| /* |
| * Copyright (c) 2015, 2019, Red Hat, Inc. All rights reserved. |
| * |
| * 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. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHCONCURRENTMARK_INLINE_HPP |
| #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHCONCURRENTMARK_INLINE_HPP |
| |
| #include "gc/shenandoah/shenandoahAsserts.hpp" |
| #include "gc/shenandoah/shenandoahBarrierSet.inline.hpp" |
| #include "gc/shenandoah/shenandoahConcurrentMark.hpp" |
| #include "gc/shenandoah/shenandoahHeap.inline.hpp" |
| #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp" |
| #include "gc/shenandoah/shenandoahStringDedup.inline.hpp" |
| #include "gc/shenandoah/shenandoahTaskqueue.inline.hpp" |
| #include "memory/iterator.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/prefetch.inline.hpp" |
| |
| template <class T> |
| void ShenandoahConcurrentMark::do_task(ShenandoahObjToScanQueue* q, T* cl, ShenandoahLiveData* live_data, ShenandoahMarkTask* task) { |
| oop obj = task->obj(); |
| |
| shenandoah_assert_not_forwarded(NULL, obj); |
| shenandoah_assert_marked(NULL, obj); |
| shenandoah_assert_not_in_cset_except(NULL, obj, _heap->cancelled_gc()); |
| |
| if (task->is_not_chunked()) { |
| if (obj->is_instance()) { |
| // Case 1: Normal oop, process as usual. |
| obj->oop_iterate(cl); |
| } else if (obj->is_objArray()) { |
| // Case 2: Object array instance and no chunk is set. Must be the first |
| // time we visit it, start the chunked processing. |
| do_chunked_array_start<T>(q, cl, obj); |
| } else { |
| // Case 3: Primitive array. Do nothing, no oops there. We use the same |
| // performance tweak TypeArrayKlass::oop_oop_iterate_impl is using: |
| // We skip iterating over the klass pointer since we know that |
| // Universe::TypeArrayKlass never moves. |
| assert (obj->is_typeArray(), "should be type array"); |
| } |
| // Count liveness the last: push the outstanding work to the queues first |
| count_liveness(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()); |
| } |
| } |
| |
| inline void ShenandoahConcurrentMark::count_liveness(ShenandoahLiveData* live_data, oop obj) { |
| 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); |
| live_data[region_idx] = 0; |
| } else { |
| // still good, remember in locals |
| live_data[region_idx] = (ShenandoahLiveData) new_val; |
| } |
| } else { |
| shenandoah_assert_in_correct_region(NULL, obj); |
| size_t num_regions = ShenandoahHeapRegion::required_regions(size * HeapWordSize); |
| |
| 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"); |
| chain_reg->increase_live_data_gc_words(chain_reg->used() >> LogHeapWordSize); |
| } |
| } |
| } |
| |
| template <class T> |
| inline void ShenandoahConcurrentMark::do_chunked_array_start(ShenandoahObjToScanQueue* q, T* cl, oop obj) { |
| assert(obj->is_objArray(), "expect object array"); |
| objArrayOop array = objArrayOop(obj); |
| int len = array->length(); |
| |
| // Mark objArray klass metadata |
| if (Devirtualizer::do_metadata(cl)) { |
| Devirtualizer::do_klass(cl, array->klass()); |
| } |
| |
| if (len <= (int) ObjArrayMarkingStride*2) { |
| // A few slices only, process directly |
| array->oop_iterate_range(cl, 0, len); |
| } else { |
| int bits = log2_long(len); |
| // Compensate for non-power-of-two arrays, cover the array in excess: |
| if (len != (1 << bits)) bits++; |
| |
| // Only allow full chunks on the queue. This frees do_chunked_array() from checking from/to |
| // boundaries against array->length(), touching the array header on every chunk. |
| // |
| // To do this, we cut the prefix in full-sized chunks, and submit them on the queue. |
| // If the array is not divided in chunk sizes, then there would be an irregular tail, |
| // which we will process separately. |
| |
| int last_idx = 0; |
| |
| int chunk = 1; |
| int pow = bits; |
| |
| // Handle overflow |
| if (pow >= 31) { |
| assert (pow == 31, "sanity"); |
| pow--; |
| chunk = 2; |
| last_idx = (1 << pow); |
| bool pushed = q->push(ShenandoahMarkTask(array, 1, pow)); |
| assert(pushed, "overflow queue should always succeed pushing"); |
| } |
| |
| // Split out tasks, as suggested in ShenandoahMarkTask docs. Record the last |
| // successful right boundary to figure out the irregular tail. |
| while ((1 << pow) > (int)ObjArrayMarkingStride && |
| (chunk*2 < ShenandoahMarkTask::chunk_size())) { |
| pow--; |
| int left_chunk = chunk*2 - 1; |
| int right_chunk = chunk*2; |
| int left_chunk_end = left_chunk * (1 << pow); |
| if (left_chunk_end < len) { |
| bool pushed = q->push(ShenandoahMarkTask(array, left_chunk, pow)); |
| assert(pushed, "overflow queue should always succeed pushing"); |
| chunk = right_chunk; |
| last_idx = left_chunk_end; |
| } else { |
| chunk = left_chunk; |
| } |
| } |
| |
| // Process the irregular tail, if present |
| int from = last_idx; |
| if (from < len) { |
| array->oop_iterate_range(cl, from, len); |
| } |
| } |
| } |
| |
| template <class T> |
| inline void ShenandoahConcurrentMark::do_chunked_array(ShenandoahObjToScanQueue* q, T* cl, oop obj, int chunk, int pow) { |
| assert(obj->is_objArray(), "expect object array"); |
| objArrayOop array = objArrayOop(obj); |
| |
| assert (ObjArrayMarkingStride > 0, "sanity"); |
| |
| // Split out tasks, as suggested in ShenandoahMarkTask docs. Avoid pushing tasks that |
| // are known to start beyond the array. |
| while ((1 << pow) > (int)ObjArrayMarkingStride && (chunk*2 < ShenandoahMarkTask::chunk_size())) { |
| pow--; |
| chunk *= 2; |
| bool pushed = q->push(ShenandoahMarkTask(array, chunk - 1, pow)); |
| assert(pushed, "overflow queue should always succeed pushing"); |
| } |
| |
| int chunk_size = 1 << pow; |
| |
| int from = (chunk - 1) * chunk_size; |
| int to = chunk * chunk_size; |
| |
| #ifdef ASSERT |
| int len = array->length(); |
| assert (0 <= from && from < len, "from is sane: %d/%d", from, len); |
| assert (0 < to && to <= len, "to is sane: %d/%d", to, len); |
| #endif |
| |
| array->oop_iterate_range(cl, from, to); |
| } |
| |
| class ShenandoahConcMarkSATBBufferClosure : public ShenandoahSATBBufferClosure { |
| private: |
| ShenandoahObjToScanQueue* _queue; |
| ShenandoahHeap* _heap; |
| ShenandoahMarkingContext* const _mark_context; |
| public: |
| ShenandoahConcMarkSATBBufferClosure(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"); |
| if (ShenandoahStringDedup::is_enabled()) { |
| do_buffer_impl<ENQUEUE_DEDUP>(buffer, size); |
| } else { |
| do_buffer_impl<NO_DEDUP>(buffer, size); |
| } |
| } |
| |
| template<StringDedupMode STRING_DEDUP> |
| void do_buffer_impl(void **buffer, size_t size) { |
| for (size_t i = 0; i < size; ++i) { |
| oop *p = (oop *) &buffer[i]; |
| ShenandoahConcurrentMark::mark_through_ref<oop, NONE, STRING_DEDUP>(p, _heap, _queue, _mark_context); |
| } |
| } |
| }; |
| |
| template<class T, UpdateRefsMode UPDATE_REFS, StringDedupMode STRING_DEDUP> |
| inline void ShenandoahConcurrentMark::mark_through_ref(T *p, ShenandoahHeap* heap, ShenandoahObjToScanQueue* q, ShenandoahMarkingContext* const mark_context) { |
| T o = RawAccess<>::oop_load(p); |
| if (!CompressedOops::is_null(o)) { |
| oop obj = CompressedOops::decode_not_null(o); |
| switch (UPDATE_REFS) { |
| case NONE: |
| break; |
| case RESOLVE: |
| obj = ShenandoahBarrierSet::resolve_forwarded_not_null(obj); |
| break; |
| case SIMPLE: |
| // We piggy-back reference updating to the marking tasks. |
| obj = heap->update_with_forwarded_not_null(p, obj); |
| break; |
| case CONCURRENT: |
| obj = heap->maybe_update_with_forwarded_not_null(p, obj); |
| break; |
| default: |
| ShouldNotReachHere(); |
| } |
| |
| // Note: Only when concurrently updating references can obj be different |
| // (that is, really different, not just different from-/to-space copies of the same) |
| // from the one we originally loaded. Mutator thread can beat us by writing something |
| // else into the location. In that case, we would mark through that updated value, |
| // on the off-chance it is not handled by other means (e.g. via SATB). However, |
| // if that write was NULL, we don't need to do anything else. |
| if (UPDATE_REFS != CONCURRENT || !CompressedOops::is_null(obj)) { |
| shenandoah_assert_not_forwarded(p, obj); |
| shenandoah_assert_not_in_cset_except(p, obj, heap->cancelled_gc()); |
| |
| if (mark_context->mark(obj)) { |
| bool pushed = q->push(ShenandoahMarkTask(obj)); |
| assert(pushed, "overflow queue should always succeed pushing"); |
| |
| if ((STRING_DEDUP == ENQUEUE_DEDUP) && ShenandoahStringDedup::is_candidate(obj)) { |
| assert(ShenandoahStringDedup::is_enabled(), "Must be enabled"); |
| ShenandoahStringDedup::enqueue_candidate(obj); |
| } |
| } |
| |
| shenandoah_assert_marked(p, obj); |
| } |
| } |
| } |
| |
| #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHCONCURRENTMARK_INLINE_HPP |