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/*
* Copyright (c) 2015, 2022, Red Hat, Inc. All rights reserved.
+ * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
}
}
}
template <class T, ShenandoahGenerationType GENERATION, StringDedupMode STRING_DEDUP>
! void ShenandoahMark::do_task(ShenandoahObjToScanQueue* q, T* cl, ShenandoahLiveData* live_data, StringDedup::Requests* const req, ShenandoahMarkTask* task) {
oop obj = task->obj();
shenandoah_assert_not_forwarded(nullptr, obj);
shenandoah_assert_marked(nullptr, obj);
shenandoah_assert_not_in_cset_except(nullptr, obj, ShenandoahHeap::heap()->cancelled_gc());
// Are we in weak subgraph scan?
}
}
}
template <class T, ShenandoahGenerationType GENERATION, StringDedupMode STRING_DEDUP>
! void ShenandoahMark::do_task(ShenandoahObjToScanQueue* q, T* cl, ShenandoahLiveData* live_data, StringDedup::Requests* const req, ShenandoahMarkTask* task, uint worker_id) {
oop obj = task->obj();
+ // TODO: This will push array chunks into the mark queue with no regard for
+ // generations. I don't think it will break anything, but the young generation
+ // scan might end up processing some old generation array chunks.
+
shenandoah_assert_not_forwarded(nullptr, obj);
shenandoah_assert_marked(nullptr, obj);
shenandoah_assert_not_in_cset_except(nullptr, obj, ShenandoahHeap::heap()->cancelled_gc());
// Are we in weak subgraph scan?
}
// Count liveness the last: push the outstanding work to the queues first
// Avoid double-counting objects that are visited twice due to upgrade
// from final- to strong mark.
if (task->count_liveness()) {
! count_liveness<GENERATION>(live_data, obj);
}
} else {
// Case 4: Array chunk, has sensible chunk id. Process it.
do_chunked_array<T>(q, cl, obj, task->chunk(), task->pow(), weak);
}
}
template <ShenandoahGenerationType GENERATION>
! inline void ShenandoahMark::count_liveness(ShenandoahLiveData* live_data, oop obj) {
! ShenandoahHeap* const heap = ShenandoahHeap::heap();
! size_t region_idx = heap->heap_region_index_containing(obj);
! ShenandoahHeapRegion* region = heap->get_region(region_idx);
! size_t size = obj->size();
if (!region->is_humongous_start()) {
assert(!region->is_humongous(), "Cannot have continuations here");
ShenandoahLiveData cur = live_data[region_idx];
size_t new_val = size + cur;
if (new_val >= SHENANDOAH_LIVEDATA_MAX) {
// overflow, flush to region data
region->increase_live_data_gc_words(new_val);
}
// Count liveness the last: push the outstanding work to the queues first
// Avoid double-counting objects that are visited twice due to upgrade
// from final- to strong mark.
if (task->count_liveness()) {
! count_liveness<GENERATION>(live_data, obj, worker_id);
}
} else {
// Case 4: Array chunk, has sensible chunk id. Process it.
do_chunked_array<T>(q, cl, obj, task->chunk(), task->pow(), weak);
}
}
template <ShenandoahGenerationType GENERATION>
! inline void ShenandoahMark::count_liveness(ShenandoahLiveData* live_data, oop obj, uint worker_id) {
! const ShenandoahHeap* const heap = ShenandoahHeap::heap();
! const size_t region_idx = heap->heap_region_index_containing(obj);
! ShenandoahHeapRegion* const region = heap->get_region(region_idx);
! const size_t size = obj->size();
+
+ // Age census for objects in the young generation
+ if (GENERATION == YOUNG || (GENERATION == GLOBAL && region->is_young())) {
+ assert(heap->mode()->is_generational(), "Only if generational");
+ if (ShenandoahGenerationalAdaptiveTenuring && !ShenandoahGenerationalCensusAtEvac) {
+ assert(region->is_young(), "Only for young objects");
+ uint age = ShenandoahHeap::get_object_age(obj);
+ CENSUS_NOISE(heap->age_census()->add(age, region->age(), region->youth(), size, worker_id);)
+ NO_CENSUS_NOISE(heap->age_census()->add(age, region->age(), size, worker_id);)
+ }
+ }
if (!region->is_humongous_start()) {
assert(!region->is_humongous(), "Cannot have continuations here");
+ assert(region->is_affiliated(), "Do not count live data within Free Regular Region " SIZE_FORMAT, region_idx);
ShenandoahLiveData cur = live_data[region_idx];
size_t new_val = size + cur;
if (new_val >= SHENANDOAH_LIVEDATA_MAX) {
// overflow, flush to region data
region->increase_live_data_gc_words(new_val);
}
} else {
shenandoah_assert_in_correct_region(nullptr, obj);
size_t num_regions = ShenandoahHeapRegion::required_regions(size * HeapWordSize);
+ assert(region->is_affiliated(), "Do not count live data within FREE Humongous Start Region " SIZE_FORMAT, region_idx);
for (size_t i = region_idx; i < region_idx + num_regions; i++) {
ShenandoahHeapRegion* chain_reg = heap->get_region(i);
assert(chain_reg->is_humongous(), "Expecting a humongous region");
+ assert(chain_reg->is_affiliated(), "Do not count live data within FREE Humongous Continuation Region " SIZE_FORMAT, i);
chain_reg->increase_live_data_gc_words(chain_reg->used() >> LogHeapWordSize);
}
}
}
template <ShenandoahGenerationType GENERATION>
class ShenandoahSATBBufferClosure : public SATBBufferClosure {
private:
ShenandoahObjToScanQueue* _queue;
ShenandoahHeap* _heap;
ShenandoahMarkingContext* const _mark_context;
public:
! ShenandoahSATBBufferClosure(ShenandoahObjToScanQueue* q) :
_queue(q),
_heap(ShenandoahHeap::heap()),
_mark_context(_heap->marking_context())
{
}
void do_buffer(void **buffer, size_t size) {
! assert(size == 0 || !_heap->has_forwarded_objects(), "Forwarded objects are not expected here");
for (size_t i = 0; i < size; ++i) {
oop *p = (oop *) &buffer[i];
! ShenandoahMark::mark_through_ref<oop, GENERATION>(p, _queue, _mark_context, false);
}
}
};
template<class T, ShenandoahGenerationType GENERATION>
! inline void ShenandoahMark::mark_through_ref(T* p, ShenandoahObjToScanQueue* q, ShenandoahMarkingContext* const mark_context, bool weak) {
T o = RawAccess<>::oop_load(p);
if (!CompressedOops::is_null(o)) {
oop obj = CompressedOops::decode_not_null(o);
shenandoah_assert_not_forwarded(p, obj);
! shenandoah_assert_not_in_cset_except(p, obj, ShenandoahHeap::heap()->cancelled_gc());
!
! bool skip_live = false;
! bool marked;
! if (weak) {
! marked = mark_context->mark_weak(obj);
! } else {
! marked = mark_context->mark_strong(obj, /* was_upgraded = */ skip_live);
! }
! if (marked) {
! bool pushed = q->push(ShenandoahMarkTask(obj, skip_live, weak));
! assert(pushed, "overflow queue should always succeed pushing");
}
! shenandoah_assert_marked(p, obj);
}
}
ShenandoahObjToScanQueueSet* ShenandoahMark::task_queues() const {
return _task_queues;
}
ShenandoahObjToScanQueue* ShenandoahMark::get_queue(uint index) const {
return _task_queues->queue(index);
}
#endif // SHARE_GC_SHENANDOAH_SHENANDOAHMARK_INLINE_HPP
template <ShenandoahGenerationType GENERATION>
class ShenandoahSATBBufferClosure : public SATBBufferClosure {
private:
ShenandoahObjToScanQueue* _queue;
+ ShenandoahObjToScanQueue* _old_queue;
ShenandoahHeap* _heap;
ShenandoahMarkingContext* const _mark_context;
public:
! ShenandoahSATBBufferClosure(ShenandoahObjToScanQueue* q, ShenandoahObjToScanQueue* old_q) :
_queue(q),
+ _old_queue(old_q),
_heap(ShenandoahHeap::heap()),
_mark_context(_heap->marking_context())
{
}
void do_buffer(void **buffer, size_t size) {
! assert(size == 0 || !_heap->has_forwarded_objects() || _heap->is_concurrent_old_mark_in_progress(), "Forwarded objects are not expected here");
for (size_t i = 0; i < size; ++i) {
oop *p = (oop *) &buffer[i];
! ShenandoahMark::mark_through_ref<oop, GENERATION>(p, _queue, _old_queue, _mark_context, false);
}
}
};
+ template<ShenandoahGenerationType GENERATION>
+ bool ShenandoahMark::in_generation(ShenandoahHeap* const heap, oop obj) {
+ // Each in-line expansion of in_generation() resolves GENERATION at compile time.
