/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
- * Copyright (c) 1991, 1992 by Xerox Corporation. All rights reserved.
+ * 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
* 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 copy this garbage collector for any purpose,
- * provided the above notices are retained on all copies.
+ * 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.
*/
-# define I_HIDE_POINTERS
-# include "gc.h"
-# include "gc_private.h"
-# ifdef __STDC__
- typedef void * void_star;
-# else
- typedef char * void_star;
-# endif
-# define LOG_TSIZE 7
-# define TSIZE (1 << LOG_TSIZE)
-# define HASH(addr) \
- ((((word)(addr) >> 3) ^ ((word)(addr) >> (3+LOG_TSIZE))) \
- & (TSIZE - 1))
-
-static struct disappearing_link {
- word dl_hidden_base; /* Pointer to object base */
- word dl_offset; /* byte offset within object. */
- struct disappearing_link * dl_next;
-} * dl_head[TSIZE] = {0};
-
-static struct finalizable_object {
- word fo_hidden_base; /* Pointer to object base */
- GC_finalization_proc fo_fn; /* Finalizer. */
+#include "private/gc_pmark.h"
+
+#ifndef GC_NO_FINALIZATION
+# include "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) \
+ ((((word)(addr) >> 3) ^ ((word)(addr) >> (3 + (log_size)))) \
+ & ((size) - 1))
+#define HASH2(addr,log_size) HASH3(addr, (word)1 << (log_size), log_size)
+
+struct hash_chain_entry {
+ word 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))
+ word dl_hidden_obj; /* Pointer to object base */
+};
+
+struct dl_hashtbl_s {
+ struct disappearing_link **head;
+ signed_word log_size;
+ word entries;
+};
+
+STATIC struct dl_hashtbl_s GC_dl_hashtbl = {
+ /* head */ NULL, /* log_size */ -1, /* entries */ 0 };
+#ifndef GC_LONG_REFS_NOT_NEEDED
+ STATIC struct dl_hashtbl_s GC_ll_hashtbl = { NULL, -1, 0 };
+#endif
+
+struct finalizable_object {
+ struct hash_chain_entry prolog;
+# define fo_hidden_base prolog.hidden_key
+ /* Pointer to object base. */
+ /* No longer hidden once object */
+ /* is on finalize_now queue. */
+# 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. */
ptr_t fo_client_data;
- word fo_object_size; /* In bytes. */
- struct finalizable_object * fo_next;
-} * fo_head[TSIZE] = {0};
+ word fo_object_size; /* In bytes. */
+ finalization_mark_proc fo_mark_proc; /* Mark-through procedure */
+};
+
+static signed_word log_fo_table_size = -1;
+
+STATIC struct fnlz_roots_s {
+ struct finalizable_object **fo_head;
+ /* List of objects that should be finalized now: */
+ struct finalizable_object *finalize_now;
+} GC_fnlz_roots = { NULL, NULL };
+
+#ifdef AO_HAVE_store
+ /* Update finalize_now atomically as GC_should_invoke_finalizers does */
+ /* not acquire the allocation lock. */
+# define SET_FINALIZE_NOW(fo) \
+ AO_store((volatile AO_t *)&GC_fnlz_roots.finalize_now, (AO_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((word)(&GC_dl_hashtbl.head) % sizeof(word) == 0);
+ GC_ASSERT((word)(&GC_fnlz_roots) % sizeof(word) == 0);
+# ifndef GC_LONG_REFS_NOT_NEEDED
+ GC_ASSERT((word)(&GC_ll_hashtbl.head) % sizeof(word) == 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);
+}
+
+/* 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 CPP_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 is a pointer to an array of hash headers. If we succeed, we */
+/* update both *table and *log_size_ptr. Lock is held. */
+STATIC void GC_grow_table(struct hash_chain_entry ***table,
+ signed_word *log_size_ptr, word *entries_ptr)
+{
+ word i;
+ struct hash_chain_entry *p;
+ signed_word log_old_size = *log_size_ptr;
+ signed_word log_new_size = log_old_size + 1;
+ word old_size = log_old_size == -1 ? 0 : (word)1 << log_old_size;
+ word new_size = (word)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 >= GC_ON_GROW_LOG_SIZE_MIN && !GC_incremental) {
+ IF_CANCEL(int cancel_state;)
-# define ALLOC(x, t) t *x = (t *)GC_malloc(sizeof (t))
+ DISABLE_CANCEL(cancel_state);
+ (void)GC_try_to_collect_inner(GC_never_stop_func);
+ RESTORE_CANCEL(cancel_state);
+ /* GC_finalize might decrease entries value. */
+ if (*entries_ptr < ((word)1 << log_old_size) - (*entries_ptr >> 2))
+ return;
+ }
+
+ new_table = (struct hash_chain_entry **)
+ GC_INTERNAL_MALLOC_IGNORE_OFF_PAGE(
+ (size_t)new_size * sizeof(struct hash_chain_entry *),
+ NORMAL);
+ if (new_table == 0) {
+ if (*table == 0) {
+ ABORT("Insufficient space for initial table allocation");
+ } else {
+ return;
+ }
+ }
+ for (i = 0; i < old_size; i++) {
+ p = (*table)[i];
+ while (p != 0) {
+ 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);
-int GC_register_disappearing_link(link)
-void_star * link;
+ p -> next = new_table[new_hash];
+ GC_dirty(p);
+ new_table[new_hash] = p;
+ p = next;
+ }
+ }
+ *log_size_ptr = log_new_size;
+ *table = new_table;
+ GC_dirty(new_table); /* entire object */
+}
+
+GC_API int GC_CALL GC_register_disappearing_link(void * * link)
{
ptr_t base;
- unsigned long offset;
+
+ 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;
- int index;
- /* Allocate before acquiring lock */
- ALLOC(new_dl, struct disappearing_link);
+ size_t index;
+ struct disappearing_link * new_dl;
DCL_LOCK_STATE;
-
- DISABLE_SIGNALS();
+
+ if (EXPECT(GC_find_leak, FALSE)) return GC_UNIMPLEMENTED;
LOCK();
- base = (ptr_t)GC_base((void_star)link);
- index = HASH(base);
- offset = (ptr_t)link - base;
- if (base == 0 || ((word)link & (ALIGNMENT-1)))
- ABORT("Bad arg to GC_register_disappearing_link");
- curr_dl = dl_head[index];
- for (curr_dl = dl_head[index]; curr_dl != 0; curr_dl = curr_dl -> dl_next) {
- if (curr_dl -> dl_hidden_base == HIDE_POINTER(base)
- && curr_dl -> dl_offset == offset) {
+ GC_ASSERT(obj != NULL && GC_base_C(obj) == obj);
+ if (dl_hashtbl -> log_size == -1
+ || dl_hashtbl -> entries > ((word)1 << dl_hashtbl -> log_size)) {
+ GC_grow_table((struct hash_chain_entry ***)&dl_hashtbl -> head,
+ &dl_hashtbl -> log_size, &dl_hashtbl -> entries);
+# ifdef LINT2
+ if (dl_hashtbl->log_size < 0) ABORT("log_size is negative");
+# endif
+ GC_COND_LOG_PRINTF("Grew %s table to %u entries\n", tbl_log_name,
+ 1 << (unsigned)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)) {
+ curr_dl -> dl_hidden_obj = GC_HIDE_POINTER(obj);
UNLOCK();
- ENABLE_SIGNALS();
- GC_free((extern_ptr_t)new_dl);
- return(1);
+ return GC_DUPLICATE;
}
}
- {
- new_dl -> dl_hidden_base = HIDE_POINTER(base);
- new_dl -> dl_offset = offset;
- new_dl -> dl_next = dl_head[index];
- dl_head[index] = new_dl;
- UNLOCK();
- ENABLE_SIGNALS();
- return(0);
+ new_dl = (struct disappearing_link *)
+ GC_INTERNAL_MALLOC(sizeof(struct disappearing_link),NORMAL);
+ if (0 == new_dl) {
+ 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((void *)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 (((word)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
-int GC_unregister_disappearing_link(link)
-void_star * link;
+/* 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)
{
- ptr_t base;
- unsigned long offset;
- struct disappearing_link *curr_dl, *prev_dl;
- int index;
- DCL_LOCK_STATE;
-
- DISABLE_SIGNALS();
- LOCK();
- base = (ptr_t)GC_base((void_star)link);
- index = HASH(base);
- offset = (ptr_t)link - base;
- if (base == 0 || ((unsigned long)link & (ALIGNMENT-1)))
- return(0);
- prev_dl = 0; curr_dl = dl_head[index];
- while (curr_dl != 0) {
- if (curr_dl -> dl_hidden_base == HIDE_POINTER(base)
- && curr_dl -> dl_offset == offset) {
- if (prev_dl == 0) {
- dl_head[index] = curr_dl -> dl_next;
+ struct disappearing_link *curr_dl;
+ struct disappearing_link *prev_dl = NULL;
+ size_t index;
+
+ GC_ASSERT(I_HOLD_LOCK());
+ if (dl_hashtbl->log_size == -1)
+ return NULL; /* prevent integer shift by a negative amount */
+
+ 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 {
- prev_dl -> dl_next = curr_dl -> dl_next;
+ dl_set_next(prev_dl, dl_next(curr_dl));
+ GC_dirty(prev_dl);
}
- UNLOCK();
- ENABLE_SIGNALS();
- GC_free((extern_ptr_t)curr_dl);
- return(1);
+ dl_hashtbl -> entries--;
+ break;
}
- curr_dl = curr_dl -> dl_next;
prev_dl = curr_dl;
}
+ return curr_dl;
+}
+
+GC_API int GC_CALL GC_unregister_disappearing_link(void * * link)
+{
+ struct disappearing_link *curr_dl;
+ DCL_LOCK_STATE;
+
+ if (((word)link & (ALIGNMENT-1)) != 0) return(0); /* Nothing to do. */
+
+ LOCK();
+ curr_dl = GC_unregister_disappearing_link_inner(&GC_dl_hashtbl, link);
UNLOCK();
- ENABLE_SIGNALS();
- return(0);
+ if (NULL == curr_dl) return 0;
+ FREE_DL_ENTRY(curr_dl);
+ return 1;
}
-bool GC_is_marked(p)
-ptr_t p;
+/* Toggle-ref support. */
+#ifndef GC_TOGGLE_REFS_NOT_NEEDED
+ typedef union {
+ /* Lowest bit is used to distinguish between choices. */
+ void *strong_ref;
+ GC_hidden_pointer weak_ref;
+ } GCToggleRef;
+
+ STATIC GC_toggleref_func GC_toggleref_callback = 0;
+ STATIC GCToggleRef *GC_toggleref_arr = NULL;
+ STATIC int GC_toggleref_array_size = 0;
+ STATIC int GC_toggleref_array_capacity = 0;
+
+ GC_INNER void GC_process_togglerefs(void)
+ {
+ int i;
+ int 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 (((word)obj & 1) != 0) {
+ obj = GC_REVEAL_POINTER(r.weak_ref);
+ }
+ 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 push_and_mark_object(void *p)
+ {
+ GC_normal_finalize_mark_proc((ptr_t)p);
+ while (!GC_mark_stack_empty()) {
+ MARK_FROM_MARK_STACK();
+ }
+ GC_set_mark_bit(p);
+ if (GC_mark_state != MS_NONE) {
+ while (!GC_mark_some(0)) {
+ /* Empty. */
+ }
+ }
+ }
+
+ STATIC void GC_mark_togglerefs(void)
+ {
+ int i;
+ if (NULL == GC_toggleref_arr)
+ return;
+
+ /* TODO: Hide GC_toggleref_arr to avoid its marking from roots. */
+ 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 && ((word)obj & 1) == 0) {
+ push_and_mark_object(obj);
+ }
+ }
+ }
+
+ STATIC void GC_clear_togglerefs(void)
+ {
+ int i;
+ for (i = 0; i < GC_toggleref_array_size; ++i) {
+ if ((GC_toggleref_arr[i].weak_ref & 1) != 0) {
+ if (!GC_is_marked(GC_REVEAL_POINTER(GC_toggleref_arr[i].weak_ref))) {
+ GC_toggleref_arr[i].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)
+ {
+ DCL_LOCK_STATE;
+
+ LOCK();
+ GC_toggleref_callback = fn;
+ UNLOCK();
+ }
+
+ GC_API GC_toggleref_func GC_CALL GC_get_toggleref_func(void)
+ {
+ GC_toggleref_func fn;
+ DCL_LOCK_STATE;
+
+ LOCK();
+ fn = GC_toggleref_callback;
+ UNLOCK();
+ return fn;
+ }
+
+ static GC_bool ensure_toggleref_capacity(int capacity_inc)
+ {
+ GC_ASSERT(capacity_inc >= 0);
+ 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 ((unsigned)GC_toggleref_array_size + (unsigned)capacity_inc
+ >= (unsigned)GC_toggleref_array_capacity) {
+ GCToggleRef *new_array;
+ while ((unsigned)GC_toggleref_array_capacity
+ < (unsigned)GC_toggleref_array_size + (unsigned)capacity_inc) {
+ GC_toggleref_array_capacity *= 2;
+ if (GC_toggleref_array_capacity < 0) /* overflow */
+ return FALSE;
+ }
+
+ 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;
+ DCL_LOCK_STATE;
+
+ GC_ASSERT(NONNULL_ARG_NOT_NULL(obj));
+ LOCK();
+ if (GC_toggleref_callback != 0) {
+ if (!ensure_toggleref_capacity(1)) {
+ res = GC_NO_MEMORY;
+ } else {
+ GC_toggleref_arr[GC_toggleref_array_size].strong_ref =
+ is_strong_ref ? obj : (void *)GC_HIDE_POINTER(obj);
+ if (is_strong_ref)
+ GC_dirty(GC_toggleref_arr + GC_toggleref_array_size);
+ 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)
{
- register struct hblk *h = HBLKPTR(p);
- register hdr * hhdr = HDR(h);
- register int word_no = (word *)p - (word *)h;
-
- return(mark_bit_from_hdr(hhdr, word_no));
+ DCL_LOCK_STATE;
+
+ LOCK();
+ GC_object_finalized_proc = fn;
+ UNLOCK();
}
-void GC_set_mark_bit(p)
-ptr_t p;
+GC_API GC_await_finalize_proc GC_CALL GC_get_await_finalize_proc(void)
{
- register struct hblk *h = HBLKPTR(p);
- register hdr * hhdr = HDR(h);
- register int word_no = (word *)p - (word *)h;
-
- set_mark_bit_from_hdr(hhdr, word_no);
+ GC_await_finalize_proc fn;
+ DCL_LOCK_STATE;
+
+ LOCK();
+ fn = GC_object_finalized_proc;
+ UNLOCK();
+ return fn;
}
-void GC_clear_mark_bit(p)
-ptr_t p;
+#ifndef GC_LONG_REFS_NOT_NEEDED
+ GC_API int GC_CALL GC_register_long_link(void * * link, const void * obj)
+ {
+ if (((word)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;
+ DCL_LOCK_STATE;
+
+ if (((word)link & (ALIGNMENT-1)) != 0) return(0); /* Nothing to do. */
+
+ 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
+ /* Moves a link. Assume the lock is held. */
+ STATIC int GC_move_disappearing_link_inner(
+ struct dl_hashtbl_s *dl_hashtbl,
+ void **link, void **new_link)
+ {
+ struct disappearing_link *curr_dl, *prev_dl, *new_dl;
+ size_t curr_index, new_index;
+ word curr_hidden_link;
+ word new_hidden_link;
+
+ GC_ASSERT(I_HOLD_LOCK());
+ if (dl_hashtbl->log_size == -1)
+ return GC_NOT_FOUND; /* prevent integer shift by a negative amount */
+
+ /* Find current link. */
+ curr_index = HASH2(link, dl_hashtbl -> log_size);
+ curr_hidden_link = GC_HIDE_POINTER(link);
+ prev_dl = NULL;
+ 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 (NULL == curr_dl) {
+ return GC_NOT_FOUND;
+ }
+
+ if (link == new_link) {
+ return GC_SUCCESS; /* Nothing to do. */
+ }
+
+ /* link 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. */
+ 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;
+ DCL_LOCK_STATE;
+
+ if (((word)new_link & (ALIGNMENT-1)) != 0
+ || !NONNULL_ARG_NOT_NULL(new_link))
+ ABORT("Bad new_link arg to GC_move_disappearing_link");
+ if (((word)link & (ALIGNMENT-1)) != 0)
+ return GC_NOT_FOUND; /* Nothing to do. */
+
+ 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;
+ DCL_LOCK_STATE;
+
+ if (((word)new_link & (ALIGNMENT-1)) != 0
+ || !NONNULL_ARG_NOT_NULL(new_link))
+ ABORT("Bad new_link arg to GC_move_long_link");
+ if (((word)link & (ALIGNMENT-1)) != 0)
+ return GC_NOT_FOUND; /* Nothing to do. */
+
+ LOCK();
+ result = GC_move_disappearing_link_inner(&GC_ll_hashtbl, link, new_link);
+ UNLOCK();
+ return result;
+ }
+# endif /* !GC_LONG_REFS_NOT_NEEDED */
+#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. */
+STATIC void GC_normal_finalize_mark_proc(ptr_t p)
{
- register struct hblk *h = HBLKPTR(p);
- register hdr * hhdr = HDR(h);
- register int word_no = (word *)p - (word *)h;
-
- clear_mark_bit_from_hdr(hhdr, word_no);
+# if defined(_MSC_VER) && defined(I386)
+ hdr * hhdr = HDR(p);
+ /* This is a manually inlined variant of GC_push_obj(). Otherwise */
+ /* some optimizer bug is tickled in VC for X86 (v19, at least). */
+# define mark_stack_top GC_mark_stack_top
+ mse * mark_stack_limit = GC_mark_stack + GC_mark_stack_size;
+ word descr = hhdr -> hb_descr;
+
+ if (descr != 0) {
+ mark_stack_top++;
+ if ((word)mark_stack_top >= (word)mark_stack_limit) {
+ mark_stack_top = GC_signal_mark_stack_overflow(mark_stack_top);
+ }
+ mark_stack_top -> mse_start = p;
+ mark_stack_top -> mse_descr.w = descr;
+ }
+# undef mark_stack_top
+# else
+ GC_mark_stack_top = GC_push_obj(p, HDR(p), GC_mark_stack_top,
+ GC_mark_stack + GC_mark_stack_size);
+# endif
}
-void GC_register_finalizer(obj, fn, cd, ofn, ocd)
-void_star obj;
-GC_finalization_proc fn;
-void_star cd;
-GC_finalization_proc * ofn;
-void_star * ocd;
+/* 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)
{
- ptr_t base;
- struct finalizable_object * curr_fo, * prev_fo;
- int index;
- /* Allocate before acquiring lock */
- ALLOC(new_fo, struct finalizable_object);
+ hdr * hhdr = HDR(p);
+ word descr = hhdr -> hb_descr;
+ ptr_t q;
+ 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(word);
+ } else {
+ scan_limit = target_limit + 1 - sizeof(word);
+ }
+ for (q = p; (word)q <= (word)scan_limit; q += ALIGNMENT) {
+ word r = *(word *)q;
+
+ if (r < (word)p || r > (word)target_limit) {
+ GC_PUSH_ONE_HEAP(r, q, GC_mark_stack_top);
+ }
+ }
+}
+
+STATIC void GC_null_finalize_mark_proc(ptr_t p GC_ATTR_UNUSED) {}
+
+/* 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)
+{
+ GC_normal_finalize_mark_proc(p);
+}
+
+/* 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;
+ hdr *hhdr = NULL; /* initialized to prevent warning. */
DCL_LOCK_STATE;
-
- DISABLE_SIGNALS();
+
+ if (EXPECT(GC_find_leak, FALSE)) return;
LOCK();
- base = (ptr_t)GC_base((void_star)obj);
- index = HASH(base);
- if (base != obj)
- ABORT("Bad arg to GC_register_finalizer");
- prev_fo = 0; curr_fo = fo_head[index];
- while (curr_fo != 0) {
- if (curr_fo -> fo_hidden_base == HIDE_POINTER(base)) {
- if (ofn) *ofn = curr_fo -> fo_fn;
- if (ocd) *ocd = (void_star) curr_fo -> fo_client_data;
- if (fn == 0) {
- /* Delete the structure for base. */
- if (prev_fo == 0) {
- fo_head[index] = curr_fo -> fo_next;
- } else {
- prev_fo -> fo_next = curr_fo -> fo_next;
- }
- UNLOCK();
- ENABLE_SIGNALS();
- GC_free((extern_ptr_t)curr_fo);
+ if (log_fo_table_size == -1
+ || GC_fo_entries > ((word)1 << log_fo_table_size)) {
+ GC_grow_table((struct hash_chain_entry ***)&GC_fnlz_roots.fo_head,
+ &log_fo_table_size, &GC_fo_entries);
+# ifdef LINT2
+ if (log_fo_table_size < 0) ABORT("log_size is negative");
+# endif
+ GC_COND_LOG_PRINTF("Grew fo table to %u entries\n",
+ 1 << (unsigned)log_fo_table_size);
+ }
+ /* in the THREADS case we hold allocation lock. */
+ for (;;) {
+ struct finalizable_object *prev_fo = NULL;
+ GC_oom_func oom_fn;
+
+ index = HASH2(obj, log_fo_table_size);
+ curr_fo = GC_fnlz_roots.fo_head[index];
+ while (curr_fo != 0) {
+ 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 = (void *) (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((void *)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 {
- curr_fo -> fo_fn = fn;
- curr_fo -> fo_client_data = (ptr_t)cd;
- UNLOCK();
- ENABLE_SIGNALS();
+ fo_set_next(prev_fo, curr_fo);
+ GC_dirty(prev_fo);
}
- GC_free((extern_ptr_t)new_fo);
- return;
+ }
+ 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((void *)new_fo);
+# endif
+ return;
}
- curr_fo = curr_fo -> fo_next;
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(0 == hhdr, FALSE)) {
+ /* We won't collect it, hence finalizer wouldn't be run. */
if (ocd) *ocd = 0;
- if (fn == 0) {
- UNLOCK();
- ENABLE_SIGNALS();
- GC_free((extern_ptr_t)new_fo);
- return;
- }
- new_fo -> fo_hidden_base = (word)HIDE_POINTER(base);
- new_fo -> fo_fn = fn;
- new_fo -> fo_client_data = (ptr_t)cd;
- new_fo -> fo_object_size = GC_size(base);
- new_fo -> fo_next = fo_head[index];
- fo_head[index] = new_fo;
+ 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 remains 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_size = 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();
- ENABLE_SIGNALS();
}
-/* Called with world stopped. Cause disappearing links to disappear, */
-/* and invoke finalizers. */
-void GC_finalize()
+GC_API void GC_CALL GC_register_finalizer(void * obj,
+ GC_finalization_proc fn, void * cd,
+ GC_finalization_proc *ofn, void ** ocd)
{
- struct disappearing_link * curr_dl, * prev_dl, * next_dl;
- struct finalizable_object * curr_fo, * prev_fo, * next_fo;
- ptr_t real_ptr;
- register int i;
-
- /* Make disappearing links disappear */
- for (i = 0; i < TSIZE; i++) {
- curr_dl = dl_head[i];
- prev_dl = 0;
- while (curr_dl != 0) {
- real_ptr = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_base);
- if (!GC_is_marked(real_ptr)) {
- *(word *)(real_ptr + curr_dl -> dl_offset) = 0;
- next_dl = curr_dl -> dl_next;
- if (prev_dl == 0) {
- dl_head[i] = next_dl;
- } else {
- prev_dl -> dl_next = next_dl;
- }
- GC_clear_mark_bit((ptr_t)curr_dl);
- curr_dl = next_dl;
- } else {
- prev_dl = curr_dl;
- curr_dl = curr_dl -> dl_next;
+ 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);
+}
+
+static GC_bool need_unreachable_finalization = FALSE;
+ /* Avoid the work if this isn't used. */
+
+GC_API void GC_CALL GC_register_finalizer_unreachable(void * obj,
+ GC_finalization_proc fn, void * cd,
+ GC_finalization_proc *ofn, void ** ocd)
+{
+ need_unreachable_finalization = TRUE;
+ 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 = dl_hashtbl->log_size == -1 ? 0 :
+ (size_t)1 << dl_hashtbl->log_size;
+ size_t i;
+
+ 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: %p\n",
+ (void *)real_ptr, (void *)real_link);
+ }
+ }
+ }
+
+ GC_API void GC_CALL GC_dump_finalization(void)
+ {
+ struct finalizable_object * curr_fo;
+ size_t fo_size = log_fo_table_size == -1 ? 0 :
+ (size_t)1 << log_fo_table_size;
+ size_t i;
+
+ GC_printf("Disappearing (short) links:\n");
+ GC_dump_finalization_links(&GC_dl_hashtbl);
+# ifndef GC_LONG_REFS_NOT_NEEDED
+ GC_printf("Disappearing long links:\n");
+ GC_dump_finalization_links(&GC_ll_hashtbl);
+# endif
+ GC_printf("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 word GC_old_dl_entries = 0; /* for stats printing */
+# ifndef GC_LONG_REFS_NOT_NEEDED
+ STATIC word 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. */
+ STATIC int GC_finalizer_nested = 0;
+ /* Only the lowest byte is used, the rest is */
+ /* padding for proper global data alignment */
+ /* required for some compilers (like Watcom). */
+ 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 = dl_hashtbl->log_size == -1 ? 0
+ : (size_t)1 << dl_hashtbl->log_size;
+ GC_bool needs_barrier = FALSE;
+
+ GC_ASSERT(I_HOLD_LOCK());
+ for (i = 0; i < dl_size; i++) {
+ struct disappearing_link *curr_dl, *next_dl;
+ struct disappearing_link *prev_dl = NULL;
+
+ for (curr_dl = dl_hashtbl->head[i]; curr_dl != NULL; curr_dl = next_dl) {
+ next_dl = dl_next(curr_dl);
+ if (is_remove_dangling) {
+ ptr_t real_link = (ptr_t)GC_base(GC_REVEAL_POINTER(
+ curr_dl->dl_hidden_link));
+
+ if (NULL == real_link || EXPECT(GC_is_marked(real_link), TRUE)) {
+ prev_dl = curr_dl;
+ continue;
+ }
+ } else {
+ if (EXPECT(GC_is_marked((ptr_t)GC_REVEAL_POINTER(
+ curr_dl->dl_hidden_obj)), TRUE)) {
+ prev_dl = curr_dl;
+ continue;
}
+ *(ptr_t *)GC_REVEAL_POINTER(curr_dl->dl_hidden_link) = NULL;
+ }
+
+ /* Delete curr_dl entry from dl_hashtbl. */
+ if (NULL == prev_dl) {
+ dl_hashtbl -> head[i] = next_dl;
+ needs_barrier = TRUE;
+ } else {
+ dl_set_next(prev_dl, next_dl);
+ GC_dirty(prev_dl);
}
+ GC_clear_mark_bit(curr_dl);
+ dl_hashtbl -> entries--;
}
- /* Mark all objects reachable via chains of 1 or more pointers */
- /* from finalizable objects. */
- for (i = 0; i < TSIZE; i++) {
- for (curr_fo = fo_head[i]; curr_fo != 0; curr_fo = curr_fo -> fo_next) {
- real_ptr = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base);
+ }
+ if (needs_barrier)
+ GC_dirty(dl_hashtbl -> head); /* entire object */
+}
+
+/* Called with held lock (but the world is running). */
+/* Cause disappearing links to disappear and unreachable objects to be */
+/* enqueued for finalization. */
+GC_INNER void GC_finalize(void)
+{
+ struct finalizable_object * curr_fo, * prev_fo, * next_fo;
+ ptr_t real_ptr;
+ size_t i;
+ size_t fo_size = log_fo_table_size == -1 ? 0 :
+ (size_t)1 << log_fo_table_size;
+ GC_bool needs_barrier = FALSE;
+
+ GC_ASSERT(I_HOLD_LOCK());
+# ifndef SMALL_CONFIG
+ /* Save current GC_[dl/ll]_entries value for stats printing */
+ GC_old_dl_entries = GC_dl_hashtbl.entries;
+# ifndef GC_LONG_REFS_NOT_NEEDED
+ GC_old_ll_entries = GC_ll_hashtbl.entries;
+# endif
+# endif
+
+# ifndef GC_TOGGLE_REFS_NOT_NEEDED
+ GC_mark_togglerefs();
+# endif
+ GC_make_disappearing_links_disappear(&GC_dl_hashtbl, FALSE);
+
+ /* Mark all objects reachable via chains of 1 or more pointers */
+ /* from finalizable objects. */
+ GC_ASSERT(GC_mark_state == MS_NONE);
+ 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)) {
+ GC_ASSERT(GC_size(curr_fo) >= sizeof(struct finalizable_object));
+ real_ptr = (ptr_t)GC_REVEAL_POINTER(curr_fo->fo_hidden_base);
if (!GC_is_marked(real_ptr)) {
- GC_mark_all(real_ptr, real_ptr + curr_fo -> fo_object_size);
- }
- /*
- if (GC_is_marked(real_ptr)) {
- --> Report finalization cycle here, if desired
+ GC_MARKED_FOR_FINALIZATION(real_ptr);
+ GC_MARK_FO(real_ptr, curr_fo -> fo_mark_proc);
+ if (GC_is_marked(real_ptr)) {
+ WARN("Finalization cycle involving %p\n", real_ptr);
+ }
}
- */
}
}
- /* Invoke finalization code for all objects that are still */
- /* unreachable. */
- for (i = 0; i < TSIZE; i++) {
- curr_fo = fo_head[i];
+ /* Enqueue for finalization all objects that are still */
+ /* unreachable. */
+ GC_bytes_finalized = 0;
+ for (i = 0; i < fo_size; i++) {
+ curr_fo = GC_fnlz_roots.fo_head[i];
prev_fo = 0;
while (curr_fo != 0) {
- real_ptr = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base);
+ real_ptr = (ptr_t)GC_REVEAL_POINTER(curr_fo->fo_hidden_base);
if (!GC_is_marked(real_ptr)) {
- (*(curr_fo -> fo_fn))(real_ptr, curr_fo -> fo_client_data);
- GC_set_mark_bit(real_ptr);
- next_fo = curr_fo -> fo_next;
- if (prev_fo == 0) {
- fo_head[i] = next_fo;
- } else {
- prev_fo -> fo_next = next_fo;
+ if (!GC_java_finalization) {
+ GC_set_mark_bit(real_ptr);
}
- if (!GC_is_marked((ptr_t)curr_fo)) {
- ABORT("GC_finalize: found accessible unmarked object\n");
- }
- GC_clear_mark_bit((ptr_t)curr_fo);
+ /* Delete from hash table */
+ next_fo = fo_next(curr_fo);
+ if (NULL == prev_fo) {
+ GC_fnlz_roots.fo_head[i] = next_fo;
+ if (GC_object_finalized_proc) {
+ GC_dirty(GC_fnlz_roots.fo_head + i);
+ } else {
+ needs_barrier = TRUE;
+ }
+ } else {
+ fo_set_next(prev_fo, next_fo);
+ GC_dirty(prev_fo);
+ }
+ GC_fo_entries--;
+ if (GC_object_finalized_proc)
+ GC_object_finalized_proc(real_ptr);
+
+ /* Add to list of objects awaiting finalization. */
+ fo_set_next(curr_fo, GC_fnlz_roots.finalize_now);
+ GC_dirty(curr_fo);
+ SET_FINALIZE_NOW(curr_fo);
+ /* unhide object pointer so any future collections will */
+ /* see it. */
+ curr_fo -> fo_hidden_base =
+ (word)GC_REVEAL_POINTER(curr_fo -> fo_hidden_base);
+ GC_bytes_finalized +=
+ curr_fo -> fo_object_size
+ + sizeof(struct finalizable_object);
+ GC_ASSERT(GC_is_marked(GC_base(curr_fo)));
curr_fo = next_fo;
} else {
prev_fo = curr_fo;
- curr_fo = curr_fo -> fo_next;
+ curr_fo = fo_next(curr_fo);
}
}
}
+
+ if (GC_java_finalization) {
+ /* make sure we mark everything reachable from objects finalized
+ using the no_order mark_proc */
+ for (curr_fo = GC_fnlz_roots.finalize_now;
+ curr_fo != NULL; curr_fo = fo_next(curr_fo)) {
+ real_ptr = (ptr_t)curr_fo -> fo_hidden_base;
+ if (!GC_is_marked(real_ptr)) {
+ if (curr_fo -> fo_mark_proc == GC_null_finalize_mark_proc) {
+ GC_MARK_FO(real_ptr, GC_normal_finalize_mark_proc);
+ }
+ if (curr_fo -> fo_mark_proc != GC_unreachable_finalize_mark_proc) {
+ GC_set_mark_bit(real_ptr);
+ }
+ }
+ }
+
+ /* now revive finalize-when-unreachable objects reachable from
+ other finalizable objects */
+ if (need_unreachable_finalization) {
+ curr_fo = GC_fnlz_roots.finalize_now;
+# if defined(GC_ASSERTIONS) || defined(LINT2)
+ if (curr_fo != NULL && log_fo_table_size < 0)
+ ABORT("log_size is negative");
+# endif
+ prev_fo = NULL;
+ while (curr_fo != NULL) {
+ next_fo = fo_next(curr_fo);
+ if (curr_fo -> fo_mark_proc == GC_unreachable_finalize_mark_proc) {
+ real_ptr = (ptr_t)curr_fo -> fo_hidden_base;
+ if (!GC_is_marked(real_ptr)) {
+ GC_set_mark_bit(real_ptr);
+ } else {
+ if (NULL == prev_fo) {
+ SET_FINALIZE_NOW(next_fo);
+ } else {
+ fo_set_next(prev_fo, next_fo);
+ GC_dirty(prev_fo);
+ }
+ curr_fo -> fo_hidden_base =
+ GC_HIDE_POINTER(curr_fo -> fo_hidden_base);
+ GC_bytes_finalized -=
+ curr_fo->fo_object_size + sizeof(struct finalizable_object);
+
+ i = HASH2(real_ptr, log_fo_table_size);
+ fo_set_next(curr_fo, GC_fnlz_roots.fo_head[i]);
+ GC_dirty(curr_fo);
+ GC_fo_entries++;
+ GC_fnlz_roots.fo_head[i] = curr_fo;
+ curr_fo = prev_fo;
+ needs_barrier = TRUE;
+ }
+ }
+ prev_fo = curr_fo;
+ curr_fo = next_fo;
+ }
+ }
+ }
+ if (needs_barrier)
+ GC_dirty(GC_fnlz_roots.fo_head); /* entire object */
+
+ /* Remove dangling disappearing links. */
+ GC_make_disappearing_links_disappear(&GC_dl_hashtbl, TRUE);
+
+# ifndef GC_TOGGLE_REFS_NOT_NEEDED
+ GC_clear_togglerefs();
+# endif
+# ifndef GC_LONG_REFS_NOT_NEEDED
+ GC_make_disappearing_links_disappear(&GC_ll_hashtbl, FALSE);
+ GC_make_disappearing_links_disappear(&GC_ll_hashtbl, TRUE);
+# endif
+
+ if (GC_fail_count) {
+ /* Don't prevent running finalizers if there has been an allocation */
+ /* failure recently. */
+# ifdef THREADS
+ GC_reset_finalizer_nested();
+# else
+ GC_finalizer_nested = 0;
+# endif
+ }
}
-# ifdef __STDC__
- void_star GC_call_with_alloc_lock(GC_fn_type fn, void_star client_data)
+#ifndef JAVA_FINALIZATION_NOT_NEEDED
+
+ /* Enqueue all remaining finalizers to be run. */
+ STATIC void GC_enqueue_all_finalizers(void)
+ {
+ struct finalizable_object * next_fo;
+ int i;
+ int fo_size;
+
+ GC_ASSERT(I_HOLD_LOCK());
+ fo_size = log_fo_table_size == -1 ? 0 : 1 << log_fo_table_size;
+ GC_bytes_finalized = 0;
+ for (i = 0; i < fo_size; i++) {
+ struct finalizable_object * curr_fo = GC_fnlz_roots.fo_head[i];
+
+ GC_fnlz_roots.fo_head[i] = NULL;
+ while (curr_fo != NULL) {
+ ptr_t real_ptr = (ptr_t)GC_REVEAL_POINTER(curr_fo->fo_hidden_base);
+
+ GC_MARK_FO(real_ptr, GC_normal_finalize_mark_proc);
+ GC_set_mark_bit(real_ptr);
+
+ next_fo = fo_next(curr_fo);
+
+ /* Add to list of objects awaiting finalization. */
+ fo_set_next(curr_fo, GC_fnlz_roots.finalize_now);
+ GC_dirty(curr_fo);
+ SET_FINALIZE_NOW(curr_fo);
+
+ /* unhide object pointer so any future collections will */
+ /* see it. */
+ curr_fo -> fo_hidden_base =
+ (word)GC_REVEAL_POINTER(curr_fo -> fo_hidden_base);
+ GC_bytes_finalized +=
+ curr_fo -> fo_object_size + sizeof(struct finalizable_object);
+ curr_fo = next_fo;
+ }
+ }
+ GC_fo_entries = 0; /* all entries deleted from the hash table */
+ }
+
+ /* Invoke all remaining finalizers that haven't yet been run.
+ * This is needed for strict compliance with the Java standard,
+ * which can make the runtime guarantee that all finalizers are run.
+ * Unfortunately, the Java standard implies we have to keep running
+ * finalizers until there are no more left, a potential infinite loop.
+ * YUCK.
+ * Note that this is even more dangerous than the usual Java
+ * finalizers, in that objects reachable from static variables
+ * may have been finalized when these finalizers are run.
+ * Finalizers run at this point must be prepared to deal with a
+ * mostly broken world.
+ * This routine is externally callable, so is called without
+ * the allocation lock.
+ */
+ GC_API void GC_CALL GC_finalize_all(void)
+ {
+ DCL_LOCK_STATE;
+
+ LOCK();
+ while (GC_fo_entries > 0) {
+ GC_enqueue_all_finalizers();
+ UNLOCK();
+ GC_invoke_finalizers();
+ /* Running the finalizers in this thread is arguably not a good */
+ /* idea when we should be notifying another thread to run them. */
+ /* But otherwise we don't have a great way to wait for them to */
+ /* run. */
+ LOCK();
+ }
+ UNLOCK();
+ }
+
+#endif /* !JAVA_FINALIZATION_NOT_NEEDED */
+
+/* Returns true if it is worth calling GC_invoke_finalizers. (Useful if */
+/* finalizers can only be called from some kind of "safe state" and */
+/* getting into that safe state is expensive.) */
+GC_API int GC_CALL GC_should_invoke_finalizers(void)
+{
+# ifdef AO_HAVE_load
+ return AO_load((volatile AO_t *)&GC_fnlz_roots.finalize_now) != 0;
# else
- void_star GC_call_with_alloc_lock(fn, client_data)
- GC_fn_type fn;
- void_star client_data;
-# endif
+ return GC_fnlz_roots.finalize_now != NULL;
+# endif /* !THREADS */
+}
+
+/* Invoke finalizers for all objects that are ready to be finalized. */
+/* Should be called without allocation lock. */
+GC_API int GC_CALL GC_invoke_finalizers(void)
{
+ int count = 0;
+ word bytes_freed_before = 0; /* initialized to prevent warning. */
DCL_LOCK_STATE;
-
- DISABLE_SIGNALS();
+
+ while (GC_should_invoke_finalizers()) {
+ struct finalizable_object * curr_fo;
+
+# ifdef THREADS
+ LOCK();
+# endif
+ if (count == 0) {
+ bytes_freed_before = GC_bytes_freed;
+ /* Don't do this outside, since we need the lock. */
+ }
+ curr_fo = GC_fnlz_roots.finalize_now;
+# ifdef THREADS
+ if (curr_fo != NULL)
+ SET_FINALIZE_NOW(fo_next(curr_fo));
+ UNLOCK();
+ if (curr_fo == 0) break;
+# else
+ GC_fnlz_roots.finalize_now = fo_next(curr_fo);
+# endif
+ fo_set_next(curr_fo, 0);
+ (*(curr_fo -> fo_fn))((ptr_t)(curr_fo -> fo_hidden_base),
+ curr_fo -> fo_client_data);
+ curr_fo -> fo_client_data = 0;
+ ++count;
+ /* Explicit freeing of curr_fo is probably a bad idea. */
+ /* It throws off accounting if nearly all objects are */
+ /* finalizable. Otherwise it should not matter. */
+ }
+ /* bytes_freed_before is initialized whenever count != 0 */
+ if (count != 0
+# if defined(THREADS) && !defined(THREAD_SANITIZER)
+ /* A quick check whether some memory was freed. */
+ /* The race with GC_free() is safe to be ignored */
+ /* because we only need to know if the current */
+ /* thread has deallocated something. */
+ && bytes_freed_before != GC_bytes_freed
+# endif
+ ) {
+ LOCK();
+ GC_finalizer_bytes_freed += (GC_bytes_freed - bytes_freed_before);
+ UNLOCK();
+ }
+ return count;
+}
+
+static word last_finalizer_notification = 0;
+
+GC_INNER void GC_notify_or_invoke_finalizers(void)
+{
+ GC_finalizer_notifier_proc notifier_fn = 0;
+# if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)
+ static word last_back_trace_gc_no = 1; /* Skip first one. */
+# endif
+ DCL_LOCK_STATE;
+
+# if defined(THREADS) && !defined(KEEP_BACK_PTRS) \
+ && !defined(MAKE_BACK_GRAPH)
+ /* Quick check (while unlocked) for an empty finalization queue. */
+ if (!GC_should_invoke_finalizers())
+ return;
+# endif
LOCK();
- (*fn)(client_data);
+
+ /* This is a convenient place to generate backtraces if appropriate, */
+ /* since that code is not callable with the allocation lock. */
+# if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)
+ if (GC_gc_no > last_back_trace_gc_no) {
+# ifdef KEEP_BACK_PTRS
+ long i;
+ /* Stops when GC_gc_no wraps; that's OK. */
+ last_back_trace_gc_no = GC_WORD_MAX; /* disable others. */
+ for (i = 0; i < GC_backtraces; ++i) {
+ /* FIXME: This tolerates concurrent heap mutation, */
+ /* which may cause occasional mysterious results. */
+ /* We need to release the GC lock, since GC_print_callers */
+ /* acquires it. It probably shouldn't. */
+ UNLOCK();
+ GC_generate_random_backtrace_no_gc();
+ LOCK();
+ }
+ last_back_trace_gc_no = GC_gc_no;
+# endif
+# ifdef MAKE_BACK_GRAPH
+ if (GC_print_back_height) {
+ GC_print_back_graph_stats();
+ }
+# endif
+ }
+# endif
+ if (NULL == GC_fnlz_roots.finalize_now) {
+ UNLOCK();
+ return;
+ }
+
+ if (!GC_finalize_on_demand) {
+ unsigned char *pnested = GC_check_finalizer_nested();
+ UNLOCK();
+ /* Skip GC_invoke_finalizers() if nested */
+ if (pnested != NULL) {
+ (void) GC_invoke_finalizers();
+ *pnested = 0; /* Reset since no more finalizers. */
+# ifndef THREADS
+ GC_ASSERT(NULL == GC_fnlz_roots.finalize_now);
+# endif /* Otherwise GC can run concurrently and add more */
+ }
+ return;
+ }
+
+ /* These variables require synchronization to avoid data races. */
+ if (last_finalizer_notification != GC_gc_no) {
+ notifier_fn = GC_finalizer_notifier;
+ last_finalizer_notification = GC_gc_no;
+ }
UNLOCK();
- ENABLE_SIGNALS();
+ if (notifier_fn != 0)
+ (*notifier_fn)(); /* Invoke the notifier */
}
+#ifndef SMALL_CONFIG
+# ifndef GC_LONG_REFS_NOT_NEEDED
+# define IF_LONG_REFS_PRESENT_ELSE(x,y) (x)
+# else
+# define IF_LONG_REFS_PRESENT_ELSE(x,y) (y)
+# endif
+
+ GC_INNER void GC_print_finalization_stats(void)
+ {
+ struct finalizable_object *fo;
+ unsigned long ready = 0;
+
+ GC_log_printf("%lu finalization entries;"
+ " %lu/%lu short/long disappearing links alive\n",
+ (unsigned long)GC_fo_entries,
+ (unsigned long)GC_dl_hashtbl.entries,
+ (unsigned long)IF_LONG_REFS_PRESENT_ELSE(
+ GC_ll_hashtbl.entries, 0));
+
+ for (fo = GC_fnlz_roots.finalize_now; fo != NULL; fo = fo_next(fo))
+ ++ready;
+ GC_log_printf("%lu finalization-ready objects;"
+ " %ld/%ld short/long links cleared\n",
+ ready,
+ (long)GC_old_dl_entries - (long)GC_dl_hashtbl.entries,
+ (long)IF_LONG_REFS_PRESENT_ELSE(
+ GC_old_ll_entries - GC_ll_hashtbl.entries, 0));
+ }
+#endif /* !SMALL_CONFIG */
+
+#endif /* !GC_NO_FINALIZATION */