1 /*
   2  * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "classfile/classListParser.hpp"
  28 #include "classfile/classLoaderExt.hpp"
  29 #include "classfile/dictionary.hpp"
  30 #include "classfile/loaderConstraints.hpp"
  31 #include "classfile/placeholders.hpp"
  32 #include "classfile/symbolTable.hpp"
  33 #include "classfile/stringTable.hpp"
  34 #include "classfile/systemDictionary.hpp"
  35 #include "classfile/systemDictionaryShared.hpp"
  36 #include "code/codeCache.hpp"
  37 #include "interpreter/bytecodeStream.hpp"
  38 #include "interpreter/bytecodes.hpp"
  39 #include "logging/log.hpp"
  40 #include "logging/logMessage.hpp"
  41 #include "memory/filemap.hpp"
  42 #include "memory/heapShared.hpp"
  43 #include "memory/metaspace.hpp"
  44 #include "memory/metaspaceClosure.hpp"
  45 #include "memory/metaspaceShared.hpp"
  46 #include "memory/resourceArea.hpp"
  47 #include "oops/compressedOops.inline.hpp"
  48 #include "oops/instanceClassLoaderKlass.hpp"
  49 #include "oops/instanceMirrorKlass.hpp"
  50 #include "oops/instanceRefKlass.hpp"
  51 #include "oops/objArrayKlass.hpp"
  52 #include "oops/objArrayOop.hpp"
  53 #include "oops/oop.inline.hpp"
  54 #include "oops/typeArrayKlass.hpp"
  55 #include "prims/jvmtiRedefineClasses.hpp"
  56 #include "runtime/handles.inline.hpp"
  57 #include "runtime/os.hpp"
  58 #include "runtime/safepointVerifiers.hpp"
  59 #include "runtime/signature.hpp"
  60 #include "runtime/timerTrace.hpp"
  61 #include "runtime/vmThread.hpp"
  62 #include "runtime/vm_operations.hpp"
  63 #include "utilities/align.hpp"
  64 #include "utilities/defaultStream.hpp"
  65 #include "utilities/hashtable.inline.hpp"
  66 #if INCLUDE_G1GC
  67 #include "gc/g1/g1Allocator.inline.hpp"
  68 #include "gc/g1/g1CollectedHeap.hpp"
  69 #endif
  70 
  71 ReservedSpace MetaspaceShared::_shared_rs;
  72 VirtualSpace MetaspaceShared::_shared_vs;
  73 MetaspaceSharedStats MetaspaceShared::_stats;
  74 bool MetaspaceShared::_has_error_classes;
  75 bool MetaspaceShared::_archive_loading_failed = false;
  76 bool MetaspaceShared::_remapped_readwrite = false;
  77 bool MetaspaceShared::_open_archive_heap_region_mapped = false;
  78 address MetaspaceShared::_cds_i2i_entry_code_buffers = NULL;
  79 size_t MetaspaceShared::_cds_i2i_entry_code_buffers_size = 0;
  80 size_t MetaspaceShared::_core_spaces_size = 0;
  81 
  82 // The CDS archive is divided into the following regions:
  83 //     mc  - misc code (the method entry trampolines)
  84 //     rw  - read-write metadata
  85 //     ro  - read-only metadata and read-only tables
  86 //     md  - misc data (the c++ vtables)
  87 //     od  - optional data (original class files)
  88 //
  89 //     s0  - shared strings(closed archive heap space) #0
  90 //     s1  - shared strings(closed archive heap space) #1 (may be empty)
  91 //     oa0 - open archive heap space #0
  92 //     oa1 - open archive heap space #1 (may be empty)
  93 //
  94 // The mc, rw, ro, md and od regions are linearly allocated, starting from
  95 // SharedBaseAddress, in the order of mc->rw->ro->md->od. The size of these 5 regions
  96 // are page-aligned, and there's no gap between any consecutive regions.
  97 //
  98 // These 5 regions are populated in the following steps:
  99 // [1] All classes are loaded in MetaspaceShared::preload_classes(). All metadata are
 100 //     temporarily allocated outside of the shared regions. Only the method entry
 101 //     trampolines are written into the mc region.
 102 // [2] ArchiveCompactor copies RW metadata into the rw region.
 103 // [3] ArchiveCompactor copies RO metadata into the ro region.
 104 // [4] SymbolTable, StringTable, SystemDictionary, and a few other read-only data
 105 //     are copied into the ro region as read-only tables.
 106 // [5] C++ vtables are copied into the md region.
 107 // [6] Original class files are copied into the od region.
 108 //
 109 // The s0/s1 and oa0/oa1 regions are populated inside MetaspaceShared::dump_java_heap_objects.
 110 // Their layout is independent of the other 5 regions.
 111 
 112 class DumpRegion {
 113 private:
 114   const char* _name;
 115   char* _base;
 116   char* _top;
 117   char* _end;
 118   bool _is_packed;
 119 
 120   char* expand_top_to(char* newtop) {
 121     assert(is_allocatable(), "must be initialized and not packed");
 122     assert(newtop >= _top, "must not grow backwards");
 123     if (newtop > _end) {
 124       MetaspaceShared::report_out_of_space(_name, newtop - _top);
 125       ShouldNotReachHere();
 126     }
 127     MetaspaceShared::commit_shared_space_to(newtop);
 128     _top = newtop;
 129     return _top;
 130   }
 131 
 132 public:
 133   DumpRegion(const char* name) : _name(name), _base(NULL), _top(NULL), _end(NULL), _is_packed(false) {}
 134 
 135   char* allocate(size_t num_bytes, size_t alignment=BytesPerWord) {
 136     char* p = (char*)align_up(_top, alignment);
 137     char* newtop = p + align_up(num_bytes, alignment);
 138     expand_top_to(newtop);
 139     memset(p, 0, newtop - p);
 140     return p;
 141   }
 142 
 143   void append_intptr_t(intptr_t n) {
 144     assert(is_aligned(_top, sizeof(intptr_t)), "bad alignment");
 145     intptr_t *p = (intptr_t*)_top;
 146     char* newtop = _top + sizeof(intptr_t);
 147     expand_top_to(newtop);
 148     *p = n;
 149   }
 150 
 151   char* base()      const { return _base;        }
 152   char* top()       const { return _top;         }
 153   char* end()       const { return _end;         }
 154   size_t reserved() const { return _end - _base; }
 155   size_t used()     const { return _top - _base; }
 156   bool is_packed()  const { return _is_packed;   }
 157   bool is_allocatable() const {
 158     return !is_packed() && _base != NULL;
 159   }
 160 
 161   void print(size_t total_bytes) const {
 162     tty->print_cr("%-3s space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used] at " INTPTR_FORMAT,
 163                   _name, used(), percent_of(used(), total_bytes), reserved(), percent_of(used(), reserved()), p2i(_base));
 164   }
 165   void print_out_of_space_msg(const char* failing_region, size_t needed_bytes) {
 166     tty->print("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d",
 167                _name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base));
 168     if (strcmp(_name, failing_region) == 0) {
 169       tty->print_cr(" required = %d", int(needed_bytes));
 170     } else {
 171       tty->cr();
 172     }
 173   }
 174 
 175   void init(const ReservedSpace* rs) {
 176     _base = _top = rs->base();
 177     _end = rs->end();
 178   }
 179   void init(char* b, char* t, char* e) {
 180     _base = b;
 181     _top = t;
 182     _end = e;
 183   }
 184 
 185   void pack(DumpRegion* next = NULL) {
 186     assert(!is_packed(), "sanity");
 187     _end = (char*)align_up(_top, Metaspace::reserve_alignment());
 188     _is_packed = true;
 189     if (next != NULL) {
 190       next->_base = next->_top = this->_end;
 191       next->_end = MetaspaceShared::shared_rs()->end();
 192     }
 193   }
 194   bool contains(char* p) {
 195     return base() <= p && p < top();
 196   }
 197 };
 198 
 199 
 200 DumpRegion _mc_region("mc"), _ro_region("ro"), _rw_region("rw"), _md_region("md"), _od_region("od");
 201 size_t _total_string_region_size = 0, _total_open_archive_region_size = 0;
 202 
 203 char* MetaspaceShared::misc_code_space_alloc(size_t num_bytes) {
 204   return _mc_region.allocate(num_bytes);
 205 }
 206 
 207 char* MetaspaceShared::read_only_space_alloc(size_t num_bytes) {
 208   return _ro_region.allocate(num_bytes);
 209 }
 210 
 211 char* MetaspaceShared::read_only_space_top() {
 212   return _ro_region.top();
 213 }
 214 
 215 void MetaspaceShared::initialize_runtime_shared_and_meta_spaces() {
 216   assert(UseSharedSpaces, "Must be called when UseSharedSpaces is enabled");
 217 
 218   // If using shared space, open the file that contains the shared space
 219   // and map in the memory before initializing the rest of metaspace (so
 220   // the addresses don't conflict)
 221   address cds_address = NULL;
 222   FileMapInfo* mapinfo = new FileMapInfo();
 223 
 224   // Open the shared archive file, read and validate the header. If
 225   // initialization fails, shared spaces [UseSharedSpaces] are
 226   // disabled and the file is closed.
 227   // Map in spaces now also
 228   if (mapinfo->initialize() && map_shared_spaces(mapinfo)) {
 229     size_t cds_total = core_spaces_size();
 230     cds_address = (address)mapinfo->header()->region_addr(0);
 231 #ifdef _LP64
 232     if (Metaspace::using_class_space()) {
 233       char* cds_end = (char*)(cds_address + cds_total);
 234       cds_end = (char *)align_up(cds_end, Metaspace::reserve_alignment());
 235       // If UseCompressedClassPointers is set then allocate the metaspace area
 236       // above the heap and above the CDS area (if it exists).
 237       Metaspace::allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
 238       // map_heap_regions() compares the current narrow oop and klass encodings
 239       // with the archived ones, so it must be done after all encodings are determined.
 240       mapinfo->map_heap_regions();
 241     }
 242     Universe::set_narrow_klass_range(CompressedClassSpaceSize);
 243 #endif // _LP64
 244   } else {
 245     assert(!mapinfo->is_open() && !UseSharedSpaces,
 246            "archive file not closed or shared spaces not disabled.");
 247   }
 248 }
 249 
 250 void MetaspaceShared::initialize_dumptime_shared_and_meta_spaces() {
 251   assert(DumpSharedSpaces, "should be called for dump time only");
 252   const size_t reserve_alignment = Metaspace::reserve_alignment();
 253   bool large_pages = false; // No large pages when dumping the CDS archive.
 254   char* shared_base = (char*)align_up((char*)SharedBaseAddress, reserve_alignment);
 255 
 256 #ifdef _LP64
 257   // On 64-bit VM, the heap and class space layout will be the same as if
 258   // you're running in -Xshare:on mode:
 259   //
 260   //                              +-- SharedBaseAddress (default = 0x800000000)
 261   //                              v
 262   // +-..---------+---------+ ... +----+----+----+----+----+---------------+
 263   // |    Heap    | Archive |     | MC | RW | RO | MD | OD | class space   |
 264   // +-..---------+---------+ ... +----+----+----+----+----+---------------+
 265   // |<--   MaxHeapSize  -->|     |<-- UnscaledClassSpaceMax = 4GB ------->|
 266   //
 267   const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
 268   const size_t cds_total = align_down(UnscaledClassSpaceMax, reserve_alignment);
 269 #else
 270   // We don't support archives larger than 256MB on 32-bit due to limited virtual address space.
 271   size_t cds_total = align_down(256*M, reserve_alignment);
 272 #endif
 273 
 274   // First try to reserve the space at the specified SharedBaseAddress.
 275   _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages, shared_base);
 276   if (_shared_rs.is_reserved()) {
 277     assert(shared_base == 0 || _shared_rs.base() == shared_base, "should match");
 278   } else {
 279     // Get a mmap region anywhere if the SharedBaseAddress fails.
 280     _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages);
 281   }
 282   if (!_shared_rs.is_reserved()) {
 283     vm_exit_during_initialization("Unable to reserve memory for shared space",
 284                                   err_msg(SIZE_FORMAT " bytes.", cds_total));
 285   }
 286 
 287 #ifdef _LP64
 288   // During dump time, we allocate 4GB (UnscaledClassSpaceMax) of space and split it up:
 289   // + The upper 1 GB is used as the "temporary compressed class space" -- preload_classes()
 290   //   will store Klasses into this space.
 291   // + The lower 3 GB is used for the archive -- when preload_classes() is done,
 292   //   ArchiveCompactor will copy the class metadata into this space, first the RW parts,
 293   //   then the RO parts.
 294 
 295   assert(UseCompressedOops && UseCompressedClassPointers,
 296       "UseCompressedOops and UseCompressedClassPointers must be set");
 297 
 298   size_t max_archive_size = align_down(cds_total * 3 / 4, reserve_alignment);
 299   ReservedSpace tmp_class_space = _shared_rs.last_part(max_archive_size);
 300   CompressedClassSpaceSize = align_down(tmp_class_space.size(), reserve_alignment);
 301   _shared_rs = _shared_rs.first_part(max_archive_size);
 302 
 303   // Set up compress class pointers.
 304   Universe::set_narrow_klass_base((address)_shared_rs.base());
 305   // Set narrow_klass_shift to be LogKlassAlignmentInBytes. This is consistent
 306   // with AOT.
 307   Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
 308   // Set the range of klass addresses to 4GB.
 309   Universe::set_narrow_klass_range(cds_total);
 310 
 311   Metaspace::initialize_class_space(tmp_class_space);
 312   tty->print_cr("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
 313                 p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift());
 314 
 315   tty->print_cr("Allocated temporary class space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
 316                 CompressedClassSpaceSize, p2i(tmp_class_space.base()));
 317 #endif
 318 
 319   // Start with 0 committed bytes. The memory will be committed as needed by
 320   // MetaspaceShared::commit_shared_space_to().
 321   if (!_shared_vs.initialize(_shared_rs, 0)) {
 322     vm_exit_during_initialization("Unable to allocate memory for shared space");
 323   }
 324 
 325   _mc_region.init(&_shared_rs);
 326   tty->print_cr("Allocated shared space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
 327                 _shared_rs.size(), p2i(_shared_rs.base()));
 328 }
 329 
 330 // Called by universe_post_init()
 331 void MetaspaceShared::post_initialize(TRAPS) {
 332   if (UseSharedSpaces) {
 333     int size = FileMapInfo::get_number_of_shared_paths();
 334     if (size > 0) {
 335       SystemDictionaryShared::allocate_shared_data_arrays(size, THREAD);
 336       FileMapInfo::FileMapHeader* header = FileMapInfo::current_info()->header();
 337       ClassLoaderExt::init_paths_start_index(header->_app_class_paths_start_index);
 338       ClassLoaderExt::init_app_module_paths_start_index(header->_app_module_paths_start_index);
 339     }
 340   }
 341 
 342   if (DumpSharedSpaces) {
 343     if (SharedArchiveConfigFile) {
 344       read_extra_data(SharedArchiveConfigFile, THREAD);
 345     }
 346   }
 347 }
 348 
 349 void MetaspaceShared::read_extra_data(const char* filename, TRAPS) {
 350   HashtableTextDump reader(filename);
 351   reader.check_version("VERSION: 1.0");
 352 
 353   while (reader.remain() > 0) {
 354     int utf8_length;
 355     int prefix_type = reader.scan_prefix(&utf8_length);
 356     ResourceMark rm(THREAD);
 357     char* utf8_buffer = NEW_RESOURCE_ARRAY(char, utf8_length);
 358     reader.get_utf8(utf8_buffer, utf8_length);
 359 
 360     if (prefix_type == HashtableTextDump::SymbolPrefix) {
 361       SymbolTable::new_symbol(utf8_buffer, utf8_length, THREAD);
 362     } else{
 363       assert(prefix_type == HashtableTextDump::StringPrefix, "Sanity");
 364       utf8_buffer[utf8_length] = '\0';
 365       oop s = StringTable::intern(utf8_buffer, THREAD);
 366     }
 367   }
 368 }
 369 
 370 void MetaspaceShared::commit_shared_space_to(char* newtop) {
 371   assert(DumpSharedSpaces, "dump-time only");
 372   char* base = _shared_rs.base();
 373   size_t need_committed_size = newtop - base;
 374   size_t has_committed_size = _shared_vs.committed_size();
 375   if (need_committed_size < has_committed_size) {
 376     return;
 377   }
 378 
 379   size_t min_bytes = need_committed_size - has_committed_size;
 380   size_t preferred_bytes = 1 * M;
 381   size_t uncommitted = _shared_vs.reserved_size() - has_committed_size;
 382 
 383   size_t commit = MAX2(min_bytes, preferred_bytes);
 384   assert(commit <= uncommitted, "sanity");
 385 
 386   bool result = _shared_vs.expand_by(commit, false);
 387   if (!result) {
 388     vm_exit_during_initialization(err_msg("Failed to expand shared space to " SIZE_FORMAT " bytes",
 389                                           need_committed_size));
 390   }
 391 
 392   log_info(cds)("Expanding shared spaces by " SIZE_FORMAT_W(7) " bytes [total " SIZE_FORMAT_W(9)  " bytes ending at %p]",
 393                 commit, _shared_vs.actual_committed_size(), _shared_vs.high());
 394 }
 395 
 396 // Read/write a data stream for restoring/preserving metadata pointers and
 397 // miscellaneous data from/to the shared archive file.
 398 
 399 void MetaspaceShared::serialize(SerializeClosure* soc) {
 400   int tag = 0;
 401   soc->do_tag(--tag);
 402 
 403   // Verify the sizes of various metadata in the system.
 404   soc->do_tag(sizeof(Method));
 405   soc->do_tag(sizeof(ConstMethod));
 406   soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
 407   soc->do_tag(sizeof(ConstantPool));
 408   soc->do_tag(sizeof(ConstantPoolCache));
 409   soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
 410   soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
 411   soc->do_tag(sizeof(Symbol));
 412 
 413   // Dump/restore miscellaneous metadata.
 414   Universe::serialize(soc, true);
 415   soc->do_tag(--tag);
 416 
 417   // Dump/restore references to commonly used names and signatures.
 418   vmSymbols::serialize(soc);
 419   soc->do_tag(--tag);
 420 
 421   // Dump/restore the symbol and string tables
 422   SymbolTable::serialize(soc);
 423   StringTable::serialize(soc);
 424   soc->do_tag(--tag);
 425 
 426   serialize_well_known_classes(soc);
 427   soc->do_tag(--tag);
 428 
 429   soc->do_tag(666);
 430 }
 431 
 432 void MetaspaceShared::serialize_well_known_classes(SerializeClosure* soc) {
 433   java_lang_Class::serialize(soc);
 434   java_lang_String::serialize(soc);
 435   java_lang_System::serialize(soc);
 436   java_lang_ClassLoader::serialize(soc);
 437   java_lang_Throwable::serialize(soc);
 438   java_lang_Thread::serialize(soc);
 439   java_lang_ThreadGroup::serialize(soc);
 440   java_lang_AssertionStatusDirectives::serialize(soc);
 441   java_lang_ref_SoftReference::serialize(soc);
 442   java_lang_invoke_MethodHandle::serialize(soc);
 443   java_lang_invoke_DirectMethodHandle::serialize(soc);
 444   java_lang_invoke_MemberName::serialize(soc);
 445   java_lang_invoke_ResolvedMethodName::serialize(soc);
 446   java_lang_invoke_LambdaForm::serialize(soc);
 447   java_lang_invoke_MethodType::serialize(soc);
 448   java_lang_invoke_CallSite::serialize(soc);
 449   java_lang_invoke_MethodHandleNatives_CallSiteContext::serialize(soc);
 450   java_security_AccessControlContext::serialize(soc);
 451   java_lang_reflect_AccessibleObject::serialize(soc);
 452   java_lang_reflect_Method::serialize(soc);
 453   java_lang_reflect_Constructor::serialize(soc);
 454   java_lang_reflect_Field::serialize(soc);
 455   java_nio_Buffer::serialize(soc);
 456   reflect_ConstantPool::serialize(soc);
 457   reflect_UnsafeStaticFieldAccessorImpl::serialize(soc);
 458   java_lang_reflect_Parameter::serialize(soc);
 459   java_lang_Module::serialize(soc);
 460   java_lang_StackTraceElement::serialize(soc);
 461   java_lang_StackFrameInfo::serialize(soc);
 462   java_lang_LiveStackFrameInfo::serialize(soc);
 463   java_util_concurrent_locks_AbstractOwnableSynchronizer::serialize(soc);
 464   jdk_internal_module_ArchivedModuleGraph::serialize(soc);
 465 }
 466 
 467 address MetaspaceShared::cds_i2i_entry_code_buffers(size_t total_size) {
 468   if (DumpSharedSpaces) {
 469     if (_cds_i2i_entry_code_buffers == NULL) {
 470       _cds_i2i_entry_code_buffers = (address)misc_code_space_alloc(total_size);
 471       _cds_i2i_entry_code_buffers_size = total_size;
 472     }
 473   } else if (UseSharedSpaces) {
 474     assert(_cds_i2i_entry_code_buffers != NULL, "must already been initialized");
 475   } else {
 476     return NULL;
 477   }
 478 
 479   assert(_cds_i2i_entry_code_buffers_size == total_size, "must not change");
 480   return _cds_i2i_entry_code_buffers;
 481 }
 482 
 483 // CDS code for dumping shared archive.
 484 
 485 // Global object for holding classes that have been loaded.  Since this
 486 // is run at a safepoint just before exit, this is the entire set of classes.
 487 static GrowableArray<Klass*>* _global_klass_objects;
 488 
 489 static void collect_array_classes(Klass* k) {
 490   _global_klass_objects->append_if_missing(k);
 491   if (k->is_array_klass()) {
 492     // Add in the array classes too
 493     ArrayKlass* ak = ArrayKlass::cast(k);
 494     Klass* h = ak->higher_dimension();
 495     if (h != NULL) {
 496       h->array_klasses_do(collect_array_classes);
 497     }
 498   }
 499 }
 500 
 501 class CollectClassesClosure : public KlassClosure {
 502   void do_klass(Klass* k) {
 503     if (!(k->is_instance_klass() && InstanceKlass::cast(k)->is_in_error_state())) {
 504       if (k->is_instance_klass() && InstanceKlass::cast(k)->signers() != NULL) {
 505         // Mark any class with signers and don't add to the _global_klass_objects
 506         k->set_has_signer_and_not_archived();
 507       } else {
 508         _global_klass_objects->append_if_missing(k);
 509       }
 510     }
 511     if (k->is_array_klass()) {
 512       // Add in the array classes too
 513       ArrayKlass* ak = ArrayKlass::cast(k);
 514       Klass* h = ak->higher_dimension();
 515       if (h != NULL) {
 516         h->array_klasses_do(collect_array_classes);
 517       }
 518     }
 519   }
 520 };
 521 
 522 static void remove_unshareable_in_classes() {
 523   for (int i = 0; i < _global_klass_objects->length(); i++) {
 524     Klass* k = _global_klass_objects->at(i);
 525     if (!k->is_objArray_klass()) {
 526       // InstanceKlass and TypeArrayKlass will in turn call remove_unshareable_info
 527       // on their array classes.
 528       assert(k->is_instance_klass() || k->is_typeArray_klass(), "must be");
 529       k->remove_unshareable_info();
 530     }
 531   }
 532 }
 533 
 534 static void remove_java_mirror_in_classes() {
 535   for (int i = 0; i < _global_klass_objects->length(); i++) {
 536     Klass* k = _global_klass_objects->at(i);
 537     if (!k->is_objArray_klass()) {
 538       // InstanceKlass and TypeArrayKlass will in turn call remove_unshareable_info
 539       // on their array classes.
 540       assert(k->is_instance_klass() || k->is_typeArray_klass(), "must be");
 541       k->remove_java_mirror();
 542     }
 543   }
 544 }
 545 
 546 static void clear_basic_type_mirrors() {
 547   assert(!MetaspaceShared::is_heap_object_archiving_allowed(), "Sanity");
 548   Universe::set_int_mirror(NULL);
 549   Universe::set_float_mirror(NULL);
 550   Universe::set_double_mirror(NULL);
 551   Universe::set_byte_mirror(NULL);
 552   Universe::set_bool_mirror(NULL);
 553   Universe::set_char_mirror(NULL);
 554   Universe::set_long_mirror(NULL);
 555   Universe::set_short_mirror(NULL);
 556   Universe::set_void_mirror(NULL);
 557 }
 558 
 559 static void rewrite_nofast_bytecode(Method* method) {
 560   BytecodeStream bcs(method);
 561   while (!bcs.is_last_bytecode()) {
 562     Bytecodes::Code opcode = bcs.next();
 563     switch (opcode) {
 564     case Bytecodes::_getfield:      *bcs.bcp() = Bytecodes::_nofast_getfield;      break;
 565     case Bytecodes::_putfield:      *bcs.bcp() = Bytecodes::_nofast_putfield;      break;
 566     case Bytecodes::_aload_0:       *bcs.bcp() = Bytecodes::_nofast_aload_0;       break;
 567     case Bytecodes::_iload: {
 568       if (!bcs.is_wide()) {
 569         *bcs.bcp() = Bytecodes::_nofast_iload;
 570       }
 571       break;
 572     }
 573     default: break;
 574     }
 575   }
 576 }
 577 
 578 // Walk all methods in the class list to ensure that they won't be modified at
 579 // run time. This includes:
 580 // [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified
 581 //     at run time by RewriteBytecodes/RewriteFrequentPairs
 582 // [2] Assign a fingerprint, so one doesn't need to be assigned at run-time.
 583 static void rewrite_nofast_bytecodes_and_calculate_fingerprints() {
 584   for (int i = 0; i < _global_klass_objects->length(); i++) {
 585     Klass* k = _global_klass_objects->at(i);
 586     if (k->is_instance_klass()) {
 587       InstanceKlass* ik = InstanceKlass::cast(k);
 588       for (int i = 0; i < ik->methods()->length(); i++) {
 589         Method* m = ik->methods()->at(i);
 590         rewrite_nofast_bytecode(m);
 591         Fingerprinter fp(m);
 592         // The side effect of this call sets method's fingerprint field.
 593         fp.fingerprint();
 594       }
 595     }
 596   }
 597 }
 598 
 599 static void relocate_cached_class_file() {
 600   for (int i = 0; i < _global_klass_objects->length(); i++) {
 601     Klass* k = _global_klass_objects->at(i);
 602     if (k->is_instance_klass()) {
 603       InstanceKlass* ik = InstanceKlass::cast(k);
 604       JvmtiCachedClassFileData* p = ik->get_archived_class_data();
 605       if (p != NULL) {
 606         int size = offset_of(JvmtiCachedClassFileData, data) + p->length;
 607         JvmtiCachedClassFileData* q = (JvmtiCachedClassFileData*)_od_region.allocate(size);
 608         q->length = p->length;
 609         memcpy(q->data, p->data, p->length);
 610         ik->set_archived_class_data(q);
 611       }
 612     }
 613   }
 614 }
 615 
 616 NOT_PRODUCT(
 617 static void assert_not_anonymous_class(InstanceKlass* k) {
 618   assert(!(k->is_anonymous()), "cannot archive anonymous classes");
 619 }
 620 
 621 // Anonymous classes are not stored inside any dictionaries. They are created by
 622 // SystemDictionary::parse_stream() with a non-null host_klass.
 623 static void assert_no_anonymoys_classes_in_dictionaries() {
 624   ClassLoaderDataGraph::dictionary_classes_do(assert_not_anonymous_class);
 625 })
 626 
 627 // Objects of the Metadata types (such as Klass and ConstantPool) have C++ vtables.
 628 // (In GCC this is the field <Type>::_vptr, i.e., first word in the object.)
 629 //
 630 // Addresses of the vtables and the methods may be different across JVM runs,
 631 // if libjvm.so is dynamically loaded at a different base address.
 632 //
 633 // To ensure that the Metadata objects in the CDS archive always have the correct vtable:
 634 //
 635 // + at dump time:  we redirect the _vptr to point to our own vtables inside
 636 //                  the CDS image
 637 // + at run time:   we clone the actual contents of the vtables from libjvm.so
 638 //                  into our own tables.
 639 
 640 // Currently, the archive contain ONLY the following types of objects that have C++ vtables.
 641 #define CPP_VTABLE_PATCH_TYPES_DO(f) \
 642   f(ConstantPool) \
 643   f(InstanceKlass) \
 644   f(InstanceClassLoaderKlass) \
 645   f(InstanceMirrorKlass) \
 646   f(InstanceRefKlass) \
 647   f(Method) \
 648   f(ObjArrayKlass) \
 649   f(TypeArrayKlass)
 650 
 651 class CppVtableInfo {
 652   intptr_t _vtable_size;
 653   intptr_t _cloned_vtable[1];
 654 public:
 655   static int num_slots(int vtable_size) {
 656     return 1 + vtable_size; // Need to add the space occupied by _vtable_size;
 657   }
 658   int vtable_size()           { return int(uintx(_vtable_size)); }
 659   void set_vtable_size(int n) { _vtable_size = intptr_t(n); }
 660   intptr_t* cloned_vtable()   { return &_cloned_vtable[0]; }
 661   void zero()                 { memset(_cloned_vtable, 0, sizeof(intptr_t) * vtable_size()); }
 662   // Returns the address of the next CppVtableInfo that can be placed immediately after this CppVtableInfo
 663   static size_t byte_size(int vtable_size) {
 664     CppVtableInfo i;
 665     return pointer_delta(&i._cloned_vtable[vtable_size], &i, sizeof(u1));
 666   }
 667 };
 668 
 669 template <class T> class CppVtableCloner : public T {
 670   static intptr_t* vtable_of(Metadata& m) {
 671     return *((intptr_t**)&m);
 672   }
 673   static CppVtableInfo* _info;
 674 
 675   static int get_vtable_length(const char* name);
 676 
 677 public:
 678   // Allocate and initialize the C++ vtable, starting from top, but do not go past end.
 679   static intptr_t* allocate(const char* name);
 680 
 681   // Clone the vtable to ...
 682   static intptr_t* clone_vtable(const char* name, CppVtableInfo* info);
 683 
 684   static void zero_vtable_clone() {
 685     assert(DumpSharedSpaces, "dump-time only");
 686     _info->zero();
 687   }
 688 
 689   // Switch the vtable pointer to point to the cloned vtable.
 690   static void patch(Metadata* obj) {
 691     assert(DumpSharedSpaces, "dump-time only");
 692     *(void**)obj = (void*)(_info->cloned_vtable());
 693   }
 694 
 695   static bool is_valid_shared_object(const T* obj) {
 696     intptr_t* vptr = *(intptr_t**)obj;
 697     return vptr == _info->cloned_vtable();
 698   }
 699 };
 700 
 701 template <class T> CppVtableInfo* CppVtableCloner<T>::_info = NULL;
 702 
 703 template <class T>
 704 intptr_t* CppVtableCloner<T>::allocate(const char* name) {
 705   assert(is_aligned(_md_region.top(), sizeof(intptr_t)), "bad alignment");
 706   int n = get_vtable_length(name);
 707   _info = (CppVtableInfo*)_md_region.allocate(CppVtableInfo::byte_size(n), sizeof(intptr_t));
 708   _info->set_vtable_size(n);
 709 
 710   intptr_t* p = clone_vtable(name, _info);
 711   assert((char*)p == _md_region.top(), "must be");
 712 
 713   return p;
 714 }
 715 
 716 template <class T>
 717 intptr_t* CppVtableCloner<T>::clone_vtable(const char* name, CppVtableInfo* info) {
 718   if (!DumpSharedSpaces) {
 719     assert(_info == 0, "_info is initialized only at dump time");
 720     _info = info; // Remember it -- it will be used by MetaspaceShared::is_valid_shared_method()
 721   }
 722   T tmp; // Allocate temporary dummy metadata object to get to the original vtable.
 723   int n = info->vtable_size();
 724   intptr_t* srcvtable = vtable_of(tmp);
 725   intptr_t* dstvtable = info->cloned_vtable();
 726 
 727   // We already checked (and, if necessary, adjusted n) when the vtables were allocated, so we are
 728   // safe to do memcpy.
 729   log_debug(cds, vtables)("Copying %3d vtable entries for %s", n, name);
 730   memcpy(dstvtable, srcvtable, sizeof(intptr_t) * n);
 731   return dstvtable + n;
 732 }
 733 
 734 // To determine the size of the vtable for each type, we use the following
 735 // trick by declaring 2 subclasses:
 736 //
 737 //   class CppVtableTesterA: public InstanceKlass {virtual int   last_virtual_method() {return 1;}    };
 738 //   class CppVtableTesterB: public InstanceKlass {virtual void* last_virtual_method() {return NULL}; };
 739 //
 740 // CppVtableTesterA and CppVtableTesterB's vtables have the following properties:
 741 // - Their size (N+1) is exactly one more than the size of InstanceKlass's vtable (N)
 742 // - The first N entries have are exactly the same as in InstanceKlass's vtable.
 743 // - Their last entry is different.
 744 //
 745 // So to determine the value of N, we just walk CppVtableTesterA and CppVtableTesterB's tables
 746 // and find the first entry that's different.
 747 //
 748 // This works on all C++ compilers supported by Oracle, but you may need to tweak it for more
 749 // esoteric compilers.
 750 
 751 template <class T> class CppVtableTesterB: public T {
 752 public:
 753   virtual int last_virtual_method() {return 1;}
 754 };
 755 
 756 template <class T> class CppVtableTesterA : public T {
 757 public:
 758   virtual void* last_virtual_method() {
 759     // Make this different than CppVtableTesterB::last_virtual_method so the C++
 760     // compiler/linker won't alias the two functions.
 761     return NULL;
 762   }
 763 };
 764 
 765 template <class T>
 766 int CppVtableCloner<T>::get_vtable_length(const char* name) {
 767   CppVtableTesterA<T> a;
 768   CppVtableTesterB<T> b;
 769 
 770   intptr_t* avtable = vtable_of(a);
 771   intptr_t* bvtable = vtable_of(b);
 772 
 773   // Start at slot 1, because slot 0 may be RTTI (on Solaris/Sparc)
 774   int vtable_len = 1;
 775   for (; ; vtable_len++) {
 776     if (avtable[vtable_len] != bvtable[vtable_len]) {
 777       break;
 778     }
 779   }
 780   log_debug(cds, vtables)("Found   %3d vtable entries for %s", vtable_len, name);
 781 
 782   return vtable_len;
 783 }
 784 
 785 #define ALLOC_CPP_VTABLE_CLONE(c) \
 786   CppVtableCloner<c>::allocate(#c);
 787 
 788 #define CLONE_CPP_VTABLE(c) \
 789   p = CppVtableCloner<c>::clone_vtable(#c, (CppVtableInfo*)p);
 790 
 791 #define ZERO_CPP_VTABLE(c) \
 792  CppVtableCloner<c>::zero_vtable_clone();
 793 
 794 // This can be called at both dump time and run time.
 795 intptr_t* MetaspaceShared::clone_cpp_vtables(intptr_t* p) {
 796   assert(DumpSharedSpaces || UseSharedSpaces, "sanity");
 797   CPP_VTABLE_PATCH_TYPES_DO(CLONE_CPP_VTABLE);
 798   return p;
 799 }
 800 
 801 void MetaspaceShared::zero_cpp_vtable_clones_for_writing() {
 802   assert(DumpSharedSpaces, "dump-time only");
 803   CPP_VTABLE_PATCH_TYPES_DO(ZERO_CPP_VTABLE);
 804 }
 805 
 806 // Allocate and initialize the C++ vtables, starting from top, but do not go past end.
 807 void MetaspaceShared::allocate_cpp_vtable_clones() {
 808   assert(DumpSharedSpaces, "dump-time only");
 809   // Layout (each slot is a intptr_t):
 810   //   [number of slots in the first vtable = n1]
 811   //   [ <n1> slots for the first vtable]
 812   //   [number of slots in the first second = n2]
 813   //   [ <n2> slots for the second vtable]
 814   //   ...
 815   // The order of the vtables is the same as the CPP_VTAB_PATCH_TYPES_DO macro.
 816   CPP_VTABLE_PATCH_TYPES_DO(ALLOC_CPP_VTABLE_CLONE);
 817 }
 818 
 819 // Switch the vtable pointer to point to the cloned vtable. We assume the
 820 // vtable pointer is in first slot in object.
 821 void MetaspaceShared::patch_cpp_vtable_pointers() {
 822   int n = _global_klass_objects->length();
 823   for (int i = 0; i < n; i++) {
 824     Klass* obj = _global_klass_objects->at(i);
 825     if (obj->is_instance_klass()) {
 826       InstanceKlass* ik = InstanceKlass::cast(obj);
 827       if (ik->is_class_loader_instance_klass()) {
 828         CppVtableCloner<InstanceClassLoaderKlass>::patch(ik);
 829       } else if (ik->is_reference_instance_klass()) {
 830         CppVtableCloner<InstanceRefKlass>::patch(ik);
 831       } else if (ik->is_mirror_instance_klass()) {
 832         CppVtableCloner<InstanceMirrorKlass>::patch(ik);
 833       } else {
 834         CppVtableCloner<InstanceKlass>::patch(ik);
 835       }
 836       ConstantPool* cp = ik->constants();
 837       CppVtableCloner<ConstantPool>::patch(cp);
 838       for (int j = 0; j < ik->methods()->length(); j++) {
 839         Method* m = ik->methods()->at(j);
 840         CppVtableCloner<Method>::patch(m);
 841         assert(CppVtableCloner<Method>::is_valid_shared_object(m), "must be");
 842       }
 843     } else if (obj->is_objArray_klass()) {
 844       CppVtableCloner<ObjArrayKlass>::patch(obj);
 845     } else {
 846       assert(obj->is_typeArray_klass(), "sanity");
 847       CppVtableCloner<TypeArrayKlass>::patch(obj);
 848     }
 849   }
 850 }
 851 
 852 bool MetaspaceShared::is_valid_shared_method(const Method* m) {
 853   assert(is_in_shared_metaspace(m), "must be");
 854   return CppVtableCloner<Method>::is_valid_shared_object(m);
 855 }
 856 
 857 // Closure for serializing initialization data out to a data area to be
 858 // written to the shared file.
 859 
 860 class WriteClosure : public SerializeClosure {
 861 private:
 862   DumpRegion* _dump_region;
 863 
 864 public:
 865   WriteClosure(DumpRegion* r) {
 866     _dump_region = r;
 867   }
 868 
 869   void do_ptr(void** p) {
 870     _dump_region->append_intptr_t((intptr_t)*p);
 871   }
 872 
 873   void do_u4(u4* p) {
 874     void* ptr = (void*)(uintx(*p));
 875     do_ptr(&ptr);
 876   }
 877 
 878   void do_tag(int tag) {
 879     _dump_region->append_intptr_t((intptr_t)tag);
 880   }
 881 
 882   void do_oop(oop* o) {
 883     if (*o == NULL) {
 884       _dump_region->append_intptr_t(0);
 885     } else {
 886       assert(MetaspaceShared::is_heap_object_archiving_allowed(),
 887              "Archiving heap object is not allowed");
 888       _dump_region->append_intptr_t(
 889         (intptr_t)CompressedOops::encode_not_null(*o));
 890     }
 891   }
 892 
 893   void do_region(u_char* start, size_t size) {
 894     assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
 895     assert(size % sizeof(intptr_t) == 0, "bad size");
 896     do_tag((int)size);
 897     while (size > 0) {
 898       _dump_region->append_intptr_t(*(intptr_t*)start);
 899       start += sizeof(intptr_t);
 900       size -= sizeof(intptr_t);
 901     }
 902   }
 903 
 904   bool reading() const { return false; }
 905 };
 906 
 907 // This is for dumping detailed statistics for the allocations
 908 // in the shared spaces.
 909 class DumpAllocStats : public ResourceObj {
 910 public:
 911 
 912   // Here's poor man's enum inheritance
 913 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
 914   METASPACE_OBJ_TYPES_DO(f) \
 915   f(SymbolHashentry) \
 916   f(SymbolBucket) \
 917   f(StringHashentry) \
 918   f(StringBucket) \
 919   f(Other)
 920 
 921   enum Type {
 922     // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
 923     SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_DECLARE)
 924     _number_of_types
 925   };
 926 
 927   static const char * type_name(Type type) {
 928     switch(type) {
 929     SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_NAME_CASE)
 930     default:
 931       ShouldNotReachHere();
 932       return NULL;
 933     }
 934   }
 935 
 936 public:
 937   enum { RO = 0, RW = 1 };
 938 
 939   int _counts[2][_number_of_types];
 940   int _bytes [2][_number_of_types];
 941 
 942   DumpAllocStats() {
 943     memset(_counts, 0, sizeof(_counts));
 944     memset(_bytes,  0, sizeof(_bytes));
 945   };
 946 
 947   void record(MetaspaceObj::Type type, int byte_size, bool read_only) {
 948     assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
 949     int which = (read_only) ? RO : RW;
 950     _counts[which][type] ++;
 951     _bytes [which][type] += byte_size;
 952   }
 953 
 954   void record_other_type(int byte_size, bool read_only) {
 955     int which = (read_only) ? RO : RW;
 956     _bytes [which][OtherType] += byte_size;
 957   }
 958   void print_stats(int ro_all, int rw_all, int mc_all, int md_all);
 959 };
 960 
 961 void DumpAllocStats::print_stats(int ro_all, int rw_all, int mc_all, int md_all) {
 962   // Calculate size of data that was not allocated by Metaspace::allocate()
 963   MetaspaceSharedStats *stats = MetaspaceShared::stats();
 964 
 965   // symbols
 966   _counts[RO][SymbolHashentryType] = stats->symbol.hashentry_count;
 967   _bytes [RO][SymbolHashentryType] = stats->symbol.hashentry_bytes;
 968 
 969   _counts[RO][SymbolBucketType] = stats->symbol.bucket_count;
 970   _bytes [RO][SymbolBucketType] = stats->symbol.bucket_bytes;
 971 
 972   // strings
 973   _counts[RO][StringHashentryType] = stats->string.hashentry_count;
 974   _bytes [RO][StringHashentryType] = stats->string.hashentry_bytes;
 975 
 976   _counts[RO][StringBucketType] = stats->string.bucket_count;
 977   _bytes [RO][StringBucketType] = stats->string.bucket_bytes;
 978 
 979   // TODO: count things like dictionary, vtable, etc
 980   _bytes[RW][OtherType] += mc_all + md_all;
 981   rw_all += mc_all + md_all; // mc/md are mapped Read/Write
 982 
 983   // prevent divide-by-zero
 984   if (ro_all < 1) {
 985     ro_all = 1;
 986   }
 987   if (rw_all < 1) {
 988     rw_all = 1;
 989   }
 990 
 991   int all_ro_count = 0;
 992   int all_ro_bytes = 0;
 993   int all_rw_count = 0;
 994   int all_rw_bytes = 0;
 995 
 996 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
 997 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
 998   const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
 999   const char *hdr = "                        ro_cnt   ro_bytes     % |   rw_cnt   rw_bytes     % |  all_cnt  all_bytes     %";
1000 
1001   LogMessage(cds) msg;
1002 
1003   msg.info("Detailed metadata info (excluding od/st regions; rw stats include md/mc regions):");
1004   msg.info("%s", hdr);
1005   msg.info("%s", sep);
1006   for (int type = 0; type < int(_number_of_types); type ++) {
1007     const char *name = type_name((Type)type);
1008     int ro_count = _counts[RO][type];
1009     int ro_bytes = _bytes [RO][type];
1010     int rw_count = _counts[RW][type];
1011     int rw_bytes = _bytes [RW][type];
1012     int count = ro_count + rw_count;
1013     int bytes = ro_bytes + rw_bytes;
1014 
1015     double ro_perc = percent_of(ro_bytes, ro_all);
1016     double rw_perc = percent_of(rw_bytes, rw_all);
1017     double perc    = percent_of(bytes, ro_all + rw_all);
1018 
1019     msg.info(fmt_stats, name,
1020                          ro_count, ro_bytes, ro_perc,
1021                          rw_count, rw_bytes, rw_perc,
1022                          count, bytes, perc);
1023 
1024     all_ro_count += ro_count;
1025     all_ro_bytes += ro_bytes;
1026     all_rw_count += rw_count;
1027     all_rw_bytes += rw_bytes;
1028   }
1029 
1030   int all_count = all_ro_count + all_rw_count;
1031   int all_bytes = all_ro_bytes + all_rw_bytes;
1032 
1033   double all_ro_perc = percent_of(all_ro_bytes, ro_all);
1034   double all_rw_perc = percent_of(all_rw_bytes, rw_all);
1035   double all_perc    = percent_of(all_bytes, ro_all + rw_all);
1036 
1037   msg.info("%s", sep);
1038   msg.info(fmt_stats, "Total",
1039                        all_ro_count, all_ro_bytes, all_ro_perc,
1040                        all_rw_count, all_rw_bytes, all_rw_perc,
1041                        all_count, all_bytes, all_perc);
1042 
1043   assert(all_ro_bytes == ro_all, "everything should have been counted");
1044   assert(all_rw_bytes == rw_all, "everything should have been counted");
1045 
1046 #undef fmt_stats
1047 }
1048 
1049 // Populate the shared space.
1050 
1051 class VM_PopulateDumpSharedSpace: public VM_Operation {
1052 private:
1053   GrowableArray<MemRegion> *_closed_archive_heap_regions;
1054   GrowableArray<MemRegion> *_open_archive_heap_regions;
1055 
1056   void dump_java_heap_objects() NOT_CDS_JAVA_HEAP_RETURN;
1057   void dump_symbols();
1058   char* dump_read_only_tables();
1059   void print_region_stats();
1060   void print_heap_region_stats(GrowableArray<MemRegion> *heap_mem,
1061                                const char *name, const size_t total_size);
1062 public:
1063 
1064   VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
1065   void doit();   // outline because gdb sucks
1066   static void write_region(FileMapInfo* mapinfo, int region, DumpRegion* space, bool read_only,  bool allow_exec);
1067   bool allow_nested_vm_operations() const { return true; }
1068 }; // class VM_PopulateDumpSharedSpace
1069 
1070 class SortedSymbolClosure: public SymbolClosure {
1071   GrowableArray<Symbol*> _symbols;
1072   virtual void do_symbol(Symbol** sym) {
1073     assert((*sym)->is_permanent(), "archived symbols must be permanent");
1074     _symbols.append(*sym);
1075   }
1076   static int compare_symbols_by_address(Symbol** a, Symbol** b) {
1077     if (a[0] < b[0]) {
1078       return -1;
1079     } else if (a[0] == b[0]) {
1080       return 0;
1081     } else {
1082       return 1;
1083     }
1084   }
1085 
1086 public:
1087   SortedSymbolClosure() {
1088     SymbolTable::symbols_do(this);
1089     _symbols.sort(compare_symbols_by_address);
1090   }
1091   GrowableArray<Symbol*>* get_sorted_symbols() {
1092     return &_symbols;
1093   }
1094 };
1095 
1096 // ArchiveCompactor --
1097 //
1098 // This class is the central piece of shared archive compaction -- all metaspace data are
1099 // initially allocated outside of the shared regions. ArchiveCompactor copies the
1100 // metaspace data into their final location in the shared regions.
1101 
1102 class ArchiveCompactor : AllStatic {
1103   static DumpAllocStats* _alloc_stats;
1104   static SortedSymbolClosure* _ssc;
1105 
1106   static unsigned my_hash(const address& a) {
1107     return primitive_hash<address>(a);
1108   }
1109   static bool my_equals(const address& a0, const address& a1) {
1110     return primitive_equals<address>(a0, a1);
1111   }
1112   typedef ResourceHashtable<
1113       address, address,
1114       ArchiveCompactor::my_hash,   // solaris compiler doesn't like: primitive_hash<address>
1115       ArchiveCompactor::my_equals, // solaris compiler doesn't like: primitive_equals<address>
1116       16384, ResourceObj::C_HEAP> RelocationTable;
1117   static RelocationTable* _new_loc_table;
1118 
1119 public:
1120   static void initialize() {
1121     _alloc_stats = new(ResourceObj::C_HEAP, mtInternal)DumpAllocStats;
1122     _new_loc_table = new(ResourceObj::C_HEAP, mtInternal)RelocationTable;
1123   }
1124   static DumpAllocStats* alloc_stats() {
1125     return _alloc_stats;
1126   }
1127 
1128   static void allocate(MetaspaceClosure::Ref* ref, bool read_only) {
1129     address obj = ref->obj();
1130     int bytes = ref->size() * BytesPerWord;
1131     char* p;
1132     size_t alignment = BytesPerWord;
1133     char* oldtop;
1134     char* newtop;
1135 
1136     if (read_only) {
1137       oldtop = _ro_region.top();
1138       p = _ro_region.allocate(bytes, alignment);
1139       newtop = _ro_region.top();
1140     } else {
1141       oldtop = _rw_region.top();
1142       p = _rw_region.allocate(bytes, alignment);
1143       newtop = _rw_region.top();
1144     }
1145     memcpy(p, obj, bytes);
1146     bool isnew = _new_loc_table->put(obj, (address)p);
1147     log_trace(cds)("Copy: " PTR_FORMAT " ==> " PTR_FORMAT " %d", p2i(obj), p2i(p), bytes);
1148     assert(isnew, "must be");
1149 
1150     _alloc_stats->record(ref->msotype(), int(newtop - oldtop), read_only);
1151     if (ref->msotype() == MetaspaceObj::SymbolType) {
1152       uintx delta = MetaspaceShared::object_delta(p);
1153       if (delta > MAX_SHARED_DELTA) {
1154         // This is just a sanity check and should not appear in any real world usage. This
1155         // happens only if you allocate more than 2GB of Symbols and would require
1156         // millions of shared classes.
1157         vm_exit_during_initialization("Too many Symbols in the CDS archive",
1158                                       "Please reduce the number of shared classes.");
1159       }
1160     }
1161   }
1162 
1163   static address get_new_loc(MetaspaceClosure::Ref* ref) {
1164     address* pp = _new_loc_table->get(ref->obj());
1165     assert(pp != NULL, "must be");
1166     return *pp;
1167   }
1168 
1169 private:
1170   // Makes a shallow copy of visited MetaspaceObj's
1171   class ShallowCopier: public UniqueMetaspaceClosure {
1172     bool _read_only;
1173   public:
1174     ShallowCopier(bool read_only) : _read_only(read_only) {}
1175 
1176     virtual void do_unique_ref(Ref* ref, bool read_only) {
1177       if (read_only == _read_only) {
1178         allocate(ref, read_only);
1179       }
1180     }
1181   };
1182 
1183   // Relocate embedded pointers within a MetaspaceObj's shallow copy
1184   class ShallowCopyEmbeddedRefRelocator: public UniqueMetaspaceClosure {
1185   public:
1186     virtual void do_unique_ref(Ref* ref, bool read_only) {
1187       address new_loc = get_new_loc(ref);
1188       RefRelocator refer;
1189       ref->metaspace_pointers_do_at(&refer, new_loc);
1190     }
1191   };
1192 
1193   // Relocate a reference to point to its shallow copy
1194   class RefRelocator: public MetaspaceClosure {
1195   public:
1196     virtual bool do_ref(Ref* ref, bool read_only) {
1197       if (ref->not_null()) {
1198         ref->update(get_new_loc(ref));
1199       }
1200       return false; // Do not recurse.
1201     }
1202   };
1203 
1204 #ifdef ASSERT
1205   class IsRefInArchiveChecker: public MetaspaceClosure {
1206   public:
1207     virtual bool do_ref(Ref* ref, bool read_only) {
1208       if (ref->not_null()) {
1209         char* obj = (char*)ref->obj();
1210         assert(_ro_region.contains(obj) || _rw_region.contains(obj),
1211                "must be relocated to point to CDS archive");
1212       }
1213       return false; // Do not recurse.
1214     }
1215   };
1216 #endif
1217 
1218 public:
1219   static void copy_and_compact() {
1220     // We should no longer allocate anything from the metaspace, so that
1221     // we can have a stable set of MetaspaceObjs to work with.
1222     Metaspace::freeze();
1223 
1224     ResourceMark rm;
1225     SortedSymbolClosure the_ssc; // StackObj
1226     _ssc = &the_ssc;
1227 
1228     tty->print_cr("Scanning all metaspace objects ... ");
1229     {
1230       // allocate and shallow-copy RW objects, immediately following the MC region
1231       tty->print_cr("Allocating RW objects ... ");
1232       _mc_region.pack(&_rw_region);
1233 
1234       ResourceMark rm;
1235       ShallowCopier rw_copier(false);
1236       iterate_roots(&rw_copier);
1237     }
1238     {
1239       // allocate and shallow-copy of RO object, immediately following the RW region
1240       tty->print_cr("Allocating RO objects ... ");
1241       _rw_region.pack(&_ro_region);
1242 
1243       ResourceMark rm;
1244       ShallowCopier ro_copier(true);
1245       iterate_roots(&ro_copier);
1246     }
1247     {
1248       tty->print_cr("Relocating embedded pointers ... ");
1249       ResourceMark rm;
1250       ShallowCopyEmbeddedRefRelocator emb_reloc;
1251       iterate_roots(&emb_reloc);
1252     }
1253     {
1254       tty->print_cr("Relocating external roots ... ");
1255       ResourceMark rm;
1256       RefRelocator ext_reloc;
1257       iterate_roots(&ext_reloc);
1258     }
1259 
1260 #ifdef ASSERT
1261     {
1262       tty->print_cr("Verifying external roots ... ");
1263       ResourceMark rm;
1264       IsRefInArchiveChecker checker;
1265       iterate_roots(&checker);
1266     }
1267 #endif
1268 
1269 
1270     // cleanup
1271     _ssc = NULL;
1272   }
1273 
1274   // We must relocate the System::_well_known_klasses only after we have copied the
1275   // java objects in during dump_java_heap_objects(): during the object copy, we operate on
1276   // old objects which assert that their klass is the original klass.
1277   static void relocate_well_known_klasses() {
1278     {
1279       tty->print_cr("Relocating SystemDictionary::_well_known_klasses[] ... ");
1280       ResourceMark rm;
1281       RefRelocator ext_reloc;
1282       SystemDictionary::well_known_klasses_do(&ext_reloc);
1283     }
1284     // NOTE: after this point, we shouldn't have any globals that can reach the old
1285     // objects.
1286 
1287     // We cannot use any of the objects in the heap anymore (except for the objects
1288     // in the CDS shared string regions) because their headers no longer point to
1289     // valid Klasses.
1290   }
1291 
1292   static void iterate_roots(MetaspaceClosure* it) {
1293     GrowableArray<Symbol*>* symbols = _ssc->get_sorted_symbols();
1294     for (int i=0; i<symbols->length(); i++) {
1295       it->push(symbols->adr_at(i));
1296     }
1297     if (_global_klass_objects != NULL) {
1298       // Need to fix up the pointers
1299       for (int i = 0; i < _global_klass_objects->length(); i++) {
1300         // NOTE -- this requires that the vtable is NOT yet patched, or else we are hosed.
1301         it->push(_global_klass_objects->adr_at(i));
1302       }
1303     }
1304     FileMapInfo::metaspace_pointers_do(it);
1305     SystemDictionary::classes_do(it);
1306     Universe::metaspace_pointers_do(it);
1307     SymbolTable::metaspace_pointers_do(it);
1308     vmSymbols::metaspace_pointers_do(it);
1309   }
1310 
1311   static Klass* get_relocated_klass(Klass* orig_klass) {
1312     assert(DumpSharedSpaces, "dump time only");
1313     address* pp = _new_loc_table->get((address)orig_klass);
1314     assert(pp != NULL, "must be");
1315     Klass* klass = (Klass*)(*pp);
1316     assert(klass->is_klass(), "must be");
1317     return klass;
1318   }
1319 };
1320 
1321 DumpAllocStats* ArchiveCompactor::_alloc_stats;
1322 SortedSymbolClosure* ArchiveCompactor::_ssc;
1323 ArchiveCompactor::RelocationTable* ArchiveCompactor::_new_loc_table;
1324 
1325 void VM_PopulateDumpSharedSpace::write_region(FileMapInfo* mapinfo, int region_idx,
1326                                               DumpRegion* dump_region, bool read_only,  bool allow_exec) {
1327   mapinfo->write_region(region_idx, dump_region->base(), dump_region->used(), read_only, allow_exec);
1328 }
1329 
1330 void VM_PopulateDumpSharedSpace::dump_symbols() {
1331   tty->print_cr("Dumping symbol table ...");
1332 
1333   NOT_PRODUCT(SymbolTable::verify());
1334   SymbolTable::write_to_archive();
1335 }
1336 
1337 char* VM_PopulateDumpSharedSpace::dump_read_only_tables() {
1338   char* oldtop = _ro_region.top();
1339   // Reorder the system dictionary. Moving the symbols affects
1340   // how the hash table indices are calculated.
1341   SystemDictionary::reorder_dictionary_for_sharing();
1342 
1343   tty->print("Removing java_mirror ... ");
1344   if (!MetaspaceShared::is_heap_object_archiving_allowed()) {
1345     clear_basic_type_mirrors();
1346   }
1347   remove_java_mirror_in_classes();
1348   tty->print_cr("done. ");
1349   NOT_PRODUCT(SystemDictionary::verify();)
1350 
1351   size_t buckets_bytes = SystemDictionary::count_bytes_for_buckets();
1352   char* buckets_top = _ro_region.allocate(buckets_bytes, sizeof(intptr_t));
1353   SystemDictionary::copy_buckets(buckets_top, _ro_region.top());
1354 
1355   size_t table_bytes = SystemDictionary::count_bytes_for_table();
1356   char* table_top = _ro_region.allocate(table_bytes, sizeof(intptr_t));
1357   SystemDictionary::copy_table(table_top, _ro_region.top());
1358 
1359   // Write the archived object sub-graph infos. For each klass with sub-graphs,
1360   // the info includes the static fields (sub-graph entry points) and Klasses
1361   // of objects included in the sub-graph.
1362   HeapShared::write_archived_subgraph_infos();
1363 
1364   // Write the other data to the output array.
1365   WriteClosure wc(&_ro_region);
1366   MetaspaceShared::serialize(&wc);
1367 
1368   char* newtop = _ro_region.top();
1369   ArchiveCompactor::alloc_stats()->record_other_type(int(newtop - oldtop), true);
1370   return buckets_top;
1371 }
1372 
1373 void VM_PopulateDumpSharedSpace::doit() {
1374   Thread* THREAD = VMThread::vm_thread();
1375 
1376   FileMapInfo::check_nonempty_dir_in_shared_path_table();
1377 
1378   NOT_PRODUCT(SystemDictionary::verify();)
1379   // The following guarantee is meant to ensure that no loader constraints
1380   // exist yet, since the constraints table is not shared.  This becomes
1381   // more important now that we don't re-initialize vtables/itables for
1382   // shared classes at runtime, where constraints were previously created.
1383   guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
1384             "loader constraints are not saved");
1385   guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
1386           "placeholders are not saved");
1387   // Revisit and implement this if we prelink method handle call sites:
1388   guarantee(SystemDictionary::invoke_method_table() == NULL ||
1389             SystemDictionary::invoke_method_table()->number_of_entries() == 0,
1390             "invoke method table is not saved");
1391 
1392   // At this point, many classes have been loaded.
1393   // Gather systemDictionary classes in a global array and do everything to
1394   // that so we don't have to walk the SystemDictionary again.
1395   _global_klass_objects = new GrowableArray<Klass*>(1000);
1396   CollectClassesClosure collect_classes;
1397   ClassLoaderDataGraph::loaded_classes_do(&collect_classes);
1398 
1399   tty->print_cr("Number of classes %d", _global_klass_objects->length());
1400   {
1401     int num_type_array = 0, num_obj_array = 0, num_inst = 0;
1402     for (int i = 0; i < _global_klass_objects->length(); i++) {
1403       Klass* k = _global_klass_objects->at(i);
1404       if (k->is_instance_klass()) {
1405         num_inst ++;
1406       } else if (k->is_objArray_klass()) {
1407         num_obj_array ++;
1408       } else {
1409         assert(k->is_typeArray_klass(), "sanity");
1410         num_type_array ++;
1411       }
1412     }
1413     tty->print_cr("    instance classes   = %5d", num_inst);
1414     tty->print_cr("    obj array classes  = %5d", num_obj_array);
1415     tty->print_cr("    type array classes = %5d", num_type_array);
1416   }
1417 
1418   // Ensure the ConstMethods won't be modified at run-time
1419   tty->print("Updating ConstMethods ... ");
1420   rewrite_nofast_bytecodes_and_calculate_fingerprints();
1421   tty->print_cr("done. ");
1422 
1423   // Move classes from platform/system dictionaries into the boot dictionary
1424   SystemDictionary::combine_shared_dictionaries();
1425 
1426   // Make sure all classes have a correct loader type.
1427   ClassLoaderData::the_null_class_loader_data()->dictionary()->classes_do(MetaspaceShared::check_shared_class_loader_type);
1428 
1429   // Remove all references outside the metadata
1430   tty->print("Removing unshareable information ... ");
1431   remove_unshareable_in_classes();
1432   tty->print_cr("done. ");
1433 
1434   // We don't support archiving anonymous classes. Verify that they are not stored in
1435   // the any dictionaries.
1436   NOT_PRODUCT(assert_no_anonymoys_classes_in_dictionaries());
1437 
1438   SystemDictionaryShared::finalize_verification_constraints();
1439 
1440   ArchiveCompactor::initialize();
1441   ArchiveCompactor::copy_and_compact();
1442 
1443   dump_symbols();
1444 
1445   // Dump supported java heap objects
1446   _closed_archive_heap_regions = NULL;
1447   _open_archive_heap_regions = NULL;
1448   dump_java_heap_objects();
1449 
1450   ArchiveCompactor::relocate_well_known_klasses();
1451 
1452   char* read_only_tables_start = dump_read_only_tables();
1453   _ro_region.pack(&_md_region);
1454 
1455   char* vtbl_list = _md_region.top();
1456   MetaspaceShared::allocate_cpp_vtable_clones();
1457   _md_region.pack(&_od_region);
1458 
1459   // Relocate the archived class file data into the od region
1460   relocate_cached_class_file();
1461   _od_region.pack();
1462 
1463   // The 5 core spaces are allocated consecutively mc->rw->ro->md->od, so there total size
1464   // is just the spaces between the two ends.
1465   size_t core_spaces_size = _od_region.end() - _mc_region.base();
1466   assert(core_spaces_size == (size_t)align_up(core_spaces_size, Metaspace::reserve_alignment()),
1467          "should already be aligned");
1468 
1469   // During patching, some virtual methods may be called, so at this point
1470   // the vtables must contain valid methods (as filled in by CppVtableCloner::allocate).
1471   MetaspaceShared::patch_cpp_vtable_pointers();
1472 
1473   // The vtable clones contain addresses of the current process.
1474   // We don't want to write these addresses into the archive.
1475   MetaspaceShared::zero_cpp_vtable_clones_for_writing();
1476 
1477   // Create and write the archive file that maps the shared spaces.
1478 
1479   FileMapInfo* mapinfo = new FileMapInfo();
1480   mapinfo->populate_header(os::vm_allocation_granularity());
1481   mapinfo->set_read_only_tables_start(read_only_tables_start);
1482   mapinfo->set_misc_data_patching_start(vtbl_list);
1483   mapinfo->set_cds_i2i_entry_code_buffers(MetaspaceShared::cds_i2i_entry_code_buffers());
1484   mapinfo->set_cds_i2i_entry_code_buffers_size(MetaspaceShared::cds_i2i_entry_code_buffers_size());
1485   mapinfo->set_core_spaces_size(core_spaces_size);
1486 
1487   for (int pass=1; pass<=2; pass++) {
1488     if (pass == 1) {
1489       // The first pass doesn't actually write the data to disk. All it
1490       // does is to update the fields in the mapinfo->_header.
1491     } else {
1492       // After the first pass, the contents of mapinfo->_header are finalized,
1493       // so we can compute the header's CRC, and write the contents of the header
1494       // and the regions into disk.
1495       mapinfo->open_for_write();
1496       mapinfo->set_header_crc(mapinfo->compute_header_crc());
1497     }
1498     mapinfo->write_header();
1499 
1500     // NOTE: md contains the trampoline code for method entries, which are patched at run time,
1501     // so it needs to be read/write.
1502     write_region(mapinfo, MetaspaceShared::mc, &_mc_region, /*read_only=*/false,/*allow_exec=*/true);
1503     write_region(mapinfo, MetaspaceShared::rw, &_rw_region, /*read_only=*/false,/*allow_exec=*/false);
1504     write_region(mapinfo, MetaspaceShared::ro, &_ro_region, /*read_only=*/true, /*allow_exec=*/false);
1505     write_region(mapinfo, MetaspaceShared::md, &_md_region, /*read_only=*/false,/*allow_exec=*/false);
1506     write_region(mapinfo, MetaspaceShared::od, &_od_region, /*read_only=*/true, /*allow_exec=*/false);
1507 
1508     _total_string_region_size = mapinfo->write_archive_heap_regions(
1509                                         _closed_archive_heap_regions,
1510                                         MetaspaceShared::first_string,
1511                                         MetaspaceShared::max_strings);
1512     _total_open_archive_region_size = mapinfo->write_archive_heap_regions(
1513                                         _open_archive_heap_regions,
1514                                         MetaspaceShared::first_open_archive_heap_region,
1515                                         MetaspaceShared::max_open_archive_heap_region);
1516   }
1517 
1518   mapinfo->close();
1519 
1520   // Restore the vtable in case we invoke any virtual methods.
1521   MetaspaceShared::clone_cpp_vtables((intptr_t*)vtbl_list);
1522 
1523   print_region_stats();
1524 
1525   if (log_is_enabled(Info, cds)) {
1526     ArchiveCompactor::alloc_stats()->print_stats(int(_ro_region.used()), int(_rw_region.used()),
1527                                                  int(_mc_region.used()), int(_md_region.used()));
1528   }
1529 
1530   if (PrintSystemDictionaryAtExit) {
1531     SystemDictionary::print();
1532   }
1533   // There may be other pending VM operations that operate on the InstanceKlasses,
1534   // which will fail because InstanceKlasses::remove_unshareable_info()
1535   // has been called. Forget these operations and exit the VM directly.
1536   vm_direct_exit(0);
1537 }
1538 
1539 void VM_PopulateDumpSharedSpace::print_region_stats() {
1540   // Print statistics of all the regions
1541   const size_t total_reserved = _ro_region.reserved()  + _rw_region.reserved() +
1542                                 _mc_region.reserved()  + _md_region.reserved() +
1543                                 _od_region.reserved()  +
1544                                 _total_string_region_size +
1545                                 _total_open_archive_region_size;
1546   const size_t total_bytes = _ro_region.used()  + _rw_region.used() +
1547                              _mc_region.used()  + _md_region.used() +
1548                              _od_region.used()  +
1549                              _total_string_region_size +
1550                              _total_open_archive_region_size;
1551   const double total_u_perc = percent_of(total_bytes, total_reserved);
1552 
1553   _mc_region.print(total_reserved);
1554   _rw_region.print(total_reserved);
1555   _ro_region.print(total_reserved);
1556   _md_region.print(total_reserved);
1557   _od_region.print(total_reserved);
1558   print_heap_region_stats(_closed_archive_heap_regions, "st", total_reserved);
1559   print_heap_region_stats(_open_archive_heap_regions, "oa", total_reserved);
1560 
1561   tty->print_cr("total    : " SIZE_FORMAT_W(9) " [100.0%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used]",
1562                  total_bytes, total_reserved, total_u_perc);
1563 }
1564 
1565 void VM_PopulateDumpSharedSpace::print_heap_region_stats(GrowableArray<MemRegion> *heap_mem,
1566                                                          const char *name, const size_t total_size) {
1567   int arr_len = heap_mem == NULL ? 0 : heap_mem->length();
1568   for (int i = 0; i < arr_len; i++) {
1569       char* start = (char*)heap_mem->at(i).start();
1570       size_t size = heap_mem->at(i).byte_size();
1571       char* top = start + size;
1572       tty->print_cr("%s%d space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [100.0%% used] at " INTPTR_FORMAT,
1573                     name, i, size, size/double(total_size)*100.0, size, p2i(start));
1574 
1575   }
1576 }
1577 
1578 // Update a Java object to point its Klass* to the new location after
1579 // shared archive has been compacted.
1580 void MetaspaceShared::relocate_klass_ptr(oop o) {
1581   assert(DumpSharedSpaces, "sanity");
1582   Klass* k = ArchiveCompactor::get_relocated_klass(o->klass());
1583   o->set_klass(k);
1584 }
1585 
1586 Klass* MetaspaceShared::get_relocated_klass(Klass *k) {
1587   assert(DumpSharedSpaces, "sanity");
1588   return ArchiveCompactor::get_relocated_klass(k);
1589 }
1590 
1591 class LinkSharedClassesClosure : public KlassClosure {
1592   Thread* THREAD;
1593   bool    _made_progress;
1594  public:
1595   LinkSharedClassesClosure(Thread* thread) : THREAD(thread), _made_progress(false) {}
1596 
1597   void reset()               { _made_progress = false; }
1598   bool made_progress() const { return _made_progress; }
1599 
1600   void do_klass(Klass* k) {
1601     if (k->is_instance_klass()) {
1602       InstanceKlass* ik = InstanceKlass::cast(k);
1603       // Link the class to cause the bytecodes to be rewritten and the
1604       // cpcache to be created. Class verification is done according
1605       // to -Xverify setting.
1606       _made_progress |= MetaspaceShared::try_link_class(ik, THREAD);
1607       guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1608 
1609       ik->constants()->resolve_class_constants(THREAD);
1610     }
1611   }
1612 };
1613 
1614 class CheckSharedClassesClosure : public KlassClosure {
1615   bool    _made_progress;
1616  public:
1617   CheckSharedClassesClosure() : _made_progress(false) {}
1618 
1619   void reset()               { _made_progress = false; }
1620   bool made_progress() const { return _made_progress; }
1621   void do_klass(Klass* k) {
1622     if (k->is_instance_klass() && InstanceKlass::cast(k)->check_sharing_error_state()) {
1623       _made_progress = true;
1624     }
1625   }
1626 };
1627 
1628 void MetaspaceShared::check_shared_class_loader_type(InstanceKlass* ik) {
1629   ResourceMark rm;
1630   if (ik->shared_classpath_index() == UNREGISTERED_INDEX) {
1631     guarantee(ik->loader_type() == 0,
1632             "Class loader type must not be set for this class %s", ik->name()->as_C_string());
1633   } else {
1634     guarantee(ik->loader_type() != 0,
1635             "Class loader type must be set for this class %s", ik->name()->as_C_string());
1636   }
1637 }
1638 
1639 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
1640   // We need to iterate because verification may cause additional classes
1641   // to be loaded.
1642   LinkSharedClassesClosure link_closure(THREAD);
1643   do {
1644     link_closure.reset();
1645     ClassLoaderDataGraph::loaded_classes_do(&link_closure);
1646     guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1647   } while (link_closure.made_progress());
1648 
1649   if (_has_error_classes) {
1650     // Mark all classes whose super class or interfaces failed verification.
1651     CheckSharedClassesClosure check_closure;
1652     do {
1653       // Not completely sure if we need to do this iteratively. Anyway,
1654       // we should come here only if there are unverifiable classes, which
1655       // shouldn't happen in normal cases. So better safe than sorry.
1656       check_closure.reset();
1657       ClassLoaderDataGraph::loaded_classes_do(&check_closure);
1658     } while (check_closure.made_progress());
1659 
1660     if (IgnoreUnverifiableClassesDuringDump) {
1661       // This is useful when running JCK or SQE tests. You should not
1662       // enable this when running real apps.
1663       SystemDictionary::remove_classes_in_error_state();
1664     } else {
1665       tty->print_cr("Please remove the unverifiable classes from your class list and try again");
1666       exit(1);
1667     }
1668   }
1669 }
1670 
1671 void MetaspaceShared::prepare_for_dumping() {
1672   Arguments::check_unsupported_dumping_properties();
1673   ClassLoader::initialize_shared_path();
1674 }
1675 
1676 // Preload classes from a list, populate the shared spaces and dump to a
1677 // file.
1678 void MetaspaceShared::preload_and_dump(TRAPS) {
1679   { TraceTime timer("Dump Shared Spaces", TRACETIME_LOG(Info, startuptime));
1680     ResourceMark rm;
1681     char class_list_path_str[JVM_MAXPATHLEN];
1682     // Preload classes to be shared.
1683     // Should use some os:: method rather than fopen() here. aB.
1684     const char* class_list_path;
1685     if (SharedClassListFile == NULL) {
1686       // Construct the path to the class list (in jre/lib)
1687       // Walk up two directories from the location of the VM and
1688       // optionally tack on "lib" (depending on platform)
1689       os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
1690       for (int i = 0; i < 3; i++) {
1691         char *end = strrchr(class_list_path_str, *os::file_separator());
1692         if (end != NULL) *end = '\0';
1693       }
1694       int class_list_path_len = (int)strlen(class_list_path_str);
1695       if (class_list_path_len >= 3) {
1696         if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
1697           if (class_list_path_len < JVM_MAXPATHLEN - 4) {
1698             jio_snprintf(class_list_path_str + class_list_path_len,
1699                          sizeof(class_list_path_str) - class_list_path_len,
1700                          "%slib", os::file_separator());
1701             class_list_path_len += 4;
1702           }
1703         }
1704       }
1705       if (class_list_path_len < JVM_MAXPATHLEN - 10) {
1706         jio_snprintf(class_list_path_str + class_list_path_len,
1707                      sizeof(class_list_path_str) - class_list_path_len,
1708                      "%sclasslist", os::file_separator());
1709       }
1710       class_list_path = class_list_path_str;
1711     } else {
1712       class_list_path = SharedClassListFile;
1713     }
1714 
1715     tty->print_cr("Loading classes to share ...");
1716     _has_error_classes = false;
1717     int class_count = preload_classes(class_list_path, THREAD);
1718     if (ExtraSharedClassListFile) {
1719       class_count += preload_classes(ExtraSharedClassListFile, THREAD);
1720     }
1721     tty->print_cr("Loading classes to share: done.");
1722 
1723     log_info(cds)("Shared spaces: preloaded %d classes", class_count);
1724 
1725     // Rewrite and link classes
1726     tty->print_cr("Rewriting and linking classes ...");
1727 
1728     // Link any classes which got missed. This would happen if we have loaded classes that
1729     // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
1730     // fails verification, all other interfaces that were not specified in the classlist but
1731     // are implemented by K are not verified.
1732     link_and_cleanup_shared_classes(CATCH);
1733     tty->print_cr("Rewriting and linking classes: done");
1734 
1735     SystemDictionary::clear_invoke_method_table();
1736 
1737     VM_PopulateDumpSharedSpace op;
1738     VMThread::execute(&op);
1739   }
1740 }
1741 
1742 
1743 int MetaspaceShared::preload_classes(const char* class_list_path, TRAPS) {
1744   ClassListParser parser(class_list_path);
1745   int class_count = 0;
1746 
1747     while (parser.parse_one_line()) {
1748       Klass* klass = ClassLoaderExt::load_one_class(&parser, THREAD);
1749       if (HAS_PENDING_EXCEPTION) {
1750         if (klass == NULL &&
1751              (PENDING_EXCEPTION->klass()->name() == vmSymbols::java_lang_ClassNotFoundException())) {
1752           // print a warning only when the pending exception is class not found
1753           tty->print_cr("Preload Warning: Cannot find %s", parser.current_class_name());
1754         }
1755         CLEAR_PENDING_EXCEPTION;
1756       }
1757       if (klass != NULL) {
1758         if (log_is_enabled(Trace, cds)) {
1759           ResourceMark rm;
1760           log_trace(cds)("Shared spaces preloaded: %s", klass->external_name());
1761         }
1762 
1763         if (klass->is_instance_klass()) {
1764           InstanceKlass* ik = InstanceKlass::cast(klass);
1765 
1766           // Link the class to cause the bytecodes to be rewritten and the
1767           // cpcache to be created. The linking is done as soon as classes
1768           // are loaded in order that the related data structures (klass and
1769           // cpCache) are located together.
1770           try_link_class(ik, THREAD);
1771           guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1772         }
1773 
1774         class_count++;
1775       }
1776     }
1777 
1778   return class_count;
1779 }
1780 
1781 // Returns true if the class's status has changed
1782 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
1783   assert(DumpSharedSpaces, "should only be called during dumping");
1784   if (ik->init_state() < InstanceKlass::linked) {
1785     bool saved = BytecodeVerificationLocal;
1786     if (ik->loader_type() == 0 && ik->class_loader() == NULL) {
1787       // The verification decision is based on BytecodeVerificationRemote
1788       // for non-system classes. Since we are using the NULL classloader
1789       // to load non-system classes for customized class loaders during dumping,
1790       // we need to temporarily change BytecodeVerificationLocal to be the same as
1791       // BytecodeVerificationRemote. Note this can cause the parent system
1792       // classes also being verified. The extra overhead is acceptable during
1793       // dumping.
1794       BytecodeVerificationLocal = BytecodeVerificationRemote;
1795     }
1796     ik->link_class(THREAD);
1797     if (HAS_PENDING_EXCEPTION) {
1798       ResourceMark rm;
1799       tty->print_cr("Preload Warning: Verification failed for %s",
1800                     ik->external_name());
1801       CLEAR_PENDING_EXCEPTION;
1802       ik->set_in_error_state();
1803       _has_error_classes = true;
1804     }
1805     BytecodeVerificationLocal = saved;
1806     return true;
1807   } else {
1808     return false;
1809   }
1810 }
1811 
1812 #if INCLUDE_CDS_JAVA_HEAP
1813 void VM_PopulateDumpSharedSpace::dump_java_heap_objects() {
1814   if (!MetaspaceShared::is_heap_object_archiving_allowed()) {
1815     if (log_is_enabled(Info, cds)) {
1816       log_info(cds)(
1817         "Archived java heap is not supported as UseG1GC, "
1818         "UseCompressedOops and UseCompressedClassPointers are required."
1819         "Current settings: UseG1GC=%s, UseCompressedOops=%s, UseCompressedClassPointers=%s.",
1820         BOOL_TO_STR(UseG1GC), BOOL_TO_STR(UseCompressedOops),
1821         BOOL_TO_STR(UseCompressedClassPointers));
1822     }
1823     return;
1824   }
1825 
1826   {
1827     NoSafepointVerifier nsv;
1828 
1829     // Cache for recording where the archived objects are copied to
1830     MetaspaceShared::create_archive_object_cache();
1831 
1832     tty->print_cr("Dumping objects to closed archive heap region ...");
1833     NOT_PRODUCT(StringTable::verify());
1834     // The closed space has maximum two regions. See FileMapInfo::write_archive_heap_regions() for details.
1835     _closed_archive_heap_regions = new GrowableArray<MemRegion>(2);
1836     MetaspaceShared::dump_closed_archive_heap_objects(_closed_archive_heap_regions);
1837 
1838     tty->print_cr("Dumping objects to open archive heap region ...");
1839     _open_archive_heap_regions = new GrowableArray<MemRegion>(2);
1840     MetaspaceShared::dump_open_archive_heap_objects(_open_archive_heap_regions);
1841 
1842     MetaspaceShared::destroy_archive_object_cache();
1843   }
1844 
1845   G1HeapVerifier::verify_archive_regions();
1846 }
1847 
1848 void MetaspaceShared::dump_closed_archive_heap_objects(
1849                                     GrowableArray<MemRegion> * closed_archive) {
1850   assert(is_heap_object_archiving_allowed(), "Cannot dump java heap objects");
1851 
1852   Thread* THREAD = Thread::current();
1853   G1CollectedHeap::heap()->begin_archive_alloc_range();
1854 
1855   // Archive interned string objects
1856   StringTable::write_to_archive();
1857 
1858   G1CollectedHeap::heap()->end_archive_alloc_range(closed_archive,
1859                                                    os::vm_allocation_granularity());
1860 }
1861 
1862 void MetaspaceShared::dump_open_archive_heap_objects(
1863                                     GrowableArray<MemRegion> * open_archive) {
1864   assert(UseG1GC, "Only support G1 GC");
1865   assert(UseCompressedOops && UseCompressedClassPointers,
1866          "Only support UseCompressedOops and UseCompressedClassPointers enabled");
1867 
1868   Thread* THREAD = Thread::current();
1869   G1CollectedHeap::heap()->begin_archive_alloc_range(true /* open */);
1870 
1871   java_lang_Class::archive_basic_type_mirrors(THREAD);
1872 
1873   MetaspaceShared::archive_klass_objects(THREAD);
1874 
1875   HeapShared::archive_module_graph_objects(THREAD);
1876 
1877   G1CollectedHeap::heap()->end_archive_alloc_range(open_archive,
1878                                                    os::vm_allocation_granularity());
1879 }
1880 
1881 unsigned MetaspaceShared::obj_hash(oop const& p) {
1882   assert(!p->mark()->has_bias_pattern(),
1883          "this object should never have been locked");  // so identity_hash won't safepoin
1884   unsigned hash = (unsigned)p->identity_hash();
1885   return hash;
1886 }
1887 
1888 MetaspaceShared::ArchivedObjectCache* MetaspaceShared::_archive_object_cache = NULL;
1889 oop MetaspaceShared::find_archived_heap_object(oop obj) {
1890   assert(DumpSharedSpaces, "dump-time only");
1891   ArchivedObjectCache* cache = MetaspaceShared::archive_object_cache();
1892   oop* p = cache->get(obj);
1893   if (p != NULL) {
1894     return *p;
1895   } else {
1896     return NULL;
1897   }
1898 }
1899 
1900 oop MetaspaceShared::archive_heap_object(oop obj, Thread* THREAD) {
1901   assert(DumpSharedSpaces, "dump-time only");
1902 
1903   oop ao = find_archived_heap_object(obj);
1904   if (ao != NULL) {
1905     // already archived
1906     return ao;
1907   }
1908 
1909   int len = obj->size();
1910   if (G1CollectedHeap::heap()->is_archive_alloc_too_large(len)) {
1911     return NULL;
1912   }
1913 
1914   int hash = obj->identity_hash();
1915   oop archived_oop = (oop)G1CollectedHeap::heap()->archive_mem_allocate(len);
1916   if (archived_oop != NULL) {
1917     Copy::aligned_disjoint_words((HeapWord*)obj, (HeapWord*)archived_oop, len);
1918     relocate_klass_ptr(archived_oop);
1919     ArchivedObjectCache* cache = MetaspaceShared::archive_object_cache();
1920     cache->put(obj, archived_oop);
1921   }
1922   log_debug(cds, heap)("Archived heap object " PTR_FORMAT " ==> " PTR_FORMAT,
1923                        p2i(obj), p2i(archived_oop));
1924   return archived_oop;
1925 }
1926 
1927 oop MetaspaceShared::materialize_archived_object(oop obj) {
1928   if (obj != NULL) {
1929     return G1CollectedHeap::heap()->materialize_archived_object(obj);
1930   }
1931   return NULL;
1932 }
1933 
1934 void MetaspaceShared::archive_klass_objects(Thread* THREAD) {
1935   int i;
1936   for (i = 0; i < _global_klass_objects->length(); i++) {
1937     Klass* k = _global_klass_objects->at(i);
1938 
1939     // archive mirror object
1940     java_lang_Class::archive_mirror(k, CHECK);
1941 
1942     // archive the resolved_referenes array
1943     if (k->is_instance_klass()) {
1944       InstanceKlass* ik = InstanceKlass::cast(k);
1945       ik->constants()->archive_resolved_references(THREAD);
1946     }
1947   }
1948 }
1949 
1950 bool MetaspaceShared::is_archive_object(oop p) {
1951   return (p == NULL) ? false : G1ArchiveAllocator::is_archive_object(p);
1952 }
1953 
1954 void MetaspaceShared::fixup_mapped_heap_regions() {
1955   FileMapInfo *mapinfo = FileMapInfo::current_info();
1956   mapinfo->fixup_mapped_heap_regions();
1957 }
1958 #endif // INCLUDE_CDS_JAVA_HEAP
1959 
1960 // Closure for serializing initialization data in from a data area
1961 // (ptr_array) read from the shared file.
1962 
1963 class ReadClosure : public SerializeClosure {
1964 private:
1965   intptr_t** _ptr_array;
1966 
1967   inline intptr_t nextPtr() {
1968     return *(*_ptr_array)++;
1969   }
1970 
1971 public:
1972   ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
1973 
1974   void do_ptr(void** p) {
1975     assert(*p == NULL, "initializing previous initialized pointer.");
1976     intptr_t obj = nextPtr();
1977     assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
1978            "hit tag while initializing ptrs.");
1979     *p = (void*)obj;
1980   }
1981 
1982   void do_u4(u4* p) {
1983     intptr_t obj = nextPtr();
1984     *p = (u4)(uintx(obj));
1985   }
1986 
1987   void do_tag(int tag) {
1988     int old_tag;
1989     old_tag = (int)(intptr_t)nextPtr();
1990     // do_int(&old_tag);
1991     assert(tag == old_tag, "old tag doesn't match");
1992     FileMapInfo::assert_mark(tag == old_tag);
1993   }
1994 
1995   void do_oop(oop *p) {
1996     narrowOop o = (narrowOop)nextPtr();
1997     if (o == 0 || !MetaspaceShared::open_archive_heap_region_mapped()) {
1998       p = NULL;
1999     } else {
2000       assert(MetaspaceShared::is_heap_object_archiving_allowed(),
2001              "Archived heap object is not allowed");
2002       assert(MetaspaceShared::open_archive_heap_region_mapped(),
2003              "Open archive heap region is not mapped");
2004       *p = CompressedOops::decode_not_null(o);
2005     }
2006   }
2007 
2008   void do_region(u_char* start, size_t size) {
2009     assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
2010     assert(size % sizeof(intptr_t) == 0, "bad size");
2011     do_tag((int)size);
2012     while (size > 0) {
2013       *(intptr_t*)start = nextPtr();
2014       start += sizeof(intptr_t);
2015       size -= sizeof(intptr_t);
2016     }
2017   }
2018 
2019   bool reading() const { return true; }
2020 };
2021 
2022 // Return true if given address is in the misc data region
2023 bool MetaspaceShared::is_in_shared_region(const void* p, int idx) {
2024   return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_region(p, idx);
2025 }
2026 
2027 bool MetaspaceShared::is_in_trampoline_frame(address addr) {
2028   if (UseSharedSpaces && is_in_shared_region(addr, MetaspaceShared::mc)) {
2029     return true;
2030   }
2031   return false;
2032 }
2033 
2034 void MetaspaceShared::print_shared_spaces() {
2035   if (UseSharedSpaces) {
2036     FileMapInfo::current_info()->print_shared_spaces();
2037   }
2038 }
2039 
2040 
2041 // Map shared spaces at requested addresses and return if succeeded.
2042 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
2043   size_t image_alignment = mapinfo->alignment();
2044 
2045 #ifndef _WINDOWS
2046   // Map in the shared memory and then map the regions on top of it.
2047   // On Windows, don't map the memory here because it will cause the
2048   // mappings of the regions to fail.
2049   ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
2050   if (!shared_rs.is_reserved()) return false;
2051 #endif
2052 
2053   assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
2054 
2055   char* ro_base = NULL; char* ro_top;
2056   char* rw_base = NULL; char* rw_top;
2057   char* mc_base = NULL; char* mc_top;
2058   char* md_base = NULL; char* md_top;
2059   char* od_base = NULL; char* od_top;
2060 
2061   // Map each shared region
2062   if ((mc_base = mapinfo->map_region(mc, &mc_top)) != NULL &&
2063       (rw_base = mapinfo->map_region(rw, &rw_top)) != NULL &&
2064       (ro_base = mapinfo->map_region(ro, &ro_top)) != NULL &&
2065       (md_base = mapinfo->map_region(md, &md_top)) != NULL &&
2066       (od_base = mapinfo->map_region(od, &od_top)) != NULL &&
2067       (image_alignment == (size_t)os::vm_allocation_granularity()) &&
2068       mapinfo->validate_shared_path_table()) {
2069     // Success -- set up MetaspaceObj::_shared_metaspace_{base,top} for
2070     // fast checking in MetaspaceShared::is_in_shared_metaspace() and
2071     // MetaspaceObj::is_shared().
2072     //
2073     // We require that mc->rw->ro->md->od to be laid out consecutively, with no
2074     // gaps between them. That way, we can ensure that the OS won't be able to
2075     // allocate any new memory spaces inside _shared_metaspace_{base,top}, which
2076     // would mess up the simple comparision in MetaspaceShared::is_in_shared_metaspace().
2077     assert(mc_base < ro_base && mc_base < rw_base && mc_base < md_base && mc_base < od_base, "must be");
2078     assert(od_top  > ro_top  && od_top  > rw_top  && od_top  > md_top  && od_top  > mc_top , "must be");
2079     assert(mc_top == rw_base, "must be");
2080     assert(rw_top == ro_base, "must be");
2081     assert(ro_top == md_base, "must be");
2082     assert(md_top == od_base, "must be");
2083 
2084     MetaspaceObj::_shared_metaspace_base = (void*)mc_base;
2085     MetaspaceObj::_shared_metaspace_top  = (void*)od_top;
2086     return true;
2087   } else {
2088     // If there was a failure in mapping any of the spaces, unmap the ones
2089     // that succeeded
2090     if (ro_base != NULL) mapinfo->unmap_region(ro);
2091     if (rw_base != NULL) mapinfo->unmap_region(rw);
2092     if (mc_base != NULL) mapinfo->unmap_region(mc);
2093     if (md_base != NULL) mapinfo->unmap_region(md);
2094     if (od_base != NULL) mapinfo->unmap_region(od);
2095 #ifndef _WINDOWS
2096     // Release the entire mapped region
2097     shared_rs.release();
2098 #endif
2099     // If -Xshare:on is specified, print out the error message and exit VM,
2100     // otherwise, set UseSharedSpaces to false and continue.
2101     if (RequireSharedSpaces || PrintSharedArchiveAndExit) {
2102       vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
2103     } else {
2104       FLAG_SET_DEFAULT(UseSharedSpaces, false);
2105     }
2106     return false;
2107   }
2108 }
2109 
2110 // Read the miscellaneous data from the shared file, and
2111 // serialize it out to its various destinations.
2112 
2113 void MetaspaceShared::initialize_shared_spaces() {
2114   FileMapInfo *mapinfo = FileMapInfo::current_info();
2115   _cds_i2i_entry_code_buffers = mapinfo->cds_i2i_entry_code_buffers();
2116   _cds_i2i_entry_code_buffers_size = mapinfo->cds_i2i_entry_code_buffers_size();
2117   _core_spaces_size = mapinfo->core_spaces_size();
2118   char* buffer = mapinfo->misc_data_patching_start();
2119   clone_cpp_vtables((intptr_t*)buffer);
2120 
2121   // The rest of the data is now stored in the RW region
2122   buffer = mapinfo->read_only_tables_start();
2123   int sharedDictionaryLen = *(intptr_t*)buffer;
2124   buffer += sizeof(intptr_t);
2125   int number_of_entries = *(intptr_t*)buffer;
2126   buffer += sizeof(intptr_t);
2127   SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer,
2128                                           sharedDictionaryLen,
2129                                           number_of_entries);
2130   buffer += sharedDictionaryLen;
2131 
2132   // The following data are the linked list elements
2133   // (HashtableEntry objects) for the shared dictionary table.
2134 
2135   int len = *(intptr_t*)buffer;     // skip over shared dictionary entries
2136   buffer += sizeof(intptr_t);
2137   buffer += len;
2138 
2139   // The table of archived java heap object sub-graph infos
2140   buffer = HeapShared::read_archived_subgraph_infos(buffer);
2141 
2142   // Verify various attributes of the archive, plus initialize the
2143   // shared string/symbol tables
2144   intptr_t* array = (intptr_t*)buffer;
2145   ReadClosure rc(&array);
2146   serialize(&rc);
2147 
2148   // Initialize the run-time symbol table.
2149   SymbolTable::create_table();
2150 
2151   // Close the mapinfo file
2152   mapinfo->close();
2153 
2154   if (PrintSharedArchiveAndExit) {
2155     if (PrintSharedDictionary) {
2156       tty->print_cr("\nShared classes:\n");
2157       SystemDictionary::print_shared(tty);
2158     }
2159     if (_archive_loading_failed) {
2160       tty->print_cr("archive is invalid");
2161       vm_exit(1);
2162     } else {
2163       tty->print_cr("archive is valid");
2164       vm_exit(0);
2165     }
2166   }
2167 }
2168 
2169 // JVM/TI RedefineClasses() support:
2170 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
2171   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
2172 
2173   if (UseSharedSpaces) {
2174     // remap the shared readonly space to shared readwrite, private
2175     FileMapInfo* mapinfo = FileMapInfo::current_info();
2176     if (!mapinfo->remap_shared_readonly_as_readwrite()) {
2177       return false;
2178     }
2179     _remapped_readwrite = true;
2180   }
2181   return true;
2182 }
2183 
2184 void MetaspaceShared::report_out_of_space(const char* name, size_t needed_bytes) {
2185   // This is highly unlikely to happen on 64-bits because we have reserved a 4GB space.
2186   // On 32-bit we reserve only 256MB so you could run out of space with 100,000 classes
2187   // or so.
2188   _mc_region.print_out_of_space_msg(name, needed_bytes);
2189   _rw_region.print_out_of_space_msg(name, needed_bytes);
2190   _ro_region.print_out_of_space_msg(name, needed_bytes);
2191   _md_region.print_out_of_space_msg(name, needed_bytes);
2192   _od_region.print_out_of_space_msg(name, needed_bytes);
2193 
2194   vm_exit_during_initialization(err_msg("Unable to allocate from '%s' region", name),
2195                                 "Please reduce the number of shared classes.");
2196 }