diff options
Diffstat (limited to 'tools/build/v2/engine/boehm_gc/finalize.c')
| -rw-r--r-- | tools/build/v2/engine/boehm_gc/finalize.c | 869 |
1 files changed, 869 insertions, 0 deletions
diff --git a/tools/build/v2/engine/boehm_gc/finalize.c b/tools/build/v2/engine/boehm_gc/finalize.c new file mode 100644 index 0000000000..6ae36c2ddc --- /dev/null +++ b/tools/build/v2/engine/boehm_gc/finalize.c @@ -0,0 +1,869 @@ +/* + * 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. + */ +/* Boehm, February 1, 1996 1:19 pm PST */ +# define I_HIDE_POINTERS +# 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; +}; + +unsigned GC_finalization_failures = 0; + /* Number of finalization requests that failed for lack of memory. */ + +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. */ + +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; + +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; + +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 noop. */ +/* *table is a pointer to an array of hash headers. If we succeed, we */ +/* update both *table and *log_size_ptr. */ +/* Lock is held. Signals are disabled. */ +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 = (ptr_t)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; +} + +int 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)); +} + +int 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)) + ABORT("Bad arg to GC_general_register_disappearing_link"); +# ifdef THREADS + LOCK(); +# endif + 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 << log_dl_table_size)); + } + } + index = HASH2(link, log_dl_table_size); + curr_dl = dl_head[index]; + for (curr_dl = dl_head[index]; curr_dl != 0; curr_dl = dl_next(curr_dl)) { + if (curr_dl -> dl_hidden_link == HIDE_POINTER(link)) { + curr_dl -> dl_hidden_obj = HIDE_POINTER(obj); +# ifdef THREADS + UNLOCK(); +# endif + return(1); + } + } + new_dl = (struct disappearing_link *) + GC_INTERNAL_MALLOC(sizeof(struct disappearing_link),NORMAL); + if (0 == new_dl) { +# ifdef THREADS + UNLOCK(); +# endif + new_dl = (struct disappearing_link *) + GC_oom_fn(sizeof(struct disappearing_link)); + if (0 == new_dl) { + GC_finalization_failures++; + return(0); + } + /* It's not likely we'll make it here, but ... */ +# ifdef THREADS + LOCK(); +# endif + } + new_dl -> dl_hidden_obj = HIDE_POINTER(obj); + new_dl -> dl_hidden_link = HIDE_POINTER(link); + dl_set_next(new_dl, dl_head[index]); + dl_head[index] = new_dl; + GC_dl_entries++; +# ifdef THREADS + UNLOCK(); +# endif + return(0); +} + +int GC_unregister_disappearing_link(void * * link) +{ + struct disappearing_link *curr_dl, *prev_dl; + size_t index; + DCL_LOCK_STATE; + + LOCK(); + index = HASH2(link, log_dl_table_size); + if (((word)link & (ALIGNMENT-1))) goto out; + prev_dl = 0; curr_dl = dl_head[index]; + while (curr_dl != 0) { + if (curr_dl -> dl_hidden_link == 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); + } +out: + UNLOCK(); + return(0); +} + +/* Possible finalization_marker procedures. Note that mark stack */ +/* overflow is handled by the caller, and is not a disaster. */ +GC_API 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. */ +GC_API void GC_ignore_self_finalize_mark_proc(ptr_t p) +{ + hdr * hhdr = HDR(p); + word descr = hhdr -> hb_descr; + ptr_t q, 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 = *(ptr_t *)q; + if (r < p || r > target_limit) { + GC_PUSH_ONE_HEAP(r, q); + } + } +} + +/*ARGSUSED*/ +GC_API 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, eve if those */ +/* other objects specify no ordering. */ +GC_API void GC_unreachable_finalize_mark_proc(ptr_t p) +{ + GC_normal_finalize_mark_proc(p); +} + + + +/* Register a finalization function. See gc.h for details. */ +/* in the nonthreads case, we try to avoid disabling signals, */ +/* since it can be expensive. Threads packages typically */ +/* make it cheaper. */ +/* 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. */ +GC_API 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; + hdr *hhdr; + DCL_LOCK_STATE; + +# ifdef THREADS + LOCK(); +# endif + 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 << log_fo_table_size)); + } + } + /* in the THREADS case signals are disabled and we hold allocation */ + /* lock; otherwise neither is true. Proceed carefully. */ + base = (ptr_t)obj; + 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 == 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); + } + } +# ifdef THREADS + UNLOCK(); +# endif + return; + } + prev_fo = curr_fo; + curr_fo = fo_next(curr_fo); + } + if (ofn) *ofn = 0; + if (ocd) *ocd = 0; + if (fn == 0) { +# ifdef THREADS + UNLOCK(); +# endif + return; + } + GET_HDR(base, hhdr); + if (0 == hhdr) { + /* We won't collect it, hence finalizer wouldn't be run. */ +# ifdef THREADS + UNLOCK(); +# endif + return; + } + new_fo = (struct finalizable_object *) + GC_INTERNAL_MALLOC(sizeof(struct finalizable_object),NORMAL); + GC_ASSERT(GC_size(new_fo) >= sizeof(struct finalizable_object)); + if (EXPECT(0 == new_fo, FALSE)) { +# ifdef THREADS + UNLOCK(); +# endif + new_fo = (struct finalizable_object *) + GC_oom_fn(sizeof(struct finalizable_object)); + if (0 == new_fo) { + GC_finalization_failures++; + return; + } + /* It's not likely we'll make it here, but ... */ +# ifdef THREADS + LOCK(); +# endif + } + 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 = 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; +# ifdef THREADS + UNLOCK(); +# endif +} + +void 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); +} + +void 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); +} + +void 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. */ + +void 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 = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_obj); + real_link = (ptr_t)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 = (ptr_t)REVEAL_POINTER(curr_fo -> fo_hidden_base); + GC_printf("Finalizable object: %p\n", real_ptr); + } + } +} +#endif + +/* Called with world stopped. Cause disappearing links to disappear, */ +/* and invoke finalizers. */ +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); + + /* 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 = (ptr_t)REVEAL_POINTER(curr_dl -> dl_hidden_obj); + real_link = (ptr_t)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 = (ptr_t)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 %lx\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 = (ptr_t)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) 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 = + (word) 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((ptr_t)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); + } + } + } +} + +#ifndef JAVA_FINALIZATION_NOT_NEEDED + +/* Enqueue all remaining finalizers to be run - Assumes lock is + * held, and signals are disabled */ +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 = (ptr_t)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) REVEAL_POINTER(curr_fo -> fo_hidden_base); + + GC_bytes_finalized += + curr_fo -> fo_object_size + sizeof(struct finalizable_object); + curr_fo = next_fo; + } + } + + return; +} + +/* 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_finalize_all(void) +{ + DCL_LOCK_STATE; + + LOCK(); + while (GC_fo_entries > 0) { + GC_enqueue_all_finalizers(); + UNLOCK(); + GC_INVOKE_FINALIZERS(); + LOCK(); + } + UNLOCK(); +} +#endif + +/* 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.) */ +int 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. */ +int GC_invoke_finalizers(void) +{ + struct finalizable_object * curr_fo; + int count = 0; + word bytes_freed_before; + 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; +} + +void (* GC_finalizer_notifier)() = (void (*) (void))0; + +static GC_word last_finalizer_notification = 0; + +void GC_notify_or_invoke_finalizers(void) +{ + /* 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) + static word last_back_trace_gc_no = 1; /* Skip first one. */ + + if (GC_gc_no > last_back_trace_gc_no) { + word i; + +# ifdef KEEP_BACK_PTRS + LOCK(); + /* 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; + UNLOCK(); +# endif +# ifdef MAKE_BACK_GRAPH + if (GC_print_back_height) + GC_print_back_graph_stats(); +# endif + } +# endif + if (GC_finalize_now == 0) return; + if (!GC_finalize_on_demand) { + (void) GC_invoke_finalizers(); +# ifndef THREADS + GC_ASSERT(GC_finalize_now == 0); +# endif /* Otherwise GC can run concurrently and add more */ + return; + } + if (GC_finalizer_notifier != (void (*) (void))0 + && last_finalizer_notification != GC_gc_no) { + last_finalizer_notification = GC_gc_no; + GC_finalizer_notifier(); + } +} + +void * 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); +} + +#if !defined(NO_DEBUGGING) + +void GC_print_finalization_stats(void) +{ + struct finalizable_object *fo = GC_finalize_now; + size_t ready = 0; + + GC_printf("%u finalization table entries; %u disappearing links\n", + GC_fo_entries, GC_dl_entries); + for (; 0 != fo; fo = fo_next(fo)) ++ready; + GC_printf("%u objects are eligible for immediate finalization\n", ready); +} + +#endif /* NO_DEBUGGING */ |