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.
22 *
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 }
247 }
248
249 inline void ShenandoahHeap::atomic_clear_oop(narrowOop* addr, narrowOop compare) {
250 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
251 Atomic::cmpxchg(addr, compare, narrowOop(), memory_order_relaxed);
252 }
253
254 inline bool ShenandoahHeap::cancelled_gc() const {
255 return _cancelled_gc.get() == CANCELLED;
256 }
257
258 inline bool ShenandoahHeap::check_cancelled_gc_and_yield(bool sts_active) {
259 if (sts_active && !cancelled_gc()) {
260 if (SuspendibleThreadSet::should_yield()) {
261 SuspendibleThreadSet::yield();
262 }
263 }
264 return cancelled_gc();
265 }
266
267 inline void ShenandoahHeap::clear_cancelled_gc() {
268 _cancelled_gc.set(CANCELLABLE);
269 _oom_evac_handler.clear();
270 }
271
272 inline HeapWord* ShenandoahHeap::allocate_from_gclab(Thread* thread, size_t size) {
273 assert(UseTLAB, "TLABs should be enabled");
274
275 PLAB* gclab = ShenandoahThreadLocalData::gclab(thread);
276 if (gclab == nullptr) {
277 assert(!thread->is_Java_thread() && !thread->is_Worker_thread(),
278 "Performance: thread should have GCLAB: %s", thread->name());
279 // No GCLABs in this thread, fallback to shared allocation
280 return nullptr;
281 }
282 HeapWord* obj = gclab->allocate(size);
283 if (obj != nullptr) {
284 return obj;
285 }
286 // Otherwise...
287 return allocate_from_gclab_slow(thread, size);
288 }
289
290 inline oop ShenandoahHeap::evacuate_object(oop p, Thread* thread) {
291 if (ShenandoahThreadLocalData::is_oom_during_evac(Thread::current())) {
292 // This thread went through the OOM during evac protocol and it is safe to return
293 // the forward pointer. It must not attempt to evacuate any more.
294 return ShenandoahBarrierSet::resolve_forwarded(p);
295 }
296
297 assert(ShenandoahThreadLocalData::is_evac_allowed(thread), "must be enclosed in oom-evac scope");
298
299 size_t size = p->size();
300
301 assert(!heap_region_containing(p)->is_humongous(), "never evacuate humongous objects");
302
303 bool alloc_from_gclab = true;
304 HeapWord* copy = nullptr;
305
306 #ifdef ASSERT
307 if (ShenandoahOOMDuringEvacALot &&
308 (os::random() & 1) == 0) { // Simulate OOM every ~2nd slow-path call
309 copy = nullptr;
310 } else {
311 #endif
312 if (UseTLAB) {
313 copy = allocate_from_gclab(thread, size);
314 }
315 if (copy == nullptr) {
316 ShenandoahAllocRequest req = ShenandoahAllocRequest::for_shared_gc(size);
317 copy = allocate_memory(req);
318 alloc_from_gclab = false;
319 }
320 #ifdef ASSERT
321 }
322 #endif
323
324 if (copy == nullptr) {
325 control_thread()->handle_alloc_failure_evac(size);
326
327 _oom_evac_handler.handle_out_of_memory_during_evacuation();
328
329 return ShenandoahBarrierSet::resolve_forwarded(p);
330 }
331
332 // Copy the object:
333 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(p), copy, size);
334
335 // Try to install the new forwarding pointer.
336 oop copy_val = cast_to_oop(copy);
337 ContinuationGCSupport::relativize_stack_chunk(copy_val);
338
339 oop result = ShenandoahForwarding::try_update_forwardee(p, copy_val);
340 if (result == copy_val) {
341 // Successfully evacuated. Our copy is now the public one!
342 shenandoah_assert_correct(nullptr, copy_val);
343 return copy_val;
344 } else {
345 // Failed to evacuate. We need to deal with the object that is left behind. Since this
346 // new allocation is certainly after TAMS, it will be considered live in the next cycle.
347 // But if it happens to contain references to evacuated regions, those references would
348 // not get updated for this stale copy during this cycle, and we will crash while scanning
349 // it the next cycle.
350 //
351 // For GCLAB allocations, it is enough to rollback the allocation ptr. Either the next
352 // object will overwrite this stale copy, or the filler object on LAB retirement will
353 // do this. For non-GCLAB allocations, we have no way to retract the allocation, and
354 // have to explicitly overwrite the copy with the filler object. With that overwrite,
355 // we have to keep the fwdptr initialized and pointing to our (stale) copy.
356 if (alloc_from_gclab) {
357 ShenandoahThreadLocalData::gclab(thread)->undo_allocation(copy, size);
358 } else {
359 fill_with_object(copy, size);
360 shenandoah_assert_correct(nullptr, copy_val);
361 }
362 shenandoah_assert_correct(nullptr, result);
363 return result;
364 }
365 }
366
367 inline bool ShenandoahHeap::requires_marking(const void* entry) const {
368 oop obj = cast_to_oop(entry);
369 return !_marking_context->is_marked_strong(obj);
370 }
371
372 inline bool ShenandoahHeap::in_collection_set(oop p) const {
373 assert(collection_set() != nullptr, "Sanity");
374 return collection_set()->is_in(p);
375 }
376
377 inline bool ShenandoahHeap::in_collection_set_loc(void* p) const {
378 assert(collection_set() != nullptr, "Sanity");
379 return collection_set()->is_in_loc(p);
380 }
381
382 inline bool ShenandoahHeap::is_stable() const {
383 return _gc_state.is_clear();
384 }
385
386 inline bool ShenandoahHeap::is_idle() const {
387 return _gc_state.is_unset(MARKING | EVACUATION | UPDATEREFS);
388 }
389
390 inline bool ShenandoahHeap::is_concurrent_mark_in_progress() const {
391 return _gc_state.is_set(MARKING);
392 }
393
394 inline bool ShenandoahHeap::is_evacuation_in_progress() const {
395 return _gc_state.is_set(EVACUATION);
396 }
397
398 inline bool ShenandoahHeap::is_degenerated_gc_in_progress() const {
399 return _degenerated_gc_in_progress.is_set();
400 }
401
402 inline bool ShenandoahHeap::is_full_gc_in_progress() const {
403 return _full_gc_in_progress.is_set();
404 }
405
406 inline bool ShenandoahHeap::is_full_gc_move_in_progress() const {
407 return _full_gc_move_in_progress.is_set();
408 }
409
410 inline bool ShenandoahHeap::is_update_refs_in_progress() const {
411 return _gc_state.is_set(UPDATEREFS);
412 }
413
414 inline bool ShenandoahHeap::is_stw_gc_in_progress() const {
415 return is_full_gc_in_progress() || is_degenerated_gc_in_progress();
416 }
417
418 inline bool ShenandoahHeap::is_concurrent_strong_root_in_progress() const {
419 return _concurrent_strong_root_in_progress.is_set();
420 }
421
422 inline bool ShenandoahHeap::is_concurrent_weak_root_in_progress() const {
423 return _gc_state.is_set(WEAK_ROOTS);
424 }
425
426 template<class T>
427 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl) {
428 marked_object_iterate(region, cl, region->top());
429 }
430
431 template<class T>
432 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit) {
433 assert(! region->is_humongous_continuation(), "no humongous continuation regions here");
434
435 ShenandoahMarkingContext* const ctx = complete_marking_context();
436 assert(ctx->is_complete(), "sanity");
437
438 HeapWord* tams = ctx->top_at_mark_start(region);
439
440 size_t skip_bitmap_delta = 1;
441 HeapWord* start = region->bottom();
442 HeapWord* end = MIN2(tams, region->end());
443
444 // Step 1. Scan below the TAMS based on bitmap data.
445 HeapWord* limit_bitmap = MIN2(limit, tams);
446
447 // Try to scan the initial candidate. If the candidate is above the TAMS, it would
448 // fail the subsequent "< limit_bitmap" checks, and fall through to Step 2.
449 HeapWord* cb = ctx->get_next_marked_addr(start, end);
450
451 intx dist = ShenandoahMarkScanPrefetch;
452 if (dist > 0) {
453 // Batched scan that prefetches the oop data, anticipating the access to
454 // either header, oop field, or forwarding pointer. Not that we cannot
455 // touch anything in oop, while it still being prefetched to get enough
456 // time for prefetch to work. This is why we try to scan the bitmap linearly,
547 HeapWord* bottom = region->bottom();
548 if (top > bottom) {
549 region = region->humongous_start_region();
550 ShenandoahObjectToOopBoundedClosure<T> objs(cl, bottom, top);
551 marked_object_iterate(region, &objs);
552 }
553 } else {
554 ShenandoahObjectToOopClosure<T> objs(cl);
555 marked_object_iterate(region, &objs, top);
556 }
557 }
558
559 inline ShenandoahHeapRegion* ShenandoahHeap::get_region(size_t region_idx) const {
560 if (region_idx < _num_regions) {
561 return _regions[region_idx];
562 } else {
563 return nullptr;
564 }
565 }
566
567 inline void ShenandoahHeap::mark_complete_marking_context() {
568 _marking_context->mark_complete();
569 }
570
571 inline void ShenandoahHeap::mark_incomplete_marking_context() {
572 _marking_context->mark_incomplete();
573 }
574
575 inline ShenandoahMarkingContext* ShenandoahHeap::complete_marking_context() const {
576 assert (_marking_context->is_complete()," sanity");
577 return _marking_context;
578 }
579
580 inline ShenandoahMarkingContext* ShenandoahHeap::marking_context() const {
581 return _marking_context;
582 }
583
584 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP
|
1 /*
2 * Copyright (c) 2015, 2020, Red Hat, Inc. All rights reserved.
3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP
27 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP
28
29 #include "gc/shenandoah/shenandoahHeap.hpp"
30
31 #include "classfile/javaClasses.inline.hpp"
32 #include "gc/shared/markBitMap.inline.hpp"
33 #include "gc/shared/threadLocalAllocBuffer.inline.hpp"
34 #include "gc/shared/continuationGCSupport.inline.hpp"
35 #include "gc/shared/suspendibleThreadSet.hpp"
36 #include "gc/shared/tlab_globals.hpp"
37 #include "gc/shenandoah/shenandoahAsserts.hpp"
38 #include "gc/shenandoah/shenandoahBarrierSet.inline.hpp"
39 #include "gc/shenandoah/shenandoahCollectionSet.inline.hpp"
40 #include "gc/shenandoah/shenandoahForwarding.inline.hpp"
41 #include "gc/shenandoah/shenandoahWorkGroup.hpp"
42 #include "gc/shenandoah/shenandoahHeapRegionSet.inline.hpp"
43 #include "gc/shenandoah/shenandoahHeapRegion.inline.hpp"
44 #include "gc/shenandoah/shenandoahGeneration.hpp"
45 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
46 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
47 #include "gc/shenandoah/mode/shenandoahMode.hpp"
48 #include "oops/compressedOops.inline.hpp"
49 #include "oops/oop.inline.hpp"
50 #include "runtime/atomic.hpp"
51 #include "runtime/javaThread.hpp"
52 #include "runtime/prefetch.inline.hpp"
53 #include "runtime/objectMonitor.inline.hpp"
54 #include "utilities/copy.hpp"
55 #include "utilities/globalDefinitions.hpp"
56
57 inline ShenandoahHeap* ShenandoahHeap::heap() {
58 return named_heap<ShenandoahHeap>(CollectedHeap::Shenandoah);
59 }
60
61 inline ShenandoahHeapRegion* ShenandoahRegionIterator::next() {
62 size_t new_index = Atomic::add(&_index, (size_t) 1, memory_order_relaxed);
63 // get_region() provides the bounds-check and returns null on OOB.
64 return _heap->get_region(new_index - 1);
65 }
66
67 inline bool ShenandoahHeap::has_forwarded_objects() const {
68 return _gc_state.is_set(HAS_FORWARDED);
69 }
70
71 inline WorkerThreads* ShenandoahHeap::workers() const {
72 return _workers;
73 }
250 }
251
252 inline void ShenandoahHeap::atomic_clear_oop(narrowOop* addr, narrowOop compare) {
253 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
254 Atomic::cmpxchg(addr, compare, narrowOop(), memory_order_relaxed);
255 }
256
257 inline bool ShenandoahHeap::cancelled_gc() const {
258 return _cancelled_gc.get() == CANCELLED;
259 }
260
261 inline bool ShenandoahHeap::check_cancelled_gc_and_yield(bool sts_active) {
262 if (sts_active && !cancelled_gc()) {
263 if (SuspendibleThreadSet::should_yield()) {
264 SuspendibleThreadSet::yield();
265 }
266 }
267 return cancelled_gc();
268 }
269
270 inline void ShenandoahHeap::clear_cancelled_gc(bool clear_oom_handler) {
271 _cancelled_gc.set(CANCELLABLE);
272 if (_cancel_requested_time > 0) {
273 double cancel_time = os::elapsedTime() - _cancel_requested_time;
274 log_info(gc)("GC cancellation took %.3fs", cancel_time);
275 _cancel_requested_time = 0;
276 }
277
278 if (clear_oom_handler) {
279 _oom_evac_handler.clear();
280 }
281 }
282
283 inline HeapWord* ShenandoahHeap::allocate_from_gclab(Thread* thread, size_t size) {
284 assert(UseTLAB, "TLABs should be enabled");
285
286 PLAB* gclab = ShenandoahThreadLocalData::gclab(thread);
287 if (gclab == nullptr) {
288 assert(!thread->is_Java_thread() && !thread->is_Worker_thread(),
289 "Performance: thread should have GCLAB: %s", thread->name());
290 // No GCLABs in this thread, fallback to shared allocation
291 return nullptr;
292 }
293 HeapWord* obj = gclab->allocate(size);
294 if (obj != nullptr) {
295 return obj;
296 }
297 return allocate_from_gclab_slow(thread, size);
298 }
299
300 inline ShenandoahAgeCensus* ShenandoahHeap::age_census() const {
301 assert(mode()->is_generational(), "Only in generational mode");
302 assert(_age_census != nullptr, "Error: not initialized");
303 return _age_census;
304 }
305
306 void ShenandoahHeap::increase_object_age(oop obj, uint additional_age) {
307 // This operates on new copy of an object. This means that the object's mark-word
308 // is thread-local and therefore safe to access. However, when the mark is
309 // displaced (i.e. stack-locked or monitor-locked), then it must be considered
310 // a shared memory location. It can be accessed by other threads.
311 // In particular, a competing evacuating thread can succeed to install its copy
312 // as the forwardee and continue to unlock the object, at which point 'our'
313 // write to the foreign stack-location would potentially over-write random
314 // information on that stack. Writing to a monitor is less problematic,
315 // but still not safe: while the ObjectMonitor would not randomly disappear,
316 // the other thread would also write to the same displaced header location,
317 // possibly leading to increase the age twice.
318 // For all these reasons, we take the conservative approach and not attempt
319 // to increase the age when the header is displaced.
320 markWord w = obj->mark();
321 // The mark-word has been copied from the original object. It can not be
322 // inflating, because inflation can not be interrupted by a safepoint,
323 // and after a safepoint, a Java thread would first have to successfully
324 // evacuate the object before it could inflate the monitor.
325 assert(!w.is_being_inflated() || LockingMode == LM_LIGHTWEIGHT, "must not inflate monitor before evacuation of object succeeds");
326 // It is possible that we have copied the object after another thread has
327 // already successfully completed evacuation. While harmless (we would never
328 // publish our copy), don't even attempt to modify the age when that
329 // happens.
330 if (!w.has_displaced_mark_helper() && !w.is_marked()) {
331 w = w.set_age(MIN2(markWord::max_age, w.age() + additional_age));
332 obj->set_mark(w);
333 }
334 }
335
336 // Return the object's age, or a sentinel value when the age can't
337 // necessarily be determined because of concurrent locking by the
338 // mutator
339 uint ShenandoahHeap::get_object_age(oop obj) {
340 // This is impossible to do unless we "freeze" ABA-type oscillations
341 // With Lilliput, we can do this more easily.
342 markWord w = obj->mark();
343 assert(!w.is_marked(), "must not be forwarded");
344 if (w.has_monitor()) {
345 w = w.monitor()->header();
346 } else if (w.is_being_inflated() || w.has_displaced_mark_helper()) {
347 // Informs caller that we aren't able to determine the age
348 return markWord::max_age + 1; // sentinel
349 }
350 assert(w.age() <= markWord::max_age, "Impossible!");
351 return w.age();
352 }
353
354 bool ShenandoahHeap::is_in(const void* p) const {
355 HeapWord* heap_base = (HeapWord*) base();
356 HeapWord* last_region_end = heap_base + ShenandoahHeapRegion::region_size_words() * num_regions();
357 return p >= heap_base && p < last_region_end;
358 }
359
360 inline bool ShenandoahHeap::is_in_active_generation(oop obj) const {
361 if (!mode()->is_generational()) {
362 // everything is the same single generation
363 return true;
364 }
365
366 if (active_generation() == nullptr) {
367 // no collection is happening, only expect this to be called
368 // when concurrent processing is active, but that could change
369 return false;
370 }
371
372 assert(is_in(obj), "only check if is in active generation for objects (" PTR_FORMAT ") in heap", p2i(obj));
373 assert((active_generation() == (ShenandoahGeneration*) old_generation()) ||
374 (active_generation() == (ShenandoahGeneration*) young_generation()) ||
375 (active_generation() == global_generation()), "Active generation must be old, young, or global");
376
377 size_t index = heap_region_containing(obj)->index();
378 switch (_affiliations[index]) {
379 case ShenandoahAffiliation::FREE:
380 // Free regions are in Old, Young, Global
381 return true;
382 case ShenandoahAffiliation::YOUNG_GENERATION:
383 // Young regions are in young_generation and global_generation, not in old_generation
384 return (active_generation() != (ShenandoahGeneration*) old_generation());
385 case ShenandoahAffiliation::OLD_GENERATION:
386 // Old regions are in old_generation and global_generation, not in young_generation
387 return (active_generation() != (ShenandoahGeneration*) young_generation());
388 default:
389 assert(false, "Bad affiliation (%d) for region " SIZE_FORMAT, _affiliations[index], index);
390 return false;
391 }
392 }
393
394 inline bool ShenandoahHeap::is_in_young(const void* p) const {
395 return is_in(p) && (_affiliations[heap_region_index_containing(p)] == ShenandoahAffiliation::YOUNG_GENERATION);
396 }
397
398 inline bool ShenandoahHeap::is_in_old(const void* p) const {
399 return is_in(p) && (_affiliations[heap_region_index_containing(p)] == ShenandoahAffiliation::OLD_GENERATION);
400 }
401
402 inline bool ShenandoahHeap::is_old(oop obj) const {
403 return active_generation()->is_young() && is_in_old(obj);
404 }
405
406 inline ShenandoahAffiliation ShenandoahHeap::region_affiliation(const ShenandoahHeapRegion *r) {
407 return (ShenandoahAffiliation) _affiliations[r->index()];
408 }
409
410 inline void ShenandoahHeap::assert_lock_for_affiliation(ShenandoahAffiliation orig_affiliation,
411 ShenandoahAffiliation new_affiliation) {
412 // A lock is required when changing from FREE to NON-FREE. Though it may be possible to elide the lock when
413 // transitioning from in-use to FREE, the current implementation uses a lock for this transition. A lock is
414 // not required to change from YOUNG to OLD (i.e. when promoting humongous region).
415 //
416 // new_affiliation is: FREE YOUNG OLD
417 // orig_affiliation is: FREE X L L
418 // YOUNG L X
419 // OLD L X X
420 // X means state transition won't happen (so don't care)
421 // L means lock should be held
422 // Blank means no lock required because affiliation visibility will not be required until subsequent safepoint
423 //
424 // Note: during full GC, all transitions between states are possible. During Full GC, we should be in a safepoint.
425
426 if ((orig_affiliation == ShenandoahAffiliation::FREE) || (new_affiliation == ShenandoahAffiliation::FREE)) {
427 shenandoah_assert_heaplocked_or_fullgc_safepoint();
428 }
429 }
430
431 inline void ShenandoahHeap::set_affiliation(ShenandoahHeapRegion* r, ShenandoahAffiliation new_affiliation) {
432 #ifdef ASSERT
433 assert_lock_for_affiliation(region_affiliation(r), new_affiliation);
434 #endif
435 _affiliations[r->index()] = (uint8_t) new_affiliation;
436 }
437
438 inline ShenandoahAffiliation ShenandoahHeap::region_affiliation(size_t index) {
439 return (ShenandoahAffiliation) _affiliations[index];
440 }
441
442 inline bool ShenandoahHeap::requires_marking(const void* entry) const {
443 oop obj = cast_to_oop(entry);
444 return !_marking_context->is_marked_strong(obj);
445 }
446
447 inline bool ShenandoahHeap::in_collection_set(oop p) const {
448 assert(collection_set() != nullptr, "Sanity");
449 return collection_set()->is_in(p);
450 }
451
452 inline bool ShenandoahHeap::in_collection_set_loc(void* p) const {
453 assert(collection_set() != nullptr, "Sanity");
454 return collection_set()->is_in_loc(p);
455 }
456
457
458 inline bool ShenandoahHeap::is_stable() const {
459 return _gc_state.is_clear();
460 }
461
462 inline bool ShenandoahHeap::is_idle() const {
463 return _gc_state.is_unset(MARKING | EVACUATION | UPDATEREFS);
464 }
465
466 inline bool ShenandoahHeap::is_concurrent_mark_in_progress() const {
467 return _gc_state.is_set(MARKING);
468 }
469
470 inline bool ShenandoahHeap::is_concurrent_young_mark_in_progress() const {
471 return _gc_state.is_set(YOUNG_MARKING);
472 }
473
474 inline bool ShenandoahHeap::is_concurrent_old_mark_in_progress() const {
475 return _gc_state.is_set(OLD_MARKING);
476 }
477
478 inline bool ShenandoahHeap::is_evacuation_in_progress() const {
479 return _gc_state.is_set(EVACUATION);
480 }
481
482 inline bool ShenandoahHeap::is_degenerated_gc_in_progress() const {
483 return _degenerated_gc_in_progress.is_set();
484 }
485
486 inline bool ShenandoahHeap::is_full_gc_in_progress() const {
487 return _full_gc_in_progress.is_set();
488 }
489
490 inline bool ShenandoahHeap::is_full_gc_move_in_progress() const {
491 return _full_gc_move_in_progress.is_set();
492 }
493
494 inline bool ShenandoahHeap::is_update_refs_in_progress() const {
495 return _gc_state.is_set(UPDATEREFS);
496 }
497
498 inline bool ShenandoahHeap::is_stw_gc_in_progress() const {
499 return is_full_gc_in_progress() || is_degenerated_gc_in_progress();
500 }
501
502 inline bool ShenandoahHeap::is_concurrent_strong_root_in_progress() const {
503 return _concurrent_strong_root_in_progress.is_set();
504 }
505
506 inline bool ShenandoahHeap::is_concurrent_weak_root_in_progress() const {
507 return _gc_state.is_set(WEAK_ROOTS);
508 }
509
510 inline bool ShenandoahHeap::is_aging_cycle() const {
511 return _is_aging_cycle.is_set();
512 }
513
514 template<class T>
515 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl) {
516 marked_object_iterate(region, cl, region->top());
517 }
518
519 template<class T>
520 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit) {
521 assert(! region->is_humongous_continuation(), "no humongous continuation regions here");
522
523 ShenandoahMarkingContext* const ctx = marking_context();
524
525 HeapWord* tams = ctx->top_at_mark_start(region);
526
527 size_t skip_bitmap_delta = 1;
528 HeapWord* start = region->bottom();
529 HeapWord* end = MIN2(tams, region->end());
530
531 // Step 1. Scan below the TAMS based on bitmap data.
532 HeapWord* limit_bitmap = MIN2(limit, tams);
533
534 // Try to scan the initial candidate. If the candidate is above the TAMS, it would
535 // fail the subsequent "< limit_bitmap" checks, and fall through to Step 2.
536 HeapWord* cb = ctx->get_next_marked_addr(start, end);
537
538 intx dist = ShenandoahMarkScanPrefetch;
539 if (dist > 0) {
540 // Batched scan that prefetches the oop data, anticipating the access to
541 // either header, oop field, or forwarding pointer. Not that we cannot
542 // touch anything in oop, while it still being prefetched to get enough
543 // time for prefetch to work. This is why we try to scan the bitmap linearly,
634 HeapWord* bottom = region->bottom();
635 if (top > bottom) {
636 region = region->humongous_start_region();
637 ShenandoahObjectToOopBoundedClosure<T> objs(cl, bottom, top);
638 marked_object_iterate(region, &objs);
639 }
640 } else {
641 ShenandoahObjectToOopClosure<T> objs(cl);
642 marked_object_iterate(region, &objs, top);
643 }
644 }
645
646 inline ShenandoahHeapRegion* ShenandoahHeap::get_region(size_t region_idx) const {
647 if (region_idx < _num_regions) {
648 return _regions[region_idx];
649 } else {
650 return nullptr;
651 }
652 }
653
654 inline ShenandoahMarkingContext* ShenandoahHeap::complete_marking_context() const {
655 assert (_marking_context->is_complete()," sanity");
656 return _marking_context;
657 }
658
659 inline ShenandoahMarkingContext* ShenandoahHeap::marking_context() const {
660 return _marking_context;
661 }
662
663 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP
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