* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers

/*
* 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.
* Copyright (c) 2008-2021 Ivan Maidanski
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*
*/

#include "private/gc_priv.h"

#include <stdio.h>
#if !defined(MACOS) && !defined(MSWINCE)
# include <signal.h>
# if !defined(GC_NO_TYPES) && !defined(SN_TARGET_PSP2) \
&& !defined(__CC_ARM)
# include <sys/types.h>
# endif
#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 lb (and NORMAL kind) as follows
* (GC_generic_malloc_inner is a wrapper over GC_allocobj which also
* fills in GC_size_map if needed):
*
* lg = GC_size_map[lb];
* op = GC_objfreelist[lg];
* if (NULL == op) {
* op = GC_generic_malloc_inner(lb, NORMAL);
* } else {
* GC_objfreelist[lg] = obj_link(op);
* GC_bytes_allocd += GRANULES_TO_BYTES((word)lg);
* }
*
* 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 NO_CLOCK
static unsigned long full_gc_total_time = 0; /* in ms, may wrap */
static unsigned full_gc_total_ns_frac = 0; /* fraction of 1 ms */
static GC_bool measure_performance = FALSE;
/* Do performance measurements if set to true (e.g., */
/* accumulation of the total time of full collections). */

GC_API void GC_CALL GC_start_performance_measurement(void)
{
measure_performance = TRUE;
}

GC_API unsigned long GC_CALL GC_get_full_gc_total_time(void)
{
return full_gc_total_time;
}
#endif /* !NO_CLOCK */

#ifndef GC_DISABLE_INCREMENTAL
GC_INNER GC_bool GC_incremental = FALSE; /* By default, stop the world. */
STATIC GC_bool GC_should_start_incremental_collection = FALSE;
#endif

GC_API int GC_CALL GC_is_incremental_mode(void)
{
return (int)GC_incremental;
}

#ifdef THREADS
int GC_parallel = FALSE; /* By default, parallel GC is off. */
#endif

#if defined(GC_FULL_FREQ) && !defined(CPPCHECK)
int GC_full_freq = GC_FULL_FREQ;
#else
int GC_full_freq = 19; /* Every 20th collection is a full */
/* collection, whether we need it */
/* or not. */
#endif

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

#ifdef THREAD_LOCAL_ALLOC
GC_INNER GC_bool GC_world_stopped = FALSE;
#endif

STATIC GC_bool GC_disable_automatic_collection = FALSE;

GC_API void GC_CALL GC_set_disable_automatic_collection(int value)
{
DCL_LOCK_STATE;

LOCK();
GC_disable_automatic_collection = (GC_bool)value;
UNLOCK();
}

GC_API int GC_CALL GC_get_disable_automatic_collection(void)
{
int value;
DCL_LOCK_STATE;

LOCK();
value = (int)GC_disable_automatic_collection;
UNLOCK();
return value;
}

STATIC word GC_used_heap_size_after_full = 0;

/* GC_copyright symbol is externally visible. */
EXTERN_C_BEGIN
extern const char * const GC_copyright[];
EXTERN_C_END
const char * const 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) 1999-2009 by Hewlett-Packard Company. All rights reserved. ",
"Copyright (c) 2008-2021 Ivan Maidanski ",
"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." };

/* Version macros are now defined in gc_version.h, which is included by */
/* gc.h, which is included by gc_priv.h. */
#ifndef GC_NO_VERSION_VAR
EXTERN_C_BEGIN
extern const unsigned GC_version;
EXTERN_C_END
const unsigned GC_version = ((GC_VERSION_MAJOR << 16) |
(GC_VERSION_MINOR << 8) | GC_VERSION_MICRO);
#endif

GC_API unsigned GC_CALL GC_get_version(void)
{
return (GC_VERSION_MAJOR << 16) | (GC_VERSION_MINOR << 8) |
GC_VERSION_MICRO;
}

/* some more variables */

#ifdef GC_DONT_EXPAND
int GC_dont_expand = TRUE;
#else
int GC_dont_expand = FALSE;
#endif

#if defined(GC_FREE_SPACE_DIVISOR) && !defined(CPPCHECK)
word GC_free_space_divisor = GC_FREE_SPACE_DIVISOR; /* must be > 0 */
#else
word GC_free_space_divisor = 3;
#endif

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

#if defined(GC_TIME_LIMIT) && !defined(CPPCHECK)
unsigned long GC_time_limit = GC_TIME_LIMIT;
/* We try to keep pause times from exceeding */
/* this by much. In milliseconds. */
#elif defined(PARALLEL_MARK)
unsigned long GC_time_limit = GC_TIME_UNLIMITED;
/* The parallel marker cannot be interrupted for */
/* now, so the time limit is absent by default. */
#else
unsigned long GC_time_limit = 50;
#endif

#ifndef NO_CLOCK
STATIC unsigned long GC_time_lim_nsec = 0;
/* The nanoseconds add-on to GC_time_limit */
/* value. Not updated by GC_set_time_limit(). */
/* Ignored if the value of GC_time_limit is */
/* GC_TIME_UNLIMITED. */

# define TV_NSEC_LIMIT (1000UL * 1000) /* amount of nanoseconds in 1 ms */

GC_API void GC_CALL GC_set_time_limit_tv(struct GC_timeval_s tv)
{
GC_ASSERT(tv.tv_ms <= GC_TIME_UNLIMITED);
GC_ASSERT(tv.tv_nsec < TV_NSEC_LIMIT);
GC_time_limit = tv.tv_ms;
GC_time_lim_nsec = tv.tv_nsec;
}

GC_API struct GC_timeval_s GC_CALL GC_get_time_limit_tv(void)
{
struct GC_timeval_s tv;

tv.tv_ms = GC_time_limit;
tv.tv_nsec = GC_time_lim_nsec;
return tv;
}

STATIC CLOCK_TYPE GC_start_time = CLOCK_TYPE_INITIALIZER;
/* Time at which we stopped world. */
/* used only in GC_timeout_stop_func. */
#endif /* !NO_CLOCK */

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

STATIC GC_stop_func GC_default_stop_func = GC_never_stop_func;
/* accessed holding the lock. */

GC_API void GC_CALL GC_set_stop_func(GC_stop_func stop_func)
{
DCL_LOCK_STATE;
GC_ASSERT(NONNULL_ARG_NOT_NULL(stop_func));
LOCK();
GC_default_stop_func = stop_func;
UNLOCK();
}

GC_API GC_stop_func GC_CALL GC_get_stop_func(void)
{
GC_stop_func stop_func;
DCL_LOCK_STATE;
LOCK();
stop_func = GC_default_stop_func;
UNLOCK();
return stop_func;
}

#if defined(GC_DISABLE_INCREMENTAL) || defined(NO_CLOCK)
# define GC_timeout_stop_func GC_default_stop_func
#else
STATIC int GC_CALLBACK GC_timeout_stop_func (void)
{
CLOCK_TYPE current_time;
static unsigned count = 0;
unsigned long time_diff, nsec_diff;

if ((*GC_default_stop_func)())
return(1);

if ((count++ & 3) != 0) return(0);
GET_TIME(current_time);
time_diff = MS_TIME_DIFF(current_time,GC_start_time);
nsec_diff = NS_FRAC_TIME_DIFF(current_time, GC_start_time);
# if defined(CPPCHECK)
GC_noop1((word)&nsec_diff);
# endif
if (time_diff >= GC_time_limit
&& (time_diff > GC_time_limit || nsec_diff >= GC_time_lim_nsec)) {
GC_COND_LOG_PRINTF("Abandoning stopped marking after %lu ms %lu ns"
" (attempt %d)\n",
time_diff, nsec_diff, GC_n_attempts);
return 1;
}
return(0);
}
#endif /* !GC_DISABLE_INCREMENTAL */

#ifdef THREADS
GC_INNER word GC_total_stacksize = 0; /* updated on every push_all_stacks */
#endif

static size_t min_bytes_allocd_minimum = 1;
/* The lowest value returned by min_bytes_allocd(). */

GC_API void GC_CALL GC_set_min_bytes_allocd(size_t value)
{
GC_ASSERT(value > 0);
min_bytes_allocd_minimum = value;
}

GC_API size_t GC_CALL GC_get_min_bytes_allocd(void)
{
return min_bytes_allocd_minimum;
}

/* Return the minimum number of bytes that must be allocated between */
/* collections to amortize the collection cost. Should be non-zero. */
static word min_bytes_allocd(void)
{
word result;
word stack_size;
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. */

# ifdef THREADS
if (GC_need_to_lock) {
/* We are multi-threaded... */
stack_size = GC_total_stacksize;
/* For now, we just use the value computed during the latest GC. */
# ifdef DEBUG_THREADS
GC_log_printf("Total stacks size: %lu\n",
(unsigned long)stack_size);
# endif
} else
# endif
/* else*/ {
# ifdef STACK_NOT_SCANNED
stack_size = 0;
# elif defined(STACK_GROWS_UP)
stack_size = GC_approx_sp() - GC_stackbottom;
# else
stack_size = GC_stackbottom - GC_approx_sp();
# endif
}

total_root_size = 2 * stack_size + GC_root_size;
scan_size = 2 * GC_composite_in_use + GC_atomic_in_use / 4
+ total_root_size;
result = scan_size / GC_free_space_divisor;
if (GC_incremental) {
result /= 2;
}
return result > min_bytes_allocd_minimum
? result : min_bytes_allocd_minimum;
}

STATIC word GC_non_gc_bytes_at_gc = 0;
/* Number of explicitly managed bytes of storage */
/* at last collection. */

/* Return the number of bytes allocated, adjusted for explicit storage */
/* management, etc.. This number is used in deciding when to trigger */
/* collections. */
STATIC 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_dropped
- (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 garbage 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. */
STATIC void GC_clear_a_few_frames(void)
{
# ifndef CLEAR_NWORDS
# define CLEAR_NWORDS 64
# endif
volatile word frames[CLEAR_NWORDS];
BZERO((word *)frames, CLEAR_NWORDS * sizeof(word));
}

/* Heap size at which we need a collection to avoid expanding past */
/* limits used by blacklisting. */
STATIC word GC_collect_at_heapsize = GC_WORD_MAX;

GC_API void GC_CALL GC_start_incremental_collection(void)
{
# ifndef GC_DISABLE_INCREMENTAL
DCL_LOCK_STATE;

if (!GC_incremental) return;
LOCK();
GC_should_start_incremental_collection = TRUE;
if (!GC_dont_gc) {
ENTER_GC();
GC_collect_a_little_inner(1);
EXIT_GC();
}
UNLOCK();
# endif
}

/* Have we allocated enough to amortize a collection? */
GC_INNER GC_bool GC_should_collect(void)
{
static word last_min_bytes_allocd;
static word last_gc_no;

GC_ASSERT(I_HOLD_LOCK());
if (last_gc_no != GC_gc_no) {
last_min_bytes_allocd = min_bytes_allocd();
last_gc_no = GC_gc_no;
}
# ifndef GC_DISABLE_INCREMENTAL
if (GC_should_start_incremental_collection) {
GC_should_start_incremental_collection = FALSE;
return TRUE;
}
# endif
if (GC_disable_automatic_collection) return FALSE;

return(GC_adj_bytes_allocd() >= last_min_bytes_allocd
|| GC_heapsize >= GC_collect_at_heapsize);
}

/* STATIC */ GC_start_callback_proc GC_start_call_back = 0;
/* Called at start of full collections. */
/* Not called if 0. Called with the allocation */
/* lock held. Not used by GC itself. */

GC_API void GC_CALL GC_set_start_callback(GC_start_callback_proc fn)
{
DCL_LOCK_STATE;
LOCK();
GC_start_call_back = fn;
UNLOCK();
}

GC_API GC_start_callback_proc GC_CALL GC_get_start_callback(void)
{
GC_start_callback_proc fn;
DCL_LOCK_STATE;
LOCK();
fn = GC_start_call_back;
UNLOCK();
return fn;
}

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

STATIC GC_bool GC_is_full_gc = FALSE;

STATIC GC_bool GC_stopped_mark(GC_stop_func stop_func);
STATIC void GC_finish_collection(void);

/*
* Initiate a garbage collection if appropriate.
* Choose judiciously
* between partial, full, and stop-world collections.
*/
STATIC void GC_maybe_gc(void)
{
GC_ASSERT(I_HOLD_LOCK());
ASSERT_CANCEL_DISABLED();
if (GC_should_collect()) {
static int n_partial_gcs = 0;

if (!GC_incremental) {
/* TODO: If possible, GC_default_stop_func should be used here */
GC_try_to_collect_inner(GC_never_stop_func);
n_partial_gcs = 0;
return;
} else {
# ifdef PARALLEL_MARK
if (GC_parallel)
GC_wait_for_reclaim();
# endif
if (GC_need_full_gc || n_partial_gcs >= GC_full_freq) {
GC_COND_LOG_PRINTF(
"***>Full mark for collection #%lu after %lu allocd bytes\n",
(unsigned long)GC_gc_no + 1, (unsigned long)GC_bytes_allocd);
GC_promote_black_lists();
(void)GC_reclaim_all((GC_stop_func)0, TRUE);
GC_notify_full_gc();
GC_clear_marks();
n_partial_gcs = 0;
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
/* TODO: If possible, GC_default_stop_func should be */
/* used instead of GC_never_stop_func here. */
if (GC_stopped_mark(GC_time_limit == GC_TIME_UNLIMITED?
GC_never_stop_func : GC_timeout_stop_func)) {
SAVE_CALLERS_TO_LAST_STACK();
GC_finish_collection();
} else {
if (!GC_is_full_gc) {
/* Count this as the first attempt */
GC_n_attempts++;
}
}
}
}

