1 /*
2 * Copyright (c) 2001, 2018, 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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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25 #ifndef SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP
26 #define SHARE_VM_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(InCSetState const state, T* p, oop const obj) {
65 if (state.is_humongous()) {
66 _g1h->set_humongous_is_live(obj);
67 }
68 }
69
70 inline void G1ScanClosureBase::trim_queue_partially() {
71 _par_scan_state->trim_queue_partially();
72 }
73
74 template <class T>
75 inline void G1ScanEvacuatedObjClosure::do_oop_work(T* p) {
76 T heap_oop = RawAccess<>::oop_load(p);
77
78 if (CompressedOops::is_null(heap_oop)) {
79 return;
80 }
81 oop obj = CompressedOops::decode_not_null(heap_oop);
82 const InCSetState state = _g1h->in_cset_state(obj);
83 if (state.is_in_cset()) {
84 prefetch_and_push(p, obj);
85 } else if (!HeapRegion::is_in_same_region(p, obj)) {
86 handle_non_cset_obj_common(state, p, obj);
87 if (_scanning_in_young) {
88 return;
89 }
90 _par_scan_state->enqueue_card_if_tracked(p, obj);
91 }
92 }
93
94 template <class T>
95 inline void G1CMOopClosure::do_oop_work(T* p) {
96 _task->deal_with_reference(p);
97 }
98
99 template <class T>
100 inline void G1RootRegionScanClosure::do_oop_work(T* p) {
101 T heap_oop = RawAccess<MO_VOLATILE>::oop_load(p);
102 if (CompressedOops::is_null(heap_oop)) {
103 return;
104 }
105 oop obj = CompressedOops::decode_not_null(heap_oop);
106 _cm->mark_in_next_bitmap(_worker_id, obj);
107 }
108
109 template <class T>
110 inline static void check_obj_during_refinement(T* p, oop const obj) {
111 #ifdef ASSERT
112 G1CollectedHeap* g1h = G1CollectedHeap::heap();
113 // can't do because of races
114 // assert(oopDesc::is_oop_or_null(obj), "expected an oop");
115 assert(check_obj_alignment(obj), "not oop aligned");
116 assert(g1h->is_in_reserved(obj), "must be in heap");
117
118 HeapRegion* from = g1h->heap_region_containing(p);
119
120 assert(from != NULL, "from region must be non-NULL");
121 assert(from->is_in_reserved(p) ||
122 (from->is_humongous() &&
123 g1h->heap_region_containing(p)->is_humongous() &&
124 from->humongous_start_region() == g1h->heap_region_containing(p)->humongous_start_region()),
125 "p " PTR_FORMAT " is not in the same region %u or part of the correct humongous object starting at region %u.",
126 p2i(p), from->hrm_index(), from->humongous_start_region()->hrm_index());
127 #endif // ASSERT
128 }
129
130 template <class T>
131 inline void G1ConcurrentRefineOopClosure::do_oop_work(T* p) {
132 T o = RawAccess<MO_VOLATILE>::oop_load(p);
133 if (CompressedOops::is_null(o)) {
134 return;
135 }
136 oop obj = CompressedOops::decode_not_null(o);
137
138 check_obj_during_refinement(p, obj);
139
140 if (HeapRegion::is_in_same_region(p, obj)) {
141 // Normally this closure should only be called with cross-region references.
142 // But since Java threads are manipulating the references concurrently and we
143 // reload the values things may have changed.
144 // Also this check lets slip through references from a humongous continues region
145 // to its humongous start region, as they are in different regions, and adds a
146 // remembered set entry. This is benign (apart from memory usage), as we never
147 // try to either evacuate or eager reclaim humonguous arrays of j.l.O.
148 return;
149 }
150
151 HeapRegionRemSet* to_rem_set = _g1h->heap_region_containing(obj)->rem_set();
152
153 assert(to_rem_set != NULL, "Need per-region 'into' remsets.");
154 if (to_rem_set->is_tracked()) {
155 to_rem_set->add_reference(p, _worker_i);
156 }
157 }
158
159 template <class T>
160 inline void G1ScanObjsDuringUpdateRSClosure::do_oop_work(T* p) {
161 T o = RawAccess<>::oop_load(p);
162 if (CompressedOops::is_null(o)) {
163 return;
164 }
165 oop obj = CompressedOops::decode_not_null(o);
166
167 check_obj_during_refinement(p, obj);
168
169 assert(!_g1h->is_in_cset((HeapWord*)p), "Oop originates from " PTR_FORMAT " (region: %u) which is in the collection set.", p2i(p), _g1h->addr_to_region((HeapWord*)p));
170 const InCSetState state = _g1h->in_cset_state(obj);
171 if (state.is_in_cset()) {
172 // Since the source is always from outside the collection set, here we implicitly know
173 // that this is a cross-region reference too.
174 prefetch_and_push(p, obj);
175 } else if (!HeapRegion::is_in_same_region(p, obj)) {
176 handle_non_cset_obj_common(state, p, obj);
177 _par_scan_state->enqueue_card_if_tracked(p, obj);
178 }
179 }
180
181 template <class T>
182 inline void G1ScanObjsDuringScanRSClosure::do_oop_work(T* p) {
183 T heap_oop = RawAccess<>::oop_load(p);
184 if (CompressedOops::is_null(heap_oop)) {
185 return;
186 }
187 oop obj = CompressedOops::decode_not_null(heap_oop);
188
189 const InCSetState state = _g1h->in_cset_state(obj);
190 if (state.is_in_cset()) {
191 prefetch_and_push(p, obj);
192 } else if (!HeapRegion::is_in_same_region(p, obj)) {
193 handle_non_cset_obj_common(state, p, obj);
194 }
195 }
196
197 void G1ParCopyHelper::do_cld_barrier(oop new_obj) {
198 if (_g1h->heap_region_containing(new_obj)->is_young()) {
199 _scanned_cld->record_modified_oops();
200 }
201 }
202
203 void G1ParCopyHelper::mark_object(oop obj) {
204 assert(!_g1h->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
205
206 // We know that the object is not moving so it's safe to read its size.
207 _cm->mark_in_next_bitmap(_worker_id, obj);
208 }
209
210 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
211 assert(from_obj->is_forwarded(), "from obj should be forwarded");
212 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
213 assert(from_obj != to_obj, "should not be self-forwarded");
214
215 assert(_g1h->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet");
216 assert(!_g1h->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet");
217
218 // The object might be in the process of being copied by another
219 // worker so we cannot trust that its to-space image is
220 // well-formed. So we have to read its size from its from-space
221 // image which we know should not be changing.
222 _cm->mark_in_next_bitmap(_worker_id, to_obj, from_obj->size());
223 }
224
225 void G1ParCopyHelper::trim_queue_partially() {
226 _par_scan_state->trim_queue_partially();
227 }
228
229 template <G1Barrier barrier, G1Mark do_mark_object>
230 template <class T>
231 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
232 T heap_oop = RawAccess<>::oop_load(p);
233
234 if (CompressedOops::is_null(heap_oop)) {
235 return;
236 }
237
238 oop obj = CompressedOops::decode_not_null(heap_oop);
239
240 assert(_worker_id == _par_scan_state->worker_id(), "sanity");
241
242 const InCSetState state = _g1h->in_cset_state(obj);
243 if (state.is_in_cset()) {
244 oop forwardee;
245 markOop m = obj->mark_raw();
246 if (m->is_marked()) {
247 forwardee = (oop) m->decode_pointer();
248 } else {
249 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
250 }
251 assert(forwardee != NULL, "forwardee should not be NULL");
252 RawAccess<IS_NOT_NULL>::oop_store(p, forwardee);
253 if (do_mark_object != G1MarkNone && forwardee != obj) {
254 // If the object is self-forwarded we don't need to explicitly
255 // mark it, the evacuation failure protocol will do so.
256 mark_forwarded_object(obj, forwardee);
257 }
258
259 if (barrier == G1BarrierCLD) {
260 do_cld_barrier(forwardee);
261 }
262 } else {
263 if (state.is_humongous()) {
264 _g1h->set_humongous_is_live(obj);
265 }
266
267 // The object is not in collection set. If we're a root scanning
268 // closure during an initial mark pause then attempt to mark the object.
269 if (do_mark_object == G1MarkFromRoot) {
270 mark_object(obj);
271 }
272 }
273 trim_queue_partially();
274 }
275
276 template <class T> void G1RebuildRemSetClosure::do_oop_work(T* p) {
277 oop const obj = RawAccess<MO_VOLATILE>::oop_load(p);
278 if (obj == NULL) {
279 return;
280 }
281
282 if (HeapRegion::is_in_same_region(p, obj)) {
283 return;
284 }
285
286 HeapRegion* to = _g1h->heap_region_containing(obj);
287 HeapRegionRemSet* rem_set = to->rem_set();
288 rem_set->add_reference(p, _worker_id);
289 }
290
291 #endif // SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP