1 /*
   2  * Copyright (c) 2012, 2019, 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/javaClasses.inline.hpp"
  33 #include "classfile/placeholders.hpp"
  34 #include "classfile/symbolTable.hpp"
  35 #include "classfile/stringTable.hpp"
  36 #include "classfile/systemDictionary.hpp"
  37 #include "classfile/systemDictionaryShared.hpp"
  38 #include "code/codeCache.hpp"
  39 #include "gc/shared/softRefPolicy.hpp"
  40 #include "interpreter/bytecodeStream.hpp"
  41 #include "interpreter/bytecodes.hpp"
  42 #include "logging/log.hpp"
  43 #include "logging/logMessage.hpp"
  44 #include "memory/filemap.hpp"
  45 #include "memory/heapShared.inline.hpp"
  46 #include "memory/metaspace.hpp"
  47 #include "memory/metaspaceClosure.hpp"
  48 #include "memory/metaspaceShared.hpp"
  49 #include "memory/resourceArea.hpp"
  50 #include "memory/universe.hpp"
  51 #include "memory/dynamicArchive.hpp"
  52 #include "oops/compressedOops.inline.hpp"
  53 #include "oops/instanceClassLoaderKlass.hpp"
  54 #include "oops/instanceMirrorKlass.hpp"
  55 #include "oops/instanceRefKlass.hpp"
  56 #include "oops/methodData.hpp"
  57 #include "oops/objArrayKlass.hpp"
  58 #include "oops/objArrayOop.hpp"
  59 #include "oops/oop.inline.hpp"
  60 #include "oops/typeArrayKlass.hpp"
  61 #include "prims/jvmtiRedefineClasses.hpp"
  62 #include "runtime/handles.inline.hpp"
  63 #include "runtime/os.hpp"
  64 #include "runtime/safepointVerifiers.hpp"
  65 #include "runtime/signature.hpp"
  66 #include "runtime/timerTrace.hpp"
  67 #include "runtime/vmThread.hpp"
  68 #include "runtime/vmOperations.hpp"
  69 #include "utilities/align.hpp"
  70 #include "utilities/bitMap.hpp"
  71 #include "utilities/defaultStream.hpp"
  72 #include "utilities/hashtable.inline.hpp"
  73 #if INCLUDE_G1GC
  74 #include "gc/g1/g1CollectedHeap.hpp"
  75 #endif
  76 
  77 ReservedSpace MetaspaceShared::_shared_rs;
  78 VirtualSpace MetaspaceShared::_shared_vs;
  79 MetaspaceSharedStats MetaspaceShared::_stats;
  80 bool MetaspaceShared::_has_error_classes;
  81 bool MetaspaceShared::_archive_loading_failed = false;
  82 bool MetaspaceShared::_remapped_readwrite = false;
  83 address MetaspaceShared::_cds_i2i_entry_code_buffers = NULL;
  84 size_t MetaspaceShared::_cds_i2i_entry_code_buffers_size = 0;
  85 size_t MetaspaceShared::_core_spaces_size = 0;
  86 void* MetaspaceShared::_shared_metaspace_static_top = NULL;
  87 
  88 // The CDS archive is divided into the following regions:
  89 //     mc  - misc code (the method entry trampolines)
  90 //     rw  - read-write metadata
  91 //     ro  - read-only metadata and read-only tables
  92 //     md  - misc data (the c++ vtables)
  93 //
  94 //     ca0 - closed archive heap space #0
  95 //     ca1 - closed archive heap space #1 (may be empty)
  96 //     oa0 - open archive heap space #0
  97 //     oa1 - open archive heap space #1 (may be empty)
  98 //
  99 // The mc, rw, ro, and md regions are linearly allocated, starting from
 100 // SharedBaseAddress, in the order of mc->rw->ro->md. The size of these 4 regions
 101 // are page-aligned, and there's no gap between any consecutive regions.
 102 //
 103 // These 4 regions are populated in the following steps:
 104 // [1] All classes are loaded in MetaspaceShared::preload_classes(). All metadata are
 105 //     temporarily allocated outside of the shared regions. Only the method entry
 106 //     trampolines are written into the mc region.
 107 // [2] ArchiveCompactor copies RW metadata into the rw region.
 108 // [3] ArchiveCompactor copies RO metadata into the ro region.
 109 // [4] SymbolTable, StringTable, SystemDictionary, and a few other read-only data
 110 //     are copied into the ro region as read-only tables.
 111 // [5] C++ vtables are copied into the md region.
 112 //
 113 // The s0/s1 and oa0/oa1 regions are populated inside HeapShared::archive_java_heap_objects.
 114 // Their layout is independent of the other 4 regions.
 115 
 116 char* DumpRegion::expand_top_to(char* newtop) {
 117   assert(is_allocatable(), "must be initialized and not packed");
 118   assert(newtop >= _top, "must not grow backwards");
 119   if (newtop > _end) {
 120     MetaspaceShared::report_out_of_space(_name, newtop - _top);
 121     ShouldNotReachHere();
 122   }
 123   uintx delta;
 124   if (DynamicDumpSharedSpaces) {
 125     delta = DynamicArchive::object_delta_uintx(newtop);
 126   } else {
 127     delta = MetaspaceShared::object_delta_uintx(newtop);
 128   }
 129   if (delta > MAX_SHARED_DELTA) {
 130     // This is just a sanity check and should not appear in any real world usage. This
 131     // happens only if you allocate more than 2GB of shared objects and would require
 132     // millions of shared classes.
 133     vm_exit_during_initialization("Out of memory in the CDS archive",
 134                                   "Please reduce the number of shared classes.");
 135   }
 136 
 137   MetaspaceShared::commit_shared_space_to(newtop);
 138   _top = newtop;
 139   return _top;
 140 }
 141 
 142 char* DumpRegion::allocate(size_t num_bytes, size_t alignment) {
 143   char* p = (char*)align_up(_top, alignment);
 144   char* newtop = p + align_up(num_bytes, alignment);
 145   expand_top_to(newtop);
 146   memset(p, 0, newtop - p);
 147   return p;
 148 }
 149 
 150 void DumpRegion::print(size_t total_bytes) const {
 151   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,
 152                 _name, used(), percent_of(used(), total_bytes), reserved(), percent_of(used(), reserved()), p2i(_base));
 153 }
 154 
 155 void DumpRegion::print_out_of_space_msg(const char* failing_region, size_t needed_bytes) {
 156   tty->print("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d",
 157              _name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base));
 158   if (strcmp(_name, failing_region) == 0) {
 159     tty->print_cr(" required = %d", int(needed_bytes));
 160   } else {
 161     tty->cr();
 162   }
 163 }
 164 
 165 void DumpRegion::pack(DumpRegion* next) {
 166   assert(!is_packed(), "sanity");
 167   _end = (char*)align_up(_top, Metaspace::reserve_alignment());
 168   _is_packed = true;
 169   if (next != NULL) {
 170     next->_base = next->_top = this->_end;
 171     next->_end = MetaspaceShared::shared_rs()->end();
 172   }
 173 }
 174 
 175 DumpRegion _mc_region("mc"), _ro_region("ro"), _rw_region("rw"), _md_region("md");
 176 size_t _total_closed_archive_region_size = 0, _total_open_archive_region_size = 0;
 177 
 178 void MetaspaceShared::init_shared_dump_space(DumpRegion* first_space, address first_space_bottom) {
 179   // Start with 0 committed bytes. The memory will be committed as needed by
 180   // MetaspaceShared::commit_shared_space_to().
 181   if (!_shared_vs.initialize(_shared_rs, 0)) {
 182     vm_exit_during_initialization("Unable to allocate memory for shared space");
 183   }
 184   first_space->init(&_shared_rs, (char*)first_space_bottom);
 185 }
 186 
 187 DumpRegion* MetaspaceShared::misc_code_dump_space() {
 188   return &_mc_region;
 189 }
 190 
 191 DumpRegion* MetaspaceShared::read_write_dump_space() {
 192   return &_rw_region;
 193 }
 194 
 195 DumpRegion* MetaspaceShared::read_only_dump_space() {
 196   return &_ro_region;
 197 }
 198 
 199 void MetaspaceShared::pack_dump_space(DumpRegion* current, DumpRegion* next,
 200                                       ReservedSpace* rs) {
 201   current->pack(next);
 202 }
 203 
 204 char* MetaspaceShared::misc_code_space_alloc(size_t num_bytes) {
 205   return _mc_region.allocate(num_bytes);
 206 }
 207 
 208 char* MetaspaceShared::read_only_space_alloc(size_t num_bytes) {
 209   return _ro_region.allocate(num_bytes);
 210 }
 211 
 212 void MetaspaceShared::initialize_runtime_shared_and_meta_spaces() {
 213   assert(UseSharedSpaces, "Must be called when UseSharedSpaces is enabled");
 214 
 215   // If using shared space, open the file that contains the shared space
 216   // and map in the memory before initializing the rest of metaspace (so
 217   // the addresses don't conflict)
 218   FileMapInfo* mapinfo = new FileMapInfo(true);
 219 
 220   // Open the shared archive file, read and validate the header. If
 221   // initialization fails, shared spaces [UseSharedSpaces] are
 222   // disabled and the file is closed.
 223   // Map in spaces now also
 224   if (mapinfo->initialize(true) && map_shared_spaces(mapinfo)) {
 225     size_t cds_total = core_spaces_size();
 226     address cds_address = (address)mapinfo->region_addr(0);
 227     char* cds_end = (char *)align_up(cds_address + cds_total,
 228                                      Metaspace::reserve_alignment());
 229 
 230     // Mapping the dynamic archive before allocating the class space
 231     cds_end = initialize_dynamic_runtime_shared_spaces((char*)cds_address, cds_end);
 232 
 233 #ifdef _LP64
 234     if (Metaspace::using_class_space()) {
 235       // If UseCompressedClassPointers is set then allocate the metaspace area
 236       // above the heap and above the CDS area (if it exists).
 237       Metaspace::allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
 238       // map_heap_regions() compares the current narrow oop and klass encodings
 239       // with the archived ones, so it must be done after all encodings are determined.
 240       mapinfo->map_heap_regions();
 241     }
 242     CompressedKlassPointers::set_range(CompressedClassSpaceSize);
 243 #endif // _LP64
 244   } else {
 245     assert(!mapinfo->is_open() && !UseSharedSpaces,
 246            "archive file not closed or shared spaces not disabled.");
 247   }
 248 }
 249 
 250 char* MetaspaceShared::initialize_dynamic_runtime_shared_spaces(
 251         char* static_start, char* static_end) {
 252   assert(UseSharedSpaces, "must be runtime");
 253   char* cds_end = static_end;
 254   if (!DynamicDumpSharedSpaces) {
 255     address dynamic_top = DynamicArchive::map();
 256     if (dynamic_top != NULL) {
 257       assert(dynamic_top > (address)static_start, "Unexpected layout");
 258       MetaspaceObj::expand_shared_metaspace_range(dynamic_top);
 259       cds_end = (char *)align_up(dynamic_top, Metaspace::reserve_alignment());
 260     }
 261   }
 262   return cds_end;
 263 }
 264 
 265 ReservedSpace* MetaspaceShared::reserve_shared_rs(size_t size, size_t alignment,
 266                                                   bool large, char* requested_address) {
 267   if (requested_address != NULL) {
 268     _shared_rs = ReservedSpace(size, alignment, large, requested_address);
 269   } else {
 270     _shared_rs = ReservedSpace(size, alignment, large);
 271   }
 272   return &_shared_rs;
 273 }
 274 
 275 void MetaspaceShared::initialize_dumptime_shared_and_meta_spaces() {
 276   assert(DumpSharedSpaces, "should be called for dump time only");
 277   const size_t reserve_alignment = Metaspace::reserve_alignment();
 278   bool large_pages = false; // No large pages when dumping the CDS archive.
 279   char* shared_base = (char*)align_up((char*)SharedBaseAddress, reserve_alignment);
 280 
 281 #ifdef _LP64
 282   // On 64-bit VM, the heap and class space layout will be the same as if
 283   // you're running in -Xshare:on mode:
 284   //
 285   //                              +-- SharedBaseAddress (default = 0x800000000)
 286   //                              v
 287   // +-..---------+---------+ ... +----+----+----+----+---------------+
 288   // |    Heap    | Archive |     | MC | RW | RO | MD | class space   |
 289   // +-..---------+---------+ ... +----+----+----+----+---------------+
 290   // |<--   MaxHeapSize  -->|     |<-- UnscaledClassSpaceMax = 4GB -->|
 291   //
 292   const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
 293   const size_t cds_total = align_down(UnscaledClassSpaceMax, reserve_alignment);
 294 #else
 295   // We don't support archives larger than 256MB on 32-bit due to limited virtual address space.
 296   size_t cds_total = align_down(256*M, reserve_alignment);
 297 #endif
 298 
 299   // First try to reserve the space at the specified SharedBaseAddress.
 300   //_shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages, shared_base);
 301   reserve_shared_rs(cds_total, reserve_alignment, large_pages, shared_base);
 302   if (_shared_rs.is_reserved()) {
 303     assert(shared_base == 0 || _shared_rs.base() == shared_base, "should match");
 304   } else {
 305     // Get a mmap region anywhere if the SharedBaseAddress fails.
 306     //_shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages);
 307     reserve_shared_rs(cds_total, reserve_alignment, large_pages, NULL);
 308   }
 309   if (!_shared_rs.is_reserved()) {
 310     vm_exit_during_initialization("Unable to reserve memory for shared space",
 311                                   err_msg(SIZE_FORMAT " bytes.", cds_total));
 312   }
 313 
 314 #ifdef _LP64
 315   // During dump time, we allocate 4GB (UnscaledClassSpaceMax) of space and split it up:
 316   // + The upper 1 GB is used as the "temporary compressed class space" -- preload_classes()
 317   //   will store Klasses into this space.
 318   // + The lower 3 GB is used for the archive -- when preload_classes() is done,
 319   //   ArchiveCompactor will copy the class metadata into this space, first the RW parts,
 320   //   then the RO parts.
 321 
 322   assert(UseCompressedOops && UseCompressedClassPointers,
 323       "UseCompressedOops and UseCompressedClassPointers must be set");
 324 
 325   size_t max_archive_size = align_down(cds_total * 3 / 4, reserve_alignment);
 326   ReservedSpace tmp_class_space = _shared_rs.last_part(max_archive_size);
 327   CompressedClassSpaceSize = align_down(tmp_class_space.size(), reserve_alignment);
 328   _shared_rs = _shared_rs.first_part(max_archive_size);
 329 
 330   // Set up compress class pointers.
 331   CompressedKlassPointers::set_base((address)_shared_rs.base());
 332   // Set narrow_klass_shift to be LogKlassAlignmentInBytes. This is consistent
 333   // with AOT.
 334   CompressedKlassPointers::set_shift(LogKlassAlignmentInBytes);
 335   // Set the range of klass addresses to 4GB.
 336   CompressedKlassPointers::set_range(cds_total);
 337 
 338   Metaspace::initialize_class_space(tmp_class_space);
 339   log_info(cds)("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
 340                 p2i(CompressedKlassPointers::base()), CompressedKlassPointers::shift());
 341 
 342   log_info(cds)("Allocated temporary class space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
 343                 CompressedClassSpaceSize, p2i(tmp_class_space.base()));
 344 #endif
 345 
 346   init_shared_dump_space(&_mc_region);
 347   SharedBaseAddress = (size_t)_shared_rs.base();
 348   tty->print_cr("Allocated shared space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
 349                 _shared_rs.size(), p2i(_shared_rs.base()));
 350 }
 351 
 352 // Called by universe_post_init()
 353 void MetaspaceShared::post_initialize(TRAPS) {
 354   if (UseSharedSpaces) {
 355     int size = FileMapInfo::get_number_of_shared_paths();
 356     if (size > 0) {
 357       SystemDictionaryShared::allocate_shared_data_arrays(size, THREAD);
 358       if (!DynamicDumpSharedSpaces) {
 359         FileMapHeader* header;
 360         if (FileMapInfo::dynamic_info() == NULL) {
 361           header = FileMapInfo::current_info()->header();
 362         } else {
 363           header = FileMapInfo::dynamic_info()->header();
 364         }
 365         ClassLoaderExt::init_paths_start_index(header->_app_class_paths_start_index);
 366         ClassLoaderExt::init_app_module_paths_start_index(header->_app_module_paths_start_index);
 367       }
 368     }
 369   }
 370 }
 371 
 372 static GrowableArray<Handle>* _extra_interned_strings = NULL;
 373 
 374 void MetaspaceShared::read_extra_data(const char* filename, TRAPS) {
 375   _extra_interned_strings = new (ResourceObj::C_HEAP, mtInternal)GrowableArray<Handle>(10000, true);
 376 
 377   HashtableTextDump reader(filename);
 378   reader.check_version("VERSION: 1.0");
 379 
 380   while (reader.remain() > 0) {
 381     int utf8_length;
 382     int prefix_type = reader.scan_prefix(&utf8_length);
 383     ResourceMark rm(THREAD);
 384     if (utf8_length == 0x7fffffff) {
 385       // buf_len will overflown 32-bit value.
 386       vm_exit_during_initialization(err_msg("string length too large: %d", utf8_length));
 387     }
 388     int buf_len = utf8_length+1;
 389     char* utf8_buffer = NEW_RESOURCE_ARRAY(char, buf_len);
 390     reader.get_utf8(utf8_buffer, utf8_length);
 391     utf8_buffer[utf8_length] = '\0';
 392 
 393     if (prefix_type == HashtableTextDump::SymbolPrefix) {
 394       SymbolTable::new_permanent_symbol(utf8_buffer);
 395     } else{
 396       assert(prefix_type == HashtableTextDump::StringPrefix, "Sanity");
 397       oop s = StringTable::intern(utf8_buffer, THREAD);
 398 
 399       if (HAS_PENDING_EXCEPTION) {
 400         log_warning(cds, heap)("[line %d] extra interned string allocation failed; size too large: %d",
 401                                reader.last_line_no(), utf8_length);
 402         CLEAR_PENDING_EXCEPTION;
 403       } else {
 404 #if INCLUDE_G1GC
 405         if (UseG1GC) {
 406           typeArrayOop body = java_lang_String::value(s);
 407           const HeapRegion* hr = G1CollectedHeap::heap()->heap_region_containing(body);
 408           if (hr->is_humongous()) {
 409             // Don't keep it alive, so it will be GC'ed before we dump the strings, in order
 410             // to maximize free heap space and minimize fragmentation.
 411             log_warning(cds, heap)("[line %d] extra interned string ignored; size too large: %d",
 412                                 reader.last_line_no(), utf8_length);
 413             continue;
 414           }
 415         }
 416 #endif
 417         // Interned strings are GC'ed if there are no references to it, so let's
 418         // add a reference to keep this string alive.
 419         assert(s != NULL, "must succeed");
 420         Handle h(THREAD, s);
 421         _extra_interned_strings->append(h);
 422       }
 423     }
 424   }
 425 }
 426 
 427 void MetaspaceShared::commit_shared_space_to(char* newtop) {
 428   assert(DumpSharedSpaces || DynamicDumpSharedSpaces, "dump-time only");
 429   char* base = _shared_rs.base();
 430   size_t need_committed_size = newtop - base;
 431   size_t has_committed_size = _shared_vs.committed_size();
 432   if (need_committed_size < has_committed_size) {
 433     return;
 434   }
 435 
 436   size_t min_bytes = need_committed_size - has_committed_size;
 437   size_t preferred_bytes = 1 * M;
 438   size_t uncommitted = _shared_vs.reserved_size() - has_committed_size;
 439 
 440   size_t commit =MAX2(min_bytes, preferred_bytes);
 441   commit = MIN2(commit, uncommitted);
 442   assert(commit <= uncommitted, "sanity");
 443 
 444   bool result = _shared_vs.expand_by(commit, false);
 445   if (!result) {
 446     vm_exit_during_initialization(err_msg("Failed to expand shared space to " SIZE_FORMAT " bytes",
 447                                           need_committed_size));
 448   }
 449 
 450   log_info(cds)("Expanding shared spaces by " SIZE_FORMAT_W(7) " bytes [total " SIZE_FORMAT_W(9)  " bytes ending at %p]",
 451                 commit, _shared_vs.actual_committed_size(), _shared_vs.high());
 452 }
 453 
 454 // Read/write a data stream for restoring/preserving metadata pointers and
 455 // miscellaneous data from/to the shared archive file.
 456 
 457 void MetaspaceShared::serialize(SerializeClosure* soc) {
 458   int tag = 0;
 459   soc->do_tag(--tag);
 460 
 461   // Verify the sizes of various metadata in the system.
 462   soc->do_tag(sizeof(Method));
 463   soc->do_tag(sizeof(ConstMethod));
 464   soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
 465   soc->do_tag(sizeof(ConstantPool));
 466   soc->do_tag(sizeof(ConstantPoolCache));
 467   soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
 468   soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
 469   soc->do_tag(sizeof(Symbol));
 470 
 471   // Dump/restore miscellaneous metadata.
 472   Universe::serialize(soc);
 473   soc->do_tag(--tag);
 474 
 475   // Dump/restore references to commonly used names and signatures.
 476   vmSymbols::serialize(soc);
 477   soc->do_tag(--tag);
 478 
 479   // Dump/restore the symbol/string/subgraph_info tables
 480   SymbolTable::serialize_shared_table_header(soc);
 481   StringTable::serialize_shared_table_header(soc);
 482   HeapShared::serialize_subgraph_info_table_header(soc);
 483   SystemDictionaryShared::serialize_dictionary_headers(soc);
 484 
 485   JavaClasses::serialize_offsets(soc);
 486   InstanceMirrorKlass::serialize_offsets(soc);
 487   soc->do_tag(--tag);
 488 
 489   serialize_cloned_cpp_vtptrs(soc);
 490   soc->do_tag(--tag);
 491 
 492   soc->do_tag(666);
 493 }
 494 
 495 address MetaspaceShared::cds_i2i_entry_code_buffers(size_t total_size) {
 496   if (DumpSharedSpaces) {
 497     if (_cds_i2i_entry_code_buffers == NULL) {
 498       _cds_i2i_entry_code_buffers = (address)misc_code_space_alloc(total_size);
 499       _cds_i2i_entry_code_buffers_size = total_size;
 500     }
 501   } else if (UseSharedSpaces) {
 502     assert(_cds_i2i_entry_code_buffers != NULL, "must already been initialized");
 503   } else {
 504     return NULL;
 505   }
 506 
 507   assert(_cds_i2i_entry_code_buffers_size == total_size, "must not change");
 508   return _cds_i2i_entry_code_buffers;
 509 }
 510 
 511 uintx MetaspaceShared::object_delta_uintx(void* obj) {
 512   assert(DumpSharedSpaces || DynamicDumpSharedSpaces,
 513          "supported only for dumping");
 514   if (DumpSharedSpaces) {
 515     assert(shared_rs()->contains(obj), "must be");
 516   } else {
 517     assert(is_in_shared_metaspace(obj) || DynamicArchive::is_in_target_space(obj), "must be");
 518   }
 519   address base_address = address(SharedBaseAddress);
 520   uintx deltax = address(obj) - base_address;
 521   return deltax;
 522 }
 523 
 524 // Global object for holding classes that have been loaded.  Since this
 525 // is run at a safepoint just before exit, this is the entire set of classes.
 526 static GrowableArray<Klass*>* _global_klass_objects;
 527 
 528 GrowableArray<Klass*>* MetaspaceShared::collected_klasses() {
 529   return _global_klass_objects;
 530 }
 531 
 532 static void collect_array_classes(Klass* k) {
 533   _global_klass_objects->append_if_missing(k);
 534   if (k->is_array_klass()) {
 535     // Add in the array classes too
 536     ArrayKlass* ak = ArrayKlass::cast(k);
 537     Klass* h = ak->higher_dimension();
 538     if (h != NULL) {
 539       h->array_klasses_do(collect_array_classes);
 540     }
 541   }
 542 }
 543 
 544 class CollectClassesClosure : public KlassClosure {
 545   void do_klass(Klass* k) {
 546     if (k->is_instance_klass() &&
 547         SystemDictionaryShared::is_excluded_class(InstanceKlass::cast(k))) {
 548       // Don't add to the _global_klass_objects
 549     } else {
 550       _global_klass_objects->append_if_missing(k);
 551     }
 552     if (k->is_array_klass()) {
 553       // Add in the array classes too
 554       ArrayKlass* ak = ArrayKlass::cast(k);
 555       Klass* h = ak->higher_dimension();
 556       if (h != NULL) {
 557         h->array_klasses_do(collect_array_classes);
 558       }
 559     }
 560   }
 561 };
 562 
 563 static void remove_unshareable_in_classes() {
 564   for (int i = 0; i < _global_klass_objects->length(); i++) {
 565     Klass* k = _global_klass_objects->at(i);
 566     if (!k->is_objArray_klass()) {
 567       // InstanceKlass and TypeArrayKlass will in turn call remove_unshareable_info
 568       // on their array classes.
 569       assert(k->is_instance_klass() || k->is_typeArray_klass(), "must be");
 570       k->remove_unshareable_info();
 571     }
 572   }
 573 }
 574 
 575 static void remove_java_mirror_in_classes() {
 576   for (int i = 0; i < _global_klass_objects->length(); i++) {
 577     Klass* k = _global_klass_objects->at(i);
 578     if (!k->is_objArray_klass()) {
 579       // InstanceKlass and TypeArrayKlass will in turn call remove_unshareable_info
 580       // on their array classes.
 581       assert(k->is_instance_klass() || k->is_typeArray_klass(), "must be");
 582       k->remove_java_mirror();
 583     }
 584   }
 585 }
 586 
 587 static void clear_basic_type_mirrors() {
 588   assert(!HeapShared::is_heap_object_archiving_allowed(), "Sanity");
 589   Universe::set_int_mirror(NULL);
 590   Universe::set_float_mirror(NULL);
 591   Universe::set_double_mirror(NULL);
 592   Universe::set_byte_mirror(NULL);
 593   Universe::set_bool_mirror(NULL);
 594   Universe::set_char_mirror(NULL);
 595   Universe::set_long_mirror(NULL);
 596   Universe::set_short_mirror(NULL);
 597   Universe::set_void_mirror(NULL);
 598 }
 599 
 600 static void rewrite_nofast_bytecode(Method* method) {
 601   BytecodeStream bcs(method);
 602   while (!bcs.is_last_bytecode()) {
 603     Bytecodes::Code opcode = bcs.next();
 604     switch (opcode) {
 605     case Bytecodes::_getfield:      *bcs.bcp() = Bytecodes::_nofast_getfield;      break;
 606     case Bytecodes::_putfield:      *bcs.bcp() = Bytecodes::_nofast_putfield;      break;
 607     case Bytecodes::_aload_0:       *bcs.bcp() = Bytecodes::_nofast_aload_0;       break;
 608     case Bytecodes::_iload: {
 609       if (!bcs.is_wide()) {
 610         *bcs.bcp() = Bytecodes::_nofast_iload;
 611       }
 612       break;
 613     }
 614     default: break;
 615     }
 616   }
 617 }
 618 
 619 // Walk all methods in the class list to ensure that they won't be modified at
 620 // run time. This includes:
 621 // [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified
 622 //     at run time by RewriteBytecodes/RewriteFrequentPairs
 623 // [2] Assign a fingerprint, so one doesn't need to be assigned at run-time.
 624 static void rewrite_nofast_bytecodes_and_calculate_fingerprints() {
 625   for (int i = 0; i < _global_klass_objects->length(); i++) {
 626     Klass* k = _global_klass_objects->at(i);
 627     if (k->is_instance_klass()) {
 628       InstanceKlass* ik = InstanceKlass::cast(k);
 629       MetaspaceShared::rewrite_nofast_bytecodes_and_calculate_fingerprints(ik);
 630     }
 631   }
 632 }
 633 
 634 void MetaspaceShared::rewrite_nofast_bytecodes_and_calculate_fingerprints(InstanceKlass* ik) {
 635   for (int i = 0; i < ik->methods()->length(); i++) {
 636     Method* m = ik->methods()->at(i);
 637     rewrite_nofast_bytecode(m);
 638     Fingerprinter fp(m);
 639     // The side effect of this call sets method's fingerprint field.
 640     fp.fingerprint();
 641   }
 642 }
 643 
 644 // Objects of the Metadata types (such as Klass and ConstantPool) have C++ vtables.
 645 // (In GCC this is the field <Type>::_vptr, i.e., first word in the object.)
 646 //
 647 // Addresses of the vtables and the methods may be different across JVM runs,
 648 // if libjvm.so is dynamically loaded at a different base address.
 649 //
 650 // To ensure that the Metadata objects in the CDS archive always have the correct vtable:
 651 //
 652 // + at dump time:  we redirect the _vptr to point to our own vtables inside
 653 //                  the CDS image
 654 // + at run time:   we clone the actual contents of the vtables from libjvm.so
 655 //                  into our own tables.
 656 
 657 // Currently, the archive contain ONLY the following types of objects that have C++ vtables.
 658 #define CPP_VTABLE_PATCH_TYPES_DO(f) \
 659   f(ConstantPool) \
 660   f(InstanceKlass) \
 661   f(InstanceClassLoaderKlass) \
 662   f(InstanceMirrorKlass) \
 663   f(InstanceRefKlass) \
 664   f(Method) \
 665   f(ObjArrayKlass) \
 666   f(TypeArrayKlass)
 667 
 668 class CppVtableInfo {
 669   intptr_t _vtable_size;
 670   intptr_t _cloned_vtable[1];
 671 public:
 672   static int num_slots(int vtable_size) {
 673     return 1 + vtable_size; // Need to add the space occupied by _vtable_size;
 674   }
 675   int vtable_size()           { return int(uintx(_vtable_size)); }
 676   void set_vtable_size(int n) { _vtable_size = intptr_t(n); }
 677   intptr_t* cloned_vtable()   { return &_cloned_vtable[0]; }
 678   void zero()                 { memset(_cloned_vtable, 0, sizeof(intptr_t) * vtable_size()); }
 679   // Returns the address of the next CppVtableInfo that can be placed immediately after this CppVtableInfo
 680   static size_t byte_size(int vtable_size) {
 681     CppVtableInfo i;
 682     return pointer_delta(&i._cloned_vtable[vtable_size], &i, sizeof(u1));
 683   }
 684 };
 685 
 686 template <class T> class CppVtableCloner : public T {
 687   static intptr_t* vtable_of(Metadata& m) {
 688     return *((intptr_t**)&m);
 689   }
 690   static CppVtableInfo* _info;
 691 
 692   static int get_vtable_length(const char* name);
 693 
 694 public:
 695   // Allocate and initialize the C++ vtable, starting from top, but do not go past end.
 696   static intptr_t* allocate(const char* name);
 697 
 698   // Clone the vtable to ...
 699   static intptr_t* clone_vtable(const char* name, CppVtableInfo* info);
 700 
 701   static void zero_vtable_clone() {
 702     assert(DumpSharedSpaces, "dump-time only");
 703     _info->zero();
 704   }
 705 
 706   // Switch the vtable pointer to point to the cloned vtable.
 707   static void patch(Metadata* obj) {
 708     assert(DumpSharedSpaces, "dump-time only");
 709     *(void**)obj = (void*)(_info->cloned_vtable());
 710   }
 711 
 712   static bool is_valid_shared_object(const T* obj) {
 713     intptr_t* vptr = *(intptr_t**)obj;
 714     return vptr == _info->cloned_vtable();
 715   }
 716 };
 717 
 718 template <class T> CppVtableInfo* CppVtableCloner<T>::_info = NULL;
 719 
 720 template <class T>
 721 intptr_t* CppVtableCloner<T>::allocate(const char* name) {
 722   assert(is_aligned(_md_region.top(), sizeof(intptr_t)), "bad alignment");
 723   int n = get_vtable_length(name);
 724   _info = (CppVtableInfo*)_md_region.allocate(CppVtableInfo::byte_size(n), sizeof(intptr_t));
 725   _info->set_vtable_size(n);
 726 
 727   intptr_t* p = clone_vtable(name, _info);
 728   assert((char*)p == _md_region.top(), "must be");
 729 
 730   return _info->cloned_vtable();
 731 }
 732 
 733 template <class T>
 734 intptr_t* CppVtableCloner<T>::clone_vtable(const char* name, CppVtableInfo* info) {
 735   if (!DumpSharedSpaces) {
 736     assert(_info == 0, "_info is initialized only at dump time");
 737     _info = info; // Remember it -- it will be used by MetaspaceShared::is_valid_shared_method()
 738   }
 739   T tmp; // Allocate temporary dummy metadata object to get to the original vtable.
 740   int n = info->vtable_size();
 741   intptr_t* srcvtable = vtable_of(tmp);
 742   intptr_t* dstvtable = info->cloned_vtable();
 743 
 744   // We already checked (and, if necessary, adjusted n) when the vtables were allocated, so we are
 745   // safe to do memcpy.
 746   log_debug(cds, vtables)("Copying %3d vtable entries for %s", n, name);
 747   memcpy(dstvtable, srcvtable, sizeof(intptr_t) * n);
 748   return dstvtable + n;
 749 }
 750 
 751 // To determine the size of the vtable for each type, we use the following
 752 // trick by declaring 2 subclasses:
 753 //
 754 //   class CppVtableTesterA: public InstanceKlass {virtual int   last_virtual_method() {return 1;}    };
 755 //   class CppVtableTesterB: public InstanceKlass {virtual void* last_virtual_method() {return NULL}; };
 756 //
 757 // CppVtableTesterA and CppVtableTesterB's vtables have the following properties:
 758 // - Their size (N+1) is exactly one more than the size of InstanceKlass's vtable (N)
 759 // - The first N entries have are exactly the same as in InstanceKlass's vtable.
 760 // - Their last entry is different.
 761 //
 762 // So to determine the value of N, we just walk CppVtableTesterA and CppVtableTesterB's tables
 763 // and find the first entry that's different.
 764 //
 765 // This works on all C++ compilers supported by Oracle, but you may need to tweak it for more
 766 // esoteric compilers.
 767 
 768 template <class T> class CppVtableTesterB: public T {
 769 public:
 770   virtual int last_virtual_method() {return 1;}
 771 };
 772 
 773 template <class T> class CppVtableTesterA : public T {
 774 public:
 775   virtual void* last_virtual_method() {
 776     // Make this different than CppVtableTesterB::last_virtual_method so the C++
 777     // compiler/linker won't alias the two functions.
 778     return NULL;
 779   }
 780 };
 781 
 782 template <class T>
 783 int CppVtableCloner<T>::get_vtable_length(const char* name) {
 784   CppVtableTesterA<T> a;
 785   CppVtableTesterB<T> b;
 786 
 787   intptr_t* avtable = vtable_of(a);
 788   intptr_t* bvtable = vtable_of(b);
 789 
 790   // Start at slot 1, because slot 0 may be RTTI (on Solaris/Sparc)
 791   int vtable_len = 1;
 792   for (; ; vtable_len++) {
 793     if (avtable[vtable_len] != bvtable[vtable_len]) {
 794       break;
 795     }
 796   }
 797   log_debug(cds, vtables)("Found   %3d vtable entries for %s", vtable_len, name);
 798 
 799   return vtable_len;
 800 }
 801 
 802 #define ALLOC_CPP_VTABLE_CLONE(c) \
 803   _cloned_cpp_vtptrs[c##_Kind] = CppVtableCloner<c>::allocate(#c);
 804 
 805 #define CLONE_CPP_VTABLE(c) \
 806   p = CppVtableCloner<c>::clone_vtable(#c, (CppVtableInfo*)p);
 807 
 808 #define ZERO_CPP_VTABLE(c) \
 809  CppVtableCloner<c>::zero_vtable_clone();
 810 
 811 //------------------------------ for DynamicDumpSharedSpaces - start
 812 #define DECLARE_CLONED_VTABLE_KIND(c) c ## _Kind,
 813 
 814 enum {
 815   CPP_VTABLE_PATCH_TYPES_DO(DECLARE_CLONED_VTABLE_KIND)
 816   _num_cloned_vtable_kinds
 817 };
 818 
 819 static intptr_t** _cloned_cpp_vtptrs = NULL;
 820 
 821 void MetaspaceShared::serialize_cloned_cpp_vtptrs(SerializeClosure* soc) {
 822   soc->do_ptr((void**)&_cloned_cpp_vtptrs);
 823 }
 824 
 825 intptr_t* MetaspaceShared::fix_cpp_vtable_for_dynamic_archive(MetaspaceObj::Type msotype, address obj) {
 826   assert(DynamicDumpSharedSpaces, "must");
 827   int kind = -1;
 828   switch (msotype) {
 829   case MetaspaceObj::SymbolType:
 830   case MetaspaceObj::TypeArrayU1Type:
 831   case MetaspaceObj::TypeArrayU2Type:
 832   case MetaspaceObj::TypeArrayU4Type:
 833   case MetaspaceObj::TypeArrayU8Type:
 834   case MetaspaceObj::TypeArrayOtherType:
 835   case MetaspaceObj::ConstMethodType:
 836   case MetaspaceObj::ConstantPoolCacheType:
 837   case MetaspaceObj::AnnotationsType:
 838   case MetaspaceObj::MethodCountersType:
 839     // These have no vtables.
 840     break;
 841   case MetaspaceObj::ClassType:
 842     {
 843       Klass* k = (Klass*)obj;
 844       assert(k->is_klass(), "must be");
 845       if (k->is_instance_klass()) {
 846         kind = InstanceKlass_Kind;
 847       } else {
 848         assert(k->is_objArray_klass(),
 849                "We shouldn't archive any other klasses in DynamicDumpSharedSpaces");
 850         kind = ObjArrayKlass_Kind;
 851       }
 852     }
 853     break;
 854 
 855   case MetaspaceObj::MethodType:
 856     {
 857       Method* m = (Method*)obj;
 858       assert(m->is_method(), "must be");
 859       kind = Method_Kind;
 860     }
 861     break;
 862 
 863   case MetaspaceObj::MethodDataType:
 864     // We don't archive MethodData <-- should have been removed in removed_unsharable_info
 865     ShouldNotReachHere();
 866     break;
 867 
 868   case MetaspaceObj::ConstantPoolType:
 869     {
 870       ConstantPool *cp = (ConstantPool*)obj;
 871       assert(cp->is_constantPool(), "must be");
 872       kind = ConstantPool_Kind;
 873     }
 874     break;
 875 
 876   default:
 877     ShouldNotReachHere();
 878   }
 879 
 880   if (kind >= 0) {
 881     assert(kind < _num_cloned_vtable_kinds, "must be");
 882     return _cloned_cpp_vtptrs[kind];
 883   } else {
 884     return NULL;
 885   }
 886 }
 887 
 888 //------------------------------ for DynamicDumpSharedSpaces - end
 889 
 890 // This can be called at both dump time and run time.
 891 intptr_t* MetaspaceShared::clone_cpp_vtables(intptr_t* p) {
 892   assert(DumpSharedSpaces || UseSharedSpaces, "sanity");
 893   CPP_VTABLE_PATCH_TYPES_DO(CLONE_CPP_VTABLE);
 894   return p;
 895 }
 896 
 897 void MetaspaceShared::zero_cpp_vtable_clones_for_writing() {
 898   assert(DumpSharedSpaces, "dump-time only");
 899   CPP_VTABLE_PATCH_TYPES_DO(ZERO_CPP_VTABLE);
 900 }
 901 
 902 // Allocate and initialize the C++ vtables, starting from top, but do not go past end.
 903 void MetaspaceShared::allocate_cpp_vtable_clones() {
 904   assert(DumpSharedSpaces, "dump-time only");
 905   // Layout (each slot is a intptr_t):
 906   //   [number of slots in the first vtable = n1]
 907   //   [ <n1> slots for the first vtable]
 908   //   [number of slots in the first second = n2]
 909   //   [ <n2> slots for the second vtable]
 910   //   ...
 911   // The order of the vtables is the same as the CPP_VTAB_PATCH_TYPES_DO macro.
 912   CPP_VTABLE_PATCH_TYPES_DO(ALLOC_CPP_VTABLE_CLONE);
 913 }
 914 
 915 // Switch the vtable pointer to point to the cloned vtable. We assume the
 916 // vtable pointer is in first slot in object.
 917 void MetaspaceShared::patch_cpp_vtable_pointers() {
 918   int n = _global_klass_objects->length();
 919   for (int i = 0; i < n; i++) {
 920     Klass* obj = _global_klass_objects->at(i);
 921     if (obj->is_instance_klass()) {
 922       InstanceKlass* ik = InstanceKlass::cast(obj);
 923       if (ik->is_class_loader_instance_klass()) {
 924         CppVtableCloner<InstanceClassLoaderKlass>::patch(ik);
 925       } else if (ik->is_reference_instance_klass()) {
 926         CppVtableCloner<InstanceRefKlass>::patch(ik);
 927       } else if (ik->is_mirror_instance_klass()) {
 928         CppVtableCloner<InstanceMirrorKlass>::patch(ik);
 929       } else {
 930         CppVtableCloner<InstanceKlass>::patch(ik);
 931       }
 932       ConstantPool* cp = ik->constants();
 933       CppVtableCloner<ConstantPool>::patch(cp);
 934       for (int j = 0; j < ik->methods()->length(); j++) {
 935         Method* m = ik->methods()->at(j);
 936         CppVtableCloner<Method>::patch(m);
 937         assert(CppVtableCloner<Method>::is_valid_shared_object(m), "must be");
 938       }
 939     } else if (obj->is_objArray_klass()) {
 940       CppVtableCloner<ObjArrayKlass>::patch(obj);
 941     } else {
 942       assert(obj->is_typeArray_klass(), "sanity");
 943       CppVtableCloner<TypeArrayKlass>::patch(obj);
 944     }
 945   }
 946 }
 947 
 948 bool MetaspaceShared::is_valid_shared_method(const Method* m) {
 949   assert(is_in_shared_metaspace(m), "must be");
 950   return CppVtableCloner<Method>::is_valid_shared_object(m);
 951 }
 952 
 953 void WriteClosure::do_oop(oop* o) {
 954   if (*o == NULL) {
 955     _dump_region->append_intptr_t(0);
 956   } else {
 957     assert(HeapShared::is_heap_object_archiving_allowed(),
 958            "Archiving heap object is not allowed");
 959     _dump_region->append_intptr_t(
 960       (intptr_t)CompressedOops::encode_not_null(*o));
 961   }
 962 }
 963 
 964 void WriteClosure::do_region(u_char* start, size_t size) {
 965   assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
 966   assert(size % sizeof(intptr_t) == 0, "bad size");
 967   do_tag((int)size);
 968   while (size > 0) {
 969     _dump_region->append_intptr_t(*(intptr_t*)start);
 970     start += sizeof(intptr_t);
 971     size -= sizeof(intptr_t);
 972   }
 973 }
 974 
 975 // This is for dumping detailed statistics for the allocations
 976 // in the shared spaces.
 977 class DumpAllocStats : public ResourceObj {
 978 public:
 979 
 980   // Here's poor man's enum inheritance
 981 #define SHAREDSPACE_OBJ_TYPES_DO(f) \
 982   METASPACE_OBJ_TYPES_DO(f) \
 983   f(SymbolHashentry) \
 984   f(SymbolBucket) \
 985   f(StringHashentry) \
 986   f(StringBucket) \
 987   f(Other)
 988 
 989   enum Type {
 990     // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
 991     SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_DECLARE)
 992     _number_of_types
 993   };
 994 
 995   static const char * type_name(Type type) {
 996     switch(type) {
 997     SHAREDSPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_NAME_CASE)
 998     default:
 999       ShouldNotReachHere();
1000       return NULL;
1001     }
1002   }
1003 
1004 public:
1005   enum { RO = 0, RW = 1 };
1006 
1007   int _counts[2][_number_of_types];
1008   int _bytes [2][_number_of_types];
1009 
1010   DumpAllocStats() {
1011     memset(_counts, 0, sizeof(_counts));
1012     memset(_bytes,  0, sizeof(_bytes));
1013   };
1014 
1015   void record(MetaspaceObj::Type type, int byte_size, bool read_only) {
1016     assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
1017     int which = (read_only) ? RO : RW;
1018     _counts[which][type] ++;
1019     _bytes [which][type] += byte_size;
1020   }
1021 
1022   void record_other_type(int byte_size, bool read_only) {
1023     int which = (read_only) ? RO : RW;
1024     _bytes [which][OtherType] += byte_size;
1025   }
1026   void print_stats(int ro_all, int rw_all, int mc_all, int md_all);
1027 };
1028 
1029 void DumpAllocStats::print_stats(int ro_all, int rw_all, int mc_all, int md_all) {
1030   // Calculate size of data that was not allocated by Metaspace::allocate()
1031   MetaspaceSharedStats *stats = MetaspaceShared::stats();
1032 
1033   // symbols
1034   _counts[RO][SymbolHashentryType] = stats->symbol.hashentry_count;
1035   _bytes [RO][SymbolHashentryType] = stats->symbol.hashentry_bytes;
1036 
1037   _counts[RO][SymbolBucketType] = stats->symbol.bucket_count;
1038   _bytes [RO][SymbolBucketType] = stats->symbol.bucket_bytes;
1039 
1040   // strings
1041   _counts[RO][StringHashentryType] = stats->string.hashentry_count;
1042   _bytes [RO][StringHashentryType] = stats->string.hashentry_bytes;
1043 
1044   _counts[RO][StringBucketType] = stats->string.bucket_count;
1045   _bytes [RO][StringBucketType] = stats->string.bucket_bytes;
1046 
1047   // TODO: count things like dictionary, vtable, etc
1048   _bytes[RW][OtherType] += mc_all + md_all;
1049   rw_all += mc_all + md_all; // mc/md are mapped Read/Write
1050 
1051   // prevent divide-by-zero
1052   if (ro_all < 1) {
1053     ro_all = 1;
1054   }
1055   if (rw_all < 1) {
1056     rw_all = 1;
1057   }
1058 
1059   int all_ro_count = 0;
1060   int all_ro_bytes = 0;
1061   int all_rw_count = 0;
1062   int all_rw_bytes = 0;
1063 
1064 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
1065 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
1066   const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
1067   const char *hdr = "                        ro_cnt   ro_bytes     % |   rw_cnt   rw_bytes     % |  all_cnt  all_bytes     %";
1068 
1069   LogMessage(cds) msg;
1070 
1071   msg.info("Detailed metadata info (excluding st regions; rw stats include md/mc regions):");
1072   msg.info("%s", hdr);
1073   msg.info("%s", sep);
1074   for (int type = 0; type < int(_number_of_types); type ++) {
1075     const char *name = type_name((Type)type);
1076     int ro_count = _counts[RO][type];
1077     int ro_bytes = _bytes [RO][type];
1078     int rw_count = _counts[RW][type];
1079     int rw_bytes = _bytes [RW][type];
1080     int count = ro_count + rw_count;
1081     int bytes = ro_bytes + rw_bytes;
1082 
1083     double ro_perc = percent_of(ro_bytes, ro_all);
1084     double rw_perc = percent_of(rw_bytes, rw_all);
1085     double perc    = percent_of(bytes, ro_all + rw_all);
1086 
1087     msg.info(fmt_stats, name,
1088                          ro_count, ro_bytes, ro_perc,
1089                          rw_count, rw_bytes, rw_perc,
1090                          count, bytes, perc);
1091 
1092     all_ro_count += ro_count;
1093     all_ro_bytes += ro_bytes;
1094     all_rw_count += rw_count;
1095     all_rw_bytes += rw_bytes;
1096   }
1097 
1098   int all_count = all_ro_count + all_rw_count;
1099   int all_bytes = all_ro_bytes + all_rw_bytes;
1100 
1101   double all_ro_perc = percent_of(all_ro_bytes, ro_all);
1102   double all_rw_perc = percent_of(all_rw_bytes, rw_all);
1103   double all_perc    = percent_of(all_bytes, ro_all + rw_all);
1104 
1105   msg.info("%s", sep);
1106   msg.info(fmt_stats, "Total",
1107                        all_ro_count, all_ro_bytes, all_ro_perc,
1108                        all_rw_count, all_rw_bytes, all_rw_perc,
1109                        all_count, all_bytes, all_perc);
1110 
1111   assert(all_ro_bytes == ro_all, "everything should have been counted");
1112   assert(all_rw_bytes == rw_all, "everything should have been counted");
1113 
1114 #undef fmt_stats
1115 }
1116 
1117 // Populate the shared space.
1118 
1119 class VM_PopulateDumpSharedSpace: public VM_Operation {
1120 private:
1121   GrowableArray<MemRegion> *_closed_archive_heap_regions;
1122   GrowableArray<MemRegion> *_open_archive_heap_regions;
1123 
1124   GrowableArray<ArchiveHeapOopmapInfo> *_closed_archive_heap_oopmaps;
1125   GrowableArray<ArchiveHeapOopmapInfo> *_open_archive_heap_oopmaps;
1126 
1127   void dump_java_heap_objects() NOT_CDS_JAVA_HEAP_RETURN;
1128   void dump_archive_heap_oopmaps() NOT_CDS_JAVA_HEAP_RETURN;
1129   void dump_archive_heap_oopmaps(GrowableArray<MemRegion>* regions,
1130                                  GrowableArray<ArchiveHeapOopmapInfo>* oopmaps);
1131   void dump_symbols();
1132   char* dump_read_only_tables();
1133   void print_region_stats();
1134   void print_heap_region_stats(GrowableArray<MemRegion> *heap_mem,
1135                                const char *name, const size_t total_size);
1136 public:
1137 
1138   VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
1139   void doit();   // outline because gdb sucks
1140   static void write_region(FileMapInfo* mapinfo, int region, DumpRegion* space, bool read_only,  bool allow_exec);
1141   bool allow_nested_vm_operations() const { return true; }
1142 }; // class VM_PopulateDumpSharedSpace
1143 
1144 class SortedSymbolClosure: public SymbolClosure {
1145   GrowableArray<Symbol*> _symbols;
1146   virtual void do_symbol(Symbol** sym) {
1147     assert((*sym)->is_permanent(), "archived symbols must be permanent");
1148     _symbols.append(*sym);
1149   }
1150   static int compare_symbols_by_address(Symbol** a, Symbol** b) {
1151     if (a[0] < b[0]) {
1152       return -1;
1153     } else if (a[0] == b[0]) {
1154       return 0;
1155     } else {
1156       return 1;
1157     }
1158   }
1159 
1160 public:
1161   SortedSymbolClosure() {
1162     SymbolTable::symbols_do(this);
1163     _symbols.sort(compare_symbols_by_address);
1164   }
1165   GrowableArray<Symbol*>* get_sorted_symbols() {
1166     return &_symbols;
1167   }
1168 };
1169 
1170 // ArchiveCompactor --
1171 //
1172 // This class is the central piece of shared archive compaction -- all metaspace data are
1173 // initially allocated outside of the shared regions. ArchiveCompactor copies the
1174 // metaspace data into their final location in the shared regions.
1175 
1176 class ArchiveCompactor : AllStatic {
1177   static const int INITIAL_TABLE_SIZE = 8087;
1178   static const int MAX_TABLE_SIZE     = 1000000;
1179 
1180   static DumpAllocStats* _alloc_stats;
1181   static SortedSymbolClosure* _ssc;
1182 
1183   typedef KVHashtable<address, address, mtInternal> RelocationTable;
1184   static RelocationTable* _new_loc_table;
1185 
1186 public:
1187   static void initialize() {
1188     _alloc_stats = new(ResourceObj::C_HEAP, mtInternal)DumpAllocStats;
1189     _new_loc_table = new RelocationTable(INITIAL_TABLE_SIZE);
1190   }
1191   static DumpAllocStats* alloc_stats() {
1192     return _alloc_stats;
1193   }
1194 
1195   // Use this when you allocate space with MetaspaceShare::read_only_space_alloc()
1196   // outside of ArchiveCompactor::allocate(). These are usually for misc tables
1197   // that are allocated in the RO space.
1198   class OtherROAllocMark {
1199     char* _oldtop;
1200   public:
1201     OtherROAllocMark() {
1202       _oldtop = _ro_region.top();
1203     }
1204     ~OtherROAllocMark() {
1205       char* newtop = _ro_region.top();
1206       ArchiveCompactor::alloc_stats()->record_other_type(int(newtop - _oldtop), true);
1207     }
1208   };
1209 
1210   static void allocate(MetaspaceClosure::Ref* ref, bool read_only) {
1211     address obj = ref->obj();
1212     int bytes = ref->size() * BytesPerWord;
1213     char* p;
1214     size_t alignment = BytesPerWord;
1215     char* oldtop;
1216     char* newtop;
1217 
1218     if (read_only) {
1219       oldtop = _ro_region.top();
1220       p = _ro_region.allocate(bytes, alignment);
1221       newtop = _ro_region.top();
1222     } else {
1223       oldtop = _rw_region.top();
1224       if (ref->msotype() == MetaspaceObj::ClassType) {
1225         // Save a pointer immediate in front of an InstanceKlass, so
1226         // we can do a quick lookup from InstanceKlass* -> RunTimeSharedClassInfo*
1227         // without building another hashtable. See RunTimeSharedClassInfo::get_for()
1228         // in systemDictionaryShared.cpp.
1229         Klass* klass = (Klass*)obj;
1230         if (klass->is_instance_klass()) {
1231           SystemDictionaryShared::validate_before_archiving(InstanceKlass::cast(klass));
1232           _rw_region.allocate(sizeof(address), BytesPerWord);
1233         }
1234       }
1235       p = _rw_region.allocate(bytes, alignment);
1236       newtop = _rw_region.top();
1237     }
1238     memcpy(p, obj, bytes);
1239     assert(_new_loc_table->lookup(obj) == NULL, "each object can be relocated at most once");
1240     _new_loc_table->add(obj, (address)p);
1241     log_trace(cds)("Copy: " PTR_FORMAT " ==> " PTR_FORMAT " %d", p2i(obj), p2i(p), bytes);
1242     if (_new_loc_table->maybe_grow(MAX_TABLE_SIZE)) {
1243       log_info(cds, hashtables)("Expanded _new_loc_table to %d", _new_loc_table->table_size());
1244     }
1245     _alloc_stats->record(ref->msotype(), int(newtop - oldtop), read_only);
1246   }
1247 
1248   static address get_new_loc(MetaspaceClosure::Ref* ref) {
1249     address* pp = _new_loc_table->lookup(ref->obj());
1250     assert(pp != NULL, "must be");
1251     return *pp;
1252   }
1253 
1254 private:
1255   // Makes a shallow copy of visited MetaspaceObj's
1256   class ShallowCopier: public UniqueMetaspaceClosure {
1257     bool _read_only;
1258   public:
1259     ShallowCopier(bool read_only) : _read_only(read_only) {}
1260 
1261     virtual bool do_unique_ref(Ref* ref, bool read_only) {
1262       if (read_only == _read_only) {
1263         allocate(ref, read_only);
1264       }
1265       return true; // recurse into ref.obj()
1266     }
1267   };
1268 
1269   // Relocate embedded pointers within a MetaspaceObj's shallow copy
1270   class ShallowCopyEmbeddedRefRelocator: public UniqueMetaspaceClosure {
1271   public:
1272     virtual bool do_unique_ref(Ref* ref, bool read_only) {
1273       address new_loc = get_new_loc(ref);
1274       RefRelocator refer;
1275       ref->metaspace_pointers_do_at(&refer, new_loc);
1276       return true; // recurse into ref.obj()
1277     }
1278   };
1279 
1280   // Relocate a reference to point to its shallow copy
1281   class RefRelocator: public MetaspaceClosure {
1282   public:
1283     virtual bool do_ref(Ref* ref, bool read_only) {
1284       if (ref->not_null()) {
1285         ref->update(get_new_loc(ref));
1286       }
1287       return false; // Do not recurse.
1288     }
1289   };
1290 
1291 #ifdef ASSERT
1292   class IsRefInArchiveChecker: public MetaspaceClosure {
1293   public:
1294     virtual bool do_ref(Ref* ref, bool read_only) {
1295       if (ref->not_null()) {
1296         char* obj = (char*)ref->obj();
1297         assert(_ro_region.contains(obj) || _rw_region.contains(obj),
1298                "must be relocated to point to CDS archive");
1299       }
1300       return false; // Do not recurse.
1301     }
1302   };
1303 #endif
1304 
1305 public:
1306   static void copy_and_compact() {
1307     ResourceMark rm;
1308     SortedSymbolClosure the_ssc; // StackObj
1309     _ssc = &the_ssc;
1310 
1311     tty->print_cr("Scanning all metaspace objects ... ");
1312     {
1313       // allocate and shallow-copy RW objects, immediately following the MC region
1314       tty->print_cr("Allocating RW objects ... ");
1315       _mc_region.pack(&_rw_region);
1316 
1317       ResourceMark rm;
1318       ShallowCopier rw_copier(false);
1319       iterate_roots(&rw_copier);
1320     }
1321     {
1322       // allocate and shallow-copy of RO object, immediately following the RW region
1323       tty->print_cr("Allocating RO objects ... ");
1324       _rw_region.pack(&_ro_region);
1325 
1326       ResourceMark rm;
1327       ShallowCopier ro_copier(true);
1328       iterate_roots(&ro_copier);
1329     }
1330     {
1331       tty->print_cr("Relocating embedded pointers ... ");
1332       ResourceMark rm;
1333       ShallowCopyEmbeddedRefRelocator emb_reloc;
1334       iterate_roots(&emb_reloc);
1335     }
1336     {
1337       tty->print_cr("Relocating external roots ... ");
1338       ResourceMark rm;
1339       RefRelocator ext_reloc;
1340       iterate_roots(&ext_reloc);
1341     }
1342 
1343 #ifdef ASSERT
1344     {
1345       tty->print_cr("Verifying external roots ... ");
1346       ResourceMark rm;
1347       IsRefInArchiveChecker checker;
1348       iterate_roots(&checker);
1349     }
1350 #endif
1351 
1352 
1353     // cleanup
1354     _ssc = NULL;
1355   }
1356 
1357   // We must relocate the System::_well_known_klasses only after we have copied the
1358   // java objects in during dump_java_heap_objects(): during the object copy, we operate on
1359   // old objects which assert that their klass is the original klass.
1360   static void relocate_well_known_klasses() {
1361     {
1362       tty->print_cr("Relocating SystemDictionary::_well_known_klasses[] ... ");
1363       ResourceMark rm;
1364       RefRelocator ext_reloc;
1365       SystemDictionary::well_known_klasses_do(&ext_reloc);
1366     }
1367     // NOTE: after this point, we shouldn't have any globals that can reach the old
1368     // objects.
1369 
1370     // We cannot use any of the objects in the heap anymore (except for the
1371     // shared strings) because their headers no longer point to valid Klasses.
1372   }
1373 
1374   static void iterate_roots(MetaspaceClosure* it) {
1375     GrowableArray<Symbol*>* symbols = _ssc->get_sorted_symbols();
1376     for (int i=0; i<symbols->length(); i++) {
1377       it->push(symbols->adr_at(i));
1378     }
1379     if (_global_klass_objects != NULL) {
1380       // Need to fix up the pointers
1381       for (int i = 0; i < _global_klass_objects->length(); i++) {
1382         // NOTE -- this requires that the vtable is NOT yet patched, or else we are hosed.
1383         it->push(_global_klass_objects->adr_at(i));
1384       }
1385     }
1386     FileMapInfo::metaspace_pointers_do(it);
1387     SystemDictionaryShared::dumptime_classes_do(it);
1388     Universe::metaspace_pointers_do(it);
1389     SymbolTable::metaspace_pointers_do(it);
1390     vmSymbols::metaspace_pointers_do(it);
1391 
1392     it->finish();
1393   }
1394 
1395   static Klass* get_relocated_klass(Klass* orig_klass) {
1396     assert(DumpSharedSpaces, "dump time only");
1397     address* pp = _new_loc_table->lookup((address)orig_klass);
1398     assert(pp != NULL, "must be");
1399     Klass* klass = (Klass*)(*pp);
1400     assert(klass->is_klass(), "must be");
1401     return klass;
1402   }
1403 };
1404 
1405 DumpAllocStats* ArchiveCompactor::_alloc_stats;
1406 SortedSymbolClosure* ArchiveCompactor::_ssc;
1407 ArchiveCompactor::RelocationTable* ArchiveCompactor::_new_loc_table;
1408 
1409 void VM_PopulateDumpSharedSpace::write_region(FileMapInfo* mapinfo, int region_idx,
1410                                               DumpRegion* dump_region, bool read_only,  bool allow_exec) {
1411   mapinfo->write_region(region_idx, dump_region->base(), dump_region->used(), read_only, allow_exec);
1412 }
1413 
1414 void VM_PopulateDumpSharedSpace::dump_symbols() {
1415   tty->print_cr("Dumping symbol table ...");
1416 
1417   NOT_PRODUCT(SymbolTable::verify());
1418   SymbolTable::write_to_archive();
1419 }
1420 
1421 char* VM_PopulateDumpSharedSpace::dump_read_only_tables() {
1422   ArchiveCompactor::OtherROAllocMark mark;
1423 
1424   tty->print("Removing java_mirror ... ");
1425   if (!HeapShared::is_heap_object_archiving_allowed()) {
1426     clear_basic_type_mirrors();
1427   }
1428   remove_java_mirror_in_classes();
1429   tty->print_cr("done. ");
1430 
1431   SystemDictionaryShared::write_to_archive();
1432 
1433   char* start = _ro_region.top();
1434 
1435   size_t vtptrs_bytes = _num_cloned_vtable_kinds * sizeof(intptr_t*);
1436   _cloned_cpp_vtptrs = (intptr_t**)_ro_region.allocate(vtptrs_bytes, sizeof(intptr_t*));
1437 
1438   // Write the other data to the output array.
1439   WriteClosure wc(&_ro_region);
1440   MetaspaceShared::serialize(&wc);
1441 
1442   // Write the bitmaps for patching the archive heap regions
1443   dump_archive_heap_oopmaps();
1444 
1445   return start;
1446 }
1447 
1448 void VM_PopulateDumpSharedSpace::doit() {
1449   // We should no longer allocate anything from the metaspace, so that:
1450   //
1451   // (1) Metaspace::allocate might trigger GC if we have run out of
1452   //     committed metaspace, but we can't GC because we're running
1453   //     in the VM thread.
1454   // (2) ArchiveCompactor needs to work with a stable set of MetaspaceObjs.
1455   Metaspace::freeze();
1456   DEBUG_ONLY(SystemDictionaryShared::NoClassLoadingMark nclm);
1457 
1458   Thread* THREAD = VMThread::vm_thread();
1459 
1460   FileMapInfo::check_nonempty_dir_in_shared_path_table();
1461 
1462   NOT_PRODUCT(SystemDictionary::verify();)
1463   // The following guarantee is meant to ensure that no loader constraints
1464   // exist yet, since the constraints table is not shared.  This becomes
1465   // more important now that we don't re-initialize vtables/itables for
1466   // shared classes at runtime, where constraints were previously created.
1467   guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
1468             "loader constraints are not saved");
1469   guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
1470           "placeholders are not saved");
1471 
1472   // At this point, many classes have been loaded.
1473   // Gather systemDictionary classes in a global array and do everything to
1474   // that so we don't have to walk the SystemDictionary again.
1475   SystemDictionaryShared::check_excluded_classes();
1476   _global_klass_objects = new GrowableArray<Klass*>(1000);
1477   CollectClassesClosure collect_classes;
1478   ClassLoaderDataGraph::loaded_classes_do(&collect_classes);
1479 
1480   tty->print_cr("Number of classes %d", _global_klass_objects->length());
1481   {
1482     int num_type_array = 0, num_obj_array = 0, num_inst = 0;
1483     for (int i = 0; i < _global_klass_objects->length(); i++) {
1484       Klass* k = _global_klass_objects->at(i);
1485       if (k->is_instance_klass()) {
1486         num_inst ++;
1487       } else if (k->is_objArray_klass()) {
1488         num_obj_array ++;
1489       } else {
1490         assert(k->is_typeArray_klass(), "sanity");
1491         num_type_array ++;
1492       }
1493     }
1494     tty->print_cr("    instance classes   = %5d", num_inst);
1495     tty->print_cr("    obj array classes  = %5d", num_obj_array);
1496     tty->print_cr("    type array classes = %5d", num_type_array);
1497   }
1498 
1499   // Ensure the ConstMethods won't be modified at run-time
1500   tty->print("Updating ConstMethods ... ");
1501   rewrite_nofast_bytecodes_and_calculate_fingerprints();
1502   tty->print_cr("done. ");
1503 
1504   // Remove all references outside the metadata
1505   tty->print("Removing unshareable information ... ");
1506   remove_unshareable_in_classes();
1507   tty->print_cr("done. ");
1508 
1509   ArchiveCompactor::initialize();
1510   ArchiveCompactor::copy_and_compact();
1511 
1512   dump_symbols();
1513 
1514   // Dump supported java heap objects
1515   _closed_archive_heap_regions = NULL;
1516   _open_archive_heap_regions = NULL;
1517   dump_java_heap_objects();
1518 
1519   ArchiveCompactor::relocate_well_known_klasses();
1520 
1521   char* read_only_tables_start = dump_read_only_tables();
1522   _ro_region.pack(&_md_region);
1523 
1524   char* vtbl_list = _md_region.top();
1525   MetaspaceShared::allocate_cpp_vtable_clones();
1526   _md_region.pack();
1527 
1528   // The 4 core spaces are allocated consecutively mc->rw->ro->md, so there total size
1529   // is just the spaces between the two ends.
1530   size_t core_spaces_size = _md_region.end() - _mc_region.base();
1531   assert(core_spaces_size == (size_t)align_up(core_spaces_size, Metaspace::reserve_alignment()),
1532          "should already be aligned");
1533 
1534   // During patching, some virtual methods may be called, so at this point
1535   // the vtables must contain valid methods (as filled in by CppVtableCloner::allocate).
1536   MetaspaceShared::patch_cpp_vtable_pointers();
1537 
1538   // The vtable clones contain addresses of the current process.
1539   // We don't want to write these addresses into the archive.
1540   MetaspaceShared::zero_cpp_vtable_clones_for_writing();
1541 
1542   // Create and write the archive file that maps the shared spaces.
1543 
1544   FileMapInfo* mapinfo = new FileMapInfo(true);
1545   mapinfo->populate_header(os::vm_allocation_granularity());
1546   mapinfo->set_read_only_tables_start(read_only_tables_start);
1547   mapinfo->set_misc_data_patching_start(vtbl_list);
1548   mapinfo->set_cds_i2i_entry_code_buffers(MetaspaceShared::cds_i2i_entry_code_buffers());
1549   mapinfo->set_cds_i2i_entry_code_buffers_size(MetaspaceShared::cds_i2i_entry_code_buffers_size());
1550   mapinfo->set_core_spaces_size(core_spaces_size);
1551 
1552   for (int pass=1; pass<=2; pass++) {
1553     bool print_archive_log = (pass==1);
1554     if (pass == 1) {
1555       // The first pass doesn't actually write the data to disk. All it
1556       // does is to update the fields in the mapinfo->_header.
1557     } else {
1558       // After the first pass, the contents of mapinfo->_header are finalized,
1559       // so we can compute the header's CRC, and write the contents of the header
1560       // and the regions into disk.
1561       mapinfo->open_for_write();
1562       mapinfo->set_header_crc(mapinfo->compute_header_crc());
1563     }
1564     mapinfo->write_header();
1565 
1566     // NOTE: md contains the trampoline code for method entries, which are patched at run time,
1567     // so it needs to be read/write.
1568     write_region(mapinfo, MetaspaceShared::mc, &_mc_region, /*read_only=*/false,/*allow_exec=*/true);
1569     write_region(mapinfo, MetaspaceShared::rw, &_rw_region, /*read_only=*/false,/*allow_exec=*/false);
1570     write_region(mapinfo, MetaspaceShared::ro, &_ro_region, /*read_only=*/true, /*allow_exec=*/false);
1571     write_region(mapinfo, MetaspaceShared::md, &_md_region, /*read_only=*/false,/*allow_exec=*/false);
1572 
1573     _total_closed_archive_region_size = mapinfo->write_archive_heap_regions(
1574                                         _closed_archive_heap_regions,
1575                                         _closed_archive_heap_oopmaps,
1576                                         MetaspaceShared::first_closed_archive_heap_region,
1577                                         MetaspaceShared::max_closed_archive_heap_region,
1578                                         print_archive_log);
1579     _total_open_archive_region_size = mapinfo->write_archive_heap_regions(
1580                                         _open_archive_heap_regions,
1581                                         _open_archive_heap_oopmaps,
1582                                         MetaspaceShared::first_open_archive_heap_region,
1583                                         MetaspaceShared::max_open_archive_heap_region,
1584                                         print_archive_log);
1585   }
1586 
1587   mapinfo->close();
1588 
1589   // Restore the vtable in case we invoke any virtual methods.
1590   MetaspaceShared::clone_cpp_vtables((intptr_t*)vtbl_list);
1591 
1592   print_region_stats();
1593 
1594   if (log_is_enabled(Info, cds)) {
1595     ArchiveCompactor::alloc_stats()->print_stats(int(_ro_region.used()), int(_rw_region.used()),
1596                                                  int(_mc_region.used()), int(_md_region.used()));
1597   }
1598 
1599   if (PrintSystemDictionaryAtExit) {
1600     SystemDictionary::print();
1601   }
1602 
1603   if (AllowArchivingWithJavaAgent) {
1604     warning("This archive was created with AllowArchivingWithJavaAgent. It should be used "
1605             "for testing purposes only and should not be used in a production environment");
1606   }
1607 
1608   // There may be other pending VM operations that operate on the InstanceKlasses,
1609   // which will fail because InstanceKlasses::remove_unshareable_info()
1610   // has been called. Forget these operations and exit the VM directly.
1611   vm_direct_exit(0);
1612 }
1613 
1614 void VM_PopulateDumpSharedSpace::print_region_stats() {
1615   // Print statistics of all the regions
1616   const size_t total_reserved = _ro_region.reserved()  + _rw_region.reserved() +
1617                                 _mc_region.reserved()  + _md_region.reserved() +
1618                                 _total_closed_archive_region_size +
1619                                 _total_open_archive_region_size;
1620   const size_t total_bytes = _ro_region.used()  + _rw_region.used() +
1621                              _mc_region.used()  + _md_region.used() +
1622                              _total_closed_archive_region_size +
1623                              _total_open_archive_region_size;
1624   const double total_u_perc = percent_of(total_bytes, total_reserved);
1625 
1626   _mc_region.print(total_reserved);
1627   _rw_region.print(total_reserved);
1628   _ro_region.print(total_reserved);
1629   _md_region.print(total_reserved);
1630   print_heap_region_stats(_closed_archive_heap_regions, "ca", total_reserved);
1631   print_heap_region_stats(_open_archive_heap_regions, "oa", total_reserved);
1632 
1633   tty->print_cr("total    : " SIZE_FORMAT_W(9) " [100.0%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used]",
1634                  total_bytes, total_reserved, total_u_perc);
1635 }
1636 
1637 void VM_PopulateDumpSharedSpace::print_heap_region_stats(GrowableArray<MemRegion> *heap_mem,
1638                                                          const char *name, const size_t total_size) {
1639   int arr_len = heap_mem == NULL ? 0 : heap_mem->length();
1640   for (int i = 0; i < arr_len; i++) {
1641       char* start = (char*)heap_mem->at(i).start();
1642       size_t size = heap_mem->at(i).byte_size();
1643       char* top = start + size;
1644       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,
1645                     name, i, size, size/double(total_size)*100.0, size, p2i(start));
1646 
1647   }
1648 }
1649 
1650 // Update a Java object to point its Klass* to the new location after
1651 // shared archive has been compacted.
1652 void MetaspaceShared::relocate_klass_ptr(oop o) {
1653   assert(DumpSharedSpaces, "sanity");
1654   Klass* k = ArchiveCompactor::get_relocated_klass(o->klass());
1655   o->set_klass(k);
1656 }
1657 
1658 Klass* MetaspaceShared::get_relocated_klass(Klass *k) {
1659   assert(DumpSharedSpaces, "sanity");
1660   return ArchiveCompactor::get_relocated_klass(k);
1661 }
1662 
1663 class LinkSharedClassesClosure : public KlassClosure {
1664   Thread* THREAD;
1665   bool    _made_progress;
1666  public:
1667   LinkSharedClassesClosure(Thread* thread) : THREAD(thread), _made_progress(false) {}
1668 
1669   void reset()               { _made_progress = false; }
1670   bool made_progress() const { return _made_progress; }
1671 
1672   void do_klass(Klass* k) {
1673     if (k->is_instance_klass()) {
1674       InstanceKlass* ik = InstanceKlass::cast(k);
1675       // Link the class to cause the bytecodes to be rewritten and the
1676       // cpcache to be created. Class verification is done according
1677       // to -Xverify setting.
1678       _made_progress |= MetaspaceShared::try_link_class(ik, THREAD);
1679       guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1680 
1681       ik->constants()->resolve_class_constants(THREAD);
1682     }
1683   }
1684 };
1685 
1686 class CheckSharedClassesClosure : public KlassClosure {
1687   bool    _made_progress;
1688  public:
1689   CheckSharedClassesClosure() : _made_progress(false) {}
1690 
1691   void reset()               { _made_progress = false; }
1692   bool made_progress() const { return _made_progress; }
1693   void do_klass(Klass* k) {
1694     if (k->is_instance_klass() && InstanceKlass::cast(k)->check_sharing_error_state()) {
1695       _made_progress = true;
1696     }
1697   }
1698 };
1699 
1700 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) {
1701   // We need to iterate because verification may cause additional classes
1702   // to be loaded.
1703   LinkSharedClassesClosure link_closure(THREAD);
1704   do {
1705     link_closure.reset();
1706     ClassLoaderDataGraph::unlocked_loaded_classes_do(&link_closure);
1707     guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1708   } while (link_closure.made_progress());
1709 
1710   if (_has_error_classes) {
1711     // Mark all classes whose super class or interfaces failed verification.
1712     CheckSharedClassesClosure check_closure;
1713     do {
1714       // Not completely sure if we need to do this iteratively. Anyway,
1715       // we should come here only if there are unverifiable classes, which
1716       // shouldn't happen in normal cases. So better safe than sorry.
1717       check_closure.reset();
1718       ClassLoaderDataGraph::unlocked_loaded_classes_do(&check_closure);
1719     } while (check_closure.made_progress());
1720   }
1721 }
1722 
1723 void MetaspaceShared::prepare_for_dumping() {
1724   Arguments::check_unsupported_dumping_properties();
1725   ClassLoader::initialize_shared_path();
1726 }
1727 
1728 // Preload classes from a list, populate the shared spaces and dump to a
1729 // file.
1730 void MetaspaceShared::preload_and_dump(TRAPS) {
1731   { TraceTime timer("Dump Shared Spaces", TRACETIME_LOG(Info, startuptime));
1732     ResourceMark rm;
1733     char class_list_path_str[JVM_MAXPATHLEN];
1734     // Preload classes to be shared.
1735     const char* class_list_path;
1736     if (SharedClassListFile == NULL) {
1737       // Construct the path to the class list (in jre/lib)
1738       // Walk up two directories from the location of the VM and
1739       // optionally tack on "lib" (depending on platform)
1740       os::jvm_path(class_list_path_str, sizeof(class_list_path_str));
1741       for (int i = 0; i < 3; i++) {
1742         char *end = strrchr(class_list_path_str, *os::file_separator());
1743         if (end != NULL) *end = '\0';
1744       }
1745       int class_list_path_len = (int)strlen(class_list_path_str);
1746       if (class_list_path_len >= 3) {
1747         if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) {
1748           if (class_list_path_len < JVM_MAXPATHLEN - 4) {
1749             jio_snprintf(class_list_path_str + class_list_path_len,
1750                          sizeof(class_list_path_str) - class_list_path_len,
1751                          "%slib", os::file_separator());
1752             class_list_path_len += 4;
1753           }
1754         }
1755       }
1756       if (class_list_path_len < JVM_MAXPATHLEN - 10) {
1757         jio_snprintf(class_list_path_str + class_list_path_len,
1758                      sizeof(class_list_path_str) - class_list_path_len,
1759                      "%sclasslist", os::file_separator());
1760       }
1761       class_list_path = class_list_path_str;
1762     } else {
1763       class_list_path = SharedClassListFile;
1764     }
1765 
1766     tty->print_cr("Loading classes to share ...");
1767     _has_error_classes = false;
1768     int class_count = preload_classes(class_list_path, THREAD);
1769     if (ExtraSharedClassListFile) {
1770       class_count += preload_classes(ExtraSharedClassListFile, THREAD);
1771     }
1772     tty->print_cr("Loading classes to share: done.");
1773 
1774     log_info(cds)("Shared spaces: preloaded %d classes", class_count);
1775 
1776     if (SharedArchiveConfigFile) {
1777       tty->print_cr("Reading extra data from %s ...", SharedArchiveConfigFile);
1778       read_extra_data(SharedArchiveConfigFile, THREAD);
1779     }
1780     tty->print_cr("Reading extra data: done.");
1781 
1782     HeapShared::init_subgraph_entry_fields(THREAD);
1783 
1784     // Rewrite and link classes
1785     tty->print_cr("Rewriting and linking classes ...");
1786 
1787     // Link any classes which got missed. This would happen if we have loaded classes that
1788     // were not explicitly specified in the classlist. E.g., if an interface implemented by class K
1789     // fails verification, all other interfaces that were not specified in the classlist but
1790     // are implemented by K are not verified.
1791     link_and_cleanup_shared_classes(CATCH);
1792     tty->print_cr("Rewriting and linking classes: done");
1793 
1794     if (HeapShared::is_heap_object_archiving_allowed()) {
1795       // Avoid fragmentation while archiving heap objects.
1796       Universe::heap()->soft_ref_policy()->set_should_clear_all_soft_refs(true);
1797       Universe::heap()->collect(GCCause::_archive_time_gc);
1798       Universe::heap()->soft_ref_policy()->set_should_clear_all_soft_refs(false);
1799     }
1800 
1801     VM_PopulateDumpSharedSpace op;
1802     VMThread::execute(&op);
1803   }
1804 }
1805 
1806 
1807 int MetaspaceShared::preload_classes(const char* class_list_path, TRAPS) {
1808   ClassListParser parser(class_list_path);
1809   int class_count = 0;
1810 
1811   while (parser.parse_one_line()) {
1812     Klass* klass = parser.load_current_class(THREAD);
1813     if (HAS_PENDING_EXCEPTION) {
1814       if (klass == NULL &&
1815           (PENDING_EXCEPTION->klass()->name() == vmSymbols::java_lang_ClassNotFoundException())) {
1816         // print a warning only when the pending exception is class not found
1817         tty->print_cr("Preload Warning: Cannot find %s", parser.current_class_name());
1818       }
1819       CLEAR_PENDING_EXCEPTION;
1820     }
1821     if (klass != NULL) {
1822       if (log_is_enabled(Trace, cds)) {
1823         ResourceMark rm;
1824         log_trace(cds)("Shared spaces preloaded: %s", klass->external_name());
1825       }
1826 
1827       if (klass->is_instance_klass()) {
1828         InstanceKlass* ik = InstanceKlass::cast(klass);
1829 
1830         // Link the class to cause the bytecodes to be rewritten and the
1831         // cpcache to be created. The linking is done as soon as classes
1832         // are loaded in order that the related data structures (klass and
1833         // cpCache) are located together.
1834         try_link_class(ik, THREAD);
1835         guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
1836       }
1837 
1838       class_count++;
1839     }
1840   }
1841 
1842   return class_count;
1843 }
1844 
1845 // Returns true if the class's status has changed
1846 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) {
1847   assert(DumpSharedSpaces, "should only be called during dumping");
1848   if (ik->init_state() < InstanceKlass::linked) {
1849     bool saved = BytecodeVerificationLocal;
1850     if (ik->loader_type() == 0 && ik->class_loader() == NULL) {
1851       // The verification decision is based on BytecodeVerificationRemote
1852       // for non-system classes. Since we are using the NULL classloader
1853       // to load non-system classes for customized class loaders during dumping,
1854       // we need to temporarily change BytecodeVerificationLocal to be the same as
1855       // BytecodeVerificationRemote. Note this can cause the parent system
1856       // classes also being verified. The extra overhead is acceptable during
1857       // dumping.
1858       BytecodeVerificationLocal = BytecodeVerificationRemote;
1859     }
1860     ik->link_class(THREAD);
1861     if (HAS_PENDING_EXCEPTION) {
1862       ResourceMark rm;
1863       tty->print_cr("Preload Warning: Verification failed for %s",
1864                     ik->external_name());
1865       CLEAR_PENDING_EXCEPTION;
1866       ik->set_in_error_state();
1867       _has_error_classes = true;
1868     }
1869     BytecodeVerificationLocal = saved;
1870     return true;
1871   } else {
1872     return false;
1873   }
1874 }
1875 
1876 #if INCLUDE_CDS_JAVA_HEAP
1877 void VM_PopulateDumpSharedSpace::dump_java_heap_objects() {
1878   // The closed and open archive heap space has maximum two regions.
1879   // See FileMapInfo::write_archive_heap_regions() for details.
1880   _closed_archive_heap_regions = new GrowableArray<MemRegion>(2);
1881   _open_archive_heap_regions = new GrowableArray<MemRegion>(2);
1882   HeapShared::archive_java_heap_objects(_closed_archive_heap_regions,
1883                                         _open_archive_heap_regions);
1884   ArchiveCompactor::OtherROAllocMark mark;
1885   HeapShared::write_subgraph_info_table();
1886 }
1887 
1888 void VM_PopulateDumpSharedSpace::dump_archive_heap_oopmaps() {
1889   if (HeapShared::is_heap_object_archiving_allowed()) {
1890     _closed_archive_heap_oopmaps = new GrowableArray<ArchiveHeapOopmapInfo>(2);
1891     dump_archive_heap_oopmaps(_closed_archive_heap_regions, _closed_archive_heap_oopmaps);
1892 
1893     _open_archive_heap_oopmaps = new GrowableArray<ArchiveHeapOopmapInfo>(2);
1894     dump_archive_heap_oopmaps(_open_archive_heap_regions, _open_archive_heap_oopmaps);
1895   }
1896 }
1897 
1898 void VM_PopulateDumpSharedSpace::dump_archive_heap_oopmaps(GrowableArray<MemRegion>* regions,
1899                                                            GrowableArray<ArchiveHeapOopmapInfo>* oopmaps) {
1900   for (int i=0; i<regions->length(); i++) {
1901     ResourceBitMap oopmap = HeapShared::calculate_oopmap(regions->at(i));
1902     size_t size_in_bits = oopmap.size();
1903     size_t size_in_bytes = oopmap.size_in_bytes();
1904     uintptr_t* buffer = (uintptr_t*)_ro_region.allocate(size_in_bytes, sizeof(intptr_t));
1905     oopmap.write_to(buffer, size_in_bytes);
1906     log_info(cds)("Oopmap = " INTPTR_FORMAT " (" SIZE_FORMAT_W(6) " bytes) for heap region "
1907                   INTPTR_FORMAT " (" SIZE_FORMAT_W(8) " bytes)",
1908                   p2i(buffer), size_in_bytes,
1909                   p2i(regions->at(i).start()), regions->at(i).byte_size());
1910 
1911     ArchiveHeapOopmapInfo info;
1912     info._oopmap = (address)buffer;
1913     info._oopmap_size_in_bits = size_in_bits;
1914     oopmaps->append(info);
1915   }
1916 }
1917 #endif // INCLUDE_CDS_JAVA_HEAP
1918 
1919 void ReadClosure::do_ptr(void** p) {
1920   assert(*p == NULL, "initializing previous initialized pointer.");
1921   intptr_t obj = nextPtr();
1922   assert((intptr_t)obj >= 0 || (intptr_t)obj < -100,
1923          "hit tag while initializing ptrs.");
1924   *p = (void*)obj;
1925 }
1926 
1927 void ReadClosure::do_u4(u4* p) {
1928   intptr_t obj = nextPtr();
1929   *p = (u4)(uintx(obj));
1930 }
1931 
1932 void ReadClosure::do_bool(bool* p) {
1933   intptr_t obj = nextPtr();
1934   *p = (bool)(uintx(obj));
1935 }
1936 
1937 void ReadClosure::do_tag(int tag) {
1938   int old_tag;
1939   old_tag = (int)(intptr_t)nextPtr();
1940   // do_int(&old_tag);
1941   assert(tag == old_tag, "old tag doesn't match");
1942   FileMapInfo::assert_mark(tag == old_tag);
1943 }
1944 
1945 void ReadClosure::do_oop(oop *p) {
1946   narrowOop o = (narrowOop)nextPtr();
1947   if (o == 0 || !HeapShared::open_archive_heap_region_mapped()) {
1948     p = NULL;
1949   } else {
1950     assert(HeapShared::is_heap_object_archiving_allowed(),
1951            "Archived heap object is not allowed");
1952     assert(HeapShared::open_archive_heap_region_mapped(),
1953            "Open archive heap region is not mapped");
1954     *p = HeapShared::decode_from_archive(o);
1955   }
1956 }
1957 
1958 void ReadClosure::do_region(u_char* start, size_t size) {
1959   assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment");
1960   assert(size % sizeof(intptr_t) == 0, "bad size");
1961   do_tag((int)size);
1962   while (size > 0) {
1963     *(intptr_t*)start = nextPtr();
1964     start += sizeof(intptr_t);
1965     size -= sizeof(intptr_t);
1966   }
1967 }
1968 
1969 void MetaspaceShared::set_shared_metaspace_range(void* base, void* top) {
1970   _shared_metaspace_static_top = top;
1971   MetaspaceObj::set_shared_metaspace_range(base, top);
1972 }
1973 
1974 // Return true if given address is in the misc data region
1975 bool MetaspaceShared::is_in_shared_region(const void* p, int idx) {
1976   return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_region(p, idx);
1977 }
1978 
1979 bool MetaspaceShared::is_in_trampoline_frame(address addr) {
1980   if (UseSharedSpaces && is_in_shared_region(addr, MetaspaceShared::mc)) {
1981     return true;
1982   }
1983   return false;
1984 }
1985 
1986 bool MetaspaceShared::is_shared_dynamic(void* p) {
1987   if ((p < MetaspaceObj::shared_metaspace_top()) &&
1988       (p >= _shared_metaspace_static_top)) {
1989     return true;
1990   } else {
1991     return false;
1992   }
1993 }
1994 
1995 // Map shared spaces at requested addresses and return if succeeded.
1996 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
1997   size_t image_alignment = mapinfo->alignment();
1998 
1999 #ifndef _WINDOWS
2000   // Map in the shared memory and then map the regions on top of it.
2001   // On Windows, don't map the memory here because it will cause the
2002   // mappings of the regions to fail.
2003   ReservedSpace shared_rs = mapinfo->reserve_shared_memory();
2004   if (!shared_rs.is_reserved()) return false;
2005 #endif
2006 
2007   assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces");
2008 
2009   // Map each shared region
2010   int regions[] = {mc, rw, ro, md};
2011   size_t len = sizeof(regions)/sizeof(int);
2012   char* saved_base[] = {NULL, NULL, NULL, NULL};
2013   char* top = mapinfo->map_regions(regions, saved_base, len );
2014 
2015   if (top != NULL &&
2016       (image_alignment == (size_t)os::vm_allocation_granularity()) &&
2017       mapinfo->validate_shared_path_table()) {
2018     // Success -- set up MetaspaceObj::_shared_metaspace_{base,top} for
2019     // fast checking in MetaspaceShared::is_in_shared_metaspace() and
2020     // MetaspaceObj::is_shared().
2021     _core_spaces_size = mapinfo->core_spaces_size();
2022     set_shared_metaspace_range((void*)saved_base[0], (void*)top);
2023     return true;
2024   } else {
2025     mapinfo->unmap_regions(regions, saved_base, len);
2026 #ifndef _WINDOWS
2027     // Release the entire mapped region
2028     shared_rs.release();
2029 #endif
2030     // If -Xshare:on is specified, print out the error message and exit VM,
2031     // otherwise, set UseSharedSpaces to false and continue.
2032     if (RequireSharedSpaces || PrintSharedArchiveAndExit) {
2033       vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on.");
2034     } else {
2035       FLAG_SET_DEFAULT(UseSharedSpaces, false);
2036     }
2037     return false;
2038   }
2039 }
2040 
2041 // Read the miscellaneous data from the shared file, and
2042 // serialize it out to its various destinations.
2043 
2044 void MetaspaceShared::initialize_shared_spaces() {
2045   FileMapInfo *mapinfo = FileMapInfo::current_info();
2046   _cds_i2i_entry_code_buffers = mapinfo->cds_i2i_entry_code_buffers();
2047   _cds_i2i_entry_code_buffers_size = mapinfo->cds_i2i_entry_code_buffers_size();
2048   // _core_spaces_size is loaded from the shared archive immediatelly after mapping
2049   assert(_core_spaces_size == mapinfo->core_spaces_size(), "sanity");
2050   char* buffer = mapinfo->misc_data_patching_start();
2051   clone_cpp_vtables((intptr_t*)buffer);
2052 
2053   // The rest of the data is now stored in the RW region
2054   buffer = mapinfo->read_only_tables_start();
2055 
2056   // Skip over _cloned_cpp_vtptrs;
2057   buffer += _num_cloned_vtable_kinds * sizeof(intptr_t*);
2058 
2059   // Verify various attributes of the archive, plus initialize the
2060   // shared string/symbol tables
2061   intptr_t* array = (intptr_t*)buffer;
2062   ReadClosure rc(&array);
2063   serialize(&rc);
2064 
2065   // Initialize the run-time symbol table.
2066   SymbolTable::create_table();
2067 
2068   mapinfo->patch_archived_heap_embedded_pointers();
2069 
2070   // Close the mapinfo file
2071   mapinfo->close();
2072 
2073   if (PrintSharedArchiveAndExit) {
2074     if (PrintSharedDictionary) {
2075       tty->print_cr("\nShared classes:\n");
2076       SystemDictionaryShared::print_on(tty);
2077     }
2078     if (_archive_loading_failed) {
2079       tty->print_cr("archive is invalid");
2080       vm_exit(1);
2081     } else {
2082       tty->print_cr("archive is valid");
2083       vm_exit(0);
2084     }
2085   }
2086 }
2087 
2088 // JVM/TI RedefineClasses() support:
2089 bool MetaspaceShared::remap_shared_readonly_as_readwrite() {
2090   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
2091 
2092   if (UseSharedSpaces) {
2093     // remap the shared readonly space to shared readwrite, private
2094     FileMapInfo* mapinfo = FileMapInfo::current_info();
2095     if (!mapinfo->remap_shared_readonly_as_readwrite()) {
2096       return false;
2097     }
2098     if (FileMapInfo::dynamic_info() != NULL) {
2099       mapinfo = FileMapInfo::dynamic_info();
2100       if (!mapinfo->remap_shared_readonly_as_readwrite()) {
2101         return false;
2102       }
2103     }
2104     _remapped_readwrite = true;
2105   }
2106   return true;
2107 }
2108 
2109 void MetaspaceShared::report_out_of_space(const char* name, size_t needed_bytes) {
2110   // This is highly unlikely to happen on 64-bits because we have reserved a 4GB space.
2111   // On 32-bit we reserve only 256MB so you could run out of space with 100,000 classes
2112   // or so.
2113   _mc_region.print_out_of_space_msg(name, needed_bytes);
2114   _rw_region.print_out_of_space_msg(name, needed_bytes);
2115   _ro_region.print_out_of_space_msg(name, needed_bytes);
2116   _md_region.print_out_of_space_msg(name, needed_bytes);
2117 
2118   vm_exit_during_initialization(err_msg("Unable to allocate from '%s' region", name),
2119                                 "Please reduce the number of shared classes.");
2120 }