1 /* 2 * Copyright (c) 2012, 2014, 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 "classfile/dictionary.hpp" 27 #include "classfile/loaderConstraints.hpp" 28 #include "classfile/placeholders.hpp" 29 #include "classfile/symbolTable.hpp" 30 #include "classfile/systemDictionary.hpp" 31 #include "code/codeCache.hpp" 32 #include "memory/filemap.hpp" 33 #include "memory/gcLocker.hpp" 34 #include "memory/metaspace.hpp" 35 #include "memory/metaspaceShared.hpp" 36 #include "oops/objArrayOop.hpp" 37 #include "oops/oop.inline.hpp" 38 #include "runtime/os.hpp" 39 #include "runtime/signature.hpp" 40 #include "runtime/vm_operations.hpp" 41 #include "runtime/vmThread.hpp" 42 #include "utilities/hashtable.inline.hpp" 43 44 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 45 46 int MetaspaceShared::_max_alignment = 0; 47 48 ReservedSpace* MetaspaceShared::_shared_rs = NULL; 49 50 // Read/write a data stream for restoring/preserving metadata pointers and 51 // miscellaneous data from/to the shared archive file. 52 53 void MetaspaceShared::serialize(SerializeClosure* soc) { 54 int tag = 0; 55 soc->do_tag(--tag); 56 57 // Verify the sizes of various metadata in the system. 58 soc->do_tag(sizeof(Method)); 59 soc->do_tag(sizeof(ConstMethod)); 60 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE)); 61 soc->do_tag(sizeof(ConstantPool)); 62 soc->do_tag(sizeof(ConstantPoolCache)); 63 soc->do_tag(objArrayOopDesc::base_offset_in_bytes()); 64 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE)); 65 soc->do_tag(sizeof(Symbol)); 66 67 // Dump/restore miscellaneous metadata. 68 Universe::serialize(soc, true); 69 soc->do_tag(--tag); 70 71 // Dump/restore references to commonly used names and signatures. 72 vmSymbols::serialize(soc); 73 soc->do_tag(--tag); 74 75 soc->do_tag(666); 76 } 77 78 79 // CDS code for dumping shared archive. 80 81 // Global object for holding classes that have been loaded. Since this 82 // is run at a safepoint just before exit, this is the entire set of classes. 83 static GrowableArray<Klass*>* _global_klass_objects; 84 static void collect_classes(Klass* k) { 85 _global_klass_objects->append_if_missing(k); 86 if (k->oop_is_instance()) { 87 // Add in the array classes too 88 InstanceKlass* ik = InstanceKlass::cast(k); 89 ik->array_klasses_do(collect_classes); 90 } 91 } 92 93 static void remove_unshareable_in_classes() { 94 for (int i = 0; i < _global_klass_objects->length(); i++) { 95 Klass* k = _global_klass_objects->at(i); 96 k->remove_unshareable_info(); 97 } 98 } 99 100 // Walk all methods in the class list and assign a fingerprint. 101 // so that this part of the ConstMethod* is read only. 102 static void calculate_fingerprints() { 103 for (int i = 0; i < _global_klass_objects->length(); i++) { 104 Klass* k = _global_klass_objects->at(i); 105 if (k->oop_is_instance()) { 106 InstanceKlass* ik = InstanceKlass::cast(k); 107 for (int i = 0; i < ik->methods()->length(); i++) { 108 Method* m = ik->methods()->at(i); 109 Fingerprinter fp(m); 110 // The side effect of this call sets method's fingerprint field. 111 fp.fingerprint(); 112 } 113 } 114 } 115 } 116 117 // Patch C++ vtable pointer in metadata. 118 119 // Klass and other metadata objects contain references to c++ vtables in the 120 // JVM library. 121 // Fix them to point to our constructed vtables. However, don't iterate 122 // across the space while doing this, as that causes the vtables to be 123 // patched, undoing our useful work. Instead, iterate to make a list, 124 // then use the list to do the fixing. 125 // 126 // Our constructed vtables: 127 // Dump time: 128 // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs 129 // 2. generate_vtable_methods: create jump table, appended to above vtbl_list 130 // 3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and 131 // associated metadata to point to jump table rather than to current vtbl 132 // Table layout: NOTE FIXED SIZE 133 // 1. vtbl pointers 134 // 2. #Klass X #virtual methods per Klass 135 // 1 entry for each, in the order: 136 // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry 137 // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry 138 // ... 139 // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry, 140 // ... Klass<vtbl_list_size>:method<num_virtuals> entry 141 // Sample entry: (Sparc): 142 // save(sp, -256, sp) 143 // ba,pt common_code 144 // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255) 145 // 146 // Restore time: 147 // 1. initialize_shared_space: reserve space for table 148 // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text 149 // 150 // Execution time: 151 // First virtual method call for any object of these metadata types: 152 // 1. object->klass 153 // 2. vtable entry for that klass points to the jump table entries 154 // 3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index 155 // 4. common_code: 156 // Get address of new vtbl pointer for this Klass from updated table 157 // Update new vtbl pointer in the Klass: future virtual calls go direct 158 // Jump to method, using new vtbl pointer and method index 159 160 161 static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) { 162 void* old_vtbl_ptr = *(void**)obj; 163 for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) { 164 if (vtbl_list[i] == old_vtbl_ptr) { 165 return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals; 166 } 167 } 168 ShouldNotReachHere(); 169 return NULL; 170 } 171 172 // Assumes the vtable is in first slot in object. 173 static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) { 174 int n = _global_klass_objects->length(); 175 for (int i = 0; i < n; i++) { 176 Klass* obj = _global_klass_objects->at(i); 177 // Note oop_is_instance() is a virtual call. After patching vtables 178 // all virtual calls on the dummy vtables will restore the original! 179 if (obj->oop_is_instance()) { 180 InstanceKlass* ik = InstanceKlass::cast(obj); 181 *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik); 182 ConstantPool* cp = ik->constants(); 183 *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp); 184 for (int j = 0; j < ik->methods()->length(); j++) { 185 Method* m = ik->methods()->at(j); 186 *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m); 187 } 188 } else { 189 // Array klasses 190 Klass* k = obj; 191 *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k); 192 } 193 } 194 } 195 196 // Closure for serializing initialization data out to a data area to be 197 // written to the shared file. 198 199 class WriteClosure : public SerializeClosure { 200 private: 201 intptr_t* top; 202 char* end; 203 204 inline void check_space() { 205 if ((char*)top + sizeof(intptr_t) > end) { 206 report_out_of_shared_space(SharedMiscData); 207 } 208 } 209 210 public: 211 WriteClosure(char* md_top, char* md_end) { 212 top = (intptr_t*)md_top; 213 end = md_end; 214 } 215 216 char* get_top() { return (char*)top; } 217 218 void do_ptr(void** p) { 219 check_space(); 220 *top = (intptr_t)*p; 221 ++top; 222 } 223 224 void do_tag(int tag) { 225 check_space(); 226 *top = (intptr_t)tag; 227 ++top; 228 } 229 230 void do_region(u_char* start, size_t size) { 231 if ((char*)top + size > end) { 232 report_out_of_shared_space(SharedMiscData); 233 } 234 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment"); 235 assert(size % sizeof(intptr_t) == 0, "bad size"); 236 do_tag((int)size); 237 while (size > 0) { 238 *top = *(intptr_t*)start; 239 ++top; 240 start += sizeof(intptr_t); 241 size -= sizeof(intptr_t); 242 } 243 } 244 245 bool reading() const { return false; } 246 }; 247 248 // This is for dumping detailed statistics for the allocations 249 // in the shared spaces. 250 class DumpAllocClosure : public Metaspace::AllocRecordClosure { 251 public: 252 253 // Here's poor man's enum inheritance 254 #define SHAREDSPACE_OBJ_TYPES_DO(f) \ 255 METASPACE_OBJ_TYPES_DO(f) \ 256 f(SymbolHashentry) \ 257 f(SymbolBuckets) \ 258 f(Other) 259 260 #define SHAREDSPACE_OBJ_TYPE_DECLARE(name) name ## Type, 261 #define SHAREDSPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name; 262 263 enum Type { 264 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc 265 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_DECLARE) 266 _number_of_types 267 }; 268 269 static const char * type_name(Type type) { 270 switch(type) { 271 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_NAME_CASE) 272 default: 273 ShouldNotReachHere(); 274 return NULL; 275 } 276 } 277 278 public: 279 enum { 280 RO = 0, 281 RW = 1 282 }; 283 284 int _counts[2][_number_of_types]; 285 int _bytes [2][_number_of_types]; 286 int _which; 287 288 DumpAllocClosure() { 289 memset(_counts, 0, sizeof(_counts)); 290 memset(_bytes, 0, sizeof(_bytes)); 291 }; 292 293 void iterate_metaspace(Metaspace* space, int which) { 294 assert(which == RO || which == RW, "sanity"); 295 _which = which; 296 space->iterate(this); 297 } 298 299 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) { 300 assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity"); 301 _counts[_which][type] ++; 302 _bytes [_which][type] += byte_size; 303 } 304 305 void dump_stats(int ro_all, int rw_all, int md_all, int mc_all); 306 }; 307 308 void DumpAllocClosure::dump_stats(int ro_all, int rw_all, int md_all, int mc_all) { 309 rw_all += (md_all + mc_all); // md and mc are all mapped Read/Write 310 int other_bytes = md_all + mc_all; 311 312 // Calculate size of data that was not allocated by Metaspace::allocate() 313 int symbol_count = _counts[RO][MetaspaceObj::SymbolType]; 314 int symhash_bytes = symbol_count * sizeof (HashtableEntry<Symbol*, mtSymbol>); 315 int symbuck_count = SymbolTable::the_table()->table_size(); 316 int symbuck_bytes = symbuck_count * sizeof(HashtableBucket<mtSymbol>); 317 318 _counts[RW][SymbolHashentryType] = symbol_count; 319 _bytes [RW][SymbolHashentryType] = symhash_bytes; 320 other_bytes -= symhash_bytes; 321 322 _counts[RW][SymbolBucketsType] = symbuck_count; 323 _bytes [RW][SymbolBucketsType] = symbuck_bytes; 324 other_bytes -= symbuck_bytes; 325 326 // TODO: count things like dictionary, vtable, etc 327 _bytes[RW][OtherType] = other_bytes; 328 329 // prevent divide-by-zero 330 if (ro_all < 1) { 331 ro_all = 1; 332 } 333 if (rw_all < 1) { 334 rw_all = 1; 335 } 336 337 int all_ro_count = 0; 338 int all_ro_bytes = 0; 339 int all_rw_count = 0; 340 int all_rw_bytes = 0; 341 342 // To make fmt_stats be a syntactic constant (for format warnings), use #define. 343 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f" 344 const char *sep = "--------------------+---------------------------+---------------------------+--------------------------"; 345 const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %"; 346 347 tty->print_cr("Detailed metadata info (rw includes md and mc):"); 348 tty->print_cr("%s", hdr); 349 tty->print_cr("%s", sep); 350 for (int type = 0; type < int(_number_of_types); type ++) { 351 const char *name = type_name((Type)type); 352 int ro_count = _counts[RO][type]; 353 int ro_bytes = _bytes [RO][type]; 354 int rw_count = _counts[RW][type]; 355 int rw_bytes = _bytes [RW][type]; 356 int count = ro_count + rw_count; 357 int bytes = ro_bytes + rw_bytes; 358 359 double ro_perc = 100.0 * double(ro_bytes) / double(ro_all); 360 double rw_perc = 100.0 * double(rw_bytes) / double(rw_all); 361 double perc = 100.0 * double(bytes) / double(ro_all + rw_all); 362 363 tty->print_cr(fmt_stats, name, 364 ro_count, ro_bytes, ro_perc, 365 rw_count, rw_bytes, rw_perc, 366 count, bytes, perc); 367 368 all_ro_count += ro_count; 369 all_ro_bytes += ro_bytes; 370 all_rw_count += rw_count; 371 all_rw_bytes += rw_bytes; 372 } 373 374 int all_count = all_ro_count + all_rw_count; 375 int all_bytes = all_ro_bytes + all_rw_bytes; 376 377 double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all); 378 double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all); 379 double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all); 380 381 tty->print_cr("%s", sep); 382 tty->print_cr(fmt_stats, "Total", 383 all_ro_count, all_ro_bytes, all_ro_perc, 384 all_rw_count, all_rw_bytes, all_rw_perc, 385 all_count, all_bytes, all_perc); 386 387 assert(all_ro_bytes == ro_all, "everything should have been counted"); 388 assert(all_rw_bytes == rw_all, "everything should have been counted"); 389 #undef fmt_stats 390 } 391 392 // Populate the shared space. 393 394 class VM_PopulateDumpSharedSpace: public VM_Operation { 395 private: 396 ClassLoaderData* _loader_data; 397 GrowableArray<Klass*> *_class_promote_order; 398 VirtualSpace _md_vs; 399 VirtualSpace _mc_vs; 400 401 public: 402 VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data, 403 GrowableArray<Klass*> *class_promote_order) : 404 _loader_data(loader_data) { 405 406 // Split up and initialize the misc code and data spaces 407 ReservedSpace* shared_rs = MetaspaceShared::shared_rs(); 408 int metadata_size = SharedReadOnlySize+SharedReadWriteSize; 409 ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size); 410 ReservedSpace misc_section = shared_rs->last_part(metadata_size); 411 412 // Now split into misc sections. 413 ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize); 414 ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize); 415 _md_vs.initialize(md_rs, SharedMiscDataSize); 416 _mc_vs.initialize(mc_rs, SharedMiscCodeSize); 417 _class_promote_order = class_promote_order; 418 } 419 420 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; } 421 void doit(); // outline because gdb sucks 422 }; // class VM_PopulateDumpSharedSpace 423 424 425 void VM_PopulateDumpSharedSpace::doit() { 426 Thread* THREAD = VMThread::vm_thread(); 427 NOT_PRODUCT(SystemDictionary::verify();) 428 // The following guarantee is meant to ensure that no loader constraints 429 // exist yet, since the constraints table is not shared. This becomes 430 // more important now that we don't re-initialize vtables/itables for 431 // shared classes at runtime, where constraints were previously created. 432 guarantee(SystemDictionary::constraints()->number_of_entries() == 0, 433 "loader constraints are not saved"); 434 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0, 435 "placeholders are not saved"); 436 // Revisit and implement this if we prelink method handle call sites: 437 guarantee(SystemDictionary::invoke_method_table() == NULL || 438 SystemDictionary::invoke_method_table()->number_of_entries() == 0, 439 "invoke method table is not saved"); 440 441 // At this point, many classes have been loaded. 442 // Gather systemDictionary classes in a global array and do everything to 443 // that so we don't have to walk the SystemDictionary again. 444 _global_klass_objects = new GrowableArray<Klass*>(1000); 445 Universe::basic_type_classes_do(collect_classes); 446 SystemDictionary::classes_do(collect_classes); 447 448 tty->print_cr("Number of classes %d", _global_klass_objects->length()); 449 450 // Update all the fingerprints in the shared methods. 451 tty->print("Calculating fingerprints ... "); 452 calculate_fingerprints(); 453 tty->print_cr("done. "); 454 455 // Remove all references outside the metadata 456 tty->print("Removing unshareable information ... "); 457 remove_unshareable_in_classes(); 458 tty->print_cr("done. "); 459 460 // Set up the share data and shared code segments. 461 char* md_low = _md_vs.low(); 462 char* md_top = md_low; 463 char* md_end = _md_vs.high(); 464 char* mc_low = _mc_vs.low(); 465 char* mc_top = mc_low; 466 char* mc_end = _mc_vs.high(); 467 468 // Reserve space for the list of Klass*s whose vtables are used 469 // for patching others as needed. 470 471 void** vtbl_list = (void**)md_top; 472 int vtbl_list_size = MetaspaceShared::vtbl_list_size; 473 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size); 474 475 md_top += vtbl_list_size * sizeof(void*); 476 void* vtable = md_top; 477 478 // Reserve space for a new dummy vtable for klass objects in the 479 // heap. Generate self-patching vtable entries. 480 481 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable, 482 &md_top, md_end, 483 &mc_top, mc_end); 484 485 // Reorder the system dictionary. (Moving the symbols affects 486 // how the hash table indices are calculated.) 487 // Not doing this either. 488 489 SystemDictionary::reorder_dictionary(); 490 491 NOT_PRODUCT(SystemDictionary::verify();) 492 493 // Copy the the symbol table, and the system dictionary to the shared 494 // space in usable form. Copy the hashtable 495 // buckets first [read-write], then copy the linked lists of entries 496 // [read-only]. 497 498 SymbolTable::reverse(md_top); 499 NOT_PRODUCT(SymbolTable::verify()); 500 SymbolTable::copy_buckets(&md_top, md_end); 501 502 SystemDictionary::reverse(); 503 SystemDictionary::copy_buckets(&md_top, md_end); 504 505 ClassLoader::verify(); 506 ClassLoader::copy_package_info_buckets(&md_top, md_end); 507 ClassLoader::verify(); 508 509 SymbolTable::copy_table(&md_top, md_end); 510 SystemDictionary::copy_table(&md_top, md_end); 511 ClassLoader::verify(); 512 ClassLoader::copy_package_info_table(&md_top, md_end); 513 ClassLoader::verify(); 514 515 // Write the other data to the output array. 516 WriteClosure wc(md_top, md_end); 517 MetaspaceShared::serialize(&wc); 518 md_top = wc.get_top(); 519 520 // Print shared spaces all the time 521 // To make fmt_space be a syntactic constant (for format warnings), use #define. 522 #define fmt_space "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " INTPTR_FORMAT 523 Metaspace* ro_space = _loader_data->ro_metaspace(); 524 Metaspace* rw_space = _loader_data->rw_metaspace(); 525 526 // Allocated size of each space (may not be all occupied) 527 const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType); 528 const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType); 529 const size_t md_alloced = md_end-md_low; 530 const size_t mc_alloced = mc_end-mc_low; 531 const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced; 532 533 // Occupied size of each space. 534 const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType); 535 const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType); 536 const size_t md_bytes = size_t(md_top - md_low); 537 const size_t mc_bytes = size_t(mc_top - mc_low); 538 539 // Percent of total size 540 const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes; 541 const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0; 542 const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0; 543 const double md_t_perc = md_bytes / double(total_bytes) * 100.0; 544 const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0; 545 546 // Percent of fullness of each space 547 const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0; 548 const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0; 549 const double md_u_perc = md_bytes / double(md_alloced) * 100.0; 550 const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0; 551 const double total_u_perc = total_bytes / double(total_alloced) * 100.0; 552 553 tty->print_cr(fmt_space, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom()); 554 tty->print_cr(fmt_space, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom()); 555 tty->print_cr(fmt_space, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low); 556 tty->print_cr(fmt_space, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low); 557 tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]", 558 total_bytes, total_alloced, total_u_perc); 559 560 // Update the vtable pointers in all of the Klass objects in the 561 // heap. They should point to newly generated vtable. 562 patch_klass_vtables(vtbl_list, vtable); 563 564 // dunno what this is for. 565 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass); 566 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*)); 567 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*)); 568 569 // Create and write the archive file that maps the shared spaces. 570 571 FileMapInfo* mapinfo = new FileMapInfo(); 572 mapinfo->populate_header(MetaspaceShared::max_alignment()); 573 574 // Pass 1 - update file offsets in header. 575 mapinfo->write_header(); 576 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true); 577 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false); 578 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(), 579 pointer_delta(md_top, _md_vs.low(), sizeof(char)), 580 SharedMiscDataSize, 581 false, false); 582 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(), 583 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)), 584 SharedMiscCodeSize, 585 true, true); 586 587 // Pass 2 - write data. 588 mapinfo->open_for_write(); 589 mapinfo->write_header(); 590 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true); 591 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false); 592 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(), 593 pointer_delta(md_top, _md_vs.low(), sizeof(char)), 594 SharedMiscDataSize, 595 false, false); 596 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(), 597 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)), 598 SharedMiscCodeSize, 599 true, true); 600 mapinfo->close(); 601 602 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*)); 603 604 if (PrintSharedSpaces) { 605 DumpAllocClosure dac; 606 dac.iterate_metaspace(_loader_data->ro_metaspace(), DumpAllocClosure::RO); 607 dac.iterate_metaspace(_loader_data->rw_metaspace(), DumpAllocClosure::RW); 608 609 dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes)); 610 } 611 #undef fmt_space 612 } 613 614 static void link_shared_classes(Klass* obj, TRAPS) { 615 Klass* k = obj; 616 if (k->oop_is_instance()) { 617 InstanceKlass* ik = (InstanceKlass*) k; 618 // Link the class to cause the bytecodes to be rewritten and the 619 // cpcache to be created. 620 if (ik->init_state() < InstanceKlass::linked) { 621 ik->link_class(THREAD); 622 guarantee(!HAS_PENDING_EXCEPTION, "exception in class rewriting"); 623 } 624 } 625 } 626 627 628 // Support for a simple checksum of the contents of the class list 629 // file to prevent trivial tampering. The algorithm matches that in 630 // the MakeClassList program used by the J2SE build process. 631 #define JSUM_SEED ((jlong)CONST64(0xcafebabebabecafe)) 632 static jlong 633 jsum(jlong start, const char *buf, const int len) 634 { 635 jlong h = start; 636 char *p = (char *)buf, *e = p + len; 637 while (p < e) { 638 char c = *p++; 639 if (c <= ' ') { 640 /* Skip spaces and control characters */ 641 continue; 642 } 643 h = 31 * h + c; 644 } 645 return h; 646 } 647 648 // Preload classes from a list, populate the shared spaces and dump to a 649 // file. 650 void MetaspaceShared::preload_and_dump(TRAPS) { 651 TraceTime timer("Dump Shared Spaces", TraceStartupTime); 652 ResourceMark rm; 653 654 // Preload classes to be shared. 655 // Should use some os:: method rather than fopen() here. aB. 656 // Construct the path to the class list (in jre/lib) 657 // Walk up two directories from the location of the VM and 658 // optionally tack on "lib" (depending on platform) 659 char class_list_path[JVM_MAXPATHLEN]; 660 os::jvm_path(class_list_path, sizeof(class_list_path)); 661 for (int i = 0; i < 3; i++) { 662 char *end = strrchr(class_list_path, *os::file_separator()); 663 if (end != NULL) *end = '\0'; 664 } 665 int class_list_path_len = (int)strlen(class_list_path); 666 if (class_list_path_len >= 3) { 667 if (strcmp(class_list_path + class_list_path_len - 3, "lib") != 0) { 668 strcat(class_list_path, os::file_separator()); 669 strcat(class_list_path, "lib"); 670 } 671 } 672 strcat(class_list_path, os::file_separator()); 673 strcat(class_list_path, "classlist"); 674 675 FILE* file = fopen(class_list_path, "r"); 676 if (file != NULL) { 677 jlong computed_jsum = JSUM_SEED; 678 jlong file_jsum = 0; 679 680 char class_name[256]; 681 int class_count = 0; 682 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>(); 683 684 // sun.io.Converters 685 static const char obj_array_sig[] = "[[Ljava/lang/Object;"; 686 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD); 687 688 // java.util.HashMap 689 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;"; 690 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD); 691 692 tty->print("Loading classes to share ... "); 693 while ((fgets(class_name, sizeof class_name, file)) != NULL) { 694 if (*class_name == '#') { 695 jint fsh, fsl; 696 if (sscanf(class_name, "# %8x%8x\n", &fsh, &fsl) == 2) { 697 file_jsum = ((jlong)(fsh) << 32) | (fsl & 0xffffffff); 698 } 699 700 continue; 701 } 702 // Remove trailing newline 703 size_t name_len = strlen(class_name); 704 class_name[name_len-1] = '\0'; 705 706 computed_jsum = jsum(computed_jsum, class_name, (const int)name_len - 1); 707 708 // Got a class name - load it. 709 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD); 710 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol."); 711 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol, 712 THREAD); 713 guarantee(!HAS_PENDING_EXCEPTION, "Exception resolving a class."); 714 if (klass != NULL) { 715 if (PrintSharedSpaces && Verbose && WizardMode) { 716 tty->print_cr("Shared spaces preloaded: %s", class_name); 717 } 718 719 720 InstanceKlass* ik = InstanceKlass::cast(klass); 721 722 // Should be class load order as per -XX:+TraceClassLoadingPreorder 723 class_promote_order->append(ik); 724 725 // Link the class to cause the bytecodes to be rewritten and the 726 // cpcache to be created. The linking is done as soon as classes 727 // are loaded in order that the related data structures (klass and 728 // cpCache) are located together. 729 730 if (ik->init_state() < InstanceKlass::linked) { 731 ik->link_class(THREAD); 732 guarantee(!(HAS_PENDING_EXCEPTION), "exception in class rewriting"); 733 } 734 735 // TODO: Resolve klasses in constant pool 736 ik->constants()->resolve_class_constants(THREAD); 737 738 class_count++; 739 } else { 740 if (PrintSharedSpaces && Verbose && WizardMode) { 741 tty->cr(); 742 tty->print_cr(" Preload failed: %s", class_name); 743 } 744 } 745 file_jsum = 0; // Checksum must be on last line of file 746 } 747 if (computed_jsum != file_jsum) { 748 tty->cr(); 749 tty->print_cr("Preload failed: checksum of class list was incorrect."); 750 exit(1); 751 } 752 753 tty->print_cr("done. "); 754 755 if (PrintSharedSpaces) { 756 tty->print_cr("Shared spaces: preloaded %d classes", class_count); 757 } 758 759 // Rewrite and unlink classes. 760 tty->print("Rewriting and linking classes ... "); 761 762 // Link any classes which got missed. (It's not quite clear why 763 // they got missed.) This iteration would be unsafe if we weren't 764 // single-threaded at this point; however we can't do it on the VM 765 // thread because it requires object allocation. 766 SystemDictionary::classes_do(link_shared_classes, CATCH); 767 tty->print_cr("done. "); 768 769 // Create and dump the shared spaces. Everything so far is loaded 770 // with the null class loader. 771 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data(); 772 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order); 773 VMThread::execute(&op); 774 775 } else { 776 char errmsg[JVM_MAXPATHLEN]; 777 os::lasterror(errmsg, JVM_MAXPATHLEN); 778 tty->print_cr("Loading classlist failed: %s", errmsg); 779 exit(1); 780 } 781 782 // Since various initialization steps have been undone by this process, 783 // it is not reasonable to continue running a java process. 784 exit(0); 785 } 786 787 788 // Closure for serializing initialization data in from a data area 789 // (ptr_array) read from the shared file. 790 791 class ReadClosure : public SerializeClosure { 792 private: 793 intptr_t** _ptr_array; 794 795 inline intptr_t nextPtr() { 796 return *(*_ptr_array)++; 797 } 798 799 public: 800 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; } 801 802 void do_ptr(void** p) { 803 assert(*p == NULL, "initializing previous initialized pointer."); 804 intptr_t obj = nextPtr(); 805 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100, 806 "hit tag while initializing ptrs."); 807 *p = (void*)obj; 808 } 809 810 void do_tag(int tag) { 811 int old_tag; 812 old_tag = (int)(intptr_t)nextPtr(); 813 // do_int(&old_tag); 814 assert(tag == old_tag, "old tag doesn't match"); 815 FileMapInfo::assert_mark(tag == old_tag); 816 } 817 818 void do_region(u_char* start, size_t size) { 819 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment"); 820 assert(size % sizeof(intptr_t) == 0, "bad size"); 821 do_tag((int)size); 822 while (size > 0) { 823 *(intptr_t*)start = nextPtr(); 824 start += sizeof(intptr_t); 825 size -= sizeof(intptr_t); 826 } 827 } 828 829 bool reading() const { return true; } 830 }; 831 832 // Return true if given address is in the mapped shared space. 833 bool MetaspaceShared::is_in_shared_space(const void* p) { 834 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p); 835 } 836 837 void MetaspaceShared::print_shared_spaces() { 838 if (UseSharedSpaces) { 839 FileMapInfo::current_info()->print_shared_spaces(); 840 } 841 } 842 843 844 // Map shared spaces at requested addresses and return if succeeded. 845 // Need to keep the bounds of the ro and rw space for the Metaspace::contains 846 // call, or is_in_shared_space. 847 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) { 848 size_t image_alignment = mapinfo->alignment(); 849 850 #ifndef _WINDOWS 851 // Map in the shared memory and then map the regions on top of it. 852 // On Windows, don't map the memory here because it will cause the 853 // mappings of the regions to fail. 854 ReservedSpace shared_rs = mapinfo->reserve_shared_memory(); 855 if (!shared_rs.is_reserved()) return false; 856 #endif 857 858 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces"); 859 860 char* _ro_base = NULL; 861 char* _rw_base = NULL; 862 char* _md_base = NULL; 863 char* _mc_base = NULL; 864 865 // Map each shared region 866 if ((_ro_base = mapinfo->map_region(ro)) != NULL && 867 (_rw_base = mapinfo->map_region(rw)) != NULL && 868 (_md_base = mapinfo->map_region(md)) != NULL && 869 (_mc_base = mapinfo->map_region(mc)) != NULL && 870 (image_alignment == (size_t)max_alignment())) { 871 // Success (no need to do anything) 872 return true; 873 } else { 874 // If there was a failure in mapping any of the spaces, unmap the ones 875 // that succeeded 876 if (_ro_base != NULL) mapinfo->unmap_region(ro); 877 if (_rw_base != NULL) mapinfo->unmap_region(rw); 878 if (_md_base != NULL) mapinfo->unmap_region(md); 879 if (_mc_base != NULL) mapinfo->unmap_region(mc); 880 #ifndef _WINDOWS 881 // Release the entire mapped region 882 shared_rs.release(); 883 #endif 884 // If -Xshare:on is specified, print out the error message and exit VM, 885 // otherwise, set UseSharedSpaces to false and continue. 886 if (RequireSharedSpaces) { 887 vm_exit_during_initialization("Unable to use shared archive.", NULL); 888 } else { 889 FLAG_SET_DEFAULT(UseSharedSpaces, false); 890 } 891 return false; 892 } 893 } 894 895 // Read the miscellaneous data from the shared file, and 896 // serialize it out to its various destinations. 897 898 void MetaspaceShared::initialize_shared_spaces() { 899 FileMapInfo *mapinfo = FileMapInfo::current_info(); 900 901 char* buffer = mapinfo->region_base(md); 902 903 // Skip over (reserve space for) a list of addresses of C++ vtables 904 // for Klass objects. They get filled in later. 905 906 void** vtbl_list = (void**)buffer; 907 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*); 908 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size); 909 910 // Skip over (reserve space for) dummy C++ vtables Klass objects. 911 // They are used as is. 912 913 intptr_t vtable_size = *(intptr_t*)buffer; 914 buffer += sizeof(intptr_t); 915 buffer += vtable_size; 916 917 // Create the symbol table using the bucket array at this spot in the 918 // misc data space. Since the symbol table is often modified, this 919 // region (of mapped pages) will be copy-on-write. 920 921 int symbolTableLen = *(intptr_t*)buffer; 922 buffer += sizeof(intptr_t); 923 int number_of_entries = *(intptr_t*)buffer; 924 buffer += sizeof(intptr_t); 925 SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen, 926 number_of_entries); 927 buffer += symbolTableLen; 928 929 // Create the shared dictionary using the bucket array at this spot in 930 // the misc data space. Since the shared dictionary table is never 931 // modified, this region (of mapped pages) will be (effectively, if 932 // not explicitly) read-only. 933 934 int sharedDictionaryLen = *(intptr_t*)buffer; 935 buffer += sizeof(intptr_t); 936 number_of_entries = *(intptr_t*)buffer; 937 buffer += sizeof(intptr_t); 938 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer, 939 sharedDictionaryLen, 940 number_of_entries); 941 buffer += sharedDictionaryLen; 942 943 // Create the package info table using the bucket array at this spot in 944 // the misc data space. Since the package info table is never 945 // modified, this region (of mapped pages) will be (effectively, if 946 // not explicitly) read-only. 947 948 int pkgInfoLen = *(intptr_t*)buffer; 949 buffer += sizeof(intptr_t); 950 number_of_entries = *(intptr_t*)buffer; 951 buffer += sizeof(intptr_t); 952 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen, 953 number_of_entries); 954 buffer += pkgInfoLen; 955 ClassLoader::verify(); 956 957 // The following data in the shared misc data region are the linked 958 // list elements (HashtableEntry objects) for the symbol table, string 959 // table, and shared dictionary. The heap objects referred to by the 960 // symbol table, string table, and shared dictionary are permanent and 961 // unmovable. Since new entries added to the string and symbol tables 962 // are always added at the beginning of the linked lists, THESE LINKED 963 // LIST ELEMENTS ARE READ-ONLY. 964 965 int len = *(intptr_t*)buffer; // skip over symbol table entries 966 buffer += sizeof(intptr_t); 967 buffer += len; 968 969 len = *(intptr_t*)buffer; // skip over shared dictionary entries 970 buffer += sizeof(intptr_t); 971 buffer += len; 972 973 len = *(intptr_t*)buffer; // skip over package info table entries 974 buffer += sizeof(intptr_t); 975 buffer += len; 976 977 len = *(intptr_t*)buffer; // skip over package info table char[] arrays. 978 buffer += sizeof(intptr_t); 979 buffer += len; 980 981 intptr_t* array = (intptr_t*)buffer; 982 ReadClosure rc(&array); 983 serialize(&rc); 984 985 // Close the mapinfo file 986 mapinfo->close(); 987 } 988 989 // JVM/TI RedefineClasses() support: 990 bool MetaspaceShared::remap_shared_readonly_as_readwrite() { 991 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 992 993 if (UseSharedSpaces) { 994 // remap the shared readonly space to shared readwrite, private 995 FileMapInfo* mapinfo = FileMapInfo::current_info(); 996 if (!mapinfo->remap_shared_readonly_as_readwrite()) { 997 return false; 998 } 999 } 1000 return true; 1001 }