finalize.c

linux下建立JAVA虚拟机的源码KAFFE

    new_fo -> fo_client_data = (ptr_t)cd;
    new_fo -> fo_object_size = hhdr -> hb_sz;
    new_fo -> fo_mark_proc = mp;
    fo_set_next(new_fo, fo_head[index]);
    GC_fo_entries++;
    fo_head[index] = new_fo;
#   ifdef THREADS
        UNLOCK();
    	ENABLE_SIGNALS();
#   endif
}

# if defined(__STDC__)
    void GC_register_finalizer(void * obj,
			       GC_finalization_proc fn, void * cd,
			       GC_finalization_proc *ofn, void ** ocd)
# else
    void GC_register_finalizer(obj, fn, cd, ofn, ocd)
    GC_PTR obj;
    GC_finalization_proc fn;
    GC_PTR cd;
    GC_finalization_proc * ofn;
    GC_PTR * ocd;
# endif
{
    GC_register_finalizer_inner(obj, fn, cd, ofn,
    				ocd, GC_normal_finalize_mark_proc);
}

# if defined(__STDC__)
    void GC_register_finalizer_ignore_self(void * obj,
			       GC_finalization_proc fn, void * cd,
			       GC_finalization_proc *ofn, void ** ocd)
# else
    void GC_register_finalizer_ignore_self(obj, fn, cd, ofn, ocd)
    GC_PTR obj;
    GC_finalization_proc fn;
    GC_PTR cd;
    GC_finalization_proc * ofn;
    GC_PTR * ocd;
# endif
{
    GC_register_finalizer_inner(obj, fn, cd, ofn,
    				ocd, GC_ignore_self_finalize_mark_proc);
}

# if defined(__STDC__)
    void GC_register_finalizer_no_order(void * obj,
			       GC_finalization_proc fn, void * cd,
			       GC_finalization_proc *ofn, void ** ocd)
# else
    void GC_register_finalizer_no_order(obj, fn, cd, ofn, ocd)
    GC_PTR obj;
    GC_finalization_proc fn;
    GC_PTR cd;
    GC_finalization_proc * ofn;
    GC_PTR * ocd;
# endif
{
    GC_register_finalizer_inner(obj, fn, cd, ofn,
    				ocd, GC_null_finalize_mark_proc);
}

#ifndef NO_DEBUGGING
void GC_dump_finalization()
{
    struct disappearing_link * curr_dl;
    struct finalizable_object * curr_fo;
    ptr_t real_ptr, real_link;
    int dl_size = (log_dl_table_size == -1 ) ? 0 : (1 << log_dl_table_size);
    int fo_size = (log_fo_table_size == -1 ) ? 0 : (1 << log_fo_table_size);
    int i;

    GC_printf0("Disappearing links:\n");
    for (i = 0; i < dl_size; i++) {
      for (curr_dl = dl_head[i]; curr_dl != 0; curr_dl = dl_next(curr_dl)) {
        real_ptr = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_obj);
        real_link = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_link);
        GC_printf2("Object: 0x%lx, Link:0x%lx\n", real_ptr, real_link);
      }
    }
    GC_printf0("Finalizers:\n");
    for (i = 0; i < fo_size; i++) {
      for (curr_fo = fo_head[i]; curr_fo != 0; curr_fo = fo_next(curr_fo)) {
        real_ptr = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base);
        GC_printf1("Finalizable object: 0x%lx\n", real_ptr);
      }
    }
}
#endif

/* Called with world stopped.  Cause disappearing links to disappear,	*/
/* and invoke finalizers.						*/
void GC_finalize()
{
    struct disappearing_link * curr_dl, * prev_dl, * next_dl;
    struct finalizable_object * curr_fo, * prev_fo, * next_fo;
    ptr_t real_ptr, real_link;
    register int i;
    int dl_size = (log_dl_table_size == -1 ) ? 0 : (1 << log_dl_table_size);
    int fo_size = (log_fo_table_size == -1 ) ? 0 : (1 << log_fo_table_size);
    
  /* Make disappearing links disappear */
    for (i = 0; i < dl_size; i++) {
      curr_dl = dl_head[i];
      prev_dl = 0;
      while (curr_dl != 0) {
        real_ptr = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_obj);
        real_link = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_link);
        if (!GC_is_marked(real_ptr)) {
            *(word *)real_link = 0;
            next_dl = dl_next(curr_dl);
            if (prev_dl == 0) {
                dl_head[i] = next_dl;
            } else {
                dl_set_next(prev_dl, next_dl);
            }
            GC_clear_mark_bit((ptr_t)curr_dl);
            GC_dl_entries--;
            curr_dl = next_dl;
        } else {
            prev_dl = curr_dl;
            curr_dl = dl_next(curr_dl);
        }
      }
    }
  /* Mark all objects reachable via chains of 1 or more pointers	*/
  /* from finalizable objects.						*/
    GC_ASSERT(GC_mark_state == MS_NONE);
    for (i = 0; i < fo_size; i++) {
      for (curr_fo = fo_head[i]; curr_fo != 0; curr_fo = fo_next(curr_fo)) {
        real_ptr = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base);
        if (!GC_is_marked(real_ptr)) {
	    GC_MARKED_FOR_FINALIZATION(real_ptr);
            GC_MARK_FO(real_ptr, curr_fo -> fo_mark_proc);
            if (GC_is_marked(real_ptr)) {
                WARN("Finalization cycle involving %lx\n", real_ptr);
            }
        }
      }
    }
  /* Enqueue for finalization all objects that are still		*/
  /* unreachable.							*/
    GC_words_finalized = 0;
    for (i = 0; i < fo_size; i++) {
      curr_fo = fo_head[i];
      prev_fo = 0;
      while (curr_fo != 0) {
        real_ptr = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base);
        if (!GC_is_marked(real_ptr)) {
	    if (!GC_java_finalization) {
              GC_set_mark_bit(real_ptr);
	    }
            /* Delete from hash table */
              next_fo = fo_next(curr_fo);
              if (prev_fo == 0) {
                fo_head[i] = next_fo;
              } else {
                fo_set_next(prev_fo, next_fo);
              }
              GC_fo_entries--;
            /* Add to list of objects awaiting finalization.	*/
              fo_set_next(curr_fo, GC_finalize_now);
              GC_finalize_now = curr_fo;
              /* unhide object pointer so any future collections will	*/
              /* see it.						*/
              curr_fo -> fo_hidden_base = 
              		(word) REVEAL_POINTER(curr_fo -> fo_hidden_base);
              GC_words_finalized +=
                 	ALIGNED_WORDS(curr_fo -> fo_object_size)
              		+ ALIGNED_WORDS(sizeof(struct finalizable_object));
	    GC_ASSERT(GC_is_marked(GC_base((ptr_t)curr_fo)));
            curr_fo = next_fo;
        } else {
            prev_fo = curr_fo;
            curr_fo = fo_next(curr_fo);
        }
      }
    }

  if (GC_java_finalization) {
    /* make sure we mark everything reachable from objects finalized
       using the no_order mark_proc */
      for (curr_fo = GC_finalize_now; 
  	 curr_fo != NULL; curr_fo = fo_next(curr_fo)) {
  	real_ptr = (ptr_t)curr_fo -> fo_hidden_base;
  	if (!GC_is_marked(real_ptr)) {
  	    if (curr_fo -> fo_mark_proc == GC_null_finalize_mark_proc) {
  	        GC_MARK_FO(real_ptr, GC_normal_finalize_mark_proc);
  	    }
  	    GC_set_mark_bit(real_ptr);
  	}
      }
  }

  /* Remove dangling disappearing links. */
    for (i = 0; i < dl_size; i++) {
      curr_dl = dl_head[i];
      prev_dl = 0;
      while (curr_dl != 0) {
        real_link = GC_base((ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_link));
        if (real_link != 0 && !GC_is_marked(real_link)) {
            next_dl = dl_next(curr_dl);
            if (prev_dl == 0) {
                dl_head[i] = next_dl;
            } else {
                dl_set_next(prev_dl, next_dl);
            }
            GC_clear_mark_bit((ptr_t)curr_dl);
            GC_dl_entries--;
            curr_dl = next_dl;
        } else {
            prev_dl = curr_dl;
            curr_dl = dl_next(curr_dl);
        }
      }
    }
}

#ifndef JAVA_FINALIZATION_NOT_NEEDED

/* Enqueue all remaining finalizers to be run - Assumes lock is
 * held, and signals are disabled */
void GC_enqueue_all_finalizers()
{
    struct finalizable_object * curr_fo, * prev_fo, * next_fo;
    ptr_t real_ptr;
    register int i;
    int fo_size;
    
    fo_size = (log_fo_table_size == -1 ) ? 0 : (1 << log_fo_table_size);
    GC_words_finalized = 0;
    for (i = 0; i < fo_size; i++) {
        curr_fo = fo_head[i];
        prev_fo = 0;
      while (curr_fo != 0) {
          real_ptr = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base);
          GC_MARK_FO(real_ptr, GC_normal_finalize_mark_proc);
          GC_set_mark_bit(real_ptr);
 
          /* Delete from hash table */
          next_fo = fo_next(curr_fo);
          if (prev_fo == 0) {
              fo_head[i] = next_fo;
          } else {
              fo_set_next(prev_fo, next_fo);
          }
          GC_fo_entries--;

          /* Add to list of objects awaiting finalization.	*/
          fo_set_next(curr_fo, GC_finalize_now);
          GC_finalize_now = curr_fo;

          /* unhide object pointer so any future collections will	*/
          /* see it.						*/
          curr_fo -> fo_hidden_base = 
        		(word) REVEAL_POINTER(curr_fo -> fo_hidden_base);

          GC_words_finalized +=
           	ALIGNED_WORDS(curr_fo -> fo_object_size)
        		+ ALIGNED_WORDS(sizeof(struct finalizable_object));
          curr_fo = next_fo;
        }
    }

    return;
}

/* Invoke all remaining finalizers that haven't yet been run. 
 * This is needed for strict compliance with the Java standard, 
 * which can make the runtime guarantee that all finalizers are run.
 * Unfortunately, the Java standard implies we have to keep running
 * finalizers until there are no more left, a potential infinite loop.
 * YUCK.
 * Note that this is even more dangerous than the usual Java
 * finalizers, in that objects reachable from static variables
 * may have been finalized when these finalizers are run.
 * Finalizers run at this point must be prepared to deal with a
 * mostly broken world.
 * This routine is externally callable, so is called without 
 * the allocation lock. 
 */
GC_API void GC_finalize_all()
{
    DCL_LOCK_STATE;

    DISABLE_SIGNALS();
    LOCK();
    while (GC_fo_entries > 0) {
      GC_enqueue_all_finalizers();
      UNLOCK();
      ENABLE_SIGNALS();
      GC_INVOKE_FINALIZERS();
      DISABLE_SIGNALS();
      LOCK();
    }
    UNLOCK();
    ENABLE_SIGNALS();
}
#endif

/* Returns true if it is worth calling GC_invoke_finalizers. (Useful if	*/
/* finalizers can only be called from some kind of `safe state' and	*/
/* getting into that safe state is expensive.)				*/
int GC_should_invoke_finalizers GC_PROTO((void))
{
    return GC_finalize_now != 0;
}

/* Invoke finalizers for all objects that are ready to be finalized.	*/
/* Should be called without allocation lock.				*/
int GC_invoke_finalizers()
{
    struct finalizable_object * curr_fo;
    int count = 0;
    word mem_freed_before;
    DCL_LOCK_STATE;
    
    while (GC_finalize_now != 0) {
#	ifdef THREADS
	    DISABLE_SIGNALS();
	    LOCK();
#	endif
	if (count == 0) {
	    mem_freed_before = GC_mem_freed;
	}
    	curr_fo = GC_finalize_now;
#	ifdef THREADS
 	    if (curr_fo != 0) GC_finalize_now = fo_next(curr_fo);
	    UNLOCK();
	    ENABLE_SIGNALS();
	    if (curr_fo == 0) break;
#	else
	    GC_finalize_now = fo_next(curr_fo);
#	endif
 	fo_set_next(curr_fo, 0);
    	(*(curr_fo -> fo_fn))((ptr_t)(curr_fo -> fo_hidden_base),
    			      curr_fo -> fo_client_data);
    	curr_fo -> fo_client_data = 0;
	++count;
#	ifdef UNDEFINED
	    /* This is probably a bad idea.  It throws off accounting if */
	    /* nearly all objects are finalizable.  O.w. it shouldn't	 */
	    /* matter.							 */
    	    GC_free((GC_PTR)curr_fo);
#	endif
    }
    if (count != 0 && mem_freed_before != GC_mem_freed) {
        LOCK();
	GC_finalizer_mem_freed += (GC_mem_freed - mem_freed_before);
	UNLOCK();
    }
    return count;
}

void (* GC_finalizer_notifier)() = (void (*) GC_PROTO((void)))0;

static GC_word last_finalizer_notification = 0;

void GC_notify_or_invoke_finalizers GC_PROTO((void))
{
    /* This is a convenient place to generate backtraces if appropriate, */
    /* since that code is not callable with the allocation lock.	 */
#   if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)
      static word last_back_trace_gc_no = 1;	/* Skip first one. */

      if (GC_gc_no > last_back_trace_gc_no) {
	word i;

#	ifdef KEEP_BACK_PTRS
	  LOCK();
	  /* Stops when GC_gc_no wraps; that's OK.	*/
	  last_back_trace_gc_no = (word)(-1);  /* disable others. */
	  for (i = 0; i < GC_backtraces; ++i) {
	      /* FIXME: This tolerates concurrent heap mutation,	*/
	      /* which may cause occasional mysterious results.		*/
	      /* We need to release the GC lock, since GC_print_callers	*/
	      /* acquires it.  It probably shouldn't.			*/
	      UNLOCK();
	      GC_generate_random_backtrace_no_gc();
	      LOCK();
	  }
	  last_back_trace_gc_no = GC_gc_no;
	  UNLOCK();
#	endif
#       ifdef MAKE_BACK_GRAPH
	  if (GC_print_back_height)
            GC_print_back_graph_stats();
#	endif
      }
#   endif
    if (GC_finalize_now == 0) return;
    if (!GC_finalize_on_demand) {
	(void) GC_invoke_finalizers();
#	ifndef THREADS
	  GC_ASSERT(GC_finalize_now == 0);
#	endif	/* Otherwise GC can run concurrently and add more */
	return;
    }
    if (GC_finalizer_notifier != (void (*) GC_PROTO((void)))0
	&& last_finalizer_notification != GC_gc_no) {
	last_finalizer_notification = GC_gc_no;
	GC_finalizer_notifier();
    }
}

# ifdef __STDC__
    GC_PTR GC_call_with_alloc_lock(GC_fn_type fn,
    					 GC_PTR client_data)
# else
    GC_PTR GC_call_with_alloc_lock(fn, client_data)
    GC_fn_type fn;
    GC_PTR client_data;
# endif
{
    GC_PTR result;
    DCL_LOCK_STATE;
    
#   ifdef THREADS
      DISABLE_SIGNALS();
      LOCK();
      SET_LOCK_HOLDER();
#   endif
    result = (*fn)(client_data);
#   ifdef THREADS
#     ifndef GC_ASSERTIONS
        UNSET_LOCK_HOLDER();
#     endif /* o.w. UNLOCK() does it implicitly */
      UNLOCK();
      ENABLE_SIGNALS();
#   endif
    return(result);
}

#if !defined(NO_DEBUGGING)

void GC_print_finalization_stats()
{
    struct finalizable_object *fo = GC_finalize_now;
    size_t ready = 0;

    GC_printf2("%lu finalization table entries; %lu disappearing links\n",
	       GC_fo_entries, GC_dl_entries);
    for (; 0 != fo; fo = fo_next(fo)) ++ready;
    GC_printf1("%lu objects are eligible for immediate finalization\n", ready);
}

#endif /* NO_DEBUGGING */