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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
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  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  *
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 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 24 
 25 #include "precompiled.hpp"
 26 #include "cds/cdsConfig.hpp"
 27 #include "cds/serializeClosure.hpp"
 28 #include "classfile/classLoaderData.inline.hpp"
 29 #include "classfile/classLoaderDataShared.hpp"
 30 #include "classfile/moduleEntry.hpp"
 31 #include "classfile/packageEntry.hpp"
 32 #include "classfile/systemDictionary.hpp"
 33 #include "logging/log.hpp"
 34 #include "runtime/handles.inline.hpp"
 35 
 36 #if INCLUDE_CDS_JAVA_HEAP
 37 
 38 bool ClassLoaderDataShared::_full_module_graph_loaded = false;
 39 
 40 class ArchivedClassLoaderData {
 41   Array<PackageEntry*>* _packages;
 42   Array<ModuleEntry*>* _modules;
 43 
 44   void assert_valid(ClassLoaderData* loader_data) {
 45     // loader_data may be null if the boot layer has loaded no modules for the platform or
 46     // system loaders (e.g., if you create a custom JDK image with only java.base).
 47     if (loader_data != nullptr) {
 48       assert(!loader_data->has_class_mirror_holder(),
 49              "loaders for non-strong hidden classes not supported");
 50     }
 51   }
 52 public:
 53   ArchivedClassLoaderData() : _packages(nullptr), _modules(nullptr) {}
 54 
 55   void iterate_symbols(ClassLoaderData* loader_data, MetaspaceClosure* closure);
 56   void allocate(ClassLoaderData* loader_data);
 57   void init_archived_entries(ClassLoaderData* loader_data);
 58 
 59   void serialize(SerializeClosure* f) {
 60     f->do_ptr(&_packages);
 61     f->do_ptr(&_modules);
 62   }
 63 
 64   void restore(ClassLoaderData* loader_data, bool do_entries, bool do_oops);
 65   void clear_archived_oops();
 66 };
 67 
 68 static ArchivedClassLoaderData _archived_boot_loader_data;
 69 static ArchivedClassLoaderData _archived_platform_loader_data;
 70 static ArchivedClassLoaderData _archived_system_loader_data;
 71 static ModuleEntry* _archived_javabase_moduleEntry = nullptr;
 72 
 73 void ArchivedClassLoaderData::iterate_symbols(ClassLoaderData* loader_data, MetaspaceClosure* closure) {
 74   assert(CDSConfig::is_dumping_full_module_graph(), "must be");
 75   assert_valid(loader_data);
 76   if (loader_data != nullptr) {
 77     loader_data->packages()->iterate_symbols(closure);
 78     loader_data->modules() ->iterate_symbols(closure);
 79   }
 80 }
 81 
 82 void ArchivedClassLoaderData::allocate(ClassLoaderData* loader_data) {
 83   assert(CDSConfig::is_dumping_full_module_graph(), "must be");
 84   assert_valid(loader_data);
 85   if (loader_data != nullptr) {
 86     // We can't create hashtables at dump time because the hashcode depends on the
 87     // address of the Symbols, which may be relocated at runtime due to ASLR.
 88     // So we store the packages/modules in Arrays. At runtime, we create
 89     // the hashtables using these arrays.
 90     _packages = loader_data->packages()->allocate_archived_entries();
 91     _modules  = loader_data->modules() ->allocate_archived_entries();
 92   }
 93 }
 94 
 95 void ArchivedClassLoaderData::init_archived_entries(ClassLoaderData* loader_data) {
 96   assert(CDSConfig::is_dumping_full_module_graph(), "must be");
 97   assert_valid(loader_data);
 98   if (loader_data != nullptr) {
 99     loader_data->packages()->init_archived_entries(_packages);
100     loader_data->modules() ->init_archived_entries(_modules);
101   }
102 }
103 
104 void ArchivedClassLoaderData::restore(ClassLoaderData* loader_data, bool do_entries, bool do_oops) {
105   assert(CDSConfig::is_loading_full_module_graph(), "must be");
106   assert_valid(loader_data);
107   if (_modules != nullptr) { // Could be null if we have archived no modules for platform/system loaders
108     ModuleEntryTable* modules = loader_data->modules();
109     PackageEntryTable* packages = loader_data->packages();
110 
111     MutexLocker m1(Module_lock);
112     if (do_entries) {
113       modules->load_archived_entries(loader_data, _modules);
114       packages->load_archived_entries(_packages);
115     }
116     if (do_oops) {
117       modules->restore_archived_oops(loader_data, _modules);
118     }
119   }
120 }
121 
122 void ArchivedClassLoaderData::clear_archived_oops() {
123   assert(!CDSConfig::is_loading_full_module_graph(), "must be");
124   if (_modules != nullptr) {
125     for (int i = 0; i < _modules->length(); i++) {
126       _modules->at(i)->clear_archived_oops();
127     }
128   }
129 }
130 
131 // ------------------------------
132 
133 static ClassLoaderData* null_class_loader_data() {
134   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
135   assert(loader_data != nullptr, "must be");
136   return loader_data;
137 }
138 
139 static ClassLoaderData* java_platform_loader_data_or_null() {
140   return ClassLoaderData::class_loader_data_or_null(SystemDictionary::java_platform_loader());
141 }
142 
143 static ClassLoaderData* java_system_loader_data_or_null() {
144   return ClassLoaderData::class_loader_data_or_null(SystemDictionary::java_system_loader());
145 }
146 
147 void ClassLoaderDataShared::iterate_symbols(MetaspaceClosure* closure) {
148   assert(CDSConfig::is_dumping_full_module_graph(), "must be");
149   _archived_boot_loader_data.iterate_symbols    (null_class_loader_data(), closure);
150   _archived_platform_loader_data.iterate_symbols(java_platform_loader_data_or_null(), closure);
151   _archived_system_loader_data.iterate_symbols  (java_system_loader_data_or_null(), closure);
152 }
153 
154 void ClassLoaderDataShared::allocate_archived_tables() {
155   assert(CDSConfig::is_dumping_full_module_graph(), "must be");
156   _archived_boot_loader_data.allocate    (null_class_loader_data());
157   _archived_platform_loader_data.allocate(java_platform_loader_data_or_null());
158   _archived_system_loader_data.allocate  (java_system_loader_data_or_null());
159 }
160 
161 void ClassLoaderDataShared::init_archived_tables() {
162   assert(CDSConfig::is_dumping_full_module_graph(), "must be");
163   _archived_boot_loader_data.init_archived_entries    (null_class_loader_data());
164   _archived_platform_loader_data.init_archived_entries(java_platform_loader_data_or_null());
165   _archived_system_loader_data.init_archived_entries  (java_system_loader_data_or_null());
166   _archived_javabase_moduleEntry = ModuleEntry::get_archived_entry(ModuleEntryTable::javabase_moduleEntry());
167 }
168 
169 void ClassLoaderDataShared::serialize(SerializeClosure* f) {
170   _archived_boot_loader_data.serialize(f);
171   _archived_platform_loader_data.serialize(f);
172   _archived_system_loader_data.serialize(f);
173   f->do_ptr(&_archived_javabase_moduleEntry);
174 
175   if (f->reading() && CDSConfig::is_loading_full_module_graph()) {
176     // Must be done before ClassLoader::create_javabase()
177     _archived_boot_loader_data.restore(null_class_loader_data(), true, false);
178     ModuleEntryTable::set_javabase_moduleEntry(_archived_javabase_moduleEntry);
179     log_info(cds)("use_full_module_graph = true; java.base = " INTPTR_FORMAT,
180                   p2i(_archived_javabase_moduleEntry));
181   }
182 }
183 
184 void ClassLoaderDataShared::clear_archived_oops() {
185   assert(!CDSConfig::is_loading_full_module_graph(), "must be");
186   _archived_boot_loader_data.clear_archived_oops();
187   _archived_platform_loader_data.clear_archived_oops();
188   _archived_system_loader_data.clear_archived_oops();
189 }
190 
191 oop ClassLoaderDataShared::restore_archived_oops_for_null_class_loader_data() {
192   assert(CDSConfig::is_loading_full_module_graph(), "must be");
193   _archived_boot_loader_data.restore(null_class_loader_data(), false, true);
194   return _archived_javabase_moduleEntry->module();
195 }
196 
197 void ClassLoaderDataShared::restore_java_platform_loader_from_archive(ClassLoaderData* loader_data) {
198   assert(CDSConfig::is_loading_full_module_graph(), "must be");
199   _archived_platform_loader_data.restore(loader_data, true, true);
200 }
201 
202 void ClassLoaderDataShared::restore_java_system_loader_from_archive(ClassLoaderData* loader_data) {
203   assert(CDSConfig::is_loading_full_module_graph(), "must be");
204   _archived_system_loader_data.restore(loader_data, true, true);
205   _full_module_graph_loaded = true;
206 }
207 
208 #endif // INCLUDE_CDS_JAVA_HEAP