1 /*
2 * Copyright (c) 2021, Amazon.com, Inc. or its affiliates. All rights reserved.
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26
27 #include "precompiled.hpp"
28
29 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
30 #include "gc/shenandoah/shenandoahOopClosures.inline.hpp"
31 #include "gc/shenandoah/shenandoahReferenceProcessor.hpp"
32 #include "gc/shenandoah/shenandoahScanRemembered.inline.hpp"
33
34 ShenandoahDirectCardMarkRememberedSet::ShenandoahDirectCardMarkRememberedSet(ShenandoahCardTable* card_table, size_t total_card_count) {
35 _heap = ShenandoahHeap::heap();
36 _card_table = card_table;
37 _total_card_count = total_card_count;
38 _cluster_count = total_card_count / ShenandoahCardCluster<ShenandoahDirectCardMarkRememberedSet>::CardsPerCluster;
39 _card_shift = CardTable::card_shift;
40
41 _byte_map = _card_table->byte_for_index(0);
42
43 _whole_heap_base = _card_table->addr_for(_byte_map);
44 _whole_heap_end = _whole_heap_base + total_card_count * CardTable::card_size;
45
46 _byte_map_base = _byte_map - (uintptr_t(_whole_heap_base) >> _card_shift);
47
48 _overreach_map = (uint8_t *) malloc(total_card_count);
49 _overreach_map_base = (_overreach_map -
50 (uintptr_t(_whole_heap_base) >> _card_shift));
51
52 assert(total_card_count % ShenandoahCardCluster<ShenandoahDirectCardMarkRememberedSet>::CardsPerCluster == 0, "Invalid card count.");
53 assert(total_card_count > 0, "Card count cannot be zero.");
54 // assert(_overreach_cards != NULL);
55 }
56
57 ShenandoahDirectCardMarkRememberedSet::~ShenandoahDirectCardMarkRememberedSet() {
58 free(_overreach_map);
59 }
60
61 void ShenandoahDirectCardMarkRememberedSet::initialize_overreach(size_t first_cluster, size_t count) {
62
63 // We can make this run faster in the future by explicitly
64 // unrolling the loop and doing wide writes if the compiler
65 // doesn't do this for us.
66 size_t first_card_index = first_cluster * ShenandoahCardCluster<ShenandoahDirectCardMarkRememberedSet>::CardsPerCluster;
67 uint8_t* omp = &_overreach_map[first_card_index];
68 uint8_t* endp = omp + count * ShenandoahCardCluster<ShenandoahDirectCardMarkRememberedSet>::CardsPerCluster;
69 while (omp < endp)
70 *omp++ = CardTable::clean_card_val();
71 }
72
73 void ShenandoahDirectCardMarkRememberedSet::merge_overreach(size_t first_cluster, size_t count) {
74
75 // We can make this run faster in the future by explicitly unrolling the loop and doing wide writes if the compiler
76 // doesn't do this for us.
77 size_t first_card_index = first_cluster * ShenandoahCardCluster<ShenandoahDirectCardMarkRememberedSet>::CardsPerCluster;
78 uint8_t* bmp = &_byte_map[first_card_index];
79 uint8_t* endp = bmp + count * ShenandoahCardCluster<ShenandoahDirectCardMarkRememberedSet>::CardsPerCluster;
80 uint8_t* omp = &_overreach_map[first_card_index];
81
82 // dirty_card is 0, clean card is 0xff; if either *bmp or *omp is dirty, we need to mark it as dirty
83 while (bmp < endp)
84 *bmp++ &= *omp++;
85 }
86
87 ShenandoahScanRememberedTask::ShenandoahScanRememberedTask(ShenandoahObjToScanQueueSet* queue_set,
88 ShenandoahObjToScanQueueSet* old_queue_set,
89 ShenandoahReferenceProcessor* rp,
90 ShenandoahRegionIterator* regions) :
91 AbstractGangTask("Scan Remembered Set"),
92 _queue_set(queue_set), _old_queue_set(old_queue_set), _rp(rp), _regions(regions) {}
93
94 void ShenandoahScanRememberedTask::work(uint worker_id) {
95 // This sets up a thread local reference to the worker_id which is necessary
96 // the weak reference processor.
97 ShenandoahParallelWorkerSession worker_session(worker_id);
98 ShenandoahWorkerTimingsTracker x(ShenandoahPhaseTimings::init_scan_rset, ShenandoahPhaseTimings::ScanClusters, worker_id);
99
100 ShenandoahObjToScanQueue* q = _queue_set->queue(worker_id);
101 ShenandoahObjToScanQueue* old = _old_queue_set == NULL ? NULL : _old_queue_set->queue(worker_id);
102 ShenandoahMarkRefsClosure<YOUNG> cl(q, _rp, old);
103 RememberedScanner* scanner = ShenandoahHeap::heap()->card_scan();
104
105 // set up thread local closure for shen ref processor
106 _rp->set_mark_closure(worker_id, &cl);
107 ShenandoahHeapRegion* region = _regions->next();
108 while (region != NULL) {
109 log_debug(gc)("ShenandoahScanRememberedTask::work(%u), looking at region " SIZE_FORMAT, worker_id, region->index());
110 if (region->affiliation() == OLD_GENERATION) {
111 scanner->process_region(region, &cl);
112 }
113 region = _regions->next();
114 }
115 }