1 /*
2 * Copyright (c) 2011, 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.
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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 */
24 #ifndef SHARE_MEMORY_METASPACE_HPP
25 #define SHARE_MEMORY_METASPACE_HPP
26
27 #include "memory/allocation.hpp"
28 #include "memory/metaspace/metaspaceEnums.hpp"
29 #include "memory/metaspaceChunkFreeListSummary.hpp"
30 #include "memory/virtualspace.hpp"
31 #include "utilities/exceptions.hpp"
32 #include "utilities/globalDefinitions.hpp"
33
34 // Metaspace
35 //
36 // Metaspaces are Arenas for the VM's metadata.
37 // They are allocated one per class loader object, and one for the null
38 // bootstrap class loader
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 //
58
59 class ClassLoaderData;
60 class MetaspaceShared;
61 class MetaspaceTracer;
62 class outputStream;
63
64
65 namespace metaspace {
66 class MetaspaceSizesSnapshot;
67 }
68
69 ////////////////// Metaspace ///////////////////////
70
71 // Metaspaces each have a SpaceManager and allocations
72 // are done by the SpaceManager. Allocations are done
73 // out of the current Metachunk. When the current Metachunk
74 // is exhausted, the SpaceManager gets a new one from
75 // the current VirtualSpace. When the VirtualSpace is exhausted
76 // the SpaceManager gets a new one. The SpaceManager
77 // also manages freelists of available Chunks.
78 //
79 // Currently the space manager maintains the list of
80 // virtual spaces and the list of chunks in use. Its
81 // allocate() method returns a block for use as a
82 // quantum of metadata.
83
84 // Namespace for important central static functions
85 // (auxiliary stuff goes into MetaspaceUtils)
86 class Metaspace : public AllStatic {
87
88 friend class MetaspaceShared;
89
90 // Base and size of the compressed class space.
91 static MetaWord* _compressed_class_space_base;
92 static size_t _compressed_class_space_size;
93
94 static size_t _commit_alignment;
95 static size_t _reserve_alignment;
96 DEBUG_ONLY(static bool _frozen;)
97
98 static const MetaspaceTracer* _tracer;
99
100 static bool _initialized;
101
102 static MetaWord* compressed_class_space_base() { return _compressed_class_space_base; }
103 static size_t compressed_class_space_size() { return _compressed_class_space_size; }
104
105 public:
106
107 static const MetaspaceTracer* tracer() { return _tracer; }
108 static void freeze() {
109 assert(DumpSharedSpaces, "sanity");
110 DEBUG_ONLY(_frozen = true;)
111 }
112 static void assert_not_frozen() {
113 assert(!_frozen, "sanity");
114 }
115 #ifdef _LP64
116 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
117 #endif
118
119 private:
120
121 #ifdef _LP64
122 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
123
124 // Returns true if can use CDS with metaspace allocated as specified address.
125 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
126
127 static void initialize_class_space(ReservedSpace rs);
128 #endif
129
130 public:
131
132 static void ergo_initialize();
133 static void global_initialize();
134 static void post_initialize();
135
136 // The alignment at which Metaspace mappings are reserved.
137 static size_t reserve_alignment() { return _reserve_alignment; }
138 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
139
140 // The granularity at which Metaspace is committed and uncommitted.
141 static size_t commit_alignment() { return _commit_alignment; }
142 static size_t commit_words() { return _commit_alignment / BytesPerWord; }
143
144 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
145 MetaspaceObj::Type type, TRAPS);
146
147 static bool contains(const void* ptr);
148 static bool contains_non_shared(const void* ptr);
149
150 // Free empty virtualspaces
151 static void purge();
152
153 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
154 MetaspaceObj::Type type, metaspace::MetadataType mdtype, TRAPS);
155
156 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});
157
158 // Return TRUE only if UseCompressedClassPointers is True.
159 static bool using_class_space() {
160 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);
161 }
162
163 static bool initialized() { return _initialized; }
164
165 };
166
167 ////////////////// MetaspaceGC ///////////////////////
168
169 // Metaspace are deallocated when their class loader are GC'ed.
170 // This class implements a policy for inducing GC's to recover
171 // Metaspaces.
172
173 class MetaspaceGCThresholdUpdater : public AllStatic {
174 public:
175 enum Type {
176 ComputeNewSize,
177 ExpandAndAllocate,
178 Last
179 };
180
181 static const char* to_string(MetaspaceGCThresholdUpdater::Type updater) {
182 switch (updater) {
183 case ComputeNewSize:
184 return "compute_new_size";
185 case ExpandAndAllocate:
186 return "expand_and_allocate";
187 default:
188 assert(false, "Got bad updater: %d", (int) updater);
189 return NULL;
190 };
191 }
192 };
193
194 class MetaspaceGC : public AllStatic {
195
196 // The current high-water-mark for inducing a GC.
197 // When committed memory of all metaspaces reaches this value,
198 // a GC is induced and the value is increased. Size is in bytes.
199 static volatile size_t _capacity_until_GC;
200
201 // For a CMS collection, signal that a concurrent collection should
202 // be started.
203 static bool _should_concurrent_collect;
204
205 static uint _shrink_factor;
206
207 static size_t shrink_factor() { return _shrink_factor; }
208 void set_shrink_factor(uint v) { _shrink_factor = v; }
209
210 public:
211
212 static void initialize();
213 static void post_initialize();
214
215 static size_t capacity_until_GC();
216 static bool inc_capacity_until_GC(size_t v,
217 size_t* new_cap_until_GC = NULL,
218 size_t* old_cap_until_GC = NULL,
219 bool* can_retry = NULL);
220 static size_t dec_capacity_until_GC(size_t v);
221
222 static bool should_concurrent_collect() { return _should_concurrent_collect; }
223 static void set_should_concurrent_collect(bool v) {
224 _should_concurrent_collect = v;
225 }
226
227 // The amount to increase the high-water-mark (_capacity_until_GC)
228 static size_t delta_capacity_until_GC(size_t bytes);
229
230 // Tells if we have can expand metaspace without hitting set limits.
231 static bool can_expand(size_t words, bool is_class);
232
233 // Returns amount that we can expand without hitting a GC,
234 // measured in words.
235 static size_t allowed_expansion();
236
237 // Calculate the new high-water mark at which to induce
238 // a GC.
239 static void compute_new_size();
240 };
241
242
243
244
245 class MetaspaceUtils : AllStatic {
246 public:
247
248 // Committed space actually in use by Metadata
249 static size_t used_words();
250 static size_t used_words(metaspace::MetadataType mdtype);
251
252 // Space committed for Metaspace
253 static size_t committed_words();
254 static size_t committed_words(metaspace::MetadataType mdtype);
255
256 // Space reserved for Metaspace
257 static size_t reserved_words();
258 static size_t reserved_words(metaspace::MetadataType mdtype);
259
260 // _bytes() variants for convenience...
261 static size_t used_bytes() { return used_words() * BytesPerWord; }
262 static size_t used_bytes(metaspace::MetadataType mdtype) { return used_words(mdtype) * BytesPerWord; }
263 static size_t committed_bytes() { return committed_words() * BytesPerWord; }
264 static size_t committed_bytes(metaspace::MetadataType mdtype) { return committed_words(mdtype) * BytesPerWord; }
265 static size_t reserved_bytes() { return reserved_words() * BytesPerWord; }
266 static size_t reserved_bytes(metaspace::MetadataType mdtype) { return reserved_words(mdtype) * BytesPerWord; }
267
268 // Todo. Consolidate.
269 // Committed space in freelists
270 static size_t free_chunks_total_words(metaspace::MetadataType mdtype);
271
272 // Todo. Implement or Consolidate.
273 static MetaspaceChunkFreeListSummary chunk_free_list_summary(metaspace::MetadataType mdtype) {
274 return MetaspaceChunkFreeListSummary(0,0,0,0,0,0,0,0);
275 }
276
277 // Log change in used metadata.
278 static void print_metaspace_change(const metaspace::MetaspaceSizesSnapshot& pre_meta_values);
279
280 // Prints an ASCII representation of the given space.
281 static void print_metaspace_map(outputStream* out, metaspace::MetadataType mdtype);
282
283 // This will print out a basic metaspace usage report but
284 // unlike print_report() is guaranteed not to lock or to walk the CLDG.
285 static void print_basic_report(outputStream* st, size_t scale = 0);
286
287 // Prints a report about the current metaspace state.
288 // Function will walk the CLDG and will lock the expand lock; if that is not
289 // convenient, use print_basic_report() instead.
290 static void print_full_report(outputStream* out, size_t scale = 0);
291
292 static void print_on(outputStream * out);
293
294 DEBUG_ONLY(static void verify(bool slow);)
295
296 };
297
298 #endif // SHARE_MEMORY_METASPACE_HPP