void*
sgen_fragment_allocator_serial_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size)
{
SgenFragment *frag, **previous, *min_frag = NULL, **prev_min_frag = NULL;
size_t current_minimum = minimum_size;
#ifdef NALLOC_DEBUG
InterlockedIncrement (&alloc_count);
#endif
previous = &allocator->alloc_head;
for (frag = *previous; frag; frag = *previous) {
size_t frag_size = frag->fragment_end - frag->fragment_next;
HEAVY_STAT (++stat_alloc_range_iterations);
if (desired_size <= frag_size) {
void *p;
*out_alloc_size = desired_size;
p = serial_alloc_from_fragment (previous, frag, desired_size);
#ifdef NALLOC_DEBUG
add_alloc_record (p, desired_size, RANGE_ALLOC);
#endif
return p;
}
if (current_minimum <= frag_size) {
min_frag = frag;
prev_min_frag = previous;
current_minimum = frag_size;
}
previous = &frag->next;
}
if (min_frag) {
void *p;
size_t frag_size = min_frag->fragment_end - min_frag->fragment_next;
*out_alloc_size = frag_size;
p = serial_alloc_from_fragment (prev_min_frag, min_frag, frag_size);
#ifdef NALLOC_DEBUG
add_alloc_record (p, frag_size, RANGE_ALLOC);
#endif
return p;
}
return NULL;
}
void*
sgen_fragment_allocator_par_alloc (SgenFragmentAllocator *allocator, size_t size)
{
SgenFragment *frag;
#ifdef NALLOC_DEBUG
InterlockedIncrement (&alloc_count);
#endif
restart:
for (frag = (SgenFragment *)unmask (allocator->alloc_head); unmask (frag); frag = (SgenFragment *)unmask (frag->next)) {
HEAVY_STAT (++stat_alloc_iterations);
if (size <= (size_t)(frag->fragment_end - frag->fragment_next)) {
void *p = par_alloc_from_fragment (allocator, frag, size);
if (!p) {
HEAVY_STAT (++stat_alloc_retries);
goto restart;
}
#ifdef NALLOC_DEBUG
add_alloc_record (p, size, FIXED_ALLOC);
#endif
return p;
}
}
return NULL;
}
void*
sgen_fragment_allocator_serial_alloc (SgenFragmentAllocator *allocator, size_t size)
{
SgenFragment *frag;
SgenFragment **previous;
#ifdef NALLOC_DEBUG
InterlockedIncrement (&alloc_count);
#endif
previous = &allocator->alloc_head;
for (frag = *previous; frag; frag = *previous) {
char *p = (char *)serial_alloc_from_fragment (previous, frag, size);
HEAVY_STAT (++stat_alloc_iterations);
if (p) {
#ifdef NALLOC_DEBUG
add_alloc_record (p, size, FIXED_ALLOC);
#endif
return p;
}
previous = &frag->next;
}
return NULL;
}
void*
mono_sgen_nursery_alloc (size_t size)
{
Fragment *frag;
DEBUG (4, fprintf (gc_debug_file, "Searching nursery for size: %zd\n", size));
size = SGEN_ALIGN_UP (size);
HEAVY_STAT (InterlockedIncrement (&stat_nursery_alloc_requests));
#ifdef NALLOC_DEBUG
InterlockedIncrement (&alloc_count);
#endif
restart:
for (frag = unmask (nursery_fragments); frag; frag = unmask (frag->next)) {
HEAVY_STAT (InterlockedIncrement (&stat_alloc_iterations));
if (size <= (frag->fragment_end - frag->fragment_next)) {
void *p = alloc_from_fragment (frag, size);
if (!p) {
HEAVY_STAT (InterlockedIncrement (&stat_alloc_retries));
goto restart;
}
#ifdef NALLOC_DEBUG
add_alloc_record (p, size, FIXED_ALLOC);
#endif
return p;
}
}
return NULL;
}
mword
mono_sgen_build_nursery_fragments (GCMemSection *nursery_section, void **start, int num_entries)
{
char *frag_start, *frag_end;
size_t frag_size;
int i;
#ifdef NALLOC_DEBUG
reset_alloc_records ();
#endif
while (unmask (nursery_fragments)) {
Fragment *nf = unmask (nursery_fragments);
Fragment *next = unmask (nf->next);
nf->next_free = fragment_freelist;
fragment_freelist = nf;
nursery_fragments = next;
}
frag_start = nursery_start;
fragment_total = 0;
/* clear scan starts */
memset (nursery_section->scan_starts, 0, nursery_section->num_scan_start * sizeof (gpointer));
for (i = 0; i < num_entries; ++i) {
