misc.c

linux下建立JAVA虚拟机的源码KAFFE

    
    r = (word)p;
    if (!GC_is_initialized) return 0;
    h = HBLKPTR(r);
    GET_BI(r, bi);
    candidate_hdr = HDR_FROM_BI(bi, r);
    if (candidate_hdr == 0) return(0);
    /* If it's a pointer to the middle of a large object, move it	*/
    /* to the beginning.						*/
	while (IS_FORWARDING_ADDR_OR_NIL(candidate_hdr)) {
	   h = FORWARDED_ADDR(h,candidate_hdr);
	   r = (word)h;
	   candidate_hdr = HDR(h);
	}
    if (candidate_hdr -> hb_map == GC_invalid_map) return(0);
    /* Make sure r points to the beginning of the object */
	r &= ~(WORDS_TO_BYTES(1) - 1);
        {
	    register int offset = HBLKDISPL(r);
	    register signed_word sz = candidate_hdr -> hb_sz;
	    register signed_word map_entry;
	      
	    map_entry = MAP_ENTRY((candidate_hdr -> hb_map), offset);
	    if (map_entry > CPP_MAX_OFFSET) {
            	map_entry = (signed_word)(BYTES_TO_WORDS(offset)) % sz;
            }
            r -= WORDS_TO_BYTES(map_entry);
            limit = r + WORDS_TO_BYTES(sz);
	    if (limit > (word)(h + 1)
	        && sz <= BYTES_TO_WORDS(HBLKSIZE)) {
	        return(0);
	    }
	    if ((word)p >= limit) return(0);
	}
    return((GC_PTR)r);
}


/* Return the size of an object, given a pointer to its base.		*/
/* (For small obects this also happens to work from interior pointers,	*/
/* but that shouldn't be relied upon.)					*/
# ifdef __STDC__
    size_t GC_size(GC_PTR p)
# else
    size_t GC_size(p)
    GC_PTR p;
# endif
{
    register int sz;
    register hdr * hhdr = HDR(p);
    
    sz = WORDS_TO_BYTES(hhdr -> hb_sz);
    return(sz);
}

size_t GC_get_heap_size GC_PROTO(())
{
    return ((size_t) GC_heapsize);
}

size_t GC_get_free_bytes GC_PROTO(())
{
    return ((size_t) GC_large_free_bytes);
}

size_t GC_get_bytes_since_gc GC_PROTO(())
{
    return ((size_t) WORDS_TO_BYTES(GC_words_allocd));
}

size_t GC_get_total_bytes GC_PROTO(())
{
    return ((size_t) WORDS_TO_BYTES(GC_words_allocd+GC_words_allocd_before_gc));
}

GC_bool GC_is_initialized = FALSE;

void GC_init()
{
    DCL_LOCK_STATE;
    
    DISABLE_SIGNALS();

#if defined(GC_WIN32_THREADS) && !defined(GC_PTHREADS)
    if (!GC_is_initialized) {
      BOOL (WINAPI *pfn) (LPCRITICAL_SECTION, DWORD) = NULL;
      HMODULE hK32 = GetModuleHandle("kernel32.dll");
      if (hK32)
          (FARPROC) pfn = GetProcAddress(hK32,
			  "InitializeCriticalSectionAndSpinCount");
      if (pfn)
          pfn(&GC_allocate_ml, 4000);
      else
	  InitializeCriticalSection (&GC_allocate_ml);
    }
#endif /* MSWIN32 */

    LOCK();
    GC_init_inner();
    UNLOCK();
    ENABLE_SIGNALS();

#   if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
	/* Make sure marker threads and started and thread local */
	/* allocation is initialized, in case we didn't get 	 */
	/* called from GC_init_parallel();			 */
        {
	  extern void GC_init_parallel(void);
	  GC_init_parallel();
	}
#   endif /* PARALLEL_MARK || THREAD_LOCAL_ALLOC */

#   if defined(DYNAMIC_LOADING) && defined(DARWIN)
    {
        /* This must be called WITHOUT the allocation lock held
        and before any threads are created */
        extern void GC_init_dyld();
        GC_init_dyld();
    }
#   endif
}

#if defined(MSWIN32) || defined(MSWINCE)
    CRITICAL_SECTION GC_write_cs;
#endif

#ifdef MSWIN32
    extern void GC_init_win32 GC_PROTO((void));
#endif

extern void GC_setpagesize();


#ifdef MSWIN32
extern GC_bool GC_no_win32_dlls;
#else
# define GC_no_win32_dlls FALSE
#endif

void GC_exit_check GC_PROTO((void))
{
   GC_gcollect();
}

#ifdef SEARCH_FOR_DATA_START
  extern void GC_init_linux_data_start GC_PROTO((void));
#endif

