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 #if INCLUDE_G1GC
  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 address MetaspaceShared::_cds_i2i_entry_code_buffers = NULL;
  78 size_t MetaspaceShared::_cds_i2i_entry_code_buffers_size = 0;
  79 size_t MetaspaceShared::_core_spaces_size = 0;
  80 
  81 // The CDS archive is divided into the following regions:
  82 //     mc  - misc code (the method entry trampolines)
  83 //     rw  - read-write metadata
  84 //     ro  - read-only metadata and read-only tables
  85 //     md  - misc data (the c++ vtables)
  86 //     od  - optional data (original class files)
  87 //
  88 //     ca0 - closed archive heap space #0
  89 //     ca1 - closed archive heap space #1 (may be empty)
  90 //     oa0 - open archive heap space #0
  91 //     oa1 - open archive heap space #1 (may be empty)
  92 //
  93 // The mc, rw, ro, md and od regions are linearly allocated, starting from
  94 // SharedBaseAddress, in the order of mc->rw->ro->md->od. The size of these 5 regions
  95 // are page-aligned, and there's no gap between any consecutive regions.
  96 //
  97 // These 5 regions are populated in the following steps:
  98 // [1] All classes are loaded in MetaspaceShared::preload_classes(). All metadata are
  99 //     temporarily allocated outside of the shared regions. Only the method entry
 100 //     trampolines are written into the mc region.
 101 // [2] ArchiveCompactor copies RW metadata into the rw region.
 102 // [3] ArchiveCompactor copies RO metadata into the ro region.
 103 // [4] SymbolTable, StringTable, SystemDictionary, and a few other read-only data
 104 //     are copied into the ro region as read-only tables.
 105 // [5] C++ vtables are copied into the md region.
 106 // [6] Original class files are copied into the od region.
 107 //
 108 // The s0/s1 and oa0/oa1 regions are populated inside HeapShared::archive_java_heap_objects.
 109 // Their layout is independent of the other 5 regions.
 110 
 111 class DumpRegion {
 112 private:
 113   const char* _name;
 114   char* _base;
 115   char* _top;
 116   char* _end;
 117   bool _is_packed;
 118 
 119   char* expand_top_to(char* newtop) {
 120     assert(is_allocatable(), "must be initialized and not packed");
 121     assert(newtop >= _top, "must not grow backwards");
 122     if (newtop > _end) {
 123       MetaspaceShared::report_out_of_space(_name, newtop - _top);
 124       ShouldNotReachHere();
 125     }
 126     uintx delta = MetaspaceShared::object_delta_uintx(newtop);
 127     if (delta > MAX_SHARED_DELTA) {
 128       // This is just a sanity check and should not appear in any real world usage. This
 129       // happens only if you allocate more than 2GB of shared objects and would require
 130       // millions of shared classes.
 131       vm_exit_during_initialization("Out of memory in the CDS archive",
 132                                     "Please reduce the number of shared classes.");
 133     }
 134 
 135     MetaspaceShared::commit_shared_space_to(newtop);
 136     _top = newtop;
 137     return _top;
 138   }
 139 
 140 public:
 141   DumpRegion(const char* name) : _name(name), _base(NULL), _top(NULL), _end(NULL), _is_packed(false) {}
 142 
 143   char* allocate(size_t num_bytes, size_t alignment=BytesPerWord) {
 144     char* p = (char*)align_up(_top, alignment);
 145     char* newtop = p + align_up(num_bytes, alignment);
 146     expand_top_to(newtop);
 147     memset(p, 0, newtop - p);
 148     return p;
 149   }
 150 
 151   void append_intptr_t(intptr_t n) {
 152     assert(is_aligned(_top, sizeof(intptr_t)), "bad alignment");
 153     intptr_t *p = (intptr_t*)_top;
 154     char* newtop = _top + sizeof(intptr_t);
 155     expand_top_to(newtop);
 156     *p = n;
 157   }
 158 
 159   char* base()      const { return _base;        }
 160   char* top()       const { return _top;         }
 161   char* end()       const { return _end;         }
 162   size_t reserved() const { return _end - _base; }
 163   size_t used()     const { return _top - _base; }
 164   bool is_packed()  const { return _is_packed;   }
 165   bool is_allocatable() const {
 166     return !is_packed() && _base != NULL;
 167   }
 168 
 169   void print(size_t total_bytes) const {
 170     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,
 171                   _name, used(), percent_of(used(), total_bytes), reserved(), percent_of(used(), reserved()), p2i(_base));
 172   }
 173   void print_out_of_space_msg(const char* failing_region, size_t needed_bytes) {
 174     tty->print("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d",
 175                _name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base));
 176     if (strcmp(_name, failing_region) == 0) {
 177       tty->print_cr(" required = %d", int(needed_bytes));
 178     } else {
 179       tty->cr();
 180     }
 181   }
 182 
 183   void init(const ReservedSpace* rs) {
 184     _base = _top = rs->base();
 185     _end = rs->end();
 186   }
 187   void init(char* b, char* t, char* e) {
 188     _base = b;
 189     _top = t;
 190     _end = e;
 191   }
 192 
 193   void pack(DumpRegion* next = NULL) {
 194     assert(!is_packed(), "sanity");
 195     _end = (char*)align_up(_top, Metaspace::reserve_alignment());
 196     _is_packed = true;
 197     if (next != NULL) {
 198       next->_base = next->_top = this->_end;
 199       next->_end = MetaspaceShared::shared_rs()->end();
 200     }
 201   }
 202   bool contains(char* p) {
 203     return base() <= p && p < top();
 204   }
 205 };
 206 
 207 
 208 DumpRegion _mc_region("mc"), _ro_region("ro"), _rw_region("rw"), _md_region("md"), _od_region("od");
 209 size_t _total_closed_archive_region_size = 0, _total_open_archive_region_size = 0;
 210 
 211 char* MetaspaceShared::misc_code_space_alloc(size_t num_bytes) {
 212   return _mc_region.allocate(num_bytes);
 213 }
 214 
 215 char* MetaspaceShared::read_only_space_alloc(size_t num_bytes) {
 216   return _ro_region.allocate(num_bytes);
 217 }
 218 
 219 char* MetaspaceShared::read_only_space_top() {
 220   return _ro_region.top();
 221 }
 222 
 223 void MetaspaceShared::initialize_runtime_shared_and_meta_spaces() {
 224   assert(UseSharedSpaces, "Must be called when UseSharedSpaces is enabled");
 225 
 226   // If using shared space, open the file that contains the shared space
 227   // and map in the memory before initializing the rest of metaspace (so
 228   // the addresses don't conflict)
 229   address cds_address = NULL;
 230   FileMapInfo* mapinfo = new FileMapInfo();
 231 
 232   // Open the shared archive file, read and validate the header. If
 233   // initialization fails, shared spaces [UseSharedSpaces] are
 234   // disabled and the file is closed.
 235   // Map in spaces now also
 236   if (mapinfo->initialize() && map_shared_spaces(mapinfo)) {
 237     size_t cds_total = core_spaces_size();
 238     cds_address = (address)mapinfo->region_addr(0);
 239 #ifdef _LP64
 240     if (Metaspace::using_class_space()) {
 241       char* cds_end = (char*)(cds_address + cds_total);
 242       cds_end = (char *)align_up(cds_end, Metaspace::reserve_alignment());
 243       // If UseCompressedClassPointers is set then allocate the metaspace area
 244       // above the heap and above the CDS area (if it exists).
 245       Metaspace::allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
 246       // map_heap_regions() compares the current narrow oop and klass encodings
 247       // with the archived ones, so it must be done after all encodings are determined.
 248       mapinfo->map_heap_regions();
 249     }
 250     Universe::set_narrow_klass_range(CompressedClassSpaceSize);
 251 #endif // _LP64
 252   } else {
 253     assert(!mapinfo->is_open() && !UseSharedSpaces,
 254            "archive file not closed or shared spaces not disabled.");
 255   }
 256 }
 257 
 258 void MetaspaceShared::initialize_dumptime_shared_and_meta_spaces() {
 259   assert(DumpSharedSpaces, "should be called for dump time only");
 260   const size_t reserve_alignment = Metaspace::reserve_alignment();
 261   bool large_pages = false; // No large pages when dumping the CDS archive.
 262   char* shared_base = (char*)align_up((char*)SharedBaseAddress, reserve_alignment);
 263 
 264 #ifdef _LP64
 265   // On 64-bit VM, the heap and class space layout will be the same as if
 266   // you're running in -Xshare:on mode:
 267   //
 268   //                              +-- SharedBaseAddress (default = 0x800000000)
 269   //                              v
 270   // +-..---------+---------+ ... +----+----+----+----+----+---------------+
 271   // |    Heap    | Archive |     | MC | RW | RO | MD | OD | class space   |
 272   // +-..---------+---------+ ... +----+----+----+----+----+---------------+
 273   // |<--   MaxHeapSize  -->|     |<-- UnscaledClassSpaceMax = 4GB ------->|
 274   //
 275   const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
 276   const size_t cds_total = align_down(UnscaledClassSpaceMax, reserve_alignment);
 277 #else
 278   // We don't support archives larger than 256MB on 32-bit due to limited virtual address space.
 279   size_t cds_total = align_down(256*M, reserve_alignment);
 280 #endif
 281 
 282   // First try to reserve the space at the specified SharedBaseAddress.
 283   _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages, shared_base);
 284   if (_shared_rs.is_reserved()) {
 285     assert(shared_base == 0 || _shared_rs.base() == shared_base, "should match");
 286   } else {
 287     // Get a mmap region anywhere if the SharedBaseAddress fails.
 288     _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages);
 289   }
 290   if (!_shared_rs.is_reserved()) {
 291     vm_exit_during_initialization("Unable to reserve memory for shared space",
 292                                   err_msg(SIZE_FORMAT " bytes.", cds_total));
 293   }
 294 
 295 #ifdef _LP64
 296   // During dump time, we allocate 4GB (UnscaledClassSpaceMax) of space and split it up:
 297   // + The upper 1 GB is used as the "temporary compressed class space" -- preload_classes()
 298   //   will store Klasses into this space.
 299   // + The lower 3 GB is used for the archive -- when preload_classes() is done,
 300   //   ArchiveCompactor will copy the class metadata into this space, first the RW parts,
 301   //   then the RO parts.
 302 
 303   assert(UseCompressedOops && UseCompressedClassPointers,
 304       "UseCompressedOops and UseCompressedClassPointers must be set");
 305 
 306   size_t max_archive_size = align_down(cds_total * 3 / 4, reserve_alignment);
 307   ReservedSpace tmp_class_space = _shared_rs.last_part(max_archive_size);
 308   CompressedClassSpaceSize = align_down(tmp_class_space.size(), reserve_alignment);
 309   _shared_rs = _shared_rs.first_part(max_archive_size);
 310 
 311   // Set up compress class pointers.
