1 /*
   2  * Copyright (c) 1997, 2024, 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 "cds/cds_globals.hpp"
  27 #include "cds/cdsConfig.hpp"
  28 #include "cds/filemap.hpp"
  29 #include "cds/heapShared.hpp"
  30 #include "classfile/classFileStream.hpp"
  31 #include "classfile/classLoader.inline.hpp"
  32 #include "classfile/classLoaderData.inline.hpp"
  33 #include "classfile/classLoaderExt.hpp"
  34 #include "classfile/classLoadInfo.hpp"
  35 #include "classfile/javaClasses.hpp"
  36 #include "classfile/klassFactory.hpp"
  37 #include "classfile/moduleEntry.hpp"
  38 #include "classfile/modules.hpp"
  39 #include "classfile/packageEntry.hpp"
  40 #include "classfile/symbolTable.hpp"
  41 #include "classfile/systemDictionary.hpp"
  42 #include "classfile/systemDictionaryShared.hpp"
  43 #include "classfile/vmClasses.hpp"
  44 #include "classfile/vmSymbols.hpp"
  45 #include "compiler/compileBroker.hpp"
  46 #include "interpreter/bytecodeStream.hpp"
  47 #include "interpreter/oopMapCache.hpp"
  48 #include "jimage.hpp"
  49 #include "jvm.h"
  50 #include "logging/log.hpp"
  51 #include "logging/logStream.hpp"
  52 #include "logging/logTag.hpp"
  53 #include "memory/allocation.inline.hpp"
  54 #include "memory/oopFactory.hpp"
  55 #include "memory/resourceArea.hpp"
  56 #include "memory/universe.hpp"
  57 #include "oops/instanceKlass.hpp"
  58 #include "oops/instanceRefKlass.hpp"
  59 #include "oops/klass.inline.hpp"
  60 #include "oops/method.inline.hpp"
  61 #include "oops/objArrayOop.inline.hpp"
  62 #include "oops/oop.inline.hpp"
  63 #include "oops/symbol.hpp"
  64 #include "prims/jvm_misc.hpp"
  65 #include "runtime/arguments.hpp"
  66 #include "runtime/handles.inline.hpp"
  67 #include "runtime/init.hpp"
  68 #include "runtime/interfaceSupport.inline.hpp"
  69 #include "runtime/java.hpp"
  70 #include "runtime/javaCalls.hpp"
  71 #include "runtime/os.hpp"
  72 #include "runtime/perfData.hpp"
  73 #include "runtime/threadCritical.hpp"
  74 #include "runtime/timer.hpp"
  75 #include "runtime/vm_version.hpp"
  76 #include "services/management.hpp"
  77 #include "services/threadService.hpp"
  78 #include "utilities/checkedCast.hpp"
  79 #include "utilities/classpathStream.hpp"
  80 #include "utilities/events.hpp"
  81 #include "utilities/macros.hpp"
  82 #include "utilities/ostream.hpp"
  83 #include "utilities/utf8.hpp"
  84 
  85 #include <stdlib.h>
  86 #include <ctype.h>
  87 
  88 // Entry point in java.dll for path canonicalization
  89 
  90 typedef int (*canonicalize_fn_t)(const char *orig, char *out, int len);
  91 
  92 static canonicalize_fn_t CanonicalizeEntry  = nullptr;
  93 
  94 // Entry points for jimage.dll for loading jimage file entries
  95 
  96 static JImageOpen_t                    JImageOpen             = nullptr;
  97 static JImageClose_t                   JImageClose            = nullptr;
  98 static JImageFindResource_t            JImageFindResource     = nullptr;
  99 static JImageGetResource_t             JImageGetResource      = nullptr;
 100 
 101 // JimageFile pointer, or null if exploded JDK build.
 102 static JImageFile*                     JImage_file            = nullptr;
 103 
 104 // Globals
 105 
 106 PerfCounter*    ClassLoader::_perf_accumulated_time = nullptr;
 107 PerfCounter*    ClassLoader::_perf_classes_inited = nullptr;
 108 PerfCounter*    ClassLoader::_perf_class_init_time = nullptr;
 109 PerfCounter*    ClassLoader::_perf_class_init_selftime = nullptr;
 110 PerfCounter*    ClassLoader::_perf_classes_verified = nullptr;
 111 PerfCounter*    ClassLoader::_perf_class_verify_time = nullptr;
 112 PerfCounter*    ClassLoader::_perf_class_verify_selftime = nullptr;
 113 PerfCounter*    ClassLoader::_perf_classes_linked = nullptr;
 114 PerfCounter*    ClassLoader::_perf_class_link_time = nullptr;
 115 PerfCounter*    ClassLoader::_perf_class_link_selftime = nullptr;
 116 PerfCounter*    ClassLoader::_perf_shared_classload_time = nullptr;
 117 PerfCounter*    ClassLoader::_perf_sys_classload_time = nullptr;
 118 PerfCounter*    ClassLoader::_perf_app_classload_time = nullptr;
 119 PerfCounter*    ClassLoader::_perf_app_classload_selftime = nullptr;
 120 PerfCounter*    ClassLoader::_perf_app_classload_count = nullptr;
 121 PerfCounter*    ClassLoader::_perf_define_appclasses = nullptr;
 122 PerfCounter*    ClassLoader::_perf_define_appclass_time = nullptr;
 123 PerfCounter*    ClassLoader::_perf_define_appclass_selftime = nullptr;
 124 PerfCounter*    ClassLoader::_perf_app_classfile_bytes_read = nullptr;
 125 PerfCounter*    ClassLoader::_perf_sys_classfile_bytes_read = nullptr;
 126 PerfCounter*    ClassLoader::_perf_ik_link_methods_time = nullptr;
 127 PerfCounter*    ClassLoader::_perf_method_adapters_time = nullptr;
 128 PerfCounter*    ClassLoader::_perf_ik_link_methods_count = nullptr;
 129 PerfCounter*    ClassLoader::_perf_method_adapters_count = nullptr;
 130 PerfCounter*    ClassLoader::_unsafe_defineClassCallCounter = nullptr;
 131 PerfCounter*    ClassLoader::_perf_secondary_hash_time = nullptr;
 132 
 133 PerfCounter*    ClassLoader::_perf_resolve_indy_time = nullptr;
 134 PerfCounter*    ClassLoader::_perf_resolve_invokehandle_time = nullptr;
 135 PerfCounter*    ClassLoader::_perf_resolve_mh_time = nullptr;
 136 PerfCounter*    ClassLoader::_perf_resolve_mt_time = nullptr;
 137 
 138 PerfCounter*    ClassLoader::_perf_resolve_indy_count = nullptr;
 139 PerfCounter*    ClassLoader::_perf_resolve_invokehandle_count = nullptr;
 140 PerfCounter*    ClassLoader::_perf_resolve_mh_count = nullptr;
 141 PerfCounter*    ClassLoader::_perf_resolve_mt_count = nullptr;
 142 
 143 void ClassLoader::print_counters(outputStream *st) {
 144   st->print_cr("ClassLoader:");
 145   st->print_cr("  clinit:               " JLONG_FORMAT "ms / " JLONG_FORMAT " events", ClassLoader::class_init_time_ms(), ClassLoader::class_init_count());
 146   st->print_cr("  link methods:         " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_ik_link_methods_time->get_value())   , _perf_ik_link_methods_count->get_value());
 147   st->print_cr("  method adapters:      " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_method_adapters_time->get_value())   , _perf_method_adapters_count->get_value());
 148   st->print_cr("  resolve...");
 149   st->print_cr("    invokedynamic:   " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_resolve_indy_time->get_value())         , _perf_resolve_indy_count->get_value());
 150   st->print_cr("    invokehandle:    " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_resolve_invokehandle_time->get_value()) , _perf_resolve_invokehandle_count->get_value());
 151   st->print_cr("    CP_MethodHandle: " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_resolve_mh_time->get_value())           , _perf_resolve_mh_count->get_value());
 152   st->print_cr("    CP_MethodType:   " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_resolve_mt_time->get_value())           , _perf_resolve_mt_count->get_value());
 153   st->cr();
 154 }
 155 
 156 GrowableArray<ModuleClassPathList*>* ClassLoader::_patch_mod_entries = nullptr;
 157 GrowableArray<ModuleClassPathList*>* ClassLoader::_exploded_entries = nullptr;
 158 ClassPathEntry* ClassLoader::_jrt_entry = nullptr;
 159 
 160 ClassPathEntry* volatile ClassLoader::_first_append_entry_list = nullptr;
 161 ClassPathEntry* volatile ClassLoader::_last_append_entry  = nullptr;
 162 #if INCLUDE_CDS
 163 ClassPathEntry* ClassLoader::_app_classpath_entries = nullptr;
 164 ClassPathEntry* ClassLoader::_last_app_classpath_entry = nullptr;
 165 ClassPathEntry* ClassLoader::_module_path_entries = nullptr;
 166 ClassPathEntry* ClassLoader::_last_module_path_entry = nullptr;
 167 #endif
 168 
 169 // helper routines
 170 #if INCLUDE_CDS
 171 static bool string_starts_with(const char* str, const char* str_to_find) {
 172   size_t str_len = strlen(str);
 173   size_t str_to_find_len = strlen(str_to_find);
 174   if (str_to_find_len > str_len) {
 175     return false;
 176   }
 177   return (strncmp(str, str_to_find, str_to_find_len) == 0);
 178 }
 179 #endif
 180 
 181 static const char* get_jimage_version_string() {
 182   static char version_string[10] = "";
 183   if (version_string[0] == '\0') {
 184     jio_snprintf(version_string, sizeof(version_string), "%d.%d",
 185                  VM_Version::vm_major_version(), VM_Version::vm_minor_version());
 186   }
 187   return (const char*)version_string;
 188 }
 189 
 190 bool ClassLoader::string_ends_with(const char* str, const char* str_to_find) {
 191   size_t str_len = strlen(str);
 192   size_t str_to_find_len = strlen(str_to_find);
 193   if (str_to_find_len > str_len) {
 194     return false;
 195   }
 196   return (strncmp(str + (str_len - str_to_find_len), str_to_find, str_to_find_len) == 0);
 197 }
 198 
 199 // Used to obtain the package name from a fully qualified class name.
 200 Symbol* ClassLoader::package_from_class_name(const Symbol* name, bool* bad_class_name) {
 201   if (name == nullptr) {
 202     if (bad_class_name != nullptr) {
 203       *bad_class_name = true;
 204     }
 205     return nullptr;
 206   }
 207 
 208   int utf_len = name->utf8_length();
 209   const jbyte* base = (const jbyte*)name->base();
 210   const jbyte* start = base;
 211   const jbyte* end = UTF8::strrchr(start, utf_len, JVM_SIGNATURE_SLASH);
 212   if (end == nullptr) {
 213     return nullptr;
 214   }
 215   // Skip over '['s
 216   if (*start == JVM_SIGNATURE_ARRAY) {
 217     do {
 218       start++;
 219     } while (start < end && *start == JVM_SIGNATURE_ARRAY);
 220 
 221     // Fully qualified class names should not contain a 'L'.
 222     // Set bad_class_name to true to indicate that the package name
 223     // could not be obtained due to an error condition.
 224     // In this situation, is_same_class_package returns false.
 225     if (*start == JVM_SIGNATURE_CLASS) {
 226       if (bad_class_name != nullptr) {
 227         *bad_class_name = true;
 228       }
 229       return nullptr;
 230     }
 231   }
 232   // A class name could have just the slash character in the name,
 233   // in which case start > end
 234   if (start >= end) {
 235     // No package name
 236     if (bad_class_name != nullptr) {
 237       *bad_class_name = true;
 238     }
 239     return nullptr;
 240   }
 241   return SymbolTable::new_symbol(name, pointer_delta_as_int(start, base), pointer_delta_as_int(end, base));
 242 }
 243 
 244 // Given a fully qualified package name, find its defining package in the class loader's
 245 // package entry table.
 246 PackageEntry* ClassLoader::get_package_entry(Symbol* pkg_name, ClassLoaderData* loader_data) {
 247   if (pkg_name == nullptr) {
 248     return nullptr;
 249   }
 250   PackageEntryTable* pkgEntryTable = loader_data->packages();
 251   return pkgEntryTable->lookup_only(pkg_name);
 252 }
 253 
 254 const char* ClassPathEntry::copy_path(const char* path) {
 255   char* copy = NEW_C_HEAP_ARRAY(char, strlen(path)+1, mtClass);
 256   strcpy(copy, path);
 257   return copy;
 258 }
 259 
 260 ClassPathDirEntry::~ClassPathDirEntry() {
 261   FREE_C_HEAP_ARRAY(char, _dir);
 262 }
 263 
 264 ClassFileStream* ClassPathDirEntry::open_stream(JavaThread* current, const char* name) {
 265   // construct full path name
 266   assert((_dir != nullptr) && (name != nullptr), "sanity");
 267   size_t path_len = strlen(_dir) + strlen(name) + strlen(os::file_separator()) + 1;
 268   char* path = NEW_RESOURCE_ARRAY_IN_THREAD(current, char, path_len);
 269   int len = jio_snprintf(path, path_len, "%s%s%s", _dir, os::file_separator(), name);
 270   assert(len == (int)(path_len - 1), "sanity");
 271   // check if file exists
 272   struct stat st;
 273   if (os::stat(path, &st) == 0) {
 274     // found file, open it
 275     int file_handle = os::open(path, 0, 0);
 276     if (file_handle != -1) {
 277       // read contents into resource array
 278       u1* buffer = NEW_RESOURCE_ARRAY_IN_THREAD(current, u1, st.st_size);
 279       size_t num_read = ::read(file_handle, (char*) buffer, st.st_size);
 280       // close file
 281       ::close(file_handle);
 282       // construct ClassFileStream
 283       if (num_read == (size_t)st.st_size) {
 284         if (UsePerfData) {
 285           ClassLoader::perf_sys_classfile_bytes_read()->inc(num_read);
 286         }
 287 #ifdef ASSERT
 288         // Freeing path is a no-op here as buffer prevents it from being reclaimed. But we keep it for
 289         // debug builds so that we guard against use-after-free bugs.
