/*
* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
* Copyright (c) 1999-2000 by Hewlett-Packard Company. All rights reserved.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*
*/
#include "private/gc_pmark.h"
#include "gc_inline.h" /* for GC_malloc_kind */
/*
* Some simple primitives for allocation with explicit type information.
* Simple objects are allocated such that they contain a GC_descr at the
* end (in the last allocated word). This descriptor may be a procedure
* which then examines an extended descriptor passed as its environment.
*
* Arrays are treated as simple objects if they have sufficiently simple
* structure. Otherwise they are allocated from an array kind that supplies
* a special mark procedure. These arrays contain a pointer to a
* complex_descriptor as their last word.
* This is done because the environment field is too small, and the collector
* must trace the complex_descriptor.
*
* Note that descriptors inside objects may appear cleared, if we encounter a
* false reference to an object on a free list. In the GC_descr case, this
* is OK, since a 0 descriptor corresponds to examining no fields.
* In the complex_descriptor case, we explicitly check for that case.
*
* MAJOR PARTS OF THIS CODE HAVE NOT BEEN TESTED AT ALL and are not testable,
* since they are not accessible through the current interface.
*/
#include "gc_typed.h"
#define TYPD_EXTRA_BYTES (sizeof(word) - EXTRA_BYTES)
STATIC int GC_explicit_kind = 0;
/* Object kind for objects with indirect */
/* (possibly extended) descriptors. */
STATIC int GC_array_kind = 0;
/* Object kind for objects with complex */
/* descriptors and GC_array_mark_proc. */
/* Extended descriptors. GC_typed_mark_proc understands these. */
/* These are used for simple objects that are larger than what */
/* can be described by a BITMAP_BITS sized bitmap. */
typedef struct {
word ed_bitmap; /* lsb corresponds to first word. */
GC_bool ed_continued; /* next entry is continuation. */
} ext_descr;
/* Array descriptors. GC_array_mark_proc understands these. */
/* We may eventually need to add provisions for headers and */
/* trailers. Hence we provide for tree structured descriptors, */
/* though we don't really use them currently. */
typedef union ComplexDescriptor {
struct LeafDescriptor { /* Describes simple array */
word ld_tag;
# define LEAF_TAG 1
size_t ld_size; /* bytes per element */
/* multiple of ALIGNMENT */
size_t ld_nelements; /* Number of elements. */
GC_descr ld_descriptor; /* A simple length, bitmap, */
/* or procedure descriptor. */
} ld;
struct ComplexArrayDescriptor {
word ad_tag;
# define ARRAY_TAG 2
size_t ad_nelements;
union ComplexDescriptor * ad_element_descr;
} ad;
struct SequenceDescriptor {
word sd_tag;
# define SEQUENCE_TAG 3
union ComplexDescriptor * sd_first;
union ComplexDescriptor * sd_second;
} sd;
} complex_descriptor;
#define TAG ad.ad_tag
STATIC ext_descr * GC_ext_descriptors = NULL;
/* Points to array of extended */
/* descriptors. */
STATIC size_t GC_ed_size = 0; /* Current size of above arrays. */
#define ED_INITIAL_SIZE 100
STATIC size_t GC_avail_descr = 0; /* Next available slot. */
STATIC int GC_typed_mark_proc_index = 0; /* Indices of my mark */
STATIC int GC_array_mark_proc_index = 0; /* procedures. */
