问boehm-gc :终结器，并缩小到适合堆。

EN

typedef void (*GC_finalization_proc)
  GC_PROTO((GC_PTR obj, GC_PTR client_data));

GC_API void GC_register_finalizer
    GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
      GC_finalization_proc *ofn, GC_PTR *ocd));
GC_API void GC_debug_register_finalizer
    GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
      GC_finalization_proc *ofn, GC_PTR *ocd));
/* When obj is no longer accessible, invoke     */
/* (*fn)(obj, cd).  If a and b are inaccessible, and    */
/* a points to b (after disappearing links have been    */
/* made to disappear), then only a will be      */
/* finalized.  (If this does not create any new     */
/* pointers to b, then b will be finalized after the    */
/* next collection.)  Any finalizable object that   */
/* is reachable from itself by following one or more    */
/* pointers will not be finalized (or collected).   */
/* Thus cycles involving finalizable objects should */
/* be avoided, or broken by disappearing links.     */
/* All but the last finalizer registered for an object  */
/* is ignored.                      */
/* Finalization may be removed by passing 0 as fn.  */
/* Finalizers are implicitly unregistered just before   */
/* they are invoked.                    */
/* The old finalizer and client data are stored in  */
/* *ofn and *ocd.                   */ 
/* Fn is never invoked on an accessible object,     */
/* provided hidden pointers are converted to real   */
/* pointers only if the allocation lock is held, and    */
/* such conversions are not performed by finalization   */
/* routines.                        */
/* If GC_register_finalizer is aborted as a result of   */
/* a signal, the object may be left with no     */
/* finalization, even if neither the old nor new    */
/* finalizer were NULL.                 */
/* Obj should be the nonNULL starting address of an     */
/* object allocated by GC_malloc or friends.        */
/* Note that any garbage collectable object referenced  */
/* by cd will be considered accessible until the    */
/* finalizer is invoked.                */

typedef <any type at all you want passed to the callback
         as data for its own use> MY_ENVIRONMENT;

void my_callback(GC_PTR void_obj, GC_PTR void_environment) {
  MY_ENVIRONMENT *env = (MY_ENVIRONMENT)void_environment;
  MY_OBJECT *obj = (MY_OBJECT*)void_obj;

  // Do finalization here.
}

MY_ENVIRONMENT *my_env = new MY_ENVIRONMENT;
// Initialize if necessary.

MY_
MY_ENVIRONMENT old_env;
GC_finalization_proc old_proc;
GC_register_finalizer(new_obj, my_callback, my_env, &old_env, &old_proc);