src/share/vm/memory/metaspace.hpp

Fri, 01 Mar 2013 10:19:29 -0800

author
jmasa
date
Fri, 01 Mar 2013 10:19:29 -0800
changeset 5007
c23dbf0e8ab7
parent 4827
42e370795a39
child 5015
868d87ed63c8
permissions
-rw-r--r--

8011268: NPG: Free unused VirtualSpaceNodes
Reviewed-by: mgerdin, coleenp, johnc

coleenp@4037 1 /*
coleenp@4037 2 * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
coleenp@4037 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
coleenp@4037 4 *
coleenp@4037 5 * This code is free software; you can redistribute it and/or modify it
coleenp@4037 6 * under the terms of the GNU General Public License version 2 only, as
coleenp@4037 7 * published by the Free Software Foundation.
coleenp@4037 8 *
coleenp@4037 9 * This code is distributed in the hope that it will be useful, but WITHOUT
coleenp@4037 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
coleenp@4037 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
coleenp@4037 12 * version 2 for more details (a copy is included in the LICENSE file that
coleenp@4037 13 * accompanied this code).
coleenp@4037 14 *
coleenp@4037 15 * You should have received a copy of the GNU General Public License version
coleenp@4037 16 * 2 along with this work; if not, write to the Free Software Foundation,
coleenp@4037 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
coleenp@4037 18 *
coleenp@4037 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
coleenp@4037 20 * or visit www.oracle.com if you need additional information or have any
coleenp@4037 21 * questions.
coleenp@4037 22 *
coleenp@4037 23 */
coleenp@4037 24 #ifndef SHARE_VM_MEMORY_METASPACE_HPP
coleenp@4037 25 #define SHARE_VM_MEMORY_METASPACE_HPP
coleenp@4037 26
coleenp@4037 27 #include "memory/allocation.hpp"
coleenp@4037 28 #include "memory/memRegion.hpp"
coleenp@4037 29 #include "runtime/virtualspace.hpp"
coleenp@4037 30 #include "utilities/exceptions.hpp"
coleenp@4037 31
coleenp@4037 32 // Metaspace
coleenp@4037 33 //
coleenp@4037 34 // Metaspaces are Arenas for the VM's metadata.
coleenp@4037 35 // They are allocated one per class loader object, and one for the null
coleenp@4037 36 // bootstrap class loader
coleenp@4037 37 // Eventually for bootstrap loader we'll have a read-only section and read-write
coleenp@4037 38 // to write for DumpSharedSpaces and read for UseSharedSpaces
coleenp@4037 39 //
coleenp@4037 40 // block X ---+ +-------------------+
coleenp@4037 41 // | | Virtualspace |
coleenp@4037 42 // | | |
coleenp@4037 43 // | | |
coleenp@4037 44 // | |-------------------|
coleenp@4037 45 // | || Chunk |
coleenp@4037 46 // | || |
coleenp@4037 47 // | ||---------- |
coleenp@4037 48 // +------>||| block 0 | |
coleenp@4037 49 // ||---------- |
coleenp@4037 50 // ||| block 1 | |
coleenp@4037 51 // ||---------- |
coleenp@4037 52 // || |
coleenp@4037 53 // |-------------------|
coleenp@4037 54 // | |
coleenp@4037 55 // | |
coleenp@4037 56 // +-------------------+
coleenp@4037 57 //
coleenp@4037 58
coleenp@4037 59 class ClassLoaderData;
jmasa@4196 60 class Metablock;
coleenp@4037 61 class MetaWord;
coleenp@4037 62 class Mutex;
coleenp@4037 63 class outputStream;
coleenp@4037 64 class SpaceManager;
coleenp@4037 65
coleenp@4037 66 // Metaspaces each have a SpaceManager and allocations
coleenp@4037 67 // are done by the SpaceManager. Allocations are done
coleenp@4037 68 // out of the current Metachunk. When the current Metachunk
coleenp@4037 69 // is exhausted, the SpaceManager gets a new one from
coleenp@4037 70 // the current VirtualSpace. When the VirtualSpace is exhausted
coleenp@4037 71 // the SpaceManager gets a new one. The SpaceManager
coleenp@4037 72 // also manages freelists of available Chunks.
coleenp@4037 73 //
coleenp@4037 74 // Currently the space manager maintains the list of
coleenp@4037 75 // virtual spaces and the list of chunks in use. Its
coleenp@4037 76 // allocate() method returns a block for use as a
coleenp@4037 77 // quantum of metadata.
coleenp@4037 78
coleenp@4037 79 class VirtualSpaceList;
coleenp@4037 80
coleenp@4037 81 class Metaspace : public CHeapObj<mtClass> {
coleenp@4037 82 friend class VMStructs;
coleenp@4037 83 friend class SpaceManager;
coleenp@4037 84 friend class VM_CollectForMetadataAllocation;
coleenp@4037 85 friend class MetaspaceGC;
coleenp@4037 86 friend class MetaspaceAux;
coleenp@4037 87
coleenp@4037 88 public:
coleenp@4037 89 enum MetadataType {ClassType, NonClassType};
jmasa@4382 90 enum MetaspaceType {
jmasa@4382 91 StandardMetaspaceType,
jmasa@4382 92 BootMetaspaceType,
jmasa@4382 93 ROMetaspaceType,
jmasa@4382 94 ReadWriteMetaspaceType,
jmasa@4382 95 AnonymousMetaspaceType,
jmasa@4382 96 ReflectionMetaspaceType
jmasa@4382 97 };
coleenp@4037 98
coleenp@4037 99 private:
jmasa@4382 100 void initialize(Mutex* lock, MetaspaceType type);
jmasa@4382 101
jmasa@4382 102 // Align up the word size to the allocation word size
jmasa@4382 103 static size_t align_word_size_up(size_t);
coleenp@4037 104
coleenp@4037 105 static size_t _first_chunk_word_size;
jmasa@4382 106 static size_t _first_class_chunk_word_size;
coleenp@4037 107
coleenp@4037 108 SpaceManager* _vsm;
coleenp@4037 109 SpaceManager* vsm() const { return _vsm; }
coleenp@4037 110
coleenp@4037 111 SpaceManager* _class_vsm;
coleenp@4037 112 SpaceManager* class_vsm() const { return _class_vsm; }
coleenp@4037 113
coleenp@4037 114 MetaWord* allocate(size_t word_size, MetadataType mdtype);
coleenp@4037 115
coleenp@4037 116 // Virtual Space lists for both classes and other metadata
coleenp@4037 117 static VirtualSpaceList* _space_list;
coleenp@4037 118 static VirtualSpaceList* _class_space_list;
coleenp@4037 119
coleenp@4037 120 static VirtualSpaceList* space_list() { return _space_list; }
coleenp@4037 121 static VirtualSpaceList* class_space_list() { return _class_space_list; }
coleenp@4037 122
coleenp@4037 123 public:
coleenp@4037 124
jmasa@4382 125 Metaspace(Mutex* lock, MetaspaceType type);
coleenp@4037 126 ~Metaspace();
coleenp@4037 127
coleenp@4037 128 // Initialize globals for Metaspace
coleenp@4037 129 static void global_initialize();
coleenp@4037 130 static void initialize_class_space(ReservedSpace rs);
coleenp@4037 131
coleenp@4037 132 static size_t first_chunk_word_size() { return _first_chunk_word_size; }
jmasa@4382 133 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
coleenp@4037 134
coleenp@4037 135 char* bottom() const;
coleenp@4037 136 size_t used_words(MetadataType mdtype) const;
coleenp@4037 137 size_t free_words(MetadataType mdtype) const;
coleenp@4037 138 size_t capacity_words(MetadataType mdtype) const;
coleenp@4037 139 size_t waste_words(MetadataType mdtype) const;
coleenp@4037 140
jmasa@4196 141 static Metablock* allocate(ClassLoaderData* loader_data, size_t size,
coleenp@4037 142 bool read_only, MetadataType mdtype, TRAPS);
jmasa@4064 143 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
coleenp@4037 144
jmasa@4064 145 MetaWord* expand_and_allocate(size_t size,
jmasa@4064 146 MetadataType mdtype);
coleenp@4037 147
roland@4159 148 static bool is_initialized() { return _class_space_list != NULL; }
roland@4159 149
coleenp@4295 150 static bool contains(const void *ptr);
coleenp@4037 151 void dump(outputStream* const out) const;
coleenp@4037 152
jmasa@5007 153 // Free empty virtualspaces
jmasa@5007 154 static void purge();
jmasa@5007 155
coleenp@4037 156 void print_on(outputStream* st) const;
coleenp@4037 157 // Debugging support
coleenp@4037 158 void verify();
coleenp@4037 159 };
coleenp@4037 160
coleenp@4037 161 class MetaspaceAux : AllStatic {
coleenp@4037 162
coleenp@4037 163 // Statistics for class space and data space in metaspace.
coleenp@4037 164 static size_t used_in_bytes(Metaspace::MetadataType mdtype);
coleenp@4037 165 static size_t free_in_bytes(Metaspace::MetadataType mdtype);
coleenp@4037 166 static size_t capacity_in_bytes(Metaspace::MetadataType mdtype);
coleenp@4037 167 static size_t reserved_in_bytes(Metaspace::MetadataType mdtype);
coleenp@4037 168
ehelin@4827 169 static size_t free_chunks_total(Metaspace::MetadataType mdtype);
ehelin@4827 170 static size_t free_chunks_total_in_bytes(Metaspace::MetadataType mdtype);
ehelin@4827 171
ehelin@4827 172 public:
coleenp@4037 173 // Total of space allocated to metadata in all Metaspaces
stefank@4371 174 static size_t used_in_bytes() {
stefank@4371 175 return used_in_bytes(Metaspace::ClassType) +
stefank@4371 176 used_in_bytes(Metaspace::NonClassType);
stefank@4371 177 }
coleenp@4037 178
coleenp@4037 179 // Total of available space in all Metaspaces
coleenp@4037 180 // Total of capacity allocated to all Metaspaces. This includes
coleenp@4037 181 // space in Metachunks not yet allocated and in the Metachunk
coleenp@4037 182 // freelist.
stefank@4371 183 static size_t capacity_in_bytes() {
stefank@4371 184 return capacity_in_bytes(Metaspace::ClassType) +
stefank@4371 185 capacity_in_bytes(Metaspace::NonClassType);
stefank@4371 186 }
coleenp@4037 187
coleenp@4037 188 // Total space reserved in all Metaspaces
stefank@4371 189 static size_t reserved_in_bytes() {
stefank@4371 190 return reserved_in_bytes(Metaspace::ClassType) +
stefank@4371 191 reserved_in_bytes(Metaspace::NonClassType);
stefank@4371 192 }
coleenp@4037 193
coleenp@4037 194 static size_t min_chunk_size();
coleenp@4037 195
coleenp@4037 196 // Print change in used metadata.
coleenp@4037 197 static void print_metaspace_change(size_t prev_metadata_used);
coleenp@4037 198 static void print_on(outputStream * out);
coleenp@4037 199 static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
coleenp@4037 200
coleenp@4037 201 static void print_waste(outputStream* out);
coleenp@4037 202 static void dump(outputStream* out);
mgerdin@4264 203 static void verify_free_chunks();
coleenp@4037 204 };
coleenp@4037 205
coleenp@4037 206 // Metaspace are deallocated when their class loader are GC'ed.
coleenp@4037 207 // This class implements a policy for inducing GC's to recover
coleenp@4037 208 // Metaspaces.
coleenp@4037 209
coleenp@4037 210 class MetaspaceGC : AllStatic {
coleenp@4037 211
coleenp@4037 212 // The current high-water-mark for inducing a GC. When
coleenp@4037 213 // the capacity of all space in the virtual lists reaches this value,
coleenp@4037 214 // a GC is induced and the value is increased. This should be changed
coleenp@4037 215 // to the space actually used for allocations to avoid affects of
coleenp@4037 216 // fragmentation losses to partially used chunks. Size is in words.
coleenp@4037 217 static size_t _capacity_until_GC;
coleenp@4037 218
coleenp@4037 219 // After a GC is done any allocation that fails should try to expand
coleenp@4037 220 // the capacity of the Metaspaces. This flag is set during attempts
coleenp@4037 221 // to allocate in the VMGCOperation that does the GC.
coleenp@4037 222 static bool _expand_after_GC;
coleenp@4037 223
coleenp@4037 224 // For a CMS collection, signal that a concurrent collection should
coleenp@4037 225 // be started.
coleenp@4037 226 static bool _should_concurrent_collect;
coleenp@4037 227
coleenp@4037 228 static uint _shrink_factor;
coleenp@4037 229
coleenp@4037 230 static void set_capacity_until_GC(size_t v) { _capacity_until_GC = v; }
coleenp@4037 231
coleenp@4037 232 static size_t shrink_factor() { return _shrink_factor; }
coleenp@4037 233 void set_shrink_factor(uint v) { _shrink_factor = v; }
coleenp@4037 234
coleenp@4037 235 public:
coleenp@4037 236
coleenp@4037 237 static size_t capacity_until_GC() { return _capacity_until_GC; }
coleenp@4037 238 static size_t capacity_until_GC_in_bytes() { return _capacity_until_GC * BytesPerWord; }
coleenp@4037 239 static void inc_capacity_until_GC(size_t v) { _capacity_until_GC += v; }
coleenp@4037 240 static void dec_capacity_until_GC(size_t v) {
coleenp@4037 241 _capacity_until_GC = _capacity_until_GC > v ? _capacity_until_GC - v : 0;
coleenp@4037 242 }
coleenp@4037 243 static bool expand_after_GC() { return _expand_after_GC; }
coleenp@4037 244 static void set_expand_after_GC(bool v) { _expand_after_GC = v; }
coleenp@4037 245
coleenp@4037 246 static bool should_concurrent_collect() { return _should_concurrent_collect; }
coleenp@4037 247 static void set_should_concurrent_collect(bool v) {
coleenp@4037 248 _should_concurrent_collect = v;
coleenp@4037 249 }
coleenp@4037 250
coleenp@4037 251 // The amount to increase the high-water-mark (_capacity_until_GC)
coleenp@4037 252 static size_t delta_capacity_until_GC(size_t word_size);
coleenp@4037 253
coleenp@4037 254 // It is expected that this will be called when the current capacity
coleenp@4037 255 // has been used and a GC should be considered.
coleenp@4037 256 static bool should_expand(VirtualSpaceList* vsl, size_t word_size);
coleenp@4037 257
coleenp@4037 258 // Calculate the new high-water mark at which to induce
coleenp@4037 259 // a GC.
coleenp@4037 260 static void compute_new_size();
coleenp@4037 261 };
coleenp@4037 262
coleenp@4037 263 #endif // SHARE_VM_MEMORY_METASPACE_HPP

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