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.
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.
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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 #include "utilities/align.hpp"
42
43 template <class T>
44 inline void G1ScanClosureBase::prefetch_and_push(T* p, const oop obj) {
45 // We're not going to even bother checking whether the object is
46 // already forwarded or not, as this usually causes an immediate
47 // stall. We'll try to prefetch the object (for write, given that
48 // we might need to install the forwarding reference) and we'll
49 // get back to it when pop it from the queue
50 Prefetch::write(obj->mark_addr_raw(), 0);
51 Prefetch::read(obj->mark_addr_raw(), (HeapWordSize*2));
52
53 // slightly paranoid test; I'm trying to catch potential
54 // problems before we go into push_on_queue to know where the
55 // problem is coming from
56 assert((obj == RawAccess<>::oop_load(p)) ||
57 (obj->is_forwarded() &&
58 obj->forwardee() == RawAccess<>::oop_load(p)),
59 "p should still be pointing to obj or to its forwardee");
60
61 _par_scan_state->push_on_queue(p);
62 }
63
64 template <class T>
65 inline void G1ScanClosureBase::handle_non_cset_obj_common(G1HeapRegionAttr const region_attr, T* p, oop const obj) {
66 if (region_attr.is_humongous()) {
67 _g1h->set_humongous_is_live(obj);
68 } else if (region_attr.is_optional()) {
69 _par_scan_state->remember_reference_into_optional_region(p);
70 }
71 }
72
73 inline void G1ScanClosureBase::trim_queue_partially() {
74 _par_scan_state->trim_queue_partially();
75 }
76
77 template <class T>
78 inline void G1ScanEvacuatedObjClosure::do_oop_work(T* p) {
79 T heap_oop = RawAccess<>::oop_load(p);
80
81 if (CompressedOops::is_null(heap_oop)) {
82 return;
83 }
84 oop obj = CompressedOops::decode_not_null(heap_oop);
85 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj);
86 if (region_attr.is_in_cset()) {
87 prefetch_and_push(p, obj);
88 } else if (!HeapRegion::is_in_same_region(p, obj)) {
89 handle_non_cset_obj_common(region_attr, p, obj);
90 assert(_scanning_in_young != Uninitialized, "Scan location has not been initialized.");
91 if (_scanning_in_young == True) {
92 return;
93 }
94 _par_scan_state->enqueue_card_if_tracked(region_attr, p, obj);
95 }
96 }
97
98 template <class T>
99 inline void G1CMOopClosure::do_oop_work(T* p) {
100 _task->deal_with_reference(p);
101 }
102
103 template <class T>
104 inline void G1RootRegionScanClosure::do_oop_work(T* p) {
105 T heap_oop = RawAccess<MO_VOLATILE>::oop_load(p);
106 if (CompressedOops::is_null(heap_oop)) {
107 return;
108 }
109 oop obj = CompressedOops::decode_not_null(heap_oop);
110 _cm->mark_in_next_bitmap(_worker_id, obj);
111 }
112
113 template <class T>
114 inline static void check_obj_during_refinement(T* p, oop const obj) {
115 #ifdef ASSERT
116 G1CollectedHeap* g1h = G1CollectedHeap::heap();
117 // can't do because of races
118 // assert(oopDesc::is_oop_or_null(obj), "expected an oop");
119 assert(is_object_aligned(obj), "oop must be aligned");
120 assert(g1h->is_in_reserved(obj), "oop must be in reserved");
121
122 HeapRegion* from = g1h->heap_region_containing(p);
123
124 assert(from != NULL, "from region must be non-NULL");
125 assert(from->is_in_reserved(p) ||
126 (from->is_humongous() &&
127 g1h->heap_region_containing(p)->is_humongous() &&
128 from->humongous_start_region() == g1h->heap_region_containing(p)->humongous_start_region()),
129 "p " PTR_FORMAT " is not in the same region %u or part of the correct humongous object starting at region %u.",
130 p2i(p), from->hrm_index(), from->humongous_start_region()->hrm_index());
131 #endif // ASSERT
132 }
133
134 template <class T>
135 inline void G1ConcurrentRefineOopClosure::do_oop_work(T* p) {
136 T o = RawAccess<MO_VOLATILE>::oop_load(p);
137 if (CompressedOops::is_null(o)) {
138 return;
139 }
140 oop obj = CompressedOops::decode_not_null(o);
141
142 check_obj_during_refinement(p, obj);
143
144 if (HeapRegion::is_in_same_region(p, obj)) {
145 // Normally this closure should only be called with cross-region references.
146 // But since Java threads are manipulating the references concurrently and we
147 // reload the values things may have changed.
148 // Also this check lets slip through references from a humongous continues region
149 // to its humongous start region, as they are in different regions, and adds a
150 // remembered set entry. This is benign (apart from memory usage), as we never
151 // try to either evacuate or eager reclaim humonguous arrays of j.l.O.
152 return;
153 }
154
155 HeapRegionRemSet* to_rem_set = _g1h->heap_region_containing(obj)->rem_set();
156
157 assert(to_rem_set != NULL, "Need per-region 'into' remsets.");
158 if (to_rem_set->is_tracked()) {
159 to_rem_set->add_reference(p, _worker_id);
160 }
161 }
162
163 template <class T>
164 inline void G1ScanCardClosure::do_oop_work(T* p) {
165 T o = RawAccess<>::oop_load(p);
166 if (CompressedOops::is_null(o)) {
167 return;
168 }
169 oop obj = CompressedOops::decode_not_null(o);
170
171 check_obj_during_refinement(p, obj);
172
173 assert(!_g1h->is_in_cset((HeapWord*)p),
174 "Oop originates from " PTR_FORMAT " (region: %u) which is in the collection set.",
175 p2i(p), _g1h->addr_to_region((HeapWord*)p));
176
177 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj);
178 if (region_attr.is_in_cset()) {
179 // Since the source is always from outside the collection set, here we implicitly know
180 // that this is a cross-region reference too.
181 prefetch_and_push(p, obj);
182 } else if (!HeapRegion::is_in_same_region(p, obj)) {
183 handle_non_cset_obj_common(region_attr, p, obj);
184 _par_scan_state->enqueue_card_if_tracked(region_attr, p, obj);
185 }
186 }
187
188 template <class T>
189 inline void G1ScanRSForOptionalClosure::do_oop_work(T* p) {
190 const G1HeapRegionAttr region_attr = _g1h->region_attr(p);
191 // Entries in the optional collection set may start to originate from the collection
192 // set after one or more increments. In this case, previously optional regions
193 // became actual collection set regions. Filter them out here.
194 if (region_attr.is_in_cset()) {
195 return;
196 }
197 _scan_cl->do_oop_work(p);
198 _scan_cl->trim_queue_partially();
199 }
200
201 void G1ParCopyHelper::do_cld_barrier(oop new_obj) {
202 if (_g1h->heap_region_containing(new_obj)->is_young()) {
203 _scanned_cld->record_modified_oops();
204 }
205 }
206
207 void G1ParCopyHelper::mark_object(oop obj) {
208 assert(!_g1h->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
209
210 // We know that the object is not moving so it's safe to read its size.
211 _cm->mark_in_next_bitmap(_worker_id, obj);
212 }
213
214 void G1ParCopyHelper::trim_queue_partially() {
215 _par_scan_state->trim_queue_partially();
216 }
217
218 template <G1Barrier barrier, G1Mark do_mark_object>
219 template <class T>
220 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
221 T heap_oop = RawAccess<>::oop_load(p);
222
223 if (CompressedOops::is_null(heap_oop)) {
224 return;
225 }
226
227 oop obj = CompressedOops::decode_not_null(heap_oop);
228
229 assert(_worker_id == _par_scan_state->worker_id(), "sanity");
230
231 const G1HeapRegionAttr state = _g1h->region_attr(obj);
232 if (state.is_in_cset()) {
233 oop forwardee;
234 markWord m = obj->mark_raw();
235 if (m.is_marked()) {
236 forwardee = (oop) m.decode_pointer();
237 } else {
238 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
239 }
240 assert(forwardee != NULL, "forwardee should not be NULL");
241 RawAccess<IS_NOT_NULL>::oop_store(p, forwardee);
242
243 if (barrier == G1BarrierCLD) {
244 do_cld_barrier(forwardee);
245 }
246 } else {
247 if (state.is_humongous()) {
248 _g1h->set_humongous_is_live(obj);
249 } else if ((barrier != G1BarrierNoOptRoots) && state.is_optional()) {
250 _par_scan_state->remember_root_into_optional_region(p);
251 }
252
253 // The object is not in collection set. If we're a root scanning
254 // closure during an initial mark pause then attempt to mark the object.
255 if (do_mark_object == G1MarkFromRoot) {
256 mark_object(obj);
257 }
258 }
259 trim_queue_partially();
260 }
261
262 template <class T> void G1RebuildRemSetClosure::do_oop_work(T* p) {
263 oop const obj = RawAccess<MO_VOLATILE>::oop_load(p);
264 if (obj == NULL) {
265 return;
266 }
267
268 if (HeapRegion::is_in_same_region(p, obj)) {
269 return;
270 }
271
272 HeapRegion* to = _g1h->heap_region_containing(obj);
273 HeapRegionRemSet* rem_set = to->rem_set();
274 rem_set->add_reference(p, _worker_id);
275 }
276
277 #endif // SHARE_GC_G1_G1OOPCLOSURES_INLINE_HPP