1 /* 2 * Copyright (c) 2017, 2021, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 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 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc/g1/g1FullGCCompactionPoint.hpp" 27 #include "gc/g1/heapRegion.hpp" 28 #include "gc/shared/slidingForwarding.inline.hpp" 29 #include "oops/oop.inline.hpp" 30 #include "utilities/debug.hpp" 31 32 G1FullGCCompactionPoint::G1FullGCCompactionPoint() : 33 _current_region(NULL), 34 _compaction_top(NULL) { 35 _compaction_regions = new (ResourceObj::C_HEAP, mtGC) GrowableArray<HeapRegion*>(32, mtGC); 36 _compaction_region_iterator = _compaction_regions->begin(); 37 } 38 39 G1FullGCCompactionPoint::~G1FullGCCompactionPoint() { 40 delete _compaction_regions; 41 } 42 43 void G1FullGCCompactionPoint::update() { 44 if (is_initialized()) { 45 _current_region->set_compaction_top(_compaction_top); 46 } 47 } 48 49 void G1FullGCCompactionPoint::initialize_values() { 50 _compaction_top = _current_region->compaction_top(); 51 } 52 53 bool G1FullGCCompactionPoint::has_regions() { 54 return !_compaction_regions->is_empty(); 55 } 56 57 bool G1FullGCCompactionPoint::is_initialized() { 58 return _current_region != NULL; 59 } 60 61 void G1FullGCCompactionPoint::initialize(HeapRegion* hr) { 62 _current_region = hr; 63 initialize_values(); 64 } 65 66 HeapRegion* G1FullGCCompactionPoint::current_region() { 67 return *_compaction_region_iterator; 68 } 69 70 HeapRegion* G1FullGCCompactionPoint::next_region() { 71 HeapRegion* next = *(++_compaction_region_iterator); 72 assert(next != NULL, "Must return valid region"); 73 return next; 74 } 75 76 GrowableArray<HeapRegion*>* G1FullGCCompactionPoint::regions() { 77 return _compaction_regions; 78 } 79 80 bool G1FullGCCompactionPoint::object_will_fit(size_t size) { 81 size_t space_left = pointer_delta(_current_region->end(), _compaction_top); 82 return size <= space_left; 83 } 84 85 void G1FullGCCompactionPoint::switch_region() { 86 // Save compaction top in the region. 87 _current_region->set_compaction_top(_compaction_top); 88 // Get the next region and re-initialize the values. 89 _current_region = next_region(); 90 initialize_values(); 91 } 92 93 void G1FullGCCompactionPoint::forward(SlidingForwarding* const forwarding, oop object, size_t size) { 94 assert(_current_region != NULL, "Must have been initialized"); 95 96 // Ensure the object fit in the current region. 97 while (!object_will_fit(size)) { 98 switch_region(); 99 } 100 101 // Store a forwarding pointer if the object should be moved. 102 if (cast_from_oop<HeapWord*>(object) != _compaction_top) { 103 forwarding->forward_to(object, cast_to_oop(_compaction_top)); 104 assert(object->is_forwarded(), "must be forwarded"); 105 } else { 106 assert(!object->is_forwarded(), "must not be forwarded"); 107 } 108 109 // Update compaction values. 110 _compaction_top += size; 111 _current_region->update_bot_for_block(_compaction_top - size, _compaction_top); 112 } 113 114 void G1FullGCCompactionPoint::add(HeapRegion* hr) { 115 _compaction_regions->append(hr); 116 } 117 118 HeapRegion* G1FullGCCompactionPoint::remove_last() { 119 return _compaction_regions->pop(); 120 }