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