1 /*
  2  * Copyright (c) 2022, 2023, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
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 24 
 25 #ifndef SHARE_GC_G1_G1FULLGCPREPARETASK_INLINE_HPP
 26 #define SHARE_GC_G1_G1FULLGCPREPARETASK_INLINE_HPP
 27 
 28 #include "gc/g1/g1FullGCPrepareTask.hpp"
 29 
 30 #include "gc/g1/g1CollectedHeap.inline.hpp"
 31 #include "gc/g1/g1FullCollector.hpp"
 32 #include "gc/g1/g1FullGCCompactionPoint.hpp"
 33 #include "gc/g1/g1FullGCScope.hpp"
 34 #include "gc/g1/heapRegion.inline.hpp"
 35 
 36 template<bool is_humongous>
 37 void G1DetermineCompactionQueueClosure::free_pinned_region(HeapRegion* hr) {
 38   if (is_humongous) {
 39     _g1h->free_humongous_region(hr, nullptr);
 40   } else {
 41     _g1h->free_region(hr, nullptr);
 42   }
 43   _collector->set_free(hr->hrm_index());
 44   add_to_compaction_queue(hr);
 45 }
 46 
 47 inline bool G1DetermineCompactionQueueClosure::should_compact(HeapRegion* hr) const {
 48   // There is no need to iterate and forward objects in pinned regions ie.
 49   // prepare them for compaction.
 50   if (hr->is_pinned()) {
 51     return false;
 52   }
 53   size_t live_words = _collector->live_words(hr->hrm_index());
 54   size_t live_words_threshold = _collector->scope()->region_compaction_threshold();
 55   // High live ratio region will not be compacted.
 56   return live_words <= live_words_threshold;
 57 }
 58 
 59 inline uint G1DetermineCompactionQueueClosure::next_worker() {
 60   uint result = _cur_worker;
 61   _cur_worker = (_cur_worker + 1) % _collector->workers();
 62   return result;
 63 }
 64 
 65 inline G1FullGCCompactionPoint* G1DetermineCompactionQueueClosure::next_compaction_point() {
 66   return _collector->compaction_point(next_worker());
 67 }
 68 
 69 inline void G1DetermineCompactionQueueClosure::add_to_compaction_queue(HeapRegion* hr) {
 70   _collector->set_compaction_top(hr, hr->bottom());
 71   _collector->set_has_compaction_targets();
 72 
 73   G1FullGCCompactionPoint* cp = next_compaction_point();
 74   if (!cp->is_initialized()) {
 75     cp->initialize(hr);
 76   }
 77   // Add region to the compaction queue.
 78   cp->add(hr);
 79 }
 80 
 81 inline bool G1DetermineCompactionQueueClosure::do_heap_region(HeapRegion* hr) {
 82   if (should_compact(hr)) {
 83     assert(!hr->is_humongous(), "moving humongous objects not supported.");
 84     add_to_compaction_queue(hr);
 85   } else {
 86     assert(hr->containing_set() == nullptr, "already cleared by PrepareRegionsClosure");
 87     if (hr->is_humongous()) {
 88       oop obj = cast_to_oop(hr->humongous_start_region()->bottom());
 89       bool is_empty = !_collector->mark_bitmap()->is_marked(obj);
 90       if (is_empty) {
 91         free_pinned_region<true>(hr);
 92       }
 93     } else if (hr->is_open_archive()) {
 94       bool is_empty = _collector->live_words(hr->hrm_index()) == 0;
 95       if (is_empty) {
 96         free_pinned_region<false>(hr);
 97       }
 98     } else if (hr->is_closed_archive()) {
 99       // nothing to do with closed archive region
100     } else {
101       assert(MarkSweepDeadRatio > 0,
102              "only skip compaction for other regions when MarkSweepDeadRatio > 0");
103 
104       // Too many live objects in the region; skip compacting it.
105       _collector->update_from_compacting_to_skip_compacting(hr->hrm_index());
106       log_trace(gc, phases)("Phase 2: skip compaction region index: %u, live words: " SIZE_FORMAT,
107                             hr->hrm_index(), _collector->live_words(hr->hrm_index()));
108     }
109   }
110 
111   return false;
112 }
113 
114 inline size_t G1SerialRePrepareClosure::apply(oop obj) {
115   if (obj->is_forwarded()) {
116     // We skip objects compiled into the first region or
117     // into regions not part of the serial compaction point.
118     if (cast_from_oop<HeapWord*>(obj->forwardee()) < _dense_prefix_top) {
119       return obj->size();
120     }
121   }
122 
123   // Get size and forward.
124   size_t size = obj->size();
125   _cp->forward(obj, size);
126 
127   return size;
128 }
129 
130 #endif // SHARE_GC_G1_G1FULLGCPREPARETASK_INLINE_HPP