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finalize.c
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finalize.c
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/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1996 by Xerox Corporation. All rights reserved.
* Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
* Copyright (c) 2007 Free Software Foundation, Inc.
* Copyright (c) 2008-2022 Ivan Maidanski
*
* 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"
#ifndef GC_NO_FINALIZATION
# include "gc/javaxfc.h" /* to get GC_finalize_all() as extern "C" */
/* Type of mark procedure used for marking from finalizable object. */
/* This procedure normally does not mark the object, only its */
/* descendants. */
typedef void (*finalization_mark_proc)(ptr_t /* finalizable_obj_ptr */);
# define HASH3(addr, size, log_size) \
((size_t)((ADDR(addr) >> 3) ^ (ADDR(addr) >> (3 + (log_size)))) \
& ((size)-1))
# define HASH2(addr, log_size) HASH3(addr, (size_t)1 << (log_size), log_size)
struct hash_chain_entry {
GC_hidden_pointer hidden_key;
struct hash_chain_entry *next;
};
struct disappearing_link {
struct hash_chain_entry prolog;
# define dl_hidden_link prolog.hidden_key /* field to be cleared */
# define dl_next(x) (struct disappearing_link *)((x)->prolog.next)
# define dl_set_next(x, y) \
(void)((x)->prolog.next = (struct hash_chain_entry *)(y))
GC_hidden_pointer dl_hidden_obj; /* pointer to object base */
};
struct finalizable_object {
struct hash_chain_entry prolog;
/* Pointer to object base. No longer hidden once object is on */
/* finalize_now queue. */
# define fo_hidden_base prolog.hidden_key
# define fo_next(x) (struct finalizable_object *)((x)->prolog.next)
# define fo_set_next(x, y) ((x)->prolog.next = (struct hash_chain_entry *)(y))
GC_finalization_proc fo_fn; /* finalizer */
finalization_mark_proc fo_mark_proc; /* mark-through procedure */
ptr_t fo_client_data;
size_t fo_object_sz; /* in bytes */
};
# ifdef AO_HAVE_store
/* Update finalize_now atomically as GC_should_invoke_finalizers does */
/* not acquire the allocator lock. */
# define SET_FINALIZE_NOW(fo) \
GC_cptr_store((volatile ptr_t *)&GC_fnlz_roots.finalize_now, (ptr_t)(fo))
# else
# define SET_FINALIZE_NOW(fo) (void)(GC_fnlz_roots.finalize_now = (fo))
# endif /* !THREADS */
GC_API void GC_CALL
GC_push_finalizer_structures(void)
{
GC_ASSERT(ADDR(&GC_dl_hashtbl.head) % sizeof(ptr_t) == 0);
GC_ASSERT(ADDR(&GC_fnlz_roots) % sizeof(ptr_t) == 0);
# ifndef GC_LONG_REFS_NOT_NEEDED
GC_ASSERT(ADDR(&GC_ll_hashtbl.head) % sizeof(ptr_t) == 0);
GC_PUSH_ALL_SYM(GC_ll_hashtbl.head);
# endif
GC_PUSH_ALL_SYM(GC_dl_hashtbl.head);
GC_PUSH_ALL_SYM(GC_fnlz_roots);
/* GC_toggleref_arr is pushed specially by GC_mark_togglerefs. */
}
/* Threshold of log_size to initiate full collection before growing */
/* a hash table. */
# ifndef GC_ON_GROW_LOG_SIZE_MIN
# define GC_ON_GROW_LOG_SIZE_MIN LOG_HBLKSIZE
# endif
/* Double the size of a hash table. *log_size_ptr is the log of its */
/* current size. May be a no-op. *table_ptr is a pointer to an array */
/* of hash headers. We update both *table_ptr and *log_size_ptr on */
/* success. */
STATIC void
GC_grow_table(struct hash_chain_entry ***table_ptr, unsigned *log_size_ptr,
const size_t *entries_ptr)
{
size_t i;
struct hash_chain_entry *p;
unsigned log_old_size = *log_size_ptr;
unsigned log_new_size = log_old_size + 1;
size_t old_size = NULL == *table_ptr ? 0 : (size_t)1 << log_old_size;
size_t new_size = (size_t)1 << log_new_size;
/* FIXME: Power of 2 size often gets rounded up to one more page. */
struct hash_chain_entry **new_table;
GC_ASSERT(I_HOLD_LOCK());
/* Avoid growing the table in case of at least 25% of entries can */
/* be deleted by enforcing a collection. Ignored for small tables. */
/* In incremental mode we skip this optimization, as we want to */
/* avoid triggering a full GC whenever possible. */
if (log_old_size >= (unsigned)GC_ON_GROW_LOG_SIZE_MIN && !GC_incremental) {
IF_CANCEL(int cancel_state;)
DISABLE_CANCEL(cancel_state);
GC_gcollect_inner();
RESTORE_CANCEL(cancel_state);
/* GC_finalize might decrease entries value. */
if (*entries_ptr < ((size_t)1 << log_old_size) - (*entries_ptr >> 2))
return;
}
new_table = (struct hash_chain_entry **)GC_INTERNAL_MALLOC_IGNORE_OFF_PAGE(
new_size * sizeof(struct hash_chain_entry *), NORMAL);
if (NULL == new_table) {
if (NULL == *table_ptr) {
ABORT("Insufficient space for initial table allocation");
} else {
return;
}
}
for (i = 0; i < old_size; i++) {
for (p = (*table_ptr)[i]; p != NULL;) {
ptr_t real_key = (ptr_t)GC_REVEAL_POINTER(p->hidden_key);
struct hash_chain_entry *next = p->next;
size_t new_hash = HASH3(real_key, new_size, log_new_size);
p->next = new_table[new_hash];
GC_dirty(p);
new_table[new_hash] = p;
p = next;
}
}
*log_size_ptr = log_new_size;
*table_ptr = new_table;
GC_dirty(new_table); /* entire object */
}
GC_API int GC_CALL
GC_register_disappearing_link(void **link)
{
ptr_t base;
base = (ptr_t)GC_base(link);
if (base == 0)
ABORT("Bad arg to GC_register_disappearing_link");
return GC_general_register_disappearing_link(link, base);
}
STATIC int
GC_register_disappearing_link_inner(struct dl_hashtbl_s *dl_hashtbl,
void **link, const void *obj,
const char *tbl_log_name)
{
struct disappearing_link *curr_dl;
size_t index;
struct disappearing_link *new_dl;
GC_ASSERT(GC_is_initialized);
if (EXPECT(GC_find_leak, FALSE))
return GC_UNIMPLEMENTED;
# ifdef GC_ASSERTIONS
GC_noop1_ptr(*link); /* check accessibility */
# endif
LOCK();
GC_ASSERT(obj != NULL && GC_base_C(obj) == obj);
if (EXPECT(NULL == dl_hashtbl->head, FALSE)
|| EXPECT(dl_hashtbl->entries > ((size_t)1 << dl_hashtbl->log_size),
FALSE)) {
GC_grow_table((struct hash_chain_entry ***)&dl_hashtbl->head,
&dl_hashtbl->log_size, &dl_hashtbl->entries);
GC_COND_LOG_PRINTF("Grew %s table to %u entries\n", tbl_log_name,
1U << dl_hashtbl->log_size);
}
index = HASH2(link, dl_hashtbl->log_size);
for (curr_dl = dl_hashtbl->head[index]; curr_dl != 0;
curr_dl = dl_next(curr_dl)) {
if (curr_dl->dl_hidden_link == GC_HIDE_POINTER(link)) {
/* Alternatively, GC_HIDE_NZ_POINTER() could be used instead. */
curr_dl->dl_hidden_obj = GC_HIDE_POINTER(obj);
UNLOCK();
return GC_DUPLICATE;
}
}
new_dl = (struct disappearing_link *)GC_INTERNAL_MALLOC(
sizeof(struct disappearing_link), NORMAL);
if (EXPECT(NULL == new_dl, FALSE)) {
GC_oom_func oom_fn = GC_oom_fn;
UNLOCK();
new_dl = (struct disappearing_link *)(*oom_fn)(
sizeof(struct disappearing_link));
if (0 == new_dl) {
return GC_NO_MEMORY;
}
/* It's not likely we'll make it here, but ... */
LOCK();
/* Recalculate index since the table may grow. */
index = HASH2(link, dl_hashtbl->log_size);
/* Check again that our disappearing link not in the table. */
for (curr_dl = dl_hashtbl->head[index]; curr_dl != 0;
curr_dl = dl_next(curr_dl)) {
if (curr_dl->dl_hidden_link == GC_HIDE_POINTER(link)) {
curr_dl->dl_hidden_obj = GC_HIDE_POINTER(obj);
UNLOCK();
# ifndef DBG_HDRS_ALL
/* Free unused new_dl returned by GC_oom_fn(). */
GC_free(new_dl);
# endif
return GC_DUPLICATE;
}
}
}
new_dl->dl_hidden_obj = GC_HIDE_POINTER(obj);
new_dl->dl_hidden_link = GC_HIDE_POINTER(link);
dl_set_next(new_dl, dl_hashtbl->head[index]);
GC_dirty(new_dl);
dl_hashtbl->head[index] = new_dl;
dl_hashtbl->entries++;
GC_dirty(dl_hashtbl->head + index);
UNLOCK();
return GC_SUCCESS;
}
GC_API int GC_CALL
GC_general_register_disappearing_link(void **link, const void *obj)
{
if ((ADDR(link) & (ALIGNMENT - 1)) != 0 || !NONNULL_ARG_NOT_NULL(link))
ABORT("Bad arg to GC_general_register_disappearing_link");
return GC_register_disappearing_link_inner(&GC_dl_hashtbl, link, obj, "dl");
}
# ifdef DBG_HDRS_ALL
# define FREE_DL_ENTRY(curr_dl) dl_set_next(curr_dl, NULL)
# else
# define FREE_DL_ENTRY(curr_dl) GC_free(curr_dl)
# endif
/* Unregisters given link and returns the link entry to free. */
GC_INLINE struct disappearing_link *
GC_unregister_disappearing_link_inner(struct dl_hashtbl_s *dl_hashtbl,
void **link)
{
struct disappearing_link *curr_dl;
struct disappearing_link *prev_dl = NULL;
size_t index;
GC_ASSERT(I_HOLD_LOCK());
if (EXPECT(NULL == dl_hashtbl->head, FALSE))
return NULL;
index = HASH2(link, dl_hashtbl->log_size);
for (curr_dl = dl_hashtbl->head[index]; curr_dl;
curr_dl = dl_next(curr_dl)) {
if (curr_dl->dl_hidden_link == GC_HIDE_POINTER(link)) {
/* Remove found entry from the table. */
if (NULL == prev_dl) {
dl_hashtbl->head[index] = dl_next(curr_dl);
GC_dirty(dl_hashtbl->head + index);
} else {
dl_set_next(prev_dl, dl_next(curr_dl));
GC_dirty(prev_dl);
}
dl_hashtbl->entries--;
break;
}
prev_dl = curr_dl;
}
return curr_dl;
}
GC_API int GC_CALL
GC_unregister_disappearing_link(void **link)
{
struct disappearing_link *curr_dl;
if ((ADDR(link) & (ALIGNMENT - 1)) != 0) {
/* Nothing to do. */
return 0;
}
LOCK();
curr_dl = GC_unregister_disappearing_link_inner(&GC_dl_hashtbl, link);
UNLOCK();
if (NULL == curr_dl)
return 0;
FREE_DL_ENTRY(curr_dl);
return 1;
}
/* Mark from one finalizable object using the specified mark proc. */
/* May not mark the object pointed to by real_ptr (i.e, it is the job */
/* of the caller, if appropriate). Note that this is called with the */
/* mutator running. This is safe only if the mutator (client) gets */
/* the allocator lock to reveal hidden pointers. */
GC_INLINE void
GC_mark_fo(ptr_t real_ptr, finalization_mark_proc fo_mark_proc)
{
GC_ASSERT(I_HOLD_LOCK());
fo_mark_proc(real_ptr);
/* Process objects pushed by the mark procedure. */
while (!GC_mark_stack_empty())
MARK_FROM_MARK_STACK();
}
/* Complete a collection in progress, if any. */
GC_INLINE void
GC_complete_ongoing_collection(void)
{
if (EXPECT(GC_collection_in_progress(), FALSE)) {
while (!GC_mark_some(NULL)) { /* empty */
}
}
}
/* Toggle-ref support. */
# ifndef GC_TOGGLE_REFS_NOT_NEEDED
typedef union toggle_ref_u GCToggleRef;
STATIC GC_toggleref_func GC_toggleref_callback = 0;
GC_INNER void
GC_process_togglerefs(void)
{
size_t i;
size_t new_size = 0;
GC_bool needs_barrier = FALSE;
GC_ASSERT(I_HOLD_LOCK());
for (i = 0; i < GC_toggleref_array_size; ++i) {
GCToggleRef *r = &GC_toggleref_arr[i];
void *obj = r->strong_ref;
if ((ADDR(obj) & 1) != 0) {
obj = GC_REVEAL_POINTER(r->weak_ref);
GC_ASSERT((ADDR(obj) & 1) == 0);
}
if (NULL == obj)
continue;
switch (GC_toggleref_callback(obj)) {
case GC_TOGGLE_REF_DROP:
break;
case GC_TOGGLE_REF_STRONG:
GC_toggleref_arr[new_size++].strong_ref = obj;
needs_barrier = TRUE;
break;
case GC_TOGGLE_REF_WEAK:
GC_toggleref_arr[new_size++].weak_ref = GC_HIDE_POINTER(obj);
break;
default:
ABORT("Bad toggle-ref status returned by callback");
}
}
if (new_size < GC_toggleref_array_size) {
BZERO(&GC_toggleref_arr[new_size],
(GC_toggleref_array_size - new_size) * sizeof(GCToggleRef));
GC_toggleref_array_size = new_size;
}
if (needs_barrier)
GC_dirty(GC_toggleref_arr); /* entire object */
}
STATIC void GC_normal_finalize_mark_proc(ptr_t);
STATIC void
GC_mark_togglerefs(void)
{
size_t i;
GC_ASSERT(I_HOLD_LOCK());
if (NULL == GC_toggleref_arr)
return;
GC_set_mark_bit(GC_toggleref_arr);
for (i = 0; i < GC_toggleref_array_size; ++i) {
void *obj = GC_toggleref_arr[i].strong_ref;
if (obj != NULL && (ADDR(obj) & 1) == 0) {
/* Push and mark the object. */
GC_mark_fo((ptr_t)obj, GC_normal_finalize_mark_proc);
GC_set_mark_bit(obj);
GC_complete_ongoing_collection();
}
}
}
STATIC void
GC_clear_togglerefs(void)
{
size_t i;
GC_ASSERT(I_HOLD_LOCK());
for (i = 0; i < GC_toggleref_array_size; ++i) {
GCToggleRef *r = &GC_toggleref_arr[i];
if ((ADDR(r->strong_ref) & 1) != 0) {
if (!GC_is_marked(GC_REVEAL_POINTER(r->weak_ref))) {
r->weak_ref = 0;
} else {
/* No need to copy, BDWGC is a non-moving collector. */
}
}
}
}
GC_API void GC_CALL
GC_set_toggleref_func(GC_toggleref_func fn)
{
LOCK();
GC_toggleref_callback = fn;
UNLOCK();
}
GC_API GC_toggleref_func GC_CALL
GC_get_toggleref_func(void)
{
GC_toggleref_func fn;
READER_LOCK();
fn = GC_toggleref_callback;
READER_UNLOCK();
return fn;
}
static GC_bool
ensure_toggleref_capacity(size_t capacity_inc)
{
GC_ASSERT(I_HOLD_LOCK());
if (NULL == GC_toggleref_arr) {
GC_toggleref_array_capacity = 32; /* initial capacity */
GC_toggleref_arr = (GCToggleRef *)GC_INTERNAL_MALLOC_IGNORE_OFF_PAGE(
GC_toggleref_array_capacity * sizeof(GCToggleRef), NORMAL);
if (NULL == GC_toggleref_arr)
return FALSE;
}
if (GC_toggleref_array_size + capacity_inc >= GC_toggleref_array_capacity) {
GCToggleRef *new_array;
while (GC_toggleref_array_capacity
< GC_toggleref_array_size + capacity_inc) {
GC_toggleref_array_capacity *= 2;
if ((GC_toggleref_array_capacity
& ((size_t)1 << (sizeof(size_t) * 8 - 1)))
!= 0)
return FALSE; /* overflow */
}
new_array = (GCToggleRef *)GC_INTERNAL_MALLOC_IGNORE_OFF_PAGE(
GC_toggleref_array_capacity * sizeof(GCToggleRef), NORMAL);
if (NULL == new_array)
return FALSE;
if (EXPECT(GC_toggleref_array_size > 0, TRUE))
BCOPY(GC_toggleref_arr, new_array,
GC_toggleref_array_size * sizeof(GCToggleRef));
GC_INTERNAL_FREE(GC_toggleref_arr);
GC_toggleref_arr = new_array;
}
return TRUE;
}
GC_API int GC_CALL
GC_toggleref_add(void *obj, int is_strong_ref)
{
int res = GC_SUCCESS;
GC_ASSERT(NONNULL_ARG_NOT_NULL(obj));
LOCK();
GC_ASSERT((ADDR(obj) & 1) == 0 && obj == GC_base(obj));
if (GC_toggleref_callback != 0) {
if (!ensure_toggleref_capacity(1)) {
res = GC_NO_MEMORY;
} else {
GCToggleRef *r = &GC_toggleref_arr[GC_toggleref_array_size];
if (is_strong_ref) {
r->strong_ref = obj;
GC_dirty(GC_toggleref_arr + GC_toggleref_array_size);
} else {
r->weak_ref = GC_HIDE_POINTER(obj);
GC_ASSERT((r->weak_ref & 1) != 0);
}
GC_toggleref_array_size++;
}
}
UNLOCK();
return res;
}
# endif /* !GC_TOGGLE_REFS_NOT_NEEDED */
/* Finalizer callback support. */
STATIC GC_await_finalize_proc GC_object_finalized_proc = 0;
GC_API void GC_CALL
