_free_box

#include <rtl.h>

int _free_box (
    void* box_mem,    /* Start address of the memory pool */
    void* box );      /* Pointer to the block to free */

The _free_box function returns a memory block, which was allocated using _alloc_box or _calloc_box, back to the memory pool where it was obtained from.

The box argument specifies the address of the memory block to be freed.

The box_mem argument specifies the start address of the memory pool where the block was obtained from.

The _free_box function is in the RL-RTX library. The prototype is defined in rtl.h.

Note

• If you return the memory block to a memory pool that did not provide the memory block, serious memory errors might occur.
• The _free_box function is reentrant and thread-safe. You can call it from the main function and from an IRQ interrupt function with no restriction.

The _free_box function returns 0 if the memory block was successfully returned to the memory pool. If there was an error while freeing the block, it returns 1.

_alloc_box, _calloc_box, _init_box

#include <rtl.h>

/* Reserve a memory for 32 blocks of 20-bytes. */
U32 mpool[32*5 + 3];

void membox_test (void) {
  U8 *box;
  U8 *cbox;

  _init_box (mpool, sizeof (mpool), 20);
  box  = _alloc_box (mpool);
  /* This block is initialized to 0. */
  cbox = _calloc_box (mpool);
   ..
  _free_box (mpool, box);
  _free_box (mpool, cbox);
}