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/classLoaderDataGraph.hpp"
  28 #include "classfile/classListParser.hpp"
  29 #include "classfile/classLoaderExt.hpp"
  30 #include "classfile/dictionary.hpp"
  31 #include "classfile/loaderConstraints.hpp"
  32 #include "classfile/placeholders.hpp"
  33 #include "classfile/symbolTable.hpp"
  34 #include "classfile/stringTable.hpp"
  35 #include "classfile/systemDictionary.hpp"
  36 #include "classfile/systemDictionaryShared.hpp"
  37 #include "code/codeCache.hpp"
  38 #include "interpreter/bytecodeStream.hpp"
  39 #include "interpreter/bytecodes.hpp"
  40 #include "logging/log.hpp"
  41 #include "logging/logMessage.hpp"
  42 #include "memory/filemap.hpp"
  43 #include "memory/heapShared.inline.hpp"
  44 #include "memory/metaspace.hpp"
  45 #include "memory/metaspaceClosure.hpp"
  46 #include "memory/metaspaceShared.hpp"
  47 #include "memory/resourceArea.hpp"
  48 #include "oops/compressedOops.inline.hpp"
  49 #include "oops/instanceClassLoaderKlass.hpp"
  50 #include "oops/instanceMirrorKlass.hpp"
  51 #include "oops/instanceRefKlass.hpp"
  52 #include "oops/objArrayKlass.hpp"
  53 #include "oops/objArrayOop.hpp"
  54 #include "oops/oop.inline.hpp"
  55 #include "oops/typeArrayKlass.hpp"
  56 #include "prims/jvmtiRedefineClasses.hpp"
  57 #include "runtime/handles.inline.hpp"
  58 #include "runtime/os.hpp"
  59 #include "runtime/safepointVerifiers.hpp"
  60 #include "runtime/signature.hpp"
  61 #include "runtime/timerTrace.hpp"
  62 #include "runtime/vmThread.hpp"
  63 #include "runtime/vm_operations.hpp"
  64 #include "utilities/align.hpp"
  65 #include "utilities/bitMap.hpp"
  66 #include "utilities/defaultStream.hpp"
  67 #include "utilities/hashtable.hpp"
  68 #if INCLUDE_G1GC
  69 #include "gc/g1/g1CollectedHeap.hpp"
  70 #endif
  71 
  72 ReservedSpace MetaspaceShared::_shared_rs;
  73 VirtualSpace MetaspaceShared::_shared_vs;
  74 MetaspaceSharedStats MetaspaceShared::_stats;
  75 bool MetaspaceShared::_has_error_classes;
  76 bool MetaspaceShared::_archive_loading_failed = false;
  77 bool MetaspaceShared::_remapped_readwrite = 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 //     ca0 - closed archive heap space #0
  90 //     ca1 - 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 HeapShared::archive_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     uintx delta = MetaspaceShared::object_delta_uintx(newtop);
 128     if (delta > MAX_SHARED_DELTA) {
 129       // This is just a sanity check and should not appear in any real world usage. This
 130       // happens only if you allocate more than 2GB of shared objects and would require
 131       // millions of shared classes.
 132       vm_exit_during_initialization("Out of memory in the CDS archive",
 133                                     "Please reduce the number of shared classes.");
 134     }
 135 
 136     MetaspaceShared::commit_shared_space_to(newtop);
 137     _top = newtop;
 138     return _top;
 139   }
 140 
 141 public:
 142   DumpRegion(const char* name) : _name(name), _base(NULL), _top(NULL), _end(NULL), _is_packed(false) {}
 143 
 144   char* allocate(size_t num_bytes, size_t alignment=BytesPerWord) {
 145     char* p = (char*)align_up(_top, alignment);
 146     char* newtop = p + align_up(num_bytes, alignment);
 147     expand_top_to(newtop);
 148     memset(p, 0, newtop - p);
 149     return p;
 150   }
 151 
 152   void append_intptr_t(intptr_t n) {
 153     assert(is_aligned(_top, sizeof(intptr_t)), "bad alignment");
 154     intptr_t *p = (intptr_t*)_top;
 155     char* newtop = _top + sizeof(intptr_t);
 156     expand_top_to(newtop);
 157     *p = n;
 158   }
 159 
 160   char* base()      const { return _base;        }
 161   char* top()       const { return _top;         }
 162   char* end()       const { return _end;         }
 163   size_t reserved() const { return _end - _base; }
 164   size_t used()     const { return _top - _base; }
 165   bool is_packed()  const { return _is_packed;   }
 166   bool is_allocatable() const {
 167     return !is_packed() && _base != NULL;
 168   }
 169 
 170   void print(size_t total_bytes) const {
 171     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,
 172                   _name, used(), percent_of(used(), total_bytes), reserved(), percent_of(used(), reserved()), p2i(_base));
 173   }
 174   void print_out_of_space_msg(const char* failing_region, size_t needed_bytes) {
 175     tty->print("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d",
 176                _name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base));
 177     if (strcmp(_name, failing_region) == 0) {
 178       tty->print_cr(" required = %d", int(needed_bytes));
 179     } else {
 180       tty->cr();
 181     }
 182   }
 183 
 184   void init(const ReservedSpace* rs) {
 185     _base = _top = rs->base();
 186     _end = rs->end();
 187   }
 188   void init(char* b, char* t, char* e) {
 189     _base = b;
 190     _top = t;
 191     _end = e;
 192   }
 193 
 194   void pack(DumpRegion* next = NULL) {
 195     assert(!is_packed(), "sanity");
 196     _end = (char*)align_up(_top, Metaspace::reserve_alignment());
 197     _is_packed = true;
 198     if (next != NULL) {
 199       next->_base = next->_top = this->_end;
 200       next->_end = MetaspaceShared::shared_rs()->end();
 201     }
 202   }
 203   bool contains(char* p) {
 204     return base() <= p && p < top();
 205   }
 206 };
 207 
 208 
 209 DumpRegion _mc_region("mc"), _ro_region("ro"), _rw_region("rw"), _md_region("md"), _od_region("od");
 210 size_t _total_closed_archive_region_size = 0, _total_open_archive_region_size = 0;
 211 
 212 char* MetaspaceShared::misc_code_space_alloc(size_t num_bytes) {
 213   return _mc_region.allocate(num_bytes);
 214 }
 215 
 216 char* MetaspaceShared::read_only_space_alloc(size_t num_bytes) {
 217   return _ro_region.allocate(num_bytes);
 218 }
 219 
 220 char* MetaspaceShared::read_only_space_top() {
 221   return _ro_region.top();
 222 }
 223 
 224 void MetaspaceShared::initialize_runtime_shared_and_meta_spaces() {
 225   assert(UseSharedSpaces, "Must be called when UseSharedSpaces is enabled");
 226 
 227   // If using shared space, open the file that contains the shared space
 228   // and map in the memory before initializing the rest of metaspace (so
 229   // the addresses don't conflict)
 230   address cds_address = NULL;
 231   FileMapInfo* mapinfo = new FileMapInfo();
 232 
 233   // Open the shared archive file, read and validate the header. If
 234   // initialization fails, shared spaces [UseSharedSpaces] are
 235   // disabled and the file is closed.
 236   // Map in spaces now also
 237   if (mapinfo->initialize() && map_shared_spaces(mapinfo)) {
 238     size_t cds_total = core_spaces_size();
 239     cds_address = (address)mapinfo->region_addr(0);
 240 #ifdef _LP64
 241     if (Metaspace::using_class_space()) {
 242       char* cds_end = (char*)(cds_address + cds_total);
 243       cds_end = (char *)align_up(cds_end, Metaspace::reserve_alignment());
 244       // If UseCompressedClassPointers is set then allocate the metaspace area
 245       // above the heap and above the CDS area (if it exists).
 246       Metaspace::allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
 247       // map_heap_regions() compares the current narrow oop and klass encodings
 248       // with the archived ones, so it must be done after all encodings are determined.
 249       mapinfo->map_heap_regions();
 250     }
 251     Universe::set_narrow_klass_range(CompressedClassSpaceSize);
 252 #endif // _LP64
 253   } else {
 254     assert(!mapinfo->is_open() && !UseSharedSpaces,
 255            "archive file not closed or shared spaces not disabled.");
 256   }
 257 }
 258 
 259 void MetaspaceShared::initialize_dumptime_shared_and_meta_spaces() {
 260   assert(DumpSharedSpaces, "should be called for dump time only");
 261   const size_t reserve_alignment = Metaspace::reserve_alignment();
 262   bool large_pages = false; // No large pages when dumping the CDS archive.
 263   char* shared_base = (char*)align_up((char*)SharedBaseAddress, reserve_alignment);
 264 
 265 #ifdef _LP64
 266   // On 64-bit VM, the heap and class space layout will be the same as if
 267   // you're running in -Xshare:on mode:
 268   //
 269   //                              +-- SharedBaseAddress (default = 0x800000000)
 270   //                              v
 271   // +-..---------+---------+ ... +----+----+----+----+----+---------------+
 272   // |    Heap    | Archive |     | MC | RW | RO | MD | OD | class space   |
 273   // +-..---------+---------+ ... +----+----+----+----+----+---------------+
 274   // |<--   MaxHeapSize  -->|     |<-- UnscaledClassSpaceMax = 4GB ------->|
 275   //
 276   const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
 277   const size_t cds_total = align_down(UnscaledClassSpaceMax, reserve_alignment);
 278 #else
 279   // We don't support archives larger than 256MB on 32-bit due to limited virtual address space.
 280   size_t cds_total = align_down(256*M, reserve_alignment);
 281 #endif
 282 
 283   // First try to reserve the space at the specified SharedBaseAddress.
 284   _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages, shared_base);
 285   if (_shared_rs.is_reserved()) {
 286     assert(shared_base == 0 || _shared_rs.base() == shared_base, "should match");
 287   } else {
 288     // Get a mmap region anywhere if the SharedBaseAddress fails.
 289     _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages);
 290   }
 291   if (!_shared_rs.is_reserved()) {
 292     vm_exit_during_initialization("Unable to reserve memory for shared space",
 293                                   err_msg(SIZE_FORMAT " bytes.", cds_total));
 294   }
 295 
 296 #ifdef _LP64
 297   // During dump time, we allocate 4GB (UnscaledClassSpaceMax) of space and split it up:
 298   // + The upper 1 GB is used as the "temporary compressed class space" -- preload_classes()
 299   //   will store Klasses into this space.
 300   // + The lower 3 GB is used for the archive -- when preload_classes() is done,
 301   //   ArchiveCompactor will copy the class metadata into this space, first the RW parts,
 302   //   then the RO parts.
 303 
 304   assert(UseCompressedOops && UseCompressedClassPointers,
 305       "UseCompressedOops and UseCompressedClassPointers must be set");
 306 
 307   size_t max_archive_size = align_down(cds_total * 3 / 4, reserve_alignment);
 308   ReservedSpace tmp_class_space = _shared_rs.last_part(max_archive_size);
 309   CompressedClassSpaceSize = align_down(tmp_class_space.size(), reserve_alignment);
 310   _shared_rs = _shared_rs.first_part(max_archive_size);
 311 
 312   // Set up compress class pointers.
 313   Universe::set_narrow_klass_base((address)_shared_rs.base());
 314   // Set narrow_klass_shift to be LogKlassAlignmentInBytes. This is consistent
 315   // with AOT.
 316   Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
 317   // Set the range of klass addresses to 4GB.
 318   Universe::set_narrow_klass_range(cds_total);
 319 
 320   Metaspace::initialize_class_space(tmp_class_space);
 321   log_info(cds)("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
 322                 p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift());
 323 
 324   log_info(cds)("Allocated temporary class space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
 325                 CompressedClassSpaceSize, p2i(tmp_class_space.base()));
 326 #endif
 327 
 328   // Start with 0 committed bytes. The memory will be committed as needed by
 329   // MetaspaceShared::commit_shared_space_to().
 330   if (!_shared_vs.initialize(_shared_rs, 0)) {
 331     vm_exit_during_initialization("Unable to allocate memory for shared space");
 332   }
 333 
 334   _mc_region.init(&_shared_rs);
 335   SharedBaseAddress = (size_t)_shared_rs.base();
 336   tty->print_cr("Allocated shared space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
 337                 _shared_rs.size(), p2i(_shared_rs.base()));
 338 }
 339 
 340 // Called by universe_post_init()
 341 void MetaspaceShared::post_initialize(TRAPS) {
 342   if (UseSharedSpaces) {
 343     int size = FileMapInfo::get_number_of_shared_paths();
 344     if (size > 0) {
 345       SystemDictionaryShared::allocate_shared_data_arrays(size, THREAD);
 346       FileMapHeader* header = FileMapInfo::current_info()->header();
 347       ClassLoaderExt::init_paths_start_index(header->_app_class_paths_start_index);
 348       ClassLoaderExt::init_app_module_paths_start_index(header->_app_module_paths_start_index);
 349     }
 350   }
 351 }
 352 
 353 void MetaspaceShared::read_extra_data(const char* filename, TRAPS) {
 354   HashtableTextDump reader(filename);
 355   reader.check_version("VERSION: 1.0");
 356 
 357   while (reader.remain() > 0) {
 358     int utf8_length;
 359     int prefix_type = reader.scan_prefix(&utf8_length);
 360     ResourceMark rm(THREAD);
 361     char* utf8_buffer = NEW_RESOURCE_ARRAY(char, utf8_length);
 362     reader.get_utf8(utf8_buffer, utf8_length);
 363 
 364     if (prefix_type == HashtableTextDump::SymbolPrefix) {
 365       SymbolTable::new_symbol(utf8_buffer, utf8_length, THREAD);
 366     } else{
 367       assert(prefix_type == HashtableTextDump::StringPrefix, "Sanity");
 368       utf8_buffer[utf8_length] = '\0';
 369       oop s = StringTable::intern(utf8_buffer, THREAD);
 370     }
 371   }
 372 }
 373 
 374 void MetaspaceShared::commit_shared_space_to(char* newtop) {
 375   assert(DumpSharedSpaces, "dump-time only");
 376   char* base = _shared_rs.base();
 377   size_t need_committed_size = newtop - base;
 378   size_t has_committed_size = _shared_vs.committed_size();
 379   if (need_committed_size < has_committed_size) {
 380     return;
 381   }
 382 
 383   size_t min_bytes = need_committed_size - has_committed_size;
 384   size_t preferred_bytes = 1 * M;
 385   size_t uncommitted = _shared_vs.reserved_size() - has_committed_size;
 386 
 387   size_t commit = MAX2(min_bytes, preferred_bytes);
 388   assert(commit <= uncommitted, "sanity");
 389 
 390   bool result = _shared_vs.expand_by(commit, false);
 391   if (!result) {
 392     vm_exit_during_initialization(err_msg("Failed to expand shared space to " SIZE_FORMAT " bytes",
 393                                           need_committed_size));
 394   }
 395 
 396   log_info(cds)("Expanding shared spaces by " SIZE_FORMAT_W(7) " bytes [total " SIZE_FORMAT_W(9)  " bytes ending at %p]",
 397                 commit, _shared_vs.actual_committed_size(), _shared_vs.high());
 398 }
 399 
 400 // Read/write a data stream for restoring/preserving metadata pointers and
 401 // miscellaneous data from/to the shared archive file.
 402 
 403 void MetaspaceShared::serialize(SerializeClosure* soc) {
 404   int tag = 0;
 405   soc->do_tag(--tag);
 406 
 407   // Verify the sizes of various metadata in the system.
 408   soc->do_tag(sizeof(Method));
 409   soc->do_tag(sizeof(ConstMethod));
 410   soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
 411   soc->do_tag(sizeof(ConstantPool));
 412   soc->do_tag(sizeof(ConstantPoolCache));
 413   soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
 414   soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
 415   soc->do_tag(sizeof(Symbol));
 416 
 417   // Dump/restore miscellaneous metadata.
 418   Universe::serialize(soc);
 419   soc->do_tag(--tag);
 420 
 421   // Dump/restore references to commonly used names and signatures.
 422   vmSymbols::serialize(soc);
 423   soc->do_tag(--tag);
 424 
 425   // Dump/restore the symbol/string/subgraph_info tables
 426   SymbolTable::serialize_shared_table_header(soc);
 427   StringTable::serialize_shared_table_header(soc);
 428   HeapShared::serialize_subgraph_info_table_header(soc);
 429   SystemDictionaryShared::serialize_dictionary_headers(soc);
 430 
 431   JavaClasses::serialize_offsets(soc);
 432   InstanceMirrorKlass::serialize_offsets(soc);
 433   soc->do_tag(--tag);
 434 
 435   soc->do_tag(666);
 436 }
 437 
 438 address MetaspaceShared::cds_i2i_entry_code_buffers(size_t total_size) {
 439   if (DumpSharedSpaces) {
 440     if (_cds_i2i_entry_code_buffers == NULL) {
 441       _cds_i2i_entry_code_buffers = (address)misc_code_space_alloc(total_size);
 442       _cds_i2i_entry_code_buffers_size = total_size;
 443     }
 444   } else if (UseSharedSpaces) {
 445     assert(_cds_i2i_entry_code_buffers != NULL, "must already been initialized");
 446   } else {
 447     return NULL;
 448   }
 449 
 450   assert(_cds_i2i_entry_code_buffers_size == total_size, "must not change");
 451   return _cds_i2i_entry_code_buffers;
 452 }
 453 
 454 // CDS code for dumping shared archive.
 455 
 456 // Global object for holding classes that have been loaded.  Since this
 457 // is run at a safepoint just before exit, this is the entire set of classes.
 458 static GrowableArray<Klass*>* _global_klass_objects;
 459 
 460 GrowableArray<Klass*>* MetaspaceShared::collected_klasses() {
 461   return _global_klass_objects;
 462 }
 463 
 464 static void collect_array_classes(Klass* k) {
 465   _global_klass_objects->append_if_missing(k);
 466   if (k->is_array_klass()) {
 467     // Add in the array classes too
 468     ArrayKlass* ak = ArrayKlass::cast(k);
 469     Klass* h = ak->higher_dimension();
 470     if (h != NULL) {
 471       h->array_klasses_do(collect_array_classes);
 472     }
 473   }
 474 }
 475 
 476 class CollectClassesClosure : public KlassClosure {
 477   void do_klass(Klass* k) {
 478     if (k->is_instance_klass() &&
 479         SystemDictionaryShared::is_excluded_class(InstanceKlass::cast(k))) {
 480       // Don't add to the _global_klass_objects
 481     } else {
 482       _global_klass_objects->append_if_missing(k);
 483     }
 484     if (k->is_array_klass()) {
 485       // Add in the array classes too
 486       ArrayKlass* ak = ArrayKlass::cast(k);
 487       Klass* h = ak->higher_dimension();
 488       if (h != NULL) {
 489         h->array_klasses_do(collect_array_classes);
 490       }
 491     }
 492   }
 493 };
 494 
 495 static void remove_unshareable_in_classes() {
 496   for (int i = 0; i < _global_klass_objects->length(); i++) {
 497     Klass* k = _global_klass_objects->at(i);
 498     if (!k->is_objArray_klass()) {
 499       // InstanceKlass and TypeArrayKlass will in turn call remove_unshareable_info
 500       // on their array classes.
 501       assert(k->is_instance_klass() || k->is_typeArray_klass(), "must be");
 502       k->remove_unshareable_info();
 503     }
 504   }
 505 }
 506 
 507 static void remove_java_mirror_in_classes() {
 508   for (int i = 0; i < _global_klass_objects->length(); i++) {
 509     Klass* k = _global_klass_objects->at(i);
 510     if (!k->is_objArray_klass()) {
 511       // InstanceKlass and TypeArrayKlass will in turn call remove_unshareable_info
 512       // on their array classes.
 513       assert(k->is_instance_klass() || k->is_typeArray_klass(), "must be");
 514       k->remove_java_mirror();
 515     }
 516   }
 517 }
 518 
 519 static void clear_basic_type_mirrors() {
 520   assert(!HeapShared::is_heap_object_archiving_allowed(), "Sanity");
 521   Universe::set_int_mirror(NULL);
 522   Universe::set_float_mirror(NULL);
 523   Universe::set_double_mirror(NULL);
 524   Universe::set_byte_mirror(NULL);
 525   Universe::set_bool_mirror(NULL);
 526   Universe::set_char_mirror(NULL);
 527   Universe::set_long_mirror(NULL);
 528   Universe::set_short_mirror(NULL);
 529   Universe::set_void_mirror(NULL);
 530 }
 531 
 532 static void rewrite_nofast_bytecode(Method* method) {
 533   BytecodeStream bcs(method);
 534   while (!bcs.is_last_bytecode()) {
 535     Bytecodes::Code opcode = bcs.next();
 536     switch (opcode) {
 537     case Bytecodes::_getfield:      *bcs.bcp() = Bytecodes::_nofast_getfield;      break;
 538     case Bytecodes::_putfield:      *bcs.bcp() = Bytecodes::_nofast_putfield;      break;
 539     case Bytecodes::_aload_0:       *bcs.bcp() = Bytecodes::_nofast_aload_0;       break;
 540     case Bytecodes::_iload: {
 541       if (!bcs.is_wide()) {
 542         *bcs.bcp() = Bytecodes::_nofast_iload;
 543       }
 544       break;
 545     }
 546     default: break;
 547     }
 548   }
 549 }
 550 
 551 // Walk all methods in the class list to ensure that they won't be modified at
 552 // run time. This includes:
 553 // [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified
 554 //     at run time by RewriteBytecodes/RewriteFrequentPairs
 555 // [2] Assign a fingerprint, so one doesn't need to be assigned at run-time.
 556 static void rewrite_nofast_bytecodes_and_calculate_fingerprints() {
 557   for (int i = 0; i < _global_klass_objects->length(); i++) {
 558     Klass* k = _global_klass_objects->at(i);
 559     if (k->is_instance_klass()) {
 560       InstanceKlass* ik = InstanceKlass::cast(k);
 561       for (int i = 0; i < ik->methods()->length(); i++) {
 562         Method* m = ik->methods()->at(i);
 563         rewrite_nofast_bytecode(m);
 564         Fingerprinter fp(m);
 565         // The side effect of this call sets method's fingerprint field.
 566         fp.fingerprint();
 567       }
 568     }
 569   }
 570 }
 571 
 572 static void relocate_cached_class_file() {
 573   for (int i = 0; i < _global_klass_objects->length(); i++) {
 574     Klass* k = _global_klass_objects->at(i);
 575     if (k->is_instance_klass()) {
 576       InstanceKlass* ik = InstanceKlass::cast(k);
 577       JvmtiCachedClassFileData* p = ik->get_archived_class_data();
 578       if (p != NULL) {
 579         int size = offset_of(JvmtiCachedClassFileData, data) + p->length;
 580         JvmtiCachedClassFileData* q = (JvmtiCachedClassFileData*)_od_region.allocate(size);
 581         q->length = p->length;
 582         memcpy(q->data, p->data, p->length);
 583         ik->set_archived_class_data(q);
 584       }
 585     }
 586   }
 587 }
 588 
 589 // Objects of the Metadata types (such as Klass and ConstantPool) have C++ vtables.
 590 // (In GCC this is the field <Type>::_vptr, i.e., first word in the object.)
 591 //
 592 // Addresses of the vtables and the methods may be different across JVM runs,
 593 // if libjvm.so is dynamically loaded at a different base address.
 594 //
 595 // To ensure that the Metadata objects in the CDS archive always have the correct vtable:
 596 //
 597 // + at dump time:  we redirect the _vptr to point to our own vtables inside
 598 //                  the CDS image
 599 // + at run time:   we clone the actual contents of the vtables from libjvm.so
 600 //                  into our own tables.
 601 
 602 // Currently, the archive contain ONLY the following types of objects that have C++ vtables.
 603 #define CPP_VTABLE_PATCH_TYPES_DO(f) \
 604   f(ConstantPool) \
 605   f(InstanceKlass) \
 606   f(InstanceClassLoaderKlass) \
 607   f(InstanceMirrorKlass) \
 608   f(InstanceRefKlass) \
 609   f(Method) \
 610   f(ObjArrayKlass) \
 611   f(TypeArrayKlass)
 612 
 613 class CppVtableInfo {
 614   intptr_t _vtable_size;
 615   intptr_t _cloned_vtable[1];
 616 public:
 617   static int num_slots(int vtable_size) {
 618     return 1 + vtable_size; // Need to add the space occupied by _vtable_size;
 619   }
 620   int vtable_size()           { return int(uintx(_vtable_size)); }
 621   void set_vtable_size(int n) { _vtable_size = intptr_t(n); }
 622   intptr_t* cloned_vtable()   { return &_cloned_vtable[0]; }
 623   void zero()                 { memset(_cloned_vtable, 0, sizeof(intptr_t) * vtable_size()); }
 624   // Returns the address of the next CppVtableInfo that can be placed immediately after this CppVtableInfo
 625   static size_t byte_size(int vtable_size) {
 626     CppVtableInfo i;
 627     return pointer_delta(&i._cloned_vtable[vtable_size], &i, sizeof(u1));
 628   }
 629 };
 630 
 631 template <class T> class CppVtableCloner : public T {
 632   static intptr_t* vtable_of(Metadata& m) {
 633     return *((intptr_t**)&m);
 634   }
 635   static CppVtableInfo* _info;
 636 
 637   static int get_vtable_length(const char* name);
 638 
 639 public:
 640   // Allocate and initialize the C++ vtable, starting from top, but do not go past end.
 641   static intptr_t* allocate(const char* name);
 642 
 643   // Clone the vtable to ...
 644   static intptr_t* clone_vtable(const char* name, CppVtableInfo* info);
 645 
 646   static void zero_vtable_clone() {
 647     assert(DumpSharedSpaces, "dump-time only");
 648     _info->zero();
 649   }
 650 
 651   // Switch the vtable pointer to point to the cloned vtable.
 652   static void patch(Metadata* obj) {
 653     assert(DumpSharedSpaces, "dump-time only");
 654     *(void**)obj = (void*)(_info->cloned_vtable());
 655   }
 656 
 657   static bool is_valid_shared_object(const T* obj) {
 658     intptr_t* vptr = *(intptr_t**)obj;
 659     return vptr == _info->cloned_vtable();
 660   }
 661 };
 662 
 663 template <class T> CppVtableInfo* CppVtableCloner<T>::_info = NULL;
 664 
 665 template <class T>
 666 intptr_t* CppVtableCloner<T>::allocate(const char* name) {
 667   assert(is_aligned(_md_region.top(), sizeof(intptr_t)), "bad alignment");
 668   int n = get_vtable_length(name);
 669   _info = (CppVtableInfo*)_md_region.allocate(CppVtableInfo::byte_size(n), sizeof(intptr_t));
 670   _info->set_vtable_size(n);
 671 
 672   intptr_t* p = clone_vtable(name, _info);
 673   assert((char*)p == _md_region.top(), "must be");
 674 
 675   return p;
 676 }
 677 
 678 template <class T>
 679 intptr_t* CppVtableCloner<T>::clone_vtable(const char* name, CppVtableInfo* info) {
 680   if (!DumpSharedSpaces) {
 681     assert(_info == 0, "_info is initialized only at dump time");
 682     _info = info; // Remember it -- it will be used by MetaspaceShared::is_valid_shared_method()
 683   }
 684   T tmp; // Allocate temporary dummy metadata object to get to the original vtable.
 685   int n = info->vtable_size();
 686   intptr_t* srcvtable = vtable_of(tmp);
 687   intptr_t* dstvtable = info->cloned_vtable();
 688 
 689   // We already checked (and, if necessary, adjusted n) when the vtables were allocated, so we are
 690   // safe to do memcpy.
 691   log_debug(cds, vtables)("Copying %3d vtable entries for %s", n, name);
 692   memcpy(dstvtable, srcvtable, sizeof(intptr_t) * n);
 693   return dstvtable + n;
 694 }
 695 
 696 // To determine the size of the vtable for each type, we use the following
 697 // trick by declaring 2 subclasses:
 698 //
 699 //   class CppVtableTesterA: public InstanceKlass {virtual int   last_virtual_method() {return 1;}    };
 700 //   class CppVtableTesterB: public InstanceKlass {virtual void* last_virtual_method() {return NULL}; };
 701 //
 702 // CppVtableTesterA and CppVtableTesterB's vtables have the following properties:
 703 // - Their size (N+1) is exactly one more than the size of InstanceKlass's vtable (N)
 704 // - The first N entries have are exactly the same as in InstanceKlass's vtable.
 705 // - Their last entry is different.
 706 //
 707 // So to determine the value of N, we just walk CppVtableTesterA and CppVtableTesterB's tables
 708 // and find the first entry that's different.
 709 //
 710 // This works on all C++ compilers supported by Oracle, but you may need to tweak it for more
 711 // esoteric compilers.
 712 
 713 template <class T> class CppVtableTesterB: public T {
 714 public:
 715   virtual int last_virtual_method() {return 1;}
 716 };
 717 
 718 template <class T> class CppVtableTesterA : public T {
 719 public:
 720   virtual void* last_virtual_method() {
 721     // Make this different than CppVtableTesterB::last_virtual_method so the C++
 722     // compiler/linker won't alias the two functions.
 723     return NULL;
 724   }
 725 };
 726 
 727 template <class T>
 728 int CppVtableCloner<T>::get_vtable_length(const char* name) {
 729   CppVtableTesterA<T> a;
 730   CppVtableTesterB<T> b;
 731 
 732   intptr_t* avtable = vtable_of(a);
 733   intptr_t* bvtable = vtable_of(b);
 734 
 735   // Start at slot 1, because slot 0 may be RTTI (on Solaris/Sparc)
 736   int vtable_len = 1;
 737   for (; ; vtable_len++) {
 738     if (avtable[vtable_len] != bvtable[vtable_len]) {
 739       break;
 740     }
 741   }
 742   log_debug(cds, vtables)("Found   %3d vtable entries for %s", vtable_len, name);
 743 
 744   return vtable_len;
 745 }
 746 
 747 #define ALLOC_CPP_VTABLE_CLONE(c) \
 748   CppVtableCloner<c>::allocate(#c);
 749 
 750 #define CLONE_CPP_VTABLE(c) \
 751   p = CppVtableCloner<c>::clone_vtable(#c, (CppVtableInfo*)p);
 752 
 753 #define ZERO_CPP_VTABLE(c) \
 754  CppVtableCloner<c>::zero_vtable_clone();
 755 
 756 // This can be called at both dump time and run time.
 757 intptr_t* MetaspaceShared::clone_cpp_vtables(intptr_t* p) {
 758   assert(DumpSharedSpaces || UseSharedSpaces, "sanity");
 759   CPP_VTABLE_PATCH_TYPES_DO(CLONE_CPP_VTABLE);
 760   return p;
 761 }
 762 
 763 void MetaspaceShared::zero_cpp_vtable_clones_for_writing() {
 764   assert(DumpSharedSpaces, "dump-time only");
 765   CPP_VTABLE_PATCH_TYPES_DO(ZERO_CPP_VTABLE);
 766 }
 767 
 768 // Allocate and initialize the C++ vtables, starting from top, but do not go past end.
 769 void MetaspaceShared::allocate_cpp_vtable_clones() {
 770   assert(DumpSharedSpaces, "dump-time only");
 771   // Layout (each slot is a intptr_t):
 772   //   [number of slots in the first vtable = n1]
 773   //   [ <n1> slots for the first vtable]
 774   //   [number of slots in the first second = n2]
 775   //   [ <n2> slots for the second vtable]
 776   //   ...
 777   // The order of the vtables is the same as the CPP_VTAB_PATCH_TYPES_DO macro.
 778   CPP_VTABLE_PATCH_TYPES_DO(ALLOC_CPP_VTABLE_CLONE);
 779 }
 780 
 781 // Switch the vtable pointer to point to the cloned vtable. We assume the
 782 // vtable pointer is in first slot in object.
 783 void MetaspaceShared::patch_cpp_vtable_pointers() {
 784   int n = _global_klass_objects->length();
 785   for (int i = 0; i < n; i++) {
 786     Klass* obj = _global_klass_objects->at(i);
 787     if (obj->is_instance_klass()) {
 788       InstanceKlass* ik = InstanceKlass::cast(obj);
 789       if (ik->is_class_loader_instance_klass()) {
 790         CppVtableCloner<InstanceClassLoaderKlass>::patch(ik);
 791       } else if (ik->is_reference_instance_klass()) {
 792         CppVtableCloner<InstanceRefKlass>::patch(ik);
 793       } else if (ik->is_mirror_instance_klass()) {
 794         CppVtableCloner<InstanceMirrorKlass>::patch(ik);
 795       } else {
 796         CppVtableCloner<InstanceKlass>::patch(ik);
 797       }
 798       ConstantPool* cp = ik->constants();
 799       CppVtableCloner<ConstantPool>::patch(cp);
 800       for (int j = 0; j < ik->methods()->length(); j++) {
 801         Method* m = ik->methods()->at(j);
 802         CppVtableCloner<Method>::patch(m);
 803         assert(CppVtableCloner<Method>::is_valid_shared_object(m), "must be");
 804       }
 805     } else if (obj->is_objArray_klass()) {
 806       CppVtableCloner<ObjArrayKlass>::patch(obj);
 807     } else {
 808       assert(obj->is_typeArray_klass(), "sanity");
 809       CppVtableCloner<TypeArrayKlass>::patch(obj);
 810     }
 811   }
 812 }
 813 
 814 bool MetaspaceShared::is_valid_shared_method(const Method* m) {
 815   assert(is_in_shared_metaspace(m), "must be");
 816   return CppVtableCloner<Method>::is_valid_shared_object(m);
 817 }
 818 
 819 // Closure for serializing initialization data out to a data area to be
 820 // written to the shared file.
 821 
 822 class WriteClosure : public SerializeClosure {
 823 private:
 824   DumpRegion* _dump_region;
 825 
 826 public:
 827   WriteClosure(DumpRegion* r) {
 828     _dump_region = r;
 829   }
 830 
 831   void do_ptr(void** p) {
 832     _dump_region->append_intptr_t((intptr_t)*p);
 833   }
 834 
 835   void do_u4(u4* p) {
 836     void* ptr = (void*)(uintx(*p));
 837     do_ptr(&ptr);
 838   }
 839 
 840   void do_tag(int tag) {
 841     _dump_region->append_intptr_t((intptr_t)tag);
 842   }
 843 
 844   void do_oop(oop* o) {
 845     if (*o == NULL) {
 846       _dump_region->append_intptr_t(0);
 847     } else {
 848       assert(HeapShared::is_heap_object_archiving_allowed(),
 849              "Archiving heap object is not allowed");
 850       _dump_region->append_intptr_t(
 851         (intptr_t)CompressedOops::encode_not_null(*o));
 852     }
 853   }
 854 
 855   void do_region(u_char* start, size_t size) {
 856     assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
 857     assert(size % sizeof(intptr_t) == 0, "bad size");
 858     do_tag((int)size);
 859     while (size > 0) {
 860       _dump_region->append_intptr_t(*(intptr_t*)start);
 861       start += sizeof(intptr_t);
 862       size -= sizeof(intptr_t);
 863     }
 864   }
 865 
 866   bool reading() const { return false; }
 867 };
 868 
 869 // This is for dumping detailed statistics for the allocations
 870 // in the shared spaces.
 871 class DumpAllocStats : public ResourceObj {
 872 public:
 873 
 874   // Here's poor man's enum inheritance
 875 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
 876   METASPACE_OBJ_TYPES_DO(f) \
 877   f(SymbolHashentry) \
 878   f(SymbolBucket) \
 879   f(StringHashentry) \
 880   f(StringBucket) \
 881   f(Other)
 882 
 883   enum Type {
 884     // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
 885     SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_DECLARE)
 886     _number_of_types
 887   };
 888 
 889   static const char * type_name(Type type) {
 890     switch(type) {
 891     SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_NAME_CASE)
 892     default:
 893       ShouldNotReachHere();
 894       return NULL;
 895     }
 896   }
 897 
 898 public:
 899   enum { RO = 0, RW = 1 };
 900 
 901   int _counts[2][_number_of_types];
 902   int _bytes [2][_number_of_types];
 903 
 904   DumpAllocStats() {
 905     memset(_counts, 0, sizeof(_counts));
 906     memset(_bytes,  0, sizeof(_bytes));
 907   };
 908 
 909   void record(MetaspaceObj::Type type, int byte_size, bool read_only) {
 910     assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
 911     int which = (read_only) ? RO : RW;
 912     _counts[which][type] ++;
 913     _bytes [which][type] += byte_size;
 914   }
 915 
 916   void record_other_type(int byte_size, bool read_only) {
 917     int which = (read_only) ? RO : RW;
 918     _bytes [which][OtherType] += byte_size;
 919   }
 920   void print_stats(int ro_all, int rw_all, int mc_all, int md_all);
 921 };
 922 
 923 void DumpAllocStats::print_stats(int ro_all, int rw_all, int mc_all, int md_all) {
 924   // Calculate size of data that was not allocated by Metaspace::allocate()
 925   MetaspaceSharedStats *stats = MetaspaceShared::stats();
 926 
 927   // symbols
 928   _counts[RO][SymbolHashentryType] = stats->symbol.hashentry_count;
 929   _bytes [RO][SymbolHashentryType] = stats->symbol.hashentry_bytes;
 930 
 931   _counts[RO][SymbolBucketType] = stats->symbol.bucket_count;
 932   _bytes [RO][SymbolBucketType] = stats->symbol.bucket_bytes;
 933 
 934   // strings
 935   _counts[RO][StringHashentryType] = stats->string.hashentry_count;
 936   _bytes [RO][StringHashentryType] = stats->string.hashentry_bytes;
 937 
 938   _counts[RO][StringBucketType] = stats->string.bucket_count;
 939   _bytes [RO][StringBucketType] = stats->string.bucket_bytes;
 940 
 941   // TODO: count things like dictionary, vtable, etc
 942   _bytes[RW][OtherType] += mc_all + md_all;
 943   rw_all += mc_all + md_all; // mc/md are mapped Read/Write
 944 
 945   // prevent divide-by-zero
 946   if (ro_all < 1) {
 947     ro_all = 1;
 948   }
 949   if (rw_all < 1) {
 950     rw_all = 1;
 951   }
 952 
 953   int all_ro_count = 0;
 954   int all_ro_bytes = 0;
 955   int all_rw_count = 0;
 956   int all_rw_bytes = 0;
 957 
 958 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
 959 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
 960   const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
 961   const char *hdr = "                        ro_cnt   ro_bytes     % |   rw_cnt   rw_bytes     % |  all_cnt  all_bytes     %";
 962 
 963   LogMessage(cds) msg;
 964 
 965   msg.info("Detailed metadata info (excluding od/st regions; rw stats include md/mc regions):");
 966   msg.info("%s", hdr);
 967   msg.info("%s", sep);
 968   for (int type = 0; type < int(_number_of_types); type ++) {
 969     const char *name = type_name((Type)type);
 970     int ro_count = _counts[RO][type];
 971     int ro_bytes = _bytes [RO][type];
 972     int rw_count = _counts[RW][type];
 973     int rw_bytes = _bytes [RW][type];
 974     int count = ro_count + rw_count;
 975     int bytes = ro_bytes + rw_bytes;
 976 
 977     double ro_perc = percent_of(ro_bytes, ro_all);
 978     double rw_perc = percent_of(rw_bytes, rw_all);
 979     double perc    = percent_of(bytes, ro_all + rw_all);
 980 
 981     msg.info(fmt_stats, name,
 982                          ro_count, ro_bytes, ro_perc,
 983                          rw_count, rw_bytes, rw_perc,
 984                          count, bytes, perc);
 985 
 986     all_ro_count += ro_count;
 987     all_ro_bytes += ro_bytes;
 988     all_rw_count += rw_count;
 989     all_rw_bytes += rw_bytes;
 990   }
 991 
 992   int all_count = all_ro_count + all_rw_count;
 993   int all_bytes = all_ro_bytes + all_rw_bytes;
 994 
 995   double all_ro_perc = percent_of(all_ro_bytes, ro_all);
 996   double all_rw_perc = percent_of(all_rw_bytes, rw_all);
 997   double all_perc    = percent_of(all_bytes, ro_all + rw_all);
 998 
 999   msg.info("%s", sep);
1000   msg.info(fmt_stats, "Total",
1001                        all_ro_count, all_ro_bytes, all_ro_perc,
1002                        all_rw_count, all_rw_bytes, all_rw_perc,
1003                        all_count, all_bytes, all_perc);
1004 
1005   assert(all_ro_bytes == ro_all, "everything should have been counted");
1006   assert(all_rw_bytes == rw_all, "everything should have been counted");
1007 
1008 #undef fmt_stats
1009 }
1010 
1011 // Populate the shared space.
1012 
1013 class VM_PopulateDumpSharedSpace: public VM_Operation {
1014 private:
1015   GrowableArray<MemRegion> *_closed_archive_heap_regions;
1016   GrowableArray<MemRegion> *_open_archive_heap_regions;
1017 
1018   GrowableArray<ArchiveHeapOopmapInfo> *_closed_archive_heap_oopmaps;
1019   GrowableArray<ArchiveHeapOopmapInfo> *_open_archive_heap_oopmaps;
1020 
1021   void dump_java_heap_objects() NOT_CDS_JAVA_HEAP_RETURN;
1022   void dump_archive_heap_oopmaps() NOT_CDS_JAVA_HEAP_RETURN;
1023   void dump_archive_heap_oopmaps(GrowableArray<MemRegion>* regions,
1024                                  GrowableArray<ArchiveHeapOopmapInfo>* oopmaps);
1025   void dump_symbols();
1026   char* dump_read_only_tables();
1027   void print_region_stats();
1028   void print_heap_region_stats(GrowableArray<MemRegion> *heap_mem,
1029                                const char *name, const size_t total_size);
1030 public:
1031 
1032   VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
1033   void doit();   // outline because gdb sucks
1034   static void write_region(FileMapInfo* mapinfo, int region, DumpRegion* space, bool read_only,  bool allow_exec);
1035   bool allow_nested_vm_operations() const { return true; }
1036 }; // class VM_PopulateDumpSharedSpace
1037 
1038 class SortedSymbolClosure: public SymbolClosure {
1039   GrowableArray<Symbol*> _symbols;
1040   virtual void do_symbol(Symbol** sym) {
1041     assert((*sym)->is_permanent(), "archived symbols must be permanent");
1042     _symbols.append(*sym);
1043   }
1044   static int compare_symbols_by_address(Symbol** a, Symbol** b) {
1045     if (a[0] < b[0]) {
1046       return -1;
1047     } else if (a[0] == b[0]) {
1048       return 0;
1049     } else {
1050       return 1;
1051     }
1052   }
1053 
1054 public:
1055   SortedSymbolClosure() {
1056     SymbolTable::symbols_do(this);
1057     _symbols.sort(compare_symbols_by_address);
1058   }
1059   GrowableArray<Symbol*>* get_sorted_symbols() {
1060     return &_symbols;
1061   }
1062 };
1063 
1064 // ArchiveCompactor --
1065 //
1066 // This class is the central piece of shared archive compaction -- all metaspace data are
1067 // initially allocated outside of the shared regions. ArchiveCompactor copies the
1068 // metaspace data into their final location in the shared regions.
1069 
1070 class ArchiveCompactor : AllStatic {
1071   static DumpAllocStats* _alloc_stats;
1072   static SortedSymbolClosure* _ssc;
1073 
1074   typedef KVHashtable<
1075       address, address> RelocationTable;









1076   static RelocationTable* _new_loc_table;
1077 
1078 public:
1079   static void initialize() {
1080     _alloc_stats = new(ResourceObj::C_HEAP, mtInternal)DumpAllocStats;
1081     _new_loc_table = new RelocationTable(8087);
1082   }
1083   static DumpAllocStats* alloc_stats() {
1084     return _alloc_stats;
1085   }
1086 
1087   // Use this when you allocate space with MetaspaceShare::read_only_space_alloc()
1088   // outside of ArchiveCompactor::allocate(). These are usually for misc tables
1089   // that are allocated in the RO space.
1090   class OtherROAllocMark {
1091     char* _oldtop;
1092   public:
1093     OtherROAllocMark() {
1094       _oldtop = _ro_region.top();
1095     }
1096     ~OtherROAllocMark() {
1097       char* newtop = _ro_region.top();
1098       ArchiveCompactor::alloc_stats()->record_other_type(int(newtop - _oldtop), true);
1099     }
1100   };
1101 
1102   static void allocate(MetaspaceClosure::Ref* ref, bool read_only) {
1103     address obj = ref->obj();
1104     int bytes = ref->size() * BytesPerWord;
1105     char* p;
1106     size_t alignment = BytesPerWord;
1107     char* oldtop;
1108     char* newtop;
1109 
1110     if (read_only) {
1111       oldtop = _ro_region.top();
1112       p = _ro_region.allocate(bytes, alignment);
1113       newtop = _ro_region.top();
1114     } else {
1115       oldtop = _rw_region.top();
1116       if (ref->msotype() == MetaspaceObj::ClassType) {
1117         // Save a pointer immediate in front of an InstanceKlass, so
1118         // we can do a quick lookup from InstanceKlass* -> RunTimeSharedClassInfo*
1119         // without building another hashtable. See RunTimeSharedClassInfo::get_for()
1120         // in systemDictionaryShared.cpp.
1121         Klass* klass = (Klass*)obj;
1122         if (klass->is_instance_klass()) {
1123           SystemDictionaryShared::validate_before_archiving(InstanceKlass::cast(klass));
1124           _rw_region.allocate(sizeof(address), BytesPerWord);
1125         }
1126       }
1127       p = _rw_region.allocate(bytes, alignment);
1128       newtop = _rw_region.top();
1129     }
1130     memcpy(p, obj, bytes);
1131     assert(_new_loc_table->lookup(obj) == NULL, "each object can be relocated at most once");
1132     _new_loc_table->add(obj, (address)p);
1133     log_trace(cds)("Copy: " PTR_FORMAT " ==> " PTR_FORMAT " %d", p2i(obj), p2i(p), bytes);
1134     if (_new_loc_table->maybe_grow()) {
1135       log_info(cds, hashtables)("Expanded _new_loc_table to %d", _new_loc_table->table_size());
1136     }
1137     _alloc_stats->record(ref->msotype(), int(newtop - oldtop), read_only);
1138   }
1139 
1140   static address get_new_loc(MetaspaceClosure::Ref* ref) {
1141     address* pp = _new_loc_table->lookup(ref->obj());
1142     assert(pp != NULL, "must be");
1143     return *pp;
1144   }
1145 
1146 private:
1147   // Makes a shallow copy of visited MetaspaceObj's
1148   class ShallowCopier: public UniqueMetaspaceClosure {
1149     bool _read_only;
1150   public:
1151     ShallowCopier(bool read_only) : _read_only(read_only) {}
1152 
1153     virtual void do_unique_ref(Ref* ref, bool read_only) {
1154       if (read_only == _read_only) {
1155         allocate(ref, read_only);
1156       }
1157     }
1158   };
1159 
1160   // Relocate embedded pointers within a MetaspaceObj's shallow copy
1161   class ShallowCopyEmbeddedRefRelocator: public UniqueMetaspaceClosure {
1162   public:
1163     virtual void do_unique_ref(Ref* ref, bool read_only) {
1164       address new_loc = get_new_loc(ref);
1165       RefRelocator refer;
1166       ref->metaspace_pointers_do_at(&refer, new_loc);
1167     }
1168   };
1169 
1170   // Relocate a reference to point to its shallow copy
1171   class RefRelocator: public MetaspaceClosure {
1172   public:
1173     virtual bool do_ref(Ref* ref, bool read_only) {
1174       if (ref->not_null()) {
1175         ref->update(get_new_loc(ref));
1176       }
1177       return false; // Do not recurse.
1178     }
1179   };
1180 
1181 #ifdef ASSERT
1182   class IsRefInArchiveChecker: public MetaspaceClosure {
1183   public:
1184     virtual bool do_ref(Ref* ref, bool read_only) {
1185       if (ref->not_null()) {
1186         char* obj = (char*)ref->obj();
1187         assert(_ro_region.contains(obj) || _rw_region.contains(obj),
1188                "must be relocated to point to CDS archive");
1189       }
1190       return false; // Do not recurse.
1191     }
1192   };
1193 #endif
1194 
1195 public:
1196   static void copy_and_compact() {
1197     ResourceMark rm;
1198     SortedSymbolClosure the_ssc; // StackObj
1199     _ssc = &the_ssc;
1200 
1201     tty->print_cr("Scanning all metaspace objects ... ");
1202     {
1203       // allocate and shallow-copy RW objects, immediately following the MC region
1204       tty->print_cr("Allocating RW objects ... ");
1205       _mc_region.pack(&_rw_region);
1206 
1207       ResourceMark rm;
1208       ShallowCopier rw_copier(false);
1209       iterate_roots(&rw_copier);
1210     }
1211     {
1212       // allocate and shallow-copy of RO object, immediately following the RW region
1213       tty->print_cr("Allocating RO objects ... ");
1214       _rw_region.pack(&_ro_region);
1215 
1216       ResourceMark rm;
1217       ShallowCopier ro_copier(true);
1218       iterate_roots(&ro_copier);
1219     }
1220     {
1221       tty->print_cr("Relocating embedded pointers ... ");
1222       ResourceMark rm;
1223       ShallowCopyEmbeddedRefRelocator emb_reloc;
1224       iterate_roots(&emb_reloc);
1225     }
1226     {
1227       tty->print_cr("Relocating external roots ... ");
1228       ResourceMark rm;
1229       RefRelocator ext_reloc;
1230       iterate_roots(&ext_reloc);
1231     }
1232 
1233 #ifdef ASSERT
1234     {
1235       tty->print_cr("Verifying external roots ... ");
1236       ResourceMark rm;
1237       IsRefInArchiveChecker checker;
1238       iterate_roots(&checker);
1239     }
1240 #endif
1241 
1242 
1243     // cleanup
1244     _ssc = NULL;
1245   }
1246 
1247   // We must relocate the System::_well_known_klasses only after we have copied the
1248   // java objects in during dump_java_heap_objects(): during the object copy, we operate on
1249   // old objects which assert that their klass is the original klass.
1250   static void relocate_well_known_klasses() {
1251     {
1252       tty->print_cr("Relocating SystemDictionary::_well_known_klasses[] ... ");
1253       ResourceMark rm;
1254       RefRelocator ext_reloc;
1255       SystemDictionary::well_known_klasses_do(&ext_reloc);
1256     }
1257     // NOTE: after this point, we shouldn't have any globals that can reach the old
1258     // objects.
1259 
1260     // We cannot use any of the objects in the heap anymore (except for the
1261     // shared strings) because their headers no longer point to valid Klasses.
1262   }
1263 
1264   static void iterate_roots(MetaspaceClosure* it) {
1265     GrowableArray<Symbol*>* symbols = _ssc->get_sorted_symbols();
1266     for (int i=0; i<symbols->length(); i++) {
1267       it->push(symbols->adr_at(i));
1268     }
1269     if (_global_klass_objects != NULL) {
1270       // Need to fix up the pointers
1271       for (int i = 0; i < _global_klass_objects->length(); i++) {
1272         // NOTE -- this requires that the vtable is NOT yet patched, or else we are hosed.
1273         it->push(_global_klass_objects->adr_at(i));
1274       }
1275     }
1276     FileMapInfo::metaspace_pointers_do(it);
1277     SystemDictionaryShared::dumptime_classes_do(it);
1278     Universe::metaspace_pointers_do(it);
1279     SymbolTable::metaspace_pointers_do(it);
1280     vmSymbols::metaspace_pointers_do(it);
1281   }
1282 
1283   static Klass* get_relocated_klass(Klass* orig_klass) {
1284     assert(DumpSharedSpaces, "dump time only");
1285     address* pp = _new_loc_table->lookup((address)orig_klass);
1286     assert(pp != NULL, "must be");
1287     Klass* klass = (Klass*)(*pp);
1288     assert(klass->is_klass(), "must be");
1289     return klass;
1290   }
1291 };
1292 
1293 DumpAllocStats* ArchiveCompactor::_alloc_stats;
1294 SortedSymbolClosure* ArchiveCompactor::_ssc;
1295 ArchiveCompactor::RelocationTable* ArchiveCompactor::_new_loc_table;
1296 
1297 void VM_PopulateDumpSharedSpace::write_region(FileMapInfo* mapinfo, int region_idx,
1298                                               DumpRegion* dump_region, bool read_only,  bool allow_exec) {
1299   mapinfo->write_region(region_idx, dump_region->base(), dump_region->used(), read_only, allow_exec);
1300 }
1301 
1302 void VM_PopulateDumpSharedSpace::dump_symbols() {
1303   tty->print_cr("Dumping symbol table ...");
1304 
1305   NOT_PRODUCT(SymbolTable::verify());
1306   SymbolTable::write_to_archive();
1307 }
1308 
1309 char* VM_PopulateDumpSharedSpace::dump_read_only_tables() {
1310   ArchiveCompactor::OtherROAllocMark mark;
1311 
1312   tty->print("Removing java_mirror ... ");
1313   if (!HeapShared::is_heap_object_archiving_allowed()) {
1314     clear_basic_type_mirrors();
1315   }
1316   remove_java_mirror_in_classes();
1317   tty->print_cr("done. ");
1318 
1319   SystemDictionaryShared::write_to_archive();
1320 
1321   char* start = _ro_region.top();
1322 
1323   // Write the other data to the output array.
1324   WriteClosure wc(&_ro_region);
1325   MetaspaceShared::serialize(&wc);
1326 
1327   // Write the bitmaps for patching the archive heap regions
1328   dump_archive_heap_oopmaps();
1329 
1330   return start;
1331 }
1332 
1333 void VM_PopulateDumpSharedSpace::doit() {
1334   // We should no longer allocate anything from the metaspace, so that:
1335   //
1336   // (1) Metaspace::allocate might trigger GC if we have run out of
1337   //     committed metaspace, but we can't GC because we're running
1338   //     in the VM thread.
1339   // (2) ArchiveCompactor needs to work with a stable set of MetaspaceObjs.
1340   Metaspace::freeze();
1341 
1342   Thread* THREAD = VMThread::vm_thread();
1343 
1344   FileMapInfo::check_nonempty_dir_in_shared_path_table();
1345 
1346   NOT_PRODUCT(SystemDictionary::verify();)
1347   // The following guarantee is meant to ensure that no loader constraints
1348   // exist yet, since the constraints table is not shared.  This becomes
1349   // more important now that we don't re-initialize vtables/itables for
1350   // shared classes at runtime, where constraints were previously created.
1351   guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
1352             "loader constraints are not saved");
1353   guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
1354           "placeholders are not saved");
1355 
1356   // At this point, many classes have been loaded.
1357   // Gather systemDictionary classes in a global array and do everything to
1358   // that so we don't have to walk the SystemDictionary again.
1359   SystemDictionaryShared::check_excluded_classes();
1360   _global_klass_objects = new GrowableArray<Klass*>(1000);
1361   CollectClassesClosure collect_classes;
1362   ClassLoaderDataGraph::loaded_classes_do(&collect_classes);
1363 
1364   tty->print_cr("Number of classes %d", _global_klass_objects->length());
1365   {
1366     int num_type_array = 0, num_obj_array = 0, num_inst = 0;
1367     for (int i = 0; i < _global_klass_objects->length(); i++) {
1368       Klass* k = _global_klass_objects->at(i);
1369       if (k->is_instance_klass()) {
1370         num_inst ++;
1371       } else if (k->is_objArray_klass()) {
1372         num_obj_array ++;
1373       } else {
1374         assert(k->is_typeArray_klass(), "sanity");
1375         num_type_array ++;
1376       }
1377     }
1378     tty->print_cr("    instance classes   = %5d", num_inst);
1379     tty->print_cr("    obj array classes  = %5d", num_obj_array);
1380     tty->print_cr("    type array classes = %5d", num_type_array);
1381   }
1382 
1383   // Ensure the ConstMethods won't be modified at run-time
1384   tty->print("Updating ConstMethods ... ");
1385   rewrite_nofast_bytecodes_and_calculate_fingerprints();
1386   tty->print_cr("done. ");
1387 
1388   // Remove all references outside the metadata
1389   tty->print("Removing unshareable information ... ");
1390   remove_unshareable_in_classes();
1391   tty->print_cr("done. ");
1392 
1393   ArchiveCompactor::initialize();
1394   ArchiveCompactor::copy_and_compact();
1395 
1396   dump_symbols();
1397 
1398   // Dump supported java heap objects
1399   _closed_archive_heap_regions = NULL;
1400   _open_archive_heap_regions = NULL;
1401   dump_java_heap_objects();
1402 
1403   ArchiveCompactor::relocate_well_known_klasses();
1404 
1405   char* read_only_tables_start = dump_read_only_tables();
1406   _ro_region.pack(&_md_region);
1407 
1408   char* vtbl_list = _md_region.top();
1409   MetaspaceShared::allocate_cpp_vtable_clones();
1410   _md_region.pack(&_od_region);
1411 
1412   // Relocate the archived class file data into the od region
1413   relocate_cached_class_file();
1414   _od_region.pack();
1415 
1416   // The 5 core spaces are allocated consecutively mc->rw->ro->md->od, so there total size
1417   // is just the spaces between the two ends.
1418   size_t core_spaces_size = _od_region.end() - _mc_region.base();
1419   assert(core_spaces_size == (size_t)align_up(core_spaces_size, Metaspace::reserve_alignment()),
1420          "should already be aligned");
1421 
1422   // During patching, some virtual methods may be called, so at this point
1423   // the vtables must contain valid methods (as filled in by CppVtableCloner::allocate).
1424   MetaspaceShared::patch_cpp_vtable_pointers();
1425 
1426   // The vtable clones contain addresses of the current process.
1427   // We don't want to write these addresses into the archive.
1428   MetaspaceShared::zero_cpp_vtable_clones_for_writing();
1429 
1430   // Create and write the archive file that maps the shared spaces.
1431 
1432   FileMapInfo* mapinfo = new FileMapInfo();
1433   mapinfo->populate_header(os::vm_allocation_granularity());
1434   mapinfo->set_read_only_tables_start(read_only_tables_start);
1435   mapinfo->set_misc_data_patching_start(vtbl_list);
1436   mapinfo->set_cds_i2i_entry_code_buffers(MetaspaceShared::cds_i2i_entry_code_buffers());
1437   mapinfo->set_cds_i2i_entry_code_buffers_size(MetaspaceShared::cds_i2i_entry_code_buffers_size());
1438   mapinfo->set_core_spaces_size(core_spaces_size);
1439 
1440   for (int pass=1; pass<=2; pass++) {
1441     bool print_archive_log = (pass==1);
1442     if (pass == 1) {
1443       // The first pass doesn't actually write the data to disk. All it
1444       // does is to update the fields in the mapinfo->_header.
1445     } else {
1446       // After the first pass, the contents of mapinfo->_header are finalized,
1447       // so we can compute the header's CRC, and write the contents of the header
1448       // and the regions into disk.
1449       mapinfo->open_for_write();
1450       mapinfo->set_header_crc(mapinfo->compute_header_crc());
1451     }
1452     mapinfo->write_header();
1453 
1454     // NOTE: md contains the trampoline code for method entries, which are patched at run time,
1455     // so it needs to be read/write.
1456     write_region(mapinfo, MetaspaceShared::mc, &_mc_region, /*read_only=*/false,/*allow_exec=*/true);
1457     write_region(mapinfo, MetaspaceShared::rw, &_rw_region, /*read_only=*/false,/*allow_exec=*/false);
1458     write_region(mapinfo, MetaspaceShared::ro, &_ro_region, /*read_only=*/true, /*allow_exec=*/false);
1459     write_region(mapinfo, MetaspaceShared::md, &_md_region, /*read_only=*/false,/*allow_exec=*/false);
1460     write_region(mapinfo, MetaspaceShared::od, &_od_region, /*read_only=*/true, /*allow_exec=*/false);
1461 
1462     _total_closed_archive_region_size = mapinfo->write_archive_heap_regions(
1463                                         _closed_archive_heap_regions,
1464                                         _closed_archive_heap_oopmaps,
1465                                         MetaspaceShared::first_closed_archive_heap_region,
1466                                         MetaspaceShared::max_closed_archive_heap_region,
1467                                         print_archive_log);
1468     _total_open_archive_region_size = mapinfo->write_archive_heap_regions(
1469                                         _open_archive_heap_regions,
1470                                         _open_archive_heap_oopmaps,
1471                                         MetaspaceShared::first_open_archive_heap_region,
1472                                         MetaspaceShared::max_open_archive_heap_region,
1473                                         print_archive_log);
1474   }
1475 
1476   mapinfo->close();
1477 
1478   // Restore the vtable in case we invoke any virtual methods.
1479   MetaspaceShared::clone_cpp_vtables((intptr_t*)vtbl_list);
1480 
1481   print_region_stats();
1482 
1483   if (log_is_enabled(Info, cds)) {
1484     ArchiveCompactor::alloc_stats()->print_stats(int(_ro_region.used()), int(_rw_region.used()),
1485                                                  int(_mc_region.used()), int(_md_region.used()));
1486   }
1487 
1488   if (PrintSystemDictionaryAtExit) {
1489     SystemDictionary::print();
1490   }
1491   // There may be other pending VM operations that operate on the InstanceKlasses,
1492   // which will fail because InstanceKlasses::remove_unshareable_info()
1493   // has been called. Forget these operations and exit the VM directly.
1494   vm_direct_exit(0);
1495 }
1496 
1497 void VM_PopulateDumpSharedSpace::print_region_stats() {
1498   // Print statistics of all the regions
1499   const size_t total_reserved = _ro_region.reserved()  + _rw_region.reserved() +
1500                                 _mc_region.reserved()  + _md_region.reserved() +
1501                                 _od_region.reserved()  +
1502                                 _total_closed_archive_region_size +
1503                                 _total_open_archive_region_size;
1504   const size_t total_bytes = _ro_region.used()  + _rw_region.used() +
1505                              _mc_region.used()  + _md_region.used() +
1506                              _od_region.used()  +
1507                              _total_closed_archive_region_size +
1508                              _total_open_archive_region_size;
1509   const double total_u_perc = percent_of(total_bytes, total_reserved);
1510 
1511   _mc_region.print(total_reserved);
1512   _rw_region.print(total_reserved);
1513   _ro_region.print(total_reserved);
1514   _md_region.print(total_reserved);
1515   _od_region.print(total_reserved);
1516   print_heap_region_stats(_closed_archive_heap_regions, "ca", total_reserved);
1517   print_heap_region_stats(_open_archive_heap_regions, "oa", total_reserved);
1518 
1519   tty->print_cr("total    : " SIZE_FORMAT_W(9) " [100.0%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used]",
1520                  total_bytes, total_reserved, total_u_perc);
1521 }
1522 
1523 void VM_PopulateDumpSharedSpace::print_heap_region_stats(GrowableArray<MemRegion> *heap_mem,
1524                                                          const char *name, const size_t total_size) {
1525   int arr_len = heap_mem == NULL ? 0 : heap_mem->length();
1526   for (int i = 0; i < arr_len; i++) {
1527       char* start = (char*)heap_mem->at(i).start();
1528       size_t size = heap_mem->at(i).byte_size();
1529       char* top = start + size;
1530       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,
1531                     name, i, size, size/double(total_size)*100.0, size, p2i(start));
1532 
1533   }
1534 }
1535 
1536 // Update a Java object to point its Klass* to the new location after
1537 // shared archive has been compacted.
1538 void MetaspaceShared::relocate_klass_ptr(oop o) {
1539   assert(DumpSharedSpaces, "sanity");
1540   Klass* k = ArchiveCompactor::get_relocated_klass(o->klass());
1541   o->set_klass(k);
1542 }
1543 
1544 Klass* MetaspaceShared::get_relocated_klass(Klass *k) {
1545   assert(DumpSharedSpaces, "sanity");
1546   return ArchiveCompactor::get_relocated_klass(k);
1547 }
1548 
1549 class LinkSharedClassesClosure : public KlassClosure {
1550   Thread* THREAD;
1551   bool    _made_progress;
1552  public:
1553   LinkSharedClassesClosure(Thread* thread) : THREAD(thread), _made_progress(false) {}
1554 
1555   void reset()               { _made_progress = false; }
1556   bool made_progress() const { return _made_progress; }
1557 
1558   void do_klass(Klass* k) {
1559     if (k->is_instance_klass()) {
1560       InstanceKlass* ik = InstanceKlass::cast(k);
1561       // Link the class to cause the bytecodes to be rewritten and the
1562       // cpcache to be created. Class verification is done according
1563       // to -Xverify setting.
1564       _made_progress |= MetaspaceShared::try_link_class(ik, THREAD);
1565       guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1566 
1567       ik->constants()->resolve_class_constants(THREAD);
1568     }
1569   }
1570 };
1571 
1572 class CheckSharedClassesClosure : public KlassClosure {
1573   bool    _made_progress;
1574  public:
1575   CheckSharedClassesClosure() : _made_progress(false) {}
1576 
1577   void reset()               { _made_progress = false; }
1578   bool made_progress() const { return _made_progress; }
1579   void do_klass(Klass* k) {
1580     if (k->is_instance_klass() && InstanceKlass::cast(k)->check_sharing_error_state()) {
1581       _made_progress = true;
1582     }
1583   }
1584 };
1585 
1586 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
1587   // We need to iterate because verification may cause additional classes
1588   // to be loaded.
1589   LinkSharedClassesClosure link_closure(THREAD);
1590   do {
1591     link_closure.reset();
1592     ClassLoaderDataGraph::unlocked_loaded_classes_do(&link_closure);
1593     guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1594   } while (link_closure.made_progress());
1595 
1596   if (_has_error_classes) {
1597     // Mark all classes whose super class or interfaces failed verification.
1598     CheckSharedClassesClosure check_closure;
1599     do {
1600       // Not completely sure if we need to do this iteratively. Anyway,
1601       // we should come here only if there are unverifiable classes, which
1602       // shouldn't happen in normal cases. So better safe than sorry.
1603       check_closure.reset();
1604       ClassLoaderDataGraph::unlocked_loaded_classes_do(&check_closure);
1605     } while (check_closure.made_progress());
1606   }
1607 }
1608 
1609 void MetaspaceShared::prepare_for_dumping() {
1610   Arguments::check_unsupported_dumping_properties();
1611   ClassLoader::initialize_shared_path();
1612 }
1613 
1614 // Preload classes from a list, populate the shared spaces and dump to a
1615 // file.
1616 void MetaspaceShared::preload_and_dump(TRAPS) {
1617   { TraceTime timer("Dump Shared Spaces", TRACETIME_LOG(Info, startuptime));
1618     ResourceMark rm;
1619     char class_list_path_str[JVM_MAXPATHLEN];
1620     // Preload classes to be shared.
1621     // Should use some os:: method rather than fopen() here. aB.
1622     const char* class_list_path;
1623     if (SharedClassListFile == NULL) {
1624       // Construct the path to the class list (in jre/lib)
1625       // Walk up two directories from the location of the VM and
1626       // optionally tack on "lib" (depending on platform)
1627       os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
1628       for (int i = 0; i < 3; i++) {
1629         char *end = strrchr(class_list_path_str, *os::file_separator());
1630         if (end != NULL) *end = '\0';
1631       }
1632       int class_list_path_len = (int)strlen(class_list_path_str);
1633       if (class_list_path_len >= 3) {
1634         if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
1635           if (class_list_path_len < JVM_MAXPATHLEN - 4) {
1636             jio_snprintf(class_list_path_str + class_list_path_len,
1637                          sizeof(class_list_path_str) - class_list_path_len,
1638                          "%slib", os::file_separator());
1639             class_list_path_len += 4;
1640           }
1641         }
1642       }
1643       if (class_list_path_len < JVM_MAXPATHLEN - 10) {
1644         jio_snprintf(class_list_path_str + class_list_path_len,
1645                      sizeof(class_list_path_str) - class_list_path_len,
1646                      "%sclasslist", os::file_separator());
1647       }
1648       class_list_path = class_list_path_str;
1649     } else {
1650       class_list_path = SharedClassListFile;
1651     }
1652 
1653     tty->print_cr("Loading classes to share ...");
1654     _has_error_classes = false;
1655     int class_count = preload_classes(class_list_path, THREAD);
1656     if (ExtraSharedClassListFile) {
1657       class_count += preload_classes(ExtraSharedClassListFile, THREAD);
1658     }
1659     tty->print_cr("Loading classes to share: done.");
1660 
1661     log_info(cds)("Shared spaces: preloaded %d classes", class_count);
1662 
1663     if (SharedArchiveConfigFile) {
1664       tty->print_cr("Reading extra data from %s ...", SharedArchiveConfigFile);
1665       read_extra_data(SharedArchiveConfigFile, THREAD);
1666     }
1667     tty->print_cr("Reading extra data: done.");
1668 
1669     HeapShared::init_subgraph_entry_fields(THREAD);
1670 
1671     // Rewrite and link classes
1672     tty->print_cr("Rewriting and linking classes ...");
1673 
1674     // Link any classes which got missed. This would happen if we have loaded classes that
1675     // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
1676     // fails verification, all other interfaces that were not specified in the classlist but
1677     // are implemented by K are not verified.
1678     link_and_cleanup_shared_classes(CATCH);
1679     tty->print_cr("Rewriting and linking classes: done");
1680 
1681     VM_PopulateDumpSharedSpace op;
1682     VMThread::execute(&op);
1683   }
1684 }
1685 
1686 
1687 int MetaspaceShared::preload_classes(const char* class_list_path, TRAPS) {
1688   ClassListParser parser(class_list_path);
1689   int class_count = 0;
1690 
1691   while (parser.parse_one_line()) {
1692     Klass* klass = parser.load_current_class(THREAD);
1693     if (HAS_PENDING_EXCEPTION) {
1694       if (klass == NULL &&
1695           (PENDING_EXCEPTION->klass()->name() == vmSymbols::java_lang_ClassNotFoundException())) {
1696         // print a warning only when the pending exception is class not found
1697         tty->print_cr("Preload Warning: Cannot find %s", parser.current_class_name());
1698       }
1699       CLEAR_PENDING_EXCEPTION;
1700     }
1701     if (klass != NULL) {
1702       if (log_is_enabled(Trace, cds)) {
1703         ResourceMark rm;
1704         log_trace(cds)("Shared spaces preloaded: %s", klass->external_name());
1705       }
1706 
1707       if (klass->is_instance_klass()) {
1708         InstanceKlass* ik = InstanceKlass::cast(klass);
1709 
1710         // Link the class to cause the bytecodes to be rewritten and the
1711         // cpcache to be created. The linking is done as soon as classes
1712         // are loaded in order that the related data structures (klass and
1713         // cpCache) are located together.
1714         try_link_class(ik, THREAD);
1715         guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1716       }
1717 
1718       class_count++;
1719     }
1720   }
1721 
1722   return class_count;
1723 }
1724 
1725 // Returns true if the class's status has changed
1726 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
1727   assert(DumpSharedSpaces, "should only be called during dumping");
1728   if (ik->init_state() < InstanceKlass::linked) {
1729     bool saved = BytecodeVerificationLocal;
1730     if (ik->loader_type() == 0 && ik->class_loader() == NULL) {
1731       // The verification decision is based on BytecodeVerificationRemote
1732       // for non-system classes. Since we are using the NULL classloader
1733       // to load non-system classes for customized class loaders during dumping,
1734       // we need to temporarily change BytecodeVerificationLocal to be the same as
1735       // BytecodeVerificationRemote. Note this can cause the parent system
1736       // classes also being verified. The extra overhead is acceptable during
1737       // dumping.
1738       BytecodeVerificationLocal = BytecodeVerificationRemote;
1739     }
1740     ik->link_class(THREAD);
1741     if (HAS_PENDING_EXCEPTION) {
1742       ResourceMark rm;
1743       tty->print_cr("Preload Warning: Verification failed for %s",
1744                     ik->external_name());
1745       CLEAR_PENDING_EXCEPTION;
1746       ik->set_in_error_state();
1747       _has_error_classes = true;
1748     }
1749     BytecodeVerificationLocal = saved;
1750     return true;
1751   } else {
1752     return false;
1753   }
1754 }
1755 
1756 #if INCLUDE_CDS_JAVA_HEAP
1757 void VM_PopulateDumpSharedSpace::dump_java_heap_objects() {
1758   // The closed and open archive heap space has maximum two regions.
1759   // See FileMapInfo::write_archive_heap_regions() for details.
1760   _closed_archive_heap_regions = new GrowableArray<MemRegion>(2);
1761   _open_archive_heap_regions = new GrowableArray<MemRegion>(2);
1762   HeapShared::archive_java_heap_objects(_closed_archive_heap_regions,
1763                                         _open_archive_heap_regions);
1764   ArchiveCompactor::OtherROAllocMark mark;
1765   HeapShared::write_subgraph_info_table();
1766 }
1767 
1768 void VM_PopulateDumpSharedSpace::dump_archive_heap_oopmaps() {
1769   if (HeapShared::is_heap_object_archiving_allowed()) {
1770     _closed_archive_heap_oopmaps = new GrowableArray<ArchiveHeapOopmapInfo>(2);
1771     dump_archive_heap_oopmaps(_closed_archive_heap_regions, _closed_archive_heap_oopmaps);
1772 
1773     _open_archive_heap_oopmaps = new GrowableArray<ArchiveHeapOopmapInfo>(2);
1774     dump_archive_heap_oopmaps(_open_archive_heap_regions, _open_archive_heap_oopmaps);
1775   }
1776 }
1777 
1778 void VM_PopulateDumpSharedSpace::dump_archive_heap_oopmaps(GrowableArray<MemRegion>* regions,
1779                                                            GrowableArray<ArchiveHeapOopmapInfo>* oopmaps) {
1780   for (int i=0; i<regions->length(); i++) {
1781     ResourceBitMap oopmap = HeapShared::calculate_oopmap(regions->at(i));
1782     size_t size_in_bits = oopmap.size();
1783     size_t size_in_bytes = oopmap.size_in_bytes();
1784     uintptr_t* buffer = (uintptr_t*)_ro_region.allocate(size_in_bytes, sizeof(intptr_t));
1785     oopmap.write_to(buffer, size_in_bytes);
1786     log_info(cds)("Oopmap = " INTPTR_FORMAT " (" SIZE_FORMAT_W(6) " bytes) for heap region "
1787                   INTPTR_FORMAT " (" SIZE_FORMAT_W(8) " bytes)",
1788                   p2i(buffer), size_in_bytes,
1789                   p2i(regions->at(i).start()), regions->at(i).byte_size());
1790 
1791     ArchiveHeapOopmapInfo info;
1792     info._oopmap = (address)buffer;
1793     info._oopmap_size_in_bits = size_in_bits;
1794     oopmaps->append(info);
1795   }
1796 }
1797 #endif // INCLUDE_CDS_JAVA_HEAP
1798 
1799 // Closure for serializing initialization data in from a data area
1800 // (ptr_array) read from the shared file.
1801 
1802 class ReadClosure : public SerializeClosure {
1803 private:
1804   intptr_t** _ptr_array;
1805 
1806   inline intptr_t nextPtr() {
1807     return *(*_ptr_array)++;
1808   }
1809 
1810 public:
1811   ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
1812 
1813   void do_ptr(void** p) {
1814     assert(*p == NULL, "initializing previous initialized pointer.");
1815     intptr_t obj = nextPtr();
1816     assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
1817            "hit tag while initializing ptrs.");
1818     *p = (void*)obj;
1819   }
1820 
1821   void do_u4(u4* p) {
1822     intptr_t obj = nextPtr();
1823     *p = (u4)(uintx(obj));
1824   }
1825 
1826   void do_tag(int tag) {
1827     int old_tag;
1828     old_tag = (int)(intptr_t)nextPtr();
1829     // do_int(&old_tag);
1830     assert(tag == old_tag, "old tag doesn't match");
1831     FileMapInfo::assert_mark(tag == old_tag);
1832   }
1833 
1834   void do_oop(oop *p) {
1835     narrowOop o = (narrowOop)nextPtr();
1836     if (o == 0 || !HeapShared::open_archive_heap_region_mapped()) {
1837       p = NULL;
1838     } else {
1839       assert(HeapShared::is_heap_object_archiving_allowed(),
1840              "Archived heap object is not allowed");
1841       assert(HeapShared::open_archive_heap_region_mapped(),
1842              "Open archive heap region is not mapped");
1843       *p = HeapShared::decode_from_archive(o);
1844     }
1845   }
1846 
1847   void do_region(u_char* start, size_t size) {
1848     assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
1849     assert(size % sizeof(intptr_t) == 0, "bad size");
1850     do_tag((int)size);
1851     while (size > 0) {
1852       *(intptr_t*)start = nextPtr();
1853       start += sizeof(intptr_t);
1854       size -= sizeof(intptr_t);
1855     }
1856   }
1857 
1858   bool reading() const { return true; }
1859 };
1860 
1861 // Return true if given address is in the misc data region
1862 bool MetaspaceShared::is_in_shared_region(const void* p, int idx) {
1863   return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_region(p, idx);
1864 }
1865 
1866 bool MetaspaceShared::is_in_trampoline_frame(address addr) {
1867   if (UseSharedSpaces && is_in_shared_region(addr, MetaspaceShared::mc)) {
1868     return true;
1869   }
1870   return false;
1871 }
1872 
1873 // Map shared spaces at requested addresses and return if succeeded.
1874 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
1875   size_t image_alignment = mapinfo->alignment();
1876 
1877 #ifndef _WINDOWS
1878   // Map in the shared memory and then map the regions on top of it.
1879   // On Windows, don't map the memory here because it will cause the
1880   // mappings of the regions to fail.
1881   ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
1882   if (!shared_rs.is_reserved()) return false;
1883 #endif
1884 
1885   assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
1886 
1887   char* ro_base = NULL; char* ro_top;
1888   char* rw_base = NULL; char* rw_top;
1889   char* mc_base = NULL; char* mc_top;
1890   char* md_base = NULL; char* md_top;
1891   char* od_base = NULL; char* od_top;
1892 
1893   // Map each shared region
1894   if ((mc_base = mapinfo->map_region(mc, &mc_top)) != NULL &&
1895       (rw_base = mapinfo->map_region(rw, &rw_top)) != NULL &&
1896       (ro_base = mapinfo->map_region(ro, &ro_top)) != NULL &&
1897       (md_base = mapinfo->map_region(md, &md_top)) != NULL &&
1898       (od_base = mapinfo->map_region(od, &od_top)) != NULL &&
1899       (image_alignment == (size_t)os::vm_allocation_granularity()) &&
1900       mapinfo->validate_shared_path_table()) {
1901     // Success -- set up MetaspaceObj::_shared_metaspace_{base,top} for
1902     // fast checking in MetaspaceShared::is_in_shared_metaspace() and
1903     // MetaspaceObj::is_shared().
1904     //
1905     // We require that mc->rw->ro->md->od to be laid out consecutively, with no
1906     // gaps between them. That way, we can ensure that the OS won't be able to
1907     // allocate any new memory spaces inside _shared_metaspace_{base,top}, which
1908     // would mess up the simple comparision in MetaspaceShared::is_in_shared_metaspace().
1909     assert(mc_base < ro_base && mc_base < rw_base && mc_base < md_base && mc_base < od_base, "must be");
1910     assert(od_top  > ro_top  && od_top  > rw_top  && od_top  > md_top  && od_top  > mc_top , "must be");
1911     assert(mc_top == rw_base, "must be");
1912     assert(rw_top == ro_base, "must be");
1913     assert(ro_top == md_base, "must be");
1914     assert(md_top == od_base, "must be");
1915 
1916     _core_spaces_size = mapinfo->core_spaces_size();
1917     MetaspaceObj::set_shared_metaspace_range((void*)mc_base, (void*)od_top);
1918     return true;
1919   } else {
1920     // If there was a failure in mapping any of the spaces, unmap the ones
1921     // that succeeded
1922     if (ro_base != NULL) mapinfo->unmap_region(ro);
1923     if (rw_base != NULL) mapinfo->unmap_region(rw);
1924     if (mc_base != NULL) mapinfo->unmap_region(mc);
1925     if (md_base != NULL) mapinfo->unmap_region(md);
1926     if (od_base != NULL) mapinfo->unmap_region(od);
1927 #ifndef _WINDOWS
1928     // Release the entire mapped region
1929     shared_rs.release();
1930 #endif
1931     // If -Xshare:on is specified, print out the error message and exit VM,
1932     // otherwise, set UseSharedSpaces to false and continue.
1933     if (RequireSharedSpaces || PrintSharedArchiveAndExit) {
1934       vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
1935     } else {
1936       FLAG_SET_DEFAULT(UseSharedSpaces, false);
1937     }
1938     return false;
1939   }
1940 }
1941 
1942 // Read the miscellaneous data from the shared file, and
1943 // serialize it out to its various destinations.
1944 
1945 void MetaspaceShared::initialize_shared_spaces() {
1946   FileMapInfo *mapinfo = FileMapInfo::current_info();
1947   _cds_i2i_entry_code_buffers = mapinfo->cds_i2i_entry_code_buffers();
1948   _cds_i2i_entry_code_buffers_size = mapinfo->cds_i2i_entry_code_buffers_size();
1949   // _core_spaces_size is loaded from the shared archive immediatelly after mapping
1950   assert(_core_spaces_size == mapinfo->core_spaces_size(), "sanity");
1951   char* buffer = mapinfo->misc_data_patching_start();
1952   clone_cpp_vtables((intptr_t*)buffer);
1953 
1954   // The rest of the data is now stored in the RW region
1955   buffer = mapinfo->read_only_tables_start();
1956 
1957   // Verify various attributes of the archive, plus initialize the
1958   // shared string/symbol tables
1959   intptr_t* array = (intptr_t*)buffer;
1960   ReadClosure rc(&array);
1961   serialize(&rc);
1962 
1963   // Initialize the run-time symbol table.
1964   SymbolTable::create_table();
1965 
1966   mapinfo->patch_archived_heap_embedded_pointers();
1967 
1968   // Close the mapinfo file
1969   mapinfo->close();
1970 
1971   if (PrintSharedArchiveAndExit) {
1972     if (PrintSharedDictionary) {
1973       tty->print_cr("\nShared classes:\n");
1974       SystemDictionaryShared::print_on(tty);
1975     }
1976     if (_archive_loading_failed) {
1977       tty->print_cr("archive is invalid");
1978       vm_exit(1);
1979     } else {
1980       tty->print_cr("archive is valid");
1981       vm_exit(0);
1982     }
1983   }
1984 }
1985 
1986 // JVM/TI RedefineClasses() support:
1987 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
1988   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1989 
1990   if (UseSharedSpaces) {
1991     // remap the shared readonly space to shared readwrite, private
1992     FileMapInfo* mapinfo = FileMapInfo::current_info();
1993     if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1994       return false;
1995     }
1996     _remapped_readwrite = true;
1997   }
1998   return true;
1999 }
2000 
2001 void MetaspaceShared::report_out_of_space(const char* name, size_t needed_bytes) {
2002   // This is highly unlikely to happen on 64-bits because we have reserved a 4GB space.
2003   // On 32-bit we reserve only 256MB so you could run out of space with 100,000 classes
2004   // or so.
2005   _mc_region.print_out_of_space_msg(name, needed_bytes);
2006   _rw_region.print_out_of_space_msg(name, needed_bytes);
2007   _ro_region.print_out_of_space_msg(name, needed_bytes);
2008   _md_region.print_out_of_space_msg(name, needed_bytes);
2009   _od_region.print_out_of_space_msg(name, needed_bytes);
2010 
2011   vm_exit_during_initialization(err_msg("Unable to allocate from '%s' region", name),
2012                                 "Please reduce the number of shared classes.");
2013 }
--- EOF ---