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/sharedClassUtil.hpp" 30 #include "classfile/symbolTable.hpp" 31 #include "classfile/systemDictionary.hpp" 32 #include "code/codeCache.hpp" 33 #include "memory/filemap.hpp" 34 #include "memory/gcLocker.hpp" 35 #include "memory/metaspace.hpp" 36 #include "memory/metaspaceShared.hpp" 37 #include "oops/objArrayOop.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "runtime/os.hpp" 40 #include "runtime/signature.hpp" 41 #include "runtime/vm_operations.hpp" 42 #include "runtime/vmThread.hpp" 43 #include "utilities/hashtable.inline.hpp" 44 45 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 46 47 int MetaspaceShared::_max_alignment = 0; 48 49 ReservedSpace* MetaspaceShared::_shared_rs = NULL; 50 51 bool MetaspaceShared::_link_classes_made_progress; 52 bool MetaspaceShared::_check_classes_made_progress; 53 bool MetaspaceShared::_has_error_classes; 54 bool MetaspaceShared::_archive_loading_failed = false; 55 // Read/write a data stream for restoring/preserving metadata pointers and 56 // miscellaneous data from/to the shared archive file. 57 58 void MetaspaceShared::serialize(SerializeClosure* soc) { 59 int tag = 0; 60 soc->do_tag(--tag); 61 62 // Verify the sizes of various metadata in the system. 63 soc->do_tag(sizeof(Method)); 64 soc->do_tag(sizeof(ConstMethod)); 65 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE)); 66 soc->do_tag(sizeof(ConstantPool)); 67 soc->do_tag(sizeof(ConstantPoolCache)); 68 soc->do_tag(objArrayOopDesc::base_offset_in_bytes()); 69 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE)); 70 soc->do_tag(sizeof(Symbol)); 71 72 // Dump/restore miscellaneous metadata. 73 Universe::serialize(soc, true); 74 soc->do_tag(--tag); 75 76 // Dump/restore references to commonly used names and signatures. 77 vmSymbols::serialize(soc); 78 soc->do_tag(--tag); 79 80 soc->do_tag(666); 81 } 82 83 84 // CDS code for dumping shared archive. 85 86 // Global object for holding classes that have been loaded. Since this 87 // is run at a safepoint just before exit, this is the entire set of classes. 88 static GrowableArray<Klass*>* _global_klass_objects; 89 static void collect_classes(Klass* k) { 90 _global_klass_objects->append_if_missing(k); 91 if (k->oop_is_instance()) { 92 // Add in the array classes too 93 InstanceKlass* ik = InstanceKlass::cast(k); 94 ik->array_klasses_do(collect_classes); 95 } 96 } 97 98 static void remove_unshareable_in_classes() { 99 for (int i = 0; i < _global_klass_objects->length(); i++) { 100 Klass* k = _global_klass_objects->at(i); 101 k->remove_unshareable_info(); 102 } 103 } 104 105 // Walk all methods in the class list and assign a fingerprint. 106 // so that this part of the ConstMethod* is read only. 107 static void calculate_fingerprints() { 108 for (int i = 0; i < _global_klass_objects->length(); i++) { 109 Klass* k = _global_klass_objects->at(i); 110 if (k->oop_is_instance()) { 111 InstanceKlass* ik = InstanceKlass::cast(k); 112 for (int i = 0; i < ik->methods()->length(); i++) { 113 Method* m = ik->methods()->at(i); 114 Fingerprinter fp(m); 115 // The side effect of this call sets method's fingerprint field. 116 fp.fingerprint(); 117 } 118 } 119 } 120 } 121 122 // Patch C++ vtable pointer in metadata. 123 124 // Klass and other metadata objects contain references to c++ vtables in the 125 // JVM library. 126 // Fix them to point to our constructed vtables. However, don't iterate 127 // across the space while doing this, as that causes the vtables to be 128 // patched, undoing our useful work. Instead, iterate to make a list, 129 // then use the list to do the fixing. 130 // 131 // Our constructed vtables: 132 // Dump time: 133 // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs 134 // 2. generate_vtable_methods: create jump table, appended to above vtbl_list 135 // 3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and 136 // associated metadata to point to jump table rather than to current vtbl 137 // Table layout: NOTE FIXED SIZE 138 // 1. vtbl pointers 139 // 2. #Klass X #virtual methods per Klass 140 // 1 entry for each, in the order: 141 // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry 142 // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry 143 // ... 144 // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry, 145 // ... Klass<vtbl_list_size>:method<num_virtuals> entry 146 // Sample entry: (Sparc): 147 // save(sp, -256, sp) 148 // ba,pt common_code 149 // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255) 150 // 151 // Restore time: 152 // 1. initialize_shared_space: reserve space for table 153 // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text 154 // 155 // Execution time: 156 // First virtual method call for any object of these metadata types: 157 // 1. object->klass 158 // 2. vtable entry for that klass points to the jump table entries 159 // 3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index 160 // 4. common_code: 161 // Get address of new vtbl pointer for this Klass from updated table 162 // Update new vtbl pointer in the Klass: future virtual calls go direct 163 // Jump to method, using new vtbl pointer and method index 164 165 166 static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) { 167 void* old_vtbl_ptr = *(void**)obj; 168 for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) { 169 if (vtbl_list[i] == old_vtbl_ptr) { 170 return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals; 171 } 172 } 173 ShouldNotReachHere(); 174 return NULL; 175 } 176 177 // Assumes the vtable is in first slot in object. 