rem: _dc = _cachedb;
add: _dc = *_cachedb;
context: int dbt_cache_destroy(){	dbt_cache_p _dc=NULL, _dc0=NULL;		if(!_cachesem)		return -1;		lock_get(_cachesem);		_dc = _cachedb;	while(_dc)	{		_dc0 = _dc;		_dc = _dc->next;		dbt_cache_free(_dc0);	}	lock_destroy(_cachesem);	lock_dealloc(_cachesem);	return 0;}