#if !defined(AO_HAVE_load_acquire) && defined(GC_FORCE_INCLUDE_ATOMIC_OPS)
# include "atomic_ops.h"
#endif
#ifdef AO_HAVE_load_acquire
STATIC volatile AO_t GC_explicit_typing_initialized = FALSE;
#else
STATIC GC_bool GC_explicit_typing_initialized = FALSE;
#endif
STATIC void GC_push_typed_structures_proc(void)
{
GC_PUSH_ALL_SYM(GC_ext_descriptors);
}
/* Add a multiword bitmap to GC_ext_descriptors arrays. Return */
/* starting index. */
/* Returns -1 on failure. */
/* Caller does not hold allocation lock. */
STATIC signed_word GC_add_ext_descriptor(const word * bm, word nbits)
{
size_t nwords = divWORDSZ(nbits + WORDSZ-1);
signed_word result;
size_t i;
word last_part;
size_t extra_bits;
DCL_LOCK_STATE;
LOCK();
while (GC_avail_descr + nwords >= GC_ed_size) {
ext_descr * new;
size_t new_size;
word ed_size = GC_ed_size;
if (ed_size == 0) {
GC_ASSERT((word)&GC_ext_descriptors % sizeof(word) == 0);
GC_push_typed_structures = GC_push_typed_structures_proc;
UNLOCK();
new_size = ED_INITIAL_SIZE;
} else {
UNLOCK();
new_size = 2 * ed_size;
if (new_size > MAX_ENV) return(-1);
}
new = (ext_descr *) GC_malloc_atomic(new_size * sizeof(ext_descr));
if (new == 0) return(-1);
LOCK();
if (ed_size == GC_ed_size) {
if (GC_avail_descr != 0) {
BCOPY(GC_ext_descriptors, new,
GC_avail_descr * sizeof(ext_descr));
}
GC_ed_size = new_size;
GC_ext_descriptors = new;
} /* else another thread already resized it in the meantime */
}
result = GC_avail_descr;
for (i = 0; i < nwords-1; i++) {
GC_ext_descriptors[result + i].ed_bitmap = bm[i];
GC_ext_descriptors[result + i].ed_continued = TRUE;
}
last_part = bm[i];
/* Clear irrelevant bits. */
extra_bits = nwords * WORDSZ - nbits;
last_part <<= extra_bits;
last_part >>= extra_bits;
GC_ext_descriptors[result + i].ed_bitmap = last_part;
GC_ext_descriptors[result + i].ed_continued = FALSE;
GC_avail_descr += nwords;
UNLOCK();
return(result);
}
/* Table of bitmap descriptors for n word long all pointer objects. */
STATIC GC_descr GC_bm_table[WORDSZ/2];
/* Return a descriptor for the concatenation of 2 nwords long objects, */
/* each of which is described by descriptor. */
/* The result is known to be short enough to fit into a bitmap */
/* descriptor. */
/* Descriptor is a GC_DS_LENGTH or GC_DS_BITMAP descriptor. */
STATIC GC_descr GC_double_descr(GC_descr descriptor, word nwords)
{
if ((descriptor & GC_DS_TAGS) == GC_DS_LENGTH) {
descriptor = GC_bm_table[BYTES_TO_WORDS((word)descriptor)];
};
descriptor |= (descriptor & ~GC_DS_TAGS) >> nwords;
return(descriptor);
}
STATIC complex_descriptor *
GC_make_sequence_descriptor(complex_descriptor *first,
complex_descriptor *second);
/* Build a descriptor for an array with nelements elements, */
/* each of which can be described by a simple descriptor. */
/* We try to optimize some common cases. */
/* If the result is COMPLEX, then a complex_descr* is returned */
/* in *complex_d. */
/* If the result is LEAF, then we built a LeafDescriptor in */
/* the structure pointed to by leaf. */
/* The tag in the leaf structure is not set. */
/* If the result is SIMPLE, then a GC_descr */
/* is returned in *simple_d. */
/* If the result is NO_MEM, then */
/* we failed to allocate the descriptor. */
/* The implementation knows that GC_DS_LENGTH is 0. */
