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	/*
	* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
	* Copyright (c) 1991-1996 by Xerox Corporation. All rights reserved.
	* Copyright (c) 1998 by Silicon Graphics. All rights reserved.
	* Copyright (c) 1999-2004 Hewlett-Packard Development Company, L.P.
	*
	* 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_priv.h"

	# include <stdio.h>
	# if !defined(MACOS) && !defined(MSWINCE)
	# include <signal.h>
	# include <sys/types.h>
	# endif

	/*
	* Separate free lists are maintained for different sized objects
	* up to MAXOBJBYTES.
	* The call GC_allocobj(i,k) ensures that the freelist for
	* kind k objects of size i points to a non-empty
	* free list. It returns a pointer to the first entry on the free list.
	* In a single-threaded world, GC_allocobj may be called to allocate
	* an object of (small) size i as follows:
	*
	* opp = &(GC_objfreelist[i]);
	* if (*opp == 0) GC_allocobj(i, NORMAL);
	* ptr = *opp;
	* *opp = obj_link(ptr);
	*
	* Note that this is very fast if the free list is non-empty; it should
	* only involve the execution of 4 or 5 simple instructions.
	* All composite objects on freelists are cleared, except for
	* their first word.
	*/

	/*
	* The allocator uses GC_allochblk to allocate large chunks of objects.
	* These chunks all start on addresses which are multiples of
	* HBLKSZ. Each allocated chunk has an associated header,
	* which can be located quickly based on the address of the chunk.
	* (See headers.c for details.)
	* This makes it possible to check quickly whether an
	* arbitrary address corresponds to an object administered by the
	* allocator.
	*/

	word GC_non_gc_bytes = 0; /* Number of bytes not intended to be collected */

	word GC_gc_no = 0;

	#ifndef SMALL_CONFIG
	int GC_incremental = 0; /* By default, stop the world. */
	#endif

	int GC_parallel = FALSE; /* By default, parallel GC is off. */

	int GC_full_freq = 19; /* Every 20th collection is a full */
	/* collection, whether we need it */
	/* or not. */

	GC_bool GC_need_full_gc = FALSE;
	/* Need full GC do to heap growth. */

	#ifdef THREADS
	GC_bool GC_world_stopped = FALSE;
	# define IF_THREADS(x) x
	#else
	# define IF_THREADS(x)
	#endif

	word GC_used_heap_size_after_full = 0;

	char * GC_copyright[] =
	{"Copyright 1988,1989 Hans-J. Boehm and Alan J. Demers ",
	"Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. ",
	"Copyright (c) 1996-1998 by Silicon Graphics. All rights reserved. ",
	"Copyright (c) 1999-2001 by Hewlett-Packard Company. All rights reserved. ",
	"THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY",
	" EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.",
	"See source code for details." };

	# include "version.h"

	/* some more variables */

	extern signed_word GC_bytes_found; /* Number of reclaimed bytes */
	/* after garbage collection */

	GC_bool GC_dont_expand = 0;

	word GC_free_space_divisor = 3;

	extern GC_bool GC_collection_in_progress();
	/* Collection is in progress, or was abandoned. */

	int GC_never_stop_func (void) { return(0); }

	unsigned long GC_time_limit = TIME_LIMIT;

	CLOCK_TYPE GC_start_time; /* Time at which we stopped world. */
	/* used only in GC_timeout_stop_func. */

	int GC_n_attempts = 0; /* Number of attempts at finishing */
	/* collection within GC_time_limit. */

	#if defined(SMALL_CONFIG) \|\| defined(NO_CLOCK)
	# define GC_timeout_stop_func GC_never_stop_func
	#else
	int GC_timeout_stop_func (void)
	{
	CLOCK_TYPE current_time;
	static unsigned count = 0;
	unsigned long time_diff;

	if ((count++ & 3) != 0) return(0);
	GET_TIME(current_time);
	time_diff = MS_TIME_DIFF(current_time,GC_start_time);
	if (time_diff >= GC_time_limit) {
	if (GC_print_stats) {
	GC_log_printf("Abandoning stopped marking after ");
	GC_log_printf("%lu msecs", time_diff);
	GC_log_printf("(attempt %d)\n", GC_n_attempts);
	}
	return(1);
	}
	return(0);
	}
	#endif /* !SMALL_CONFIG */

	/* Return the minimum number of words that must be allocated between */
	/* collections to amortize the collection cost. */
	static word min_bytes_allocd()
	{
	# ifdef THREADS
	/* We punt, for now. */
	signed_word stack_size = 10000;
	# else
	int dummy;
	signed_word stack_size = (ptr_t)(&dummy) - GC_stackbottom;
	# endif
	word total_root_size; /* includes double stack size, */
	/* since the stack is expensive */
	/* to scan. */
	word scan_size; /* Estimate of memory to be scanned */
	/* during normal GC. */

	if (stack_size < 0) stack_size = -stack_size;
	total_root_size = 2 * stack_size + GC_root_size;
	scan_size = 2 * GC_composite_in_use + GC_atomic_in_use
	+ total_root_size;
	if (TRUE_INCREMENTAL) {
	return scan_size / (2 * GC_free_space_divisor);
	} else {
	return scan_size / GC_free_space_divisor;
	}
	}

	/* Return the number of bytes allocated, adjusted for explicit storage */
	/* management, etc.. This number is used in deciding when to trigger */
	/* collections. */
	word GC_adj_bytes_allocd(void)
	{
	signed_word result;
	signed_word expl_managed =
	(signed_word)GC_non_gc_bytes
	- (signed_word)GC_non_gc_bytes_at_gc;

	/* Don't count what was explicitly freed, or newly allocated for */
	/* explicit management. Note that deallocating an explicitly */
	/* managed object should not alter result, assuming the client */
	/* is playing by the rules. */
	result = (signed_word)GC_bytes_allocd
	- (signed_word)GC_bytes_freed
	+ (signed_word)GC_finalizer_bytes_freed
	- expl_managed;
	if (result > (signed_word)GC_bytes_allocd) {
	result = GC_bytes_allocd;
	/* probably client bug or unfortunate scheduling */
	}
	result += GC_bytes_finalized;
	/* We count objects enqueued for finalization as though they */
	/* had been reallocated this round. Finalization is user */
	/* visible progress. And if we don't count this, we have */
	/* stability problems for programs that finalize all objects. */
	if (result < (signed_word)(GC_bytes_allocd >> 3)) {
	/* Always count at least 1/8 of the allocations. We don't want */
	/* to collect too infrequently, since that would inhibit */
	/* coalescing of free storage blocks. */
	/* This also makes us partially robust against client bugs. */
	return(GC_bytes_allocd >> 3);
	} else {
	return(result);
	}
	}


	/* Clear up a few frames worth of garbage left at the top of the stack. */
	/* This is used to prevent us from accidentally treating garbade left */
	/* on the stack by other parts of the collector as roots. This */
	/* differs from the code in misc.c, which actually tries to keep the */
	/* stack clear of long-lived, client-generated garbage. */
	void GC_clear_a_few_frames()
	{
	# define NWORDS 64
	word frames[NWORDS];
	int i;

	for (i = 0; i < NWORDS; i++) frames[i] = 0;
	}

	/* Heap size at which we need a collection to avoid expanding past */
	/* limits used by blacklisting. */
	static word GC_collect_at_heapsize = (word)(-1);

	/* Have we allocated enough to amortize a collection? */
	GC_bool GC_should_collect(void)
	{
	return(GC_adj_bytes_allocd() >= min_bytes_allocd()
	\|\| GC_heapsize >= GC_collect_at_heapsize);
	}


	void GC_notify_full_gc(void)
	{
	if (GC_start_call_back != (void (*) (void))0) {
	(*GC_start_call_back)();
	}
	}

	GC_bool GC_is_full_gc = FALSE;

	/*
	* Initiate a garbage collection if appropriate.
	* Choose judiciously
	* between partial, full, and stop-world collections.
	* Assumes lock held, signals disabled.
	*/
	void GC_maybe_gc(void)
	{
	static int n_partial_gcs = 0;

	if (GC_should_collect()) {
	if (!GC_incremental) {
	GC_gcollect_inner();
	n_partial_gcs = 0;
	return;
	} else {
	# ifdef PARALLEL_MARK
	GC_wait_for_reclaim();
	# endif
	if (GC_need_full_gc \|\| n_partial_gcs >= GC_full_freq) {
	if (GC_print_stats) {
	GC_log_printf(
	"***>Full mark for collection %lu after %ld allocd bytes\n",
	(unsigned long)GC_gc_no+1,
	(long)GC_bytes_allocd);
	}
	GC_promote_black_lists();
	(void)GC_reclaim_all((GC_stop_func)0, TRUE);
	GC_clear_marks();
	n_partial_gcs = 0;
	GC_notify_full_gc();
	GC_is_full_gc = TRUE;
	} else {
	n_partial_gcs++;
	}
	}
	/* We try to mark with the world stopped. */
	/* If we run out of time, this turns into */
	/* incremental marking. */
	# ifndef NO_CLOCK
	if (GC_time_limit != GC_TIME_UNLIMITED) { GET_TIME(GC_start_time); }
	# endif
	if (GC_stopped_mark(GC_time_limit == GC_TIME_UNLIMITED?
	GC_never_stop_func : GC_timeout_stop_func)) {
	# ifdef SAVE_CALL_CHAIN
	GC_save_callers(GC_last_stack);
	# endif
	GC_finish_collection();
	} else {
	if (!GC_is_full_gc) {
	/* Count this as the first attempt */
	GC_n_attempts++;
	}
	}
	}
	}


	/*
	* Stop the world garbage collection. Assumes lock held, signals disabled.
	* If stop_func is not GC_never_stop_func, then abort if stop_func returns TRUE.
	* Return TRUE if we successfully completed the collection.
	*/
	GC_bool GC_try_to_collect_inner(GC_stop_func stop_func)
	{
	CLOCK_TYPE start_time, current_time;
	if (GC_dont_gc) return FALSE;
	if (GC_incremental && GC_collection_in_progress()) {
	if (GC_print_stats) {
	GC_log_printf(
	"GC_try_to_collect_inner: finishing collection in progress\n");
	}
	/* Just finish collection already in progress. */
	while(GC_collection_in_progress()) {
	if (stop_func()) return(FALSE);
	GC_collect_a_little_inner(1);
	}
	}
	if (stop_func == GC_never_stop_func) GC_notify_full_gc();
	if (GC_print_stats) {
	GET_TIME(start_time);
	GC_log_printf(
	"Initiating full world-stop collection %lu after %ld allocd bytes\n",
	(unsigned long)GC_gc_no+1, (long)GC_bytes_allocd);
	}
	GC_promote_black_lists();
	/* Make sure all blocks have been reclaimed, so sweep routines */
	/* don't see cleared mark bits. */
	/* If we're guaranteed to finish, then this is unnecessary. */
	/* In the find_leak case, we have to finish to guarantee that */
	/* previously unmarked objects are not reported as leaks. */
	# ifdef PARALLEL_MARK
	GC_wait_for_reclaim();
	# endif
	if ((GC_find_leak \|\| stop_func != GC_never_stop_func)
	&& !GC_reclaim_all(stop_func, FALSE)) {
	/* Aborted. So far everything is still consistent. */
	return(FALSE);
	}
	GC_invalidate_mark_state(); /* Flush mark stack. */
	GC_clear_marks();
	# ifdef SAVE_CALL_CHAIN
	GC_save_callers(GC_last_stack);
	# endif
	GC_is_full_gc = TRUE;
	if (!GC_stopped_mark(stop_func)) {
	if (!GC_incremental) {
	/* We're partially done and have no way to complete or use */
	/* current work. Reestablish invariants as cheaply as */
	/* possible. */
	GC_invalidate_mark_state();
	GC_unpromote_black_lists();
	} /* else we claim the world is already still consistent. We'll */
	/* finish incrementally. */
	return(FALSE);
	}
	GC_finish_collection();
	if (GC_print_stats) {
	GET_TIME(current_time);
	GC_log_printf("Complete collection took %lu msecs\n",
	MS_TIME_DIFF(current_time,start_time));
	}
	return(TRUE);
	}



	/*
	* Perform n units of garbage collection work. A unit is intended to touch
	* roughly GC_RATE pages. Every once in a while, we do more than that.
	* This needs to be a fairly large number with our current incremental
	* GC strategy, since otherwise we allocate too much during GC, and the
	* cleanup gets expensive.
	*/
	# define GC_RATE 10
	# define MAX_PRIOR_ATTEMPTS 1
	/* Maximum number of prior attempts at world stop marking */
	/* A value of 1 means that we finish the second time, no matter */
	/* how long it takes. Doesn't count the initial root scan */
	/* for a full GC. */

	int GC_deficit = 0; /* The number of extra calls to GC_mark_some */
	/* that we have made. */

	void GC_collect_a_little_inner(int n)
	{
	int i;

	if (GC_dont_gc) return;
	if (GC_incremental && GC_collection_in_progress()) {
	for (i = GC_deficit; i < GC_RATE*n; i++) {
	if (GC_mark_some((ptr_t)0)) {
	/* Need to finish a collection */
	# ifdef SAVE_CALL_CHAIN
	GC_save_callers(GC_last_stack);
	# endif
	# ifdef PARALLEL_MARK
	GC_wait_for_reclaim();
	# endif
	if (GC_n_attempts < MAX_PRIOR_ATTEMPTS
	&& GC_time_limit != GC_TIME_UNLIMITED) {
	GET_TIME(GC_start_time);
	if (!GC_stopped_mark(GC_timeout_stop_func)) {
	GC_n_attempts++;
	break;
	}
	} else {
	(void)GC_stopped_mark(GC_never_stop_func);
	}
	GC_finish_collection();
	break;
	}
	}
	if (GC_deficit > 0) GC_deficit -= GC_RATE*n;
	if (GC_deficit < 0) GC_deficit = 0;
	} else {
	GC_maybe_gc();
	}
	}

	int GC_collect_a_little(void)
	{
	int result;
	DCL_LOCK_STATE;

	LOCK();
	GC_collect_a_little_inner(1);
	result = (int)GC_collection_in_progress();
	UNLOCK();
	if (!result && GC_debugging_started) GC_print_all_smashed();
	return(result);
	}

	/*
	* Assumes lock is held, signals are disabled.
	* We stop the world.
	* If stop_func() ever returns TRUE, we may fail and return FALSE.
	* Increment GC_gc_no if we succeed.
	*/
	GC_bool GC_stopped_mark(GC_stop_func stop_func)
	{
	unsigned i;
	int dummy;
	CLOCK_TYPE start_time, current_time;

	if (GC_print_stats)
	GET_TIME(start_time);

	# if defined(REGISTER_LIBRARIES_EARLY)
	GC_cond_register_dynamic_libraries();
	# endif
	STOP_WORLD();
	IF_THREADS(GC_world_stopped = TRUE);
	if (GC_print_stats) {
	GC_log_printf("--> Marking for collection %lu ",
	(unsigned long)GC_gc_no + 1);
	GC_log_printf("after %lu allocd bytes\n",
	(unsigned long) GC_bytes_allocd);
	}
	# ifdef MAKE_BACK_GRAPH
	if (GC_print_back_height) {
	GC_build_back_graph();
	}
	# endif

	/* Mark from all roots. */
	/* Minimize junk left in my registers and on the stack */
	GC_clear_a_few_frames();
	GC_noop(0,0,0,0,0,0);
	GC_initiate_gc();
	for(i = 0;;i++) {
	if ((*stop_func)()) {
	if (GC_print_stats) {
	GC_log_printf("Abandoned stopped marking after ");
	GC_log_printf("%u iterations\n", i);
	}
	GC_deficit = i; /* Give the mutator a chance. */
	IF_THREADS(GC_world_stopped = FALSE);
	START_WORLD();
	return(FALSE);
	}
	if (GC_mark_some((ptr_t)(&dummy))) break;
	}

	GC_gc_no++;
	if (GC_print_stats) {
	GC_log_printf("Collection %lu reclaimed %ld bytes",
	(unsigned long)GC_gc_no - 1,
	(long)GC_bytes_found);
	GC_log_printf(" ---> heapsize = %lu bytes\n",
	(unsigned long) GC_heapsize);
	/* Printf arguments may be pushed in funny places. Clear the */
	/* space. */
	GC_log_printf("");
	}

	/* Check all debugged objects for consistency */
	if (GC_debugging_started) {
	(*GC_check_heap)();
	}

	IF_THREADS(GC_world_stopped = FALSE);
	START_WORLD();
	if (GC_print_stats) {
	GET_TIME(current_time);
	GC_log_printf("World-stopped marking took %lu msecs\n",
	MS_TIME_DIFF(current_time,start_time));
	}
	return(TRUE);
	}

	/* Set all mark bits for the free list whose first entry is q */
	void GC_set_fl_marks(ptr_t q)
	{
	ptr_t p;
	struct hblk * h, * last_h = 0;
	hdr hhdr; / gcc "might be uninitialized" warning is bogus. */
	IF_PER_OBJ(size_t sz;)
	unsigned bit_no;

	for (p = q; p != 0; p = obj_link(p)){
	h = HBLKPTR(p);
	if (h != last_h) {
	last_h = h;
	hhdr = HDR(h);
	IF_PER_OBJ(sz = hhdr->hb_sz;)
	}
	bit_no = MARK_BIT_NO((ptr_t)p - (ptr_t)h, sz);
	if (!mark_bit_from_hdr(hhdr, bit_no)) {
	set_mark_bit_from_hdr(hhdr, bit_no);
	++hhdr -> hb_n_marks;
	}
	}
	}

	#ifdef GC_ASSERTIONS
	/* Check that all mark bits for the free list whose first entry is q */
	/* are set. */
	void GC_check_fl_marks(ptr_t q)
	{
	ptr_t p;

	for (p = q; p != 0; p = obj_link(p)){
	if (!GC_is_marked(p)) {
	GC_err_printf("Unmarked object %p on list %p\n", p, q);
	ABORT("Unmarked local free list entry.");
	}
	}
	}
	#endif

	/* Clear all mark bits for the free list whose first entry is q */
	/* Decrement GC_bytes_found by number of bytes on free list. */
	void GC_clear_fl_marks(ptr_t q)
	{
	ptr_t p;
	struct hblk * h, * last_h = 0;
	hdr *hhdr;
	size_t sz;
	unsigned bit_no;

	for (p = q; p != 0; p = obj_link(p)){
	h = HBLKPTR(p);
	if (h != last_h) {
	last_h = h;
	hhdr = HDR(h);
	sz = hhdr->hb_sz; /* Normally set only once. */
	}
	bit_no = MARK_BIT_NO((ptr_t)p - (ptr_t)h, sz);
	if (mark_bit_from_hdr(hhdr, bit_no)) {
	size_t n_marks = hhdr -> hb_n_marks - 1;
	clear_mark_bit_from_hdr(hhdr, bit_no);
	# ifdef PARALLEL_MARK
	/* Appr. count, don't decrement to zero! */
	if (0 != n_marks) {
	hhdr -> hb_n_marks = n_marks;
	}
	# else
	hhdr -> hb_n_marks = n_marks;
	# endif
	}
	GC_bytes_found -= sz;
	}
	}

	#if defined(GC_ASSERTIONS) && defined(THREADS) && defined(THREAD_LOCAL_ALLOC)
	extern void GC_check_tls(void);
	#endif

	/* Finish up a collection. Assumes lock is held, signals are disabled, */
	/* but the world is otherwise running. */
	void GC_finish_collection()
	{
	CLOCK_TYPE start_time;
	CLOCK_TYPE finalize_time;
	CLOCK_TYPE done_time;

	# if defined(GC_ASSERTIONS) && defined(THREADS) \
	&& defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
	/* Check that we marked some of our own data. */
	/* FIXME: Add more checks. */
	GC_check_tls();
	# endif

	if (GC_print_stats)
	GET_TIME(start_time);

	GC_bytes_found = 0;
	# if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
	if (getenv("GC_PRINT_ADDRESS_MAP") != 0) {
	GC_print_address_map();
	}
	# endif
	COND_DUMP;
	if (GC_find_leak) {
	/* Mark all objects on the free list. All objects should be */
	/* marked when we're done. */
	{
	word size; /* current object size */
	unsigned kind;
	ptr_t q;

	for (kind = 0; kind < GC_n_kinds; kind++) {
	for (size = 1; size <= MAXOBJGRANULES; size++) {
	q = GC_obj_kinds[kind].ok_freelist[size];
	if (q != 0) GC_set_fl_marks(q);
	}
	}
	}
	GC_start_reclaim(TRUE);
	/* The above just checks; it doesn't really reclaim anything. */
	}

	GC_finalize();
	# ifdef STUBBORN_ALLOC
	GC_clean_changing_list();
	# endif

	if (GC_print_stats)
	GET_TIME(finalize_time);

	if (GC_print_back_height) {
	# ifdef MAKE_BACK_GRAPH
	GC_traverse_back_graph();
	# else
	# ifndef SMALL_CONFIG
	GC_err_printf("Back height not available: "
	"Rebuild collector with -DMAKE_BACK_GRAPH\n");
	# endif
	# endif
	}

	/* Clear free list mark bits, in case they got accidentally marked */
	/* (or GC_find_leak is set and they were intentionally marked). */
	/* Also subtract memory remaining from GC_bytes_found count. */
	/* Note that composite objects on free list are cleared. */
	/* Thus accidentally marking a free list is not a problem; only */
	/* objects on the list itself will be marked, and that's fixed here. */
	{
	word size; /* current object size */
	ptr_t q; /* pointer to current object */
	unsigned kind;

	for (kind = 0; kind < GC_n_kinds; kind++) {
	for (size = 1; size <= MAXOBJGRANULES; size++) {
	q = GC_obj_kinds[kind].ok_freelist[size];
	if (q != 0) GC_clear_fl_marks(q);
	}
	}
	}


	if (GC_print_stats == VERBOSE)
	GC_log_printf("Bytes recovered before sweep - f.l. count = %ld\n",
	(long)GC_bytes_found);

	/* Reconstruct free lists to contain everything not marked */
	GC_start_reclaim(FALSE);
	if (GC_print_stats) {
	GC_log_printf("Heap contains %lu pointer-containing "
	"+ %lu pointer-free reachable bytes\n",
	(unsigned long)GC_composite_in_use,
	(unsigned long)GC_atomic_in_use);
	}
	if (GC_is_full_gc) {
	GC_used_heap_size_after_full = USED_HEAP_SIZE;
	GC_need_full_gc = FALSE;
	} else {
	GC_need_full_gc =
	USED_HEAP_SIZE - GC_used_heap_size_after_full
	> min_bytes_allocd();
	}

	if (GC_print_stats == VERBOSE) {
	GC_log_printf(
	"Immediately reclaimed %ld bytes in heap of size %lu bytes",
	(long)GC_bytes_found,
	(unsigned long)GC_heapsize);
	# ifdef USE_MUNMAP
	GC_log_printf("(%lu unmapped)", (unsigned long)GC_unmapped_bytes);
	# endif
	GC_log_printf("\n");
	}

	/* Reset or increment counters for next cycle */
	GC_n_attempts = 0;
	GC_is_full_gc = FALSE;
	GC_bytes_allocd_before_gc += GC_bytes_allocd;
	GC_non_gc_bytes_at_gc = GC_non_gc_bytes;
	GC_bytes_allocd = 0;
	GC_bytes_freed = 0;
	GC_finalizer_bytes_freed = 0;

	# ifdef USE_MUNMAP
	GC_unmap_old();
	# endif
	if (GC_print_stats) {
	GET_TIME(done_time);
	GC_log_printf("Finalize + initiate sweep took %lu + %lu msecs\n",
	MS_TIME_DIFF(finalize_time,start_time),
	MS_TIME_DIFF(done_time,finalize_time));
	}
	}

	/* Externally callable routine to invoke full, stop-world collection */
	int GC_try_to_collect(GC_stop_func stop_func)
	{
	int result;
	DCL_LOCK_STATE;

	if (!GC_is_initialized) GC_init();
	if (GC_debugging_started) GC_print_all_smashed();
	GC_INVOKE_FINALIZERS();
	LOCK();
	ENTER_GC();
	if (!GC_is_initialized) GC_init_inner();
	/* Minimize junk left in my registers */
	GC_noop(0,0,0,0,0,0);
	result = (int)GC_try_to_collect_inner(stop_func);
	EXIT_GC();
	UNLOCK();
	if(result) {
	if (GC_debugging_started) GC_print_all_smashed();
	GC_INVOKE_FINALIZERS();
	}
	return(result);
	}

	void GC_gcollect(void)
	{
	(void)GC_try_to_collect(GC_never_stop_func);
	if (GC_have_errors) GC_print_all_errors();
	}

	word GC_n_heap_sects = 0; /* Number of sections currently in heap. */

	/*
	* Use the chunk of memory starting at p of size bytes as part of the heap.
	* Assumes p is HBLKSIZE aligned, and bytes is a multiple of HBLKSIZE.
	*/
	void GC_add_to_heap(struct hblk *p, size_t bytes)
	{
	hdr * phdr;

	if (GC_n_heap_sects >= MAX_HEAP_SECTS) {
	ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS");
	}
	phdr = GC_install_header(p);
	if (0 == phdr) {
	/* This is extremely unlikely. Can't add it. This will */
	/* almost certainly result in a 0 return from the allocator, */
	/* which is entirely appropriate. */
	return;
	}
	GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p;
	GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes;
	GC_n_heap_sects++;
	phdr -> hb_sz = bytes;
	phdr -> hb_flags = 0;
	GC_freehblk(p);
	GC_heapsize += bytes;
	if ((ptr_t)p <= (ptr_t)GC_least_plausible_heap_addr
	\|\| GC_least_plausible_heap_addr == 0) {
	GC_least_plausible_heap_addr = (void *)((ptr_t)p - sizeof(word));
	/* Making it a little smaller than necessary prevents */
	/* us from getting a false hit from the variable */
	/* itself. There's some unintentional reflection */
	/* here. */
	}
	if ((ptr_t)p + bytes >= (ptr_t)GC_greatest_plausible_heap_addr) {
	GC_greatest_plausible_heap_addr = (void *)((ptr_t)p + bytes);
	}
	}

	# if !defined(NO_DEBUGGING)
	void GC_print_heap_sects(void)
	{
	unsigned i;

	GC_printf("Total heap size: %lu\n", (unsigned long) GC_heapsize);
	for (i = 0; i < GC_n_heap_sects; i++) {
	ptr_t start = GC_heap_sects[i].hs_start;
	size_t len = GC_heap_sects[i].hs_bytes;
	struct hblk *h;
	unsigned nbl = 0;

	GC_printf("Section %d from %p to %p ", i,
	start, start + len);
	for (h = (struct hblk )start; h < (struct hblk )(start + len); h++) {
	if (GC_is_black_listed(h, HBLKSIZE)) nbl++;
	}
	GC_printf("%lu/%lu blacklisted\n", (unsigned long)nbl,
	(unsigned long)(len/HBLKSIZE));
	}
	}
	# endif

	void * GC_least_plausible_heap_addr = (void *)ONES;
	void * GC_greatest_plausible_heap_addr = 0;

	static INLINE ptr_t GC_max(ptr_t x, ptr_t y)
	{
	return(x > y? x : y);
	}

	static INLINE ptr_t GC_min(ptr_t x, ptr_t y)
	{
	return(x < y? x : y);
	}

	void GC_set_max_heap_size(GC_word n)
	{
	GC_max_heapsize = n;
	}

	GC_word GC_max_retries = 0;

	/*
	* this explicitly increases the size of the heap. It is used
	* internally, but may also be invoked from GC_expand_hp by the user.
	* The argument is in units of HBLKSIZE.
	* Tiny values of n are rounded up.
	* Returns FALSE on failure.
	*/
	GC_bool GC_expand_hp_inner(word n)
	{
	word bytes;
	struct hblk * space;
	word expansion_slop; /* Number of bytes by which we expect the */
	/* heap to expand soon. */

	if (n < MINHINCR) n = MINHINCR;
	bytes = n * HBLKSIZE;
	/* Make sure bytes is a multiple of GC_page_size */
	{
	word mask = GC_page_size - 1;
	bytes += mask;
	bytes &= ~mask;
	}

	if (GC_max_heapsize != 0 && GC_heapsize + bytes > GC_max_heapsize) {
	/* Exceeded self-imposed limit */
	return(FALSE);
	}
	space = GET_MEM(bytes);
	if( space == 0 ) {
	if (GC_print_stats) {
	GC_log_printf("Failed to expand heap by %ld bytes\n",
	(unsigned long)bytes);
	}
	return(FALSE);
	}
	if (GC_print_stats) {
	GC_log_printf("Increasing heap size by %lu after %lu allocated bytes\n",
	(unsigned long)bytes,
	(unsigned long)GC_bytes_allocd);
	}
	expansion_slop = min_bytes_allocd() + 4MAXHINCRHBLKSIZE;
	if ((GC_last_heap_addr == 0 && !((word)space & SIGNB))
	\|\| (GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space)) {
	/* Assume the heap is growing up */
	GC_greatest_plausible_heap_addr =
	(void *)GC_max((ptr_t)GC_greatest_plausible_heap_addr,
	(ptr_t)space + bytes + expansion_slop);
	} else {
	/* Heap is growing down */
	GC_least_plausible_heap_addr =
	(void *)GC_min((ptr_t)GC_least_plausible_heap_addr,
	(ptr_t)space - expansion_slop);
	}
	# if defined(LARGE_CONFIG)
	if (((ptr_t)GC_greatest_plausible_heap_addr <= (ptr_t)space + bytes
	\|\| (ptr_t)GC_least_plausible_heap_addr >= (ptr_t)space)
	&& GC_heapsize > 0) {
	/* GC_add_to_heap will fix this, but ... */
	WARN("Too close to address space limit: blacklisting ineffective\n", 0);
	}
	# endif
	GC_prev_heap_addr = GC_last_heap_addr;
	GC_last_heap_addr = (ptr_t)space;
	GC_add_to_heap(space, bytes);
	/* Force GC before we are likely to allocate past expansion_slop */
	GC_collect_at_heapsize =
	GC_heapsize + expansion_slop - 2MAXHINCRHBLKSIZE;
	# if defined(LARGE_CONFIG)
	if (GC_collect_at_heapsize < GC_heapsize /* wrapped */)
	GC_collect_at_heapsize = (word)(-1);
	# endif
	return(TRUE);
	}

	/* Really returns a bool, but it's externally visible, so that's clumsy. */
	/* Arguments is in bytes. */
	int GC_expand_hp(size_t bytes)
	{
	int result;
	DCL_LOCK_STATE;

	LOCK();
	if (!GC_is_initialized) GC_init_inner();
	result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes));
	if (result) GC_requested_heapsize += bytes;
	UNLOCK();
	return(result);
	}

	unsigned GC_fail_count = 0;
	/* How many consecutive GC/expansion failures? */
	/* Reset by GC_allochblk. */

	GC_bool GC_collect_or_expand(word needed_blocks, GC_bool ignore_off_page)
	{
	if (!GC_incremental && !GC_dont_gc &&
	((GC_dont_expand && GC_bytes_allocd > 0) \|\| GC_should_collect())) {
	GC_gcollect_inner();
	} else {
	word blocks_to_get = GC_heapsize/(HBLKSIZE*GC_free_space_divisor)
	+ needed_blocks;

	if (blocks_to_get > MAXHINCR) {
	word slop;

	/* Get the minimum required to make it likely that we */
	/* can satisfy the current request in the presence of black- */
	/* listing. This will probably be more than MAXHINCR. */
	if (ignore_off_page) {
	slop = 4;
	} else {
	slop = 2*divHBLKSZ(BL_LIMIT);
	if (slop > needed_blocks) slop = needed_blocks;
	}
	if (needed_blocks + slop > MAXHINCR) {
	blocks_to_get = needed_blocks + slop;
	} else {
	blocks_to_get = MAXHINCR;
	}
	}
	if (!GC_expand_hp_inner(blocks_to_get)
	&& !GC_expand_hp_inner(needed_blocks)) {
	if (GC_fail_count++ < GC_max_retries) {
	WARN("Out of Memory! Trying to continue ...\n", 0);
	GC_gcollect_inner();
	} else {
	# if !defined(AMIGA) \|\| !defined(GC_AMIGA_FASTALLOC)
	WARN("Out of Memory! Returning NIL!\n", 0);
	# endif
	return(FALSE);
	}
	} else {
	if (GC_fail_count && GC_print_stats) {
	GC_printf("Memory available again ...\n");
	}
	}
	}
	return(TRUE);
	}

	/*
	* Make sure the object free list for size gran (in granules) is not empty.
	* Return a pointer to the first object on the free list.
	* The object MUST BE REMOVED FROM THE FREE LIST BY THE CALLER.
	* Assumes we hold the allocator lock and signals are disabled.
	*
	*/
	ptr_t GC_allocobj(size_t gran, int kind)
	{
	void ** flh = &(GC_obj_kinds[kind].ok_freelist[gran]);
	GC_bool tried_minor = FALSE;

	if (gran == 0) return(0);

	while (*flh == 0) {
	ENTER_GC();
	/* Do our share of marking work */
	if(TRUE_INCREMENTAL) GC_collect_a_little_inner(1);
	/* Sweep blocks for objects of this size */
	GC_continue_reclaim(gran, kind);
	EXIT_GC();
	if (*flh == 0) {
	GC_new_hblk(gran, kind);
	}
	if (*flh == 0) {
	ENTER_GC();
	if (GC_incremental && GC_time_limit == GC_TIME_UNLIMITED
	&& ! tried_minor ) {
	GC_collect_a_little_inner(1);
	tried_minor = TRUE;
	} else {
	if (!GC_collect_or_expand((word)1,FALSE)) {
	EXIT_GC();
	return(0);
	}
	}
	EXIT_GC();
	}
	}
	/* Successful allocation; reset failure count. */
	GC_fail_count = 0;

	return(*flh);
	}