ESMF_VMBarrier Subroutine

  subroutine ESMF_VMBarrier(vm, keywordEnforcer, rc)
!
! !ARGUMENTS:
    type(ESMF_VM),  intent(in),  optional :: vm
type(ESMF_KeywordEnforcer), optional:: keywordEnforcer ! must use keywords below
    integer,        intent(out), optional :: rc
!
! !STATUS:
! \begin{itemize}
! \item\apiStatusCompatibleVersion{5.2.0r}
! \item\apiStatusModifiedSinceVersion{5.2.0r}
! \begin{description}
! \item[8.1.0] Made argument {\tt vm} optional to simplify usage when calling
!   on the current VM.
! \end{description}
! \end{itemize}
!
! !DESCRIPTION:
!   Collective {\tt ESMF\_VM} communication call that blocks calling PET until
!   all PETs of the VM context have issued the call.
!
!   The arguments are:
!   \begin{description}
!   \item[{[vm]}] 
!        {\tt ESMF\_VM} object. Default use current VM.
!   \item[{[rc]}] 
!        Return code; equals {\tt ESMF\_SUCCESS} if there are no errors.
!   \end{description}
!
!EOP
!------------------------------------------------------------------------------
    integer                 :: localrc      ! local return code
    type(ESMF_VM)           :: currentVM

    ! initialize return code; assume routine not implemented
    localrc = ESMF_RC_NOT_IMPL
    if (present(rc)) rc = ESMF_RC_NOT_IMPL

    ! Check init status of arguments
    ESMF_INIT_CHECK_DEEP(ESMF_VMGetInit, vm, rc)

    ! Call into the C++ interface.
    if (present(vm)) then
      call c_ESMC_VMBarrier(vm, localrc)
      if (ESMF_LogFoundError(localrc, ESMF_ERR_PASSTHRU, &
        ESMF_CONTEXT, rcToReturn=rc)) return
    else
      call ESMF_VMGetCurrent(currentVM, rc=localrc)
      if (ESMF_LogFoundError(localrc, ESMF_ERR_PASSTHRU, &
        ESMF_CONTEXT, rcToReturn=rc)) return
      call c_ESMC_VMBarrier(currentVM, localrc)
      if (ESMF_LogFoundError(localrc, ESMF_ERR_PASSTHRU, &
        ESMF_CONTEXT, rcToReturn=rc)) return
    endif

    ! return successfully
    if (present(rc)) rc = ESMF_SUCCESS

  end subroutine ESMF_VMBarrier