Tue, 08 Aug 2017 15:57:29 +0800
merge
1 /*
2 * Copyright (c) 2002, 2013, 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
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23 */
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_HPP
28 #include "gc_implementation/parallelScavenge/cardTableExtension.hpp"
29 #include "gc_implementation/parallelScavenge/psVirtualspace.hpp"
30 #include "gc_implementation/shared/collectorCounters.hpp"
31 #include "gc_implementation/shared/gcTrace.hpp"
32 #include "memory/allocation.hpp"
33 #include "oops/oop.hpp"
34 #include "utilities/stack.hpp"
36 class GCTaskManager;
37 class GCTaskQueue;
38 class OopStack;
39 class ReferenceProcessor;
40 class ParallelScavengeHeap;
41 class ParallelScavengeTracer;
42 class PSIsAliveClosure;
43 class PSRefProcTaskExecutor;
44 class STWGCTimer;
46 class PSScavenge: AllStatic {
47 friend class PSIsAliveClosure;
48 friend class PSKeepAliveClosure;
49 friend class PSPromotionManager;
51 enum ScavengeSkippedCause {
52 not_skipped = 0,
53 to_space_not_empty,
54 promoted_too_large,
55 full_follows_scavenge
56 };
58 // Saved value of to_space->top(), used to prevent objects in to_space from
59 // being rescanned.
60 static HeapWord* _to_space_top_before_gc;
62 // Number of consecutive attempts to scavenge that were skipped
63 static int _consecutive_skipped_scavenges;
66 protected:
67 // Flags/counters
68 static ReferenceProcessor* _ref_processor; // Reference processor for scavenging.
69 static PSIsAliveClosure _is_alive_closure; // Closure used for reference processing
70 static CardTableExtension* _card_table; // We cache the card table for fast access.
71 static bool _survivor_overflow; // Overflow this collection
72 static uint _tenuring_threshold; // tenuring threshold for next scavenge
73 static elapsedTimer _accumulated_time; // total time spent on scavenge
74 static STWGCTimer _gc_timer; // GC time book keeper
75 static ParallelScavengeTracer _gc_tracer; // GC tracing
76 // The lowest address possible for the young_gen.
77 // This is used to decide if an oop should be scavenged,
78 // cards should be marked, etc.
79 static HeapWord* _young_generation_boundary;
80 // Used to optimize compressed oops young gen boundary checking.
81 static uintptr_t _young_generation_boundary_compressed;
82 static Stack<markOop, mtGC> _preserved_mark_stack; // List of marks to be restored after failed promotion
83 static Stack<oop, mtGC> _preserved_oop_stack; // List of oops that need their mark restored.
84 static CollectorCounters* _counters; // collector performance counters
86 static void clean_up_failed_promotion();
88 static bool should_attempt_scavenge();
90 static HeapWord* to_space_top_before_gc() { return _to_space_top_before_gc; }
91 static inline void save_to_space_top_before_gc();
93 // Private accessors
94 static CardTableExtension* const card_table() { assert(_card_table != NULL, "Sanity"); return _card_table; }
96 public:
97 // Accessors
98 static uint tenuring_threshold() { return _tenuring_threshold; }
99 static elapsedTimer* accumulated_time() { return &_accumulated_time; }
100 static int consecutive_skipped_scavenges()
101 { return _consecutive_skipped_scavenges; }
103 // Performance Counters
104 static CollectorCounters* counters() { return _counters; }
106 // Used by scavenge_contents && psMarkSweep
107 static ReferenceProcessor* const reference_processor() {
108 assert(_ref_processor != NULL, "Sanity");
109 return _ref_processor;
110 }
111 // Used to add tasks
112 static GCTaskManager* const gc_task_manager();
113 // The promotion managers tell us if they encountered overflow
114 static void set_survivor_overflow(bool state) {
115 _survivor_overflow = state;
116 }
117 // Adaptive size policy support. When the young generation/old generation
118 // boundary moves, _young_generation_boundary must be reset
119 static void set_young_generation_boundary(HeapWord* v) {
120 _young_generation_boundary = v;
121 if (UseCompressedOops) {
122 _young_generation_boundary_compressed = (uintptr_t)oopDesc::encode_heap_oop((oop)v);
123 }
124 }
126 // Called by parallelScavengeHeap to init the tenuring threshold
127 static void initialize();
129 // Scavenge entry point. This may invoke a full gc; return true if so.
130 static bool invoke();
131 // Return true if a collection was done; false otherwise.
132 static bool invoke_no_policy();
134 // If an attempt to promote fails, this method is invoked
135 static void oop_promotion_failed(oop obj, markOop obj_mark);
137 template <class T> static inline bool should_scavenge(T* p);
139 // These call should_scavenge() above and, if it returns true, also check that
140 // the object was not newly copied into to_space. The version with the bool
141 // argument is a convenience wrapper that fetches the to_space pointer from
142 // the heap and calls the other version (if the arg is true).
143 template <class T> static inline bool should_scavenge(T* p, MutableSpace* to_space);
144 template <class T> static inline bool should_scavenge(T* p, bool check_to_space);
146 template <class T, bool promote_immediately>
147 inline static void copy_and_push_safe_barrier(PSPromotionManager* pm, T* p);
149 static void copy_and_push_safe_barrier_from_klass(PSPromotionManager* pm, oop* p);
151 // Is an object in the young generation
152 // This assumes that the 'o' is in the heap,
153 // so it only checks one side of the complete predicate.
155 inline static bool is_obj_in_young(oop o) {
156 return (HeapWord*)o >= _young_generation_boundary;
157 }
159 inline static bool is_obj_in_young(narrowOop o) {
160 return (uintptr_t)o >= _young_generation_boundary_compressed;
161 }
163 inline static bool is_obj_in_young(HeapWord* o) {
164 return o >= _young_generation_boundary;
165 }
166 };
168 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_HPP