1 /*
2 * Copyright (c) 2001, 2015, 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.
18 *
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
21 * questions.
22 *
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/concurrentMark.inline.hpp"
29 #include "gc/g1/g1CollectedHeap.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 /*
40 * This really ought to be an inline function, but apparently the C++
41 * compiler sometimes sees fit to ignore inline declarations. Sigh.
42 */
43
44 template <class T>
45 inline void FilterIntoCSClosure::do_oop_work(T* p) {
46 T heap_oop = oopDesc::load_heap_oop(p);
47 if (!oopDesc::is_null(heap_oop) &&
48 _g1->is_in_cset_or_humongous(oopDesc::decode_heap_oop_not_null(heap_oop))) {
49 _oc->do_oop(p);
50 }
51 }
52
53 template <class T>
54 inline void FilterOutOfRegionClosure::do_oop_nv(T* p) {
55 T heap_oop = oopDesc::load_heap_oop(p);
56 if (!oopDesc::is_null(heap_oop)) {
57 HeapWord* obj_hw = (HeapWord*)oopDesc::decode_heap_oop_not_null(heap_oop);
58 if (obj_hw < _r_bottom || obj_hw >= _r_end) {
59 _oc->do_oop(p);
60 }
61 }
62 }
63
64 // This closure is applied to the fields of the objects that have just been copied.
65 template <class T>
66 inline void G1ParScanClosure::do_oop_nv(T* p) {
67 T heap_oop = oopDesc::load_heap_oop(p);
68
69 if (!oopDesc::is_null(heap_oop)) {
70 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
71 const InCSetState state = _g1->in_cset_state(obj);
72 if (state.is_in_cset()) {
73 // We're not going to even bother checking whether the object is
74 // already forwarded or not, as this usually causes an immediate
75 // stall. We'll try to prefetch the object (for write, given that
76 // we might need to install the forwarding reference) and we'll
77 // get back to it when pop it from the queue
78 Prefetch::write(obj->mark_addr(), 0);
79 Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
80
81 // slightly paranoid test; I'm trying to catch potential
82 // problems before we go into push_on_queue to know where the
83 // problem is coming from
84 assert((obj == oopDesc::load_decode_heap_oop(p)) ||
85 (obj->is_forwarded() &&
86 obj->forwardee() == oopDesc::load_decode_heap_oop(p)),
87 "p should still be pointing to obj or to its forwardee");
88
89 _par_scan_state->push_on_queue(p);
90 } else {
91 if (state.is_humongous()) {
92 _g1->set_humongous_is_live(obj);
93 } else if (state.is_ext()) {
94 _par_scan_state->do_oop_ext(p);
95 }
96 _par_scan_state->update_rs(_from, p, obj);
97 }
98 }
99 }
100
101 template <class T>
102 inline void G1ParPushHeapRSClosure::do_oop_nv(T* p) {
103 T heap_oop = oopDesc::load_heap_oop(p);
104
105 if (!oopDesc::is_null(heap_oop)) {
106 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
107 const InCSetState state = _g1->in_cset_state(obj);
108 if (state.is_in_cset_or_humongous()) {
109 Prefetch::write(obj->mark_addr(), 0);
110 Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
111
112 // Place on the references queue
113 _par_scan_state->push_on_queue(p);
114 } else if (state.is_ext()) {
115 _par_scan_state->do_oop_ext(p);
116 } else {
117 assert(!_g1->obj_in_cs(obj), "checking");
118 }
119 }
120 }
121
122 template <class T>
123 inline void G1CMOopClosure::do_oop_nv(T* p) {
124 oop obj = oopDesc::load_decode_heap_oop(p);
125 _task->deal_with_reference(obj);
126 }
127
128 template <class T>
129 inline void G1RootRegionScanClosure::do_oop_nv(T* p) {
130 T heap_oop = oopDesc::load_heap_oop(p);
131 if (!oopDesc::is_null(heap_oop)) {
132 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
133 HeapRegion* hr = _g1h->heap_region_containing((HeapWord*) obj);
134 _cm->grayRoot(obj, obj->size(), _worker_id, hr);
135 }
136 }
137
138 template <class T>
139 inline void G1Mux2Closure::do_oop_work(T* p) {
140 // Apply first closure; then apply the second.
141 _c1->do_oop(p);
142 _c2->do_oop(p);
143 }
144
145 template <class T>
146 inline void G1TriggerClosure::do_oop_work(T* p) {
147 // Record that this closure was actually applied (triggered).
148 _triggered = true;
149 }
150
151 template <class T>
152 inline void G1InvokeIfNotTriggeredClosure::do_oop_work(T* p) {
153 if (!_trigger_cl->triggered()) {
154 _oop_cl->do_oop(p);
155 }
156 }
157
158 template <class T>
159 inline void G1UpdateRSOrPushRefOopClosure::do_oop_work(T* p) {
160 oop obj = oopDesc::load_decode_heap_oop(p);
161 if (obj == NULL) {
162 return;
163 }
164
165 #ifdef ASSERT
166 // can't do because of races
167 // assert(obj == NULL || obj->is_oop(), "expected an oop");
168
169 // Do the safe subset of is_oop
170 #ifdef CHECK_UNHANDLED_OOPS
171 oopDesc* o = obj.obj();
172 #else
173 oopDesc* o = obj;
174 #endif // CHECK_UNHANDLED_OOPS
175 assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned");
176 assert(_g1->is_in_reserved(obj), "must be in heap");
177 #endif // ASSERT
178
179 assert(_from != NULL, "from region must be non-NULL");
180 assert(_from->is_in_reserved(p), "p is not in from");
181
182 HeapRegion* to = _g1->heap_region_containing(obj);
183 if (_from == to) {
184 // Normally this closure should only be called with cross-region references.
185 // But since Java threads are manipulating the references concurrently and we
186 // reload the values things may have changed.
187 return;
188 }
189
190 // The _record_refs_into_cset flag is true during the RSet
191 // updating part of an evacuation pause. It is false at all
192 // other times:
193 // * rebuilding the remembered sets after a full GC
194 // * during concurrent refinement.
195 // * updating the remembered sets of regions in the collection
196 // set in the event of an evacuation failure (when deferred
197 // updates are enabled).
198
199 if (_record_refs_into_cset && to->in_collection_set()) {
200 // We are recording references that point into the collection
201 // set and this particular reference does exactly that...
202 // If the referenced object has already been forwarded
203 // to itself, we are handling an evacuation failure and
204 // we have already visited/tried to copy this object
205 // there is no need to retry.
206 if (!self_forwarded(obj)) {
207 assert(_push_ref_cl != NULL, "should not be null");
208 // Push the reference in the refs queue of the G1ParScanThreadState
209 // instance for this worker thread.
210 _push_ref_cl->do_oop(p);
211 }
212
213 // Deferred updates to the CSet are either discarded (in the normal case),
214 // or processed (if an evacuation failure occurs) at the end
215 // of the collection.
216 // See G1RemSet::cleanup_after_oops_into_collection_set_do().
217 } else {
218 // We either don't care about pushing references that point into the
219 // collection set (i.e. we're not during an evacuation pause) _or_
220 // the reference doesn't point into the collection set. Either way
221 // we add the reference directly to the RSet of the region containing
222 // the referenced object.
223 assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
224 to->rem_set()->add_reference(p, _worker_i);
225 }
226 }
227
228 template <class T>
229 void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) {
230 if (_g1->heap_region_containing(new_obj)->is_young()) {
231 _scanned_klass->record_modified_oops();
232 }
233 }
234
235 void G1ParCopyHelper::mark_object(oop obj) {
236 assert(!_g1->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
237
238 // We know that the object is not moving so it's safe to read its size.
239 _cm->grayRoot(obj, (size_t) obj->size(), _worker_id);
240 }
241
242 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
243 assert(from_obj->is_forwarded(), "from obj should be forwarded");
244 assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
245 assert(from_obj != to_obj, "should not be self-forwarded");
246
247 assert(_g1->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet");
248 assert(!_g1->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet");
249
250 // The object might be in the process of being copied by another
251 // worker so we cannot trust that its to-space image is
252 // well-formed. So we have to read its size from its from-space
253 // image which we know should not be changing.
254 _cm->grayRoot(to_obj, (size_t) from_obj->size(), _worker_id);
255 }
256
257 template <G1Barrier barrier, G1Mark do_mark_object, bool use_ext>
258 template <class T>
259 void G1ParCopyClosure<barrier, do_mark_object, use_ext>::do_oop_work(T* p) {
260 T heap_oop = oopDesc::load_heap_oop(p);
261
262 if (oopDesc::is_null(heap_oop)) {
263 return;
264 }
265
266 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
267
268 assert(_worker_id == _par_scan_state->worker_id(), "sanity");
269
270 const InCSetState state = _g1->in_cset_state(obj);
271 if (state.is_in_cset()) {
272 oop forwardee;
273 markOop m = obj->mark();
274 if (m->is_marked()) {
275 forwardee = (oop) m->decode_pointer();
276 } else {
277 forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
278 }
279 assert(forwardee != NULL, "forwardee should not be NULL");
280 oopDesc::encode_store_heap_oop(p, forwardee);
281 if (do_mark_object != G1MarkNone && forwardee != obj) {
282 // If the object is self-forwarded we don't need to explicitly
283 // mark it, the evacuation failure protocol will do so.
284 mark_forwarded_object(obj, forwardee);
285 }
286
287 if (barrier == G1BarrierKlass) {
288 do_klass_barrier(p, forwardee);
289 }
290 } else {
291 if (state.is_humongous()) {
292 _g1->set_humongous_is_live(obj);
293 }
294
295 if (use_ext && state.is_ext()) {
296 _par_scan_state->do_oop_ext(p);
297 }
298 // The object is not in collection set. If we're a root scanning
299 // closure during an initial mark pause then attempt to mark the object.
300 if (do_mark_object == G1MarkFromRoot) {
301 mark_object(obj);
302 }
303 }
304 }
305
306 #endif // SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP