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 }
71
72 inline WorkerThreads* ShenandoahHeap::safepoint_workers() {
73 return _safepoint_workers;
74 }
75
76 inline size_t ShenandoahHeap::heap_region_index_containing(const void* addr) const {
77 uintptr_t region_start = ((uintptr_t) addr);
78 uintptr_t index = (region_start - (uintptr_t) base()) >> ShenandoahHeapRegion::region_size_bytes_shift();
79 assert(index < num_regions(), "Region index is in bounds: " PTR_FORMAT, p2i(addr));
80 return index;
81 }
82
83 inline ShenandoahHeapRegion* const ShenandoahHeap::heap_region_containing(const void* addr) const {
84 size_t index = heap_region_index_containing(addr);
85 ShenandoahHeapRegion* const result = get_region(index);
86 assert(addr >= result->bottom() && addr < result->end(), "Heap region contains the address: " PTR_FORMAT, p2i(addr));
87 return result;
88 }
89
90 inline void ShenandoahHeap::enter_evacuation(Thread* t) {
91 _oom_evac_handler.enter_evacuation(t);
92 }
93
94 inline void ShenandoahHeap::leave_evacuation(Thread* t) {
95 _oom_evac_handler.leave_evacuation(t);
96 }
97
98 template <class T>
99 inline void ShenandoahHeap::update_with_forwarded(T* p) {
100 T o = RawAccess<>::oop_load(p);
101 if (!CompressedOops::is_null(o)) {
102 oop obj = CompressedOops::decode_not_null(o);
103 if (in_collection_set(obj)) {
235 }
236
237 inline void ShenandoahHeap::atomic_clear_oop(narrowOop* addr, narrowOop compare) {
238 assert(is_aligned(addr, sizeof(narrowOop)), "Address should be aligned: " PTR_FORMAT, p2i(addr));
239 Atomic::cmpxchg(addr, compare, narrowOop(), memory_order_relaxed);
240 }
241
242 inline bool ShenandoahHeap::cancelled_gc() const {
243 return _cancelled_gc.get() == CANCELLED;
244 }
245
246 inline bool ShenandoahHeap::check_cancelled_gc_and_yield(bool sts_active) {
247 if (sts_active && !cancelled_gc()) {
248 if (SuspendibleThreadSet::should_yield()) {
249 SuspendibleThreadSet::yield();
250 }
251 }
252 return cancelled_gc();
253 }
254
255 inline void ShenandoahHeap::clear_cancelled_gc() {
256 _cancelled_gc.set(CANCELLABLE);
257 _oom_evac_handler.clear();
258 }
259
260 inline HeapWord* ShenandoahHeap::allocate_from_gclab(Thread* thread, size_t size) {
261 assert(UseTLAB, "TLABs should be enabled");
262
263 PLAB* gclab = ShenandoahThreadLocalData::gclab(thread);
264 if (gclab == nullptr) {
265 assert(!thread->is_Java_thread() && !thread->is_Worker_thread(),
266 "Performance: thread should have GCLAB: %s", thread->name());
267 // No GCLABs in this thread, fallback to shared allocation
268 return nullptr;
269 }
270 HeapWord* obj = gclab->allocate(size);
271 if (obj != nullptr) {
272 return obj;
273 }
274 // Otherwise...
275 return allocate_from_gclab_slow(thread, size);
276 }
277
278 inline oop ShenandoahHeap::evacuate_object(oop p, Thread* thread) {
279 if (ShenandoahThreadLocalData::is_oom_during_evac(Thread::current())) {
280 // This thread went through the OOM during evac protocol and it is safe to return
281 // the forward pointer. It must not attempt to evacuate any more.
282 return ShenandoahBarrierSet::resolve_forwarded(p);
283 }
284
285 assert(ShenandoahThreadLocalData::is_evac_allowed(thread), "must be enclosed in oom-evac scope");
286
287 size_t size = p->size();
288
289 assert(!heap_region_containing(p)->is_humongous(), "never evacuate humongous objects");
290
291 bool alloc_from_gclab = true;
292 HeapWord* copy = nullptr;
293
294 #ifdef ASSERT
295 if (ShenandoahOOMDuringEvacALot &&
296 (os::random() & 1) == 0) { // Simulate OOM every ~2nd slow-path call
297 copy = nullptr;
298 } else {
299 #endif
300 if (UseTLAB) {
301 copy = allocate_from_gclab(thread, size);
302 }
303 if (copy == nullptr) {
304 ShenandoahAllocRequest req = ShenandoahAllocRequest::for_shared_gc(size);
305 copy = allocate_memory(req);
306 alloc_from_gclab = false;
307 }
308 #ifdef ASSERT
309 }
310 #endif
311
312 if (copy == nullptr) {
313 control_thread()->handle_alloc_failure_evac(size);
314
315 _oom_evac_handler.handle_out_of_memory_during_evacuation();
316
317 return ShenandoahBarrierSet::resolve_forwarded(p);
318 }
319
320 // Copy the object:
321 Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(p), copy, size);
322
323 // Try to install the new forwarding pointer.
324 oop copy_val = cast_to_oop(copy);
325 ContinuationGCSupport::relativize_stack_chunk(copy_val);
326
327 oop result = ShenandoahForwarding::try_update_forwardee(p, copy_val);
328 if (result == copy_val) {
329 // Successfully evacuated. Our copy is now the public one!
330 shenandoah_assert_correct(nullptr, copy_val);
331 return copy_val;
332 } else {
333 // Failed to evacuate. We need to deal with the object that is left behind. Since this
334 // new allocation is certainly after TAMS, it will be considered live in the next cycle.
335 // But if it happens to contain references to evacuated regions, those references would
336 // not get updated for this stale copy during this cycle, and we will crash while scanning
337 // it the next cycle.
338 //
339 // For GCLAB allocations, it is enough to rollback the allocation ptr. Either the next
340 // object will overwrite this stale copy, or the filler object on LAB retirement will
341 // do this. For non-GCLAB allocations, we have no way to retract the allocation, and
342 // have to explicitly overwrite the copy with the filler object. With that overwrite,
343 // we have to keep the fwdptr initialized and pointing to our (stale) copy.
344 if (alloc_from_gclab) {
345 ShenandoahThreadLocalData::gclab(thread)->undo_allocation(copy, size);
346 } else {
347 fill_with_object(copy, size);
348 shenandoah_assert_correct(nullptr, copy_val);
349 }
350 shenandoah_assert_correct(nullptr, result);
351 return result;
352 }
353 }
354
355 inline bool ShenandoahHeap::requires_marking(const void* entry) const {
356 oop obj = cast_to_oop(entry);
357 return !_marking_context->is_marked_strong(obj);
358 }
359
360 inline bool ShenandoahHeap::in_collection_set(oop p) const {
361 assert(collection_set() != nullptr, "Sanity");
362 return collection_set()->is_in(p);
363 }
364
365 inline bool ShenandoahHeap::in_collection_set_loc(void* p) const {
366 assert(collection_set() != nullptr, "Sanity");
367 return collection_set()->is_in_loc(p);
368 }
369
370 inline bool ShenandoahHeap::is_stable() const {
371 return _gc_state.is_clear();
372 }
373
374 inline bool ShenandoahHeap::is_idle() const {
375 return _gc_state.is_unset(MARKING | EVACUATION | UPDATEREFS);
376 }
377
378 inline bool ShenandoahHeap::is_concurrent_mark_in_progress() const {
379 return _gc_state.is_set(MARKING);
380 }
381
382 inline bool ShenandoahHeap::is_evacuation_in_progress() const {
383 return _gc_state.is_set(EVACUATION);
384 }
385
386 inline bool ShenandoahHeap::is_degenerated_gc_in_progress() const {
387 return _degenerated_gc_in_progress.is_set();
388 }
389
390 inline bool ShenandoahHeap::is_full_gc_in_progress() const {
391 return _full_gc_in_progress.is_set();
392 }
393
394 inline bool ShenandoahHeap::is_full_gc_move_in_progress() const {
395 return _full_gc_move_in_progress.is_set();
396 }
397
398 inline bool ShenandoahHeap::is_update_refs_in_progress() const {
399 return _gc_state.is_set(UPDATEREFS);
400 }
401
403 return is_full_gc_in_progress() || is_degenerated_gc_in_progress();
404 }
405
406 inline bool ShenandoahHeap::is_concurrent_strong_root_in_progress() const {
407 return _concurrent_strong_root_in_progress.is_set();
408 }
409
410 inline bool ShenandoahHeap::is_concurrent_weak_root_in_progress() const {
411 return _gc_state.is_set(WEAK_ROOTS);
412 }
413
414 template<class T>
415 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl) {
416 marked_object_iterate(region, cl, region->top());
417 }
418
419 template<class T>
420 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit) {
421 assert(! region->is_humongous_continuation(), "no humongous continuation regions here");
422
423 ShenandoahMarkingContext* const ctx = complete_marking_context();
424 assert(ctx->is_complete(), "sanity");
425
426 HeapWord* tams = ctx->top_at_mark_start(region);
427
428 size_t skip_bitmap_delta = 1;
429 HeapWord* start = region->bottom();
430 HeapWord* end = MIN2(tams, region->end());
431
432 // Step 1. Scan below the TAMS based on bitmap data.
433 HeapWord* limit_bitmap = MIN2(limit, tams);
434
435 // Try to scan the initial candidate. If the candidate is above the TAMS, it would
436 // fail the subsequent "< limit_bitmap" checks, and fall through to Step 2.
437 HeapWord* cb = ctx->get_next_marked_addr(start, end);
438
439 intx dist = ShenandoahMarkScanPrefetch;
440 if (dist > 0) {
441 // Batched scan that prefetches the oop data, anticipating the access to
442 // either header, oop field, or forwarding pointer. Not that we cannot
443 // touch anything in oop, while it still being prefetched to get enough
444 // time for prefetch to work. This is why we try to scan the bitmap linearly,
527 void do_object(oop obj) {
528 obj->oop_iterate(_cl, _bounds);
529 }
530 };
531
532 template<class T>
533 inline void ShenandoahHeap::marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* top) {
534 if (region->is_humongous()) {
535 HeapWord* bottom = region->bottom();
536 if (top > bottom) {
537 region = region->humongous_start_region();
538 ShenandoahObjectToOopBoundedClosure<T> objs(cl, bottom, top);
539 marked_object_iterate(region, &objs);
540 }
541 } else {
542 ShenandoahObjectToOopClosure<T> objs(cl);
543 marked_object_iterate(region, &objs, top);
544 }
545 }
546
547 inline ShenandoahHeapRegion* const ShenandoahHeap::get_region(size_t region_idx) const {
548 if (region_idx < _num_regions) {
549 return _regions[region_idx];
550 } else {
551 return nullptr;
552 }
553 }
554
555 inline void ShenandoahHeap::mark_complete_marking_context() {
556 _marking_context->mark_complete();
557 }
558
559 inline void ShenandoahHeap::mark_incomplete_marking_context() {
560 _marking_context->mark_incomplete();
561 }
562
563 inline ShenandoahMarkingContext* ShenandoahHeap::complete_marking_context() const {
564 assert (_marking_context->is_complete()," sanity");
565 return _marking_context;
566 }
567
568 inline ShenandoahMarkingContext* ShenandoahHeap::marking_context() const {
569 return _marking_context;
570 }
571
572 #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 }
74
75 inline WorkerThreads* ShenandoahHeap::safepoint_workers() {
76 return _safepoint_workers;
77 }
78
79 inline void ShenandoahHeap::notify_gc_progress() {
80 Atomic::store(&_gc_no_progress_count, (size_t) 0);
81
82 }
83 inline void ShenandoahHeap::notify_gc_no_progress() {
84 Atomic::inc(&_gc_no_progress_count);
85 }
86
87 inline size_t ShenandoahHeap::get_gc_no_progress_count() const {
88 return Atomic::load(&_gc_no_progress_count);
89 }
90
91 inline size_t ShenandoahHeap::heap_region_index_containing(const void* addr) const {
92 uintptr_t region_start = ((uintptr_t) addr);
93 uintptr_t index = (region_start - (uintptr_t) base()) >> ShenandoahHeapRegion::region_size_bytes_shift();
94 assert(index < num_regions(), "Region index is in bounds: " PTR_FORMAT, p2i(addr));
95 return index;
96 }
97
98 inline ShenandoahHeapRegion* ShenandoahHeap::heap_region_containing(const void* addr) const {
99 size_t index = heap_region_index_containing(addr);
100 ShenandoahHeapRegion* const result = get_region(index);
101 assert(addr >= result->bottom() && addr < result->end(), "Heap region contains the address: " PTR_FORMAT, p2i(addr));
102 return result;
103 }
104
105 inline void ShenandoahHeap::enter_evacuation(Thread* t) {
106 _oom_evac_handler.enter_evacuation(t);
107 }
108
109 inline void ShenandoahHeap::leave_evacuation(Thread* t) {
110 _oom_evac_handler.leave_evacuation(t);
111 }
112
113 template <class T>
114 inline void ShenandoahHeap::update_with_forwarded(T* p) {
115 T o = RawAccess<>::oop_load(p);
116 if (!CompressedOops::is_null(o)) {
117 oop obj = CompressedOops::decode_not_null(o);
118 if (in_collection_set(obj)) {
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 void ShenandoahHeap::increase_object_age(oop obj, uint additional_age) {
301 // This operates on new copy of an object. This means that the object's mark-word
302 // is thread-local and therefore safe to access. However, when the mark is
303 // displaced (i.e. stack-locked or monitor-locked), then it must be considered
304 // a shared memory location. It can be accessed by other threads.
305 // In particular, a competing evacuating thread can succeed to install its copy
306 // as the forwardee and continue to unlock the object, at which point 'our'
307 // write to the foreign stack-location would potentially over-write random
308 // information on that stack. Writing to a monitor is less problematic,
309 // but still not safe: while the ObjectMonitor would not randomly disappear,
310 // the other thread would also write to the same displaced header location,
311 // possibly leading to increase the age twice.
312 // For all these reasons, we take the conservative approach and not attempt
313 // to increase the age when the header is displaced.
314 markWord w = obj->mark();
315 // The mark-word has been copied from the original object. It can not be
316 // inflating, because inflation can not be interrupted by a safepoint,
317 // and after a safepoint, a Java thread would first have to successfully
318 // evacuate the object before it could inflate the monitor.
319 assert(!w.is_being_inflated() || LockingMode == LM_LIGHTWEIGHT, "must not inflate monitor before evacuation of object succeeds");
320 // It is possible that we have copied the object after another thread has
321 // already successfully completed evacuation. While harmless (we would never
322 // publish our copy), don't even attempt to modify the age when that
323 // happens.
324 if (!w.has_displaced_mark_helper() && !w.is_marked()) {
325 w = w.set_age(MIN2(markWord::max_age, w.age() + additional_age));
326 obj->set_mark(w);
327 }
328 }
329
330 // Return the object's age, or a sentinel value when the age can't
331 // necessarily be determined because of concurrent locking by the
332 // mutator
333 uint ShenandoahHeap::get_object_age(oop obj) {
334 // This is impossible to do unless we "freeze" ABA-type oscillations
335 // With Lilliput, we can do this more easily.
336 markWord w = obj->mark();
337 assert(!w.is_marked(), "must not be forwarded");
338 if (w.has_monitor()) {
339 w = w.monitor()->header();
340 } else if (w.is_being_inflated() || w.has_displaced_mark_helper()) {
341 // Informs caller that we aren't able to determine the age
342 return markWord::max_age + 1; // sentinel
343 }
344 assert(w.age() <= markWord::max_age, "Impossible!");
345 return w.age();
346 }
347
348 bool ShenandoahHeap::is_in(const void* p) const {
349 HeapWord* heap_base = (HeapWord*) base();
350 HeapWord* last_region_end = heap_base + ShenandoahHeapRegion::region_size_words() * num_regions();
351 return p >= heap_base && p < last_region_end;
352 }
353
354 inline bool ShenandoahHeap::is_in_active_generation(oop obj) const {
355 if (!mode()->is_generational()) {
356 // everything is the same single generation
357 assert(is_in(obj), "Otherwise shouldn't return true below");
358 return true;
359 }
360
361 ShenandoahGeneration* const gen = active_generation();
362
363 if (gen == nullptr) {
364 // no collection is happening: only expect this to be called
365 // when concurrent processing is active, but that could change
366 return false;
367 }
368
369 assert(is_in(obj), "only check if is in active generation for objects (" PTR_FORMAT ") in heap", p2i(obj));
370 assert(gen->is_old() || gen->is_young() || gen->is_global(),
371 "Active generation must be old, young, or global");
372
373 size_t index = heap_region_containing(obj)->index();
374
375 // No flickering!
376 assert(gen == active_generation(), "Race?");
377
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 gen != (ShenandoahGeneration*)old_generation();
385 case ShenandoahAffiliation::OLD_GENERATION:
386 // Old regions are in old_generation and global_generation, not in young_generation
387 return gen != (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
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 template<class T>
511 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl) {
512 marked_object_iterate(region, cl, region->top());
513 }
514
515 template<class T>
516 inline void ShenandoahHeap::marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit) {
517 assert(! region->is_humongous_continuation(), "no humongous continuation regions here");
518
519 ShenandoahMarkingContext* const ctx = marking_context();
520
521 HeapWord* tams = ctx->top_at_mark_start(region);
522
523 size_t skip_bitmap_delta = 1;
524 HeapWord* start = region->bottom();
525 HeapWord* end = MIN2(tams, region->end());
526
527 // Step 1. Scan below the TAMS based on bitmap data.
528 HeapWord* limit_bitmap = MIN2(limit, tams);
529
530 // Try to scan the initial candidate. If the candidate is above the TAMS, it would
531 // fail the subsequent "< limit_bitmap" checks, and fall through to Step 2.
532 HeapWord* cb = ctx->get_next_marked_addr(start, end);
533
534 intx dist = ShenandoahMarkScanPrefetch;
535 if (dist > 0) {
536 // Batched scan that prefetches the oop data, anticipating the access to
537 // either header, oop field, or forwarding pointer. Not that we cannot
538 // touch anything in oop, while it still being prefetched to get enough
539 // time for prefetch to work. This is why we try to scan the bitmap linearly,
622 void do_object(oop obj) {
623 obj->oop_iterate(_cl, _bounds);
624 }
625 };
626
627 template<class T>
628 inline void ShenandoahHeap::marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* top) {
629 if (region->is_humongous()) {
630 HeapWord* bottom = region->bottom();
631 if (top > bottom) {
632 region = region->humongous_start_region();
633 ShenandoahObjectToOopBoundedClosure<T> objs(cl, bottom, top);
634 marked_object_iterate(region, &objs);
635 }
636 } else {
637 ShenandoahObjectToOopClosure<T> objs(cl);
638 marked_object_iterate(region, &objs, top);
639 }
640 }
641
642 inline ShenandoahHeapRegion* ShenandoahHeap::get_region(size_t region_idx) const {
643 if (region_idx < _num_regions) {
644 return _regions[region_idx];
645 } else {
646 return nullptr;
647 }
648 }
649
650 inline ShenandoahMarkingContext* ShenandoahHeap::complete_marking_context() const {
651 assert (_marking_context->is_complete()," sanity");
652 return _marking_context;
653 }
654
655 inline ShenandoahMarkingContext* ShenandoahHeap::marking_context() const {
656 return _marking_context;
657 }
658
659 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_INLINE_HPP
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