1 /* 2 * Copyright (c) 2012, 2015, 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 "interpreter/bytecodes.hpp" 34 #include "interpreter/bytecodeStream.hpp" 35 #include "memory/filemap.hpp" 36 #include "memory/gcLocker.hpp" 37 #include "memory/metaspace.hpp" 38 #include "memory/metaspaceShared.hpp" 39 #include "oops/objArrayOop.hpp" 40 #include "oops/oop.inline.hpp" 41 #include "runtime/os.hpp" 42 #include "runtime/signature.hpp" 43 #include "runtime/vm_operations.hpp" 44 #include "runtime/vmThread.hpp" 45 #include "utilities/hashtable.inline.hpp" 46 47 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 48 49 int MetaspaceShared::_max_alignment = 0; 50 51 ReservedSpace* MetaspaceShared::_shared_rs = NULL; 52 53 MetaspaceSharedStats MetaspaceShared::_stats; 54 55 bool MetaspaceShared::_link_classes_made_progress; 56 bool MetaspaceShared::_check_classes_made_progress; 57 bool MetaspaceShared::_has_error_classes; 58 bool MetaspaceShared::_archive_loading_failed = false; 59 // Read/write a data stream for restoring/preserving metadata pointers and 60 // miscellaneous data from/to the shared archive file. 61 62 void MetaspaceShared::serialize(SerializeClosure* soc) { 63 int tag = 0; 64 soc->do_tag(--tag); 65 66 // Verify the sizes of various metadata in the system. 67 soc->do_tag(sizeof(Method)); 68 soc->do_tag(sizeof(ConstMethod)); 69 soc->do_tag(arrayOopDesc::base_offset_in_bytes(T_BYTE)); 70 soc->do_tag(sizeof(ConstantPool)); 71 soc->do_tag(sizeof(ConstantPoolCache)); 72 soc->do_tag(objArrayOopDesc::base_offset_in_bytes()); 73 soc->do_tag(typeArrayOopDesc::base_offset_in_bytes(T_BYTE)); 74 soc->do_tag(sizeof(Symbol)); 75 76 // Dump/restore miscellaneous metadata. 77 Universe::serialize(soc, true); 78 soc->do_tag(--tag); 79 80 // Dump/restore references to commonly used names and signatures. 81 vmSymbols::serialize(soc); 82 soc->do_tag(--tag); 83 84 soc->do_tag(666); 85 } 86 87 88 // CDS code for dumping shared archive. 89 90 // Global object for holding classes that have been loaded. Since this 91 // is run at a safepoint just before exit, this is the entire set of classes. 92 static GrowableArray<Klass*>* _global_klass_objects; 93 static void collect_classes(Klass* k) { 94 _global_klass_objects->append_if_missing(k); 95 if (k->oop_is_instance()) { 96 // Add in the array classes too 97 InstanceKlass* ik = InstanceKlass::cast(k); 98 ik->array_klasses_do(collect_classes); 99 } 100 } 101 102 static void remove_unshareable_in_classes() { 103 for (int i = 0; i < _global_klass_objects->length(); i++) { 104 Klass* k = _global_klass_objects->at(i); 105 k->remove_unshareable_info(); 106 } 107 } 108 109 static void rewrite_nofast_bytecode(Method* method) { 110 RawBytecodeStream bcs(method); 111 while (!bcs.is_last_bytecode()) { 112 Bytecodes::Code opcode = bcs.raw_next(); 113 switch (opcode) { 114 case Bytecodes::_getfield: *bcs.bcp() = Bytecodes::_nofast_getfield; break; 115 case Bytecodes::_putfield: *bcs.bcp() = Bytecodes::_nofast_putfield; break; 116 case Bytecodes::_aload_0: *bcs.bcp() = Bytecodes::_nofast_aload_0; break; 117 case Bytecodes::_iload: *bcs.bcp() = Bytecodes::_nofast_iload; break; 118 default: break; 119 } 120 } 121 } 122 123 // Walk all methods in the class list to ensure that they won't be modified at 124 // run time. This includes: 125 // [1] Rewrite all bytecodes as needed, so that the ConstMethod* will not be modified 126 // at run time by RewriteBytecodes/RewriteFrequentPairs 127 // [2] Assign a fingerprint, so one doesn't need to be assigned at run-time. 128 static void rewrite_nofast_bytecodes_and_calculate_fingerprints() { 129 for (int i = 0; i < _global_klass_objects->length(); i++) { 130 Klass* k = _global_klass_objects->at(i); 131 if (k->oop_is_instance()) { 132 InstanceKlass* ik = InstanceKlass::cast(k); 133 for (int i = 0; i < ik->methods()->length(); i++) { 134 Method* m = ik->methods()->at(i); 135 rewrite_nofast_bytecode(m); 136 Fingerprinter fp(m); 137 // The side effect of this call sets method's fingerprint field. 138 fp.fingerprint(); 139 } 140 } 141 } 142 } 143 144 // Patch C++ vtable pointer in metadata. 145 146 // Klass and other metadata objects contain references to c++ vtables in the 147 // JVM library. 148 // Fix them to point to our constructed vtables. However, don't iterate 149 // across the space while doing this, as that causes the vtables to be 150 // patched, undoing our useful work. Instead, iterate to make a list, 151 // then use the list to do the fixing. 152 // 153 // Our constructed vtables: 154 // Dump time: 155 // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs 156 // 2. generate_vtable_methods: create jump table, appended to above vtbl_list 157 // 3. patch_klass_vtables: for Klass list, patch the vtable entry in klass and 158 // associated metadata to point to jump table rather than to current vtbl 159 // Table layout: NOTE FIXED SIZE 160 // 1. vtbl pointers 161 // 2. #Klass X #virtual methods per Klass 162 // 1 entry for each, in the order: 163 // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry 164 // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry 165 // ... 166 // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry, 167 // ... Klass<vtbl_list_size>:method<num_virtuals> entry 168 // Sample entry: (Sparc): 169 // save(sp, -256, sp) 170 // ba,pt common_code 171 // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255) 172 // 173 // Restore time: 174 // 1. initialize_shared_space: reserve space for table 175 // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text 176 // 177 // Execution time: 178 // First virtual method call for any object of these metadata types: 179 // 1. object->klass 180 // 2. vtable entry for that klass points to the jump table entries 181 // 3. branches to common_code with %O0/klass, %L0: Klass index <<8 + method index 182 // 4. common_code: 183 // Get address of new vtbl pointer for this Klass from updated table 184 // Update new vtbl pointer in the Klass: future virtual calls go direct 185 // Jump to method, using new vtbl pointer and method index 186 187 188 static void* find_matching_vtbl_ptr(void** vtbl_list, void* new_vtable_start, void* obj) { 189 void* old_vtbl_ptr = *(void**)obj; 190 for (int i = 0; i < MetaspaceShared::vtbl_list_size; i++) { 191 if (vtbl_list[i] == old_vtbl_ptr) { 192 return (void**)new_vtable_start + i * MetaspaceShared::num_virtuals; 193 } 194 } 195 ShouldNotReachHere(); 196 return NULL; 197 } 198 199 // Assumes the vtable is in first slot in object. 200 static void patch_klass_vtables(void** vtbl_list, void* new_vtable_start) { 201 int n = _global_klass_objects->length(); 202 for (int i = 0; i < n; i++) { 203 Klass* obj = _global_klass_objects->at(i); 204 // Note oop_is_instance() is a virtual call. After patching vtables 205 // all virtual calls on the dummy vtables will restore the original! 206 if (obj->oop_is_instance()) { 207 InstanceKlass* ik = InstanceKlass::cast(obj); 208 *(void**)ik = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, ik); 209 ConstantPool* cp = ik->constants(); 210 *(void**)cp = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, cp); 211 for (int j = 0; j < ik->methods()->length(); j++) { 212 Method* m = ik->methods()->at(j); 213 *(void**)m = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, m); 214 } 215 } else { 216 // Array klasses 217 Klass* k = obj; 218 *(void**)k = find_matching_vtbl_ptr(vtbl_list, new_vtable_start, k); 219 } 220 } 221 } 222 223 // Closure for serializing initialization data out to a data area to be 224 // written to the shared file. 225 226 class WriteClosure : public SerializeClosure { 227 private: 228 intptr_t* top; 229 char* end; 230 231 inline void check_space() { 232 if ((char*)top + sizeof(intptr_t) > end) { 233 report_out_of_shared_space(SharedMiscData); 234 } 235 } 236 237 public: 238 WriteClosure(char* md_top, char* md_end) { 239 top = (intptr_t*)md_top; 240 end = md_end; 241 } 242 243 char* get_top() { return (char*)top; } 244 245 void do_ptr(void** p) { 246 check_space(); 247 *top = (intptr_t)*p; 248 ++top; 249 } 250 251 void do_tag(int tag) { 252 check_space(); 253 *top = (intptr_t)tag; 254 ++top; 255 } 256 257 void do_region(u_char* start, size_t size) { 258 if ((char*)top + size > end) { 259 report_out_of_shared_space(SharedMiscData); 260 } 261 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment"); 262 assert(size % sizeof(intptr_t) == 0, "bad size"); 263 do_tag((int)size); 264 while (size > 0) { 265 *top = *(intptr_t*)start; 266 ++top; 267 start += sizeof(intptr_t); 268 size -= sizeof(intptr_t); 269 } 270 } 271 272 bool reading() const { return false; } 273 }; 274 275 // This is for dumping detailed statistics for the allocations 276 // in the shared spaces. 277 class DumpAllocClosure : public Metaspace::AllocRecordClosure { 278 public: 279 280 // Here's poor man's enum inheritance 281 #define SHAREDSPACE_OBJ_TYPES_DO(f) \ 282 METASPACE_OBJ_TYPES_DO(f) \ 283 f(SymbolHashentry) \ 284 f(SymbolBucket) \ 285 f(Other) 286 287 #define SHAREDSPACE_OBJ_TYPE_DECLARE(name) name ## Type, 288 #define SHAREDSPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name; 289 290 enum Type { 291 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc 292 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_DECLARE) 293 _number_of_types 294 }; 295 296 static const char * type_name(Type type) { 297 switch(type) { 298 SHAREDSPACE_OBJ_TYPES_DO(SHAREDSPACE_OBJ_TYPE_NAME_CASE) 299 default: 300 ShouldNotReachHere(); 301 return NULL; 302 } 303 } 304 305 public: 306 enum { 307 RO = 0, 308 RW = 1 309 }; 310 311 int _counts[2][_number_of_types]; 312 int _bytes [2][_number_of_types]; 313 int _which; 314 315 DumpAllocClosure() { 316 memset(_counts, 0, sizeof(_counts)); 317 memset(_bytes, 0, sizeof(_bytes)); 318 }; 319 320 void iterate_metaspace(Metaspace* space, int which) { 321 assert(which == RO || which == RW, "sanity"); 322 _which = which; 323 space->iterate(this); 324 } 325 326 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) { 327 assert(int(type) >= 0 && type < MetaspaceObj::_number_of_types, "sanity"); 328 _counts[_which][type] ++; 329 _bytes [_which][type] += byte_size; 330 } 331 332 void dump_stats(int ro_all, int rw_all, int md_all, int mc_all); 333 }; 334 335 void DumpAllocClosure::dump_stats(int ro_all, int rw_all, int md_all, int mc_all) { 336 rw_all += (md_all + mc_all); // md and mc are all mapped Read/Write 337 int other_bytes = md_all + mc_all; 338 339 // Calculate size of data that was not allocated by Metaspace::allocate() 340 MetaspaceSharedStats *stats = MetaspaceShared::stats(); 341 342 // symbols 343 _counts[RW][SymbolHashentryType] = stats->symbol.hashentry_count; 344 _bytes [RW][SymbolHashentryType] = stats->symbol.hashentry_bytes; 345 other_bytes -= stats->symbol.hashentry_bytes; 346 347 _counts[RW][SymbolBucketType] = stats->symbol.bucket_count; 348 _bytes [RW][SymbolBucketType] = stats->symbol.bucket_bytes; 349 other_bytes -= stats->symbol.bucket_bytes; 350 351 // TODO: count things like dictionary, vtable, etc 352 _bytes[RW][OtherType] = other_bytes; 353 354 // prevent divide-by-zero 355 if (ro_all < 1) { 356 ro_all = 1; 357 } 358 if (rw_all < 1) { 359 rw_all = 1; 360 } 361 362 int all_ro_count = 0; 363 int all_ro_bytes = 0; 364 int all_rw_count = 0; 365 int all_rw_bytes = 0; 366 367 // To make fmt_stats be a syntactic constant (for format warnings), use #define. 368 #define fmt_stats "%-20s: %8d %10d %5.1f | %8d %10d %5.1f | %8d %10d %5.1f" 369 const char *sep = "--------------------+---------------------------+---------------------------+--------------------------"; 370 const char *hdr = " ro_cnt ro_bytes % | rw_cnt rw_bytes % | all_cnt all_bytes %"; 371 372 tty->print_cr("Detailed metadata info (rw includes md and mc):"); 373 tty->print_cr("%s", hdr); 374 tty->print_cr("%s", sep); 375 for (int type = 0; type < int(_number_of_types); type ++) { 376 const char *name = type_name((Type)type); 377 int ro_count = _counts[RO][type]; 378 int ro_bytes = _bytes [RO][type]; 379 int rw_count = _counts[RW][type]; 380 int rw_bytes = _bytes [RW][type]; 381 int count = ro_count + rw_count; 382 int bytes = ro_bytes + rw_bytes; 383 384 double ro_perc = 100.0 * double(ro_bytes) / double(ro_all); 385 double rw_perc = 100.0 * double(rw_bytes) / double(rw_all); 386 double perc = 100.0 * double(bytes) / double(ro_all + rw_all); 387 388 tty->print_cr(fmt_stats, name, 389 ro_count, ro_bytes, ro_perc, 390 rw_count, rw_bytes, rw_perc, 391 count, bytes, perc); 392 393 all_ro_count += ro_count; 394 all_ro_bytes += ro_bytes; 395 all_rw_count += rw_count; 396 all_rw_bytes += rw_bytes; 397 } 398 399 int all_count = all_ro_count + all_rw_count; 400 int all_bytes = all_ro_bytes + all_rw_bytes; 401 402 double all_ro_perc = 100.0 * double(all_ro_bytes) / double(ro_all); 403 double all_rw_perc = 100.0 * double(all_rw_bytes) / double(rw_all); 404 double all_perc = 100.0 * double(all_bytes) / double(ro_all + rw_all); 405 406 tty->print_cr("%s", sep); 407 tty->print_cr(fmt_stats, "Total", 408 all_ro_count, all_ro_bytes, all_ro_perc, 409 all_rw_count, all_rw_bytes, all_rw_perc, 410 all_count, all_bytes, all_perc); 411 412 assert(all_ro_bytes == ro_all, "everything should have been counted"); 413 assert(all_rw_bytes == rw_all, "everything should have been counted"); 414 #undef fmt_stats 415 } 416 417 // Populate the shared space. 418 419 class VM_PopulateDumpSharedSpace: public VM_Operation { 420 private: 421 ClassLoaderData* _loader_data; 422 GrowableArray<Klass*> *_class_promote_order; 423 VirtualSpace _md_vs; 424 VirtualSpace _mc_vs; 425 426 public: 427 VM_PopulateDumpSharedSpace(ClassLoaderData* loader_data, 428 GrowableArray<Klass*> *class_promote_order) : 429 _loader_data(loader_data) { 430 431 // Split up and initialize the misc code and data spaces 432 ReservedSpace* shared_rs = MetaspaceShared::shared_rs(); 433 size_t metadata_size = SharedReadOnlySize + SharedReadWriteSize; 434 ReservedSpace shared_ro_rw = shared_rs->first_part(metadata_size); 435 ReservedSpace misc_section = shared_rs->last_part(metadata_size); 436 437 // Now split into misc sections. 438 ReservedSpace md_rs = misc_section.first_part(SharedMiscDataSize); 439 ReservedSpace mc_rs = misc_section.last_part(SharedMiscDataSize); 440 _md_vs.initialize(md_rs, SharedMiscDataSize); 441 _mc_vs.initialize(mc_rs, SharedMiscCodeSize); 442 _class_promote_order = class_promote_order; 443 } 444 445 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; } 446 void doit(); // outline because gdb sucks 447 448 private: 449 void handle_misc_data_space_failure(bool success) { 450 if (!success) { 451 report_out_of_shared_space(SharedMiscData); 452 } 453 } 454 }; // class VM_PopulateDumpSharedSpace 455 456 457 void VM_PopulateDumpSharedSpace::doit() { 458 Thread* THREAD = VMThread::vm_thread(); 459 NOT_PRODUCT(SystemDictionary::verify();) 460 // The following guarantee is meant to ensure that no loader constraints 461 // exist yet, since the constraints table is not shared. This becomes 462 // more important now that we don't re-initialize vtables/itables for 463 // shared classes at runtime, where constraints were previously created. 464 guarantee(SystemDictionary::constraints()->number_of_entries() == 0, 465 "loader constraints are not saved"); 466 guarantee(SystemDictionary::placeholders()->number_of_entries() == 0, 467 "placeholders are not saved"); 468 // Revisit and implement this if we prelink method handle call sites: 469 guarantee(SystemDictionary::invoke_method_table() == NULL || 470 SystemDictionary::invoke_method_table()->number_of_entries() == 0, 471 "invoke method table is not saved"); 472 473 // At this point, many classes have been loaded. 