typd_mlc.c

Boost provides free peer-reviewed portable C++ source libraries. We emphasize libraries that work

      for (i = 0; i < WORDSZ/2; i++) {
          GC_descr d = (((word)(-1)) >> (WORDSZ - i)) << (WORDSZ - i);
          d |= GC_DS_BITMAP;
          GC_bm_table[i] = d;
      }
    UNLOCK();
}

mse * GC_typed_mark_proc(word * addr, mse * mark_stack_ptr,
			 mse * mark_stack_limit, word env)
{
    word bm = GC_ext_descriptors[env].ed_bitmap;
    word * current_p = addr;
    word current;
    ptr_t greatest_ha = GC_greatest_plausible_heap_addr;
    ptr_t least_ha = GC_least_plausible_heap_addr;
    DECLARE_HDR_CACHE;

    INIT_HDR_CACHE;
    for (; bm != 0; bm >>= 1, current_p++) {
    	if (bm & 1) {
    	    current = *current_p;
	    FIXUP_POINTER(current);
    	    if ((ptr_t)current >= least_ha && (ptr_t)current <= greatest_ha) {
    	        PUSH_CONTENTS((ptr_t)current, mark_stack_ptr,
			      mark_stack_limit, current_p, exit1);
    	    }
    	}
    }
    if (GC_ext_descriptors[env].ed_continued) {
        /* Push an entry with the rest of the descriptor back onto the	*/
        /* stack.  Thus we never do too much work at once.  Note that	*/
        /* we also can't overflow the mark stack unless we actually 	*/
        /* mark something.						*/
        mark_stack_ptr++;
        if (mark_stack_ptr >= mark_stack_limit) {
            mark_stack_ptr = GC_signal_mark_stack_overflow(mark_stack_ptr);
        }
        mark_stack_ptr -> mse_start = (ptr_t)(addr + WORDSZ);
        mark_stack_ptr -> mse_descr =
        	GC_MAKE_PROC(GC_typed_mark_proc_index, env+1);
    }
    return(mark_stack_ptr);
}

/* Return the size of the object described by d.  It would be faster to	*/
/* store this directly, or to compute it as part of			*/
/* GC_push_complex_descriptor, but hopefully it doesn't matter.		*/
word GC_descr_obj_size(complex_descriptor *d)
{
    switch(d -> TAG) {
      case LEAF_TAG:
      	return(d -> ld.ld_nelements * d -> ld.ld_size);
      case ARRAY_TAG:
        return(d -> ad.ad_nelements
               * GC_descr_obj_size(d -> ad.ad_element_descr));
      case SEQUENCE_TAG:
        return(GC_descr_obj_size(d -> sd.sd_first)
               + GC_descr_obj_size(d -> sd.sd_second));
      default:
        ABORT("Bad complex descriptor");
        /*NOTREACHED*/ return 0; /*NOTREACHED*/
    }
}

/* Push descriptors for the object at addr with complex descriptor d	*/
/* onto the mark stack.  Return 0 if the mark stack overflowed.  	*/
mse * GC_push_complex_descriptor(word *addr, complex_descriptor *d,
				 mse *msp, mse *msl)
{
    register ptr_t current = (ptr_t) addr;
    register word nelements;
    register word sz;
    register word i;
    
    switch(d -> TAG) {
      case LEAF_TAG:
        {
          register GC_descr descr = d -> ld.ld_descriptor;
          
          nelements = d -> ld.ld_nelements;
          if (msl - msp <= (ptrdiff_t)nelements) return(0);
          sz = d -> ld.ld_size;
          for (i = 0; i < nelements; i++) {
              msp++;
              msp -> mse_start = current;
              msp -> mse_descr = descr;
              current += sz;
          }
          return(msp);
        }
      case ARRAY_TAG:
        {
          register complex_descriptor *descr = d -> ad.ad_element_descr;
          
          nelements = d -> ad.ad_nelements;
          sz = GC_descr_obj_size(descr);
          for (i = 0; i < nelements; i++) {
              msp = GC_push_complex_descriptor((word *)current, descr,
              					msp, msl);
              if (msp == 0) return(0);
              current += sz;
          }
          return(msp);
        }
      case SEQUENCE_TAG:
        {
          sz = GC_descr_obj_size(d -> sd.sd_first);
          msp = GC_push_complex_descriptor((word *)current, d -> sd.sd_first,
          				   msp, msl);
          if (msp == 0) return(0);
          current += sz;
          msp = GC_push_complex_descriptor((word *)current, d -> sd.sd_second,
          				   msp, msl);
          return(msp);
        }
      default:
        ABORT("Bad complex descriptor");
        /*NOTREACHED*/ return 0; /*NOTREACHED*/
   }
}

/*ARGSUSED*/
mse * GC_array_mark_proc(word * addr, mse * mark_stack_ptr,
			 mse * mark_stack_limit, word env)
{
    hdr * hhdr = HDR(addr);
    size_t sz = hhdr -> hb_sz;
    size_t nwords = BYTES_TO_WORDS(sz);
    complex_descriptor * descr = (complex_descriptor *)(addr[nwords-1]);
    mse * orig_mark_stack_ptr = mark_stack_ptr;
    mse * new_mark_stack_ptr;
    
    if (descr == 0) {
    	/* Found a reference to a free list entry.  Ignore it. */
    	return(orig_mark_stack_ptr);
    }
    /* In use counts were already updated when array descriptor was	*/
    /* pushed.  Here we only replace it by subobject descriptors, so 	*/
    /* no update is necessary.						*/
    new_mark_stack_ptr = GC_push_complex_descriptor(addr, descr,
    						    mark_stack_ptr,
    						    mark_stack_limit-1);
    if (new_mark_stack_ptr == 0) {
    	/* Doesn't fit.  Conservatively push the whole array as a unit	*/
    	/* and request a mark stack expansion.				*/
    	/* This cannot cause a mark stack overflow, since it replaces	*/
    	/* the original array entry.					*/
    	GC_mark_stack_too_small = TRUE;
    	new_mark_stack_ptr = orig_mark_stack_ptr + 1;
    	new_mark_stack_ptr -> mse_start = (ptr_t)addr;
    	new_mark_stack_ptr -> mse_descr = sz | GC_DS_LENGTH;
    } else {
        /* Push descriptor itself */
        new_mark_stack_ptr++;
        new_mark_stack_ptr -> mse_start = (ptr_t)(addr + nwords - 1);
        new_mark_stack_ptr -> mse_descr = sizeof(word) | GC_DS_LENGTH;
    }
    return new_mark_stack_ptr;
}

GC_descr GC_make_descriptor(GC_bitmap bm, size_t len)
{
    signed_word last_set_bit = len - 1;
    GC_descr result;
    signed_word i;
#   define HIGH_BIT (((word)1) << (WORDSZ - 1))
    
    if (!GC_explicit_typing_initialized) GC_init_explicit_typing();
    while (last_set_bit >= 0 && !GC_get_bit(bm, last_set_bit)) last_set_bit --;
    if (last_set_bit < 0) return(0 /* no pointers */);
#   if ALIGNMENT == CPP_WORDSZ/8
    {
      register GC_bool all_bits_set = TRUE;
      for (i = 0; i < last_set_bit; i++) {
    	if (!GC_get_bit(bm, i)) {
    	    all_bits_set = FALSE;
    	    break;
    	}
      }
      if (all_bits_set) {
    	/* An initial section contains all pointers.  Use length descriptor. */
        return (WORDS_TO_BYTES(last_set_bit+1) | GC_DS_LENGTH);
      }
    }
#   endif
    if (last_set_bit < BITMAP_BITS) {
    	/* Hopefully the common case.			*/
    	/* Build bitmap descriptor (with bits reversed)	*/
    	result = HIGH_BIT;
    	for (i = last_set_bit - 1; i >= 0; i--) {
    	    result >>= 1;
    	    if (GC_get_bit(bm, i)) result |= HIGH_BIT;
    	}
    	result |= GC_DS_BITMAP;
    	return(result);
    } else {
    	signed_word index;
    	
    	index = GC_add_ext_descriptor(bm, (word)last_set_bit+1);
    	if (index == -1) return(WORDS_TO_BYTES(last_set_bit+1) | GC_DS_LENGTH);
    				/* Out of memory: use conservative	*/
    				/* approximation.			*/
    	result = GC_MAKE_PROC(GC_typed_mark_proc_index, (word)index);
    	return result;
    }
}

/* ptr_t GC_clear_stack(); */

#define GENERAL_MALLOC(lb,k) \
    (void *)GC_clear_stack(GC_generic_malloc((word)lb, k))
    
#define GENERAL_MALLOC_IOP(lb,k) \
    (void *)GC_clear_stack(GC_generic_malloc_ignore_off_page(lb, k))

void * GC_malloc_explicitly_typed(size_t lb, GC_descr d)
{
    ptr_t op;
    ptr_t * opp;
    size_t lg;
    DCL_LOCK_STATE;

    lb += TYPD_EXTRA_BYTES;
    if(SMALL_OBJ(lb)) {
	lg = GC_size_map[lb];
	opp = &(GC_eobjfreelist[lg]);
	LOCK();
        if( (op = *opp) == 0 ) {
            UNLOCK();
            op = (ptr_t)GENERAL_MALLOC((word)lb, GC_explicit_kind);
	    if (0 == op) return 0;
	    lg = GC_size_map[lb];	/* May have been uninitialized.	*/
        } else {
            *opp = obj_link(op);
	    obj_link(op) = 0;
            GC_bytes_allocd += GRANULES_TO_BYTES(lg);
            UNLOCK();
        }
   } else {
       op = (ptr_t)GENERAL_MALLOC((word)lb, GC_explicit_kind);
       if (op != NULL)
	    lg = BYTES_TO_GRANULES(GC_size(op));
   }
   if (op != NULL)
       ((word *)op)[GRANULES_TO_WORDS(lg) - 1] = d;
   return((void *) op);
}

void * GC_malloc_explicitly_typed_ignore_off_page(size_t lb, GC_descr d)
{
ptr_t op;
ptr_t * opp;
size_t lg;
DCL_LOCK_STATE;

    lb += TYPD_EXTRA_BYTES;
    if( SMALL_OBJ(lb) ) {
	lg = GC_size_map[lb];
	opp = &(GC_eobjfreelist[lg]);
	LOCK();
        if( (op = *opp) == 0 ) {
            UNLOCK();
            op = (ptr_t)GENERAL_MALLOC_IOP(lb, GC_explicit_kind);
	    lg = GC_size_map[lb];	/* May have been uninitialized.	*/
        } else {
            *opp = obj_link(op);
	    obj_link(op) = 0;
            GC_bytes_allocd += GRANULES_TO_BYTES(lg);
            UNLOCK();
        }
   } else {
       op = (ptr_t)GENERAL_MALLOC_IOP(lb, GC_explicit_kind);
       if (op != NULL)
         lg = BYTES_TO_WORDS(GC_size(op));
   }
   if (op != NULL)
       ((word *)op)[GRANULES_TO_WORDS(lg) - 1] = d;
   return((void *) op);
}

void * GC_calloc_explicitly_typed(size_t n, size_t lb, GC_descr d)
{
ptr_t op;
ptr_t * opp;
size_t lg;
GC_descr simple_descr;
complex_descriptor *complex_descr;
register int descr_type;
struct LeafDescriptor leaf;
DCL_LOCK_STATE;

    descr_type = GC_make_array_descriptor((word)n, (word)lb, d,
    					  &simple_descr, &complex_descr, &leaf);
    switch(descr_type) {
    	case NO_MEM: return(0);
    	case SIMPLE: return(GC_malloc_explicitly_typed(n*lb, simple_descr));
    	case LEAF:
    	    lb *= n;
    	    lb += sizeof(struct LeafDescriptor) + TYPD_EXTRA_BYTES;
    	    break;
    	case COMPLEX:
    	    lb *= n;
    	    lb += TYPD_EXTRA_BYTES;
    	    break;
    }
    if( SMALL_OBJ(lb) ) {
	lg = GC_size_map[lb];
	opp = &(GC_arobjfreelist[lg]);
	LOCK();
        if( (op = *opp) == 0 ) {
            UNLOCK();
            op = (ptr_t)GENERAL_MALLOC((word)lb, GC_array_kind);
	    if (0 == op) return(0);
	    lg = GC_size_map[lb];	/* May have been uninitialized.	*/            
        } else {
            *opp = obj_link(op);
	    obj_link(op) = 0;
            GC_bytes_allocd += GRANULES_TO_BYTES(lg);
            UNLOCK();
        }
   } else {
       op = (ptr_t)GENERAL_MALLOC((word)lb, GC_array_kind);
       if (0 == op) return(0);
       lg = BYTES_TO_GRANULES(GC_size(op));
   }
   if (descr_type == LEAF) {
       /* Set up the descriptor inside the object itself. */
       volatile struct LeafDescriptor * lp =
           (struct LeafDescriptor *)
               ((word *)op
                + GRANULES_TO_WORDS(lg)
		- (BYTES_TO_WORDS(sizeof(struct LeafDescriptor)) + 1));
                
       lp -> ld_tag = LEAF_TAG;
       lp -> ld_size = leaf.ld_size;
       lp -> ld_nelements = leaf.ld_nelements;
       lp -> ld_descriptor = leaf.ld_descriptor;
       ((volatile word *)op)[GRANULES_TO_WORDS(lg) - 1] = (word)lp;
   } else {
       extern unsigned GC_finalization_failures;
       unsigned ff = GC_finalization_failures;
       size_t lw = GRANULES_TO_WORDS(lg);
       
       ((word *)op)[lw - 1] = (word)complex_descr;
       /* Make sure the descriptor is cleared once there is any danger	*/
       /* it may have been collected.					*/
       (void)
         GC_general_register_disappearing_link((void * *)
         					  ((word *)op+lw-1),
       					          (void *) op);
       if (ff != GC_finalization_failures) {
	   /* Couldn't register it due to lack of memory.  Punt.	*/
	   /* This will probably fail too, but gives the recovery code  */
	   /* a chance.							*/
	   return(GC_malloc(n*lb));
       }			          
   }
   return((void *) op);
}