gc_priv.h

gcc的组建

  word GC_words_allocd;
  	/* Number of words allocated during this collection cycle */
  ptr_t GC_objfreelist[MAXOBJSZ+1];
			  /* free list for NORMAL objects */
# define beginGC_objfreelist ((ptr_t)(&GC_objfreelist))
# define endGC_objfreelist (beginGC_objfreelist + sizeof(GC_objfreelist))

  ptr_t GC_aobjfreelist[MAXOBJSZ+1];
			  /* free list for atomic (PTRFREE) objs 	*/
# define beginGC_aobjfreelist ((ptr_t)(&GC_aobjfreelist))
# define endGC_aobjfreelist (beginGC_aobjfreelist + sizeof(GC_aobjfreelist))
#endif

/* Predefined kinds: */
# define PTRFREE 0
# define NORMAL  1
# define UNCOLLECTABLE 2
# ifdef ATOMIC_UNCOLLECTABLE
#   define AUNCOLLECTABLE 3
#   define STUBBORN 4
#   define IS_UNCOLLECTABLE(k) (((k) & ~1) == UNCOLLECTABLE)
# else
#   define STUBBORN 3
#   define IS_UNCOLLECTABLE(k) ((k) == UNCOLLECTABLE)
# endif

extern int GC_n_kinds;

GC_API word GC_fo_entries;

extern word GC_n_heap_sects;	/* Number of separately added heap	*/
				/* sections.				*/

extern word GC_page_size;

# if defined(MSWIN32) || defined(MSWINCE)
  struct _SYSTEM_INFO;
  extern struct _SYSTEM_INFO GC_sysinfo;
  extern word GC_n_heap_bases;	/* See GC_heap_bases.	*/
# endif

extern word GC_total_stack_black_listed;
			/* Number of bytes on stack blacklist. 	*/

extern word GC_black_list_spacing;
			/* Average number of bytes between blacklisted	*/
			/* blocks. Approximate.				*/
			/* Counts only blocks that are 			*/
			/* "stack-blacklisted", i.e. that are 		*/
			/* problematic in the interior of an object.	*/

extern map_entry_type * GC_invalid_map;
			/* Pointer to the nowhere valid hblk map */
			/* Blocks pointing to this map are free. */

extern struct hblk * GC_hblkfreelist[];
				/* List of completely empty heap blocks	*/
				/* Linked through hb_next field of 	*/
				/* header structure associated with	*/
				/* block.				*/

extern GC_bool GC_objects_are_marked;	/* There are marked objects in  */
					/* the heap.			*/

#ifndef SMALL_CONFIG
  extern GC_bool GC_incremental;
			/* Using incremental/generational collection. */
# define TRUE_INCREMENTAL \
	(GC_incremental && GC_time_limit != GC_TIME_UNLIMITED)
	/* True incremental, not just generational, mode */
#else
# define GC_incremental FALSE
			/* Hopefully allow optimizer to remove some code. */
# define TRUE_INCREMENTAL FALSE
#endif

extern GC_bool GC_dirty_maintained;
				/* Dirty bits are being maintained, 	*/
				/* either for incremental collection,	*/
				/* or to limit the root set.		*/

extern word GC_root_size;	/* Total size of registered root sections */

extern GC_bool GC_debugging_started;	/* GC_debug_malloc has been called. */ 

extern long GC_large_alloc_warn_interval;
	/* Interval between unsuppressed warnings.	*/

extern long GC_large_alloc_warn_suppressed;
	/* Number of warnings suppressed so far.	*/

#ifdef THREADS
  extern GC_bool GC_world_stopped;
#endif

/* Operations */
# ifndef abs
#   define abs(x)  ((x) < 0? (-(x)) : (x))
# endif


/*  Marks are in a reserved area in                          */
/*  each heap block.  Each word has one mark bit associated  */
/*  with it. Only those corresponding to the beginning of an */
/*  object are used.                                         */

/* Set mark bit correctly, even if mark bits may be concurrently 	*/
/* accessed.								*/
#ifdef PARALLEL_MARK
# define OR_WORD(addr, bits) \
	{ word old; \
	  do { \
	    old = *((volatile word *)addr); \
	  } while (!GC_compare_and_exchange((addr), old, old | (bits))); \
	}
# define OR_WORD_EXIT_IF_SET(addr, bits, exit_label) \
	{ word old; \
	  word my_bits = (bits); \
	  do { \
	    old = *((volatile word *)addr); \
	    if (old & my_bits) goto exit_label; \
	  } while (!GC_compare_and_exchange((addr), old, old | my_bits)); \
	}
#else
# define OR_WORD(addr, bits) *(addr) |= (bits)
# define OR_WORD_EXIT_IF_SET(addr, bits, exit_label) \
	{ \
	  word old = *(addr); \
	  word my_bits = (bits); \
	  if (old & my_bits) goto exit_label; \
	  *(addr) = (old | my_bits); \
	}
#endif

/* Mark bit operations */

/*
 * Retrieve, set, clear the mark bit corresponding
 * to the nth word in a given heap block.
 *
 * (Recall that bit n corresponds to object beginning at word n
 * relative to the beginning of the block, including unused words)
 */

#ifdef USE_MARK_BYTES
# define mark_bit_from_hdr(hhdr,n) ((hhdr)->hb_marks[(n) >> 1])
# define set_mark_bit_from_hdr(hhdr,n) ((hhdr)->hb_marks[(n)>>1]) = 1
# define clear_mark_bit_from_hdr(hhdr,n) ((hhdr)->hb_marks[(n)>>1]) = 0
#else /* !USE_MARK_BYTES */
# define mark_bit_from_hdr(hhdr,n) (((hhdr)->hb_marks[divWORDSZ(n)] \
			    >> (modWORDSZ(n))) & (word)1)
# define set_mark_bit_from_hdr(hhdr,n) \
			    OR_WORD((hhdr)->hb_marks+divWORDSZ(n), \
				    (word)1 << modWORDSZ(n))
# define clear_mark_bit_from_hdr(hhdr,n) (hhdr)->hb_marks[divWORDSZ(n)] \
				&= ~((word)1 << modWORDSZ(n))
#endif /* !USE_MARK_BYTES */

/* Important internal collector routines */

ptr_t GC_approx_sp GC_PROTO((void));
  
GC_bool GC_should_collect GC_PROTO((void));
  