 312   Universe::set_narrow_klass_base((address)_shared_rs.base());
 313   // Set narrow_klass_shift to be LogKlassAlignmentInBytes. This is consistent
 314   // with AOT.
 315   Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
 316   // Set the range of klass addresses to 4GB.
 317   Universe::set_narrow_klass_range(cds_total);
 318 
 319   Metaspace::initialize_class_space(tmp_class_space);
 320   log_info(cds)("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
 321                 p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift());
 322 
 323   log_info(cds)("Allocated temporary class space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
 324                 CompressedClassSpaceSize, p2i(tmp_class_space.base()));
 325 #endif
 326 
 327   // Start with 0 committed bytes. The memory will be committed as needed by
 328   // MetaspaceShared::commit_shared_space_to().
 329   if (!_shared_vs.initialize(_shared_rs, 0)) {
 330     vm_exit_during_initialization("Unable to allocate memory for shared space");
 331   }
 332 
 333   _mc_region.init(&_shared_rs);
 334   SharedBaseAddress = (size_t)_shared_rs.base();
 335   tty->print_cr("Allocated shared space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
 336                 _shared_rs.size(), p2i(_shared_rs.base()));
 337 }
 338 
 339 // Called by universe_post_init()
 340 void MetaspaceShared::post_initialize(TRAPS) {
 341   if (UseSharedSpaces) {
 342     int size = FileMapInfo::get_number_of_shared_paths();
 343     if (size > 0) {
 344       SystemDictionaryShared::allocate_shared_data_arrays(size, THREAD);
 345       FileMapHeader* header = FileMapInfo::current_info()->header();
 346       ClassLoaderExt::init_paths_start_index(header->_app_class_paths_start_index);
 347       ClassLoaderExt::init_app_module_paths_start_index(header->_app_module_paths_start_index);
 348     }
 349   }
 350 }
 351 
 352 void MetaspaceShared::read_extra_data(const char* filename, TRAPS) {
 353   HashtableTextDump reader(filename);
 354   reader.check_version("VERSION: 1.0");
 355 
 356   while (reader.remain() > 0) {
 357     int utf8_length;
 358     int prefix_type = reader.scan_prefix(&utf8_length);
 359     ResourceMark rm(THREAD);
 360     char* utf8_buffer = NEW_RESOURCE_ARRAY(char, utf8_length);
 361     reader.get_utf8(utf8_buffer, utf8_length);
 362 
 363     if (prefix_type == HashtableTextDump::SymbolPrefix) {
 364       SymbolTable::new_symbol(utf8_buffer, utf8_length, THREAD);
 365     } else{
 366       assert(prefix_type == HashtableTextDump::StringPrefix, "Sanity");
 367       utf8_buffer[utf8_length] = '\0';
 368       oop s = StringTable::intern(utf8_buffer, THREAD);
 369     }
 370   }
 371 }
 372 
 373 void MetaspaceShared::commit_shared_space_to(char* newtop) {
 374   assert(DumpSharedSpaces, "dump-time only");
 375   char* base = _shared_rs.base();
 376   size_t need_committed_size = newtop - base;
 377   size_t has_committed_size = _shared_vs.committed_size();
 378   if (need_committed_size < has_committed_size) {
 379     return;
 380   }
 381 
 382   size_t min_bytes = need_committed_size - has_committed_size;
 383   size_t preferred_bytes = 1 * M;
 384   size_t uncommitted = _shared_vs.reserved_size() - has_committed_size;
 385 
 386   size_t commit = MAX2(min_bytes, preferred_bytes);
 387   assert(commit <= uncommitted, "sanity");
 388 
 389   bool result = _shared_vs.expand_by(commit, false);
 390   if (!result) {
 391     vm_exit_during_initialization(err_msg("Failed to expand shared space to " SIZE_FORMAT " bytes",
 392                                           need_committed_size));
 393   }
 394 
 395   log_info(cds)("Expanding shared spaces by " SIZE_FORMAT_W(7) " bytes [total " SIZE_FORMAT_W(9)  " bytes ending at %p]",
 396                 commit, _shared_vs.actual_committed_size(), _shared_vs.high());
 397 }
 398 
 399 // Read/write a data stream for restoring/preserving metadata pointers and
 400 // miscellaneous data from/to the shared archive file.
 401 
 402 void MetaspaceShared::serialize(SerializeClosure* soc) {
 403   int tag = 0;
 404   soc->do_tag(--tag);
 405 
 406   // Verify the sizes of various metadata in the system.
 407   soc->do_tag(sizeof(Method));
 408   soc->do_tag(sizeof(ConstMethod));
 409   soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
 410   soc->do_tag(sizeof(ConstantPool));
 411   soc->do_tag(sizeof(ConstantPoolCache));
 412   soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
 413   soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
 414   soc->do_tag(sizeof(Symbol));
 415 
 416   // Dump/restore miscellaneous metadata.
 417   Universe::serialize(soc);
 418   soc->do_tag(--tag);
 419 
 420   // Dump/restore references to commonly used names and signatures.
 421   vmSymbols::serialize(soc);
 422   soc->do_tag(--tag);
 423 
 424   // Dump/restore the symbol/string/subgraph_info tables
 425   SymbolTable::serialize_shared_table_header(soc);
 426   StringTable::serialize_shared_table_header(soc);
 427   HeapShared::serialize_subgraph_info_table_header(soc);
 428   SystemDictionaryShared::serialize_dictionary_headers(soc);
 429 
 430   JavaClasses::serialize_offsets(soc);
 431   InstanceMirrorKlass::serialize_offsets(soc);
 432   soc->do_tag(--tag);
 433 
 434   soc->do_tag(666);
 435 }
 436 
 437 address MetaspaceShared::cds_i2i_entry_code_buffers(size_t total_size) {
 438   if (DumpSharedSpaces) {
 439     if (_cds_i2i_entry_code_buffers == NULL) {
 440       _cds_i2i_entry_code_buffers = (address)misc_code_space_alloc(total_size);
 441       _cds_i2i_entry_code_buffers_size = total_size;
 442     }
 443   } else if (UseSharedSpaces) {
 444     assert(_cds_i2i_entry_code_buffers != NULL, "must already been initialized");
 445   } else {
 446     return NULL;
 447   }
 448 
 449   assert(_cds_i2i_entry_code_buffers_size == total_size, "must not change");
 450   return _cds_i2i_entry_code_buffers;
 451 }
 452 
 453 // CDS code for dumping shared archive.
 454 
 455 // Global object for holding classes that have been loaded.  Since this
 456 // is run at a safepoint just before exit, this is the entire set of classes.
 457 static GrowableArray<Klass*>* _global_klass_objects;
 458 
 459 GrowableArray<Klass*>* MetaspaceShared::collected_klasses() {
 460   return _global_klass_objects;
 461 }
 462 
 463 static void collect_array_classes(Klass* k) {
 464   _global_klass_objects->append_if_missing(k);
 465   if (k->is_array_klass()) {
 466     // Add in the array classes too
 467     ArrayKlass* ak = ArrayKlass::cast(k);
 468     Klass* h = ak->higher_dimension();
 469     if (h != NULL) {
 470       h->array_klasses_do(collect_array_classes);
 471     }
 472   }
 473 }
 474 
 475 class CollectClassesClosure : public KlassClosure {
 476   void do_klass(Klass* k) {
 477     if (k->is_instance_klass() &&
 478         SystemDictionaryShared::is_excluded_class(InstanceKlass::cast(k))) {
 479       // Don't add to the _global_klass_objects
 480     } else {
 481       _global_klass_objects->append_if_missing(k);
 482     }
 483     if (k->is_array_klass()) {
 484       // Add in the array classes too
 485       ArrayKlass* ak = ArrayKlass::cast(k);
 486       Klass* h = ak->higher_dimension();
 487       if (h != NULL) {
 488         h->array_klasses_do(collect_array_classes);
 489       }
 490     }
 491   }
 492 };
 493 
 494 static void remove_unshareable_in_classes() {
 495   for (int i = 0; i < _global_klass_objects->length(); i++) {
 496     Klass* k = _global_klass_objects->at(i);
 497     if (!k->is_objArray_klass()) {
 498       // InstanceKlass and TypeArrayKlass will in turn call remove_unshareable_info
 499       // on their array classes.
 500       assert(k->is_instance_klass() || k->is_typeArray_klass(), "must be");
 501       k->remove_unshareable_info();
 502     }
 503   }
 504 }
 505 
 506 static void remove_java_mirror_in_classes() {
 507   for (int i = 0; i < _global_klass_objects->length(); i++) {
 508     Klass* k = _global_klass_objects->at(i);
 509     if (!k->is_objArray_klass()) {
 510       // InstanceKlass and TypeArrayKlass will in turn call remove_unshareable_info
 511       // on their array classes.
 512       assert(k->is_instance_klass() || k->is_typeArray_klass(), "must be");
 513       k->remove_java_mirror();
 514     }
 515   }
 516 }
 517 
 518 static void clear_basic_type_mirrors() {
 519   assert(!HeapShared::is_heap_object_archiving_allowed(), "Sanity");
 520   Universe::set_int_mirror(NULL);
 521   Universe::set_float_mirror(NULL);
 522   Universe::set_double_mirror(NULL);
 523   Universe::set_byte_mirror(NULL);
 524   Universe::set_bool_mirror(NULL);
 525   Universe::set_char_mirror(NULL);
 526   Universe::set_long_mirror(NULL);
 527   Universe::set_short_mirror(NULL);
 528   Universe::set_void_mirror(NULL);
 529 }
 530 
 531 static void rewrite_nofast_bytecode(Method* method) {
 532   BytecodeStream bcs(method);
 533   while (!bcs.is_last_bytecode()) {
 534     Bytecodes::Code opcode = bcs.next();
 535     switch (opcode) {
 536     case Bytecodes::_getfield:      *bcs.bcp() = Bytecodes::_nofast_getfield;      break;
 537     case Bytecodes::_putfield:      *bcs.bcp() = Bytecodes::_nofast_putfield;      break;
 538     case Bytecodes::_aload_0:       *bcs.bcp() = Bytecodes::_nofast_aload_0;       break;
 539     case Bytecodes::_iload: {
 540       if (!bcs.is_wide()) {
 541         *bcs.bcp() = Bytecodes::_nofast_iload;
 542       }
 543       break;
 544     }
 545     default: break;
 546     }
 547   }
 548 }
 549 
 550 // Walk all methods in the class list to ensure that they won't be modified at
 551 // run time. This includes:
 552 // [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified
 553 //     at run time by RewriteBytecodes/RewriteFrequentPairs
 554 // [2] Assign a fingerprint, so one doesn't need to be assigned at run-time.
 555 static void rewrite_nofast_bytecodes_and_calculate_fingerprints() {
 556   for (int i = 0; i < _global_klass_objects->length(); i++) {
 557     Klass* k = _global_klass_objects->at(i);
 558     if (k->is_instance_klass()) {
 559       InstanceKlass* ik = InstanceKlass::cast(k);
 560       for (int i = 0; i < ik->methods()->length(); i++) {
 561         Method* m = ik->methods()->at(i);
 562         rewrite_nofast_bytecode(m);
 563         Fingerprinter fp(m);
 564         // The side effect of this call sets method's fingerprint field.
 565         fp.fingerprint();
 566       }
 567     }
 568   }
 569 }
 570 
 571 static void relocate_cached_class_file() {
 572   for (int i = 0; i < _global_klass_objects->length(); i++) {
 573     Klass* k = _global_klass_objects->at(i);
 574     if (k->is_instance_klass()) {
 575       InstanceKlass* ik = InstanceKlass::cast(k);
 576       JvmtiCachedClassFileData* p = ik->get_archived_class_data();
 577       if (p != NULL) {
 578         int size = offset_of(JvmtiCachedClassFileData, data) + p->length;
 579         JvmtiCachedClassFileData* q = (JvmtiCachedClassFileData*)_od_region.allocate(size);
 580         q->length = p->length;
 581         memcpy(q->data, p->data, p->length);
 582         ik->set_archived_class_data(q);
 583       }
 584     }
 585   }
 586 }
 587 
 588 // Objects of the Metadata types (such as Klass and ConstantPool) have C++ vtables.
 589 // (In GCC this is the field <Type>::_vptr, i.e., first word in the object.)
 590 //
 591 // Addresses of the vtables and the methods may be different across JVM runs,
 592 // if libjvm.so is dynamically loaded at a different base address.
 593 //
 594 // To ensure that the Metadata objects in the CDS archive always have the correct vtable:
 595 //
 596 // + at dump time:  we redirect the _vptr to point to our own vtables inside
 597 //                  the CDS image
 598 // + at run time:   we clone the actual contents of the vtables from libjvm.so
 599 //                  into our own tables.
 600 
 601 // Currently, the archive contain ONLY the following types of objects that have C++ vtables.
 602 #define CPP_VTABLE_PATCH_TYPES_DO(f) \
 603   f(ConstantPool) \
 604   f(InstanceKlass) \
 605   f(InstanceClassLoaderKlass) \
 606   f(InstanceMirrorKlass) \
 607   f(InstanceRefKlass) \
 608   f(Method) \
 609   f(ObjArrayKlass) \
 610   f(TypeArrayKlass)
 611 
 612 class CppVtableInfo {
 613   intptr_t _vtable_size;
 614   intptr_t _cloned_vtable[1];
 615 public:
 616   static int num_slots(int vtable_size) {
 617     return 1 + vtable_size; // Need to add the space occupied by _vtable_size;
 618   }
 619   int vtable_size()           { return int(uintx(_vtable_size)); }
 620   void set_vtable_size(int n) { _vtable_size = intptr_t(n); }
 621   intptr_t* cloned_vtable()   { return &_cloned_vtable[0]; }
 622   void zero()                 { memset(_cloned_vtable, 0, sizeof(intptr_t) * vtable_size()); }
 623   // Returns the address of the next CppVtableInfo that can be placed immediately after this CppVtableInfo
 624   static size_t byte_size(int vtable_size) {
 625     CppVtableInfo i;
 626     return pointer_delta(&i._cloned_vtable[vtable_size], &i, sizeof(u1));
 627   }
 628 };
 629 
 630 template <class T> class CppVtableCloner : public T {
 631   static intptr_t* vtable_of(Metadata& m) {
 632     return *((intptr_t**)&m);
 633   }
 634   static CppVtableInfo* _info;
 635 
 636   static int get_vtable_length(const char* name);
 637 
 638 public:
 639   // Allocate and initialize the C++ vtable, starting from top, but do not go past end.
 640   static intptr_t* allocate(const char* name);
 641 
 642   // Clone the vtable to ...
 643   static intptr_t* clone_vtable(const char* name, CppVtableInfo* info);
 644 
 645   static void zero_vtable_clone() {
 646     assert(DumpSharedSpaces, "dump-time only");
 647     _info->zero();
 648   }
 649 
 650   // Switch the vtable pointer to point to the cloned vtable.
 651   static void patch(Metadata* obj) {
 652     assert(DumpSharedSpaces, "dump-time only");
 653     *(void**)obj = (void*)(_info->cloned_vtable());
 654   }
 655 
 656   static bool is_valid_shared_object(const T* obj) {
 657     intptr_t* vptr = *(intptr_t**)obj;
 658     return vptr == _info->cloned_vtable();
 659   }
 660 };
 661 
 662 template <class T> CppVtableInfo* CppVtableCloner<T>::_info = NULL;
 663 
 664 template <class T>
 665 intptr_t* CppVtableCloner<T>::allocate(const char* name) {
 666   assert(is_aligned(_md_region.top(), sizeof(intptr_t)), "bad alignment");
 667   int n = get_vtable_length(name);
 668   _info = (CppVtableInfo*)_md_region.allocate(CppVtableInfo::byte_size(n), sizeof(intptr_t));
 669   _info->set_vtable_size(n);
 670 
 671   intptr_t* p = clone_vtable(name, _info);
 672   assert((char*)p == _md_region.top(), "must be");
 673 
 674   return p;
 675 }
 676 
 677 template <class T>
 678 intptr_t* CppVtableCloner<T>::clone_vtable(const char* name, CppVtableInfo* info) {
 679   if (!DumpSharedSpaces) {
 680     assert(_info == 0, "_info is initialized only at dump time");
 681     _info = info; // Remember it -- it will be used by MetaspaceShared::is_valid_shared_method()
 682   }
 683   T tmp; // Allocate temporary dummy metadata object to get to the original vtable.
 684   int n = info->vtable_size();
 685   intptr_t* srcvtable = vtable_of(tmp);
 686   intptr_t* dstvtable = info->cloned_vtable();
 687 
 688   // We already checked (and, if necessary, adjusted n) when the vtables were allocated, so we are
 689   // safe to do memcpy.
 690   log_debug(cds, vtables)("Copying %3d vtable entries for %s", n, name);
 691   memcpy(dstvtable, srcvtable, sizeof(intptr_t) * n);
 692   return dstvtable + n;
 693 }
 694 
 695 // To determine the size of the vtable for each type, we use the following
 696 // trick by declaring 2 subclasses:
 697 //
 698 //   class CppVtableTesterA: public InstanceKlass {virtual int   last_virtual_method() {return 1;}    };
 699 //   class CppVtableTesterB: public InstanceKlass {virtual void* last_virtual_method() {return NULL}; };
 700 //
 701 // CppVtableTesterA and CppVtableTesterB's vtables have the following properties:
 702 // - Their size (N+1) is exactly one more than the size of InstanceKlass's vtable (N)
 703 // - The first N entries have are exactly the same as in InstanceKlass's vtable.
 704 // - Their last entry is different.
 705 //
 706 // So to determine the value of N, we just walk CppVtableTesterA and CppVtableTesterB's tables
 707 // and find the first entry that's different.
 708 //
 709 // This works on all C++ compilers supported by Oracle, but you may need to tweak it for more
 710 // esoteric compilers.
 711 
 712 template <class T> class CppVtableTesterB: public T {
 713 public:
 714   virtual int last_virtual_method() {return 1;}
 715 };
 716 
 717 template <class T> class CppVtableTesterA : public T {
 718 public:
 719   virtual void* last_virtual_method() {
 720     // Make this different than CppVtableTesterB::last_virtual_method so the C++
 721     // compiler/linker won't alias the two functions.
 722     return NULL;
 723   }
 724 };
 725 
 726 template <class T>
 727 int CppVtableCloner<T>::get_vtable_length(const char* name) {
 728   CppVtableTesterA<T> a;
 729   CppVtableTesterB<T> b;
 730 
 731   intptr_t* avtable = vtable_of(a);
 732   intptr_t* bvtable = vtable_of(b);
 733 
 734   // Start at slot 1, because slot 0 may be RTTI (on Solaris/Sparc)
 735   int vtable_len = 1;
 736   for (; ; vtable_len++) {
 737     if (avtable[vtable_len] != bvtable[vtable_len]) {
 738       break;
 739     }
 740   }
 741   log_debug(cds, vtables)("Found   %3d vtable entries for %s", vtable_len, name);
 742 
 743   return vtable_len;
 744 }
 745 
 746 #define ALLOC_CPP_VTABLE_CLONE(c) \
 747   CppVtableCloner<c>::allocate(#c);
 748 
 749 #define CLONE_CPP_VTABLE(c) \
 750   p = CppVtableCloner<c>::clone_vtable(#c, (CppVtableInfo*)p);
 751 
 752 #define ZERO_CPP_VTABLE(c) \
 753  CppVtableCloner<c>::zero_vtable_clone();
 754 
 755 // This can be called at both dump time and run time.
 756 intptr_t* MetaspaceShared::clone_cpp_vtables(intptr_t* p) {
 757   assert(DumpSharedSpaces || UseSharedSpaces, "sanity");
 758   CPP_VTABLE_PATCH_TYPES_DO(CLONE_CPP_VTABLE);
 759   return p;
 760 }
 761 
 762 void MetaspaceShared::zero_cpp_vtable_clones_for_writing() {
 763   assert(DumpSharedSpaces, "dump-time only");
 764   CPP_VTABLE_PATCH_TYPES_DO(ZERO_CPP_VTABLE);
 765 }
 766 
 767 // Allocate and initialize the C++ vtables, starting from top, but do not go past end.
 768 void MetaspaceShared::allocate_cpp_vtable_clones() {
 769   assert(DumpSharedSpaces, "dump-time only");
 770   // Layout (each slot is a intptr_t):
 771   //   [number of slots in the first vtable = n1]
 772   //   [ <n1> slots for the first vtable]
 773   //   [number of slots in the first second = n2]
 774   //   [ <n2> slots for the second vtable]
 775   //   ...
 776   // The order of the vtables is the same as the CPP_VTAB_PATCH_TYPES_DO macro.
 777   CPP_VTABLE_PATCH_TYPES_DO(ALLOC_CPP_VTABLE_CLONE);
 778 }
 779 
 780 // Switch the vtable pointer to point to the cloned vtable. We assume the
 781 // vtable pointer is in first slot in object.
 782 void MetaspaceShared::patch_cpp_vtable_pointers() {
 783   int n = _global_klass_objects->length();
 784   for (int i = 0; i < n; i++) {
 785     Klass* obj = _global_klass_objects->at(i);
 786     if (obj->is_instance_klass()) {
 787       InstanceKlass* ik = InstanceKlass::cast(obj);
 788       if (ik->is_class_loader_instance_klass()) {
 789         CppVtableCloner<InstanceClassLoaderKlass>::patch(ik);
 790       } else if (ik->is_reference_instance_klass()) {
 791         CppVtableCloner<InstanceRefKlass>::patch(ik);
 792       } else if (ik->is_mirror_instance_klass()) {
 793         CppVtableCloner<InstanceMirrorKlass>::patch(ik);
 794       } else {
 795         CppVtableCloner<InstanceKlass>::patch(ik);
 796       }
 797       ConstantPool* cp = ik->constants();
 798       CppVtableCloner<ConstantPool>::patch(cp);
 799       for (int j = 0; j < ik->methods()->length(); j++) {
 800         Method* m = ik->methods()->at(j);
 801         CppVtableCloner<Method>::patch(m);
 802         assert(CppVtableCloner<Method>::is_valid_shared_object(m), "must be");
 803       }
 804     } else if (obj->is_objArray_klass()) {
 805       CppVtableCloner<ObjArrayKlass>::patch(obj);
 806     } else {
 807       assert(obj->is_typeArray_klass(), "sanity");
 808       CppVtableCloner<TypeArrayKlass>::patch(obj);
 809     }
 810   }
 811 }
 812 
 813 bool MetaspaceShared::is_valid_shared_method(const Method* m) {
 814   assert(is_in_shared_metaspace(m), "must be");
 815   return CppVtableCloner<Method>::is_valid_shared_object(m);
 816 }
 817 
 818 // Closure for serializing initialization data out to a data area to be
 819 // written to the shared file.
 820 
 821 class WriteClosure : public SerializeClosure {
 822 private:
 823   DumpRegion* _dump_region;
 824 
 825 public:
 826   WriteClosure(DumpRegion* r) {
 827     _dump_region = r;
 828   }
 829 
 830   void do_ptr(void** p) {
 831     _dump_region->append_intptr_t((intptr_t)*p);
 832   }
 833 
 834   void do_u4(u4* p) {
 835     void* ptr = (void*)(uintx(*p));
 836     do_ptr(&ptr);
 837   }
 838 
 839   void do_tag(int tag) {
 840     _dump_region->append_intptr_t((intptr_t)tag);
 841   }
 842 
 843   void do_oop(oop* o) {
 844     if (*o == NULL) {
 845       _dump_region->append_intptr_t(0);
 846     } else {
 847       assert(HeapShared::is_heap_object_archiving_allowed(),
 848              "Archiving heap object is not allowed");
 849       _dump_region->append_intptr_t(
 850         (intptr_t)CompressedOops::encode_not_null(*o));
 851     }
 852   }
 853 
 854   void do_region(u_char* start, size_t size) {
 855     assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
 856     assert(size % sizeof(intptr_t) == 0, "bad size");
 857     do_tag((int)size);
 858     while (size > 0) {
 859       _dump_region->append_intptr_t(*(intptr_t*)start);
 860       start += sizeof(intptr_t);
 861       size -= sizeof(intptr_t);
 862     }
 863   }
 864 
 865   bool reading() const { return false; }
 866 };
 867 
 868 // This is for dumping detailed statistics for the allocations
 869 // in the shared spaces.
 870 class DumpAllocStats : public ResourceObj {
 871 public:
 872 
 873   // Here's poor man's enum inheritance
 874 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
 875   METASPACE_OBJ_TYPES_DO(f) \
 876   f(SymbolHashentry) \
 877   f(SymbolBucket) \
 878   f(StringHashentry) \
 879   f(StringBucket) \
 880   f(Other)
 881 
 882   enum Type {
 883     // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
 884     SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_DECLARE)
 885     _number_of_types
 886   };
 887 
 888   static const char * type_name(Type type) {
 889     switch(type) {
 890     SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_NAME_CASE)
 891     default:
 892       ShouldNotReachHere();
 893       return NULL;
 894     }
 895   }
 896 
 897 public:
 898   enum { RO = 0, RW = 1 };
 899 
 900   int _counts[2][_number_of_types];
 901   int _bytes [2][_number_of_types];
 902 
 903   DumpAllocStats() {
 904     memset(_counts, 0, sizeof(_counts));
 905     memset(_bytes,  0, sizeof(_bytes));
 906   };
 907 
 908   void record(MetaspaceObj::Type type, int byte_size, bool read_only) {
 909     assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
 910     int which = (read_only) ? RO : RW;
 911     _counts[which][type] ++;
 912     _bytes [which][type] += byte_size;
 913   }
 914 
 915   void record_other_type(int byte_size, bool read_only) {
 916     int which = (read_only) ? RO : RW;
 917     _bytes [which][OtherType] += byte_size;
 918   }
 919   void print_stats(int ro_all, int rw_all, int mc_all, int md_all);
 920 };
 921 
 922 void DumpAllocStats::print_stats(int ro_all, int rw_all, int mc_all, int md_all) {
 923   // Calculate size of data that was not allocated by Metaspace::allocate()
 924   MetaspaceSharedStats *stats = MetaspaceShared::stats();
 925 
 926   // symbols
 927   _counts[RO][SymbolHashentryType] = stats->symbol.hashentry_count;
 928   _bytes [RO][SymbolHashentryType] = stats->symbol.hashentry_bytes;
 929 
 930   _counts[RO][SymbolBucketType] = stats->symbol.bucket_count;
 931   _bytes [RO][SymbolBucketType] = stats->symbol.bucket_bytes;
 932 
 933   // strings
 934   _counts[RO][StringHashentryType] = stats->string.hashentry_count;
 935   _bytes [RO][StringHashentryType] = stats->string.hashentry_bytes;
 936 
 937   _counts[RO][StringBucketType] = stats->string.bucket_count;
 938   _bytes [RO][StringBucketType] = stats->string.bucket_bytes;
 939 
 940   // TODO: count things like dictionary, vtable, etc
 941   _bytes[RW][OtherType] += mc_all + md_all;
 942   rw_all += mc_all + md_all; // mc/md are mapped Read/Write
 943 
 944   // prevent divide-by-zero
 945   if (ro_all < 1) {
 946     ro_all = 1;
 947   }
 948   if (rw_all < 1) {
 949     rw_all = 1;
 950   }
 951 
 952   int all_ro_count = 0;
 953   int all_ro_bytes = 0;
 954   int all_rw_count = 0;
 955   int all_rw_bytes = 0;
 956 
 957 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
 958 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
 959   const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
 960   const char *hdr = "                        ro_cnt   ro_bytes     % |   rw_cnt   rw_bytes     % |  all_cnt  all_bytes     %";
 961 
 962   LogMessage(cds) msg;
 963 
 964   msg.info("Detailed metadata info (excluding od/st regions; rw stats include md/mc regions):");
 965   msg.info("%s", hdr);
 966   msg.info("%s", sep);
 967   for (int type = 0; type < int(_number_of_types); type ++) {
 968     const char *name = type_name((Type)type);
 969     int ro_count = _counts[RO][type];
 970     int ro_bytes = _bytes [RO][type];
 971     int rw_count = _counts[RW][type];
 972     int rw_bytes = _bytes [RW][type];
 973     int count = ro_count + rw_count;
 974     int bytes = ro_bytes + rw_bytes;
 975 
 976     double ro_perc = percent_of(ro_bytes, ro_all);
 977     double rw_perc = percent_of(rw_bytes, rw_all);
 978     double perc    = percent_of(bytes, ro_all + rw_all);
 979 
 980     msg.info(fmt_stats, name,
 981                          ro_count, ro_bytes, ro_perc,
 982                          rw_count, rw_bytes, rw_perc,
 983                          count, bytes, perc);
 984 
 985     all_ro_count += ro_count;
 986     all_ro_bytes += ro_bytes;
 987     all_rw_count += rw_count;
 988     all_rw_bytes += rw_bytes;
 989   }
 990 
 991   int all_count = all_ro_count + all_rw_count;
 992   int all_bytes = all_ro_bytes + all_rw_bytes;
 993 
 994   double all_ro_perc = percent_of(all_ro_bytes, ro_all);
 995   double all_rw_perc = percent_of(all_rw_bytes, rw_all);
 996   double all_perc    = percent_of(all_bytes, ro_all + rw_all);
 997 
 998   msg.info("%s", sep);
 999   msg.info(fmt_stats, "Total",
1000                        all_ro_count, all_ro_bytes, all_ro_perc,
1001                        all_rw_count, all_rw_bytes, all_rw_perc,
1002                        all_count, all_bytes, all_perc);
1003 
1004   assert(all_ro_bytes == ro_all, "everything should have been counted");
1005   assert(all_rw_bytes == rw_all, "everything should have been counted");
1006 
1007 #undef fmt_stats
1008 }
1009 
1010 // Populate the shared space.
1011 
1012 class VM_PopulateDumpSharedSpace: public VM_Operation {
1013 private:
1014   GrowableArray<MemRegion> *_closed_archive_heap_regions;
1015   GrowableArray<MemRegion> *_open_archive_heap_regions;
1016 
1017   GrowableArray<ArchiveHeapOopmapInfo> *_closed_archive_heap_oopmaps;
1018   GrowableArray<ArchiveHeapOopmapInfo> *_open_archive_heap_oopmaps;
1019 
1020   void dump_java_heap_objects() NOT_CDS_JAVA_HEAP_RETURN;
1021   void dump_archive_heap_oopmaps() NOT_CDS_JAVA_HEAP_RETURN;
1022   void dump_archive_heap_oopmaps(GrowableArray<MemRegion>* regions,
1023                                  GrowableArray<ArchiveHeapOopmapInfo>* oopmaps);
1024   void dump_symbols();
1025   char* dump_read_only_tables();
1026   void print_region_stats();
1027   void print_heap_region_stats(GrowableArray<MemRegion> *heap_mem,
1028                                const char *name, const size_t total_size);
1029 public:
1030 
1031   VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
1032   void doit();   // outline because gdb sucks
1033   static void write_region(FileMapInfo* mapinfo, int region, DumpRegion* space, bool read_only,  bool allow_exec);
1034   bool allow_nested_vm_operations() const { return true; }
1035 }; // class VM_PopulateDumpSharedSpace
1036 
1037 class SortedSymbolClosure: public SymbolClosure {
1038   GrowableArray<Symbol*> _symbols;
1039   virtual void do_symbol(Symbol** sym) {
1040     assert((*sym)->is_permanent(), "archived symbols must be permanent");
1041     _symbols.append(*sym);
1042   }
1043   static int compare_symbols_by_address(Symbol** a, Symbol** b) {
1044     if (a[0] < b[0]) {
1045       return -1;
1046     } else if (a[0] == b[0]) {
1047       return 0;
1048     } else {
1049       return 1;
1050     }
1051   }
1052 
1053 public:
1054   SortedSymbolClosure() {
1055     SymbolTable::symbols_do(this);
1056     _symbols.sort(compare_symbols_by_address);
1057   }
1058   GrowableArray<Symbol*>* get_sorted_symbols() {
1059     return &_symbols;
1060   }
1061 };
1062 
1063 // ArchiveCompactor --
1064 //
1065 // This class is the central piece of shared archive compaction -- all metaspace data are
1066 // initially allocated outside of the shared regions. ArchiveCompactor copies the
1067 // metaspace data into their final location in the shared regions.
1068 
1069 class ArchiveCompactor : AllStatic {
1070   static DumpAllocStats* _alloc_stats;
1071   static SortedSymbolClosure* _ssc;
1072 
1073   static unsigned my_hash(const address& a) {
1074     return primitive_hash<address>(a);
1075   }
1076   static bool my_equals(const address& a0, const address& a1) {
1077     return primitive_equals<address>(a0, a1);
1078   }
1079   typedef ResourceHashtable<
1080       address, address,
1081       ArchiveCompactor::my_hash,   // solaris compiler doesn't like: primitive_hash<address>
1082       ArchiveCompactor::my_equals, // solaris compiler doesn't like: primitive_equals<address>
1083       16384, ResourceObj::C_HEAP> RelocationTable;
1084   static RelocationTable* _new_loc_table;
1085 
1086 public:
1087   static void initialize() {
1088     _alloc_stats = new(ResourceObj::C_HEAP, mtInternal)DumpAllocStats;
1089     _new_loc_table = new(ResourceObj::C_HEAP, mtInternal)RelocationTable;
1090   }
1091   static DumpAllocStats* alloc_stats() {
1092     return _alloc_stats;
1093   }
1094 
1095   // Use this when you allocate space with MetaspaceShare::read_only_space_alloc()
1096   // outside of ArchiveCompactor::allocate(). These are usually for misc tables
1097   // that are allocated in the RO space.
1098   class OtherROAllocMark {
1099     char* _oldtop;
1100   public:
1101     OtherROAllocMark() {
1102       _oldtop = _ro_region.top();
1103     }
1104     ~OtherROAllocMark() {
1105       char* newtop = _ro_region.top();
1106       ArchiveCompactor::alloc_stats()->record_other_type(int(newtop - _oldtop), true);
1107     }
1108   };
1109 
1110   static void allocate(MetaspaceClosure::Ref* ref, bool read_only) {
1111     address obj = ref->obj();
1112     int bytes = ref->size() * BytesPerWord;
1113     char* p;
1114     size_t alignment = BytesPerWord;
1115     char* oldtop;
1116     char* newtop;
1117 
1118     if (read_only) {
1119       oldtop = _ro_region.top();
1120       p = _ro_region.allocate(bytes, alignment);
1121       newtop = _ro_region.top();
1122     } else {
1123       oldtop = _rw_region.top();
1124       if (ref->msotype() == MetaspaceObj::ClassType) {
1125         // Save a pointer immediate in front of an InstanceKlass, so
1126         // we can do a quick lookup from InstanceKlass* -> RunTimeSharedClassInfo*
1127         // without building another hashtable. See RunTimeSharedClassInfo::get_for()
1128         // in systemDictionaryShared.cpp.
1129         Klass* klass = (Klass*)obj;
1130         if (klass->is_instance_klass()) {
1131           SystemDictionaryShared::validate_before_archiving(InstanceKlass::cast(klass));
1132           _rw_region.allocate(sizeof(address), BytesPerWord);
1133         }
1134       }
1135       p = _rw_region.allocate(bytes, alignment);
1136       newtop = _rw_region.top();
1137     }
1138     memcpy(p, obj, bytes);
1139     bool isnew = _new_loc_table->put(obj, (address)p);

1140     log_trace(cds)("Copy: " PTR_FORMAT " ==> " PTR_FORMAT " %d", p2i(obj), p2i(p), bytes);
1141     assert(isnew, "must be");
1142 

1143     _alloc_stats->record(ref->msotype(), int(newtop - oldtop), read_only);
1144   }
1145 
1146   static address get_new_loc(MetaspaceClosure::Ref* ref) {
1147     address* pp = _new_loc_table->get(ref->obj());
1148     assert(pp != NULL, "must be");
1149     return *pp;
1150   }
1151 
1152 private:
1153   // Makes a shallow copy of visited MetaspaceObj's
1154   class ShallowCopier: public UniqueMetaspaceClosure {
1155     bool _read_only;
1156   public:
1157     ShallowCopier(bool read_only) : _read_only(read_only) {}
1158 
1159     virtual void do_unique_ref(Ref* ref, bool read_only) {
1160       if (read_only == _read_only) {
1161         allocate(ref, read_only);
1162       }
1163     }
1164   };
1165 
1166   // Relocate embedded pointers within a MetaspaceObj's shallow copy
1167   class ShallowCopyEmbeddedRefRelocator: public UniqueMetaspaceClosure {
1168   public:
1169     virtual void do_unique_ref(Ref* ref, bool read_only) {
1170       address new_loc = get_new_loc(ref);
1171       RefRelocator refer;
1172       ref->metaspace_pointers_do_at(&refer, new_loc);
1173     }
1174   };
1175 
1176   // Relocate a reference to point to its shallow copy
1177   class RefRelocator: public MetaspaceClosure {
1178   public:
1179     virtual bool do_ref(Ref* ref, bool read_only) {
1180       if (ref->not_null()) {
1181         ref->update(get_new_loc(ref));
1182       }
1183       return false; // Do not recurse.
1184     }
1185   };
1186 
1187 #ifdef ASSERT
1188   class IsRefInArchiveChecker: public MetaspaceClosure {
1189   public:
1190     virtual bool do_ref(Ref* ref, bool read_only) {
1191       if (ref->not_null()) {
1192         char* obj = (char*)ref->obj();
1193         assert(_ro_region.contains(obj) || _rw_region.contains(obj),
1194                "must be relocated to point to CDS archive");
1195       }
1196       return false; // Do not recurse.
1197     }
1198   };
1199 #endif
1200 
1201 public:
1202   static void copy_and_compact() {
1203     ResourceMark rm;
1204     SortedSymbolClosure the_ssc; // StackObj
1205     _ssc = &the_ssc;
1206 
1207     tty->print_cr("Scanning all metaspace objects ... ");
1208     {
1209       // allocate and shallow-copy RW objects, immediately following the MC region
1210       tty->print_cr("Allocating RW objects ... ");
1211       _mc_region.pack(&_rw_region);
1212 
1213       ResourceMark rm;
1214       ShallowCopier rw_copier(false);
1215       iterate_roots(&rw_copier);
1216     }
1217     {
1218       // allocate and shallow-copy of RO object, immediately following the RW region
1219       tty->print_cr("Allocating RO objects ... ");
1220       _rw_region.pack(&_ro_region);
1221 
1222       ResourceMark rm;
1223       ShallowCopier ro_copier(true);
1224       iterate_roots(&ro_copier);
1225     }
1226     {
1227       tty->print_cr("Relocating embedded pointers ... ");
1228       ResourceMark rm;
1229       ShallowCopyEmbeddedRefRelocator emb_reloc;
1230       iterate_roots(&emb_reloc);
1231     }
1232     {
1233       tty->print_cr("Relocating external roots ... ");
1234       ResourceMark rm;
1235       RefRelocator ext_reloc;
1236       iterate_roots(&ext_reloc);
1237     }
1238 
1239 #ifdef ASSERT
1240     {
1241       tty->print_cr("Verifying external roots ... ");
1242       ResourceMark rm;
1243       IsRefInArchiveChecker checker;
1244       iterate_roots(&checker);
1245     }
1246 #endif
1247 
1248 
1249     // cleanup
1250     _ssc = NULL;
1251   }
1252 
1253   // We must relocate the System::_well_known_klasses only after we have copied the
1254   // java objects in during dump_java_heap_objects(): during the object copy, we operate on
1255   // old objects which assert that their klass is the original klass.
1256   static void relocate_well_known_klasses() {
1257     {
1258       tty->print_cr("Relocating SystemDictionary::_well_known_klasses[] ... ");
1259       ResourceMark rm;
1260       RefRelocator ext_reloc;
1261       SystemDictionary::well_known_klasses_do(&ext_reloc);
1262     }
1263     // NOTE: after this point, we shouldn't have any globals that can reach the old
1264     // objects.
1265 
1266     // We cannot use any of the objects in the heap anymore (except for the
1267     // shared strings) because their headers no longer point to valid Klasses.
1268   }
1269 
1270   static void iterate_roots(MetaspaceClosure* it) {
1271     GrowableArray<Symbol*>* symbols = _ssc->get_sorted_symbols();
1272     for (int i=0; i<symbols->length(); i++) {
1273       it->push(symbols->adr_at(i));
1274     }
1275     if (_global_klass_objects != NULL) {
1276       // Need to fix up the pointers
1277       for (int i = 0; i < _global_klass_objects->length(); i++) {
1278         // NOTE -- this requires that the vtable is NOT yet patched, or else we are hosed.
1279         it->push(_global_klass_objects->adr_at(i));
1280       }
1281     }
1282     FileMapInfo::metaspace_pointers_do(it);
1283     SystemDictionaryShared::dumptime_classes_do(it);
1284     Universe::metaspace_pointers_do(it);
1285     SymbolTable::metaspace_pointers_do(it);
1286     vmSymbols::metaspace_pointers_do(it);
1287   }
1288 
1289   static Klass* get_relocated_klass(Klass* orig_klass) {
1290     assert(DumpSharedSpaces, "dump time only");
1291     address* pp = _new_loc_table->get((address)orig_klass);
1292     assert(pp != NULL, "must be");
1293     Klass* klass = (Klass*)(*pp);
1294     assert(klass->is_klass(), "must be");
1295     return klass;
1296   }
1297 };
1298 
1299 DumpAllocStats* ArchiveCompactor::_alloc_stats;
1300 SortedSymbolClosure* ArchiveCompactor::_ssc;
1301 ArchiveCompactor::RelocationTable* ArchiveCompactor::_new_loc_table;
1302 
1303 void VM_PopulateDumpSharedSpace::write_region(FileMapInfo* mapinfo, int region_idx,
1304                                               DumpRegion* dump_region, bool read_only,  bool allow_exec) {
1305   mapinfo->write_region(region_idx, dump_region->base(), dump_region->used(), read_only, allow_exec);
1306 }
1307 
1308 void VM_PopulateDumpSharedSpace::dump_symbols() {
1309   tty->print_cr("Dumping symbol table ...");
1310 
1311   NOT_PRODUCT(SymbolTable::verify());
1312   SymbolTable::write_to_archive();
1313 }
1314 
1315 char* VM_PopulateDumpSharedSpace::dump_read_only_tables() {
1316   ArchiveCompactor::OtherROAllocMark mark;
1317 
1318   tty->print("Removing java_mirror ... ");
1319   if (!HeapShared::is_heap_object_archiving_allowed()) {
1320     clear_basic_type_mirrors();
1321   }
1322   remove_java_mirror_in_classes();
1323   tty->print_cr("done. ");
1324 
1325   SystemDictionaryShared::write_to_archive();
1326 
1327   char* start = _ro_region.top();
1328 
1329   // Write the other data to the output array.
1330   WriteClosure wc(&_ro_region);
1331   MetaspaceShared::serialize(&wc);
1332 
1333   // Write the bitmaps for patching the archive heap regions
1334   dump_archive_heap_oopmaps();
1335 
1336   return start;
1337 }
1338 
1339 void VM_PopulateDumpSharedSpace::doit() {
1340   // We should no longer allocate anything from the metaspace, so that:
1341   //
1342   // (1) Metaspace::allocate might trigger GC if we have run out of
1343   //     committed metaspace, but we can't GC because we're running
1344   //     in the VM thread.
1345   // (2) ArchiveCompactor needs to work with a stable set of MetaspaceObjs.
1346   Metaspace::freeze();
1347 
1348   Thread* THREAD = VMThread::vm_thread();
1349 
1350   FileMapInfo::check_nonempty_dir_in_shared_path_table();
1351 
1352   NOT_PRODUCT(SystemDictionary::verify();)
1353   // The following guarantee is meant to ensure that no loader constraints
1354   // exist yet, since the constraints table is not shared.  This becomes
1355   // more important now that we don't re-initialize vtables/itables for
1356   // shared classes at runtime, where constraints were previously created.
1357   guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
1358             "loader constraints are not saved");
1359   guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
1360           "placeholders are not saved");
1361 
1362   // At this point, many classes have been loaded.
1363   // Gather systemDictionary classes in a global array and do everything to
1364   // that so we don't have to walk the SystemDictionary again.
1365   SystemDictionaryShared::check_excluded_classes();
1366   _global_klass_objects = new GrowableArray<Klass*>(1000);
1367   CollectClassesClosure collect_classes;
1368   ClassLoaderDataGraph::loaded_classes_do(&collect_classes);
1369 
1370   tty->print_cr("Number of classes %d", _global_klass_objects->length());
1371   {
1372     int num_type_array = 0, num_obj_array = 0, num_inst = 0;
1373     for (int i = 0; i < _global_klass_objects->length(); i++) {
1374       Klass* k = _global_klass_objects->at(i);
1375       if (k->is_instance_klass()) {
1376         num_inst ++;
1377       } else if (k->is_objArray_klass()) {
1378         num_obj_array ++;
1379       } else {
1380         assert(k->is_typeArray_klass(), "sanity");
1381         num_type_array ++;
1382       }
1383     }
1384     tty->print_cr("    instance classes   = %5d", num_inst);
1385     tty->print_cr("    obj array classes  = %5d", num_obj_array);
1386     tty->print_cr("    type array classes = %5d", num_type_array);
1387   }
1388 
1389   // Ensure the ConstMethods won't be modified at run-time
1390   tty->print("Updating ConstMethods ... ");
1391   rewrite_nofast_bytecodes_and_calculate_fingerprints();
1392   tty->print_cr("done. ");
1393 
1394   // Remove all references outside the metadata
1395   tty->print("Removing unshareable information ... ");
1396   remove_unshareable_in_classes();
1397   tty->print_cr("done. ");
1398 
1399   ArchiveCompactor::initialize();
1400   ArchiveCompactor::copy_and_compact();
1401 
1402   dump_symbols();
1403 
1404   // Dump supported java heap objects
1405   _closed_archive_heap_regions = NULL;
1406   _open_archive_heap_regions = NULL;
1407   dump_java_heap_objects();
1408 
1409   ArchiveCompactor::relocate_well_known_klasses();
1410 
1411   char* read_only_tables_start = dump_read_only_tables();
1412   _ro_region.pack(&_md_region);
1413 
1414   char* vtbl_list = _md_region.top();
1415   MetaspaceShared::allocate_cpp_vtable_clones();
1416   _md_region.pack(&_od_region);
1417 
1418   // Relocate the archived class file data into the od region
1419   relocate_cached_class_file();
1420   _od_region.pack();
1421 
1422   // The 5 core spaces are allocated consecutively mc->rw->ro->md->od, so there total size
1423   // is just the spaces between the two ends.
1424   size_t core_spaces_size = _od_region.end() - _mc_region.base();
1425   assert(core_spaces_size == (size_t)align_up(core_spaces_size, Metaspace::reserve_alignment()),
1426          "should already be aligned");
1427 
1428   // During patching, some virtual methods may be called, so at this point
1429   // the vtables must contain valid methods (as filled in by CppVtableCloner::allocate).
1430   MetaspaceShared::patch_cpp_vtable_pointers();
1431 
1432   // The vtable clones contain addresses of the current process.
1433   // We don't want to write these addresses into the archive.
1434   MetaspaceShared::zero_cpp_vtable_clones_for_writing();
1435 
1436   // Create and write the archive file that maps the shared spaces.
1437 
1438   FileMapInfo* mapinfo = new FileMapInfo();
1439   mapinfo->populate_header(os::vm_allocation_granularity());
1440   mapinfo->set_read_only_tables_start(read_only_tables_start);
1441   mapinfo->set_misc_data_patching_start(vtbl_list);
1442   mapinfo->set_cds_i2i_entry_code_buffers(MetaspaceShared::cds_i2i_entry_code_buffers());
1443   mapinfo->set_cds_i2i_entry_code_buffers_size(MetaspaceShared::cds_i2i_entry_code_buffers_size());
1444   mapinfo->set_core_spaces_size(core_spaces_size);
1445 
1446   for (int pass=1; pass<=2; pass++) {
1447     bool print_archive_log = (pass==1);
1448     if (pass == 1) {
1449       // The first pass doesn't actually write the data to disk. All it
1450       // does is to update the fields in the mapinfo->_header.
1451     } else {
1452       // After the first pass, the contents of mapinfo->_header are finalized,
1453       // so we can compute the header's CRC, and write the contents of the header
1454       // and the regions into disk.
1455       mapinfo->open_for_write();
1456       mapinfo->set_header_crc(mapinfo->compute_header_crc());
1457     }
1458     mapinfo->write_header();
1459 
1460     // NOTE: md contains the trampoline code for method entries, which are patched at run time,
1461     // so it needs to be read/write.
1462     write_region(mapinfo, MetaspaceShared::mc, &_mc_region, /*read_only=*/false,/*allow_exec=*/true);
1463     write_region(mapinfo, MetaspaceShared::rw, &_rw_region, /*read_only=*/false,/*allow_exec=*/false);
1464     write_region(mapinfo, MetaspaceShared::ro, &_ro_region, /*read_only=*/true, /*allow_exec=*/false);
1465     write_region(mapinfo, MetaspaceShared::md, &_md_region, /*read_only=*/false,/*allow_exec=*/false);
1466     write_region(mapinfo, MetaspaceShared::od, &_od_region, /*read_only=*/true, /*allow_exec=*/false);
1467 
1468     _total_closed_archive_region_size = mapinfo->write_archive_heap_regions(
1469                                         _closed_archive_heap_regions,
1470                                         _closed_archive_heap_oopmaps,
1471                                         MetaspaceShared::first_closed_archive_heap_region,
1472                                         MetaspaceShared::max_closed_archive_heap_region,
1473                                         print_archive_log);
1474     _total_open_archive_region_size = mapinfo->write_archive_heap_regions(
1475                                         _open_archive_heap_regions,
1476                                         _open_archive_heap_oopmaps,
1477                                         MetaspaceShared::first_open_archive_heap_region,
1478                                         MetaspaceShared::max_open_archive_heap_region,
1479                                         print_archive_log);
1480   }
1481 
1482   mapinfo->close();
1483 
1484   // Restore the vtable in case we invoke any virtual methods.
1485   MetaspaceShared::clone_cpp_vtables((intptr_t*)vtbl_list);
1486 
1487   print_region_stats();
1488 
1489   if (log_is_enabled(Info, cds)) {
1490     ArchiveCompactor::alloc_stats()->print_stats(int(_ro_region.used()), int(_rw_region.used()),
1491                                                  int(_mc_region.used()), int(_md_region.used()));
1492   }
1493 
1494   if (PrintSystemDictionaryAtExit) {
1495     SystemDictionary::print();
1496   }
1497   // There may be other pending VM operations that operate on the InstanceKlasses,
1498   // which will fail because InstanceKlasses::remove_unshareable_info()
1499   // has been called. Forget these operations and exit the VM directly.
1500   vm_direct_exit(0);
1501 }
1502 
1503 void VM_PopulateDumpSharedSpace::print_region_stats() {
1504   // Print statistics of all the regions
1505   const size_t total_reserved = _ro_region.reserved()  + _rw_region.reserved() +
1506                                 _mc_region.reserved()  + _md_region.reserved() +
1507                                 _od_region.reserved()  +
1508                                 _total_closed_archive_region_size +
1509                                 _total_open_archive_region_size;
1510   const size_t total_bytes = _ro_region.used()  + _rw_region.used() +
1511                              _mc_region.used()  + _md_region.used() +
1512                              _od_region.used()  +
1513                              _total_closed_archive_region_size +
1514                              _total_open_archive_region_size;
1515   const double total_u_perc = percent_of(total_bytes, total_reserved);
1516 
1517   _mc_region.print(total_reserved);
1518   _rw_region.print(total_reserved);
1519   _ro_region.print(total_reserved);
1520   _md_region.print(total_reserved);
1521   _od_region.print(total_reserved);
1522   print_heap_region_stats(_closed_archive_heap_regions, "ca", total_reserved);
1523   print_heap_region_stats(_open_archive_heap_regions, "oa", total_reserved);
1524 
1525   tty->print_cr("total    : " SIZE_FORMAT_W(9) " [100.0%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used]",
1526                  total_bytes, total_reserved, total_u_perc);
1527 }
1528 
1529 void VM_PopulateDumpSharedSpace::print_heap_region_stats(GrowableArray<MemRegion> *heap_mem,
1530                                                          const char *name, const size_t total_size) {
1531   int arr_len = heap_mem == NULL ? 0 : heap_mem->length();
1532   for (int i = 0; i < arr_len; i++) {
1533       char* start = (char*)heap_mem->at(i).start();
1534       size_t size = heap_mem->at(i).byte_size();
1535       char* top = start + size;
1536       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,
1537                     name, i, size, size/double(total_size)*100.0, size, p2i(start));
1538 
1539   }
1540 }
1541 
1542 // Update a Java object to point its Klass* to the new location after
1543 // shared archive has been compacted.
1544 void MetaspaceShared::relocate_klass_ptr(oop o) {
1545   assert(DumpSharedSpaces, "sanity");
1546   Klass* k = ArchiveCompactor::get_relocated_klass(o->klass());
1547   o->set_klass(k);
1548 }
1549 
1550 Klass* MetaspaceShared::get_relocated_klass(Klass *k) {
1551   assert(DumpSharedSpaces, "sanity");
1552   return ArchiveCompactor::get_relocated_klass(k);
1553 }
1554 
1555 class LinkSharedClassesClosure : public KlassClosure {
1556   Thread* THREAD;
1557   bool    _made_progress;
1558  public:
1559   LinkSharedClassesClosure(Thread* thread) : THREAD(thread), _made_progress(false) {}
1560 
1561   void reset()               { _made_progress = false; }
1562   bool made_progress() const { return _made_progress; }
1563 
1564   void do_klass(Klass* k) {
1565     if (k->is_instance_klass()) {
1566       InstanceKlass* ik = InstanceKlass::cast(k);
1567       // Link the class to cause the bytecodes to be rewritten and the
1568       // cpcache to be created. Class verification is done according
1569       // to -Xverify setting.
1570       _made_progress |= MetaspaceShared::try_link_class(ik, THREAD);
1571       guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1572 
1573       ik->constants()->resolve_class_constants(THREAD);
1574     }
1575   }
1576 };
1577 
1578 class CheckSharedClassesClosure : public KlassClosure {
1579   bool    _made_progress;
1580  public:
1581   CheckSharedClassesClosure() : _made_progress(false) {}
1582 
1583   void reset()               { _made_progress = false; }
1584   bool made_progress() const { return _made_progress; }
1585   void do_klass(Klass* k) {
1586     if (k->is_instance_klass() && InstanceKlass::cast(k)->check_sharing_error_state()) {
1587       _made_progress = true;
1588     }
1589   }
1590 };
1591 
1592 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
1593   // We need to iterate because verification may cause additional classes
1594   // to be loaded.
1595   LinkSharedClassesClosure link_closure(THREAD);
1596   do {
1597     link_closure.reset();
1598     ClassLoaderDataGraph::unlocked_loaded_classes_do(&link_closure);
1599     guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1600   } while (link_closure.made_progress());
1601 
1602   if (_has_error_classes) {
1603     // Mark all classes whose super class or interfaces failed verification.
1604     CheckSharedClassesClosure check_closure;
1605     do {
1606       // Not completely sure if we need to do this iteratively. Anyway,
1607       // we should come here only if there are unverifiable classes, which
1608       // shouldn't happen in normal cases. So better safe than sorry.
1609       check_closure.reset();
1610       ClassLoaderDataGraph::unlocked_loaded_classes_do(&check_closure);
1611     } while (check_closure.made_progress());
1612   }
1613 }
1614 
1615 void MetaspaceShared::prepare_for_dumping() {
1616   Arguments::check_unsupported_dumping_properties();
1617   ClassLoader::initialize_shared_path();
1618 }
1619 
1620 // Preload classes from a list, populate the shared spaces and dump to a
1621 // file.
1622 void MetaspaceShared::preload_and_dump(TRAPS) {
1623   { TraceTime timer("Dump Shared Spaces", TRACETIME_LOG(Info, startuptime));
1624     ResourceMark rm;
1625     char class_list_path_str[JVM_MAXPATHLEN];
1626     // Preload classes to be shared.
1627     // Should use some os:: method rather than fopen() here. aB.
1628     const char* class_list_path;
1629     if (SharedClassListFile == NULL) {
1630       // Construct the path to the class list (in jre/lib)
1631       // Walk up two directories from the location of the VM and
1632       // optionally tack on "lib" (depending on platform)
1633       os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
1634       for (int i = 0; i < 3; i++) {
1635         char *end = strrchr(class_list_path_str, *os::file_separator());
1636         if (end != NULL) *end = '\0';
1637       }
1638       int class_list_path_len = (int)strlen(class_list_path_str);
1639       if (class_list_path_len >= 3) {
1640         if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
1641           if (class_list_path_len < JVM_MAXPATHLEN - 4) {
1642             jio_snprintf(class_list_path_str + class_list_path_len,
1643                          sizeof(class_list_path_str) - class_list_path_len,
1644                          "%slib", os::file_separator());
1645             class_list_path_len += 4;
1646           }
1647         }
1648       }
1649       if (class_list_path_len < JVM_MAXPATHLEN - 10) {
1650         jio_snprintf(class_list_path_str + class_list_path_len,
1651                      sizeof(class_list_path_str) - class_list_path_len,
1652                      "%sclasslist", os::file_separator());
1653       }
1654       class_list_path = class_list_path_str;
1655     } else {
1656       class_list_path = SharedClassListFile;
1657     }
1658 
1659     tty->print_cr("Loading classes to share ...");
1660     _has_error_classes = false;
1661     int class_count = preload_classes(class_list_path, THREAD);
1662     if (ExtraSharedClassListFile) {
1663       class_count += preload_classes(ExtraSharedClassListFile, THREAD);
1664     }
1665     tty->print_cr("Loading classes to share: done.");
1666 
1667     log_info(cds)("Shared spaces: preloaded %d classes", class_count);
1668 
1669     if (SharedArchiveConfigFile) {
1670       tty->print_cr("Reading extra data from %s ...", SharedArchiveConfigFile);
1671       read_extra_data(SharedArchiveConfigFile, THREAD);
1672     }
1673     tty->print_cr("Reading extra data: done.");
1674 
1675     HeapShared::init_subgraph_entry_fields(THREAD);
1676 
1677     // Rewrite and link classes
1678     tty->print_cr("Rewriting and linking classes ...");
1679 
1680     // Link any classes which got missed. This would happen if we have loaded classes that
1681     // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
1682     // fails verification, all other interfaces that were not specified in the classlist but
1683     // are implemented by K are not verified.
1684     link_and_cleanup_shared_classes(CATCH);
1685     tty->print_cr("Rewriting and linking classes: done");
1686 
1687     VM_PopulateDumpSharedSpace op;
1688     VMThread::execute(&op);
1689   }
1690 }
1691 
1692 
1693 int MetaspaceShared::preload_classes(const char* class_list_path, TRAPS) {
1694   ClassListParser parser(class_list_path);
1695   int class_count = 0;
1696 
1697   while (parser.parse_one_line()) {
1698     Klass* klass = parser.load_current_class(THREAD);
1699     if (HAS_PENDING_EXCEPTION) {
1700       if (klass == NULL &&
1701           (PENDING_EXCEPTION->klass()->name() == vmSymbols::java_lang_ClassNotFoundException())) {
1702         // print a warning only when the pending exception is class not found
1703         tty->print_cr("Preload Warning: Cannot find %s", parser.current_class_name());
1704       }
1705       CLEAR_PENDING_EXCEPTION;
1706     }
1707     if (klass != NULL) {
1708       if (log_is_enabled(Trace, cds)) {
1709         ResourceMark rm;
1710         log_trace(cds)("Shared spaces preloaded: %s", klass->external_name());
1711       }
1712 
1713       if (klass->is_instance_klass()) {
1714         InstanceKlass* ik = InstanceKlass::cast(klass);
1715 
1716         // Link the class to cause the bytecodes to be rewritten and the
1717         // cpcache to be created. The linking is done as soon as classes
1718         // are loaded in order that the related data structures (klass and
1719         // cpCache) are located together.
1720         try_link_class(ik, THREAD);
1721         guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1722       }
1723 
1724       class_count++;
1725     }
1726   }
1727 
1728   return class_count;
1729 }
1730 
1731 // Returns true if the class's status has changed
1732 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
1733   assert(DumpSharedSpaces, "should only be called during dumping");
1734   if (ik->init_state() < InstanceKlass::linked) {
1735     bool saved = BytecodeVerificationLocal;
1736     if (ik->loader_type() == 0 && ik->class_loader() == NULL) {
1737       // The verification decision is based on BytecodeVerificationRemote
1738       // for non-system classes. Since we are using the NULL classloader
1739       // to load non-system classes for customized class loaders during dumping,
1740       // we need to temporarily change BytecodeVerificationLocal to be the same as
1741       // BytecodeVerificationRemote. Note this can cause the parent system
1742       // classes also being verified. The extra overhead is acceptable during
1743       // dumping.
1744       BytecodeVerificationLocal = BytecodeVerificationRemote;
1745     }
1746     ik->link_class(THREAD);
1747     if (HAS_PENDING_EXCEPTION) {
1748       ResourceMark rm;
1749       tty->print_cr("Preload Warning: Verification failed for %s",
1750                     ik->external_name());
1751       CLEAR_PENDING_EXCEPTION;
1752       ik->set_in_error_state();
1753       _has_error_classes = true;
1754     }
1755     BytecodeVerificationLocal = saved;
1756     return true;
1757   } else {
1758     return false;
1759   }
1760 }
1761 
1762 #if INCLUDE_CDS_JAVA_HEAP
1763 void VM_PopulateDumpSharedSpace::dump_java_heap_objects() {
1764   // The closed and open archive heap space has maximum two regions.
1765   // See FileMapInfo::write_archive_heap_regions() for details.
1766   _closed_archive_heap_regions = new GrowableArray<MemRegion>(2);
1767   _open_archive_heap_regions = new GrowableArray<MemRegion>(2);
1768   HeapShared::archive_java_heap_objects(_closed_archive_heap_regions,
1769                                         _open_archive_heap_regions);
1770   ArchiveCompactor::OtherROAllocMark mark;
1771   HeapShared::write_subgraph_info_table();
1772 }
1773 
1774 void VM_PopulateDumpSharedSpace::dump_archive_heap_oopmaps() {
1775   if (HeapShared::is_heap_object_archiving_allowed()) {
1776     _closed_archive_heap_oopmaps = new GrowableArray<ArchiveHeapOopmapInfo>(2);
1777     dump_archive_heap_oopmaps(_closed_archive_heap_regions, _closed_archive_heap_oopmaps);
1778 
1779     _open_archive_heap_oopmaps = new GrowableArray<ArchiveHeapOopmapInfo>(2);
1780     dump_archive_heap_oopmaps(_open_archive_heap_regions, _open_archive_heap_oopmaps);
1781   }
1782 }
1783 
1784 void VM_PopulateDumpSharedSpace::dump_archive_heap_oopmaps(GrowableArray<MemRegion>* regions,
1785                                                            GrowableArray<ArchiveHeapOopmapInfo>* oopmaps) {
1786   for (int i=0; i<regions->length(); i++) {
1787     ResourceBitMap oopmap = HeapShared::calculate_oopmap(regions->at(i));
1788     size_t size_in_bits = oopmap.size();
1789     size_t size_in_bytes = oopmap.size_in_bytes();
1790     uintptr_t* buffer = (uintptr_t*)_ro_region.allocate(size_in_bytes, sizeof(intptr_t));
1791     oopmap.write_to(buffer, size_in_bytes);
1792     log_info(cds)("Oopmap = " INTPTR_FORMAT " (" SIZE_FORMAT_W(6) " bytes) for heap region "
1793                   INTPTR_FORMAT " (" SIZE_FORMAT_W(8) " bytes)",
1794                   p2i(buffer), size_in_bytes,
1795                   p2i(regions->at(i).start()), regions->at(i).byte_size());
1796 
1797     ArchiveHeapOopmapInfo info;
1798     info._oopmap = (address)buffer;
1799     info._oopmap_size_in_bits = size_in_bits;
1800     oopmaps->append(info);
1801   }
1802 }
1803 #endif // INCLUDE_CDS_JAVA_HEAP
1804 
1805 // Closure for serializing initialization data in from a data area
1806 // (ptr_array) read from the shared file.
1807 
1808 class ReadClosure : public SerializeClosure {
1809 private:
1810   intptr_t** _ptr_array;
1811 
1812   inline intptr_t nextPtr() {
1813     return *(*_ptr_array)++;
1814   }
1815 
1816 public:
1817   ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
1818 
1819   void do_ptr(void** p) {
1820     assert(*p == NULL, "initializing previous initialized pointer.");
1821     intptr_t obj = nextPtr();
1822     assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
1823            "hit tag while initializing ptrs.");
1824     *p = (void*)obj;
1825   }
1826 
1827   void do_u4(u4* p) {
1828     intptr_t obj = nextPtr();
1829     *p = (u4)(uintx(obj));
1830   }
1831 
1832   void do_tag(int tag) {
1833     int old_tag;
1834     old_tag = (int)(intptr_t)nextPtr();
1835     // do_int(&old_tag);
1836     assert(tag == old_tag, "old tag doesn't match");
1837     FileMapInfo::assert_mark(tag == old_tag);
1838   }
1839 
1840   void do_oop(oop *p) {
1841     narrowOop o = (narrowOop)nextPtr();
1842     if (o == 0 || !HeapShared::open_archive_heap_region_mapped()) {
1843       p = NULL;
1844     } else {
1845       assert(HeapShared::is_heap_object_archiving_allowed(),
1846              "Archived heap object is not allowed");
1847       assert(HeapShared::open_archive_heap_region_mapped(),
1848              "Open archive heap region is not mapped");
1849       *p = HeapShared::decode_from_archive(o);
1850     }
1851   }
1852 
1853   void do_region(u_char* start, size_t size) {
1854     assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
1855     assert(size % sizeof(intptr_t) == 0, "bad size");
1856     do_tag((int)size);
1857     while (size > 0) {
1858       *(intptr_t*)start = nextPtr();
1859       start += sizeof(intptr_t);
1860       size -= sizeof(intptr_t);
1861     }
1862   }
1863 
1864   bool reading() const { return true; }
1865 };
1866 
1867 // Return true if given address is in the misc data region
1868 bool MetaspaceShared::is_in_shared_region(const void* p, int idx) {
1869   return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_region(p, idx);
1870 }
1871 
1872 bool MetaspaceShared::is_in_trampoline_frame(address addr) {
1873   if (UseSharedSpaces && is_in_shared_region(addr, MetaspaceShared::mc)) {
1874     return true;
1875   }
1876   return false;
1877 }
1878 
1879 // Map shared spaces at requested addresses and return if succeeded.
1880 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
1881   size_t image_alignment = mapinfo->alignment();
1882 
1883 #ifndef _WINDOWS
1884   // Map in the shared memory and then map the regions on top of it.
1885   // On Windows, don't map the memory here because it will cause the
1886   // mappings of the regions to fail.
1887   ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
1888   if (!shared_rs.is_reserved()) return false;
1889 #endif
1890 
1891   assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
1892 
1893   char* ro_base = NULL; char* ro_top;
1894   char* rw_base = NULL; char* rw_top;
1895   char* mc_base = NULL; char* mc_top;
1896   char* md_base = NULL; char* md_top;
1897   char* od_base = NULL; char* od_top;
1898 
1899   // Map each shared region
1900   if ((mc_base = mapinfo->map_region(mc, &mc_top)) != NULL &&
1901       (rw_base = mapinfo->map_region(rw, &rw_top)) != NULL &&
1902       (ro_base = mapinfo->map_region(ro, &ro_top)) != NULL &&
1903       (md_base = mapinfo->map_region(md, &md_top)) != NULL &&
1904       (od_base = mapinfo->map_region(od, &od_top)) != NULL &&
1905       (image_alignment == (size_t)os::vm_allocation_granularity()) &&
1906       mapinfo->validate_shared_path_table()) {
1907     // Success -- set up MetaspaceObj::_shared_metaspace_{base,top} for
1908     // fast checking in MetaspaceShared::is_in_shared_metaspace() and
1909     // MetaspaceObj::is_shared().
1910     //
1911     // We require that mc->rw->ro->md->od to be laid out consecutively, with no
1912     // gaps between them. That way, we can ensure that the OS won't be able to
1913     // allocate any new memory spaces inside _shared_metaspace_{base,top}, which
1914     // would mess up the simple comparision in MetaspaceShared::is_in_shared_metaspace().
1915     assert(mc_base < ro_base && mc_base < rw_base && mc_base < md_base && mc_base < od_base, "must be");
1916     assert(od_top  > ro_top  && od_top  > rw_top  && od_top  > md_top  && od_top  > mc_top , "must be");
1917     assert(mc_top == rw_base, "must be");
1918     assert(rw_top == ro_base, "must be");
1919     assert(ro_top == md_base, "must be");
1920     assert(md_top == od_base, "must be");
1921 
1922     _core_spaces_size = mapinfo->core_spaces_size();
1923     MetaspaceObj::set_shared_metaspace_range((void*)mc_base, (void*)od_top);
1924     return true;
1925   } else {
1926     // If there was a failure in mapping any of the spaces, unmap the ones
1927     // that succeeded
1928     if (ro_base != NULL) mapinfo->unmap_region(ro);
1929     if (rw_base != NULL) mapinfo->unmap_region(rw);
1930     if (mc_base != NULL) mapinfo->unmap_region(mc);
1931     if (md_base != NULL) mapinfo->unmap_region(md);
1932     if (od_base != NULL) mapinfo->unmap_region(od);
1933 #ifndef _WINDOWS
1934     // Release the entire mapped region
1935     shared_rs.release();
1936 #endif
1937     // If -Xshare:on is specified, print out the error message and exit VM,
1938     // otherwise, set UseSharedSpaces to false and continue.
1939     if (RequireSharedSpaces || PrintSharedArchiveAndExit) {
1940       vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
1941     } else {
1942       FLAG_SET_DEFAULT(UseSharedSpaces, false);
1943     }
1944     return false;
1945   }
1946 }
1947 
1948 // Read the miscellaneous data from the shared file, and
1949 // serialize it out to its various destinations.
1950 
1951 void MetaspaceShared::initialize_shared_spaces() {
1952   FileMapInfo *mapinfo = FileMapInfo::current_info();
1953   _cds_i2i_entry_code_buffers = mapinfo->cds_i2i_entry_code_buffers();
1954   _cds_i2i_entry_code_buffers_size = mapinfo->cds_i2i_entry_code_buffers_size();
1955   // _core_spaces_size is loaded from the shared archive immediatelly after mapping
1956   assert(_core_spaces_size == mapinfo->core_spaces_size(), "sanity");
1957   char* buffer = mapinfo->misc_data_patching_start();
1958   clone_cpp_vtables((intptr_t*)buffer);
1959 
1960   // The rest of the data is now stored in the RW region
1961   buffer = mapinfo->read_only_tables_start();
1962 
1963   // Verify various attributes of the archive, plus initialize the
1964   // shared string/symbol tables
1965   intptr_t* array = (intptr_t*)buffer;
1966   ReadClosure rc(&array);
1967   serialize(&rc);
1968 
1969   // Initialize the run-time symbol table.
1970   SymbolTable::create_table();
1971 
1972   mapinfo->patch_archived_heap_embedded_pointers();
1973 
1974   // Close the mapinfo file
1975   mapinfo->close();
1976 
1977   if (PrintSharedArchiveAndExit) {
1978     if (PrintSharedDictionary) {
1979       tty->print_cr("\nShared classes:\n");
1980       SystemDictionaryShared::print_on(tty);
1981     }
1982     if (_archive_loading_failed) {
1983       tty->print_cr("archive is invalid");
1984       vm_exit(1);
1985     } else {
1986       tty->print_cr("archive is valid");
1987       vm_exit(0);
1988     }
1989   }
1990 }
1991 
1992 // JVM/TI RedefineClasses() support:
1993 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
1994   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1995 
1996   if (UseSharedSpaces) {
1997     // remap the shared readonly space to shared readwrite, private
1998     FileMapInfo* mapinfo = FileMapInfo::current_info();
1999     if (!mapinfo->remap_shared_readonly_as_readwrite()) {
2000       return false;
2001     }
2002     _remapped_readwrite = true;
2003   }
2004   return true;
2005 }
2006 
2007 void MetaspaceShared::report_out_of_space(const char* name, size_t needed_bytes) {
2008   // This is highly unlikely to happen on 64-bits because we have reserved a 4GB space.
2009   // On 32-bit we reserve only 256MB so you could run out of space with 100,000 classes
2010   // or so.
2011   _mc_region.print_out_of_space_msg(name, needed_bytes);
2012   _rw_region.print_out_of_space_msg(name, needed_bytes);
2013   _ro_region.print_out_of_space_msg(name, needed_bytes);
2014   _md_region.print_out_of_space_msg(name, needed_bytes);
2015   _od_region.print_out_of_space_msg(name, needed_bytes);
2016 
2017   vm_exit_during_initialization(err_msg("Unable to allocate from '%s' region", name),
2018                                 "Please reduce the number of shared classes.");
2019 }
--- EOF ---