178 static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) { 179 int n = _global_klass_objects->length(); 180 for (int i = 0; i < n; i++) { 181 Klass* obj = _global_klass_objects->at(i); 182 // Note oop_is_instance() is a virtual call. After patching vtables 183 // all virtual calls on the dummy vtables will restore the original! 184 if (obj->oop_is_instance()) { 185 InstanceKlass* ik = InstanceKlass::cast(obj); 186 *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik); 187 ConstantPool* cp = ik->constants(); 188 *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp); 189 for (int j = 0; j < ik->methods()->length(); j++) { 190 Method* m = ik->methods()->at(j); 191 *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m); 192 } 193 } else { 194 // Array klasses 195 Klass* k = obj; 196 *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k); 197 } 198 } 199 } 200 201 // Closure for serializing initialization data out to a data area to be 202 // written to the shared file. 203 204 class WriteClosure : public SerializeClosure { 205 private: 206 intptr_t* top; 207 char* end; 208 209 inline void check_space() { 210 if ((char*)top + sizeof(intptr_t) > end) { 211 report_out_of_shared_space(SharedMiscData); 212 } 213 } 214 215 public: 216 WriteClosure(char* md_top, char* md_end) { 217 top = (intptr_t*)md_top; 218 end = md_end; 219 } 220 221 char* get_top() { return (char*)top; } 222 223 void do_ptr(void** p) { 224 check_space(); 225 *top = (intptr_t)*p; 226 ++top; 227 } 228 229 void do_tag(int tag) { 230 check_space(); 231 *top = (intptr_t)tag; 232 ++top; 233 } 234 235 void do_region(u_char* start, size_t size) { 236 if ((char*)top + size > end) { 237 report_out_of_shared_space(SharedMiscData); 238 } 239 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment"); 240 assert(size % sizeof(intptr_t) == 0, "bad size"); 241 do_tag((int)size); 242 while (size > 0) { 243 *top = *(intptr_t*)start; 244 ++top; 245 start += sizeof(intptr_t); 246 size -= sizeof(intptr_t); 247 } 248 } 249 250 bool reading() const { return false; } 251 }; 252 253 // This is for dumping detailed statistics for the allocations 254 // in the shared spaces. 255 class DumpAllocClosure : public Metaspace::AllocRecordClosure { 256 public: 257 258 // Here's poor man's enum inheritance 259 #define SHAREDSPACE_OBJ_TYPES_DO(f) \ 260 METASPACE_OBJ_TYPES_DO(f) \ 261 f(SymbolHashentry) \ 262 f(SymbolBuckets) \ 263 f(Other) 264 265 #define SHAREDSPACE_OBJ_TYPE_DECLARE(name) name ## Type, 266 #define SHAREDSPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name; 267 268 enum Type { 269 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc 270 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_DECLARE) 271 _number_of_types 272 }; 273 274 static const char * type_name(Type type) { 275 switch(type) { 276 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_NAME_CASE) 277 default: 278 ShouldNotReachHere(); 279 return NULL; 280 } 281 } 282 283 public: 284 enum { 285 RO = 0, 286 RW = 1 287 }; 288 289 int _counts[2][_number_of_types]; 290 int _bytes [2][_number_of_types]; 291 int _which; 292 293 DumpAllocClosure() { 294 memset(_counts, 0, sizeof(_counts)); 295 memset(_bytes, 0, sizeof(_bytes)); 296 }; 297 298 void iterate_metaspace(Metaspace* space, int which) { 299 assert(which == RO || which == RW, "sanity"); 300 _which = which; 301 space->iterate(this); 302 } 303 304 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) { 305 assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity"); 306 _counts[_which][type] ++; 307 _bytes [_which][type] += byte_size; 308 } 309 310 void dump_stats(int ro_all, int rw_all, int md_all, int mc_all); 311 }; 312 313 void DumpAllocClosure::dump_stats(int ro_all, int rw_all, int md_all, int mc_all) { 314 rw_all += (md_all + mc_all); // md and mc are all mapped Read/Write 315 int other_bytes = md_all + mc_all; 316 317 // Calculate size of data that was not allocated by Metaspace::allocate() 318 int symbol_count = _counts[RO][MetaspaceObj::SymbolType]; 319 int symhash_bytes = symbol_count * sizeof (HashtableEntry<Symbol*, mtSymbol>); 320 int symbuck_count = SymbolTable::the_table()->table_size(); 321 int symbuck_bytes = symbuck_count * sizeof(HashtableBucket<mtSymbol>); 322 323 _counts[RW][SymbolHashentryType] = symbol_count; 324 _bytes [RW][SymbolHashentryType] = symhash_bytes; 325 other_bytes -= symhash_bytes; 326 327 _counts[RW][SymbolBucketsType] = symbuck_count; 328 _bytes [RW][SymbolBucketsType] = symbuck_bytes; 329 other_bytes -= symbuck_bytes; 330 331 // TODO: count things like dictionary, vtable, etc 332 _bytes[RW][OtherType] = other_bytes; 333 334 // prevent divide-by-zero 335 if (ro_all < 1) { 336 ro_all = 1; 337 } 338 if (rw_all < 1) { 339 rw_all = 1; 340 } 341 342 int all_ro_count = 0; 343 int all_ro_bytes = 0; 344 int all_rw_count = 0; 345 int all_rw_bytes = 0; 346 347 // To make fmt_stats be a syntactic constant (for format warnings), use #define. 