Thu, 29 Nov 2012 11:23:15 -0800
Merge
1 /*
2 * Copyright (c) 2011, 2012, 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 #ifndef SHARE_VM_MEMORY_METASPACE_HPP
25 #define SHARE_VM_MEMORY_METASPACE_HPP
27 #include "memory/allocation.hpp"
28 #include "memory/memRegion.hpp"
29 #include "runtime/virtualspace.hpp"
30 #include "utilities/exceptions.hpp"
32 // Metaspace
33 //
34 // Metaspaces are Arenas for the VM's metadata.
35 // They are allocated one per class loader object, and one for the null
36 // bootstrap class loader
37 // Eventually for bootstrap loader we'll have a read-only section and read-write
38 // to write for DumpSharedSpaces and read for UseSharedSpaces
39 //
40 // block X ---+ +-------------------+
41 // | | Virtualspace |
42 // | | |
43 // | | |
44 // | |-------------------|
45 // | || Chunk |
46 // | || |
47 // | ||---------- |
48 // +------>||| block 0 | |
49 // ||---------- |
50 // ||| block 1 | |
51 // ||---------- |
52 // || |
53 // |-------------------|
54 // | |
55 // | |
56 // +-------------------+
57 //
59 class ClassLoaderData;
60 class Metablock;
61 class MetaWord;
62 class Mutex;
63 class outputStream;
64 class SpaceManager;
66 // Metaspaces each have a SpaceManager and allocations
67 // are done by the SpaceManager. Allocations are done
68 // out of the current Metachunk. When the current Metachunk
69 // is exhausted, the SpaceManager gets a new one from
70 // the current VirtualSpace. When the VirtualSpace is exhausted
71 // the SpaceManager gets a new one. The SpaceManager
72 // also manages freelists of available Chunks.
73 //
74 // Currently the space manager maintains the list of
75 // virtual spaces and the list of chunks in use. Its
76 // allocate() method returns a block for use as a
77 // quantum of metadata.
79 class VirtualSpaceList;
81 class Metaspace : public CHeapObj<mtClass> {
82 friend class VMStructs;
83 friend class SpaceManager;
84 friend class VM_CollectForMetadataAllocation;
85 friend class MetaspaceGC;
86 friend class MetaspaceAux;
88 public:
89 enum MetadataType {ClassType, NonClassType};
91 private:
92 void initialize(Mutex* lock, size_t initial_size = 0);
94 static size_t _first_chunk_word_size;
96 SpaceManager* _vsm;
97 SpaceManager* vsm() const { return _vsm; }
99 SpaceManager* _class_vsm;
100 SpaceManager* class_vsm() const { return _class_vsm; }
102 MetaWord* allocate(size_t word_size, MetadataType mdtype);
104 // Virtual Space lists for both classes and other metadata
105 static VirtualSpaceList* _space_list;
106 static VirtualSpaceList* _class_space_list;
108 static VirtualSpaceList* space_list() { return _space_list; }
109 static VirtualSpaceList* class_space_list() { return _class_space_list; }
111 public:
113 Metaspace(Mutex* lock, size_t initial_size);
114 Metaspace(Mutex* lock);
115 ~Metaspace();
117 // Initialize globals for Metaspace
118 static void global_initialize();
119 static void initialize_class_space(ReservedSpace rs);
121 static size_t first_chunk_word_size() { return _first_chunk_word_size; }
123 char* bottom() const;
124 size_t used_words(MetadataType mdtype) const;
125 size_t free_words(MetadataType mdtype) const;
126 size_t capacity_words(MetadataType mdtype) const;
127 size_t waste_words(MetadataType mdtype) const;
129 static Metablock* allocate(ClassLoaderData* loader_data, size_t size,
130 bool read_only, MetadataType mdtype, TRAPS);
131 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
133 MetaWord* expand_and_allocate(size_t size,
134 MetadataType mdtype);
136 static bool is_initialized() { return _class_space_list != NULL; }
138 static bool contains(const void *ptr);
139 void dump(outputStream* const out) const;
141 void print_on(outputStream* st) const;
142 // Debugging support
143 void verify();
144 };
146 class MetaspaceAux : AllStatic {
148 // Statistics for class space and data space in metaspace.
149 static size_t used_in_bytes(Metaspace::MetadataType mdtype);
150 static size_t free_in_bytes(Metaspace::MetadataType mdtype);
151 static size_t capacity_in_bytes(Metaspace::MetadataType mdtype);
152 static size_t reserved_in_bytes(Metaspace::MetadataType mdtype);
154 static size_t free_chunks_total(Metaspace::MetadataType mdtype);
155 static size_t free_chunks_total_in_bytes(Metaspace::MetadataType mdtype);
157 public:
158 // Total of space allocated to metadata in all Metaspaces
159 static size_t used_in_bytes() {
160 return used_in_bytes(Metaspace::ClassType) +
161 used_in_bytes(Metaspace::NonClassType);
162 }
164 // Total of available space in all Metaspaces
165 // Total of capacity allocated to all Metaspaces. This includes
166 // space in Metachunks not yet allocated and in the Metachunk
167 // freelist.
168 static size_t capacity_in_bytes() {
169 return capacity_in_bytes(Metaspace::ClassType) +
170 capacity_in_bytes(Metaspace::NonClassType);
171 }
173 // Total space reserved in all Metaspaces
174 static size_t reserved_in_bytes() {
175 return reserved_in_bytes(Metaspace::ClassType) +
176 reserved_in_bytes(Metaspace::NonClassType);
177 }
179 static size_t min_chunk_size();
181 // Print change in used metadata.
182 static void print_metaspace_change(size_t prev_metadata_used);
183 static void print_on(outputStream * out);
184 static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
186 static void print_waste(outputStream* out);
187 static void dump(outputStream* out);
188 static void verify_free_chunks();
189 };
191 // Metaspace are deallocated when their class loader are GC'ed.
192 // This class implements a policy for inducing GC's to recover
193 // Metaspaces.
195 class MetaspaceGC : AllStatic {
197 // The current high-water-mark for inducing a GC. When
198 // the capacity of all space in the virtual lists reaches this value,
199 // a GC is induced and the value is increased. This should be changed
200 // to the space actually used for allocations to avoid affects of
201 // fragmentation losses to partially used chunks. Size is in words.
202 static size_t _capacity_until_GC;
204 // After a GC is done any allocation that fails should try to expand
205 // the capacity of the Metaspaces. This flag is set during attempts
206 // to allocate in the VMGCOperation that does the GC.
207 static bool _expand_after_GC;
209 // For a CMS collection, signal that a concurrent collection should
210 // be started.
211 static bool _should_concurrent_collect;
213 static uint _shrink_factor;
215 static void set_capacity_until_GC(size_t v) { _capacity_until_GC = v; }
217 static size_t shrink_factor() { return _shrink_factor; }
218 void set_shrink_factor(uint v) { _shrink_factor = v; }
220 public:
222 static size_t capacity_until_GC() { return _capacity_until_GC; }
223 static size_t capacity_until_GC_in_bytes() { return _capacity_until_GC * BytesPerWord; }
224 static void inc_capacity_until_GC(size_t v) { _capacity_until_GC += v; }
225 static void dec_capacity_until_GC(size_t v) {
226 _capacity_until_GC = _capacity_until_GC > v ? _capacity_until_GC - v : 0;
227 }
228 static bool expand_after_GC() { return _expand_after_GC; }
229 static void set_expand_after_GC(bool v) { _expand_after_GC = v; }
231 static bool should_concurrent_collect() { return _should_concurrent_collect; }
232 static void set_should_concurrent_collect(bool v) {
233 _should_concurrent_collect = v;
234 }
236 // The amount to increase the high-water-mark (_capacity_until_GC)
237 static size_t delta_capacity_until_GC(size_t word_size);
239 // It is expected that this will be called when the current capacity
240 // has been used and a GC should be considered.
241 static bool should_expand(VirtualSpaceList* vsl, size_t word_size);
243 // Calculate the new high-water mark at which to induce
244 // a GC.
245 static void compute_new_size();
246 };
248 #endif // SHARE_VM_MEMORY_METASPACE_HPP