/*
 *  Heap Handler
 *
 *  COPYRIGHT (c) 1989-2000.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.com/license/LICENSE.
 *
 *  $Id$
 */

#if HAVE_CONFIG_H
#include "config.h"
#endif

#include <rtems/system.h>
#include <rtems/score/sysstate.h>
#include <rtems/score/heap.h>

/*PAGE
 *
 *  _Heap_Get_information
 *
 *  This kernel routine walks the heap and tots up the free and allocated
 *  sizes.  Derived from _Heap_Walk.
 *
 *  Input parameters:
 *    the_heap  - pointer to heap header
 *    the_info  - pointer for information to be returned
 *
 *  Output parameters:
 *    *the_info  - contains information about heap
 *    return 0=success, otherwise heap is corrupt.
 */

Heap_Get_information_status _Heap_Get_information(
  Heap_Control            *the_heap,
  Heap_Information_block  *the_info
)
{
  Heap_Block *the_block = the_heap->start;
  Heap_Block *const end = the_heap->final;

  _HAssert(the_block->prev_size == HEAP_PREV_USED);
  _HAssert(_Heap_Is_prev_used(the_block));

  the_info->Free.number  = 0;
  the_info->Free.total   = 0;
  the_info->Free.largest = 0;
  the_info->Used.number  = 0;
  the_info->Used.total   = 0;
  the_info->Used.largest = 0;

  while ( the_block != end ) {
    uint32_t const the_size = _Heap_Block_size(the_block);
    Heap_Block *const next_block = _Heap_Block_at(the_block, the_size);

    if ( _Heap_Is_prev_used(next_block) ) {
      the_info->Used.number++;
      the_info->Used.total += the_size;
      if ( the_info->Used.largest < the_size )
        the_info->Used.largest = the_size;
    } else {
      the_info->Free.number++;
      the_info->Free.total += the_size;
      if ( the_info->Free.largest < the_size )
        the_info->Free.largest = the_size;
      if ( the_size != next_block->prev_size )
        return HEAP_GET_INFORMATION_BLOCK_ERROR;
    }

    the_block = next_block;
  }

  /* Handle the last dummy block. Don't consider this block to be
     "used" as client never allocated it. Make 'Used.total' contain this
     blocks' overhead though. */
  the_info->Used.total += HEAP_OVERHEAD;

  return HEAP_GET_INFORMATION_SUCCESSFUL;
}