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 || UseShenandoahGC) && UseCompressedClassPointers)) {
 277       vm_exit_during_initialization("Cannot create the CacheDataStore",
 278                                     "UseCompressedClassPointers must be enabled, and collector must be G1, Parallel, Serial, Epsilon, or Shenandoah");
 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         ClassLoaderExt::init_num_module_paths(info->header()->num_module_paths());
 325       }
 326     }
 327   }
 328 }
 329 
 330 static GrowableArrayCHeap<OopHandle, mtClassShared>* _extra_interned_strings = nullptr;
 331 static GrowableArrayCHeap<Symbol*, mtClassShared>* _extra_symbols = nullptr;
 332 static GrowableArray<Method*>* _method_handle_intrinsics = nullptr;
 333 
 334 void MetaspaceShared::read_extra_data(JavaThread* current, const char* filename) {
 335   _extra_interned_strings = new GrowableArrayCHeap<OopHandle, mtClassShared>(10000);
 336   _extra_symbols = new GrowableArrayCHeap<Symbol*, mtClassShared>(1000);
 337 
 338   HashtableTextDump reader(filename);
 339   reader.check_version("VERSION: 1.0");
 340 
 341   while (reader.remain() > 0) {
 342     int utf8_length;
 343     int prefix_type = reader.scan_prefix(&utf8_length);
 344     ResourceMark rm(current);
 345     if (utf8_length == 0x7fffffff) {
 346       // buf_len will overflown 32-bit value.
 347       log_error(cds)("string length too large: %d", utf8_length);
 348       MetaspaceShared::unrecoverable_loading_error();
 349     }
 350     int buf_len = utf8_length+1;
 351     char* utf8_buffer = NEW_RESOURCE_ARRAY(char, buf_len);
 352     reader.get_utf8(utf8_buffer, utf8_length);
 353     utf8_buffer[utf8_length] = '\0';
 354 
 355     if (prefix_type == HashtableTextDump::SymbolPrefix) {
 356       _extra_symbols->append(SymbolTable::new_permanent_symbol(utf8_buffer));
 357     } else{
 358       assert(prefix_type == HashtableTextDump::StringPrefix, "Sanity");
 359       ExceptionMark em(current);
 360       JavaThread* THREAD = current; // For exception macros.
 361       oop str = StringTable::intern(utf8_buffer, THREAD);
 362 
 363       if (HAS_PENDING_EXCEPTION) {
 364         log_warning(cds, heap)("[line %d] extra interned string allocation failed; size too large: %d",
 365                                reader.last_line_no(), utf8_length);
 366         CLEAR_PENDING_EXCEPTION;
 367       } else {
 368 #if INCLUDE_CDS_JAVA_HEAP
 369         if (ArchiveHeapWriter::is_string_too_large_to_archive(str)) {
 370           log_warning(cds, heap)("[line %d] extra interned string ignored; size too large: %d",
 371                                  reader.last_line_no(), utf8_length);
 372           continue;
 373         }
 374         // Make sure this string is included in the dumped interned string table.
 375         assert(str != nullptr, "must succeed");
 376         _extra_interned_strings->append(OopHandle(Universe::vm_global(), str));
 377 #endif
 378       }
 379     }
 380   }
 381 }
 382 
 383 void MetaspaceShared::make_method_handle_intrinsics_shareable() {
 384   for (int i = 0; i < _method_handle_intrinsics->length(); i++) {
 385     Method* m = ArchiveBuilder::current()->get_buffered_addr(_method_handle_intrinsics->at(i));
 386     m->remove_unshareable_info();
 387     // Each method has its own constant pool (which is distinct from m->method_holder()->constants());
 388     m->constants()->remove_unshareable_info();
 389   }
 390 }
 391 
 392 void MetaspaceShared::write_method_handle_intrinsics() {
 393   int len = _method_handle_intrinsics->length();
 394   _archived_method_handle_intrinsics = ArchiveBuilder::new_ro_array<Method*>(len);
 395   for (int i = 0; i < len; i++) {
 396     ArchiveBuilder::current()->write_pointer_in_buffer(_archived_method_handle_intrinsics->adr_at(i),
 397                                                        _method_handle_intrinsics->at(i));
 398   }
 399   log_info(cds)("Archived %d method handle intrinsics", len);
 400 }
 401 
 402 // Read/write a data stream for restoring/preserving metadata pointers and
 403 // miscellaneous data from/to the shared archive file.
 404 
 405 void MetaspaceShared::serialize(SerializeClosure* soc) {
 406   int tag = 0;
 407   soc->do_tag(--tag);
 408 
 409   // Verify the sizes of various metadata in the system.
 410   soc->do_tag(sizeof(Method));
 411   soc->do_tag(sizeof(ConstMethod));
 412   soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
 413   soc->do_tag(sizeof(ConstantPool));
 414   soc->do_tag(sizeof(ConstantPoolCache));
 415   soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
 416   soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
 417   soc->do_tag(sizeof(Symbol));
 418 
 419   // Need to do this first, as subsequent steps may call virtual functions
 420   // in archived Metadata objects.
 421   CppVtables::serialize(soc);
 422   soc->do_tag(--tag);
 423 
 424   // Dump/restore miscellaneous metadata.
 425   JavaClasses::serialize_offsets(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   _method_handle_intrinsics = new (mtClassShared) GrowableArray<Method*>(256, mtClassShared);
 576   SystemDictionary::get_all_method_handle_intrinsics(_method_handle_intrinsics);
 577   _method_handle_intrinsics->sort([] (Method** a, Method** b) -> int {
 578     Symbol* a_holder = (*a)->method_holder()->name();
 579     Symbol* b_holder = (*b)->method_holder()->name();
 580     if (a_holder != b_holder) {
 581       return a_holder->cmp(b_holder);
 582     }
 583     Symbol* a_name = (*a)->name();
 584     Symbol* b_name = (*b)->name();
 585     if (a_name != b_name) {
 586       return a_name->cmp(b_name);
 587     }
 588     Symbol* a_signature = (*a)->signature();
 589     Symbol* b_signature = (*b)->signature();
 590     if (a_signature != b_signature) {
 591       return a_signature->cmp(b_signature);
 592     }
 593     return 0;
 594   });
 595 
 596   FileMapInfo::check_nonempty_dir_in_shared_path_table();
 597 
 598   NOT_PRODUCT(SystemDictionary::verify();)
 599 
 600   // Block concurrent class unloading from changing the _dumptime_table
 601   MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
 602 
 603   SystemDictionaryShared::find_all_archivable_classes();
 604 
 605   _builder.gather_source_objs();
 606   _builder.reserve_buffer();
 607 
 608   CppVtables::dumptime_init(&_builder);
 609 
 610   _builder.sort_metadata_objs();
 611   _builder.dump_rw_metadata();
 612   _builder.dump_ro_metadata();
 613   _builder.relocate_metaspaceobj_embedded_pointers();
 614 
 615   dump_java_heap_objects(_builder.klasses());
 616   dump_shared_symbol_table(_builder.symbols());
 617 
 618   log_info(cds)("Make classes shareable");
 619   _builder.make_klasses_shareable();
 620   MetaspaceShared::make_method_handle_intrinsics_shareable();
 621 
 622   char* serialized_data = dump_read_only_tables();
 623 
 624   SystemDictionaryShared::adjust_lambda_proxy_class_dictionary();
 625 
 626   log_info(cds)("Make training data shareable");
 627   _builder.make_training_data_shareable();
 628 
 629   // The vtable clones contain addresses of the current process.
 630   // We don't want to write these addresses into the archive.
 631   CppVtables::zero_archived_vtables();
 632 
 633   // Write the archive file
 634   const char* static_archive;
 635   if (CDSConfig::is_dumping_final_static_archive()) {
 636     static_archive = CacheDataStore;
 637     assert(FileMapInfo::current_info() != nullptr, "sanity");
 638     delete FileMapInfo::current_info();
 639   } else {
 640     static_archive = CDSConfig::static_archive_path();
 641   }
 642   assert(static_archive != nullptr, "SharedArchiveFile not set?");
 643   _map_info = new FileMapInfo(static_archive, true);
 644   _map_info->populate_header(MetaspaceShared::core_region_alignment());
 645   _map_info->set_serialized_data(serialized_data);
 646   _map_info->set_cloned_vtables(CppVtables::vtables_serialized_base());
 647 }
 648 
 649 class CollectCLDClosure : public CLDClosure {
 650   GrowableArray<ClassLoaderData*> _loaded_cld;
 651   GrowableArray<OopHandle> _loaded_cld_handles; // keep the CLDs alive
 652   Thread* _current_thread;
 653 public:
 654   CollectCLDClosure(Thread* thread) : _current_thread(thread) {}
 655   ~CollectCLDClosure() {
 656     for (int i = 0; i < _loaded_cld_handles.length(); i++) {
 657       _loaded_cld_handles.at(i).release(Universe::vm_global());
 658     }
 659   }
 660   void do_cld(ClassLoaderData* cld) {
 661     assert(cld->is_alive(), "must be");
 662     _loaded_cld.append(cld);
 663     _loaded_cld_handles.append(OopHandle(Universe::vm_global(), cld->holder()));
 664   }
 665 
 666   int nof_cld() const                { return _loaded_cld.length(); }
 667   ClassLoaderData* cld_at(int index) { return _loaded_cld.at(index); }
 668 };
 669 
 670 // Check if we can eagerly link this class at dump time, so we can avoid the
 671 // runtime linking overhead (especially verification)
 672 bool MetaspaceShared::may_be_eagerly_linked(InstanceKlass* ik) {
 673   if (CDSConfig::preserve_all_dumptime_verification_states(ik)) {
 674     assert(ik->can_be_verified_at_dumptime(), "sanity");
 675   }
 676   if (!ik->can_be_verified_at_dumptime()) {
 677     // For old classes, try to leave them in the unlinked state, so
 678     // we can still store them in the archive. They must be
 679     // linked/verified at runtime.
 680     return false;
 681   }
 682 
 683   if (CDSConfig::is_dumping_dynamic_archive() && ik->is_shared_unregistered_class()) {
 684     // Linking of unregistered classes at this stage may cause more
 685     // classes to be resolved, resulting in calls to ClassLoader.loadClass()
 686     // that may not be expected by custom class loaders.
 687     //
 688     // It's OK to do this for the built-in loaders as we know they can
 689     // tolerate this.
 690     return false;
 691   }
 692   return true;
 693 }
 694 
 695 void MetaspaceShared::link_shared_classes(bool jcmd_request, TRAPS) {
 696   AOTClassLinker::initialize();
 697 
 698   if (!jcmd_request && !CDSConfig::is_dumping_dynamic_archive()
 699       && !CDSConfig::is_dumping_preimage_static_archive()
 700       && !CDSConfig::is_dumping_final_static_archive()) {
 701     // If we have regenerated invoker classes in the dynamic archive,
 702     // they will conflict with the resolved CONSTANT_Klass references that are stored
 703     // in the static archive. This is not easy to handle. Let's disable
 704     // it for dynamic archive for now.
 705     LambdaFormInvokers::regenerate_holder_classes(CHECK);
 706   }
 707 
 708   // Collect all loaded ClassLoaderData.
 709   CollectCLDClosure collect_cld(THREAD);
 710   {
 711     // ClassLoaderDataGraph::loaded_cld_do requires ClassLoaderDataGraph_lock.
 712     // We cannot link the classes while holding this lock (or else we may run into deadlock).
 713     // Therefore, we need to first collect all the CLDs, and then link their classes after
 714     // releasing the lock.
 715     MutexLocker lock(ClassLoaderDataGraph_lock);
 716     ClassLoaderDataGraph::loaded_cld_do(&collect_cld);
 717   }
 718 
 719   while (true) {
 720     bool has_linked = false;
 721     for (int i = 0; i < collect_cld.nof_cld(); i++) {
 722       ClassLoaderData* cld = collect_cld.cld_at(i);
 723       for (Klass* klass = cld->klasses(); klass != nullptr; klass = klass->next_link()) {
 724         if (klass->is_instance_klass()) {
 725           InstanceKlass* ik = InstanceKlass::cast(klass);
 726           if (may_be_eagerly_linked(ik)) {
 727             has_linked |= try_link_class(THREAD, ik);
 728           }
 729           if (CDSConfig::is_dumping_heap() && ik->is_linked() && !ik->is_initialized()) {
 730             AOTClassInitializer::maybe_preinit_class(ik, CHECK);
 731           }
 732         }
 733       }
 734     }
 735 
 736     if (!has_linked) {
 737       break;
 738     }
 739     // Class linking includes verification which may load more classes.
 740     // Keep scanning until we have linked no more classes.
 741   }
 742 
 743   // Resolve constant pool entries -- we don't load any new classes during this stage
 744   for (int i = 0; i < collect_cld.nof_cld(); i++) {
 745     ClassLoaderData* cld = collect_cld.cld_at(i);
 746     for (Klass* klass = cld->klasses(); klass != nullptr; klass = klass->next_link()) {
 747       if (klass->is_instance_klass()) {
 748         InstanceKlass* ik = InstanceKlass::cast(klass);
 749         AOTConstantPoolResolver::dumptime_resolve_constants(ik, CHECK);
 750         if (CDSConfig::is_dumping_preimage_static_archive()) {
 751           FinalImageRecipes::add_reflection_data_flags(ik, CHECK);
 752         }
 753       }
 754     }
 755   }
 756 
 757   if (CDSConfig::is_dumping_preimage_static_archive()) {
 758     // Do this after all classes are verified by the above loop.
 759     // Any classes loaded from here on will be automatically excluded, so
 760     // there's no need to force verification or resolve CP entries.
 761     RecordTraining = false;
 762     SystemDictionaryShared::ignore_new_classes();
 763     LambdaFormInvokers::regenerate_holder_classes(CHECK);
 764     RecordTraining = true;
 765   }
 766 
 767   if (CDSConfig::is_dumping_final_static_archive()) {
 768     FinalImageRecipes::apply_recipes(CHECK);
 769   }
 770 }
 771 
 772 void MetaspaceShared::prepare_for_dumping() {
 773   assert(CDSConfig::is_dumping_archive(), "sanity");
 774   CDSConfig::check_unsupported_dumping_module_options();
 775   ClassLoader::initialize_shared_path(JavaThread::current());
 776 }
 777 
 778 // Preload classes from a list, populate the shared spaces and dump to a
 779 // file.
 780 void MetaspaceShared::preload_and_dump(TRAPS) {
 781   ResourceMark rm(THREAD);
 782   HandleMark hm(THREAD);
 783 
 784   if (CDSConfig::is_dumping_final_static_archive() && PrintTrainingInfo) {
 785     tty->print_cr("==================== archived_training_data ** before dumping ====================");
 786     TrainingData::print_archived_training_data_on(tty);
 787   }
 788 
 789   StaticArchiveBuilder builder;
 790   preload_and_dump_impl(builder, THREAD);
 791   if (HAS_PENDING_EXCEPTION) {
 792     if (PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())) {
 793       log_error(cds)("Out of memory. Please run with a larger Java heap, current MaxHeapSize = "
 794                      SIZE_FORMAT "M", MaxHeapSize/M);
 795       MetaspaceShared::writing_error();
 796     } else {
 797       log_error(cds)("%s: %s", PENDING_EXCEPTION->klass()->external_name(),
 798                      java_lang_String::as_utf8_string(java_lang_Throwable::message(PENDING_EXCEPTION)));
 799       MetaspaceShared::writing_error("Unexpected exception, use -Xlog:cds,exceptions=trace for detail");
 800     }
 801   }
 802 }
 803 
 804 #if INCLUDE_CDS_JAVA_HEAP && defined(_LP64)
 805 void MetaspaceShared::adjust_heap_sizes_for_dumping() {
 806   if (!CDSConfig::is_dumping_heap() || UseCompressedOops) {
 807     return;
 808   }
 809   // CDS heap dumping requires all string oops to have an offset
 810   // from the heap bottom that can be encoded in 32-bit.
 811   julong max_heap_size = (julong)(4 * G);
 812 
 813   if (MinHeapSize > max_heap_size) {
 814     log_debug(cds)("Setting MinHeapSize to 4G for CDS dumping, original size = " SIZE_FORMAT "M", MinHeapSize/M);
 815     FLAG_SET_ERGO(MinHeapSize, max_heap_size);
 816   }
 817   if (InitialHeapSize > max_heap_size) {
 818     log_debug(cds)("Setting InitialHeapSize to 4G for CDS dumping, original size = " SIZE_FORMAT "M", InitialHeapSize/M);
 819     FLAG_SET_ERGO(InitialHeapSize, max_heap_size);
 820   }
 821   if (MaxHeapSize > max_heap_size) {
 822     log_debug(cds)("Setting MaxHeapSize to 4G for CDS dumping, original size = " SIZE_FORMAT "M", MaxHeapSize/M);
 823     FLAG_SET_ERGO(MaxHeapSize, max_heap_size);
 824   }
 825 }
 826 #endif // INCLUDE_CDS_JAVA_HEAP && _LP64
 827 
 828 void MetaspaceShared::get_default_classlist(char* default_classlist, const size_t buf_size) {
 829   // Construct the path to the class list (in jre/lib)
 830   // Walk up two directories from the location of the VM and
 831   // optionally tack on "lib" (depending on platform)
 832   os::jvm_path(default_classlist, (jint)(buf_size));
 833   for (int i = 0; i < 3; i++) {
 834     char *end = strrchr(default_classlist, *os::file_separator());
 835     if (end != nullptr) *end = '\0';
 836   }
 837   size_t classlist_path_len = strlen(default_classlist);
 838   if (classlist_path_len >= 3) {
 839     if (strcmp(default_classlist + classlist_path_len - 3, "lib") != 0) {
 840       if (classlist_path_len < buf_size - 4) {
 841         jio_snprintf(default_classlist + classlist_path_len,
 842                      buf_size - classlist_path_len,
 843                      "%slib", os::file_separator());
 844         classlist_path_len += 4;
 845       }
 846     }
 847   }
 848   if (classlist_path_len < buf_size - 10) {
 849     jio_snprintf(default_classlist + classlist_path_len,
 850                  buf_size - classlist_path_len,
 851                  "%sclasslist", os::file_separator());
 852   }
 853 }
 854 
 855 void MetaspaceShared::preload_classes(TRAPS) {
 856   char default_classlist[JVM_MAXPATHLEN];
 857   const char* classlist_path;
 858 
 859   get_default_classlist(default_classlist, sizeof(default_classlist));
 860   if (SharedClassListFile == nullptr) {
 861     classlist_path = default_classlist;
 862   } else {
 863     classlist_path = SharedClassListFile;
 864   }
 865 
 866   log_info(cds)("Loading classes to share ...");
 867   ClassListParser::parse_classlist(classlist_path,
 868                                    ClassListParser::_parse_all, CHECK);
 869   if (ExtraSharedClassListFile) {
 870     ClassListParser::parse_classlist(ExtraSharedClassListFile,
 871                                      ClassListParser::_parse_all, CHECK);
 872   }
 873   if (classlist_path != default_classlist) {
 874     struct stat statbuf;
 875     if (os::stat(default_classlist, &statbuf) == 0) {
 876       // File exists, let's use it.
 877       ClassListParser::parse_classlist(default_classlist,
 878                                        ClassListParser::_parse_lambda_forms_invokers_only, CHECK);
 879     }
 880   }
 881 
 882   // Exercise the manifest processing code to ensure classes used by CDS at runtime
 883   // are always archived
 884   const char* dummy = "Manifest-Version: 1.0\n";
 885   CDSProtectionDomain::create_jar_manifest(dummy, strlen(dummy), CHECK);
 886 
 887   log_info(cds)("Loading classes to share: done.");
 888 }
 889 
 890 void MetaspaceShared::preload_and_dump_impl(StaticArchiveBuilder& builder, TRAPS) {
 891   if (CDSConfig::is_dumping_classic_static_archive()) {
 892     // We are running with -Xshare:dump
 893     preload_classes(CHECK);
 894 
 895     if (SharedArchiveConfigFile) {
 896       log_info(cds)("Reading extra data from %s ...", SharedArchiveConfigFile);
 897       read_extra_data(THREAD, SharedArchiveConfigFile);
 898       log_info(cds)("Reading extra data: done.");
 899     }
 900   }
 901 
 902   if (CDSConfig::is_dumping_preimage_static_archive()) {
 903     log_info(cds)("Reading lambda form invokers of in JDK default classlist ...");
 904     char default_classlist[JVM_MAXPATHLEN];
 905     get_default_classlist(default_classlist, sizeof(default_classlist));
 906     struct stat statbuf;
 907     if (os::stat(default_classlist, &statbuf) == 0) {
 908       ClassListParser::parse_classlist(default_classlist,
 909                                        ClassListParser::_parse_lambda_forms_invokers_only, CHECK);
 910     }
 911   }
 912 
 913   // Rewrite and link classes
 914   log_info(cds)("Rewriting and linking classes ...");
 915   // Link any classes which got missed. This would happen if we have loaded classes that
 916   // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
 917   // fails verification, all other interfaces that were not specified in the classlist but
 918   // are implemented by K are not verified.
 919   link_shared_classes(false/*not from jcmd*/, CHECK);
 920   log_info(cds)("Rewriting and linking classes: done");
 921 
 922   if (CDSConfig::is_dumping_final_static_archive()) {
 923     assert(RecordTraining == false, "must be");
 924     RecordTraining = true;
 925   }
 926 
 927   TrainingData::init_dumptime_table(CHECK); // captures TrainingDataSetLocker
 928 
 929 #if INCLUDE_CDS_JAVA_HEAP
 930   if (CDSConfig::is_dumping_heap()) {
 931     if (!HeapShared::is_archived_boot_layer_available(THREAD)) {
 932       log_info(cds)("archivedBootLayer not available, disabling full module graph");
 933       CDSConfig::stop_dumping_full_module_graph();
 934     }
 935     HeapShared::init_for_dumping(CHECK);
 936     ArchiveHeapWriter::init();
 937     if (CDSConfig::is_dumping_full_module_graph()) {
 938       HeapShared::reset_archived_object_states(CHECK);
 939     }
 940 
 941     if (ArchiveLoaderLookupCache) {
 942       SystemDictionaryShared::create_loader_positive_lookup_cache(CHECK);
 943     }
 944 
 945     if (CDSConfig::is_dumping_invokedynamic()) {
 946       // This makes sure that the MethodType and MethodTypeForm tables won't be updated
 947       // concurrently when we are saving their contents into a side table.
 948       assert(CDSConfig::allow_only_single_java_thread(), "Required");
 949 
 950       JavaValue result(T_VOID);
 951       JavaCalls::call_static(&result, vmClasses::MethodType_klass(),
 952                              vmSymbols::createArchivedObjects(),
 953                              vmSymbols::void_method_signature(),
 954                              CHECK);
 955     }
 956 
 957     // Do this at the very end, when no Java code will be executed. Otherwise
 958     // some new strings may be added to the intern table.
 959     StringTable::allocate_shared_strings_array(CHECK);
 960   } else {
 961     log_info(cds)("Not dumping heap, reset CDSConfig::_is_using_optimized_module_handling");
 962     CDSConfig::stop_using_optimized_module_handling();
 963   }
 964 #endif
 965 
 966   // Dummy call to load classes used at CDS runtime
 967   JavaValue result(T_OBJECT);
 968   Handle path_string = java_lang_String::create_from_str("dummy.jar", CHECK);
 969   JavaCalls::call_static(&result,
 970                          vmClasses::jdk_internal_loader_ClassLoaders_klass(),
 971                          vmSymbols::toFileURL_name(),
 972                          vmSymbols::toFileURL_signature(),
 973                          path_string,
 974                          CHECK);
 975 
 976   VM_PopulateDumpSharedSpace op(builder);
 977   VMThread::execute(&op);
 978   FileMapInfo* mapinfo = op.map_info();
 979   ArchiveHeapInfo* heap_info = op.heap_info();
 980   bool status;
 981   if (CDSConfig::is_dumping_preimage_static_archive()) {
 982     if ((status = write_static_archive(&builder, mapinfo, heap_info))) {
 983       fork_and_dump_final_static_archive();
 984     }
 985   } else if (CDSConfig::is_dumping_final_static_archive()) {
 986     RecordTraining = false;
 987     if (StoreCachedCode && CachedCodeFile != nullptr) { // FIXME: new workflow -- remove the CachedCodeFile flag
 988       if (log_is_enabled(Info, cds, jit)) {
 989         CDSAccess::test_heap_access_api();
 990       }
 991 
 992       // We have just created the final image. Let's run the AOT compiler
 993       if (PrintTrainingInfo) {
 994         tty->print_cr("==================== archived_training_data ** after dumping ====================");
 995         TrainingData::print_archived_training_data_on(tty);
 996       }
 997 
 998       CDSConfig::enable_dumping_cached_code();
 999       {
1000         builder.start_cc_region();
1001         Precompiler::compile_cached_code(&builder, CHECK);
1002         builder.end_cc_region();
1003       }
1004       CDSConfig::disable_dumping_cached_code();
1005 
1006       SCCache::close(); // Write final data and close archive
1007     }
1008     status = write_static_archive(&builder, mapinfo, heap_info);
1009   } else {
1010     status = write_static_archive(&builder, mapinfo, heap_info);
1011   }
1012 
1013   if (!status) {
1014     THROW_MSG(vmSymbols::java_io_IOException(), "Encountered error while dumping");
1015   }
1016 }
1017 
1018 bool MetaspaceShared::write_static_archive(ArchiveBuilder* builder, FileMapInfo* map_info, ArchiveHeapInfo* heap_info) {
1019   // relocate the data so that it can be mapped to MetaspaceShared::requested_base_address()
1020   // without runtime relocation.
1021   builder->relocate_to_requested();
1022 
1023   map_info->open_for_write();
1024   if (!map_info->is_open()) {
1025     return false;
1026   }
1027   builder->write_archive(map_info, heap_info);
1028 
1029   if (AllowArchivingWithJavaAgent) {
1030     log_warning(cds)("This archive was created with AllowArchivingWithJavaAgent. It should be used "
1031             "for testing purposes only and should not be used in a production environment");
1032   }
1033   return true;
1034 }
1035 
1036 static void print_java_launcher(outputStream* st) {
1037   st->print("%s%sbin%sjava", Arguments::get_java_home(), os::file_separator(), os::file_separator());
1038 }
1039 
1040 static void print_vm_arguments(outputStream* st) {
1041   const char* cp = Arguments::get_appclasspath();
1042   if (cp != nullptr && strlen(cp) > 0 && strcmp(cp, ".") != 0) {
1043     st->print(" -cp ");  st->print_raw(cp);
1044   }
1045   for (int i = 0; i < Arguments::num_jvm_flags(); i++) {
1046     st->print(" %s", Arguments::jvm_flags_array()[i]);
1047   }
1048   for (int i = 0; i < Arguments::num_jvm_args(); i++) {
1049     st->print(" %s", Arguments::jvm_args_array()[i]);
1050   }
1051 }
1052 
1053 void MetaspaceShared::fork_and_dump_final_static_archive() {
1054   assert(CDSConfig::is_dumping_preimage_static_archive(), "sanity");
1055 
1056   ResourceMark rm;
1057   stringStream ss;
1058   print_java_launcher(&ss);
1059   print_vm_arguments(&ss);
1060   ss.print(" -XX:CDSPreimage=%s", SharedArchiveFile);
1061 
1062   const char* cmd = ss.freeze();
1063   if (CDSManualFinalImage) {
1064     tty->print_cr("-XX:+CDSManualFinalImage is specified");
1065     tty->print_cr("Please manually execute the following command to create the final CDS image:");
1066     tty->print("    "); tty->print_raw_cr(cmd);
1067 
1068     // The following is useful if the dumping was trigger by a script that builds
1069     // a complex command-line.
1070     tty->print_cr("Note: to recreate the preimage only:");
1071     tty->print_cr("    rm -f %s", CacheDataStore);
1072     tty->print("    ");
1073     print_java_launcher(tty);
1074     print_vm_arguments(tty);
1075     if (Arguments::java_command() != nullptr) {
1076       tty->print(" %s", Arguments::java_command());
1077     }
1078     tty->cr();
1079   } else {
1080     // FIXME: space characters are not properly quoated. E.g.,
1081     //      java -Dfoo='a b c' HelloWorld
1082     log_info(cds)("Launching child process to create final CDS image:");
1083     log_info(cds)("    %s", cmd);
1084     int status = os::fork_and_exec(cmd);
1085     if (status != 0) {
1086       log_error(cds)("Child process finished; status = %d", status);
1087       log_error(cds)("To reproduce the error");
1088       ResourceMark rm;
1089       LogStream ls(Log(cds)::error());
1090       ls.print("    "); ls.print_raw_cr(cmd);
1091 
1092       // The following is useful if the dumping was trigger by a script that builds
1093       // a complex command-line.
1094       ls.print_cr("Note: to recreate the preimage only:");
1095       ls.print_cr("    rm -f %s", CacheDataStore);
1096       ls.print("    ");
1097       print_java_launcher(&ls);
1098       print_vm_arguments(&ls);
1099       ls.print(" -XX:+UnlockDiagnosticVMOptions -XX:+CDSManualFinalImage");
1100       if (Arguments::java_command() != nullptr) {
1101         ls.print(" %s", Arguments::java_command());
1102       }
1103       ls.cr();
1104 
1105       vm_direct_exit(status);
1106     } else {
1107       log_info(cds)("Child process finished; status = %d", status);
1108       // On Windows, need WRITE permission to remove the file.
1109       WINDOWS_ONLY(chmod(SharedArchiveFile, _S_IREAD | _S_IWRITE));
1110       status = remove(SharedArchiveFile);
1111       if (status != 0) {
1112         log_error(cds)("Failed to remove CDSPreimage file %s", SharedArchiveFile);
1113       } else {
1114         log_info(cds)("Removed CDSPreimage file %s", SharedArchiveFile);
1115       }
1116     }
1117   }
1118 }
1119 
1120 // Returns true if the class's status has changed.
1121 bool MetaspaceShared::try_link_class(JavaThread* current, InstanceKlass* ik) {
1122   ExceptionMark em(current);
1123   JavaThread* THREAD = current; // For exception macros.
1124   assert(CDSConfig::is_dumping_archive(), "sanity");
1125 
1126   if (ik->is_shared() && !CDSConfig::is_dumping_final_static_archive()) {
1127     assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1128     return false;
1129   }
1130 
1131   if (ik->is_loaded() && !ik->is_linked() && ik->can_be_verified_at_dumptime() &&
1132       !SystemDictionaryShared::has_class_failed_verification(ik)) {
1133     bool saved = BytecodeVerificationLocal;
1134     if (ik->is_shared_unregistered_class() && ik->class_loader() == nullptr) {
1135       // The verification decision is based on BytecodeVerificationRemote
1136       // for non-system classes. Since we are using the null classloader
1137       // to load non-system classes for customized class loaders during dumping,
1138       // we need to temporarily change BytecodeVerificationLocal to be the same as
1139       // BytecodeVerificationRemote. Note this can cause the parent system
1140       // classes also being verified. The extra overhead is acceptable during
1141       // dumping.
1142       BytecodeVerificationLocal = BytecodeVerificationRemote;
1143     }
1144     ik->link_class(THREAD);
1145     if (HAS_PENDING_EXCEPTION) {
1146       ResourceMark rm(THREAD);
1147       log_warning(cds)("Preload Warning: Verification failed for %s",
1148                     ik->external_name());
1149       CLEAR_PENDING_EXCEPTION;
1150       SystemDictionaryShared::set_class_has_failed_verification(ik);
1151     }
1152     ik->compute_has_loops_flag_for_methods();
1153     BytecodeVerificationLocal = saved;
1154     return true;
1155   } else {
1156     return false;
1157   }
1158 }
1159 
1160 #if INCLUDE_CDS_JAVA_HEAP
1161 void VM_PopulateDumpSharedSpace::dump_java_heap_objects(GrowableArray<Klass*>* klasses) {
1162   if(!HeapShared::can_write()) {
1163     if (!CDSConfig::is_dumping_preimage_static_archive()) {
1164      log_info(cds)(
1165       "Archived java heap is not supported as UseG1GC "
1166       "and UseCompressedClassPointers are required."
1167       "Current settings: UseG1GC=%s, UseCompressedClassPointers=%s.",
1168       BOOL_TO_STR(UseG1GC), BOOL_TO_STR(UseCompressedClassPointers));
1169     }
1170     return;
1171   }
1172   // Find all the interned strings that should be dumped.
1173   int i;
1174   for (i = 0; i < klasses->length(); i++) {
1175     Klass* k = klasses->at(i);
1176     if (k->is_instance_klass()) {
1177       InstanceKlass* ik = InstanceKlass::cast(k);
1178       if (ik->is_linked()) {
1179         ik->constants()->add_dumped_interned_strings();
1180       }
1181     }
1182   }
1183   if (_extra_interned_strings != nullptr) {
1184     for (i = 0; i < _extra_interned_strings->length(); i ++) {
1185       OopHandle string = _extra_interned_strings->at(i);
1186       HeapShared::add_to_dumped_interned_strings(string.resolve());
1187     }
1188   }
1189 
1190   HeapShared::archive_objects(&_heap_info);
1191   ArchiveBuilder::OtherROAllocMark mark;
1192   HeapShared::write_subgraph_info_table();
1193 }
1194 #endif // INCLUDE_CDS_JAVA_HEAP
1195 
1196 void MetaspaceShared::set_shared_metaspace_range(void* base, void *static_top, void* top) {
1197   assert(base <= static_top && static_top <= top, "must be");
1198   _shared_metaspace_static_top = static_top;
1199   MetaspaceObj::set_shared_metaspace_range(base, top);
1200 }
1201 
1202 bool MetaspaceShared::is_shared_dynamic(void* p) {
1203   if ((p < MetaspaceObj::shared_metaspace_top()) &&
1204       (p >= _shared_metaspace_static_top)) {
1205     return true;
1206   } else {
1207     return false;
1208   }
1209 }
1210 
1211 bool MetaspaceShared::is_shared_static(void* p) {
1212   if (is_in_shared_metaspace(p) && !is_shared_dynamic(p)) {
1213     return true;
1214   } else {
1215     return false;
1216   }
1217 }
1218 
1219 // This function is called when the JVM is unable to load the specified archive(s) due to one
1220 // of the following conditions.
1221 // - There's an error that indicates that the archive(s) files were corrupt or otherwise damaged.
1222 // - When -XX:+RequireSharedSpaces is specified, AND the JVM cannot load the archive(s) due
1223 //   to version or classpath mismatch.
1224 void MetaspaceShared::unrecoverable_loading_error(const char* message) {
1225   log_error(cds)("An error has occurred while processing the shared archive file.");
1226   if (message != nullptr) {
1227     log_error(cds)("%s", message);
1228   }
1229   vm_exit_during_initialization("Unable to use shared archive.", nullptr);
1230 }
1231 
1232 // This function is called when the JVM is unable to write the specified CDS archive due to an
1233 // unrecoverable error.
1234 void MetaspaceShared::unrecoverable_writing_error(const char* message) {
1235   writing_error(message);
1236   vm_direct_exit(1);
1237 }
1238 
1239 // This function is called when the JVM is unable to write the specified CDS archive due to a
1240 // an error. The error will be propagated
1241 void MetaspaceShared::writing_error(const char* message) {
1242   log_error(cds)("An error has occurred while writing the shared archive file.");
1243   if (message != nullptr) {
1244     log_error(cds)("%s", message);
1245   }
1246 }
1247 
1248 void MetaspaceShared::initialize_runtime_shared_and_meta_spaces() {
1249   assert(CDSConfig::is_using_archive(), "Must be called when UseSharedSpaces is enabled");
1250   MapArchiveResult result = MAP_ARCHIVE_OTHER_FAILURE;
1251 
1252   FileMapInfo* static_mapinfo = FileMapInfo::current_info();
1253   FileMapInfo* dynamic_mapinfo = nullptr;
1254 
1255   if (static_mapinfo != nullptr) {
1256     log_info(cds)("Core region alignment: " SIZE_FORMAT, static_mapinfo->core_region_alignment());
1257     dynamic_mapinfo = open_dynamic_archive();
1258 
1259     // First try to map at the requested address
1260     result = map_archives(static_mapinfo, dynamic_mapinfo, true);
1261     if (result == MAP_ARCHIVE_MMAP_FAILURE) {
1262       // Mapping has failed (probably due to ASLR). Let's map at an address chosen
1263       // by the OS.
1264       log_info(cds)("Try to map archive(s) at an alternative address");
1265       result = map_archives(static_mapinfo, dynamic_mapinfo, false);
1266     }
1267   }
1268 
1269   if (result == MAP_ARCHIVE_SUCCESS) {
1270     bool dynamic_mapped = (dynamic_mapinfo != nullptr && dynamic_mapinfo->is_mapped());
1271     char* cds_base = static_mapinfo->mapped_base();
1272     char* cds_end =  dynamic_mapped ? dynamic_mapinfo->mapped_end() : static_mapinfo->mapped_end();
1273     // Register CDS memory region with LSan.
1274     LSAN_REGISTER_ROOT_REGION(cds_base, cds_end - cds_base);
1275     set_shared_metaspace_range(cds_base, static_mapinfo->mapped_end(), cds_end);
1276     _relocation_delta = static_mapinfo->relocation_delta();
1277     _requested_base_address = static_mapinfo->requested_base_address();
1278     if (dynamic_mapped) {
1279       FileMapInfo::set_shared_path_table(dynamic_mapinfo);
1280       // turn AutoCreateSharedArchive off if successfully mapped
1281       AutoCreateSharedArchive = false;
1282     } else {
1283       FileMapInfo::set_shared_path_table(static_mapinfo);
1284     }
1285   } else {
1286     set_shared_metaspace_range(nullptr, nullptr, nullptr);
1287     if (CDSConfig::is_dumping_dynamic_archive()) {
1288       log_warning(cds)("-XX:ArchiveClassesAtExit is unsupported when base CDS archive is not loaded. Run with -Xlog:cds for more info.");
1289     }
1290     UseSharedSpaces = false;
1291     // The base archive cannot be mapped. We cannot dump the dynamic shared archive.
1292     AutoCreateSharedArchive = false;
1293     CDSConfig::disable_dumping_dynamic_archive();
1294     log_info(cds)("Unable to map shared spaces");
1295     if (PrintSharedArchiveAndExit) {
1296       MetaspaceShared::unrecoverable_loading_error("Unable to use shared archive.");
1297     } else if (RequireSharedSpaces) {
1298       MetaspaceShared::unrecoverable_loading_error("Unable to map shared spaces");
1299     } else if (CDSConfig::is_dumping_final_static_archive()) {
1300       assert(CDSPreimage != nullptr, "must be");
1301       log_error(cds)("Unable to map shared spaces for CDSPreimage = %s", CDSPreimage);
1302       MetaspaceShared::unrecoverable_loading_error();
1303     }
1304   }
1305 
1306   // If mapping failed and -XShare:on, the vm should exit
1307   bool has_failed = false;
1308   if (static_mapinfo != nullptr && !static_mapinfo->is_mapped()) {
1309     has_failed = true;
1310     delete static_mapinfo;
1311   }
1312   if (dynamic_mapinfo != nullptr && !dynamic_mapinfo->is_mapped()) {
1313     has_failed = true;
1314     delete dynamic_mapinfo;
1315   }
1316   if (RequireSharedSpaces && has_failed) {
1317     // static archive mapped but dynamic archive failed
1318       MetaspaceShared::unrecoverable_loading_error("Unable to map shared spaces");
1319   }
1320 }
1321 
1322 // This is called very early at VM start up to get the size of the cached_code region, which
1323 // is used in CodeCache::initialize_heaps()
1324 void MetaspaceShared::open_static_archive() {
1325   if (!UseSharedSpaces) {
1326     return;
1327   }
1328   const char* static_archive = CDSConfig::static_archive_path();
1329   assert(static_archive != nullptr, "sanity");
1330   FileMapInfo* mapinfo = new FileMapInfo(static_archive, true);
1331   if (!mapinfo->initialize()) {
1332     delete(mapinfo);
1333   } else {
1334     FileMapRegion* r = mapinfo->region_at(MetaspaceShared::cc);
1335     CDSAccess::set_cached_code_size(r->used_aligned());
1336   }
1337 }
1338 
1339 FileMapInfo* MetaspaceShared::open_dynamic_archive() {
1340   if (CDSConfig::is_dumping_dynamic_archive()) {
1341     return nullptr;
1342   }
1343   const char* dynamic_archive = CDSConfig::dynamic_archive_path();
1344   if (dynamic_archive == nullptr) {
1345     return nullptr;
1346   }
1347 
1348   FileMapInfo* mapinfo = new FileMapInfo(dynamic_archive, false);
1349   if (!mapinfo->initialize()) {
1350     delete(mapinfo);
1351     if (RequireSharedSpaces) {
1352       MetaspaceShared::unrecoverable_loading_error("Failed to initialize dynamic archive");
1353     }
1354     return nullptr;
1355   }
1356   return mapinfo;
1357 }
1358 
1359 // use_requested_addr:
1360 //  true  = map at FileMapHeader::_requested_base_address
1361 //  false = map at an alternative address picked by OS.
1362 MapArchiveResult MetaspaceShared::map_archives(FileMapInfo* static_mapinfo, FileMapInfo* dynamic_mapinfo,
1363                                                bool use_requested_addr) {
1364   if (use_requested_addr && static_mapinfo->requested_base_address() == nullptr) {
1365     log_info(cds)("Archive(s) were created with -XX:SharedBaseAddress=0. Always map at os-selected address.");
1366     return MAP_ARCHIVE_MMAP_FAILURE;
1367   }
1368 
1369   PRODUCT_ONLY(if (ArchiveRelocationMode == 1 && use_requested_addr) {
1370       // For product build only -- this is for benchmarking the cost of doing relocation.
1371       // For debug builds, the check is done below, after reserving the space, for better test coverage
1372       // (see comment below).
1373       log_info(cds)("ArchiveRelocationMode == 1: always map archive(s) at an alternative address");
1374       return MAP_ARCHIVE_MMAP_FAILURE;
1375     });
1376 
1377   if (ArchiveRelocationMode == 2 && !use_requested_addr) {
1378     log_info(cds)("ArchiveRelocationMode == 2: never map archive(s) at an alternative address");
1379     return MAP_ARCHIVE_MMAP_FAILURE;
1380   };
1381 
1382   if (dynamic_mapinfo != nullptr) {
1383     // Ensure that the OS won't be able to allocate new memory spaces between the two
1384     // archives, or else it would mess up the simple comparison in MetaspaceObj::is_shared().
1385     assert(static_mapinfo->mapping_end_offset() == dynamic_mapinfo->mapping_base_offset(), "no gap");
1386   }
1387 
1388   ReservedSpace total_space_rs, archive_space_rs, class_space_rs;
1389   MapArchiveResult result = MAP_ARCHIVE_OTHER_FAILURE;
1390   char* mapped_base_address = reserve_address_space_for_archives(static_mapinfo,
1391                                                                  dynamic_mapinfo,
1392                                                                  use_requested_addr,
1393                                                                  total_space_rs,
1394                                                                  archive_space_rs,
1395                                                                  class_space_rs);
1396   if (mapped_base_address == nullptr) {
1397     result = MAP_ARCHIVE_MMAP_FAILURE;
1398     log_debug(cds)("Failed to reserve spaces (use_requested_addr=%u)", (unsigned)use_requested_addr);
1399   } else {
1400 
1401 #ifdef ASSERT
1402     // Some sanity checks after reserving address spaces for archives
1403     //  and class space.
1404     assert(archive_space_rs.is_reserved(), "Sanity");
1405     if (Metaspace::using_class_space()) {
1406       // Class space must closely follow the archive space. Both spaces
1407       //  must be aligned correctly.
1408       assert(class_space_rs.is_reserved(),
1409              "A class space should have been reserved");
1410       assert(class_space_rs.base() >= archive_space_rs.end(),
1411              "class space should follow the cds archive space");
1412       assert(is_aligned(archive_space_rs.base(),
1413                         core_region_alignment()),
1414              "Archive space misaligned");
1415       assert(is_aligned(class_space_rs.base(),
1416                         Metaspace::reserve_alignment()),
1417              "class space misaligned");
1418     }
1419 #endif // ASSERT
1420 
1421     log_info(cds)("Reserved archive_space_rs [" INTPTR_FORMAT " - " INTPTR_FORMAT "] (" SIZE_FORMAT ") bytes",
1422                    p2i(archive_space_rs.base()), p2i(archive_space_rs.end()), archive_space_rs.size());
1423     log_info(cds)("Reserved class_space_rs   [" INTPTR_FORMAT " - " INTPTR_FORMAT "] (" SIZE_FORMAT ") bytes",
1424                    p2i(class_space_rs.base()), p2i(class_space_rs.end()), class_space_rs.size());
1425 
1426     if (MetaspaceShared::use_windows_memory_mapping()) {
1427       // We have now reserved address space for the archives, and will map in
1428       //  the archive files into this space.
1429       //
1430       // Special handling for Windows: on Windows we cannot map a file view
1431       //  into an existing memory mapping. So, we unmap the address range we
1432       //  just reserved again, which will make it available for mapping the
1433       //  archives.
1434       // Reserving this range has not been for naught however since it makes
1435       //  us reasonably sure the address range is available.
1436       //
1437       // But still it may fail, since between unmapping the range and mapping
1438       //  in the archive someone else may grab the address space. Therefore
1439       //  there is a fallback in FileMap::map_region() where we just read in
1440       //  the archive files sequentially instead of mapping it in. We couple
1441       //  this with use_requested_addr, since we're going to patch all the
1442       //  pointers anyway so there's no benefit to mmap.
1443       if (use_requested_addr) {
1444         assert(!total_space_rs.is_reserved(), "Should not be reserved for Windows");
1445         log_info(cds)("Windows mmap workaround: releasing archive space.");
1446         archive_space_rs.release();
1447       }
1448     }
1449     MapArchiveResult static_result = map_archive(static_mapinfo, mapped_base_address, archive_space_rs);
1450     MapArchiveResult dynamic_result = (static_result == MAP_ARCHIVE_SUCCESS) ?
1451                                      map_archive(dynamic_mapinfo, mapped_base_address, archive_space_rs) : MAP_ARCHIVE_OTHER_FAILURE;
1452 
1453     DEBUG_ONLY(if (ArchiveRelocationMode == 1 && use_requested_addr) {
1454       // This is for simulating mmap failures at the requested address. In
1455       //  debug builds, we do it here (after all archives have possibly been
1456       //  mapped), so we can thoroughly test the code for failure handling
1457       //  (releasing all allocated resource, etc).
1458       log_info(cds)("ArchiveRelocationMode == 1: always map archive(s) at an alternative address");
1459       if (static_result == MAP_ARCHIVE_SUCCESS) {
1460         static_result = MAP_ARCHIVE_MMAP_FAILURE;
1461       }
1462       if (dynamic_result == MAP_ARCHIVE_SUCCESS) {
1463         dynamic_result = MAP_ARCHIVE_MMAP_FAILURE;
1464       }
1465     });
1466 
1467     if (static_result == MAP_ARCHIVE_SUCCESS) {
1468       if (dynamic_result == MAP_ARCHIVE_SUCCESS) {
1469         result = MAP_ARCHIVE_SUCCESS;
1470       } else if (dynamic_result == MAP_ARCHIVE_OTHER_FAILURE) {
1471         assert(dynamic_mapinfo != nullptr && !dynamic_mapinfo->is_mapped(), "must have failed");
1472         // No need to retry mapping the dynamic archive again, as it will never succeed
1473         // (bad file, etc) -- just keep the base archive.
1474         log_warning(cds, dynamic)("Unable to use shared archive. The top archive failed to load: %s",
1475                                   dynamic_mapinfo->full_path());
1476         result = MAP_ARCHIVE_SUCCESS;
1477         // TODO, we can give the unused space for the dynamic archive to class_space_rs, but there's no
1478         // easy API to do that right now.
1479       } else {
1480         result = MAP_ARCHIVE_MMAP_FAILURE;
1481       }
1482     } else if (static_result == MAP_ARCHIVE_OTHER_FAILURE) {
1483       result = MAP_ARCHIVE_OTHER_FAILURE;
1484     } else {
1485       result = MAP_ARCHIVE_MMAP_FAILURE;
1486     }
1487   }
1488 
1489   if (result == MAP_ARCHIVE_SUCCESS) {
1490     SharedBaseAddress = (size_t)mapped_base_address;
1491 #ifdef _LP64
1492         if (Metaspace::using_class_space()) {
1493           // Set up ccs in metaspace.
1494           Metaspace::initialize_class_space(class_space_rs);
1495 
1496           // Set up compressed Klass pointer encoding: the encoding range must
1497           //  cover both archive and class space.
1498           address cds_base = (address)static_mapinfo->mapped_base();
1499           address ccs_end = (address)class_space_rs.end();
1500           assert(ccs_end > cds_base, "Sanity check");
1501 #if INCLUDE_CDS_JAVA_HEAP
1502           // We archived objects with pre-computed narrow Klass id. Set up encoding such that these Ids stay valid.
1503           address precomputed_narrow_klass_base = cds_base;
1504           const int precomputed_narrow_klass_shift = ArchiveHeapWriter::precomputed_narrow_klass_shift;
1505           CompressedKlassPointers::initialize_for_given_encoding(
1506             cds_base, ccs_end - cds_base, // Klass range
1507             precomputed_narrow_klass_base, precomputed_narrow_klass_shift // precomputed encoding, see ArchiveHeapWriter
1508             );
1509 #else
1510           CompressedKlassPointers::initialize (
1511             cds_base, ccs_end - cds_base // Klass range
1512             );
1513 #endif // INCLUDE_CDS_JAVA_HEAP
1514           // map_or_load_heap_region() compares the current narrow oop and klass encodings
1515           // with the archived ones, so it must be done after all encodings are determined.
1516           static_mapinfo->map_or_load_heap_region();
1517         }
1518 #endif // _LP64
1519     log_info(cds)("initial optimized module handling: %s", CDSConfig::is_using_optimized_module_handling() ? "enabled" : "disabled");
1520     log_info(cds)("initial full module graph: %s", CDSConfig::is_using_full_module_graph() ? "enabled" : "disabled");
1521   } else {
1522     unmap_archive(static_mapinfo);
1523     unmap_archive(dynamic_mapinfo);
1524     release_reserved_spaces(total_space_rs, archive_space_rs, class_space_rs);
1525   }
1526 
1527   return result;
1528 }
1529 
1530 
1531 // This will reserve two address spaces suitable to house Klass structures, one
1532 //  for the cds archives (static archive and optionally dynamic archive) and
1533 //  optionally one move for ccs.
1534 //
1535 // Since both spaces must fall within the compressed class pointer encoding
1536 //  range, they are allocated close to each other.
1537 //
1538 // Space for archives will be reserved first, followed by a potential gap,
1539 //  followed by the space for ccs:
1540 //
1541 // +-- Base address             A        B                     End
1542 // |                            |        |                      |
1543 // v                            v        v                      v
1544 // +-------------+--------------+        +----------------------+
1545 // | static arc  | [dyn. arch]  | [gap]  | compr. class space   |
1546 // +-------------+--------------+        +----------------------+
1547 //
1548 // (The gap may result from different alignment requirements between metaspace
1549 //  and CDS)
1550 //
1551 // If UseCompressedClassPointers is disabled, only one address space will be
1552 //  reserved:
1553 //
1554 // +-- Base address             End
1555 // |                            |
1556 // v                            v
1557 // +-------------+--------------+
1558 // | static arc  | [dyn. arch]  |
1559 // +-------------+--------------+
1560 //
1561 // Base address: If use_archive_base_addr address is true, the Base address is
1562 //  determined by the address stored in the static archive. If
1563 //  use_archive_base_addr address is false, this base address is determined
1564 //  by the platform.
1565 //
1566 // If UseCompressedClassPointers=1, the range encompassing both spaces will be
1567 //  suitable to en/decode narrow Klass pointers: the base will be valid for
1568 //  encoding, the range [Base, End) not surpass KlassEncodingMetaspaceMax.
1569 //
1570 // Return:
1571 //
1572 // - On success:
1573 //    - total_space_rs will be reserved as whole for archive_space_rs and
1574 //      class_space_rs if UseCompressedClassPointers is true.
1575 //      On Windows, try reserve archive_space_rs and class_space_rs
1576 //      separately first if use_archive_base_addr is true.
1577 //    - archive_space_rs will be reserved and large enough to host static and
1578 //      if needed dynamic archive: [Base, A).
1579 //      archive_space_rs.base and size will be aligned to CDS reserve
1580 //      granularity.
1581 //    - class_space_rs: If UseCompressedClassPointers=1, class_space_rs will
1582 //      be reserved. Its start address will be aligned to metaspace reserve
1583 //      alignment, which may differ from CDS alignment. It will follow the cds
1584 //      archive space, close enough such that narrow class pointer encoding
1585 //      covers both spaces.
1586 //      If UseCompressedClassPointers=0, class_space_rs remains unreserved.
1587 // - On error: null is returned and the spaces remain unreserved.
1588 char* MetaspaceShared::reserve_address_space_for_archives(FileMapInfo* static_mapinfo,
1589                                                           FileMapInfo* dynamic_mapinfo,
1590                                                           bool use_archive_base_addr,
1591                                                           ReservedSpace& total_space_rs,
1592                                                           ReservedSpace& archive_space_rs,
1593                                                           ReservedSpace& class_space_rs) {
1594 
1595   address const base_address = (address) (use_archive_base_addr ? static_mapinfo->requested_base_address() : nullptr);
1596   const size_t archive_space_alignment = core_region_alignment();
1597 
1598   // Size and requested location of the archive_space_rs (for both static and dynamic archives)
1599   assert(static_mapinfo->mapping_base_offset() == 0, "Must be");
1600   size_t archive_end_offset  = (dynamic_mapinfo == nullptr) ? static_mapinfo->mapping_end_offset() : dynamic_mapinfo->mapping_end_offset();
1601   size_t archive_space_size = align_up(archive_end_offset, archive_space_alignment);
1602 
1603   if (!Metaspace::using_class_space()) {
1604     // Get the simple case out of the way first:
1605     // no compressed class space, simple allocation.
1606 
1607     // When running without class space, requested archive base should be aligned to cds core alignment.
1608     assert(is_aligned(base_address, archive_space_alignment),
1609              "Archive base address unaligned: " PTR_FORMAT ", needs alignment: %zu.",
1610              p2i(base_address), archive_space_alignment);
1611 
1612     archive_space_rs = ReservedSpace(archive_space_size, archive_space_alignment,
1613                                      os::vm_page_size(), (char*)base_address);
1614     if (archive_space_rs.is_reserved()) {
1615       assert(base_address == nullptr ||
1616              (address)archive_space_rs.base() == base_address, "Sanity");
1617       // Register archive space with NMT.
1618       MemTracker::record_virtual_memory_tag(archive_space_rs.base(), mtClassShared);
1619       return archive_space_rs.base();
1620     }
1621     return nullptr;
1622   }
1623 
1624 #ifdef _LP64
1625 
1626   // Complex case: two spaces adjacent to each other, both to be addressable
1627   //  with narrow class pointers.
1628   // We reserve the whole range spanning both spaces, then split that range up.
1629 
1630   const size_t class_space_alignment = Metaspace::reserve_alignment();
1631 
1632   // When running with class space, requested archive base must satisfy both cds core alignment
1633   // and class space alignment.
1634   const size_t base_address_alignment = MAX2(class_space_alignment, archive_space_alignment);
1635   assert(is_aligned(base_address, base_address_alignment),
1636            "Archive base address unaligned: " PTR_FORMAT ", needs alignment: %zu.",
1637            p2i(base_address), base_address_alignment);
1638 
1639   size_t class_space_size = CompressedClassSpaceSize;
1640   assert(CompressedClassSpaceSize > 0 &&
1641          is_aligned(CompressedClassSpaceSize, class_space_alignment),
1642          "CompressedClassSpaceSize malformed: "
1643          SIZE_FORMAT, CompressedClassSpaceSize);
1644 
1645   const size_t ccs_begin_offset = align_up(archive_space_size, class_space_alignment);
1646   const size_t gap_size = ccs_begin_offset - archive_space_size;
1647 
1648   // Reduce class space size if it would not fit into the Klass encoding range
1649   constexpr size_t max_encoding_range_size = 4 * G;
1650   guarantee(archive_space_size < max_encoding_range_size - class_space_alignment, "Archive too large");
1651   if ((archive_space_size + gap_size + class_space_size) > max_encoding_range_size) {
1652     class_space_size = align_down(max_encoding_range_size - archive_space_size - gap_size, class_space_alignment);
1653     log_info(metaspace)("CDS initialization: reducing class space size from " SIZE_FORMAT " to " SIZE_FORMAT,
1654         CompressedClassSpaceSize, class_space_size);
1655     FLAG_SET_ERGO(CompressedClassSpaceSize, class_space_size);
1656   }
1657 
1658   const size_t total_range_size =
1659       archive_space_size + gap_size + class_space_size;
1660 
1661   assert(total_range_size > ccs_begin_offset, "must be");
1662   if (use_windows_memory_mapping() && use_archive_base_addr) {
1663     if (base_address != nullptr) {
1664       // On Windows, we cannot safely split a reserved memory space into two (see JDK-8255917).
1665       // Hence, we optimistically reserve archive space and class space side-by-side. We only
1666       // do this for use_archive_base_addr=true since for use_archive_base_addr=false case
1667       // caller will not split the combined space for mapping, instead read the archive data
1668       // via sequential file IO.
1669       address ccs_base = base_address + archive_space_size + gap_size;
1670       archive_space_rs = ReservedSpace(archive_space_size, archive_space_alignment,
1671                                        os::vm_page_size(), (char*)base_address);
1672       class_space_rs   = ReservedSpace(class_space_size, class_space_alignment,
1673                                        os::vm_page_size(), (char*)ccs_base);
1674     }
1675     if (!archive_space_rs.is_reserved() || !class_space_rs.is_reserved()) {
1676       release_reserved_spaces(total_space_rs, archive_space_rs, class_space_rs);
1677       return nullptr;
1678     }
1679     // NMT: fix up the space tags
1680     MemTracker::record_virtual_memory_tag(archive_space_rs.base(), mtClassShared);
1681     MemTracker::record_virtual_memory_tag(class_space_rs.base(), mtClass);
1682   } else {
1683     if (use_archive_base_addr && base_address != nullptr) {
1684       total_space_rs = ReservedSpace(total_range_size, base_address_alignment,
1685                                      os::vm_page_size(), (char*) base_address);
1686     } else {
1687       // We did not manage to reserve at the preferred address, or were instructed to relocate. In that
1688       // case we reserve wherever possible, but the start address needs to be encodable as narrow Klass
1689       // encoding base since the archived heap objects contain nKlass IDs pre-calculated toward the start
1690       // of the shared Metaspace. That prevents us from using zero-based encoding and therefore we won't
1691       // try allocating in low-address regions.
1692       total_space_rs = Metaspace::reserve_address_space_for_compressed_classes(total_range_size, false /* optimize_for_zero_base */);
1693     }
1694 
1695     if (!total_space_rs.is_reserved()) {
1696       return nullptr;
1697     }
1698 
1699     // Paranoid checks:
1700     assert(base_address == nullptr || (address)total_space_rs.base() == base_address,
1701            "Sanity (" PTR_FORMAT " vs " PTR_FORMAT ")", p2i(base_address), p2i(total_space_rs.base()));
1702     assert(is_aligned(total_space_rs.base(), base_address_alignment), "Sanity");
1703     assert(total_space_rs.size() == total_range_size, "Sanity");
1704 
1705     // Now split up the space into ccs and cds archive. For simplicity, just leave
1706     //  the gap reserved at the end of the archive space. Do not do real splitting.
1707     archive_space_rs = total_space_rs.first_part(ccs_begin_offset,
1708                                                  (size_t)archive_space_alignment);
1709     class_space_rs = total_space_rs.last_part(ccs_begin_offset);
1710     MemTracker::record_virtual_memory_split_reserved(total_space_rs.base(), total_space_rs.size(),
1711                                                      ccs_begin_offset, mtClassShared, mtClass);
1712   }
1713   assert(is_aligned(archive_space_rs.base(), archive_space_alignment), "Sanity");
1714   assert(is_aligned(archive_space_rs.size(), archive_space_alignment), "Sanity");
1715   assert(is_aligned(class_space_rs.base(), class_space_alignment), "Sanity");
1716   assert(is_aligned(class_space_rs.size(), class_space_alignment), "Sanity");
1717 
1718 
1719   return archive_space_rs.base();
1720 
1721 #else
1722   ShouldNotReachHere();
1723   return nullptr;
1724 #endif
1725 
1726 }
1727 
1728 void MetaspaceShared::release_reserved_spaces(ReservedSpace& total_space_rs,
1729                                               ReservedSpace& archive_space_rs,
1730                                               ReservedSpace& class_space_rs) {
1731   if (total_space_rs.is_reserved()) {
1732     log_debug(cds)("Released shared space (archive + class) " INTPTR_FORMAT, p2i(total_space_rs.base()));
1733     total_space_rs.release();
1734   } else {
1735     if (archive_space_rs.is_reserved()) {
1736       log_debug(cds)("Released shared space (archive) " INTPTR_FORMAT, p2i(archive_space_rs.base()));
1737       archive_space_rs.release();
1738     }
1739     if (class_space_rs.is_reserved()) {
1740       log_debug(cds)("Released shared space (classes) " INTPTR_FORMAT, p2i(class_space_rs.base()));
1741       class_space_rs.release();
1742     }
1743   }
1744 }
1745 
1746 static int archive_regions[]     = { MetaspaceShared::rw, MetaspaceShared::ro };
1747 static int archive_regions_count = 2;
1748 
1749 MapArchiveResult MetaspaceShared::map_archive(FileMapInfo* mapinfo, char* mapped_base_address, ReservedSpace rs) {
1750   assert(CDSConfig::is_using_archive(), "must be runtime");
1751   if (mapinfo == nullptr) {
1752     return MAP_ARCHIVE_SUCCESS; // The dynamic archive has not been specified. No error has happened -- trivially succeeded.
1753   }
1754 
1755   if (!mapinfo->validate_aot_class_linking()) {
1756     return MAP_ARCHIVE_OTHER_FAILURE;
1757   }
1758 
1759   mapinfo->set_is_mapped(false);
1760   if (mapinfo->core_region_alignment() != (size_t)core_region_alignment()) {
1761     log_info(cds)("Unable to map CDS archive -- core_region_alignment() expected: " SIZE_FORMAT
1762                   " actual: " SIZE_FORMAT, mapinfo->core_region_alignment(), core_region_alignment());
1763     return MAP_ARCHIVE_OTHER_FAILURE;
1764   }
1765 
1766   MapArchiveResult result =
1767     mapinfo->map_regions(archive_regions, archive_regions_count, mapped_base_address, rs);
1768 
1769   if (result != MAP_ARCHIVE_SUCCESS) {
1770     unmap_archive(mapinfo);
1771     return result;
1772   }
1773 
1774   if (!mapinfo->validate_shared_path_table()) {
1775     unmap_archive(mapinfo);
1776     return MAP_ARCHIVE_OTHER_FAILURE;
1777   }
1778 
1779   mapinfo->set_is_mapped(true);
1780   return MAP_ARCHIVE_SUCCESS;
1781 }
1782 
1783 void MetaspaceShared::unmap_archive(FileMapInfo* mapinfo) {
1784   assert(CDSConfig::is_using_archive(), "must be runtime");
1785   if (mapinfo != nullptr) {
1786     mapinfo->unmap_regions(archive_regions, archive_regions_count);
1787     mapinfo->unmap_region(MetaspaceShared::bm);
1788     mapinfo->set_is_mapped(false);
1789   }
1790 }
1791 
1792 // For -XX:PrintSharedArchiveAndExit
1793 class CountSharedSymbols : public SymbolClosure {
1794  private:
1795    int _count;
1796  public:
1797    CountSharedSymbols() : _count(0) {}
1798   void do_symbol(Symbol** sym) {
1799     _count++;
1800   }
1801   int total() { return _count; }
1802 
1803 };
1804 
1805 // Read the miscellaneous data from the shared file, and
1806 // serialize it out to its various destinations.
1807 
1808 void MetaspaceShared::initialize_shared_spaces() {
1809   FileMapInfo *static_mapinfo = FileMapInfo::current_info();
1810 
1811   // Verify various attributes of the archive, plus initialize the
1812   // shared string/symbol tables.
1813   char* buffer = static_mapinfo->serialized_data();
1814   intptr_t* array = (intptr_t*)buffer;
1815   ReadClosure rc(&array);
1816   serialize(&rc);
1817 
1818   // Finish up archived heap initialization. These must be
1819   // done after ReadClosure.
1820   static_mapinfo->patch_heap_embedded_pointers();
1821   ArchiveHeapLoader::finish_initialization();
1822   Universe::load_archived_object_instances();
1823   SCCache::new_workflow_load_cache();
1824 
1825   // Close the mapinfo file
1826   static_mapinfo->close();
1827 
1828   static_mapinfo->unmap_region(MetaspaceShared::bm);
1829 
1830   FileMapInfo *dynamic_mapinfo = FileMapInfo::dynamic_info();
1831   if (dynamic_mapinfo != nullptr) {
1832     intptr_t* buffer = (intptr_t*)dynamic_mapinfo->serialized_data();
1833     ReadClosure rc(&buffer);
1834     ArchiveBuilder::serialize_dynamic_archivable_items(&rc);
1835     DynamicArchive::setup_array_klasses();
1836     dynamic_mapinfo->close();
1837     dynamic_mapinfo->unmap_region(MetaspaceShared::bm);
1838   }
1839 
1840   log_info(cds)("Using AOT-linked classes: %s (%s%s)",
1841                 CDSConfig::is_using_aot_linked_classes() ? "true" : "false",
1842                 static_mapinfo->header()->has_aot_linked_classes() ? "static archive: true" : "static archive: false",
1843                 (dynamic_mapinfo == nullptr) ? "" :
1844                    (dynamic_mapinfo->header()->has_aot_linked_classes() ? ", dynamic archive: true" : ", dynamic archive: false"));
1845 
1846   // Set up LambdaFormInvokers::_lambdaform_lines for dynamic dump
1847   if (CDSConfig::is_dumping_dynamic_archive()) {
1848     // Read stored LF format lines stored in static archive
1849     LambdaFormInvokers::read_static_archive_invokers();
1850   }
1851 
1852   if (PrintSharedArchiveAndExit) {
1853     // Print archive names
1854     if (dynamic_mapinfo != nullptr) {
1855       tty->print_cr("\n\nBase archive name: %s", CDSConfig::static_archive_path());
1856       tty->print_cr("Base archive version %d", static_mapinfo->version());
1857     } else {
1858       tty->print_cr("Static archive name: %s", static_mapinfo->full_path());
1859       tty->print_cr("Static archive version %d", static_mapinfo->version());
1860     }
1861 
1862     SystemDictionaryShared::print_shared_archive(tty);
1863     if (dynamic_mapinfo != nullptr) {
1864       tty->print_cr("\n\nDynamic archive name: %s", dynamic_mapinfo->full_path());
1865       tty->print_cr("Dynamic archive version %d", dynamic_mapinfo->version());
1866       SystemDictionaryShared::print_shared_archive(tty, false/*dynamic*/);
1867     }
1868     TrainingData::print_archived_training_data_on(tty);
1869 
1870     if (LoadCachedCode) {
1871       tty->print_cr("\n\nCached Code file: %s", CachedCodeFile);
1872       SCCache::print_on(tty);
1873     }
1874 
1875     // collect shared symbols and strings
1876     CountSharedSymbols cl;
1877     SymbolTable::shared_symbols_do(&cl);
1878     tty->print_cr("Number of shared symbols: %d", cl.total());
1879     tty->print_cr("Number of shared strings: %zu", StringTable::shared_entry_count());
1880     tty->print_cr("VM version: %s\r\n", static_mapinfo->vm_version());
1881     if (FileMapInfo::current_info() == nullptr || _archive_loading_failed) {
1882       tty->print_cr("archive is invalid");
1883       vm_exit(1);
1884     } else {
1885       tty->print_cr("archive is valid");
1886       vm_exit(0);
1887     }
1888   }
1889 }
1890 
1891 // JVM/TI RedefineClasses() support:
1892 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
1893   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1894 
1895   if (CDSConfig::is_using_archive()) {
1896     // remap the shared readonly space to shared readwrite, private
1897     FileMapInfo* mapinfo = FileMapInfo::current_info();
1898     if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1899       return false;
1900     }
1901     if (FileMapInfo::dynamic_info() != nullptr) {
1902       mapinfo = FileMapInfo::dynamic_info();
1903       if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1904         return false;
1905       }
1906     }
1907     _remapped_readwrite = true;
1908   }
1909   return true;
1910 }
1911 
1912 void MetaspaceShared::print_on(outputStream* st) {
1913   if (CDSConfig::is_using_archive()) {
1914     st->print("CDS archive(s) mapped at: ");
1915     address base = (address)MetaspaceObj::shared_metaspace_base();
1916     address static_top = (address)_shared_metaspace_static_top;
1917     address top = (address)MetaspaceObj::shared_metaspace_top();
1918     st->print("[" PTR_FORMAT "-" PTR_FORMAT "-" PTR_FORMAT "), ", p2i(base), p2i(static_top), p2i(top));
1919     st->print("size " SIZE_FORMAT ", ", top - base);
1920     st->print("SharedBaseAddress: " PTR_FORMAT ", ArchiveRelocationMode: %d.", SharedBaseAddress, ArchiveRelocationMode);
1921   } else {
1922     st->print("CDS archive(s) not mapped");
1923   }
1924   st->cr();
1925 }