348 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f" 349 const char *sep = "--------------------+---------------------------+---------------------------+--------------------------"; 350 const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %"; 351 352 tty->print_cr("Detailed metadata info (rw includes md and mc):"); 353 tty->print_cr("%s", hdr); 354 tty->print_cr("%s", sep); 355 for (int type = 0; type < int(_number_of_types); type ++) { 356 const char *name = type_name((Type)type); 357 int ro_count = _counts[RO][type]; 358 int ro_bytes = _bytes [RO][type]; 359 int rw_count = _counts[RW][type]; 360 int rw_bytes = _bytes [RW][type]; 361 int count = ro_count + rw_count; 362 int bytes = ro_bytes + rw_bytes; 363 364 double ro_perc = 100.0 * double(ro_bytes) / double(ro_all); 365 double rw_perc = 100.0 * double(rw_bytes) / double(rw_all); 366 double perc = 100.0 * double(bytes) / double(ro_all + rw_all); 367 368 tty->print_cr(fmt_stats, name, 369 ro_count, ro_bytes, ro_perc, 370 rw_count, rw_bytes, rw_perc, 371 count, bytes, perc); 372 373 all_ro_count += ro_count; 374 all_ro_bytes += ro_bytes; 375 all_rw_count += rw_count; 376 all_rw_bytes += rw_bytes; 377 } 378 379 int all_count = all_ro_count + all_rw_count; 380 int all_bytes = all_ro_bytes + all_rw_bytes; 381 382 double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all); 383 double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all); 384 double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all); 385 386 tty->print_cr("%s", sep); 387 tty->print_cr(fmt_stats, "Total", 388 all_ro_count, all_ro_bytes, all_ro_perc, 389 all_rw_count, all_rw_bytes, all_rw_perc, 390 all_count, all_bytes, all_perc); 391 392 assert(all_ro_bytes == ro_all, "everything should have been counted"); 393 assert(all_rw_bytes == rw_all, "everything should have been counted"); 394 #undef fmt_stats 395 } 396 397 // Populate the shared space. 398 399 class VM_PopulateDumpSharedSpace: public VM_Operation { 400 private: 401 ClassLoaderData* _loader_data; 402 GrowableArray<Klass*> *_class_promote_order; 403 VirtualSpace _md_vs; 404 VirtualSpace _mc_vs; 405 406 public: 407 VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data, 408 GrowableArray<Klass*> *class_promote_order) : 409 _loader_data(loader_data) { 410 411 // Split up and initialize the misc code and data spaces 412 ReservedSpace* shared_rs = MetaspaceShared::shared_rs(); 413 int metadata_size = SharedReadOnlySize+SharedReadWriteSize; 414 ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size); 415 ReservedSpace misc_section = shared_rs->last_part(metadata_size); 416 417 // Now split into misc sections. 418 ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize); 419 ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize); 420 _md_vs.initialize(md_rs, SharedMiscDataSize); 421 _mc_vs.initialize(mc_rs, SharedMiscCodeSize); 422 _class_promote_order = class_promote_order; 423 } 424 425 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; } 426 void doit(); // outline because gdb sucks 427 }; // class VM_PopulateDumpSharedSpace 428 429 430 void VM_PopulateDumpSharedSpace::doit() { 431 Thread* THREAD = VMThread::vm_thread(); 432 NOT_PRODUCT(SystemDictionary::verify();) 433 // The following guarantee is meant to ensure that no loader constraints 434 // exist yet, since the constraints table is not shared. This becomes 435 // more important now that we don't re-initialize vtables/itables for 436 // shared classes at runtime, where constraints were previously created. 437 guarantee(SystemDictionary::constraints()->number_of_entries() == 0, 438 "loader constraints are not saved"); 439 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0, 440 "placeholders are not saved"); 441 // Revisit and implement this if we prelink method handle call sites: 442 guarantee(SystemDictionary::invoke_method_table() == NULL || 443 SystemDictionary::invoke_method_table()->number_of_entries() == 0, 444 "invoke method table is not saved"); 445 446 // At this point, many classes have been loaded. 447 // Gather systemDictionary classes in a global array and do everything to 448 // that so we don't have to walk the SystemDictionary again. 449 _global_klass_objects = new GrowableArray<Klass*>(1000); 450 Universe::basic_type_classes_do(collect_classes); 451 SystemDictionary::classes_do(collect_classes); 452 453 tty->print_cr("Number of classes %d", _global_klass_objects->length()); 454 { 455 int num_type_array = 0, num_obj_array = 0, num_inst = 0; 456 for (int i = 0; i < _global_klass_objects->length(); i++) { 457 Klass* k = _global_klass_objects->at(i); 458 if (k->oop_is_instance()) { 459 num_inst ++; 460 } else if (k->oop_is_objArray()) { 461 num_obj_array ++; 462 } else { 463 assert(k->oop_is_typeArray(), "sanity"); 464 num_type_array ++; 465 } 466 } 467 tty->print_cr(" instance classes = %5d", num_inst); 468 tty->print_cr(" obj array classes = %5d", num_obj_array); 469 tty->print_cr(" type array classes = %5d", num_type_array); 470 } 471 472 // Update all the fingerprints in the shared methods. 473 tty->print("Calculating fingerprints ... "); 474 calculate_fingerprints(); 475 tty->print_cr("done. "); 476 477 // Remove all references outside the metadata 478 tty->print("Removing unshareable information ... "); 479 remove_unshareable_in_classes(); 480 tty->print_cr("done. "); 481 482 // Set up the share data and shared code segments. 483 char* md_low = _md_vs.low(); 484 char* md_top = md_low; 485 char* md_end = _md_vs.high(); 486 char* mc_low = _mc_vs.low(); 487 char* mc_top = mc_low; 488 char* mc_end = _mc_vs.high(); 489 490 // Reserve space for the list of Klass*s whose vtables are used 491 // for patching others as needed. 492 493 void** vtbl_list = (void**)md_top; 494 int vtbl_list_size = MetaspaceShared::vtbl_list_size; 495 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size); 496 497 md_top += vtbl_list_size * sizeof(void*); 498 void* vtable = md_top; 499 500 // Reserve space for a new dummy vtable for klass objects in the 501 // heap. Generate self-patching vtable entries. 502 503 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable, 504 &md_top, md_end, 505 &mc_top, mc_end); 506 507 // Reorder the system dictionary. (Moving the symbols affects 508 // how the hash table indices are calculated.) 509 // Not doing this either. 510 511 SystemDictionary::reorder_dictionary(); 512 513 NOT_PRODUCT(SystemDictionary::verify();) 514 515 // Copy the the symbol table, and the system dictionary to the shared 516 // space in usable form. Copy the hashtable 517 // buckets first [read-write], then copy the linked lists of entries 518 // [read-only]. 519 520 SymbolTable::reverse(md_top); 521 NOT_PRODUCT(SymbolTable::verify()); 522 SymbolTable::copy_buckets(&md_top, md_end); 523 524 SystemDictionary::reverse(); 525 SystemDictionary::copy_buckets(&md_top, md_end); 526 527 ClassLoader::verify(); 528 ClassLoader::copy_package_info_buckets(&md_top, md_end); 529 ClassLoader::verify(); 530 531 SymbolTable::copy_table(&md_top, md_end); 532 SystemDictionary::copy_table(&md_top, md_end); 533 ClassLoader::verify(); 534 ClassLoader::copy_package_info_table(&md_top, md_end); 535 ClassLoader::verify(); 536 537 // Write the other data to the output array. 538 WriteClosure wc(md_top, md_end); 539 MetaspaceShared::serialize(&wc); 540 md_top = wc.get_top(); 541 542 // Print shared spaces all the time 543 // To make fmt_space be a syntactic constant (for format warnings), use #define. 544 #define fmt_space "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " INTPTR_FORMAT 545 Metaspace* ro_space = _loader_data->ro_metaspace(); 546 Metaspace* rw_space = _loader_data->rw_metaspace(); 547 548 // Allocated size of each space (may not be all occupied) 549 const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType); 550 const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType); 551 const size_t md_alloced = md_end-md_low; 552 const size_t mc_alloced = mc_end-mc_low; 553 const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced; 554 555 // Occupied size of each space. 556 const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType); 557 const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType); 558 const size_t md_bytes = size_t(md_top - md_low); 559 const size_t mc_bytes = size_t(mc_top - mc_low); 560 561 // Percent of total size 562 const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes; 563 const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0; 564 const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0; 565 const double md_t_perc = md_bytes / double(total_bytes) * 100.0; 566 const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0; 567 568 // Percent of fullness of each space 569 const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0; 570 const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0; 571 const double md_u_perc = md_bytes / double(md_alloced) * 100.0; 572 const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0; 573 const double total_u_perc = total_bytes / double(total_alloced) * 100.0; 574 575 tty->print_cr(fmt_space, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom()); 576 tty->print_cr(fmt_space, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom()); 577 tty->print_cr(fmt_space, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low); 578 tty->print_cr(fmt_space, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low); 579 tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]", 580 total_bytes, total_alloced, total_u_perc); 581 582 // Update the vtable pointers in all of the Klass objects in the 583 // heap. They should point to newly generated vtable. 