1 /*
2 * Copyright (c) 2011, 2023, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2017, 2021 SAP SE. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
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17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24 */
25 #ifndef SHARE_MEMORY_METASPACE_HPP
26 #define SHARE_MEMORY_METASPACE_HPP
27
28 #include "memory/allocation.hpp"
29 #include "memory/virtualspace.hpp"
30 #include "runtime/globals.hpp"
31 #include "utilities/exceptions.hpp"
32 #include "utilities/globalDefinitions.hpp"
33
34 class ClassLoaderData;
35 class MetaspaceShared;
36 class MetaspaceTracer;
37 class Mutex;
38 class outputStream;
39
40 ////////////////// Metaspace ///////////////////////
41
42 // Namespace for important central static functions
43 // (auxiliary stuff goes into MetaspaceUtils)
44 class Metaspace : public AllStatic {
45
46 friend class MetaspaceShared;
47
48 public:
49 enum MetadataType {
50 ClassType,
51 NonClassType,
52 MetadataTypeCount
53 };
54 enum MetaspaceType {
55 ZeroMetaspaceType = 0,
56 StandardMetaspaceType = ZeroMetaspaceType,
57 BootMetaspaceType = StandardMetaspaceType + 1,
58 ClassMirrorHolderMetaspaceType = BootMetaspaceType + 1,
59 ReflectionMetaspaceType = ClassMirrorHolderMetaspaceType + 1,
60 MetaspaceTypeCount
61 };
62
63 private:
64
65 static const MetaspaceTracer* _tracer;
66
67 // For quick pointer testing: extent of class space; nullptr if no class space.
68 static const void* _class_space_start;
69 static const void* _class_space_end;
70
71 public:
72
73 static const MetaspaceTracer* tracer() { return _tracer; }
74
75 private:
76
77 #ifdef _LP64
78
79 // Reserve a range of memory that is to contain narrow Klass IDs. If "try_in_low_address_ranges"
80 // is true, we will attempt to reserve memory suitable for zero-based encoding.
81 static ReservedSpace reserve_address_space_for_compressed_classes(size_t size, bool optimize_for_zero_base);
82
83 // Given a prereserved space, use that to set up the compressed class space list.
84 static void initialize_class_space(ReservedSpace rs);
85
86 // Returns true if class space has been setup (initialize_class_space).
87 static bool class_space_is_initialized();
88
89 #endif
90
91 public:
92
93 static void ergo_initialize();
94 static void global_initialize();
95 static void post_initialize();
96
97 // Alignment, in bytes, of metaspace mappings
98 static size_t reserve_alignment() { return reserve_alignment_words() * BytesPerWord; }
99 // Alignment, in words, of metaspace mappings
100 static size_t reserve_alignment_words();
101
102 // The granularity at which Metaspace is committed and uncommitted.
103 // (Todo: Why does this have to be exposed?)
104 static size_t commit_alignment() { return commit_alignment_words() * BytesPerWord; }
105 static size_t commit_alignment_words();
106
107 // The largest possible single allocation
108 static size_t max_allocation_word_size();
109
110 // Minimum allocation alignment, in bytes. All MetaData shall be aligned correclty
111 // to be able to hold 64-bit data types. Unlike malloc, we don't care for larger
112 // data types.
113 static constexpr size_t min_allocation_alignment_bytes = sizeof(uint64_t);
114
115 // Minimum allocation alignment, in words, Metaspace observes.
116 static constexpr size_t min_allocation_alignment_words = min_allocation_alignment_bytes / BytesPerWord;
117
118 // Every allocation will get rounded up to the minimum word size.
119 static constexpr size_t min_allocation_word_size = min_allocation_alignment_words;
120
121 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
122 MetaspaceObj::Type type, TRAPS);
123
124 // Non-TRAPS version of allocate which can be called by a non-Java thread, that returns
125 // null on failure.
126 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
127 MetaspaceObj::Type type);
128
129 static bool contains(const void* ptr) {
130 return is_in_shared_metaspace(ptr) || // in cds
131 is_in_class_space(ptr) || // in class space
132 is_in_nonclass_metaspace(ptr); // in one of the non-class regions?
133 }
134
135 // kept for now for backward compat reasons, but lets test if callers really need this
136 static bool contains_non_shared(const void* ptr) {
137 return is_in_class_space(ptr) || // in class space
138 is_in_nonclass_metaspace(ptr); // in one of the non-class regions?
139 }
140
141 // Returns true if pointer points into one of the metaspace regions, or
142 // into the class space.
143 static bool is_in_shared_metaspace(const void* ptr);
144
145 // Returns true if pointer points into one of the non-class-space metaspace regions.
146 static bool is_in_nonclass_metaspace(const void* ptr);
147
148 // Returns true if ptr points into class space, false if it doesn't or if
149 // there is no class space.
150 static inline bool is_in_class_space(const void* ptr) {
151 return ptr < _class_space_end && ptr >= _class_space_start;
152 }
153
154 // Free empty virtualspaces
155 static void purge(bool classes_unloaded);
156
157 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
158 MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
159
160 static const char* metadata_type_name(Metaspace::MetadataType mdtype);
161
162 static void print_compressed_class_space(outputStream* st) NOT_LP64({});
163
164 // Return TRUE only if UseCompressedClassPointers is True.
165 static bool using_class_space() {
166 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);
167 }
168
169 static bool is_class_space_allocation(MetadataType mdType) {
170 return mdType == ClassType && using_class_space();
171 }
172
173 static bool initialized();
174
175 };
176
177
178 #endif // SHARE_MEMORY_METASPACE_HPP