1 /*
2 * Copyright (c) 2014, 2018, 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_G1_G1PARSCANTHREADSTATE_HPP
26 #define SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP
27
28 #include "gc/g1/dirtyCardQueue.hpp"
29 #include "gc/g1/g1CardTable.hpp"
30 #include "gc/g1/g1CollectedHeap.hpp"
31 #include "gc/g1/g1OopClosures.hpp"
32 #include "gc/g1/g1Policy.hpp"
33 #include "gc/g1/g1RemSet.hpp"
34 #include "gc/g1/heapRegionRemSet.hpp"
35 #include "gc/shared/ageTable.hpp"
36 #include "memory/allocation.hpp"
37 #include "oops/oop.hpp"
38 #include "utilities/ticks.hpp"
39
40 class G1PLABAllocator;
41 class G1EvacuationRootClosures;
42 class HeapRegion;
43 class outputStream;
44
45 class G1ParScanThreadState : public CHeapObj<mtGC> {
46 G1CollectedHeap* _g1h;
47 RefToScanQueue* _refs;
48 DirtyCardQueue _dcq;
49 G1CardTable* _ct;
50 G1EvacuationRootClosures* _closures;
51
52 G1PLABAllocator* _plab_allocator;
53
54 AgeTable _age_table;
55 InCSetState _dest[InCSetState::Num];
56 // Local tenuring threshold.
57 uint _tenuring_threshold;
58 G1ScanEvacuatedObjClosure _scanner;
59
60 uint _worker_id;
61
62 // Upper and lower threshold to start and end work queue draining.
63 uint const _stack_trim_upper_threshold;
64 uint const _stack_trim_lower_threshold;
65
66 Tickspan _trim_ticks;
67 // Map from young-age-index (0 == not young, 1 is youngest) to
68 // surviving words. base is what we get back from the malloc call
69 size_t* _surviving_young_words_base;
70 // this points into the array, as we use the first few entries for padding
71 size_t* _surviving_young_words;
72
73 // Indicates whether in the last generation (old) there is no more space
74 // available for allocation.
75 bool _old_gen_is_full;
76
77 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
78
79 DirtyCardQueue& dirty_card_queue() { return _dcq; }
80 G1CardTable* ct() { return _ct; }
81
82 InCSetState dest(InCSetState original) const {
83 assert(original.is_valid(),
84 "Original state invalid: " CSETSTATE_FORMAT, original.value());
85 assert(_dest[original.value()].is_valid_gen(),
86 "Dest state is invalid: " CSETSTATE_FORMAT, _dest[original.value()].value());
87 return _dest[original.value()];
88 }
89
90 public:
91 G1ParScanThreadState(G1CollectedHeap* g1h, uint worker_id, size_t young_cset_length);
92 virtual ~G1ParScanThreadState();
93
94 void set_ref_discoverer(ReferenceDiscoverer* rd) { _scanner.set_ref_discoverer(rd); }
95
96 #ifdef ASSERT
97 bool queue_is_empty() const { return _refs->is_empty(); }
98
99 bool verify_ref(narrowOop* ref) const;
100 bool verify_ref(oop* ref) const;
101 bool verify_task(StarTask ref) const;
102 #endif // ASSERT
103
104 template <class T> void do_oop_ext(T* ref);
105 template <class T> void push_on_queue(T* ref);
106
107 template <class T> void enqueue_card_if_tracked(T* p, oop o) {
108 assert(!HeapRegion::is_in_same_region(p, o), "Should have filtered out cross-region references already.");
109 assert(!_g1h->heap_region_containing(p)->is_young(), "Should have filtered out from-young references already.");
110 if (!_g1h->heap_region_containing((HeapWord*)o)->rem_set()->is_tracked()) {
111 return;
112 }
113 size_t card_index = ct()->index_for(p);
114 // If the card hasn't been added to the buffer, do it.
115 if (ct()->mark_card_deferred(card_index)) {
116 dirty_card_queue().enqueue((jbyte*)ct()->byte_for_index(card_index));
117 }
118 }
119
120 G1EvacuationRootClosures* closures() { return _closures; }
121 uint worker_id() { return _worker_id; }
122
123 // Returns the current amount of waste due to alignment or not being able to fit
124 // objects within LABs and the undo waste.
125 virtual void waste(size_t& wasted, size_t& undo_wasted);
126
127 size_t* surviving_young_words() {
128 // We add one to hide entry 0 which accumulates surviving words for
129 // age -1 regions (i.e. non-young ones)
130 return _surviving_young_words + 1;
131 }
132
133 void flush(size_t* surviving_young_words);
134
135 private:
136 #define G1_PARTIAL_ARRAY_MASK 0x2
137
138 inline bool has_partial_array_mask(oop* ref) const {
139 return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
140 }
141
142 // We never encode partial array oops as narrowOop*, so return false immediately.
143 // This allows the compiler to create optimized code when popping references from
144 // the work queue.
145 inline bool has_partial_array_mask(narrowOop* ref) const {
146 assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
147 return false;
148 }
149
150 // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
151 // We always encode partial arrays as regular oop, to allow the
152 // specialization for has_partial_array_mask() for narrowOops above.
153 // This means that unintentional use of this method with narrowOops are caught
154 // by the compiler.
155 inline oop* set_partial_array_mask(oop obj) const {
156 assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
157 return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
158 }
159
160 inline oop clear_partial_array_mask(oop* ref) const {
161 return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
162 }
163
164 inline void do_oop_partial_array(oop* p);
165
166 // This method is applied to the fields of the objects that have just been copied.
167 template <class T> inline void do_oop_evac(T* p);
168
169 inline void deal_with_reference(oop* ref_to_scan);
170 inline void deal_with_reference(narrowOop* ref_to_scan);
171
172 inline void dispatch_reference(StarTask ref);
173
174 // Tries to allocate word_sz in the PLAB of the next "generation" after trying to
175 // allocate into dest. State is the original (source) cset state for the object
176 // that is allocated for. Previous_plab_refill_failed indicates whether previously
177 // a PLAB refill into "state" failed.
178 // Returns a non-NULL pointer if successful, and updates dest if required.
179 // Also determines whether we should continue to try to allocate into the various
180 // generations or just end trying to allocate.
181 HeapWord* allocate_in_next_plab(InCSetState const state,
182 InCSetState* dest,
183 size_t word_sz,
184 bool previous_plab_refill_failed);
185
186 inline InCSetState next_state(InCSetState const state, markOop const m, uint& age);
187
188 void report_promotion_event(InCSetState const dest_state,
189 oop const old, size_t word_sz, uint age,
190 HeapWord * const obj_ptr) const;
191
192 inline bool needs_partial_trimming() const;
193 inline bool is_partially_trimmed() const;
194
195 inline void trim_queue_to_threshold(uint threshold);
196 public:
197 oop copy_to_survivor_space(InCSetState const state, oop const obj, markOop const old_mark);
198
199 void trim_queue();
200 void trim_queue_partially();
201
202 Tickspan trim_ticks() const;
203 void reset_trim_ticks();
204
205 inline void steal_and_trim_queue(RefToScanQueueSet *task_queues);
206
207 // An attempt to evacuate "obj" has failed; take necessary steps.
208 oop handle_evacuation_failure_par(oop obj, markOop m);
209 };
210
211 class G1ParScanThreadStateSet : public StackObj {
212 G1CollectedHeap* _g1h;
213 G1ParScanThreadState** _states;
214 size_t* _surviving_young_words_total;
215 size_t _young_cset_length;
216 uint _n_workers;
217 bool _flushed;
218
219 public:
220 G1ParScanThreadStateSet(G1CollectedHeap* g1h, uint n_workers, size_t young_cset_length);
221 ~G1ParScanThreadStateSet();
222
223 void flush();
224
225 G1ParScanThreadState* state_for_worker(uint worker_id);
226
227 const size_t* surviving_young_words() const;
228
229 private:
230 G1ParScanThreadState* new_par_scan_state(uint worker_id, size_t young_cset_length);
231 };
232
233 #endif // SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP