1 /*
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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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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
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24
25 #ifndef SHARE_GC_G1_G1OOPCLOSURES_INLINE_HPP
26 #define SHARE_GC_G1_G1OOPCLOSURES_INLINE_HPP
27
28 #include "gc/g1/g1OopClosures.hpp"
29
30 #include "gc/g1/g1CollectedHeap.hpp"
31 #include "gc/g1/g1ConcurrentMark.inline.hpp"
32 #include "gc/g1/g1ParScanThreadState.inline.hpp"
33 #include "gc/g1/g1RemSet.hpp"
34 #include "gc/g1/heapRegion.inline.hpp"
35 #include "gc/g1/heapRegionRemSet.inline.hpp"
36 #include "memory/iterator.inline.hpp"
37 #include "oops/access.inline.hpp"
38 #include "oops/compressedOops.inline.hpp"
39 #include "oops/oopsHierarchy.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "runtime/prefetch.inline.hpp"
42 #include "utilities/align.hpp"
43
44 template <class T>
45 inline void G1ScanClosureBase::prefetch_and_push(T* p, const oop obj) {
46 // We're not going to even bother checking whether the object is
47 // already forwarded or not, as this usually causes an immediate
48 // stall. We'll try to prefetch the object (for write, given that
49 // we might need to install the forwarding reference) and we'll
50 // get back to it when pop it from the queue
51 Prefetch::write(obj->mark_addr(), 0);
52 Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
53
54 // slightly paranoid test; I'm trying to catch potential
55 // problems before we go into push_on_queue to know where the
56 // problem is coming from
57 assert((obj == RawAccess<>::oop_load(p)) ||
58 (obj->is_forwarded() &&
59 obj->forwardee() == RawAccess<>::oop_load(p)),
60 "p should still be pointing to obj or to its forwardee");
61
62 _par_scan_state->push_on_queue(ScannerTask(p));
63 }
64
65 template <class T>
66 inline void G1ScanClosureBase::handle_non_cset_obj_common(G1HeapRegionAttr const region_attr, T* p, oop const obj) {
67 if (region_attr.is_humongous_candidate()) {
68 _g1h->set_humongous_is_live(obj);
69 } else if (region_attr.is_optional()) {
70 _par_scan_state->remember_reference_into_optional_region(p);
71 }
72 }
73
74 inline void G1ScanClosureBase::trim_queue_partially() {
75 _par_scan_state->trim_queue_partially();
76 }
77
78 template <class T>
79 inline void G1ScanEvacuatedObjClosure::do_oop_work(T* p) {
80 T heap_oop = RawAccess<>::oop_load(p);
81
82 if (CompressedOops::is_null(heap_oop)) {
83 return;
84 }
85 oop obj = CompressedOops::decode_not_null(heap_oop);
86 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj);
87 if (region_attr.is_in_cset()) {
88 prefetch_and_push(p, obj);
89 } else if (!HeapRegion::is_in_same_region(p, obj)) {
90 handle_non_cset_obj_common(region_attr, p, obj);
91 assert(_skip_card_enqueue != Uninitialized, "Scan location has not been initialized.");
92 if (_skip_card_enqueue == True) {
93 return;
94 }
95 _par_scan_state->enqueue_card_if_tracked(region_attr, p, obj);
96 }
97 }
98
99 template <class T>
100 inline void G1CMOopClosure::do_oop_work(T* p) {
101 _task->deal_with_reference(p);
102 }
103
104 template <class T>
105 inline void G1RootRegionScanClosure::do_oop_work(T* p) {
106 T heap_oop = RawAccess<MO_RELAXED>::oop_load(p);
107 if (CompressedOops::is_null(heap_oop)) {
108 return;
109 }
110 oop obj = CompressedOops::decode_not_null(heap_oop);
111 _cm->mark_in_bitmap(_worker_id, obj);
112 }
113
114 template <class T>
115 inline static void check_obj_during_refinement(T* p, oop const obj) {
116 #ifdef ASSERT
117 G1CollectedHeap* g1h = G1CollectedHeap::heap();
118 // can't do because of races
119 // assert(oopDesc::is_oop_or_null(obj), "expected an oop");
120 assert(is_object_aligned(obj), "obj must be aligned");
121 assert(g1h->is_in(obj), "invariant");
122 assert(g1h->is_in(p), "invariant");
123 #endif // ASSERT
124 }
125
126 template <class T>
127 inline void G1ConcurrentRefineOopClosure::do_oop_work(T* p) {
128 T o = RawAccess<MO_RELAXED>::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_id);
152 }
153 }
154
155 template <class T>
156 inline void G1ScanCardClosure::do_oop_work(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),
166 "Oop originates from " PTR_FORMAT " (region: %u) which is in the collection set.",
167 p2i(p), _g1h->addr_to_region(p));
168
169 const G1HeapRegionAttr region_attr = _g1h->region_attr(obj);
170 if (region_attr.is_in_cset()) {
171 // Since the source is always from outside the collection set, here we implicitly know
172 // that this is a cross-region reference too.
173 prefetch_and_push(p, obj);
174 _heap_roots_found++;
175 } else if (!HeapRegion::is_in_same_region(p, obj)) {
176 handle_non_cset_obj_common(region_attr, p, obj);
177 _par_scan_state->enqueue_card_if_tracked(region_attr, p, obj);
178 }
179 }
180
181 template <class T>
182 inline void G1ScanRSForOptionalClosure::do_oop_work(T* p) {
183 const G1HeapRegionAttr region_attr = _g1h->region_attr(p);
184 // Entries in the optional collection set may start to originate from the collection
185 // set after one or more increments. In this case, previously optional regions
186 // became actual collection set regions. Filter them out here.
187 if (region_attr.is_in_cset()) {
188 return;
189 }
190 _scan_cl->do_oop_work(p);
191 _scan_cl->trim_queue_partially();
192 }
193
194 void G1ParCopyHelper::do_cld_barrier(oop new_obj) {
195 if (_g1h->heap_region_containing(new_obj)->is_young()) {
196 _scanned_cld->record_modified_oops();
197 }
198 }
199
200 void G1ParCopyHelper::mark_object(oop obj) {
201 assert(!_g1h->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
202
203 // We know that the object is not moving so it's safe to read its size.
204 _cm->mark_in_bitmap(_worker_id, obj);
205 }
206
207 void G1ParCopyHelper::trim_queue_partially() {
208 _par_scan_state->trim_queue_partially();
209 }
210
211 template <G1Barrier barrier, bool should_mark>
212 template <class T>
213 void G1ParCopyClosure<barrier, should_mark>::do_oop_work(T* p) {
214 T heap_oop = RawAccess<>::oop_load(p);
215
216 if (CompressedOops::is_null(heap_oop)) {
217 return;
218 }
219
220 oop obj = CompressedOops::decode_not_null(heap_oop);
221
222 assert(_worker_id == _par_scan_state->worker_id(), "sanity");
223
224 const G1HeapRegionAttr state = _g1h->region_attr(obj);
225 if (state.is_in_cset()) {
226 oop forwardee;
227 markWord m = obj->mark();
228 if (m.is_marked()) {
229 forwardee = cast_to_oop(m.decode_pointer());
230 } else {
231 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
232 }
233 assert(forwardee != NULL, "forwardee should not be NULL");
234 RawAccess<IS_NOT_NULL>::oop_store(p, forwardee);
235
236 if (barrier == G1BarrierCLD) {
237 do_cld_barrier(forwardee);
238 }
239 } else {
240 if (state.is_humongous_candidate()) {
241 _g1h->set_humongous_is_live(obj);
242 } else if ((barrier != G1BarrierNoOptRoots) && state.is_optional()) {
243 _par_scan_state->remember_root_into_optional_region(p);
244 }
245
246 // The object is not in the collection set. should_mark is true iff the
247 // current closure is applied on strong roots (and weak roots when class
248 // unloading is disabled) in a concurrent mark start pause.
249 if (should_mark) {
250 mark_object(obj);
251 }
252 }
253 trim_queue_partially();
254 }
255
256 template <class T> void G1RebuildRemSetClosure::do_oop_work(T* p) {
257 oop const obj = RawAccess<MO_RELAXED>::oop_load(p);
258 if (obj == NULL) {
259 return;
260 }
261
262 if (HeapRegion::is_in_same_region(p, obj)) {
263 return;
264 }
265
266 HeapRegion* to = _g1h->heap_region_containing(obj);
267 HeapRegionRemSet* rem_set = to->rem_set();
268 if (rem_set->is_tracked()) {
269 rem_set->add_reference(p, _worker_id);
270 }
271 }
272
273 #endif // SHARE_GC_G1_G1OOPCLOSURES_INLINE_HPP