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.
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
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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/oop.inline.hpp"
38 #include "runtime/prefetch.inline.hpp"
39
40 template <class T>
41 inline void G1ScanClosureBase::prefetch_and_push(T* p, const oop obj) {
42 // We're not going to even bother checking whether the object is
43 // already forwarded or not, as this usually causes an immediate
44 // stall. We'll try to prefetch the object (for write, given that
45 // we might need to install the forwarding reference) and we'll
46 // get back to it when pop it from the queue
47 Prefetch::write(obj->mark_addr_raw(), 0);
48 Prefetch::read(obj->mark_addr_raw(), (HeapWordSize*2));
49
50 // slightly paranoid test; I'm trying to catch potential
51 // problems before we go into push_on_queue to know where the
52 // problem is coming from
53 assert((obj == oopDesc::load_decode_heap_oop(p)) ||
54 (obj->is_forwarded() &&
55 obj->forwardee() == oopDesc::load_decode_heap_oop(p)),
56 "p should still be pointing to obj or to its forwardee");
57
58 _par_scan_state->push_on_queue(p);
59 }
60
61 template <class T>
62 inline void G1ScanClosureBase::handle_non_cset_obj_common(InCSetState const state, T* p, oop const obj) {
63 if (state.is_humongous()) {
64 _g1->set_humongous_is_live(obj);
65 }
66 }
67
68 template <class T>
69 inline void G1ScanEvacuatedObjClosure::do_oop_nv(T* p) {
70 T heap_oop = oopDesc::load_heap_oop(p);
71
72 if (oopDesc::is_null(heap_oop)) {
73 return;
74 }
75 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
76 const InCSetState state = _g1->in_cset_state(obj);
77 if (state.is_in_cset()) {
78 prefetch_and_push(p, obj);
79 } else {
80 if (HeapRegion::is_in_same_region(p, obj)) {
81 return;
82 }
83 handle_non_cset_obj_common(state, p, obj);
84 _par_scan_state->update_rs(_from, p, obj);
85 }
86 }
87
88 template <class T>
89 inline void G1CMOopClosure::do_oop_nv(T* p) {
90 oop obj = RawAccess<MO_VOLATILE>::oop_load(p);
91 _task->deal_with_reference(obj);
92 }
93
94 template <class T>
95 inline void G1RootRegionScanClosure::do_oop_nv(T* p) {
96 T heap_oop = RawAccess<MO_VOLATILE>::oop_load(p);
97 if (oopDesc::is_null(heap_oop)) {
98 return;
99 }
100 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
101 _cm->mark_in_next_bitmap(obj);
102 }
103
104 template <class T>
105 inline static void check_obj_during_refinement(T* p, oop const obj) {
106 #ifdef ASSERT
107 G1CollectedHeap* g1 = G1CollectedHeap::heap();
108 // can't do because of races
109 // assert(oopDesc::is_oop_or_null(obj), "expected an oop");
110 assert(check_obj_alignment(obj), "not oop aligned");
111 assert(g1->is_in_reserved(obj), "must be in heap");
112
113 HeapRegion* from = g1->heap_region_containing(p);
114
115 assert(from != NULL, "from region must be non-NULL");
116 assert(from->is_in_reserved(p) ||
117 (from->is_humongous() &&
118 g1->heap_region_containing(p)->is_humongous() &&
119 from->humongous_start_region() == g1->heap_region_containing(p)->humongous_start_region()),
120 "p " PTR_FORMAT " is not in the same region %u or part of the correct humongous object starting at region %u.",
121 p2i(p), from->hrm_index(), from->humongous_start_region()->hrm_index());
122 #endif // ASSERT
123 }
124
125 template <class T>
126 inline void G1ConcurrentRefineOopClosure::do_oop_nv(T* p) {
127 T o = RawAccess<MO_VOLATILE>::oop_load(p);
128 if (oopDesc::is_null(o)) {
129 return;
130 }
131 oop obj = oopDesc::decode_heap_oop_not_null(o);
132
133 check_obj_during_refinement(p, obj);
134
135 if (HeapRegion::is_in_same_region(p, obj)) {
136 // Normally this closure should only be called with cross-region references.
137 // But since Java threads are manipulating the references concurrently and we
138 // reload the values things may have changed.
139 // Also this check lets slip through references from a humongous continues region
140 // to its humongous start region, as they are in different regions, and adds a
141 // remembered set entry. This is benign (apart from memory usage), as we never
142 // try to either evacuate or eager reclaim humonguous arrays of j.l.O.
143 return;
144 }
145
146 HeapRegion* to = _g1->heap_region_containing(obj);
147
148 assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
149 to->rem_set()->add_reference(p, _worker_i);
150 }
151
152 template <class T>
153 inline void G1ScanObjsDuringUpdateRSClosure::do_oop_nv(T* p) {
154 T o = oopDesc::load_heap_oop(p);
155 if (oopDesc::is_null(o)) {
156 return;
157 }
158 oop obj = oopDesc::decode_heap_oop_not_null(o);
159
160 check_obj_during_refinement(p, obj);
161
162 assert(!_g1->is_in_cset((HeapWord*)p), "Oop originates from " PTR_FORMAT " (region: %u) which is in the collection set.", p2i(p), _g1->addr_to_region((HeapWord*)p));
163 const InCSetState state = _g1->in_cset_state(obj);
164 if (state.is_in_cset()) {
165 // Since the source is always from outside the collection set, here we implicitly know
166 // that this is a cross-region reference too.
167 prefetch_and_push(p, obj);
168 } else {
169 HeapRegion* to = _g1->heap_region_containing(obj);
170 if (_from == to) {
171 return;
172 }
173 handle_non_cset_obj_common(state, p, obj);
174 to->rem_set()->add_reference(p, _worker_i);
175 }
176 }
177
178 template <class T>
179 inline void G1ScanObjsDuringScanRSClosure::do_oop_nv(T* p) {
180 T heap_oop = oopDesc::load_heap_oop(p);
181 if (oopDesc::is_null(heap_oop)) {
182 return;
183 }
184 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
185
186 const InCSetState state = _g1->in_cset_state(obj);
187 if (state.is_in_cset()) {
188 prefetch_and_push(p, obj);
189 } else {
190 if (HeapRegion::is_in_same_region(p, obj)) {
191 return;
192 }
193 handle_non_cset_obj_common(state, p, obj);
194 }
195 }
196
197 void G1ParCopyHelper::do_cld_barrier(oop new_obj) {
198 if (_g1->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(!_g1->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
205
206 _cm->mark_in_next_bitmap(obj);
207 }
208
209 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
210 assert(from_obj->is_forwarded(), "from obj should be forwarded");
211 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
212 assert(from_obj != to_obj, "should not be self-forwarded");
213
214 assert(_g1->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet");
215 assert(!_g1->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet");
216
217 _cm->mark_in_next_bitmap(to_obj);
218 }
219
220 template <G1Barrier barrier, G1Mark do_mark_object>
221 template <class T>
222 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
223 T heap_oop = oopDesc::load_heap_oop(p);
224
225 if (oopDesc::is_null(heap_oop)) {
226 return;
227 }
228
229 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
230
231 assert(_worker_id == _par_scan_state->worker_id(), "sanity");
232
233 const InCSetState state = _g1->in_cset_state(obj);
234 if (state.is_in_cset()) {
235 oop forwardee;
236 markOop m = obj->mark_raw();
237 if (m->is_marked()) {
238 forwardee = (oop) m->decode_pointer();
239 } else {
240 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
241 }
242 assert(forwardee != NULL, "forwardee should not be NULL");
243 oopDesc::encode_store_heap_oop(p, forwardee);
244 if (do_mark_object != G1MarkNone && forwardee != obj) {
245 // If the object is self-forwarded we don't need to explicitly
246 // mark it, the evacuation failure protocol will do so.
247 mark_forwarded_object(obj, forwardee);
248 }
249
250 if (barrier == G1BarrierCLD) {
251 do_cld_barrier(forwardee);
252 }
253 } else {
254 if (state.is_humongous()) {
255 _g1->set_humongous_is_live(obj);
256 }
257
258 // The object is not in collection set. If we're a root scanning
259 // closure during an initial mark pause then attempt to mark the object.
260 if (do_mark_object == G1MarkFromRoot) {
261 mark_object(obj);
262 }
263 }
264 }
265 #endif // SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP