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
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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/g1RemSet.inline.hpp"
34 #include "gc/g1/heapRegion.inline.hpp"
35 #include "gc/g1/heapRegionRemSet.hpp"
36 #include "memory/iterator.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 } else if (state.is_ext()) {
65 _par_scan_state->do_oop_ext(p);
66 }
67 }
68
69 template <class T>
70 inline void G1ScanEvacuatedObjClosure::do_oop_nv(T* p) {
71 T heap_oop = oopDesc::load_heap_oop(p);
72
73 if (oopDesc::is_null(heap_oop)) {
74 return;
75 }
76 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
77 const InCSetState state = _g1->in_cset_state(obj);
78 if (state.is_in_cset()) {
79 prefetch_and_push(p, obj);
80 } else {
81 handle_non_cset_obj_common(state, p, obj);
82
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 = oopDesc::load_decode_heap_oop(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 = oopDesc::load_heap_oop(p);
96 if (!oopDesc::is_null(heap_oop)) {
97 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
98 HeapRegion* hr = _g1h->heap_region_containing((HeapWord*) obj);
99 _cm->grayRoot(obj, hr);
100 }
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(obj == NULL || obj->is_oop(), "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 = oopDesc::load_heap_oop(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
168 _has_refs_into_cset = true;
169 } else {
170 HeapRegion* to = _g1->heap_region_containing(obj);
171 if (_from == to) {
172 return;
173 }
174
175 handle_non_cset_obj_common(state, p, obj);
176
177 to->rem_set()->add_reference(p, _worker_i);
178 }
179 }
180
181 template <class T>
182 inline void G1ScanObjsDuringScanRSClosure::do_oop_nv(T* p) {
183 T heap_oop = oopDesc::load_heap_oop(p);
184 if (oopDesc::is_null(heap_oop)) {
185 return;
186 }
187 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
188
189 const InCSetState state = _g1->in_cset_state(obj);
190 if (state.is_in_cset()) {
191 prefetch_and_push(p, obj);
192 } else {
193 handle_non_cset_obj_common(state, p, obj);
194 }
195 }
196
197 template <class T>
198 void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) {
199 if (_g1->heap_region_containing(new_obj)->is_young()) {
200 _scanned_klass->record_modified_oops();
201 }
202 }
203
204 void G1ParCopyHelper::mark_object(oop obj) {
205 assert(!_g1->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
206
207 // We know that the object is not moving so it's safe to read its size.
208 _cm->grayRoot(obj);
209 }
210
211 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
212 assert(from_obj->is_forwarded(), "from obj should be forwarded");
213 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
214 assert(from_obj != to_obj, "should not be self-forwarded");
215
216 assert(_g1->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet");
217 assert(!_g1->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet");
218
219 // The object might be in the process of being copied by another
220 // worker so we cannot trust that its to-space image is
221 // well-formed. So we have to read its size from its from-space
222 // image which we know should not be changing.
223 _cm->grayRoot(to_obj);
224 }
225
226 template <G1Barrier barrier, G1Mark do_mark_object, bool use_ext>
227 template <class T>
228 void G1ParCopyClosure<barrier, do_mark_object, use_ext>::do_oop_work(T* p) {
229 T heap_oop = oopDesc::load_heap_oop(p);
230
231 if (oopDesc::is_null(heap_oop)) {
232 return;
233 }
234
235 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
236
237 assert(_worker_id == _par_scan_state->worker_id(), "sanity");
238
239 const InCSetState state = _g1->in_cset_state(obj);
240 if (state.is_in_cset()) {
241 oop forwardee;
242 markOop m = obj->mark();
243 if (m->is_marked()) {
244 forwardee = (oop) m->decode_pointer();
245 } else {
246 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
247 }
248 assert(forwardee != NULL, "forwardee should not be NULL");
249 oopDesc::encode_store_heap_oop(p, forwardee);
250 if (do_mark_object != G1MarkNone && forwardee != obj) {
251 // If the object is self-forwarded we don't need to explicitly
252 // mark it, the evacuation failure protocol will do so.
253 mark_forwarded_object(obj, forwardee);
254 }
255
256 if (barrier == G1BarrierKlass) {
257 do_klass_barrier(p, forwardee);
258 }
259 } else {
260 if (state.is_humongous()) {
261 _g1->set_humongous_is_live(obj);
262 }
263
264 if (use_ext && state.is_ext()) {
265 _par_scan_state->do_oop_ext(p);
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 }
274
275 #endif // SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP