program main !*****************************************************************************80 ! !! hello_mpi() is a simple MPI test program. ! ! Discussion: ! ! Each process prints out a "Hello, world!" message. ! ! The master process also prints out a short message. ! ! Licensing: ! ! This code is distributed under the MIT license. ! ! Modified: ! ! 30 October 2008 ! ! Author: ! ! John Burkardt ! ! Reference: ! ! William Gropp, Ewing Lusk, Anthony Skjellum, ! Using MPI: Portable Parallel Programming with the ! Message-Passing Interface, ! Second Edition, ! MIT Press, 1999, ! ISBN: 0262571323, ! LC: QA76.642.G76. ! use mpi implicit none integer, parameter :: rk = kind ( 1.0D+00 ) integer error integer id integer p real ( kind = rk ) wtime ! ! Initialize MPI. ! call MPI_Init ( error ) ! ! Get the number of processes. ! call MPI_Comm_size ( MPI_COMM_WORLD, p, error ) ! ! Get the individual process ID. ! call MPI_Comm_rank ( MPI_COMM_WORLD, id, error ) ! ! Print a message. ! if ( id == 0 ) then wtime = MPI_Wtime ( ) call timestamp ( ) write ( *, '(a)' ) '' write ( *, '(a,i1,2x,a)' ) 'P', id, 'HELLO_MPI - Master process:' write ( *, '(a,i1,2x,a)' ) 'P', id, ' FORTRAN90/MPI version' write ( *, '(a,i1,2x,a)' ) 'P', id, ' An MPI test program.' write ( *, '(a,i1,2x,a,i8)' ) 'P', id, ' The number of MPI processes is ', p end if ! ! Every MPI process will print this message. ! write ( *, '(a,i1,2x,a)' ) 'P', id, '"Hello, world!"' if ( id == 0 ) then write ( *, '(a)' ) '' write ( *, '(a,i1,2x,a)' ) 'P', id, 'HELLO_MPI - Master process:' write ( *, '(a,i1,2x,a)' ) 'P', id, ' Normal end of execution: "Goodbye, world!".' wtime = MPI_Wtime ( ) - wtime write ( *, '(a)' ) '' write ( *, '(a,i1,2x,a,g14.6,a)' ) & 'P', id, ' Elapsed wall clock time = ', wtime, ' seconds.' end if ! ! Shut down MPI. ! call MPI_Finalize ( error ) ! ! Terminate. ! if ( id == 0 ) then write ( *, '(a)' ) '' write ( *, '(a,i1,2x,a)' ) 'P', id, 'HELLO_MPI - Master process:' write ( *, '(a,i1,2x,a)' ) 'P', id, ' Normal end of execution.' write ( *, '(a)' ) '' call timestamp ( ) end if stop end subroutine timestamp ( ) !*****************************************************************************80 ! !! TIMESTAMP prints the current YMDHMS date as a time stamp. ! ! Example: ! ! 31 May 2001 9:45:54.872 AM ! ! Licensing: ! ! This code is distributed under the MIT license. ! ! Modified: ! ! 06 August 2005 ! ! Author: ! ! John Burkardt ! implicit none character ( len = 8 ) ampm integer d integer h integer m integer mm character ( len = 9 ), parameter, dimension(12) :: month = (/ & 'January ', 'February ', 'March ', 'April ', & 'May ', 'June ', 'July ', 'August ', & 'September', 'October ', 'November ', 'December ' /) integer n integer s integer values(8) integer y call date_and_time ( values = values ) y = values(1) m = values(2) d = values(3) h = values(5) n = values(6) s = values(7) mm = values(8) if ( h < 12 ) then ampm = 'AM' else if ( h == 12 ) then if ( n == 0 .and. s == 0 ) then ampm = 'Noon' else ampm = 'PM' end if else h = h - 12 if ( h < 12 ) then ampm = 'PM' else if ( h == 12 ) then if ( n == 0 .and. s == 0 ) then ampm = 'Midnight' else ampm = 'AM' end if end if end if write ( *, '(i2,1x,a,1x,i4,2x,i2,a1,i2.2,a1,i2.2,a1,i3.3,1x,a)' ) & d, trim ( month(m) ), y, h, ':', n, ':', s, '.', mm, trim ( ampm ) return end