/* LICENSE:
  =========================================================================
    CMPack'04 Source Code Release for OPEN-R SDK 1.1.5-r2 for ERS7
    Copyright (C) 2004 Multirobot Lab [Project Head: Manuela Veloso]
    School of Computer Science, Carnegie Mellon University
    All rights reserved.
  ========================================================================= */

#ifndef __FAST_ALLOC_H__
#define __FAST_ALLOC_H__

#define FSTALC_TEM template <class item_t>
#define FSTALC_FUN fast_allocator<item_t>

// #define DEBUG 1

FSTALC_TEM
class fast_allocator{
  item_t *free_list;
  int num_alloc,num_free;
public:
  fast_allocator() {free_list=NULL; num_alloc=num_free=0;}
  ~fast_allocator();

  item_t *alloc();
  void free(item_t *item);
  void freelist(item_t *item);

  int count_allocated() {return(num_alloc);}
  int count_free() {return(num_free);}
};

FSTALC_TEM
FSTALC_FUN::~fast_allocator()
{
  item_t *p,*q;

  p = free_list;
  while(q = p){
    p = p->next;
    q->next = NULL;
    delete(q);
  }

  free_list = NULL;
  num_alloc = num_free = 0;
}

FSTALC_TEM
item_t *FSTALC_FUN::alloc()
{
  item_t *p;

  if(free_list){
    p = free_list;
    free_list = p->next;
    p->next = NULL;
    num_free--;
  }else{
    p = new item_t;
  }
  num_alloc++;

  return(p);
}

FSTALC_TEM
void FSTALC_FUN::free(item_t *item)
{
  //item_t *check_item;
  //for(check_item=free_list; check_item!=NULL; check_item=check_item->next){
  //  if(check_item==item){
  //    printf("double free of %p\n",item);
  //    return;
  //  }
  //}

  //printf("free of %p\n",item);

  item->next = free_list;
  free_list = item;
  num_free++;
  num_alloc--;
  if(num_alloc < 0){
    *((ulong *)0)=0;
  }
}

FSTALC_TEM
void FSTALC_FUN::freelist(item_t *item)
{
  item_t *n;

  while(item){
    n = item->next;
    item->next = free_list;
    free_list = item;
    item = n;

    num_free++;
    num_alloc--;
  }
}

#endif /*__FAST_ALLOC_H__*/