void GC_apply_to_all_blocks GC_PROTO(( \
    void (*fn) GC_PROTO((struct hblk *h, word client_data)), \
    word client_data));
  			/* Invoke fn(hbp, client_data) for each 	*/
  			/* allocated heap block.			*/
struct hblk * GC_next_used_block GC_PROTO((struct hblk * h));
  			/* Return first in-use block >= h	*/
struct hblk * GC_prev_block GC_PROTO((struct hblk * h));
  			/* Return last block <= h.  Returned block	*/
  			/* is managed by GC, but may or may not be in	*/
			/* use.						*/
void GC_mark_init GC_PROTO((void));
void GC_clear_marks GC_PROTO((void));	/* Clear mark bits for all heap objects. */
void GC_invalidate_mark_state GC_PROTO((void));
					/* Tell the marker that	marked 	   */
  					/* objects may point to	unmarked   */
  					/* ones, and roots may point to	   */
  					/* unmarked objects.		   */
  					/* Reset mark stack.		   */
GC_bool GC_mark_stack_empty GC_PROTO((void));
GC_bool GC_mark_some GC_PROTO((ptr_t cold_gc_frame));
  			/* Perform about one pages worth of marking	*/
  			/* work of whatever kind is needed.  Returns	*/
  			/* quickly if no collection is in progress.	*/
  			/* Return TRUE if mark phase finished.		*/
void GC_initiate_gc GC_PROTO((void));
				/* initiate collection.			*/
  				/* If the mark state is invalid, this	*/
  				/* becomes full colleection.  Otherwise */
  				/* it's partial.			*/
void GC_push_all GC_PROTO((ptr_t bottom, ptr_t top));
				/* Push everything in a range 		*/
  				/* onto mark stack.			*/
void GC_push_selected GC_PROTO(( \
    ptr_t bottom, \
    ptr_t top, \
    int (*dirty_fn) GC_PROTO((struct hblk *h)), \
    void (*push_fn) GC_PROTO((ptr_t bottom, ptr_t top)) ));
				  /* Push all pages h in [b,t) s.t. 	*/
				  /* select_fn(h) != 0 onto mark stack. */
#ifndef SMALL_CONFIG
  void GC_push_conditional GC_PROTO((ptr_t b, ptr_t t, GC_bool all));
#else
# define GC_push_conditional(b, t, all) GC_push_all(b, t)
#endif
                                /* Do either of the above, depending	*/
				/* on the third arg.			*/
void GC_push_all_stack GC_PROTO((ptr_t b, ptr_t t));
				    /* As above, but consider		*/
				    /*  interior pointers as valid  	*/
void GC_push_all_eager GC_PROTO((ptr_t b, ptr_t t));
				    /* Same as GC_push_all_stack, but   */
				    /* ensures that stack is scanned	*/
				    /* immediately, not just scheduled  */
				    /* for scanning.			*/
#ifndef THREADS
  void GC_push_all_stack_partially_eager GC_PROTO(( \
      ptr_t bottom, ptr_t top, ptr_t cold_gc_frame ));
			/* Similar to GC_push_all_eager, but only the	*/
			/* part hotter than cold_gc_frame is scanned	*/
			/* immediately.  Needed to ensure that callee-	*/
			/* save registers are not missed.		*/
#else
  /* In the threads case, we push part of the current thread stack	*/
  /* with GC_push_all_eager when we push the registers.  This gets the  */
  /* callee-save registers that may disappear.  The remainder of the	*/
  /* stacks are scheduled for scanning in *GC_push_other_roots, which	*/
  /* is thread-package-specific.					*/
#endif
void GC_push_current_stack GC_PROTO((ptr_t cold_gc_frame));
  			/* Push enough of the current stack eagerly to	*/
  			/* ensure that callee-save registers saved in	*/
  			/* GC frames are scanned.			*/
  			/* In the non-threads case, schedule entire	*/
  			/* stack for scanning.				*/
void GC_push_roots GC_PROTO((GC_bool all, ptr_t cold_gc_frame));
  			/* Push all or dirty roots.	*/
extern void (*GC_push_other_roots) GC_PROTO((void));
  			/* Push system or application specific roots	*/
  			/* onto the mark stack.  In some environments	*/
  			/* (e.g. threads environments) this is		*/
  			/* predfined to be non-zero.  A client supplied */
  			/* replacement should also call the original	*/
  			/* function.					*/
extern void GC_push_gc_structures GC_PROTO((void));
			/* Push GC internal roots.  These are normally	*/
			/* included in the static data segment, and 	*/
			/* Thus implicitly pushed.  But we must do this	*/
			/* explicitly if normal root processing is 	*/
			/* disabled.  Calls the following:		*/
	extern void GC_push_finalizer_structures GC_PROTO((void));
	extern void GC_push_stubborn_structures GC_PROTO((void));
#	ifdef THREADS
	  extern void GC_push_thread_structures GC_PROTO((void));
#	endif
extern void (*GC_start_call_back) GC_PROTO((void));
  			/* Called at start of full collections.		*/
  			/* Not called if 0.  Called with allocation 	*/
  			/* lock held.					*/
  			/* 0 by default.				*/
# if defined(USE_GENERIC_PUSH_REGS)
  void GC_generic_push_regs GC_PROTO((ptr_t cold_gc_frame));
# else
  void GC_push_regs GC_PROTO((void));
# endif
# if defined(SPARC) || defined(IA64)
  /* Cause all stacked registers to be saved in memory.  Return a	*/
  /* pointer to the top of the corresponding memory stack.		*/
  word GC_save_regs_in_stack GC_PROTO((void));
# endif
			/* Push register contents onto mark stack.	*/
  			/* If NURSERY is defined, the default push	*/
  			/* action can be overridden with GC_push_proc	*/

