c**********************************************************************
c
c This program deadlocks using MPI/F
c M.G.N. 2001
c
c**********************************************************************/

        program main 
        include 'mpif.h'
	implicit none
	integer ierr,whoami,npes,status
	double precision a,b
C
C    Initialize environment
C
        call mpi_init(ierr)
        call mpi_comm_rank(MPI_COMM_WORLD, whoami, ierr)
        call mpi_comm_size(MPI_COMM_WORLD, npes, ierr)
		
        if (npes .ne. 2) then
	   write(*,*) 'Run on two processors only!'
	   goto 555
	endif 
	
	a =  999.999 
        if (whoami.eq.0) then 
           call MPI_send(a, 1, MPI_DOUBLE_PRECISION, 1, 1,
     >       MPI_COMM_WORLD, status, ierr)
	   call MPI_recv(b, 1, MPI_DOUBLE_PRECISION, 1, 2,
     >       MPI_COMM_WORLD, status, ierr)
	   write(*,*) 'Processor 0 got ',b,' from Processor 1'
	else
           call MPI_send(a, 1, MPI_DOUBLE_PRECISION, 0, 1,
     >       MPI_COMM_WORLD, status, ierr)
	   call MPI_recv(b, 1, MPI_DOUBLE_PRECISION, 0, 2,
     >       MPI_COMM_WORLD, status, ierr)
	   write(*,*) 'Processor 1 got ',b,' from Processor 0'	   
        endif
	
555     call mpi_finalize(ierr)  ! Shut down and clean up MPI 
        END