computeAreaMesh Subroutine

subroutine computeAreaMesh(mesh, vm, petNo, petCnt, area, rc)
  type(ESMF_Mesh) :: mesh
  type(ESMF_VM) :: VM
  integer :: petNo,petCnt
  real (ESMF_KIND_R8), pointer :: area(:)
  integer :: rc
  real (ESMF_KIND_R8), pointer :: localArea(:)
  integer :: localrc
  integer :: localElemCount,i
  integer (ESMF_KIND_I4) :: localCount(1)
  integer (ESMF_KIND_I4),pointer :: globalCount(:),globalDispl(:)
  integer :: totalCount

   ! Get local size of mesh areas
   call ESMF_MeshGet(mesh, numOwnedElements=localElemCount, &
          rc=localrc)
   if (ESMF_LogFoundError(localrc, &
                       ESMF_ERR_PASSTHRU, &
                       ESMF_CONTEXT, rcToReturn=rc)) return

  ! allocate space for areas
  allocate(localArea(localElemCount))

  ! Get local Areas
  call ESMF_MeshGetElemArea(mesh, areaList=localArea, rc=localrc)
  if (ESMF_LogFoundError(localrc, &
                       ESMF_ERR_PASSTHRU, &
                       ESMF_CONTEXT, rcToReturn=rc)) return

  ! Allocate List of counts
  allocate(globalCount(petCnt))

  ! Get List of counts
  localCount(1)=localElemCount
  call ESMF_VMGather(vm,localCount,globalCount,count=1,rootPet=0,rc=localrc)
  if (ESMF_LogFoundError(localrc, &
                         ESMF_ERR_PASSTHRU, &
                         ESMF_CONTEXT, rcToReturn=rc)) return

  ! Calculate Displacements
  allocate(globalDispl(petCnt))
  if (petNo==0) then
     globalDispl(1)=0
     do i=2,petCnt
        globalDispl(i)=globalDispl(i-1)+globalCount(i-1)
     enddo
  else
    globalDispl=0
  endif


  ! Sum size
  if (petNo==0) then
    totalCount=0
    do i=1,petCnt
       totalCount=totalCount+globalCount(i)
    enddo
  else
    totalCount=1 ! Because I'm not sure what happens
                 ! if array is not allocated in VM
  endif

  ! Allocate final area list
  allocate(area(totalCount))

  ! Gather all areas
  call ESMF_VMGatherV(vm,sendData=localArea, sendCount=localElemCount,&
         recvData=area,recvCounts=globalCount,recvOffsets=globalDispl,&
         rootPet=0, rc=localrc)
  if (ESMF_LogFoundError(localrc, &
                         ESMF_ERR_PASSTHRU, &
                         ESMF_CONTEXT, rcToReturn=rc)) return

  ! Get rid of helper variables
  deallocate(localArea)
  deallocate(globalCount)
  deallocate(globalDispl)
  if (petNo .ne. 0) deallocate(area)

end subroutine computeAreaMesh