+    logical :: error
+    integer :: i, j, n1, n2
+
+    n1 = 2
+    n2 = 3
+
+    ! Initialize MPI
+    call MPI_Init(ierr)
+    call MPI_Comm_rank(MPI_COMM_WORLD, rank, ierr)
+    call MPI_Comm_size(MPI_COMM_WORLD, size, ierr)
+
+    ! Set up ring communication
+    next = mod(rank + 1, size)  ! Send to next process
+    prev = mod(rank - 1 + size, size)  ! Receive from previous process
+
+    ! Allocate and initialize send/recv buffers
+    allocate(sendbuf(n1, n2))
+    allocate(recvbuf(n1, n2))
+    sendbuf = rank
+    recvbuf = -1.0d0
+
+    ! Perform sendrecv
+    call MPI_Sendrecv(sendbuf, n1*n2, MPI_REAL8, next, 0, &
+                      recvbuf, n1*n2, MPI_REAL8, prev, 0, &
+                      MPI_COMM_WORLD, status, ierr)
+
+    ! Verify result
+    error = .false.
+    do i = 1, n1
+        do j = 1, n2
+            if (recvbuf(i,j) /= real(prev,8)) then
+                print *, "Rank ", rank, ": Error at (",i,",",j,"): Expected ", prev, ", got ", recvbuf(i,j)
+                error = .true.
+            end if
+        end do
+    end do
+
+    if (.not. error .and. rank == 0) then
+        print *, "MPI_Sendrecv test passed: rank ", rank, " received correct data"
+    end if
+
+    ! Clean up
+    call MPI_Finalize(ierr)
+
+    if (error) error stop 1
+end program sendrecv_1