#+TITLE: Memory management
#+SETUPFILE: ../docs/theme.setup

We override the allocation functions to enable the possibility of
optimized libraries to fine-tune the memory allocation.


* Headers                                                          :noexport:

  #+NAME: filename
  #+begin_src elisp tangle: no 
(file-name-nondirectory (substring buffer-file-name 0 -4))
  #+end_src

  #+begin_src c :tangle (eval c)
#include <stdint.h>
#include <stdlib.h>
#include "qmckl_error.h"
#include "qmckl_context.h"
#include "qmckl_memory.h"
  #+end_src

  #+begin_src c :tangle (eval c_test) :noweb yes
#include "qmckl.h"
#include "munit.h"
MunitResult test_<<filename()>>() {
  #+end_src

* ~qmckl_malloc~

  Memory allocation function, letting the library choose how the
  memory will be allocated, and a pointer is returned to the user.
  The context is passed to let the library store data related to the
  allocation inside the context. If the allocation failed, the ~NULL~
  pointer is returned.

  #+begin_src c :tangle (eval h)
void* qmckl_malloc(qmckl_context ctx,
                   const size_t size);
  #+end_src

  #+begin_src f90 :tangle (eval fh)
  interface
     type (c_ptr) function qmckl_malloc (context, size) bind(C)
       use, intrinsic :: iso_c_binding
       integer (c_int64_t), intent(in), value :: context
       integer (c_int64_t), intent(in), value :: size
     end function qmckl_malloc
  end interface
  #+end_src

** Source

   #+begin_src c :tangle (eval c)
void* qmckl_malloc(qmckl_context ctx, const size_t size) {

  if (ctx == (qmckl_context) 0) {}; /* Avoid unused argument warning */
  void * result = malloc( (size_t) size );
  return result;

}

   #+end_src

** Test                                                            :noexport:
   #+begin_src c :tangle (eval c_test)
    int *a = NULL;
    munit_assert(a == NULL);
    a = (int*) qmckl_malloc( (qmckl_context) 1, 3*sizeof(int));
    munit_assert(a != NULL);
    a[0] = 1;
    a[1] = 2;
    a[2] = 3;
    munit_assert_int(a[0], ==, 1);
    munit_assert_int(a[1], ==, 2);
    munit_assert_int(a[2], ==, 3);
   #+end_src

* ~qmckl_free~

  The context is passed, in case some important information has been
  stored related to memory allocation and needs to be updated.

  #+begin_src c :tangle (eval h)
qmckl_exit_code qmckl_free(qmckl_context context,
                           void *ptr);
  #+end_src

  #+begin_src f90 :tangle (eval fh)
  interface
     integer (c_int32_t) function qmckl_free (context, ptr) bind(C)
       use, intrinsic :: iso_c_binding
       integer (c_int64_t), intent(in), value :: context
       type (c_ptr), intent(in), value :: ptr
     end function qmckl_free
  end interface
  #+end_src

** Source
   #+begin_src c :tangle (eval c)
qmckl_exit_code qmckl_free(qmckl_context context, void *ptr) {

  if (context == 0) return QMCKL_INVALID_ARG_1;
  if (ptr == NULL)  return QMCKL_INVALID_ARG_2;
  free(ptr);
  return QMCKL_SUCCESS;

}
   #+end_src

** Test                                                            :noexport:
   #+begin_src c :tangle (eval c_test)
munit_assert(a != NULL);
qmckl_exit_code rc;
rc = qmckl_free( (qmckl_context) 1, a);
munit_assert(rc == QMCKL_SUCCESS);

   #+end_src

* End of files                                                     :noexport:

** Test
  #+begin_src c :comments org :tangle (eval c_test)
  return MUNIT_OK;
}

  #+end_src
 

# -*- mode: org -*-
# vim: syntax=c