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, bool ALWAYS_ENQUEUE>
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 bool evac;
45 o = _heap->evac_update_with_forwarded(p, evac);
46 if ((ALWAYS_ENQUEUE || evac) && !CompressedOops::is_null(o)) {
47 ShenandoahBarrierSet::enqueue(o);
48 }
49 } else {
50 o = _heap->maybe_update_with_forwarded(p);
51 }
52 if (UPDATE_MATRIX && !CompressedOops::is_null(o)) {
53 _heap->connection_matrix()->set_connected(p, o);
54 }
55 }
56 public:
57 ShenandoahUpdateRefsForOopClosure() : _heap(ShenandoahHeap::heap()) {
58 assert(UseShenandoahGC && ShenandoahCloneBarrier, "should be enabled");
59 }
60 void do_oop(oop* p) { do_oop_work(p); }
61 void do_oop(narrowOop* p) { do_oop_work(p); }
62 };
63
64 ShenandoahBarrierSet::ShenandoahBarrierSet(ShenandoahHeap* heap) :
65 BarrierSet(make_barrier_set_assembler<ShenandoahBarrierSetAssembler>(),
66 BarrierSet::FakeRtti(BarrierSet::Shenandoah)),
67 _heap(heap)
68 {
69 }
70
71 void ShenandoahBarrierSet::print_on(outputStream* st) const {
72 st->print("ShenandoahBarrierSet");
73 }
74
75 bool ShenandoahBarrierSet::is_a(BarrierSet::Name bsn) {
76 return bsn == BarrierSet::Shenandoah;
77 }
78
79 bool ShenandoahBarrierSet::is_aligned(HeapWord* hw) {
80 return true;
81 }
82
83 void ShenandoahBarrierSet::resize_covered_region(MemRegion mr) {
84 Unimplemented();
85 }
86
87 bool ShenandoahBarrierSet::need_update_refs_barrier() {
88 if (UseShenandoahMatrix || _heap->is_concurrent_traversal_in_progress()) {
89 return true;
90 }
91 if (_heap->shenandoahPolicy()->update_refs()) {
92 return _heap->is_update_refs_in_progress();
93 } else {
94 return _heap->is_concurrent_mark_in_progress() && _heap->has_forwarded_objects();
95 }
96 }
97
98 void ShenandoahBarrierSet::write_ref_array_work(MemRegion r) {
99 ShouldNotReachHere();
100 }
101
102 template <class T, bool UPDATE_MATRIX, bool STOREVAL_WRITE_BARRIER, bool ALWAYS_ENQUEUE>
103 void ShenandoahBarrierSet::write_ref_array_loop(HeapWord* start, size_t count) {
104 assert(UseShenandoahGC && ShenandoahCloneBarrier, "should be enabled");
105 ShenandoahUpdateRefsForOopClosure<UPDATE_MATRIX, STOREVAL_WRITE_BARRIER, ALWAYS_ENQUEUE> cl;
106 ShenandoahEvacOOMScope oom_evac_scope;
107 T* dst = (T*) start;
108 for (size_t i = 0; i < count; i++) {
109 cl.do_oop(dst++);
110 }
111 }
112
113 void ShenandoahBarrierSet::write_ref_array(HeapWord* start, size_t count) {
114 assert(UseShenandoahGC, "should be enabled");
115 if (!ShenandoahCloneBarrier) return;
116 if (!need_update_refs_barrier()) return;
117
118 if (UseShenandoahMatrix) {
119 assert(! _heap->is_concurrent_traversal_in_progress(), "traversal GC should take another branch");
120 if (_heap->is_concurrent_partial_in_progress()) {
121 if (UseCompressedOops) {
122 write_ref_array_loop<narrowOop, /* matrix = */ true, /* wb = */ true, /* enqueue = */ false>(start, count);
123 } else {
124 write_ref_array_loop<oop, /* matrix = */ true, /* wb = */ true, /* enqueue = */ false>(start, count);
125 }
126 } else {
127 if (UseCompressedOops) {
128 write_ref_array_loop<narrowOop, /* matrix = */ true, /* wb = */ false, /* enqueue = */ false>(start, count);
129 } else {
130 write_ref_array_loop<oop, /* matrix = */ true, /* wb = */ false, /* enqueue = */ false>(start, count);
131 }
132 }
133 } else if (_heap->is_concurrent_traversal_in_progress()) {
134 if (UseCompressedOops) {
135 write_ref_array_loop<narrowOop, /* matrix = */ false, /* wb = */ true, /* enqueue = */ true>(start, count);
136 } else {
137 write_ref_array_loop<oop, /* matrix = */ false, /* wb = */ true, /* enqueue = */ true>(start, count);
138 }
139 } else {
140 if (UseCompressedOops) {
141 write_ref_array_loop<narrowOop, /* matrix = */ false, /* wb = */ false, /* enqueue = */ false>(start, count);
142 } else {
143 write_ref_array_loop<oop, /* matrix = */ false, /* wb = */ false, /* enqueue = */ false>(start, count);
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 ||
168 (ShenandoahConditionalSATBBarrier && _heap->is_concurrent_mark_in_progress())) {
169 T* elem_ptr = dst;
170 for (int i = 0; i < count; i++, elem_ptr++) {
171 T heap_oop = RawAccess<>::oop_load(elem_ptr);
172 if (!CompressedOops::is_null(heap_oop)) {
173 enqueue(CompressedOops::decode_not_null(heap_oop));
174 }
175 }
176 }
177 }
178
179 void ShenandoahBarrierSet::write_ref_array_pre(oop* dst, int count, bool dest_uninitialized) {
180 if (! dest_uninitialized) {
181 write_ref_array_pre_work(dst, count);
182 }
183 }
184
185 void ShenandoahBarrierSet::write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized) {
186 if (! dest_uninitialized) {
187 write_ref_array_pre_work(dst, count);
188 }
189 }
190
191 template <class T>
192 inline void ShenandoahBarrierSet::inline_write_ref_field_pre(T* field, oop new_val) {
193 shenandoah_assert_not_in_cset_loc_except(field, _heap->cancelled_concgc());
194 if (_heap->is_concurrent_mark_in_progress()) {
195 T heap_oop = RawAccess<>::oop_load(field);
196 if (!CompressedOops::is_null(heap_oop)) {
197 enqueue(CompressedOops::decode(heap_oop));
198 }
199 }
200 if (UseShenandoahMatrix && ! CompressedOops::is_null(new_val)) {
201 ShenandoahConnectionMatrix* matrix = _heap->connection_matrix();
202 matrix->set_connected(field, new_val);
203 }
204 }
205
206 // These are the more general virtual versions.
207 void ShenandoahBarrierSet::write_ref_field_pre_work(oop* field, oop new_val) {
208 inline_write_ref_field_pre(field, new_val);
209 }
210
211 void ShenandoahBarrierSet::write_ref_field_pre_work(narrowOop* field, oop new_val) {
212 inline_write_ref_field_pre(field, new_val);
213 }
214
215 void ShenandoahBarrierSet::write_ref_field_pre_work(void* field, oop new_val) {
216 guarantee(false, "Not needed");
217 }
218
219 void ShenandoahBarrierSet::write_ref_field_work(void* v, oop o, bool release) {
220 shenandoah_assert_not_in_cset_loc_except(v, _heap->cancelled_concgc());
221 shenandoah_assert_not_forwarded_except (v, o, o == NULL || _heap->cancelled_concgc() || !_heap->is_concurrent_mark_in_progress());
222 shenandoah_assert_not_in_cset_except (v, o, o == NULL || _heap->cancelled_concgc() || !_heap->is_concurrent_mark_in_progress());
223 }
224
225 void ShenandoahBarrierSet::write_region(MemRegion mr) {
226 assert(UseShenandoahGC, "should be enabled");
227 if (!ShenandoahCloneBarrier) return;
228 if (! need_update_refs_barrier()) return;
229
230 // This is called for cloning an object (see jvm.cpp) after the clone
231 // has been made. We are not interested in any 'previous value' because
232 // it would be NULL in any case. But we *are* interested in any oop*
233 // that potentially need to be updated.
234
235 ShenandoahEvacOOMScope oom_evac_scope;
236 oop obj = oop(mr.start());
237 assert(oopDesc::is_oop(obj), "must be an oop");
238 if (UseShenandoahMatrix) {
239 assert(! _heap->is_concurrent_traversal_in_progress(), "traversal GC should take another branch");
240 if (_heap->is_concurrent_partial_in_progress()) {
241 ShenandoahUpdateRefsForOopClosure<true, true, false> cl;
242 obj->oop_iterate(&cl);
243 } else {
244 ShenandoahUpdateRefsForOopClosure<true, false, false> cl;
245 obj->oop_iterate(&cl);
246 }
247 } else {
248 assert(! _heap->is_concurrent_partial_in_progress(), "partial GC needs matrix");
249 if (_heap->is_concurrent_traversal_in_progress()) {
250 ShenandoahUpdateRefsForOopClosure<false, true, true> cl;
251 obj->oop_iterate(&cl);
252 } else {
253 ShenandoahUpdateRefsForOopClosure<false, false, false> cl;
254 obj->oop_iterate(&cl);
255 }
256 }
257 }
258
259 oop ShenandoahBarrierSet::read_barrier(oop src) {
260 // Check for forwarded objects, because on Full GC path we might deal with
261 // non-trivial fwdptrs that contain Full GC specific metadata. We could check
262 // for is_full_gc_in_progress(), but this also covers the case of stable heap,
263 // which provides a bit of performance improvement.
264 if (ShenandoahReadBarrier && _heap->has_forwarded_objects()) {
265 return ShenandoahBarrierSet::resolve_forwarded(src);
266 } else {
267 return src;
268 }
269 }
270
271 bool ShenandoahBarrierSet::obj_equals(oop obj1, oop obj2) {
272 bool eq = oopDesc::unsafe_equals(obj1, obj2);
273 if (! eq && ShenandoahAcmpBarrier) {
274 OrderAccess::loadload();
275 obj1 = resolve_forwarded(obj1);
276 obj2 = resolve_forwarded(obj2);
277 eq = oopDesc::unsafe_equals(obj1, obj2);
278 }
279 return eq;
280 }
281
282 JRT_LEAF(oopDesc*, ShenandoahBarrierSet::write_barrier_JRT(oopDesc* src))
283 oop result = ((ShenandoahBarrierSet*)BarrierSet::barrier_set())->write_barrier(src);
284 return (oopDesc*) result;
285 JRT_END
286
287 IRT_LEAF(oopDesc*, ShenandoahBarrierSet::write_barrier_IRT(oopDesc* src))
288 oop result = ((ShenandoahBarrierSet*)BarrierSet::barrier_set())->write_barrier(src);
289 return (oopDesc*) result;
290 IRT_END
291
292 oop ShenandoahBarrierSet::write_barrier_impl(oop obj) {
293 assert(UseShenandoahGC && (ShenandoahWriteBarrier || ShenandoahStoreValWriteBarrier), "should be enabled");
294 if (!CompressedOops::is_null(obj)) {
295 bool evac_in_progress = _heap->is_gc_in_progress_mask(ShenandoahHeap::EVACUATION | ShenandoahHeap::PARTIAL | ShenandoahHeap::TRAVERSAL);
296 oop fwd = resolve_forwarded_not_null(obj);
297 if (evac_in_progress &&
298 _heap->in_collection_set(obj) &&
299 oopDesc::unsafe_equals(obj, fwd)) {
300 ShenandoahEvacOOMScope oom_evac_scope;
301 bool evac;
302 oop copy = _heap->evacuate_object(obj, Thread::current(), evac);
303 if (evac && _heap->is_concurrent_partial_in_progress()) {
304 enqueue(copy);
305 }
306 return copy;
307 } else {
308 return fwd;
309 }
310 } else {
311 return obj;
312 }
313 }
314
315 oop ShenandoahBarrierSet::write_barrier(oop obj) {
316 if (ShenandoahWriteBarrier) {
317 return write_barrier_impl(obj);
318 } else {
319 return obj;
320 }
321 }
322
323 oop ShenandoahBarrierSet::storeval_barrier(oop obj) {
324 if (ShenandoahStoreValWriteBarrier || ShenandoahStoreValEnqueueBarrier) {
325 obj = write_barrier(obj);
326 }
327 if (ShenandoahStoreValEnqueueBarrier && !CompressedOops::is_null(obj)) {
328 enqueue(obj);
329 }
330 if (ShenandoahStoreValReadBarrier) {
331 obj = resolve_forwarded(obj);
332 }
333 return obj;
334 }
335
336 void ShenandoahBarrierSet::keep_alive_barrier(oop obj) {
337 if (ShenandoahKeepAliveBarrier) {
338 if (_heap->is_concurrent_mark_in_progress()) {
339 enqueue(obj);
340 } else if (_heap->is_concurrent_partial_in_progress()) {
341 write_barrier_impl(obj);
342 }
343 }
344 }
345
346 void ShenandoahBarrierSet::enqueue(oop obj) {
347 shenandoah_assert_not_forwarded_if(NULL, obj, ShenandoahHeap::heap()->is_concurrent_traversal_in_progress());
348 // Nulls should have been already filtered.
349 assert(oopDesc::is_oop(obj, true), "Error");
350
351 if (!_satb_mark_queue_set.is_active()) return;
352 Thread* thr = Thread::current();
353 if (thr->is_Java_thread()) {
354 ShenandoahThreadLocalData::satb_mark_queue(thr).enqueue(obj);
355 } else {
356 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
357 _satb_mark_queue_set.shared_satb_queue()->enqueue(obj);
358 }
359 }
360
361 #ifdef ASSERT
362 void ShenandoahBarrierSet::verify_safe_oop(oop p) {
363 shenandoah_assert_not_in_cset_except(NULL, p, (p == NULL) || ShenandoahHeap::heap()->cancelled_concgc());
364 }
365 #endif
366
367 void ShenandoahBarrierSet::on_thread_create(Thread* thread) {
368 // Create thread local data
369 ShenandoahThreadLocalData::create(thread);
370 }
371
372 void ShenandoahBarrierSet::on_thread_destroy(Thread* thread) {
373 // Destroy thread local data
374 ShenandoahThreadLocalData::destroy(thread);
375 }
376
377
378 void ShenandoahBarrierSet::on_thread_attach(JavaThread* thread) {
379 assert(!SafepointSynchronize::is_at_safepoint(), "We should not be at a safepoint");
380 assert(!ShenandoahThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active");
381 assert(ShenandoahThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty");
382 if (ShenandoahBarrierSet::satb_mark_queue_set().is_active()) {
383 ShenandoahThreadLocalData::satb_mark_queue(thread).set_active(true);
384 }
385 ShenandoahThreadLocalData::set_gc_state(thread, ShenandoahHeap::heap()->gc_state());
386 }
387
388 void ShenandoahBarrierSet::on_thread_detach(JavaThread* thread) {
389 ShenandoahThreadLocalData::satb_mark_queue(thread).flush();
390 if (UseTLAB && thread->gclab().is_initialized()) {
391 thread->gclab().make_parsable(true);
392 }
393 }