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/shenandoahObjectUtils.inline.hpp"
46 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
47 #include "oops/compressedOops.inline.hpp"
48 #include "oops/oop.inline.hpp"
49 #include "runtime/atomic.hpp"
50 #include "runtime/javaThread.hpp"
51 #include "runtime/prefetch.inline.hpp"
52 #include "utilities/copy.hpp"
53 #include "utilities/globalDefinitions.hpp"
54
55 inline ShenandoahHeap* ShenandoahHeap::heap() {
56 return named_heap<ShenandoahHeap>(CollectedHeap::Shenandoah);
57 }
58
59 inline ShenandoahHeapRegion* ShenandoahRegionIterator::next() {
60 size_t new_index = Atomic::add(&_index, (size_t) 1, memory_order_relaxed);
61 // get_region() provides the bounds-check and returns null on OOB.
62 return _heap->get_region(new_index - 1);
63 }
64
65 inline bool ShenandoahHeap::has_forwarded_objects() const {
66 return _gc_state.is_set(HAS_FORWARDED);
67 }
68
69 inline WorkerThreads* ShenandoahHeap::workers() const {
70 return _workers;
71 }
72
73 inline WorkerThreads* ShenandoahHeap::safepoint_workers() {
74 return _safepoint_workers;
75 }
76
77 inline size_t ShenandoahHeap::heap_region_index_containing(const void* addr) const {
78 uintptr_t region_start = ((uintptr_t) addr);
79 uintptr_t index = (region_start - (uintptr_t) base()) >> ShenandoahHeapRegion::region_size_bytes_shift();
80 assert(index < num_regions(), "Region index is in bounds: " PTR_FORMAT, p2i(addr));
81 return index;
82 }
83
84 inline ShenandoahHeapRegion* const ShenandoahHeap::heap_region_containing(const void* addr) const {
85 size_t index = heap_region_index_containing(addr);
86 ShenandoahHeapRegion* const result = get_region(index);
87 assert(addr >= result->bottom() && addr < result->end(), "Heap region contains the address: " PTR_FORMAT, p2i(addr));
88 return result;
89 }
90
91 inline void ShenandoahHeap::enter_evacuation(Thread* t) {
92 _oom_evac_handler.enter_evacuation(t);
93 }
94
95 inline void ShenandoahHeap::leave_evacuation(Thread* t) {
96 _oom_evac_handler.leave_evacuation(t);
97 }
98
99 template <class T>
100 inline void ShenandoahHeap::update_with_forwarded(T* p) {
101 T o = RawAccess<>::oop_load(p);
102 if (!CompressedOops::is_null(o)) {
103 oop obj = CompressedOops::decode_not_null(o);
104 if (in_collection_set(obj)) {
105 // Corner case: when evacuation fails, there are objects in collection
106 // set that are not really forwarded. We can still go and try and update them
107 // (uselessly) to simplify the common path.
108 shenandoah_assert_forwarded_except(p, obj, cancelled_gc());
109 oop fwd = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
110 shenandoah_assert_not_in_cset_except(p, fwd, cancelled_gc());
111
112 // Unconditionally store the update: no concurrent updates expected.
113 RawAccess<IS_NOT_NULL>::oop_store(p, fwd);
114 }
115 }
116 }
117
118 template <class T>
119 inline void ShenandoahHeap::conc_update_with_forwarded(T* p) {
120 T o = RawAccess<>::oop_load(p);
121 if (!CompressedOops::is_null(o)) {
122 oop obj = CompressedOops::decode_not_null(o);
123 if (in_collection_set(obj)) {
124 // Corner case: when evacuation fails, there are objects in collection
125 // set that are not really forwarded. We can still go and try CAS-update them
126 // (uselessly) to simplify the common path.
127 shenandoah_assert_forwarded_except(p, obj, cancelled_gc());
128 oop fwd = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
129 shenandoah_assert_not_in_cset_except(p, fwd, cancelled_gc());
130
131 // Sanity check: we should not be updating the cset regions themselves,
132 // unless we are recovering from the evacuation failure.
133 shenandoah_assert_not_in_cset_loc_except(p, !is_in(p) || cancelled_gc());
134
135 // Either we succeed in updating the reference, or something else gets in our way.
136 // We don't care if that is another concurrent GC update, or another mutator update.
137 atomic_update_oop(fwd, p, obj);
138 }
139 }
140 }
141
142 // Atomic updates of heap location. This is only expected to work with updating the same
143 // logical object with its forwardee. The reason why we need stronger-than-relaxed memory
144 // ordering has to do with coordination with GC barriers and mutator accesses.
145 //
146 // In essence, stronger CAS access is required to maintain the transitive chains that mutator
147 // accesses build by themselves. To illustrate this point, consider the following example.
148 //
149 // Suppose "o" is the object that has a field "x" and the reference to "o" is stored
150 // to field at "addr", which happens to be Java volatile field. Normally, the accesses to volatile
151 // field at "addr" would be matched with release/acquire barriers. This changes when GC moves
152 // the object under mutator feet.
153 //
154 // Thread 1 (Java)
155 // // --- previous access starts here
156 // ...
157 // T1.1: store(&o.x, 1, mo_relaxed)
158 // T1.2: store(&addr, o, mo_release) // volatile store
159 //
160 // // --- new access starts here
161 // // LRB: copy and install the new copy to fwdptr
162 // T1.3: var copy = copy(o)
163 // T1.4: cas(&fwd, t, copy, mo_release) // pointer-mediated publication
164 // <access continues>
165 //
166 // Thread 2 (GC updater)
167 // T2.1: var f = load(&fwd, mo_{consume|acquire}) // pointer-mediated acquisition
168 // T2.2: cas(&addr, o, f, mo_release) // this method
169 //
170 // Thread 3 (Java)
171 // T3.1: var o = load(&addr, mo_acquire) // volatile read
172 // T3.2: if (o != null)
173 // T3.3: var r = load(&o.x, mo_relaxed)
174 //
175 // r is guaranteed to contain "1".
176 //
177 // Without GC involvement, there is synchronizes-with edge from T1.2 to T3.1,
178 // which guarantees this. With GC involvement, when LRB copies the object and
179 // another thread updates the reference to it, we need to have the transitive edge
180 // from T1.4 to T2.1 (that one is guaranteed by forwarding accesses), plus the edge
181 // from T2.2 to T3.1 (which is brought by this CAS).
182 //
183 // Note that we do not need to "acquire" in these methods, because we do not read the
184 // failure witnesses contents on any path, and "release" is enough.
185 //
186
187 inline void ShenandoahHeap::atomic_update_oop(oop update, oop* addr, oop compare) {
188 assert(is_aligned(addr, HeapWordSize), "Address should be aligned: " PTR_FORMAT, p2i(addr));
189 Atomic::cmpxchg(addr, compare, update, memory_order_release);
190 }
191
192 inline void ShenandoahHeap::atomic_update_oop(oop update, narrowOop* addr, narrowOop compare) {
193 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
194 narrowOop u = CompressedOops::encode(update);
195 Atomic::cmpxchg(addr, compare, u, memory_order_release);
196 }
197
198 inline void ShenandoahHeap::atomic_update_oop(oop update, narrowOop* addr, oop compare) {
199 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
200 narrowOop c = CompressedOops::encode(compare);
201 narrowOop u = CompressedOops::encode(update);
202 Atomic::cmpxchg(addr, c, u, memory_order_release);
203 }
204
205 inline bool ShenandoahHeap::atomic_update_oop_check(oop update, oop* addr, oop compare) {
206 assert(is_aligned(addr, HeapWordSize), "Address should be aligned: " PTR_FORMAT, p2i(addr));
207 return (oop) Atomic::cmpxchg(addr, compare, update, memory_order_release) == compare;
208 }
209
210 inline bool ShenandoahHeap::atomic_update_oop_check(oop update, narrowOop* addr, narrowOop compare) {
211 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
212 narrowOop u = CompressedOops::encode(update);
213 return (narrowOop) Atomic::cmpxchg(addr, compare, u, memory_order_release) == compare;
214 }
215
216 inline bool ShenandoahHeap::atomic_update_oop_check(oop update, narrowOop* addr, oop compare) {
217 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
218 narrowOop c = CompressedOops::encode(compare);
219 narrowOop u = CompressedOops::encode(update);
220 return CompressedOops::decode(Atomic::cmpxchg(addr, c, u, memory_order_release)) == compare;
221 }
222
223 // The memory ordering discussion above does not apply for methods that store nulls:
224 // then, there is no transitive reads in mutator (as we see nulls), and we can do
225 // relaxed memory ordering there.
226
227 inline void ShenandoahHeap::atomic_clear_oop(oop* addr, oop compare) {
228 assert(is_aligned(addr, HeapWordSize), "Address should be aligned: " PTR_FORMAT, p2i(addr));
229 Atomic::cmpxchg(addr, compare, oop(), memory_order_relaxed);
230 }
231
232 inline void ShenandoahHeap::atomic_clear_oop(narrowOop* addr, oop compare) {
233 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
234 narrowOop cmp = CompressedOops::encode(compare);
235 Atomic::cmpxchg(addr, cmp, narrowOop(), memory_order_relaxed);
236 }
237
238 inline void ShenandoahHeap::atomic_clear_oop(narrowOop* addr, narrowOop compare) {
239 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
240 Atomic::cmpxchg(addr, compare, narrowOop(), memory_order_relaxed);
241 }
242
243 inline bool ShenandoahHeap::cancelled_gc() const {
244 return _cancelled_gc.get() == CANCELLED;
245 }
246
247 inline bool ShenandoahHeap::check_cancelled_gc_and_yield(bool sts_active) {
248 if (! (sts_active && ShenandoahSuspendibleWorkers)) {
249 return cancelled_gc();
250 }
251
252 jbyte prev = _cancelled_gc.cmpxchg(NOT_CANCELLED, CANCELLABLE);
253 if (prev == CANCELLABLE || prev == NOT_CANCELLED) {
254 if (SuspendibleThreadSet::should_yield()) {
255 SuspendibleThreadSet::yield();
256 }
257
258 // Back to CANCELLABLE. The thread that poked NOT_CANCELLED first gets
259 // to restore to CANCELLABLE.
260 if (prev == CANCELLABLE) {
261 _cancelled_gc.set(CANCELLABLE);
262 }
263 return false;
264 } else {
265 return true;
266 }
267 }
268
269 inline void ShenandoahHeap::clear_cancelled_gc() {
270 _cancelled_gc.set(CANCELLABLE);
271 _oom_evac_handler.clear();
272 }
273
274 inline HeapWord* ShenandoahHeap::allocate_from_gclab(Thread* thread, size_t size) {
275 assert(UseTLAB, "TLABs should be enabled");
276
277 PLAB* gclab = ShenandoahThreadLocalData::gclab(thread);
278 if (gclab == nullptr) {
279 assert(!thread->is_Java_thread() && !thread->is_Worker_thread(),
280 "Performance: thread should have GCLAB: %s", thread->name());
281 // No GCLABs in this thread, fallback to shared allocation
282 return nullptr;
283 }
284 HeapWord* obj = gclab->allocate(size);
285 if (obj != nullptr) {
286 return obj;
287 }
288 // Otherwise...
289 return allocate_from_gclab_slow(thread, size);
290 }
291
292 inline oop ShenandoahHeap::evacuate_object(oop p, Thread* thread) {
293 if (ShenandoahThreadLocalData::is_oom_during_evac(Thread::current())) {
294 // This thread went through the OOM during evac protocol and it is safe to return
295 // the forward pointer. It must not attempt to evacuate any more.
296 return ShenandoahBarrierSet::resolve_forwarded(p);
297 }
298
299 assert(ShenandoahThreadLocalData::is_evac_allowed(thread), "must be enclosed in oom-evac scope");
300
301 size_t size = ShenandoahObjectUtils::size(p);
302
303 assert(!heap_region_containing(p)->is_humongous(), "never evacuate humongous objects");
304
305 bool alloc_from_gclab = true;
306 HeapWord* copy = nullptr;
307
308 #ifdef ASSERT
309 if (ShenandoahOOMDuringEvacALot &&
310 (os::random() & 1) == 0) { // Simulate OOM every ~2nd slow-path call
311 copy = nullptr;
312 } else {
313 #endif
314 if (UseTLAB) {
315 copy = allocate_from_gclab(thread, size);
316 }
317 if (copy == nullptr) {
318 ShenandoahAllocRequest req = ShenandoahAllocRequest::for_shared_gc(size);
319 copy = allocate_memory(req);
320 alloc_from_gclab = false;
321 }
322 #ifdef ASSERT
323 }
324 #endif
325
326 if (copy == nullptr) {
327 control_thread()->handle_alloc_failure_evac(size);
328
329 _oom_evac_handler.handle_out_of_memory_during_evacuation();
330
331 return ShenandoahBarrierSet::resolve_forwarded(p);
332 }
333
334 // Copy the object:
335 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(p), copy, size);
336
337 // Try to install the new forwarding pointer.
338 oop copy_val = cast_to_oop(copy);
339 if (!copy_val->mark().is_marked()) {
340 // If we copied a mark-word that indicates 'forwarded' state, then
341 // another thread beat us, and this new copy will never be published.
342 // ContinuationGCSupport would get a corrupt Klass* in that case,
343 // so don't even attempt it.
344 ContinuationGCSupport::relativize_stack_chunk(copy_val);
345 }
346 oop result = ShenandoahForwarding::try_update_forwardee(p, copy_val);
347 if (result == copy_val) {
348 // Successfully evacuated. Our copy is now the public one!
349 shenandoah_assert_correct(nullptr, copy_val);
350 return copy_val;
351 } else {
352 // Failed to evacuate. We need to deal with the object that is left behind. Since this
353 // new allocation is certainly after TAMS, it will be considered live in the next cycle.
354 // But if it happens to contain references to evacuated regions, those references would
355 // not get updated for this stale copy during this cycle, and we will crash while scanning
356 // it the next cycle.
357 //
358 // For GCLAB allocations, it is enough to rollback the allocation ptr. Either the next
359 // object will overwrite this stale copy, or the filler object on LAB retirement will
360 // do this. For non-GCLAB allocations, we have no way to retract the allocation, and
361 // have to explicitly overwrite the copy with the filler object. With that overwrite,
362 // we have to keep the fwdptr initialized and pointing to our (stale) copy.
363 if (alloc_from_gclab) {
364 ShenandoahThreadLocalData::gclab(thread)->undo_allocation(copy, size);
365 } else {
366 fill_with_object(copy, size);
367 shenandoah_assert_correct(nullptr, copy_val);
368 }
369 shenandoah_assert_correct(nullptr, result);
370 return result;
371 }
372 }
373
374 inline bool ShenandoahHeap::requires_marking(const void* entry) const {
375 oop obj = cast_to_oop(entry);
376 return !_marking_context->is_marked_strong(obj);
377 }
378
379 inline bool ShenandoahHeap::in_collection_set(oop p) const {
380 assert(collection_set() != nullptr, "Sanity");
381 return collection_set()->is_in(p);
382 }
383
384 inline bool ShenandoahHeap::in_collection_set_loc(void* p) const {
385 assert(collection_set() != nullptr, "Sanity");
386 return collection_set()->is_in_loc(p);
387 }
388
389 inline bool ShenandoahHeap::is_stable() const {
390 return _gc_state.is_clear();
391 }
392
393 inline bool ShenandoahHeap::is_idle() const {
394 return _gc_state.is_unset(MARKING | EVACUATION | UPDATEREFS);
395 }
396
397 inline bool ShenandoahHeap::is_concurrent_mark_in_progress() const {
398 return _gc_state.is_set(MARKING);
399 }
400
401 inline bool ShenandoahHeap::is_evacuation_in_progress() const {
402 return _gc_state.is_set(EVACUATION);
403 }
404
405 inline bool ShenandoahHeap::is_gc_in_progress_mask(uint mask) const {
406 return _gc_state.is_set(mask);
407 }
408
409 inline bool ShenandoahHeap::is_degenerated_gc_in_progress() const {
410 return _degenerated_gc_in_progress.is_set();
411 }
412
413 inline bool ShenandoahHeap::is_full_gc_in_progress() const {
414 return _full_gc_in_progress.is_set();
415 }
416
417 inline bool ShenandoahHeap::is_full_gc_move_in_progress() const {
418 return _full_gc_move_in_progress.is_set();
419 }
420
421 inline bool ShenandoahHeap::is_update_refs_in_progress() const {
422 return _gc_state.is_set(UPDATEREFS);
423 }
424
425 inline bool ShenandoahHeap::is_stw_gc_in_progress() const {
426 return is_full_gc_in_progress() || is_degenerated_gc_in_progress();
427 }
428
429 inline bool ShenandoahHeap::is_concurrent_strong_root_in_progress() const {
430 return _concurrent_strong_root_in_progress.is_set();
431 }
432
433 inline bool ShenandoahHeap::is_concurrent_weak_root_in_progress() const {
434 return _gc_state.is_set(WEAK_ROOTS);
435 }
436
437 template<class T>
438 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl) {
439 marked_object_iterate(region, cl, region->top());
440 }
441
442 template<class T>
443 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit) {
444 assert(! region->is_humongous_continuation(), "no humongous continuation regions here");
445
446 ShenandoahMarkingContext* const ctx = complete_marking_context();
447 assert(ctx->is_complete(), "sanity");
448
449 HeapWord* tams = ctx->top_at_mark_start(region);
450
451 size_t skip_bitmap_delta = 1;
452 HeapWord* start = region->bottom();
453 HeapWord* end = MIN2(tams, region->end());
454
455 // Step 1. Scan below the TAMS based on bitmap data.
456 HeapWord* limit_bitmap = MIN2(limit, tams);
457
458 // Try to scan the initial candidate. If the candidate is above the TAMS, it would
459 // fail the subsequent "< limit_bitmap" checks, and fall through to Step 2.
460 HeapWord* cb = ctx->get_next_marked_addr(start, end);
461
462 intx dist = ShenandoahMarkScanPrefetch;
463 if (dist > 0) {
464 // Batched scan that prefetches the oop data, anticipating the access to
465 // either header, oop field, or forwarding pointer. Not that we cannot
466 // touch anything in oop, while it still being prefetched to get enough
467 // time for prefetch to work. This is why we try to scan the bitmap linearly,
468 // disregarding the object size. However, since we know forwarding pointer
469 // precedes the object, we can skip over it. Once we cannot trust the bitmap,
470 // there is no point for prefetching the oop contents, as oop->size() will
471 // touch it prematurely.
472
473 // No variable-length arrays in standard C++, have enough slots to fit
474 // the prefetch distance.
475 static const int SLOT_COUNT = 256;
476 guarantee(dist <= SLOT_COUNT, "adjust slot count");
477 HeapWord* slots[SLOT_COUNT];
478
479 int avail;
480 do {
481 avail = 0;
482 for (int c = 0; (c < dist) && (cb < limit_bitmap); c++) {
483 Prefetch::read(cb, oopDesc::mark_offset_in_bytes());
484 slots[avail++] = cb;
485 cb += skip_bitmap_delta;
486 if (cb < limit_bitmap) {
487 cb = ctx->get_next_marked_addr(cb, limit_bitmap);
488 }
489 }
490
491 for (int c = 0; c < avail; c++) {
492 assert (slots[c] < tams, "only objects below TAMS here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(slots[c]), p2i(tams));
493 assert (slots[c] < limit, "only objects below limit here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(slots[c]), p2i(limit));
494 oop obj = cast_to_oop(slots[c]);
495 assert(oopDesc::is_oop(obj), "sanity");
496 assert(ctx->is_marked(obj), "object expected to be marked");
497 cl->do_object(obj);
498 }
499 } while (avail > 0);
500 } else {
501 while (cb < limit_bitmap) {
502 assert (cb < tams, "only objects below TAMS here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(cb), p2i(tams));
503 assert (cb < limit, "only objects below limit here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(cb), p2i(limit));
504 oop obj = cast_to_oop(cb);
505 assert(oopDesc::is_oop(obj), "sanity");
506 assert(ctx->is_marked(obj), "object expected to be marked");
507 cl->do_object(obj);
508 cb += skip_bitmap_delta;
509 if (cb < limit_bitmap) {
510 cb = ctx->get_next_marked_addr(cb, limit_bitmap);
511 }
512 }
513 }
514
515 // Step 2. Accurate size-based traversal, happens past the TAMS.
516 // This restarts the scan at TAMS, which makes sure we traverse all objects,
517 // regardless of what happened at Step 1.
518 HeapWord* cs = tams;
519 while (cs < limit) {
520 assert (cs >= tams, "only objects past TAMS here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(cs), p2i(tams));
521 assert (cs < limit, "only objects below limit here: " PTR_FORMAT " (" PTR_FORMAT ")", p2i(cs), p2i(limit));
522 oop obj = cast_to_oop(cs);
523 assert(oopDesc::is_oop(obj), "sanity");
524 assert(ctx->is_marked(obj), "object expected to be marked");
525 size_t size = ShenandoahObjectUtils::size(obj);
526 cl->do_object(obj);
527 cs += size;
528 }
529 }
530
531 template <class T>
532 class ShenandoahObjectToOopClosure : public ObjectClosure {
533 T* _cl;
534 public:
535 ShenandoahObjectToOopClosure(T* cl) : _cl(cl) {}
536
537 void do_object(oop obj) {
538 obj->oop_iterate(_cl);
539 }
540 };
541
542 template <class T>
543 class ShenandoahObjectToOopBoundedClosure : public ObjectClosure {
544 T* _cl;
545 MemRegion _bounds;
546 public:
547 ShenandoahObjectToOopBoundedClosure(T* cl, HeapWord* bottom, HeapWord* top) :
548 _cl(cl), _bounds(bottom, top) {}
549
550 void do_object(oop obj) {
551 obj->oop_iterate(_cl, _bounds);
552 }
553 };
554
555 template<class T>
556 inline void ShenandoahHeap::marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* top) {
557 if (region->is_humongous()) {
558 HeapWord* bottom = region->bottom();
559 if (top > bottom) {
560 region = region->humongous_start_region();
561 ShenandoahObjectToOopBoundedClosure<T> objs(cl, bottom, top);
562 marked_object_iterate(region, &objs);
563 }
564 } else {
565 ShenandoahObjectToOopClosure<T> objs(cl);
566 marked_object_iterate(region, &objs, top);
567 }
568 }
569
570 inline ShenandoahHeapRegion* const ShenandoahHeap::get_region(size_t region_idx) const {
571 if (region_idx < _num_regions) {
572 return _regions[region_idx];
573 } else {
574 return nullptr;
575 }
576 }
577
578 inline void ShenandoahHeap::mark_complete_marking_context() {
579 _marking_context->mark_complete();
580 }
581
582 inline void ShenandoahHeap::mark_incomplete_marking_context() {
583 _marking_context->mark_incomplete();
584 }
585
586 inline ShenandoahMarkingContext* ShenandoahHeap::complete_marking_context() const {
587 assert (_marking_context->is_complete()," sanity");
588 return _marking_context;
589 }
590
591 inline ShenandoahMarkingContext* ShenandoahHeap::marking_context() const {
592 return _marking_context;
593 }
594
595 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP