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.
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5 * This code is free software; you can redistribute it and/or modify it
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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,
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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 #include "utilities/ticks.inline.hpp"
42
43 template <class T>
44 inline void G1ScanClosureBase::prefetch_and_push(T* p, const oop obj) {
45 // We're not going to even bother checking whether the object is
46 // already forwarded or not, as this usually causes an immediate
47 // stall. We'll try to prefetch the object (for write, given that
48 // we might need to install the forwarding reference) and we'll
49 // get back to it when pop it from the queue
50 Prefetch::write(obj->mark_addr_raw(), 0);
51 Prefetch::read(obj->mark_addr_raw(), (HeapWordSize*2));
52
53 // slightly paranoid test; I'm trying to catch potential
54 // problems before we go into push_on_queue to know where the
55 // problem is coming from
56 assert((obj == RawAccess<>::oop_load(p)) ||
57 (obj->is_forwarded() &&
58 obj->forwardee() == RawAccess<>::oop_load(p)),
59 "p should still be pointing to obj or to its forwardee");
60
61 _par_scan_state->push_on_queue(p);
62 }
63
64 template <class T>
65 inline void G1ScanClosureBase::handle_non_cset_obj_common(InCSetState const state, T* p, oop const obj) {
66 if (state.is_humongous()) {
67 _g1h->set_humongous_is_live(obj);
68 }
69 }
70
71 inline void G1ScanClosureBase::trim_queue_partially() {
72 _trim_ticks += _par_scan_state->trim_queue_partially();
73 }
74
75 inline Tickspan G1ScanClosureBase::trim_ticks_and_reset() {
76 Tickspan result = _trim_ticks;
77 _trim_ticks = Tickspan();
78 return result;
79 }
80
81 template <class T>
82 inline void G1ScanEvacuatedObjClosure::do_oop_nv(T* p) {
83 T heap_oop = RawAccess<>::oop_load(p);
84
85 if (CompressedOops::is_null(heap_oop)) {
86 return;
87 }
88 oop obj = CompressedOops::decode_not_null(heap_oop);
89 const InCSetState state = _g1h->in_cset_state(obj);
90 if (state.is_in_cset()) {
91 prefetch_and_push(p, obj);
92 } else {
93 if (HeapRegion::is_in_same_region(p, obj)) {
94 return;
95 }
96 handle_non_cset_obj_common(state, p, obj);
97 _par_scan_state->update_rs(_from, p, obj);
98 }
99 }
100
101 template <class T>
102 inline void G1CMOopClosure::do_oop_nv(T* p) {
103 _task->deal_with_reference(p);
104 }
105
106 template <class T>
107 inline void G1RootRegionScanClosure::do_oop_nv(T* p) {
108 T heap_oop = RawAccess<MO_VOLATILE>::oop_load(p);
109 if (CompressedOops::is_null(heap_oop)) {
110 return;
111 }
112 oop obj = CompressedOops::decode_not_null(heap_oop);
113 _cm->mark_in_next_bitmap(_worker_id, obj);
114 }
115
116 template <class T>
117 inline static void check_obj_during_refinement(T* p, oop const obj) {
118 #ifdef ASSERT
119 G1CollectedHeap* g1h = G1CollectedHeap::heap();
120 // can't do because of races
121 // assert(oopDesc::is_oop_or_null(obj), "expected an oop");
122 assert(check_obj_alignment(obj), "not oop aligned");
123 assert(g1h->is_in_reserved(obj), "must be in heap");
124
125 HeapRegion* from = g1h->heap_region_containing(p);
126
127 assert(from != NULL, "from region must be non-NULL");
128 assert(from->is_in_reserved(p) ||
129 (from->is_humongous() &&
130 g1h->heap_region_containing(p)->is_humongous() &&
131 from->humongous_start_region() == g1h->heap_region_containing(p)->humongous_start_region()),
132 "p " PTR_FORMAT " is not in the same region %u or part of the correct humongous object starting at region %u.",
133 p2i(p), from->hrm_index(), from->humongous_start_region()->hrm_index());
134 #endif // ASSERT
135 }
136
137 template <class T>
138 inline void G1ConcurrentRefineOopClosure::do_oop_nv(T* p) {
139 T o = RawAccess<MO_VOLATILE>::oop_load(p);
140 if (CompressedOops::is_null(o)) {
141 return;
142 }
143 oop obj = CompressedOops::decode_not_null(o);
144
145 check_obj_during_refinement(p, obj);
146
147 if (HeapRegion::is_in_same_region(p, obj)) {
148 // Normally this closure should only be called with cross-region references.
149 // But since Java threads are manipulating the references concurrently and we
150 // reload the values things may have changed.
151 // Also this check lets slip through references from a humongous continues region
152 // to its humongous start region, as they are in different regions, and adds a
153 // remembered set entry. This is benign (apart from memory usage), as we never
154 // try to either evacuate or eager reclaim humonguous arrays of j.l.O.
