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