1 /*
2 * Copyright (c) 2002, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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,
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23 */
24
25 #ifndef SHARE_GC_PARALLEL_PSPROMOTIONMANAGER_HPP
26 #define SHARE_GC_PARALLEL_PSPROMOTIONMANAGER_HPP
27
28 #include "gc/parallel/psPromotionLAB.hpp"
29 #include "gc/shared/copyFailedInfo.hpp"
30 #include "gc/shared/gcTrace.hpp"
31 #include "gc/shared/preservedMarks.hpp"
32 #include "gc/shared/taskqueue.hpp"
33 #include "memory/padded.hpp"
34 #include "utilities/globalDefinitions.hpp"
35
36 //
37 // psPromotionManager is used by a single thread to manage object survival
38 // during a scavenge. The promotion manager contains thread local data only.
39 //
40 // NOTE! Be careful when allocating the stacks on cheap. If you are going
41 // to use a promotion manager in more than one thread, the stacks MUST be
42 // on cheap. This can lead to memory leaks, though, as they are not auto
43 // deallocated.
44 //
45 // FIX ME FIX ME Add a destructor, and don't rely on the user to drain/flush/deallocate!
46 //
47
48 class MutableSpace;
49 class PSOldGen;
50 class ParCompactionManager;
51
52 class PSPromotionManager {
53 friend class PSScavenge;
54 friend class ScavengeRootsTask;
55 friend class PSRefProcTaskExecutor;
56 friend class PSRefProcTask;
57
58 private:
59 static PaddedEnd<PSPromotionManager>* _manager_array;
60 static OopStarTaskQueueSet* _stack_array_depth;
61 static PreservedMarksSet* _preserved_marks_set;
62 static PSOldGen* _old_gen;
63 static MutableSpace* _young_space;
64
65 #if TASKQUEUE_STATS
66 size_t _masked_pushes;
67 size_t _masked_steals;
68 size_t _arrays_chunked;
69 size_t _array_chunks_processed;
70
71 void print_local_stats(outputStream* const out, uint i) const;
72 static void print_taskqueue_stats();
73
74 void reset_stats();
75 #endif // TASKQUEUE_STATS
76
77 PSYoungPromotionLAB _young_lab;
78 PSOldPromotionLAB _old_lab;
79 bool _young_gen_is_full;
80 bool _old_gen_is_full;
81
82 OopStarTaskQueue _claimed_stack_depth;
83 OverflowTaskQueue<oop, mtGC> _claimed_stack_breadth;
84
85 bool _totally_drain;
86 uint _target_stack_size;
87
88 uint _array_chunk_size;
89 uint _min_array_size_for_chunking;
90
91 PreservedMarks* _preserved_marks;
92 PromotionFailedInfo _promotion_failed_info;
93
94 // Accessors
95 static PSOldGen* old_gen() { return _old_gen; }
96 static MutableSpace* young_space() { return _young_space; }
97
98 inline static PSPromotionManager* manager_array(uint index);
99 template <class T> inline void claim_or_forward_internal_depth(T* p);
100
101 // On the task queues we push reference locations as well as
102 // partially-scanned arrays (in the latter case, we push an oop to
103 // the from-space image of the array and the length on the
104 // from-space image indicates how many entries on the array we still
105 // need to scan. To be able to distinguish between reference
106 // locations and partially-scanned array oops we simply mask the
107 // latter oops with 0x01. The next three methods do the masking,
108 // unmasking, and checking whether the oop is masked or not. Notice
109 // that the signature of the mask and unmask methods looks a bit
110 // strange, as they accept and return different types (oop and
111 // oop*). This is because of the difference in types between what
112 // the task queue holds (oop*) and oops to partially-scanned arrays
113 // (oop). We do all the necessary casting in the mask / unmask
114 // methods to avoid sprinkling the rest of the code with more casts.
115
116 // These are added to the taskqueue so PS_CHUNKED_ARRAY_OOP_MASK (or any
117 // future masks) can't conflict with COMPRESSED_OOP_MASK
118 #define PS_CHUNKED_ARRAY_OOP_MASK 0x2
119
120 bool is_oop_masked(StarTask p) {
121 // If something is marked chunked it's always treated like wide oop*
122 return (((intptr_t)(oop*)p) & PS_CHUNKED_ARRAY_OOP_MASK) ==
123 PS_CHUNKED_ARRAY_OOP_MASK;
124 }
125
126 oop* mask_chunked_array_oop(oop obj) {
127 assert(!is_oop_masked(cast_from_oop<oop*>(obj)), "invariant");
128 oop* ret = (oop*) (cast_from_oop<uintptr_t>(obj) | PS_CHUNKED_ARRAY_OOP_MASK);
129 assert(is_oop_masked(ret), "invariant");
130 return ret;
131 }
132
133 oop unmask_chunked_array_oop(StarTask p) {
134 assert(is_oop_masked(p), "invariant");
135 assert(!p.is_narrow(), "chunked array oops cannot be narrow");
136 oop *chunk = (oop*)p; // cast p to oop (uses conversion operator)
137 oop ret = oop((oop*)((uintptr_t)chunk & ~PS_CHUNKED_ARRAY_OOP_MASK));
138 assert(!is_oop_masked(cast_from_oop<oop*>(ret)), "invariant");
139 return ret;
140 }
141
142 template <class T> void process_array_chunk_work(oop obj,
143 int start, int end);
144 void process_array_chunk(oop old);
145
146 template <class T> void push_depth(T* p);
147
148 inline void promotion_trace_event(oop new_obj, oop old_obj, size_t obj_size,
149 uint age, bool tenured,
150 const PSPromotionLAB* lab);
151
152 protected:
153 static OopStarTaskQueueSet* stack_array_depth() { return _stack_array_depth; }
154 public:
155 // Static
156 static void initialize();
157
158 static void pre_scavenge();
159 static bool post_scavenge(YoungGCTracer& gc_tracer);
160
161 static PSPromotionManager* gc_thread_promotion_manager(uint index);
162 static PSPromotionManager* vm_thread_promotion_manager();
163
164 static bool steal_depth(int queue_num, StarTask& t);
165
166 PSPromotionManager();
167
168 // Accessors
169 OopStarTaskQueue* claimed_stack_depth() {
170 return &_claimed_stack_depth;
171 }
172
173 bool young_gen_is_full() { return _young_gen_is_full; }
174
175 bool old_gen_is_full() { return _old_gen_is_full; }
176 void set_old_gen_is_full(bool state) { _old_gen_is_full = state; }
177
178 // Promotion methods
179 template<bool promote_immediately> oop copy_to_survivor_space(oop o);
180 oop oop_promotion_failed(oop obj, markWord obj_mark);
181
182 void reset();
183 void register_preserved_marks(PreservedMarks* preserved_marks);
184 static void restore_preserved_marks();
185
186 void flush_labs();
187 void drain_stacks(bool totally_drain) {
188 drain_stacks_depth(totally_drain);
189 }
190 public:
191 void drain_stacks_cond_depth() {
192 if (claimed_stack_depth()->size() > _target_stack_size) {
193 drain_stacks_depth(false);
194 }
195 }
196 void drain_stacks_depth(bool totally_drain);
197
198 bool stacks_empty() {
199 return claimed_stack_depth()->is_empty();
200 }
201
202 inline void process_popped_location_depth(StarTask p);
203
204 static bool should_scavenge(oop* p, bool check_to_space = false);
205 static bool should_scavenge(narrowOop* p, bool check_to_space = false);
206
207 template <class T, bool promote_immediately>
208 void copy_and_push_safe_barrier(T* p);
209
210 template <class T> inline void claim_or_forward_depth(T* p);
211
212 TASKQUEUE_STATS_ONLY(inline void record_steal(StarTask& p);)
213
214 void push_contents(oop obj);
215 };
216
217 #endif // SHARE_GC_PARALLEL_PSPROMOTIONMANAGER_HPP