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_implementation/g1/g1CollectedHeap.inline.hpp"
27 #include "gc_implementation/g1/satbQueue.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/sharedHeap.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "runtime/mutexLocker.hpp"
32 #include "runtime/thread.hpp"
33 #include "runtime/vmThread.hpp"
34
35 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
36
37 void ObjPtrQueue::flush() {
38 // Filter now to possibly save work later. If filtering empties the
39 // buffer then flush_impl can deallocate the buffer.
40 filter();
41 flush_impl();
42 }
43
44 // Return true if a SATB buffer entry refers to an object that
45 // requires marking.
46 //
47 // The entry must point into the G1 heap. In particular, it must not
48 // be a NULL pointer. NULL pointers are pre-filtered and never
49 // inserted into a SATB buffer.
50 //
51 // An entry that is below the NTAMS pointer for the containing heap
145 assert(entries == entries_calc, "the number of entries we counted "
146 "should match the number of entries we calculated");
147 size_t retained_calc = (sz - new_index) / oopSize;
148 assert(retained == retained_calc, "the number of retained entries we counted "
149 "should match the number of retained entries we calculated");
150 #endif // ASSERT
151
152 _index = new_index;
153 }
154
155 // This method will first apply the above filtering to the buffer. If
156 // post-filtering a large enough chunk of the buffer has been cleared
157 // we can re-use the buffer (instead of enqueueing it) and we can just
158 // allow the mutator to carry on executing using the same buffer
159 // instead of replacing it.
160
161 bool ObjPtrQueue::should_enqueue_buffer() {
162 assert(_lock == NULL || _lock->owned_by_self(),
163 "we should have taken the lock before calling this");
164
165 // Even if G1SATBBufferEnqueueingThresholdPercent == 0 we have to
166 // filter the buffer given that this will remove any references into
167 // the CSet as we currently assume that no such refs will appear in
168 // enqueued buffers.
169
170 // This method should only be called if there is a non-NULL buffer
171 // that is full.
172 assert(_index == 0, "pre-condition");
173 assert(_buf != NULL, "pre-condition");
174
175 filter();
176
177 size_t sz = _sz;
178 size_t all_entries = sz / oopSize;
179 size_t retained_entries = (sz - _index) / oopSize;
180 size_t perc = retained_entries * 100 / all_entries;
181 bool should_enqueue = perc > (size_t) G1SATBBufferEnqueueingThresholdPercent;
182 return should_enqueue;
183 }
184
185 void ObjPtrQueue::apply_closure_and_empty(ObjectClosure* cl) {
186 if (_buf != NULL) {
187 apply_closure_to_buffer(cl, _buf, _index, _sz);
188 _index = _sz;
189 }
190 }
191
192 void ObjPtrQueue::apply_closure_to_buffer(ObjectClosure* cl,
193 void** buf, size_t index, size_t sz) {
194 if (cl == NULL) return;
195 for (size_t i = index; i < sz; i += oopSize) {
196 oop obj = (oop)buf[byte_index_to_index((int)i)];
197 // There can be NULL entries because of destructors.
198 if (obj != NULL) {
199 cl->do_object(obj);
200 }
201 }
202 }
203
204 #ifndef PRODUCT
205 // Helpful for debugging
206
207 void ObjPtrQueue::print(const char* name) {
208 print(name, _buf, _index, _sz);
209 }
210
211 void ObjPtrQueue::print(const char* name,
212 void** buf, size_t index, size_t sz) {
213 gclog_or_tty->print_cr(" SATB BUFFER [%s] buf: "PTR_FORMAT" "
214 "index: "SIZE_FORMAT" sz: "SIZE_FORMAT,
215 name, buf, index, sz);
216 }
217 #endif // PRODUCT
218
219 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
220 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
221 #endif // _MSC_VER
222
223 SATBMarkQueueSet::SATBMarkQueueSet() :
274
275 void SATBMarkQueueSet::set_active_all_threads(bool active, bool expected_active) {
276 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
277 #ifdef ASSERT
278 verify_active_states(expected_active);
279 #endif // ASSERT
280 _all_active = active;
281 for (JavaThread* t = Threads::first(); t; t = t->next()) {
282 t->satb_mark_queue().set_active(active);
283 }
284 shared_satb_queue()->set_active(active);
285 }
286
287 void SATBMarkQueueSet::filter_thread_buffers() {
288 for(JavaThread* t = Threads::first(); t; t = t->next()) {
289 t->satb_mark_queue().filter();
290 }
291 shared_satb_queue()->filter();
292 }
293
294 bool SATBMarkQueueSet::apply_closure_to_completed_buffer(ObjectClosure* cl) {
295 BufferNode* nd = NULL;
296 {
297 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
298 if (_completed_buffers_head != NULL) {
299 nd = _completed_buffers_head;
300 _completed_buffers_head = nd->next();
301 if (_completed_buffers_head == NULL) _completed_buffers_tail = NULL;
302 _n_completed_buffers--;
303 if (_n_completed_buffers == 0) _process_completed = false;
304 }
305 }
306 if (nd != NULL) {
307 void **buf = BufferNode::make_buffer_from_node(nd);
308 ObjPtrQueue::apply_closure_to_buffer(cl, buf, 0, _sz);
309 deallocate_buffer(buf);
310 return true;
311 } else {
312 return false;
313 }
314 }
315
316 #ifndef PRODUCT
317 // Helpful for debugging
318
319 #define SATB_PRINTER_BUFFER_SIZE 256
320
321 void SATBMarkQueueSet::print_all(const char* msg) {
322 char buffer[SATB_PRINTER_BUFFER_SIZE];
323 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
324
325 gclog_or_tty->cr();
326 gclog_or_tty->print_cr("SATB BUFFERS [%s]", msg);
327
328 BufferNode* nd = _completed_buffers_head;
|
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_implementation/g1/g1CollectedHeap.inline.hpp"
27 #include "gc_implementation/g1/satbQueue.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/sharedHeap.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "runtime/mutexLocker.hpp"
32 #include "runtime/safepoint.hpp"
33 #include "runtime/thread.hpp"
34 #include "runtime/vmThread.hpp"
35
36 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
37
38 void ObjPtrQueue::flush() {
39 // Filter now to possibly save work later. If filtering empties the
40 // buffer then flush_impl can deallocate the buffer.
41 filter();
42 flush_impl();
43 }
44
45 // Return true if a SATB buffer entry refers to an object that
46 // requires marking.
47 //
48 // The entry must point into the G1 heap. In particular, it must not
49 // be a NULL pointer. NULL pointers are pre-filtered and never
50 // inserted into a SATB buffer.
51 //
52 // An entry that is below the NTAMS pointer for the containing heap
146 assert(entries == entries_calc, "the number of entries we counted "
147 "should match the number of entries we calculated");
148 size_t retained_calc = (sz - new_index) / oopSize;
149 assert(retained == retained_calc, "the number of retained entries we counted "
150 "should match the number of retained entries we calculated");
151 #endif // ASSERT
152
153 _index = new_index;
154 }
155
156 // This method will first apply the above filtering to the buffer. If
157 // post-filtering a large enough chunk of the buffer has been cleared
158 // we can re-use the buffer (instead of enqueueing it) and we can just
159 // allow the mutator to carry on executing using the same buffer
160 // instead of replacing it.
161
162 bool ObjPtrQueue::should_enqueue_buffer() {
163 assert(_lock == NULL || _lock->owned_by_self(),
164 "we should have taken the lock before calling this");
165
166 // If G1SATBBufferEnqueueingThresholdPercent == 0 we could skip filtering.
167
168 // This method should only be called if there is a non-NULL buffer
169 // that is full.
170 assert(_index == 0, "pre-condition");
171 assert(_buf != NULL, "pre-condition");
172
173 filter();
174
175 size_t sz = _sz;
176 size_t all_entries = sz / oopSize;
177 size_t retained_entries = (sz - _index) / oopSize;
178 size_t perc = retained_entries * 100 / all_entries;
179 bool should_enqueue = perc > (size_t) G1SATBBufferEnqueueingThresholdPercent;
180 return should_enqueue;
181 }
182
183 void ObjPtrQueue::apply_closure_and_empty(SATBBufferClosure* cl) {
184 assert(SafepointSynchronize::is_at_safepoint(),
185 "SATB queues must only be processed at safepoints");
186 if (_buf != NULL) {
187 assert(_index % sizeof(void*) == 0, "invariant");
188 assert(_sz % sizeof(void*) == 0, "invariant");
189 assert(_index <= _sz, "invariant");
190 cl->do_buffer(_buf + byte_index_to_index((int)_index),
191 byte_index_to_index((int)(_sz - _index)));
192 _index = _sz;
193 }
194 }
195
196 #ifndef PRODUCT
197 // Helpful for debugging
198
199 void ObjPtrQueue::print(const char* name) {
200 print(name, _buf, _index, _sz);
201 }
202
203 void ObjPtrQueue::print(const char* name,
204 void** buf, size_t index, size_t sz) {
205 gclog_or_tty->print_cr(" SATB BUFFER [%s] buf: "PTR_FORMAT" "
206 "index: "SIZE_FORMAT" sz: "SIZE_FORMAT,
207 name, buf, index, sz);
208 }
209 #endif // PRODUCT
210
211 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
212 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
213 #endif // _MSC_VER
214
215 SATBMarkQueueSet::SATBMarkQueueSet() :
266
267 void SATBMarkQueueSet::set_active_all_threads(bool active, bool expected_active) {
268 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
269 #ifdef ASSERT
270 verify_active_states(expected_active);
271 #endif // ASSERT
272 _all_active = active;
273 for (JavaThread* t = Threads::first(); t; t = t->next()) {
274 t->satb_mark_queue().set_active(active);
275 }
276 shared_satb_queue()->set_active(active);
277 }
278
279 void SATBMarkQueueSet::filter_thread_buffers() {
280 for(JavaThread* t = Threads::first(); t; t = t->next()) {
281 t->satb_mark_queue().filter();
282 }
283 shared_satb_queue()->filter();
284 }
285
286 bool SATBMarkQueueSet::apply_closure_to_completed_buffer(SATBBufferClosure* cl) {
287 BufferNode* nd = NULL;
288 {
289 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
290 if (_completed_buffers_head != NULL) {
291 nd = _completed_buffers_head;
292 _completed_buffers_head = nd->next();
293 if (_completed_buffers_head == NULL) _completed_buffers_tail = NULL;
294 _n_completed_buffers--;
295 if (_n_completed_buffers == 0) _process_completed = false;
296 }
297 }
298 if (nd != NULL) {
299 void **buf = BufferNode::make_buffer_from_node(nd);
300 // Skip over NULL entries at beginning (e.g. push end) of buffer.
301 // Filtering can result in non-full completed buffers; see
302 // should_enqueue_buffer.
303 assert(_sz % sizeof(void*) == 0, "invariant");
304 size_t limit = ObjPtrQueue::byte_index_to_index((int)_sz);
305 for (size_t i = 0; i < limit; ++i) {
306 if (buf[i] != NULL) {
307 // Found the end of the block of NULLs; process the remainder.
308 cl->do_buffer(buf + i, limit - i);
309 break;
310 }
311 }
312 deallocate_buffer(buf);
313 return true;
314 } else {
315 return false;
316 }
317 }
318
319 #ifndef PRODUCT
320 // Helpful for debugging
321
322 #define SATB_PRINTER_BUFFER_SIZE 256
323
324 void SATBMarkQueueSet::print_all(const char* msg) {
325 char buffer[SATB_PRINTER_BUFFER_SIZE];
326 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
327
328 gclog_or_tty->cr();
329 gclog_or_tty->print_cr("SATB BUFFERS [%s]", msg);
330
331 BufferNode* nd = _completed_buffers_head;
|