multithreading - To host functions within a threaded subroutine -

i encountered problem when port fortran project openmp. in original code, there 2 functions named add , mpy being passed threaded subroutine submodel throws respective function subroutine defined in module toolbox.

now, new code, wondering whether there way produce same outcome original code tiny twist moves 2 functions add , mpy hosted (i.e., contained) within subroutine submodel.

thanks.

lee

--- original code consists of 4 files: main.f90, model.f90, variable.f90, , toolbox.f90

output:

--- addition ---     3    7   11   15 --- multiplication ---     2   12   30   56 press key continue . . . 

main.f90

program main     use model     implicit none       call sandbox() end program main 

model.f90

module model     use omp_lib     use variable     implicit none contains     subroutine submodel(func,x,y)         implicit none         interface             function func(z)                 implicit none                 integer :: z,func             end function func         end interface         integer :: x,y         call tool(func,x,y)     end subroutine submodel      function add(a)         implicit none         integer :: a,add         add=a+thread_private     end function add       function mpy(m)         implicit none         integer :: m,mpy         mpy=m*thread_private     end function mpy      subroutine sandbox()         implicit none         integer :: a(4),b(4),c(4),i         a=[((i),i=1,7,2)]         b=[((i),i=2,8,2)]         !$omp parallel         i=1,4             thread_private=b(i)             call submodel(add,a(i),c(i))             enddo         !$omp end parallel         write(6,'(a)') '--- addition ---'         write(6,'(4(i5))') c          !$omp parallel         i=1,4             thread_private=b(i)             call submodel(mpy,a(i),c(i))         enddo         !$omp end parallel         write(6,'(a)') '--- multiplication ---'         write(6,'(4(i5))') c       end subroutine sandbox end module model 

toolbox.f90

module toolbox     implicit none contains     subroutine tool(funct,input,output)         implicit none         interface            function funct(x)                 implicit none                 integer :: x,funct             end function funct         end interface         integer :: input,output         output = funct(input)     end subroutine tool end module toolbox 

variable.f90

module variable     use toolbox     implicit none     integer :: thread_private     !$omp threadprivate(thread_private) end module variable 

is possible rearrange them in way? (i have tried , apparently failed):

subroutine submodel(func,x,y)     implicit none     interface         function func(z)             implicit none             integer :: z,func         end function func     end interface     integer :: x,y     call tool(func,x,y) contains     function add(a)         implicit none         integer :: a,add         add=a+thread_private     end function add       function mpy(m)         implicit none         integer :: m,mpy         mpy=m*thread_private     end function mpy end subroutine submodel 

you can make 2 procedures internal subroutine submodel did in last code snippet. problem cannot pass these 2 subroutines actual arguments outside of subroutine, because have no access them there.

even if have procedure pointers them stored somewhere, these invalid original run of submodel have created them ended.

i think using switch:

subroutine submodel(switch,x,y)     implicit none     integer :: switch,x,y      select case(switch)       case(use_add)         call tool(add,x,y)       case(use_mpy)         call tool(mpy,x,y)       case default         stop "unknown switch value"     end select contains     function add(a)         implicit none         integer :: a,add         add=a+thread_private     end function add       function mpy(m)         implicit none         integer :: m,mpy         mpy=m*thread_private     end function mpy end subroutine submodel 

another option keep original design.