1 /*
2 * Copyright (c) 2001, 2017, 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
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 "runtime/prefetch.inline.hpp"
38
39 template <class T>
40 inline void G1ScanClosureBase::prefetch_and_push(T* p, const oop obj) {
41 // We're not going to even bother checking whether the object is
42 // already forwarded or not, as this usually causes an immediate
43 // stall. We'll try to prefetch the object (for write, given that
44 // we might need to install the forwarding reference) and we'll
45 // get back to it when pop it from the queue
46 Prefetch::write(obj->mark_addr(), 0);
47 Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
48
49 // slightly paranoid test; I'm trying to catch potential
50 // problems before we go into push_on_queue to know where the
51 // problem is coming from
52 assert((obj == oopDesc::load_decode_heap_oop(p)) ||
53 (obj->is_forwarded() &&
54 obj->forwardee() == oopDesc::load_decode_heap_oop(p)),
55 "p should still be pointing to obj or to its forwardee");
56
57 _par_scan_state->push_on_queue(p);
58 }
59
60 template <class T>
61 inline void G1ScanClosureBase::handle_non_cset_obj_common(InCSetState const state, T* p, oop const obj) {
62 if (state.is_humongous()) {
63 _g1->set_humongous_is_live(obj);
64 }
65 }
66
67 template <class T>
68 inline void G1ScanEvacuatedObjClosure::do_oop_nv(T* p) {
69 T heap_oop = oopDesc::load_heap_oop(p);
70
71 if (oopDesc::is_null(heap_oop)) {
72 return;
73 }
74 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
75 const InCSetState state = _g1->in_cset_state(obj);
76 if (state.is_in_cset()) {
77 prefetch_and_push(p, obj);
78 } else {
79 if (HeapRegion::is_in_same_region(p, obj)) {
80 return;
81 }
82 handle_non_cset_obj_common(state, p, obj);
83 _par_scan_state->update_rs(_from, p, obj);
84 }
85 }
86
87 template <class T>
88 inline void G1CMOopClosure::do_oop_nv(T* p) {
89 oop obj = RawAccess<MO_VOLATILE>::oop_load(p);
90 _task->deal_with_reference(obj);
91 }
92
93 template <class T>
94 inline void G1RootRegionScanClosure::do_oop_nv(T* p) {
95 T heap_oop = RawAccess<MO_VOLATILE>::oop_load(p);
96 if (oopDesc::is_null(heap_oop)) {
97 return;
98 }
99 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
100 _cm->mark_in_next_bitmap(obj);
101 }
102
103 template <class T>
104 inline static void check_obj_during_refinement(T* p, oop const obj) {
105 #ifdef ASSERT
106 G1CollectedHeap* g1 = G1CollectedHeap::heap();
107 // can't do because of races
108 // assert(oopDesc::is_oop_or_null(obj), "expected an oop");
109 assert(check_obj_alignment(obj), "not oop aligned");
110 assert(g1->is_in_reserved(obj), "must be in heap");
111
112 HeapRegion* from = g1->heap_region_containing(p);
113
114 assert(from != NULL, "from region must be non-NULL");
115 assert(from->is_in_reserved(p) ||
116 (from->is_humongous() &&
117 g1->heap_region_containing(p)->is_humongous() &&
118 from->humongous_start_region() == g1->heap_region_containing(p)->humongous_start_region()),
119 "p " PTR_FORMAT " is not in the same region %u or part of the correct humongous object starting at region %u.",
120 p2i(p), from->hrm_index(), from->humongous_start_region()->hrm_index());
121 #endif // ASSERT
122 }
123
124 template <class T>
125 inline void G1ConcurrentRefineOopClosure::do_oop_nv(T* p) {
126 T o = RawAccess<MO_VOLATILE>::oop_load(p);
127 if (oopDesc::is_null(o)) {
128 return;
129 }
130 oop obj = oopDesc::decode_heap_oop_not_null(o);
131
132 check_obj_during_refinement(p, obj);
133
134 if (HeapRegion::is_in_same_region(p, obj)) {
135 // Normally this closure should only be called with cross-region references.
136 // But since Java threads are manipulating the references concurrently and we
137 // reload the values things may have changed.