 290         FREE_RESOURCE_ARRAY_IN_THREAD(current, char, path, path_len);
 291 #endif
 292         // We don't verify the length of the classfile stream fits in an int, but this is the
 293         // bootloader so we have control of this.
 294         // Resource allocated
 295         return new ClassFileStream(buffer,
 296                                    checked_cast<int>(st.st_size),
 297                                    _dir);
 298       }
 299     }
 300   }
 301   FREE_RESOURCE_ARRAY_IN_THREAD(current, char, path, path_len);
 302   return nullptr;
 303 }
 304 
 305 ClassPathZipEntry::ClassPathZipEntry(jzfile* zip, const char* zip_name,
 306                                      bool is_boot_append, bool from_class_path_attr) : ClassPathEntry() {
 307   _zip = zip;
 308   _zip_name = copy_path(zip_name);
 309   _from_class_path_attr = from_class_path_attr;
 310 }
 311 
 312 ClassPathZipEntry::~ClassPathZipEntry() {
 313   ZipLibrary::close(_zip);
 314   FREE_C_HEAP_ARRAY(char, _zip_name);
 315 }
 316 
 317 u1* ClassPathZipEntry::open_entry(JavaThread* current, const char* name, jint* filesize, bool nul_terminate) {
 318   // enable call to C land
 319   ThreadToNativeFromVM ttn(current);
 320   // check whether zip archive contains name
 321   jint name_len;
 322   jzentry* entry = ZipLibrary::find_entry(_zip, name, filesize, &name_len);
 323   if (entry == nullptr) return nullptr;
 324   u1* buffer;
 325   char name_buf[128];
 326   char* filename;
 327   if (name_len < 128) {
 328     filename = name_buf;
 329   } else {
 330     filename = NEW_RESOURCE_ARRAY(char, name_len + 1);
 331   }
 332 
 333   // read contents into resource array
 334   size_t size = (uint32_t)(*filesize);
 335   if (nul_terminate) {
 336     if (sizeof(size) == sizeof(uint32_t) && size == UINT_MAX) {
 337       return nullptr; // 32-bit integer overflow will occur.
 338     }
 339     size++;
 340   }
 341   buffer = NEW_RESOURCE_ARRAY(u1, size);
 342   if (!ZipLibrary::read_entry(_zip, entry, buffer, filename)) {
 343     return nullptr;
 344   }
 345 
 346   // return result
 347   if (nul_terminate) {
 348     buffer[size - 1] = 0;
 349   }
 350   return buffer;
 351 }
 352 
 353 ClassFileStream* ClassPathZipEntry::open_stream(JavaThread* current, const char* name) {
 354   jint filesize;
 355   u1* buffer = open_entry(current, name, &filesize, false);
 356   if (buffer == nullptr) {
 357     return nullptr;
 358   }
 359   if (UsePerfData) {
 360     ClassLoader::perf_sys_classfile_bytes_read()->inc(filesize);
 361   }
 362   // Resource allocated
 363   return new ClassFileStream(buffer,
 364                              filesize,
 365                              _zip_name);
 366 }
 367 
 368 DEBUG_ONLY(ClassPathImageEntry* ClassPathImageEntry::_singleton = nullptr;)
 369 
 370 JImageFile* ClassPathImageEntry::jimage() const {
 371   return JImage_file;
 372 }
 373 
 374 JImageFile* ClassPathImageEntry::jimage_non_null() const {
 375   assert(ClassLoader::has_jrt_entry(), "must be");
 376   assert(jimage() != nullptr, "should have been opened by ClassLoader::lookup_vm_options "
 377                            "and remained throughout normal JVM lifetime");
 378   return jimage();
 379 }
 380 
 381 void ClassPathImageEntry::close_jimage() {
 382   if (jimage() != nullptr) {
 383     (*JImageClose)(jimage());
 384     JImage_file = nullptr;
 385   }
 386 }
 387 
 388 ClassPathImageEntry::ClassPathImageEntry(JImageFile* jimage, const char* name) :
 389   ClassPathEntry() {
 390   guarantee(jimage != nullptr, "jimage file is null");
 391   guarantee(name != nullptr, "jimage file name is null");
 392   assert(_singleton == nullptr, "VM supports only one jimage");
 393   DEBUG_ONLY(_singleton = this);
 394   size_t len = strlen(name) + 1;
 395   _name = copy_path(name);
 396 }
 397 
 398 ClassFileStream* ClassPathImageEntry::open_stream(JavaThread* current, const char* name) {
 399   return open_stream_for_loader(current, name, ClassLoaderData::the_null_class_loader_data());
 400 }
 401 
 402 // For a class in a named module, look it up in the jimage file using this syntax:
 403 //    /<module-name>/<package-name>/<base-class>
 404 //
 405 // Assumptions:
 406 //     1. There are no unnamed modules in the jimage file.
 407 //     2. A package is in at most one module in the jimage file.
 408 //
 409 ClassFileStream* ClassPathImageEntry::open_stream_for_loader(JavaThread* current, const char* name, ClassLoaderData* loader_data) {
 410   jlong size;
 411   JImageLocationRef location = (*JImageFindResource)(jimage_non_null(), "", get_jimage_version_string(), name, &size);
 412 
 413   if (location == 0) {
 414     TempNewSymbol class_name = SymbolTable::new_symbol(name);
 415     TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
 416 
 417     if (pkg_name != nullptr) {
 418       if (!Universe::is_module_initialized()) {
 419         location = (*JImageFindResource)(jimage_non_null(), JAVA_BASE_NAME, get_jimage_version_string(), name, &size);
 420       } else {
 421         PackageEntry* package_entry = ClassLoader::get_package_entry(pkg_name, loader_data);
 422         if (package_entry != nullptr) {
 423           ResourceMark rm(current);
 424           // Get the module name
 425           ModuleEntry* module = package_entry->module();
 426           assert(module != nullptr, "Boot classLoader package missing module");
 427           assert(module->is_named(), "Boot classLoader package is in unnamed module");
 428           const char* module_name = module->name()->as_C_string();
 429           if (module_name != nullptr) {
 430             location = (*JImageFindResource)(jimage_non_null(), module_name, get_jimage_version_string(), name, &size);
 431           }
 432         }
 433       }
 434     }
 435   }
 436   if (location != 0) {
 437     if (UsePerfData) {
 438       ClassLoader::perf_sys_classfile_bytes_read()->inc(size);
 439     }
 440     char* data = NEW_RESOURCE_ARRAY(char, size);
 441     (*JImageGetResource)(jimage_non_null(), location, data, size);
 442     // Resource allocated
 443     assert(this == (ClassPathImageEntry*)ClassLoader::get_jrt_entry(), "must be");
 444     return new ClassFileStream((u1*)data,
 445                                checked_cast<int>(size),
 446                                _name,
 447                                true); // from_boot_loader_modules_image
 448   }
 449 
 450   return nullptr;
 451 }
 452 
 453 JImageLocationRef ClassLoader::jimage_find_resource(JImageFile* jf,
 454                                                     const char* module_name,
 455                                                     const char* file_name,
 456                                                     jlong &size) {
 457   return ((*JImageFindResource)(jf, module_name, get_jimage_version_string(), file_name, &size));
 458 }
 459 
 460 bool ClassPathImageEntry::is_modules_image() const {
 461   assert(this == _singleton, "VM supports a single jimage");
 462   assert(this == (ClassPathImageEntry*)ClassLoader::get_jrt_entry(), "must be used for jrt entry");
 463   return true;
 464 }
 465 
 466 #if INCLUDE_CDS
 467 void ClassLoader::exit_with_path_failure(const char* error, const char* message) {
 468   assert(CDSConfig::is_dumping_archive(), "sanity");
 469   tty->print_cr("Hint: enable -Xlog:class+path=info to diagnose the failure");
 470   vm_exit_during_cds_dumping(error, message);
 471 }
 472 #endif
 473 
 474 ModuleClassPathList::ModuleClassPathList(Symbol* module_name) {
 475   _module_name = module_name;
 476   _module_first_entry = nullptr;
 477   _module_last_entry = nullptr;
 478 }
 479 
 480 ModuleClassPathList::~ModuleClassPathList() {
 481   // Clean out each ClassPathEntry on list
 482   ClassPathEntry* e = _module_first_entry;
 483   while (e != nullptr) {
 484     ClassPathEntry* next_entry = e->next();
 485     delete e;
 486     e = next_entry;
 487   }
 488 }
 489 
 490 void ModuleClassPathList::add_to_list(ClassPathEntry* new_entry) {
 491   if (new_entry != nullptr) {
 492     if (_module_last_entry == nullptr) {
 493       _module_first_entry = _module_last_entry = new_entry;
 494     } else {
 495       _module_last_entry->set_next(new_entry);
 496       _module_last_entry = new_entry;
 497     }
 498   }
 499 }
 500 
 501 void ClassLoader::trace_class_path(const char* msg, const char* name) {
 502   LogTarget(Info, class, path) lt;
 503   if (lt.is_enabled()) {
 504     LogStream ls(lt);
 505     if (msg) {
 506       ls.print("%s", msg);
 507     }
 508     if (name) {
 509       if (strlen(name) < 256) {
 510         ls.print("%s", name);
 511       } else {
 512         // For very long paths, we need to print each character separately,
 513         // as print_cr() has a length limit
 514         while (name[0] != '\0') {
 515           ls.print("%c", name[0]);
 516           name++;
 517         }
 518       }
 519     }
 520     ls.cr();
 521   }
 522 }
 523 
 524 void ClassLoader::setup_bootstrap_search_path(JavaThread* current) {
 525   const char* bootcp = Arguments::get_boot_class_path();
 526   assert(bootcp != nullptr, "Boot class path must not be nullptr");
 527   if (PrintSharedArchiveAndExit) {
 528     // Don't print bootcp - this is the bootcp of this current VM process, not necessarily
 529     // the same as the boot classpath of the shared archive.
 530   } else {
 531     trace_class_path("bootstrap loader class path=", bootcp);
 532   }
 533   setup_bootstrap_search_path_impl(current, bootcp);
 534 }
 535 
 536 #if INCLUDE_CDS
 537 void ClassLoader::setup_app_search_path(JavaThread* current, const char *class_path) {
 538   assert(CDSConfig::is_dumping_archive(), "sanity");
 539 
 540   ResourceMark rm(current);
 541   ClasspathStream cp_stream(class_path);
 542 
 543   while (cp_stream.has_next()) {
 544     const char* path = cp_stream.get_next();
 545     update_class_path_entry_list(current, path, /* check_for_duplicates */ true,
 546                                  /* is_boot_append */ false, /* from_class_path_attr */ false);
 547   }
 548 }
 549 
 550 void ClassLoader::add_to_module_path_entries(const char* path,
 551                                              ClassPathEntry* entry) {
 552   assert(entry != nullptr, "ClassPathEntry should not be nullptr");
 553   assert(CDSConfig::is_dumping_archive(), "sanity");
 554 
 555   // The entry does not exist, add to the list
 556   if (_module_path_entries == nullptr) {
 557     assert(_last_module_path_entry == nullptr, "Sanity");
 558     _module_path_entries = _last_module_path_entry = entry;
 559   } else {
 560     _last_module_path_entry->set_next(entry);
 561     _last_module_path_entry = entry;
 562   }
 563 }
 564 
 565 // Add a module path to the _module_path_entries list.
 566 void ClassLoader::setup_module_search_path(JavaThread* current, const char* path) {
 567   assert(CDSConfig::is_dumping_archive(), "sanity");
 568   struct stat st;
 569   if (os::stat(path, &st) != 0) {
 570     tty->print_cr("os::stat error %d (%s). CDS dump aborted (path was \"%s\").",
 571       errno, os::errno_name(errno), path);
 572     vm_exit_during_initialization();
 573   }
 574   // File or directory found
 575   ClassPathEntry* new_entry = nullptr;
 576   new_entry = create_class_path_entry(current, path, &st,
 577                                       false /*is_boot_append */, false /* from_class_path_attr */);
 578   if (new_entry != nullptr) {
 579     // ClassLoaderExt::process_module_table() filters out non-jar entries before calling this function.
 580     assert(new_entry->is_jar_file(), "module path entry %s is not a jar file", new_entry->name());
 581     add_to_module_path_entries(path, new_entry);
 582   }
 583 }
 584 
 585 #endif // INCLUDE_CDS
 586 
 587 void ClassLoader::close_jrt_image() {
 588   // Not applicable for exploded builds
 589   if (!ClassLoader::has_jrt_entry()) return;
 590   _jrt_entry->close_jimage();
 591 }
 592 
 593 // Construct the array of module/path pairs as specified to --patch-module
 594 // for the boot loader to search ahead of the jimage, if the class being
 595 // loaded is defined to a module that has been specified to --patch-module.
