1 /*
   2  * Copyright (c) 2012, 2026, 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 "cds/aotArtifactFinder.hpp"
  26 #include "cds/aotCacheAccess.hpp"
  27 #include "cds/aotClassInitializer.hpp"
  28 #include "cds/aotClassLinker.hpp"
  29 #include "cds/aotClassLocation.hpp"
  30 #include "cds/aotConstantPoolResolver.hpp"
  31 #include "cds/aotLinkedClassBulkLoader.hpp"
  32 #include "cds/aotLogging.hpp"
  33 #include "cds/aotMapLogger.hpp"
  34 #include "cds/aotMappedHeapLoader.hpp"
  35 #include "cds/aotMetaspace.hpp"
  36 #include "cds/aotReferenceObjSupport.hpp"
  37 #include "cds/archiveBuilder.hpp"
  38 #include "cds/cds_globals.hpp"
  39 #include "cds/cdsConfig.hpp"
  40 #include "cds/cdsProtectionDomain.hpp"
  41 #include "cds/classListParser.hpp"
  42 #include "cds/classListWriter.hpp"
  43 #include "cds/cppVtables.hpp"
  44 #include "cds/dumpAllocStats.hpp"
  45 #include "cds/dynamicArchive.hpp"
  46 #include "cds/filemap.hpp"
  47 #include "cds/finalImageRecipes.hpp"
  48 #include "cds/heapShared.inline.hpp"
  49 #include "cds/lambdaFormInvokers.hpp"
  50 #include "cds/lambdaProxyClassDictionary.hpp"
  51 #include "classfile/classLoaderDataGraph.hpp"
  52 #include "classfile/classLoaderDataShared.hpp"
  53 #include "classfile/javaClasses.inline.hpp"
  54 #include "classfile/loaderConstraints.hpp"
  55 #include "classfile/modules.hpp"
  56 #include "classfile/placeholders.hpp"
  57 #include "classfile/stringTable.hpp"
  58 #include "classfile/symbolTable.hpp"
  59 #include "classfile/systemDictionary.hpp"
  60 #include "classfile/systemDictionaryShared.hpp"
  61 #include "classfile/vmClasses.hpp"
  62 #include "classfile/vmSymbols.hpp"
  63 #include "code/aotCodeCache.hpp"
  64 #include "code/codeCache.hpp"
  65 #include "compiler/compileBroker.hpp"
  66 #include "compiler/precompiler.hpp"
  67 #include "gc/shared/gcVMOperations.hpp"
  68 #include "interpreter/bytecodes.hpp"
  69 #include "interpreter/bytecodeStream.hpp"
  70 #include "jvm_io.h"
  71 #include "logging/log.hpp"
  72 #include "logging/logMessage.hpp"
  73 #include "logging/logStream.hpp"
  74 #include "memory/memoryReserver.hpp"
  75 #include "memory/metaspace.hpp"
  76 #include "memory/metaspaceClosure.hpp"
  77 #include "memory/oopFactory.hpp"
  78 #include "memory/resourceArea.hpp"
  79 #include "memory/universe.hpp"
  80 #include "nmt/memTracker.hpp"
  81 #include "oops/compressedKlass.hpp"
  82 #include "oops/constantPool.inline.hpp"
  83 #include "oops/instanceMirrorKlass.hpp"
  84 #include "oops/klass.inline.hpp"
  85 #include "oops/method.inline.hpp"
  86 #include "oops/objArrayOop.hpp"
  87 #include "oops/oop.inline.hpp"
  88 #include "oops/oopHandle.hpp"
  89 #include "oops/resolvedFieldEntry.hpp"
  90 #include "oops/trainingData.hpp"
  91 #include "prims/jvmtiExport.hpp"
  92 #include "prims/whitebox.hpp"
  93 #include "runtime/arguments.hpp"
  94 #include "runtime/globals.hpp"
  95 #include "runtime/globals_extension.hpp"
  96 #include "runtime/handles.inline.hpp"
  97 #include "runtime/javaCalls.hpp"
  98 #include "runtime/os.inline.hpp"
  99 #include "runtime/safepointVerifiers.hpp"
 100 #include "runtime/sharedRuntime.hpp"
 101 #include "runtime/vmOperations.hpp"
 102 #include "runtime/vmThread.hpp"
 103 #include "sanitizers/leak.hpp"
 104 #include "services/management.hpp"
 105 #include "utilities/align.hpp"
 106 #include "utilities/bitMap.inline.hpp"
 107 #include "utilities/defaultStream.hpp"
 108 #include "utilities/hashTable.hpp"
 109 #include "utilities/macros.hpp"
 110 #include "utilities/ostream.hpp"
 111 
 112 #include <sys/stat.h>
 113 
 114 ReservedSpace AOTMetaspace::_symbol_rs;
 115 VirtualSpace AOTMetaspace::_symbol_vs;
 116 bool AOTMetaspace::_archive_loading_failed = false;
 117 bool AOTMetaspace::_remapped_readwrite = false;
 118 void* AOTMetaspace::_aot_metaspace_static_top = nullptr;
 119 intx AOTMetaspace::_relocation_delta;
 120 char* AOTMetaspace::_requested_base_address;
 121 Array<Method*>* AOTMetaspace::_archived_method_handle_intrinsics = nullptr;
 122 bool AOTMetaspace::_use_optimized_module_handling = true;
 123 int volatile AOTMetaspace::_preimage_static_archive_dumped = 0;
 124 FileMapInfo* AOTMetaspace::_output_mapinfo = nullptr;
 125 
 126 // The CDS archive is divided into the following regions:
 127 //     rw  - read-write metadata
 128 //     ro  - read-only metadata and read-only tables
 129 //     hp  - heap region
 130 //     bm  - bitmap for relocating the above 7 regions.
 131 //
 132 // The rw and ro regions are linearly allocated, in the order of rw->ro.
 133 // These regions are aligned with AOTMetaspace::core_region_alignment().
 134 //
 135 // These 2 regions are populated in the following steps:
 136 // [0] All classes are loaded in AOTMetaspace::load_classes(). All metadata are
 137 //     temporarily allocated outside of the shared regions.
 138 // [1] We enter a safepoint and allocate a buffer for the rw/ro regions.
 139 // [2] C++ vtables are copied into the rw region.
 140 // [3] ArchiveBuilder copies RW metadata into the rw region.
 141 // [4] ArchiveBuilder copies RO metadata into the ro region.
 142 // [5] SymbolTable, StringTable, SystemDictionary, and a few other read-only data
 143 //     are copied into the ro region as read-only tables.
 144 //
 145 // The heap region is written by HeapShared::write_heap().
 146 //
 147 // The bitmap region is used to relocate the ro/rw/hp regions.
 148 
 149 static DumpRegion _symbol_region("symbols");
 150 
 151 char* AOTMetaspace::symbol_space_alloc(size_t num_bytes) {
 152   return _symbol_region.allocate(num_bytes);
 153 }
 154 
 155 // os::vm_allocation_granularity() is usually 4K for most OSes. However, some platforms
 156 // such as linux-aarch64 and macos-x64 ...
 157 // it can be either 4K or 64K and on macos-aarch64 it is 16K. To generate archives that are
 158 // compatible for both settings, an alternative cds core region alignment can be enabled
 159 // at building time:
 160 //   --enable-compactible-cds-alignment
 161 // Upon successful configuration, the compactible alignment then can be defined in:
 162 //   os_linux_aarch64.cpp
 163 //   os_bsd_x86.cpp
 164 size_t AOTMetaspace::core_region_alignment() {
 165   return os::cds_core_region_alignment();
 166 }
 167 
 168 size_t AOTMetaspace::protection_zone_size() {
 169   return os::cds_core_region_alignment();
 170 }
 171 
 172 static bool shared_base_valid(char* shared_base) {
 173   // We check user input for SharedBaseAddress at dump time.
 174 
 175   // At CDS runtime, "shared_base" will be the (attempted) mapping start. It will also
 176   // be the encoding base, since the headers of archived base objects (and with Lilliput,
 177   // the prototype mark words) carry pre-computed narrow Klass IDs that refer to the mapping
 178   // start as base.
 179   //
 180   // On AARCH64, The "shared_base" may not be later usable as encoding base, depending on the
 181   // total size of the reserved area and the precomputed_narrow_klass_shift. This is checked
 182   // before reserving memory.  Here we weed out values already known to be invalid later.
 183   return AARCH64_ONLY(is_aligned(shared_base, 4 * G)) NOT_AARCH64(true);
 184 }
 185 
 186 class DumpClassListCLDClosure : public CLDClosure {
 187   static const int INITIAL_TABLE_SIZE = 1987;
 188   static const int MAX_TABLE_SIZE = 61333;
 189 
 190   fileStream *_stream;
 191   ResizeableHashTable<InstanceKlass*, bool,
 192                               AnyObj::C_HEAP, mtClassShared> _dumped_classes;
 193 
 194   void dump(InstanceKlass* ik) {
 195     bool created;
 196     _dumped_classes.put_if_absent(ik, &created);
 197     if (!created) {
 198       return;
 199     }
 200     if (_dumped_classes.maybe_grow()) {
 201       log_info(aot, hashtables)("Expanded _dumped_classes table to %d", _dumped_classes.table_size());
 202     }
 203     if (ik->super()) {
 204       dump(ik->super());
 205     }
 206     Array<InstanceKlass*>* interfaces = ik->local_interfaces();
 207     int len = interfaces->length();
 208     for (int i = 0; i < len; i++) {
 209       dump(interfaces->at(i));
 210     }
 211     ClassListWriter::write_to_stream(ik, _stream);
 212   }
 213 
 214 public:
 215   DumpClassListCLDClosure(fileStream* f)
 216   : CLDClosure(), _dumped_classes(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE) {
 217     _stream = f;
 218   }
 219 
 220   void do_cld(ClassLoaderData* cld) {
 221     for (Klass* klass = cld->klasses(); klass != nullptr; klass = klass->next_link()) {
 222       if (klass->is_instance_klass()) {
 223         dump(InstanceKlass::cast(klass));
 224       }
 225     }
 226   }
 227 };
 228 
 229 void AOTMetaspace::dump_loaded_classes(const char* file_name, TRAPS) {
 230   fileStream stream(file_name, "w");
 231   if (stream.is_open()) {
 232     MutexLocker lock(ClassLoaderDataGraph_lock);
 233     MutexLocker lock2(ClassListFile_lock, Mutex::_no_safepoint_check_flag);
 234     DumpClassListCLDClosure collect_classes(&stream);
 235     ClassLoaderDataGraph::loaded_cld_do(&collect_classes);
 236   } else {
 237     THROW_MSG(vmSymbols::java_io_IOException(), "Failed to open file");
 238   }
 239 }
 240 
 241 static bool shared_base_too_high(char* specified_base, char* aligned_base, size_t cds_max) {
 242   // Caller should have checked that aligned_base was successfully aligned and is not nullptr.
 243   // Comparing specified_base with nullptr is UB.
 244   assert(aligned_base != nullptr, "sanity");
 245   assert(aligned_base >= specified_base, "sanity");
 246 
 247   if (max_uintx - uintx(aligned_base) < uintx(cds_max)) {
 248     // Not enough address space to hold an archive of cds_max bytes from aligned_base.
 249     return true;
 250   } else {
 251     return false;
 252   }
 253 }
 254 
 255 static char* compute_shared_base(size_t cds_max) {
 256   char* specified_base = (char*)SharedBaseAddress;
 257   size_t alignment = AOTMetaspace::core_region_alignment();
 258   if (UseCompressedClassPointers && CompressedKlassPointers::needs_class_space()) {
 259     alignment = MAX2(alignment, Metaspace::reserve_alignment());
 260   }
 261 
 262   if (SharedBaseAddress == 0) {
 263     // Special meaning of -XX:SharedBaseAddress=0 -> Always map archive at os-selected address.
 264     return specified_base;
 265   }
 266 
 267   char* aligned_base = can_align_up(specified_base, alignment)
 268                            ? align_up(specified_base, alignment)
 269                            : nullptr;
 270 
 271   if (aligned_base != specified_base) {
 272     aot_log_info(aot)("SharedBaseAddress (" INTPTR_FORMAT ") aligned up to " INTPTR_FORMAT,
 273                    p2i(specified_base), p2i(aligned_base));
 274   }
 275 
 276   const char* err = nullptr;
 277   if (aligned_base == nullptr) {
 278     err = "too high";
 279   } else if (shared_base_too_high(specified_base, aligned_base, cds_max)) {
 280     err = "too high";
 281   } else if (!shared_base_valid(aligned_base)) {
 282     err = "invalid for this platform";
 283   } else {
 284     return aligned_base;
 285   }
 286 
 287   // Arguments::default_SharedBaseAddress() is hard-coded in cds_globals.hpp. It must be carefully
 288   // picked that (a) the align_up() below will always return a valid value; (b) none of
 289   // the following asserts will fail.
 290   aot_log_warning(aot)("SharedBaseAddress (" INTPTR_FORMAT ") is %s. Reverted to " INTPTR_FORMAT,
 291                    p2i((void*)SharedBaseAddress), err,
 292                    p2i((void*)Arguments::default_SharedBaseAddress()));
 293 
 294   specified_base = (char*)Arguments::default_SharedBaseAddress();
 295   aligned_base = align_up(specified_base, alignment);
 296 
 297   // Make sure the default value of SharedBaseAddress specified in globals.hpp is sane.
 298   assert(!shared_base_too_high(specified_base, aligned_base, cds_max), "Sanity");
 299   assert(shared_base_valid(aligned_base), "Sanity");
 300   return aligned_base;
 301 }
 302 
 303 void AOTMetaspace::initialize_for_static_dump() {
 304   assert(CDSConfig::is_dumping_static_archive(), "sanity");
 305   aot_log_info(aot)("Core region alignment: %zu", core_region_alignment());
 306   // The max allowed size for CDS archive. We use this to limit SharedBaseAddress
 307   // to avoid address space wrap around.
 308   size_t cds_max;
 309   const size_t reserve_alignment = core_region_alignment();
 310 
 311 #ifdef _LP64
 312   const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
 313   cds_max = align_down(UnscaledClassSpaceMax, reserve_alignment);
 314 #else
 315   // We don't support archives larger than 256MB on 32-bit due to limited
 316   //  virtual address space.
 317   cds_max = align_down(256*M, reserve_alignment);
 318 #endif
 319 
 320   _requested_base_address = compute_shared_base(cds_max);
 321   SharedBaseAddress = (size_t)_requested_base_address;
 322 
 323   size_t symbol_rs_size = LP64_ONLY(3 * G) NOT_LP64(128 * M);
 324   _symbol_rs = MemoryReserver::reserve(symbol_rs_size,
 325                                        os::vm_allocation_granularity(),
 326                                        os::vm_page_size(),
 327                                        mtClassShared);
 328   if (!_symbol_rs.is_reserved()) {
 329     aot_log_error(aot)("Unable to reserve memory for symbols: %zu bytes.", symbol_rs_size);
 330     AOTMetaspace::unrecoverable_writing_error();
 331   }
 332   _symbol_region.init(&_symbol_rs, &_symbol_vs);
 333   if (CDSConfig::is_dumping_preimage_static_archive()) {
 334     // We are in the AOT training run. User code is executed.
 335     //
 336     // On Windows, if the user code closes System.out and we open the AOT config file for output
 337     // only at VM exit, we might get back the same file HANDLE as stdout, and the AOT config
 338     // file may get corrupted by UL logs. By opening early, we ensure that the output
 339     // HANDLE is different than stdout so we can avoid such corruption.
 340     open_output_mapinfo();
 341   } else {
 342     // No need for the above as we won't execute any user code.
 343   }
 344 }
 345 
 346 void AOTMetaspace::open_output_mapinfo() {
 347   const char* static_archive = CDSConfig::output_archive_path();
 348   assert(static_archive != nullptr, "sanity");
 349   _output_mapinfo = new FileMapInfo(static_archive, true);
 350   _output_mapinfo->open_as_output();
 351 }
 352 
 353 // Called by universe_post_init()
 354 void AOTMetaspace::post_initialize(TRAPS) {
 355   if (CDSConfig::is_using_archive()) {
 356     FileMapInfo *static_mapinfo = FileMapInfo::current_info();
 357     FileMapInfo *dynamic_mapinfo = FileMapInfo::dynamic_info();
 358 
 359     if (AOTMapLogger::is_logging_at_bootstrap()) {
 360       // The map logging needs to be done here, as it requires some stubs on Windows,
 361       // which are not generated until the end of init_globals().
 362       AOTMapLogger::runtime_log(static_mapinfo, dynamic_mapinfo);
 363     }
 364 
 365     // Close any open file descriptors. However, mmap'ed pages will remain in memory.
 366     static_mapinfo->close();
 367 
 368     if (HeapShared::is_loading() && HeapShared::is_loading_mapping_mode()) {
 369       static_mapinfo->unmap_region(AOTMetaspace::bm);
 370     }
 371 
 372     if (dynamic_mapinfo != nullptr) {
 373       dynamic_mapinfo->close();
 374       dynamic_mapinfo->unmap_region(AOTMetaspace::bm);
 375     }
 376 
 377     int size = AOTClassLocationConfig::runtime()->length();
 378     if (size > 0) {
 379       CDSProtectionDomain::allocate_shared_data_arrays(size, CHECK);
 380     }
 381   }
 382 }
 383 
 384 // Extra java.lang.Strings to be added to the archive
 385 static GrowableArrayCHeap<OopHandle, mtClassShared>* _extra_interned_strings = nullptr;
 386 // Extra Symbols to be added to the archive
 387 static GrowableArrayCHeap<Symbol*, mtClassShared>* _extra_symbols = nullptr;
 388 // Methods managed by SystemDictionary::find_method_handle_intrinsic() to be added to the archive
 389 static GrowableArray<Method*>* _pending_method_handle_intrinsics = nullptr;
 390 
 391 void AOTMetaspace::read_extra_data(JavaThread* current, const char* filename) {
 392   _extra_interned_strings = new GrowableArrayCHeap<OopHandle, mtClassShared>(10000);
 393   _extra_symbols = new GrowableArrayCHeap<Symbol*, mtClassShared>(1000);
 394 
 395   HashtableTextDump reader(filename);
 396   reader.check_version("VERSION: 1.0");
 397 
 398   while (reader.remain() > 0) {
 399     int utf8_length;
 400     int prefix_type = reader.scan_prefix(&utf8_length);
 401     ResourceMark rm(current);
 402     if (utf8_length == 0x7fffffff) {
 403       // buf_len will overflown 32-bit value.
 404       aot_log_error(aot)("string length too large: %d", utf8_length);
 405       AOTMetaspace::unrecoverable_loading_error();
 406     }
 407     int buf_len = utf8_length+1;
 408     char* utf8_buffer = NEW_RESOURCE_ARRAY(char, buf_len);
 409     reader.get_utf8(utf8_buffer, utf8_length);
 410     utf8_buffer[utf8_length] = '\0';
 411 
 412     if (prefix_type == HashtableTextDump::SymbolPrefix) {
 413       _extra_symbols->append(SymbolTable::new_permanent_symbol(utf8_buffer));
 414     } else{
 415       assert(prefix_type == HashtableTextDump::StringPrefix, "Sanity");
 416       ExceptionMark em(current);
 417       JavaThread* THREAD = current; // For exception macros.
 418       oop str = StringTable::intern(utf8_buffer, THREAD);
 419 
 420       if (HAS_PENDING_EXCEPTION) {
 421         log_warning(aot, heap)("[line %d] extra interned string allocation failed; size too large: %d",
 422                                reader.last_line_no(), utf8_length);
 423         CLEAR_PENDING_EXCEPTION;
 424       } else {
 425 #if INCLUDE_CDS_JAVA_HEAP
 426         if (HeapShared::is_string_too_large_to_archive(str)) {
 427           log_warning(aot, heap)("[line %d] extra interned string ignored; size too large: %d",
 428                                  reader.last_line_no(), utf8_length);
 429           continue;
 430         }
 431         // Make sure this string is included in the dumped interned string table.
 432         assert(str != nullptr, "must succeed");
 433         _extra_interned_strings->append(OopHandle(Universe::vm_global(), str));
 434 #endif
 435       }
 436     }
 437   }
 438 }
 439 
 440 void AOTMetaspace::make_method_handle_intrinsics_shareable() {
 441   for (int i = 0; i < _pending_method_handle_intrinsics->length(); i++) {
 442     Method* m = ArchiveBuilder::current()->get_buffered_addr(_pending_method_handle_intrinsics->at(i));
 443     m->remove_unshareable_info();
 444     // Each method has its own constant pool (which is distinct from m->method_holder()->constants());
 445     m->constants()->remove_unshareable_info();
 446   }
 447 }
 448 
 449 void AOTMetaspace::write_method_handle_intrinsics() {
 450   int len = _pending_method_handle_intrinsics->length();
 451   _archived_method_handle_intrinsics = ArchiveBuilder::new_ro_array<Method*>(len);
 452   int word_size = _archived_method_handle_intrinsics->size();
 453   for (int i = 0; i < len; i++) {
 454     Method* m = _pending_method_handle_intrinsics->at(i);
 455     ArchiveBuilder::current()->write_pointer_in_buffer(_archived_method_handle_intrinsics->adr_at(i), m);
 456     word_size += m->size() + m->constMethod()->size() + m->constants()->size();
 457     if (m->constants()->cache() != nullptr) {
 458       word_size += m->constants()->cache()->size();
 459     }
 460   }
 461   log_info(aot)("Archived %d method handle intrinsics (%d bytes)", len, word_size * BytesPerWord);
 462 }
 463 
 464 // About "serialize" --
 465 //
 466 // This is (probably a badly named) way to read/write a data stream of pointers and
 467 // miscellaneous data from/to the shared archive file. The usual code looks like this:
 468 //
 469 //     // These two global C++ variables are initialized during dump time.
 470 //     static int _archived_int;
 471 //     static MetaspaceObj* archived_ptr;
 472 //
 473 //     void MyClass::serialize(SerializeClosure* soc) {
 474 //         soc->do_int(&_archived_int);
 475 //         soc->do_int(&_archived_ptr);
 476 //     }
 477 //
 478 //     At dumptime, these two variables are stored into the CDS archive.
 479 //     At runtime, these two variables are loaded from the CDS archive.
 480 //     In addition, the pointer is relocated as necessary.
 481 //
 482 // Some of the xxx::serialize() functions may have side effects and assume that
 483 // the archive is already mapped. For example, SymbolTable::serialize_shared_table_header()
 484 // unconditionally makes the set of archived symbols available. Therefore, we put most
 485 // of these xxx::serialize() functions inside AOTMetaspace::serialize(), which
 486 // is called AFTER we made the decision to map the archive.
 487 //
 488 // However, some of the "serialized" data are used to decide whether an archive should
 489 // be mapped or not (e.g., for checking if the -Djdk.module.main property is compatible
 490 // with the archive). The xxx::serialize() functions for these data must be put inside
 491 // AOTMetaspace::early_serialize(). Such functions must not produce side effects that
 492 // assume we will always decides to map the archive.
 493 
 494 void AOTMetaspace::early_serialize(SerializeClosure* soc) {
 495   int tag = 0;
 496   soc->do_tag(--tag);
 497   CDS_JAVA_HEAP_ONLY(Modules::serialize_archived_module_info(soc);)
 498   soc->do_tag(666);
 499 }
 500 
 501 void AOTMetaspace::serialize(SerializeClosure* soc) {
 502   int tag = 0;
 503   soc->do_tag(--tag);
 504 
 505   // Verify the sizes of various metadata in the system.
 506   soc->do_tag(sizeof(Method));
 507   soc->do_tag(sizeof(ConstMethod));
 508   soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
 509   soc->do_tag(sizeof(ConstantPool));
 510   soc->do_tag(sizeof(ConstantPoolCache));
 511   soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
 512   soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
 513   soc->do_tag(sizeof(Symbol));
 514 
 515   // Need to do this first, as subsequent steps may call virtual functions
 516   // in archived Metadata objects.
 517   CppVtables::serialize(soc);
 518   soc->do_tag(--tag);
 519 
 520   // Dump/restore miscellaneous metadata.
 521   JavaClasses::serialize_offsets(soc);
 522   Universe::serialize(soc);
 523   soc->do_tag(--tag);
 524 
 525   // Dump/restore references to commonly used names and signatures.
 526   vmSymbols::serialize(soc);
 527   soc->do_tag(--tag);
 528 
 529   // Dump/restore the symbol/string/subgraph_info tables
 530   SymbolTable::serialize_shared_table_header(soc);
 531   StringTable::serialize_shared_table_header(soc);
 532   HeapShared::serialize_tables(soc);
 533   SystemDictionaryShared::serialize_dictionary_headers(soc);
 534   AOTLinkedClassBulkLoader::serialize(soc);
 535   FinalImageRecipes::serialize(soc);
 536   TrainingData::serialize(soc);
 537   InstanceMirrorKlass::serialize_offsets(soc);
 538 
 539   // Dump/restore well known classes (pointers)
 540   SystemDictionaryShared::serialize_vm_classes(soc);
 541   soc->do_tag(--tag);
 542 
 543   CDS_JAVA_HEAP_ONLY(ClassLoaderDataShared::serialize(soc);)
 544   soc->do_ptr((void**)&_archived_method_handle_intrinsics);
 545 
 546   LambdaFormInvokers::serialize(soc);
 547   AdapterHandlerLibrary::serialize_shared_table_header(soc);
 548 
 549   soc->do_tag(666);
 550 }
 551 
 552 // In AOTCache workflow, when dumping preimage, the constant pool entries are stored in unresolved state.
 553 // So the fast version of getfield/putfield needs to be converted to nofast version.
 554 // When dumping the final image in the assembly phase, these nofast versions are converted back to fast versions
 555 // if the constant pool entry refered by these bytecodes is stored in resolved state.
 556 // Same principle applies to static and dynamic archives. If the constant pool entry is in resolved state, then
 557 // the fast version of the bytecodes can be preserved, else use the nofast version.
 558 //
 559 // The fast versions of aload_0 (i.e. _fast_Xaccess_0) merges the bytecode pair (aload_0, fast_Xgetfield).
 560 // If the fast version of aload_0 is preserved in AOTCache, then the JVMTI notifications for field access and
 561 // breakpoint events will be skipped for the second bytecode (fast_Xgetfield) in the pair.
 562 // Same holds for fast versions of iload_0. So for these bytecodes, nofast version is used.
 563 static void rewrite_bytecodes(const methodHandle& method) {
 564   ConstantPool* cp = method->constants();
 565   BytecodeStream bcs(method);
 566   Bytecodes::Code new_code;
 567 
 568   LogStreamHandle(Trace, aot, resolve) lsh;
 569   if (lsh.is_enabled()) {
 570     lsh.print("Rewriting bytecodes for ");
 571     method()->print_external_name(&lsh);
 572     lsh.print("\n");
 573   }
 574 
 575   while (!bcs.is_last_bytecode()) {
 576     Bytecodes::Code opcode = bcs.next();
 577     // Use current opcode as the default value of new_code
 578     new_code = opcode;
 579     switch(opcode) {
 580     case Bytecodes::_getfield: {
 581       uint rfe_index = bcs.get_index_u2();
 582       bool is_resolved = cp->is_resolved(rfe_index, opcode);
 583       if (is_resolved) {
 584         assert(!CDSConfig::is_dumping_preimage_static_archive(), "preimage should not have resolved field references");
 585         ResolvedFieldEntry* rfe = cp->resolved_field_entry_at(bcs.get_index_u2());
 586         switch(rfe->tos_state()) {
 587         case btos:
 588           // fallthrough
 589         case ztos: new_code = Bytecodes::_fast_bgetfield; break;
 590         case atos: new_code = Bytecodes::_fast_agetfield; break;
 591         case itos: new_code = Bytecodes::_fast_igetfield; break;
 592         case ctos: new_code = Bytecodes::_fast_cgetfield; break;
 593         case stos: new_code = Bytecodes::_fast_sgetfield; break;
 594         case ltos: new_code = Bytecodes::_fast_lgetfield; break;
 595         case ftos: new_code = Bytecodes::_fast_fgetfield; break;
 596         case dtos: new_code = Bytecodes::_fast_dgetfield; break;
 597         default:
 598           ShouldNotReachHere();
 599           break;
 600         }
 601       } else {
 602         new_code = Bytecodes::_nofast_getfield;
 603       }
 604       break;
 605     }
 606     case Bytecodes::_putfield: {
 607       uint rfe_index = bcs.get_index_u2();
 608       bool is_resolved = cp->is_resolved(rfe_index, opcode);
 609       if (is_resolved) {
 610         assert(!CDSConfig::is_dumping_preimage_static_archive(), "preimage should not have resolved field references");
 611         ResolvedFieldEntry* rfe = cp->resolved_field_entry_at(bcs.get_index_u2());
 612         switch(rfe->tos_state()) {
 613         case btos: new_code = Bytecodes::_fast_bputfield; break;
 614         case ztos: new_code = Bytecodes::_fast_zputfield; break;
 615         case atos: new_code = Bytecodes::_fast_aputfield; break;
 616         case itos: new_code = Bytecodes::_fast_iputfield; break;
 617         case ctos: new_code = Bytecodes::_fast_cputfield; break;
 618         case stos: new_code = Bytecodes::_fast_sputfield; break;
 619         case ltos: new_code = Bytecodes::_fast_lputfield; break;
 620         case ftos: new_code = Bytecodes::_fast_fputfield; break;
 621         case dtos: new_code = Bytecodes::_fast_dputfield; break;
 622         default:
 623           ShouldNotReachHere();
 624           break;
 625         }
 626       } else {
 627         new_code = Bytecodes::_nofast_putfield;
 628       }
 629       break;
 630     }
 631     case Bytecodes::_aload_0:
 632       // Revert _fast_Xaccess_0 or _aload_0 to _nofast_aload_0
 633       new_code = Bytecodes::_nofast_aload_0;
 634       break;
 635     case Bytecodes::_iload:
 636       if (!bcs.is_wide()) {
 637         new_code = Bytecodes::_nofast_iload;
 638       }
 639       break;
 640     default:
 641       break;
 642     }
 643     if (opcode != new_code) {
 644       *bcs.bcp() = new_code;
 645       if (lsh.is_enabled()) {
 646         lsh.print_cr("%d:%s -> %s", bcs.bci(), Bytecodes::name(opcode), Bytecodes::name(new_code));
 647       }
 648     }
 649   }
 650 }
 651 
 652 // [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified
 653 //     at run time by RewriteBytecodes/RewriteFrequentPairs
 654 // [2] Assign a fingerprint, so one doesn't need to be assigned at run-time.
 655 void AOTMetaspace::rewrite_bytecodes_and_calculate_fingerprints(Thread* thread, InstanceKlass* ik) {
 656   for (int i = 0; i < ik->methods()->length(); i++) {
 657     methodHandle m(thread, ik->methods()->at(i));
 658     if (ik->can_be_verified_at_dumptime() && ik->is_linked()) {
 659       rewrite_bytecodes(m);
 660     }
 661     Fingerprinter fp(m);
 662     // The side effect of this call sets method's fingerprint field.
 663     fp.fingerprint();
 664   }
 665 }
 666 
 667 class VM_PopulateDumpSharedSpace : public VM_Operation {
 668 private:
 669   ArchiveMappedHeapInfo _mapped_heap_info;
 670   ArchiveStreamedHeapInfo _streamed_heap_info;
 671   FileMapInfo* _map_info;
 672   StaticArchiveBuilder& _builder;
 673 
 674   void dump_java_heap_objects();
 675   void dump_shared_symbol_table(GrowableArray<Symbol*>* symbols) {
 676     log_info(aot)("Dumping symbol table ...");
 677     SymbolTable::write_to_archive(symbols);
 678   }
 679   char* dump_early_read_only_tables();
 680   char* dump_read_only_tables(AOTClassLocationConfig*& cl_config);
 681 
 682 public:
 683 
 684   VM_PopulateDumpSharedSpace(StaticArchiveBuilder& b, FileMapInfo* map_info) :
 685     VM_Operation(), _mapped_heap_info(), _streamed_heap_info(), _map_info(map_info), _builder(b) {}
 686 
 687   bool skip_operation() const { return false; }
 688 
 689   VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
 690   ArchiveMappedHeapInfo* mapped_heap_info()  { return &_mapped_heap_info; }
 691   ArchiveStreamedHeapInfo* streamed_heap_info()  { return &_streamed_heap_info; }
 692   void doit();   // outline because gdb sucks
 693   bool allow_nested_vm_operations() const { return true; }
 694 }; // class VM_PopulateDumpSharedSpace
 695 
 696 class StaticArchiveBuilder : public ArchiveBuilder {
 697 public:
 698   StaticArchiveBuilder() : ArchiveBuilder() {}
 699 
 700   virtual void iterate_roots(MetaspaceClosure* it) {
 701     AOTArtifactFinder::all_cached_classes_do(it);
 702     SystemDictionaryShared::dumptime_classes_do(it);
 703     Universe::metaspace_pointers_do(it);
 704     vmSymbols::metaspace_pointers_do(it);
 705     TrainingData::iterate_roots(it);
 706     if (CDSConfig::is_dumping_full_module_graph()) {
 707       ClassLoaderDataShared::iterate_roots(it);
 708     }
 709 
 710     // The above code should find all the symbols that are referenced by the
 711     // archived classes. We just need to add the extra symbols which
 712     // may not be used by any of the archived classes -- these are usually
 713     // symbols that we anticipate to be used at run time, so we can store
 714     // them in the RO region, to be shared across multiple processes.
 715     if (_extra_symbols != nullptr) {
 716       for (int i = 0; i < _extra_symbols->length(); i++) {
 717         it->push(_extra_symbols->adr_at(i));
 718       }
 719     }
 720 
 721     for (int i = 0; i < _pending_method_handle_intrinsics->length(); i++) {
 722       it->push(_pending_method_handle_intrinsics->adr_at(i));
 723     }
 724   }
 725 };
 726 
 727 char* VM_PopulateDumpSharedSpace::dump_early_read_only_tables() {
 728   ArchiveBuilder::OtherROAllocMark mark;
 729 
 730   CDS_JAVA_HEAP_ONLY(Modules::dump_archived_module_info());
 731 
 732   DumpRegion* ro_region = ArchiveBuilder::current()->ro_region();
 733   char* start = ro_region->top();
 734   WriteClosure wc(ro_region);
 735   AOTMetaspace::early_serialize(&wc);
 736   return start;
 737 }
 738 
 739 char* VM_PopulateDumpSharedSpace::dump_read_only_tables(AOTClassLocationConfig*& cl_config) {
 740   ArchiveBuilder::OtherROAllocMark mark;
 741 
 742   SystemDictionaryShared::write_to_archive();
 743   cl_config = AOTClassLocationConfig::dumptime()->write_to_archive();
 744   AOTClassLinker::write_to_archive();
 745   if (CDSConfig::is_dumping_preimage_static_archive()) {
 746     FinalImageRecipes::record_recipes();
 747   }
 748 
 749   TrainingData::dump_training_data();
 750 
 751   AOTMetaspace::write_method_handle_intrinsics();
 752 
 753   // Write lambform lines into archive
 754   LambdaFormInvokers::dump_static_archive_invokers();
 755 
 756   if (CDSConfig::is_dumping_adapters()) {
 757     AdapterHandlerLibrary::dump_aot_adapter_table();
 758   }
 759 
 760   // Write the other data to the output array.
 761   DumpRegion* ro_region = ArchiveBuilder::current()->ro_region();
 762   char* start = ro_region->top();
 763   WriteClosure wc(ro_region);
 764   AOTMetaspace::serialize(&wc);
 765 
 766   return start;
 767 }
 768 
 769 void VM_PopulateDumpSharedSpace::doit() {
 770   CDSConfig::set_is_at_aot_safepoint(true);
 771 
 772   if (!CDSConfig::is_dumping_final_static_archive()) {
 773     guarantee(!CDSConfig::is_using_archive(), "We should not be using an archive when we dump");
 774   }
 775 
 776   DEBUG_ONLY(SystemDictionaryShared::NoClassLoadingMark nclm);
 777 
 778   _pending_method_handle_intrinsics = new (mtClassShared) GrowableArray<Method*>(256, mtClassShared);
 779   if (CDSConfig::is_dumping_method_handles()) {
 780     // When dumping AOT-linked classes, some classes may have direct references to a method handle
 781     // intrinsic. The easiest thing is to save all of them into the AOT cache.
 782     SystemDictionary::get_all_method_handle_intrinsics(_pending_method_handle_intrinsics);
 783   }
 784 
 785   AOTClassLocationConfig::dumptime_check_nonempty_dirs();
 786 
 787   NOT_PRODUCT(SystemDictionary::verify();)
 788 
 789   // Block concurrent class unloading from changing the _dumptime_table
 790   MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
 791 
 792   _builder.gather_source_objs();
 793   _builder.reserve_buffer();
 794 
 795   CppVtables::dumptime_init(&_builder);
 796 
 797   _builder.sort_metadata_objs();
 798   _builder.dump_rw_metadata();
 799   _builder.dump_ro_metadata();
 800   _builder.relocate_metaspaceobj_embedded_pointers();
 801 
 802   log_info(aot)("Make classes shareable");
 803   _builder.make_klasses_shareable();
 804   AOTMetaspace::make_method_handle_intrinsics_shareable();
 805 
 806   if (CDSConfig::is_dumping_full_module_graph()) {
 807     ClassLoaderDataShared::remove_unshareable_info();
 808   }
 809 
 810   dump_java_heap_objects();
 811   dump_shared_symbol_table(_builder.symbols());
 812 
 813   char* early_serialized_data = dump_early_read_only_tables();
 814   AOTClassLocationConfig* cl_config;
 815   char* serialized_data = dump_read_only_tables(cl_config);
 816 
 817   if (CDSConfig::is_dumping_lambdas_in_legacy_mode()) {
 818     log_info(aot)("Adjust lambda proxy class dictionary");
 819     LambdaProxyClassDictionary::adjust_dumptime_table();
 820   }
 821 
 822   log_info(cds)("Make training data shareable");
 823   _builder.make_training_data_shareable();
 824 
 825   // The vtable clones contain addresses of the current process.
 826   // We don't want to write these addresses into the archive.
 827   CppVtables::zero_archived_vtables();
 828 
 829   // Write the archive file
 830   _map_info->populate_header(AOTMetaspace::core_region_alignment());
 831   _map_info->set_early_serialized_data(early_serialized_data);
 832   _map_info->set_serialized_data(serialized_data);
 833   _map_info->set_cloned_vtables(CppVtables::vtables_serialized_base());
 834   _map_info->header()->set_class_location_config(cl_config);
 835 
 836   HeapShared::delete_tables_with_raw_oops();
 837   CDSConfig::set_is_at_aot_safepoint(false);
 838 }
 839 
 840 class CollectClassesForLinking : public KlassClosure {
 841   GrowableArray<OopHandle> _mirrors;
 842 
 843 public:
 844    CollectClassesForLinking() : _mirrors() {
 845      // ClassLoaderDataGraph::loaded_classes_do_keepalive() requires ClassLoaderDataGraph_lock.
 846      // We cannot link the classes while holding this lock (or else we may run into deadlock).
 847      // Therefore, we need to first collect all the classes, keeping them alive by
 848      // holding onto their java_mirrors in global OopHandles. We then link the classes after
 849      // releasing the lock.
 850      MutexLocker lock(ClassLoaderDataGraph_lock);
 851      ClassLoaderDataGraph::loaded_classes_do_keepalive(this);
 852    }
 853 
 854   ~CollectClassesForLinking() {
 855     for (int i = 0; i < _mirrors.length(); i++) {
 856       _mirrors.at(i).release(Universe::vm_global());
 857     }
 858   }
 859 
 860   void do_cld(ClassLoaderData* cld) {
 861     assert(cld->is_alive(), "must be");
 862   }
 863 
 864   void do_klass(Klass* k) {
 865     if (k->is_instance_klass()) {
 866       _mirrors.append(OopHandle(Universe::vm_global(), k->java_mirror()));
 867     }
 868   }
 869 
 870   const GrowableArray<OopHandle>* mirrors() const { return &_mirrors; }
 871 };
 872 
 873 // Check if we can eagerly link this class at dump time, so we can avoid the
 874 // runtime linking overhead (especially verification)
 875 bool AOTMetaspace::may_be_eagerly_linked(InstanceKlass* ik) {
 876   if (!ik->can_be_verified_at_dumptime()) {
 877     // For old classes, try to leave them in the unlinked state, so
 878     // we can still store them in the archive. They must be
 879     // linked/verified at runtime.
 880     return false;
 881   }
 882   if (CDSConfig::is_dumping_dynamic_archive() && ik->defined_by_other_loaders()) {
 883     // Linking of unregistered classes at this stage may cause more
 884     // classes to be resolved, resulting in calls to ClassLoader.loadClass()
 885     // that may not be expected by custom class loaders.
 886     //
 887     // It's OK to do this for the built-in loaders as we know they can
 888     // tolerate this.
 889     return false;
 890   }
 891   return true;
 892 }
 893 
 894 void AOTMetaspace::link_all_loaded_classes(JavaThread* current) {
 895   while (true) {
 896     ResourceMark rm(current);
 897     CollectClassesForLinking collect_classes;
 898     bool has_linked = false;
 899     const GrowableArray<OopHandle>* mirrors = collect_classes.mirrors();
 900     for (int i = 0; i < mirrors->length(); i++) {
 901       OopHandle mirror = mirrors->at(i);
 902       InstanceKlass* ik = java_lang_Class::as_InstanceKlass(mirror.resolve());
 903       if (may_be_eagerly_linked(ik)) {
 904         has_linked |= try_link_class(current, ik);
 905       }
 906       if (CDSConfig::is_dumping_heap() && ik->is_linked() && !ik->is_initialized()) {
 907         AOTClassInitializer::maybe_preinit_class(ik, current);
 908       }
 909     }
 910 
 911     if (!has_linked) {
 912       break;
 913     }
 914     // Class linking includes verification which may load more classes.
 915     // Keep scanning until we have linked no more classes.
 916   }
 917 }
 918 
 919 void AOTMetaspace::link_shared_classes(TRAPS) {
 920   AOTClassLinker::initialize();
 921   AOTClassInitializer::init_test_class(CHECK);
 922 
 923   if (CDSConfig::is_dumping_final_static_archive()) {
 924     // - Load and link all classes used in the training run.
 925     // - Initialize @AOTSafeClassInitializer classes that were
 926     //   initialized in the training run.
 927     // - Perform per-class optimization such as AOT-resolution of
 928     //   constant pool entries that were resolved during the training run.
 929     FinalImageRecipes::apply_recipes(CHECK);
 930 
 931     // Because the AOT assembly phase does not run the same exact code as in the
 932     // training run (e.g., we use different lambda form invoker classes;
 933     // generated lambda form classes are not recorded in FinalImageRecipes),
 934     // the recipes do not cover all classes that have been loaded so far. As
 935     // a result, we might have some unlinked classes at this point. Since we
 936     // require cached classes to be linked, all such classes will be linked
 937     // by the following step.
 938   }
 939 
 940   link_all_loaded_classes(THREAD);
 941 
 942   // Eargerly resolve all string constants in constant pools
 943   {
 944     ResourceMark rm(THREAD);
 945     CollectClassesForLinking collect_classes;
 946     const GrowableArray<OopHandle>* mirrors = collect_classes.mirrors();
 947     for (int i = 0; i < mirrors->length(); i++) {
 948       OopHandle mirror = mirrors->at(i);
 949       InstanceKlass* ik = java_lang_Class::as_InstanceKlass(mirror.resolve());
 950       AOTConstantPoolResolver::preresolve_string_cp_entries(ik, CHECK);
 951       if (CDSConfig::is_dumping_preimage_static_archive()) {
 952         FinalImageRecipes::add_reflection_data_flags(ik, CHECK);
 953       }
 954     }
 955   }
 956 }
 957 
 958 void AOTMetaspace::dump_static_archive(TRAPS) {
 959   CDSConfig::DumperThreadMark dumper_thread_mark(THREAD);
 960   ResourceMark rm(THREAD);
 961   HandleMark hm(THREAD);
 962 
 963   if (CDSConfig::is_dumping_final_static_archive() && AOTPrintTrainingInfo) {
 964     tty->print_cr("==================== archived_training_data ** before dumping ====================");
 965     TrainingData::print_archived_training_data_on(tty);
 966   }
 967 
 968   StaticArchiveBuilder builder;
 969   dump_static_archive_impl(builder, THREAD);
 970   if (HAS_PENDING_EXCEPTION) {
 971     if (PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())) {
 972       aot_log_error(aot)("Out of memory. Please run with a larger Java heap, current MaxHeapSize = "
 973                      "%zuM", MaxHeapSize/M);
 974       AOTMetaspace::writing_error();
 975     } else {
 976       oop message = java_lang_Throwable::message(PENDING_EXCEPTION);
 977       aot_log_error(aot)("%s: %s", PENDING_EXCEPTION->klass()->external_name(),
 978                          message == nullptr ? "(null)" : java_lang_String::as_utf8_string(message));
 979       AOTMetaspace::writing_error(err_msg("Unexpected exception, use -Xlog:aot%s,exceptions=trace for detail",
 980                                              CDSConfig::new_aot_flags_used() ? "" : ",cds"));
 981     }
 982   }
 983 
 984   if (CDSConfig::new_aot_flags_used()) {
 985     if (CDSConfig::is_dumping_preimage_static_archive()) {
 986       // We are in the JVM that runs the training run. Continue execution,
 987       // so that it can finish all clean-up and return the correct exit
 988       // code to the OS.
 989     } else {
 990       // The JLI launcher only recognizes the "old" -Xshare:dump flag.
 991       // When the new -XX:AOTMode=create flag is used, we can't return
 992       // to the JLI launcher, as the launcher will fail when trying to
 993       // run the main class, which is not what we want.
 994       struct stat st;
 995       if (os::stat(AOTCache, &st) != 0) {
 996         tty->print_cr("AOTCache creation failed: %s", AOTCache);
 997       } else {
 998         tty->print_cr("AOTCache creation is complete: %s " INT64_FORMAT " bytes", AOTCache, (int64_t)(st.st_size));
 999       }
1000       vm_direct_exit(0);
1001     }
1002   }
1003 }
1004 
1005 #if INCLUDE_CDS_JAVA_HEAP && defined(_LP64)
1006 void AOTMetaspace::adjust_heap_sizes_for_dumping() {
1007   if (!CDSConfig::is_dumping_heap() || UseCompressedOops) {
1008     return;
1009   }
1010   // CDS heap dumping requires all string oops to have an offset
1011   // from the heap bottom that can be encoded in 32-bit.
1012   julong max_heap_size = (julong)(4 * G);
1013 
1014   if (MinHeapSize > max_heap_size) {
1015     log_debug(aot)("Setting MinHeapSize to 4G for CDS dumping, original size = %zuM", MinHeapSize/M);
1016     FLAG_SET_ERGO(MinHeapSize, max_heap_size);
1017   }
1018   if (InitialHeapSize > max_heap_size) {
1019     log_debug(aot)("Setting InitialHeapSize to 4G for CDS dumping, original size = %zuM", InitialHeapSize/M);
1020     FLAG_SET_ERGO(InitialHeapSize, max_heap_size);
1021   }
1022   if (MaxHeapSize > max_heap_size) {
1023     log_debug(aot)("Setting MaxHeapSize to 4G for CDS dumping, original size = %zuM", MaxHeapSize/M);
1024     FLAG_SET_ERGO(MaxHeapSize, max_heap_size);
1025   }
1026 }
1027 #endif // INCLUDE_CDS_JAVA_HEAP && _LP64
1028 
1029 void AOTMetaspace::get_default_classlist(char* default_classlist, const size_t buf_size) {
1030   const char* filesep = os::file_separator();
1031   jio_snprintf(default_classlist, buf_size, "%s%slib%sclasslist",
1032                Arguments::get_java_home(), filesep, filesep);
1033 }
1034 
1035 void AOTMetaspace::load_classes(TRAPS) {
1036   char default_classlist[JVM_MAXPATHLEN];
1037   const char* classlist_path;
1038 
1039   get_default_classlist(default_classlist, JVM_MAXPATHLEN);
1040   if (SharedClassListFile == nullptr) {
1041     classlist_path = default_classlist;
1042   } else {
1043     classlist_path = SharedClassListFile;
1044   }
1045 
1046   aot_log_info(aot)("Loading classes to share ...");
1047   ClassListParser::parse_classlist(classlist_path,
1048                                    ClassListParser::_parse_all, CHECK);
1049   if (ExtraSharedClassListFile) {
1050     ClassListParser::parse_classlist(ExtraSharedClassListFile,
1051                                      ClassListParser::_parse_all, CHECK);
1052   }
1053   if (classlist_path != default_classlist) {
1054     struct stat statbuf;
1055     if (os::stat(default_classlist, &statbuf) == 0) {
1056       // File exists, let's use it.
1057       ClassListParser::parse_classlist(default_classlist,
1058                                        ClassListParser::_parse_lambda_forms_invokers_only, CHECK);
1059     }
1060   }
1061 
1062   // Some classes are used at CDS runtime but are not yet loaded at this point.
1063   // We can perform dummmy calls to these classes at dumptime to ensure they
1064   // are archived.
1065   exercise_runtime_cds_code(CHECK);
1066 
1067   aot_log_info(aot)("Loading classes to share: done.");
1068 }
1069 
1070 void AOTMetaspace::exercise_runtime_cds_code(TRAPS) {
1071   // Exercise the manifest processing code
1072   const char* dummy = "Manifest-Version: 1.0\n";
1073   CDSProtectionDomain::create_jar_manifest(dummy, strlen(dummy), CHECK);
1074 
1075   // Exercise FileSystem and URL code
1076   CDSProtectionDomain::to_file_URL("dummy.jar", Handle(), CHECK);
1077 }
1078 
1079 bool AOTMetaspace::preimage_static_archive_dumped() {
1080   assert(CDSConfig::is_dumping_preimage_static_archive(), "Required");
1081   return AtomicAccess::load_acquire(&_preimage_static_archive_dumped) == 1;
1082 }
1083 
1084 void AOTMetaspace::dump_static_archive_impl(StaticArchiveBuilder& builder, TRAPS) {
1085   if (CDSConfig::is_dumping_preimage_static_archive()) {
1086     // When dumping to the AOT configuration file ensure this function is only executed once.
1087     // Multiple invocations may happen via JCmd, during VM exit or other means (in the future)
1088     // from different threads and possibly concurrently.
1089     if (AtomicAccess::cmpxchg(&_preimage_static_archive_dumped, 0, 1) != 0) {
1090       return;
1091     }
1092   }
1093 
1094   if (CDSConfig::is_dumping_classic_static_archive()) {
1095     // We are running with -Xshare:dump
1096     load_classes(CHECK);
1097 
1098     if (SharedArchiveConfigFile) {
1099       log_info(aot)("Reading extra data from %s ...", SharedArchiveConfigFile);
1100       read_extra_data(THREAD, SharedArchiveConfigFile);
1101       log_info(aot)("Reading extra data: done.");
1102     }
1103   }
1104 
1105   if (CDSConfig::is_dumping_preimage_static_archive()) {
1106     log_info(aot)("Reading lambda form invokers from JDK default classlist ...");
1107     char default_classlist[JVM_MAXPATHLEN];
1108     get_default_classlist(default_classlist, JVM_MAXPATHLEN);
1109     struct stat statbuf;
1110     if (os::stat(default_classlist, &statbuf) == 0) {
1111       ClassListParser::parse_classlist(default_classlist,
1112                                        ClassListParser::_parse_lambda_forms_invokers_only, CHECK);
1113     }
1114   }
1115 
1116 #if INCLUDE_CDS_JAVA_HEAP
1117   if (CDSConfig::is_dumping_heap()) {
1118     if (!CDSConfig::is_dumping_preimage_static_archive()) {
1119       // A single thread is required for Reference handling and deterministic CDS archive.
1120       // Its's not required for dumping preimage, where References won't be archived and
1121       // determinism is not needed.
1122       assert(CDSConfig::allow_only_single_java_thread(), "Required");
1123     }
1124     if (!HeapShared::is_archived_boot_layer_available(THREAD)) {
1125       report_loading_error("archivedBootLayer not available, disabling full module graph");
1126       CDSConfig::stop_dumping_full_module_graph();
1127     }
1128     // Do this before link_shared_classes(), as the following line may load new classes.
1129     HeapShared::init_for_dumping(CHECK);
1130   }
1131 #endif
1132 
1133   if (CDSConfig::is_dumping_final_static_archive()) {
1134     if (ExtraSharedClassListFile) {
1135       log_info(aot)("Loading extra classes from %s ...", ExtraSharedClassListFile);
1136       ClassListParser::parse_classlist(ExtraSharedClassListFile,
1137                                        ClassListParser::_parse_all, CHECK);
1138     }
1139   }
1140 
1141   // Rewrite and link classes
1142   log_info(aot)("Rewriting and linking classes ...");
1143 
1144   // Link any classes which got missed. This would happen if we have loaded classes that
1145   // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
1146   // fails verification, all other interfaces that were not specified in the classlist but
1147   // are implemented by K are not verified.
1148   link_shared_classes(CHECK);
1149   log_info(aot)("Rewriting and linking classes: done");
1150   TrainingData::init_dumptime_table(CHECK); // captures TrainingDataSetLocker
1151 
1152   if (CDSConfig::is_dumping_regenerated_lambdaform_invokers()) {
1153     LambdaFormInvokers::regenerate_holder_classes(CHECK);
1154   }
1155 
1156 #if INCLUDE_CDS_JAVA_HEAP
1157   if (CDSConfig::is_dumping_heap()) {
1158     HeapShared::init_heap_writer();
1159     if (CDSConfig::is_dumping_full_module_graph()) {
1160       ClassLoaderDataShared::ensure_module_entry_tables_exist();
1161       ClassLoaderDataShared::build_tables(CHECK);
1162       HeapShared::reset_archived_object_states(CHECK);
1163     }
1164 
1165     if (ArchiveLoaderLookupCache) {
1166       SystemDictionaryShared::create_loader_positive_lookup_cache(CHECK);
1167     }
1168 
1169     AOTReferenceObjSupport::initialize(CHECK);
1170     AOTReferenceObjSupport::stabilize_cached_reference_objects(CHECK);
1171 
1172     if (CDSConfig::is_dumping_aot_linked_classes()) {
1173       // java.lang.Class::reflectionFactory cannot be archived yet. We set this field
1174       // to null, and it will be initialized again at runtime.
1175       log_debug(aot)("Resetting Class::reflectionFactory");
1176       TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
1177       Symbol* method_sig = vmSymbols::void_method_signature();
1178       JavaValue result(T_VOID);
1179       JavaCalls::call_static(&result, vmClasses::Class_klass(),
1180                              method_name, method_sig, CHECK);
1181 
1182       // Perhaps there is a way to avoid hard-coding these names here.
1183       // See discussion in JDK-8342481.
1184     }
1185   } else {
1186     log_info(aot)("Not dumping heap, reset CDSConfig::_is_using_optimized_module_handling");
1187     CDSConfig::stop_using_optimized_module_handling();
1188   }
1189 #endif
1190 
1191   if (!CDSConfig::is_dumping_preimage_static_archive()) {
1192     if (CDSConfig::is_dumping_final_static_archive()) {
1193       FileMapInfo::free_current_info(); // FIXME: should not free current info
1194     }
1195     open_output_mapinfo();
1196   }
1197 
1198   VM_PopulateDumpSharedSpace op(builder, _output_mapinfo);
1199   VMThread::execute(&op);
1200 
1201   if (CDSConfig::is_dumping_final_static_archive()) {
1202     if (AOTCodeCache::is_caching_enabled()) {
1203       // We have just created the final image. Let's run the AOT compiler
1204       if (AOTPrintTrainingInfo) {
1205         tty->print_cr("==================== archived_training_data ** after dumping ====================");
1206         TrainingData::print_archived_training_data_on(tty);
1207       }
1208 
1209       {
1210         builder.start_ac_region();
1211         if (AOTCodeCache::is_dumping_code()) {
1212           CDSConfig::enable_dumping_aot_code();
1213           log_info(aot)("Compiling AOT code");
1214           Precompiler::compile_aot_code(&builder, CHECK);
1215           log_info(aot)("Finished compiling AOT code");
1216           CDSConfig::disable_dumping_aot_code();
1217         }
1218         // Write the contents to aot code region and close AOTCodeCache before packing the region
1219         AOTCodeCache::close();
1220         log_info(aot)("Dumped AOT code Cache");
1221         builder.end_ac_region();
1222       }
1223     }
1224   }
1225 
1226   bool status = write_static_archive(&builder, _output_mapinfo, op.mapped_heap_info(), op.streamed_heap_info());
1227   assert(!_output_mapinfo->is_open(), "Must be closed already");
1228   _output_mapinfo = nullptr;
1229   if (status && CDSConfig::is_dumping_preimage_static_archive()) {
1230     tty->print_cr("%s AOTConfiguration recorded: %s",
1231                   CDSConfig::has_temp_aot_config_file() ? "Temporary" : "", AOTConfiguration);
1232     if (CDSConfig::is_single_command_training()) {
1233       fork_and_dump_final_static_archive(CHECK);
1234     }
1235   }
1236 
1237   if (!status) {
1238     THROW_MSG(vmSymbols::java_io_IOException(), "Encountered error while dumping");
1239   }
1240 }
1241 
1242 bool AOTMetaspace::write_static_archive(ArchiveBuilder* builder,
1243                                         FileMapInfo* map_info,
1244                                         ArchiveMappedHeapInfo* mapped_heap_info,
1245                                         ArchiveStreamedHeapInfo* streamed_heap_info) {
1246   // relocate the data so that it can be mapped to AOTMetaspace::requested_base_address()
1247   // without runtime relocation.
1248   builder->relocate_to_requested();
1249   if (!map_info->is_open()) {
1250     return false;
1251   }
1252   map_info->prepare_for_writing();
1253   builder->write_archive(map_info, mapped_heap_info, streamed_heap_info);
1254   return true;
1255 }
1256 
1257 static void print_java_launcher(outputStream* st) {
1258   st->print("%s%sbin%sjava", Arguments::get_java_home(), os::file_separator(), os::file_separator());
1259 }
1260 
1261 static void append_args(GrowableArray<Handle>* args, const char* arg, TRAPS) {
1262   Handle string = java_lang_String::create_from_str(arg, CHECK);
1263   args->append(string);
1264 }
1265 
1266 // Pass all options in Arguments::jvm_args_array() to a child JVM process
1267 // using the JAVA_TOOL_OPTIONS environment variable.
1268 static int exec_jvm_with_java_tool_options(const char* java_launcher_path, TRAPS) {
1269   ResourceMark rm(THREAD);
1270   HandleMark hm(THREAD);
1271   GrowableArray<Handle> args;
1272 
1273   const char* cp = Arguments::get_appclasspath();
1274   if (cp != nullptr && strlen(cp) > 0 && strcmp(cp, ".") != 0) {
1275     // We cannot use "-cp", because "-cp" is only interpreted by the java launcher,
1276     // and is not interpreter by arguments.cpp when it loads args from JAVA_TOOL_OPTIONS
1277     stringStream ss;
1278     ss.print("-Djava.class.path=");
1279     ss.print_raw(cp);
1280     append_args(&args, ss.freeze(), CHECK_0);
1281     // CDS$ProcessLauncher::execWithJavaToolOptions() must unset CLASSPATH, which has
1282     // a higher priority than -Djava.class.path=
1283   }
1284 
1285   // Pass all arguments. These include those from JAVA_TOOL_OPTIONS and _JAVA_OPTIONS.
1286   for (int i = 0; i < Arguments::num_jvm_args(); i++) {
1287     const char* arg = Arguments::jvm_args_array()[i];
1288     if (strstr(arg, "-XX:AOTCacheOutput=") == arg || // arg starts with ...
1289         strstr(arg, "-XX:AOTConfiguration=") == arg ||
1290         strstr(arg, "-XX:AOTMode=") == arg) {
1291       // Filter these out. They wiill be set below.
1292     } else {
1293       append_args(&args, arg, CHECK_0);
1294     }
1295   }
1296 
1297   // Note: because we are running in AOTMode=record, JDK_AOT_VM_OPTIONS have not been
1298   // parsed, so they are not in Arguments::jvm_args_array. If JDK_AOT_VM_OPTIONS is in
1299   // the environment, it will be inherited and parsed by the child JVM process
1300   // in Arguments::parse_java_tool_options_environment_variable().
1301   precond(strcmp(AOTMode, "record") == 0);
1302 
1303   // We don't pass Arguments::jvm_flags_array(), as those will be added by
1304   // the child process when it loads .hotspotrc
1305 
1306   {
1307     // If AOTCacheOutput contains %p, it should have been already substituted with the
1308     // pid of the training process.
1309     stringStream ss;
1310     ss.print("-XX:AOTCacheOutput=");
1311     ss.print_raw(AOTCacheOutput);
1312     append_args(&args, ss.freeze(), CHECK_0);
1313   }
1314   {
1315     // If AOTCacheConfiguration contains %p, it should have been already substituted with the
1316     // pid of the training process.
1317     // If AOTCacheConfiguration was not explicitly specified, it should have been assigned a
1318     // temporary file name.
1319     stringStream ss;
1320     ss.print("-XX:AOTConfiguration=");
1321     ss.print_raw(AOTConfiguration);
1322     append_args(&args, ss.freeze(), CHECK_0);
1323   }
1324 
1325   append_args(&args, "-XX:AOTMode=create", CHECK_0);
1326 
1327   Symbol* klass_name = SymbolTable::new_symbol("jdk/internal/misc/CDS$ProcessLauncher");
1328   Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, CHECK_0);
1329   Symbol* methodName = SymbolTable::new_symbol("execWithJavaToolOptions");
1330   Symbol* methodSignature = SymbolTable::new_symbol("(Ljava/lang/String;[Ljava/lang/String;)I");
1331 
1332   Handle launcher = java_lang_String::create_from_str(java_launcher_path, CHECK_0);
1333   objArrayOop array = oopFactory::new_objArray(vmClasses::String_klass(), args.length(), CHECK_0);
1334   for (int i = 0; i < args.length(); i++) {
1335     array->obj_at_put(i, args.at(i)());
1336   }
1337   objArrayHandle launcher_args(THREAD, array);
1338 
1339   // The following call will pass all options inside the JAVA_TOOL_OPTIONS env variable to
1340   // the child process. It will also clear the _JAVA_OPTIONS and CLASSPATH env variables for
1341   // the child process.
1342   //
1343   // Note: the env variables are set only for the child process. They are not changed
1344   // for the current process. See java.lang.ProcessBuilder::environment().
1345   JavaValue result(T_OBJECT);
1346   JavaCallArguments javacall_args(2);
1347   javacall_args.push_oop(launcher);
1348   javacall_args.push_oop(launcher_args);
1349   JavaCalls::call_static(&result,
1350                           InstanceKlass::cast(k),
1351                           methodName,
1352                           methodSignature,
1353                           &javacall_args,
1354                           CHECK_0);
1355   return result.get_jint();
1356 }
1357 
1358 void AOTMetaspace::fork_and_dump_final_static_archive(TRAPS) {
1359   assert(CDSConfig::is_dumping_preimage_static_archive(), "sanity");
1360 
1361   ResourceMark rm;
1362   stringStream ss;
1363   print_java_launcher(&ss);
1364   const char* cmd = ss.freeze();
1365   tty->print_cr("Launching child process %s to assemble AOT cache %s using configuration %s", cmd, AOTCacheOutput, AOTConfiguration);
1366   int status = exec_jvm_with_java_tool_options(cmd, CHECK);
1367   if (status != 0) {
1368     log_error(aot)("Child process failed; status = %d", status);
1369     // We leave the temp config file for debugging
1370   } else if (CDSConfig::has_temp_aot_config_file()) {
1371     const char* tmp_config = AOTConfiguration;
1372     // On Windows, need WRITE permission to remove the file.
1373     WINDOWS_ONLY(chmod(tmp_config, _S_IREAD | _S_IWRITE));
1374     status = remove(tmp_config);
1375     if (status != 0) {
1376       log_error(aot)("Failed to remove temporary AOT configuration file %s", tmp_config);
1377     } else {
1378       tty->print_cr("Removed temporary AOT configuration file %s", tmp_config);
1379     }
1380   }
1381 }
1382 
1383 // Returns true if the class's status has changed.
1384 bool AOTMetaspace::try_link_class(JavaThread* current, InstanceKlass* ik) {
1385   ExceptionMark em(current);
1386   JavaThread* THREAD = current; // For exception macros.
1387   assert(CDSConfig::is_dumping_archive(), "sanity");
1388 
1389   if (ik->in_aot_cache() && !CDSConfig::is_dumping_final_static_archive()) {
1390     assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
1391     return false;
1392   }
1393 
1394   if (ik->is_loaded() && !ik->is_linked() && ik->can_be_verified_at_dumptime() &&
1395       !SystemDictionaryShared::has_class_failed_verification(ik)) {
1396     bool saved = BytecodeVerificationLocal;
1397     if (ik->defined_by_other_loaders() && ik->class_loader() == nullptr) {
1398       // The verification decision is based on BytecodeVerificationRemote
1399       // for non-system classes. Since we are using the null classloader
1400       // to load non-system classes for customized class loaders during dumping,
1401       // we need to temporarily change BytecodeVerificationLocal to be the same as
1402       // BytecodeVerificationRemote. Note this can cause the parent system
1403       // classes also being verified. The extra overhead is acceptable during
1404       // dumping.
1405       BytecodeVerificationLocal = BytecodeVerificationRemote;
1406     }
1407     ik->link_class(THREAD);
1408     if (HAS_PENDING_EXCEPTION) {
1409       ResourceMark rm(THREAD);
1410       oop message = java_lang_Throwable::message(current->pending_exception());
1411       aot_log_warning(aot)("Preload Warning: Verification failed for %s because a %s was thrown: %s",
1412                             ik->external_name(),
1413                             current->pending_exception()->klass()->external_name(),
1414                             message == nullptr ? "(no message)" : java_lang_String::as_utf8_string(message));
1415       CLEAR_PENDING_EXCEPTION;
1416       SystemDictionaryShared::set_class_has_failed_verification(ik);
1417     } else {
1418       assert(!SystemDictionaryShared::has_class_failed_verification(ik), "sanity");
1419       ik->compute_has_loops_flag_for_methods();
1420     }
1421     BytecodeVerificationLocal = saved;
1422     return true;
1423   } else {
1424     return false;
1425   }
1426 }
1427 
1428 void VM_PopulateDumpSharedSpace::dump_java_heap_objects() {
1429   if (CDSConfig::is_dumping_heap()) {
1430     HeapShared::write_heap(&_mapped_heap_info, &_streamed_heap_info);
1431   } else if (!CDSConfig::is_dumping_preimage_static_archive()) {
1432     CDSConfig::log_reasons_for_not_dumping_heap();
1433   }
1434 }
1435 
1436 void AOTMetaspace::set_aot_metaspace_range(void* base, void *static_top, void* top) {
1437   assert(base <= static_top && static_top <= top, "must be");
1438   _aot_metaspace_static_top = static_top;
1439   MetaspaceObj::set_aot_metaspace_range(base, top);
1440 }
1441 
1442 bool AOTMetaspace::in_aot_cache_dynamic_region(void* p) {
1443   if ((p < MetaspaceObj::aot_metaspace_top()) &&
1444       (p >= _aot_metaspace_static_top)) {
1445     return true;
1446   } else {
1447     return false;
1448   }
1449 }
1450 
1451 bool AOTMetaspace::in_aot_cache_static_region(void* p) {
1452   if (in_aot_cache(p) && !in_aot_cache_dynamic_region(p)) {
1453     return true;
1454   } else {
1455     return false;
1456   }
1457 }
1458 
1459 // This function is called when the JVM is unable to load the specified archive(s) due to one
1460 // of the following conditions.
1461 // - There's an error that indicates that the archive(s) files were corrupt or otherwise damaged.
1462 // - When -XX:+RequireSharedSpaces is specified, AND the JVM cannot load the archive(s) due
1463 //   to version or classpath mismatch.
1464 void AOTMetaspace::unrecoverable_loading_error(const char* message) {
1465   report_loading_error("%s", message);
1466 
1467   if (CDSConfig::is_dumping_final_static_archive()) {
1468     vm_exit_during_initialization("Must be a valid AOT configuration generated by the current JVM", AOTConfiguration);
1469   } else if (CDSConfig::new_aot_flags_used()) {
1470     vm_exit_during_initialization("Unable to use AOT cache.", nullptr);
1471   } else {
1472     vm_exit_during_initialization("Unable to use shared archive. Unrecoverable archive loading error (run with -Xlog:aot,cds for details)", message);
1473   }
1474 }
1475 
1476 void AOTMetaspace::report_loading_error(const char* format, ...) {
1477   // When using AOT cache, errors messages are always printed on the error channel.
1478   LogStream ls_aot(LogLevel::Error, LogTagSetMapping<LOG_TAGS(aot)>::tagset());
1479 
1480   // If we are loading load the default CDS archive, it may fail due to incompatible VM options.
1481   // Print at the info level to avoid excessive verbosity.
1482   // However, if the user has specified a CDS archive (or AOT cache), they would be interested in
1483   // knowing that the loading fails, so we print at the error level.
1484   LogLevelType level = (!CDSConfig::is_using_archive() || CDSConfig::is_using_only_default_archive()) ?
1485                         LogLevel::Info : LogLevel::Error;
1486   LogStream ls_cds(level, LogTagSetMapping<LOG_TAGS(cds)>::tagset());
1487 
1488   LogStream& ls = CDSConfig::new_aot_flags_used() ? ls_aot : ls_cds;
1489   if (!ls.is_enabled()) {
1490     return;
1491   }
1492 
1493   va_list ap;
1494   va_start(ap, format);
1495 
1496   static bool printed_error = false;
1497   if (!printed_error) { // No need for locks. Loading error checks happen only in main thread.
1498     ls.print_cr("An error has occurred while processing the %s. Run with -Xlog:%s for details.",
1499                 CDSConfig::type_of_archive_being_loaded(), CDSConfig::new_aot_flags_used() ? "aot" : "aot,cds");
1500     printed_error = true;
1501   }
1502   ls.vprint_cr(format, ap);
1503 
1504   va_end(ap);
1505 }
1506 
1507 // This function is called when the JVM is unable to write the specified CDS archive due to an
1508 // unrecoverable error.
1509 void AOTMetaspace::unrecoverable_writing_error(const char* message) {
1510   writing_error(message);
1511   vm_direct_exit(1);
1512 }
1513 
1514 // This function is called when the JVM is unable to write the specified CDS archive due to a
1515 // an error. The error will be propagated
1516 void AOTMetaspace::writing_error(const char* message) {
1517   aot_log_error(aot)("An error has occurred while writing the shared archive file.");
1518   if (message != nullptr) {
1519     aot_log_error(aot)("%s", message);
1520   }
1521 }
1522 
1523 void AOTMetaspace::initialize_runtime_shared_and_meta_spaces() {
1524   assert(CDSConfig::is_using_archive(), "Must be called when UseSharedSpaces is enabled");
1525   MapArchiveResult result = MAP_ARCHIVE_OTHER_FAILURE;
1526 
1527   FileMapInfo* static_mapinfo = FileMapInfo::current_info();
1528   FileMapInfo* dynamic_mapinfo = nullptr;
1529 
1530   if (static_mapinfo != nullptr) {
1531     aot_log_info(aot)("Core region alignment: %zu", static_mapinfo->core_region_alignment());
1532     dynamic_mapinfo = open_dynamic_archive();
1533 
1534     aot_log_info(aot)("ArchiveRelocationMode: %d", ArchiveRelocationMode);
1535 
1536     // First try to map at the requested address
1537     result = map_archives(static_mapinfo, dynamic_mapinfo, true);
1538     if (result == MAP_ARCHIVE_MMAP_FAILURE) {
1539       // Mapping has failed (probably due to ASLR). Let's map at an address chosen
1540       // by the OS.
1541       aot_log_info(aot)("Try to map archive(s) at an alternative address");
1542       result = map_archives(static_mapinfo, dynamic_mapinfo, false);
1543     }
1544   }
1545 
1546   if (result == MAP_ARCHIVE_SUCCESS) {
1547     bool dynamic_mapped = (dynamic_mapinfo != nullptr && dynamic_mapinfo->is_mapped());
1548     char* cds_base = static_mapinfo->mapped_base();
1549     char* cds_end =  dynamic_mapped ? dynamic_mapinfo->mapped_end() : static_mapinfo->mapped_end();
1550     // Register CDS memory region with LSan.
1551     LSAN_REGISTER_ROOT_REGION(cds_base, cds_end - cds_base);
1552     set_aot_metaspace_range(cds_base, static_mapinfo->mapped_end(), cds_end);
1553     _relocation_delta = static_mapinfo->relocation_delta();
1554     _requested_base_address = static_mapinfo->requested_base_address();
1555     if (dynamic_mapped) {
1556       // turn AutoCreateSharedArchive off if successfully mapped
1557       AutoCreateSharedArchive = false;
1558     }
1559   } else {
1560     set_aot_metaspace_range(nullptr, nullptr, nullptr);
1561     if (CDSConfig::is_dumping_dynamic_archive()) {
1562       aot_log_warning(aot)("-XX:ArchiveClassesAtExit is unsupported when base CDS archive is not loaded. Run with -Xlog:cds for more info.");
1563     }
1564     UseSharedSpaces = false;
1565     // The base archive cannot be mapped. We cannot dump the dynamic shared archive.
1566     AutoCreateSharedArchive = false;
1567     CDSConfig::disable_dumping_dynamic_archive();
1568     if (PrintSharedArchiveAndExit) {
1569       AOTMetaspace::unrecoverable_loading_error("Unable to use shared archive.");
1570     } else {
1571       if (RequireSharedSpaces) {
1572         AOTMetaspace::unrecoverable_loading_error("Unable to map shared spaces");
1573       } else {
1574         report_loading_error("Unable to map shared spaces");
1575       }
1576     }
1577   }
1578 
1579   // If mapping failed and -XShare:on, the vm should exit
1580   bool has_failed = false;
1581   if (static_mapinfo != nullptr && !static_mapinfo->is_mapped()) {
1582     has_failed = true;
1583     delete static_mapinfo;
1584   }
1585   if (dynamic_mapinfo != nullptr && !dynamic_mapinfo->is_mapped()) {
1586     has_failed = true;
1587     delete dynamic_mapinfo;
1588   }
1589   if (RequireSharedSpaces && has_failed) {
1590     // static archive mapped but dynamic archive failed
1591       AOTMetaspace::unrecoverable_loading_error("Unable to map shared spaces");
1592   }
1593 }
1594 
1595 // This is called very early at VM start up to get the size of the cached_code region
1596 void AOTMetaspace::open_static_archive() {
1597   if (!UseSharedSpaces) { // FIXME -- is this still needed??
1598     return;
1599   }
1600   const char* static_archive = CDSConfig::input_static_archive_path();
1601   assert(static_archive != nullptr, "sanity");
1602   FileMapInfo* mapinfo = new FileMapInfo(static_archive, true);
1603   if (!mapinfo->open_as_input()) {
1604     delete(mapinfo);
1605     log_info(cds)("Opening of static archive %s failed", static_archive);
1606   } else {
1607     FileMapRegion* r = mapinfo->region_at(AOTMetaspace::ac);
1608     AOTCacheAccess::set_aot_code_region_size(r->used_aligned());
1609   }
1610 }
1611 
1612 FileMapInfo* AOTMetaspace::open_dynamic_archive() {
1613   if (CDSConfig::is_dumping_dynamic_archive()) {
1614     return nullptr;
1615   }
1616   const char* dynamic_archive = CDSConfig::input_dynamic_archive_path();
1617   if (dynamic_archive == nullptr) {
1618     return nullptr;
1619   }
1620 
1621   FileMapInfo* mapinfo = new FileMapInfo(dynamic_archive, false);
1622   if (!mapinfo->open_as_input()) {
1623     delete(mapinfo);
1624     if (RequireSharedSpaces) {
1625       AOTMetaspace::unrecoverable_loading_error("Failed to initialize dynamic archive");
1626     }
1627     return nullptr;
1628   }
1629   return mapinfo;
1630 }
1631 
1632 // use_requested_addr:
1633 //  true  = map at FileMapHeader::_requested_base_address
1634 //  false = map at an alternative address picked by OS.
1635 MapArchiveResult AOTMetaspace::map_archives(FileMapInfo* static_mapinfo, FileMapInfo* dynamic_mapinfo,
1636                                             bool use_requested_addr) {
1637   if (use_requested_addr && static_mapinfo->requested_base_address() == nullptr) {
1638     aot_log_info(aot)("Archive(s) were created with -XX:SharedBaseAddress=0. Always map at os-selected address.");
1639     return MAP_ARCHIVE_MMAP_FAILURE;
1640   }
1641 
1642   PRODUCT_ONLY(if (ArchiveRelocationMode == 1 && use_requested_addr) {
1643       // For product build only -- this is for benchmarking the cost of doing relocation.
1644       // For debug builds, the check is done below, after reserving the space, for better test coverage
1645       // (see comment below).
1646       aot_log_info(aot)("ArchiveRelocationMode == 1: always map archive(s) at an alternative address");
1647       return MAP_ARCHIVE_MMAP_FAILURE;
1648     });
1649 
1650   if (ArchiveRelocationMode == 2 && !use_requested_addr) {
1651     aot_log_info(aot)("ArchiveRelocationMode == 2: never map archive(s) at an alternative address");
1652     return MAP_ARCHIVE_MMAP_FAILURE;
1653   };
1654 
1655   if (dynamic_mapinfo != nullptr) {
1656     // Ensure that the OS won't be able to allocate new memory spaces between the two
1657     // archives, or else it would mess up the simple comparison in MetaspaceObj::in_aot_cache().
1658     assert(static_mapinfo->mapping_end_offset() == dynamic_mapinfo->mapping_base_offset(), "no gap");
1659   }
1660 
1661   ReservedSpace total_space_rs, archive_space_rs, class_space_rs;
1662   MapArchiveResult result = MAP_ARCHIVE_OTHER_FAILURE;
1663   size_t prot_zone_size = 0;
1664   char* mapped_base_address = reserve_address_space_for_archives(static_mapinfo,
1665                                                                  dynamic_mapinfo,
1666                                                                  use_requested_addr,
1667                                                                  total_space_rs,
1668                                                                  archive_space_rs,
1669                                                                  class_space_rs);
1670   if (mapped_base_address == nullptr) {
1671     result = MAP_ARCHIVE_MMAP_FAILURE;
1672     aot_log_debug(aot)("Failed to reserve spaces (use_requested_addr=%u)", (unsigned)use_requested_addr);
1673   } else {
1674 
1675     if (Metaspace::using_class_space()) {
1676       prot_zone_size = protection_zone_size();
1677     }
1678 
1679 #ifdef ASSERT
1680     // Some sanity checks after reserving address spaces for archives
1681     //  and class space.
1682     assert(archive_space_rs.is_reserved(), "Sanity");
1683     if (Metaspace::using_class_space()) {
1684       assert(archive_space_rs.base() == mapped_base_address &&
1685           archive_space_rs.size() > protection_zone_size(),
1686           "Archive space must lead and include the protection zone");
1687       // Class space must closely follow the archive space. Both spaces
1688       //  must be aligned correctly.
1689       assert(class_space_rs.is_reserved() && class_space_rs.size() > 0,
1690              "A class space should have been reserved");
1691       assert(class_space_rs.base() >= archive_space_rs.end(),
1692              "class space should follow the cds archive space");
1693       assert(is_aligned(archive_space_rs.base(),
1694                         core_region_alignment()),
1695              "Archive space misaligned");
1696       assert(is_aligned(class_space_rs.base(),
1697                         Metaspace::reserve_alignment()),
1698              "class space misaligned");
1699     }
1700 #endif // ASSERT
1701 
1702     aot_log_info(aot)("Reserved archive_space_rs [" INTPTR_FORMAT " - " INTPTR_FORMAT "] (%zu) bytes%s",
1703                    p2i(archive_space_rs.base()), p2i(archive_space_rs.end()), archive_space_rs.size(),
1704                    (prot_zone_size > 0 ? " (includes protection zone)" : ""));
1705     aot_log_info(aot)("Reserved class_space_rs   [" INTPTR_FORMAT " - " INTPTR_FORMAT "] (%zu) bytes",
1706                    p2i(class_space_rs.base()), p2i(class_space_rs.end()), class_space_rs.size());
1707 
1708     if (AOTMetaspace::use_windows_memory_mapping()) {
1709       // We have now reserved address space for the archives, and will map in
1710       //  the archive files into this space.
1711       //
1712       // Special handling for Windows: on Windows we cannot map a file view
1713       //  into an existing memory mapping. So, we unmap the address range we
1714       //  just reserved again, which will make it available for mapping the
1715       //  archives.
1716       // Reserving this range has not been for naught however since it makes
1717       //  us reasonably sure the address range is available.
1718       //
1719       // But still it may fail, since between unmapping the range and mapping
1720       //  in the archive someone else may grab the address space. Therefore
1721       //  there is a fallback in FileMap::map_region() where we just read in
1722       //  the archive files sequentially instead of mapping it in. We couple
1723       //  this with use_requested_addr, since we're going to patch all the
1724       //  pointers anyway so there's no benefit to mmap.
1725       if (use_requested_addr) {
1726         assert(!total_space_rs.is_reserved(), "Should not be reserved for Windows");
1727         aot_log_info(aot)("Windows mmap workaround: releasing archive space.");
1728         MemoryReserver::release(archive_space_rs);
1729         // Mark as not reserved
1730         archive_space_rs = {};
1731         // The protection zone is part of the archive:
1732         // See comment above, the Windows way of loading CDS is to mmap the individual
1733         // parts of the archive into the address region we just vacated. The protection
1734         // zone will not be mapped (and, in fact, does not exist as physical region in
1735         // the archive). Therefore, after removing the archive space above, we must
1736         // re-reserve the protection zone part lest something else gets mapped into that
1737         // area later.
1738         if (prot_zone_size > 0) {
1739           assert(prot_zone_size >= os::vm_allocation_granularity(), "must be"); // not just page size!
1740           char* p = os::attempt_reserve_memory_at(mapped_base_address, prot_zone_size,
1741                                                   mtClassShared);
1742           assert(p == mapped_base_address || p == nullptr, "must be");
1743           if (p == nullptr) {
1744             aot_log_debug(aot)("Failed to re-reserve protection zone");
1745             return MAP_ARCHIVE_MMAP_FAILURE;
1746           }
1747         }
1748       }
1749     }
1750 
1751     if (prot_zone_size > 0) {
1752       os::commit_memory(mapped_base_address, prot_zone_size, false); // will later be protected
1753       // Before mapping the core regions into the newly established address space, we mark
1754       // start and the end of the future protection zone with canaries. That way we easily
1755       // catch mapping errors (accidentally mapping data into the future protection zone).
1756       *(mapped_base_address) = 'P';
1757       *(mapped_base_address + prot_zone_size - 1) = 'P';
1758     }
1759 
1760     MapArchiveResult static_result = map_archive(static_mapinfo, mapped_base_address, archive_space_rs);
1761     MapArchiveResult dynamic_result = (static_result == MAP_ARCHIVE_SUCCESS) ?
1762                                      map_archive(dynamic_mapinfo, mapped_base_address, archive_space_rs) : MAP_ARCHIVE_OTHER_FAILURE;
1763 
1764     DEBUG_ONLY(if (ArchiveRelocationMode == 1 && use_requested_addr) {
1765       // This is for simulating mmap failures at the requested address. In
1766       //  debug builds, we do it here (after all archives have possibly been
1767       //  mapped), so we can thoroughly test the code for failure handling
1768       //  (releasing all allocated resource, etc).
1769       aot_log_info(aot)("ArchiveRelocationMode == 1: always map archive(s) at an alternative address");
1770       if (static_result == MAP_ARCHIVE_SUCCESS) {
1771         static_result = MAP_ARCHIVE_MMAP_FAILURE;
1772       }
1773       if (dynamic_result == MAP_ARCHIVE_SUCCESS) {
1774         dynamic_result = MAP_ARCHIVE_MMAP_FAILURE;
1775       }
1776     });
1777 
1778     if (static_result == MAP_ARCHIVE_SUCCESS) {
1779       if (dynamic_result == MAP_ARCHIVE_SUCCESS) {
1780         result = MAP_ARCHIVE_SUCCESS;
1781       } else if (dynamic_result == MAP_ARCHIVE_OTHER_FAILURE) {
1782         assert(dynamic_mapinfo != nullptr && !dynamic_mapinfo->is_mapped(), "must have failed");
1783         // No need to retry mapping the dynamic archive again, as it will never succeed
1784         // (bad file, etc) -- just keep the base archive.
1785         log_warning(cds, dynamic)("Unable to use shared archive. The top archive failed to load: %s",
1786                                   dynamic_mapinfo->full_path());
1787         result = MAP_ARCHIVE_SUCCESS;
1788         // TODO, we can give the unused space for the dynamic archive to class_space_rs, but there's no
1789         // easy API to do that right now.
1790       } else {
1791         result = MAP_ARCHIVE_MMAP_FAILURE;
1792       }
1793     } else if (static_result == MAP_ARCHIVE_OTHER_FAILURE) {
1794       result = MAP_ARCHIVE_OTHER_FAILURE;
1795     } else {
1796       result = MAP_ARCHIVE_MMAP_FAILURE;
1797     }
1798   }
1799 
1800   if (result == MAP_ARCHIVE_SUCCESS) {
1801     SharedBaseAddress = (size_t)mapped_base_address;
1802 #ifdef _LP64
1803     if (Metaspace::using_class_space()) {
1804       assert(prot_zone_size > 0 &&
1805              *(mapped_base_address) == 'P' &&
1806              *(mapped_base_address + prot_zone_size - 1) == 'P',
1807              "Protection zone was overwritten?");
1808       // Set up ccs in metaspace.
1809       Metaspace::initialize_class_space(class_space_rs);
1810 
1811       // Set up compressed Klass pointer encoding: the encoding range must
1812       //  cover both archive and class space.
1813       const address klass_range_start = (address)mapped_base_address;
1814       const size_t klass_range_size = (address)class_space_rs.end() - klass_range_start;
1815       if (INCLUDE_CDS_JAVA_HEAP || UseCompactObjectHeaders) {
1816         // The CDS archive may contain narrow Klass IDs that were precomputed at archive generation time:
1817         // - every archived java object header (only if INCLUDE_CDS_JAVA_HEAP)
1818         // - every archived Klass' prototype   (only if +UseCompactObjectHeaders)
1819         //
1820         // In order for those IDs to still be valid, we need to dictate base and shift: base should be the
1821         // mapping start (including protection zone), shift should be the shift used at archive generation time.
1822         CompressedKlassPointers::initialize_for_given_encoding(
1823           klass_range_start, klass_range_size,
1824           klass_range_start, ArchiveBuilder::precomputed_narrow_klass_shift() // precomputed encoding, see ArchiveBuilder
1825         );
1826         assert(CompressedKlassPointers::base() == klass_range_start, "must be");
1827       } else {
1828         // Let JVM freely choose encoding base and shift
1829         CompressedKlassPointers::initialize(klass_range_start, klass_range_size);
1830         assert(CompressedKlassPointers::base() == nullptr ||
1831                CompressedKlassPointers::base() == klass_range_start, "must be");
1832       }
1833       // Establish protection zone, but only if we need one
1834       if (CompressedKlassPointers::base() == klass_range_start) {
1835         CompressedKlassPointers::establish_protection_zone(klass_range_start, prot_zone_size);
1836       }
1837 
1838       if (static_mapinfo->can_use_heap_region()) {
1839         if (static_mapinfo->object_streaming_mode()) {
1840           HeapShared::initialize_loading_mode(HeapArchiveMode::_streaming);
1841         } else {
1842           // map_or_load_heap_region() compares the current narrow oop and klass encodings
1843           // with the archived ones, so it must be done after all encodings are determined.
1844           static_mapinfo->map_or_load_heap_region();
1845           HeapShared::initialize_loading_mode(HeapArchiveMode::_mapping);
1846         }
1847       } else {
1848         FileMapRegion* r = static_mapinfo->region_at(AOTMetaspace::hp);
1849         if (r->used() > 0) {
1850           if (static_mapinfo->object_streaming_mode()) {
1851             AOTMetaspace::report_loading_error("Cannot use CDS heap data.");
1852           } else {
1853             if (!UseCompressedOops && !AOTMappedHeapLoader::can_map()) {
1854               AOTMetaspace::report_loading_error("Cannot use CDS heap data. Selected GC not compatible -XX:-UseCompressedOops");
1855             } else {
1856               AOTMetaspace::report_loading_error("Cannot use CDS heap data. UseEpsilonGC, UseG1GC, UseSerialGC, UseParallelGC, or UseShenandoahGC are required.");
1857             }
1858           }
1859         }
1860       }
1861     }
1862 #endif // _LP64
1863     log_info(aot)("initial optimized module handling: %s", CDSConfig::is_using_optimized_module_handling() ? "enabled" : "disabled");
1864     log_info(aot)("initial full module graph: %s", CDSConfig::is_using_full_module_graph() ? "enabled" : "disabled");
1865   } else {
1866     unmap_archive(static_mapinfo);
1867     unmap_archive(dynamic_mapinfo);
1868     release_reserved_spaces(total_space_rs, archive_space_rs, class_space_rs);
1869   }
1870 
1871   return result;
1872 }
1873 
1874 
1875 // This will reserve two address spaces suitable to house Klass structures, one
1876 //  for the cds archives (static archive and optionally dynamic archive) and
1877 //  optionally one move for ccs.
1878 //
1879 // Since both spaces must fall within the compressed class pointer encoding
1880 //  range, they are allocated close to each other.
1881 //
1882 // Space for archives will be reserved first, followed by a potential gap,
1883 //  followed by the space for ccs:
1884 //
1885 // +-- Base address             A        B                     End
1886 // |                            |        |                      |
1887 // v                            v        v                      v
1888 // +-------------+--------------+        +----------------------+
1889 // | static arc  | [dyn. arch]  | [gap]  | compr. class space   |
1890 // +-------------+--------------+        +----------------------+
1891 //
1892 // (The gap may result from different alignment requirements between metaspace
1893 //  and CDS)
1894 //
1895 // If UseCompressedClassPointers is disabled, only one address space will be
1896 //  reserved:
1897 //
1898 // +-- Base address             End
1899 // |                            |
1900 // v                            v
1901 // +-------------+--------------+
1902 // | static arc  | [dyn. arch]  |
1903 // +-------------+--------------+
1904 //
1905 // Base address: If use_archive_base_addr address is true, the Base address is
1906 //  determined by the address stored in the static archive. If
1907 //  use_archive_base_addr address is false, this base address is determined
1908 //  by the platform.
1909 //
1910 // If UseCompressedClassPointers=1, the range encompassing both spaces will be
1911 //  suitable to en/decode narrow Klass pointers: the base will be valid for
1912 //  encoding, the range [Base, End) and not surpass the max. range for that encoding.
1913 //
1914 // Return:
1915 //
1916 // - On success:
1917 //    - total_space_rs will be reserved as whole for archive_space_rs and
1918 //      class_space_rs if UseCompressedClassPointers is true.
1919 //      On Windows, try reserve archive_space_rs and class_space_rs
1920 //      separately first if use_archive_base_addr is true.
1921 //    - archive_space_rs will be reserved and large enough to host static and
1922 //      if needed dynamic archive: [Base, A).
1923 //      archive_space_rs.base and size will be aligned to CDS reserve
1924 //      granularity.
1925 //    - class_space_rs: If UseCompressedClassPointers=1, class_space_rs will
1926 //      be reserved. Its start address will be aligned to metaspace reserve
1927 //      alignment, which may differ from CDS alignment. It will follow the cds
1928 //      archive space, close enough such that narrow class pointer encoding
1929 //      covers both spaces.
1930 //      If UseCompressedClassPointers=0, class_space_rs remains unreserved.
1931 // - On error: null is returned and the spaces remain unreserved.
1932 char* AOTMetaspace::reserve_address_space_for_archives(FileMapInfo* static_mapinfo,
1933                                                        FileMapInfo* dynamic_mapinfo,
1934                                                        bool use_archive_base_addr,
1935                                                        ReservedSpace& total_space_rs,
1936                                                        ReservedSpace& archive_space_rs,
1937                                                        ReservedSpace& class_space_rs) {
1938 
1939   address const base_address = (address) (use_archive_base_addr ? static_mapinfo->requested_base_address() : nullptr);
1940   const size_t archive_space_alignment = core_region_alignment();
1941 
1942   // Size and requested location of the archive_space_rs (for both static and dynamic archives)
1943   size_t archive_end_offset  = (dynamic_mapinfo == nullptr) ? static_mapinfo->mapping_end_offset() : dynamic_mapinfo->mapping_end_offset();
1944   size_t archive_space_size = align_up(archive_end_offset, archive_space_alignment);
1945 
1946   if (!Metaspace::using_class_space()) {
1947     // Get the simple case out of the way first:
1948     // no compressed class space, simple allocation.
1949 
1950     // When running without class space, requested archive base should be aligned to cds core alignment.
1951     assert(is_aligned(base_address, archive_space_alignment),
1952              "Archive base address unaligned: " PTR_FORMAT ", needs alignment: %zu.",
1953              p2i(base_address), archive_space_alignment);
1954 
1955     archive_space_rs = MemoryReserver::reserve((char*)base_address,
1956                                                archive_space_size,
1957                                                archive_space_alignment,
1958                                                os::vm_page_size(),
1959                                                mtNone);
1960     if (archive_space_rs.is_reserved()) {
1961       assert(base_address == nullptr ||
1962              (address)archive_space_rs.base() == base_address, "Sanity");
1963       // Register archive space with NMT.
1964       MemTracker::record_virtual_memory_tag(archive_space_rs, mtClassShared);
1965       return archive_space_rs.base();
1966     }
1967     return nullptr;
1968   }
1969 
1970 #ifdef _LP64
1971 
1972   // Complex case: two spaces adjacent to each other, both to be addressable
1973   //  with narrow class pointers.
1974   // We reserve the whole range spanning both spaces, then split that range up.
1975 
1976   const size_t class_space_alignment = Metaspace::reserve_alignment();
1977 
1978   // When running with class space, requested archive base must satisfy both cds core alignment
1979   // and class space alignment.
1980   const size_t base_address_alignment = MAX2(class_space_alignment, archive_space_alignment);
1981   assert(is_aligned(base_address, base_address_alignment),
1982            "Archive base address unaligned: " PTR_FORMAT ", needs alignment: %zu.",
1983            p2i(base_address), base_address_alignment);
1984 
1985   size_t class_space_size = CompressedClassSpaceSize;
1986   assert(CompressedClassSpaceSize > 0 &&
1987          is_aligned(CompressedClassSpaceSize, class_space_alignment),
1988          "CompressedClassSpaceSize malformed: %zu", CompressedClassSpaceSize);
1989 
1990   const size_t ccs_begin_offset = align_up(archive_space_size, class_space_alignment);
1991   const size_t gap_size = ccs_begin_offset - archive_space_size;
1992 
1993   // Reduce class space size if it would not fit into the Klass encoding range
1994   constexpr size_t max_encoding_range_size = 4 * G;
1995   guarantee(archive_space_size < max_encoding_range_size - class_space_alignment, "Archive too large");
1996   if ((archive_space_size + gap_size + class_space_size) > max_encoding_range_size) {
1997     class_space_size = align_down(max_encoding_range_size - archive_space_size - gap_size, class_space_alignment);
1998     log_info(metaspace)("CDS initialization: reducing class space size from %zu to %zu",
1999         CompressedClassSpaceSize, class_space_size);
2000     FLAG_SET_ERGO(CompressedClassSpaceSize, class_space_size);
2001   }
2002 
2003   const size_t total_range_size =
2004       archive_space_size + gap_size + class_space_size;
2005 
2006   // Test that class space base address plus shift can be decoded by aarch64, when restored.
2007   const int precomputed_narrow_klass_shift = ArchiveBuilder::precomputed_narrow_klass_shift();
2008   if (!CompressedKlassPointers::check_klass_decode_mode(base_address, precomputed_narrow_klass_shift,
2009                                                         total_range_size)) {
2010     aot_log_info(aot)("CDS initialization: Cannot use SharedBaseAddress " PTR_FORMAT " with precomputed shift %d.",
2011                   p2i(base_address), precomputed_narrow_klass_shift);
2012     use_archive_base_addr = false;
2013   }
2014 
2015   assert(total_range_size > ccs_begin_offset, "must be");
2016   if (use_windows_memory_mapping() && use_archive_base_addr) {
2017     if (base_address != nullptr) {
2018       // On Windows, we cannot safely split a reserved memory space into two (see JDK-8255917).
2019       // Hence, we optimistically reserve archive space and class space side-by-side. We only
2020       // do this for use_archive_base_addr=true since for use_archive_base_addr=false case
2021       // caller will not split the combined space for mapping, instead read the archive data
2022       // via sequential file IO.
2023       address ccs_base = base_address + archive_space_size + gap_size;
2024       archive_space_rs = MemoryReserver::reserve((char*)base_address,
2025                                                  archive_space_size,
2026                                                  archive_space_alignment,
2027                                                  os::vm_page_size(),
2028                                                  mtNone);
2029       class_space_rs   = MemoryReserver::reserve((char*)ccs_base,
2030                                                  class_space_size,
2031                                                  class_space_alignment,
2032                                                  os::vm_page_size(),
2033                                                  mtNone);
2034     }
2035     if (!archive_space_rs.is_reserved() || !class_space_rs.is_reserved()) {
2036       release_reserved_spaces(total_space_rs, archive_space_rs, class_space_rs);
2037       return nullptr;
2038     }
2039     MemTracker::record_virtual_memory_tag(archive_space_rs, mtClassShared);
2040     MemTracker::record_virtual_memory_tag(class_space_rs, mtClass);
2041   } else {
2042     if (use_archive_base_addr && base_address != nullptr) {
2043       total_space_rs = MemoryReserver::reserve((char*) base_address,
2044                                                total_range_size,
2045                                                base_address_alignment,
2046                                                os::vm_page_size(),
2047                                                mtNone);
2048     } else {
2049       // We did not manage to reserve at the preferred address, or were instructed to relocate. In that
2050       // case we reserve wherever possible, but the start address needs to be encodable as narrow Klass
2051       // encoding base since the archived heap objects contain narrow Klass IDs pre-calculated toward the start
2052       // of the shared Metaspace. That prevents us from using zero-based encoding and therefore we won't
2053       // try allocating in low-address regions.
2054       total_space_rs = Metaspace::reserve_address_space_for_compressed_classes(total_range_size, false /* optimize_for_zero_base */);
2055     }
2056 
2057     if (!total_space_rs.is_reserved()) {
2058       return nullptr;
2059     }
2060 
2061     // Paranoid checks:
2062     assert(!use_archive_base_addr || (address)total_space_rs.base() == base_address,
2063            "Sanity (" PTR_FORMAT " vs " PTR_FORMAT ")", p2i(base_address), p2i(total_space_rs.base()));
2064     assert(is_aligned(total_space_rs.base(), base_address_alignment), "Sanity");
2065     assert(total_space_rs.size() == total_range_size, "Sanity");
2066 
2067     // Now split up the space into ccs and cds archive. For simplicity, just leave
2068     //  the gap reserved at the end of the archive space. Do not do real splitting.
2069     archive_space_rs = total_space_rs.first_part(ccs_begin_offset,
2070                                                  (size_t)archive_space_alignment);
2071     class_space_rs = total_space_rs.last_part(ccs_begin_offset);
2072     MemTracker::record_virtual_memory_split_reserved(total_space_rs.base(), total_space_rs.size(),
2073                                                      ccs_begin_offset, mtClassShared, mtClass);
2074   }
2075   assert(is_aligned(archive_space_rs.base(), archive_space_alignment), "Sanity");
2076   assert(is_aligned(archive_space_rs.size(), archive_space_alignment), "Sanity");
2077   assert(is_aligned(class_space_rs.base(), class_space_alignment), "Sanity");
2078   assert(is_aligned(class_space_rs.size(), class_space_alignment), "Sanity");
2079 
2080 
2081   return archive_space_rs.base();
2082 
2083 #else
2084   ShouldNotReachHere();
2085   return nullptr;
2086 #endif
2087 
2088 }
2089 
2090 void AOTMetaspace::release_reserved_spaces(ReservedSpace& total_space_rs,
2091                                            ReservedSpace& archive_space_rs,
2092                                            ReservedSpace& class_space_rs) {
2093   if (total_space_rs.is_reserved()) {
2094     aot_log_debug(aot)("Released shared space (archive + class) " INTPTR_FORMAT, p2i(total_space_rs.base()));
2095     MemoryReserver::release(total_space_rs);
2096     total_space_rs = {};
2097   } else {
2098     if (archive_space_rs.is_reserved()) {
2099       aot_log_debug(aot)("Released shared space (archive) " INTPTR_FORMAT, p2i(archive_space_rs.base()));
2100       MemoryReserver::release(archive_space_rs);
2101       archive_space_rs = {};
2102     }
2103     if (class_space_rs.is_reserved()) {
2104       aot_log_debug(aot)("Released shared space (classes) " INTPTR_FORMAT, p2i(class_space_rs.base()));
2105       MemoryReserver::release(class_space_rs);
2106       class_space_rs = {};
2107     }
2108   }
2109 }
2110 
2111 static int archive_regions[]     = { AOTMetaspace::rw, AOTMetaspace::ro };
2112 static int archive_regions_count = 2;
2113 
2114 MapArchiveResult AOTMetaspace::map_archive(FileMapInfo* mapinfo, char* mapped_base_address, ReservedSpace rs) {
2115   assert(CDSConfig::is_using_archive(), "must be runtime");
2116   if (mapinfo == nullptr) {
2117     return MAP_ARCHIVE_SUCCESS; // The dynamic archive has not been specified. No error has happened -- trivially succeeded.
2118   }
2119 
2120   if (!mapinfo->validate_aot_class_linking()) {
2121     return MAP_ARCHIVE_OTHER_FAILURE;
2122   }
2123 
2124   mapinfo->set_is_mapped(false);
2125   if (mapinfo->core_region_alignment() != (size_t)core_region_alignment()) {
2126     report_loading_error("Unable to map CDS archive -- core_region_alignment() expected: %zu"
2127                          " actual: %zu", mapinfo->core_region_alignment(), core_region_alignment());
2128     return MAP_ARCHIVE_OTHER_FAILURE;
2129   }
2130 
2131   MapArchiveResult result =
2132     mapinfo->map_regions(archive_regions, archive_regions_count, mapped_base_address, rs);
2133 
2134   if (result != MAP_ARCHIVE_SUCCESS) {
2135     unmap_archive(mapinfo);
2136     return result;
2137   }
2138 
2139   if (!mapinfo->validate_class_location()) {
2140     unmap_archive(mapinfo);
2141     return MAP_ARCHIVE_OTHER_FAILURE;
2142   }
2143 
2144   if (mapinfo->is_static()) {
2145     // Currently, only static archive uses early serialized data.
2146     char* buffer = mapinfo->early_serialized_data();
2147     intptr_t* array = (intptr_t*)buffer;
2148     ReadClosure rc(&array, (intptr_t)mapped_base_address);
2149     early_serialize(&rc);
2150   }
2151 
2152   if (!mapinfo->validate_aot_class_linking()) {
2153     unmap_archive(mapinfo);
2154     return MAP_ARCHIVE_OTHER_FAILURE;
2155   }
2156 
2157   mapinfo->set_is_mapped(true);
2158   return MAP_ARCHIVE_SUCCESS;
2159 }
2160 
2161 void AOTMetaspace::unmap_archive(FileMapInfo* mapinfo) {
2162   assert(CDSConfig::is_using_archive(), "must be runtime");
2163   if (mapinfo != nullptr) {
2164     mapinfo->unmap_regions(archive_regions, archive_regions_count);
2165     mapinfo->unmap_region(AOTMetaspace::bm);
2166     mapinfo->set_is_mapped(false);
2167   }
2168 }
2169 
2170 // For -XX:PrintSharedArchiveAndExit
2171 class CountSharedSymbols : public SymbolClosure {
2172  private:
2173    size_t _count;
2174  public:
2175    CountSharedSymbols() : _count(0) {}
2176   void do_symbol(Symbol** sym) {
2177     _count++;
2178   }
2179   size_t total() { return _count; }
2180 
2181 };
2182 
2183 // Read the miscellaneous data from the shared file, and
2184 // serialize it out to its various destinations.
2185 
2186 void AOTMetaspace::initialize_shared_spaces() {
2187   FileMapInfo *static_mapinfo = FileMapInfo::current_info();
2188   FileMapInfo *dynamic_mapinfo = FileMapInfo::dynamic_info();
2189 
2190   // Verify various attributes of the archive, plus initialize the
2191   // shared string/symbol tables.
2192   char* buffer = static_mapinfo->serialized_data();
2193   intptr_t* array = (intptr_t*)buffer;
2194   ReadClosure rc(&array, (intptr_t)SharedBaseAddress);
2195   serialize(&rc);
2196 
2197   // Finish initializing the heap dump mode used in the archive
2198   // Heap initialization can be done only after vtables are initialized by ReadClosure.
2199   HeapShared::finalize_initialization(static_mapinfo);
2200   Universe::load_archived_object_instances();
2201 
2202   AOTCodeCache::initialize();
2203 
2204   if (dynamic_mapinfo != nullptr) {
2205     intptr_t* buffer = (intptr_t*)dynamic_mapinfo->serialized_data();
2206     ReadClosure rc(&buffer, (intptr_t)SharedBaseAddress);
2207     DynamicArchive::serialize(&rc);
2208   }
2209 
2210   LogStreamHandle(Info, aot) lsh;
2211   if (lsh.is_enabled()) {
2212     lsh.print("Using AOT-linked classes: %s (static archive: %s aot-linked classes",
2213               BOOL_TO_STR(CDSConfig::is_using_aot_linked_classes()),
2214               static_mapinfo->header()->has_aot_linked_classes() ? "has" : "no");
2215     if (dynamic_mapinfo != nullptr) {
2216       lsh.print(", dynamic archive: %s aot-linked classes",
2217                 dynamic_mapinfo->header()->has_aot_linked_classes() ? "has" : "no");
2218     }
2219     lsh.print_cr(")");
2220   }
2221 
2222   // Set up LambdaFormInvokers::_lambdaform_lines for dynamic dump
2223   if (CDSConfig::is_dumping_dynamic_archive()) {
2224     // Read stored LF format lines stored in static archive
2225     LambdaFormInvokers::read_static_archive_invokers();
2226   }
2227 
2228   if (PrintSharedArchiveAndExit) {
2229     // Print archive names
2230     if (dynamic_mapinfo != nullptr) {
2231       tty->print_cr("\n\nBase archive name: %s", CDSConfig::input_static_archive_path());
2232       tty->print_cr("Base archive version %d", static_mapinfo->version());
2233     } else {
2234       tty->print_cr("Static archive name: %s", static_mapinfo->full_path());
2235       tty->print_cr("Static archive version %d", static_mapinfo->version());
2236     }
2237 
2238     SystemDictionaryShared::print_shared_archive(tty);
2239     if (dynamic_mapinfo != nullptr) {
2240       tty->print_cr("\n\nDynamic archive name: %s", dynamic_mapinfo->full_path());
2241       tty->print_cr("Dynamic archive version %d", dynamic_mapinfo->version());
2242       SystemDictionaryShared::print_shared_archive(tty, false/*dynamic*/);
2243     }
2244 
2245     TrainingData::print_archived_training_data_on(tty);
2246 
2247     AOTCodeCache::print_on(tty);
2248 
2249     // collect shared symbols and strings
2250     CountSharedSymbols cl;
2251     SymbolTable::shared_symbols_do(&cl);
2252     tty->print_cr("Number of shared symbols: %zu", cl.total());
2253     if (HeapShared::is_loading() && HeapShared::is_loading_mapping_mode()) {
2254       tty->print_cr("Number of shared strings: %zu", StringTable::shared_entry_count());
2255     }
2256     tty->print_cr("VM version: %s\r\n", static_mapinfo->vm_version());
2257     if (FileMapInfo::current_info() == nullptr || _archive_loading_failed) {
2258       tty->print_cr("archive is invalid");
2259       vm_exit(1);
2260     } else {
2261       tty->print_cr("archive is valid");
2262       vm_exit(0);
2263     }
2264   }
2265 }
2266 
2267 // JVM/TI RedefineClasses() support:
2268 bool AOTMetaspace::remap_shared_readonly_as_readwrite() {
2269   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
2270 
2271   if (CDSConfig::is_using_archive()) {
2272     // remap the shared readonly space to shared readwrite, private
2273     FileMapInfo* mapinfo = FileMapInfo::current_info();
2274     if (!mapinfo->remap_shared_readonly_as_readwrite()) {
2275       return false;
2276     }
2277     if (FileMapInfo::dynamic_info() != nullptr) {
2278       mapinfo = FileMapInfo::dynamic_info();
2279       if (!mapinfo->remap_shared_readonly_as_readwrite()) {
2280         return false;
2281       }
2282     }
2283     _remapped_readwrite = true;
2284   }
2285   return true;
2286 }
2287 
2288 void AOTMetaspace::print_on(outputStream* st) {
2289   if (CDSConfig::is_using_archive()) {
2290     st->print("CDS archive(s) mapped at: ");
2291     address base = (address)MetaspaceObj::aot_metaspace_base();
2292     address static_top = (address)_aot_metaspace_static_top;
2293     address top = (address)MetaspaceObj::aot_metaspace_top();
2294     st->print("[" PTR_FORMAT "-" PTR_FORMAT "-" PTR_FORMAT "), ", p2i(base), p2i(static_top), p2i(top));
2295     st->print("size %zu, ", top - base);
2296     st->print("SharedBaseAddress: " PTR_FORMAT ", ArchiveRelocationMode: %d.", SharedBaseAddress, ArchiveRelocationMode);
2297   } else {
2298     st->print("CDS archive(s) not mapped");
2299   }
2300   st->cr();
2301 }