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/g1CollectedHeap.hpp" 27 #include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp" 28 #include "gc/g1/g1FullCollector.hpp" 29 #include "gc/g1/g1FullCollector.inline.hpp" 30 #include "gc/g1/g1FullGCCompactionPoint.hpp" 31 #include "gc/g1/g1FullGCCompactTask.hpp" 32 #include "gc/g1/heapRegion.inline.hpp" 33 #include "gc/shared/gcTraceTime.inline.hpp" 34 #include "gc/shared/slidingForwarding.inline.hpp" 35 #include "logging/log.hpp" 36 #include "oops/oop.inline.hpp" 37 #include "utilities/ticks.hpp" 38 39 // Do work for all skip-compacting regions. 40 class G1ResetSkipCompactingClosure : public HeapRegionClosure { 41 G1FullCollector* _collector; 42 43 public: 44 G1ResetSkipCompactingClosure(G1FullCollector* collector) : _collector(collector) { } 45 46 bool do_heap_region(HeapRegion* r) { 47 uint region_index = r->hrm_index(); 48 // Only for skip-compaction regions; early return otherwise. 49 if (!_collector->is_skip_compacting(region_index)) { 50 51 return false; 52 } 53 assert(_collector->live_words(region_index) > _collector->scope()->region_compaction_threshold() || 54 !r->is_starts_humongous() || 55 _collector->mark_bitmap()->is_marked(cast_to_oop(r->bottom())), 56 "must be, otherwise reclaimed earlier"); 57 r->reset_skip_compacting_after_full_gc(); 58 return false; 59 } 60 }; 61 62 size_t G1FullGCCompactTask::G1CompactRegionClosure::apply(oop obj) { 63 size_t size = obj->size(); 64 if (!obj->is_forwarded()) { 65 // Object not moving 66 return size; 67 } 68 69 HeapWord* destination = cast_from_oop<HeapWord*>(_forwarding->forwardee(obj)); 70 71 // copy object and reinit its mark 72 HeapWord* obj_addr = cast_from_oop<HeapWord*>(obj); 73 assert(obj_addr != destination, "everything in this pass should be moving"); 74 Copy::aligned_conjoint_words(obj_addr, destination, size); 75 cast_to_oop(destination)->init_mark(); 76 assert(cast_to_oop(destination)->klass() != NULL, "should have a class"); 77 78 return size; 79 } 80 81 void G1FullGCCompactTask::compact_region(HeapRegion* hr) { 82 assert(!hr->is_pinned(), "Should be no pinned region in compaction queue"); 83 assert(!hr->is_humongous(), "Should be no humongous regions in compaction queue"); 84 G1CompactRegionClosure compact(collector()->mark_bitmap()); 85 hr->apply_to_marked_objects(collector()->mark_bitmap(), &compact); 86 // Clear the liveness information for this region if necessary i.e. if we actually look at it 87 // for bitmap verification. Otherwise it is sufficient that we move the TAMS to bottom(). 88 if (G1VerifyBitmaps) { 89 collector()->mark_bitmap()->clear_region(hr); 90 } 91 hr->reset_compacted_after_full_gc(); 92 } 93 94 void G1FullGCCompactTask::work(uint worker_id) { 95 Ticks start = Ticks::now(); 96 GrowableArray<HeapRegion*>* compaction_queue = collector()->compaction_point(worker_id)->regions(); 97 for (GrowableArrayIterator<HeapRegion*> it = compaction_queue->begin(); 98 it != compaction_queue->end(); 99 ++it) { 100 compact_region(*it); 101 } 102 103 G1ResetSkipCompactingClosure hc(collector()); 104 G1CollectedHeap::heap()->heap_region_par_iterate_from_worker_offset(&hc, &_claimer, worker_id); 105 log_task("Compaction task", worker_id, start); 106 } 107 108 void G1FullGCCompactTask::serial_compaction() { 109 GCTraceTime(Debug, gc, phases) tm("Phase 4: Serial Compaction", collector()->scope()->timer()); 110 GrowableArray<HeapRegion*>* compaction_queue = collector()->serial_compaction_point()->regions(); 111 for (GrowableArrayIterator<HeapRegion*> it = compaction_queue->begin(); 112 it != compaction_queue->end(); 113 ++it) { 114 compact_region(*it); 115 } 116 }