155 return;
156 }
157
158 HeapRegionRemSet* to_rem_set = _g1h->heap_region_containing(obj)->rem_set();
159
160 assert(to_rem_set != NULL, "Need per-region 'into' remsets.");
161 if (to_rem_set->is_tracked()) {
162 to_rem_set->add_reference(p, _worker_i);
163 }
164 }
165
166 template <class T>
167 inline void G1ScanObjsDuringUpdateRSClosure::do_oop_nv(T* p) {
168 T o = RawAccess<>::oop_load(p);
169 if (CompressedOops::is_null(o)) {
170 return;
171 }
172 oop obj = CompressedOops::decode_not_null(o);
173
174 check_obj_during_refinement(p, obj);
175
176 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));
177 const InCSetState state = _g1h->in_cset_state(obj);
178 if (state.is_in_cset()) {
179 // Since the source is always from outside the collection set, here we implicitly know
180 // that this is a cross-region reference too.
181 prefetch_and_push(p, obj);
182 } else {
183 HeapRegion* to = _g1h->heap_region_containing(obj);
184 if (_from == to) {
185 return;
186 }
187 handle_non_cset_obj_common(state, p, obj);
188 to->rem_set()->add_reference(p, _worker_i);
189 }
190 }
191
192 template <class T>
193 inline void G1ScanObjsDuringScanRSClosure::do_oop_nv(T* p) {
194 T heap_oop = RawAccess<>::oop_load(p);
195 if (CompressedOops::is_null(heap_oop)) {
196 return;
197 }
198 oop obj = CompressedOops::decode_not_null(heap_oop);
199
200 const InCSetState state = _g1h->in_cset_state(obj);
201 if (state.is_in_cset()) {
202 prefetch_and_push(p, obj);
203 } else {
204 if (HeapRegion::is_in_same_region(p, obj)) {
205 return;
206 }
207 handle_non_cset_obj_common(state, p, obj);
208 }
209 }
210
211 void G1ParCopyHelper::do_cld_barrier(oop new_obj) {
212 if (_g1h->heap_region_containing(new_obj)->is_young()) {
213 _scanned_cld->record_modified_oops();
214 }
215 }
216
217 inline Tickspan G1ParCopyHelper::trim_ticks_and_reset() {
218 Tickspan result = _trim_ticks;
219 _trim_ticks = Tickspan();
220 return result;
221 }
222
223 void G1ParCopyHelper::mark_object(oop obj) {
224 assert(!_g1h->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
225
226 // We know that the object is not moving so it's safe to read its size.
227 _cm->mark_in_next_bitmap(_worker_id, obj);
228 }
229
230 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
231 assert(from_obj->is_forwarded(), "from obj should be forwarded");
232 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
233 assert(from_obj != to_obj, "should not be self-forwarded");
234
235 assert(_g1h->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet");
236 assert(!_g1h->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet");
237
238 // The object might be in the process of being copied by another
239 // worker so we cannot trust that its to-space image is
240 // well-formed. So we have to read its size from its from-space
241 // image which we know should not be changing.
242 _cm->mark_in_next_bitmap(_worker_id, to_obj, from_obj->size());
243 }
244
245 void G1ParCopyHelper::trim_queue_partially() {
246 _trim_ticks += _par_scan_state->trim_queue_partially();
247 }
248
249 template <G1Barrier barrier, G1Mark do_mark_object>
250 template <class T>
251 void G1ParCopyClosure<barrier, do_mark_object>::do_oop_work(T* p) {
252 T heap_oop = RawAccess<>::oop_load(p);
253
254 if (CompressedOops::is_null(heap_oop)) {
255 return;
256 }
257
258 oop obj = CompressedOops::decode_not_null(heap_oop);
259
260 assert(_worker_id == _par_scan_state->worker_id(), "sanity");
261
262 const InCSetState state = _g1h->in_cset_state(obj);
263 if (state.is_in_cset()) {
264 oop forwardee;
265 markOop m = obj->mark_raw();
266 if (m->is_marked()) {
267 forwardee = (oop) m->decode_pointer();
268 } else {
269 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
270 }
271 assert(forwardee != NULL, "forwardee should not be NULL");
272 RawAccess<OOP_NOT_NULL>::oop_store(p, forwardee);
273 if (do_mark_object != G1MarkNone && forwardee != obj) {
274 // If the object is self-forwarded we don't need to explicitly
275 // mark it, the evacuation failure protocol will do so.
276 mark_forwarded_object(obj, forwardee);
277 }
278
279 if (barrier == G1BarrierCLD) {
280 do_cld_barrier(forwardee);
281 }
282 } else {
283 if (state.is_humongous()) {
284 _g1h->set_humongous_is_live(obj);
285 }
286
287 // The object is not in collection set. If we're a root scanning
288 // closure during an initial mark pause then attempt to mark the object.
289 if (do_mark_object == G1MarkFromRoot) {
290 mark_object(obj);
291 }
292 }
293 trim_queue_partially();
294 }
295
296 template <class T> void G1RebuildRemSetClosure::do_oop_nv(T* p) {
297 oop const obj = RawAccess<MO_VOLATILE>::oop_load(p);
298 if (obj == NULL) {
299 return;
300 }
301
302 if (HeapRegion::is_in_same_region(p, obj)) {
303 return;
304 }
305
306 HeapRegion* to = _g1h->heap_region_containing(obj);
307 HeapRegionRemSet* rem_set = to->rem_set();
308 rem_set->add_reference(p, _worker_id);
309 }
310
311 #endif // SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP