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 "gc/shenandoah/shenandoahHeuristics.hpp"
33 #include "gc/shenandoah/shenandoahTraversalGC.hpp"
34 #include "memory/iterator.inline.hpp"
35 #include "runtime/interfaceSupport.inline.hpp"
36 #ifdef COMPILER1
37 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
38 #endif
39 #ifdef COMPILER2
40 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
41 #endif
42
43 class ShenandoahBarrierSetC1;
44 class ShenandoahBarrierSetC2;
45
46 ShenandoahSATBMarkQueueSet ShenandoahBarrierSet::_satb_mark_queue_set;
47
48 template <bool UPDATE_MATRIX, bool STOREVAL_WRITE_BARRIER>
49 class ShenandoahUpdateRefsForOopClosure: public BasicOopIterateClosure {
50 private:
51 ShenandoahHeap* _heap;
52 ShenandoahBarrierSet* _bs;
53
54 template <class T>
55 inline void do_oop_work(T* p) {
56 oop o;
57 if (STOREVAL_WRITE_BARRIER) {
58 o = _heap->evac_update_with_forwarded(p);
59 if (!CompressedOops::is_null(o)) {
60 _bs->enqueue(o);
61 }
62 } else {
63 o = _heap->maybe_update_with_forwarded(p);
64 }
65 if (UPDATE_MATRIX && !CompressedOops::is_null(o)) {
66 _heap->connection_matrix()->set_connected(p, o);
67 }
68 }
69 public:
70 ShenandoahUpdateRefsForOopClosure() : _heap(ShenandoahHeap::heap()), _bs(ShenandoahBarrierSet::barrier_set()) {
71 assert(UseShenandoahGC && ShenandoahCloneBarrier, "should be enabled");
72 }
73
74 virtual void do_oop(oop* p) { do_oop_work(p); }
75 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
76 };
77
78 ShenandoahBarrierSet::ShenandoahBarrierSet(ShenandoahHeap* heap) :
79 BarrierSet(make_barrier_set_assembler<ShenandoahBarrierSetAssembler>(),
80 make_barrier_set_c1<ShenandoahBarrierSetC1>(),
81 make_barrier_set_c2<ShenandoahBarrierSetC2>(),
82 BarrierSet::FakeRtti(BarrierSet::Shenandoah)),
83 _heap(heap)
84 {
85 }
86
87 void ShenandoahBarrierSet::print_on(outputStream* st) const {
88 st->print("ShenandoahBarrierSet");
89 }
90
91 bool ShenandoahBarrierSet::is_a(BarrierSet::Name bsn) {
92 return bsn == BarrierSet::Shenandoah;
93 }
94
95 bool ShenandoahBarrierSet::is_aligned(HeapWord* hw) {
96 return true;
97 }
98
99 void ShenandoahBarrierSet::resize_covered_region(MemRegion mr) {
100 Unimplemented();
101 }
102
103 void ShenandoahBarrierSet::write_ref_array_work(MemRegion r) {
104 ShouldNotReachHere();
105 }
106
107 template <class T, bool UPDATE_MATRIX, bool STOREVAL_WRITE_BARRIER>
108 void ShenandoahBarrierSet::write_ref_array_loop(HeapWord* start, size_t count) {
109 assert(UseShenandoahGC && ShenandoahCloneBarrier, "should be enabled");
110 ShenandoahUpdateRefsForOopClosure<UPDATE_MATRIX, STOREVAL_WRITE_BARRIER> cl;
111 T* dst = (T*) start;
112 for (size_t i = 0; i < count; i++) {
113 cl.do_oop(dst++);
114 }
115 }
116
117 void ShenandoahBarrierSet::write_ref_array(HeapWord* start, size_t count) {
118 assert(UseShenandoahGC, "should be enabled");
119 if (count == 0) return;
120 if (!ShenandoahCloneBarrier) return;
121
122 if (!need_update_refs_barrier()) return;
123
124 if (_heap->is_concurrent_traversal_in_progress()) {
125 if (count > ShenandoahEnqueueArrayCopyThreshold) {
126 _heap->traversal_gc()->push_arraycopy(start, count);
127 } else {
128 ShenandoahEvacOOMScope oom_evac_scope;
129 if (UseShenandoahMatrix) {
130 if (UseCompressedOops) {
131 write_ref_array_loop<narrowOop, /* matrix = */ true, /* wb = */ true>(start, count);
132 } else {
133 write_ref_array_loop<oop, /* matrix = */ true, /* wb = */ true>(start, count);
134 }
135 } else {
136 if (UseCompressedOops) {
137 write_ref_array_loop<narrowOop, /* matrix = */ false, /* wb = */ true>(start, count);
138 } else {
139 write_ref_array_loop<oop, /* matrix = */ false, /* wb = */ true>(start, count);
140 }
141 }
142 }
143 } else {
144 if (UseShenandoahMatrix) {
145 if (UseCompressedOops) {
146 write_ref_array_loop<narrowOop, /* matrix = */ true, /* wb = */ false>(start, count);
147 } else {
148 write_ref_array_loop<oop, /* matrix = */ true, /* wb = */ false>(start, count);
149 }
150 } else {
151 if (UseCompressedOops) {
152 write_ref_array_loop<narrowOop, /* matrix = */ false, /* wb = */ false>(start, count);
153 } else {
154 write_ref_array_loop<oop, /* matrix = */ false, /* wb = */ false>(start, count);
155 }
156 }
157 }
158 }
159
160 template <class T>
161 void ShenandoahBarrierSet::write_ref_array_pre_work(T* dst, size_t count) {
162 shenandoah_assert_not_in_cset_loc_except(dst, _heap->cancelled_gc());
163 if (ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
164 T* elem_ptr = dst;
165 for (size_t i = 0; i < count; i++, elem_ptr++) {
166 T heap_oop = RawAccess<>::oop_load(elem_ptr);
167 if (!CompressedOops::is_null(heap_oop)) {
168 enqueue(CompressedOops::decode_not_null(heap_oop));
169 }
170 }
171 }
172 }
173
174 void ShenandoahBarrierSet::write_ref_array_pre(oop* dst, size_t count, bool dest_uninitialized) {
175 if (! dest_uninitialized) {
176 write_ref_array_pre_work(dst, count);
177 }
178 }
179
180 void ShenandoahBarrierSet::write_ref_array_pre(narrowOop* dst, size_t count, bool dest_uninitialized) {
181 if (! dest_uninitialized) {
182 write_ref_array_pre_work(dst, count);
183 }
184 }
185
186 template <class T>
187 inline void ShenandoahBarrierSet::inline_write_ref_field_pre(T* field, oop new_val) {
188 shenandoah_assert_not_in_cset_loc_except(field, _heap->cancelled_gc());
189 if (_heap->is_concurrent_mark_in_progress()) {
190 T heap_oop = RawAccess<>::oop_load(field);
191 if (!CompressedOops::is_null(heap_oop)) {
192 enqueue(CompressedOops::decode(heap_oop));
193 }
194 }
195 if (UseShenandoahMatrix && ! CompressedOops::is_null(new_val)) {
196 ShenandoahConnectionMatrix* matrix = _heap->connection_matrix();
197 matrix->set_connected(field, new_val);
198 }
199 }
200
201 // These are the more general virtual versions.
202 void ShenandoahBarrierSet::write_ref_field_pre_work(oop* field, oop new_val) {
203 inline_write_ref_field_pre(field, new_val);
204 }
205
206 void ShenandoahBarrierSet::write_ref_field_pre_work(narrowOop* field, oop new_val) {
207 inline_write_ref_field_pre(field, new_val);
208 }
209
210 void ShenandoahBarrierSet::write_ref_field_pre_work(void* field, oop new_val) {
211 guarantee(false, "Not needed");
212 }
213
214 void ShenandoahBarrierSet::write_ref_field_work(void* v, oop o, bool release) {
215 shenandoah_assert_not_in_cset_loc_except(v, _heap->cancelled_gc());
216 shenandoah_assert_not_forwarded_except (v, o, o == NULL || _heap->cancelled_gc() || !_heap->is_concurrent_mark_in_progress());
217 shenandoah_assert_not_in_cset_except (v, o, o == NULL || _heap->cancelled_gc() || !_heap->is_concurrent_mark_in_progress());
218 }
219
220 void ShenandoahBarrierSet::write_region(MemRegion mr) {
221 assert(UseShenandoahGC, "should be enabled");
222 if (!ShenandoahCloneBarrier) return;
223 if (! need_update_refs_barrier()) return;
224
225 // This is called for cloning an object (see jvm.cpp) after the clone
226 // has been made. We are not interested in any 'previous value' because
227 // it would be NULL in any case. But we *are* interested in any oop*
228 // that potentially need to be updated.