STATIC GC_on_collection_event_proc GC_on_collection_event = 0;

GC_API void GC_CALL GC_set_on_collection_event(GC_on_collection_event_proc fn)
{
/* fn may be 0 (means no event notifier). */
DCL_LOCK_STATE;
LOCK();
GC_on_collection_event = fn;
UNLOCK();
}

GC_API GC_on_collection_event_proc GC_CALL GC_get_on_collection_event(void)
{
GC_on_collection_event_proc fn;
DCL_LOCK_STATE;
LOCK();
fn = GC_on_collection_event;
UNLOCK();
return fn;
}

/* Stop the world garbage collection. 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_INNER GC_bool GC_try_to_collect_inner(GC_stop_func stop_func)
{
# ifndef NO_CLOCK
CLOCK_TYPE start_time = CLOCK_TYPE_INITIALIZER;
GC_bool start_time_valid;
# endif

ASSERT_CANCEL_DISABLED();
GC_ASSERT(I_HOLD_LOCK());
if (GC_dont_gc || (*stop_func)()) return FALSE;
if (GC_on_collection_event)
GC_on_collection_event(GC_EVENT_START);
if (GC_incremental && GC_collection_in_progress()) {
GC_COND_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)()) {
/* TODO: Notify GC_EVENT_ABANDON */
return(FALSE);
}
ENTER_GC();
GC_collect_a_little_inner(1);
EXIT_GC();
}
}
GC_notify_full_gc();
# ifndef NO_CLOCK
start_time_valid = FALSE;
if ((GC_print_stats | (int)measure_performance) != 0) {
if (GC_print_stats)
GC_log_printf("Initiating full world-stop collection!\n");
start_time_valid = TRUE;
GET_TIME(start_time);
}
# endif
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
if (GC_parallel)
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. */
/* TODO: Notify GC_EVENT_ABANDON */
return(FALSE);
}
GC_invalidate_mark_state(); /* Flush mark stack. */
GC_clear_marks();
SAVE_CALLERS_TO_LAST_STACK();
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. */
/* TODO: Notify GC_EVENT_ABANDON */
return(FALSE);
}
GC_finish_collection();
# ifndef NO_CLOCK
if (start_time_valid) {
CLOCK_TYPE current_time;
unsigned long time_diff, ns_frac_diff;

GET_TIME(current_time);
time_diff = MS_TIME_DIFF(current_time, start_time);
ns_frac_diff = NS_FRAC_TIME_DIFF(current_time, start_time);
if (measure_performance) {
full_gc_total_time += time_diff; /* may wrap */
full_gc_total_ns_frac += (unsigned)ns_frac_diff;
if (full_gc_total_ns_frac >= 1000000U) {
/* Overflow of the nanoseconds part. */
full_gc_total_ns_frac -= 1000000U;
full_gc_total_time++;
}
}
if (GC_print_stats)
GC_log_printf("Complete collection took %lu ms %lu ns\n",
time_diff, ns_frac_diff);
}
# endif
if (GC_on_collection_event)
GC_on_collection_event(GC_EVENT_END);
return(TRUE);
}

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

/* The default value of GC_rate. */
#ifndef GC_RATE
# define GC_RATE 10
#endif

/* When GC_collect_a_little_inner() performs n units of GC work, a unit */
/* is intended to touch roughly GC_rate pages. (But, 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. */
STATIC int GC_rate = GC_RATE;

GC_API void GC_CALL GC_set_rate(int value)
{
GC_ASSERT(value > 0);
GC_rate = value;
}

GC_API int GC_CALL GC_get_rate(void)
{
return GC_rate;
}

/* The default maximum number of prior attempts at world stop marking. */
#ifndef MAX_PRIOR_ATTEMPTS
# define MAX_PRIOR_ATTEMPTS 1
#endif

/* The 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. Does not count the initial root scan for a full GC. */
static int max_prior_attempts = MAX_PRIOR_ATTEMPTS;

GC_API void GC_CALL GC_set_max_prior_attempts(int value)
{
GC_ASSERT(value >= 0);
max_prior_attempts = value;
}

GC_API int GC_CALL GC_get_max_prior_attempts(void)
{
return max_prior_attempts;
}

GC_INNER void GC_collect_a_little_inner(int n)
{
IF_CANCEL(int cancel_state;)

GC_ASSERT(I_HOLD_LOCK());
DISABLE_CANCEL(cancel_state);
if (GC_incremental && GC_collection_in_progress()) {
int i;
int max_deficit = GC_rate * n;

# ifdef PARALLEL_MARK
if (GC_time_limit != GC_TIME_UNLIMITED)
GC_parallel_mark_disabled = TRUE;
# endif
for (i = GC_deficit; i < max_deficit; i++) {
if (GC_mark_some(NULL))
break;
}
# ifdef PARALLEL_MARK
GC_parallel_mark_disabled = FALSE;
# endif

if (i < max_deficit && !GC_dont_gc) {
/* Need to finish a collection. */
SAVE_CALLERS_TO_LAST_STACK();
# ifdef PARALLEL_MARK
if (GC_parallel)
GC_wait_for_reclaim();
# endif
if (GC_n_attempts < max_prior_attempts
&& GC_time_limit != GC_TIME_UNLIMITED) {
# ifndef NO_CLOCK
GET_TIME(GC_start_time);
# endif
if (GC_stopped_mark(GC_timeout_stop_func)) {
GC_finish_collection();
} else {
GC_n_attempts++;
}
} else {
/* TODO: If possible, GC_default_stop_func should be */
/* used here. */
(void)GC_stopped_mark(GC_never_stop_func);
GC_finish_collection();
}
}
if (GC_deficit > 0) {
GC_deficit -= max_deficit;
if (GC_deficit < 0)
GC_deficit = 0;
}
} else if (!GC_dont_gc) {
GC_maybe_gc();
}
RESTORE_CANCEL(cancel_state);
}

