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.
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_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; this is basically how ParNew does partial array
106 // scanning too). To be able to distinguish between reference
107 // locations and partially-scanned array oops we simply mask the
108 // latter oops with 0x01. The next three methods do the masking,
109 // unmasking, and checking whether the oop is masked or not. Notice
110 // that the signature of the mask and unmask methods looks a bit
111 // strange, as they accept and return different types (oop and
112 // oop*). This is because of the difference in types between what
113 // the task queue holds (oop*) and oops to partially-scanned arrays
114 // (oop). We do all the necessary casting in the mask / unmask
115 // methods to avoid sprinkling the rest of the code with more casts.
116
117 // These are added to the taskqueue so PS_CHUNKED_ARRAY_OOP_MASK (or any
118 // future masks) can't conflict with COMPRESSED_OOP_MASK
119 #define PS_CHUNKED_ARRAY_OOP_MASK 0x2
120
121 bool is_oop_masked(StarTask p) {
122 // If something is marked chunked it's always treated like wide oop*
123 return (((intptr_t)(oop*)p) & PS_CHUNKED_ARRAY_OOP_MASK) ==
124 PS_CHUNKED_ARRAY_OOP_MASK;
125 }
126
127 oop* mask_chunked_array_oop(oop obj) {
128 assert(!is_oop_masked((oop*) obj), "invariant");
129 oop* ret = (oop*) (cast_from_oop<uintptr_t>(obj) | PS_CHUNKED_ARRAY_OOP_MASK);
130 assert(is_oop_masked(ret), "invariant");
131 return ret;
132 }
133
134 oop unmask_chunked_array_oop(StarTask p) {
135 assert(is_oop_masked(p), "invariant");
136 assert(!p.is_narrow(), "chunked array oops cannot be narrow");
137 oop *chunk = (oop*)p; // cast p to oop (uses conversion operator)
138 oop ret = oop((oop*)((uintptr_t)chunk & ~PS_CHUNKED_ARRAY_OOP_MASK));
139 assert(!is_oop_masked((oop*) ret), "invariant");
140 return ret;
141 }
142
143 template <class T> void process_array_chunk_work(oop obj,
144 int start, int end);
145 void process_array_chunk(oop old);
146
147 template <class T> void push_depth(T* p);
148
149 inline void promotion_trace_event(oop new_obj, oop old_obj, size_t obj_size,
150 uint age, bool tenured,
151 const PSPromotionLAB* lab);
152
153 protected:
154 static OopStarTaskQueueSet* stack_array_depth() { return _stack_array_depth; }
155 public:
156 // Static
157 static void initialize();
158
159 static void pre_scavenge();
160 static bool post_scavenge(YoungGCTracer& gc_tracer);
161
162 static PSPromotionManager* gc_thread_promotion_manager(uint index);
163 static PSPromotionManager* vm_thread_promotion_manager();
164
165 static bool steal_depth(int queue_num, StarTask& t);
166
167 PSPromotionManager();
168
169 // Accessors
170 OopStarTaskQueue* claimed_stack_depth() {
171 return &_claimed_stack_depth;
172 }
173
174 bool young_gen_is_full() { return _young_gen_is_full; }
175
176 bool old_gen_is_full() { return _old_gen_is_full; }
177 void set_old_gen_is_full(bool state) { _old_gen_is_full = state; }
178
179 // Promotion methods
180 template<bool promote_immediately> oop copy_to_survivor_space(oop o);
181 oop oop_promotion_failed(oop obj, markOop obj_mark);
182
183 void reset();
184 void register_preserved_marks(PreservedMarks* preserved_marks);
185 static void restore_preserved_marks();
186
187 void flush_labs();
188 void drain_stacks(bool totally_drain) {
189 drain_stacks_depth(totally_drain);
190 }
191 public:
192 void drain_stacks_cond_depth() {
193 if (claimed_stack_depth()->size() > _target_stack_size) {
194 drain_stacks_depth(false);
195 }
196 }
197 void drain_stacks_depth(bool totally_drain);
198
199 bool stacks_empty() {
200 return claimed_stack_depth()->is_empty();
201 }
202
203 inline void process_popped_location_depth(StarTask p);
204
205 static bool should_scavenge(oop* p, bool check_to_space = false);
206 static bool should_scavenge(narrowOop* p, bool check_to_space = false);
207
208 template <class T, bool promote_immediately>
209 void copy_and_push_safe_barrier(T* p);
210
211 template <class T> inline void claim_or_forward_depth(T* p);
212
213 TASKQUEUE_STATS_ONLY(inline void record_steal(StarTask& p);)
214
215 void push_contents(oop obj);
216 };
217
218 #endif // SHARE_GC_PARALLEL_PSPROMOTIONMANAGER_HPP