Method alloc

3rd_party/Src/ode/ode/src/obstack.cpp:62–92

void *dObStack::alloc (int num_bytes)
{
  if ((size_t)num_bytes > MAX_ALLOC_SIZE) dDebug (0,"num_bytes too large");

  // allocate or move to a new arena if necessary
  if (!first) {
    // allocate the first arena if necessary
    first = last = (Arena *) dAlloc (dOBSTACK_ARENA_SIZE);
    first->next = 0;
    first->used = sizeof (Arena);
    ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (first,first->used);
  }
  else {
    // we already have one or more arenas, see if a new arena must be used
    if ((last->used + num_bytes) > dOBSTACK_ARENA_SIZE) {
      if (!last->next) {
	last->next = (Arena *) dAlloc (dOBSTACK_ARENA_SIZE);
	last->next->next = 0;
      }
      last = last->next;
      last->used = sizeof (Arena);
      ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (last,last->used);
    }
  }

  // allocate an area in the arena
  char *c = ((char*) last) + last->used;
  last->used += num_bytes;
  ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (last,last->used);
  return c;
}


void dObStack::freeAll()