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_GC_SHARED_SPACE_INLINE_HPP
26 #define SHARE_GC_SHARED_SPACE_INLINE_HPP
27
28 #include "gc/shared/space.hpp"
29
30 #include "gc/shared/blockOffsetTable.inline.hpp"
31 #include "gc/shared/collectedHeap.hpp"
32 #include "gc/shared/generation.hpp"
33 #include "gc/shared/spaceDecorator.hpp"
34 #include "oops/oopsHierarchy.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "runtime/prefetch.inline.hpp"
37 #include "runtime/safepoint.hpp"
38 #if INCLUDE_SERIALGC
39 #include "gc/serial/markSweep.inline.hpp"
40 #endif
41
42 inline HeapWord* Space::block_start(const void* p) {
43 return block_start_const(p);
44 }
45
46 inline HeapWord* OffsetTableContigSpace::allocate(size_t size) {
47 HeapWord* res = ContiguousSpace::allocate(size);
48 if (res != NULL) {
49 _offsets.alloc_block(res, size);
50 }
51 return res;
52 }
146 assert(cp->gen != NULL, "need a generation");
147 assert(cp->threshold == NULL, "just checking");
148 assert(cp->gen->first_compaction_space() == space, "just checking");
149 cp->space = cp->gen->first_compaction_space();
150 cp->threshold = cp->space->initialize_threshold();
151 cp->space->set_compaction_top(cp->space->bottom());
152 }
153
154 HeapWord* compact_top = cp->space->compaction_top(); // This is where we are currently compacting to.
155
156 DeadSpacer dead_spacer(space);
157
158 HeapWord* end_of_live = space->bottom(); // One byte beyond the last byte of the last live object.
159 HeapWord* first_dead = NULL; // The first dead object.
160
161 const intx interval = PrefetchScanIntervalInBytes;
162
163 HeapWord* cur_obj = space->bottom();
164 HeapWord* scan_limit = space->scan_limit();
165
166 while (cur_obj < scan_limit) {
167 if (space->scanned_block_is_obj(cur_obj) && cast_to_oop(cur_obj)->is_gc_marked()) {
168 // prefetch beyond cur_obj
169 Prefetch::write(cur_obj, interval);
170 size_t size = space->scanned_block_size(cur_obj);
171 compact_top = cp->space->forward(cast_to_oop(cur_obj), size, cp, compact_top);
172 cur_obj += size;
173 end_of_live = cur_obj;
174 } else {
175 // run over all the contiguous dead objects
176 HeapWord* end = cur_obj;
177 do {
178 // prefetch beyond end
179 Prefetch::write(end, interval);
180 end += space->scanned_block_size(end);
181 } while (end < scan_limit && (!space->scanned_block_is_obj(end) || !cast_to_oop(end)->is_gc_marked()));
182
183 // see if we might want to pretend this object is alive so that
184 // we don't have to compact quite as often.
185 if (cur_obj == compact_top && dead_spacer.insert_deadspace(cur_obj, end)) {
186 oop obj = cast_to_oop(cur_obj);
187 compact_top = cp->space->forward(obj, obj->size(), cp, compact_top);
188 end_of_live = end;
189 } else {
190 // otherwise, it really is a free region.
191
192 // cur_obj is a pointer to a dead object. Use this dead memory to store a pointer to the next live object.
193 *(HeapWord**)cur_obj = end;
194
195 // see if this is the first dead region.
196 if (first_dead == NULL) {
197 first_dead = cur_obj;
198 }
199 }
200
201 // move on to the next object
202 cur_obj = end;
203 }
204 }
205
206 assert(cur_obj == scan_limit, "just checking");
207 space->_end_of_live = end_of_live;
208 if (first_dead != NULL) {
209 space->_first_dead = first_dead;
210 } else {
211 space->_first_dead = end_of_live;
212 }
213
214 // save the compaction_top of the compaction space.
215 cp->space->set_compaction_top(compact_top);
216 }
217
218 template <class SpaceType>
219 inline void CompactibleSpace::scan_and_adjust_pointers(SpaceType* space) {
220 // adjust all the interior pointers to point at the new locations of objects
221 // Used by MarkSweep::mark_sweep_phase3()
222
223 HeapWord* cur_obj = space->bottom();
224 HeapWord* const end_of_live = space->_end_of_live; // Established by "scan_and_forward".
225 HeapWord* const first_dead = space->_first_dead; // Established by "scan_and_forward".
226
227 assert(first_dead <= end_of_live, "Stands to reason, no?");
228
229 const intx interval = PrefetchScanIntervalInBytes;
230
231 debug_only(HeapWord* prev_obj = NULL);
232 while (cur_obj < end_of_live) {
233 Prefetch::write(cur_obj, interval);
234 if (cur_obj < first_dead || cast_to_oop(cur_obj)->is_gc_marked()) {
235 // cur_obj is alive
236 // point all the oops to the new location
237 size_t size = MarkSweep::adjust_pointers(cast_to_oop(cur_obj));
238 size = space->adjust_obj_size(size);
239 debug_only(prev_obj = cur_obj);
240 cur_obj += size;
241 } else {
242 debug_only(prev_obj = cur_obj);
243 // cur_obj is not a live object, instead it points at the next live object
244 cur_obj = *(HeapWord**)cur_obj;
245 assert(cur_obj > prev_obj, "we should be moving forward through memory, cur_obj: " PTR_FORMAT ", prev_obj: " PTR_FORMAT, p2i(cur_obj), p2i(prev_obj));
246 }
247 }
248
249 assert(cur_obj == end_of_live, "just checking");
250 }
251
252 #ifdef ASSERT
253 template <class SpaceType>
254 inline void CompactibleSpace::verify_up_to_first_dead(SpaceType* space) {
255 HeapWord* cur_obj = space->bottom();
256
257 if (cur_obj < space->_end_of_live && space->_first_dead > cur_obj && !cast_to_oop(cur_obj)->is_gc_marked()) {
299 HeapWord* const end_of_live = space->_end_of_live;
300
301 assert(space->_first_dead <= end_of_live, "Invariant. _first_dead: " PTR_FORMAT " <= end_of_live: " PTR_FORMAT, p2i(space->_first_dead), p2i(end_of_live));
302 if (space->_first_dead == end_of_live && (bottom == end_of_live || !cast_to_oop(bottom)->is_gc_marked())) {
303 // Nothing to compact. The space is either empty or all live object should be left in place.
304 clear_empty_region(space);
305 return;
306 }
307
308 const intx scan_interval = PrefetchScanIntervalInBytes;
309 const intx copy_interval = PrefetchCopyIntervalInBytes;
310
311 assert(bottom < end_of_live, "bottom: " PTR_FORMAT " should be < end_of_live: " PTR_FORMAT, p2i(bottom), p2i(end_of_live));
312 HeapWord* cur_obj = bottom;
313 if (space->_first_dead > cur_obj && !cast_to_oop(cur_obj)->is_gc_marked()) {
314 // All object before _first_dead can be skipped. They should not be moved.
315 // A pointer to the first live object is stored at the memory location for _first_dead.
316 cur_obj = *(HeapWord**)(space->_first_dead);
317 }
318
319 debug_only(HeapWord* prev_obj = NULL);
320 while (cur_obj < end_of_live) {
321 if (!cast_to_oop(cur_obj)->is_gc_marked()) {
322 debug_only(prev_obj = cur_obj);
323 // The first word of the dead object contains a pointer to the next live object or end of space.
324 cur_obj = *(HeapWord**)cur_obj;
325 assert(cur_obj > prev_obj, "we should be moving forward through memory");
326 } else {
327 // prefetch beyond q
328 Prefetch::read(cur_obj, scan_interval);
329
330 // size and destination
331 size_t size = space->obj_size(cur_obj);
332 HeapWord* compaction_top = cast_from_oop<HeapWord*>(cast_to_oop(cur_obj)->forwardee());
333
334 // prefetch beyond compaction_top
335 Prefetch::write(compaction_top, copy_interval);
336
337 // copy object and reinit its mark
338 assert(cur_obj != compaction_top, "everything in this pass should be moving");
339 Copy::aligned_conjoint_words(cur_obj, compaction_top, size);
340 cast_to_oop(compaction_top)->init_mark();
341 assert(cast_to_oop(compaction_top)->klass() != NULL, "should have a class");
342
343 debug_only(prev_obj = cur_obj);
344 cur_obj += size;
345 }
346 }
347
348 clear_empty_region(space);
349 }
350
351 #endif // INCLUDE_SERIALGC
352
|
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_GC_SHARED_SPACE_INLINE_HPP
26 #define SHARE_GC_SHARED_SPACE_INLINE_HPP
27
28 #include "gc/shared/space.hpp"
29
30 #include "gc/shared/blockOffsetTable.inline.hpp"
31 #include "gc/shared/collectedHeap.hpp"
32 #include "gc/shared/generation.hpp"
33 #include "gc/shared/genCollectedHeap.hpp"
34 #include "gc/shared/spaceDecorator.hpp"
35 #include "oops/oopsHierarchy.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "runtime/prefetch.inline.hpp"
38 #include "runtime/safepoint.hpp"
39 #if INCLUDE_SERIALGC
40 #include "gc/serial/markSweep.inline.hpp"
41 #endif
42
43 inline HeapWord* Space::block_start(const void* p) {
44 return block_start_const(p);
45 }
46
47 inline HeapWord* OffsetTableContigSpace::allocate(size_t size) {
48 HeapWord* res = ContiguousSpace::allocate(size);
49 if (res != NULL) {
50 _offsets.alloc_block(res, size);
51 }
52 return res;
53 }
147 assert(cp->gen != NULL, "need a generation");
148 assert(cp->threshold == NULL, "just checking");
149 assert(cp->gen->first_compaction_space() == space, "just checking");
150 cp->space = cp->gen->first_compaction_space();
151 cp->threshold = cp->space->initialize_threshold();
152 cp->space->set_compaction_top(cp->space->bottom());
153 }
154
155 HeapWord* compact_top = cp->space->compaction_top(); // This is where we are currently compacting to.
156
157 DeadSpacer dead_spacer(space);
158
159 HeapWord* end_of_live = space->bottom(); // One byte beyond the last byte of the last live object.
160 HeapWord* first_dead = NULL; // The first dead object.
161
162 const intx interval = PrefetchScanIntervalInBytes;
163
164 HeapWord* cur_obj = space->bottom();
165 HeapWord* scan_limit = space->scan_limit();
166
167 SlidingForwarding* const forwarding = GenCollectedHeap::heap()->forwarding();
168 while (cur_obj < scan_limit) {
169 if (space->scanned_block_is_obj(cur_obj) && cast_to_oop(cur_obj)->is_gc_marked()) {
170 // prefetch beyond cur_obj
171 Prefetch::write(cur_obj, interval);
172 size_t size = space->scanned_block_size(cur_obj);
173 compact_top = cp->space->forward(cast_to_oop(cur_obj), size, cp, compact_top, forwarding);
174 cur_obj += size;
175 end_of_live = cur_obj;
176 } else {
177 // run over all the contiguous dead objects
178 HeapWord* end = cur_obj;
179 do {
180 // prefetch beyond end
181 Prefetch::write(end, interval);
182 end += space->scanned_block_size(end);
183 } while (end < scan_limit && (!space->scanned_block_is_obj(end) || !cast_to_oop(end)->is_gc_marked()));
184
185 // see if we might want to pretend this object is alive so that
186 // we don't have to compact quite as often.
187 if (cur_obj == compact_top && dead_spacer.insert_deadspace(cur_obj, end)) {
188 oop obj = cast_to_oop(cur_obj);
189 compact_top = cp->space->forward(obj, obj->size(), cp, compact_top, forwarding);
190 end_of_live = end;
191 } else {
192 // otherwise, it really is a free region.
193
194 // cur_obj is a pointer to a dead object. Use this dead memory to store a pointer to the next live object.
195 *(HeapWord**)cur_obj = end;
196
197 // see if this is the first dead region.
198 if (first_dead == NULL) {
199 first_dead = cur_obj;
200 }
201 }
202
203 // move on to the next object
204 cur_obj = end;
205 }
206 }
207
208 assert(cur_obj == scan_limit, "just checking");
209 space->_end_of_live = end_of_live;
210 if (first_dead != NULL) {
211 space->_first_dead = first_dead;
212 } else {
213 space->_first_dead = end_of_live;
214 }
215
216 // save the compaction_top of the compaction space.
217 cp->space->set_compaction_top(compact_top);
218 }
219
220 template <class SpaceType>
221 inline void CompactibleSpace::scan_and_adjust_pointers(SpaceType* space) {
222 // adjust all the interior pointers to point at the new locations of objects
223 // Used by MarkSweep::mark_sweep_phase3()
224
225 HeapWord* cur_obj = space->bottom();
226 HeapWord* const end_of_live = space->_end_of_live; // Established by "scan_and_forward".
227 HeapWord* const first_dead = space->_first_dead; // Established by "scan_and_forward".
228 const SlidingForwarding* const forwarding = GenCollectedHeap::heap()->forwarding();
229
230 assert(first_dead <= end_of_live, "Stands to reason, no?");
231
232 const intx interval = PrefetchScanIntervalInBytes;
233
234 debug_only(HeapWord* prev_obj = NULL);
235 while (cur_obj < end_of_live) {
236 Prefetch::write(cur_obj, interval);
237 if (cur_obj < first_dead || cast_to_oop(cur_obj)->is_gc_marked()) {
238 // cur_obj is alive
239 // point all the oops to the new location
240 size_t size = MarkSweep::adjust_pointers(forwarding, cast_to_oop(cur_obj));
241 size = space->adjust_obj_size(size);
242 debug_only(prev_obj = cur_obj);
243 cur_obj += size;
244 } else {
245 debug_only(prev_obj = cur_obj);
246 // cur_obj is not a live object, instead it points at the next live object
247 cur_obj = *(HeapWord**)cur_obj;
248 assert(cur_obj > prev_obj, "we should be moving forward through memory, cur_obj: " PTR_FORMAT ", prev_obj: " PTR_FORMAT, p2i(cur_obj), p2i(prev_obj));
249 }
250 }
251
252 assert(cur_obj == end_of_live, "just checking");
253 }
254
255 #ifdef ASSERT
256 template <class SpaceType>
257 inline void CompactibleSpace::verify_up_to_first_dead(SpaceType* space) {
258 HeapWord* cur_obj = space->bottom();
259
260 if (cur_obj < space->_end_of_live && space->_first_dead > cur_obj && !cast_to_oop(cur_obj)->is_gc_marked()) {
302 HeapWord* const end_of_live = space->_end_of_live;
303
304 assert(space->_first_dead <= end_of_live, "Invariant. _first_dead: " PTR_FORMAT " <= end_of_live: " PTR_FORMAT, p2i(space->_first_dead), p2i(end_of_live));
305 if (space->_first_dead == end_of_live && (bottom == end_of_live || !cast_to_oop(bottom)->is_gc_marked())) {
306 // Nothing to compact. The space is either empty or all live object should be left in place.
307 clear_empty_region(space);
308 return;
309 }
310
311 const intx scan_interval = PrefetchScanIntervalInBytes;
312 const intx copy_interval = PrefetchCopyIntervalInBytes;
313
314 assert(bottom < end_of_live, "bottom: " PTR_FORMAT " should be < end_of_live: " PTR_FORMAT, p2i(bottom), p2i(end_of_live));
315 HeapWord* cur_obj = bottom;
316 if (space->_first_dead > cur_obj && !cast_to_oop(cur_obj)->is_gc_marked()) {
317 // All object before _first_dead can be skipped. They should not be moved.
318 // A pointer to the first live object is stored at the memory location for _first_dead.
319 cur_obj = *(HeapWord**)(space->_first_dead);
320 }
321
322 const SlidingForwarding* const forwarding = GenCollectedHeap::heap()->forwarding();
323
324 debug_only(HeapWord* prev_obj = NULL);
325 while (cur_obj < end_of_live) {
326 if (!cast_to_oop(cur_obj)->is_gc_marked()) {
327 debug_only(prev_obj = cur_obj);
328 // The first word of the dead object contains a pointer to the next live object or end of space.
329 cur_obj = *(HeapWord**)cur_obj;
330 assert(cur_obj > prev_obj, "we should be moving forward through memory");
331 } else {
332 // prefetch beyond q
333 Prefetch::read(cur_obj, scan_interval);
334
335 // size and destination
336 size_t size = space->obj_size(cur_obj);
337 HeapWord* compaction_top = cast_from_oop<HeapWord*>(forwarding->forwardee(cast_to_oop(cur_obj)));
338
339 // prefetch beyond compaction_top
340 Prefetch::write(compaction_top, copy_interval);
341
342 // copy object and reinit its mark
343 assert(cur_obj != compaction_top, "everything in this pass should be moving");
344 Copy::aligned_conjoint_words(cur_obj, compaction_top, size);
345 cast_to_oop(compaction_top)->init_mark();
346 assert(cast_to_oop(compaction_top)->klass() != NULL, "should have a class");
347
348 debug_only(prev_obj = cur_obj);
349 cur_obj += size;
350 }
351 }
352
353 clear_empty_region(space);
354 }
355
356 #endif // INCLUDE_SERIALGC
357
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