GC_INNER void (*GC_check_heap)(void) = 0;
GC_INNER void (*GC_print_all_smashed)(void) = 0;

GC_API int GC_CALL GC_collect_a_little(void)
{
int result;
DCL_LOCK_STATE;

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

#ifndef NO_CLOCK
/* Variables for world-stop average delay time statistic computation. */
/* "divisor" is incremented every world-stop and halved when reached */
/* its maximum (or upon "total_time" overflow). */
static unsigned world_stopped_total_time = 0;
static unsigned world_stopped_total_divisor = 0;
# ifndef MAX_TOTAL_TIME_DIVISOR
/* We shall not use big values here (so "outdated" delay time */
/* values would have less impact on "average" delay time value than */
/* newer ones). */
# define MAX_TOTAL_TIME_DIVISOR 1000
# endif
#endif /* !NO_CLOCK */

#ifdef USE_MUNMAP
# define IF_USE_MUNMAP(x) x
# define COMMA_IF_USE_MUNMAP(x) /* comma */, x
#else
# define IF_USE_MUNMAP(x) /* empty */
# define COMMA_IF_USE_MUNMAP(x) /* empty */
#endif

/*
* We stop the world and mark from all roots.
* If stop_func() ever returns TRUE, we may fail and return FALSE.
* Increment GC_gc_no if we succeed.
*/
STATIC GC_bool GC_stopped_mark(GC_stop_func stop_func)
{
int i;
# ifndef NO_CLOCK
CLOCK_TYPE start_time = CLOCK_TYPE_INITIALIZER;
# endif

GC_ASSERT(I_HOLD_LOCK());
# if !defined(REDIRECT_MALLOC) && defined(USE_WINALLOC)
GC_add_current_malloc_heap();
# endif
# if defined(REGISTER_LIBRARIES_EARLY)
GC_cond_register_dynamic_libraries();
# endif

# ifndef NO_CLOCK
if (GC_PRINT_STATS_FLAG)
GET_TIME(start_time);
# endif

# if !defined(GC_NO_FINALIZATION) && !defined(GC_TOGGLE_REFS_NOT_NEEDED)
GC_process_togglerefs();
# endif
# ifdef THREADS
if (GC_on_collection_event)
GC_on_collection_event(GC_EVENT_PRE_STOP_WORLD);
# endif
STOP_WORLD();
# ifdef THREADS
if (GC_on_collection_event)
GC_on_collection_event(GC_EVENT_POST_STOP_WORLD);
# endif

# ifdef THREAD_LOCAL_ALLOC
GC_world_stopped = TRUE;
# endif
/* Output blank line for convenience here */
GC_COND_LOG_PRINTF(
"\n--> Marking for collection #%lu after %lu allocated bytes\n",
(unsigned long)GC_gc_no + 1, (unsigned long) GC_bytes_allocd);
# ifdef MAKE_BACK_GRAPH
if (GC_print_back_height) {
GC_build_back_graph();
}
# endif

/* Mark from all roots. */
if (GC_on_collection_event)
GC_on_collection_event(GC_EVENT_MARK_START);

/* Minimize junk left in my registers and on the stack */
GC_clear_a_few_frames();
GC_noop6(0,0,0,0,0,0);

GC_initiate_gc();
# ifdef PARALLEL_MARK
if (stop_func != GC_never_stop_func)
GC_parallel_mark_disabled = TRUE;
# endif
for (i = 0; !(*stop_func)(); i++) {
if (GC_mark_some(GC_approx_sp())) {
# ifdef PARALLEL_MARK
if (GC_parallel && GC_parallel_mark_disabled) {
GC_COND_LOG_PRINTF("Stopped marking done after %d iterations"
" with disabled parallel marker\n", i);
}
# endif
i = -1;
break;
}
}
# ifdef PARALLEL_MARK
GC_parallel_mark_disabled = FALSE;
# endif

if (i >= 0) {
GC_COND_LOG_PRINTF("Abandoned stopped marking after"
" %d iterations\n", i);
GC_deficit = i; /* Give the mutator a chance. */
# ifdef THREAD_LOCAL_ALLOC
GC_world_stopped = FALSE;
# endif

# ifdef THREADS
if (GC_on_collection_event)
GC_on_collection_event(GC_EVENT_PRE_START_WORLD);
# endif

START_WORLD();

# ifdef THREADS
if (GC_on_collection_event)
GC_on_collection_event(GC_EVENT_POST_START_WORLD);
# endif

/* TODO: Notify GC_EVENT_MARK_ABANDON */
return FALSE;
}

GC_gc_no++;
# ifdef USE_MUNMAP
GC_ASSERT(GC_heapsize >= GC_unmapped_bytes);
# endif
GC_ASSERT(GC_our_mem_bytes >= GC_heapsize);
GC_DBGLOG_PRINTF("GC #%lu freed %ld bytes, heap %lu KiB ("
IF_USE_MUNMAP("+ %lu KiB unmapped ")
"+ %lu KiB internal)\n",
(unsigned long)GC_gc_no, (long)GC_bytes_found,
TO_KiB_UL(GC_heapsize - GC_unmapped_bytes) /*, */
COMMA_IF_USE_MUNMAP(TO_KiB_UL(GC_unmapped_bytes)),
TO_KiB_UL(GC_our_mem_bytes - GC_heapsize));

/* Check all debugged objects for consistency */
if (GC_debugging_started) {
(*GC_check_heap)();
}
if (GC_on_collection_event) {
GC_on_collection_event(GC_EVENT_MARK_END);
# ifdef THREADS
GC_on_collection_event(GC_EVENT_PRE_START_WORLD);
# endif
}
# ifdef THREAD_LOCAL_ALLOC
GC_world_stopped = FALSE;
# endif

START_WORLD();

# ifdef THREADS
if (GC_on_collection_event)
GC_on_collection_event(GC_EVENT_POST_START_WORLD);
# endif

# ifndef NO_CLOCK
if (GC_PRINT_STATS_FLAG) {
unsigned long time_diff;
unsigned total_time, divisor;
CLOCK_TYPE current_time;

GET_TIME(current_time);
time_diff = MS_TIME_DIFF(current_time,start_time);

/* Compute new world-stop delay total time */
total_time = world_stopped_total_time;
divisor = world_stopped_total_divisor;
if ((int)total_time < 0 || divisor >= MAX_TOTAL_TIME_DIVISOR) {
/* Halve values if overflow occurs */
total_time >>= 1;
divisor >>= 1;
}
total_time += time_diff < (((unsigned)-1) >> 1) ?
(unsigned)time_diff : ((unsigned)-1) >> 1;
/* Update old world_stopped_total_time and its divisor */
world_stopped_total_time = total_time;
world_stopped_total_divisor = ++divisor;

GC_ASSERT(divisor != 0);
GC_log_printf("World-stopped marking took %lu ms %lu ns"
" (%u ms in average)\n",
time_diff, NS_FRAC_TIME_DIFF(current_time, start_time),
total_time / divisor);
}
# endif
return(TRUE);
}

/* Set all mark bits for the free list whose first entry is q */
GC_INNER void GC_set_fl_marks(ptr_t q)
{
if (q /* != NULL */) { /* CPPCHECK */
struct hblk *h = HBLKPTR(q);
struct hblk *last_h = h;
hdr *hhdr = HDR(h);
IF_PER_OBJ(word sz = hhdr->hb_sz;)

for (;;) {
word bit_no = MARK_BIT_NO((ptr_t)q - (ptr_t)h, sz);

if (!mark_bit_from_hdr(hhdr, bit_no)) {
set_mark_bit_from_hdr(hhdr, bit_no);
++hhdr -> hb_n_marks;
}

q = (ptr_t)obj_link(q);
if (q == NULL)
break;

h = HBLKPTR(q);
if (h != last_h) {
last_h = h;
hhdr = HDR(h);
IF_PER_OBJ(sz = hhdr->hb_sz;)
}
}
}
}

#if defined(GC_ASSERTIONS) && defined(THREAD_LOCAL_ALLOC)
/* Check that all mark bits for the free list whose first entry is */
/* (*pfreelist) are set. Check skipped if points to a special value. */
void GC_check_fl_marks(void **pfreelist)
{
/* TODO: There is a data race with GC_FAST_MALLOC_GRANS (which does */
/* not do atomic updates to the free-list). The race seems to be */
/* harmless, and for now we just skip this check in case of TSan. */
# if defined(AO_HAVE_load_acquire_read) && !defined(THREAD_SANITIZER)
AO_t *list = (AO_t *)AO_load_acquire_read((AO_t *)pfreelist);
/* Atomic operations are used because the world is running. */
AO_t *prev;
AO_t *p;

if ((word)list <= HBLKSIZE) return;

prev = (AO_t *)pfreelist;
for (p = list; p != NULL;) {
AO_t *next;

if (!GC_is_marked(p)) {
ABORT_ARG2("Unmarked local free list entry",
": object %p on list %p", (void *)p, (void *)list);
}

/* While traversing the free-list, it re-reads the pointer to */
/* the current node before accepting its next pointer and */
/* bails out if the latter has changed. That way, it won't */
/* try to follow the pointer which might be been modified */
/* after the object was returned to the client. It might */
/* perform the mark-check on the just allocated object but */
/* that should be harmless. */
next = (AO_t *)AO_load_acquire_read(p);
if (AO_load(prev) != (AO_t)p)
break;
prev = p;
p = next;
}
# else
/* FIXME: Not implemented (just skipped). */
(void)pfreelist;
# endif
}
#endif /* GC_ASSERTIONS && THREAD_LOCAL_ALLOC */

/* Clear all mark bits for the free list whose first entry is q */
/* Decrement GC_bytes_found by number of bytes on free list. */
STATIC void GC_clear_fl_marks(ptr_t q)
{
struct hblk *h = HBLKPTR(q);
struct hblk *last_h = h;
hdr *hhdr = HDR(h);
word sz = hhdr->hb_sz; /* Normally set only once. */

for (;;) {
word bit_no = MARK_BIT_NO((ptr_t)q - (ptr_t)h, sz);

if (mark_bit_from_hdr(hhdr, bit_no)) {
size_t n_marks = hhdr -> hb_n_marks;

GC_ASSERT(n_marks != 0);
clear_mark_bit_from_hdr(hhdr, bit_no);
n_marks--;
# ifdef PARALLEL_MARK
/* Appr. count, don't decrement to zero! */
if (0 != n_marks || !GC_parallel) {
hhdr -> hb_n_marks = n_marks;
}
# else
hhdr -> hb_n_marks = n_marks;
# endif
}
GC_bytes_found -= sz;

q = (ptr_t)obj_link(q);
if (q == NULL)
break;

h = HBLKPTR(q);
if (h != last_h) {
last_h = h;
hhdr = HDR(h);
sz = hhdr->hb_sz;
}
}
}

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

GC_on_heap_resize_proc GC_on_heap_resize = 0;

/* Used for logging only. */
GC_INLINE int GC_compute_heap_usage_percent(void)
{
word used = GC_composite_in_use + GC_atomic_in_use;
word heap_sz = GC_heapsize - GC_unmapped_bytes;
# if defined(CPPCHECK)
word limit = (GC_WORD_MAX >> 1) / 50; /* to avoid a false positive */
# else
const word limit = GC_WORD_MAX / 100;
# endif

return used >= heap_sz ? 0 : used < limit ?
(int)((used * 100) / heap_sz) : (int)(used / (heap_sz / 100));
}

/* Finish up a collection. Assumes mark bits are consistent, lock is */
/* held, but the world is otherwise running. */
STATIC void GC_finish_collection(void)
{
# ifndef NO_CLOCK
CLOCK_TYPE start_time = CLOCK_TYPE_INITIALIZER;
CLOCK_TYPE finalize_time = CLOCK_TYPE_INITIALIZER;
# endif

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

# ifndef NO_CLOCK
if (GC_print_stats)
GET_TIME(start_time);
# endif
if (GC_on_collection_event)
GC_on_collection_event(GC_EVENT_RECLAIM_START);

# ifndef GC_GET_HEAP_USAGE_NOT_NEEDED
if (GC_bytes_found > 0)
GC_reclaimed_bytes_before_gc += (word)GC_bytes_found;
# endif
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 = (ptr_t)GC_obj_kinds[kind].ok_freelist[size];
if (q != NULL)
GC_set_fl_marks(q);
}
}
GC_start_reclaim(TRUE);
/* The above just checks; it doesn't really reclaim anything. */
}

# ifndef GC_NO_FINALIZATION
GC_finalize();
# endif
# ifndef NO_CLOCK
if (GC_print_stats)
GET_TIME(finalize_time);
# endif

if (GC_print_back_height) {
# ifdef MAKE_BACK_GRAPH
GC_traverse_back_graph();
# elif !defined(SMALL_CONFIG)
GC_err_printf("Back height not available: "
"Rebuild collector with -DMAKE_BACK_GRAPH\n");
# 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 = (ptr_t)GC_obj_kinds[kind].ok_freelist[size];
if (q != NULL)
GC_clear_fl_marks(q);
}
}
}

GC_VERBOSE_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);
GC_DBGLOG_PRINTF("In-use heap: %d%% (%lu KiB pointers + %lu KiB other)\n",
GC_compute_heap_usage_percent(),
TO_KiB_UL(GC_composite_in_use),
TO_KiB_UL(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();
}

GC_VERBOSE_LOG_PRINTF("Immediately reclaimed %ld bytes, heapsize:"
" %lu bytes" IF_USE_MUNMAP(" (%lu unmapped)") "\n",
(long)GC_bytes_found,
(unsigned long)GC_heapsize /*, */
COMMA_IF_USE_MUNMAP((unsigned long)
GC_unmapped_bytes));

/* 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_dropped = 0;
GC_bytes_freed = 0;
GC_finalizer_bytes_freed = 0;

IF_USE_MUNMAP(GC_unmap_old());

if (GC_on_collection_event)
GC_on_collection_event(GC_EVENT_RECLAIM_END);
# ifndef NO_CLOCK
if (GC_print_stats) {
CLOCK_TYPE done_time;

GET_TIME(done_time);
# if !defined(SMALL_CONFIG) && !defined(GC_NO_FINALIZATION)
/* A convenient place to output finalization statistics. */
GC_print_finalization_stats();
# endif
GC_log_printf("Finalize and initiate sweep took %lu ms %lu ns"
" + %lu ms %lu ns\n",
MS_TIME_DIFF(finalize_time, start_time),
NS_FRAC_TIME_DIFF(finalize_time, start_time),
MS_TIME_DIFF(done_time, finalize_time),
NS_FRAC_TIME_DIFF(done_time, finalize_time));
}
# elif !defined(SMALL_CONFIG) && !defined(GC_NO_FINALIZATION)
if (GC_print_stats)
GC_print_finalization_stats();
# endif
}

STATIC word GC_heapsize_at_forced_unmap = 0;
/* accessed with the allocation lock held */

/* If stop_func == 0 then GC_default_stop_func is used instead. */
STATIC GC_bool GC_try_to_collect_general(GC_stop_func stop_func,
GC_bool force_unmap)
{
GC_bool result;
IF_USE_MUNMAP(int old_unmap_threshold;)
IF_CANCEL(int cancel_state;)
DCL_LOCK_STATE;

if (!EXPECT(GC_is_initialized, TRUE)) GC_init();
if (GC_debugging_started) GC_print_all_smashed();
GC_INVOKE_FINALIZERS();
LOCK();
if (force_unmap) {
/* Record current heap size to make heap growth more conservative */
/* afterwards (as if the heap is growing from zero size again). */
GC_heapsize_at_forced_unmap = GC_heapsize;
}
DISABLE_CANCEL(cancel_state);
# ifdef USE_MUNMAP
old_unmap_threshold = GC_unmap_threshold;
if (force_unmap ||
(GC_force_unmap_on_gcollect && old_unmap_threshold > 0))
GC_unmap_threshold = 1; /* unmap as much as possible */
# endif
ENTER_GC();
/* Minimize junk left in my registers */
GC_noop6(0,0,0,0,0,0);
result = GC_try_to_collect_inner(stop_func != 0 ? stop_func :
GC_default_stop_func);
EXIT_GC();
IF_USE_MUNMAP(GC_unmap_threshold = old_unmap_threshold); /* restore */
RESTORE_CANCEL(cancel_state);
UNLOCK();
if (result) {
if (GC_debugging_started) GC_print_all_smashed();
GC_INVOKE_FINALIZERS();
}
return(result);
}

/* Externally callable routines to invoke full, stop-the-world collection. */

GC_API int GC_CALL GC_try_to_collect(GC_stop_func stop_func)
{
GC_ASSERT(NONNULL_ARG_NOT_NULL(stop_func));
return (int)GC_try_to_collect_general(stop_func, FALSE);
}

GC_API void GC_CALL GC_gcollect(void)
{
/* 0 is passed as stop_func to get GC_default_stop_func value */
/* while holding the allocation lock (to prevent data races). */
(void)GC_try_to_collect_general(0, FALSE);
if (get_have_errors())
GC_print_all_errors();
}

GC_API void GC_CALL GC_gcollect_and_unmap(void)
{
/* Collect and force memory unmapping to OS. */
(void)GC_try_to_collect_general(GC_never_stop_func, TRUE);
}

#ifdef USE_PROC_FOR_LIBRARIES
/* Add HBLKSIZE aligned, GET_MEM-generated block to GC_our_memory. */
GC_INNER void GC_add_to_our_memory(ptr_t p, size_t bytes)
{
GC_ASSERT(p != NULL);
if (GC_n_memory >= MAX_HEAP_SECTS)
ABORT("Too many GC-allocated memory sections: Increase MAX_HEAP_SECTS");
GC_our_memory[GC_n_memory].hs_start = p;
GC_our_memory[GC_n_memory].hs_bytes = bytes;
GC_n_memory++;
GC_our_mem_bytes += bytes;
}
#endif

/* Use the chunk of memory starting at p of size bytes as part of the heap. */
/* Assumes p is HBLKSIZE aligned, bytes argument is a multiple of HBLKSIZE. */
STATIC void GC_add_to_heap(struct hblk *p, size_t bytes)
{
hdr * phdr;
word endp;
size_t old_capacity = 0;
void *old_heap_sects = NULL;
# ifdef GC_ASSERTIONS
unsigned i;
# endif

GC_ASSERT((word)p % HBLKSIZE == 0);
GC_ASSERT(bytes % HBLKSIZE == 0);
GC_ASSERT(bytes > 0);
GC_ASSERT(GC_all_nils != NULL);

if (GC_n_heap_sects == GC_capacity_heap_sects) {
/* Allocate new GC_heap_sects with sufficient capacity. */
# ifndef INITIAL_HEAP_SECTS
# define INITIAL_HEAP_SECTS 32
# endif
size_t new_capacity = GC_n_heap_sects > 0 ?
(size_t)GC_n_heap_sects * 2 : INITIAL_HEAP_SECTS;
void *new_heap_sects =
GC_scratch_alloc(new_capacity * sizeof(struct HeapSect));