+ if (GENERATION == YOUNG) {
+ return heap->is_in_young(obj);
+ } else if (GENERATION == OLD) {
+ return heap->is_in_old(obj);
+ } else if (GENERATION == GLOBAL || GENERATION == NON_GEN) {
+ return true;
+ } else {
+ return false;
+ }
+ }
+
template<class T, ShenandoahGenerationType GENERATION>
! inline void ShenandoahMark::mark_through_ref(T *p, ShenandoahObjToScanQueue* q, ShenandoahObjToScanQueue* old_q, ShenandoahMarkingContext* const mark_context, bool weak) {
+ // Note: This is a very hot code path, so the code should be conditional on GENERATION template
+ // parameter where possible, in order to generate the most efficient code.
+
T o = RawAccess<>::oop_load(p);
if (!CompressedOops::is_null(o)) {
oop obj = CompressedOops::decode_not_null(o);
+ ShenandoahHeap* heap = ShenandoahHeap::heap();
shenandoah_assert_not_forwarded(p, obj);
! shenandoah_assert_not_in_cset_except(p, obj, heap->cancelled_gc());
! if (in_generation<GENERATION>(heap, obj)) {
! mark_ref(q, mark_context, weak, obj);
! shenandoah_assert_marked(p, obj);
! // TODO: As implemented herein, GLOBAL collections reconstruct the card table during GLOBAL concurrent
! // marking. Note that the card table is cleaned at init_mark time so it needs to be reconstructed to support
! // future young-gen collections. It might be better to reconstruct card table in a different phase. We could
! // either mark all live memory as dirty, or could use the GLOBAL update-refs scanning of pointers to determine
! // precisely which cards to flag as dirty.
! if (GENERATION == YOUNG && heap->is_in_old(p)) {
! // Mark card as dirty because remembered set scanning still finds interesting pointer.
! heap->mark_card_as_dirty((HeapWord*)p);
+ } else if (GENERATION == GLOBAL && heap->is_in_old(p) && heap->is_in_young(obj)) {
+ // Mark card as dirty because GLOBAL marking finds interesting pointer.
+ heap->mark_card_as_dirty((HeapWord*)p);
+ }
+ } else if (old_q != nullptr) {
+ // Young mark, bootstrapping old_q or concurrent with old_q marking.
+ mark_ref(old_q, mark_context, weak, obj);
+ shenandoah_assert_marked(p, obj);
+ } else if (GENERATION == OLD) {
+ // Old mark, found a young pointer.
+ // TODO: Rethink this: may be redundant with dirtying of cards identified during young-gen remembered set scanning
+ // and by mutator write barriers. Assert
+ if (heap->is_in(p)) {
+ assert(heap->is_in_young(obj), "Expected young object.");
+ heap->mark_card_as_dirty(p);
+ }
}
+ }
+ }
! inline void ShenandoahMark::mark_ref(ShenandoahObjToScanQueue* q,
+ ShenandoahMarkingContext* const mark_context,
+ bool weak, oop obj) {
+ bool skip_live = false;
+ bool marked;
+ if (weak) {
+ marked = mark_context->mark_weak(obj);
+ } else {
+ marked = mark_context->mark_strong(obj, /* was_upgraded = */ skip_live);
+ }
+ if (marked) {
+ bool pushed = q->push(ShenandoahMarkTask(obj, skip_live, weak));
+ assert(pushed, "overflow queue should always succeed pushing");
}
}
ShenandoahObjToScanQueueSet* ShenandoahMark::task_queues() const {
return _task_queues;
}
ShenandoahObjToScanQueue* ShenandoahMark::get_queue(uint index) const {
return _task_queues->queue(index);
}
+
+ ShenandoahObjToScanQueue* ShenandoahMark::get_old_queue(uint index) const {
+ if (_old_gen_task_queues != nullptr) {
+ return _old_gen_task_queues->queue(index);
+ }
+ return nullptr;
+ }
+
#endif // SHARE_GC_SHENANDOAH_SHENANDOAHMARK_INLINE_HPP
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