1 /*
2 * Copyright (c) 2015, 2020, Red Hat, Inc. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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
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23 */
24
25 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP
26 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP
27
28 #include "gc/shenandoah/shenandoahHeap.hpp"
29
30 #include "classfile/javaClasses.inline.hpp"
31 #include "gc/shared/markBitMap.inline.hpp"
32 #include "gc/shared/threadLocalAllocBuffer.inline.hpp"
33 #include "gc/shared/continuationGCSupport.inline.hpp"
34 #include "gc/shared/suspendibleThreadSet.hpp"
35 #include "gc/shared/tlab_globals.hpp"
36 #include "gc/shenandoah/shenandoahAsserts.hpp"
37 #include "gc/shenandoah/shenandoahBarrierSet.inline.hpp"
38 #include "gc/shenandoah/shenandoahCollectionSet.inline.hpp"
39 #include "gc/shenandoah/shenandoahForwarding.inline.hpp"
40 #include "gc/shenandoah/shenandoahWorkGroup.hpp"
41 #include "gc/shenandoah/shenandoahHeapRegionSet.inline.hpp"
42 #include "gc/shenandoah/shenandoahHeapRegion.inline.hpp"
43 #include "gc/shenandoah/shenandoahControlThread.hpp"
44 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
45 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
46 #include "oops/compressedOops.inline.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "runtime/atomic.hpp"
49 #include "runtime/javaThread.hpp"
50 #include "runtime/prefetch.inline.hpp"
51 #include "utilities/copy.hpp"
52 #include "utilities/globalDefinitions.hpp"
53
54 inline ShenandoahHeap* ShenandoahHeap::heap() {
55 return named_heap<ShenandoahHeap>(CollectedHeap::Shenandoah);
56 }
57
58 inline ShenandoahHeapRegion* ShenandoahRegionIterator::next() {
59 size_t new_index = Atomic::add(&_index, (size_t) 1, memory_order_relaxed);
60 // get_region() provides the bounds-check and returns null on OOB.
61 return _heap->get_region(new_index - 1);
62 }
63
64 inline bool ShenandoahHeap::has_forwarded_objects() const {
65 return _gc_state.is_set(HAS_FORWARDED);
66 }
67
68 inline WorkerThreads* ShenandoahHeap::workers() const {
69 return _workers;
70 }
71
72 inline WorkerThreads* ShenandoahHeap::safepoint_workers() {
73 return _safepoint_workers;
74 }
75
76 inline size_t ShenandoahHeap::heap_region_index_containing(const void* addr) const {
77 uintptr_t region_start = ((uintptr_t) addr);
78 uintptr_t index = (region_start - (uintptr_t) base()) >> ShenandoahHeapRegion::region_size_bytes_shift();
79 assert(index < num_regions(), "Region index is in bounds: " PTR_FORMAT, p2i(addr));
80 return index;
81 }
82
83 inline ShenandoahHeapRegion* const ShenandoahHeap::heap_region_containing(const void* addr) const {
84 size_t index = heap_region_index_containing(addr);
85 ShenandoahHeapRegion* const result = get_region(index);
86 assert(addr >= result->bottom() && addr < result->end(), "Heap region contains the address: " PTR_FORMAT, p2i(addr));
87 return result;
88 }
89
90 inline void ShenandoahHeap::enter_evacuation(Thread* t) {
91 _oom_evac_handler.enter_evacuation(t);
92 }
93
94 inline void ShenandoahHeap::leave_evacuation(Thread* t) {
95 _oom_evac_handler.leave_evacuation(t);
96 }
97
98 template <class T>
99 inline void ShenandoahHeap::update_with_forwarded(T* p) {
100 T o = RawAccess<>::oop_load(p);
101 if (!CompressedOops::is_null(o)) {
102 oop obj = CompressedOops::decode_not_null(o);
103 if (in_collection_set(obj)) {
104 // Corner case: when evacuation fails, there are objects in collection
105 // set that are not really forwarded. We can still go and try and update them
106 // (uselessly) to simplify the common path.
107 shenandoah_assert_forwarded_except(p, obj, cancelled_gc());
108 oop fwd = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
109 shenandoah_assert_not_in_cset_except(p, fwd, cancelled_gc());
110
111 // Unconditionally store the update: no concurrent updates expected.
112 RawAccess<IS_NOT_NULL>::oop_store(p, fwd);
113 }
114 }
115 }
116
117 template <class T>
118 inline void ShenandoahHeap::conc_update_with_forwarded(T* p) {
119 T o = RawAccess<>::oop_load(p);
120 if (!CompressedOops::is_null(o)) {
121 oop obj = CompressedOops::decode_not_null(o);
122 if (in_collection_set(obj)) {
123 // Corner case: when evacuation fails, there are objects in collection
124 // set that are not really forwarded. We can still go and try CAS-update them
125 // (uselessly) to simplify the common path.
126 shenandoah_assert_forwarded_except(p, obj, cancelled_gc());
127 oop fwd = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
128 shenandoah_assert_not_in_cset_except(p, fwd, cancelled_gc());
129
130 // Sanity check: we should not be updating the cset regions themselves,
131 // unless we are recovering from the evacuation failure.
132 shenandoah_assert_not_in_cset_loc_except(p, !is_in(p) || cancelled_gc());
133
134 // Either we succeed in updating the reference, or something else gets in our way.
135 // We don't care if that is another concurrent GC update, or another mutator update.
136 atomic_update_oop(fwd, p, obj);
137 }
138 }
139 }
140
141 // Atomic updates of heap location. This is only expected to work with updating the same
142 // logical object with its forwardee. The reason why we need stronger-than-relaxed memory
143 // ordering has to do with coordination with GC barriers and mutator accesses.
144 //
145 // In essence, stronger CAS access is required to maintain the transitive chains that mutator
146 // accesses build by themselves. To illustrate this point, consider the following example.
147 //
148 // Suppose "o" is the object that has a field "x" and the reference to "o" is stored
149 // to field at "addr", which happens to be Java volatile field. Normally, the accesses to volatile
150 // field at "addr" would be matched with release/acquire barriers. This changes when GC moves
151 // the object under mutator feet.
152 //
153 // Thread 1 (Java)
154 // // --- previous access starts here
155 // ...
156 // T1.1: store(&o.x, 1, mo_relaxed)
157 // T1.2: store(&addr, o, mo_release) // volatile store
158 //
159 // // --- new access starts here
160 // // LRB: copy and install the new copy to fwdptr
161 // T1.3: var copy = copy(o)
162 // T1.4: cas(&fwd, t, copy, mo_release) // pointer-mediated publication
163 // <access continues>
164 //
165 // Thread 2 (GC updater)
166 // T2.1: var f = load(&fwd, mo_{consume|acquire}) // pointer-mediated acquisition
167 // T2.2: cas(&addr, o, f, mo_release) // this method
168 //
169 // Thread 3 (Java)
170 // T3.1: var o = load(&addr, mo_acquire) // volatile read
171 // T3.2: if (o != null)
172 // T3.3: var r = load(&o.x, mo_relaxed)
173 //
174 // r is guaranteed to contain "1".
175 //
176 // Without GC involvement, there is synchronizes-with edge from T1.2 to T3.1,
177 // which guarantees this. With GC involvement, when LRB copies the object and
178 // another thread updates the reference to it, we need to have the transitive edge
179 // from T1.4 to T2.1 (that one is guaranteed by forwarding accesses), plus the edge
180 // from T2.2 to T3.1 (which is brought by this CAS).
181 //
182 // Note that we do not need to "acquire" in these methods, because we do not read the
183 // failure witnesses contents on any path, and "release" is enough.