138 // Also this check lets slip through references from a humongous continues region
139 // to its humongous start region, as they are in different regions, and adds a
140 // remembered set entry. This is benign (apart from memory usage), as we never
141 // try to either evacuate or eager reclaim humonguous arrays of j.l.O.
142 return;
143 }
144
145 HeapRegion* to = _g1->heap_region_containing(obj);
146
147 assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
148 to->rem_set()->add_reference(p, _worker_i);
149 }
150
151 template <class T>
152 inline void G1ScanObjsDuringUpdateRSClosure::do_oop_nv(T* p) {
153 T o = oopDesc::load_heap_oop(p);
154 if (oopDesc::is_null(o)) {
155 return;
156 }
157 oop obj = oopDesc::decode_heap_oop_not_null(o);
158
159 check_obj_during_refinement(p, obj);
160
161 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));
162 const InCSetState state = _g1->in_cset_state(obj);
163 if (state.is_in_cset()) {
164 // Since the source is always from outside the collection set, here we implicitly know
165 // that this is a cross-region reference too.
166 prefetch_and_push(p, obj);
167 } else {
168 HeapRegion* to = _g1->heap_region_containing(obj);
169 if (_from == to) {
170 return;
171 }
172 handle_non_cset_obj_common(state, p, obj);
173 to->rem_set()->add_reference(p, _worker_i);
174 }
175 }
176
177 template <class T>
178 inline void G1ScanObjsDuringScanRSClosure::do_oop_nv(T* p) {
179 T heap_oop = oopDesc::load_heap_oop(p);
180 if (oopDesc::is_null(heap_oop)) {
181 return;
182 }
183 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
184
185 const InCSetState state = _g1->in_cset_state(obj);
186 if (state.is_in_cset()) {
187 prefetch_and_push(p, obj);
188 } else {
189 if (HeapRegion::is_in_same_region(p, obj)) {
190 return;
191 }
192 handle_non_cset_obj_common(state, p, obj);
193 }
194 }
195
196 void G1ParCopyHelper::do_cld_barrier(oop new_obj) {
197 if (_g1->heap_region_containing(new_obj)->is_young()) {
198 _scanned_cld->record_modified_oops();
199 }
200 }
201
202 void G1ParCopyHelper::mark_object(oop obj) {
203 assert(!_g1->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
204
205 _cm->mark_in_next_bitmap(obj);
206 }
207
208 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
209 assert(from_obj->is_forwarded(), "from obj should be forwarded");
210 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
211 assert(from_obj != to_obj, "should not be self-forwarded");
212
213 assert(_g1->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet");
214 assert(!_g1->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet");
215
216 _cm->mark_in_next_bitmap(to_obj);
217 }
218
219 template <G1Barrier barrier, G1Mark do_mark_object>
220 template <class T>
221 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
222 T heap_oop = oopDesc::load_heap_oop(p);
223
224 if (oopDesc::is_null(heap_oop)) {
225 return;
226 }
227
228 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
229
230 assert(_worker_id == _par_scan_state->worker_id(), "sanity");
231
232 const InCSetState state = _g1->in_cset_state(obj);
233 if (state.is_in_cset()) {
234 oop forwardee;
235 markOop m = obj->mark();
236 if (m->is_marked()) {
237 forwardee = (oop) m->decode_pointer();
238 } else {
239 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
240 }
241 assert(forwardee != NULL, "forwardee should not be NULL");
242 oopDesc::encode_store_heap_oop(p, forwardee);
243 if (do_mark_object != G1MarkNone && forwardee != obj) {
244 // If the object is self-forwarded we don't need to explicitly
245 // mark it, the evacuation failure protocol will do so.
246 mark_forwarded_object(obj, forwardee);
247 }
248
249 if (barrier == G1BarrierCLD) {
250 do_cld_barrier(forwardee);
251 }
252 } else {
253 if (state.is_humongous()) {
254 _g1->set_humongous_is_live(obj);
255 }
256
257 // The object is not in collection set. If we're a root scanning
258 // closure during an initial mark pause then attempt to mark the object.
259 if (do_mark_object == G1MarkFromRoot) {
260 mark_object(obj);
261 }
262 }
263 }
264 #endif // SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP