fix access violation crash

[likeuclinux]

TYPE: bug fix

KEYWORDS: crash, access violation error

SOURCE: Charlie Li, software developer from lakes environmental, Canada

DESCRIPTION OF CHANGES:
Problem:
wrf crashed for access violation frequently, due to the change made in PR #1991
when namelist.input has sf_urban_physics = 0 and bl_pbl_physics = 1.

In inc/allocs_5.F
IF(okay_to_alloc.AND.in_use_for_config(id,'dlg_bep').AND.(.NOT.grid%is_intermediate))THEN
will be false, then it would go to following branch:

ELSE
ALLOCATE(grid%dlg_bep(1,1,1),STAT=ierr)
if (ierr.ne.0) then
CALL wrf_error_fatal ( &
'frame/module_domain.f: Failed to allocate grid%dlg_bep(1,1,1). ')
endif
ENDIF

it only allocate (1,1,1) for memory, then it trigger crash in phys/module_bl_ysu.F

if(present(a_u_bep) .and. present(a_v_bep) .and. present(a_t_bep) .and. &
present(a_q_bep) .and. present(a_e_bep) .and. present(b_u_bep) .and. &
present(b_v_bep) .and. present(b_t_bep) .and. present(b_q_bep) .and. &
present(b_e_bep) .and. present(dlg_bep) .and. present(dl_u_bep) .and. &
present(sf_bep) .and. present(vl_bep) .and. present(frc_urb2d)) then

    do k = kts, kte
       do i = its,ite
          a_u_hv(i,k)  = a_u_bep(i,k,j)
          a_v_hv(i,k)  = a_v_bep(i,k,j)
          a_t_hv(i,k)  = a_t_bep(i,k,j)
          a_q_hv(i,k)  = a_q_bep(i,k,j)
          a_e_hv(i,k)  = a_e_bep(i,k,j)
          b_u_hv(i,k)  = b_u_bep(i,k,j)
          b_v_hv(i,k)  = b_v_bep(i,k,j)
          b_t_hv(i,k)  = b_t_bep(i,k,j)
          b_q_hv(i,k)  = b_q_bep(i,k,j)
          b_e_hv(i,k)  = b_e_bep(i,k,j)
          dlg_hv(i,k)  = dlg_bep(i,k,j)
          dl_u_hv(i,k) = dl_u_bep(i,k,j)
          vlk_hv(i,k) = vl_bep(i,k,j)
          sfk_hv(i,k)  = sf_bep(i,k,j)
       enddo
    enddo
    do i = its, ite
       frcurb_hv(i) = frc_urb2d(i,j)
    enddo

endif

the present() check in code won't help, since upper level in
dyn_em\module_first_rk_step_part1.F
will always call pbl_driver with DLG_BEP=grid%dlg_bep, then it pass down to module_pbl_driver to module_bl_ysu

Solution:

the fix is actually using v4.5 logic like following:

if(present(a_u_bep) .and. present(a_v_bep) .and. present(a_t_bep) .and. &
present(a_q_bep) .and. present(a_e_bep) .and. present(b_u_bep) .and. &
present(b_v_bep) .and. present(b_t_bep) .and. present(b_q_bep) .and. &
present(b_e_bep) .and. present(dlg_bep) .and. present(dl_u_bep) .and. &
present(sf_bep) .and. present(vl_bep) .and. present(frc_urb2d)) then

 ! following v4.5 logic to fix access violation
 if(flag_bep) then

    do k = kts, kte
       do i = its,ite
          a_u_hv(i,k)  = a_u_bep(i,k,j)
          a_v_hv(i,k)  = a_v_bep(i,k,j)
          a_t_hv(i,k)  = a_t_bep(i,k,j)
          a_q_hv(i,k)  = a_q_bep(i,k,j)
          a_e_hv(i,k)  = a_e_bep(i,k,j)
          b_u_hv(i,k)  = b_u_bep(i,k,j)
          b_v_hv(i,k)  = b_v_bep(i,k,j)
          b_t_hv(i,k)  = b_t_bep(i,k,j)
          b_q_hv(i,k)  = b_q_bep(i,k,j)
          b_e_hv(i,k)  = b_e_bep(i,k,j)
          dlg_hv(i,k)  = dlg_bep(i,k,j)
          dl_u_hv(i,k) = dl_u_bep(i,k,j)
          vlk_hv(i,k) = vl_bep(i,k,j)
          sfk_hv(i,k)  = sf_bep(i,k,j)
       enddo
    enddo
    do i = its, ite
       frcurb_hv(i) = frc_urb2d(i,j)
    enddo

 endif

endif

the flag_bep came from:

SELECT CASE(sf_urban_physics)
CASE (BEPSCHEME)
flag_bep=.true.
CASE (BEP_BEMSCHEME)
flag_bep=.true.
CASE DEFAULT
flag_bep=.false.
END SELECT

when namelist.inpu has sf_urban_physics = 0, flag_bep will be false, thus the code to access array with (1,1,1) allocation won't execute

LIST OF MODIFIED FILES:
phys/module_bl_ysu.F

TESTS CONDUCTED:
The Jenkins tests are all passing.

RELEASE NOTE: This PR fixes a access violation error with PGI compiler in module_bl_ysu.F if urban option is turned off.

[weiwangncar]

The regression test results:

Test Type              | Expected  | Received |  Failed
= = = = = = = = = = = = = = = = = = = = = = = =  = = = =
Number of Tests        : 23           24
Number of Builds       : 60           57
Number of Simulations  : 158           150        0
Number of Comparisons  : 95           86        0

Failed Simulations are: 
None
Which comparisons are not bit-for-bit: 
None

[islas]

@likeuclinux Could you separate out the edits in wrf_timeseries.F and start_em.F into their own PR? As it sounds like they are a separate issue from the not fully allocated dlg_bep array, it would help the review process if each PR was limited in scope to the exact issue being resolved.

[likeuclinux]

Can I just create another PR for both wrf_timeseries.F and start_em.F changes?

[likeuclinux]

great, I will do now

[islas]

Yes, sorry. That is what I meant. Those two files' edits appear to be related to improper deallocations which could be its own single PR

[likeuclinux]

I just create this PR for memory leak issue:
only memory leak related#2139
#2139

[likeuclinux]

I don't need re-create current PR 2137 for single file change relate to phys/module_bl_ysu.F ?

[dudhia]

@likeuclinux This one has #2139 as a subset. Need to remove one. Do we want all these changes?

[dudhia]

Note that #2139 looks like a subset and if so can be closed.

[likeuclinux]

This issue is fatal that cause wrf executable crash, while #2139 is just memory leak

[dudhia]

@weiwangncar This needs another review. It has #2137 as a subset and so needs to be merged after that one.

[weiwangncar]

@likeuclinux Are the changes made in the PR for wrf_timeseries.F completely the same as in PR-2139?

[weiwangncar]

@likeuclinux It looks like there is an extra empty line in the version of wrf_timeseries.F in this PR.

[weiwangncar]

@likeuclinux It looks like when I merged PR-2139, it resulted in a conflict in this PR. In your local tree, you can delete this file and checkout one from the repository (hence remove the change to wrf_timeseries.F from this PR), or resolve the conflict as indicated explicitly.

[weiwangncar]

@likeuclinux I was able to resolve the conflicit. Once regression tests are passed, it is good to go.