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24
25 #ifndef SHARE_GC_G1_G1CONCURRENTMARK_INLINE_HPP
26 #define SHARE_GC_G1_G1CONCURRENTMARK_INLINE_HPP
27
28 #include "gc/g1/g1CollectedHeap.inline.hpp"
29 #include "gc/g1/g1ConcurrentMark.hpp"
30 #include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"
31 #include "gc/g1/g1ConcurrentMarkObjArrayProcessor.inline.hpp"
32 #include "gc/g1/g1OopClosures.inline.hpp"
33 #include "gc/g1/g1Policy.hpp"
34 #include "gc/g1/g1RegionMarkStatsCache.inline.hpp"
35 #include "gc/g1/g1RemSetTrackingPolicy.hpp"
36 #include "gc/g1/heapRegionRemSet.hpp"
37 #include "gc/g1/heapRegion.hpp"
38 #include "gc/shared/suspendibleThreadSet.hpp"
39 #include "gc/shared/taskqueue.inline.hpp"
40 #include "utilities/bitMap.inline.hpp"
41
42 inline bool G1CMIsAliveClosure::do_object_b(oop obj) {
43 return !_g1h->is_obj_ill(obj);
44 }
45
46 inline bool G1CMSubjectToDiscoveryClosure::do_object_b(oop obj) {
47 // Re-check whether the passed object is null. With ReferentBasedDiscovery the
48 // mutator may have changed the referent's value (i.e. cleared it) between the
49 // time the referent was determined to be potentially alive and calling this
50 // method.
51 if (obj == NULL) {
52 return false;
53 }
54 assert(_g1h->is_in_reserved(obj), "Trying to discover obj " PTR_FORMAT " not in heap", p2i(obj));
55 return _g1h->heap_region_containing(obj)->is_old_or_humongous_or_archive();
56 }
57
58 inline bool G1ConcurrentMark::mark_in_next_bitmap(uint const worker_id, oop const obj) {
59 HeapRegion* const hr = _g1h->heap_region_containing(obj);
60 return mark_in_next_bitmap(worker_id, hr, obj);
61 }
62
63 inline bool G1ConcurrentMark::mark_in_next_bitmap(uint const worker_id, HeapRegion* const hr, oop const obj) {
64 assert(hr != NULL, "just checking");
65 assert(hr->is_in_reserved(obj), "Attempting to mark object at " PTR_FORMAT " that is not contained in the given region %u", p2i(obj), hr->hrm_index());
66
67 if (hr->obj_allocated_since_next_marking(obj)) {
68 return false;
69 }
70
71 // Some callers may have stale objects to mark above nTAMS after humongous reclaim.
72 // Can't assert that this is a valid object at this point, since it might be in the process of being copied by another thread.
73 assert(!hr->is_continues_humongous(), "Should not try to mark object " PTR_FORMAT " in Humongous continues region %u above nTAMS " PTR_FORMAT, p2i(obj), hr->hrm_index(), p2i(hr->next_top_at_mark_start()));
74
75 bool success = _next_mark_bitmap->par_mark(obj);
76 if (success) {
77 add_to_liveness(worker_id, obj, obj->size());
78 }
79 return success;
80 }
81
82 #ifndef PRODUCT
83 template<typename Fn>
84 inline void G1CMMarkStack::iterate(Fn fn) const {
85 assert_at_safepoint_on_vm_thread();
86
87 size_t num_chunks = 0;
88
89 TaskQueueEntryChunk* cur = _chunk_list;
90 while (cur != NULL) {
91 guarantee(num_chunks <= _chunks_in_chunk_list, "Found " SIZE_FORMAT " oop chunks which is more than there should be", num_chunks);
92
93 for (size_t i = 0; i < EntriesPerChunk; ++i) {
94 if (cur->data[i].is_null()) {
95 break;
96 }
97 fn(cur->data[i]);
98 }
99 cur = cur->next;
100 num_chunks++;
101 }
102 }
103 #endif
104
105 // It scans an object and visits its children.
106 inline void G1CMTask::scan_task_entry(G1TaskQueueEntry task_entry) { process_grey_task_entry<true>(task_entry); }
107
108 inline void G1CMTask::push(G1TaskQueueEntry task_entry) {
109 assert(task_entry.is_array_slice() || _g1h->is_in_g1_reserved(task_entry.obj()), "invariant");
110 assert(task_entry.is_array_slice() || !_g1h->is_on_master_free_list(
111 _g1h->heap_region_containing(task_entry.obj())), "invariant");
112 assert(task_entry.is_array_slice() || !_g1h->is_obj_ill(task_entry.obj()), "invariant"); // FIXME!!!
113 assert(task_entry.is_array_slice() || _next_mark_bitmap->is_marked(cast_from_oop<HeapWord*>(task_entry.obj())), "invariant");
114
115 if (!_task_queue->push(task_entry)) {
116 // The local task queue looks full. We need to push some entries
117 // to the global stack.
118 move_entries_to_global_stack();
119
120 // this should succeed since, even if we overflow the global
121 // stack, we should have definitely removed some entries from the
122 // local queue. So, there must be space on it.
123 bool success = _task_queue->push(task_entry);
124 assert(success, "invariant");
125 }
126 }
127
128 inline bool G1CMTask::is_below_finger(oop obj, HeapWord* global_finger) const {
129 // If obj is above the global finger, then the mark bitmap scan
130 // will find it later, and no push is needed. Similarly, if we have
131 // a current region and obj is between the local finger and the
132 // end of the current region, then no push is needed. The tradeoff
133 // of checking both vs only checking the global finger is that the
134 // local check will be more accurate and so result in fewer pushes,
135 // but may also be a little slower.
136 HeapWord* objAddr = cast_from_oop<HeapWord*>(obj);
137 if (_finger != NULL) {
138 // We have a current region.
139
140 // Finger and region values are all NULL or all non-NULL. We
141 // use _finger to check since we immediately use its value.
142 assert(_curr_region != NULL, "invariant");
143 assert(_region_limit != NULL, "invariant");
144 assert(_region_limit <= global_finger, "invariant");
145
146 // True if obj is less than the local finger, or is between
147 // the region limit and the global finger.
148 if (objAddr < _finger) {
149 return true;
150 } else if (objAddr < _region_limit) {
151 return false;
152 } // Else check global finger.
153 }
154 // Check global finger.
155 return objAddr < global_finger;
156 }
157
158 template<bool scan>
159 inline void G1CMTask::process_grey_task_entry(G1TaskQueueEntry task_entry) {
160 assert(scan || (task_entry.is_oop() && task_entry.obj()->is_typeArray()), "Skipping scan of grey non-typeArray");
161 assert(task_entry.is_array_slice() || _next_mark_bitmap->is_marked(cast_from_oop<HeapWord*>(task_entry.obj())),
162 "Any stolen object should be a slice or marked");
163
164 if (scan) {
165 if (task_entry.is_array_slice()) {
166 _words_scanned += _objArray_processor.process_slice(task_entry.slice());
167 } else {
168 oop obj = task_entry.obj();
169 if (G1CMObjArrayProcessor::should_be_sliced(obj)) {
170 _words_scanned += _objArray_processor.process_obj(obj);
171 } else {
172 _words_scanned += obj->oop_iterate_size(_cm_oop_closure);;
173 }
174 }
175 }
176 check_limits();
177 }
178
179 inline size_t G1CMTask::scan_objArray(objArrayOop obj, MemRegion mr) {
180 obj->oop_iterate(_cm_oop_closure, mr);
181 return mr.word_size();
182 }
183
184 inline HeapWord* G1ConcurrentMark::top_at_rebuild_start(uint region) const {
185 assert(region < _g1h->max_regions(), "Tried to access TARS for region %u out of bounds", region);
186 return _top_at_rebuild_starts[region];
187 }
188
189 inline void G1ConcurrentMark::update_top_at_rebuild_start(HeapRegion* r) {
190 uint const region = r->hrm_index();
191 assert(region < _g1h->max_regions(), "Tried to access TARS for region %u out of bounds", region);
192 assert(_top_at_rebuild_starts[region] == NULL,
193 "TARS for region %u has already been set to " PTR_FORMAT " should be NULL",
194 region, p2i(_top_at_rebuild_starts[region]));
195 G1RemSetTrackingPolicy* tracker = _g1h->policy()->remset_tracker();
196 if (tracker->needs_scan_for_rebuild(r)) {
197 _top_at_rebuild_starts[region] = r->top();
198 } else {
199 // Leave TARS at NULL.
