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 #include "precompiled.hpp"
26 #include "gc/g1/g1FullCollector.inline.hpp"
27 #include "gc/g1/g1FullGCCompactionPoint.hpp"
28 #include "gc/g1/g1HeapRegion.hpp"
29 #include "gc/shared/preservedMarks.inline.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "utilities/debug.hpp"
32
33 G1FullGCCompactionPoint::G1FullGCCompactionPoint(G1FullCollector* collector, PreservedMarks* preserved_stack) :
34 _collector(collector),
35 _current_region(nullptr),
36 _compaction_top(nullptr),
37 _preserved_stack(preserved_stack) {
38 _compaction_regions = new (mtGC) GrowableArray<HeapRegion*>(32, mtGC);
39 _compaction_region_iterator = _compaction_regions->begin();
40 }
41
42 G1FullGCCompactionPoint::~G1FullGCCompactionPoint() {
43 delete _compaction_regions;
44 }
45
46 void G1FullGCCompactionPoint::update() {
47 if (is_initialized()) {
48 _collector->set_compaction_top(_current_region, _compaction_top);
49 }
76 return next;
77 }
78
79 GrowableArray<HeapRegion*>* G1FullGCCompactionPoint::regions() {
80 return _compaction_regions;
81 }
82
83 bool G1FullGCCompactionPoint::object_will_fit(size_t size) {
84 size_t space_left = pointer_delta(_current_region->end(), _compaction_top);
85 return size <= space_left;
86 }
87
88 void G1FullGCCompactionPoint::switch_region() {
89 // Save compaction top in the region.
90 _collector->set_compaction_top(_current_region, _compaction_top);
91 // Get the next region and re-initialize the values.
92 _current_region = next_region();
93 initialize_values();
94 }
95
96 void G1FullGCCompactionPoint::forward(oop object, size_t size) {
97 assert(_current_region != nullptr, "Must have been initialized");
98
99 // Ensure the object fit in the current region.
100 while (!object_will_fit(size)) {
101 switch_region();
102 }
103
104 // Store a forwarding pointer if the object should be moved.
105 if (cast_from_oop<HeapWord*>(object) != _compaction_top) {
106 if (!object->is_forwarded()) {
107 preserved_stack()->push_if_necessary(object, object->mark());
108 }
109 object->forward_to(cast_to_oop(_compaction_top));
110 assert(object->is_forwarded(), "must be forwarded");
111 } else {
112 assert(!object->is_forwarded(), "must not be forwarded");
113 }
114
115 // Update compaction values.
116 _compaction_top += size;
117 _current_region->update_bot_for_block(_compaction_top - size, _compaction_top);
118 }
119
120 void G1FullGCCompactionPoint::add(HeapRegion* hr) {
121 _compaction_regions->append(hr);
122 }
123
124 void G1FullGCCompactionPoint::remove_at_or_above(uint bottom) {
125 HeapRegion* cur = current_region();
126 assert(cur->hrm_index() >= bottom, "Sanity!");
127
128 int start_index = 0;
129 for (HeapRegion* r : *_compaction_regions) {
130 if (r->hrm_index() < bottom) {
131 start_index++;
132 }
133 }
134
135 assert(start_index >= 0, "Should have at least one region");
136 _compaction_regions->trunc_to(start_index);
137 }
138
139 void G1FullGCCompactionPoint::add_humongous(HeapRegion* hr) {
140 assert(hr->is_starts_humongous(), "Sanity!");
141
142 _collector->add_humongous_region(hr);
143
144 G1CollectedHeap* g1h = G1CollectedHeap::heap();
145 g1h->humongous_obj_regions_iterate(hr,
146 [&] (HeapRegion* r) {
147 add(r);
148 _collector->update_from_skip_compacting_to_compacting(r->hrm_index());
149 });
150 }
151
152 void G1FullGCCompactionPoint::forward_humongous(HeapRegion* hr) {
153 assert(hr->is_starts_humongous(), "Sanity!");
154
155 oop obj = cast_to_oop(hr->bottom());
156 size_t obj_size = obj->size();
157 uint num_regions = (uint)G1CollectedHeap::humongous_obj_size_in_regions(obj_size);
158
159 if (!has_regions()) {
160 return;
161 }
162
163 // Find contiguous compaction target regions for the humongous object.
164 uint range_begin = find_contiguous_before(hr, num_regions);
165
166 if (range_begin == UINT_MAX) {
167 // No contiguous compaction target regions found, so the object cannot be moved.
168 return;
169 }
170
171 // Preserve the mark for the humongous object as the region was initially not compacting.
172 preserved_stack()->push_if_necessary(obj, obj->mark());
173
174 HeapRegion* dest_hr = _compaction_regions->at(range_begin);
175 obj->forward_to(cast_to_oop(dest_hr->bottom()));
176 assert(obj->is_forwarded(), "Object must be forwarded!");
177
178 // Add the humongous object regions to the compaction point.
179 add_humongous(hr);
180
181 // Remove covered regions from compaction target candidates.
182 _compaction_regions->remove_range(range_begin, (range_begin + num_regions));
183
184 return;
185 }
186
187 uint G1FullGCCompactionPoint::find_contiguous_before(HeapRegion* hr, uint num_regions) {
188 assert(num_regions > 0, "Sanity!");
189 assert(has_regions(), "Sanity!");
190
191 if (num_regions == 1) {
192 // If only one region, return the first region.
193 return 0;
194 }
195
196 uint contiguous_region_count = 1;
197
198 uint range_end = 1;
199 uint range_limit = (uint)_compaction_regions->length();
200
201 for (; range_end < range_limit; range_end++) {
202 if (contiguous_region_count == num_regions) {
203 break;
204 }
205 // Check if the current region and the previous region are contiguous.
206 bool regions_are_contiguous = (_compaction_regions->at(range_end)->hrm_index() - _compaction_regions->at(range_end - 1)->hrm_index()) == 1;
|
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 #include "precompiled.hpp"
26 #include "gc/g1/g1FullCollector.inline.hpp"
27 #include "gc/g1/g1FullGCCompactionPoint.hpp"
28 #include "gc/g1/g1HeapRegion.hpp"
29 #include "gc/shared/preservedMarks.inline.hpp"
30 #include "gc/shared/slidingForwarding.inline.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "utilities/debug.hpp"
33
34 G1FullGCCompactionPoint::G1FullGCCompactionPoint(G1FullCollector* collector, PreservedMarks* preserved_stack) :
35 _collector(collector),
36 _current_region(nullptr),
37 _compaction_top(nullptr),
38 _preserved_stack(preserved_stack) {
39 _compaction_regions = new (mtGC) GrowableArray<HeapRegion*>(32, mtGC);
40 _compaction_region_iterator = _compaction_regions->begin();
41 }
42
43 G1FullGCCompactionPoint::~G1FullGCCompactionPoint() {
44 delete _compaction_regions;
45 }
46
47 void G1FullGCCompactionPoint::update() {
48 if (is_initialized()) {
49 _collector->set_compaction_top(_current_region, _compaction_top);
50 }
77 return next;
78 }
79
80 GrowableArray<HeapRegion*>* G1FullGCCompactionPoint::regions() {
81 return _compaction_regions;
82 }
83
84 bool G1FullGCCompactionPoint::object_will_fit(size_t size) {
85 size_t space_left = pointer_delta(_current_region->end(), _compaction_top);
86 return size <= space_left;
87 }
88
89 void G1FullGCCompactionPoint::switch_region() {
90 // Save compaction top in the region.
91 _collector->set_compaction_top(_current_region, _compaction_top);
92 // Get the next region and re-initialize the values.
93 _current_region = next_region();
94 initialize_values();
95 }
96
97 template <bool ALT_FWD>
98 void G1FullGCCompactionPoint::forward(oop object, size_t size) {
99 assert(_current_region != nullptr, "Must have been initialized");
100
101 // Ensure the object fit in the current region.
102 while (!object_will_fit(size)) {
103 switch_region();
104 }
105
106 // Store a forwarding pointer if the object should be moved.
107 if (cast_from_oop<HeapWord*>(object) != _compaction_top) {
108 if (!object->is_forwarded()) {
109 preserved_stack()->push_if_necessary(object, object->mark());
110 }
111 SlidingForwarding::forward_to<ALT_FWD>(object, cast_to_oop(_compaction_top));
112 assert(SlidingForwarding::is_forwarded(object), "must be forwarded");
113 } else {
114 assert(SlidingForwarding::is_not_forwarded(object), "must not be forwarded");
115 }
116
117 // Update compaction values.
118 _compaction_top += size;
119 _current_region->update_bot_for_block(_compaction_top - size, _compaction_top);
120 }
121
122 template void G1FullGCCompactionPoint::forward<true>(oop object, size_t size);
123 template void G1FullGCCompactionPoint::forward<false>(oop object, size_t size);
124
125 void G1FullGCCompactionPoint::add(HeapRegion* hr) {
126 _compaction_regions->append(hr);
127 }
128
129 void G1FullGCCompactionPoint::remove_at_or_above(uint bottom) {
130 HeapRegion* cur = current_region();
131 assert(cur->hrm_index() >= bottom, "Sanity!");
132
133 int start_index = 0;
134 for (HeapRegion* r : *_compaction_regions) {
135 if (r->hrm_index() < bottom) {
136 start_index++;
137 }
138 }
139
140 assert(start_index >= 0, "Should have at least one region");
141 _compaction_regions->trunc_to(start_index);
142 }
143
144 void G1FullGCCompactionPoint::add_humongous(HeapRegion* hr) {
145 assert(hr->is_starts_humongous(), "Sanity!");
146
147 _collector->add_humongous_region(hr);
148
149 G1CollectedHeap* g1h = G1CollectedHeap::heap();
150 g1h->humongous_obj_regions_iterate(hr,
151 [&] (HeapRegion* r) {
152 add(r);
153 _collector->update_from_skip_compacting_to_compacting(r->hrm_index());
154 });
155 }
156
157 template <bool ALT_FWD>
158 void G1FullGCCompactionPoint::forward_humongous(HeapRegion* hr) {
159 assert(hr->is_starts_humongous(), "Sanity!");
160
161 oop obj = cast_to_oop(hr->bottom());
162 size_t obj_size = obj->size();
163 uint num_regions = (uint)G1CollectedHeap::humongous_obj_size_in_regions(obj_size);
164
165 if (!has_regions()) {
166 return;
167 }
168
169 // Find contiguous compaction target regions for the humongous object.
170 uint range_begin = find_contiguous_before(hr, num_regions);
171
172 if (range_begin == UINT_MAX) {
173 // No contiguous compaction target regions found, so the object cannot be moved.
174 return;
175 }
176
177 // Preserve the mark for the humongous object as the region was initially not compacting.
178 preserved_stack()->push_if_necessary(obj, obj->mark());
179
180 HeapRegion* dest_hr = _compaction_regions->at(range_begin);
181 SlidingForwarding::forward_to<ALT_FWD>(obj, cast_to_oop(dest_hr->bottom()));
182 assert(SlidingForwarding::is_forwarded(obj), "Object must be forwarded!");
183
184 // Add the humongous object regions to the compaction point.
185 add_humongous(hr);
186
187 // Remove covered regions from compaction target candidates.
188 _compaction_regions->remove_range(range_begin, (range_begin + num_regions));
189
190 return;
191 }
192
193 template void G1FullGCCompactionPoint::forward_humongous<true>(HeapRegion* hr);
194 template void G1FullGCCompactionPoint::forward_humongous<false>(HeapRegion* hr);
195
196 uint G1FullGCCompactionPoint::find_contiguous_before(HeapRegion* hr, uint num_regions) {
197 assert(num_regions > 0, "Sanity!");
198 assert(has_regions(), "Sanity!");
199
200 if (num_regions == 1) {
201 // If only one region, return the first region.
202 return 0;
203 }
204
205 uint contiguous_region_count = 1;
206
207 uint range_end = 1;
208 uint range_limit = (uint)_compaction_regions->length();
209
210 for (; range_end < range_limit; range_end++) {
211 if (contiguous_region_count == num_regions) {
212 break;
213 }
214 // Check if the current region and the previous region are contiguous.
215 bool regions_are_contiguous = (_compaction_regions->at(range_end)->hrm_index() - _compaction_regions->at(range_end - 1)->hrm_index()) == 1;
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