alloc.c

linux下建立JAVA虚拟机的源码KAFFE

	    && !GC_reclaim_all(stop_func, FALSE)) {
	    /* Aborted.  So far everything is still consistent.	*/
	    return(FALSE);
	}
    GC_invalidate_mark_state();  /* Flush mark stack.	*/
    GC_clear_marks();
#   ifdef SAVE_CALL_CHAIN_IN_GC
        GC_save_callers(GC_last_stack);
#   endif
    GC_is_full_gc = TRUE;
    if (!GC_stopped_mark(stop_func)) {
      if (!GC_incremental) {
    	/* We're partially done and have no way to complete or use 	*/
    	/* current work.  Reestablish invariants as cheaply as		*/
    	/* possible.							*/
    	GC_invalidate_mark_state();
	GC_unpromote_black_lists();
      } /* else we claim the world is already still consistent.  We'll 	*/
        /* finish incrementally.					*/
      return(FALSE);
    }
    GC_finish_collection();
#   if defined(CONDPRINT)
      if (GC_print_stats) {
        GET_TIME(current_time);
        GC_printf1("Complete collection took %lu msecs\n",
                   MS_TIME_DIFF(current_time,start_time));
      }
#   endif
    return(TRUE);
}



/*
 * Perform n units of garbage collection work.  A unit is intended to touch
 * roughly GC_RATE pages.  Every once in a while, we do more than that.
 * This needa to be a fairly large number with our current incremental
 * GC strategy, since otherwise we allocate too much during GC, and the
 * cleanup gets expensive.
 */
# define GC_RATE 10 
# define MAX_PRIOR_ATTEMPTS 1
 	/* Maximum number of prior attempts at world stop marking	*/
 	/* A value of 1 means that we finish the second time, no matter */
 	/* how long it takes.  Doesn't count the initial root scan	*/
 	/* for a full GC.						*/

int GC_deficit = 0;	/* The number of extra calls to GC_mark_some	*/
			/* that we have made.				*/

void GC_collect_a_little_inner(n)
int n;
{
    register int i;
    
    if (GC_dont_gc) return;
    if (GC_incremental && GC_collection_in_progress()) {
    	for (i = GC_deficit; i < GC_RATE*n; i++) {
    	    if (GC_mark_some((ptr_t)0)) {
    	        /* Need to finish a collection */
#     		ifdef SAVE_CALL_CHAIN_IN_GC
        	    GC_save_callers(GC_last_stack);
#     		endif
#		ifdef PARALLEL_MARK
		    GC_wait_for_reclaim();
#		endif
		if (GC_n_attempts < MAX_PRIOR_ATTEMPTS
		    && GC_time_limit != GC_TIME_UNLIMITED) {
		  GET_TIME(GC_start_time);
		  if (!GC_stopped_mark(GC_timeout_stop_func)) {
		    GC_n_attempts++;
		    break;
		  }
		} else {
		  (void)GC_stopped_mark(GC_never_stop_func);
		}
    	        GC_finish_collection();
    	        break;
    	    }
    	}
    	if (GC_deficit > 0) GC_deficit -= GC_RATE*n;
	if (GC_deficit < 0) GC_deficit = 0;
    } else {
        GC_maybe_gc();
    }
}

int GC_collect_a_little GC_PROTO(())
{
    int result;
    DCL_LOCK_STATE;

    DISABLE_SIGNALS();
    LOCK();
    GC_collect_a_little_inner(1);
    result = (int)GC_collection_in_progress();
    UNLOCK();
    ENABLE_SIGNALS();
    if (!result && GC_debugging_started) GC_print_all_smashed();
    return(result);
}

/*
 * Assumes lock is held, signals are disabled.
 * We stop the world.
 * If stop_func() ever returns TRUE, we may fail and return FALSE.
 * Increment GC_gc_no if we succeed.
 */
GC_bool GC_stopped_mark(stop_func)
GC_stop_func stop_func;
{
    register int i;
    int dummy;
#   if defined(PRINTTIMES) || defined(CONDPRINT)
	CLOCK_TYPE start_time, current_time;
#   endif
	
#   ifdef PRINTTIMES
	GET_TIME(start_time);
#   endif
#   if defined(CONDPRINT) && !defined(PRINTTIMES)
	if (GC_print_stats) GET_TIME(start_time);
#   endif
#   if defined(REGISTER_LIBRARIES_EARLY)
        GC_cond_register_dynamic_libraries();
#   endif
    STOP_WORLD();
    IF_THREADS(GC_world_stopped = TRUE);
#   ifdef CONDPRINT
      if (GC_print_stats) {
	GC_printf1("--> Marking for collection %lu ",
	           (unsigned long) GC_gc_no + 1);
	GC_printf2("after %lu allocd bytes + %lu wasted bytes\n",
	   	   (unsigned long) WORDS_TO_BYTES(GC_words_allocd),
	   	   (unsigned long) WORDS_TO_BYTES(GC_words_wasted));
      }
#   endif
#   ifdef MAKE_BACK_GRAPH
      if (GC_print_back_height) {
        GC_build_back_graph();
      }
#   endif

    /* Mark from all roots.  */
        /* Minimize junk left in my registers and on the stack */
            GC_clear_a_few_frames();
            GC_noop(0,0,0,0,0,0);
	GC_initiate_gc();
	for(i = 0;;i++) {
	    if ((*stop_func)()) {
#   		    ifdef CONDPRINT
		      if (GC_print_stats) {
		    	GC_printf0("Abandoned stopped marking after ");
			GC_printf1("%lu iterations\n",
				   (unsigned long)i);
		      }
#		    endif
		    GC_deficit = i; /* Give the mutator a chance. */
                    IF_THREADS(GC_world_stopped = FALSE);
	            START_WORLD();
	            return(FALSE);
	    }
	    if (GC_mark_some((ptr_t)(&dummy))) break;
	}
	
    GC_gc_no++;
#   ifdef PRINTSTATS
      GC_printf2("Collection %lu reclaimed %ld bytes",
		  (unsigned long) GC_gc_no - 1,
	   	  (long)WORDS_TO_BYTES(GC_mem_found));
#   else
#     ifdef CONDPRINT
        if (GC_print_stats) {
	  GC_printf1("Collection %lu finished", (unsigned long) GC_gc_no - 1);
	}
#     endif
#   endif /* !PRINTSTATS */
#   ifdef CONDPRINT
      if (GC_print_stats) {
        GC_printf1(" ---> heapsize = %lu bytes\n",
      	           (unsigned long) GC_heapsize);
        /* Printf arguments may be pushed in funny places.  Clear the	*/
        /* space.							*/
        GC_printf0("");
      }
#   endif  /* CONDPRINT  */

    /* Check all debugged objects for consistency */
        if (GC_debugging_started) {
            (*GC_check_heap)();
        }
    
    IF_THREADS(GC_world_stopped = FALSE);
    START_WORLD();
#   ifdef PRINTTIMES
	GET_TIME(current_time);
	GC_printf1("World-stopped marking took %lu msecs\n",
	           MS_TIME_DIFF(current_time,start_time));
#   else
#     ifdef CONDPRINT
	if (GC_print_stats) {
	  GET_TIME(current_time);
	  GC_printf1("World-stopped marking took %lu msecs\n",
	             MS_TIME_DIFF(current_time,start_time));
	}
#     endif
#   endif
    return(TRUE);
}

/* Set all mark bits for the free list whose first entry is q	*/
#ifdef __STDC__
  void GC_set_fl_marks(ptr_t q)
#else
  void GC_set_fl_marks(q)
  ptr_t q;
#endif
{
   ptr_t p;
   struct hblk * h, * last_h = 0;
   hdr *hhdr;
   int word_no;

   for (p = q; p != 0; p = obj_link(p)){
	h = HBLKPTR(p);
	if (h != last_h) {
	  last_h = h; 
	  hhdr = HDR(h);
	}
	word_no = (((word *)p) - ((word *)h));
	set_mark_bit_from_hdr(hhdr, word_no);
   }
}

/* Clear all mark bits for the free list whose first entry is q	*/
/* Decrement GC_mem_found by number of words on free list.	*/
#ifdef __STDC__
  void GC_clear_fl_marks(ptr_t q)
#else
  void GC_clear_fl_marks(q)
  ptr_t q;
#endif
{
   ptr_t p;
   struct hblk * h, * last_h = 0;
   hdr *hhdr;
   int word_no;

   for (p = q; p != 0; p = obj_link(p)){
	h = HBLKPTR(p);
	if (h != last_h) {
	  last_h = h; 
	  hhdr = HDR(h);
	}
	word_no = (((word *)p) - ((word *)h));
	clear_mark_bit_from_hdr(hhdr, word_no);
#	ifdef GATHERSTATS
	    GC_mem_found -= hhdr -> hb_sz;
#	endif
   }
}

/* Finish up a collection.  Assumes lock is held, signals are disabled,	*/
/* but the world is otherwise running.					*/
void GC_finish_collection()
{
#   ifdef PRINTTIMES
	CLOCK_TYPE start_time;
	CLOCK_TYPE finalize_time;
	CLOCK_TYPE done_time;
	
	GET_TIME(start_time);
	finalize_time = start_time;
#   endif

#   ifdef GATHERSTATS
        GC_mem_found = 0;
#   endif
#   if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
	if (getenv("GC_PRINT_ADDRESS_MAP") != 0) {
	  GC_print_address_map();
	}
#   endif
    COND_DUMP;
    if (GC_find_leak) {
      /* Mark all objects on the free list.  All objects should be */
      /* marked when we're done.				   */
	{
	  register word size;		/* current object size		*/
	  int kind;
	  ptr_t q;

	  for (kind = 0; kind < GC_n_kinds; kind++) {
	    for (size = 1; size <= MAXOBJSZ; size++) {
	      q = GC_obj_kinds[kind].ok_freelist[size];
	      if (q != 0) GC_set_fl_marks(q);
	    }
	  }
	}
	GC_start_reclaim(TRUE);
	  /* The above just checks; it doesn't really reclaim anything. */
    }

    GC_finalize();
#   ifdef STUBBORN_ALLOC
      GC_clean_changing_list();
#   endif

#   ifdef PRINTTIMES
      GET_TIME(finalize_time);
#   endif

    if (GC_print_back_height) {
#     ifdef MAKE_BACK_GRAPH
	GC_traverse_back_graph();
#     else
#	ifndef SMALL_CONFIG
	  GC_err_printf0("Back height not available: "
		         "Rebuild collector with -DMAKE_BACK_GRAPH\n");
#  	endif
#     endif
    }

    /* Clear free list mark bits, in case they got accidentally marked   */
    /* (or GC_find_leak is set and they were intentionally marked).	 */
    /* Also subtract memory remaining from GC_mem_found count.           */
    /* Note that composite objects on free list are cleared.             */
    /* Thus accidentally marking a free list is not a problem;  only     */
    /* objects on the list itself will be marked, and that's fixed here. */
      {
	register word size;		/* current object size		*/
	register ptr_t q;	/* pointer to current object	*/
	int kind;

	for (kind = 0; kind < GC_n_kinds; kind++) {
	  for (size = 1; size <= MAXOBJSZ; size++) {
	    q = GC_obj_kinds[kind].ok_freelist[size];
	    if (q != 0) GC_clear_fl_marks(q);
	  }
	}
      }


#   ifdef PRINTSTATS
	GC_printf1("Bytes recovered before sweep - f.l. count = %ld\n",
	          (long)WORDS_TO_BYTES(GC_mem_found));
#   endif
    /* Reconstruct free lists to contain everything not marked */
        GC_start_reclaim(FALSE);
        if (GC_is_full_gc)  {
	    GC_used_heap_size_after_full = USED_HEAP_SIZE;
	    GC_need_full_gc = FALSE;
	} else {
	    GC_need_full_gc =
		 BYTES_TO_WORDS(USED_HEAP_SIZE - GC_used_heap_size_after_full)
		 > min_words_allocd();
	}

#   ifdef PRINTSTATS
	GC_printf2(
		  "Immediately reclaimed %ld bytes in heap of size %lu bytes",
	          (long)WORDS_TO_BYTES(GC_mem_found),
	          (unsigned long)GC_heapsize);
#	ifdef USE_MUNMAP
	  GC_printf1("(%lu unmapped)", GC_unmapped_bytes);
#	endif