474 // Gather systemDictionary classes in a global array and do everything to 475 // that so we don't have to walk the SystemDictionary again. 476 _global_klass_objects = new GrowableArray<Klass*>(1000); 477 Universe::basic_type_classes_do(collect_classes); 478 SystemDictionary::classes_do(collect_classes); 479 480 tty->print_cr("Number of classes %d", _global_klass_objects->length()); 481 { 482 int num_type_array = 0, num_obj_array = 0, num_inst = 0; 483 for (int i = 0; i < _global_klass_objects->length(); i++) { 484 Klass* k = _global_klass_objects->at(i); 485 if (k->oop_is_instance()) { 486 num_inst ++; 487 } else if (k->oop_is_objArray()) { 488 num_obj_array ++; 489 } else { 490 assert(k->oop_is_typeArray(), "sanity"); 491 num_type_array ++; 492 } 493 } 494 tty->print_cr(" instance classes = %5d", num_inst); 495 tty->print_cr(" obj array classes = %5d", num_obj_array); 496 tty->print_cr(" type array classes = %5d", num_type_array); 497 } 498 499 500 // Ensure the ConstMethods won't be modified at run-time 501 tty->print("Updating ConstMethods ... "); 502 rewrite_nofast_bytecodes_and_calculate_fingerprints(); 503 tty->print_cr("done. "); 504 505 // Remove all references outside the metadata 506 tty->print("Removing unshareable information ... "); 507 remove_unshareable_in_classes(); 508 tty->print_cr("done. "); 509 510 // Set up the share data and shared code segments. 511 char* md_low = _md_vs.low(); 512 char* md_top = md_low; 513 char* md_end = _md_vs.high(); 514 char* mc_low = _mc_vs.low(); 515 char* mc_top = mc_low; 516 char* mc_end = _mc_vs.high(); 517 518 // Reserve space for the list of Klass*s whose vtables are used 519 // for patching others as needed. 520 521 void** vtbl_list = (void**)md_top; 522 int vtbl_list_size = MetaspaceShared::vtbl_list_size; 523 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size); 524 525 md_top += vtbl_list_size * sizeof(void*); 526 void* vtable = md_top; 527 528 // Reserve space for a new dummy vtable for klass objects in the 529 // heap. Generate self-patching vtable entries. 530 531 MetaspaceShared::generate_vtable_methods(vtbl_list, &vtable, 532 &md_top, md_end, 533 &mc_top, mc_end); 534 535 // Reorder the system dictionary. (Moving the symbols affects 536 // how the hash table indices are calculated.) 537 // Not doing this either. 538 539 SystemDictionary::reorder_dictionary(); 540 541 NOT_PRODUCT(SystemDictionary::verify();) 542 543 // Copy the the symbol table, and the system dictionary to the shared 544 // space in usable form. Copy the hashtable 545 // buckets first [read-write], then copy the linked lists of entries 546 // [read-only]. 547 548 NOT_PRODUCT(SymbolTable::verify()); 549 handle_misc_data_space_failure(SymbolTable::copy_compact_table(&md_top, md_end)); 550 551 SystemDictionary::reverse(); 552 SystemDictionary::copy_buckets(&md_top, md_end); 553 554 ClassLoader::verify(); 555 ClassLoader::copy_package_info_buckets(&md_top, md_end); 556 ClassLoader::verify(); 557 558 SystemDictionary::copy_table(&md_top, md_end); 559 ClassLoader::verify(); 560 ClassLoader::copy_package_info_table(&md_top, md_end); 561 ClassLoader::verify(); 562 563 // Write the other data to the output array. 564 WriteClosure wc(md_top, md_end); 565 MetaspaceShared::serialize(&wc); 566 md_top = wc.get_top(); 567 568 // Print shared spaces all the time 569 // To make fmt_space be a syntactic constant (for format warnings), use #define. 570 #define fmt_space "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " INTPTR_FORMAT 571 Metaspace* ro_space = _loader_data->ro_metaspace(); 572 Metaspace* rw_space = _loader_data->rw_metaspace(); 573 574 // Allocated size of each space (may not be all occupied) 575 const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType); 576 const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType); 577 const size_t md_alloced = md_end-md_low; 578 const size_t mc_alloced = mc_end-mc_low; 579 const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced; 580 581 // Occupied size of each space. 582 const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType); 583 const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType); 584 const size_t md_bytes = size_t(md_top - md_low); 585 const size_t mc_bytes = size_t(mc_top - mc_low); 586 587 // Percent of total size 588 const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes; 589 const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0; 590 const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0; 591 const double md_t_perc = md_bytes / double(total_bytes) * 100.0; 592 const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0; 593 594 // Percent of fullness of each space 595 const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0; 596 const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0; 597 const double md_u_perc = md_bytes / double(md_alloced) * 100.0; 598 const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0; 599 const double total_u_perc = total_bytes / double(total_alloced) * 100.0; 600 601 tty->print_cr(fmt_space, "ro", ro_bytes, ro_t_perc, ro_alloced, ro_u_perc, ro_space->bottom()); 602 tty->print_cr(fmt_space, "rw", rw_bytes, rw_t_perc, rw_alloced, rw_u_perc, rw_space->bottom()); 603 tty->print_cr(fmt_space, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, md_low); 604 tty->print_cr(fmt_space, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, mc_low); 605 tty->print_cr("total : %9d [100.0%% of total] out of %9d bytes [%4.1f%% used]", 606 total_bytes, total_alloced, total_u_perc); 607 608 // Update the vtable pointers in all of the Klass objects in the 609 // heap. They should point to newly generated vtable. 610 patch_klass_vtables(vtbl_list, vtable); 611 612 // dunno what this is for. 613 char* saved_vtbl = (char*)os::malloc(vtbl_list_size * sizeof(void*), mtClass); 614 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*)); 615 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*)); 616 617 // Create and write the archive file that maps the shared spaces. 618 619 FileMapInfo* mapinfo = new FileMapInfo(); 620 mapinfo->populate_header(MetaspaceShared::max_alignment()); 621 622 // Pass 1 - update file offsets in header. 623 mapinfo->write_header(); 624 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true); 625 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false); 626 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(), 627 pointer_delta(md_top, _md_vs.low(), sizeof(char)), 628 SharedMiscDataSize, 629 false, false); 630 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(), 631 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)), 632 SharedMiscCodeSize, 633 true, true); 634 635 // Pass 2 - write data. 636 mapinfo->open_for_write(); 637 mapinfo->set_header_crc(mapinfo->compute_header_crc()); 638 mapinfo->write_header(); 639 mapinfo->write_space(MetaspaceShared::ro, _loader_data->ro_metaspace(), true); 640 mapinfo->write_space(MetaspaceShared::rw, _loader_data->rw_metaspace(), false); 641 mapinfo->write_region(MetaspaceShared::md, _md_vs.low(), 642 pointer_delta(md_top, _md_vs.low(), sizeof(char)), 643 SharedMiscDataSize, 644 false, false); 645 mapinfo->write_region(MetaspaceShared::mc, _mc_vs.low(), 646 pointer_delta(mc_top, _mc_vs.low(), sizeof(char)), 647 SharedMiscCodeSize, 648 true, true); 649 mapinfo->close(); 650 651 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*)); 652 653 if (PrintSharedSpaces) { 654 DumpAllocClosure dac; 655 dac.iterate_metaspace(_loader_data->ro_metaspace(), DumpAllocClosure::RO); 656 dac.iterate_metaspace(_loader_data->rw_metaspace(), DumpAllocClosure::RW); 657 658 dac.dump_stats(int(ro_bytes), int(rw_bytes), int(md_bytes), int(mc_bytes)); 659 } 660 #undef fmt_space 661 } 662 663 664 void MetaspaceShared::link_one_shared_class(Klass* obj, TRAPS) { 665 Klass* k = obj; 666 if (k->oop_is_instance()) { 667 InstanceKlass* ik = (InstanceKlass*) k; 668 // Link the class to cause the bytecodes to be rewritten and the 669 // cpcache to be created. Class verification is done according 670 // to -Xverify setting. 671 _link_classes_made_progress |= try_link_class(ik, THREAD); 672 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class"); 673 } 674 } 675 676 void MetaspaceShared::check_one_shared_class(Klass* k) { 677 if (k->oop_is_instance() && InstanceKlass::cast(k)->check_sharing_error_state()) { 678 _check_classes_made_progress = true; 679 } 680 } 681 682 void MetaspaceShared::link_and_cleanup_shared_classes(TRAPS) { 683 // We need to iterate because verification may cause additional classes 684 // to be loaded. 685 do { 686 _link_classes_made_progress = false; 687 SystemDictionary::classes_do(link_one_shared_class, THREAD); 688 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class"); 689 } while (_link_classes_made_progress); 690 691 if (_has_error_classes) { 692 // Mark all classes whose super class or interfaces failed verification. 693 do { 694 // Not completely sure if we need to do this iteratively. Anyway, 695 // we should come here only if there are unverifiable classes, which 696 // shouldn't happen in normal cases. So better safe than sorry. 697 _check_classes_made_progress = false; 698 SystemDictionary::classes_do(check_one_shared_class); 699 } while (_check_classes_made_progress); 700 701 if (IgnoreUnverifiableClassesDuringDump) { 702 // This is useful when running JCK or SQE tests. You should not 703 // enable this when running real apps. 704 SystemDictionary::remove_classes_in_error_state(); 705 } else { 706 tty->print_cr("Please remove the unverifiable classes from your class list and try again"); 707 exit(1); 708 } 709 } 710 } 711 712 void MetaspaceShared::prepare_for_dumping() { 713 ClassLoader::initialize_shared_path(); 714 FileMapInfo::allocate_classpath_entry_table(); 715 } 716 717 // Preload classes from a list, populate the shared spaces and dump to a 718 // file. 719 void MetaspaceShared::preload_and_dump(TRAPS) { 720 TraceTime timer("Dump Shared Spaces", TraceStartupTime); 721 ResourceMark rm; 722 723 tty->print_cr("Allocated shared space: %d bytes at " PTR_FORMAT, 724 MetaspaceShared::shared_rs()->size(), 725 MetaspaceShared::shared_rs()->base()); 726 727 // Preload classes to be shared. 728 // Should use some os:: method rather than fopen() here. aB. 729 const char* class_list_path; 730 if (SharedClassListFile == NULL) { 731 // Construct the path to the class list (in jre/lib) 732 // Walk up two directories from the location of the VM and 733 // optionally tack on "lib" (depending on platform) 734 char class_list_path_str[JVM_MAXPATHLEN]; 735 os::jvm_path(class_list_path_str, sizeof(class_list_path_str)); 736 for (int i = 0; i < 3; i++) { 737 char *end = strrchr(class_list_path_str, *os::file_separator()); 738 if (end != NULL) *end = '\0'; 739 } 740 int class_list_path_len = (int)strlen(class_list_path_str); 741 if (class_list_path_len >= 3) { 742 if (strcmp(class_list_path_str + class_list_path_len - 3, "lib") != 0) { 743 if (class_list_path_len < JVM_MAXPATHLEN - 4) { 744 jio_snprintf(class_list_path_str + class_list_path_len, 745 sizeof(class_list_path_str) - class_list_path_len, 746 "%slib", os::file_separator()); 747 class_list_path_len += 4; 748 } 749 } 750 } 751 if (class_list_path_len < JVM_MAXPATHLEN - 10) { 752 jio_snprintf(class_list_path_str + class_list_path_len, 753 sizeof(class_list_path_str) - class_list_path_len, 754 "%sclasslist", os::file_separator()); 755 } 756 class_list_path = class_list_path_str; 757 } else { 758 class_list_path = SharedClassListFile; 759 } 760 761 int class_count = 0; 762 GrowableArray<Klass*>* class_promote_order = new GrowableArray<Klass*>(); 763 764 // sun.io.Converters 765 static const char obj_array_sig[] = "[[Ljava/lang/Object;"; 766 SymbolTable::new_permanent_symbol(obj_array_sig, THREAD); 767 768 // java.util.HashMap 769 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;"; 770 SymbolTable::new_permanent_symbol(map_entry_array_sig, THREAD); 771 772 tty->print_cr("Loading classes to share ..."); 773 _has_error_classes = false; 774 class_count += preload_and_dump(class_list_path, class_promote_order, 775 THREAD); 776 if (ExtraSharedClassListFile) { 777 class_count += preload_and_dump(ExtraSharedClassListFile, class_promote_order, 778 THREAD); 779 } 780 tty->print_cr("Loading classes to share: done."); 781 782 if (PrintSharedSpaces) { 783 tty->print_cr("Shared spaces: preloaded %d classes", class_count); 784 } 785 786 // Rewrite and link classes 787 tty->print_cr("Rewriting and linking classes ..."); 788 789 // Link any classes which got missed. This would happen if we have loaded classes that 790 // were not explicitly specified in the classlist. E.g., if an interface implemented by class K 791 // fails verification, all other interfaces that were not specified in the classlist but 792 // are implemented by K are not verified. 793 link_and_cleanup_shared_classes(CATCH); 794 tty->print_cr("Rewriting and linking classes: done"); 795 796 // Create and dump the shared spaces. Everything so far is loaded 797 // with the null class loader. 798 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data(); 799 VM_PopulateDumpSharedSpace op(loader_data, class_promote_order); 800 VMThread::execute(&op); 801 802 // Since various initialization steps have been undone by this process, 803 // it is not reasonable to continue running a java process. 804 exit(0); 805 } 806 807 int MetaspaceShared::preload_and_dump(const char * class_list_path, 808 GrowableArray<Klass*>* class_promote_order, 809 TRAPS) { 810 FILE* file = fopen(class_list_path, "r"); 811 char class_name[256]; 812 int class_count = 0; 813 814 if (file != NULL) { 815 while ((fgets(class_name, sizeof class_name, file)) != NULL) { 816 if (*class_name == '#') { // comment 817 continue; 818 } 819 // Remove trailing newline 820 size_t name_len = strlen(class_name); 821 if (class_name[name_len-1] == '\n') { 822 class_name[name_len-1] = '\0'; 823 } 824 825 // Got a class name - load it. 826 TempNewSymbol class_name_symbol = SymbolTable::new_permanent_symbol(class_name, THREAD); 827 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol."); 828 Klass* klass = SystemDictionary::resolve_or_null(class_name_symbol, 829 THREAD); 830 CLEAR_PENDING_EXCEPTION; 831 if (klass != NULL) { 832 if (PrintSharedSpaces && Verbose && WizardMode) { 833 tty->print_cr("Shared spaces preloaded: %s", class_name); 834 } 835 836 InstanceKlass* ik = InstanceKlass::cast(klass); 837 838 // Should be class load order as per -XX:+TraceClassLoadingPreorder 839 class_promote_order->append(ik); 840 841 // Link the class to cause the bytecodes to be rewritten and the 842 // cpcache to be created. The linking is done as soon as classes 843 // are loaded in order that the related data structures (klass and 844 // cpCache) are located together. 