1 /*
   2  * Copyright (c) 2012, 2024, 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.
  18  *
  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
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "cds/aotClassInitializer.hpp"
  27 #include "cds/aotClassLinker.hpp"
  28 #include "cds/aotConstantPoolResolver.hpp"
  29 #include "cds/aotLinkedClassBulkLoader.hpp"
  30 #include "cds/archiveBuilder.hpp"
  31 #include "cds/archiveHeapLoader.hpp"
  32 #include "cds/archiveHeapWriter.hpp"
  33 #include "cds/cds_globals.hpp"
  34 #include "cds/cdsAccess.hpp"
  35 #include "cds/cdsConfig.hpp"
  36 #include "cds/cdsProtectionDomain.hpp"
  37 #include "cds/cds_globals.hpp"
  38 #include "cds/classListParser.hpp"
  39 #include "cds/classListWriter.hpp"
  40 #include "cds/cppVtables.hpp"
  41 #include "cds/dumpAllocStats.hpp"
  42 #include "cds/dynamicArchive.hpp"
  43 #include "cds/filemap.hpp"
  44 #include "cds/finalImageRecipes.hpp"
  45 #include "cds/heapShared.hpp"
  46 #include "cds/lambdaFormInvokers.hpp"
  47 #include "cds/metaspaceShared.hpp"
  48 #include "classfile/classLoaderDataGraph.hpp"
  49 #include "classfile/classLoaderDataShared.hpp"
  50 #include "classfile/classLoaderExt.hpp"
  51 #include "classfile/javaClasses.inline.hpp"
  52 #include "classfile/loaderConstraints.hpp"
  53 #include "classfile/modules.hpp"
  54 #include "classfile/placeholders.hpp"
  55 #include "classfile/stringTable.hpp"
  56 #include "classfile/symbolTable.hpp"
  57 #include "classfile/systemDictionary.hpp"
  58 #include "classfile/systemDictionaryShared.hpp"
  59 #include "classfile/vmClasses.hpp"
  60 #include "classfile/vmSymbols.hpp"
  61 #include "code/codeCache.hpp"
  62 #include "code/SCCache.hpp"
  63 #include "compiler/compileBroker.hpp"
  64 #include "compiler/precompiler.hpp"
  65 #include "gc/shared/gcVMOperations.hpp"
  66 #include "interpreter/bytecodeStream.hpp"
  67 #include "interpreter/bytecodes.hpp"
  68 #include "jvm_io.h"
  69 #include "logging/log.hpp"
  70 #include "logging/logMessage.hpp"
  71 #include "logging/logStream.hpp"
  72 #include "memory/metaspace.hpp"
  73 #include "memory/metaspaceClosure.hpp"
  74 #include "memory/resourceArea.hpp"
  75 #include "memory/universe.hpp"
  76 #include "nmt/memTracker.hpp"
  77 #include "oops/compressedKlass.hpp"
  78 #include "oops/instanceMirrorKlass.hpp"
  79 #include "oops/klass.inline.hpp"
  80 #include "oops/method.inline.hpp"
  81 #include "oops/objArrayOop.hpp"
  82 #include "oops/oop.inline.hpp"
  83 #include "oops/oopHandle.hpp"
  84 #include "oops/trainingData.hpp"
  85 #include "prims/jvmtiExport.hpp"
  86 #include "prims/whitebox.hpp"
  87 #include "runtime/arguments.hpp"
  88 #include "runtime/globals.hpp"
  89 #include "runtime/globals_extension.hpp"
  90 #include "runtime/handles.inline.hpp"
  91 #include "runtime/javaCalls.hpp"
  92 #include "runtime/os.inline.hpp"
  93 #include "runtime/safepointVerifiers.hpp"
  94 #include "runtime/sharedRuntime.hpp"
  95 #include "runtime/vmOperations.hpp"
  96 #include "runtime/vmThread.hpp"
  97 #include "sanitizers/leak.hpp"
  98 #include "utilities/align.hpp"
  99 #include "utilities/bitMap.inline.hpp"
 100 #include "utilities/defaultStream.hpp"
 101 #include "utilities/ostream.hpp"
 102 #include "utilities/resourceHash.hpp"
 103 
 104 ReservedSpace MetaspaceShared::_symbol_rs;
 105 VirtualSpace MetaspaceShared::_symbol_vs;
 106 bool MetaspaceShared::_archive_loading_failed = false;
 107 bool MetaspaceShared::_remapped_readwrite = false;
 108 void* MetaspaceShared::_shared_metaspace_static_top = nullptr;
 109 intx MetaspaceShared::_relocation_delta;
 110 char* MetaspaceShared::_requested_base_address;
 111 Array<Method*>* MetaspaceShared::_archived_method_handle_intrinsics = nullptr;
 112 bool MetaspaceShared::_use_optimized_module_handling = true;
 113 
 114 // The CDS archive is divided into the following regions:
 115 //     rw  - read-write metadata
 116 //     ro  - read-only metadata and read-only tables
 117 //     hp  - heap region
 118 //     bm  - bitmap for relocating the above 7 regions.
 119 //
 120 // The rw and ro regions are linearly allocated, in the order of rw->ro.
 121 // These regions are aligned with MetaspaceShared::core_region_alignment().
 122 //
 123 // These 2 regions are populated in the following steps:
 124 // [0] All classes are loaded in MetaspaceShared::preload_classes(). All metadata are
 125 //     temporarily allocated outside of the shared regions.
 126 // [1] We enter a safepoint and allocate a buffer for the rw/ro regions.
 127 // [2] C++ vtables are copied into the rw region.
 128 // [3] ArchiveBuilder copies RW metadata into the rw region.
 129 // [4] ArchiveBuilder copies RO metadata into the ro region.
 130 // [5] SymbolTable, StringTable, SystemDictionary, and a few other read-only data
 131 //     are copied into the ro region as read-only tables.
 132 //
 133 // The heap region is populated by HeapShared::archive_objects.
 134 //
 135 // The bitmap region is used to relocate the ro/rw/hp regions.
 136 
 137 static DumpRegion _symbol_region("symbols");
 138 
 139 char* MetaspaceShared::symbol_space_alloc(size_t num_bytes) {
 140   return _symbol_region.allocate(num_bytes);
 141 }
 142 
 143 // os::vm_allocation_granularity() is usually 4K for most OSes. However, some platforms
 144 // such as linux-aarch64 and macos-x64 ...
 145 // it can be either 4K or 64K and on macos-aarch64 it is 16K. To generate archives that are
 146 // compatible for both settings, an alternative cds core region alignment can be enabled
 147 // at building time:
 148 //   --enable-compactible-cds-alignment
 149 // Upon successful configuration, the compactible alignment then can be defined in:
 150 //   os_linux_aarch64.cpp
 151 //   os_bsd_x86.cpp
 152 size_t MetaspaceShared::core_region_alignment() {
 153   return os::cds_core_region_alignment();
 154 }
 155 
 156 static bool shared_base_valid(char* shared_base) {
 157   // We check user input for SharedBaseAddress at dump time. We must weed out values
 158   // we already know to be invalid later.
 159 
 160   // At CDS runtime, "shared_base" will be the (attempted) mapping start. It will also
 161   // be the encoding base, since the the headers of archived base objects (and with Lilliput,
 162   // the prototype mark words) carry pre-computed narrow Klass IDs that refer to the mapping
 163   // start as base.
 164   //
 165   // Therefore, "shared_base" must be later usable as encoding base.
 166   return AARCH64_ONLY(is_aligned(shared_base, 4 * G)) NOT_AARCH64(true);
 167 }
 168 
 169 class DumpClassListCLDClosure : public CLDClosure {
 170   static const int INITIAL_TABLE_SIZE = 1987;
 171   static const int MAX_TABLE_SIZE = 61333;
 172 
 173   fileStream *_stream;
 174   ResizeableResourceHashtable<InstanceKlass*, bool,
 175                               AnyObj::C_HEAP, mtClassShared> _dumped_classes;
 176 
 177   void dump(InstanceKlass* ik) {
 178     bool created;
 179     _dumped_classes.put_if_absent(ik, &created);
 180     if (!created) {
 181       return;
 182     }
 183     if (_dumped_classes.maybe_grow()) {
 184       log_info(cds, hashtables)("Expanded _dumped_classes table to %d", _dumped_classes.table_size());
 185     }
 186     if (ik->java_super()) {
 187       dump(ik->java_super());
 188     }
 189     Array<InstanceKlass*>* interfaces = ik->local_interfaces();
 190     int len = interfaces->length();
 191     for (int i = 0; i < len; i++) {
 192       dump(interfaces->at(i));
 193     }
 194     ClassListWriter::write_to_stream(ik, _stream);
 195   }
 196 
 197 public:
 198   DumpClassListCLDClosure(fileStream* f)
 199   : CLDClosure(), _dumped_classes(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE) {
 200     _stream = f;
 201   }
 202 
 203   void do_cld(ClassLoaderData* cld) {
 204     for (Klass* klass = cld->klasses(); klass != nullptr; klass = klass->next_link()) {
 205       if (klass->is_instance_klass()) {
 206         dump(InstanceKlass::cast(klass));
 207       }
 208     }
 209   }
 210 };
 211 
 212 void MetaspaceShared::dump_loaded_classes(const char* file_name, TRAPS) {
 213   fileStream stream(file_name, "w");
 214   if (stream.is_open()) {
 215     MutexLocker lock(ClassLoaderDataGraph_lock);
 216     MutexLocker lock2(ClassListFile_lock, Mutex::_no_safepoint_check_flag);
 217     DumpClassListCLDClosure collect_classes(&stream);
 218     ClassLoaderDataGraph::loaded_cld_do(&collect_classes);
 219   } else {
 220     THROW_MSG(vmSymbols::java_io_IOException(), "Failed to open file");
 221   }
 222 }
 223 
 224 static bool shared_base_too_high(char* specified_base, char* aligned_base, size_t cds_max) {
 225   if (specified_base != nullptr && aligned_base < specified_base) {
 226     // SharedBaseAddress is very high (e.g., 0xffffffffffffff00) so
 227     // align_up(SharedBaseAddress, MetaspaceShared::core_region_alignment()) has wrapped around.
 228     return true;
 229   }
 230   if (max_uintx - uintx(aligned_base) < uintx(cds_max)) {
 231     // The end of the archive will wrap around
 232     return true;
 233   }
 234 
 235   return false;
 236 }
 237 
 238 static char* compute_shared_base(size_t cds_max) {
 239   char* specified_base = (char*)SharedBaseAddress;
 240   char* aligned_base = align_up(specified_base, MetaspaceShared::core_region_alignment());
 241   if (UseCompressedClassPointers) {
 242     aligned_base = align_up(specified_base, Metaspace::reserve_alignment());
 243   }
 244 
 245   if (aligned_base != specified_base) {
 246     log_info(cds)("SharedBaseAddress (" INTPTR_FORMAT ") aligned up to " INTPTR_FORMAT,
 247                    p2i(specified_base), p2i(aligned_base));
 248   }
 249 
 250   const char* err = nullptr;
 251   if (shared_base_too_high(specified_base, aligned_base, cds_max)) {
 252     err = "too high";
 253   } else if (!shared_base_valid(aligned_base)) {
 254     err = "invalid for this platform";
 255   } else {
 256     return aligned_base;
 257   }
 258 
 259   log_warning(cds)("SharedBaseAddress (" INTPTR_FORMAT ") is %s. Reverted to " INTPTR_FORMAT,
 260                    p2i((void*)SharedBaseAddress), err,
 261                    p2i((void*)Arguments::default_SharedBaseAddress()));
 262 
 263   specified_base = (char*)Arguments::default_SharedBaseAddress();
 264   aligned_base = align_up(specified_base, MetaspaceShared::core_region_alignment());
 265 
 266   // Make sure the default value of SharedBaseAddress specified in globals.hpp is sane.
 267   assert(!shared_base_too_high(specified_base, aligned_base, cds_max), "Sanity");
 268   assert(shared_base_valid(aligned_base), "Sanity");
 269   return aligned_base;
 270 }
 271 
 272 void MetaspaceShared::initialize_for_static_dump() {
 273   assert(CDSConfig::is_dumping_static_archive(), "sanity");
 274 
 275   if (CDSConfig::is_dumping_preimage_static_archive() || CDSConfig::is_dumping_final_static_archive()) {
 276     if (!((UseG1GC || UseParallelGC || UseSerialGC || UseEpsilonGC) && UseCompressedClassPointers)) {
 277       vm_exit_during_initialization("Cannot create the CacheDataStore",
 278                                     "UseCompressedClassPointers must be enabled, and collector must be G1, Parallel, Serial, or Epsilon");
 279     }
 280   }
 281 
 282   log_info(cds)("Core region alignment: " SIZE_FORMAT, core_region_alignment());
 283   // The max allowed size for CDS archive. We use this to limit SharedBaseAddress
 284   // to avoid address space wrap around.
 285   size_t cds_max;
 286   const size_t reserve_alignment = core_region_alignment();
 287 
 288 #ifdef _LP64
 289   const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
 290   cds_max = align_down(UnscaledClassSpaceMax, reserve_alignment);
 291 #else
 292   // We don't support archives larger than 256MB on 32-bit due to limited
 293   //  virtual address space.
 294   cds_max = align_down(256*M, reserve_alignment);
 295 #endif
 296 
 297   _requested_base_address = compute_shared_base(cds_max);
 298   SharedBaseAddress = (size_t)_requested_base_address;
 299 
 300   size_t symbol_rs_size = LP64_ONLY(3 * G) NOT_LP64(128 * M);
 301   _symbol_rs = ReservedSpace(symbol_rs_size);
 302   if (!_symbol_rs.is_reserved()) {
 303     log_error(cds)("Unable to reserve memory for symbols: " SIZE_FORMAT " bytes.", symbol_rs_size);
 304     MetaspaceShared::unrecoverable_writing_error();
 305   }
 306   _symbol_region.init(&_symbol_rs, &_symbol_vs);
 307 }
 308 
 309 // Called by universe_post_init()
 310 void MetaspaceShared::post_initialize(TRAPS) {
 311   if (CDSConfig::is_using_archive()) {
 312     int size = FileMapInfo::get_number_of_shared_paths();
 313     if (size > 0) {
 314       CDSProtectionDomain::allocate_shared_data_arrays(size, CHECK);
 315       if (!CDSConfig::is_dumping_dynamic_archive()) {
 316         FileMapInfo* info;
 317         if (FileMapInfo::dynamic_info() == nullptr) {
 318           info = FileMapInfo::current_info();
 319         } else {
 320           info = FileMapInfo::dynamic_info();
 321         }
 322         ClassLoaderExt::init_paths_start_index(info->app_class_paths_start_index());
 323         ClassLoaderExt::init_app_module_paths_start_index(info->app_module_paths_start_index());
 324       }
 325     }
 326   }
 327 }
 328 
 329 static GrowableArrayCHeap<OopHandle, mtClassShared>* _extra_interned_strings = nullptr;
 330 static GrowableArrayCHeap<Symbol*, mtClassShared>* _extra_symbols = nullptr;
 331 static GrowableArray<Method*>* _method_handle_intrinsics = nullptr;
 332 
 333 void MetaspaceShared::read_extra_data(JavaThread* current, const char* filename) {
 334   _extra_interned_strings = new GrowableArrayCHeap<OopHandle, mtClassShared>(10000);
 335   _extra_symbols = new GrowableArrayCHeap<Symbol*, mtClassShared>(1000);
 336 
 337   HashtableTextDump reader(filename);
 338   reader.check_version("VERSION: 1.0");
 339 
 340   while (reader.remain() > 0) {
 341     int utf8_length;
 342     int prefix_type = reader.scan_prefix(&utf8_length);
 343     ResourceMark rm(current);
 344     if (utf8_length == 0x7fffffff) {
 345       // buf_len will overflown 32-bit value.
 346       log_error(cds)("string length too large: %d", utf8_length);
 347       MetaspaceShared::unrecoverable_loading_error();
 348     }
 349     int buf_len = utf8_length+1;
 350     char* utf8_buffer = NEW_RESOURCE_ARRAY(char, buf_len);
 351     reader.get_utf8(utf8_buffer, utf8_length);
 352     utf8_buffer[utf8_length] = '\0';
 353 
 354     if (prefix_type == HashtableTextDump::SymbolPrefix) {
 355       _extra_symbols->append(SymbolTable::new_permanent_symbol(utf8_buffer));
 356     } else{
 357       assert(prefix_type == HashtableTextDump::StringPrefix, "Sanity");
 358       ExceptionMark em(current);
 359       JavaThread* THREAD = current; // For exception macros.
 360       oop str = StringTable::intern(utf8_buffer, THREAD);
 361 
 362       if (HAS_PENDING_EXCEPTION) {
 363         log_warning(cds, heap)("[line %d] extra interned string allocation failed; size too large: %d",
 364                                reader.last_line_no(), utf8_length);
 365         CLEAR_PENDING_EXCEPTION;
 366       } else {
 367 #if INCLUDE_CDS_JAVA_HEAP
 368         if (ArchiveHeapWriter::is_string_too_large_to_archive(str)) {
 369           log_warning(cds, heap)("[line %d] extra interned string ignored; size too large: %d",
 370                                  reader.last_line_no(), utf8_length);
 371           continue;
 372         }
 373         // Make sure this string is included in the dumped interned string table.
 374         assert(str != nullptr, "must succeed");
 375         _extra_interned_strings->append(OopHandle(Universe::vm_global(), str));
 376 #endif
 377       }
 378     }
 379   }
 380 }
 381 
 382 void MetaspaceShared::make_method_handle_intrinsics_shareable() {
 383   for (int i = 0; i < _method_handle_intrinsics->length(); i++) {
 384     Method* m = ArchiveBuilder::current()->get_buffered_addr(_method_handle_intrinsics->at(i));
 385     m->remove_unshareable_info();
 386     // Each method has its own constant pool (which is distinct from m->method_holder()->constants());
 387     m->constants()->remove_unshareable_info();
 388   }
 389 }
 390 
 391 void MetaspaceShared::write_method_handle_intrinsics() {
 392   int len = _method_handle_intrinsics->length();
 393   _archived_method_handle_intrinsics = ArchiveBuilder::new_ro_array<Method*>(len);
 394   for (int i = 0; i < len; i++) {
 395     ArchiveBuilder::current()->write_pointer_in_buffer(_archived_method_handle_intrinsics->adr_at(i),
 396                                                        _method_handle_intrinsics->at(i));
 397   }
 398   log_info(cds)("Archived %d method handle intrinsics", len);
 399 }
 400 
 401 // Read/write a data stream for restoring/preserving metadata pointers and
 402 // miscellaneous data from/to the shared archive file.
 403 
 404 void MetaspaceShared::serialize(SerializeClosure* soc) {
 405   int tag = 0;
 406   soc->do_tag(--tag);
 407 
 408   // Verify the sizes of various metadata in the system.
 409   soc->do_tag(sizeof(Method));
 410   soc->do_tag(sizeof(ConstMethod));
 411   soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
 412   soc->do_tag(sizeof(ConstantPool));
 413   soc->do_tag(sizeof(ConstantPoolCache));
 414   soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
 415   soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
 416   soc->do_tag(sizeof(Symbol));
 417 
 418   // Need to do this first, as subsequent steps may call virtual functions
 419   // in archived Metadata objects.
 420   CppVtables::serialize(soc);
 421   soc->do_tag(--tag);
 422 
 423   // Dump/restore miscellaneous metadata.
 424   JavaClasses::serialize_offsets(soc);
 425   HeapShared::serialize_misc_info(soc);
 426   Universe::serialize(soc);
 427   soc->do_tag(--tag);
 428 
 429   // Dump/restore references to commonly used names and signatures.
 430   vmSymbols::serialize(soc);
 431   soc->do_tag(--tag);
 432 
 433   // Dump/restore the symbol/string/subgraph_info tables
 434   SymbolTable::serialize_shared_table_header(soc);
 435   StringTable::serialize_shared_table_header(soc);
 436   HeapShared::serialize_tables(soc);
 437   SystemDictionaryShared::serialize_dictionary_headers(soc);
 438   AOTLinkedClassBulkLoader::serialize(soc, true);
 439   FinalImageRecipes::serialize(soc, true);
 440   TrainingData::serialize_training_data(soc);
 441   InstanceMirrorKlass::serialize_offsets(soc);
 442 
 443   // Dump/restore well known classes (pointers)
 444   SystemDictionaryShared::serialize_vm_classes(soc);
 445   soc->do_tag(--tag);
 446 
 447   CDS_JAVA_HEAP_ONLY(Modules::serialize(soc);)
 448   CDS_JAVA_HEAP_ONLY(ClassLoaderDataShared::serialize(soc);)
 449   soc->do_ptr((void**)&_archived_method_handle_intrinsics);
 450 
 451 
 452   LambdaFormInvokers::serialize(soc);
 453   soc->do_tag(666);
 454 }
 455 
 456 static void rewrite_nofast_bytecode(const methodHandle& method) {
 457   BytecodeStream bcs(method);
 458   while (!bcs.is_last_bytecode()) {
 459     Bytecodes::Code opcode = bcs.next();
 460     switch (opcode) {
 461     case Bytecodes::_getfield:      *bcs.bcp() = Bytecodes::_nofast_getfield;      break;
 462     case Bytecodes::_putfield:      *bcs.bcp() = Bytecodes::_nofast_putfield;      break;
 463     case Bytecodes::_aload_0:       *bcs.bcp() = Bytecodes::_nofast_aload_0;       break;
 464     case Bytecodes::_iload: {
 465       if (!bcs.is_wide()) {
 466         *bcs.bcp() = Bytecodes::_nofast_iload;
 467       }
 468       break;
 469     }
 470     default: break;
 471     }
 472   }
 473 }
 474 
 475 // [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified
 476 //     at run time by RewriteBytecodes/RewriteFrequentPairs
 477 // [2] Assign a fingerprint, so one doesn't need to be assigned at run-time.
 478 void MetaspaceShared::rewrite_nofast_bytecodes_and_calculate_fingerprints(Thread* thread, InstanceKlass* ik) {
 479   for (int i = 0; i < ik->methods()->length(); i++) {
 480     methodHandle m(thread, ik->methods()->at(i));
 481     if (ik->can_be_verified_at_dumptime() && ik->is_linked()) {
 482       rewrite_nofast_bytecode(m);
 483     }
 484     Fingerprinter fp(m);
 485     // The side effect of this call sets method's fingerprint field.
 486     fp.fingerprint();
 487   }
 488 }
 489 
 490 class VM_PopulateDumpSharedSpace : public VM_Operation {
 491 private:
 492   ArchiveHeapInfo _heap_info;
 493   FileMapInfo* _map_info;
 494   StaticArchiveBuilder& _builder;
 495 
 496   void dump_java_heap_objects(GrowableArray<Klass*>* klasses) NOT_CDS_JAVA_HEAP_RETURN;
 497   void dump_shared_symbol_table(GrowableArray<Symbol*>* symbols) {
 498     log_info(cds)("Dumping symbol table ...");
 499     SymbolTable::write_to_archive(symbols);
 500   }
 501   char* dump_read_only_tables();
 502 
 503 public:
 504 
 505   VM_PopulateDumpSharedSpace(StaticArchiveBuilder& b) :
 506     VM_Operation(), _heap_info(), _map_info(nullptr), _builder(b) {}
 507 
 508   bool skip_operation() const { return false; }
 509 
 510   VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
 511   ArchiveHeapInfo* heap_info()  { return &_heap_info; }
 512   FileMapInfo* map_info() const { return _map_info; }
 513   void doit();   // outline because gdb sucks
 514   bool allow_nested_vm_operations() const { return true; }
 515 }; // class VM_PopulateDumpSharedSpace
 516 
 517 class StaticArchiveBuilder : public ArchiveBuilder {
 518 public:
 519   StaticArchiveBuilder() : ArchiveBuilder() {}
 520 
 521   virtual void iterate_roots(MetaspaceClosure* it) {
 522     FileMapInfo::metaspace_pointers_do(it);
 523     SystemDictionaryShared::dumptime_classes_do(it);
 524     Universe::metaspace_pointers_do(it);
 525     vmSymbols::metaspace_pointers_do(it);
 526     TrainingData::iterate_roots(it);
 527 
 528     // The above code should find all the symbols that are referenced by the
 529     // archived classes. We just need to add the extra symbols which
 530     // may not be used by any of the archived classes -- these are usually
 531     // symbols that we anticipate to be used at run time, so we can store
 532     // them in the RO region, to be shared across multiple processes.
 533     if (_extra_symbols != nullptr) {
 534       for (int i = 0; i < _extra_symbols->length(); i++) {
 535         it->push(_extra_symbols->adr_at(i));
 536       }
 537     }
 538 
 539     for (int i = 0; i < _method_handle_intrinsics->length(); i++) {
 540       it->push(_method_handle_intrinsics->adr_at(i));
 541     }
 542   }
 543 };
 544 
 545 char* VM_PopulateDumpSharedSpace::dump_read_only_tables() {
 546   ArchiveBuilder::OtherROAllocMark mark;
 547 
 548   SystemDictionaryShared::write_to_archive();
 549   AOTClassLinker::write_to_archive();
 550   if (CDSConfig::is_dumping_preimage_static_archive()) {
 551     FinalImageRecipes::record_recipes();
 552   }
 553   AOTLinkedClassBulkLoader::record_unregistered_classes();
 554   TrainingData::dump_training_data();
 555   MetaspaceShared::write_method_handle_intrinsics();
 556 
 557   // Write lambform lines into archive
 558   LambdaFormInvokers::dump_static_archive_invokers();
 559   // Write module name into archive
 560   CDS_JAVA_HEAP_ONLY(Modules::dump_main_module_name();)
 561   // Write the other data to the output array.
 562   DumpRegion* ro_region = ArchiveBuilder::current()->ro_region();
 563   char* start = ro_region->top();
 564   WriteClosure wc(ro_region);
 565   MetaspaceShared::serialize(&wc);
 566 
 567   return start;
 568 }
 569 
 570 void VM_PopulateDumpSharedSpace::doit() {
 571   //guarantee(!CDSConfig::is_using_archive(), "We should not be using an archive when we dump");
 572 
 573   DEBUG_ONLY(SystemDictionaryShared::NoClassLoadingMark nclm);
 574 
 575   FileMapInfo::check_nonempty_dir_in_shared_path_table();
 576 
 577   NOT_PRODUCT(SystemDictionary::verify();)
 578 
 579   // Block concurrent class unloading from changing the _dumptime_table
 580   MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
 581 
 582   HeapShared::start_finding_archivable_hidden_classes();
 583   SystemDictionaryShared::check_excluded_classes();
 584   HeapShared::end_finding_archivable_hidden_classes();
 585 
 586   _builder.gather_source_objs();
 587   _builder.reserve_buffer();
 588 
 589   CppVtables::dumptime_init(&_builder);
 590 
 591   _builder.sort_metadata_objs();
 592   _builder.dump_rw_metadata();
 593   _builder.dump_ro_metadata();
 594   _builder.relocate_metaspaceobj_embedded_pointers();
 595 
 596   dump_java_heap_objects(_builder.klasses());
 597   dump_shared_symbol_table(_builder.symbols());
 598 
 599   log_info(cds)("Make classes shareable");
 600   _builder.make_klasses_shareable();
 601   MetaspaceShared::make_method_handle_intrinsics_shareable();
 602 
 603   char* serialized_data = dump_read_only_tables();
 604 
 605   SystemDictionaryShared::adjust_lambda_proxy_class_dictionary();
 606 
 607   log_info(cds)("Adjust method info dictionary");
 608   SystemDictionaryShared::adjust_method_info_dictionary();
 609 
 610   log_info(cds)("Make training data shareable");
 611   _builder.make_training_data_shareable();
 612 
 613   // The vtable clones contain addresses of the current process.
 614   // We don't want to write these addresses into the archive.
 615   CppVtables::zero_archived_vtables();
 616 
 617   // Write the archive file
 618   const char* static_archive;
 619   if (CDSConfig::is_dumping_final_static_archive()) {
 620     static_archive = CacheDataStore;
 621     assert(FileMapInfo::current_info() != nullptr, "sanity");
 622     delete FileMapInfo::current_info();
 623   } else {
 624     static_archive = CDSConfig::static_archive_path();
 625   }
 626   assert(static_archive != nullptr, "SharedArchiveFile not set?");
 627   _map_info = new FileMapInfo(static_archive, true);
 628   _map_info->populate_header(MetaspaceShared::core_region_alignment());
 629   _map_info->set_serialized_data(serialized_data);
 630   _map_info->set_cloned_vtables(CppVtables::vtables_serialized_base());
 631 }
 632 
 633 class CollectCLDClosure : public CLDClosure {
 634   GrowableArray<ClassLoaderData*> _loaded_cld;
 635   GrowableArray<OopHandle> _loaded_cld_handles; // keep the CLDs alive
 636   Thread* _current_thread;
 637 public:
 638   CollectCLDClosure(Thread* thread) : _current_thread(thread) {}
 639   ~CollectCLDClosure() {
 640     for (int i = 0; i < _loaded_cld_handles.length(); i++) {
 641       _loaded_cld_handles.at(i).release(Universe::vm_global());
 642     }
 643   }
 644   void do_cld(ClassLoaderData* cld) {
 645     assert(cld->is_alive(), "must be");
 646     _loaded_cld.append(cld);
 647     _loaded_cld_handles.append(OopHandle(Universe::vm_global(), cld->holder()));
 648   }
 649 
 650   int nof_cld() const                { return _loaded_cld.length(); }
 651   ClassLoaderData* cld_at(int index) { return _loaded_cld.at(index); }
 652 };
 653 
 654 // Check if we can eagerly link this class at dump time, so we can avoid the
 655 // runtime linking overhead (especially verification)
 656 bool MetaspaceShared::may_be_eagerly_linked(InstanceKlass* ik) {
 657   if (CDSConfig::preserve_all_dumptime_verification_states(ik)) {
 658     assert(ik->can_be_verified_at_dumptime(), "sanity");
 659   }
 660   if (!ik->can_be_verified_at_dumptime()) {
 661     // For old classes, try to leave them in the unlinked state, so
 662     // we can still store them in the archive. They must be
 663     // linked/verified at runtime.
 664     return false;
 665   }
 666 
 667   if (CDSConfig::is_dumping_dynamic_archive() && ik->is_shared_unregistered_class()) {
 668     // Linking of unregistered classes at this stage may cause more
 669     // classes to be resolved, resulting in calls to ClassLoader.loadClass()
 670     // that may not be expected by custom class loaders.
 671     //
 672     // It's OK to do this for the built-in loaders as we know they can
 673     // tolerate this.
 674     return false;
 675   }
 676   return true;
 677 }
 678 
 679 void MetaspaceShared::link_shared_classes(bool jcmd_request, TRAPS) {
 680   AOTClassLinker::initialize();
 681 
 682   if (!jcmd_request && !CDSConfig::is_dumping_dynamic_archive()
 683       && !CDSConfig::is_dumping_preimage_static_archive()
 684       && !CDSConfig::is_dumping_final_static_archive()) {
 685     // If we have regenerated invoker classes in the dynamic archive,
 686     // they will conflict with the resolved CONSTANT_Klass references that are stored
 687     // in the static archive. This is not easy to handle. Let's disable
 688     // it for dynamic archive for now.
 689     LambdaFormInvokers::regenerate_holder_classes(CHECK);
 690   }
 691 
 692   // Collect all loaded ClassLoaderData.
 693   CollectCLDClosure collect_cld(THREAD);
 694   {
 695     // ClassLoaderDataGraph::loaded_cld_do requires ClassLoaderDataGraph_lock.
 696     // We cannot link the classes while holding this lock (or else we may run into deadlock).
 697     // Therefore, we need to first collect all the CLDs, and then link their classes after
 698     // releasing the lock.
 699     MutexLocker lock(ClassLoaderDataGraph_lock);
 700     ClassLoaderDataGraph::loaded_cld_do(&collect_cld);
 701   }
 702 
 703   while (true) {
 704     bool has_linked = false;
 705     for (int i = 0; i < collect_cld.nof_cld(); i++) {
 706       ClassLoaderData* cld = collect_cld.cld_at(i);
 707       for (Klass* klass = cld->klasses(); klass != nullptr; klass = klass->next_link()) {
 708         if (klass->is_instance_klass()) {
 709           InstanceKlass* ik = InstanceKlass::cast(klass);
 710           if (may_be_eagerly_linked(ik)) {
 711             has_linked |= try_link_class(THREAD, ik);
 712           }
 713           if (CDSConfig::is_dumping_heap() && ik->is_linked() && !ik->is_initialized()) {
 714             AOTClassInitializer::maybe_preinit_class(ik, CHECK);
 715           }
 716         }
 717       }
 718     }
 719 
 720     if (!has_linked) {
 721       break;
 722     }
 723     // Class linking includes verification which may load more classes.
 724     // Keep scanning until we have linked no more classes.
 725   }
 726 
 727   // Resolve constant pool entries -- we don't load any new classes during this stage
 728   for (int i = 0; i < collect_cld.nof_cld(); i++) {
 729     ClassLoaderData* cld = collect_cld.cld_at(i);
 730     for (Klass* klass = cld->klasses(); klass != nullptr; klass = klass->next_link()) {
 731       if (klass->is_instance_klass()) {
 732         InstanceKlass* ik = InstanceKlass::cast(klass);
 733         AOTConstantPoolResolver::dumptime_resolve_constants(ik, CHECK);
 734         if (CDSConfig::is_dumping_preimage_static_archive()) {
 735           FinalImageRecipes::add_reflection_data_flags(ik, CHECK);
 736         }
 737       }
 738     }
 739   }
 740 
 741   if (CDSConfig::is_dumping_preimage_static_archive()) {
 742     // Do this after all classes are verified by the above loop.
 743     // Any classes loaded from here on will be automatically excluded, so
 744     // there's no need to force verification or resolve CP entries. 
 745     RecordTraining = false;
 746     SystemDictionaryShared::ignore_new_classes();
 747     LambdaFormInvokers::regenerate_holder_classes(CHECK);
 748     RecordTraining = true;
 749   }
 750 
 751   if (CDSConfig::is_dumping_final_static_archive()) {
 752     FinalImageRecipes::apply_recipes(CHECK);
 753   }
 754 }
 755 
 756 void MetaspaceShared::prepare_for_dumping() {
 757   assert(CDSConfig::is_dumping_archive(), "sanity");
 758   CDSConfig::check_unsupported_dumping_module_options();
 759   ClassLoader::initialize_shared_path(JavaThread::current());
 760 }
 761 
 762 // Preload classes from a list, populate the shared spaces and dump to a
 763 // file.
 764 void MetaspaceShared::preload_and_dump(TRAPS) {
 765   ResourceMark rm(THREAD);
 766   HandleMark hm(THREAD);
 767 
 768   if (CDSConfig::is_dumping_final_static_archive() && PrintTrainingInfo) {
 769     tty->print_cr("==================== archived_training_data ** before dumping ====================");
 770     TrainingData::print_archived_training_data_on(tty);
 771   }
 772 
 773   StaticArchiveBuilder builder;
 774   preload_and_dump_impl(builder, THREAD);
 775   if (HAS_PENDING_EXCEPTION) {
 776     if (PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())) {
 777       log_error(cds)("Out of memory. Please run with a larger Java heap, current MaxHeapSize = "
 778                      SIZE_FORMAT "M", MaxHeapSize/M);
 779       MetaspaceShared::writing_error();
 780     } else {
 781       log_error(cds)("%s: %s", PENDING_EXCEPTION->klass()->external_name(),
 782                      java_lang_String::as_utf8_string(java_lang_Throwable::message(PENDING_EXCEPTION)));
 783       MetaspaceShared::writing_error("Unexpected exception, use -Xlog:cds,exceptions=trace for detail");
 784     }
 785   }
 786 }
 787 
 788 #if INCLUDE_CDS_JAVA_HEAP && defined(_LP64)
 789 void MetaspaceShared::adjust_heap_sizes_for_dumping() {
 790   if (!CDSConfig::is_dumping_heap() || UseCompressedOops) {
 791     return;
 792   }
 793   // CDS heap dumping requires all string oops to have an offset
 794   // from the heap bottom that can be encoded in 32-bit.
 795   julong max_heap_size = (julong)(4 * G);
 796 
 797   if (MinHeapSize > max_heap_size) {
 798     log_debug(cds)("Setting MinHeapSize to 4G for CDS dumping, original size = " SIZE_FORMAT "M", MinHeapSize/M);
 799     FLAG_SET_ERGO(MinHeapSize, max_heap_size);
 800   }
 801   if (InitialHeapSize > max_heap_size) {
 802     log_debug(cds)("Setting InitialHeapSize to 4G for CDS dumping, original size = " SIZE_FORMAT "M", InitialHeapSize/M);
 803     FLAG_SET_ERGO(InitialHeapSize, max_heap_size);
 804   }
 805   if (MaxHeapSize > max_heap_size) {
 806     log_debug(cds)("Setting MaxHeapSize to 4G for CDS dumping, original size = " SIZE_FORMAT "M", MaxHeapSize/M);
 807     FLAG_SET_ERGO(MaxHeapSize, max_heap_size);
 808   }
 809 }
 810 #endif // INCLUDE_CDS_JAVA_HEAP && _LP64
 811 
 812 void MetaspaceShared::get_default_classlist(char* default_classlist, const size_t buf_size) {
 813   // Construct the path to the class list (in jre/lib)
 814   // Walk up two directories from the location of the VM and
 815   // optionally tack on "lib" (depending on platform)
 816   os::jvm_path(default_classlist, (jint)(buf_size));
 817   for (int i = 0; i < 3; i++) {
 818     char *end = strrchr(default_classlist, *os::file_separator());
 819     if (end != nullptr) *end = '\0';
 820   }
 821   size_t classlist_path_len = strlen(default_classlist);
 822   if (classlist_path_len >= 3) {
 823     if (strcmp(default_classlist + classlist_path_len - 3, "lib") != 0) {
 824       if (classlist_path_len < buf_size - 4) {
 825         jio_snprintf(default_classlist + classlist_path_len,
 826                      buf_size - classlist_path_len,
 827                      "%slib", os::file_separator());
 828         classlist_path_len += 4;
 829       }
 830     }
 831   }
 832   if (classlist_path_len < buf_size - 10) {
 833     jio_snprintf(default_classlist + classlist_path_len,
 834                  buf_size - classlist_path_len,
 835                  "%sclasslist", os::file_separator());
 836   }
 837 }
 838 
 839 void MetaspaceShared::preload_classes(TRAPS) {
 840   char default_classlist[JVM_MAXPATHLEN];
 841   const char* classlist_path;
 842 
 843   get_default_classlist(default_classlist, sizeof(default_classlist));
 844   if (SharedClassListFile == nullptr) {
 845     classlist_path = default_classlist;
 846   } else {
 847     classlist_path = SharedClassListFile;
 848   }
 849 
 850   log_info(cds)("Loading classes to share ...");
 851   ClassListParser::parse_classlist(classlist_path,
 852                                    ClassListParser::_parse_all, CHECK);
 853   if (ExtraSharedClassListFile) {
 854     ClassListParser::parse_classlist(ExtraSharedClassListFile,
 855                                      ClassListParser::_parse_all, CHECK);
 856   }
 857   if (classlist_path != default_classlist) {
 858     struct stat statbuf;
 859     if (os::stat(default_classlist, &statbuf) == 0) {
 860       // File exists, let's use it.
 861       ClassListParser::parse_classlist(default_classlist,
 862                                        ClassListParser::_parse_lambda_forms_invokers_only, CHECK);
 863     }
 864   }
 865 
 866   // Exercise the manifest processing code to ensure classes used by CDS at runtime
 867   // are always archived
 868   const char* dummy = "Manifest-Version: 1.0\n";
 869   CDSProtectionDomain::create_jar_manifest(dummy, strlen(dummy), CHECK);
 870 
 871   log_info(cds)("Loading classes to share: done.");
 872 }
 873 
 874 void MetaspaceShared::preload_and_dump_impl(StaticArchiveBuilder& builder, TRAPS) {
 875   if (CDSConfig::is_dumping_classic_static_archive()) {
 876     // We are running with -Xshare:dump
 877     preload_classes(CHECK);
 878 
 879     if (SharedArchiveConfigFile) {
 880       log_info(cds)("Reading extra data from %s ...", SharedArchiveConfigFile);
 881       read_extra_data(THREAD, SharedArchiveConfigFile);
 882       log_info(cds)("Reading extra data: done.");
 883     }
 884   }
 885 
 886   if (CDSConfig::is_dumping_preimage_static_archive()) {
 887     log_info(cds)("Reading lambda form invokers of in JDK default classlist ...");
 888     char default_classlist[JVM_MAXPATHLEN];
 889     get_default_classlist(default_classlist, sizeof(default_classlist));
 890     struct stat statbuf;
 891     if (os::stat(default_classlist, &statbuf) == 0) {
 892       ClassListParser::parse_classlist(default_classlist,
 893                                        ClassListParser::_parse_lambda_forms_invokers_only, CHECK);
 894     }
 895   }
 896 
 897 #if INCLUDE_CDS_JAVA_HEAP
 898   if (CDSConfig::is_dumping_invokedynamic()) {
 899     // This makes sure that the MethodType and MethodTypeForm tables won't be updated
 900     // concurrently when we are saving their contents into a side table.
 901     assert(CDSConfig::allow_only_single_java_thread(), "Required");
 902 
 903     JavaValue result(T_VOID);
 904     JavaCalls::call_static(&result, vmClasses::MethodType_klass(),
 905                            vmSymbols::createArchivedObjects(),
 906                            vmSymbols::void_method_signature(),
 907                            CHECK);
 908   }
 909 #endif
 910 
 911   // Rewrite and link classes
 912   log_info(cds)("Rewriting and linking classes ...");
 913   // Link any classes which got missed. This would happen if we have loaded classes that
 914   // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
 915   // fails verification, all other interfaces that were not specified in the classlist but
 916   // are implemented by K are not verified.
 917   link_shared_classes(false/*not from jcmd*/, CHECK);
 918   log_info(cds)("Rewriting and linking classes: done");
 919 
 920   if (CDSConfig::is_dumping_final_static_archive()) {
 921     assert(RecordTraining == false, "must be");
 922     RecordTraining = true;
 923   }
 924 
 925   TrainingData::init_dumptime_table(CHECK); // captures TrainingDataSetLocker
 926 
 927   _method_handle_intrinsics = new (mtClassShared) GrowableArray<Method*>(256, mtClassShared);
 928   SystemDictionary::get_all_method_handle_intrinsics(_method_handle_intrinsics);
 929   _method_handle_intrinsics->sort([] (Method** a, Method** b) -> int {
 930     Symbol* a_holder = (*a)->method_holder()->name();
 931     Symbol* b_holder = (*b)->method_holder()->name();
 932     if (a_holder != b_holder) {
 933       return a_holder->cmp(b_holder);
 934     }
 935     Symbol* a_name = (*a)->name();
 936     Symbol* b_name = (*b)->name();
 937     if (a_name != b_name) {
 938       return a_name->cmp(b_name);
 939     }
 940     Symbol* a_signature = (*a)->signature();
 941     Symbol* b_signature = (*b)->signature();
 942     if (a_signature != b_signature) {
 943       return a_signature->cmp(b_signature);
 944     }
 945     return 0;
 946   });
 947 
 948 #if INCLUDE_CDS_JAVA_HEAP
 949   if (CDSConfig::is_dumping_heap()) {
 950     if (!HeapShared::is_archived_boot_layer_available(THREAD)) {
 951       log_info(cds)("archivedBootLayer not available, disabling full module graph");
 952       CDSConfig::stop_dumping_full_module_graph();
 953     }
 954     HeapShared::init_for_dumping(CHECK);
 955     ArchiveHeapWriter::init();
 956     if (CDSConfig::is_dumping_full_module_graph()) {
 957       HeapShared::reset_archived_object_states(CHECK);
 958     }
 959 
 960     if (ArchiveLoaderLookupCache) {
 961       SystemDictionaryShared::create_loader_positive_lookup_cache(CHECK);
 962     }
 963 
 964     // Do this at the very end, when no Java code will be executed. Otherwise
 965     // some new strings may be added to the intern table.
 966     StringTable::allocate_shared_strings_array(CHECK);
 967   }
 968 #endif
 969 
 970   VM_PopulateDumpSharedSpace op(builder);
 971   VMThread::execute(&op);
 972   FileMapInfo* mapinfo = op.map_info();
 973   ArchiveHeapInfo* heap_info = op.heap_info();
 974   bool status;
 975   if (CDSConfig::is_dumping_preimage_static_archive()) {
 976     if ((status = write_static_archive(&builder, mapinfo, heap_info))) {
 977       fork_and_dump_final_static_archive();
 978     }
 979   } else if (CDSConfig::is_dumping_final_static_archive()) {
 980     RecordTraining = false;
 981     if (StoreCachedCode && CachedCodeFile != nullptr) { // FIXME: new workflow -- remove the CachedCodeFile flag
 982       if (log_is_enabled(Info, cds, jit)) {
 983         CDSAccess::test_heap_access_api();
 984       }
 985 
 986       // We have just created the final image. Let's run the AOT compiler
 987       if (PrintTrainingInfo) {
 988         tty->print_cr("==================== archived_training_data ** after dumping ====================");
 989         TrainingData::print_archived_training_data_on(tty);
 990       }
 991 
 992       CDSConfig::enable_dumping_cached_code();
 993       {
 994         builder.start_cc_region();
 995         Precompiler::compile_cached_code(&builder, CHECK);
 996         builder.end_cc_region();
 997       }
 998       CDSConfig::disable_dumping_cached_code();
 999 
1000       SCCache::close(); // Write final data and close archive
1001     }
1002     status = write_static_archive(&builder, mapinfo, heap_info);
1003   } else {
1004     status = write_static_archive(&builder, mapinfo, heap_info);
1005   }
1006 
1007   if (!status) {
1008     THROW_MSG(vmSymbols::java_io_IOException(), "Encountered error while dumping");
1009   }
1010 }
1011 
1012 bool MetaspaceShared::write_static_archive(ArchiveBuilder* builder, FileMapInfo* map_info, ArchiveHeapInfo* heap_info) {
1013   // relocate the data so that it can be mapped to MetaspaceShared::requested_base_address()
1014   // without runtime relocation.
1015   builder->relocate_to_requested();
1016 
1017   map_info->open_for_write();
1018   if (!map_info->is_open()) {
1019     return false;
1020   }
1021   builder->write_archive(map_info, heap_info);
1022 
1023   if (AllowArchivingWithJavaAgent) {
1024     log_warning(cds)("This archive was created with AllowArchivingWithJavaAgent. It should be used "
1025             "for testing purposes only and should not be used in a production environment");
1026   }
1027   return true;
1028 }
1029 
1030 static void print_java_launcher(outputStream* st) {
1031   st->print("%s%sbin%sjava", Arguments::get_java_home(), os::file_separator(), os::file_separator());
1032 }
1033 
1034 static void print_vm_arguments(outputStream* st) {
1035   const char* cp = Arguments::get_appclasspath();
1036   if (cp != nullptr && strlen(cp) > 0 && strcmp(cp, ".") != 0) {
1037     st->print(" -cp ");  st->print_raw(cp);
1038   }
1039   for (int i = 0; i < Arguments::num_jvm_flags(); i++) {
1040     st->print(" %s", Arguments::jvm_flags_array()[i]);
1041   }
1042   for (int i = 0; i < Arguments::num_jvm_args(); i++) {
1043     st->print(" %s", Arguments::jvm_args_array()[i]);
1044   }
1045 }
1046 
1047 void MetaspaceShared::fork_and_dump_final_static_archive() {
1048   assert(CDSConfig::is_dumping_preimage_static_archive(), "sanity");
1049 
1050   ResourceMark rm;
1051   stringStream ss;
1052   print_java_launcher(&ss);
1053   print_vm_arguments(&ss);
1054   ss.print(" -XX:CDSPreimage=%s", SharedArchiveFile);
1055 
1056   const char* cmd = ss.freeze();
1057   if (CDSManualFinalImage) {
1058     tty->print_cr("-XX:+CDSManualFinalImage is specified");
1059     tty->print_cr("Please manually execute the following command to create the final CDS image:");
1060     tty->print("    "); tty->print_raw_cr(cmd);
1061 
1062     // The following is useful if the dumping was trigger by a script that builds
1063     // a complex command-line.
1064     tty->print_cr("Note: to recreate the preimage only:");
1065     tty->print_cr("    rm -f %s", CacheDataStore);
1066     tty->print("    ");
1067     print_java_launcher(tty);
1068     print_vm_arguments(tty);
1069     if (Arguments::java_command() != nullptr) {
1070       tty->print(" %s", Arguments::java_command());
1071     }
1072     tty->cr();
1073   } else {
1074     // FIXME: space characters are not properly quoated. E.g.,
1075     //      java -Dfoo='a b c' HelloWorld
1076     log_info(cds)("Launching child process to create final CDS image:");
1077     log_info(cds)("    %s", cmd);
1078     int status = os::fork_and_exec(cmd);
1079     if (status != 0) {
1080       log_error(cds)("Child process finished; status = %d", status);
1081       log_error(cds)("To reproduce the error");
1082       ResourceMark rm;
1083       LogStream ls(Log(cds)::error());
1084       ls.print("    "); ls.print_raw_cr(cmd);
1085 
1086       // The following is useful if the dumping was trigger by a script that builds
1087       // a complex command-line.
1088       ls.print_cr("Note: to recreate the preimage only:");
1089       ls.print_cr("    rm -f %s", CacheDataStore);
1090       ls.print("    ");
1091       print_java_launcher(&ls);
1092       print_vm_arguments(&ls);
1093       ls.print(" -XX:+UnlockDiagnosticVMOptions -XX:+CDSManualFinalImage");
1094       if (Arguments::java_command() != nullptr) {
1095         ls.print(" %s", Arguments::java_command());
1096       }
1097       ls.cr();
1098 
1099       vm_direct_exit(status);
1100     } else {
1101       log_info(cds)("Child process finished; status = %d", status);
1102       // On Windows, need WRITE permission to remove the file.
1103       WINDOWS_ONLY(chmod(SharedArchiveFile, _S_IREAD | _S_IWRITE));
1104       status = remove(SharedArchiveFile);
1105       if (status != 0) {
1106         log_error(cds)("Failed to remove CDSPreimage file %s", SharedArchiveFile);
1107       } else {
1108         log_info(cds)("Removed CDSPreimage file %s", SharedArchiveFile);
1109       }
1110     }
1111   }
1112 }
1113 
1114 // Returns true if the class's status has changed.
1115 bool MetaspaceShared::try_link_class(JavaThread* current, InstanceKlass* ik) {
1116   ExceptionMark em(current);
1117   JavaThread* THREAD = current; // For exception macros.
1118   assert(CDSConfig::is_dumping_archive(), "sanity");
1119 
1120   if (ik->is_shared() && !CDSConfig::is_dumping_final_static_archive()) {
1121     assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1122     return false;
1123   }
1124 
1125   if (ik->is_loaded() && !ik->is_linked() && ik->can_be_verified_at_dumptime() &&
1126       !SystemDictionaryShared::has_class_failed_verification(ik)) {
1127     bool saved = BytecodeVerificationLocal;
1128     if (ik->is_shared_unregistered_class() && ik->class_loader() == nullptr) {
1129       // The verification decision is based on BytecodeVerificationRemote
1130       // for non-system classes. Since we are using the null classloader
1131       // to load non-system classes for customized class loaders during dumping,
1132       // we need to temporarily change BytecodeVerificationLocal to be the same as
1133       // BytecodeVerificationRemote. Note this can cause the parent system
1134       // classes also being verified. The extra overhead is acceptable during
1135       // dumping.
1136       BytecodeVerificationLocal = BytecodeVerificationRemote;
1137     }
1138     ik->link_class(THREAD);
1139     if (HAS_PENDING_EXCEPTION) {
1140       ResourceMark rm(THREAD);
1141       log_warning(cds)("Preload Warning: Verification failed for %s",
1142                     ik->external_name());
1143       CLEAR_PENDING_EXCEPTION;
1144       SystemDictionaryShared::set_class_has_failed_verification(ik);
1145     }
1146     ik->compute_has_loops_flag_for_methods();
1147     BytecodeVerificationLocal = saved;
1148     return true;
1149   } else {
1150     return false;
1151   }
1152 }
1153 
1154 #if INCLUDE_CDS_JAVA_HEAP
1155 void VM_PopulateDumpSharedSpace::dump_java_heap_objects(GrowableArray<Klass*>* klasses) {
1156   if(!HeapShared::can_write()) {
1157     if (!CDSConfig::is_dumping_preimage_static_archive()) {
1158      log_info(cds)(
1159       "Archived java heap is not supported as UseG1GC "
1160       "and UseCompressedClassPointers are required."
1161       "Current settings: UseG1GC=%s, UseCompressedClassPointers=%s.",
1162       BOOL_TO_STR(UseG1GC), BOOL_TO_STR(UseCompressedClassPointers));
1163     }
1164     return;
1165   }
1166   // Find all the interned strings that should be dumped.
1167   int i;
1168   for (i = 0; i < klasses->length(); i++) {
1169     Klass* k = klasses->at(i);
1170     if (k->is_instance_klass()) {
1171       InstanceKlass* ik = InstanceKlass::cast(k);
1172       if (ik->is_linked()) {
1173         ik->constants()->add_dumped_interned_strings();
1174       }
1175     }
1176   }
1177   if (_extra_interned_strings != nullptr) {
1178     for (i = 0; i < _extra_interned_strings->length(); i ++) {
1179       OopHandle string = _extra_interned_strings->at(i);
1180       HeapShared::add_to_dumped_interned_strings(string.resolve());
1181     }
1182   }
1183 
1184   HeapShared::archive_objects(&_heap_info);
1185   ArchiveBuilder::OtherROAllocMark mark;
1186   HeapShared::write_subgraph_info_table();
1187 }
1188 #endif // INCLUDE_CDS_JAVA_HEAP
1189 
1190 void MetaspaceShared::set_shared_metaspace_range(void* base, void *static_top, void* top) {
1191   assert(base <= static_top && static_top <= top, "must be");
1192   _shared_metaspace_static_top = static_top;
1193   MetaspaceObj::set_shared_metaspace_range(base, top);
1194 }
1195 
1196 bool MetaspaceShared::is_shared_dynamic(void* p) {
1197   if ((p < MetaspaceObj::shared_metaspace_top()) &&
1198       (p >= _shared_metaspace_static_top)) {
1199     return true;
1200   } else {
1201     return false;
1202   }
1203 }
1204 
1205 bool MetaspaceShared::is_shared_static(void* p) {
1206   if (is_in_shared_metaspace(p) && !is_shared_dynamic(p)) {
1207     return true;
1208   } else {
1209     return false;
1210   }
1211 }
1212 
1213 // This function is called when the JVM is unable to load the specified archive(s) due to one
1214 // of the following conditions.
1215 // - There's an error that indicates that the archive(s) files were corrupt or otherwise damaged.
1216 // - When -XX:+RequireSharedSpaces is specified, AND the JVM cannot load the archive(s) due
1217 //   to version or classpath mismatch.
1218 void MetaspaceShared::unrecoverable_loading_error(const char* message) {
1219   log_error(cds)("An error has occurred while processing the shared archive file.");
1220   if (message != nullptr) {
1221     log_error(cds)("%s", message);
1222   }
1223   vm_exit_during_initialization("Unable to use shared archive.", nullptr);
1224 }
1225 
1226 // This function is called when the JVM is unable to write the specified CDS archive due to an
1227 // unrecoverable error.
1228 void MetaspaceShared::unrecoverable_writing_error(const char* message) {
1229   writing_error(message);
1230   vm_direct_exit(1);
1231 }
1232 
1233 // This function is called when the JVM is unable to write the specified CDS archive due to a
1234 // an error. The error will be propagated
1235 void MetaspaceShared::writing_error(const char* message) {
1236   log_error(cds)("An error has occurred while writing the shared archive file.");
1237   if (message != nullptr) {
1238     log_error(cds)("%s", message);
1239   }
1240 }
1241 
1242 void MetaspaceShared::initialize_runtime_shared_and_meta_spaces() {
1243   assert(CDSConfig::is_using_archive(), "Must be called when UseSharedSpaces is enabled");
1244   MapArchiveResult result = MAP_ARCHIVE_OTHER_FAILURE;
1245 
1246   FileMapInfo* static_mapinfo = FileMapInfo::current_info();
1247   FileMapInfo* dynamic_mapinfo = nullptr;
1248 
1249   if (static_mapinfo != nullptr) {
1250     log_info(cds)("Core region alignment: " SIZE_FORMAT, static_mapinfo->core_region_alignment());
1251     dynamic_mapinfo = open_dynamic_archive();
1252 
1253     // First try to map at the requested address
1254     result = map_archives(static_mapinfo, dynamic_mapinfo, true);
1255     if (result == MAP_ARCHIVE_MMAP_FAILURE) {
1256       // Mapping has failed (probably due to ASLR). Let's map at an address chosen
1257       // by the OS.
1258       log_info(cds)("Try to map archive(s) at an alternative address");
1259       result = map_archives(static_mapinfo, dynamic_mapinfo, false);
1260     }
1261   }
1262 
1263   if (result == MAP_ARCHIVE_SUCCESS) {
1264     bool dynamic_mapped = (dynamic_mapinfo != nullptr && dynamic_mapinfo->is_mapped());
1265     char* cds_base = static_mapinfo->mapped_base();
1266     char* cds_end =  dynamic_mapped ? dynamic_mapinfo->mapped_end() : static_mapinfo->mapped_end();
1267     // Register CDS memory region with LSan.
1268     LSAN_REGISTER_ROOT_REGION(cds_base, cds_end - cds_base);
1269     set_shared_metaspace_range(cds_base, static_mapinfo->mapped_end(), cds_end);
1270     _relocation_delta = static_mapinfo->relocation_delta();
1271     _requested_base_address = static_mapinfo->requested_base_address();
1272     if (dynamic_mapped) {
1273       FileMapInfo::set_shared_path_table(dynamic_mapinfo);
1274       // turn AutoCreateSharedArchive off if successfully mapped
1275       AutoCreateSharedArchive = false;
1276     } else {
1277       FileMapInfo::set_shared_path_table(static_mapinfo);
1278     }
1279   } else {
1280     set_shared_metaspace_range(nullptr, nullptr, nullptr);
1281     if (CDSConfig::is_dumping_dynamic_archive()) {
1282       log_warning(cds)("-XX:ArchiveClassesAtExit is unsupported when base CDS archive is not loaded. Run with -Xlog:cds for more info.");
1283     }
1284     UseSharedSpaces = false;
1285     // The base archive cannot be mapped. We cannot dump the dynamic shared archive.
1286     AutoCreateSharedArchive = false;
1287     CDSConfig::disable_dumping_dynamic_archive();
1288     log_info(cds)("Unable to map shared spaces");
1289     if (PrintSharedArchiveAndExit) {
1290       MetaspaceShared::unrecoverable_loading_error("Unable to use shared archive.");
1291     } else if (RequireSharedSpaces) {
1292       MetaspaceShared::unrecoverable_loading_error("Unable to map shared spaces");
1293     } else if (CDSConfig::is_dumping_final_static_archive()) {
1294       assert(CDSPreimage != nullptr, "must be");
1295       log_error(cds)("Unable to map shared spaces for CDSPreimage = %s", CDSPreimage);
1296       MetaspaceShared::unrecoverable_loading_error();
1297     }
1298   }
1299 
1300   // If mapping failed and -XShare:on, the vm should exit
1301   bool has_failed = false;
1302   if (static_mapinfo != nullptr && !static_mapinfo->is_mapped()) {
1303     has_failed = true;
1304     delete static_mapinfo;
1305   }
1306   if (dynamic_mapinfo != nullptr && !dynamic_mapinfo->is_mapped()) {
1307     has_failed = true;
1308     delete dynamic_mapinfo;
1309   }
1310   if (RequireSharedSpaces && has_failed) {
1311     // static archive mapped but dynamic archive failed
1312       MetaspaceShared::unrecoverable_loading_error("Unable to map shared spaces");
1313   }
1314 }
1315 
1316 // This is called very early at VM start up to get the size of the cached_code region, which
1317 // is used in CodeCache::initialize_heaps()
1318 void MetaspaceShared::open_static_archive() {
1319   if (!UseSharedSpaces) {
1320     return;
1321   }
1322   const char* static_archive = CDSConfig::static_archive_path();
1323   assert(static_archive != nullptr, "sanity");
1324   FileMapInfo* mapinfo = new FileMapInfo(static_archive, true);
1325   if (!mapinfo->initialize()) {
1326     delete(mapinfo);
1327   } else {
1328     FileMapRegion* r = mapinfo->region_at(MetaspaceShared::cc);
1329     CDSAccess::set_cached_code_size(r->used());
1330   }
1331 }
1332 
1333 FileMapInfo* MetaspaceShared::open_dynamic_archive() {
1334   if (CDSConfig::is_dumping_dynamic_archive()) {
1335     return nullptr;
1336   }
1337   const char* dynamic_archive = CDSConfig::dynamic_archive_path();
1338   if (dynamic_archive == nullptr) {
1339     return nullptr;
1340   }
1341 
1342   FileMapInfo* mapinfo = new FileMapInfo(dynamic_archive, false);
1343   if (!mapinfo->initialize()) {
1344     delete(mapinfo);
1345     if (RequireSharedSpaces) {
1346       MetaspaceShared::unrecoverable_loading_error("Failed to initialize dynamic archive");
1347     }
1348     return nullptr;
1349   }
1350   return mapinfo;
1351 }
1352 
1353 // use_requested_addr:
1354 //  true  = map at FileMapHeader::_requested_base_address
1355 //  false = map at an alternative address picked by OS.
1356 MapArchiveResult MetaspaceShared::map_archives(FileMapInfo* static_mapinfo, FileMapInfo* dynamic_mapinfo,
1357                                                bool use_requested_addr) {
1358   if (use_requested_addr && static_mapinfo->requested_base_address() == nullptr) {
1359     log_info(cds)("Archive(s) were created with -XX:SharedBaseAddress=0. Always map at os-selected address.");
1360     return MAP_ARCHIVE_MMAP_FAILURE;
1361   }
1362 
1363   PRODUCT_ONLY(if (ArchiveRelocationMode == 1 && use_requested_addr) {
1364       // For product build only -- this is for benchmarking the cost of doing relocation.
1365       // For debug builds, the check is done below, after reserving the space, for better test coverage
1366       // (see comment below).
1367       log_info(cds)("ArchiveRelocationMode == 1: always map archive(s) at an alternative address");
1368       return MAP_ARCHIVE_MMAP_FAILURE;
1369     });
1370 
1371   if (ArchiveRelocationMode == 2 && !use_requested_addr) {
1372     log_info(cds)("ArchiveRelocationMode == 2: never map archive(s) at an alternative address");
1373     return MAP_ARCHIVE_MMAP_FAILURE;
1374   };
1375 
1376   if (dynamic_mapinfo != nullptr) {
1377     // Ensure that the OS won't be able to allocate new memory spaces between the two
1378     // archives, or else it would mess up the simple comparison in MetaspaceObj::is_shared().
1379     assert(static_mapinfo->mapping_end_offset() == dynamic_mapinfo->mapping_base_offset(), "no gap");
1380   }
1381 
1382   ReservedSpace total_space_rs, archive_space_rs, class_space_rs;
1383   MapArchiveResult result = MAP_ARCHIVE_OTHER_FAILURE;
1384   char* mapped_base_address = reserve_address_space_for_archives(static_mapinfo,
1385                                                                  dynamic_mapinfo,
1386                                                                  use_requested_addr,
1387                                                                  total_space_rs,
1388                                                                  archive_space_rs,
1389                                                                  class_space_rs);
1390   if (mapped_base_address == nullptr) {
1391     result = MAP_ARCHIVE_MMAP_FAILURE;
1392     log_debug(cds)("Failed to reserve spaces (use_requested_addr=%u)", (unsigned)use_requested_addr);
1393   } else {
1394 
1395 #ifdef ASSERT
1396     // Some sanity checks after reserving address spaces for archives
1397     //  and class space.
1398     assert(archive_space_rs.is_reserved(), "Sanity");
1399     if (Metaspace::using_class_space()) {
1400       // Class space must closely follow the archive space. Both spaces
1401       //  must be aligned correctly.
1402       assert(class_space_rs.is_reserved(),
1403              "A class space should have been reserved");
1404       assert(class_space_rs.base() >= archive_space_rs.end(),
1405              "class space should follow the cds archive space");
1406       assert(is_aligned(archive_space_rs.base(),
1407                         core_region_alignment()),
1408              "Archive space misaligned");
1409       assert(is_aligned(class_space_rs.base(),
1410                         Metaspace::reserve_alignment()),
1411              "class space misaligned");
1412     }
1413 #endif // ASSERT
1414 
1415     log_info(cds)("Reserved archive_space_rs [" INTPTR_FORMAT " - " INTPTR_FORMAT "] (" SIZE_FORMAT ") bytes",
1416                    p2i(archive_space_rs.base()), p2i(archive_space_rs.end()), archive_space_rs.size());
1417     log_info(cds)("Reserved class_space_rs   [" INTPTR_FORMAT " - " INTPTR_FORMAT "] (" SIZE_FORMAT ") bytes",
1418                    p2i(class_space_rs.base()), p2i(class_space_rs.end()), class_space_rs.size());
1419 
1420     if (MetaspaceShared::use_windows_memory_mapping()) {
1421       // We have now reserved address space for the archives, and will map in
1422       //  the archive files into this space.
1423       //
1424       // Special handling for Windows: on Windows we cannot map a file view
1425       //  into an existing memory mapping. So, we unmap the address range we
1426       //  just reserved again, which will make it available for mapping the
1427       //  archives.
1428       // Reserving this range has not been for naught however since it makes
1429       //  us reasonably sure the address range is available.
1430       //
1431       // But still it may fail, since between unmapping the range and mapping
1432       //  in the archive someone else may grab the address space. Therefore
1433       //  there is a fallback in FileMap::map_region() where we just read in
1434       //  the archive files sequentially instead of mapping it in. We couple
1435       //  this with use_requested_addr, since we're going to patch all the
1436       //  pointers anyway so there's no benefit to mmap.
1437       if (use_requested_addr) {
1438         assert(!total_space_rs.is_reserved(), "Should not be reserved for Windows");
1439         log_info(cds)("Windows mmap workaround: releasing archive space.");
1440         archive_space_rs.release();
1441       }
1442     }
1443     MapArchiveResult static_result = map_archive(static_mapinfo, mapped_base_address, archive_space_rs);
1444     MapArchiveResult dynamic_result = (static_result == MAP_ARCHIVE_SUCCESS) ?
1445                                      map_archive(dynamic_mapinfo, mapped_base_address, archive_space_rs) : MAP_ARCHIVE_OTHER_FAILURE;
1446 
1447     DEBUG_ONLY(if (ArchiveRelocationMode == 1 && use_requested_addr) {
1448       // This is for simulating mmap failures at the requested address. In
1449       //  debug builds, we do it here (after all archives have possibly been
1450       //  mapped), so we can thoroughly test the code for failure handling
1451       //  (releasing all allocated resource, etc).
1452       log_info(cds)("ArchiveRelocationMode == 1: always map archive(s) at an alternative address");
1453       if (static_result == MAP_ARCHIVE_SUCCESS) {
1454         static_result = MAP_ARCHIVE_MMAP_FAILURE;
1455       }
1456       if (dynamic_result == MAP_ARCHIVE_SUCCESS) {
1457         dynamic_result = MAP_ARCHIVE_MMAP_FAILURE;
1458       }
1459     });
1460 
1461     if (static_result == MAP_ARCHIVE_SUCCESS) {
1462       if (dynamic_result == MAP_ARCHIVE_SUCCESS) {
1463         result = MAP_ARCHIVE_SUCCESS;
1464       } else if (dynamic_result == MAP_ARCHIVE_OTHER_FAILURE) {
1465         assert(dynamic_mapinfo != nullptr && !dynamic_mapinfo->is_mapped(), "must have failed");
1466         // No need to retry mapping the dynamic archive again, as it will never succeed
1467         // (bad file, etc) -- just keep the base archive.
1468         log_warning(cds, dynamic)("Unable to use shared archive. The top archive failed to load: %s",
1469                                   dynamic_mapinfo->full_path());
1470         result = MAP_ARCHIVE_SUCCESS;
1471         // TODO, we can give the unused space for the dynamic archive to class_space_rs, but there's no
1472         // easy API to do that right now.
1473       } else {
1474         result = MAP_ARCHIVE_MMAP_FAILURE;
1475       }
1476     } else if (static_result == MAP_ARCHIVE_OTHER_FAILURE) {
1477       result = MAP_ARCHIVE_OTHER_FAILURE;
1478     } else {
1479       result = MAP_ARCHIVE_MMAP_FAILURE;
1480     }
1481   }
1482 
1483   if (result == MAP_ARCHIVE_SUCCESS) {
1484     SharedBaseAddress = (size_t)mapped_base_address;
1485 #ifdef _LP64
1486         if (Metaspace::using_class_space()) {
1487           // Set up ccs in metaspace.
1488           Metaspace::initialize_class_space(class_space_rs);
1489 
1490           // Set up compressed Klass pointer encoding: the encoding range must
1491           //  cover both archive and class space.
1492           address cds_base = (address)static_mapinfo->mapped_base();
1493           address ccs_end = (address)class_space_rs.end();
1494           assert(ccs_end > cds_base, "Sanity check");
1495 #if INCLUDE_CDS_JAVA_HEAP
1496           // We archived objects with pre-computed narrow Klass id. Set up encoding such that these Ids stay valid.
1497           address precomputed_narrow_klass_base = cds_base;
1498           const int precomputed_narrow_klass_shift = ArchiveHeapWriter::precomputed_narrow_klass_shift;
1499           CompressedKlassPointers::initialize_for_given_encoding(
1500             cds_base, ccs_end - cds_base, // Klass range
1501             precomputed_narrow_klass_base, precomputed_narrow_klass_shift // precomputed encoding, see ArchiveHeapWriter
1502             );
1503 #else
1504           CompressedKlassPointers::initialize (
1505             cds_base, ccs_end - cds_base // Klass range
1506             );
1507 #endif // INCLUDE_CDS_JAVA_HEAP
1508           // map_or_load_heap_region() compares the current narrow oop and klass encodings
1509           // with the archived ones, so it must be done after all encodings are determined.
1510           static_mapinfo->map_or_load_heap_region();
1511         }
1512 #endif // _LP64
1513     log_info(cds)("initial optimized module handling: %s", CDSConfig::is_using_optimized_module_handling() ? "enabled" : "disabled");
1514     log_info(cds)("initial full module graph: %s", CDSConfig::is_using_full_module_graph() ? "enabled" : "disabled");
1515   } else {
1516     unmap_archive(static_mapinfo);
1517     unmap_archive(dynamic_mapinfo);
1518     release_reserved_spaces(total_space_rs, archive_space_rs, class_space_rs);
1519   }
1520 
1521   return result;
1522 }
1523 
1524 
1525 // This will reserve two address spaces suitable to house Klass structures, one
1526 //  for the cds archives (static archive and optionally dynamic archive) and
1527 //  optionally one move for ccs.
1528 //
1529 // Since both spaces must fall within the compressed class pointer encoding
1530 //  range, they are allocated close to each other.
1531 //
1532 // Space for archives will be reserved first, followed by a potential gap,
1533 //  followed by the space for ccs:
1534 //
1535 // +-- Base address             A        B                     End
1536 // |                            |        |                      |
1537 // v                            v        v                      v
1538 // +-------------+--------------+        +----------------------+
1539 // | static arc  | [dyn. arch]  | [gap]  | compr. class space   |
1540 // +-------------+--------------+        +----------------------+
1541 //
1542 // (The gap may result from different alignment requirements between metaspace
1543 //  and CDS)
1544 //
1545 // If UseCompressedClassPointers is disabled, only one address space will be
1546 //  reserved:
1547 //
1548 // +-- Base address             End
1549 // |                            |
1550 // v                            v
1551 // +-------------+--------------+
1552 // | static arc  | [dyn. arch]  |
1553 // +-------------+--------------+
1554 //
1555 // Base address: If use_archive_base_addr address is true, the Base address is
1556 //  determined by the address stored in the static archive. If
1557 //  use_archive_base_addr address is false, this base address is determined
1558 //  by the platform.
1559 //
1560 // If UseCompressedClassPointers=1, the range encompassing both spaces will be
1561 //  suitable to en/decode narrow Klass pointers: the base will be valid for
1562 //  encoding, the range [Base, End) not surpass KlassEncodingMetaspaceMax.
1563 //
1564 // Return:
1565 //
1566 // - On success:
1567 //    - total_space_rs will be reserved as whole for archive_space_rs and
1568 //      class_space_rs if UseCompressedClassPointers is true.
1569 //      On Windows, try reserve archive_space_rs and class_space_rs
1570 //      separately first if use_archive_base_addr is true.
1571 //    - archive_space_rs will be reserved and large enough to host static and
1572 //      if needed dynamic archive: [Base, A).
1573 //      archive_space_rs.base and size will be aligned to CDS reserve
1574 //      granularity.
1575 //    - class_space_rs: If UseCompressedClassPointers=1, class_space_rs will
1576 //      be reserved. Its start address will be aligned to metaspace reserve
1577 //      alignment, which may differ from CDS alignment. It will follow the cds
1578 //      archive space, close enough such that narrow class pointer encoding
1579 //      covers both spaces.
1580 //      If UseCompressedClassPointers=0, class_space_rs remains unreserved.
1581 // - On error: null is returned and the spaces remain unreserved.
1582 char* MetaspaceShared::reserve_address_space_for_archives(FileMapInfo* static_mapinfo,
1583                                                           FileMapInfo* dynamic_mapinfo,
1584                                                           bool use_archive_base_addr,
1585                                                           ReservedSpace& total_space_rs,
1586                                                           ReservedSpace& archive_space_rs,
1587                                                           ReservedSpace& class_space_rs) {
1588 
1589   address const base_address = (address) (use_archive_base_addr ? static_mapinfo->requested_base_address() : nullptr);
1590   const size_t archive_space_alignment = core_region_alignment();
1591 
1592   // Size and requested location of the archive_space_rs (for both static and dynamic archives)
1593   assert(static_mapinfo->mapping_base_offset() == 0, "Must be");
1594   size_t archive_end_offset  = (dynamic_mapinfo == nullptr) ? static_mapinfo->mapping_end_offset() : dynamic_mapinfo->mapping_end_offset();
1595   size_t archive_space_size = align_up(archive_end_offset, archive_space_alignment);
1596 
1597   if (!Metaspace::using_class_space()) {
1598     // Get the simple case out of the way first:
1599     // no compressed class space, simple allocation.
1600 
1601     // When running without class space, requested archive base should be aligned to cds core alignment.
1602     assert(is_aligned(base_address, archive_space_alignment),
1603              "Archive base address unaligned: " PTR_FORMAT ", needs alignment: %zu.",
1604              p2i(base_address), archive_space_alignment);
1605 
1606     archive_space_rs = ReservedSpace(archive_space_size, archive_space_alignment,
1607                                      os::vm_page_size(), (char*)base_address);
1608     if (archive_space_rs.is_reserved()) {
1609       assert(base_address == nullptr ||
1610              (address)archive_space_rs.base() == base_address, "Sanity");
1611       // Register archive space with NMT.
1612       MemTracker::record_virtual_memory_type(archive_space_rs.base(), mtClassShared);
1613       return archive_space_rs.base();
1614     }
1615     return nullptr;
1616   }
1617 
1618 #ifdef _LP64
1619 
1620   // Complex case: two spaces adjacent to each other, both to be addressable
1621   //  with narrow class pointers.
1622   // We reserve the whole range spanning both spaces, then split that range up.
1623 
1624   const size_t class_space_alignment = Metaspace::reserve_alignment();
1625 
1626   // When running with class space, requested archive base must satisfy both cds core alignment
1627   // and class space alignment.
1628   const size_t base_address_alignment = MAX2(class_space_alignment, archive_space_alignment);
1629   assert(is_aligned(base_address, base_address_alignment),
1630            "Archive base address unaligned: " PTR_FORMAT ", needs alignment: %zu.",
1631            p2i(base_address), base_address_alignment);
1632 
1633   size_t class_space_size = CompressedClassSpaceSize;
1634   assert(CompressedClassSpaceSize > 0 &&
1635          is_aligned(CompressedClassSpaceSize, class_space_alignment),
1636          "CompressedClassSpaceSize malformed: "
1637          SIZE_FORMAT, CompressedClassSpaceSize);
1638 
1639   const size_t ccs_begin_offset = align_up(archive_space_size, class_space_alignment);
1640   const size_t gap_size = ccs_begin_offset - archive_space_size;
1641 
1642   // Reduce class space size if it would not fit into the Klass encoding range
1643   constexpr size_t max_encoding_range_size = 4 * G;
1644   guarantee(archive_space_size < max_encoding_range_size - class_space_alignment, "Archive too large");
1645   if ((archive_space_size + gap_size + class_space_size) > max_encoding_range_size) {
1646     class_space_size = align_down(max_encoding_range_size - archive_space_size - gap_size, class_space_alignment);
1647     log_info(metaspace)("CDS initialization: reducing class space size from " SIZE_FORMAT " to " SIZE_FORMAT,
1648         CompressedClassSpaceSize, class_space_size);
1649     FLAG_SET_ERGO(CompressedClassSpaceSize, class_space_size);
1650   }
1651 
1652   const size_t total_range_size =
1653       archive_space_size + gap_size + class_space_size;
1654 
1655   assert(total_range_size > ccs_begin_offset, "must be");
1656   if (use_windows_memory_mapping() && use_archive_base_addr) {
1657     if (base_address != nullptr) {
1658       // On Windows, we cannot safely split a reserved memory space into two (see JDK-8255917).
1659       // Hence, we optimistically reserve archive space and class space side-by-side. We only
1660       // do this for use_archive_base_addr=true since for use_archive_base_addr=false case
1661       // caller will not split the combined space for mapping, instead read the archive data
1662       // via sequential file IO.
1663       address ccs_base = base_address + archive_space_size + gap_size;
1664       archive_space_rs = ReservedSpace(archive_space_size, archive_space_alignment,
1665                                        os::vm_page_size(), (char*)base_address);
1666       class_space_rs   = ReservedSpace(class_space_size, class_space_alignment,
1667                                        os::vm_page_size(), (char*)ccs_base);
1668     }
1669     if (!archive_space_rs.is_reserved() || !class_space_rs.is_reserved()) {
1670       release_reserved_spaces(total_space_rs, archive_space_rs, class_space_rs);
1671       return nullptr;
1672     }
1673     // NMT: fix up the space tags
1674     MemTracker::record_virtual_memory_type(archive_space_rs.base(), mtClassShared);
1675     MemTracker::record_virtual_memory_type(class_space_rs.base(), mtClass);
1676   } else {
1677     if (use_archive_base_addr && base_address != nullptr) {
1678       total_space_rs = ReservedSpace(total_range_size, base_address_alignment,
1679                                      os::vm_page_size(), (char*) base_address);
1680     } else {
1681       // We did not manage to reserve at the preferred address, or were instructed to relocate. In that
1682       // case we reserve wherever possible, but the start address needs to be encodable as narrow Klass
1683       // encoding base since the archived heap objects contain nKlass IDs pre-calculated toward the start
1684       // of the shared Metaspace. That prevents us from using zero-based encoding and therefore we won't
1685       // try allocating in low-address regions.
1686       total_space_rs = Metaspace::reserve_address_space_for_compressed_classes(total_range_size, false /* optimize_for_zero_base */);
1687     }
1688 
1689     if (!total_space_rs.is_reserved()) {
1690       return nullptr;
1691     }
1692 
1693     // Paranoid checks:
1694     assert(base_address == nullptr || (address)total_space_rs.base() == base_address,
1695            "Sanity (" PTR_FORMAT " vs " PTR_FORMAT ")", p2i(base_address), p2i(total_space_rs.base()));
1696     assert(is_aligned(total_space_rs.base(), base_address_alignment), "Sanity");
1697     assert(total_space_rs.size() == total_range_size, "Sanity");
1698 
1699     // Now split up the space into ccs and cds archive. For simplicity, just leave
1700     //  the gap reserved at the end of the archive space. Do not do real splitting.
1701     archive_space_rs = total_space_rs.first_part(ccs_begin_offset,
1702                                                  (size_t)archive_space_alignment);
1703     class_space_rs = total_space_rs.last_part(ccs_begin_offset);
1704     MemTracker::record_virtual_memory_split_reserved(total_space_rs.base(), total_space_rs.size(),
1705                                                      ccs_begin_offset, mtClassShared, mtClass);
1706   }
1707   assert(is_aligned(archive_space_rs.base(), archive_space_alignment), "Sanity");
1708   assert(is_aligned(archive_space_rs.size(), archive_space_alignment), "Sanity");
1709   assert(is_aligned(class_space_rs.base(), class_space_alignment), "Sanity");
1710   assert(is_aligned(class_space_rs.size(), class_space_alignment), "Sanity");
1711 
1712 
1713   return archive_space_rs.base();
1714 
1715 #else
1716   ShouldNotReachHere();
1717   return nullptr;
1718 #endif
1719 
1720 }
1721 
1722 void MetaspaceShared::release_reserved_spaces(ReservedSpace& total_space_rs,
1723                                               ReservedSpace& archive_space_rs,
1724                                               ReservedSpace& class_space_rs) {
1725   if (total_space_rs.is_reserved()) {
1726     log_debug(cds)("Released shared space (archive + class) " INTPTR_FORMAT, p2i(total_space_rs.base()));
1727     total_space_rs.release();
1728   } else {
1729     if (archive_space_rs.is_reserved()) {
1730       log_debug(cds)("Released shared space (archive) " INTPTR_FORMAT, p2i(archive_space_rs.base()));
1731       archive_space_rs.release();
1732     }
1733     if (class_space_rs.is_reserved()) {
1734       log_debug(cds)("Released shared space (classes) " INTPTR_FORMAT, p2i(class_space_rs.base()));
1735       class_space_rs.release();
1736     }
1737   }
1738 }
1739 
1740 static int archive_regions[]     = { MetaspaceShared::rw, MetaspaceShared::ro };
1741 static int archive_regions_count = 2;
1742 
1743 MapArchiveResult MetaspaceShared::map_archive(FileMapInfo* mapinfo, char* mapped_base_address, ReservedSpace rs) {
1744   assert(CDSConfig::is_using_archive(), "must be runtime");
1745   if (mapinfo == nullptr) {
1746     return MAP_ARCHIVE_SUCCESS; // The dynamic archive has not been specified. No error has happened -- trivially succeeded.
1747   }
1748 
1749   if (!mapinfo->validate_aot_class_linking()) {
1750     return MAP_ARCHIVE_OTHER_FAILURE;
1751   }
1752 
1753   mapinfo->set_is_mapped(false);
1754   if (mapinfo->core_region_alignment() != (size_t)core_region_alignment()) {
1755     log_info(cds)("Unable to map CDS archive -- core_region_alignment() expected: " SIZE_FORMAT
1756                   " actual: " SIZE_FORMAT, mapinfo->core_region_alignment(), core_region_alignment());
1757     return MAP_ARCHIVE_OTHER_FAILURE;
1758   }
1759 
1760   MapArchiveResult result =
1761     mapinfo->map_regions(archive_regions, archive_regions_count, mapped_base_address, rs);
1762 
1763   if (result != MAP_ARCHIVE_SUCCESS) {
1764     unmap_archive(mapinfo);
1765     return result;
1766   }
1767 
1768   if (!mapinfo->validate_shared_path_table()) {
1769     unmap_archive(mapinfo);
1770     return MAP_ARCHIVE_OTHER_FAILURE;
1771   }
1772 
1773   mapinfo->set_is_mapped(true);
1774   return MAP_ARCHIVE_SUCCESS;
1775 }
1776 
1777 void MetaspaceShared::unmap_archive(FileMapInfo* mapinfo) {
1778   assert(CDSConfig::is_using_archive(), "must be runtime");
1779   if (mapinfo != nullptr) {
1780     mapinfo->unmap_regions(archive_regions, archive_regions_count);
1781     mapinfo->unmap_region(MetaspaceShared::bm);
1782     mapinfo->set_is_mapped(false);
1783   }
1784 }
1785 
1786 // For -XX:PrintSharedArchiveAndExit
1787 class CountSharedSymbols : public SymbolClosure {
1788  private:
1789    int _count;
1790  public:
1791    CountSharedSymbols() : _count(0) {}
1792   void do_symbol(Symbol** sym) {
1793     _count++;
1794   }
1795   int total() { return _count; }
1796 
1797 };
1798 
1799 // Read the miscellaneous data from the shared file, and
1800 // serialize it out to its various destinations.
1801 
1802 void MetaspaceShared::initialize_shared_spaces() {
1803   FileMapInfo *static_mapinfo = FileMapInfo::current_info();
1804 
1805   // Verify various attributes of the archive, plus initialize the
1806   // shared string/symbol tables.
1807   char* buffer = static_mapinfo->serialized_data();
1808   intptr_t* array = (intptr_t*)buffer;
1809   ReadClosure rc(&array);
1810   serialize(&rc);
1811 
1812   // Finish up archived heap initialization. These must be
1813   // done after ReadClosure.
1814   static_mapinfo->patch_heap_embedded_pointers();
1815   ArchiveHeapLoader::finish_initialization();
1816   Universe::load_archived_object_instances();
1817   SCCache::new_workflow_load_cache();
1818 
1819   // Close the mapinfo file
1820   static_mapinfo->close();
1821 
1822   static_mapinfo->unmap_region(MetaspaceShared::bm);
1823 
1824   FileMapInfo *dynamic_mapinfo = FileMapInfo::dynamic_info();
1825   if (dynamic_mapinfo != nullptr) {
1826     intptr_t* buffer = (intptr_t*)dynamic_mapinfo->serialized_data();
1827     ReadClosure rc(&buffer);
1828     ArchiveBuilder::serialize_dynamic_archivable_items(&rc);
1829     DynamicArchive::setup_array_klasses();
1830     dynamic_mapinfo->close();
1831     dynamic_mapinfo->unmap_region(MetaspaceShared::bm);
1832   }
1833 
1834   log_info(cds)("Using AOT-linked classes: %s (%s%s)",
1835                 CDSConfig::is_using_aot_linked_classes() ? "true" : "false",
1836                 static_mapinfo->header()->has_aot_linked_classes() ? "static archive: true" : "static archive: false",
1837                 (dynamic_mapinfo == nullptr) ? "" :
1838                    (dynamic_mapinfo->header()->has_aot_linked_classes() ? ", dynamic archive: true" : ", dynamic archive: false"));
1839 
1840   // Set up LambdaFormInvokers::_lambdaform_lines for dynamic dump
1841   if (CDSConfig::is_dumping_dynamic_archive()) {
1842     // Read stored LF format lines stored in static archive
1843     LambdaFormInvokers::read_static_archive_invokers();
1844   }
1845 
1846   if (PrintSharedArchiveAndExit) {
1847     // Print archive names
1848     if (dynamic_mapinfo != nullptr) {
1849       tty->print_cr("\n\nBase archive name: %s", CDSConfig::static_archive_path());
1850       tty->print_cr("Base archive version %d", static_mapinfo->version());
1851     } else {
1852       tty->print_cr("Static archive name: %s", static_mapinfo->full_path());
1853       tty->print_cr("Static archive version %d", static_mapinfo->version());
1854     }
1855 
1856     SystemDictionaryShared::print_shared_archive(tty);
1857     if (dynamic_mapinfo != nullptr) {
1858       tty->print_cr("\n\nDynamic archive name: %s", dynamic_mapinfo->full_path());
1859       tty->print_cr("Dynamic archive version %d", dynamic_mapinfo->version());
1860       SystemDictionaryShared::print_shared_archive(tty, false/*dynamic*/);
1861     }
1862     TrainingData::print_archived_training_data_on(tty);
1863 
1864     if (LoadCachedCode) {
1865       tty->print_cr("\n\nCached Code file: %s", CachedCodeFile);
1866       SCCache::print_on(tty);
1867     }
1868 
1869     // collect shared symbols and strings
1870     CountSharedSymbols cl;
1871     SymbolTable::shared_symbols_do(&cl);
1872     tty->print_cr("Number of shared symbols: %d", cl.total());
1873     tty->print_cr("Number of shared strings: %zu", StringTable::shared_entry_count());
1874     tty->print_cr("VM version: %s\r\n", static_mapinfo->vm_version());
1875     if (FileMapInfo::current_info() == nullptr || _archive_loading_failed) {
1876       tty->print_cr("archive is invalid");
1877       vm_exit(1);
1878     } else {
1879       tty->print_cr("archive is valid");
1880       vm_exit(0);
1881     }
1882   }
1883 }
1884 
1885 // JVM/TI RedefineClasses() support:
1886 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
1887   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1888 
1889   if (CDSConfig::is_using_archive()) {
1890     // remap the shared readonly space to shared readwrite, private
1891     FileMapInfo* mapinfo = FileMapInfo::current_info();
1892     if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1893       return false;
1894     }
1895     if (FileMapInfo::dynamic_info() != nullptr) {
1896       mapinfo = FileMapInfo::dynamic_info();
1897       if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1898         return false;
1899       }
1900     }
1901     _remapped_readwrite = true;
1902   }
1903   return true;
1904 }
1905 
1906 void MetaspaceShared::print_on(outputStream* st) {
1907   if (CDSConfig::is_using_archive()) {
1908     st->print("CDS archive(s) mapped at: ");
1909     address base = (address)MetaspaceObj::shared_metaspace_base();
1910     address static_top = (address)_shared_metaspace_static_top;
1911     address top = (address)MetaspaceObj::shared_metaspace_top();
1912     st->print("[" PTR_FORMAT "-" PTR_FORMAT "-" PTR_FORMAT "), ", p2i(base), p2i(static_top), p2i(top));
1913     st->print("size " SIZE_FORMAT ", ", top - base);
1914     st->print("SharedBaseAddress: " PTR_FORMAT ", ArchiveRelocationMode: %d.", SharedBaseAddress, ArchiveRelocationMode);
1915   } else {
1916     st->print("CDS archive(s) not mapped");
1917   }
1918   st->cr();
1919 }