if (EXPECT(NULL == new_heap_sects, FALSE)) {
/* Retry with smaller yet sufficient capacity. */
new_capacity = (size_t)GC_n_heap_sects + INITIAL_HEAP_SECTS;
new_heap_sects =
GC_scratch_alloc(new_capacity * sizeof(struct HeapSect));
if (NULL == new_heap_sects)
ABORT("Insufficient memory for heap sections");
}
old_capacity = GC_capacity_heap_sects;
old_heap_sects = GC_heap_sects;
/* Transfer GC_heap_sects contents to the newly allocated array. */
if (GC_n_heap_sects > 0)
BCOPY(old_heap_sects, new_heap_sects,
GC_n_heap_sects * sizeof(struct HeapSect));
GC_capacity_heap_sects = new_capacity;
GC_heap_sects = (struct HeapSect *)new_heap_sects;
GC_COND_LOG_PRINTF("Grew heap sections array to %lu elements\n",
(unsigned long)new_capacity);
}

while ((word)p <= HBLKSIZE) {
/* Can't handle memory near address zero. */
++p;
bytes -= HBLKSIZE;
if (0 == bytes) return;
}
endp = (word)p + bytes;
while (endp <= (word)p) {
/* Address wrapped. */
bytes -= HBLKSIZE;
if (0 == bytes) return;
endp -= HBLKSIZE;
}
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_ASSERT(endp > (word)p && endp == (word)p + bytes);
# ifdef GC_ASSERTIONS
/* Ensure no intersection between sections. */
for (i = 0; i < GC_n_heap_sects; i++) {
word hs_start = (word)GC_heap_sects[i].hs_start;
word hs_end = hs_start + GC_heap_sects[i].hs_bytes;
word p_e = (word)p + bytes;

GC_ASSERT(!((hs_start <= (word)p && (word)p < hs_end)
|| (hs_start < p_e && p_e <= hs_end)
|| ((word)p < hs_start && hs_end < p_e)));
}
# endif
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;

/* Normally the caller calculates a new GC_collect_at_heapsize,
* but this is also called directly from GC_scratch_recycle_inner, so
* adjust here. It will be recalculated when called from
* GC_expand_hp_inner.
*/
GC_collect_at_heapsize += bytes;
if (GC_collect_at_heapsize < GC_heapsize /* wrapped */)
GC_collect_at_heapsize = GC_WORD_MAX;

if ((word)p <= (word)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 ((word)p + bytes >= (word)GC_greatest_plausible_heap_addr) {
GC_greatest_plausible_heap_addr = (void *)endp;
}
# ifdef SET_REAL_HEAP_BOUNDS
if ((word)p < GC_least_real_heap_addr
|| EXPECT(0 == GC_least_real_heap_addr, FALSE))
GC_least_real_heap_addr = (word)p - sizeof(word);
if (endp > GC_greatest_real_heap_addr) {
# ifdef INCLUDE_LINUX_THREAD_DESCR
/* Avoid heap intersection with the static data roots. */
GC_exclude_static_roots_inner((void *)p, (void *)endp);
# endif
GC_greatest_real_heap_addr = endp;
}
# endif
GC_handle_protected_regions_limit();
if (old_capacity > 0) {
# ifndef GWW_VDB
/* Recycling may call GC_add_to_heap() again but should not */
/* cause resizing of GC_heap_sects. */
GC_scratch_recycle_no_gww(old_heap_sects,
old_capacity * sizeof(struct HeapSect));
# else
/* TODO: implement GWW-aware recycling as in alloc_mark_stack */
GC_noop1((word)old_heap_sects);
# endif
}
}

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

GC_printf("Total heap size: %lu" IF_USE_MUNMAP(" (%lu unmapped)") "\n",
(unsigned long)GC_heapsize /*, */
COMMA_IF_USE_MUNMAP((unsigned long)GC_unmapped_bytes));

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;

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

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

GC_INLINE word GC_max(word x, word y)
{
return(x > y? x : y);
}

GC_INLINE word GC_min(word x, word y)
{
return(x < y? x : y);
}

STATIC word GC_max_heapsize = 0;

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

GC_word GC_max_retries = 0;

GC_INNER void GC_scratch_recycle_inner(void *ptr, size_t bytes)
{
size_t page_offset;
size_t displ = 0;
size_t recycled_bytes;

if (NULL == ptr) return;

GC_ASSERT(bytes != 0);
GC_ASSERT(GC_page_size != 0);
/* TODO: Assert correct memory flags if GWW_VDB */
page_offset = (word)ptr & (GC_page_size - 1);
if (page_offset != 0)
displ = GC_page_size - page_offset;
recycled_bytes = bytes > displ ? (bytes - displ) & ~(GC_page_size - 1) : 0;
GC_COND_LOG_PRINTF("Recycle %lu/%lu scratch-allocated bytes at %p\n",
(unsigned long)recycled_bytes, (unsigned long)bytes, ptr);
if (recycled_bytes > 0)
GC_add_to_heap((struct hblk *)((word)ptr + displ), recycled_bytes);
}

/* 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 are rounded up). */
/* Returns FALSE on failure. */
GC_INNER GC_bool GC_expand_hp_inner(word n)
{
size_t bytes;
struct hblk * space;
word expansion_slop; /* Number of bytes by which we expect */
/* the heap to expand soon. */

GC_ASSERT(I_HOLD_LOCK());
GC_ASSERT(GC_page_size != 0);
if (n < MINHINCR) n = MINHINCR;
bytes = ROUNDUP_PAGESIZE((size_t)n * HBLKSIZE);
if (GC_max_heapsize != 0
&& (GC_max_heapsize < (word)bytes
|| GC_heapsize > GC_max_heapsize - (word)bytes)) {
/* Exceeded self-imposed limit */
return(FALSE);
}
space = GET_MEM(bytes);
if (EXPECT(NULL == space, FALSE)) {
WARN("Failed to expand heap by %" WARN_PRIuPTR " KiB\n", bytes >> 10);
return(FALSE);
}
GC_add_to_our_memory((ptr_t)space, bytes);
GC_INFOLOG_PRINTF("Grow heap to %lu KiB after %lu bytes allocated\n",
TO_KiB_UL(GC_heapsize + bytes),
(unsigned long)GC_bytes_allocd);

/* Adjust heap limits generously for blacklisting to work better. */
/* GC_add_to_heap performs minimal adjustment needed for */
/* correctness. */
expansion_slop = min_bytes_allocd() + 4 * MAXHINCR * HBLKSIZE;
if ((GC_last_heap_addr == 0 && !((word)space & SIGNB))
|| (GC_last_heap_addr != 0
&& (word)GC_last_heap_addr < (word)space)) {
/* Assume the heap is growing up. */
word new_limit = (word)space + (word)bytes + expansion_slop;
if (new_limit > (word)space) {
GC_greatest_plausible_heap_addr =
(void *)GC_max((word)GC_greatest_plausible_heap_addr,
(word)new_limit);
}
} else {
/* Heap is growing down. */
word new_limit = (word)space - expansion_slop;
if (new_limit < (word)space) {
GC_least_plausible_heap_addr =
(void *)GC_min((word)GC_least_plausible_heap_addr,
(word)space - expansion_slop);
}
}
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 - 2 * MAXHINCR * HBLKSIZE;
if (GC_collect_at_heapsize < GC_heapsize /* wrapped */)
GC_collect_at_heapsize = GC_WORD_MAX;
if (GC_on_heap_resize)
(*GC_on_heap_resize)(GC_heapsize);

return(TRUE);
}

/* Really returns a bool, but it's externally visible, so that's clumsy. */
/* The argument is in bytes. Includes GC_init() call. */
GC_API int GC_CALL GC_expand_hp(size_t bytes)
{
int result;
DCL_LOCK_STATE;

if (!EXPECT(GC_is_initialized, TRUE)) GC_init();
LOCK();
result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes));
if (result) GC_requested_heapsize += bytes;
UNLOCK();
return(result);
}

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

/* The minimum value of the ratio of allocated bytes since the latest */
/* GC to the amount of finalizers created since that GC which triggers */
/* the collection instead heap expansion. Has no effect in the */
/* incremental mode. */
#if defined(GC_ALLOCD_BYTES_PER_FINALIZER) && !defined(CPPCHECK)
STATIC word GC_allocd_bytes_per_finalizer = GC_ALLOCD_BYTES_PER_FINALIZER;
#else
STATIC word GC_allocd_bytes_per_finalizer = 10000;
#endif

GC_API void GC_CALL GC_set_allocd_bytes_per_finalizer(GC_word value)
{
GC_allocd_bytes_per_finalizer = value;
}

GC_API GC_word GC_CALL GC_get_allocd_bytes_per_finalizer(void)
{
return GC_allocd_bytes_per_finalizer;
}

static word last_fo_entries = 0;
static word last_bytes_finalized = 0;

/* Collect or expand heap in an attempt make the indicated number of */
/* free blocks available. Should be called until the blocks are */
/* available (setting retry value to TRUE unless this is the first call */
/* in a loop) or until it fails by returning FALSE. */
GC_INNER GC_bool GC_collect_or_expand(word needed_blocks,
GC_bool ignore_off_page,
GC_bool retry)
{
GC_bool gc_not_stopped = TRUE;
word blocks_to_get;
IF_CANCEL(int cancel_state;)

GC_ASSERT(I_HOLD_LOCK());
DISABLE_CANCEL(cancel_state);
if (!GC_incremental && !GC_dont_gc &&
((GC_dont_expand && GC_bytes_allocd > 0)
|| (GC_fo_entries > last_fo_entries
&& (last_bytes_finalized | GC_bytes_finalized) != 0
&& (GC_fo_entries - last_fo_entries)
* GC_allocd_bytes_per_finalizer > GC_bytes_allocd)
|| GC_should_collect())) {
/* Try to do a full collection using 'default' stop_func (unless */
/* nothing has been allocated since the latest collection or heap */
/* expansion is disabled). */
gc_not_stopped = GC_try_to_collect_inner(
GC_bytes_allocd > 0 && (!GC_dont_expand || !retry) ?
GC_default_stop_func : GC_never_stop_func);
if (gc_not_stopped == TRUE || !retry) {
/* Either the collection hasn't been aborted or this is the */
/* first attempt (in a loop). */
last_fo_entries = GC_fo_entries;
last_bytes_finalized = GC_bytes_finalized;
RESTORE_CANCEL(cancel_state);
return(TRUE);
}
}

blocks_to_get = (GC_heapsize - GC_heapsize_at_forced_unmap)
/ (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 (blocks_to_get > divHBLKSZ(GC_WORD_MAX))
blocks_to_get = divHBLKSZ(GC_WORD_MAX);
}

if (!GC_expand_hp_inner(blocks_to_get)
&& (blocks_to_get == needed_blocks
|| !GC_expand_hp_inner(needed_blocks))) {
if (gc_not_stopped == FALSE) {
/* Don't increment GC_fail_count here (and no warning). */
GC_gcollect_inner();
GC_ASSERT(GC_bytes_allocd == 0);
} else 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)
# ifdef USE_MUNMAP
GC_ASSERT(GC_heapsize >= GC_unmapped_bytes);
# endif
WARN("Out of Memory! Heap size: %" WARN_PRIuPTR " MiB."
" Returning NULL!\n", (GC_heapsize - GC_unmapped_bytes) >> 20);
# endif
RESTORE_CANCEL(cancel_state);
return(FALSE);
}
} else if (GC_fail_count) {
GC_COND_LOG_PRINTF("Memory available again...\n");
}
RESTORE_CANCEL(cancel_state);
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.
*/
GC_INNER ptr_t GC_allocobj(size_t gran, int kind)
{
void ** flh = &(GC_obj_kinds[kind].ok_freelist[gran]);
GC_bool tried_minor = FALSE;
GC_bool retry = FALSE;

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

while (*flh == 0) {
ENTER_GC();
# ifndef GC_DISABLE_INCREMENTAL
if (GC_incremental && GC_time_limit != GC_TIME_UNLIMITED
&& !GC_dont_gc) {
/* True incremental mode, not just generational. */
/* Do our share of marking work. */
GC_collect_a_little_inner(1);
}
# endif
/* Sweep blocks for objects of this size */
GC_ASSERT(!GC_is_full_gc
|| NULL == GC_obj_kinds[kind].ok_reclaim_list
|| NULL == GC_obj_kinds[kind].ok_reclaim_list[gran]);
GC_continue_reclaim(gran, kind);
EXIT_GC();
# if defined(CPPCHECK)
GC_noop1((word)&flh);
# endif
if (NULL == *flh) {
GC_new_hblk(gran, kind);
# if defined(CPPCHECK)
GC_noop1((word)&flh);
# endif
if (NULL == *flh) {
ENTER_GC();
if (GC_incremental && GC_time_limit == GC_TIME_UNLIMITED
&& !tried_minor && !GC_dont_gc) {
GC_collect_a_little_inner(1);
tried_minor = TRUE;
} else {
if (!GC_collect_or_expand(1, FALSE, retry)) {
EXIT_GC();
return(0);
}
retry = TRUE;
}
EXIT_GC();
}
}
}
/* Successful allocation; reset failure count. */
GC_fail_count = 0;

return (ptr_t)(*flh);
}