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src/share/vm/memory/metaspaceShared.cpp

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  54 #include "runtime/timerTrace.hpp"
  55 #include "runtime/os.hpp"
  56 #include "runtime/signature.hpp"
  57 #include "runtime/vmThread.hpp"
  58 #include "runtime/vm_operations.hpp"
  59 #include "utilities/align.hpp"
  60 #include "utilities/defaultStream.hpp"
  61 #include "utilities/hashtable.inline.hpp"
  62 #include "memory/metaspaceClosure.hpp"
  63 
  64 ReservedSpace MetaspaceShared::_shared_rs;
  65 VirtualSpace MetaspaceShared::_shared_vs;
  66 MetaspaceSharedStats MetaspaceShared::_stats;
  67 bool MetaspaceShared::_has_error_classes;
  68 bool MetaspaceShared::_archive_loading_failed = false;
  69 bool MetaspaceShared::_remapped_readwrite = false;
  70 address MetaspaceShared::_cds_i2i_entry_code_buffers = NULL;
  71 size_t MetaspaceShared::_cds_i2i_entry_code_buffers_size = 0;
  72 size_t MetaspaceShared::_core_spaces_size = 0;
  73 
  74 // The CDS archive is divided into 6 regions:
  75 //     mc - misc code (the method entry trampolines)
  76 //     rw - read-write metadata
  77 //     ro - read-only metadata and read-only tables
  78 //     md - misc data (the c++ vtables)
  79 //     od - other data (original class files)
  80 //     st - shared strings
  81 //
  82 // Except for the st region, the other 5 regions are linearly allocated, starting from



  83 // SharedBaseAddress, in the order of mc->rw->ro->md->od. The size of these 5 regions
  84 // are page-aligned, and there's no gap between any consecutive regions.
  85 //
  86 // These 5 regions are populated in the following steps:
  87 // [1] All classes are loaded in MetaspaceShared::preload_classes(). All metadata are
  88 //     temporarily allocated outside of the shared regions. Only the method entry
  89 //     trampolines are written into the mc region.
  90 // [2] ArchiveCompactor copies RW metadata into the rw region.
  91 // [3] ArchiveCompactor copies RO metadata into the ro region.
  92 // [4] SymbolTable, StringTable, SystemDictionary, and a few other read-only data
  93 //     are copied into the ro region as read-only tables.
  94 // [5] C++ vtables are copied into the md region.
  95 // [6] Original class files are copied into the od region.
  96 //
  97 // The st region is populated inside MetaspaceShared::dump_string_and_symbols. Its
  98 // layout is independent of the other 5 regions.
  99 
 100 class DumpRegion {
 101 private:
 102   const char* _name;
 103   char* _base;
 104   char* _top;
 105   char* _end;
 106   bool _is_packed;
 107 
 108   char* expand_top_to(char* newtop) {
 109     assert(is_allocatable(), "must be initialized and not packed");
 110     assert(newtop >= _top, "must not grow backwards");
 111     if (newtop > _end) {
 112       MetaspaceShared::report_out_of_space(_name, newtop - _top);
 113       ShouldNotReachHere();
 114     }
 115     MetaspaceShared::commit_shared_space_to(newtop);
 116     _top = newtop;
 117     return _top;
 118   }
 119 
 120 public:
 121   DumpRegion(const char* name) : _name(name), _base(NULL), _top(NULL), _end(NULL), _is_packed(false) {}
 122 
 123   char* allocate(size_t num_bytes, size_t alignment=BytesPerWord) {
 124     char* p = (char*)align_ptr_up(_top, alignment);
 125     char* newtop = p + align_size_up(num_bytes, alignment);
 126     expand_top_to(newtop);
 127     memset(p, 0, newtop - p);
 128     return p;
 129   }
 130 
 131   void append_intptr_t(intptr_t n) {
 132     assert(is_ptr_aligned(_top, sizeof(intptr_t)), "bad alignment");
 133     intptr_t *p = (intptr_t*)_top;
 134     char* newtop = _top + sizeof(intptr_t);
 135     expand_top_to(newtop);
 136     *p = n;
 137   }
 138 
 139   char* base()      const { return _base;        }
 140   char* top()       const { return _top;         }
 141   char* end()       const { return _end;         }
 142   size_t reserved() const { return _end - _base; }
 143   size_t used()     const { return _top - _base; }
 144   bool is_packed()  const { return _is_packed;   }
 145   bool is_allocatable() const {
 146     return !is_packed() && _base != NULL;
 147   }
 148 
 149   double perc(size_t used, size_t total) const {
 150     if (total == 0) {total = 1;}


 151     return used / double(total) * 100.0;
 152   }
 153 
 154   void print(size_t total_bytes) const {
 155     tty->print_cr("%s space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used] at " INTPTR_FORMAT,
 156                   _name, used(), perc(used(), total_bytes), reserved(), perc(used(), reserved()), p2i(_base));
 157   }
 158   void print_out_of_space_msg(const char* failing_region, size_t needed_bytes) {
 159     tty->print("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d",
 160                _name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base));
 161     if (strcmp(_name, failing_region) == 0) {
 162       tty->print_cr(" required = %d", int(needed_bytes));
 163     } else {
 164       tty->cr();
 165     }
 166   }
 167 
 168   void init(const ReservedSpace* rs) {
 169     _base = _top = rs->base();
 170     _end = rs->end();
 171   }
 172   void init(char* b, char* t, char* e) {
 173     _base = b;
 174     _top = t;
 175     _end = e;
 176   }
 177 
 178   void pack(DumpRegion* next = NULL) {
 179     assert(!is_packed(), "sanity");
 180     _end = (char*)align_ptr_up(_top, Metaspace::reserve_alignment());
 181     _is_packed = true;
 182     if (next != NULL) {
 183       next->_base = next->_top = this->_end;
 184       next->_end = MetaspaceShared::shared_rs()->end();
 185     }
 186   }
 187   bool contains(char* p) {
 188     return base() <= p && p < top();
 189   }
 190 };
 191 
 192 DumpRegion _mc_region("mc"), _ro_region("ro"), _rw_region("rw"), _md_region("md");
 193 DumpRegion _st_region("st"), _od_region("od");
 194 
 195 char* MetaspaceShared::misc_code_space_alloc(size_t num_bytes) {
 196   return _mc_region.allocate(num_bytes);
 197 }
 198 
 199 char* MetaspaceShared::read_only_space_alloc(size_t num_bytes) {
 200   return _ro_region.allocate(num_bytes);
 201 }
 202 
 203 void MetaspaceShared::initialize_shared_rs() {
 204   const size_t reserve_alignment = Metaspace::reserve_alignment();
 205   bool large_pages = false; // No large pages when dumping the CDS archive.
 206   char* shared_base = (char*)align_ptr_up((char*)SharedBaseAddress, reserve_alignment);
 207 
 208 #ifdef _LP64
 209   const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
 210   const size_t cds_total = align_size_down(UnscaledClassSpaceMax, reserve_alignment);
 211 #else
 212   // We don't support archives larger than 256MB on 32-bit due to limited virtual address space.
 213   size_t cds_total = align_size_down(256*M, reserve_alignment);
 214 #endif
 215 
 216   // First try to reserve the space at the specified SharedBaseAddress.
 217   _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages, shared_base);
 218   if (_shared_rs.is_reserved()) {
 219     assert(shared_base == 0 || _shared_rs.base() == shared_base, "should match");
 220   } else {
 221     // Get a mmap region anywhere if the SharedBaseAddress fails.
 222     _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages);
 223   }
 224   if (!_shared_rs.is_reserved()) {
 225     vm_exit_during_initialization("Unable to reserve memory for shared space",
 226                                   err_msg(SIZE_FORMAT " bytes.", cds_total));
 227   }
 228 
 229 #ifdef _LP64
 230   // During dump time, we allocate 4GB (UnscaledClassSpaceMax) of space and split it up:
 231   // + The upper 1 GB is used as the "temporary compressed class space" -- preload_classes()
 232   //   will store Klasses into this space.
 233   // + The lower 3 GB is used for the archive -- when preload_classes() is done,
 234   //   ArchiveCompactor will copy the class metadata into this space, first the RW parts,
 235   //   then the RO parts.
 236 
 237   assert(UseCompressedOops && UseCompressedClassPointers,
 238       "UseCompressedOops and UseCompressedClassPointers must be set");
 239 
 240   size_t max_archive_size = align_size_down(cds_total * 3 / 4, reserve_alignment);
 241   ReservedSpace tmp_class_space = _shared_rs.last_part(max_archive_size);
 242   CompressedClassSpaceSize = align_size_down(tmp_class_space.size(), reserve_alignment);
 243   _shared_rs = _shared_rs.first_part(max_archive_size);
 244 
 245   // Set up compress class pointers.
 246   Universe::set_narrow_klass_base((address)_shared_rs.base());
 247   if (UseAOT || cds_total > UnscaledClassSpaceMax) {
 248     // AOT forces narrow_klass_shift=LogKlassAlignmentInBytes
 249     Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
 250   } else {
 251     Universe::set_narrow_klass_shift(0);
 252   }
 253 
 254   Metaspace::initialize_class_space(tmp_class_space);
 255   tty->print_cr("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
 256                 p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift());
 257 
 258   tty->print_cr("Allocated temporary class space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
 259                 CompressedClassSpaceSize, p2i(tmp_class_space.base()));
 260 #endif
 261 
 262   // Start with 0 committed bytes. The memory will be committed as needed by