184 //
185
186 inline void ShenandoahHeap::atomic_update_oop(oop update, oop* addr, oop compare) {
187 assert(is_aligned(addr, HeapWordSize), "Address should be aligned: " PTR_FORMAT, p2i(addr));
188 Atomic::cmpxchg(addr, compare, update, memory_order_release);
189 }
190
191 inline void ShenandoahHeap::atomic_update_oop(oop update, narrowOop* addr, narrowOop compare) {
192 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
193 narrowOop u = CompressedOops::encode(update);
194 Atomic::cmpxchg(addr, compare, u, memory_order_release);
195 }
196
197 inline void ShenandoahHeap::atomic_update_oop(oop update, narrowOop* addr, oop compare) {
198 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
199 narrowOop c = CompressedOops::encode(compare);
200 narrowOop u = CompressedOops::encode(update);
201 Atomic::cmpxchg(addr, c, u, memory_order_release);
202 }
203
204 inline bool ShenandoahHeap::atomic_update_oop_check(oop update, oop* addr, oop compare) {
205 assert(is_aligned(addr, HeapWordSize), "Address should be aligned: " PTR_FORMAT, p2i(addr));
206 return (oop) Atomic::cmpxchg(addr, compare, update, memory_order_release) == compare;
207 }
208
209 inline bool ShenandoahHeap::atomic_update_oop_check(oop update, narrowOop* addr, narrowOop compare) {
210 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
211 narrowOop u = CompressedOops::encode(update);
212 return (narrowOop) Atomic::cmpxchg(addr, compare, u, memory_order_release) == compare;
213 }
214
215 inline bool ShenandoahHeap::atomic_update_oop_check(oop update, narrowOop* addr, oop compare) {
216 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
217 narrowOop c = CompressedOops::encode(compare);
218 narrowOop u = CompressedOops::encode(update);
219 return CompressedOops::decode(Atomic::cmpxchg(addr, c, u, memory_order_release)) == compare;
220 }
221
222 // The memory ordering discussion above does not apply for methods that store nulls:
223 // then, there is no transitive reads in mutator (as we see nulls), and we can do
224 // relaxed memory ordering there.
225
226 inline void ShenandoahHeap::atomic_clear_oop(oop* addr, oop compare) {
227 assert(is_aligned(addr, HeapWordSize), "Address should be aligned: " PTR_FORMAT, p2i(addr));
228 Atomic::cmpxchg(addr, compare, oop(), memory_order_relaxed);
229 }
230
231 inline void ShenandoahHeap::atomic_clear_oop(narrowOop* addr, oop compare) {
232 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
233 narrowOop cmp = CompressedOops::encode(compare);
234 Atomic::cmpxchg(addr, cmp, narrowOop(), memory_order_relaxed);
235 }
236
237 inline void ShenandoahHeap::atomic_clear_oop(narrowOop* addr, narrowOop compare) {
238 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
239 Atomic::cmpxchg(addr, compare, narrowOop(), memory_order_relaxed);
240 }
241
242 inline bool ShenandoahHeap::cancelled_gc() const {
243 return _cancelled_gc.get() == CANCELLED;
244 }
245
246 inline bool ShenandoahHeap::check_cancelled_gc_and_yield(bool sts_active) {
247 if (! (sts_active && ShenandoahSuspendibleWorkers)) {
248 return cancelled_gc();
249 }
250
251 jbyte prev = _cancelled_gc.cmpxchg(NOT_CANCELLED, CANCELLABLE);
252 if (prev == CANCELLABLE || prev == NOT_CANCELLED) {
253 if (SuspendibleThreadSet::should_yield()) {
254 SuspendibleThreadSet::yield();
255 }
256
257 // Back to CANCELLABLE. The thread that poked NOT_CANCELLED first gets
258 // to restore to CANCELLABLE.
259 if (prev == CANCELLABLE) {
260 _cancelled_gc.set(CANCELLABLE);
261 }
262 return false;
263 } else {
264 return true;
265 }
266 }
267
268 inline void ShenandoahHeap::clear_cancelled_gc() {
269 _cancelled_gc.set(CANCELLABLE);
270 _oom_evac_handler.clear();
271 }
272
273 inline HeapWord* ShenandoahHeap::allocate_from_gclab(Thread* thread, size_t size) {
274 assert(UseTLAB, "TLABs should be enabled");
275
276 PLAB* gclab = ShenandoahThreadLocalData::gclab(thread);
277 if (gclab == nullptr) {
278 assert(!thread->is_Java_thread() && !thread->is_Worker_thread(),
279 "Performance: thread should have GCLAB: %s", thread->name());
280 // No GCLABs in this thread, fallback to shared allocation
281 return nullptr;
282 }
283 HeapWord* obj = gclab->allocate(size);
284 if (obj != nullptr) {
285 return obj;
286 }
287 // Otherwise...
288 return allocate_from_gclab_slow(thread, size);
289 }
290
291 inline oop ShenandoahHeap::evacuate_object(oop p, Thread* thread) {
292 if (ShenandoahThreadLocalData::is_oom_during_evac(Thread::current())) {
293 // This thread went through the OOM during evac protocol and it is safe to return
294 // the forward pointer. It must not attempt to evacuate any more.
295 return ShenandoahBarrierSet::resolve_forwarded(p);
296 }
297
298 assert(ShenandoahThreadLocalData::is_evac_allowed(thread), "must be enclosed in oom-evac scope");
299
300 size_t size = p->size();
301
302 assert(!heap_region_containing(p)->is_humongous(), "never evacuate humongous objects");
303
304 bool alloc_from_gclab = true;
305 HeapWord* copy = nullptr;
306
307 #ifdef ASSERT
308 if (ShenandoahOOMDuringEvacALot &&
309 (os::random() & 1) == 0) { // Simulate OOM every ~2nd slow-path call
310 copy = nullptr;
311 } else {
312 #endif
313 if (UseTLAB) {
314 copy = allocate_from_gclab(thread, size);
315 }
316 if (copy == nullptr) {
317 ShenandoahAllocRequest req = ShenandoahAllocRequest::for_shared_gc(size);
318 copy = allocate_memory(req);
319 alloc_from_gclab = false;
320 }
321 #ifdef ASSERT
322 }
323 #endif
324
325 if (copy == nullptr) {
326 control_thread()->handle_alloc_failure_evac(size);
327
328 _oom_evac_handler.handle_out_of_memory_during_evacuation();
329
330 return ShenandoahBarrierSet::resolve_forwarded(p);
331 }
332
333 // Copy the object:
334 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(p), copy, size);
335
336 // Try to install the new forwarding pointer.
337 oop copy_val = cast_to_oop(copy);
338 ContinuationGCSupport::relativize_stack_chunk(copy_val);
339
340 oop result = ShenandoahForwarding::try_update_forwardee(p, copy_val);
341 if (result == copy_val) {
342 // Successfully evacuated. Our copy is now the public one!
343 shenandoah_assert_correct(nullptr, copy_val);
344 return copy_val;
345 } else {
346 // Failed to evacuate. We need to deal with the object that is left behind. Since this
347 // new allocation is certainly after TAMS, it will be considered live in the next cycle.
348 // But if it happens to contain references to evacuated regions, those references would
349 // not get updated for this stale copy during this cycle, and we will crash while scanning
350 // it the next cycle.
351 //
352 // For GCLAB allocations, it is enough to rollback the allocation ptr. Either the next
353 // object will overwrite this stale copy, or the filler object on LAB retirement will
354 // do this. For non-GCLAB allocations, we have no way to retract the allocation, and
355 // have to explicitly overwrite the copy with the filler object. With that overwrite,
356 // we have to keep the fwdptr initialized and pointing to our (stale) copy.
357 if (alloc_from_gclab) {
358 ShenandoahThreadLocalData::gclab(thread)->undo_allocation(copy, size);
359 } else {
360 fill_with_object(copy, size);
361 shenandoah_assert_correct(nullptr, copy_val);
362 }
363 shenandoah_assert_correct(nullptr, result);
364 return result;
365 }
366 }
367
368 inline bool ShenandoahHeap::requires_marking(const void* entry) const {
369 oop obj = cast_to_oop(entry);
370 return !_marking_context->is_marked_strong(obj);
371 }
372
373 inline bool ShenandoahHeap::in_collection_set(oop p) const {
374 assert(collection_set() != nullptr, "Sanity");
375 return collection_set()->is_in(p);
376 }
377
378 inline bool ShenandoahHeap::in_collection_set_loc(void* p) const {
379 assert(collection_set() != nullptr, "Sanity");
380 return collection_set()->is_in_loc(p);
381 }
382
383 inline bool ShenandoahHeap::is_stable() const {
384 return _gc_state.is_clear();
385 }
386
387 inline bool ShenandoahHeap::is_idle() const {
388 return _gc_state.is_unset(MARKING | EVACUATION | UPDATEREFS);
389 }
390
391 inline bool ShenandoahHeap::is_concurrent_mark_in_progress() const {
392 return _gc_state.is_set(MARKING);
393 }
394
395 inline bool ShenandoahHeap::is_evacuation_in_progress() const {
396 return _gc_state.is_set(EVACUATION);
397 }
398
399 inline bool ShenandoahHeap::is_gc_in_progress_mask(uint mask) const {
400 return _gc_state.is_set(mask);
401 }
402
403 inline bool ShenandoahHeap::is_degenerated_gc_in_progress() const {
404 return _degenerated_gc_in_progress.is_set();
405 }
406
407 inline bool ShenandoahHeap::is_full_gc_in_progress() const {
408 return _full_gc_in_progress.is_set();
409 }
410
411 inline bool ShenandoahHeap::is_full_gc_move_in_progress() const {
412 return _full_gc_move_in_progress.is_set();
413 }
414
415 inline bool ShenandoahHeap::is_update_refs_in_progress() const {
416 return _gc_state.is_set(UPDATEREFS);
417 }
418
419 inline bool ShenandoahHeap::is_stw_gc_in_progress() const {
420 return is_full_gc_in_progress() || is_degenerated_gc_in_progress();
421 }
422
423 inline bool ShenandoahHeap::is_concurrent_strong_root_in_progress() const {
424 return _concurrent_strong_root_in_progress.is_set();
425 }
426
427 inline bool ShenandoahHeap::is_concurrent_weak_root_in_progress() const {
428 return _gc_state.is_set(WEAK_ROOTS);
429 }
430
431 template<class T>
432 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl) {
433 marked_object_iterate(region, cl, region->top());
434 }
435
436 template<class T>
437 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit) {
438 assert(! region->is_humongous_continuation(), "no humongous continuation regions here");
439
440 ShenandoahMarkingContext* const ctx = complete_marking_context();
441 assert(ctx->is_complete(), "sanity");
442
443 HeapWord* tams = ctx->top_at_mark_start(region);
444
445 size_t skip_bitmap_delta = 1;
446 HeapWord* start = region->bottom();
447 HeapWord* end = MIN2(tams, region->end());
448
449 // Step 1. Scan below the TAMS based on bitmap data.
450 HeapWord* limit_bitmap = MIN2(limit, tams);
451
452 // Try to scan the initial candidate. If the candidate is above the TAMS, it would
453 // fail the subsequent "< limit_bitmap" checks, and fall through to Step 2.
454 HeapWord* cb = ctx->get_next_marked_addr(start, end);
455
456 intx dist = ShenandoahMarkScanPrefetch;
457 if (dist > 0) {
458 // Batched scan that prefetches the oop data, anticipating the access to
459 // either header, oop field, or forwarding pointer. Not that we cannot
460 // touch anything in oop, while it still being prefetched to get enough
461 // time for prefetch to work. This is why we try to scan the bitmap linearly,
462 // disregarding the object size. However, since we know forwarding pointer
463 // precedes the object, we can skip over it. Once we cannot trust the bitmap,
464 // there is no point for prefetching the oop contents, as oop->size() will
465 // touch it prematurely.
466
467 // No variable-length arrays in standard C++, have enough slots to fit
468 // the prefetch distance.
