140 }
141 }
142 #endif // ASSERT
143
144 void G1ParScanThreadState::trim_queue() {
145 assert(_evac_failure_cl != NULL, "not set");
146
147 StarTask ref;
148 do {
149 // Drain the overflow stack first, so other threads can steal.
150 while (_refs->pop_overflow(ref)) {
151 dispatch_reference(ref);
152 }
153
154 while (_refs->pop_local(ref)) {
155 dispatch_reference(ref);
156 }
157 } while (!_refs->is_empty());
158 }
159
160 HeapWord* G1ParScanThreadState::allocate_in_next_plab(in_cset_state_t const state,
161 in_cset_state_t* dest,
162 size_t word_sz,
163 AllocationContext_t const context) {
164 assert(state != InCSetState::NotInCSet, err_msg("Unexpected state: %u", state));
165 assert(*dest != InCSetState::NotInCSet, err_msg("Unexpected dest: %u", *dest));
166
167 // Right now we only have two types of regions (young / old) so
168 // let's keep the logic here simple. We can generalize it when necessary.
169 if (*dest == InCSetState::Young) {
170 HeapWord* const obj_ptr = _g1_par_allocator->allocate(InCSetState::Old,
171 word_sz, context);
172 if (obj_ptr == NULL) {
173 return NULL;
174 }
175 // Make sure that we won't attempt to copy any other objects out
176 // of a survivor region (given that apparently we cannot allocate
177 // any new ones) to avoid coming into this slow path.
178 _tenuring_threshold = 0;
179 *dest = InCSetState::Old;
180 return obj_ptr;
181 } else {
182 assert(*dest == InCSetState::Old, err_msg("Unexpected dest: %u", *dest));
183 // no other space to try.
184 return NULL;
185 }
186 }
187
188 in_cset_state_t G1ParScanThreadState::next_state(in_cset_state_t const state, markOop const m, uint& age) {
189 if (state == InCSetState::Young) {
190 age = !m->has_displaced_mark_helper() ? m->age()
191 : m->displaced_mark_helper()->age();
192 if (age < _tenuring_threshold) {
193 return state;
194 }
195 }
196 return dest(state);
197 }
198
199 oop G1ParScanThreadState::copy_to_survivor_space(in_cset_state_t const state,
200 oop const old,
201 markOop const old_mark) {
202 const size_t word_sz = old->size();
203 HeapRegion* const from_region = _g1h->heap_region_containing_raw(old);
204 // +1 to make the -1 indexes valid...
205 const int young_index = from_region->young_index_in_cset()+1;
206 assert( (from_region->is_young() && young_index > 0) ||
207 (!from_region->is_young() && young_index == 0), "invariant" );
208 const AllocationContext_t context = from_region->allocation_context();
209
210 uint age = 0;
211 in_cset_state_t dest_state = next_state(state, old_mark, age);
212 HeapWord* obj_ptr = _g1_par_allocator->plab_allocate(dest_state, word_sz, context);
213
214 // PLAB allocations should succeed most of the time, so we'll
215 // normally check against NULL once and that's it.
216 if (obj_ptr == NULL) {
217 obj_ptr = _g1_par_allocator->allocate_direct_or_new_plab(dest_state, word_sz, context);
218 if (obj_ptr == NULL) {
219 obj_ptr = allocate_in_next_plab(state, &dest_state, word_sz, context);
220 if (obj_ptr == NULL) {
221 // This will either forward-to-self, or detect that someone else has
222 // installed a forwarding pointer.
223 return _g1h->handle_evacuation_failure_par(this, old);
224 }
225 }
226 }
227
228 assert(obj_ptr != NULL, "when we get here, allocation should have succeeded");
229 #ifndef PRODUCT
230 // Should this evacuation fail?
231 if (_g1h->evacuation_should_fail()) {
232 // Doing this after all the allocation attempts also tests the
233 // undo_allocation() method too.
234 _g1_par_allocator->undo_allocation(dest_state, obj_ptr, word_sz, context);
235 return _g1h->handle_evacuation_failure_par(this, old);
236 }
237 #endif // !PRODUCT
238
239 // We're going to allocate linearly, so might as well prefetch ahead.
240 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
241
242 const oop obj = oop(obj_ptr);
243 const oop forward_ptr = old->forward_to_atomic(obj);
244 if (forward_ptr == NULL) {
245 Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
246
247 if (dest_state == InCSetState::Young) {
248 if (age < markOopDesc::max_age) {
249 age++;
250 }
251 if (old_mark->has_displaced_mark_helper()) {
252 // In this case, we have to install the mark word first,
253 // otherwise obj looks to be forwarded (the old mark word,
254 // which contains the forward pointer, was copied)
255 obj->set_mark(old_mark);
256 markOop new_mark = old_mark->displaced_mark_helper()->set_age(age);
257 old_mark->set_displaced_mark_helper(new_mark);
258 } else {
259 obj->set_mark(old_mark->set_age(age));
260 }
261 age_table()->add(age, word_sz);
262 } else {
263 obj->set_mark(old_mark);
264 }
265
266 if (G1StringDedup::is_enabled()) {
267 const bool is_from_young = state == InCSetState::Young;
268 const bool is_to_young = dest_state == InCSetState::Young;
269 assert(is_from_young == _g1h->heap_region_containing_raw(old)->is_young(),
270 "sanity");
271 assert(is_to_young == _g1h->heap_region_containing_raw(obj)->is_young(),
272 "sanity");
273 G1StringDedup::enqueue_from_evacuation(is_from_young,
274 is_to_young,
275 queue_num(),
276 obj);
277 }
278
279 size_t* const surv_young_words = surviving_young_words();
280 surv_young_words[young_index] += word_sz;
281
282 if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
283 // We keep track of the next start index in the length field of
284 // the to-space object. The actual length can be found in the
285 // length field of the from-space object.
286 arrayOop(obj)->set_length(0);
287 oop* old_p = set_partial_array_mask(old);
288 push_on_queue(old_p);
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140 }
141 }
142 #endif // ASSERT
143
144 void G1ParScanThreadState::trim_queue() {
145 assert(_evac_failure_cl != NULL, "not set");
146
147 StarTask ref;
148 do {
149 // Drain the overflow stack first, so other threads can steal.
150 while (_refs->pop_overflow(ref)) {
151 dispatch_reference(ref);
152 }
153
154 while (_refs->pop_local(ref)) {
155 dispatch_reference(ref);
156 }
157 } while (!_refs->is_empty());
158 }
159
160 HeapWord* G1ParScanThreadState::allocate_in_next_plab(InCSetState const state,
161 InCSetState* dest,
162 size_t word_sz,
163 AllocationContext_t const context) {
164 assert(state.is_in_cset_or_humongous(), err_msg("Unexpected state: %u", state.value()));
165 assert(dest->is_in_cset_or_humongous(), err_msg("Unexpected dest: %u", dest->value()));
166
167 // Right now we only have two types of regions (young / old) so
168 // let's keep the logic here simple. We can generalize it when necessary.
169 if (dest->is_young()) {
170 HeapWord* const obj_ptr = _g1_par_allocator->allocate(InCSetState::Old,
171 word_sz, context);
172 if (obj_ptr == NULL) {
173 return NULL;
174 }
175 // Make sure that we won't attempt to copy any other objects out
176 // of a survivor region (given that apparently we cannot allocate
177 // any new ones) to avoid coming into this slow path.
178 _tenuring_threshold = 0;
179 dest->set_old();
180 return obj_ptr;
181 } else {
182 assert(dest->is_old(), err_msg("Unexpected dest: %u", dest->value()));
183 // no other space to try.
184 return NULL;
185 }
186 }
187
188 InCSetState G1ParScanThreadState::next_state(InCSetState const state, markOop const m, uint& age) {
189 if (state.is_young()) {
190 age = !m->has_displaced_mark_helper() ? m->age()
191 : m->displaced_mark_helper()->age();
192 if (age < _tenuring_threshold) {
193 return state;
194 }
195 }
196 return dest(state);
197 }
198
199 oop G1ParScanThreadState::copy_to_survivor_space(InCSetState const state,
200 oop const old,
201 markOop const old_mark) {
202 const size_t word_sz = old->size();
203 HeapRegion* const from_region = _g1h->heap_region_containing_raw(old);
204 // +1 to make the -1 indexes valid...
205 const int young_index = from_region->young_index_in_cset()+1;
206 assert( (from_region->is_young() && young_index > 0) ||
207 (!from_region->is_young() && young_index == 0), "invariant" );
208 const AllocationContext_t context = from_region->allocation_context();
209
210 uint age = 0;
211 InCSetState dest_state = next_state(state, old_mark, age);
212 HeapWord* obj_ptr = _g1_par_allocator->plab_allocate(dest_state, word_sz, context);
213
214 // PLAB allocations should succeed most of the time, so we'll
215 // normally check against NULL once and that's it.
216 if (obj_ptr == NULL) {
217 obj_ptr = _g1_par_allocator->allocate_direct_or_new_plab(dest_state, word_sz, context);
218 if (obj_ptr == NULL) {
219 obj_ptr = allocate_in_next_plab(state, &dest_state, word_sz, context);
220 if (obj_ptr == NULL) {
221 // This will either forward-to-self, or detect that someone else has
222 // installed a forwarding pointer.
223 return _g1h->handle_evacuation_failure_par(this, old);
224 }
225 }
226 }
227
228 assert(obj_ptr != NULL, "when we get here, allocation should have succeeded");
229 #ifndef PRODUCT
230 // Should this evacuation fail?
231 if (_g1h->evacuation_should_fail()) {
232 // Doing this after all the allocation attempts also tests the
233 // undo_allocation() method too.
234 _g1_par_allocator->undo_allocation(dest_state, obj_ptr, word_sz, context);
235 return _g1h->handle_evacuation_failure_par(this, old);
236 }
237 #endif // !PRODUCT
238
239 // We're going to allocate linearly, so might as well prefetch ahead.
240 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
241
242 const oop obj = oop(obj_ptr);
243 const oop forward_ptr = old->forward_to_atomic(obj);
244 if (forward_ptr == NULL) {
245 Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
246
247 if (dest_state.is_young()) {
248 if (age < markOopDesc::max_age) {
249 age++;
250 }
251 if (old_mark->has_displaced_mark_helper()) {
252 // In this case, we have to install the mark word first,
253 // otherwise obj looks to be forwarded (the old mark word,
254 // which contains the forward pointer, was copied)
255 obj->set_mark(old_mark);
256 markOop new_mark = old_mark->displaced_mark_helper()->set_age(age);
257 old_mark->set_displaced_mark_helper(new_mark);
258 } else {
259 obj->set_mark(old_mark->set_age(age));
260 }
261 age_table()->add(age, word_sz);
262 } else {
263 obj->set_mark(old_mark);
264 }
265
266 if (G1StringDedup::is_enabled()) {
267 const bool is_from_young = state.is_young();
268 const bool is_to_young = dest_state.is_young();
269 assert(is_from_young == _g1h->heap_region_containing_raw(old)->is_young(),
270 "sanity");
271 assert(is_to_young == _g1h->heap_region_containing_raw(obj)->is_young(),
272 "sanity");
273 G1StringDedup::enqueue_from_evacuation(is_from_young,
274 is_to_young,
275 queue_num(),
276 obj);
277 }
278
279 size_t* const surv_young_words = surviving_young_words();
280 surv_young_words[young_index] += word_sz;
281
282 if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
283 // We keep track of the next start index in the length field of
284 // the to-space object. The actual length can be found in the
285 // length field of the from-space object.
286 arrayOop(obj)->set_length(0);
287 oop* old_p = set_partial_array_mask(old);
288 push_on_queue(old_p);
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