584 patch_klass_vtables(vtbl_list, vtable); 585 586 // dunno what this is for. 587 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass); 588 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*)); 589 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*)); 590 591 // Create and write the archive file that maps the shared spaces. 592 593 FileMapInfo* mapinfo = new FileMapInfo(); 594 mapinfo->populate_header(MetaspaceShared::max_alignment()); 595 596 // Pass 1 - update file offsets in header. 597 mapinfo->write_header(); 598 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true); 599 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false); 600 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(), 601 pointer_delta(md_top, _md_vs.low(), sizeof(char)), 602 SharedMiscDataSize, 603 false, false); 604 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(), 605 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)), 606 SharedMiscCodeSize, 607 true, true); 608 609 // Pass 2 - write data. 610 mapinfo->open_for_write(); 611 mapinfo->set_header_crc(mapinfo->compute_header_crc()); 612 mapinfo->write_header(); 613 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true); 614 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false); 615 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(), 616 pointer_delta(md_top, _md_vs.low(), sizeof(char)), 617 SharedMiscDataSize, 618 false, false); 619 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(), 620 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)), 621 SharedMiscCodeSize, 622 true, true); 623 mapinfo->close(); 624 625 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*)); 626 627 if (PrintSharedSpaces) { 628 DumpAllocClosure dac; 629 dac.iterate_metaspace(_loader_data->ro_metaspace(), DumpAllocClosure::RO); 630 dac.iterate_metaspace(_loader_data->rw_metaspace(), DumpAllocClosure::RW); 631 632 dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes)); 633 } 634 #undef fmt_space 635 } 636 637 638 void MetaspaceShared::link_one_shared_class(Klass* obj, TRAPS) { 639 Klass* k = obj; 640 if (k->oop_is_instance()) { 641 InstanceKlass* ik = (InstanceKlass*) k; 642 // Link the class to cause the bytecodes to be rewritten and the 643 // cpcache to be created. Class verification is done according 644 // to -Xverify setting. 645 _link_classes_made_progress |= try_link_class(ik, THREAD); 646 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class"); 647 } 648 } 649 650 void MetaspaceShared::check_one_shared_class(Klass* k) { 651 if (k->oop_is_instance() && InstanceKlass::cast(k)->check_sharing_error_state()) { 652 _check_classes_made_progress = true; 653 } 654 } 655 656 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) { 657 // We need to iterate because verification may cause additional classes 658 // to be loaded. 659 do { 660 _link_classes_made_progress = false; 661 SystemDictionary::classes_do(link_one_shared_class, THREAD); 662 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class"); 663 } while (_link_classes_made_progress); 664 665 if (_has_error_classes) { 666 // Mark all classes whose super class or interfaces failed verification. 667 do { 668 // Not completely sure if we need to do this iteratively. Anyway, 669 // we should come here only if there are unverifiable classes, which 670 // shouldn't happen in normal cases. So better safe than sorry. 671 _check_classes_made_progress = false; 672 SystemDictionary::classes_do(check_one_shared_class); 673 } while (_check_classes_made_progress); 674 675 if (IgnoreUnverifiableClassesDuringDump) { 676 // This is useful when running JCK or SQE tests. You should not 677 // enable this when running real apps. 678 SystemDictionary::remove_classes_in_error_state(); 679 } else { 680 tty->print_cr("Please remove the unverifiable classes from your class list and try again"); 681 exit(1); 682 } 683 } 684 } 685 686 void MetaspaceShared::prepare_for_dumping() { 687 ClassLoader::initialize_shared_path(); 688 FileMapInfo::allocate_classpath_entry_table(); 689 } 690 691 // Preload classes from a list, populate the shared spaces and dump to a 692 // file. 693 void MetaspaceShared::preload_and_dump(TRAPS) { 694 TraceTime timer("Dump Shared Spaces", TraceStartupTime); 695 ResourceMark rm; 696 697 tty->print_cr("Allocated shared space: %d bytes at " PTR_FORMAT, 698 MetaspaceShared::shared_rs()->size(), 699 MetaspaceShared::shared_rs()->base()); 700 701 // Preload classes to be shared. 