469 static const int SLOT_COUNT = 256;
470 guarantee(dist <= SLOT_COUNT, "adjust slot count");
471 HeapWord* slots[SLOT_COUNT];
472
473 int avail;
474 do {
475 avail = 0;
476 for (int c = 0; (c < dist) && (cb < limit_bitmap); c++) {
477 Prefetch::read(cb, oopDesc::mark_offset_in_bytes());
478 slots[avail++] = cb;
479 cb += skip_bitmap_delta;
480 if (cb < limit_bitmap) {
481 cb = ctx->get_next_marked_addr(cb, limit_bitmap);
482 }
483 }
484
485 for (int c = 0; c < avail; c++) {
486 assert (slots[c] < tams, "only objects below TAMS here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(slots[c]), p2i(tams));
487 assert (slots[c] < limit, "only objects below limit here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(slots[c]), p2i(limit));
488 oop obj = cast_to_oop(slots[c]);
489 assert(oopDesc::is_oop(obj), "sanity");
490 assert(ctx->is_marked(obj), "object expected to be marked");
491 cl->do_object(obj);
492 }
493 } while (avail > 0);
494 } else {
495 while (cb < limit_bitmap) {
496 assert (cb < tams, "only objects below TAMS here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(cb), p2i(tams));
497 assert (cb < limit, "only objects below limit here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(cb), p2i(limit));
498 oop obj = cast_to_oop(cb);
499 assert(oopDesc::is_oop(obj), "sanity");
500 assert(ctx->is_marked(obj), "object expected to be marked");
501 cl->do_object(obj);
502 cb += skip_bitmap_delta;
503 if (cb < limit_bitmap) {
504 cb = ctx->get_next_marked_addr(cb, limit_bitmap);
505 }
506 }
507 }
508
509 // Step 2. Accurate size-based traversal, happens past the TAMS.
510 // This restarts the scan at TAMS, which makes sure we traverse all objects,
511 // regardless of what happened at Step 1.
512 HeapWord* cs = tams;
513 while (cs < limit) {
514 assert (cs >= tams, "only objects past TAMS here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(cs), p2i(tams));
515 assert (cs < limit, "only objects below limit here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(cs), p2i(limit));
516 oop obj = cast_to_oop(cs);
517 assert(oopDesc::is_oop(obj), "sanity");
518 assert(ctx->is_marked(obj), "object expected to be marked");
519 size_t size = obj->size();
520 cl->do_object(obj);
521 cs += size;
522 }
523 }
524
525 template <class T>
526 class ShenandoahObjectToOopClosure : public ObjectClosure {
527 T* _cl;
528 public:
529 ShenandoahObjectToOopClosure(T* cl) : _cl(cl) {}
530
531 void do_object(oop obj) {
532 obj->oop_iterate(_cl);
533 }
534 };
535
536 template <class T>
537 class ShenandoahObjectToOopBoundedClosure : public ObjectClosure {
538 T* _cl;
539 MemRegion _bounds;
540 public:
541 ShenandoahObjectToOopBoundedClosure(T* cl, HeapWord* bottom, HeapWord* top) :
542 _cl(cl), _bounds(bottom, top) {}
543
544 void do_object(oop obj) {
545 obj->oop_iterate(_cl, _bounds);
546 }
547 };
548
549 template<class T>
550 inline void ShenandoahHeap::marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* top) {
551 if (region->is_humongous()) {
552 HeapWord* bottom = region->bottom();
553 if (top > bottom) {
554 region = region->humongous_start_region();
555 ShenandoahObjectToOopBoundedClosure<T> objs(cl, bottom, top);
556 marked_object_iterate(region, &objs);
557 }
558 } else {
559 ShenandoahObjectToOopClosure<T> objs(cl);
560 marked_object_iterate(region, &objs, top);
561 }
562 }
563
564 inline ShenandoahHeapRegion* const ShenandoahHeap::get_region(size_t region_idx) const {
565 if (region_idx < _num_regions) {
566 return _regions[region_idx];
567 } else {
568 return nullptr;
569 }
570 }
571
572 inline void ShenandoahHeap::mark_complete_marking_context() {
573 _marking_context->mark_complete();
574 }
575
576 inline void ShenandoahHeap::mark_incomplete_marking_context() {
577 _marking_context->mark_incomplete();
578 }
579
580 inline ShenandoahMarkingContext* ShenandoahHeap::complete_marking_context() const {
581 assert (_marking_context->is_complete()," sanity");
582 return _marking_context;
583 }
584
585 inline ShenandoahMarkingContext* ShenandoahHeap::marking_context() const {
586 return _marking_context;
587 }
588
589 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP