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