#ifdef UNIX_LIKE

extern void GC_set_and_save_fault_handler GC_PROTO((void (*handler)(int)));

static void looping_handler(sig)
int sig;
{
    GC_err_printf1("Caught signal %d: looping in handler\n", sig);
    for(;;);
}

static GC_bool installed_looping_handler = FALSE;

static void maybe_install_looping_handler()
{
    /* Install looping handler before the write fault handler, so we	*/
    /* handle write faults correctly.					*/
      if (!installed_looping_handler && 0 != GETENV("GC_LOOP_ON_ABORT")) {
        GC_set_and_save_fault_handler(looping_handler);
        installed_looping_handler = TRUE;
      }
}

#else /* !UNIX_LIKE */

# define maybe_install_looping_handler()

#endif

void GC_init_inner()
{
#   if !defined(THREADS) && defined(GC_ASSERTIONS)
        word dummy;
#   endif
    word initial_heap_sz = (word)MINHINCR;
    
    if (GC_is_initialized) return;
#   ifdef PRINTSTATS
      GC_print_stats = 1;
#   endif
#   if defined(MSWIN32) || defined(MSWINCE)
      InitializeCriticalSection(&GC_write_cs);
#   endif
    if (0 != GETENV("GC_PRINT_STATS")) {
      GC_print_stats = 1;
    } 
#   ifndef NO_DEBUGGING
      if (0 != GETENV("GC_DUMP_REGULARLY")) {
        GC_dump_regularly = 1;
      }
#   endif
#   ifdef KEEP_BACK_PTRS
      {
        char * backtraces_string = GETENV("GC_BACKTRACES");
        if (0 != backtraces_string) {
          GC_backtraces = atol(backtraces_string);
	  if (backtraces_string[0] == '\0') GC_backtraces = 1;
        }
      }
#   endif
    if (0 != GETENV("GC_FIND_LEAK")) {
      GC_find_leak = 1;
#     ifdef __STDC__
        atexit(GC_exit_check);
#     endif
    }
    if (0 != GETENV("GC_ALL_INTERIOR_POINTERS")) {
      GC_all_interior_pointers = 1;
    }
    if (0 != GETENV("GC_DONT_GC")) {
      GC_dont_gc = 1;
    }
    if (0 != GETENV("GC_PRINT_BACK_HEIGHT")) {
      GC_print_back_height = 1;
    }
    if (0 != GETENV("GC_NO_BLACKLIST_WARNING")) {
      GC_large_alloc_warn_interval = LONG_MAX;
    }
    {
      char * time_limit_string = GETENV("GC_PAUSE_TIME_TARGET");
      if (0 != time_limit_string) {
        long time_limit = atol(time_limit_string);
        if (time_limit < 5) {
	  WARN("GC_PAUSE_TIME_TARGET environment variable value too small "
	       "or bad syntax: Ignoring\n", 0);
        } else {
	  GC_time_limit = time_limit;
        }
      }
    }
    {
      char * interval_string = GETENV("GC_LARGE_ALLOC_WARN_INTERVAL");
      if (0 != interval_string) {
        long interval = atol(interval_string);
        if (interval <= 0) {
	  WARN("GC_LARGE_ALLOC_WARN_INTERVAL environment variable has "
	       "bad value: Ignoring\n", 0);
        } else {
	  GC_large_alloc_warn_interval = interval;
        }
      }
    }
    maybe_install_looping_handler();
    /* Adjust normal object descriptor for extra allocation.	*/
    if (ALIGNMENT > GC_DS_TAGS && EXTRA_BYTES != 0) {
      GC_obj_kinds[NORMAL].ok_descriptor = ((word)(-ALIGNMENT) | GC_DS_LENGTH);
    }
    GC_setpagesize();
    GC_exclude_static_roots(beginGC_arrays, endGC_arrays);
    GC_exclude_static_roots(beginGC_obj_kinds, endGC_obj_kinds);
#   ifdef SEPARATE_GLOBALS
      GC_exclude_static_roots(beginGC_objfreelist, endGC_objfreelist);
      GC_exclude_static_roots(beginGC_aobjfreelist, endGC_aobjfreelist);
#   endif
#   ifdef MSWIN32
 	GC_init_win32();
#   endif
#   if defined(SEARCH_FOR_DATA_START)
	GC_init_linux_data_start();
#   endif
#   if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
	GC_init_netbsd_elf();
#   endif
#   if defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS) \
       || defined(GC_WIN32_THREADS)
        GC_thr_init();
#   endif
#   ifdef GC_SOLARIS_THREADS
	/* We need dirty bits in order to find live stack sections.	*/
        GC_dirty_init();
#   endif
#   if !defined(THREADS) || defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) \
	|| defined(GC_SOLARIS_THREADS)
      if (GC_stackbottom == 0) {
	GC_stackbottom = GC_get_stack_base();
#       if (defined(LINUX) || defined(HPUX)) && defined(IA64)
	  GC_register_stackbottom = GC_get_register_stack_base();
#       endif
      } else {
#       if (defined(LINUX) || defined(HPUX)) && defined(IA64)
	  if (GC_register_stackbottom == 0) {
	    WARN("GC_register_stackbottom should be set with GC_stackbottom", 0);
	    /* The following may fail, since we may rely on	 	*/
	    /* alignment properties that may not hold with a user set	*/
	    /* GC_stackbottom.						*/
	    GC_register_stackbottom = GC_get_register_stack_base();
	  }
#	endif
      }
#   endif
    GC_STATIC_ASSERT(sizeof (ptr_t) == sizeof(word));
    GC_STATIC_ASSERT(sizeof (signed_word) == sizeof(word));
    GC_STATIC_ASSERT(sizeof (struct hblk) == HBLKSIZE);
#   ifndef THREADS
#     if defined(STACK_GROWS_UP) && defined(STACK_GROWS_DOWN)
  	ABORT(
  	  "Only one of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
#     endif
#     if !defined(STACK_GROWS_UP) && !defined(STACK_GROWS_DOWN)
  	ABORT(
  	  "One of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
#     endif
#     ifdef STACK_GROWS_DOWN
        GC_ASSERT((word)(&dummy) <= (word)GC_stackbottom);
#     else
        GC_ASSERT((word)(&dummy) >= (word)GC_stackbottom);
#     endif
#   endif
#   if !defined(_AUX_SOURCE) || defined(__GNUC__)
      GC_ASSERT((word)(-1) > (word)0);
      /* word should be unsigned */
#   endif
    GC_ASSERT((signed_word)(-1) < (signed_word)0);
    