GC_set_await_finalize_proc(GC_await_finalize_proc fn)
{
LOCK();
GC_object_finalized_proc = fn;
UNLOCK();
}
GC_API GC_await_finalize_proc GC_CALL
GC_get_await_finalize_proc(void)
{
GC_await_finalize_proc fn;
READER_LOCK();
fn = GC_object_finalized_proc;
READER_UNLOCK();
return fn;
}
# ifndef GC_LONG_REFS_NOT_NEEDED
GC_API int GC_CALL
GC_register_long_link(void **link, const void *obj)
{
if ((ADDR(link) & (ALIGNMENT - 1)) != 0 || !NONNULL_ARG_NOT_NULL(link))
ABORT("Bad arg to GC_register_long_link");
return GC_register_disappearing_link_inner(&GC_ll_hashtbl, link, obj,
"long dl");
}
GC_API int GC_CALL
GC_unregister_long_link(void **link)
{
struct disappearing_link *curr_dl;
if ((ADDR(link) & (ALIGNMENT - 1)) != 0) {
/* Nothing to do. */
return 0;
}
LOCK();
curr_dl = GC_unregister_disappearing_link_inner(&GC_ll_hashtbl, link);
UNLOCK();
if (NULL == curr_dl)
return 0;
FREE_DL_ENTRY(curr_dl);
return 1;
}
# endif /* !GC_LONG_REFS_NOT_NEEDED */
# ifndef GC_MOVE_DISAPPEARING_LINK_NOT_NEEDED
STATIC int
GC_move_disappearing_link_inner(struct dl_hashtbl_s *dl_hashtbl, void **link,
void **new_link)
{
struct disappearing_link *curr_dl, *new_dl;
struct disappearing_link *prev_dl = NULL;
size_t curr_index, new_index;
GC_hidden_pointer curr_hidden_link, new_hidden_link;
# ifdef GC_ASSERTIONS
GC_noop1_ptr(*new_link);
# endif
GC_ASSERT(I_HOLD_LOCK());
if (EXPECT(NULL == dl_hashtbl->head, FALSE))
return GC_NOT_FOUND;
/* Find current link. */
curr_index = HASH2(link, dl_hashtbl->log_size);
curr_hidden_link = GC_HIDE_POINTER(link);
for (curr_dl = dl_hashtbl->head[curr_index]; curr_dl;
curr_dl = dl_next(curr_dl)) {
if (curr_dl->dl_hidden_link == curr_hidden_link)
break;
prev_dl = curr_dl;
}
if (EXPECT(NULL == curr_dl, FALSE)) {
return GC_NOT_FOUND;
} else if (link == new_link) {
/* Nothing to do. */
return GC_SUCCESS;
}
/* link is found; now check new_link not present. */
new_index = HASH2(new_link, dl_hashtbl->log_size);
new_hidden_link = GC_HIDE_POINTER(new_link);
for (new_dl = dl_hashtbl->head[new_index]; new_dl;
new_dl = dl_next(new_dl)) {
if (new_dl->dl_hidden_link == new_hidden_link) {
/* Target already registered; bail out. */
return GC_DUPLICATE;
}
}
/* Remove from old, add to new, update link. */
if (NULL == prev_dl) {
dl_hashtbl->head[curr_index] = dl_next(curr_dl);
} else {
dl_set_next(prev_dl, dl_next(curr_dl));
GC_dirty(prev_dl);
}
curr_dl->dl_hidden_link = new_hidden_link;
dl_set_next(curr_dl, dl_hashtbl->head[new_index]);
dl_hashtbl->head[new_index] = curr_dl;
GC_dirty(curr_dl);
GC_dirty(dl_hashtbl->head); /* entire object */
return GC_SUCCESS;
}
GC_API int GC_CALL
GC_move_disappearing_link(void **link, void **new_link)
{
int result;
if ((ADDR(new_link) & (ALIGNMENT - 1)) != 0
|| !NONNULL_ARG_NOT_NULL(new_link))
ABORT("Bad new_link arg to GC_move_disappearing_link");
if ((ADDR(link) & (ALIGNMENT - 1)) != 0) {
/* Nothing to do. */
return GC_NOT_FOUND;
}
LOCK();
result = GC_move_disappearing_link_inner(&GC_dl_hashtbl, link, new_link);
UNLOCK();
return result;
}
# ifndef GC_LONG_REFS_NOT_NEEDED
GC_API int GC_CALL
GC_move_long_link(void **link, void **new_link)
{
int result;
if ((ADDR(new_link) & (ALIGNMENT - 1)) != 0
|| !NONNULL_ARG_NOT_NULL(new_link))
ABORT("Bad new_link arg to GC_move_long_link");
if ((ADDR(link) & (ALIGNMENT - 1)) != 0) {
/* Nothing to do. */
return GC_NOT_FOUND;
}
LOCK();
result = GC_move_disappearing_link_inner(&GC_ll_hashtbl, link, new_link);
UNLOCK();
return result;
}
# endif
# endif /* !GC_MOVE_DISAPPEARING_LINK_NOT_NEEDED */
/* Possible finalization_marker procedures. Note that mark stack */
/* overflow is handled by the caller, and is not a disaster. */
# if defined(_MSC_VER) && defined(I386)
GC_ATTR_NOINLINE
/* Otherwise some optimizer bug is tickled in VC for x86 (v19, at least). */
# endif
STATIC void
GC_normal_finalize_mark_proc(ptr_t p)
{
GC_mark_stack_top = GC_push_obj(p, HDR(p), GC_mark_stack_top,
GC_mark_stack + GC_mark_stack_size);
}
/* This only pays very partial attention to the mark descriptor. */
/* It does the right thing for normal and atomic objects, and treats */
/* most others as normal. */
STATIC void
GC_ignore_self_finalize_mark_proc(ptr_t p)
{
const hdr *hhdr = HDR(p);
word descr = hhdr->hb_descr;
ptr_t current_p;
ptr_t scan_limit;
ptr_t target_limit = p + hhdr->hb_sz - 1;
if ((descr & GC_DS_TAGS) == GC_DS_LENGTH) {
scan_limit = p + descr - sizeof(ptr_t);
} else {
scan_limit = target_limit + 1 - sizeof(ptr_t);
}
for (current_p = p; ADDR_GE(scan_limit, current_p); current_p += ALIGNMENT) {
ptr_t q;
LOAD_PTR_OR_CONTINUE(q, current_p);
if (ADDR_LT(q, p) || ADDR_LT(target_limit, q)) {
GC_PUSH_ONE_HEAP(q, current_p, GC_mark_stack_top);
}
}
}
STATIC void
GC_null_finalize_mark_proc(ptr_t p)
{
UNUSED_ARG(p);
}
/* Possible finalization_marker procedures. Note that mark stack */
/* overflow is handled by the caller, and is not a disaster. */
/* GC_unreachable_finalize_mark_proc is an alias for normal marking, */
/* but it is explicitly tested for, and triggers different */
/* behavior. Objects registered in this way are not finalized */
/* if they are reachable by other finalizable objects, even if those */
/* other objects specify no ordering. */
STATIC void
GC_unreachable_finalize_mark_proc(ptr_t p)
{
/* A dummy comparison to ensure the compiler not to optimize two */
/* identical functions into a single one (thus, to ensure a unique */
/* address of each). Alternatively, GC_noop1_ptr(p) could be used. */
if (EXPECT(NULL == p, FALSE))
return;
GC_normal_finalize_mark_proc(p);
}
/* Avoid the work if unreachable finalizable objects are not used. */
/* TODO: turn need_unreachable_finalization into a counter */
static GC_bool need_unreachable_finalization = FALSE;
/* Register a finalization function. See gc.h for details. */
/* The last parameter is a procedure that determines */
/* marking for finalization ordering. Any objects marked */
/* by that procedure will be guaranteed to not have been */
/* finalized when this finalizer is invoked. */
STATIC void
GC_register_finalizer_inner(void *obj, GC_finalization_proc fn, void *cd,
GC_finalization_proc *ofn, void **ocd,
finalization_mark_proc mp)
{
struct finalizable_object *curr_fo;
size_t index;
struct finalizable_object *new_fo = 0;
const hdr *hhdr = NULL; /* initialized to prevent warning. */
GC_ASSERT(GC_is_initialized);
if (EXPECT(GC_find_leak, FALSE)) {
/* No-op. *ocd and *ofn remain unchanged. */
return;
}
LOCK();
GC_ASSERT(obj != NULL && GC_base_C(obj) == obj);
if (mp == GC_unreachable_finalize_mark_proc)
need_unreachable_finalization = TRUE;
if (EXPECT(NULL == GC_fnlz_roots.fo_head, FALSE)
|| EXPECT(GC_fo_entries > ((size_t)1 << GC_log_fo_table_size), FALSE)) {
GC_grow_table((struct hash_chain_entry ***)&GC_fnlz_roots.fo_head,
&GC_log_fo_table_size, &GC_fo_entries);
GC_COND_LOG_PRINTF("Grew fo table to %u entries\n",
1U << GC_log_fo_table_size);
}
for (;;) {
struct finalizable_object *prev_fo = NULL;
GC_oom_func oom_fn;
index = HASH2(obj, GC_log_fo_table_size);
curr_fo = GC_fnlz_roots.fo_head[index];
while (curr_fo != NULL) {
GC_ASSERT(GC_size(curr_fo) >= sizeof(struct finalizable_object));
if (curr_fo->fo_hidden_base == GC_HIDE_POINTER(obj)) {
/* Interruption by a signal in the middle of this */
/* should be safe. The client may see only *ocd */
/* updated, but we'll declare that to be his problem. */
if (ocd)
*ocd = curr_fo->fo_client_data;
if (ofn)
*ofn = curr_fo->fo_fn;
/* Delete the structure for obj. */
if (prev_fo == 0) {
GC_fnlz_roots.fo_head[index] = fo_next(curr_fo);
} else {
fo_set_next(prev_fo, fo_next(curr_fo));
GC_dirty(prev_fo);
}
if (fn == 0) {
GC_fo_entries--;
/* May not happen if we get a signal. But a high */
/* estimate will only make the table larger than */
/* necessary. */
# if !defined(THREADS) && !defined(DBG_HDRS_ALL)
GC_free(curr_fo);
# endif
} else {
curr_fo->fo_fn = fn;
curr_fo->fo_client_data = (ptr_t)cd;
curr_fo->fo_mark_proc = mp;
GC_dirty(curr_fo);
/* Reinsert it. We deleted it first to maintain */
/* consistency in the event of a signal. */
if (prev_fo == 0) {
GC_fnlz_roots.fo_head[index] = curr_fo;
} else {
fo_set_next(prev_fo, curr_fo);
GC_dirty(prev_fo);
}
}
if (NULL == prev_fo)
GC_dirty(GC_fnlz_roots.fo_head + index);
UNLOCK();
# ifndef DBG_HDRS_ALL
/* Free unused new_fo returned by GC_oom_fn() */
GC_free(new_fo);
# endif
return;
}
prev_fo = curr_fo;
curr_fo = fo_next(curr_fo);
}
if (EXPECT(new_fo != 0, FALSE)) {
/* new_fo is returned by GC_oom_fn(). */
GC_ASSERT(fn != 0);
# ifdef LINT2
if (NULL == hhdr)
ABORT("Bad hhdr in GC_register_finalizer_inner");
# endif
break;
}
if (fn == 0) {
if (ocd)
*ocd = 0;
if (ofn)
*ofn = 0;
UNLOCK();
return;
}
GET_HDR(obj, hhdr);
if (EXPECT(NULL == hhdr, FALSE)) {
/* We won't collect it, hence finalizer wouldn't be run. */
if (ocd)
*ocd = 0;
if (ofn)
*ofn = 0;
UNLOCK();
return;
}
new_fo = (struct finalizable_object *)GC_INTERNAL_MALLOC(
sizeof(struct finalizable_object), NORMAL);
if (EXPECT(new_fo != 0, TRUE))
break;
oom_fn = GC_oom_fn;
UNLOCK();
new_fo = (struct finalizable_object *)(*oom_fn)(
sizeof(struct finalizable_object));
if (0 == new_fo) {
/* No enough memory. *ocd and *ofn remain unchanged. */
return;
}
/* It's not likely we'll make it here, but ... */
LOCK();
/* Recalculate index since the table may grow and */
/* check again that our finalizer is not in the table. */
}
GC_ASSERT(GC_size(new_fo) >= sizeof(struct finalizable_object));
if (ocd)
*ocd = 0;
if (ofn)
*ofn = 0;
new_fo->fo_hidden_base = GC_HIDE_POINTER(obj);
new_fo->fo_fn = fn;
new_fo->fo_client_data = (ptr_t)cd;
new_fo->fo_object_sz = hhdr->hb_sz;
new_fo->fo_mark_proc = mp;
fo_set_next(new_fo, GC_fnlz_roots.fo_head[index]);
GC_dirty(new_fo);
GC_fo_entries++;
GC_fnlz_roots.fo_head[index] = new_fo;
GC_dirty(GC_fnlz_roots.fo_head + index);
UNLOCK();
}
GC_API void GC_CALL
GC_register_finalizer(void *obj, GC_finalization_proc fn, void *cd,
GC_finalization_proc *ofn, void **ocd)
{
GC_register_finalizer_inner(obj, fn, cd, ofn, ocd,
GC_normal_finalize_mark_proc);
}
GC_API void GC_CALL
GC_register_finalizer_ignore_self(void *obj, GC_finalization_proc fn, void *cd,
GC_finalization_proc *ofn, void **ocd)
{
GC_register_finalizer_inner(obj, fn, cd, ofn, ocd,
GC_ignore_self_finalize_mark_proc);
}
GC_API void GC_CALL
GC_register_finalizer_no_order(void *obj, GC_finalization_proc fn, void *cd,
GC_finalization_proc *ofn, void **ocd)
{
GC_register_finalizer_inner(obj, fn, cd, ofn, ocd,
GC_null_finalize_mark_proc);
}
GC_API void GC_CALL
GC_register_finalizer_unreachable(void *obj, GC_finalization_proc fn, void *cd,
GC_finalization_proc *ofn, void **ocd)
{
GC_ASSERT(GC_java_finalization);
GC_register_finalizer_inner(obj, fn, cd, ofn, ocd,
GC_unreachable_finalize_mark_proc);
}
# ifndef NO_DEBUGGING
STATIC void
GC_dump_finalization_links(const struct dl_hashtbl_s *dl_hashtbl)
{
size_t dl_size = (size_t)1 << dl_hashtbl->log_size;
size_t i;
if (NULL == dl_hashtbl->head) {
/* The table is empty. */
return;
}
for (i = 0; i < dl_size; i++) {
struct disappearing_link *curr_dl;
for (curr_dl = dl_hashtbl->head[i]; curr_dl != 0;
curr_dl = dl_next(curr_dl)) {
ptr_t real_ptr = (ptr_t)GC_REVEAL_POINTER(curr_dl->dl_hidden_obj);
ptr_t real_link = (ptr_t)GC_REVEAL_POINTER(curr_dl->dl_hidden_link);
GC_printf("Object: %p, link value: %p, link addr: %p\n",
(void *)real_ptr, *(void **)real_link, (void *)real_link);
}
}
}
GC_API void GC_CALL
GC_dump_finalization(void)
{
struct finalizable_object *curr_fo;
size_t i;
size_t fo_size
= GC_fnlz_roots.fo_head == NULL ? 0 : (size_t)1 << GC_log_fo_table_size;
GC_printf("\n***Disappearing (short) links:\n");
GC_dump_finalization_links(&GC_dl_hashtbl);
# ifndef GC_LONG_REFS_NOT_NEEDED
GC_printf("\n***Disappearing long links:\n");
GC_dump_finalization_links(&GC_ll_hashtbl);
# endif
GC_printf("\n***Finalizers:\n");
for (i = 0; i < fo_size; i++) {
for (curr_fo = GC_fnlz_roots.fo_head[i]; curr_fo != NULL;
curr_fo = fo_next(curr_fo)) {
ptr_t real_ptr = (ptr_t)GC_REVEAL_POINTER(curr_fo->fo_hidden_base);
GC_printf("Finalizable object: %p\n", (void *)real_ptr);
}
}
}
# endif /* !NO_DEBUGGING */
# ifndef SMALL_CONFIG
STATIC size_t GC_old_dl_entries = 0; /* for stats printing */
# ifndef GC_LONG_REFS_NOT_NEEDED
STATIC size_t GC_old_ll_entries = 0;
# endif
# endif /* !SMALL_CONFIG */
# ifndef THREADS
/* Global variables to minimize the level of recursion when a client */
/* finalizer allocates memory. (Only the lowest byte of */
/* GC_finalizer_nested is used, the rest of the variable is padding */
/* for the proper global data alignment required for some compilers */
/* like Watcom.) */
STATIC int GC_finalizer_nested = 0;
STATIC unsigned GC_finalizer_skipped = 0;
/* Checks and updates the level of finalizers recursion. */
/* Returns NULL if GC_invoke_finalizers() should not be called by the */
/* collector (to minimize the risk of a deep finalizers recursion), */
/* otherwise returns a pointer to GC_finalizer_nested. */
STATIC unsigned char *
GC_check_finalizer_nested(void)
{
unsigned nesting_level = *(unsigned char *)&GC_finalizer_nested;
if (nesting_level) {
/* We are inside another GC_invoke_finalizers(). */
/* Skip some implicitly-called GC_invoke_finalizers() */
/* depending on the nesting (recursion) level. */
if (++GC_finalizer_skipped < (1U << nesting_level))
return NULL;
GC_finalizer_skipped = 0;
}
*(char *)&GC_finalizer_nested = (char)(nesting_level + 1);
return (unsigned char *)&GC_finalizer_nested;
}
# endif /* !THREADS */
GC_INLINE void
GC_make_disappearing_links_disappear(struct dl_hashtbl_s *dl_hashtbl,
GC_bool is_remove_dangling)
{
size_t i;
size_t dl_size = (size_t)1 << dl_hashtbl->log_size;
GC_bool needs_barrier = FALSE;
GC_ASSERT(I_HOLD_LOCK());
if (NULL == dl_hashtbl->head) {
/* The table is empty. */
return;