/* *leaf, *complex_d, and *simple_d may be used as temporaries */
/* during the construction. */
#define COMPLEX 2
#define LEAF 1
#define SIMPLE 0
#define NO_MEM (-1)
STATIC int GC_make_array_descriptor(size_t nelements, size_t size,
GC_descr descriptor, GC_descr *simple_d,
complex_descriptor **complex_d,
struct LeafDescriptor * leaf)
{
# define OPT_THRESHOLD 50
/* For larger arrays, we try to combine descriptors of adjacent */
/* descriptors to speed up marking, and to reduce the amount */
/* of space needed on the mark stack. */
if ((descriptor & GC_DS_TAGS) == GC_DS_LENGTH) {
if (descriptor == (GC_descr)size) {
*simple_d = nelements * descriptor;
return(SIMPLE);
} else if ((word)descriptor == 0) {
*simple_d = (GC_descr)0;
return(SIMPLE);
}
}
if (nelements <= OPT_THRESHOLD) {
if (nelements <= 1) {
if (nelements == 1) {
*simple_d = descriptor;
return(SIMPLE);
} else {
*simple_d = (GC_descr)0;
return(SIMPLE);
}
}
} else if (size <= BITMAP_BITS/2
&& (descriptor & GC_DS_TAGS) != GC_DS_PROC
&& (size & (sizeof(word)-1)) == 0) {
int result =
GC_make_array_descriptor(nelements/2, 2*size,
GC_double_descr(descriptor,
BYTES_TO_WORDS(size)),
simple_d, complex_d, leaf);
if ((nelements & 1) == 0) {
return(result);
} else {
struct LeafDescriptor * one_element =
(struct LeafDescriptor *)
GC_malloc_atomic(sizeof(struct LeafDescriptor));
if (result == NO_MEM || one_element == 0) return(NO_MEM);
one_element -> ld_tag = LEAF_TAG;
one_element -> ld_size = size;
one_element -> ld_nelements = 1;
one_element -> ld_descriptor = descriptor;
switch(result) {
case SIMPLE:
{
struct LeafDescriptor * beginning =
(struct LeafDescriptor *)
GC_malloc_atomic(sizeof(struct LeafDescriptor));
if (beginning == 0) return(NO_MEM);
beginning -> ld_tag = LEAF_TAG;
beginning -> ld_size = size;
beginning -> ld_nelements = 1;
beginning -> ld_descriptor = *simple_d;
*complex_d = GC_make_sequence_descriptor(
(complex_descriptor *)beginning,
(complex_descriptor *)one_element);
break;
}
case LEAF:
{
struct LeafDescriptor * beginning =
(struct LeafDescriptor *)
GC_malloc_atomic(sizeof(struct LeafDescriptor));
if (beginning == 0) return(NO_MEM);
beginning -> ld_tag = LEAF_TAG;
beginning -> ld_size = leaf -> ld_size;
beginning -> ld_nelements = leaf -> ld_nelements;
beginning -> ld_descriptor = leaf -> ld_descriptor;
*complex_d = GC_make_sequence_descriptor(
(complex_descriptor *)beginning,
(complex_descriptor *)one_element);
break;
}
case COMPLEX:
*complex_d = GC_make_sequence_descriptor(
*complex_d,
(complex_descriptor *)one_element);
break;
}
return(COMPLEX);
}
}
leaf -> ld_size = size;
leaf -> ld_nelements = nelements;
leaf -> ld_descriptor = descriptor;
return(LEAF);
}
STATIC complex_descriptor *
GC_make_sequence_descriptor(complex_descriptor *first,
complex_descriptor *second)
{
struct SequenceDescriptor * result =
(struct SequenceDescriptor *)
GC_malloc(sizeof(struct SequenceDescriptor));
/* Can't result in overly conservative marking, since tags are */
/* very small integers. Probably faster than maintaining type */
/* info. */
if (result != 0) {
result -> sd_tag = SEQUENCE_TAG;
result -> sd_first = first;
result -> sd_second = second;
}
return((complex_descriptor *)result);
}
STATIC ptr_t * GC_eobjfreelist = NULL;
STATIC mse * GC_typed_mark_proc(word * addr, mse * mark_stack_ptr,
mse * mark_stack_limit, word env);
STATIC mse * GC_array_mark_proc(word * addr, mse * mark_stack_ptr,
mse * mark_stack_limit, word env);
STATIC void GC_init_explicit_typing(void)
{
unsigned i;
GC_STATIC_ASSERT(sizeof(struct LeafDescriptor) % sizeof(word) == 0);
/* Set up object kind with simple indirect descriptor. */
GC_eobjfreelist = (ptr_t *)GC_new_free_list_inner();
GC_explicit_kind = GC_new_kind_inner(
(void **)GC_eobjfreelist,
(WORDS_TO_BYTES((word)-1) | GC_DS_PER_OBJECT),
TRUE, TRUE);
/* Descriptors are in the last word of the object. */
GC_typed_mark_proc_index = GC_new_proc_inner(GC_typed_mark_proc);
/* Set up object kind with array descriptor. */
GC_array_mark_proc_index = GC_new_proc_inner(GC_array_mark_proc);
GC_array_kind = GC_new_kind_inner(GC_new_free_list_inner(),
GC_MAKE_PROC(GC_array_mark_proc_index, 0),
FALSE, TRUE);
GC_bm_table[0] = GC_DS_BITMAP;
for (i = 1; i < WORDSZ/2; i++) {
GC_bm_table[i] = (((word)-1) << (WORDSZ - i)) | GC_DS_BITMAP;
}
}
STATIC 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 (current >= (word)least_ha && current <= (word)greatest_ha) {
PUSH_CONTENTS((ptr_t)current, mark_stack_ptr,
mark_stack_limit, (ptr_t)current_p);
}
}
}
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 ((word)mark_stack_ptr >= (word)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.w =
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. */
STATIC 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_RET("Bad complex descriptor");
return 0;
}
}
/* Push descriptors for the object at addr with complex descriptor d */
/* onto the mark stack. Return 0 if the mark stack overflowed. */
STATIC 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.w = 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_RET("Bad complex descriptor");
return 0;
}
}
STATIC mse * GC_array_mark_proc(word * addr, mse * mark_stack_ptr,
mse * mark_stack_limit,
word env GC_ATTR_UNUSED)
{
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) {
/* Explicitly instruct Clang Static Analyzer that ptr is non-null. */
if (NULL == mark_stack_ptr) ABORT("Bad mark_stack_ptr");
/* 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. */
# ifdef PARALLEL_MARK
/* We might be using a local_mark_stack in parallel mode. */
if (GC_mark_stack + GC_mark_stack_size == mark_stack_limit)
# endif
{
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.w = 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.w = sizeof(word) | GC_DS_LENGTH;
}
return new_mark_stack_ptr;
}
GC_API GC_descr GC_CALL GC_make_descriptor(const GC_word * bm, size_t len)
{
signed_word last_set_bit = len - 1;
GC_descr result;
# define HIGH_BIT (((word)1) << (WORDSZ - 1))
DCL_LOCK_STATE;
# if defined(AO_HAVE_load_acquire) && defined(AO_HAVE_store_release)
if (!EXPECT(AO_load_acquire(&GC_explicit_typing_initialized), TRUE)) {
LOCK();
if (!GC_explicit_typing_initialized) {
GC_init_explicit_typing();
AO_store_release(&GC_explicit_typing_initialized, TRUE);
}
UNLOCK();
}
# else
LOCK();
if (!EXPECT(GC_explicit_typing_initialized, TRUE)) {
GC_init_explicit_typing();
GC_explicit_typing_initialized = TRUE;
}
UNLOCK();
# endif
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
{
signed_word i;
for (i = 0; i < last_set_bit; i++) {
if (!GC_get_bit(bm, i)) {
break;
}
}
if (i == last_set_bit) {
/* An initial section contains all pointers. Use length descriptor. */
return (WORDS_TO_BYTES(last_set_bit+1) | GC_DS_LENGTH);
}
}
# endif
if ((word)last_set_bit < BITMAP_BITS) {
signed_word i;
/* 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;
} else {
signed_word 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;
}
GC_API GC_ATTR_MALLOC void * GC_CALL GC_malloc_explicitly_typed(size_t lb,
GC_descr d)
{
word *op;
size_t lg;
GC_ASSERT(GC_explicit_typing_initialized);
lb = SIZET_SAT_ADD(lb, TYPD_EXTRA_BYTES);
op = GC_malloc_kind(lb, GC_explicit_kind);
if (EXPECT(NULL == op, FALSE))
return NULL;
/* It is not safe to use GC_size_map[lb] to compute lg here as the */
/* the former might be updated asynchronously. */
lg = BYTES_TO_GRANULES(GC_size(op));
op[GRANULES_TO_WORDS(lg) - 1] = d;
return op;
}
GC_API GC_ATTR_MALLOC void * GC_CALL
GC_malloc_explicitly_typed_ignore_off_page(size_t lb, GC_descr d)
{
ptr_t op;
size_t lg;
DCL_LOCK_STATE;
GC_ASSERT(GC_explicit_typing_initialized);
lb = SIZET_SAT_ADD(lb, TYPD_EXTRA_BYTES);
if (SMALL_OBJ(lb)) {
GC_DBG_COLLECT_AT_MALLOC(lb);
lg = GC_size_map[lb];
LOCK();
op = GC_eobjfreelist[lg];
if (EXPECT(0 == op, FALSE)) {
UNLOCK();
op = (ptr_t)GENERAL_MALLOC_IOP(lb, GC_explicit_kind);
if (0 == op) return 0;
/* See the comment in GC_malloc_explicitly_typed. */
lg = BYTES_TO_GRANULES(GC_size(op));
} else {
GC_eobjfreelist[lg] = obj_link(op);
obj_link(op) = 0;
GC_bytes_allocd += GRANULES_TO_BYTES((word)lg);
UNLOCK();
}
((word *)op)[GRANULES_TO_WORDS(lg) - 1] = d;
} else {
op = (ptr_t)GENERAL_MALLOC_IOP(lb, GC_explicit_kind);
if (op != NULL) {
lg = BYTES_TO_GRANULES(GC_size(op));
((word *)op)[GRANULES_TO_WORDS(lg) - 1] = d;
}
}
return((void *) op);
}
GC_API GC_ATTR_MALLOC void * GC_CALL GC_calloc_explicitly_typed(size_t n,
size_t lb, GC_descr d)
{
word *op;
size_t lg;
GC_descr simple_descr;
complex_descriptor *complex_descr;
int descr_type;
struct LeafDescriptor leaf;
GC_ASSERT(GC_explicit_typing_initialized);
descr_type = GC_make_array_descriptor((word)n, (word)lb, d, &simple_descr,
&complex_descr, &leaf);
if ((lb | n) > GC_SQRT_SIZE_MAX /* fast initial check */
&& lb > 0 && n > GC_SIZE_MAX / lb)
return (*GC_get_oom_fn())(GC_SIZE_MAX); /* n*lb overflow */
lb *= n;
switch(descr_type) {
case NO_MEM: return(0);
case SIMPLE:
return GC_malloc_explicitly_typed(lb, simple_descr);
case LEAF:
lb = SIZET_SAT_ADD(lb,
sizeof(struct LeafDescriptor) + TYPD_EXTRA_BYTES);
break;
case COMPLEX:
lb = SIZET_SAT_ADD(lb, TYPD_EXTRA_BYTES);
break;
}
op = GC_malloc_kind(lb, GC_array_kind);
if (EXPECT(NULL == op, FALSE))
return NULL;
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 *)
(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 {
# ifndef GC_NO_FINALIZATION
size_t lw = GRANULES_TO_WORDS(lg);
op[lw - 1] = (word)complex_descr;
/* Make sure the descriptor is cleared once there is any danger */
/* it may have been collected. */
if (EXPECT(GC_general_register_disappearing_link(
(void **)(op + lw - 1), op)
== GC_NO_MEMORY, FALSE))
# endif
{
/* Couldn't register it due to lack of memory. Punt. */
return (*GC_get_oom_fn())(lb);
}
}
return op;
}