 270                 _shared_rs.size(), p2i(_shared_rs.base()));
 271 }
 272 
 273 void MetaspaceShared::commit_shared_space_to(char* newtop) {
 274   assert(DumpSharedSpaces, "dump-time only");
 275   char* base = _shared_rs.base();
 276   size_t need_committed_size = newtop - base;
 277   size_t has_committed_size = _shared_vs.committed_size();
 278   if (need_committed_size < has_committed_size) {
 279     return;
 280   }
 281 
 282   size_t min_bytes = need_committed_size - has_committed_size;
 283   size_t preferred_bytes = 1 * M;
 284   size_t uncommitted = _shared_vs.reserved_size() - has_committed_size;
 285 
 286   size_t commit = MAX2(min_bytes, preferred_bytes);
 287   assert(commit <= uncommitted, "sanity");
 288 
 289   bool result = _shared_vs.expand_by(commit, false);
 290   assert(result, "Failed to commit memory");



 291 
 292   log_info(cds)("Expanding shared spaces by %7d bytes [total %8d bytes ending at %p]",
 293                 int(commit), int(_shared_vs.actual_committed_size()), _shared_vs.high());
 294 }
 295 
 296 // Read/write a data stream for restoring/preserving metadata pointers and
 297 // miscellaneous data from/to the shared archive file.
 298 
 299 void MetaspaceShared::serialize(SerializeClosure* soc) {
 300   int tag = 0;
 301   soc->do_tag(--tag);
 302 
 303   // Verify the sizes of various metadata in the system.
 304   soc->do_tag(sizeof(Method));
 305   soc->do_tag(sizeof(ConstMethod));
 306   soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
 307   soc->do_tag(sizeof(ConstantPool));
 308   soc->do_tag(sizeof(ConstantPoolCache));
 309   soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
 310   soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
 311   soc->do_tag(sizeof(Symbol));
 312 
 313   // Dump/restore miscellaneous metadata.


 480     assert(DumpSharedSpaces, "dump-time only");
 481     _info->zero();
 482   }
 483 
 484   // Switch the vtable pointer to point to the cloned vtable.
 485   static void patch(Metadata* obj) {
 486     assert(DumpSharedSpaces, "dump-time only");
 487     *(void**)obj = (void*)(_info->cloned_vtable());
 488   }
 489 
 490   static bool is_valid_shared_object(const T* obj) {
 491     intptr_t* vptr = *(intptr_t**)obj;
 492     return vptr == _info->cloned_vtable();
 493   }
 494 };
 495 
 496 template <class T> CppVtableInfo* CppVtableCloner<T>::_info = NULL;
 497 
 498 template <class T>
 499 intptr_t* CppVtableCloner<T>::allocate(const char* name) {
 500   assert(is_ptr_aligned(_md_region.top(), sizeof(intptr_t)), "bad alignment");
 501   int n = get_vtable_length(name);
 502   _info = (CppVtableInfo*)_md_region.allocate(CppVtableInfo::byte_size(n), sizeof(intptr_t));
 503   _info->set_vtable_size(n);
 504 
 505   intptr_t* p = clone_vtable(name, _info);
 506   assert((char*)p == _md_region.top(), "must be");
 507 
 508   return p;
 509 }
 510 
 511 template <class T>
 512 intptr_t* CppVtableCloner<T>::clone_vtable(const char* name, CppVtableInfo* info) {
 513   if (!DumpSharedSpaces) {
 514     assert(_info == 0, "_info is initialized only at dump time");
 515     _info = info; // Remember it -- it will be used by MetaspaceShared::is_valid_shared_method()
 516   }
 517   T tmp; // Allocate temporary dummy metadata object to get to the original vtable.
 518   int n = info->vtable_size();
 519   intptr_t* srcvtable = vtable_of(tmp);
 520   intptr_t* dstvtable = info->cloned_vtable();


 718   }
 719 
 720 public:
 721   enum { RO = 0, RW = 1 };
 722 
 723   int _counts[2][_number_of_types];
 724   int _bytes [2][_number_of_types];
 725 
 726   DumpAllocStats() {
 727     memset(_counts, 0, sizeof(_counts));
 728     memset(_bytes,  0, sizeof(_bytes));
 729   };
 730 
 731   void record(MetaspaceObj::Type type, int byte_size, bool read_only) {
 732     assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
 733     int which = (read_only) ? RO : RW;
 734     _counts[which][type] ++;
 735     _bytes [which][type] += byte_size;
 736   }
 737 




 738   void print_stats(int ro_all, int rw_all, int mc_all, int md_all);
 739 };
 740 
 741 void DumpAllocStats::print_stats(int ro_all, int rw_all, int mc_all, int md_all) {
 742   // Calculate size of data that was not allocated by Metaspace::allocate()
 743   MetaspaceSharedStats *stats = MetaspaceShared::stats();
 744 
 745   // symbols
 746   _counts[RO][SymbolHashentryType] = stats->symbol.hashentry_count;
 747   _bytes [RO][SymbolHashentryType] = stats->symbol.hashentry_bytes;
 748 
 749   _counts[RO][SymbolBucketType] = stats->symbol.bucket_count;
 750   _bytes [RO][SymbolBucketType] = stats->symbol.bucket_bytes;
 751 
 752   // strings
 753   _counts[RO][StringHashentryType] = stats->string.hashentry_count;
 754   _bytes [RO][StringHashentryType] = stats->string.hashentry_bytes;
 755 
 756   _counts[RO][StringBucketType] = stats->string.bucket_count;
 757   _bytes [RO][StringBucketType] = stats->string.bucket_bytes;


 765     ro_all = 1;
 766   }
 767   if (rw_all < 1) {
 768     rw_all = 1;
 769   }
 770 
 771   int all_ro_count = 0;
 772   int all_ro_bytes = 0;
 773   int all_rw_count = 0;
 774   int all_rw_bytes = 0;
 775 
 776 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
 777 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
 778   const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
 779   const char *hdr = "                        ro_cnt   ro_bytes     % |   rw_cnt   rw_bytes     % |  all_cnt  all_bytes     %";
 780 
 781   ResourceMark rm;
 782   LogMessage(cds) msg;
 783   stringStream info_stream;
 784 
 785   info_stream.print_cr("Detailed metadata info (rw includes md and mc):");
 786   info_stream.print_cr("%s", hdr);
 787   info_stream.print_cr("%s", sep);
 788   for (int type = 0; type < int(_number_of_types); type ++) {
 789     const char *name = type_name((Type)type);
 790     int ro_count = _counts[RO][type];
 791     int ro_bytes = _bytes [RO][type];
 792     int rw_count = _counts[RW][type];
 793     int rw_bytes = _bytes [RW][type];
 794     int count = ro_count + rw_count;
 795     int bytes = ro_bytes + rw_bytes;
 796 
 797     double ro_perc = 100.0 * double(ro_bytes) / double(ro_all);
 798     double rw_perc = 100.0 * double(rw_bytes) / double(rw_all);
 799     double perc    = 100.0 * double(bytes)    / double(ro_all + rw_all);
 800 
 801     info_stream.print_cr(fmt_stats, name,
 802                          ro_count, ro_bytes, ro_perc,
 803                          rw_count, rw_bytes, rw_perc,
 804                          count, bytes, perc);
 805 
 806     all_ro_count += ro_count;
 807     all_ro_bytes += ro_bytes;
 808     all_rw_count += rw_count;
 809     all_rw_bytes += rw_bytes;
 810   }
 811 
 812   int all_count = all_ro_count + all_rw_count;
 813   int all_bytes = all_ro_bytes + all_rw_bytes;
 814 
 815   double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all);
 816   double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all);
 817   double all_perc    = 100.0 * double(all_bytes)    / double(ro_all + rw_all);
 818 
 819   info_stream.print_cr("%s", sep);
 820   info_stream.print_cr(fmt_stats, "Total",
 821                        all_ro_count, all_ro_bytes, all_ro_perc,
 822                        all_rw_count, all_rw_bytes, all_rw_perc,
 823                        all_count, all_bytes, all_perc);
 824 
 825 //assert(all_ro_bytes == ro_all, "everything should have been counted");
 826   assert(all_rw_bytes == rw_all, "everything should have been counted");
 827 
 828   msg.info("%s", info_stream.as_string());
 829 #undef fmt_stats
 830 }
 831 
 832 // Populate the shared space.
 833 
 834 class VM_PopulateDumpSharedSpace: public VM_Operation {
 835 private:
 836   GrowableArray<MemRegion> *_string_regions;
 837 
 838   void dump_string_and_symbols();
 839   char* dump_read_only_tables();

 840 public:
 841 
 842   VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
 843   void doit();   // outline because gdb sucks
 844   static void write_region(FileMapInfo* mapinfo, int region, DumpRegion* space, bool read_only,  bool allow_exec);
 845 }; // class VM_PopulateDumpSharedSpace
 846 
 847 class SortedSymbolClosure: public SymbolClosure {
 848   GrowableArray<Symbol*> _symbols;
 849   virtual void do_symbol(Symbol** sym) {
 850     assert((*sym)->is_permanent(), "archived symbols must be permanent");
 851     _symbols.append(*sym);
 852   }
 853   static int compare_symbols_by_address(Symbol** a, Symbol** b) {
 854     if (a[0] < b[0]) {
 855       return -1;
 856     } else if (a[0] == b[0]) {
 857       return 0;
 858     } else {
 859       return 1;


 873 // ArchiveCompactor --
 874 //
 875 // This class is the central piece of shared archive compaction -- all metaspace data are
 876 // initially allocated outside of the shared regions. ArchiveCompactor copies the
 877 // metaspace data into their final location in the shared regions.
 878 
 879 class ArchiveCompactor : AllStatic {
 880   static DumpAllocStats* _alloc_stats;
 881   static SortedSymbolClosure* _ssc;
 882 
 883   static unsigned my_hash(const address& a) {
 884     return primitive_hash<address>(a);
 885   }
 886   static bool my_equals(const address& a0, const address& a1) {
 887     return primitive_equals<address>(a0, a1);
 888   }
 889   typedef ResourceHashtable<
 890       address, address,
 891       ArchiveCompactor::my_hash,   // solaris compiler doesn't like: primitive_hash<address>
 892       ArchiveCompactor::my_equals, // solaris compiler doesn't like: primitive_equals<address>
 893       16384, ResourceObj::C_HEAP> MyTable;
 894   static MyTable* _new_loc_table;
 895 
 896 public:
 897   static void initialize() {
 898     _alloc_stats = new(ResourceObj::C_HEAP, mtInternal)DumpAllocStats;
 899     _new_loc_table = new(ResourceObj::C_HEAP, mtInternal)MyTable;
 900   }
 901   static DumpAllocStats* alloc_stats() {
 902     return _alloc_stats;
 903   }
 904 
 905   static void allocate(MetaspaceClosure::Ref* ref, bool read_only) {
 906     address obj = ref->obj();
 907     int bytes = ref->size() * BytesPerWord;
 908     char* p;
 909     size_t alignment = BytesPerWord;    



 910     if (read_only) {

 911       p = _ro_region.allocate(bytes, alignment);

 912     } else {

 913       p = _rw_region.allocate(bytes, alignment);

 914     }
 915     memcpy(p, obj, bytes);
 916     bool isnew = _new_loc_table->put(obj, (address)p);
 917     assert(isnew, "must be");
 918     log_trace(cds)("Copy: " PTR_FORMAT " ==> " PTR_FORMAT " %d", p2i(obj), p2i(p), bytes);
 919 
 920     _alloc_stats->record(ref->msotype(), bytes, read_only);
 921     if (ref->msotype() == MetaspaceObj::SymbolType) {
 922       uintx delta = MetaspaceShared::object_delta(p);
 923       if (delta > MAX_SHARED_DELTA) {
 924         // This is just a sanity check and should not appear in any real world usage. This
 925         // happens only if you allocate more than 2GB of Symbols and would require
 926         // millions of shared classes.
 927         vm_exit_during_initialization("Too many Symbols in the CDS archive",
 928                                       "Please reduce the number of shared classes.");
 929       }
 930     }
 931   }
 932 
 933   static address get_new_loc(MetaspaceClosure::Ref* ref) {
 934     address* pp = _new_loc_table->get(ref->obj());
 935     assert(pp != NULL, "must be");
 936     return *pp;
 937   }
 938 
 939 private:
 940   // Makes a shallow copy of visited MetaspaceObj's


1025       ResourceMark rm;
1026       RefRelocator ext_reloc;
1027       iterate_roots(&ext_reloc);
1028     }
1029 
1030 #ifdef ASSERT
1031     {
1032       tty->print_cr("Verifying external roots ... ");
1033       ResourceMark rm;
1034       IsRefInArchiveChecker checker;
1035       iterate_roots(&checker);
1036     }
1037 #endif
1038 
1039 
1040     // cleanup
1041     _ssc = NULL;
1042   }
1043 
1044   // We must relocate the System::_well_known_klasses only after we have copied the
1045   // strings in during dump_string_and_symbols(): during the copy, we operate on old
1046   // String objects which assert that their klass is the old
1047   // SystemDictionary::String_klass().
1048   static void relocate_well_known_klasses() {
1049     {
1050       tty->print_cr("Relocating _well_known_klasses[] ... ");
1051       ResourceMark rm;
1052       RefRelocator ext_reloc;
1053       SystemDictionary::well_known_klasses_do(&ext_reloc);
1054     }
1055     // NOTE: after this point, we shouldn't have any globals that can reach the old
1056     // objects.
1057 
1058     // We cannot use any of the objects in the heap anymore (except for the objects
1059     // in the CDS shared string regions) because their headers no longer point to
1060     // valid Klasses.
1061   }
1062 
1063   static void iterate_roots(MetaspaceClosure* it) {
1064     GrowableArray<Symbol*>* symbols = _ssc->get_sorted_symbols();
1065     for (int i=0; i<symbols->length(); i++) {
1066       it->push(symbols->adr_at(i));
1067     }
1068     if (_global_klass_objects != NULL) {
1069       // Need to fix up the pointers
1070       for (int i = 0; i < _global_klass_objects->length(); i++) {


1073       }
1074     }
1075     FileMapInfo::metaspace_pointers_do(it);
1076     SystemDictionary::classes_do(it);
1077     Universe::metaspace_pointers_do(it);
1078     SymbolTable::metaspace_pointers_do(it);
1079     vmSymbols::metaspace_pointers_do(it);
1080   }
1081 
1082   static Klass* get_relocated_klass(Klass* orig_klass) {
1083     address* pp = _new_loc_table->get((address)orig_klass);
1084     assert(pp != NULL, "must be");
1085     Klass* klass = (Klass*)(*pp);
1086     assert(klass->is_klass(), "must be");
1087     return klass;
1088   }
1089 };
1090 
1091 DumpAllocStats* ArchiveCompactor::_alloc_stats;
1092 SortedSymbolClosure* ArchiveCompactor::_ssc;
1093 ArchiveCompactor::MyTable* ArchiveCompactor::_new_loc_table;
1094 
1095 void VM_PopulateDumpSharedSpace::write_region(FileMapInfo* mapinfo, int region_idx,
1096                                               DumpRegion* dump_region, bool read_only,  bool allow_exec) {
1097   mapinfo->write_region(region_idx, dump_region->base(), dump_region->used(), read_only, allow_exec);
1098 }
1099 
1100 void VM_PopulateDumpSharedSpace::dump_string_and_symbols() {
1101   tty->print_cr("Dumping string and symbol tables ...");
1102 
1103   NOT_PRODUCT(SymbolTable::verify());
1104   NOT_PRODUCT(StringTable::verify());
1105   SymbolTable::write_to_archive();
1106 
1107   // The string space has maximum two regions. See FileMapInfo::write_string_regions() for details.
1108   _string_regions = new GrowableArray<MemRegion>(2);
1109   size_t shared_string_bytes = 0;
1110   StringTable::write_to_archive(_string_regions, &shared_string_bytes);
1111   char* st_base = _string_regions->is_empty() ? NULL : (char*)_string_regions->first().start();
1112   char* st_top = st_base + shared_string_bytes;
1113   _st_region.init(st_base, st_top, st_top);
1114   _st_region.pack();
1115 }
1116 
1117 char* VM_PopulateDumpSharedSpace::dump_read_only_tables() {

1118   // Reorder the system dictionary. Moving the symbols affects
1119   // how the hash table indices are calculated.
1120   SystemDictionary::reorder_dictionary_for_sharing();
1121   NOT_PRODUCT(SystemDictionary::verify();)
1122 
1123   size_t buckets_bytes = SystemDictionary::count_bytes_for_buckets();
1124   char* buckets_top = _ro_region.allocate(buckets_bytes, sizeof(intptr_t));
1125   SystemDictionary::copy_buckets(buckets_top, _ro_region.top());
1126 
1127   size_t table_bytes = SystemDictionary::count_bytes_for_table();
1128   char* table_top = _ro_region.allocate(table_bytes, sizeof(intptr_t));
1129   SystemDictionary::copy_table(table_top, _ro_region.top());
1130 
1131   // Write the other data to the output array.
1132   WriteClosure wc(&_ro_region);
1133   MetaspaceShared::serialize(&wc);
1134 


1135   return buckets_top;
1136 }
1137 
1138 void VM_PopulateDumpSharedSpace::doit() {
1139   Thread* THREAD = VMThread::vm_thread();
1140 
1141   NOT_PRODUCT(SystemDictionary::verify();)
1142   // The following guarantee is meant to ensure that no loader constraints
1143   // exist yet, since the constraints table is not shared.  This becomes
1144   // more important now that we don't re-initialize vtables/itables for
1145   // shared classes at runtime, where constraints were previously created.
1146   guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
1147             "loader constraints are not saved");
1148   guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
1149           "placeholders are not saved");
1150   // Revisit and implement this if we prelink method handle call sites:
1151   guarantee(SystemDictionary::invoke_method_table() == NULL ||
1152             SystemDictionary::invoke_method_table()->number_of_entries() == 0,
1153             "invoke method table is not saved");
1154 


1192   ArchiveCompactor::initialize();
1193   ArchiveCompactor::copy_and_compact();
1194 
1195   dump_string_and_symbols();
1196   ArchiveCompactor::relocate_well_known_klasses();
1197 
1198   char* read_only_tables_start = dump_read_only_tables();
1199   _ro_region.pack(&_md_region);
1200 
1201   char* vtbl_list = _md_region.top();
1202   MetaspaceShared::allocate_cpp_vtable_clones();
1203   _md_region.pack(&_od_region);
1204 
1205   // Relocate the archived class file data into the od region
1206   relocate_cached_class_file();
1207   _od_region.pack();
1208 
1209   // The 5 core spaces are allocated consecutively mc->rw->ro->md->od, so there total size
1210   // is just the spaces between the two ends.
1211   size_t core_spaces_size = _od_region.end() - _mc_region.base();
1212   assert(core_spaces_size == (size_t)align_size_up(core_spaces_size, Metaspace::reserve_alignment()),
1213          "should already be aligned");
1214 
1215   // Print statistics of all the regions
1216   const size_t total_reserved = _ro_region.reserved() + _rw_region.reserved() +
1217                                 _mc_region.reserved() + _md_region.reserved() +
1218                                 _st_region.reserved() + _od_region.reserved();
1219   const size_t total_bytes = _ro_region.used() + _rw_region.used() +
1220                              _mc_region.used() + _md_region.used() +
1221                              _st_region.used() + _od_region.used();
1222   const double total_u_perc = total_bytes / double(total_reserved) * 100.0;
1223 
1224   _mc_region.print(total_reserved);
1225   _rw_region.print(total_reserved);
1226   _ro_region.print(total_reserved);
1227   _md_region.print(total_reserved);
1228   _st_region.print(total_reserved);
1229   _od_region.print(total_reserved);
1230 
1231   tty->print_cr("total   : " SIZE_FORMAT_W(9) " [100.0%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used]",
1232                  total_bytes, total_reserved, total_u_perc);
1233 
1234   // During patching, some virtual methods may be called, so at this point
1235   // the vtables must contain valid methods (as filled in by CppVtableCloner::allocate).
1236   MetaspaceShared::patch_cpp_vtable_pointers();
1237 
1238   // The vtable clones contain addresses of the current process.
1239   // We don't want to write these addresses into the archive.
1240   MetaspaceShared::zero_cpp_vtable_clones_for_writing();
1241 
1242   // Create and write the archive file that maps the shared spaces.
1243 
1244   FileMapInfo* mapinfo = new FileMapInfo();
1245   mapinfo->populate_header(os::vm_allocation_granularity());
1246   mapinfo->set_read_only_tables_start(read_only_tables_start);
1247   mapinfo->set_misc_data_patching_start(vtbl_list);
1248   mapinfo->set_cds_i2i_entry_code_buffers(MetaspaceShared::cds_i2i_entry_code_buffers());
1249   mapinfo->set_cds_i2i_entry_code_buffers_size(MetaspaceShared::cds_i2i_entry_code_buffers_size());
1250   mapinfo->set_core_spaces_size(core_spaces_size);
1251 



1252   for (int pass=1; pass<=2; pass++) {
1253     if (pass == 1) {
1254       // The first pass doesn't actually write the data to disk. All it
1255       // does is to update the fields in the mapinfo->_header.
1256     } else {
1257       // After the first pass, the contents of mapinfo->_header are finalized,
1258       // so we can compute the header's CRC, and write the contents of the header
1259       // and the regions into disk.
1260       mapinfo->open_for_write();
1261       mapinfo->set_header_crc(mapinfo->compute_header_crc());
1262     }
1263     mapinfo->write_header();
1264 
1265     // NOTE: md contains the trampoline code for method entries, which are patched at run time,
1266     // so it needs to be read/write.
1267     write_region(mapinfo, MetaspaceShared::mc, &_mc_region, /*read_only=*/false,/*allow_exec=*/true);
1268     write_region(mapinfo, MetaspaceShared::rw, &_rw_region, /*read_only=*/false,/*allow_exec=*/false);
1269     write_region(mapinfo, MetaspaceShared::ro, &_ro_region, /*read_only=*/true, /*allow_exec=*/false);
1270     write_region(mapinfo, MetaspaceShared::md, &_md_region, /*read_only=*/false,/*allow_exec=*/false);
1271     write_region(mapinfo, MetaspaceShared::od, &_od_region, /*read_only=*/true, /*allow_exec=*/false);
1272     mapinfo->write_string_regions(_string_regions);



1273   }
1274 
1275   mapinfo->close();
1276 
1277   // Restore the vtable in case we invoke any virtual methods.
1278   MetaspaceShared::clone_cpp_vtables((intptr_t*)vtbl_list);
1279 




1280   if (log_is_enabled(Info, cds)) {
1281     ArchiveCompactor::alloc_stats()->print_stats(int(_ro_region.used()), int(_rw_region.used()),
1282                                                  int(_mc_region.used()), int(_md_region.used()));
1283   }
1284 }
1285 

























1286 // Update a Java object to point its Klass* to the new location after
1287 // shared archive has been compacted.
1288 void MetaspaceShared::relocate_klass_ptr(oop o) {
1289   assert(DumpSharedSpaces, "sanity");
1290   Klass* k = ArchiveCompactor::get_relocated_klass(o->klass());
1291   o->set_klass(k);
1292 }
1293 
1294 class LinkSharedClassesClosure : public KlassClosure {
1295   Thread* THREAD;
1296   bool    _made_progress;
1297  public:
1298   LinkSharedClassesClosure(Thread* thread) : THREAD(thread), _made_progress(false) {}
1299 
1300   void reset()               { _made_progress = false; }
1301   bool made_progress() const { return _made_progress; }
1302 
1303   void do_klass(Klass* k) {
1304     if (k->is_instance_klass()) {
1305       InstanceKlass* ik = InstanceKlass::cast(k);


1710 
1711   if (UseSharedSpaces) {
1712     // remap the shared readonly space to shared readwrite, private
1713     FileMapInfo* mapinfo = FileMapInfo::current_info();
1714     if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1715       return false;
1716     }
1717     _remapped_readwrite = true;
1718   }
1719   return true;
1720 }
1721 
1722 void MetaspaceShared::report_out_of_space(const char* name, size_t needed_bytes) {
1723   // This is highly unlikely to happen on 64-bits because we have reserved a 4GB space.
1724   // On 32-bit we reserve only 256MB so you could run out of space with 100,000 classes
1725   // or so.
1726   _mc_region.print_out_of_space_msg(name, needed_bytes);
1727   _rw_region.print_out_of_space_msg(name, needed_bytes);
1728   _ro_region.print_out_of_space_msg(name, needed_bytes);
1729   _md_region.print_out_of_space_msg(name, needed_bytes);
1730   _st_region.print_out_of_space_msg(name, needed_bytes);
1731   _od_region.print_out_of_space_msg(name, needed_bytes);
1732 
1733   vm_exit_during_initialization(err_msg("Unable to allocate from '%s' region", name),
1734                                 "Please reduce the number of shared classes.");
1735 }


  54 #include "runtime/timerTrace.hpp"
  55 #include "runtime/os.hpp"
  56 #include "runtime/signature.hpp"
  57 #include "runtime/vmThread.hpp"
  58 #include "runtime/vm_operations.hpp"
  59 #include "utilities/align.hpp"
  60 #include "utilities/defaultStream.hpp"
  61 #include "utilities/hashtable.inline.hpp"
  62 #include "memory/metaspaceClosure.hpp"
  63 
  64 ReservedSpace MetaspaceShared::_shared_rs;
  65 VirtualSpace MetaspaceShared::_shared_vs;
  66 MetaspaceSharedStats MetaspaceShared::_stats;
  67 bool MetaspaceShared::_has_error_classes;
  68 bool MetaspaceShared::_archive_loading_failed = false;
  69 bool MetaspaceShared::_remapped_readwrite = false;
  70 address MetaspaceShared::_cds_i2i_entry_code_buffers = NULL;
  71 size_t MetaspaceShared::_cds_i2i_entry_code_buffers_size = 0;
  72 size_t MetaspaceShared::_core_spaces_size = 0;
  73 
  74 // The CDS archive is divided into the following regions:
  75 //     mc - misc code (the method entry trampolines)
  76 //     rw - read-write metadata
  77 //     ro - read-only metadata and read-only tables
  78 //     md - misc data (the c++ vtables)
  79 //     od - optional data (original class files)

  80 //
  81 //     s0 - shared strings #0
  82 //     s1 - shared strings #1 (may be empty)
  83 //
  84 // Except for the s0/s1 regions, the other 5 regions are linearly allocated, starting from
  85 // SharedBaseAddress, in the order of mc->rw->ro->md->od. The size of these 5 regions
  86 // are page-aligned, and there's no gap between any consecutive regions.
  87 //
  88 // These 5 regions are populated in the following steps:
  89 // [1] All classes are loaded in MetaspaceShared::preload_classes(). All metadata are
  90 //     temporarily allocated outside of the shared regions. Only the method entry
  91 //     trampolines are written into the mc region.
  92 // [2] ArchiveCompactor copies RW metadata into the rw region.
  93 // [3] ArchiveCompactor copies RO metadata into the ro region.
  94 // [4] SymbolTable, StringTable, SystemDictionary, and a few other read-only data
  95 //     are copied into the ro region as read-only tables.
  96 // [5] C++ vtables are copied into the md region.
  97 // [6] Original class files are copied into the od region.
  98 //
  99 // The s0/s1 regions are populated inside MetaspaceShared::dump_string_and_symbols. Their
 100 // layout is independent of the other 5 regions.
 101 
 102 class DumpRegion {
 103 private:
 104   const char* _name;
 105   char* _base;
 106   char* _top;
 107   char* _end;
 108   bool _is_packed;
 109 
 110   char* expand_top_to(char* newtop) {
 111     assert(is_allocatable(), "must be initialized and not packed");
 112     assert(newtop >= _top, "must not grow backwards");
 113     if (newtop > _end) {
 114       MetaspaceShared::report_out_of_space(_name, newtop - _top);
 115       ShouldNotReachHere();
 116     }
 117     MetaspaceShared::commit_shared_space_to(newtop);
 118     _top = newtop;
 119     return _top;
 120   }
 121 
 122 public:
 123   DumpRegion(const char* name) : _name(name), _base(NULL), _top(NULL), _end(NULL), _is_packed(false) {}
 124 
 125   char* allocate(size_t num_bytes, size_t alignment=BytesPerWord) {
 126     char* p = (char*)align_up(_top, alignment);
 127     char* newtop = p + align_up(num_bytes, alignment);
 128     expand_top_to(newtop);
 129     memset(p, 0, newtop - p);
 130     return p;
 131   }
 132 
 133   void append_intptr_t(intptr_t n) {
 134     assert(is_aligned(_top, sizeof(intptr_t)), "bad alignment");
 135     intptr_t *p = (intptr_t*)_top;
 136     char* newtop = _top + sizeof(intptr_t);
 137     expand_top_to(newtop);
 138     *p = n;
 139   }
 140 
 141   char* base()      const { return _base;        }
 142   char* top()       const { return _top;         }
 143   char* end()       const { return _end;         }
 144   size_t reserved() const { return _end - _base; }
 145   size_t used()     const { return _top - _base; }
 146   bool is_packed()  const { return _is_packed;   }
 147   bool is_allocatable() const {
 148     return !is_packed() && _base != NULL;
 149   }
 150 
 151   double perc(size_t used, size_t total) const {
 152     if (total == 0) {
 153       total = 1;
 154     }
 155     return used / double(total) * 100.0;
 156   }
 157 
 158   void print(size_t total_bytes) const {
 159     tty->print_cr("%s space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used] at " INTPTR_FORMAT,
 160                   _name, used(), perc(used(), total_bytes), reserved(), perc(used(), reserved()), p2i(_base));
 161   }
 162   void print_out_of_space_msg(const char* failing_region, size_t needed_bytes) {
 163     tty->print("[%-8s] " PTR_FORMAT " - " PTR_FORMAT " capacity =%9d, allocated =%9d",
 164                _name, p2i(_base), p2i(_top), int(_end - _base), int(_top - _base));
 165     if (strcmp(_name, failing_region) == 0) {
 166       tty->print_cr(" required = %d", int(needed_bytes));
 167     } else {
 168       tty->cr();
 169     }
 170   }
 171 
 172   void init(const ReservedSpace* rs) {
 173     _base = _top = rs->base();
 174     _end = rs->end();
 175   }
 176   void init(char* b, char* t, char* e) {
 177     _base = b;
 178     _top = t;
 179     _end = e;
 180   }
 181 
 182   void pack(DumpRegion* next = NULL) {
 183     assert(!is_packed(), "sanity");
 184     _end = (char*)align_up(_top, Metaspace::reserve_alignment());
 185     _is_packed = true;
 186     if (next != NULL) {
 187       next->_base = next->_top = this->_end;
 188       next->_end = MetaspaceShared::shared_rs()->end();
 189     }
 190   }
 191   bool contains(char* p) {
 192     return base() <= p && p < top();
 193   }
 194 };
 195 
 196 DumpRegion _mc_region("mc"), _ro_region("ro"), _rw_region("rw"), _md_region("md"), _od_region("od");
 197 DumpRegion _s0_region("s0"), _s1_region("s1");
 198 
 199 char* MetaspaceShared::misc_code_space_alloc(size_t num_bytes) {
 200   return _mc_region.allocate(num_bytes);
 201 }
 202 
 203 char* MetaspaceShared::read_only_space_alloc(size_t num_bytes) {
 204   return _ro_region.allocate(num_bytes);
 205 }
 206 
 207 void MetaspaceShared::initialize_shared_rs() {
 208   const size_t reserve_alignment = Metaspace::reserve_alignment();
 209   bool large_pages = false; // No large pages when dumping the CDS archive.
 210   char* shared_base = (char*)align_up((char*)SharedBaseAddress, reserve_alignment);
 211 
 212 #ifdef _LP64
 213   const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1);
 214   const size_t cds_total = align_down(UnscaledClassSpaceMax, reserve_alignment);
 215 #else
 216   // We don't support archives larger than 256MB on 32-bit due to limited virtual address space.
 217   size_t cds_total = align_down(256*M, reserve_alignment);
 218 #endif
 219 
 220   // First try to reserve the space at the specified SharedBaseAddress.
 221   _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages, shared_base);
 222   if (_shared_rs.is_reserved()) {
 223     assert(shared_base == 0 || _shared_rs.base() == shared_base, "should match");
 224   } else {
 225     // Get a mmap region anywhere if the SharedBaseAddress fails.
 226     _shared_rs = ReservedSpace(cds_total, reserve_alignment, large_pages);
 227   }
 228   if (!_shared_rs.is_reserved()) {
 229     vm_exit_during_initialization("Unable to reserve memory for shared space",
 230                                   err_msg(SIZE_FORMAT " bytes.", cds_total));
 231   }
 232 
 233 #ifdef _LP64
 234   // During dump time, we allocate 4GB (UnscaledClassSpaceMax) of space and split it up:
 235   // + The upper 1 GB is used as the "temporary compressed class space" -- preload_classes()
 236   //   will store Klasses into this space.
 237   // + The lower 3 GB is used for the archive -- when preload_classes() is done,
 238   //   ArchiveCompactor will copy the class metadata into this space, first the RW parts,
 239   //   then the RO parts.
 240 
 241   assert(UseCompressedOops && UseCompressedClassPointers,
 242       "UseCompressedOops and UseCompressedClassPointers must be set");
 243 
 244   size_t max_archive_size = align_down(cds_total * 3 / 4, reserve_alignment);
 245   ReservedSpace tmp_class_space = _shared_rs.last_part(max_archive_size);
 246   CompressedClassSpaceSize = align_down(tmp_class_space.size(), reserve_alignment);
 247   _shared_rs = _shared_rs.first_part(max_archive_size);
 248 
 249   // Set up compress class pointers.
 250   Universe::set_narrow_klass_base((address)_shared_rs.base());
 251   if (UseAOT || cds_total > UnscaledClassSpaceMax) {
 252     // AOT forces narrow_klass_shift=LogKlassAlignmentInBytes
 253     Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
 254   } else {
 255     Universe::set_narrow_klass_shift(0);
 256   }
 257 
 258   Metaspace::initialize_class_space(tmp_class_space);
 259   tty->print_cr("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",
 260                 p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift());
 261 
 262   tty->print_cr("Allocated temporary class space: " SIZE_FORMAT " bytes at " PTR_FORMAT,
 263                 CompressedClassSpaceSize, p2i(tmp_class_space.base()));
 264 #endif
 265 
 266   // Start with 0 committed bytes. The memory will be committed as needed by


 274                 _shared_rs.size(), p2i(_shared_rs.base()));
 275 }
 276 
 277 void MetaspaceShared::commit_shared_space_to(char* newtop) {
 278   assert(DumpSharedSpaces, "dump-time only");
 279   char* base = _shared_rs.base();
 280   size_t need_committed_size = newtop - base;
 281   size_t has_committed_size = _shared_vs.committed_size();
 282   if (need_committed_size < has_committed_size) {
 283     return;
 284   }
 285 
 286   size_t min_bytes = need_committed_size - has_committed_size;
 287   size_t preferred_bytes = 1 * M;
 288   size_t uncommitted = _shared_vs.reserved_size() - has_committed_size;
 289 
 290   size_t commit = MAX2(min_bytes, preferred_bytes);
 291   assert(commit <= uncommitted, "sanity");
 292 
 293   bool result = _shared_vs.expand_by(commit, false);
 294   if (!result) {
 295     vm_exit_during_initialization(err_msg("Failed to expand shared space to " SIZE_FORMAT " bytes",
 296                                           need_committed_size));
 297   }
 298 
 299   log_info(cds)("Expanding shared spaces by " SIZE_FORMAT_W(7) " bytes [total " SIZE_FORMAT_W(9)  " bytes ending at %p]",
 300                 commit, _shared_vs.actual_committed_size(), _shared_vs.high());
 301 }
 302 
 303 // Read/write a data stream for restoring/preserving metadata pointers and
 304 // miscellaneous data from/to the shared archive file.
 305 
 306 void MetaspaceShared::serialize(SerializeClosure* soc) {
 307   int tag = 0;
 308   soc->do_tag(--tag);
 309 
 310   // Verify the sizes of various metadata in the system.
 311   soc->do_tag(sizeof(Method));
 312   soc->do_tag(sizeof(ConstMethod));
 313   soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE));
 314   soc->do_tag(sizeof(ConstantPool));
 315   soc->do_tag(sizeof(ConstantPoolCache));
 316   soc->do_tag(objArrayOopDesc::base_offset_in_bytes());
 317   soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE));
 318   soc->do_tag(sizeof(Symbol));
 319 
 320   // Dump/restore miscellaneous metadata.


 487     assert(DumpSharedSpaces, "dump-time only");
 488     _info->zero();
 489   }
 490 
 491   // Switch the vtable pointer to point to the cloned vtable.
 492   static void patch(Metadata* obj) {
 493     assert(DumpSharedSpaces, "dump-time only");
 494     *(void**)obj = (void*)(_info->cloned_vtable());
 495   }
 496 
 497   static bool is_valid_shared_object(const T* obj) {
 498     intptr_t* vptr = *(intptr_t**)obj;
 499     return vptr == _info->cloned_vtable();
 500   }
 501 };
 502 
 503 template <class T> CppVtableInfo* CppVtableCloner<T>::_info = NULL;
 504 
 505 template <class T>
 506 intptr_t* CppVtableCloner<T>::allocate(const char* name) {
 507   assert(is_aligned(_md_region.top(), sizeof(intptr_t)), "bad alignment");
 508   int n = get_vtable_length(name);
 509   _info = (CppVtableInfo*)_md_region.allocate(CppVtableInfo::byte_size(n), sizeof(intptr_t));
 510   _info->set_vtable_size(n);
 511 
 512   intptr_t* p = clone_vtable(name, _info);
 513   assert((char*)p == _md_region.top(), "must be");
 514 
 515   return p;
 516 }
 517 
 518 template <class T>
 519 intptr_t* CppVtableCloner<T>::clone_vtable(const char* name, CppVtableInfo* info) {
 520   if (!DumpSharedSpaces) {
 521     assert(_info == 0, "_info is initialized only at dump time");
 522     _info = info; // Remember it -- it will be used by MetaspaceShared::is_valid_shared_method()
 523   }
 524   T tmp; // Allocate temporary dummy metadata object to get to the original vtable.
 525   int n = info->vtable_size();
 526   intptr_t* srcvtable = vtable_of(tmp);
 527   intptr_t* dstvtable = info->cloned_vtable();


 725   }
 726 
 727 public:
 728   enum { RO = 0, RW = 1 };
 729 
 730   int _counts[2][_number_of_types];
 731   int _bytes [2][_number_of_types];
 732 
 733   DumpAllocStats() {
 734     memset(_counts, 0, sizeof(_counts));
 735     memset(_bytes,  0, sizeof(_bytes));
 736   };
 737 
 738   void record(MetaspaceObj::Type type, int byte_size, bool read_only) {
 739     assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity");
 740     int which = (read_only) ? RO : RW;
 741     _counts[which][type] ++;
 742     _bytes [which][type] += byte_size;
 743   }
 744 
 745   void record_other_type(int byte_size, bool read_only) {
 746     int which = (read_only) ? RO : RW;
 747     _bytes [which][OtherType] += byte_size;
 748   }
 749   void print_stats(int ro_all, int rw_all, int mc_all, int md_all);
 750 };
 751 
 752 void DumpAllocStats::print_stats(int ro_all, int rw_all, int mc_all, int md_all) {
 753   // Calculate size of data that was not allocated by Metaspace::allocate()
 754   MetaspaceSharedStats *stats = MetaspaceShared::stats();
 755 
 756   // symbols
 757   _counts[RO][SymbolHashentryType] = stats->symbol.hashentry_count;
 758   _bytes [RO][SymbolHashentryType] = stats->symbol.hashentry_bytes;
 759 
 760   _counts[RO][SymbolBucketType] = stats->symbol.bucket_count;
 761   _bytes [RO][SymbolBucketType] = stats->symbol.bucket_bytes;
 762 
 763   // strings
 764   _counts[RO][StringHashentryType] = stats->string.hashentry_count;
 765   _bytes [RO][StringHashentryType] = stats->string.hashentry_bytes;
 766 
 767   _counts[RO][StringBucketType] = stats->string.bucket_count;
 768   _bytes [RO][StringBucketType] = stats->string.bucket_bytes;


 776     ro_all = 1;
 777   }
 778   if (rw_all < 1) {
 779     rw_all = 1;
 780   }
 781 
 782   int all_ro_count = 0;
 783   int all_ro_bytes = 0;
 784   int all_rw_count = 0;
 785   int all_rw_bytes = 0;
 786 
 787 // To make fmt_stats be a syntactic constant (for format warnings), use #define.
 788 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f"
 789   const char *sep = "--------------------+---------------------------+---------------------------+--------------------------";
 790   const char *hdr = "                        ro_cnt   ro_bytes     % |   rw_cnt   rw_bytes     % |  all_cnt  all_bytes     %";
 791 
 792   ResourceMark rm;
 793   LogMessage(cds) msg;
 794   stringStream info_stream;
 795 
 796   info_stream.print_cr("Detailed metadata info (excluding od/st regions; rw stats include md/mc regions):");
 797   info_stream.print_cr("%s", hdr);
 798   info_stream.print_cr("%s", sep);
 799   for (int type = 0; type < int(_number_of_types); type ++) {
 800     const char *name = type_name((Type)type);
 801     int ro_count = _counts[RO][type];
 802     int ro_bytes = _bytes [RO][type];
 803     int rw_count = _counts[RW][type];
 804     int rw_bytes = _bytes [RW][type];
 805     int count = ro_count + rw_count;
 806     int bytes = ro_bytes + rw_bytes;
 807 
 808     double ro_perc = 100.0 * double(ro_bytes) / double(ro_all);
 809     double rw_perc = 100.0 * double(rw_bytes) / double(rw_all);
 810     double perc    = 100.0 * double(bytes)    / double(ro_all + rw_all);
 811 
 812     info_stream.print_cr(fmt_stats, name,
 813                          ro_count, ro_bytes, ro_perc,
 814                          rw_count, rw_bytes, rw_perc,
 815                          count, bytes, perc);
 816 
 817     all_ro_count += ro_count;
 818     all_ro_bytes += ro_bytes;
 819     all_rw_count += rw_count;
 820     all_rw_bytes += rw_bytes;
 821   }
 822 
 823   int all_count = all_ro_count + all_rw_count;
 824   int all_bytes = all_ro_bytes + all_rw_bytes;
 825 
 826   double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all);
 827   double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all);
 828   double all_perc    = 100.0 * double(all_bytes)    / double(ro_all + rw_all);
 829 
 830   info_stream.print_cr("%s", sep);
 831   info_stream.print_cr(fmt_stats, "Total",
 832                        all_ro_count, all_ro_bytes, all_ro_perc,
 833                        all_rw_count, all_rw_bytes, all_rw_perc,
 834                        all_count, all_bytes, all_perc);
 835 
 836   assert(all_ro_bytes == ro_all, "everything should have been counted");
 837   assert(all_rw_bytes == rw_all, "everything should have been counted");
 838 
 839   msg.info("%s", info_stream.as_string());
 840 #undef fmt_stats
 841 }
 842 
 843 // Populate the shared space.
 844 
 845 class VM_PopulateDumpSharedSpace: public VM_Operation {
 846 private:
 847   GrowableArray<MemRegion> *_string_regions;
 848 
 849   void dump_string_and_symbols();
 850   char* dump_read_only_tables();
 851   void print_region_stats();
 852 public:
 853 
 854   VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
 855   void doit();   // outline because gdb sucks
 856   static void write_region(FileMapInfo* mapinfo, int region, DumpRegion* space, bool read_only,  bool allow_exec);
 857 }; // class VM_PopulateDumpSharedSpace
 858 
 859 class SortedSymbolClosure: public SymbolClosure {
 860   GrowableArray<Symbol*> _symbols;
 861   virtual void do_symbol(Symbol** sym) {
 862     assert((*sym)->is_permanent(), "archived symbols must be permanent");
 863     _symbols.append(*sym);
 864   }
 865   static int compare_symbols_by_address(Symbol** a, Symbol** b) {
 866     if (a[0] < b[0]) {
 867       return -1;
 868     } else if (a[0] == b[0]) {
 869       return 0;
 870     } else {
 871       return 1;


 885 // ArchiveCompactor --
 886 //
 887 // This class is the central piece of shared archive compaction -- all metaspace data are
 888 // initially allocated outside of the shared regions. ArchiveCompactor copies the
 889 // metaspace data into their final location in the shared regions.
 890 
 891 class ArchiveCompactor : AllStatic {
 892   static DumpAllocStats* _alloc_stats;
 893   static SortedSymbolClosure* _ssc;
 894 
 895   static unsigned my_hash(const address& a) {
 896     return primitive_hash<address>(a);
 897   }
 898   static bool my_equals(const address& a0, const address& a1) {
 899     return primitive_equals<address>(a0, a1);
 900   }
 901   typedef ResourceHashtable<
 902       address, address,
 903       ArchiveCompactor::my_hash,   // solaris compiler doesn't like: primitive_hash<address>
 904       ArchiveCompactor::my_equals, // solaris compiler doesn't like: primitive_equals<address>
 905       16384, ResourceObj::C_HEAP> RelocationTable;
 906   static RelocationTable* _new_loc_table;
 907 
 908 public:
 909   static void initialize() {
 910     _alloc_stats = new(ResourceObj::C_HEAP, mtInternal)DumpAllocStats;
 911     _new_loc_table = new(ResourceObj::C_HEAP, mtInternal)RelocationTable;
 912   }
 913   static DumpAllocStats* alloc_stats() {
 914     return _alloc_stats;
 915   }
 916 
 917   static void allocate(MetaspaceClosure::Ref* ref, bool read_only) {
 918     address obj = ref->obj();
 919     int bytes = ref->size() * BytesPerWord;
 920     char* p;
 921     size_t alignment = BytesPerWord;
 922     char* oldtop;
 923     char* newtop;
 924 
 925     if (read_only) {
 926       oldtop = _ro_region.top();
 927       p = _ro_region.allocate(bytes, alignment);
 928       newtop = _ro_region.top();
 929     } else {
 930       oldtop = _rw_region.top();
 931       p = _rw_region.allocate(bytes, alignment);
 932       newtop = _rw_region.top();
 933     }
 934     memcpy(p, obj, bytes);
 935     bool isnew = _new_loc_table->put(obj, (address)p);
 936     assert(isnew, "must be");
 937     log_trace(cds)("Copy: " PTR_FORMAT " ==> " PTR_FORMAT " %d", p2i(obj), p2i(p), bytes);
 938 
 939     _alloc_stats->record(ref->msotype(), int(newtop - oldtop), read_only);
 940     if (ref->msotype() == MetaspaceObj::SymbolType) {
 941       uintx delta = MetaspaceShared::object_delta(p);
 942       if (delta > MAX_SHARED_DELTA) {
 943         // This is just a sanity check and should not appear in any real world usage. This
 944         // happens only if you allocate more than 2GB of Symbols and would require
 945         // millions of shared classes.
 946         vm_exit_during_initialization("Too many Symbols in the CDS archive",
 947                                       "Please reduce the number of shared classes.");
 948       }
 949     }
 950   }
 951 
 952   static address get_new_loc(MetaspaceClosure::Ref* ref) {
 953     address* pp = _new_loc_table->get(ref->obj());
 954     assert(pp != NULL, "must be");
 955     return *pp;
 956   }
 957 
 958 private:
 959   // Makes a shallow copy of visited MetaspaceObj's


1044       ResourceMark rm;
1045       RefRelocator ext_reloc;
1046       iterate_roots(&ext_reloc);
1047     }
1048 
1049 #ifdef ASSERT
1050     {
1051       tty->print_cr("Verifying external roots ... ");
1052       ResourceMark rm;
1053       IsRefInArchiveChecker checker;
1054       iterate_roots(&checker);
1055     }
1056 #endif
1057 
1058 
1059     // cleanup
1060     _ssc = NULL;
1061   }
1062 
1063   // We must relocate the System::_well_known_klasses only after we have copied the
1064   // strings in during dump_string_and_symbols(): during the string copy, we operate on old
1065   // String objects which assert that their klass is the old
1066   // SystemDictionary::String_klass().
1067   static void relocate_well_known_klasses() {
1068     {
1069       tty->print_cr("Relocating SystemDictionary::_well_known_klasses[] ... ");
1070       ResourceMark rm;
1071       RefRelocator ext_reloc;
1072       SystemDictionary::well_known_klasses_do(&ext_reloc);
1073     }
1074     // NOTE: after this point, we shouldn't have any globals that can reach the old
1075     // objects.
1076 
1077     // We cannot use any of the objects in the heap anymore (except for the objects
1078     // in the CDS shared string regions) because their headers no longer point to
1079     // valid Klasses.
1080   }
1081 
1082   static void iterate_roots(MetaspaceClosure* it) {
1083     GrowableArray<Symbol*>* symbols = _ssc->get_sorted_symbols();
1084     for (int i=0; i<symbols->length(); i++) {
1085       it->push(symbols->adr_at(i));
1086     }
1087     if (_global_klass_objects != NULL) {
1088       // Need to fix up the pointers
1089       for (int i = 0; i < _global_klass_objects->length(); i++) {


1092       }
1093     }
1094     FileMapInfo::metaspace_pointers_do(it);
1095     SystemDictionary::classes_do(it);
1096     Universe::metaspace_pointers_do(it);
1097     SymbolTable::metaspace_pointers_do(it);
1098     vmSymbols::metaspace_pointers_do(it);
1099   }
1100 
1101   static Klass* get_relocated_klass(Klass* orig_klass) {
1102     address* pp = _new_loc_table->get((address)orig_klass);
1103     assert(pp != NULL, "must be");
1104     Klass* klass = (Klass*)(*pp);
1105     assert(klass->is_klass(), "must be");
1106     return klass;
1107   }
1108 };
1109 
1110 DumpAllocStats* ArchiveCompactor::_alloc_stats;
1111 SortedSymbolClosure* ArchiveCompactor::_ssc;
1112 ArchiveCompactor::RelocationTable* ArchiveCompactor::_new_loc_table;
1113 
1114 void VM_PopulateDumpSharedSpace::write_region(FileMapInfo* mapinfo, int region_idx,
1115                                               DumpRegion* dump_region, bool read_only,  bool allow_exec) {
1116   mapinfo->write_region(region_idx, dump_region->base(), dump_region->used(), read_only, allow_exec);
1117 }
1118 
1119 void VM_PopulateDumpSharedSpace::dump_string_and_symbols() {
1120   tty->print_cr("Dumping string and symbol tables ...");
1121 
1122   NOT_PRODUCT(SymbolTable::verify());
1123   NOT_PRODUCT(StringTable::verify());
1124   SymbolTable::write_to_archive();
1125 
1126   // The string space has maximum two regions. See FileMapInfo::write_string_regions() for details.
1127   _string_regions = new GrowableArray<MemRegion>(2);
1128   StringTable::write_to_archive(_string_regions);





1129 }
1130 
1131 char* VM_PopulateDumpSharedSpace::dump_read_only_tables() {
1132   char* oldtop = _ro_region.top();
1133   // Reorder the system dictionary. Moving the symbols affects
1134   // how the hash table indices are calculated.
1135   SystemDictionary::reorder_dictionary_for_sharing();
1136   NOT_PRODUCT(SystemDictionary::verify();)
1137 
1138   size_t buckets_bytes = SystemDictionary::count_bytes_for_buckets();
1139   char* buckets_top = _ro_region.allocate(buckets_bytes, sizeof(intptr_t));
1140   SystemDictionary::copy_buckets(buckets_top, _ro_region.top());
1141 
1142   size_t table_bytes = SystemDictionary::count_bytes_for_table();
1143   char* table_top = _ro_region.allocate(table_bytes, sizeof(intptr_t));
1144   SystemDictionary::copy_table(table_top, _ro_region.top());
1145 
1146   // Write the other data to the output array.
1147   WriteClosure wc(&_ro_region);
1148   MetaspaceShared::serialize(&wc);
1149 
1150   char* newtop = _ro_region.top();
1151   ArchiveCompactor::alloc_stats()->record_other_type(int(newtop - oldtop), true);
1152   return buckets_top;
1153 }
1154 
1155 void VM_PopulateDumpSharedSpace::doit() {
1156   Thread* THREAD = VMThread::vm_thread();
1157 
1158   NOT_PRODUCT(SystemDictionary::verify();)
1159   // The following guarantee is meant to ensure that no loader constraints
1160   // exist yet, since the constraints table is not shared.  This becomes
1161   // more important now that we don't re-initialize vtables/itables for
1162   // shared classes at runtime, where constraints were previously created.
1163   guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
1164             "loader constraints are not saved");
1165   guarantee(SystemDictionary::placeholders()->number_of_entries() == 0,
1166           "placeholders are not saved");
1167   // Revisit and implement this if we prelink method handle call sites:
1168   guarantee(SystemDictionary::invoke_method_table() == NULL ||
1169             SystemDictionary::invoke_method_table()->number_of_entries() == 0,
1170             "invoke method table is not saved");
1171 


1209   ArchiveCompactor::initialize();
1210   ArchiveCompactor::copy_and_compact();
1211 
1212   dump_string_and_symbols();
1213   ArchiveCompactor::relocate_well_known_klasses();
1214 
1215   char* read_only_tables_start = dump_read_only_tables();
1216   _ro_region.pack(&_md_region);
1217 
1218   char* vtbl_list = _md_region.top();
1219   MetaspaceShared::allocate_cpp_vtable_clones();
1220   _md_region.pack(&_od_region);
1221 
1222   // Relocate the archived class file data into the od region
1223   relocate_cached_class_file();
1224   _od_region.pack();
1225 
1226   // The 5 core spaces are allocated consecutively mc->rw->ro->md->od, so there total size
1227   // is just the spaces between the two ends.
1228   size_t core_spaces_size = _od_region.end() - _mc_region.base();
1229   assert(core_spaces_size == (size_t)align_up(core_spaces_size, Metaspace::reserve_alignment()),
1230          "should already be aligned");
1231 



















1232   // During patching, some virtual methods may be called, so at this point
1233   // the vtables must contain valid methods (as filled in by CppVtableCloner::allocate).
1234   MetaspaceShared::patch_cpp_vtable_pointers();
1235 
1236   // The vtable clones contain addresses of the current process.
1237   // We don't want to write these addresses into the archive.
1238   MetaspaceShared::zero_cpp_vtable_clones_for_writing();
1239 
1240   // Create and write the archive file that maps the shared spaces.
1241 
1242   FileMapInfo* mapinfo = new FileMapInfo();
1243   mapinfo->populate_header(os::vm_allocation_granularity());
1244   mapinfo->set_read_only_tables_start(read_only_tables_start);
1245   mapinfo->set_misc_data_patching_start(vtbl_list);
1246   mapinfo->set_cds_i2i_entry_code_buffers(MetaspaceShared::cds_i2i_entry_code_buffers());
1247   mapinfo->set_cds_i2i_entry_code_buffers_size(MetaspaceShared::cds_i2i_entry_code_buffers_size());
1248   mapinfo->set_core_spaces_size(core_spaces_size);
1249 
1250   char* s0_start, *s0_top, *s0_end;
1251   char* s1_start, *s1_top, *s1_end;
1252 
1253   for (int pass=1; pass<=2; pass++) {
1254     if (pass == 1) {
1255       // The first pass doesn't actually write the data to disk. All it
1256       // does is to update the fields in the mapinfo->_header.
1257     } else {
1258       // After the first pass, the contents of mapinfo->_header are finalized,
1259       // so we can compute the header's CRC, and write the contents of the header
1260       // and the regions into disk.
1261       mapinfo->open_for_write();
1262       mapinfo->set_header_crc(mapinfo->compute_header_crc());
1263     }
1264     mapinfo->write_header();
1265 
1266     // NOTE: md contains the trampoline code for method entries, which are patched at run time,
1267     // so it needs to be read/write.
1268     write_region(mapinfo, MetaspaceShared::mc, &_mc_region, /*read_only=*/false,/*allow_exec=*/true);
1269     write_region(mapinfo, MetaspaceShared::rw, &_rw_region, /*read_only=*/false,/*allow_exec=*/false);
1270     write_region(mapinfo, MetaspaceShared::ro, &_ro_region, /*read_only=*/true, /*allow_exec=*/false);
1271     write_region(mapinfo, MetaspaceShared::md, &_md_region, /*read_only=*/false,/*allow_exec=*/false);
1272     write_region(mapinfo, MetaspaceShared::od, &_od_region, /*read_only=*/true, /*allow_exec=*/false);
1273 
1274     mapinfo->write_string_regions(_string_regions,
1275                                   &s0_start, &s0_top, &s0_end,
1276                                   &s1_start, &s1_top, &s1_end);
1277   }
1278 
1279   mapinfo->close();
1280 
1281   // Restore the vtable in case we invoke any virtual methods.
1282   MetaspaceShared::clone_cpp_vtables((intptr_t*)vtbl_list);
1283 
1284   _s0_region.init(s0_start, s0_top, s0_end);
1285   _s1_region.init(s1_start, s1_top, s1_end);
1286   print_region_stats();
1287 
1288   if (log_is_enabled(Info, cds)) {
1289     ArchiveCompactor::alloc_stats()->print_stats(int(_ro_region.used()), int(_rw_region.used()),
1290                                                  int(_mc_region.used()), int(_md_region.used()));
1291   }
1292 }
1293 
1294 void VM_PopulateDumpSharedSpace::print_region_stats() {
1295   // Print statistics of all the regions
1296   const size_t total_reserved = _ro_region.reserved() + _rw_region.reserved() +
1297                                 _mc_region.reserved() + _md_region.reserved() +
1298                                 _od_region.reserved() +
1299                                 _s0_region.reserved() + _s1_region.reserved();
1300   const size_t total_bytes = _ro_region.used() + _rw_region.used() +
1301                              _mc_region.used() + _md_region.used() +
1302                              _od_region.used() +
1303                              _s0_region.used() + _s1_region.used();
1304   const double total_u_perc = total_bytes / double(total_reserved) * 100.0;
1305 
1306   _mc_region.print(total_reserved);
1307   _rw_region.print(total_reserved);
1308   _ro_region.print(total_reserved);
1309   _md_region.print(total_reserved);
1310   _od_region.print(total_reserved);
1311   _s0_region.print(total_reserved);
1312   _s1_region.print(total_reserved);
1313 
1314   tty->print_cr("total   : " SIZE_FORMAT_W(9) " [100.0%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used]",
1315                  total_bytes, total_reserved, total_u_perc);
1316 }
1317 
1318 
1319 // Update a Java object to point its Klass* to the new location after
1320 // shared archive has been compacted.
1321 void MetaspaceShared::relocate_klass_ptr(oop o) {
1322   assert(DumpSharedSpaces, "sanity");
1323   Klass* k = ArchiveCompactor::get_relocated_klass(o->klass());
1324   o->set_klass(k);
1325 }
1326 
1327 class LinkSharedClassesClosure : public KlassClosure {
1328   Thread* THREAD;
1329   bool    _made_progress;
1330  public:
1331   LinkSharedClassesClosure(Thread* thread) : THREAD(thread), _made_progress(false) {}
1332 
1333   void reset()               { _made_progress = false; }
1334   bool made_progress() const { return _made_progress; }
1335 
1336   void do_klass(Klass* k) {
1337     if (k->is_instance_klass()) {
1338       InstanceKlass* ik = InstanceKlass::cast(k);


1743 
1744   if (UseSharedSpaces) {
1745     // remap the shared readonly space to shared readwrite, private
1746     FileMapInfo* mapinfo = FileMapInfo::current_info();
1747     if (!mapinfo->remap_shared_readonly_as_readwrite()) {
1748       return false;
1749     }
1750     _remapped_readwrite = true;
1751   }
1752   return true;
1753 }
1754 
1755 void MetaspaceShared::report_out_of_space(const char* name, size_t needed_bytes) {
1756   // This is highly unlikely to happen on 64-bits because we have reserved a 4GB space.
1757   // On 32-bit we reserve only 256MB so you could run out of space with 100,000 classes
1758   // or so.
1759   _mc_region.print_out_of_space_msg(name, needed_bytes);
1760   _rw_region.print_out_of_space_msg(name, needed_bytes);
1761   _ro_region.print_out_of_space_msg(name, needed_bytes);
1762   _md_region.print_out_of_space_msg(name, needed_bytes);

1763   _od_region.print_out_of_space_msg(name, needed_bytes);
1764 
1765   vm_exit_during_initialization(err_msg("Unable to allocate from '%s' region", name),
1766                                 "Please reduce the number of shared classes.");
1767 }
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