100
101 if (policy->use_adaptive_young_list_length()) {
102 double delay_end_sec = mmu_delay_end(policy, remark);
103 // Wait for timeout or thread termination request.
104 MonitorLocker ml(CGC_lock, Monitor::_no_safepoint_check_flag);
105 while (!_cm->has_aborted() && !should_terminate()) {
106 double sleep_time_sec = (delay_end_sec - os::elapsedTime());
107 jlong sleep_time_ms = ceil(sleep_time_sec * MILLIUNITS);
108 if (sleep_time_ms <= 0) {
109 break; // Passed end time.
110 } else if (ml.wait(sleep_time_ms, Monitor::_no_safepoint_check_flag)) {
111 break; // Timeout => reached end time.
112 }
113 // Other (possibly spurious) wakeup. Retry with updated sleep time.
114 }
115 }
116 }
117
118 class G1ConcPhaseTimer : public GCTraceConcTimeImpl<LogLevel::Info, LOG_TAGS(gc, marking)> {
119 G1ConcurrentMark* _cm;
120 const char* _t;
121 public:
122 G1ConcPhaseTimer(G1ConcurrentMark* cm, const char* title) :
123 GCTraceConcTimeImpl<LogLevel::Info, LogTag::_gc, LogTag::_marking>(title),
124 _cm(cm)
125 {
126 _cm->gc_timer_cm()->register_gc_concurrent_start(title);
127 }
128
129 ~G1ConcPhaseTimer() {
130 _cm->gc_timer_cm()->register_gc_concurrent_end();
131 }
132 };
133
134 void G1ConcurrentMarkThread::run_service() {
135 _vtime_start = os::elapsedVTime();
136
137 while (!should_terminate()) {
138 if (wait_for_next_cycle()) {
139 break;
140 }
166
167 if (started()) {
168 set_in_progress();
169 }
170
171 return should_terminate();
172 }
173
174 bool G1ConcurrentMarkThread::phase_clear_cld_claimed_marks() {
175 G1ConcPhaseTimer p(_cm, "Concurrent Clear Claimed Marks");
176 ClassLoaderDataGraph::clear_claimed_marks();
177 return _cm->has_aborted();
178 }
179
180 bool G1ConcurrentMarkThread::phase_scan_root_regions() {
181 G1ConcPhaseTimer p(_cm, "Concurrent Scan Root Regions");
182 _cm->scan_root_regions();
183 return _cm->has_aborted();
184 }
185
186 bool G1ConcurrentMarkThread::phase_mark_from_roots() {
187 ConcurrentGCBreakpoints::at("AFTER MARKING STARTED");
188 G1ConcPhaseTimer p(_cm, "Concurrent Mark From Roots");
189 _cm->mark_from_roots();
190 return _cm->has_aborted();
191 }
192
193 bool G1ConcurrentMarkThread::phase_preclean() {
194 G1ConcPhaseTimer p(_cm, "Concurrent Preclean");
195 _cm->preclean();
196 return _cm->has_aborted();
197 }
198
199 bool G1ConcurrentMarkThread::phase_delay_to_keep_mmu_before_remark() {
200 delay_to_keep_mmu(true /* remark */);
201 return _cm->has_aborted();
202 }
203
204 bool G1ConcurrentMarkThread::phase_remark(bool& has_overflown) {
205 ConcurrentGCBreakpoints::at("BEFORE MARKING COMPLETED");
206 CMRemark cl(_cm);
207 VM_G1Concurrent op(&cl, "Pause Remark");
208 VMThread::execute(&op);
209 has_overflown = _cm->has_overflown();
210 return _cm->has_aborted();
211 }
212
213 bool G1ConcurrentMarkThread::phase_rebuild_remembered_sets() {
214 G1ConcPhaseTimer p(_cm, "Concurrent Rebuild Remembered Sets");
215 _cm->rebuild_rem_set_concurrently();
216 return _cm->has_aborted();
217 }
218
219 bool G1ConcurrentMarkThread::phase_delay_to_keep_mmu_before_cleanup() {
220 delay_to_keep_mmu(false /* cleanup */);
221 return _cm->has_aborted();
222 }
223
224 bool G1ConcurrentMarkThread::phase_cleanup() {
225 CMCleanup cl(_cm);
226 VM_G1Concurrent op(&cl, "Pause Cleanup");
227 VMThread::execute(&op);
228 return _cm->has_aborted();
229 }
234 return _cm->has_aborted();
235 }
236
237 void G1ConcurrentMarkThread::concurrent_cycle_start() {
238 _cm->concurrent_cycle_start();
239 }
240
241 void G1ConcurrentMarkThread::full_concurrent_cycle_do() {
242 HandleMark hm(Thread::current());
243 ResourceMark rm;
244
245 // Phase 1: Clear CLD claimed marks.
246 phase_clear_cld_claimed_marks();
247
248 // Do not return before the scan root regions phase as a GC waits for a
249 // notification from it.
250
251 // Phase 2: Scan root regions.
252 if (phase_scan_root_regions()) return;
253
254 Ticks mark_start = Ticks::now();
255 log_info(gc, marking)("Concurrent Mark (%.3fs)", mark_start.seconds());
256
257 bool needs_restart;
258 uint iter = 1;
259 do {
260 // Phase 3: Mark From Roots.
261 if (phase_mark_from_roots()) return;
262
263 // Phase 4: Preclean (optional)
264 if (G1UseReferencePrecleaning) {
265 if (phase_preclean()) return;
266 }
267
268 // Phase 5: Wait for Remark.
269 if (phase_delay_to_keep_mmu_before_remark()) return;
270
271 // Phase 6: Remark pause
272 if (phase_remark(needs_restart)) return;
273 if (needs_restart) {
274 log_info(gc, marking)("Concurrent Mark Restart for Mark Stack Overflow (iteration #%u)",
275 iter++);
276 }
277 } while (needs_restart);
278
279 Ticks mark_end = Ticks::now();
280 log_info(gc, marking)("Concurrent Mark (%.3fs, %.3fs) %.3fms",
281 mark_start.seconds(), mark_end.seconds(),
282 (mark_end - mark_start).seconds() * 1000.0);
283
284 // Phase 7: Rebuild remembered sets.
285 if (phase_rebuild_remembered_sets()) return;
286
287 // Phase 8: Wait for Cleanup.
288 if (phase_delay_to_keep_mmu_before_cleanup()) return;
289
290 // Phase 9: Cleanup pause
291 if (phase_cleanup()) return;
292
293 // Phase 10: Clear bitmap for next mark.
294 phase_clear_bitmap_for_next_mark();
295 }
296
297 void G1ConcurrentMarkThread::concurrent_cycle_end() {
298 // Update the number of full collections that have been
299 // completed. This will also notify the G1OldGCCount_lock in case a
300 // Java thread is waiting for a full GC to happen (e.g., it
301 // called System.gc() with +ExplicitGCInvokesConcurrent).
302 SuspendibleThreadSetJoiner sts_join;
303 G1CollectedHeap::heap()->increment_old_marking_cycles_completed(true /* concurrent */,
304 !_cm->has_aborted());
305
306 _cm->concurrent_cycle_end();
307 ConcurrentGCBreakpoints::notify_active_to_idle();
308 }
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100
101 if (policy->use_adaptive_young_list_length()) {
102 double delay_end_sec = mmu_delay_end(policy, remark);
103 // Wait for timeout or thread termination request.
104 MonitorLocker ml(CGC_lock, Monitor::_no_safepoint_check_flag);
105 while (!_cm->has_aborted() && !should_terminate()) {
106 double sleep_time_sec = (delay_end_sec - os::elapsedTime());
107 jlong sleep_time_ms = ceil(sleep_time_sec * MILLIUNITS);
108 if (sleep_time_ms <= 0) {
109 break; // Passed end time.
110 } else if (ml.wait(sleep_time_ms, Monitor::_no_safepoint_check_flag)) {
111 break; // Timeout => reached end time.
112 }
113 // Other (possibly spurious) wakeup. Retry with updated sleep time.
114 }
115 }
116 }
117
118 class G1ConcPhaseTimer : public GCTraceConcTimeImpl<LogLevel::Info, LOG_TAGS(gc, marking)> {
119 G1ConcurrentMark* _cm;
120
121 public:
122 G1ConcPhaseTimer(G1ConcurrentMark* cm, const char* title) :
123 GCTraceConcTimeImpl<LogLevel::Info, LogTag::_gc, LogTag::_marking>(title),
124 _cm(cm)
125 {
126 _cm->gc_timer_cm()->register_gc_concurrent_start(title);
127 }
128
129 ~G1ConcPhaseTimer() {
130 _cm->gc_timer_cm()->register_gc_concurrent_end();
131 }
132 };
133
134 void G1ConcurrentMarkThread::run_service() {
135 _vtime_start = os::elapsedVTime();
136
137 while (!should_terminate()) {
138 if (wait_for_next_cycle()) {
139 break;
140 }
166
167 if (started()) {
168 set_in_progress();
169 }
170
171 return should_terminate();
172 }
173
174 bool G1ConcurrentMarkThread::phase_clear_cld_claimed_marks() {
175 G1ConcPhaseTimer p(_cm, "Concurrent Clear Claimed Marks");
176 ClassLoaderDataGraph::clear_claimed_marks();
177 return _cm->has_aborted();
178 }
179
180 bool G1ConcurrentMarkThread::phase_scan_root_regions() {
181 G1ConcPhaseTimer p(_cm, "Concurrent Scan Root Regions");
182 _cm->scan_root_regions();
183 return _cm->has_aborted();
184 }
185
186 bool G1ConcurrentMarkThread::phase_mark_loop() {
187 Ticks mark_start = Ticks::now();
188 log_info(gc, marking)("Concurrent Mark (%.3fs)", mark_start.seconds());
189
190 uint iter = 1;
191 while (true) {
192 // Subphase 1: Mark From Roots.
193 if (subphase_mark_from_roots()) return true;
194
195 // Subphase 2: Preclean (optional)
196 if (G1UseReferencePrecleaning) {
197 if (subphase_preclean()) return true;
198 }
199
200 // Subphase 3: Wait for Remark.
201 if (subphase_delay_to_keep_mmu_before_remark()) return true;
202
203 // Subphase 4: Remark pause
204 if (subphase_remark()) return true;
205
206 // Check if we need to restart the marking loop.
207 if (!mark_loop_needs_restart()) break;
208
209 log_info(gc, marking)("Concurrent Mark Restart for Mark Stack Overflow (iteration #%u)",
210 iter++);
211 }
212
213 Ticks mark_end = Ticks::now();
214 log_info(gc, marking)("Concurrent Mark (%.3fs, %.3fs) %.3fms",
215 mark_start.seconds(), mark_end.seconds(),
216 (mark_end - mark_start).seconds() * 1000.0);
217
218 return false;
219 }
220
221 bool G1ConcurrentMarkThread::mark_loop_needs_restart() const {
222 return _cm->has_overflown();
223 }
224
225 bool G1ConcurrentMarkThread::subphase_mark_from_roots() {
226 ConcurrentGCBreakpoints::at("AFTER MARKING STARTED");
227 G1ConcPhaseTimer p(_cm, "Concurrent Mark From Roots");
228 _cm->mark_from_roots();
229 return _cm->has_aborted();
230 }
231
232 bool G1ConcurrentMarkThread::subphase_preclean() {
233 G1ConcPhaseTimer p(_cm, "Concurrent Preclean");
234 _cm->preclean();
235 return _cm->has_aborted();
236 }
237
238 bool G1ConcurrentMarkThread::subphase_delay_to_keep_mmu_before_remark() {
239 delay_to_keep_mmu(true /* remark */);
240 return _cm->has_aborted();
241 }
242
243 bool G1ConcurrentMarkThread::subphase_remark() {
244 ConcurrentGCBreakpoints::at("BEFORE MARKING COMPLETED");
245 CMRemark cl(_cm);
246 VM_G1Concurrent op(&cl, "Pause Remark");
247 VMThread::execute(&op);
248 return _cm->has_aborted();
249 }
250
251 bool G1ConcurrentMarkThread::phase_rebuild_remembered_sets() {
252 G1ConcPhaseTimer p(_cm, "Concurrent Rebuild Remembered Sets");
253 _cm->rebuild_rem_set_concurrently();
254 return _cm->has_aborted();
255 }
256
257 bool G1ConcurrentMarkThread::phase_delay_to_keep_mmu_before_cleanup() {
258 delay_to_keep_mmu(false /* cleanup */);
259 return _cm->has_aborted();
260 }
261
262 bool G1ConcurrentMarkThread::phase_cleanup() {
263 CMCleanup cl(_cm);
264 VM_G1Concurrent op(&cl, "Pause Cleanup");
265 VMThread::execute(&op);
266 return _cm->has_aborted();
267 }
272 return _cm->has_aborted();
273 }
274
275 void G1ConcurrentMarkThread::concurrent_cycle_start() {
276 _cm->concurrent_cycle_start();
277 }
278
279 void G1ConcurrentMarkThread::full_concurrent_cycle_do() {
280 HandleMark hm(Thread::current());
281 ResourceMark rm;
282
283 // Phase 1: Clear CLD claimed marks.
284 phase_clear_cld_claimed_marks();
285
286 // Do not return before the scan root regions phase as a GC waits for a
287 // notification from it.
288
289 // Phase 2: Scan root regions.
290 if (phase_scan_root_regions()) return;
291
292 // Phase 3: Actual mark loop.
293 if (phase_mark_loop()) return;
294
295 // Phase 4: Rebuild remembered sets.
296 if (phase_rebuild_remembered_sets()) return;
297
298 // Phase 5: Wait for Cleanup.
299 if (phase_delay_to_keep_mmu_before_cleanup()) return;
300
301 // Phase 6: Cleanup pause
302 if (phase_cleanup()) return;
303
304 // Phase 7: Clear bitmap for next mark.
305 phase_clear_bitmap_for_next_mark();
306 }
307
308 void G1ConcurrentMarkThread::concurrent_cycle_end() {
309 // Update the number of full collections that have been
310 // completed. This will also notify the G1OldGCCount_lock in case a
311 // Java thread is waiting for a full GC to happen (e.g., it
312 // called System.gc() with +ExplicitGCInvokesConcurrent).
313 SuspendibleThreadSetJoiner sts_join;
314 G1CollectedHeap::heap()->increment_old_marking_cycles_completed(true /* concurrent */,
315 !_cm->has_aborted());
316
317 _cm->concurrent_cycle_end();
318 ConcurrentGCBreakpoints::notify_active_to_idle();
319 }
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