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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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).
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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 typedef OverflowTaskQueue<StarTask, mtGC> OopStarTaskQueue;
60 typedef GenericTaskQueueSet<OopStarTaskQueue, mtGC> OopStarTaskQueueSet;
61
62 static PaddedEnd<PSPromotionManager>* _manager_array;
63 static OopStarTaskQueueSet* _stack_array_depth;
64 static PreservedMarksSet* _preserved_marks_set;
65 static PSOldGen* _old_gen;
66 static MutableSpace* _young_space;
67
68 #if TASKQUEUE_STATS
69 size_t _masked_pushes;
70 size_t _masked_steals;
71 size_t _arrays_chunked;
72 size_t _array_chunks_processed;
73
74 void print_local_stats(outputStream* const out, uint i) const;
75 static void print_taskqueue_stats();
76
77 void reset_stats();
78 #endif // TASKQUEUE_STATS
79
80 PSYoungPromotionLAB _young_lab;
81 PSOldPromotionLAB _old_lab;
82 bool _young_gen_is_full;
83 bool _old_gen_is_full;
84
85 OopStarTaskQueue _claimed_stack_depth;
86 OverflowTaskQueue<oop, mtGC> _claimed_stack_breadth;
87
88 bool _totally_drain;
89 uint _target_stack_size;
90
91 uint _array_chunk_size;
92 uint _min_array_size_for_chunking;
93
94 PreservedMarks* _preserved_marks;
95 PromotionFailedInfo _promotion_failed_info;
96
97 // Accessors
98 static PSOldGen* old_gen() { return _old_gen; }
99 static MutableSpace* young_space() { return _young_space; }
100
101 inline static PSPromotionManager* manager_array(uint index);
102 template <class T> inline void claim_or_forward_internal_depth(T* p);
103
104 // On the task queues we push reference locations as well as
105 // partially-scanned arrays (in the latter case, we push an oop to
106 // the from-space image of the array and the length on the
107 // from-space image indicates how many entries on the array we still
108 // need to scan. To be able to distinguish between reference
109 // locations and partially-scanned array oops we simply mask the
110 // latter oops with 0x01. The next three methods do the masking,
111 // unmasking, and checking whether the oop is masked or not. Notice
112 // that the signature of the mask and unmask methods looks a bit
113 // strange, as they accept and return different types (oop and
114 // oop*). This is because of the difference in types between what
115 // the task queue holds (oop*) and oops to partially-scanned arrays
116 // (oop). We do all the necessary casting in the mask / unmask
117 // methods to avoid sprinkling the rest of the code with more casts.
118
119 // These are added to the taskqueue so PS_CHUNKED_ARRAY_OOP_MASK (or any
120 // future masks) can't conflict with COMPRESSED_OOP_MASK
121 #define PS_CHUNKED_ARRAY_OOP_MASK 0x2
122
123 bool is_oop_masked(StarTask p) {
124 // If something is marked chunked it's always treated like wide oop*
125 return (((intptr_t)(oop*)p) & PS_CHUNKED_ARRAY_OOP_MASK) ==
126 PS_CHUNKED_ARRAY_OOP_MASK;
127 }
128
129 oop* mask_chunked_array_oop(oop obj) {
130 assert(!is_oop_masked(cast_from_oop<oop*>(obj)), "invariant");
131 oop* ret = (oop*) (cast_from_oop<uintptr_t>(obj) | PS_CHUNKED_ARRAY_OOP_MASK);
132 assert(is_oop_masked(ret), "invariant");
133 return ret;
134 }
135
136 oop unmask_chunked_array_oop(StarTask p) {
137 assert(is_oop_masked(p), "invariant");
138 assert(!p.is_narrow(), "chunked array oops cannot be narrow");
139 oop *chunk = (oop*)p; // cast p to oop (uses conversion operator)
140 oop ret = oop((oop*)((uintptr_t)chunk & ~PS_CHUNKED_ARRAY_OOP_MASK));
141 assert(!is_oop_masked(cast_from_oop<oop*>(ret)), "invariant");
142 return ret;
143 }
144
145 template <class T> void process_array_chunk_work(oop obj,
146 int start, int end);
147 void process_array_chunk(oop old);
148
149 template <class T> void push_depth(T* p);
150
151 inline void promotion_trace_event(oop new_obj, oop old_obj, size_t obj_size,
152 uint age, bool tenured,
153 const PSPromotionLAB* lab);
154
155 protected:
156 static OopStarTaskQueueSet* stack_array_depth() { return _stack_array_depth; }
157 public:
158 // Static
159 static void initialize();
160
161 static void pre_scavenge();
162 static bool post_scavenge(YoungGCTracer& gc_tracer);
163
164 static PSPromotionManager* gc_thread_promotion_manager(uint index);
165 static PSPromotionManager* vm_thread_promotion_manager();
166
167 static bool steal_depth(int queue_num, StarTask& t);
168
169 PSPromotionManager();
170
171 // Accessors
172 OopStarTaskQueue* claimed_stack_depth() {
173 return &_claimed_stack_depth;
174 }
175
176 bool young_gen_is_full() { return _young_gen_is_full; }
177
178 bool old_gen_is_full() { return _old_gen_is_full; }
179 void set_old_gen_is_full(bool state) { _old_gen_is_full = state; }
180
181 // Promotion methods
182 template<bool promote_immediately> oop copy_to_survivor_space(oop o);
183 oop oop_promotion_failed(oop obj, markWord obj_mark);
184
185 void reset();
186 void register_preserved_marks(PreservedMarks* preserved_marks);
187 static void restore_preserved_marks();
188
189 void flush_labs();
190 void drain_stacks(bool totally_drain) {
191 drain_stacks_depth(totally_drain);
192 }
193 public:
194 void drain_stacks_cond_depth() {
195 if (claimed_stack_depth()->size() > _target_stack_size) {
196 drain_stacks_depth(false);
197 }
198 }
199 void drain_stacks_depth(bool totally_drain);
200
201 bool stacks_empty() {
202 return claimed_stack_depth()->is_empty();
203 }
204
205 inline void process_popped_location_depth(StarTask p);
206
207 static bool should_scavenge(oop* p, bool check_to_space = false);
208 static bool should_scavenge(narrowOop* p, bool check_to_space = false);
209
210 template <class T, bool promote_immediately>
211 void copy_and_push_safe_barrier(T* p);
212
213 template <class T> inline void claim_or_forward_depth(T* p);
214
215 TASKQUEUE_STATS_ONLY(inline void record_steal(StarTask& p);)
216
217 void push_contents(oop obj);
218 };
219
220 #endif // SHARE_GC_PARALLEL_PSPROMOTIONMANAGER_HPP