702 // Should use some os:: method rather than fopen() here. aB. 703 const char* class_list_path; 704 if (SharedClassListFile == NULL) { 705 // Construct the path to the class list (in jre/lib) 706 // Walk up two directories from the location of the VM and 707 // optionally tack on "lib" (depending on platform) 708 char class_list_path_str[JVM_MAXPATHLEN]; 709 os::jvm_path(class_list_path_str, sizeof(class_list_path_str)); 710 for (int i = 0; i < 3; i++) { 711 char *end = strrchr(class_list_path_str, *os::file_separator()); 712 if (end != NULL) *end = '\0'; 713 } 714 int class_list_path_len = (int)strlen(class_list_path_str); 715 if (class_list_path_len >= 3) { 716 if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) { 717 if (class_list_path_len < JVM_MAXPATHLEN - 4) { 718 jio_snprintf(class_list_path_str + class_list_path_len, 719 sizeof(class_list_path_str) - class_list_path_len, 720 "%slib", os::file_separator()); 721 class_list_path_len += 4; 722 } 723 } 724 } 725 if (class_list_path_len < JVM_MAXPATHLEN - 10) { 726 jio_snprintf(class_list_path_str + class_list_path_len, 727 sizeof(class_list_path_str) - class_list_path_len, 728 "%sclasslist", os::file_separator()); 729 } 730 class_list_path = class_list_path_str; 731 } else { 732 class_list_path = SharedClassListFile; 733 } 734 735 int class_count = 0; 736 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>(); 737 738 // sun.io.Converters 739 static const char obj_array_sig[] = "[[Ljava/lang/Object;"; 740 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD); 741 742 // java.util.HashMap 743 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;"; 744 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD); 745 746 tty->print_cr("Loading classes to share ..."); 747 _has_error_classes = false; 748 class_count += preload_and_dump(class_list_path, class_promote_order, 749 THREAD); 750 if (ExtraSharedClassListFile) { 751 class_count += preload_and_dump(ExtraSharedClassListFile, class_promote_order, 752 THREAD); 753 } 754 tty->print_cr("Loading classes to share: done."); 755 756 if (PrintSharedSpaces) { 757 tty->print_cr("Shared spaces: preloaded %d classes", class_count); 758 } 759 760 // Rewrite and link classes 761 tty->print_cr("Rewriting and linking classes ..."); 762 763 // Link any classes which got missed. This would happen if we have loaded classes that 764 // were not explicitly specified in the classlist. E.g., if an interface implemented by class K 765 // fails verification, all other interfaces that were not specified in the classlist but 766 // are implemented by K are not verified. 767 link_and_cleanup_shared_classes(CATCH); 768 tty->print_cr("Rewriting and linking classes: done"); 769 770 // Create and dump the shared spaces. Everything so far is loaded 771 // with the null class loader. 772 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data(); 773 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order); 774 VMThread::execute(&op); 775 776 // Since various initialization steps have been undone by this process, 777 // it is not reasonable to continue running a java process. 778 exit(0); 779 } 780 781 int MetaspaceShared::preload_and_dump(const char * class_list_path, 782 GrowableArray<Klass*>* class_promote_order, 783 TRAPS) { 784 FILE* file = fopen(class_list_path, "r"); 785 char class_name[256]; 786 int class_count = 0; 787 788 if (file != NULL) { 789 while ((fgets(class_name, sizeof class_name, file)) != NULL) { 790 if (*class_name == '#') { // comment 791 continue; 792 } 793 // Remove trailing newline 794 size_t name_len = strlen(class_name); 795 if (class_name[name_len-1] == '\n') { 796 class_name[name_len-1] = '\0'; 797 } 798 799 // Got a class name - load it. 800 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD); 801 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol."); 802 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol, 803 THREAD); 804 CLEAR_PENDING_EXCEPTION; 805 if (klass != NULL) { 806 if (PrintSharedSpaces && Verbose && WizardMode) { 807 tty->print_cr("Shared spaces preloaded: %s", class_name); 808 } 809 810 InstanceKlass* ik = InstanceKlass::cast(klass); 811 812 // Should be class load order as per -XX:+TraceClassLoadingPreorder 813 class_promote_order->append(ik); 814 815 // Link the class to cause the bytecodes to be rewritten and the 816 // cpcache to be created. The linking is done as soon as classes 817 // are loaded in order that the related data structures (klass and 818 // cpCache) are located together. 819 try_link_class(ik, THREAD); 820 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class"); 821 822 class_count++; 823 } else { 824 //tty->print_cr("Preload failed: %s", class_name); 825 } 826 } 827 fclose(file); 828 } else { 829 char errmsg[JVM_MAXPATHLEN]; 830 os::lasterror(errmsg, JVM_MAXPATHLEN); 831 tty->print_cr("Loading classlist failed: %s", errmsg); 832 exit(1); 833 } 834 835 return class_count; 836 } 837 838 // Returns true if the class's status has changed 839 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) { 840 assert(DumpSharedSpaces, "should only be called during dumping"); 841 if (ik->init_state() < InstanceKlass::linked) { 842 bool saved = BytecodeVerificationLocal; 843 if (!SharedClassUtil::is_shared_boot_class(ik)) { 844 // The verification decision is based on BytecodeVerificationRemote 845 // for non-system classes. Since we are using the NULL classloader 846 // to load non-system classes during dumping, we need to temporarily 847 // change BytecodeVerificationLocal to be the same as 848 // BytecodeVerificationRemote. Note this can cause the parent system 849 // classes also being verified. The extra overhead is acceptable during 850 // dumping. 851 BytecodeVerificationLocal = BytecodeVerificationRemote; 852 } 853 ik->link_class(THREAD); 854 if (HAS_PENDING_EXCEPTION) { 855 ResourceMark rm; 856 tty->print_cr("Preload Warning: Verification failed for %s", 857 ik->external_name()); 858 CLEAR_PENDING_EXCEPTION; 859 ik->set_in_error_state(); 860 _has_error_classes = true; 861 } 862 BytecodeVerificationLocal = saved; 863 return true; 864 } else { 865 return false; 866 } 867 } 868 869 // Closure for serializing initialization data in from a data area 870 // (ptr_array) read from the shared file. 871 872 class ReadClosure : public SerializeClosure { 873 private: 874 intptr_t** _ptr_array; 875 876 inline intptr_t nextPtr() { 877 return *(*_ptr_array)++; 878 } 879 880 public: 881 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; } 882 883 void do_ptr(void** p) { 884 assert(*p == NULL, "initializing previous initialized pointer."); 885 intptr_t obj = nextPtr(); 886 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100, 887 "hit tag while initializing ptrs."); 888 *p = (void*)obj; 889 } 890 891 void do_tag(int tag) { 892 int old_tag; 893 old_tag = (int)(intptr_t)nextPtr(); 894 // do_int(&old_tag); 895 assert(tag == old_tag, "old tag doesn't match"); 896 FileMapInfo::assert_mark(tag == old_tag); 897 } 898 899 void do_region(u_char* start, size_t size) { 900 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment"); 901 assert(size % sizeof(intptr_t) == 0, "bad size"); 902 do_tag((int)size); 903 while (size > 0) { 904 *(intptr_t*)start = nextPtr(); 905 start += sizeof(intptr_t); 906 size -= sizeof(intptr_t); 907 } 908 } 909 910 bool reading() const { return true; } 911 }; 912 913 // Return true if given address is in the mapped shared space. 914 bool MetaspaceShared::is_in_shared_space(const void* p) { 915 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p); 916 } 917 918 void MetaspaceShared::print_shared_spaces() { 919 if (UseSharedSpaces) { 920 FileMapInfo::current_info()->print_shared_spaces(); 921 } 922 } 923 924 925 // Map shared spaces at requested addresses and return if succeeded. 926 // Need to keep the bounds of the ro and rw space for the Metaspace::contains 927 // call, or is_in_shared_space. 928 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) { 929 size_t image_alignment = mapinfo->alignment(); 930 931 #ifndef _WINDOWS 932 // Map in the shared memory and then map the regions on top of it. 933 // On Windows, don't map the memory here because it will cause the 934 // mappings of the regions to fail. 935 ReservedSpace shared_rs = mapinfo->reserve_shared_memory(); 936 if (!shared_rs.is_reserved()) return false; 937 #endif 938 939 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces"); 940 941 char* _ro_base = NULL; 942 char* _rw_base = NULL; 943 char* _md_base = NULL; 944 char* _mc_base = NULL; 945 946 // Map each shared region 947 if ((_ro_base = mapinfo->map_region(ro)) != NULL && 948 mapinfo->verify_region_checksum(ro) && 949 (_rw_base = mapinfo->map_region(rw)) != NULL && 950 mapinfo->verify_region_checksum(rw) && 951 (_md_base = mapinfo->map_region(md)) != NULL && 952 mapinfo->verify_region_checksum(md) && 953 (_mc_base = mapinfo->map_region(mc)) != NULL && 954 mapinfo->verify_region_checksum(mc) && 955 (image_alignment == (size_t)max_alignment()) && 956 mapinfo->validate_classpath_entry_table()) { 957 // Success (no need to do anything) 958 return true; 959 } else { 960 // If there was a failure in mapping any of the spaces, unmap the ones 961 // that succeeded 962 if (_ro_base != NULL) mapinfo->unmap_region(ro); 963 if (_rw_base != NULL) mapinfo->unmap_region(rw); 964 if (_md_base != NULL) mapinfo->unmap_region(md); 965 if (_mc_base != NULL) mapinfo->unmap_region(mc); 966 #ifndef _WINDOWS 967 // Release the entire mapped region 968 shared_rs.release(); 969 #endif 970 // If -Xshare:on is specified, print out the error message and exit VM, 971 // otherwise, set UseSharedSpaces to false and continue. 972 if (RequireSharedSpaces || PrintSharedArchiveAndExit) { 973 vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on."); 974 } else { 975 FLAG_SET_DEFAULT(UseSharedSpaces, false); 976 } 977 return false; 978 } 979 } 980 981 // Read the miscellaneous data from the shared file, and 982 // serialize it out to its various destinations. 983 984 void MetaspaceShared::initialize_shared_spaces() { 985 FileMapInfo *mapinfo = FileMapInfo::current_info(); 986 987 char* buffer = mapinfo->region_base(md); 988 989 // Skip over (reserve space for) a list of addresses of C++ vtables 990 // for Klass objects. They get filled in later. 991 992 void** vtbl_list = (void**)buffer; 993 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*); 994 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size); 995 996 // Skip over (reserve space for) dummy C++ vtables Klass objects. 997 // They are used as is. 998 999 intptr_t vtable_size = *(intptr_t*)buffer; 1000 buffer += sizeof(intptr_t); 1001 buffer += vtable_size; 1002 1003 // Create the symbol table using the bucket array at this spot in the 1004 // misc data space. Since the symbol table is often modified, this 1005 // region (of mapped pages) will be copy-on-write. 1006 1007 int symbolTableLen = *(intptr_t*)buffer; 1008 buffer += sizeof(intptr_t); 1009 int number_of_entries = *(intptr_t*)buffer; 1010 buffer += sizeof(intptr_t); 1011 SymbolTable::create_table((HashtableBucket<mtSymbol>*)buffer, symbolTableLen, 1012 number_of_entries); 1013 buffer += symbolTableLen; 1014 1015 // Create the shared dictionary using the bucket array at this spot in 1016 // the misc data space. Since the shared dictionary table is never 1017 // modified, this region (of mapped pages) will be (effectively, if 1018 // not explicitly) read-only. 1019 1020 int sharedDictionaryLen = *(intptr_t*)buffer; 1021 buffer += sizeof(intptr_t); 1022 number_of_entries = *(intptr_t*)buffer; 1023 buffer += sizeof(intptr_t); 1024 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer, 1025 sharedDictionaryLen, 1026 number_of_entries); 1027 buffer += sharedDictionaryLen; 1028 1029 // Create the package info table using the bucket array at this spot in 1030 // the misc data space. Since the package info table is never 1031 // modified, this region (of mapped pages) will be (effectively, if 1032 // not explicitly) read-only. 1033 1034 int pkgInfoLen = *(intptr_t*)buffer; 1035 buffer += sizeof(intptr_t); 1036 number_of_entries = *(intptr_t*)buffer; 1037 buffer += sizeof(intptr_t); 1038 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen, 1039 number_of_entries); 1040 buffer += pkgInfoLen; 1041 ClassLoader::verify(); 1042 1043 // The following data in the shared misc data region are the linked 1044 // list elements (HashtableEntry objects) for the symbol table, string 1045 // table, and shared dictionary. The heap objects referred to by the 1046 // symbol table, string table, and shared dictionary are permanent and 1047 // unmovable. Since new entries added to the string and symbol tables 1048 // are always added at the beginning of the linked lists, THESE LINKED 1049 // LIST ELEMENTS ARE READ-ONLY. 1050 1051 int len = *(intptr_t*)buffer; // skip over symbol table entries 1052 buffer += sizeof(intptr_t); 1053 buffer += len; 1054 1055 len = *(intptr_t*)buffer; // skip over shared dictionary entries 1056 buffer += sizeof(intptr_t); 1057 buffer += len; 1058 1059 len = *(intptr_t*)buffer; // skip over package info table entries 1060 buffer += sizeof(intptr_t); 1061 buffer += len; 1062 1063 len = *(intptr_t*)buffer; // skip over package info table char[] arrays. 1064 buffer += sizeof(intptr_t); 1065 buffer += len; 1066 1067 intptr_t* array = (intptr_t*)buffer; 1068 ReadClosure rc(&array); 1069 serialize(&rc); 1070 1071 // Close the mapinfo file 1072 mapinfo->close(); 1073 1074 if (PrintSharedArchiveAndExit) { 1075 if (PrintSharedDictionary) { 1076 tty->print_cr("\nShared classes:\n"); 1077 SystemDictionary::print_shared(false); 1078 } 1079 if (_archive_loading_failed) { 1080 tty->print_cr("archive is invalid"); 1081 vm_exit(1); 1082 } else { 1083 tty->print_cr("archive is valid"); 1084 vm_exit(0); 1085 } 1086 } 1087 } 1088 1089 // JVM/TI RedefineClasses() support: 1090 bool MetaspaceShared::remap_shared_readonly_as_readwrite() { 1091 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1092 1093 if (UseSharedSpaces) { 1094 // remap the shared readonly space to shared readwrite, private 1095 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1096 if (!mapinfo->remap_shared_readonly_as_readwrite()) { 1097 return false; 1098 } 1099 } 1100 return true; 1101 } 1102 1103 int MetaspaceShared::count_class(const char* classlist_file) { 1104 if (classlist_file == NULL) { 1105 return 0; 1106 } 1107 char class_name[256]; 1108 int class_count = 0; 1109 FILE* file = fopen(classlist_file, "r"); 1110 if (file != NULL) { 1111 while ((fgets(class_name, sizeof class_name, file)) != NULL) { 1112 if (*class_name == '#') { // comment 1113 continue; 1114 } 1115 class_count++; 1116 } 1117 fclose(file); 1118 } else { 1119 char errmsg[JVM_MAXPATHLEN]; 1120 os::lasterror(errmsg, JVM_MAXPATHLEN); 1121 tty->print_cr("Loading classlist failed: %s", errmsg); 1122 exit(1); 1123 } 1124 1125 return class_count; 1126 } 1127 1128 // the sizes are good for typical large applications that have a lot of shared 1129 // classes 1130 void MetaspaceShared::estimate_regions_size() { 1131 int class_count = count_class(SharedClassListFile); 1132 class_count += count_class(ExtraSharedClassListFile); 1133 1134 if (class_count > LargeThresholdClassCount) { 1135 if (class_count < HugeThresholdClassCount) { 1136 SET_ESTIMATED_SIZE(Large, ReadOnly); 1137 SET_ESTIMATED_SIZE(Large, ReadWrite); 1138 SET_ESTIMATED_SIZE(Large, MiscData); 1139 SET_ESTIMATED_SIZE(Large, MiscCode); 1140 } else { 1141 SET_ESTIMATED_SIZE(Huge, ReadOnly); 1142 SET_ESTIMATED_SIZE(Huge, ReadWrite); 1143 SET_ESTIMATED_SIZE(Huge, MiscData); 1144 SET_ESTIMATED_SIZE(Huge, MiscCode); 1145 } 1146 } 1147 }