Why matlab crash when program tries to deallocate the dynamic memory allocated in fortran module

Hi, every one! I'm trying to write a little lengthy program. This program is speeded up with mex function in language C. However, in my program, I also have to call some functions written in fortran, and these functions has been well validated since others also use these functions. When I program, I write a interface program in language C and functions written in fortran are called from the interface program.

In this process, some dynamic memory in fortran part has to be allocated at the very begining and deallocated at the end. These dynamic memory are allocated at the first call as follows:

TURBULENCE_mp_INIT_TURBULENCE(NameList, buf, &nlev, buflen);  

The above sentence is run to call the following function in fortran:

subroutine init_turbulence(namlst,fn,nlev)
  IMPLICIT NONE
   integer,          intent(in)        :: namlst
   character(len=*), intent(in)        :: fn
   integer,          intent(in)        :: nlev
   integer                            :: rc
   REALTYPE                           :: L_min
!
   namelist /turbulence/    turb_method,tke_method,            &
                            len_scale_method,stab_method

   namelist /bc/            k_ubc,k_lbc,kb_ubc,kb_lbc,         &
                            psi_ubc,psi_lbc,                   &
                            ubc_type,lbc_type

   namelist /turb_param/    cm0_fix,Prandtl0_fix,cw,           &
                            compute_kappa,kappa,               &
                            compute_c3,ri_st,length_lim,galp,  &
                            const_num,const_nuh,k_min,eps_min, &
                            kb_min,epsb_min

   namelist /generic/       compute_param,gen_m,gen_n,gen_p,   &
                            cpsi1,cpsi2,cpsi3minus,cpsi3plus,  &
                            sig_kpsi,sig_psi,                  &
                            gen_d,gen_alpha,gen_l

   namelist /keps/          ce1,ce2,ce3minus,ce3plus,sig_k,    &
                            sig_e,sig_peps

   namelist /my/            e1,e2,e3,sq,sl,my_length,new_constr

   namelist /scnd/          scnd_method,kb_method,epsb_method, &
                            scnd_coeff,                        &
                            cc1,cc2,cc3,cc4,cc5,cc6,           &
                            ct1,ct2,ct3,ct4,ct5,ctt

   namelist /iw/            iw_model,alpha,klimiw,rich_cr,     &
                            numiw,nuhiw,numshear
!
   
!  allocate memory

   LEVEL2 'allocation memory..'
   allocate(tke(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (tke)'
   tke = k_min

   allocate(tkeo(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (tkeo)'
   tkeo = k_min

   allocate(eps(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (eps)'
   eps = eps_min

   allocate(L(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (L)'
   L = _ZERO_

   LEVEL2 'allocation memory..'
   allocate(kb(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (kb)'
   kb = kb_min

   LEVEL2 'allocation memory..'
   allocate(epsb(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (epsb)'
   epsb = epsb_min

   allocate(P(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (P)'
   P = _ZERO_

   allocate(B(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (B)'
   B = _ZERO_

   allocate(Pb(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (Pb)'
   Pb = _ZERO_

   allocate(num(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (num)'
   num = 1.0D-6

   allocate(nuh(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (nuh)'
   nuh = 1.0D-6

   allocate(nus(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (nus)'
   nus = 1.0D-6

   allocate(gamu(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (gamu)'
   gamu = _ZERO_

   allocate(gamv(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (gamv)'
   gamv = _ZERO_

   allocate(gamb(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (gamb)'
   gamb = _ZERO_

   allocate(gamh(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (gamh)'
   gamh = _ZERO_

   allocate(gams(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (gams)'
   gams = _ZERO_

   allocate(cmue1(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (cmue1)'
   cmue1 = _ZERO_

   allocate(cmue2(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (cmue2)'
   cmue2 = _ZERO_

   allocate(gam(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (gam)'
   gam = _ZERO_

   allocate(an(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (an)'
   an = _ZERO_

   allocate(as(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (as)'
   as = _ZERO_

   allocate(at(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (at)'
   at = _ZERO_

   allocate(r(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (r)'
   r = _ZERO_

   allocate(Rig(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (Rig)'
   Rig = _ZERO_

   allocate(xRf(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (xRf)'
   xRf = _ZERO_

   allocate(uu(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (uu)'
   uu = _ZERO_

   allocate(vv(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (vv)'
   vv = _ZERO_

   allocate(ww(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (ww)'
   ww = _ZERO_

# ifdef EXTRA_OUTPUT

   allocate(turb1(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (turb1)'
   turb1 = _ZERO_

   allocate(turb2(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (turb2)'
   turb2 = _ZERO_

   allocate(turb3(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (turb3)'
   turb3 = _ZERO_

   allocate(turb4(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (turb4)'
   turb4 = _ZERO_

   allocate(turb5(0:nlev),stat=rc)
   if (rc /= 0) stop 'init_turbulence: Error allocating (turb5)'
   turb5 = _ZERO_
   
   return
   end subroutine init_turbulence
   

This part runs smoothly, and no errors occured. After finish all the work, the memory allocated above is deallocated with the following function call from the interface program:

   TURBULENCE_mp_CLEAN_TURBULENCE();

The above sentence is used to call the follwing function in fortran:

   subroutine clean_turbulence()
    LEVEL2 'de-allocating turbulence memory ...'
   if (allocated(tke)) deallocate(tke)
   if (allocated(tkeo)) deallocate(tkeo)
   if (allocated(eps)) deallocate(eps)
   if (allocated(L)) deallocate(L)
   if (allocated(kb)) deallocate(kb)
   if (allocated(epsb)) deallocate(epsb)
   if (allocated(P)) deallocate(P)
   if (allocated(B)) deallocate(B)
   if (allocated(Pb)) deallocate(Pb)
   if (allocated(num)) deallocate(num)
   if (allocated(nuh)) deallocate(nuh)
   if (allocated(nus)) deallocate(nus)
   if (allocated(gamu)) deallocate(gamu)
   if (allocated(gamv)) deallocate(gamv)
   if (allocated(gamb)) deallocate(gamb)
   if (allocated(gamh)) deallocate(gamh)
   if (allocated(gams)) deallocate(gams)
   if (allocated(cmue1)) deallocate(cmue1)
   if (allocated(cmue2)) deallocate(cmue2)
   if (allocated(gam)) deallocate(gam)
   if (allocated(an)) deallocate(an)
   if (allocated(as)) deallocate(as)
   if (allocated(at)) deallocate(at)
   if (allocated(r)) deallocate(r)
   if (allocated(Rig)) deallocate(Rig)
   if (allocated(xRf)) deallocate(xRf)
   if (allocated(uu)) deallocate(uu)
   if (allocated(vv)) deallocate(vv)
   if (allocated(ww)) deallocate(ww)
# ifdef EXTRA_OUTPUT
   if (allocated(turb1)) deallocate(turb1)
   if (allocated(turb2)) deallocate(turb2)
   if (allocated(turb3)) deallocate(turb3)
   if (allocated(turb4)) deallocate(turb4)
   if (allocated(turb5)) deallocate(turb5)
# endif
   LEVEL2 'done.'

   return
   end subroutine clean_turbulence

However, program crashed in this function call. I tried to debug this part and found it crashed when it call the first sentence:

   if (allocated(tke)) deallocate(tke)

I wonder why the program crashes here.

Thanks in advace

[James Tursa]

Some questions:

In your C interface code, is NameList a pointer to an integer type? How can you be sure that it is the same integer size that Fortran is expecting? How is it declared? How do you know what size the integer is on the Fortran side?

In your C interface code, it appears you pass the character string length buflen (the length of buf) as the last argument. Are you sure your Fortran compiler puts this at the end of the argument list and not next to buf? And are you sure you are using the correct integer size for buflen that your Fortran compiler uses for this (32-bit or 64-bit integer)?

In your Fortran code, I don't see your allocatable variables (tke, tkeo, etc.) declared anywhere. Are they module variables? Are your subroutines part of a module? Can you clarify where these variables live and how your code is structured?

When you write "After finish all the work", does this mean you deallocate the Fortran variables inside the code before returning to the C interface code? Or does that mean you return to the C interface code, and then on a subsequent call try to deallocate the Fortran variables that were allocated on a previous call? Do you return all the way to MATLAB inbetween the allocation and deallocation calls?

Is the Fortran code a regular compiled object file that is linked in with the C interface object file via the mex command?

[Rylan]

Thanks for your questions.

According to your questions, I have found the exact reason. I made a careless mistake. During the computation, the address the pointer scheduled to point to is frequently changed.

Sorry for this careless mistake and thanks for your time!