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 #include "precompiled.hpp"
26 #include "gc/g1/g1CollectedHeap.hpp"
27 #include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"
28 #include "gc/g1/g1FullCollector.inline.hpp"
29 #include "gc/g1/g1FullGCCompactionPoint.hpp"
30 #include "gc/g1/g1FullGCMarker.hpp"
31 #include "gc/g1/g1FullGCOopClosures.inline.hpp"
32 #include "gc/g1/g1FullGCPrepareTask.hpp"
33 #include "gc/g1/g1HotCardCache.hpp"
34 #include "gc/g1/heapRegion.inline.hpp"
35 #include "gc/shared/gcTraceTime.inline.hpp"
36 #include "gc/shared/referenceProcessor.hpp"
37 #include "logging/log.hpp"
38 #include "memory/iterator.inline.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "utilities/ticks.hpp"
41
42 template<bool is_humongous>
43 void G1FullGCPrepareTask::G1CalculatePointersClosure::free_pinned_region(HeapRegion* hr) {
44 _regions_freed = true;
45 if (is_humongous) {
46 _g1h->free_humongous_region(hr, nullptr);
47 } else {
48 _g1h->free_region(hr, nullptr);
49 }
50 prepare_for_compaction(hr);
51 _collector->set_invalid(hr->hrm_index());
52 }
53
54 bool G1FullGCPrepareTask::G1CalculatePointersClosure::do_heap_region(HeapRegion* hr) {
55 bool force_not_compacted = false;
56 if (should_compact(hr)) {
139 bool G1FullGCPrepareTask::G1CalculatePointersClosure::should_compact(HeapRegion* hr) {
140 if (hr->is_pinned()) {
141 return false;
142 }
143 size_t live_words = _collector->live_words(hr->hrm_index());
144 size_t live_words_threshold = _collector->scope()->region_compaction_threshold();
145 // High live ratio region will not be compacted.
146 return live_words <= live_words_threshold;
147 }
148
149 void G1FullGCPrepareTask::G1CalculatePointersClosure::reset_region_metadata(HeapRegion* hr) {
150 hr->rem_set()->clear();
151 hr->clear_cardtable();
152
153 G1HotCardCache* hcc = _g1h->hot_card_cache();
154 if (hcc->use_cache()) {
155 hcc->reset_card_counts(hr);
156 }
157 }
158
159 G1FullGCPrepareTask::G1PrepareCompactLiveClosure::G1PrepareCompactLiveClosure(G1FullGCCompactionPoint* cp) :
160 _cp(cp) { }
161
162 size_t G1FullGCPrepareTask::G1PrepareCompactLiveClosure::apply(oop object) {
163 size_t size = object->size();
164 _cp->forward(object, size);
165 return size;
166 }
167
168 size_t G1FullGCPrepareTask::G1RePrepareClosure::apply(oop obj) {
169 // We only re-prepare objects forwarded within the current region, so
170 // skip objects that are already forwarded to another region.
171 oop forwarded_to = obj->forwardee();
172 if (forwarded_to != NULL && !_current->is_in(forwarded_to)) {
173 return obj->size();
174 }
175
176 // Get size and forward.
177 size_t size = obj->size();
178 _cp->forward(obj, size);
179
180 return size;
181 }
182
183 void G1FullGCPrepareTask::G1CalculatePointersClosure::prepare_for_compaction_work(G1FullGCCompactionPoint* cp,
184 HeapRegion* hr) {
185 G1PrepareCompactLiveClosure prepare_compact(cp);
186 hr->set_compaction_top(hr->bottom());
187 hr->apply_to_marked_objects(_bitmap, &prepare_compact);
188 }
189
190 void G1FullGCPrepareTask::G1CalculatePointersClosure::prepare_for_compaction(HeapRegion* hr) {
191 if (!_cp->is_initialized()) {
192 hr->set_compaction_top(hr->bottom());
193 _cp->initialize(hr, true);
194 }
195 // Add region to the compaction queue and prepare it.
196 _cp->add(hr);
197 prepare_for_compaction_work(_cp, hr);
198 }
199
200 void G1FullGCPrepareTask::prepare_serial_compaction() {
201 GCTraceTime(Debug, gc, phases) debug("Phase 2: Prepare Serial Compaction", collector()->scope()->timer());
202 // At this point we know that no regions were completely freed by
203 // the parallel compaction. That means that the last region of
204 // all compaction queues still have data in them. We try to compact
205 // these regions in serial to avoid a premature OOM.
206 for (uint i = 0; i < collector()->workers(); i++) {
207 G1FullGCCompactionPoint* cp = collector()->compaction_point(i);
208 if (cp->has_regions()) {
209 collector()->serial_compaction_point()->add(cp->remove_last());
210 }
211 }
212
213 // Update the forwarding information for the regions in the serial
214 // compaction point.
215 G1FullGCCompactionPoint* cp = collector()->serial_compaction_point();
216 for (GrowableArrayIterator<HeapRegion*> it = cp->regions()->begin(); it != cp->regions()->end(); ++it) {
217 HeapRegion* current = *it;
218 if (!cp->is_initialized()) {
219 // Initialize the compaction point. Nothing more is needed for the first heap region
220 // since it is already prepared for compaction.
221 cp->initialize(current, false);
222 } else {
223 assert(!current->is_humongous(), "Should be no humongous regions in compaction queue");
224 G1RePrepareClosure re_prepare(cp, current);
225 current->set_compaction_top(current->bottom());
226 current->apply_to_marked_objects(collector()->mark_bitmap(), &re_prepare);
227 }
228 }
229 cp->update();
230 }
231
232 bool G1FullGCPrepareTask::G1CalculatePointersClosure::freed_regions() {
233 if (_regions_freed) {
234 return true;
235 }
236
237 if (!_cp->has_regions()) {
238 // No regions in queue, so no free ones either.
239 return false;
240 }
241
242 if (_cp->current_region() != _cp->regions()->last()) {
243 // The current region used for compaction is not the last in the
244 // queue. That means there is at least one free region in the queue.
245 return true;
246 }
247
248 // No free regions in the queue.
249 return false;
250 }
|
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 #include "precompiled.hpp"
26 #include "gc/g1/g1CollectedHeap.hpp"
27 #include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"
28 #include "gc/g1/g1FullCollector.inline.hpp"
29 #include "gc/g1/g1FullGCCompactionPoint.hpp"
30 #include "gc/g1/g1FullGCMarker.hpp"
31 #include "gc/g1/g1FullGCOopClosures.inline.hpp"
32 #include "gc/g1/g1FullGCPrepareTask.hpp"
33 #include "gc/g1/g1HotCardCache.hpp"
34 #include "gc/g1/heapRegion.inline.hpp"
35 #include "gc/shared/gcTraceTime.inline.hpp"
36 #include "gc/shared/referenceProcessor.hpp"
37 #include "gc/shared/slidingForwarding.inline.hpp"
38 #include "logging/log.hpp"
39 #include "memory/iterator.inline.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "utilities/ticks.hpp"
42
43 template<bool is_humongous>
44 void G1FullGCPrepareTask::G1CalculatePointersClosure::free_pinned_region(HeapRegion* hr) {
45 _regions_freed = true;
46 if (is_humongous) {
47 _g1h->free_humongous_region(hr, nullptr);
48 } else {
49 _g1h->free_region(hr, nullptr);
50 }
51 prepare_for_compaction(hr);
52 _collector->set_invalid(hr->hrm_index());
53 }
54
55 bool G1FullGCPrepareTask::G1CalculatePointersClosure::do_heap_region(HeapRegion* hr) {
56 bool force_not_compacted = false;
57 if (should_compact(hr)) {
140 bool G1FullGCPrepareTask::G1CalculatePointersClosure::should_compact(HeapRegion* hr) {
141 if (hr->is_pinned()) {
142 return false;
143 }
144 size_t live_words = _collector->live_words(hr->hrm_index());
145 size_t live_words_threshold = _collector->scope()->region_compaction_threshold();
146 // High live ratio region will not be compacted.
147 return live_words <= live_words_threshold;
148 }
149
150 void G1FullGCPrepareTask::G1CalculatePointersClosure::reset_region_metadata(HeapRegion* hr) {
151 hr->rem_set()->clear();
152 hr->clear_cardtable();
153
154 G1HotCardCache* hcc = _g1h->hot_card_cache();
155 if (hcc->use_cache()) {
156 hcc->reset_card_counts(hr);
157 }
158 }
159
160 template <bool ALT_FWD>
161 G1FullGCPrepareTask::G1PrepareCompactLiveClosure<ALT_FWD>::G1PrepareCompactLiveClosure(G1FullGCCompactionPoint* cp) :
162 _cp(cp) { }
163
164 template <bool ALT_FWD>
165 size_t G1FullGCPrepareTask::G1PrepareCompactLiveClosure<ALT_FWD>::apply(oop object) {
166 size_t size = object->size();
167 _cp->forward<ALT_FWD>(object, size);
168 return size;
169 }
170
171 template <bool ALT_FWD>
172 size_t G1FullGCPrepareTask::G1RePrepareClosure<ALT_FWD>::apply(oop obj) {
173 // We only re-prepare objects forwarded within the current region, so
174 // skip objects that are already forwarded to another region.
175 if (SlidingForwarding::is_forwarded(obj)) {
176 oop forwarded_to = SlidingForwarding::forwardee<ALT_FWD>(obj);
177 assert(forwarded_to != NULL, "must have forwardee");
178 if (!_current->is_in(forwarded_to)) {
179 return obj->size();
180 }
181 }
182 // Get size and forward.
183 size_t size = obj->size();
184 _cp->forward<ALT_FWD>(obj, size);
185
186 return size;
187 }
188
189 void G1FullGCPrepareTask::G1CalculatePointersClosure::prepare_for_compaction_work(G1FullGCCompactionPoint* cp,
190 HeapRegion* hr) {
191 if (UseAltGCForwarding) {
192 G1PrepareCompactLiveClosure<true> prepare_compact(cp);
193 hr->set_compaction_top(hr->bottom());
194 hr->apply_to_marked_objects(_bitmap, &prepare_compact);
195 } else {
196 G1PrepareCompactLiveClosure<false> prepare_compact(cp);
197 hr->set_compaction_top(hr->bottom());
198 hr->apply_to_marked_objects(_bitmap, &prepare_compact);
199 }
200 }
201
202 void G1FullGCPrepareTask::G1CalculatePointersClosure::prepare_for_compaction(HeapRegion* hr) {
203 if (!_cp->is_initialized()) {
204 hr->set_compaction_top(hr->bottom());
205 _cp->initialize(hr, true);
206 }
207 // Add region to the compaction queue and prepare it.
208 _cp->add(hr);
209 prepare_for_compaction_work(_cp, hr);
210 }
211
212 template <bool ALT_FWD>
213 void G1FullGCPrepareTask::prepare_serial_compaction_impl() {
214 GCTraceTime(Debug, gc, phases) debug("Phase 2: Prepare Serial Compaction", collector()->scope()->timer());
215 // At this point we know that no regions were completely freed by
216 // the parallel compaction. That means that the last region of
217 // all compaction queues still have data in them. We try to compact
218 // these regions in serial to avoid a premature OOM.
219 for (uint i = 0; i < collector()->workers(); i++) {
220 G1FullGCCompactionPoint* cp = collector()->compaction_point(i);
221 if (cp->has_regions()) {
222 collector()->serial_compaction_point()->add(cp->remove_last());
223 }
224 }
225
226 // Update the forwarding information for the regions in the serial
227 // compaction point.
228 G1FullGCCompactionPoint* cp = collector()->serial_compaction_point();
229 for (GrowableArrayIterator<HeapRegion*> it = cp->regions()->begin(); it != cp->regions()->end(); ++it) {
230 HeapRegion* current = *it;
231 if (!cp->is_initialized()) {
232 // Initialize the compaction point. Nothing more is needed for the first heap region
233 // since it is already prepared for compaction.
234 cp->initialize(current, false);
235 } else {
236 assert(!current->is_humongous(), "Should be no humongous regions in compaction queue");
237 G1RePrepareClosure<ALT_FWD> re_prepare(cp, current);
238 current->set_compaction_top(current->bottom());
239 current->apply_to_marked_objects(collector()->mark_bitmap(), &re_prepare);
240 }
241 }
242 cp->update();
243 }
244
245 void G1FullGCPrepareTask::prepare_serial_compaction() {
246 if (UseAltGCForwarding) {
247 prepare_serial_compaction_impl<true>();
248 } else {
249 prepare_serial_compaction_impl<false>();
250 }
251 }
252
253 bool G1FullGCPrepareTask::G1CalculatePointersClosure::freed_regions() {
254 if (_regions_freed) {
255 return true;
256 }
257
258 if (!_cp->has_regions()) {
259 // No regions in queue, so no free ones either.
260 return false;
261 }
262
263 if (_cp->current_region() != _cp->regions()->last()) {
264 // The current region used for compaction is not the last in the
265 // queue. That means there is at least one free region in the queue.
266 return true;
267 }
268
269 // No free regions in the queue.
270 return false;
271 }
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