1 /*
2 * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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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.
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23 */
24
25 #ifndef SHARE_GC_G1_G1OOPCLOSURES_INLINE_HPP
26 #define SHARE_GC_G1_G1OOPCLOSURES_INLINE_HPP
27
28 #include "gc/g1/g1CollectedHeap.hpp"
29 #include "gc/g1/g1ConcurrentMark.inline.hpp"
30 #include "gc/g1/g1OopClosures.hpp"
31 #include "gc/g1/g1ParScanThreadState.inline.hpp"
32 #include "gc/g1/g1RemSet.hpp"
33 #include "gc/g1/heapRegion.inline.hpp"
34 #include "gc/g1/heapRegionRemSet.hpp"
35 #include "memory/iterator.inline.hpp"
36 #include "oops/access.inline.hpp"
37 #include "oops/compressedOops.inline.hpp"
38 #include "oops/oopsHierarchy.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "runtime/prefetch.inline.hpp"
41
42 template <class T>
43 inline void G1ScanClosureBase::prefetch_and_push(T* p, const oop obj) {
44 // We're not going to even bother checking whether the object is
45 // already forwarded or not, as this usually causes an immediate
46 // stall. We'll try to prefetch the object (for write, given that
47 // we might need to install the forwarding reference) and we'll
48 // get back to it when pop it from the queue
49 Prefetch::write(obj->mark_addr_raw(), 0);
50 Prefetch::read(obj->mark_addr_raw(), (HeapWordSize*2));
51
52 // slightly paranoid test; I'm trying to catch potential
53 // problems before we go into push_on_queue to know where the
54 // problem is coming from
55 assert((obj == RawAccess<>::oop_load(p)) ||
56 (obj->is_forwarded() &&
57 obj->forwardee() == RawAccess<>::oop_load(p)),
58 "p should still be pointing to obj or to its forwardee");
59
60 _par_scan_state->push_on_queue(p);
61 }
62
63 template <class T>
64 inline void G1ScanClosureBase::handle_non_cset_obj_common(G1HeapRegionAttr const region_attr, T* p, oop const obj) {
65 if (region_attr.is_humongous()) {
66 _g1h->set_humongous_is_live(obj);
67 } else if (region_attr.is_optional()) {
68 _par_scan_state->remember_reference_into_optional_region(p);
69 }
70 }
71
72 inline void G1ScanClosureBase::trim_queue_partially() {
73 _par_scan_state->trim_queue_partially();
74 }
75
76 template <class T>
77 inline void G1ScanEvacuatedObjClosure::do_oop_work(T* p) {
78 T heap_oop = RawAccess<>::oop_load(p);
79
80 if (CompressedOops::is_null(heap_oop)) {
81 return;
82 }
83 oop obj = CompressedOops::decode_not_null(heap_oop);
84 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj);
85 if (region_attr.is_in_cset()) {
86 prefetch_and_push(p, obj);
87 } else if (!HeapRegion::is_in_same_region(p, obj)) {
88 handle_non_cset_obj_common(region_attr, p, obj);
89 assert(_scanning_in_young != Uninitialized, "Scan location has not been initialized.");
90 if (_scanning_in_young == True) {
91 return;
92 }
93 _par_scan_state->enqueue_card_if_tracked(region_attr, p, obj);
94 }
95 }
96
97 template <class T>
98 inline void G1CMOopClosure::do_oop_work(T* p) {
99 _task->deal_with_reference(p);
100 }
101
102 template <class T>
103 inline void G1RootRegionScanClosure::do_oop_work(T* p) {
104 T heap_oop = RawAccess<MO_VOLATILE>::oop_load(p);
105 if (CompressedOops::is_null(heap_oop)) {
106 return;
107 }
108 oop obj = CompressedOops::decode_not_null(heap_oop);
109 _cm->mark_in_next_bitmap(_worker_id, obj);
110 }
111
112 template <class T>
113 inline static void check_obj_during_refinement(T* p, oop const obj) {
114 #ifdef ASSERT
115 G1CollectedHeap* g1h = G1CollectedHeap::heap();
116 // can't do because of races
117 // assert(oopDesc::is_oop_or_null(obj), "expected an oop");
118 g1h->check_oop_location(obj);
119
120 HeapRegion* from = g1h->heap_region_containing(p);
121
122 assert(from != NULL, "from region must be non-NULL");
123 assert(from->is_in_reserved(p) ||
124 (from->is_humongous() &&
125 g1h->heap_region_containing(p)->is_humongous() &&
126 from->humongous_start_region() == g1h->heap_region_containing(p)->humongous_start_region()),
127 "p " PTR_FORMAT " is not in the same region %u or part of the correct humongous object starting at region %u.",
128 p2i(p), from->hrm_index(), from->humongous_start_region()->hrm_index());
129 #endif // ASSERT
130 }
131
132 template <class T>
133 inline void G1ConcurrentRefineOopClosure::do_oop_work(T* p) {
134 T o = RawAccess<MO_VOLATILE>::oop_load(p);
135 if (CompressedOops::is_null(o)) {
136 return;
137 }
138 oop obj = CompressedOops::decode_not_null(o);
139
140 check_obj_during_refinement(p, obj);
141
142 if (HeapRegion::is_in_same_region(p, obj)) {
143 // Normally this closure should only be called with cross-region references.
144 // But since Java threads are manipulating the references concurrently and we
145 // reload the values things may have changed.
146 // Also this check lets slip through references from a humongous continues region
147 // to its humongous start region, as they are in different regions, and adds a
148 // remembered set entry. This is benign (apart from memory usage), as we never
149 // try to either evacuate or eager reclaim humonguous arrays of j.l.O.
150 return;
151 }
152
153 HeapRegionRemSet* to_rem_set = _g1h->heap_region_containing(obj)->rem_set();
154
155 assert(to_rem_set != NULL, "Need per-region 'into' remsets.");
156 if (to_rem_set->is_tracked()) {
157 to_rem_set->add_reference(p, _worker_id);
158 }
159 }
160
161 template <class T>
162 inline void G1ScanCardClosure::do_oop_work(T* p) {
163 T o = RawAccess<>::oop_load(p);
164 if (CompressedOops::is_null(o)) {
165 return;
166 }
167 oop obj = CompressedOops::decode_not_null(o);
168
169 check_obj_during_refinement(p, obj);
170
171 assert(!_g1h->is_in_cset((HeapWord*)p),
172 "Oop originates from " PTR_FORMAT " (region: %u) which is in the collection set.",
173 p2i(p), _g1h->addr_to_region((HeapWord*)p));
174
175 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj);
176 if (region_attr.is_in_cset()) {
177 // Since the source is always from outside the collection set, here we implicitly know
178 // that this is a cross-region reference too.
179 prefetch_and_push(p, obj);
180 } else if (!HeapRegion::is_in_same_region(p, obj)) {
181 handle_non_cset_obj_common(region_attr, p, obj);
182 _par_scan_state->enqueue_card_if_tracked(region_attr, p, obj);
183 }
184 }
185
186 template <class T>
187 inline void G1ScanRSForOptionalClosure::do_oop_work(T* p) {
188 const G1HeapRegionAttr region_attr = _g1h->region_attr(p);
189 // Entries in the optional collection set may start to originate from the collection
190 // set after one or more increments. In this case, previously optional regions
191 // became actual collection set regions. Filter them out here.
192 if (region_attr.is_in_cset()) {
193 return;
194 }
195 _scan_cl->do_oop_work(p);
196 _scan_cl->trim_queue_partially();
197 }
198
199 void G1ParCopyHelper::do_cld_barrier(oop new_obj) {
200 if (_g1h->heap_region_containing(new_obj)->is_young()) {
201 _scanned_cld->record_modified_oops();
202 }
203 }
204
205 void G1ParCopyHelper::mark_object(oop obj) {
206 assert(!_g1h->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
207
208 // We know that the object is not moving so it's safe to read its size.
209 _cm->mark_in_next_bitmap(_worker_id, obj);
210 }
211
212 void G1ParCopyHelper::trim_queue_partially() {
213 _par_scan_state->trim_queue_partially();
214 }
215
216 template <G1Barrier barrier, G1Mark do_mark_object>
217 template <class T>
218 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
219 T heap_oop = RawAccess<>::oop_load(p);
220
221 if (CompressedOops::is_null(heap_oop)) {
222 return;
223 }
224
225 oop obj = CompressedOops::decode_not_null(heap_oop);
226
227 assert(_worker_id == _par_scan_state->worker_id(), "sanity");
228
229 const G1HeapRegionAttr state = _g1h->region_attr(obj);
230 if (state.is_in_cset()) {
231 oop forwardee;
232 markWord m = obj->mark_raw();
233 if (m.is_marked()) {
234 forwardee = (oop) m.decode_pointer();
235 } else {
236 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
237 }
238 assert(forwardee != NULL, "forwardee should not be NULL");
239 RawAccess<IS_NOT_NULL>::oop_store(p, forwardee);
240
241 if (barrier == G1BarrierCLD) {
242 do_cld_barrier(forwardee);
243 }
244 } else {
245 if (state.is_humongous()) {
246 _g1h->set_humongous_is_live(obj);
247 } else if (state.is_optional()) {
248 _par_scan_state->remember_root_into_optional_region(p);
249 }
250
251 // The object is not in collection set. If we're a root scanning
252 // closure during an initial mark pause then attempt to mark the object.
253 if (do_mark_object == G1MarkFromRoot) {
254 mark_object(obj);
255 }
256 }
257 trim_queue_partially();
258 }
259
260 template <class T> void G1RebuildRemSetClosure::do_oop_work(T* p) {
261 oop const obj = RawAccess<MO_VOLATILE>::oop_load(p);
262 if (obj == NULL) {
263 return;
264 }
265
266 if (HeapRegion::is_in_same_region(p, obj)) {
267 return;
268 }
269
270 HeapRegion* to = _g1h->heap_region_containing(obj);
271 HeapRegionRemSet* rem_set = to->rem_set();
272 rem_set->add_reference(p, _worker_id);
273 }
274
275 #endif // SHARE_GC_G1_G1OOPCLOSURES_INLINE_HPP