frag_end = start [i];
/* remove the pin bit from pinned objects */
SGEN_UNPIN_OBJECT (frag_end);
nursery_section->scan_starts [((char*)frag_end - (char*)nursery_section->data)/SGEN_SCAN_START_SIZE] = frag_end;
frag_size = frag_end - frag_start;
if (frag_size)
add_nursery_frag (frag_size, frag_start, frag_end);
frag_size = SGEN_ALIGN_UP (mono_sgen_safe_object_get_size ((MonoObject*)start [i]));
#ifdef NALLOC_DEBUG
add_alloc_record (start [i], frag_size, PINNING);
#endif
frag_start = (char*)start [i] + frag_size;
}
nursery_last_pinned_end = frag_start;
frag_end = nursery_end;
frag_size = frag_end - frag_start;
if (frag_size)
add_nursery_frag (frag_size, frag_start, frag_end);
if (!unmask (nursery_fragments)) {
DEBUG (1, fprintf (gc_debug_file, "Nursery fully pinned (%d)\n", num_entries));
for (i = 0; i < num_entries; ++i) {
DEBUG (3, fprintf (gc_debug_file, "Bastard pinning obj %p (%s), size: %d\n", start [i], mono_sgen_safe_name (start [i]), mono_sgen_safe_object_get_size (start [i])));
}
}
return fragment_total;
}
void
sgen_clear_allocator_fragments (SgenFragmentAllocator *allocator)
{
SgenFragment *frag;
for (frag = (SgenFragment *)unmask (allocator->alloc_head); frag; frag = (SgenFragment *)unmask (frag->next)) {
SGEN_LOG (4, "Clear nursery frag %p-%p", frag->fragment_next, frag->fragment_end);
sgen_clear_range (frag->fragment_next, frag->fragment_end);
#ifdef NALLOC_DEBUG
add_alloc_record (frag->fragment_next, frag->fragment_end - frag->fragment_next, CLEAR_NURSERY_FRAGS);
#endif
}
}
/* Clear all remaining nursery fragments */
void
mono_sgen_clear_nursery_fragments (void)
{
Fragment *frag;
if (mono_sgen_get_nursery_clear_policy () == CLEAR_AT_TLAB_CREATION) {
mono_sgen_clear_current_nursery_fragment ();
for (frag = unmask (nursery_fragments); frag; frag = unmask (frag->next)) {
DEBUG (4, fprintf (gc_debug_file, "Clear nursery frag %p-%p\n", frag->fragment_next, frag->fragment_end));
memset (frag->fragment_next, 0, frag->fragment_end - frag->fragment_next);
#ifdef NALLOC_DEBUG
add_alloc_record (frag->fragment_next, frag->fragment_end - frag->fragment_next, CLEAR_NURSERY_FRAGS);
#endif
}
}
}
mword
sgen_build_nursery_fragments (GCMemSection *nursery_section, SgenGrayQueue *unpin_queue)
{
char *frag_start, *frag_end;
size_t frag_size;
SgenFragment *frags_ranges;
void **pin_start, **pin_entry, **pin_end;
#ifdef NALLOC_DEBUG
reset_alloc_records ();
#endif
/*The mutator fragments are done. We no longer need them. */
sgen_fragment_allocator_release (&mutator_allocator);
frag_start = sgen_nursery_start;
fragment_total = 0;
/* The current nursery might give us a fragment list to exclude [start, next[*/
frags_ranges = sgen_minor_collector.build_fragments_get_exclude_head ();
/* clear scan starts */
memset (nursery_section->scan_starts, 0, nursery_section->num_scan_start * sizeof (gpointer));
pin_start = pin_entry = sgen_pinning_get_entry (nursery_section->pin_queue_first_entry);
pin_end = sgen_pinning_get_entry (nursery_section->pin_queue_last_entry);
while (pin_entry < pin_end || frags_ranges) {
char *addr0, *addr1;
size_t size;
addr0 = addr1 = sgen_nursery_end;
if (pin_entry < pin_end)
addr0 = (char *)*pin_entry;
if (frags_ranges)
addr1 = frags_ranges->fragment_start;
if (addr0 < addr1) {
if (unpin_queue)
GRAY_OBJECT_ENQUEUE (unpin_queue, (GCObject*)addr0, sgen_obj_get_descriptor_safe ((GCObject*)addr0));
else
SGEN_UNPIN_OBJECT (addr0);
size = SGEN_ALIGN_UP (sgen_safe_object_get_size ((GCObject*)addr0));
CANARIFY_SIZE (size);
sgen_set_nursery_scan_start (addr0);
frag_end = addr0;
++pin_entry;
} else {
frag_end = addr1;
size = frags_ranges->fragment_next - addr1;
frags_ranges = frags_ranges->next_in_order;
}
frag_size = frag_end - frag_start;
if (size == 0)
continue;
g_assert (frag_size >= 0);
g_assert (size > 0);
if (frag_size && size)
add_nursery_frag (&mutator_allocator, frag_size, frag_start, frag_end);
frag_size = size;
#ifdef NALLOC_DEBUG
add_alloc_record (*pin_entry, frag_size, PINNING);
#endif
frag_start = frag_end + frag_size;
}
nursery_last_pinned_end = frag_start;
frag_end = sgen_nursery_end;
frag_size = frag_end - frag_start;
if (frag_size)
add_nursery_frag (&mutator_allocator, frag_size, frag_start, frag_end);
/* Now it's safe to release the fragments exclude list. */
sgen_minor_collector.build_fragments_release_exclude_head ();
/* First we reorder the fragment list to be in ascending address order. This makes H/W prefetchers happier. */
fragment_list_reverse (&mutator_allocator);
/*The collector might want to do something with the final nursery fragment list.*/
sgen_minor_collector.build_fragments_finish (&mutator_allocator);
if (!unmask (mutator_allocator.alloc_head)) {
SGEN_LOG (1, "Nursery fully pinned");
for (pin_entry = pin_start; pin_entry < pin_end; ++pin_entry) {
GCObject *p = (GCObject *)*pin_entry;
SGEN_LOG (3, "Bastard pinning obj %p (%s), size: %zd", p, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (p)), sgen_safe_object_get_size (p));
}
}
return fragment_total;
}
void*
sgen_fragment_allocator_par_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size)
{
SgenFragment *frag, *min_frag;
size_t current_minimum;
restart:
min_frag = NULL;
current_minimum = minimum_size;
#ifdef NALLOC_DEBUG
InterlockedIncrement (&alloc_count);
#endif
for (frag = (SgenFragment *)unmask (allocator->alloc_head); frag; frag = (SgenFragment *)unmask (frag->next)) {
size_t frag_size = frag->fragment_end - frag->fragment_next;
HEAVY_STAT (++stat_alloc_range_iterations);
if (desired_size <= frag_size) {
void *p;
*out_alloc_size = desired_size;
p = par_alloc_from_fragment (allocator, frag, desired_size);
if (!p) {
HEAVY_STAT (++stat_alloc_range_retries);
goto restart;
}
#ifdef NALLOC_DEBUG
add_alloc_record (p, desired_size, RANGE_ALLOC);
#endif
return p;
}
if (current_minimum <= frag_size) {
min_frag = frag;
current_minimum = frag_size;
}
}
/* The second fragment_next read should be ordered in respect to the first code block */
mono_memory_barrier ();
if (min_frag) {
void *p;
size_t frag_size;
frag_size = min_frag->fragment_end - min_frag->fragment_next;
if (frag_size < minimum_size)
goto restart;
*out_alloc_size = frag_size;
mono_memory_barrier ();
p = par_alloc_from_fragment (allocator, min_frag, frag_size);
/*XXX restarting here is quite dubious given this is already second chance allocation. */
if (!p) {
HEAVY_STAT (++stat_alloc_retries);
goto restart;
}
#ifdef NALLOC_DEBUG
add_alloc_record (p, frag_size, RANGE_ALLOC);
#endif
return p;
}
return NULL;
}
static void*
par_alloc_from_fragment (SgenFragmentAllocator *allocator, SgenFragment *frag, size_t size)
{
char *p = frag->fragment_next;
char *end = p + size;
if (end > frag->fragment_end)
return NULL;
/* p = frag->fragment_next must happen before */
mono_memory_barrier ();
if (InterlockedCompareExchangePointer ((volatile gpointer*)&frag->fragment_next, end, p) != p)
return NULL;
if (frag->fragment_end - end < SGEN_MAX_NURSERY_WASTE) {
SgenFragment *next, **prev_ptr;
/*
* Before we clean the remaining nursery, we must claim the remaining space
* as it could end up been used by the range allocator since it can end up
* allocating from this dying fragment as it doesn't respect SGEN_MAX_NURSERY_WASTE
* when doing second chance allocation.
*/
if ((sgen_get_nursery_clear_policy () == CLEAR_AT_TLAB_CREATION || sgen_get_nursery_clear_policy () == CLEAR_AT_TLAB_CREATION_DEBUG) && claim_remaining_size (frag, end)) {
sgen_clear_range (end, frag->fragment_end);
HEAVY_STAT (stat_wasted_bytes_trailer += frag->fragment_end - end);
#ifdef NALLOC_DEBUG
add_alloc_record (end, frag->fragment_end - end, BLOCK_ZEROING);
#endif
}
prev_ptr = find_previous_pointer_fragment (allocator, frag);
/*Use Michaels linked list remove*/
/*prev_ptr will be null if the fragment was removed concurrently */
while (prev_ptr) {
next = frag->next;
/*already deleted*/
if (!get_mark (next)) {
/*frag->next read must happen before the first CAS*/
mono_memory_write_barrier ();
/*Fail if the next node is removed concurrently and its CAS wins */
if (InterlockedCompareExchangePointer ((volatile gpointer*)&frag->next, mask (next, 1), next) != next) {
continue;
}
}
/* The second CAS must happen after the first CAS or frag->next. */
mono_memory_write_barrier ();
/* Fail if the previous node was deleted and its CAS wins */
if (InterlockedCompareExchangePointer ((volatile gpointer*)prev_ptr, unmask (next), frag) != frag) {
prev_ptr = find_previous_pointer_fragment (allocator, frag);
continue;
}
break;
}
}
return p;
}
mword
sgen_build_nursery_fragments (GCMemSection *nursery_section, void **start, size_t num_entries, SgenGrayQueue *unpin_queue)
{
char *frag_start, *frag_end;
size_t frag_size;
size_t i = 0;
SgenFragment *frags_ranges;
#ifdef NALLOC_DEBUG
reset_alloc_records ();
#endif
/*The mutator fragments are done. We no longer need them. */
sgen_fragment_allocator_release (&mutator_allocator);
frag_start = sgen_nursery_start;
fragment_total = 0;
/* The current nursery might give us a fragment list to exclude [start, next[*/
frags_ranges = sgen_minor_collector.build_fragments_get_exclude_head ();
/* clear scan starts */
memset (nursery_section->scan_starts, 0, nursery_section->num_scan_start * sizeof (gpointer));
while (i < num_entries || frags_ranges) {
char *addr0, *addr1;
size_t size;
SgenFragment *last_frag = NULL;
addr0 = addr1 = sgen_nursery_end;
if (i < num_entries)
addr0 = start [i];
if (frags_ranges)
addr1 = frags_ranges->fragment_start;
if (addr0 < addr1) {
if (unpin_queue)
GRAY_OBJECT_ENQUEUE (unpin_queue, addr0);
else
SGEN_UNPIN_OBJECT (addr0);
sgen_set_nursery_scan_start (addr0);
frag_end = addr0;
size = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)addr0));
++i;
} else {
frag_end = addr1;
size = frags_ranges->fragment_next - addr1;
last_frag = frags_ranges;
frags_ranges = frags_ranges->next_in_order;
}
frag_size = frag_end - frag_start;
if (size == 0)
continue;
g_assert (frag_size >= 0);
g_assert (size > 0);
if (frag_size && size)
add_nursery_frag (&mutator_allocator, frag_size, frag_start, frag_end);
frag_size = size;
#ifdef NALLOC_DEBUG
add_alloc_record (start [i], frag_size, PINNING);
#endif
frag_start = frag_end + frag_size;
}
nursery_last_pinned_end = frag_start;
frag_end = sgen_nursery_end;
frag_size = frag_end - frag_start;
if (frag_size)
add_nursery_frag (&mutator_allocator, frag_size, frag_start, frag_end);
/* Now it's safe to release the fragments exclude list. */
sgen_minor_collector.build_fragments_release_exclude_head ();
/* First we reorder the fragment list to be in ascending address order. This makes H/W prefetchers happier. */
fragment_list_reverse (&mutator_allocator);
/*The collector might want to do something with the final nursery fragment list.*/
sgen_minor_collector.build_fragments_finish (&mutator_allocator);
if (!unmask (mutator_allocator.alloc_head)) {
SGEN_LOG (1, "Nursery fully pinned (%zd)", num_entries);
for (i = 0; i < num_entries; ++i) {
SGEN_LOG (3, "Bastard pinning obj %p (%s), size: %zd", start [i], sgen_safe_name (start [i]), sgen_safe_object_get_size (start [i]));
}
}
return fragment_total;
}
void*
mono_sgen_nursery_alloc_range (size_t desired_size, size_t minimum_size, int *out_alloc_size)
{
Fragment *frag, *min_frag;
DEBUG (4, fprintf (gc_debug_file, "Searching for byte range desired size: %zd minimum size %zd\n", desired_size, minimum_size));
HEAVY_STAT (InterlockedIncrement (&stat_nursery_alloc_range_requests));
restart:
min_frag = NULL;
#ifdef NALLOC_DEBUG
InterlockedIncrement (&alloc_count);
#endif
for (frag = unmask (nursery_fragments); frag; frag = unmask (frag->next)) {
int frag_size = frag->fragment_end - frag->fragment_next;
HEAVY_STAT (InterlockedIncrement (&stat_alloc_range_iterations));
if (desired_size <= frag_size) {
void *p;
*out_alloc_size = desired_size;
p = alloc_from_fragment (frag, desired_size);
if (!p) {
HEAVY_STAT (InterlockedIncrement (&stat_alloc_range_retries));
goto restart;
}
#ifdef NALLOC_DEBUG
add_alloc_record (p, desired_size, RANGE_ALLOC);
#endif
return p;
}
if (minimum_size <= frag_size)
min_frag = frag;
}
/* The second fragment_next read should be ordered in respect to the first code block */
mono_memory_barrier ();
if (min_frag) {
void *p;
int frag_size;
frag_size = min_frag->fragment_end - min_frag->fragment_next;
if (frag_size < minimum_size)
goto restart;
*out_alloc_size = frag_size;
mono_memory_barrier ();
p = alloc_from_fragment (min_frag, frag_size);
/*XXX restarting here is quite dubious given this is already second chance allocation. */
if (!p) {
HEAVY_STAT (InterlockedIncrement (&stat_alloc_retries));
goto restart;
}
#ifdef NALLOC_DEBUG
add_alloc_record (p, frag_size, RANGE_ALLOC);
#endif
return p;
}
return NULL;
}
static void*
alloc_from_fragment (Fragment *frag, size_t size)
{
char *p = frag->fragment_next;
char *end = p + size;
if (end > frag->fragment_end)
return NULL;
/* p = frag->fragment_next must happen before */
mono_memory_barrier ();
if (InterlockedCompareExchangePointer ((volatile gpointer*)&frag->fragment_next, end, p) != p)
return NULL;
if (frag->fragment_end - end < SGEN_MAX_NURSERY_WASTE) {
Fragment *next, **prev_ptr;
/*
* Before we clean the remaining nursery, we must claim the remaining space
* as it could end up been used by the range allocator since it can end up
* allocating from this dying fragment as it doesn't respect SGEN_MAX_NURSERY_WASTE
* when doing second chance allocation.
*/
if (mono_sgen_get_nursery_clear_policy () == CLEAR_AT_TLAB_CREATION && claim_remaining_size (frag, end)) {
/* Clear the remaining space, pinning depends on this. FIXME move this to use phony arrays */
memset (end, 0, frag->fragment_end - end);
HEAVY_STAT (InterlockedExchangeAdd (&stat_wasted_bytes_trailer, frag->fragment_end - end));
#ifdef NALLOC_DEBUG
add_alloc_record (end, frag->fragment_end - end, BLOCK_ZEROING);
#endif
}
prev_ptr = find_previous_pointer_fragment (frag);
/*Use Michaels linked list remove*/
/*prev_ptr will be null is the fragment was removed concurrently */
while (prev_ptr) {
next = frag->next;
/*already deleted*/
if (!get_mark (next)) {
/*frag->next read must happen before the first CAS*/
mono_memory_write_barrier ();
/*Fail if the next done is removed concurrently and its CAS wins */
if (InterlockedCompareExchangePointer ((volatile gpointer*)&frag->next, mask (next, 1), next) != next) {
continue;
}
}
/* The second CAS must happen after the first CAS or frag->next. */
mono_memory_write_barrier ();
/* Fail if the previous node was deleted and its CAS wins */
if (InterlockedCompareExchangePointer ((volatile gpointer*)prev_ptr, next, frag) != frag) {
prev_ptr = find_previous_pointer_fragment (frag);
continue;
}
/* No need to membar here since the worst that can happen is a CAS failure. */
do {
frag->next_free = fragment_freelist;
} while (InterlockedCompareExchangePointer ((volatile gpointer*)&fragment_freelist, frag, frag->next_free) != frag->next_free);
break;
}
}
return p;
}
