1 /*
2 * Copyright (c) 2001, 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
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_MEMORY_TENUREDGENERATION_HPP
26 #define SHARE_VM_MEMORY_TENUREDGENERATION_HPP
27
28 #include "gc_implementation/shared/cSpaceCounters.hpp"
29 #include "gc_implementation/shared/gcStats.hpp"
30 #include "gc_implementation/shared/generationCounters.hpp"
31 #include "memory/cardGeneration.hpp"
32 #include "utilities/macros.hpp"
33
34 // TenuredGeneration models the heap containing old (promoted/tenured) objects
35 // contained in a single contiguous space.
36 //
37 // Garbage collection is performed using mark-compact.
38
39 class TenuredGeneration: public CardGeneration {
40 friend class VMStructs;
41 // Abstractly, this is a subtype that gets access to protected fields.
42 friend class VM_PopulateDumpSharedSpace;
43
44 protected:
45 ContiguousSpace* _the_space; // actual space holding objects
46
47 GenerationCounters* _gen_counters;
48 CSpaceCounters* _space_counters;
49
50 // Grow generation with specified size (returns false if unable to grow)
51 virtual bool grow_by(size_t bytes);
52 // Grow generation to reserved size.
53 virtual bool grow_to_reserved();
54 // Shrink generation with specified size (returns false if unable to shrink)
55 void shrink_by(size_t bytes);
56
57 // Allocation failure
58 virtual bool expand(size_t bytes, size_t expand_bytes);
59 void shrink(size_t bytes);
60
61 // Accessing spaces
62 ContiguousSpace* the_space() const { return _the_space; }
63
64 public:
65 TenuredGeneration(ReservedSpace rs, size_t initial_byte_size,
66 int level, GenRemSet* remset);
67
68 Generation::Name kind() { return Generation::MarkSweepCompact; }
69
70 // Printing
71 const char* name() const { return "tenured generation"; }
72 const char* short_name() const { return "Tenured"; }
73
74 // Does a "full" (forced) collection invoked on this generation collect
75 // all younger generations as well? Note that this is a
76 // hack to allow the collection of the younger gen first if the flag is
77 // set.
78 virtual bool full_collects_younger_generations() const {
79 return !ScavengeBeforeFullGC;
80 }
81
82 inline bool is_in(const void* p) const;
83
84 // Space enquiries
85 size_t capacity() const;
86 size_t used() const;
87 size_t free() const;
88
89 MemRegion used_region() const;
90
91 size_t unsafe_max_alloc_nogc() const;
92 size_t contiguous_available() const;
93
94 // Iteration
95 void object_iterate(ObjectClosure* blk);
96 void space_iterate(SpaceClosure* blk, bool usedOnly = false);
97
98 void younger_refs_iterate(OopsInGenClosure* blk);
99
100 inline CompactibleSpace* first_compaction_space() const;
101
102 virtual inline HeapWord* allocate(size_t word_size, bool is_tlab);
103 virtual inline HeapWord* par_allocate(size_t word_size, bool is_tlab);
104
105 #define TenuredGen_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \
106 void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
107 TenuredGen_SINCE_SAVE_MARKS_DECL(OopsInGenClosure,_v)
108 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(TenuredGen_SINCE_SAVE_MARKS_DECL)
109
110 void save_marks();
111 void reset_saved_marks();
112 bool no_allocs_since_save_marks();
113
114 inline size_t block_size(const HeapWord* addr) const;
115
116 inline bool block_is_obj(const HeapWord* addr) const;
117
118 virtual void collect(bool full,
119 bool clear_all_soft_refs,
120 size_t size,
121 bool is_tlab);
122 HeapWord* expand_and_allocate(size_t size,
123 bool is_tlab,
124 bool parallel = false);
125
126 virtual void prepare_for_verify();
127
128
129 virtual void gc_prologue(bool full);
130 virtual void gc_epilogue(bool full);
131 bool should_collect(bool full,
132 size_t word_size,
133 bool is_tlab);
134
135 virtual void compute_new_size();
136
137 // Performance Counter support
138 void update_counters();
139
140 virtual void record_spaces_top();
141
142 // Statistics
143
144 virtual void update_gc_stats(int level, bool full);
145
146 virtual bool promotion_attempt_is_safe(size_t max_promoted_in_bytes) const;
147
148 virtual void verify();
149 virtual void print_on(outputStream* st) const;
150 };
151
152 #endif // SHARE_VM_MEMORY_TENUREDGENERATION_HPP