ESMF_VMGatherR8 Subroutine

  subroutine ESMF_VMGatherR8(vm, sendData, recvData, count, rootPet, &
    keywordEnforcer, syncflag, commhandle, rc)
!
! !ARGUMENTS:
    type(ESMF_VM),              intent(in)            :: vm
    real(ESMF_KIND_R8), target, intent(in)            :: sendData(:)
    real(ESMF_KIND_R8), target, intent(out)           :: recvData(:)
    integer,                    intent(in)            :: count
    integer,                    intent(in)            :: rootPet
type(ESMF_KeywordEnforcer), optional:: keywordEnforcer ! must use keywords below
    type(ESMF_Sync_Flag),       intent(in),  optional :: syncflag
    type(ESMF_CommHandle),      intent(out), optional :: commhandle
    integer,                    intent(out), optional :: rc
!         
!EOPI
!------------------------------------------------------------------------------
    integer                 :: localrc      ! local return code
    integer                 :: size
    logical                 :: blocking
    type(ESMF_CommHandle)   :: localcommhandle

    ! 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)

    ! Initialize commhandle to an invalid pointer
    if (present(commhandle)) commhandle%this = ESMF_NULL_POINTER

    ! Decide whether this is blocking or non-blocking
    blocking = .true. !default is blocking
    if (present(syncflag)) then
      if (syncflag == ESMF_SYNC_NONBLOCKING) blocking = .false. ! non-blocking
    endif
    
    size = count * 8 ! 8 bytes
    ! Call into the C++ interface.
    if (blocking) then
      call c_ESMC_VMGather(vm, sendData, recvData, size, rootPet, localrc)
      if (ESMF_LogFoundError(localrc, ESMF_ERR_PASSTHRU, &
        ESMF_CONTEXT, rcToReturn=rc)) return
    else
      call c_ESMC_VMGatherNB(vm, sendData, recvData, size, rootPet, &
        localcommhandle, localrc)
      if (ESMF_LogFoundError(localrc, ESMF_ERR_PASSTHRU, &
        ESMF_CONTEXT, rcToReturn=rc)) return
      ! Check if we need to pass back the commhandle
      if (present(commhandle)) then
        commhandle = localcommhandle  ! copy the commhandle pointer back
        ! Set init code
        ESMF_INIT_SET_CREATED(commhandle)
      endif
    endif

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

  end subroutine ESMF_VMGatherR8