1 /*
2 * Copyright (c) 2013, 2018, Red Hat, Inc. and/or its affiliates.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #include "precompiled.hpp"
25 #include "gc/g1/g1BarrierSet.hpp"
26 #include "gc/shenandoah/shenandoahAsserts.hpp"
27 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
28 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
29 #include "gc/shenandoah/shenandoahCollectorPolicy.hpp"
30 #include "gc/shenandoah/shenandoahConnectionMatrix.inline.hpp"
31 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
32 #include "runtime/interfaceSupport.inline.hpp"
33
34 ShenandoahSATBMarkQueueSet ShenandoahBarrierSet::_satb_mark_queue_set;
35
36 template <bool UPDATE_MATRIX, bool STOREVAL_WRITE_BARRIER>
37 class ShenandoahUpdateRefsForOopClosure: public ExtendedOopClosure {
38 private:
39 ShenandoahHeap* _heap;
40 template <class T>
41 inline void do_oop_work(T* p) {
42 oop o;
43 if (STOREVAL_WRITE_BARRIER) {
44 o = _heap->evac_update_with_forwarded(p);
45 if (!CompressedOops::is_null(o)) {
46 ShenandoahBarrierSet::enqueue(o);
47 }
48 } else {
49 o = _heap->maybe_update_with_forwarded(p);
50 }
51 if (UPDATE_MATRIX && !CompressedOops::is_null(o)) {
52 _heap->connection_matrix()->set_connected(p, o);
53 }
54 }
55 public:
56 ShenandoahUpdateRefsForOopClosure() : _heap(ShenandoahHeap::heap()) {
57 assert(UseShenandoahGC && ShenandoahCloneBarrier, "should be enabled");
58 }
59 void do_oop(oop* p) { do_oop_work(p); }
60 void do_oop(narrowOop* p) { do_oop_work(p); }
61 };
62
63 ShenandoahBarrierSet::ShenandoahBarrierSet(ShenandoahHeap* heap) :
64 BarrierSet(make_barrier_set_assembler<ShenandoahBarrierSetAssembler>(),
65 BarrierSet::FakeRtti(BarrierSet::Shenandoah)),
66 _heap(heap)
67 {
68 }
69
70 void ShenandoahBarrierSet::print_on(outputStream* st) const {
71 st->print("ShenandoahBarrierSet");
72 }
73
74 bool ShenandoahBarrierSet::is_a(BarrierSet::Name bsn) {
75 return bsn == BarrierSet::Shenandoah;
76 }
77
78 bool ShenandoahBarrierSet::is_aligned(HeapWord* hw) {
79 return true;
80 }
81
82 void ShenandoahBarrierSet::resize_covered_region(MemRegion mr) {
83 Unimplemented();
84 }
85
86 bool ShenandoahBarrierSet::need_update_refs_barrier() {
87 if (UseShenandoahMatrix || _heap->is_concurrent_traversal_in_progress()) {
88 return true;
89 }
90 if (_heap->shenandoahPolicy()->update_refs()) {
91 return _heap->is_update_refs_in_progress();
92 } else {
93 return _heap->is_concurrent_mark_in_progress() && _heap->has_forwarded_objects();
94 }
95 }
96
97 void ShenandoahBarrierSet::write_ref_array_work(MemRegion r) {
98 ShouldNotReachHere();
99 }
100
101 template <class T, bool UPDATE_MATRIX, bool STOREVAL_WRITE_BARRIER>
102 void ShenandoahBarrierSet::write_ref_array_loop(HeapWord* start, size_t count) {
103 assert(UseShenandoahGC && ShenandoahCloneBarrier, "should be enabled");
104 ShenandoahUpdateRefsForOopClosure<UPDATE_MATRIX, STOREVAL_WRITE_BARRIER> cl;
105 ShenandoahEvacOOMScope oom_evac_scope;
106 T* dst = (T*) start;
107 for (size_t i = 0; i < count; i++) {
108 cl.do_oop(dst++);
109 }
110 }
111
112 void ShenandoahBarrierSet::write_ref_array(HeapWord* start, size_t count) {
113 assert(UseShenandoahGC, "should be enabled");
114 if (!ShenandoahCloneBarrier) return;
115 if (!need_update_refs_barrier()) return;
116
117 if (UseShenandoahMatrix) {
118 if (_heap->is_concurrent_traversal_in_progress()) {
119 if (UseCompressedOops) {
120 write_ref_array_loop<narrowOop, /* matrix = */ true, /* wb = */ true>(start, count);
121 } else {
122 write_ref_array_loop<oop, /* matrix = */ true, /* wb = */ true>(start, count);
123 }
124 } else {
125 if (UseCompressedOops) {
126 write_ref_array_loop<narrowOop, /* matrix = */ true, /* wb = */ false>(start, count);
127 } else {
128 write_ref_array_loop<oop, /* matrix = */ true, /* wb = */ false>(start, count);
129 }
130 }
131 } else {
132 if (_heap->is_concurrent_traversal_in_progress()) {
133 if (UseCompressedOops) {
134 write_ref_array_loop<narrowOop, /* matrix = */ false, /* wb = */ true>(start, count);
135 } else {
136 write_ref_array_loop<oop, /* matrix = */ false, /* wb = */ true>(start, count);
137 }
138 } else {
139 if (UseCompressedOops) {
140 write_ref_array_loop<narrowOop, /* matrix = */ false, /* wb = */ false>(start, count);
141 } else {
142 write_ref_array_loop<oop, /* matrix = */ false, /* wb = */ false>(start, count);
143 }
144 }
145 }
146 }
147
148 void ShenandoahBarrierSet::write_ref_array_pre_oop_entry(oop* dst, size_t length) {
149 ShenandoahBarrierSet *bs = barrier_set_cast<ShenandoahBarrierSet>(BarrierSet::barrier_set());
150 bs->write_ref_array_pre(dst, length, false);
151 }
152
153 void ShenandoahBarrierSet::write_ref_array_pre_narrow_oop_entry(narrowOop* dst, size_t length) {
154 ShenandoahBarrierSet *bs = barrier_set_cast<ShenandoahBarrierSet>(BarrierSet::barrier_set());
155 bs->write_ref_array_pre(dst, length, false);
156 }
157
158 void ShenandoahBarrierSet::write_ref_array_post_entry(HeapWord* dst, size_t length) {
159 ShenandoahBarrierSet *bs = barrier_set_cast<ShenandoahBarrierSet>(BarrierSet::barrier_set());
160 bs->ShenandoahBarrierSet::write_ref_array(dst, length);
161 }
162
163
164 template <class T>
165 void ShenandoahBarrierSet::write_ref_array_pre_work(T* dst, int count) {
166 shenandoah_assert_not_in_cset_loc_except(dst, _heap->cancelled_concgc());
167 if (ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
168 T* elem_ptr = dst;
169 for (int i = 0; i < count; i++, elem_ptr++) {
170 T heap_oop = RawAccess<>::oop_load(elem_ptr);
171 if (!CompressedOops::is_null(heap_oop)) {
172 enqueue(CompressedOops::decode_not_null(heap_oop));
173 }
174 }
175 }
176 }
177
178 void ShenandoahBarrierSet::write_ref_array_pre(oop* dst, int count, bool dest_uninitialized) {
179 if (! dest_uninitialized) {
180 write_ref_array_pre_work(dst, count);
181 }
182 }
183
184 void ShenandoahBarrierSet::write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized) {
185 if (! dest_uninitialized) {
186 write_ref_array_pre_work(dst, count);
187 }
188 }
189
190 template <class T>
191 inline void ShenandoahBarrierSet::inline_write_ref_field_pre(T* field, oop new_val) {
192 shenandoah_assert_not_in_cset_loc_except(field, _heap->cancelled_concgc());
193 if (_heap->is_concurrent_mark_in_progress()) {
194 T heap_oop = RawAccess<>::oop_load(field);
195 if (!CompressedOops::is_null(heap_oop)) {
196 enqueue(CompressedOops::decode(heap_oop));
197 }
198 }
199 if (UseShenandoahMatrix && ! CompressedOops::is_null(new_val)) {
200 ShenandoahConnectionMatrix* matrix = _heap->connection_matrix();
201 matrix->set_connected(field, new_val);
202 }
203 }
204
205 // These are the more general virtual versions.
206 void ShenandoahBarrierSet::write_ref_field_pre_work(oop* field, oop new_val) {
207 inline_write_ref_field_pre(field, new_val);
208 }
209
210 void ShenandoahBarrierSet::write_ref_field_pre_work(narrowOop* field, oop new_val) {
211 inline_write_ref_field_pre(field, new_val);
212 }
213
214 void ShenandoahBarrierSet::write_ref_field_pre_work(void* field, oop new_val) {
215 guarantee(false, "Not needed");
216 }
217
218 void ShenandoahBarrierSet::write_ref_field_work(void* v, oop o, bool release) {
219 shenandoah_assert_not_in_cset_loc_except(v, _heap->cancelled_concgc());
220 shenandoah_assert_not_forwarded_except (v, o, o == NULL || _heap->cancelled_concgc() || !_heap->is_concurrent_mark_in_progress());
221 shenandoah_assert_not_in_cset_except (v, o, o == NULL || _heap->cancelled_concgc() || !_heap->is_concurrent_mark_in_progress());
222 }
223
224 void ShenandoahBarrierSet::write_region(MemRegion mr) {
225 assert(UseShenandoahGC, "should be enabled");
226 if (!ShenandoahCloneBarrier) return;
227 if (! need_update_refs_barrier()) return;
228
229 // This is called for cloning an object (see jvm.cpp) after the clone
230 // has been made. We are not interested in any 'previous value' because
231 // it would be NULL in any case. But we *are* interested in any oop*
232 // that potentially need to be updated.
233
234 ShenandoahEvacOOMScope oom_evac_scope;
235 oop obj = oop(mr.start());
236 assert(oopDesc::is_oop(obj), "must be an oop");
237 if (UseShenandoahMatrix) {
238 if (_heap->is_concurrent_traversal_in_progress()) {
239 ShenandoahUpdateRefsForOopClosure<true, true> cl;
240 obj->oop_iterate(&cl);
241 } else {
242 ShenandoahUpdateRefsForOopClosure<true, false> cl;
243 obj->oop_iterate(&cl);
244 }
245 } else {
246 if (_heap->is_concurrent_traversal_in_progress()) {
247 ShenandoahUpdateRefsForOopClosure<false, true> cl;
248 obj->oop_iterate(&cl);
249 } else {
250 ShenandoahUpdateRefsForOopClosure<false, false> cl;
251 obj->oop_iterate(&cl);
252 }
253 }
254 }
255
256 oop ShenandoahBarrierSet::read_barrier(oop src) {
257 // Check for forwarded objects, because on Full GC path we might deal with
258 // non-trivial fwdptrs that contain Full GC specific metadata. We could check
259 // for is_full_gc_in_progress(), but this also covers the case of stable heap,
260 // which provides a bit of performance improvement.
261 if (ShenandoahReadBarrier && _heap->has_forwarded_objects()) {
262 return ShenandoahBarrierSet::resolve_forwarded(src);
263 } else {
264 return src;
265 }
266 }
267
268 bool ShenandoahBarrierSet::obj_equals(oop obj1, oop obj2) {
269 bool eq = oopDesc::unsafe_equals(obj1, obj2);
270 if (! eq && ShenandoahAcmpBarrier) {
271 OrderAccess::loadload();
272 obj1 = resolve_forwarded(obj1);
273 obj2 = resolve_forwarded(obj2);
274 eq = oopDesc::unsafe_equals(obj1, obj2);
275 }
276 return eq;
277 }
278
279 JRT_LEAF(oopDesc*, ShenandoahBarrierSet::write_barrier_JRT(oopDesc* src))
280 oop result = ((ShenandoahBarrierSet*)BarrierSet::barrier_set())->write_barrier(src);
281 return (oopDesc*) result;
282 JRT_END
283
284 IRT_LEAF(oopDesc*, ShenandoahBarrierSet::write_barrier_IRT(oopDesc* src))
285 oop result = ((ShenandoahBarrierSet*)BarrierSet::barrier_set())->write_barrier(src);
286 return (oopDesc*) result;
287 IRT_END
288
289 oop ShenandoahBarrierSet::write_barrier_impl(oop obj) {
290 assert(UseShenandoahGC && ShenandoahWriteBarrier, "should be enabled");
291 if (!CompressedOops::is_null(obj)) {
292 bool evac_in_progress = _heap->is_gc_in_progress_mask(ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
293 oop fwd = resolve_forwarded_not_null(obj);
294 if (evac_in_progress &&
295 _heap->in_collection_set(obj) &&
296 oopDesc::unsafe_equals(obj, fwd)) {
297 ShenandoahEvacOOMScope oom_evac_scope;
298 return _heap->evacuate_object(obj, Thread::current());
299 } else {
300 return fwd;
301 }
302 } else {
303 return obj;
304 }
305 }
306
307 oop ShenandoahBarrierSet::write_barrier(oop obj) {
308 if (ShenandoahWriteBarrier) {
309 return write_barrier_impl(obj);
310 } else {
311 return obj;
312 }
313 }
314
315 oop ShenandoahBarrierSet::storeval_barrier(oop obj) {
316 if (ShenandoahStoreValEnqueueBarrier) {
317 if (!CompressedOops::is_null(obj)) {
318 obj = write_barrier(obj);
319 enqueue(obj);
320 }
321 }
322 if (ShenandoahStoreValEnqueueBarrier && !CompressedOops::is_null(obj)) {
323 enqueue(obj);
324 }
325 if (ShenandoahStoreValReadBarrier) {
326 obj = resolve_forwarded(obj);
327 }
328 return obj;
329 }
330
331 void ShenandoahBarrierSet::keep_alive_barrier(oop obj) {
332 if (ShenandoahKeepAliveBarrier && _heap->is_concurrent_mark_in_progress()) {
333 enqueue(obj);
334 }
335 }
336
337 void ShenandoahBarrierSet::enqueue(oop obj) {
338 shenandoah_assert_not_forwarded_if(NULL, obj, ShenandoahHeap::heap()->is_concurrent_traversal_in_progress());
339 // Nulls should have been already filtered.
340 assert(oopDesc::is_oop(obj, true), "Error");
341
342 if (!_satb_mark_queue_set.is_active()) return;
343 Thread* thr = Thread::current();
344 if (thr->is_Java_thread()) {
345 ShenandoahThreadLocalData::satb_mark_queue(thr).enqueue(obj);
346 } else {
347 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
348 _satb_mark_queue_set.shared_satb_queue()->enqueue(obj);
349 }
350 }
351
352 #ifdef ASSERT
353 void ShenandoahBarrierSet::verify_safe_oop(oop p) {
354 shenandoah_assert_not_in_cset_except(NULL, p, (p == NULL) || ShenandoahHeap::heap()->cancelled_concgc());
355 }
356 #endif
357
358 void ShenandoahBarrierSet::on_thread_create(Thread* thread) {
359 // Create thread local data
360 ShenandoahThreadLocalData::create(thread);
361 }
362
363 void ShenandoahBarrierSet::on_thread_destroy(Thread* thread) {
364 // Destroy thread local data
365 ShenandoahThreadLocalData::destroy(thread);
366 }
367
368
369 void ShenandoahBarrierSet::on_thread_attach(JavaThread* thread) {
370 assert(!SafepointSynchronize::is_at_safepoint(), "We should not be at a safepoint");
371 assert(!ShenandoahThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active");
372 assert(ShenandoahThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty");
373 if (ShenandoahBarrierSet::satb_mark_queue_set().is_active()) {
374 ShenandoahThreadLocalData::satb_mark_queue(thread).set_active(true);
375 }
376 ShenandoahThreadLocalData::set_gc_state(thread, ShenandoahHeap::heap()->gc_state());
377 }
378
379 void ShenandoahBarrierSet::on_thread_detach(JavaThread* thread) {
380 ShenandoahThreadLocalData::satb_mark_queue(thread).flush();
381 if (UseTLAB && thread->gclab().is_initialized()) {
382 thread->gclab().make_parsable(true);
383 }
384 }