1 /*
2 * Copyright (c) 2017, 2020, 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 "classfile/classLoaderDataGraph.hpp"
27 #include "gc/g1/g1CollectedHeap.hpp"
28 #include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"
29 #include "gc/g1/g1FullCollector.inline.hpp"
30 #include "gc/g1/g1FullGCAdjustTask.hpp"
31 #include "gc/g1/g1FullGCCompactionPoint.hpp"
32 #include "gc/g1/g1FullGCMarker.hpp"
33 #include "gc/g1/g1FullGCOopClosures.inline.hpp"
34 #include "gc/g1/heapRegion.inline.hpp"
35 #include "gc/shared/gcTraceTime.inline.hpp"
36 #include "gc/shared/referenceProcessor.hpp"
37 #include "gc/shared/weakProcessor.inline.hpp"
38 #include "logging/log.hpp"
39 #include "memory/iterator.inline.hpp"
40 #include "runtime/atomic.hpp"
41
42 class G1AdjustLiveClosure : public StackObj {
43 G1AdjustClosure* _adjust_closure;
44 public:
G1AdjustLiveClosure(G1AdjustClosure * cl)45 G1AdjustLiveClosure(G1AdjustClosure* cl) :
46 _adjust_closure(cl) { }
47
apply(oop object)48 size_t apply(oop object) {
49 return object->oop_iterate_size(_adjust_closure);
50 }
51 };
52
53 class G1AdjustRegionClosure : public HeapRegionClosure {
54 G1FullCollector* _collector;
55 G1CMBitMap* _bitmap;
56 uint _worker_id;
57 public:
G1AdjustRegionClosure(G1FullCollector * collector,uint worker_id)58 G1AdjustRegionClosure(G1FullCollector* collector, uint worker_id) :
59 _collector(collector),
60 _bitmap(collector->mark_bitmap()),
61 _worker_id(worker_id) { }
62
do_heap_region(HeapRegion * r)63 bool do_heap_region(HeapRegion* r) {
64 G1AdjustClosure cl(_collector);
65 if (r->is_humongous()) {
66 // Special handling for humongous regions to get somewhat better
67 // work distribution.
68 oop obj = oop(r->humongous_start_region()->bottom());
69 obj->oop_iterate(&cl, MemRegion(r->bottom(), r->top()));
70 } else if (!r->is_closed_archive() && !r->is_free()) {
71 // Closed archive regions never change references and only contain
72 // references into other closed regions and are always live. Free
73 // regions do not contain objects to iterate. So skip both.
74 G1AdjustLiveClosure adjust(&cl);
75 r->apply_to_marked_objects(_bitmap, &adjust);
76 }
77 return false;
78 }
79 };
80
G1FullGCAdjustTask(G1FullCollector * collector)81 G1FullGCAdjustTask::G1FullGCAdjustTask(G1FullCollector* collector) :
82 G1FullGCTask("G1 Adjust", collector),
83 _root_processor(G1CollectedHeap::heap(), collector->workers()),
84 _references_done(0),
85 _weak_proc_task(collector->workers()),
86 _hrclaimer(collector->workers()),
87 _adjust(collector),
88 _string_dedup_cleaning_task(NULL, &_adjust, false) {
89 // Need cleared claim bits for the roots processing
90 ClassLoaderDataGraph::clear_claimed_marks();
91 }
92
work(uint worker_id)93 void G1FullGCAdjustTask::work(uint worker_id) {
94 Ticks start = Ticks::now();
95 ResourceMark rm;
96
97 // Adjust preserved marks first since they are not balanced.
98 G1FullGCMarker* marker = collector()->marker(worker_id);
99 marker->preserved_stack()->adjust_during_full_gc();
100
101 // Adjust the weak roots.
102
103 if (Atomic::add(&_references_done, 1u) == 1u) { // First incr claims task.
104 G1CollectedHeap::heap()->ref_processor_stw()->weak_oops_do(&_adjust);
105 }
106
107 AlwaysTrueClosure always_alive;
108 _weak_proc_task.work(worker_id, &always_alive, &_adjust);
109
110 CLDToOopClosure adjust_cld(&_adjust, ClassLoaderData::_claim_strong);
111 CodeBlobToOopClosure adjust_code(&_adjust, CodeBlobToOopClosure::FixRelocations);
112 _root_processor.process_all_roots(&_adjust, &adjust_cld, &adjust_code);
113
114 // Adjust string dedup data structures.
115 _string_dedup_cleaning_task.work(worker_id);
116
117 // Now adjust pointers region by region
118 G1AdjustRegionClosure blk(collector(), worker_id);
119 G1CollectedHeap::heap()->heap_region_par_iterate_from_worker_offset(&blk, &_hrclaimer, worker_id);
120 log_task("Adjust task", worker_id, start);
121 }
122