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