200 }
201 }
202
203 inline void G1CMTask::update_liveness(oop const obj, const size_t obj_size) {
204 _mark_stats_cache.add_live_words(_g1h->addr_to_region(cast_from_oop<HeapWord*>(obj)), obj_size);
205 }
206
207 inline void G1ConcurrentMark::add_to_liveness(uint worker_id, oop const obj, size_t size) {
208 task(worker_id)->update_liveness(obj, size);
209 }
210
211 inline void G1CMTask::abort_marking_if_regular_check_fail() {
212 if (!regular_clock_call()) {
213 set_has_aborted();
214 }
215 }
216
217 inline bool G1CMTask::make_reference_grey(oop obj) {
218 if (!_cm->mark_in_next_bitmap(_worker_id, obj)) {
219 return false;
220 }
221
222 // No OrderAccess:store_load() is needed. It is implicit in the
223 // CAS done in G1CMBitMap::parMark() call in the routine above.
224 HeapWord* global_finger = _cm->finger();
225
226 // We only need to push a newly grey object on the mark
227 // stack if it is in a section of memory the mark bitmap
228 // scan has already examined. Mark bitmap scanning
229 // maintains progress "fingers" for determining that.
230 //
231 // Notice that the global finger might be moving forward
232 // concurrently. This is not a problem. In the worst case, we
233 // mark the object while it is above the global finger and, by
234 // the time we read the global finger, it has moved forward
235 // past this object. In this case, the object will probably
236 // be visited when a task is scanning the region and will also
237 // be pushed on the stack. So, some duplicate work, but no
238 // correctness problems.
239 if (is_below_finger(obj, global_finger)) {
240 G1TaskQueueEntry entry = G1TaskQueueEntry::from_oop(obj);
241 if (obj->is_typeArray()) {
242 // Immediately process arrays of primitive types, rather
243 // than pushing on the mark stack. This keeps us from
244 // adding humongous objects to the mark stack that might
245 // be reclaimed before the entry is processed - see
246 // selection of candidates for eager reclaim of humongous
247 // objects. The cost of the additional type test is
248 // mitigated by avoiding a trip through the mark stack,
249 // by only doing a bookkeeping update and avoiding the
250 // actual scan of the object - a typeArray contains no
251 // references, and the metadata is built-in.
252 process_grey_task_entry<false>(entry);
253 } else {
254 push(entry);
255 }
256 }
257 return true;
258 }
259
260 template <class T>
261 inline bool G1CMTask::deal_with_reference(T* p) {
262 increment_refs_reached();
263 oop const obj = RawAccess<MO_RELAXED>::oop_load(p);
264 if (obj == NULL) {
265 return false;
266 }
267 return make_reference_grey(obj);
268 }
269
270 inline void G1ConcurrentMark::mark_in_prev_bitmap(oop p) {
271 assert(!_prev_mark_bitmap->is_marked(p), "sanity");
272 _prev_mark_bitmap->mark(p);
273 }
274
275 bool G1ConcurrentMark::is_marked_in_prev_bitmap(oop p) const {
276 assert(p != NULL && oopDesc::is_oop(p), "expected an oop");
277 return _prev_mark_bitmap->is_marked(cast_from_oop<HeapWord*>(p));
278 }
279
280 bool G1ConcurrentMark::is_marked_in_next_bitmap(oop p) const {
281 assert(p != NULL && oopDesc::is_oop(p), "expected an oop");
282 return _next_mark_bitmap->is_marked(cast_from_oop<HeapWord*>(p));
283 }
284
285 inline bool G1ConcurrentMark::do_yield_check() {
286 if (SuspendibleThreadSet::should_yield()) {
287 SuspendibleThreadSet::yield();
288 return true;
289 } else {
290 return false;
291 }
292 }
293
294 #endif // SHARE_GC_G1_G1CONCURRENTMARK_INLINE_HPP