1 /*
2 * Copyright (c) 2020, 2021, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2020 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 *
16 * You should have received a copy of the GNU General Public License version
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.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "logging/log.hpp"
28 #include "memory/classLoaderMetaspace.hpp"
29 #include "memory/metaspace.hpp"
30 #include "memory/metaspaceUtils.hpp"
31 #include "memory/metaspace/metaspaceAlignment.hpp"
32 #include "memory/metaspace/chunkManager.hpp"
33 #include "memory/metaspace/internalStats.hpp"
34 #include "memory/metaspace/metaspaceArena.hpp"
35 #include "memory/metaspace/metaspaceArenaGrowthPolicy.hpp"
36 #include "memory/metaspace/metaspaceSettings.hpp"
37 #include "memory/metaspace/metaspaceStatistics.hpp"
38 #include "memory/metaspace/runningCounters.hpp"
39 #include "memory/metaspaceTracer.hpp"
40 #include "oops/compressedKlass.hpp"
41 #include "utilities/align.hpp"
42 #include "utilities/debug.hpp"
43 #include "utilities/globalDefinitions.hpp"
44
45 using metaspace::ChunkManager;
46 using metaspace::MetaspaceArena;
47 using metaspace::ArenaGrowthPolicy;
48 using metaspace::RunningCounters;
49 using metaspace::InternalStats;
50
51 #define LOGFMT "CLMS @" PTR_FORMAT " "
52 #define LOGFMT_ARGS p2i(this)
53
54 ClassLoaderMetaspace::ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType space_type) :
55 _lock(lock),
56 _space_type(space_type),
57 _non_class_space_arena(NULL),
58 _class_space_arena(NULL)
59 {
60 ChunkManager* const non_class_cm =
61 ChunkManager::chunkmanager_nonclass();
62
63 const int klass_alignment_words = KlassAlignmentInBytes / BytesPerWord;
64
65 // Initialize non-class Arena
66 _non_class_space_arena = new MetaspaceArena(
67 non_class_cm,
68 ArenaGrowthPolicy::policy_for_space_type(space_type, false),
69 metaspace::MetaspaceMinAlignmentWords,
70 lock,
71 RunningCounters::used_nonclass_counter(),
72 "non-class sm");
73
74 // If needed, initialize class arena
75 if (Metaspace::using_class_space()) {
76 // Klass instances live in class space and must be aligned correctly.
77 ChunkManager* const class_cm =
78 ChunkManager::chunkmanager_class();
79 _class_space_arena = new MetaspaceArena(
80 class_cm,
81 ArenaGrowthPolicy::policy_for_space_type(space_type, true),
82 klass_alignment_words,
83 lock,
84 RunningCounters::used_class_counter(),
85 "class sm");
86 } else {
87 // note for lilliput, this path should be restricted to 32bit only. There, klass alignment
88 // should be compatible with metaspace minimal alignment since we store Klass structures
89 // in regular metaspace.
90 NOT_LP64(STATIC_ASSERT(metaspace::MetaspaceMinAlignmentBytes == KlassAlignmentInBytes));
91 }
92
93 UL2(debug, "born (nonclass arena: " PTR_FORMAT ", class arena: " PTR_FORMAT ".",
94 p2i(_non_class_space_arena), p2i(_class_space_arena));
95 }
96
97 ClassLoaderMetaspace::~ClassLoaderMetaspace() {
98 UL(debug, "dies.");
99
100 delete _non_class_space_arena;
101 delete _class_space_arena;
102
103 }
104
105 // Allocate word_size words from Metaspace.
106 MetaWord* ClassLoaderMetaspace::allocate(size_t word_size, Metaspace::MetadataType mdType) {
107 if (Metaspace::is_class_space_allocation(mdType)) {
108 return class_space_arena()->allocate(word_size);
109 } else {
110 return non_class_space_arena()->allocate(word_size);
111 }
112 }
113
114 // Attempt to expand the GC threshold to be good for at least another word_size words
115 // and allocate. Returns NULL if failure. Used during Metaspace GC.
116 MetaWord* ClassLoaderMetaspace::expand_and_allocate(size_t word_size, Metaspace::MetadataType mdType) {
117 size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size * BytesPerWord);
118 assert(delta_bytes > 0, "Must be");
119
120 size_t before = 0;
121 size_t after = 0;
122 bool can_retry = true;
123 MetaWord* res;
124 bool incremented;
125
126 // Each thread increments the HWM at most once. Even if the thread fails to increment
127 // the HWM, an allocation is still attempted. This is because another thread must then
128 // have incremented the HWM and therefore the allocation might still succeed.
129 do {
130 incremented = MetaspaceGC::inc_capacity_until_GC(delta_bytes, &after, &before, &can_retry);
131 res = allocate(word_size, mdType);
132 } while (!incremented && res == NULL && can_retry);
133
134 if (incremented) {
135 Metaspace::tracer()->report_gc_threshold(before, after,
136 MetaspaceGCThresholdUpdater::ExpandAndAllocate);
137 // Keeping both for now until I am sure the old variant (gc + metaspace) is not needed anymore
138 log_trace(gc, metaspace)("Increase capacity to GC from " SIZE_FORMAT " to " SIZE_FORMAT, before, after);
139 UL2(info, "GC threshold increased: " SIZE_FORMAT "->" SIZE_FORMAT ".", before, after);
140 }
141
142 return res;
143 }
144
145 // Prematurely returns a metaspace allocation to the _block_freelists
146 // because it is not needed anymore.
147 void ClassLoaderMetaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
148 if (Metaspace::using_class_space() && is_class) {
149 class_space_arena()->deallocate(ptr, word_size);
150 } else {
151 non_class_space_arena()->deallocate(ptr, word_size);
152 }
153 DEBUG_ONLY(InternalStats::inc_num_deallocs();)
154 }
155
156 // Update statistics. This walks all in-use chunks.
157 void ClassLoaderMetaspace::add_to_statistics(metaspace::ClmsStats* out) const {
158 if (non_class_space_arena() != NULL) {
159 non_class_space_arena()->add_to_statistics(&out->_arena_stats_nonclass);
160 }
161 if (class_space_arena() != NULL) {
162 class_space_arena()->add_to_statistics(&out->_arena_stats_class);
163 }
164 }
165
166 #ifdef ASSERT
167 void ClassLoaderMetaspace::verify() const {
168 if (non_class_space_arena() != NULL) {
169 non_class_space_arena()->verify();
170 }
171 if (class_space_arena() != NULL) {
172 class_space_arena()->verify();
173 }
174 }
175 #endif // ASSERT
176
177 // This only exists for JFR and jcmd VM.classloader_stats. We may want to
178 // change this. Capacity as a stat is of questionable use since it may
179 // contain committed and uncommitted areas. For now we do this to maintain
180 // backward compatibility with JFR.
181 void ClassLoaderMetaspace::calculate_jfr_stats(size_t* p_used_bytes, size_t* p_capacity_bytes) const {
182 // Implement this using the standard statistics objects.
183 size_t used_c = 0, cap_c = 0, used_nc = 0, cap_nc = 0;
184 if (non_class_space_arena() != NULL) {
185 non_class_space_arena()->usage_numbers(&used_nc, NULL, &cap_nc);
186 }
187 if (class_space_arena() != NULL) {
188 class_space_arena()->usage_numbers(&used_c, NULL, &cap_c);
189 }
190 if (p_used_bytes != NULL) {
191 *p_used_bytes = used_c + used_nc;
192 }
193 if (p_capacity_bytes != NULL) {
194 *p_capacity_bytes = cap_c + cap_nc;
195 }
196 }
197