    /* Add initial guess of root sets.  Do this first, since sbrk(0)	*/
    /* might be used.							*/
      if (GC_REGISTER_MAIN_STATIC_DATA()) GC_register_data_segments();
    GC_init_headers();
    GC_bl_init();
    GC_mark_init();
    {
	char * sz_str = GETENV("GC_INITIAL_HEAP_SIZE");
	if (sz_str != NULL) {
	  initial_heap_sz = atoi(sz_str);
	  if (initial_heap_sz <= MINHINCR * HBLKSIZE) {
	    WARN("Bad initial heap size %s - ignoring it.\n",
		 sz_str);
	  } 
	  initial_heap_sz = divHBLKSZ(initial_heap_sz);
	}
    }
    {
	char * sz_str = GETENV("GC_MAXIMUM_HEAP_SIZE");
	if (sz_str != NULL) {
	  word max_heap_sz = (word)atol(sz_str);
	  if (max_heap_sz < initial_heap_sz * HBLKSIZE) {
	    WARN("Bad maximum heap size %s - ignoring it.\n",
		 sz_str);
	  } 
	  if (0 == GC_max_retries) GC_max_retries = 2;
	  GC_set_max_heap_size(max_heap_sz);
	}
    }
    if (!GC_expand_hp_inner(initial_heap_sz)) {
        GC_err_printf0("Can't start up: not enough memory\n");
        EXIT();
    }
    /* Preallocate large object map.  It's otherwise inconvenient to 	*/
    /* deal with failure.						*/
      if (!GC_add_map_entry((word)0)) {
        GC_err_printf0("Can't start up: not enough memory\n");
        EXIT();
      }
    GC_register_displacement_inner(0L);
#   ifdef MERGE_SIZES
      GC_init_size_map();
#   endif
#   ifdef PCR
      if (PCR_IL_Lock(PCR_Bool_false, PCR_allSigsBlocked, PCR_waitForever)
          != PCR_ERes_okay) {
          ABORT("Can't lock load state\n");
      } else if (PCR_IL_Unlock() != PCR_ERes_okay) {
          ABORT("Can't unlock load state\n");
      }
      PCR_IL_Unlock();
      GC_pcr_install();
#   endif
#   if !defined(SMALL_CONFIG)
      if (!GC_no_win32_dlls && 0 != GETENV("GC_ENABLE_INCREMENTAL")) {
	GC_ASSERT(!GC_incremental);
        GC_setpagesize();
#       ifndef GC_SOLARIS_THREADS
          GC_dirty_init();
#       endif
        GC_ASSERT(GC_words_allocd == 0)
    	GC_incremental = TRUE;
      }
#   endif /* !SMALL_CONFIG */
    COND_DUMP;
    /* Get black list set up and/or incremental GC started */
      if (!GC_dont_precollect || GC_incremental) GC_gcollect_inner();
    GC_is_initialized = TRUE;
#   ifdef STUBBORN_ALLOC
    	GC_stubborn_init();
#   endif