1 /*
2 * Copyright (c) 2015, 2017, 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 #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP
25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP
26
27 #include "classfile/javaClasses.inline.hpp"
28 #include "gc/g1/suspendibleThreadSet.hpp"
29 #include "gc/shared/markBitMap.inline.hpp"
30 #include "gc/shared/threadLocalAllocBuffer.inline.hpp"
31 #include "gc/shenandoah/brooksPointer.inline.hpp"
32 #include "gc/shenandoah/shenandoahBarrierSet.inline.hpp"
33 #include "gc/shenandoah/shenandoahCollectionSet.hpp"
34 #include "gc/shenandoah/shenandoahCollectionSet.inline.hpp"
35 #include "gc/shenandoah/shenandoahConnectionMatrix.inline.hpp"
36 #include "gc/shenandoah/shenandoahHeap.hpp"
37 #include "gc/shenandoah/shenandoahHeapRegionSet.hpp"
38 #include "gc/shenandoah/shenandoahHeapRegion.inline.hpp"
39 #include "gc/shenandoah/shenandoahStringDedup.hpp"
40 #include "gc/shenandoah/shenandoahUtils.hpp"
41 #include "oops/oop.inline.hpp"
42 #include "runtime/atomic.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/prefetch.hpp"
45 #include "runtime/prefetch.inline.hpp"
46 #include "runtime/thread.hpp"
47 #include "utilities/copy.hpp"
48
49 template <class T>
50 void ShenandoahUpdateRefsClosure::do_oop_work(T* p) {
51 T o = oopDesc::load_heap_oop(p);
52 if (! oopDesc::is_null(o)) {
53 oop obj = oopDesc::decode_heap_oop_not_null(o);
54 _heap->update_oop_ref_not_null(p, obj);
55 }
56 }
57
58 void ShenandoahUpdateRefsClosure::do_oop(oop* p) { do_oop_work(p); }
59 void ShenandoahUpdateRefsClosure::do_oop(narrowOop* p) { do_oop_work(p); }
60
61 /*
62 * Marks the object. Returns true if the object has not been marked before and has
63 * been marked by this thread. Returns false if the object has already been marked,
64 * or if a competing thread succeeded in marking this object.
65 */
66 inline bool ShenandoahHeap::mark(oop obj) {
67 #ifdef ASSERT
68 if (! oopDesc::unsafe_equals(obj, oopDesc::bs()->read_barrier(obj))) {
69 tty->print_cr("heap region containing obj:");
70 ShenandoahHeapRegion* obj_region = heap_region_containing(obj);
71 obj_region->print();
72 tty->print_cr("heap region containing forwardee:");
73 ShenandoahHeapRegion* forward_region = heap_region_containing(oopDesc::bs()->read_barrier(obj));
74 forward_region->print();
75 }
76 #endif
77
78 assert(oopDesc::unsafe_equals(obj, oopDesc::bs()->read_barrier(obj)), "only mark forwarded copy of objects");
79 return mark_no_checks(obj);
80 }
81
82 inline bool ShenandoahHeap::mark_no_checks(oop obj) {
83 HeapWord* addr = (HeapWord*) obj;
84 return !allocated_after_mark_start(addr) && _mark_bit_map.parMark(addr);
85 }
86
87 inline bool ShenandoahHeap::is_marked(oop obj) const {
88 HeapWord* addr = (HeapWord*) obj;
89 return allocated_after_mark_start(addr) || _mark_bit_map.isMarked(addr);
90 }
91
92 inline bool ShenandoahHeap::need_update_refs() const {
93 return _need_update_refs;
94 }
95
96 inline size_t ShenandoahHeap::heap_region_index_containing(const void* addr) const {
97 uintptr_t region_start = ((uintptr_t) addr);
98 uintptr_t index = (region_start - (uintptr_t) base()) >> ShenandoahHeapRegion::region_size_bytes_shift();
99 #ifdef ASSERT
100 if (index >= num_regions()) {
101 tty->print_cr("heap region does not contain address, heap base: "PTR_FORMAT \
102 ", real bottom of first region: "PTR_FORMAT", num_regions: "SIZE_FORMAT", region_size: "SIZE_FORMAT,
103 p2i(base()),
104 p2i(_ordered_regions->get(0)->bottom()),
105 num_regions(),
106 ShenandoahHeapRegion::region_size_bytes());
107 }
108 #endif
109 assert(index < num_regions(), "heap region index must be in range");
110 return index;
111 }
112
113 inline ShenandoahHeapRegion* ShenandoahHeap::heap_region_containing(const void* addr) const {
114 size_t index = heap_region_index_containing(addr);
115 ShenandoahHeapRegion* result = _ordered_regions->get(index);
116 #ifdef ASSERT
117 if (!(addr >= result->bottom() && addr < result->end())) {
118 tty->print_cr("heap region does not contain address, heap base: "PTR_FORMAT \
119 ", real bottom of first region: "PTR_FORMAT", num_regions: "SIZE_FORMAT,
120 p2i(base()),
121 p2i(_ordered_regions->get(0)->bottom()),
122 num_regions());
123 }
124 #endif
125 assert(addr >= result->bottom() && addr < result->end(), "address must be in found region");
126 return result;
127 }
128
129 template <class T>
130 inline oop ShenandoahHeap::update_oop_ref_not_null(T* p, oop obj) {
131 if (in_collection_set(obj)) {
132 oop forw = ShenandoahBarrierSet::resolve_oop_static_not_null(obj);
133 assert(! oopDesc::unsafe_equals(forw, obj) || is_full_gc_in_progress() || cancelled_concgc(), "expect forwarded object");
134 obj = forw;
135 oopDesc::encode_store_heap_oop(p, obj);
136 }
137 #ifdef ASSERT
138 else {
139 assert(oopDesc::unsafe_equals(obj, ShenandoahBarrierSet::resolve_oop_static_not_null(obj)), "expect not forwarded");
140 }
141 #endif
142 return obj;
143 }
144
145 template <class T>
146 inline oop ShenandoahHeap::maybe_update_oop_ref(T* p) {
147 T o = oopDesc::load_heap_oop(p);
148 if (! oopDesc::is_null(o)) {
149 oop obj = oopDesc::decode_heap_oop_not_null(o);
150 return maybe_update_oop_ref_not_null(p, obj);
151 } else {
152 return NULL;
153 }
154 }
155
156 template <class T>
157 inline oop ShenandoahHeap::evac_update_oop_ref(T* p, bool& evac) {
158 evac = false;
159 T o = oopDesc::load_heap_oop(p);
160 if (! oopDesc::is_null(o)) {
161 oop heap_oop = oopDesc::decode_heap_oop_not_null(o);
162 if (in_collection_set(heap_oop)) {
163 oop forwarded_oop = ShenandoahBarrierSet::resolve_oop_static_not_null(heap_oop); // read brooks ptr
164 if (oopDesc::unsafe_equals(forwarded_oop, heap_oop)) {
165 forwarded_oop = evacuate_object(heap_oop, Thread::current(), evac);
166 }
167 oop prev = atomic_compare_exchange_oop(forwarded_oop, p, heap_oop);
168 if (prev == heap_oop) {
169 return forwarded_oop;
170 } else {
171 return NULL;
172 }
173 }
174 return heap_oop;
175 } else {
176 return NULL;
177 }
178 }
179
180 inline oop ShenandoahHeap::atomic_compare_exchange_oop(oop n, oop* addr, oop c) {
181 return (oop) Atomic::cmpxchg_ptr(n, addr, c);
182 }
183
184 inline oop ShenandoahHeap::atomic_compare_exchange_oop(oop n, narrowOop* addr, oop c) {
185 narrowOop cmp = oopDesc::encode_heap_oop(c);
186 narrowOop val = oopDesc::encode_heap_oop(n);
187 return oopDesc::decode_heap_oop((narrowOop) Atomic::cmpxchg(val, addr, cmp));
188 }
189
190 template <class T>
191 inline oop ShenandoahHeap::maybe_update_oop_ref_not_null(T* p, oop heap_oop) {
192
193 assert((! is_in(p)) || (! in_collection_set(p))
194 || is_full_gc_in_progress(),
195 "never update refs in from-space, unless evacuation has been cancelled");
196
197 #ifdef ASSERT
198 if (! is_in(heap_oop)) {
199 print_heap_regions_on(tty);
200 tty->print_cr("object not in heap: "PTR_FORMAT", referenced by: "PTR_FORMAT, p2i((HeapWord*) heap_oop), p2i(p));
201 assert(is_in(heap_oop), "object must be in heap");
202 }
203 #endif
204 assert(is_in(heap_oop), "only ever call this on objects in the heap");
205 if (in_collection_set(heap_oop)) {
206 oop forwarded_oop = ShenandoahBarrierSet::resolve_oop_static_not_null(heap_oop); // read brooks ptr
207 if (oopDesc::unsafe_equals(forwarded_oop, heap_oop)) {
208 // E.g. during evacuation.
209 return forwarded_oop;
210 }
211
212 assert(! oopDesc::unsafe_equals(forwarded_oop, heap_oop) || is_full_gc_in_progress(), "expect forwarded object");
213
214 log_develop_trace(gc)("Updating old ref: "PTR_FORMAT" pointing to "PTR_FORMAT" to new ref: "PTR_FORMAT,
215 p2i(p), p2i(heap_oop), p2i(forwarded_oop));
216
217 assert(oopDesc::is_oop(forwarded_oop), "oop required");
218 assert(is_in(forwarded_oop), "forwardee must be in heap");
219 assert(oopDesc::bs()->is_safe(forwarded_oop), "forwardee must not be in collection set");
220 // If this fails, another thread wrote to p before us, it will be logged in SATB and the
221 // reference be updated later.
222 oop result = atomic_compare_exchange_oop(forwarded_oop, p, heap_oop);
223
224 if (oopDesc::unsafe_equals(result, heap_oop)) { // CAS successful.
225 return forwarded_oop;
226 } else {
227 // Note: we used to assert the following here. This doesn't work because sometimes, during
228 // marking/updating-refs, it can happen that a Java thread beats us with an arraycopy,
229 // which first copies the array, which potentially contains from-space refs, and only afterwards
230 // updates all from-space refs to to-space refs, which leaves a short window where the new array
231 // elements can be from-space.
232 // assert(oopDesc::is_null(result) ||
233 // oopDesc::unsafe_equals(result, ShenandoahBarrierSet::resolve_oop_static_not_null(result)),
234 // "expect not forwarded");
235 return NULL;
236 }
237 } else {
238 assert(oopDesc::unsafe_equals(heap_oop, ShenandoahBarrierSet::resolve_oop_static_not_null(heap_oop)),
239 "expect not forwarded");
240 return heap_oop;
241 }
242 }
243
244 inline bool ShenandoahHeap::cancelled_concgc() const {
245 return OrderAccess::load_acquire((jbyte*) &_cancelled_concgc) == CANCELLED;
246 }
247
248 inline bool ShenandoahHeap::check_cancelled_concgc_and_yield(bool sts_active) {
249 if (! (sts_active && ShenandoahSuspendibleWorkers)) {
250 return cancelled_concgc();
251 }
252 jbyte prev = Atomic::cmpxchg((jbyte)NOT_CANCELLED, &_cancelled_concgc, (jbyte)CANCELLABLE);
253 if (prev == CANCELLABLE || prev == NOT_CANCELLED) {
254
255 if (SuspendibleThreadSet::should_yield()) {
256 SuspendibleThreadSet::yield();
257 }
258
259 // Back to CANCELLABLE. The thread that poked NOT_CANCELLED first gets
260 // to restore to CANCELLABLE.
261 if (prev == CANCELLABLE) {
262 OrderAccess::release_store_fence(&_cancelled_concgc, CANCELLABLE);
263 }
264 return false;
265 } else {
266 return true;
267 }
268 }
269
270 inline bool ShenandoahHeap::try_cancel_concgc() {
271 while (true) {
272 jbyte prev = Atomic::cmpxchg((jbyte)CANCELLED, &_cancelled_concgc, (jbyte)CANCELLABLE);
273 if (prev == CANCELLABLE) return true;
274 else if (prev == CANCELLED) return false;
275 assert(ShenandoahSuspendibleWorkers, "should not get here when not using suspendible workers");
276 assert(prev == NOT_CANCELLED, "must be NOT_CANCELLED");
277 {
278 // We need to provide a safepoint here, otherwise we might
279 // spin forever if a SP is pending.
280 ThreadBlockInVM sp(JavaThread::current());
281 SpinPause();
282 }
283 }
284 }
285
286 inline void ShenandoahHeap::clear_cancelled_concgc() {
287 OrderAccess::release_store_fence(&_cancelled_concgc, CANCELLABLE);
288 }
289
290 inline HeapWord* ShenandoahHeap::allocate_from_gclab(Thread* thread, size_t size) {
291 if (UseTLAB) {
292 if (!thread->gclab().is_initialized()) {
293 assert(!thread->is_Java_thread() && !thread->is_Worker_thread(),
294 "Performance: thread should have GCLAB: %s", thread->name());
295 // No GCLABs in this thread, fallback to shared allocation
296 return NULL;
297 }
298 HeapWord* obj = thread->gclab().allocate(size);
299 if (obj != NULL) {
300 return obj;
301 }
302 // Otherwise...
303 return allocate_from_gclab_slow(thread, size);
304 } else {
305 return NULL;
306 }
307 }
308
309 inline oop ShenandoahHeap::evacuate_object(oop p, Thread* thread, bool& evacuated) {
310 evacuated = false;
311
312 size_t size_no_fwdptr = (size_t) p->size();
313 size_t size_with_fwdptr = size_no_fwdptr + BrooksPointer::word_size();
314
315 assert(!heap_region_containing(p)->is_humongous(), "never evacuate humongous objects");
316
317 bool alloc_from_gclab = true;
318 HeapWord* filler = allocate_from_gclab(thread, size_with_fwdptr);
319 if (filler == NULL) {
320 filler = allocate_memory(size_with_fwdptr, _alloc_shared_gc);
321 alloc_from_gclab = false;
322 }
323
324 #ifdef ASSERT
325 // Checking that current Java thread does not hold Threads_lock when we get here.
326 // If that ever be the case, we'd deadlock in oom_during_evacuation.
327 if ((! Thread::current()->is_GC_task_thread()) && (! Thread::current()->is_ConcurrentGC_thread())) {
328 assert(! Threads_lock->owned_by_self()
329 || SafepointSynchronize::is_at_safepoint(), "must not hold Threads_lock here");
330 }
331 #endif
332
333 if (filler == NULL) {
334 oom_during_evacuation();
335 // If this is a Java thread, it should have waited
336 // until all GC threads are done, and then we
337 // return the forwardee.
338 oop resolved = ShenandoahBarrierSet::resolve_oop_static(p);
339 return resolved;
340 }
341
342 // Copy the object and initialize its forwarding ptr:
343 HeapWord* copy = filler + BrooksPointer::word_size();
344 oop copy_val = oop(copy);
345
346 Copy::aligned_disjoint_words((HeapWord*) p, copy, size_no_fwdptr);
347 BrooksPointer::initialize(oop(copy));
348
349 log_develop_trace(gc, compaction)("Copy object: " PTR_FORMAT " -> " PTR_FORMAT,
350 p2i(p), p2i(copy));
351
352 // String dedup support
353 bool need_str_dedup = false;
354 if (ShenandoahStringDedup::is_enabled()
355 && java_lang_String::is_instance_inlined(copy_val)) {
356 // We need to increase age before CAS to avoid race condition.
357 // Once new copy is published, other threads may set hash code,
358 // or perform locking, etc. which will race age bits manipulation.
359 copy_val->incr_age();
360
361 need_str_dedup = ShenandoahStringDedup::is_candidate(copy_val);
362 }
363
364 // Try to install the new forwarding pointer.
365 oop result = BrooksPointer::try_update_forwardee(p, copy_val);
366
367 if (oopDesc::unsafe_equals(result, p)) {
368 // Successfully evacuated. Our copy is now the public one!
369 evacuated = true;
370 log_develop_trace(gc, compaction)("Copy object: " PTR_FORMAT " -> " PTR_FORMAT " succeeded",
371 p2i(p), p2i(copy));
372
373 // Only dedup evacuated string
374 if (need_str_dedup) {
375 // Shenandoah evacuates objects inside and outside of safepoints.
376 // But string dedup protocol requires deduplication outside of safepoints,
377 // so we need to queue candidates during safepoints.
378 if (SafepointSynchronize::is_at_safepoint()) {
379 assert(thread->is_Worker_thread(), "Must be a worker thread during a safepoint");
380 // Use worker thread id instead of worker_id to avoid passing down worker_id.
381 // This may cause imbalance among the queues, but it is okay, since deduplication is
382 // single threaded.
383 ShenandoahStringDedup::enqueue_from_safepoint(copy_val, thread->as_Worker_thread()->id());
384 } else {
385 ShenandoahStringDedup::deduplicate(copy_val);
386 }
387 }
388
389 #ifdef ASSERT
390 assert(oopDesc::is_oop(copy_val), "expect oop");
391 assert(p->klass() == copy_val->klass(), "Should have the same class p: "PTR_FORMAT", copy: "PTR_FORMAT,
392 p2i(p), p2i(copy));
393 #endif
394 return copy_val;
395 } else {
396 // Failed to evacuate. We need to deal with the object that is left behind. Since this
397 // new allocation is certainly after TAMS, it will be considered live in the next cycle.
398 // But if it happens to contain references to evacuated regions, those references would
399 // not get updated for this stale copy during this cycle, and we will crash while scanning
400 // it the next cycle.
401 //
402 // For GCLAB allocations, it is enough to rollback the allocation ptr. Either the next
403 // object will overwrite this stale copy, or the filler object on LAB retirement will
404 // do this. For non-GCLAB allocations, we have no way to retract the allocation, and
405 // have to explicitly overwrite the copy with the filler object. With that overwrite,
406 // we have to keep the fwdptr initialized and pointing to our (stale) copy.
407 if (alloc_from_gclab) {
408 thread->gclab().rollback(size_with_fwdptr);
409 } else {
410 fill_with_object(copy, size_no_fwdptr);
411 }
412 log_develop_trace(gc, compaction)("Copy object: " PTR_FORMAT " -> " PTR_FORMAT " failed, use other: " PTR_FORMAT,
413 p2i(p), p2i(copy), p2i(result));
414 return result;
415 }
416 }
417
418 inline bool ShenandoahHeap::requires_marking(const void* entry) const {
419 // TODO: Make this faster! It's used in a hot path.
420 // TODO: it's not strictly matrix-related, but used only in partial (i.e. matrix) GCs.
421 if (is_concurrent_partial_in_progress()) {
422 assert(! in_collection_set((oop) entry), "must not get cset objects here");
423 // assert(free_regions()->contains(heap_region_containing(entry)), "expect to-space object");
424 return true;
425 } else if (concurrent_mark_in_progress()) {
426 return ! is_marked(oop(entry));
427 } else {
428 return false;
429 }
430 }
431
432 bool ShenandoahHeap::region_in_collection_set(size_t region_index) const {
433 assert(collection_set() != NULL, "Sanity");
434 return collection_set()->is_in(region_index);
435 }
436
437 bool ShenandoahHeap::in_collection_set(ShenandoahHeapRegion* r) const {
438 return region_in_collection_set(r->region_number());
439 }
440
441 template <class T>
442 inline bool ShenandoahHeap::in_collection_set(T p) const {
443 HeapWord* obj = (HeapWord*) p;
444 assert(collection_set() != NULL, "Sanity");
445 assert(is_in(obj), "should be in heap");
446
447 return collection_set()->is_in(obj);
448 }
449
450 inline bool ShenandoahHeap::concurrent_mark_in_progress() const {
451 return _concurrent_mark_in_progress != 0;
452 }
453
454 inline bool ShenandoahHeap::is_concurrent_partial_in_progress() const {
455 return _concurrent_partial_in_progress;
456 }
457
458 inline address ShenandoahHeap::update_refs_in_progress_addr() {
459 return (address) &(ShenandoahHeap::heap()->_update_refs_in_progress);
460 }
461
462 inline bool ShenandoahHeap::is_evacuation_in_progress() const {
463 return _evacuation_in_progress != 0;
464 }
465
466 inline address ShenandoahHeap::evacuation_in_progress_addr() {
467 return (address) &(ShenandoahHeap::heap()->_evacuation_in_progress);
468 }
469
470 inline bool ShenandoahHeap::allocated_after_mark_start(HeapWord* addr) const {
471 uintx index = ((uintx) addr) >> ShenandoahHeapRegion::region_size_bytes_shift();
472 HeapWord* top_at_mark_start = _top_at_mark_starts[index];
473 bool alloc_after_mark_start = addr >= top_at_mark_start;
474 return alloc_after_mark_start;
475 }
476
477 template<class T>
478 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl) {
479 marked_object_iterate(region, cl, region->top());
480 }
481
482 template<class T>
483 inline void ShenandoahHeap::marked_object_safe_iterate(ShenandoahHeapRegion* region, T* cl) {
484 marked_object_iterate(region, cl, region->concurrent_iteration_safe_limit());
485 }
486
487 template<class T>
488 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit) {
489 assert(BrooksPointer::word_offset() < 0, "skip_delta calculation below assumes the forwarding ptr is before obj");
490
491 assert(! region->is_humongous_continuation(), "no humongous continuation regions here");
492 assert(is_bitmap_valid(), "only try this with complete marking bitmap");
493
494 MarkBitMap mark_bit_map = _mark_bit_map;
495 HeapWord* tams = top_at_mark_start(region->bottom());
496
497 size_t skip_bitmap_delta = BrooksPointer::word_size() + 1;
498 size_t skip_objsize_delta = BrooksPointer::word_size() /* + actual obj.size() below */;
499 HeapWord* start = region->bottom() + BrooksPointer::word_size();
500
501 HeapWord* end = MIN2(tams + BrooksPointer::word_size(), region->end());
502 HeapWord* addr = mark_bit_map.getNextMarkedWordAddress(start, end);
503
504 intx dist = ShenandoahMarkScanPrefetch;
505 if (dist > 0) {
506 // Batched scan that prefetches the oop data, anticipating the access to
507 // either header, oop field, or forwarding pointer. Not that we cannot
508 // touch anything in oop, while it still being prefetched to get enough
509 // time for prefetch to work. This is why we try to scan the bitmap linearly,
510 // disregarding the object size. However, since we know forwarding pointer
511 // preceeds the object, we can skip over it. Once we cannot trust the bitmap,
512 // there is no point for prefetching the oop contents, as oop->size() will
513 // touch it prematurely.
514
515 // No variable-length arrays in standard C++, have enough slots to fit
516 // the prefetch distance.
517 static const int SLOT_COUNT = 256;
518 guarantee(dist <= SLOT_COUNT, "adjust slot count");
519 oop slots[SLOT_COUNT];
520
521 bool aborting = false;
522 int avail;
523 do {
524 avail = 0;
525 for (int c = 0; (c < dist) && (addr < limit); c++) {
526 Prefetch::read(addr, BrooksPointer::byte_offset());
527 oop obj = oop(addr);
528 slots[avail++] = obj;
529 if (addr < tams) {
530 addr += skip_bitmap_delta;
531 addr = mark_bit_map.getNextMarkedWordAddress(addr, end);
532 } else {
533 // cannot trust mark bitmap anymore, finish the current stride,
534 // and switch to accurate traversal
535 addr += obj->size() + skip_objsize_delta;
536 aborting = true;
537 }
538 }
539
540 for (int c = 0; c < avail; c++) {
541 do_marked_object(cl, slots[c]);
542 }
543 } while (avail > 0 && !aborting);
544
545 // accurate traversal
546 while (addr < limit) {
547 oop obj = oop(addr);
548 int size = obj->size();
549 do_marked_object(cl, obj);
550 addr += size + skip_objsize_delta;
551 }
552 } else {
553 while (addr < limit) {
554 oop obj = oop(addr);
555 int size = obj->size();
556 do_marked_object(cl, obj);
557 addr += size + skip_objsize_delta;
558 if (addr < tams) {
559 addr = mark_bit_map.getNextMarkedWordAddress(addr, end);
560 }
561 }
562 }
563 }
564
565 template<class T>
566 inline void ShenandoahHeap::do_marked_object(T* cl, oop obj) {
567 assert(!oopDesc::is_null(obj), "sanity");
568 assert(oopDesc::is_oop(obj), "sanity");
569 assert(is_in(obj), "sanity");
570 assert(is_marked(obj), "object expected to be marked");
571 cl->do_object(obj);
572 }
573
574 template <class T>
575 class ShenandoahObjectToOopClosure : public ObjectClosure {
576 T* _cl;
577 public:
578 ShenandoahObjectToOopClosure(T* cl) : _cl(cl) {}
579
580 void do_object(oop obj) {
581 obj->oop_iterate(_cl);
582 }
583 };
584
585 template <class T>
586 class ShenandoahObjectToOopBoundedClosure : public ObjectClosure {
587 T* _cl;
588 MemRegion _bounds;
589 public:
590 ShenandoahObjectToOopBoundedClosure(T* cl, HeapWord* bottom, HeapWord* top) :
591 _cl(cl), _bounds(bottom, top) {}
592
593 void do_object(oop obj) {
594 obj->oop_iterate(_cl, _bounds);
595 }
596 };
597
598 template<class T>
599 inline void ShenandoahHeap::marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* top) {
600 if (region->is_humongous()) {
601 HeapWord* bottom = region->bottom();
602 if (top > bottom) {
603 region = region->humongous_start_region();
604 ShenandoahObjectToOopBoundedClosure<T> objs(cl, bottom, top);
605 marked_object_iterate(region, &objs);
606 }
607 } else {
608 ShenandoahObjectToOopClosure<T> objs(cl);
609 marked_object_iterate(region, &objs, top);
610 }
611 }
612
613 template<class T>
614 inline void ShenandoahHeap::marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl) {
615 marked_object_oop_iterate(region, cl, region->top());
616 }
617
618 template<class T>
619 inline void ShenandoahHeap::marked_object_oop_safe_iterate(ShenandoahHeapRegion* region, T* cl) {
620 marked_object_oop_iterate(region, cl, region->concurrent_iteration_safe_limit());
621 }
622 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP