xref: /petsc/src/snes/tests/ex18f90.F90 (revision f51a5268c6b8e4f2d40024d7e7d67866ed2bae1c)
1c4762a1bSJed Brown!
2c4762a1bSJed Brown! Example usage of Fortran 2003/2008 classes (extended derived types) as
3c4762a1bSJed Brown! user-defined contexts in PETSc. Example contributed by Glenn Hammond.
4c4762a1bSJed Brown!
577d968b7SBarry Smithmodule ex18f90base_module
6c4762a1bSJed Brown#include "petsc/finclude/petscsnes.h"
7c4762a1bSJed Brown      implicit none
8c4762a1bSJed Brown  private
9c4762a1bSJed Brown
10c4762a1bSJed Brown  type, public :: base_type
11c4762a1bSJed Brown    PetscInt :: A  ! junk
12c4762a1bSJed Brown    PetscReal :: I ! junk
13c4762a1bSJed Brown  contains
14c4762a1bSJed Brown    procedure, public :: Print => BasePrint
15c4762a1bSJed Brown  end type base_type
16c4762a1bSJed Browncontains
17c4762a1bSJed Brownsubroutine BasePrint(this)
18c4762a1bSJed Brown  implicit none
19c4762a1bSJed Brown  class(base_type) :: this
20c4762a1bSJed Brown  print *
21c4762a1bSJed Brown  print *, 'Base printout'
22c4762a1bSJed Brown  print *
23c4762a1bSJed Brownend subroutine BasePrint
2477d968b7SBarry Smithend module ex18f90base_module
25c4762a1bSJed Brown
2677d968b7SBarry Smithmodule ex18f90extended_module
2777d968b7SBarry Smith  use ex18f90base_module
28c4762a1bSJed Brown  implicit none
29c4762a1bSJed Brown  private
30c4762a1bSJed Brown  type, public, extends(base_type) :: extended_type
31c4762a1bSJed Brown    PetscInt :: B  ! junk
32c4762a1bSJed Brown    PetscReal :: J ! junk
33c4762a1bSJed Brown  contains
34c4762a1bSJed Brown    procedure, public :: Print =>  ExtendedPrint
35c4762a1bSJed Brown  end type extended_type
36c4762a1bSJed Browncontains
37c4762a1bSJed Brownsubroutine ExtendedPrint(this)
38c4762a1bSJed Brown  implicit none
39c4762a1bSJed Brown  class(extended_type) :: this
40c4762a1bSJed Brown  print *
41c4762a1bSJed Brown  print *, 'Extended printout'
42c4762a1bSJed Brown  print *
43c4762a1bSJed Brownend subroutine ExtendedPrint
4477d968b7SBarry Smithend module ex18f90extended_module
45c4762a1bSJed Brown
4677d968b7SBarry Smithmodule ex18f90function_module
47c4762a1bSJed Brown  use petscsnes
48c4762a1bSJed Brown  implicit none
49c4762a1bSJed Brown  public :: TestFunction
50c4762a1bSJed Brown  contains
51c4762a1bSJed Brownsubroutine TestFunction(snes,xx,r,ctx,ierr)
5277d968b7SBarry Smith  use ex18f90base_module
53c4762a1bSJed Brown  implicit none
54c4762a1bSJed Brown  SNES :: snes
55c4762a1bSJed Brown  Vec :: xx
56c4762a1bSJed Brown  Vec :: r
57c4762a1bSJed Brown  class(base_type) :: ctx ! yes, this should be base_type in order to handle all
58c4762a1bSJed Brown  PetscErrorCode :: ierr  ! polymorphic extensions
59c4762a1bSJed Brown  call ctx%Print()
60c4762a1bSJed Brownend subroutine TestFunction
6177d968b7SBarry Smithend module ex18f90function_module
62c4762a1bSJed Brown
63c4762a1bSJed Brownprogram ex18f90
64c4762a1bSJed Brown
6577d968b7SBarry Smith  use ex18f90base_module
6677d968b7SBarry Smith  use ex18f90extended_module
6777d968b7SBarry Smith  use ex18f90function_module
68c4762a1bSJed Brown  implicit none
69c4762a1bSJed Brown
70*f51a5268SBarry Smith!
71*f51a5268SBarry Smith! Since class(base_type) has a bound function (method), Print, one must
72*f51a5268SBarry Smith! provide an interface definition as below and use SNESSetFunctionNoInterface()
73*f51a5268SBarry Smith! instead of SNESSetFunction()
74*f51a5268SBarry Smith!
75c4762a1bSJed Brown  interface
76*f51a5268SBarry Smith  subroutine SNESSetFunctionNoInterface(snes_base,x,TestFunction,base,ierr)
7777d968b7SBarry Smith    use ex18f90base_module
78c4762a1bSJed Brown    use petscsnes
79c4762a1bSJed Brown    SNES snes_base
80c4762a1bSJed Brown    Vec x
81c4762a1bSJed Brown    external TestFunction
82c4762a1bSJed Brown    class(base_type) :: base
83c4762a1bSJed Brown    PetscErrorCode ierr
84c4762a1bSJed Brown  end subroutine
85c4762a1bSJed Brown  end interface
86c4762a1bSJed Brown
87c4762a1bSJed Brown  PetscMPIInt :: size
88c4762a1bSJed Brown  PetscMPIInt :: rank
89c4762a1bSJed Brown
90c4762a1bSJed Brown  SNES :: snes_base, snes_extended
91c4762a1bSJed Brown  Vec :: x
92c4762a1bSJed Brown  class(base_type), pointer :: base
93c4762a1bSJed Brown  class(extended_type), pointer :: extended
94c4762a1bSJed Brown  PetscErrorCode :: ierr
95c4762a1bSJed Brown
96c4762a1bSJed Brown  print *, 'Start of Fortran2003 test program'
97c4762a1bSJed Brown
98c4762a1bSJed Brown  nullify(base)
99c4762a1bSJed Brown  nullify(extended)
100c4762a1bSJed Brown  allocate(base)
101c4762a1bSJed Brown  allocate(extended)
102d8606c27SBarry Smith  PetscCallA(PetscInitialize(ierr))
103d8606c27SBarry Smith  PetscCallMPIA(MPI_Comm_size(PETSC_COMM_WORLD,size,ierr))
104d8606c27SBarry Smith  PetscCallMPIA(MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr))
105c4762a1bSJed Brown
106d8606c27SBarry Smith  PetscCallA(VecCreate(PETSC_COMM_WORLD,x,ierr))
107c4762a1bSJed Brown
108c4762a1bSJed Brown  ! use the base class as the context
109c4762a1bSJed Brown  print *
110c4762a1bSJed Brown  print *, 'the base class will succeed by printing out Base printout below'
111d8606c27SBarry Smith  PetscCallA(SNESCreate(PETSC_COMM_WORLD,snes_base,ierr))
112*f51a5268SBarry Smith  PetscCallA(SNESSetFunctionNoInterface(snes_base,x,TestFunction,base,ierr))
113d8606c27SBarry Smith  PetscCallA(SNESComputeFunction(snes_base,x,x,ierr))
114d8606c27SBarry Smith  PetscCallA(SNESDestroy(snes_base,ierr))
115c4762a1bSJed Brown
116c4762a1bSJed Brown  ! use the extended class as the context
117c4762a1bSJed Brown  print *, 'the extended class will succeed by printing out Extended printout below'
118d8606c27SBarry Smith  PetscCallA(SNESCreate(PETSC_COMM_WORLD,snes_extended,ierr))
119*f51a5268SBarry Smith  PetscCallA(SNESSetFunctionNoInterface(snes_extended,x,TestFunction,extended,ierr))
120d8606c27SBarry Smith  PetscCallA(SNESComputeFunction(snes_extended,x,x,ierr))
121d8606c27SBarry Smith  PetscCallA(VecDestroy(x,ierr))
122d8606c27SBarry Smith  PetscCallA(SNESDestroy(snes_extended,ierr))
123c4762a1bSJed Brown  if (associated(base)) deallocate(base)
124c4762a1bSJed Brown  if (associated(extended)) deallocate(extended)
125d8606c27SBarry Smith  PetscCallA(PetscFinalize(ierr))
126c4762a1bSJed Brown
127c4762a1bSJed Brown  print *, 'End of Fortran2003 test program'
128c4762a1bSJed Brownend program ex18f90
129c4762a1bSJed Brown
130c4762a1bSJed Brown!/*TEST
131c4762a1bSJed Brown!
132c4762a1bSJed Brown!   build:
133dfd57a17SPierre Jolivet!      requires: defined(PETSC_USING_F2003) defined(PETSC_USING_F90FREEFORM)
134c4762a1bSJed Brown!   test:
135c4762a1bSJed Brown!     requires: !pgf90_compiler
136c4762a1bSJed Brown!
137c4762a1bSJed Brown!TEST*/
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