+/*
+ * 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
+
+ * 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"
+
+#ifdef FINALIZE_ON_DEMAND
+ int GC_finalize_on_demand = 1;
+#else
+ int GC_finalize_on_demand = 0;
+#endif
+
+#ifdef JAVA_FINALIZATION
+ int GC_java_finalization = 1;
+#else
+ int GC_java_finalization = 0;
+#endif
+
+/* Type of mark procedure used for marking from finalizable object. */
+/* This procedure normally does not mark the object, only its */
+/* descendents. */
+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, 1 << log_size, log_size)
+
+struct hash_chain_entry {
+ word hidden_key;
+ struct hash_chain_entry * next;
+};
+
+static 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) (x)->prolog.next = (struct hash_chain_entry *)(y)
+
+ word dl_hidden_obj; /* Pointer to object base */
+} **dl_head = 0;
+
+static signed_word log_dl_table_size = -1;
+ /* Binary log of */
+ /* current size of array pointed to by dl_head. */
+ /* -1 ==> size is 0. */
+
+STATIC word GC_dl_entries = 0;
+ /* Number of entries currently in disappearing */
+ /* link table. */
+
+static 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. */
+ finalization_mark_proc fo_mark_proc; /* Mark-through procedure */
+} **fo_head = 0;
+
+STATIC struct finalizable_object * GC_finalize_now = 0;
+ /* List of objects that should be finalized now. */
+
+static signed_word log_fo_table_size = -1;
+
+word GC_fo_entries = 0; /* used also in extra/MacOS.c */
+
+GC_INNER void GC_push_finalizer_structures(void)
+{
+ GC_push_all((ptr_t)(&dl_head), (ptr_t)(&dl_head) + sizeof(word));
+ GC_push_all((ptr_t)(&fo_head), (ptr_t)(&fo_head) + sizeof(word));
+ GC_push_all((ptr_t)(&GC_finalize_now),
+ (ptr_t)(&GC_finalize_now) + sizeof(word));
+}
+
+/* Double the size of a hash table. *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)
+{
+ register word i;
+ register 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: (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 = (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 = 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];
+ new_table[new_hash] = p;
+ p = next;
+ }
+ }
+ *log_size_ptr = log_new_size;
+ *table = new_table;
+}
+
+GC_API int GC_CALL GC_register_disappearing_link(void * * link)
+{
+ ptr_t base;
+
+ base = (ptr_t)GC_base((void *)link);
+ if (base == 0)
+ ABORT("Bad arg to GC_register_disappearing_link");
+ return(GC_general_register_disappearing_link(link, base));
+}
+
+GC_API int GC_CALL GC_general_register_disappearing_link(void * * link,
+ void * obj)
+{
+ struct disappearing_link *curr_dl;
+ size_t index;
+ struct disappearing_link * new_dl;
+ DCL_LOCK_STATE;
+
+ if (((word)link & (ALIGNMENT-1)) || link == NULL)
+ ABORT("Bad arg to GC_general_register_disappearing_link");
+ LOCK();
+ GC_ASSERT(obj != NULL && GC_base(obj) == obj);
+ if (log_dl_table_size == -1
+ || GC_dl_entries > ((word)1 << log_dl_table_size)) {
+ GC_grow_table((struct hash_chain_entry ***)(&dl_head),
+ &log_dl_table_size);
+ if (GC_print_stats) {
+ GC_log_printf("Grew dl table to %u entries\n",
+ (1 << (unsigned)log_dl_table_size));
+ }
+ }
+ index = HASH2(link, log_dl_table_size);
+ for (curr_dl = dl_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();
+ return GC_DUPLICATE;
+ }
+ }
+ 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, log_dl_table_size);
+ /* Check again that our disappearing link not in the table. */
+ for (curr_dl = dl_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_head[index]);
+ dl_head[index] = new_dl;
+ GC_dl_entries++;
+ UNLOCK();
+ return GC_SUCCESS;
+}
+
+GC_API int GC_CALL GC_unregister_disappearing_link(void * * link)
+{
+ struct disappearing_link *curr_dl, *prev_dl;
+ size_t index;
+ DCL_LOCK_STATE;
+
+ if (((word)link & (ALIGNMENT-1)) != 0) return(0); /* Nothing to do. */
+
+ LOCK();
+ index = HASH2(link, log_dl_table_size);
+ prev_dl = 0; curr_dl = dl_head[index];
+ while (curr_dl != 0) {
+ if (curr_dl -> dl_hidden_link == GC_HIDE_POINTER(link)) {
+ if (prev_dl == 0) {
+ dl_head[index] = dl_next(curr_dl);
+ } else {
+ dl_set_next(prev_dl, dl_next(curr_dl));
+ }
+ GC_dl_entries--;
+ UNLOCK();
+# ifdef DBG_HDRS_ALL
+ dl_set_next(curr_dl, 0);
+# else
+ GC_free((void *)curr_dl);
+# endif
+ return(1);
+ }
+ prev_dl = curr_dl;
+ curr_dl = dl_next(curr_dl);
+ }
+ UNLOCK();
+ return(0);
+}
+
+/* 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)
+{
+ hdr * hhdr = HDR(p);
+
+ PUSH_OBJ(p, hhdr, 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)
+{
+ hdr * hhdr = HDR(p);
+ word descr = hhdr -> hb_descr;
+ ptr_t q;
+ word r;
+ 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; q <= scan_limit; q += ALIGNMENT) {
+ r = *(word *)q;
+ if ((ptr_t)r < p || (ptr_t)r > target_limit) {
+ GC_PUSH_ONE_HEAP(r, q);
+ }
+ }
+}
+
+/*ARGSUSED*/
+STATIC void GC_null_finalize_mark_proc(ptr_t 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)
+{
+ 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)
+{
+ ptr_t base;
+ struct finalizable_object * curr_fo, * prev_fo;
+ size_t index;
+ struct finalizable_object *new_fo = 0;
+ hdr *hhdr = NULL; /* initialized to prevent warning. */
+ GC_oom_func oom_fn;
+ DCL_LOCK_STATE;
+
+ LOCK();
+ if (log_fo_table_size == -1
+ || GC_fo_entries > ((word)1 << log_fo_table_size)) {
+ GC_grow_table((struct hash_chain_entry ***)(&fo_head),
+ &log_fo_table_size);
+ if (GC_print_stats) {
+ GC_log_printf("Grew fo table to %u entries\n",
+ (1 << (unsigned)log_fo_table_size));
+ }
+ }
+ /* in the THREADS case we hold allocation lock. */
+ base = (ptr_t)obj;
+ for (;;) {
+ index = HASH2(base, log_fo_table_size);
+ prev_fo = 0; curr_fo = 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(base)) {
+ /* 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 base. */
+ if (prev_fo == 0) {
+ fo_head[index] = fo_next(curr_fo);
+ } else {
+ fo_set_next(prev_fo, fo_next(curr_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;
+ /* Reinsert it. We deleted it first to maintain */
+ /* consistency in the event of a signal. */
+ if (prev_fo == 0) {
+ fo_head[index] = curr_fo;
+ } else {
+ fo_set_next(prev_fo, curr_fo);
+ }
+ }
+ UNLOCK();
+# ifndef DBG_HDRS_ALL
+ if (EXPECT(new_fo != 0, FALSE)) {
+ /* Free unused new_fo returned by GC_oom_fn() */
+ GC_free((void *)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(), so fn != 0 and hhdr != 0. */
+ break;
+ }
+ if (fn == 0) {
+ if (ocd) *ocd = 0;
+ if (ofn) *ofn = 0;
+ UNLOCK();
+ return;
+ }
+ GET_HDR(base, hhdr);
+ if (EXPECT(0 == 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 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(base);
+ 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, fo_head[index]);
+ GC_fo_entries++;
+ fo_head[index] = new_fo;
+ 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);
+}
+
+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
+ void GC_dump_finalization(void)
+ {
+ struct disappearing_link * curr_dl;
+ struct finalizable_object * curr_fo;
+ ptr_t real_ptr, real_link;
+ int dl_size = (log_dl_table_size == -1 ) ? 0 : (1 << log_dl_table_size);
+ int fo_size = (log_fo_table_size == -1 ) ? 0 : (1 << log_fo_table_size);
+ int i;
+
+ GC_printf("Disappearing links:\n");
+ for (i = 0; i < dl_size; i++) {
+ for (curr_dl = dl_head[i]; curr_dl != 0; curr_dl = dl_next(curr_dl)) {
+ real_ptr = GC_REVEAL_POINTER(curr_dl -> dl_hidden_obj);
+ real_link = GC_REVEAL_POINTER(curr_dl -> dl_hidden_link);
+ GC_printf("Object: %p, Link:%p\n", real_ptr, real_link);
+ }
+ }
+ GC_printf("Finalizers:\n");
+ for (i = 0; i < fo_size; i++) {
+ for (curr_fo = fo_head[i]; curr_fo != 0; curr_fo = fo_next(curr_fo)) {
+ real_ptr = GC_REVEAL_POINTER(curr_fo -> fo_hidden_base);
+ GC_printf("Finalizable object: %p\n", real_ptr);
+ }
+ }
+ }
+#endif /* !NO_DEBUGGING */
+
+#ifndef SMALL_CONFIG
+ STATIC word GC_old_dl_entries = 0; /* for stats printing */
+#endif
+
+#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 */
+
+/* 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 disappearing_link * curr_dl, * prev_dl, * next_dl;
+ struct finalizable_object * curr_fo, * prev_fo, * next_fo;
+ ptr_t real_ptr, real_link;
+ size_t i;
+ size_t dl_size = (log_dl_table_size == -1 ) ? 0 : (1 << log_dl_table_size);
+ size_t fo_size = (log_fo_table_size == -1 ) ? 0 : (1 << log_fo_table_size);
+
+# ifndef SMALL_CONFIG
+ /* Save current GC_dl_entries value for stats printing */
+ GC_old_dl_entries = GC_dl_entries;
+# endif
+
+ /* Make disappearing links disappear */
+ for (i = 0; i < dl_size; i++) {
+ curr_dl = dl_head[i];
+ prev_dl = 0;
+ while (curr_dl != 0) {
+ real_ptr = GC_REVEAL_POINTER(curr_dl -> dl_hidden_obj);
+ real_link = GC_REVEAL_POINTER(curr_dl -> dl_hidden_link);
+ if (!GC_is_marked(real_ptr)) {
+ *(word *)real_link = 0;
+ next_dl = dl_next(curr_dl);
+ if (prev_dl == 0) {
+ dl_head[i] = next_dl;
+ } else {
+ dl_set_next(prev_dl, next_dl);
+ }
+ GC_clear_mark_bit((ptr_t)curr_dl);
+ GC_dl_entries--;
+ curr_dl = next_dl;
+ } else {
+ prev_dl = curr_dl;
+ curr_dl = dl_next(curr_dl);
+ }
+ }
+ }
+ /* 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 = fo_head[i]; curr_fo != 0; curr_fo = fo_next(curr_fo)) {
+ GC_ASSERT(GC_size(curr_fo) >= sizeof(struct finalizable_object));
+ real_ptr = GC_REVEAL_POINTER(curr_fo -> fo_hidden_base);
+ if (!GC_is_marked(real_ptr)) {
+ 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);
+ }
+ }
+ }
+ }
+ /* Enqueue for finalization all objects that are still */
+ /* unreachable. */
+ GC_bytes_finalized = 0;
+ for (i = 0; i < fo_size; i++) {
+ curr_fo = fo_head[i];
+ prev_fo = 0;
+ while (curr_fo != 0) {
+ real_ptr = GC_REVEAL_POINTER(curr_fo -> fo_hidden_base);
+ if (!GC_is_marked(real_ptr)) {
+ if (!GC_java_finalization) {
+ GC_set_mark_bit(real_ptr);
+ }
+ /* Delete from hash table */
+ next_fo = fo_next(curr_fo);
+ if (prev_fo == 0) {
+ fo_head[i] = next_fo;
+ } else {
+ fo_set_next(prev_fo, next_fo);
+ }
+ GC_fo_entries--;
+ /* Add to list of objects awaiting finalization. */
+ fo_set_next(curr_fo, GC_finalize_now);
+ GC_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((ptr_t)curr_fo)));
+ curr_fo = next_fo;
+ } else {
+ prev_fo = curr_fo;
+ 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_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_finalize_now;
+ prev_fo = 0;
+ while (curr_fo != 0) {
+ 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 (prev_fo == 0)
+ GC_finalize_now = next_fo;
+ else
+ fo_set_next(prev_fo, next_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, fo_head[i]);
+ GC_fo_entries++;
+ fo_head[i] = curr_fo;
+ curr_fo = prev_fo;
+ }
+ }
+ prev_fo = curr_fo;
+ curr_fo = next_fo;
+ }
+ }
+ }
+
+ /* Remove dangling disappearing links. */
+ for (i = 0; i < dl_size; i++) {
+ curr_dl = dl_head[i];
+ prev_dl = 0;
+ while (curr_dl != 0) {
+ real_link = GC_base(GC_REVEAL_POINTER(curr_dl -> dl_hidden_link));
+ if (real_link != 0 && !GC_is_marked(real_link)) {
+ next_dl = dl_next(curr_dl);
+ if (prev_dl == 0) {
+ dl_head[i] = next_dl;
+ } else {
+ dl_set_next(prev_dl, next_dl);
+ }
+ GC_clear_mark_bit((ptr_t)curr_dl);
+ GC_dl_entries--;
+ curr_dl = next_dl;
+ } else {
+ prev_dl = curr_dl;
+ curr_dl = dl_next(curr_dl);
+ }
+ }
+ }
+ 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
+ }
+}
+
+#ifndef JAVA_FINALIZATION_NOT_NEEDED
+
+ /* Enqueue all remaining finalizers to be run - Assumes lock is held. */
+ STATIC void GC_enqueue_all_finalizers(void)
+ {
+ struct finalizable_object * curr_fo, * prev_fo, * next_fo;
+ ptr_t real_ptr;
+ register int i;
+ int fo_size;
+
+ fo_size = (log_fo_table_size == -1 ) ? 0 : (1 << log_fo_table_size);
+ GC_bytes_finalized = 0;
+ for (i = 0; i < fo_size; i++) {
+ curr_fo = fo_head[i];
+ prev_fo = 0;
+ while (curr_fo != 0) {
+ real_ptr = GC_REVEAL_POINTER(curr_fo -> fo_hidden_base);
+ GC_MARK_FO(real_ptr, GC_normal_finalize_mark_proc);
+ GC_set_mark_bit(real_ptr);
+
+ /* Delete from hash table */
+ next_fo = fo_next(curr_fo);
+ if (prev_fo == 0) {
+ fo_head[i] = next_fo;
+ } else {
+ fo_set_next(prev_fo, next_fo);
+ }
+ GC_fo_entries--;
+
+ /* Add to list of objects awaiting finalization. */
+ fo_set_next(curr_fo, GC_finalize_now);
+ GC_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;
+ }
+ }
+ }
+
+ /* 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)
+{
+ return GC_finalize_now != 0;
+}
+
+/* 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)
+{
+ struct finalizable_object * curr_fo;
+ int count = 0;
+ word bytes_freed_before = 0; /* initialized to prevent warning. */
+ DCL_LOCK_STATE;
+
+ while (GC_finalize_now != 0) {
+# 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_finalize_now;
+# ifdef THREADS
+ if (curr_fo != 0) GC_finalize_now = fo_next(curr_fo);
+ UNLOCK();
+ if (curr_fo == 0) break;
+# else
+ GC_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;
+# ifdef UNDEFINED
+ /* This is probably a bad idea. It throws off accounting if */
+ /* nearly all objects are finalizable. O.w. it shouldn't */
+ /* matter. */
+ GC_free((void *)curr_fo);
+# endif
+ }
+ /* bytes_freed_before is initialized whenever count != 0 */
+ if (count != 0 && bytes_freed_before != GC_bytes_freed) {
+ LOCK();
+ GC_finalizer_bytes_freed += (GC_bytes_freed - bytes_freed_before);
+ UNLOCK();
+ }
+ return count;
+}
+
+/* All accesses to it should be synchronized to avoid data races. */
+GC_finalizer_notifier_proc GC_finalizer_notifier =
+ (GC_finalizer_notifier_proc)0;
+
+static GC_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_finalize_now == 0) return;
+# endif
+ LOCK();
+
+ /* 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 = (word)(-1); /* 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) {
+ UNLOCK();
+ GC_print_back_graph_stats();
+ LOCK();
+ }
+# endif
+ }
+# endif
+ if (GC_finalize_now == 0) {
+ 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(GC_finalize_now == 0);
+# 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) {
+ last_finalizer_notification = GC_gc_no;
+ notifier_fn = GC_finalizer_notifier;
+ }
+ UNLOCK();
+ if (notifier_fn != 0)
+ (*notifier_fn)(); /* Invoke the notifier */
+}
+
+GC_API void * GC_CALL GC_call_with_alloc_lock(GC_fn_type fn,
+ void * client_data)
+{
+ void * result;
+ DCL_LOCK_STATE;
+
+# ifdef THREADS
+ LOCK();
+ /* FIXME - This looks wrong!! */
+ SET_LOCK_HOLDER();
+# endif
+ result = (*fn)(client_data);
+# ifdef THREADS
+# ifndef GC_ASSERTIONS
+ UNSET_LOCK_HOLDER();
+# endif /* o.w. UNLOCK() does it implicitly */
+ UNLOCK();
+# endif
+ return(result);
+}
+
+#ifndef SMALL_CONFIG
+ GC_INNER void GC_print_finalization_stats(void)
+ {
+ struct finalizable_object *fo = GC_finalize_now;
+ unsigned long ready = 0;
+
+ GC_log_printf(
+ "%lu finalization table entries; %lu disappearing links alive\n",
+ (unsigned long)GC_fo_entries, (unsigned long)GC_dl_entries);
+ for (; 0 != fo; fo = fo_next(fo)) ++ready;
+ GC_log_printf("%lu objects are eligible for immediate finalization; "
+ "%ld links cleared\n",
+ ready, (long)GC_old_dl_entries - (long)GC_dl_entries);
+ }
+#endif /* !SMALL_CONFIG */
projects / hs-boehmgc.git / blobdiff