# ifdef NURSERY
    extern void (*GC_push_proc)(ptr_t);
# endif
# if defined(MSWIN32) || defined(MSWINCE)
  void __cdecl GC_push_one GC_PROTO((word p));
# else
  void GC_push_one GC_PROTO((word p));
			      /* If p points to an object, mark it    */
                              /* and push contents on the mark stack  */
  			      /* Pointer recognition test always      */
  			      /* accepts interior pointers, i.e. this */
  			      /* is appropriate for pointers found on */
  			      /* stack.				      */
# endif
# if defined(PRINT_BLACK_LIST) || defined(KEEP_BACK_PTRS)
  void GC_mark_and_push_stack GC_PROTO((word p, ptr_t source));
				/* Ditto, omits plausibility test	*/
# else
  void GC_mark_and_push_stack GC_PROTO((word p));
# endif
void GC_push_marked GC_PROTO((struct hblk * h, hdr * hhdr));
		/* Push contents of all marked objects in h onto	*/
		/* mark stack.						*/
#ifdef SMALL_CONFIG
# define GC_push_next_marked_dirty(h) GC_push_next_marked(h)
#else
  struct hblk * GC_push_next_marked_dirty GC_PROTO((struct hblk * h));
		/* Invoke GC_push_marked on next dirty block above h.	*/
		/* Return a pointer just past the end of this block.	*/
#endif /* !SMALL_CONFIG */
struct hblk * GC_push_next_marked GC_PROTO((struct hblk * h));
  		/* Ditto, but also mark from clean pages.	*/
struct hblk * GC_push_next_marked_uncollectable GC_PROTO((struct hblk * h));
  		/* Ditto, but mark only from uncollectable pages.	*/
GC_bool GC_stopped_mark GC_PROTO((GC_stop_func stop_func));
 			/* Stop world and mark from all roots	*/
  			/* and rescuers.			*/
void GC_clear_hdr_marks GC_PROTO((hdr * hhdr));
				    /* Clear the mark bits in a header */
void GC_set_hdr_marks GC_PROTO((hdr * hhdr));
 				    /* Set the mark bits in a header */
void GC_set_fl_marks GC_PROTO((ptr_t p));
				    /* Set all mark bits associated with */
				    /* a free list.			 */
void GC_add_roots_inner GC_PROTO((char * b, char * e, GC_bool tmp));
void GC_remove_roots_inner GC_PROTO((char * b, char * e));
GC_bool GC_is_static_root GC_PROTO((ptr_t p));
  		/* Is the address p in one of the registered static	*/
  		/* root sections?					*/
# if defined(MSWIN32) || defined(_WIN32_WCE_EMULATION)
GC_bool GC_is_tmp_root GC_PROTO((ptr_t p));
		/* Is the address p in one of the temporary static	*/
		/* root sections?					*/
# endif
void GC_register_dynamic_libraries GC_PROTO((void));
  		/* Add dynamic library data sections to the root set. */

GC_bool GC_register_main_static_data GC_PROTO((void));
		/* We need to register the main data segment.  Returns	*/
		/* TRUE unless this is done implicitly as part of	*/
		/* dynamic library registration.			*/
  
/* Machine dependent startup routines */
ptr_t GC_get_stack_base GC_PROTO((void));	/* Cold end of stack */
#ifdef IA64
  ptr_t GC_get_register_stack_base GC_PROTO((void));
  					/* Cold end of register stack.	*/
#endif
void GC_register_data_segments GC_PROTO((void));
  
/* Black listing: */
void GC_bl_init GC_PROTO((void));
# ifdef PRINT_BLACK_LIST
      void GC_add_to_black_list_normal GC_PROTO((word p, ptr_t source));
			/* Register bits as a possible future false	*/
			/* reference from the heap or static data	*/
#     define GC_ADD_TO_BLACK_LIST_NORMAL(bits, source) \
      		if (GC_all_interior_pointers) { \
		  GC_add_to_black_list_stack(bits, (ptr_t)(source)); \
		} else { \
  		  GC_add_to_black_list_normal(bits, (ptr_t)(source)); \
		}
# else
      void GC_add_to_black_list_normal GC_PROTO((word p));
#     define GC_ADD_TO_BLACK_LIST_NORMAL(bits, source) \
      		if (GC_all_interior_pointers) { \
		  GC_add_to_black_list_stack(bits); \
		} else { \
  		  GC_add_to_black_list_normal(bits); \
		}