845 try_link_class(ik, THREAD); 846 guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class"); 847 848 class_count++; 849 } else { 850 //tty->print_cr("Preload failed: %s", class_name); 851 } 852 } 853 fclose(file); 854 } else { 855 char errmsg[JVM_MAXPATHLEN]; 856 os::lasterror(errmsg, JVM_MAXPATHLEN); 857 tty->print_cr("Loading classlist failed: %s", errmsg); 858 exit(1); 859 } 860 861 return class_count; 862 } 863 864 // Returns true if the class's status has changed 865 bool MetaspaceShared::try_link_class(InstanceKlass* ik, TRAPS) { 866 assert(DumpSharedSpaces, "should only be called during dumping"); 867 if (ik->init_state() < InstanceKlass::linked) { 868 bool saved = BytecodeVerificationLocal; 869 if (!SharedClassUtil::is_shared_boot_class(ik)) { 870 // The verification decision is based on BytecodeVerificationRemote 871 // for non-system classes. Since we are using the NULL classloader 872 // to load non-system classes during dumping, we need to temporarily 873 // change BytecodeVerificationLocal to be the same as 874 // BytecodeVerificationRemote. Note this can cause the parent system 875 // classes also being verified. The extra overhead is acceptable during 876 // dumping. 877 BytecodeVerificationLocal = BytecodeVerificationRemote; 878 } 879 ik->link_class(THREAD); 880 if (HAS_PENDING_EXCEPTION) { 881 ResourceMark rm; 882 tty->print_cr("Preload Warning: Verification failed for %s", 883 ik->external_name()); 884 CLEAR_PENDING_EXCEPTION; 885 ik->set_in_error_state(); 886 _has_error_classes = true; 887 } 888 BytecodeVerificationLocal = saved; 889 return true; 890 } else { 891 return false; 892 } 893 } 894 895 // Closure for serializing initialization data in from a data area 896 // (ptr_array) read from the shared file. 897 898 class ReadClosure : public SerializeClosure { 899 private: 900 intptr_t** _ptr_array; 901 902 inline intptr_t nextPtr() { 903 return *(*_ptr_array)++; 904 } 905 906 public: 907 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; } 908 909 void do_ptr(void** p) { 910 assert(*p == NULL, "initializing previous initialized pointer."); 911 intptr_t obj = nextPtr(); 912 assert((intptr_t)obj >= 0 || (intptr_t)obj < -100, 913 "hit tag while initializing ptrs."); 914 *p = (void*)obj; 915 } 916 917 void do_tag(int tag) { 918 int old_tag; 919 old_tag = (int)(intptr_t)nextPtr(); 920 // do_int(&old_tag); 921 assert(tag == old_tag, "old tag doesn't match"); 922 FileMapInfo::assert_mark(tag == old_tag); 923 } 924 925 void do_region(u_char* start, size_t size) { 926 assert((intptr_t)start % sizeof(intptr_t) == 0, "bad alignment"); 927 assert(size % sizeof(intptr_t) == 0, "bad size"); 928 do_tag((int)size); 929 while (size > 0) { 930 *(intptr_t*)start = nextPtr(); 931 start += sizeof(intptr_t); 932 size -= sizeof(intptr_t); 933 } 934 } 935 936 bool reading() const { return true; } 937 }; 938 939 // Return true if given address is in the mapped shared space. 940 bool MetaspaceShared::is_in_shared_space(const void* p) { 941 return UseSharedSpaces && FileMapInfo::current_info()->is_in_shared_space(p); 942 } 943 944 void MetaspaceShared::print_shared_spaces() { 945 if (UseSharedSpaces) { 946 FileMapInfo::current_info()->print_shared_spaces(); 947 } 948 } 949 950 951 // Map shared spaces at requested addresses and return if succeeded. 952 // Need to keep the bounds of the ro and rw space for the Metaspace::contains 953 // call, or is_in_shared_space. 954 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) { 955 size_t image_alignment = mapinfo->alignment(); 956 957 #ifndef _WINDOWS 958 // Map in the shared memory and then map the regions on top of it. 959 // On Windows, don't map the memory here because it will cause the 960 // mappings of the regions to fail. 961 ReservedSpace shared_rs = mapinfo->reserve_shared_memory(); 962 if (!shared_rs.is_reserved()) return false; 963 #endif 964 965 assert(!DumpSharedSpaces, "Should not be called with DumpSharedSpaces"); 966 967 char* _ro_base = NULL; 968 char* _rw_base = NULL; 969 char* _md_base = NULL; 970 char* _mc_base = NULL; 971 972 // Map each shared region 973 if ((_ro_base = mapinfo->map_region(ro)) != NULL && 974 mapinfo->verify_region_checksum(ro) && 975 (_rw_base = mapinfo->map_region(rw)) != NULL && 976 mapinfo->verify_region_checksum(rw) && 977 (_md_base = mapinfo->map_region(md)) != NULL && 978 mapinfo->verify_region_checksum(md) && 979 (_mc_base = mapinfo->map_region(mc)) != NULL && 980 mapinfo->verify_region_checksum(mc) && 981 (image_alignment == (size_t)max_alignment()) && 982 mapinfo->validate_classpath_entry_table()) { 983 // Success (no need to do anything) 984 return true; 985 } else { 986 // If there was a failure in mapping any of the spaces, unmap the ones 987 // that succeeded 988 if (_ro_base != NULL) mapinfo->unmap_region(ro); 989 if (_rw_base != NULL) mapinfo->unmap_region(rw); 990 if (_md_base != NULL) mapinfo->unmap_region(md); 991 if (_mc_base != NULL) mapinfo->unmap_region(mc); 992 #ifndef _WINDOWS 993 // Release the entire mapped region 994 shared_rs.release(); 995 #endif 996 // If -Xshare:on is specified, print out the error message and exit VM, 997 // otherwise, set UseSharedSpaces to false and continue. 998 if (RequireSharedSpaces || PrintSharedArchiveAndExit) { 999 vm_exit_during_initialization("Unable to use shared archive.", "Failed map_region for using -Xshare:on."); 1000 } else { 1001 FLAG_SET_DEFAULT(UseSharedSpaces, false); 1002 } 1003 return false; 1004 } 1005 } 1006 1007 // Read the miscellaneous data from the shared file, and 1008 // serialize it out to its various destinations. 1009 1010 void MetaspaceShared::initialize_shared_spaces() { 1011 FileMapInfo *mapinfo = FileMapInfo::current_info(); 1012 1013 char* buffer = mapinfo->region_base(md); 1014 1015 // Skip over (reserve space for) a list of addresses of C++ vtables 1016 // for Klass objects. They get filled in later. 1017 1018 void** vtbl_list = (void**)buffer; 1019 buffer += MetaspaceShared::vtbl_list_size * sizeof(void*); 1020 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size); 1021 1022 // Skip over (reserve space for) dummy C++ vtables Klass objects. 1023 // They are used as is. 1024 1025 intptr_t vtable_size = *(intptr_t*)buffer; 1026 buffer += sizeof(intptr_t); 1027 buffer += vtable_size; 1028 1029 // Create the shared symbol table using the bucket array at this spot in the 1030 // misc data space. (Todo: move this to read-only space. Currently 1031 // this is mapped copy-on-write but will never be written into). 1032 1033 buffer = (char*)SymbolTable::init_shared_table(buffer); 1034 SymbolTable::create_table(); 1035 1036 // Create the shared dictionary using the bucket array at this spot in 1037 // the misc data space. Since the shared dictionary table is never 1038 // modified, this region (of mapped pages) will be (effectively, if 1039 // not explicitly) read-only. 1040 1041 int sharedDictionaryLen = *(intptr_t*)buffer; 1042 buffer += sizeof(intptr_t); 1043 int number_of_entries = *(intptr_t*)buffer; 1044 buffer += sizeof(intptr_t); 1045 SystemDictionary::set_shared_dictionary((HashtableBucket<mtClass>*)buffer, 1046 sharedDictionaryLen, 1047 number_of_entries); 1048 buffer += sharedDictionaryLen; 1049 1050 // Create the package info table using the bucket array at this spot in 1051 // the misc data space. Since the package info table is never 1052 // modified, this region (of mapped pages) will be (effectively, if 1053 // not explicitly) read-only. 1054 1055 int pkgInfoLen = *(intptr_t*)buffer; 1056 buffer += sizeof(intptr_t); 1057 number_of_entries = *(intptr_t*)buffer; 1058 buffer += sizeof(intptr_t); 1059 ClassLoader::create_package_info_table((HashtableBucket<mtClass>*)buffer, pkgInfoLen, 1060 number_of_entries); 1061 buffer += pkgInfoLen; 1062 ClassLoader::verify(); 1063 1064 // The following data in the shared misc data region are the linked 1065 // list elements (HashtableEntry objects) for the shared dictionary 1066 // and package info table. 1067 1068 int len = *(intptr_t*)buffer; // skip over shared dictionary entries 1069 buffer += sizeof(intptr_t); 1070 buffer += len; 1071 1072 len = *(intptr_t*)buffer; // skip over package info table entries 1073 buffer += sizeof(intptr_t); 1074 buffer += len; 1075 1076 len = *(intptr_t*)buffer; // skip over package info table char[] arrays. 1077 buffer += sizeof(intptr_t); 1078 buffer += len; 1079 1080 intptr_t* array = (intptr_t*)buffer; 1081 ReadClosure rc(&array); 1082 serialize(&rc); 1083 1084 // Close the mapinfo file 1085 mapinfo->close(); 1086 1087 if (PrintSharedArchiveAndExit) { 1088 if (PrintSharedDictionary) { 1089 tty->print_cr("\nShared classes:\n"); 1090 SystemDictionary::print_shared(false); 1091 } 1092 if (_archive_loading_failed) { 1093 tty->print_cr("archive is invalid"); 1094 vm_exit(1); 1095 } else { 1096 tty->print_cr("archive is valid"); 1097 vm_exit(0); 1098 } 1099 } 1100 } 1101 1102 // JVM/TI RedefineClasses() support: 1103 bool MetaspaceShared::remap_shared_readonly_as_readwrite() { 1104 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1105 1106 if (UseSharedSpaces) { 1107 // remap the shared readonly space to shared readwrite, private 1108 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1109 if (!mapinfo->remap_shared_readonly_as_readwrite()) { 1110 return false; 1111 } 1112 } 1113 return true; 1114 } 1115 1116 int MetaspaceShared::count_class(const char* classlist_file) { 1117 if (classlist_file == NULL) { 1118 return 0; 1119 } 1120 char class_name[256]; 1121 int class_count = 0; 1122 FILE* file = fopen(classlist_file, "r"); 1123 if (file != NULL) { 1124 while ((fgets(class_name, sizeof class_name, file)) != NULL) { 1125 if (*class_name == '#') { // comment 1126 continue; 1127 } 1128 class_count++; 1129 } 1130 fclose(file); 1131 } else { 1132 char errmsg[JVM_MAXPATHLEN]; 1133 os::lasterror(errmsg, JVM_MAXPATHLEN); 1134 tty->print_cr("Loading classlist failed: %s", errmsg); 1135 exit(1); 1136 } 1137 1138 return class_count; 1139 } 1140 1141 // the sizes are good for typical large applications that have a lot of shared 1142 // classes 1143 void MetaspaceShared::estimate_regions_size() { 1144 int class_count = count_class(SharedClassListFile); 1145 class_count += count_class(ExtraSharedClassListFile); 1146 1147 if (class_count > LargeThresholdClassCount) { 1148 if (class_count < HugeThresholdClassCount) { 1149 SET_ESTIMATED_SIZE(Large, ReadOnly); 1150 SET_ESTIMATED_SIZE(Large, ReadWrite); 1151 SET_ESTIMATED_SIZE(Large, MiscData); 1152 SET_ESTIMATED_SIZE(Large, MiscCode); 1153 } else { 1154 SET_ESTIMATED_SIZE(Huge, ReadOnly); 1155 SET_ESTIMATED_SIZE(Huge, ReadWrite); 1156 SET_ESTIMATED_SIZE(Huge, MiscData); 1157 SET_ESTIMATED_SIZE(Huge, MiscCode); 1158 } 1159 } 1160 }