1 /*
2 * Copyright (c) 2014, Oracle and/or its affiliates. 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_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP
27
28 #include "gc_implementation/g1/dirtyCardQueue.hpp"
29 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
30 #include "gc_implementation/g1/g1CollectedHeap.hpp"
31 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
32 #include "gc_implementation/g1/g1OopClosures.hpp"
33 #include "gc_implementation/g1/g1RemSet.hpp"
34 #include "gc_implementation/shared/ageTable.hpp"
35 #include "memory/allocation.hpp"
36 #include "oops/oop.hpp"
37
38 class HeapRegion;
39 class outputStream;
40
41 class G1ParScanThreadState : public StackObj {
42 protected:
43 G1CollectedHeap* _g1h;
44 RefToScanQueue* _refs;
45 DirtyCardQueue _dcq;
46 G1SATBCardTableModRefBS* _ct_bs;
47 G1RemSet* _g1_rem;
48
49 G1ParGCAllocBuffer _surviving_alloc_buffer;
50 G1ParGCAllocBuffer _tenured_alloc_buffer;
51 G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];
52 ageTable _age_table;
53
54 G1ParScanClosure _scanner;
55
56 size_t _alloc_buffer_waste;
57 size_t _undo_waste;
58
59 OopsInHeapRegionClosure* _evac_failure_cl;
60
61 int _hash_seed;
62 uint _queue_num;
63
64 size_t _term_attempts;
65
66 double _start;
67 double _start_strong_roots;
68 double _strong_roots_time;
69 double _start_term;
70 double _term_time;
71
72 // Map from young-age-index (0 == not young, 1 is youngest) to
73 // surviving words. base is what we get back from the malloc call
74 size_t* _surviving_young_words_base;
75 // this points into the array, as we use the first few entries for padding
76 size_t* _surviving_young_words;
77
78 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
79
80 void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; }
81
82 void add_to_undo_waste(size_t waste) { _undo_waste += waste; }
83
84 DirtyCardQueue& dirty_card_queue() { return _dcq; }
85 G1SATBCardTableModRefBS* ctbs() { return _ct_bs; }
86
87 template <class T> inline void immediate_rs_update(HeapRegion* from, T* p, int tid);
88
89 template <class T> void deferred_rs_update(HeapRegion* from, T* p, int tid) {
90 // If the new value of the field points to the same region or
91 // is the to-space, we don't need to include it in the Rset updates.
92 if (!from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) && !from->is_survivor()) {
93 size_t card_index = ctbs()->index_for(p);
94 // If the card hasn't been added to the buffer, do it.
95 if (ctbs()->mark_card_deferred(card_index)) {
96 dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index));
97 }
98 }
99 }
100
101 public:
102 G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp);
103 ~G1ParScanThreadState();
104
105 RefToScanQueue* refs() { return _refs; }
106 ageTable* age_table() { return &_age_table; }
107
108 G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) {
109 return _alloc_buffers[purpose];
110 }
111
112 size_t alloc_buffer_waste() const { return _alloc_buffer_waste; }
113 size_t undo_waste() const { return _undo_waste; }
114
115 #ifdef ASSERT
116 bool verify_ref(narrowOop* ref) const;
117 bool verify_ref(oop* ref) const;
118 bool verify_task(StarTask ref) const;
119 #endif // ASSERT
120
121 template <class T> void push_on_queue(T* ref) {
122 assert(verify_ref(ref), "sanity");
123 refs()->push(ref);
124 }
125
126 template <class T> inline void update_rs(HeapRegion* from, T* p, int tid);
127
128 HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) {
129 HeapWord* obj = NULL;
130 size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
131 if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
132 G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose);
133 add_to_alloc_buffer_waste(alloc_buf->words_remaining());
134 alloc_buf->retire(false /* end_of_gc */, false /* retain */);
135
136 HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size);
137 if (buf == NULL) return NULL; // Let caller handle allocation failure.
138 // Otherwise.
139 alloc_buf->set_word_size(gclab_word_size);
140 alloc_buf->set_buf(buf);
141
142 obj = alloc_buf->allocate(word_sz);
143 assert(obj != NULL, "buffer was definitely big enough...");
144 } else {
145 obj = _g1h->par_allocate_during_gc(purpose, word_sz);
146 }
147 return obj;
148 }
149
150 HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz) {
151 HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz);
152 if (obj != NULL) return obj;
153 return allocate_slow(purpose, word_sz);
154 }
155
156 void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) {
157 if (alloc_buffer(purpose)->contains(obj)) {
158 assert(alloc_buffer(purpose)->contains(obj + word_sz - 1),
159 "should contain whole object");
160 alloc_buffer(purpose)->undo_allocation(obj, word_sz);
161 } else {
162 CollectedHeap::fill_with_object(obj, word_sz);
163 add_to_undo_waste(word_sz);
164 }
165 }
166
167 void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) {
168 _evac_failure_cl = evac_failure_cl;
169 }
170 OopsInHeapRegionClosure* evac_failure_closure() {
171 return _evac_failure_cl;
172 }
173
174 int* hash_seed() { return &_hash_seed; }
175 uint queue_num() { return _queue_num; }
176
177 size_t term_attempts() const { return _term_attempts; }
178 void note_term_attempt() { _term_attempts++; }
179
180 void start_strong_roots() {
181 _start_strong_roots = os::elapsedTime();
182 }
183 void end_strong_roots() {
184 _strong_roots_time += (os::elapsedTime() - _start_strong_roots);
185 }
186 double strong_roots_time() const { return _strong_roots_time; }
187
188 void start_term_time() {
189 note_term_attempt();
190 _start_term = os::elapsedTime();
191 }
192 void end_term_time() {
193 _term_time += (os::elapsedTime() - _start_term);
194 }
195 double term_time() const { return _term_time; }
196
197 double elapsed_time() const {
198 return os::elapsedTime() - _start;
199 }
200
201 static void
202 print_termination_stats_hdr(outputStream* const st = gclog_or_tty);
203 void
204 print_termination_stats(int i, outputStream* const st = gclog_or_tty) const;
205
206 size_t* surviving_young_words() {
207 // We add on to hide entry 0 which accumulates surviving words for
208 // age -1 regions (i.e. non-young ones)
209 return _surviving_young_words;
210 }
211
212 private:
213 void retire_alloc_buffers() {
214 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
215 size_t waste = _alloc_buffers[ap]->words_remaining();
216 add_to_alloc_buffer_waste(waste);
217 _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap),
218 true /* end_of_gc */,
219 false /* retain */);
220 }
221 }
222
223 #define G1_PARTIAL_ARRAY_MASK 0x2
224
225 inline bool has_partial_array_mask(oop* ref) const {
226 return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
227 }
228
229 // We never encode partial array oops as narrowOop*, so return false immediately.
230 // This allows the compiler to create optimized code when popping references from
231 // the work queue.
232 inline bool has_partial_array_mask(narrowOop* ref) const {
233 assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
234 return false;
235 }
236
237 // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
238 // We always encode partial arrays as regular oop, to allow the
239 // specialization for has_partial_array_mask() for narrowOops above.
240 // This means that unintentional use of this method with narrowOops are caught
241 // by the compiler.
242 inline oop* set_partial_array_mask(oop obj) const {
243 assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
244 return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
245 }
246
247 inline oop clear_partial_array_mask(oop* ref) const {
248 return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
249 }
250
251 inline void do_oop_partial_array(oop* p);
252
253 // This method is applied to the fields of the objects that have just been copied.
254 template <class T> void do_oop_evac(T* p, HeapRegion* from) {
255 assert(!oopDesc::is_null(oopDesc::load_decode_heap_oop(p)),
256 "Reference should not be NULL here as such are never pushed to the task queue.");
257 oop obj = oopDesc::load_decode_heap_oop_not_null(p);
258
259 // Although we never intentionally push references outside of the collection
260 // set, due to (benign) races in the claim mechanism during RSet scanning more
261 // than one thread might claim the same card. So the same card may be
262 // processed multiple times. So redo this check.
263 if (_g1h->in_cset_fast_test(obj)) {
264 oop forwardee;
265 if (obj->is_forwarded()) {
266 forwardee = obj->forwardee();
267 } else {
268 forwardee = copy_to_survivor_space(obj);
269 }
270 assert(forwardee != NULL, "forwardee should not be NULL");
271 oopDesc::encode_store_heap_oop(p, forwardee);
272 }
273
274 assert(obj != NULL, "Must be");
275 update_rs(from, p, queue_num());
276 }
277 public:
278
279 oop copy_to_survivor_space(oop const obj);
280
281 template <class T> inline void deal_with_reference(T* ref_to_scan);
282
283 inline void deal_with_reference(StarTask ref);
284
285 public:
286 void trim_queue();
287 };
288
289 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP