alloc.c

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	GC_printf2(
		"\n%lu (atomic) + %lu (composite) collectable bytes in use\n",
	        (unsigned long)WORDS_TO_BYTES(GC_atomic_in_use),
	        (unsigned long)WORDS_TO_BYTES(GC_composite_in_use));
#   endif

      GC_n_attempts = 0;
      GC_is_full_gc = FALSE;
    /* Reset or increment counters for next cycle */
      GC_words_allocd_before_gc += GC_words_allocd;
      GC_non_gc_bytes_at_gc = GC_non_gc_bytes;
      GC_words_allocd = 0;
      GC_words_wasted = 0;
      GC_mem_freed = 0;
      GC_finalizer_mem_freed = 0;
      
#   ifdef USE_MUNMAP
      GC_unmap_old();
#   endif
#   ifdef PRINTTIMES
	GET_TIME(done_time);
	GC_printf2("Finalize + initiate sweep took %lu + %lu msecs\n",
	           MS_TIME_DIFF(finalize_time,start_time),
	           MS_TIME_DIFF(done_time,finalize_time));
#   endif
}

/* Externally callable routine to invoke full, stop-world collection */
# if defined(__STDC__) || defined(__cplusplus)
    int GC_try_to_collect(GC_stop_func stop_func)
# else
    int GC_try_to_collect(stop_func)
    GC_stop_func stop_func;
# endif
{
    int result;
    DCL_LOCK_STATE;
    
    if (GC_debugging_started) GC_print_all_smashed();
    GC_INVOKE_FINALIZERS();
    DISABLE_SIGNALS();
    LOCK();
    ENTER_GC();
    if (!GC_is_initialized) GC_init_inner();
    /* Minimize junk left in my registers */
      GC_noop(0,0,0,0,0,0);
    result = (int)GC_try_to_collect_inner(stop_func);
    EXIT_GC();
    UNLOCK();
    ENABLE_SIGNALS();
    if(result) {
        if (GC_debugging_started) GC_print_all_smashed();
        GC_INVOKE_FINALIZERS();
    }
    return(result);
}

void GC_gcollect GC_PROTO(())
{
    (void)GC_try_to_collect(GC_never_stop_func);
    if (GC_have_errors) GC_print_all_errors();
}

word GC_n_heap_sects = 0;	/* Number of sections currently in heap. */

/*
 * Use the chunk of memory starting at p of size bytes as part of the heap.
 * Assumes p is HBLKSIZE aligned, and bytes is a multiple of HBLKSIZE.
 */
void GC_add_to_heap(p, bytes)
struct hblk *p;
word bytes;
{
    word words;
    hdr * phdr;
    
    if (GC_n_heap_sects >= MAX_HEAP_SECTS) {
    	ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS");
    }
    phdr = GC_install_header(p);
    if (0 == phdr) {
    	/* This is extremely unlikely. Can't add it.  This will		*/
    	/* almost certainly result in a	0 return from the allocator,	*/
    	/* which is entirely appropriate.				*/
    	return;
    }
    GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p;
    GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes;
    GC_n_heap_sects++;
    words = BYTES_TO_WORDS(bytes);
    phdr -> hb_sz = words;
    phdr -> hb_map = (unsigned char *)1;   /* A value != GC_invalid_map	*/
    phdr -> hb_flags = 0;
    GC_freehblk(p);
    GC_heapsize += bytes;
    if ((ptr_t)p <= (ptr_t)GC_least_plausible_heap_addr
        || GC_least_plausible_heap_addr == 0) {
        GC_least_plausible_heap_addr = (GC_PTR)((ptr_t)p - sizeof(word));
        	/* Making it a little smaller than necessary prevents	*/
        	/* us from getting a false hit from the variable	*/
        	/* itself.  There's some unintentional reflection	*/
        	/* here.						*/
    }
    if ((ptr_t)p + bytes >= (ptr_t)GC_greatest_plausible_heap_addr) {
        GC_greatest_plausible_heap_addr = (GC_PTR)((ptr_t)p + bytes);
    }
}

# if !defined(NO_DEBUGGING)
void GC_print_heap_sects()
{
    register unsigned i;
    
    GC_printf1("Total heap size: %lu\n", (unsigned long) GC_heapsize);
    for (i = 0; i < GC_n_heap_sects; i++) {
        unsigned long start = (unsigned long) GC_heap_sects[i].hs_start;
        unsigned long len = (unsigned long) GC_heap_sects[i].hs_bytes;
        struct hblk *h;
        unsigned nbl = 0;
        
    	GC_printf3("Section %ld from 0x%lx to 0x%lx ", (unsigned long)i,
    		   start, (unsigned long)(start + len));
    	for (h = (struct hblk *)start; h < (struct hblk *)(start + len); h++) {
    	    if (GC_is_black_listed(h, HBLKSIZE)) nbl++;
    	}
    	GC_printf2("%lu/%lu blacklisted\n", (unsigned long)nbl,
    		   (unsigned long)(len/HBLKSIZE));
    }
}
# endif

GC_PTR GC_least_plausible_heap_addr = (GC_PTR)ONES;
GC_PTR GC_greatest_plausible_heap_addr = 0;

ptr_t GC_max(x,y)
ptr_t x, y;
{
    return(x > y? x : y);
}

ptr_t GC_min(x,y)
ptr_t x, y;
{
    return(x < y? x : y);
}

# if defined(__STDC__) || defined(__cplusplus)
    void GC_set_max_heap_size(GC_word n)
# else
    void GC_set_max_heap_size(n)
    GC_word n;
# endif
{
    GC_max_heapsize = n;
}

GC_word GC_max_retries = 0;

/*
 * this explicitly increases the size of the heap.  It is used
 * internally, but may also be invoked from GC_expand_hp by the user.
 * The argument is in units of HBLKSIZE.
 * Tiny values of n are rounded up.
 * Returns FALSE on failure.
 */
GC_bool GC_expand_hp_inner(n)
word n;
{
    word bytes;
    struct hblk * space;
    word expansion_slop;	/* Number of bytes by which we expect the */
    				/* heap to expand soon.			  */

    if (n < MINHINCR) n = MINHINCR;
    bytes = n * HBLKSIZE;
    /* Make sure bytes is a multiple of GC_page_size */
      {
	word mask = GC_page_size - 1;
	bytes += mask;
	bytes &= ~mask;
      }
    
    if (GC_max_heapsize != 0 && GC_heapsize + bytes > GC_max_heapsize) {
        /* Exceeded self-imposed limit */
        return(FALSE);
    }
    space = GET_MEM(bytes);
    if( space == 0 ) {
#	ifdef CONDPRINT
	  if (GC_print_stats) {
	    GC_printf1("Failed to expand heap by %ld bytes\n",
		       (unsigned long)bytes);
	  }
#       endif
	return(FALSE);
    }
#   ifdef CONDPRINT
      if (GC_print_stats) {
	GC_printf2("Increasing heap size by %lu after %lu allocated bytes\n",
	           (unsigned long)bytes,
	           (unsigned long)WORDS_TO_BYTES(GC_words_allocd));
# 	ifdef UNDEFINED
	  GC_printf1("Root size = %lu\n", GC_root_size);
	  GC_print_block_list(); GC_print_hblkfreelist();
	  GC_printf0("\n");
#	endif
      }
#   endif
    expansion_slop = WORDS_TO_BYTES(min_words_allocd()) + 4*MAXHINCR*HBLKSIZE;
    if (GC_last_heap_addr == 0 && !((word)space & SIGNB)
        || (GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space)) {
        /* Assume the heap is growing up */
        GC_greatest_plausible_heap_addr =
            (GC_PTR)GC_max((ptr_t)GC_greatest_plausible_heap_addr,
                           (ptr_t)space + bytes + expansion_slop);
    } else {
        /* Heap is growing down */
        GC_least_plausible_heap_addr =
            (GC_PTR)GC_min((ptr_t)GC_least_plausible_heap_addr,
                           (ptr_t)space - expansion_slop);
    }
#   if defined(LARGE_CONFIG)
      if (((ptr_t)GC_greatest_plausible_heap_addr <= (ptr_t)space + bytes
           || (ptr_t)GC_least_plausible_heap_addr >= (ptr_t)space)
	  && GC_heapsize > 0) {
	/* GC_add_to_heap will fix this, but ... */
	WARN("Too close to address space limit: blacklisting ineffective\n", 0);
      }
#   endif
    GC_prev_heap_addr = GC_last_heap_addr;
    GC_last_heap_addr = (ptr_t)space;
    GC_add_to_heap(space, bytes);
    /* Force GC before we are likely to allocate past expansion_slop */
      GC_collect_at_heapsize =
	  GC_heapsize + expansion_slop - 2*MAXHINCR*HBLKSIZE;
#     if defined(LARGE_CONFIG)
        if (GC_collect_at_heapsize < GC_heapsize /* wrapped */)
	  GC_collect_at_heapsize = (word)(-1);
#     endif
    return(TRUE);
}

/* Really returns a bool, but it's externally visible, so that's clumsy. */
/* Arguments is in bytes.						*/
# if defined(__STDC__) || defined(__cplusplus)
  int GC_expand_hp(size_t bytes)
# else
  int GC_expand_hp(bytes)
  size_t bytes;
# endif
{
    int result;
    DCL_LOCK_STATE;
    
    DISABLE_SIGNALS();
    LOCK();
    if (!GC_is_initialized) GC_init_inner();
    result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes));
    if (result) GC_requested_heapsize += bytes;
    UNLOCK();
    ENABLE_SIGNALS();
    return(result);
}

unsigned GC_fail_count = 0;  
			/* How many consecutive GC/expansion failures?	*/
			/* Reset by GC_allochblk.			*/

GC_bool GC_collect_or_expand(needed_blocks, ignore_off_page)
word needed_blocks;
GC_bool ignore_off_page;
{
    if (!GC_incremental && !GC_dont_gc &&
	((GC_dont_expand && GC_words_allocd > 0) || GC_should_collect())) {
      GC_gcollect_inner();
    } else {
      word blocks_to_get = GC_heapsize/(HBLKSIZE*GC_free_space_divisor)
      			   + needed_blocks;
      
      if (blocks_to_get > MAXHINCR) {
          word slop;
          
	  /* Get the minimum required to make it likely that we		*/
	  /* can satisfy the current request in the presence of black-	*/
	  /* listing.  This will probably be more than MAXHINCR.	*/
          if (ignore_off_page) {
              slop = 4;
          } else {
	      slop = 2*divHBLKSZ(BL_LIMIT);
	      if (slop > needed_blocks) slop = needed_blocks;
	  }
          if (needed_blocks + slop > MAXHINCR) {
              blocks_to_get = needed_blocks + slop;
          } else {
              blocks_to_get = MAXHINCR;
          }
      }
      if (!GC_expand_hp_inner(blocks_to_get)
        && !GC_expand_hp_inner(needed_blocks)) {
      	if (GC_fail_count++ < GC_max_retries) {
      	    WARN("Out of Memory!  Trying to continue ...\n", 0);
	    GC_gcollect_inner();
	} else {
#	    if !defined(AMIGA) || !defined(GC_AMIGA_FASTALLOC)
	      WARN("Out of Memory!  Returning NIL!\n", 0);
#	    endif
	    return(FALSE);
	}
      } else {
#	  ifdef CONDPRINT
            if (GC_fail_count && GC_print_stats) {
	      GC_printf0("Memory available again ...\n");
	    }
#	  endif
      }
    }
    return(TRUE);
}

/*
 * Make sure the object free list for sz is not empty.
 * Return a pointer to the first object on the free list.
 * The object MUST BE REMOVED FROM THE FREE LIST BY THE CALLER.
 * Assumes we hold the allocator lock and signals are disabled.
 *
 */
ptr_t GC_allocobj(sz, kind)
word sz;
int kind;
{
    ptr_t * flh = &(GC_obj_kinds[kind].ok_freelist[sz]);
    GC_bool tried_minor = FALSE;
    
    if (sz == 0) return(0);

    while (*flh == 0) {
      ENTER_GC();
      /* Do our share of marking work */
        if(TRUE_INCREMENTAL) GC_collect_a_little_inner(1);
      /* Sweep blocks for objects of this size */
        GC_continue_reclaim(sz, kind);
      EXIT_GC();
      if (*flh == 0) {
        GC_new_hblk(sz, kind);
      }
      if (*flh == 0) {
        ENTER_GC();
	if (GC_incremental && GC_time_limit == GC_TIME_UNLIMITED
	    && ! tried_minor ) {
	    GC_collect_a_little_inner(1);
	    tried_minor = TRUE;
	} else {
          if (!GC_collect_or_expand((word)1,FALSE)) {
	    EXIT_GC();
	    return(0);
	  }
	}
	EXIT_GC();
      }
    }
    /* Successful allocation; reset failure count.	*/
    GC_fail_count = 0;
    
    return(*flh);
}