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