229
230 oop obj = oop(mr.start());
231 assert(oopDesc::is_oop(obj), "must be an oop");
232 if (_heap->is_concurrent_traversal_in_progress()) {
233 if ((size_t) obj->size() > ShenandoahEnqueueArrayCopyThreshold) {
234 _heap->traversal_gc()->push_arraycopy(mr.start(), 0);
235 } else {
236 ShenandoahEvacOOMScope oom_evac_scope;
237 if (UseShenandoahMatrix) {
238 ShenandoahUpdateRefsForOopClosure</* matrix = */ true, /* wb = */ true> cl;
239 obj->oop_iterate(&cl);
240 } else {
241 ShenandoahUpdateRefsForOopClosure</* matrix = */ false, /* wb = */ true> cl;
242 obj->oop_iterate(&cl);
243 }
244 }
245 } else {
246 if (UseShenandoahMatrix) {
247 ShenandoahUpdateRefsForOopClosure</* matrix = */ true, /* wb = */ false> cl;
248 obj->oop_iterate(&cl);
249 } else {
250 ShenandoahUpdateRefsForOopClosure</* matrix = */ false, /* wb = */ 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 oop ShenandoahBarrierSet::write_barrier_impl(oop obj) {
280 assert(UseShenandoahGC && ShenandoahWriteBarrier, "should be enabled");
281 if (!CompressedOops::is_null(obj)) {
282 bool evac_in_progress = _heap->is_gc_in_progress_mask(ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
283 oop fwd = resolve_forwarded_not_null(obj);
284 if (evac_in_progress &&
285 _heap->in_collection_set(obj) &&
286 oopDesc::unsafe_equals(obj, fwd)) {
287 ShenandoahEvacOOMScope oom_evac_scope;
288 return _heap->evacuate_object(obj, Thread::current());
289 } else {
290 return fwd;
291 }
292 } else {
293 return obj;
294 }
295 }
296
297 oop ShenandoahBarrierSet::write_barrier(oop obj) {
298 if (ShenandoahWriteBarrier) {
299 return write_barrier_impl(obj);
300 } else {
301 return obj;
302 }
303 }
304
305 oop ShenandoahBarrierSet::storeval_barrier(oop obj) {
306 if (ShenandoahStoreValEnqueueBarrier) {
307 if (!CompressedOops::is_null(obj)) {
308 obj = write_barrier(obj);
309 enqueue(obj);
310 }
311 }
312 if (ShenandoahStoreValReadBarrier) {
313 obj = resolve_forwarded(obj);
314 }
315 return obj;
316 }
317
318 void ShenandoahBarrierSet::keep_alive_barrier(oop obj) {
319 if (ShenandoahKeepAliveBarrier && _heap->is_concurrent_mark_in_progress()) {
320 enqueue(obj);
321 }
322 }
323
324 void ShenandoahBarrierSet::enqueue(oop obj) {
325 shenandoah_assert_not_forwarded_if(NULL, obj, ShenandoahHeap::heap()->is_concurrent_traversal_in_progress());
326 // Nulls should have been already filtered.
327 assert(oopDesc::is_oop(obj, true), "Error");
328
329 if (!_satb_mark_queue_set.is_active()) return;
330
331 // Filter marked objects before hitting the SATB queues. The same predicate would
332 // be used by SATBMQ::filter to eliminate already marked objects downstream, but
333 // filtering here helps to avoid wasteful SATB queueing work to begin with.
334 if (!_heap->requires_marking(obj)) return;
335
336 Thread* thr = Thread::current();
337 if (thr->is_Java_thread()) {
338 ShenandoahThreadLocalData::satb_mark_queue(thr).enqueue(obj);
339 } else {
340 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
341 _satb_mark_queue_set.shared_satb_queue()->enqueue(obj);
342 }
343 }
344
345 void ShenandoahBarrierSet::on_thread_create(Thread* thread) {
346 // Create thread local data
347 ShenandoahThreadLocalData::create(thread);
348 }
349
350 void ShenandoahBarrierSet::on_thread_destroy(Thread* thread) {
351 // Destroy thread local data
352 ShenandoahThreadLocalData::destroy(thread);
353 }
354
355
356 void ShenandoahBarrierSet::on_thread_attach(JavaThread* thread) {
357 assert(!SafepointSynchronize::is_at_safepoint(), "We should not be at a safepoint");
358 assert(!ShenandoahThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active");
359 assert(ShenandoahThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty");
360 if (ShenandoahBarrierSet::satb_mark_queue_set().is_active()) {
361 ShenandoahThreadLocalData::satb_mark_queue(thread).set_active(true);
362 }
363 ShenandoahThreadLocalData::set_gc_state(thread, ShenandoahHeap::heap()->gc_state());
364 ShenandoahThreadLocalData::initialize_gclab(thread);
365 }
366
367 void ShenandoahBarrierSet::on_thread_detach(JavaThread* thread) {
368 ShenandoahThreadLocalData::satb_mark_queue(thread).flush();
369 PLAB* gclab = ShenandoahThreadLocalData::gclab(thread);
370 if (gclab != NULL) {
371 gclab->flush_and_retire_stats(_heap->mutator_gclab_stats());
372 }
373 }