 596 void ClassLoader::setup_patch_mod_entries() {
 597   JavaThread* current = JavaThread::current();
 598   GrowableArray<ModulePatchPath*>* patch_mod_args = Arguments::get_patch_mod_prefix();
 599   int num_of_entries = patch_mod_args->length();
 600 
 601   // Set up the boot loader's _patch_mod_entries list
 602   _patch_mod_entries = new (mtModule) GrowableArray<ModuleClassPathList*>(num_of_entries, mtModule);
 603 
 604   for (int i = 0; i < num_of_entries; i++) {
 605     const char* module_name = (patch_mod_args->at(i))->module_name();
 606     Symbol* const module_sym = SymbolTable::new_symbol(module_name);
 607     assert(module_sym != nullptr, "Failed to obtain Symbol for module name");
 608     ModuleClassPathList* module_cpl = new ModuleClassPathList(module_sym);
 609 
 610     char* class_path = (patch_mod_args->at(i))->path_string();
 611     ResourceMark rm(current);
 612     ClasspathStream cp_stream(class_path);
 613 
 614     while (cp_stream.has_next()) {
 615       const char* path = cp_stream.get_next();
 616       struct stat st;
 617       if (os::stat(path, &st) == 0) {
 618         // File or directory found
 619         ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
 620         // If the path specification is valid, enter it into this module's list
 621         if (new_entry != nullptr) {
 622           module_cpl->add_to_list(new_entry);
 623         }
 624       }
 625     }
 626 
 627     // Record the module into the list of --patch-module entries only if
 628     // valid ClassPathEntrys have been created
 629     if (module_cpl->module_first_entry() != nullptr) {
 630       _patch_mod_entries->push(module_cpl);
 631     }
 632   }
 633 }
 634 
 635 // Determine whether the module has been patched via the command-line
 636 // option --patch-module
 637 bool ClassLoader::is_in_patch_mod_entries(Symbol* module_name) {
 638   if (_patch_mod_entries != nullptr && _patch_mod_entries->is_nonempty()) {
 639     int table_len = _patch_mod_entries->length();
 640     for (int i = 0; i < table_len; i++) {
 641       ModuleClassPathList* patch_mod = _patch_mod_entries->at(i);
 642       if (module_name->fast_compare(patch_mod->module_name()) == 0) {
 643         return true;
 644       }
 645     }
 646   }
 647   return false;
 648 }
 649 
 650 // Set up the _jrt_entry if present and boot append path
 651 void ClassLoader::setup_bootstrap_search_path_impl(JavaThread* current, const char *class_path) {
 652   ResourceMark rm(current);
 653   ClasspathStream cp_stream(class_path);
 654   bool set_base_piece = true;
 655 
 656 #if INCLUDE_CDS
 657   if (CDSConfig::is_dumping_archive()) {
 658     if (!Arguments::has_jimage()) {
 659       vm_exit_during_initialization("CDS is not supported in exploded JDK build", nullptr);
 660     }
 661   }
 662 #endif
 663 
 664   while (cp_stream.has_next()) {
 665     const char* path = cp_stream.get_next();
 666 
 667     if (set_base_piece) {
 668       // The first time through the bootstrap_search setup, it must be determined
 669       // what the base or core piece of the boot loader search is.  Either a java runtime
 670       // image is present or this is an exploded module build situation.
 671       assert(string_ends_with(path, MODULES_IMAGE_NAME) || string_ends_with(path, JAVA_BASE_NAME),
 672              "Incorrect boot loader search path, no java runtime image or " JAVA_BASE_NAME " exploded build");
 673       struct stat st;
 674       if (os::stat(path, &st) == 0) {
 675         // Directory found
 676         if (JImage_file != nullptr) {
 677           assert(Arguments::has_jimage(), "sanity check");
 678           const char* canonical_path = get_canonical_path(path, current);
 679           assert(canonical_path != nullptr, "canonical_path issue");
 680 
 681           _jrt_entry = new ClassPathImageEntry(JImage_file, canonical_path);
 682           assert(_jrt_entry != nullptr && _jrt_entry->is_modules_image(), "No java runtime image present");
 683           assert(_jrt_entry->jimage() != nullptr, "No java runtime image");
 684         } // else it's an exploded build.
 685       } else {
 686         // If path does not exist, exit
 687         vm_exit_during_initialization("Unable to establish the boot loader search path", path);
 688       }
 689       set_base_piece = false;
 690     } else {
 691       // Every entry on the boot class path after the initial base piece,
 692       // which is set by os::set_boot_path(), is considered an appended entry.
 693       update_class_path_entry_list(current, path, /* check_for_duplicates */ false,
 694                                     /* is_boot_append */ true, /* from_class_path_attr */ false);
 695     }
 696   }
 697 }
 698 
 699 // Gets the exploded path for the named module. The memory for the path
 700 // is allocated on the C heap if `c_heap` is true otherwise in the resource area.
 701 static const char* get_exploded_module_path(const char* module_name, bool c_heap) {
 702   const char *home = Arguments::get_java_home();
 703   const char file_sep = os::file_separator()[0];
 704   // 10 represents the length of "modules" + 2 file separators + \0
 705   size_t len = strlen(home) + strlen(module_name) + 10;
 706   char *path = c_heap ? NEW_C_HEAP_ARRAY(char, len, mtModule) : NEW_RESOURCE_ARRAY(char, len);
 707   jio_snprintf(path, len, "%s%cmodules%c%s", home, file_sep, file_sep, module_name);
 708   return path;
 709 }
 710 
 711 // During an exploded modules build, each module defined to the boot loader
 712 // will be added to the ClassLoader::_exploded_entries array.
 713 void ClassLoader::add_to_exploded_build_list(JavaThread* current, Symbol* module_sym) {
 714   assert(!ClassLoader::has_jrt_entry(), "Exploded build not applicable");
 715   assert(_exploded_entries != nullptr, "_exploded_entries was not initialized");
 716 
 717   // Find the module's symbol
 718   ResourceMark rm(current);
 719   const char *module_name = module_sym->as_C_string();
 720   const char *path = get_exploded_module_path(module_name, false);
 721 
 722   struct stat st;
 723   if (os::stat(path, &st) == 0) {
 724     // Directory found
 725     ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
 726 
 727     // If the path specification is valid, enter it into this module's list.
 728     // There is no need to check for duplicate modules in the exploded entry list,
 729     // since no two modules with the same name can be defined to the boot loader.
 730     // This is checked at module definition time in Modules::define_module.
 731     if (new_entry != nullptr) {
 732       ModuleClassPathList* module_cpl = new ModuleClassPathList(module_sym);
 733       module_cpl->add_to_list(new_entry);
 734       {
 735         MutexLocker ml(current, Module_lock);
 736         _exploded_entries->push(module_cpl);
 737       }
 738       log_info(class, load)("path: %s", path);
 739     }
 740   }
 741 }
 742 
 743 jzfile* ClassLoader::open_zip_file(const char* canonical_path, char** error_msg, JavaThread* thread) {
 744   // enable call to C land
 745   ThreadToNativeFromVM ttn(thread);
 746   HandleMark hm(thread);
 747   return ZipLibrary::open(canonical_path, error_msg);
 748 }
 749 
 750 ClassPathEntry* ClassLoader::create_class_path_entry(JavaThread* current,
 751                                                      const char *path, const struct stat* st,
 752                                                      bool is_boot_append,
 753                                                      bool from_class_path_attr) {
 754   ClassPathEntry* new_entry = nullptr;
 755   if ((st->st_mode & S_IFMT) == S_IFREG) {
 756     ResourceMark rm(current);
 757     // Regular file, should be a zip file
 758     // Canonicalized filename
 759     const char* canonical_path = get_canonical_path(path, current);
 760     if (canonical_path == nullptr) {
 761       return nullptr;
 762     }
 763     char* error_msg = nullptr;
 764     jzfile* zip = open_zip_file(canonical_path, &error_msg, current);
 765     if (zip != nullptr && error_msg == nullptr) {
 766       new_entry = new ClassPathZipEntry(zip, path, is_boot_append, from_class_path_attr);
 767     } else {
 768 #if INCLUDE_CDS
 769       ClassLoaderExt::set_has_non_jar_in_classpath();
 770 #endif
 771       return nullptr;
 772     }
 773     log_info(class, path)("opened: %s", path);
 774     log_info(class, load)("opened: %s", path);
 775   } else {
 776     // Directory
 777     new_entry = new ClassPathDirEntry(path);
 778     log_info(class, load)("path: %s", path);
 779   }
 780   return new_entry;
 781 }
 782 
 783 
 784 // Create a class path zip entry for a given path (return null if not found
 785 // or zip/JAR file cannot be opened)
 786 ClassPathZipEntry* ClassLoader::create_class_path_zip_entry(const char *path, bool is_boot_append) {
 787   // check for a regular file
 788   struct stat st;
 789   if (os::stat(path, &st) == 0) {
 790     if ((st.st_mode & S_IFMT) == S_IFREG) {
 791       JavaThread* thread = JavaThread::current();
 792       ResourceMark rm(thread);
 793       const char* canonical_path = get_canonical_path(path, thread);
 794       if (canonical_path != nullptr) {
 795         char* error_msg = nullptr;
 796         jzfile* zip = open_zip_file(canonical_path, &error_msg, thread);
 797         if (zip != nullptr && error_msg == nullptr) {
 798           // create using canonical path
 799           return new ClassPathZipEntry(zip, canonical_path, is_boot_append, false);
 800         }
 801       }
 802     }
 803   }
 804   return nullptr;
 805 }
 806 
 807 // The boot append entries are added with a lock, and read lock free.
 808 void ClassLoader::add_to_boot_append_entries(ClassPathEntry *new_entry) {
 809   if (new_entry != nullptr) {
 810     MutexLocker ml(Bootclasspath_lock, Mutex::_no_safepoint_check_flag);
 811     if (_last_append_entry == nullptr) {
 812       _last_append_entry = new_entry;
 813       assert(first_append_entry() == nullptr, "boot loader's append class path entry list not empty");
 814       Atomic::release_store(&_first_append_entry_list, new_entry);
 815     } else {
 816       _last_append_entry->set_next(new_entry);
 817       _last_append_entry = new_entry;
 818     }
 819   }
 820 }
 821 
 822 // Record the path entries specified in -cp during dump time. The recorded
 823 // information will be used at runtime for loading the archived app classes.
 824 //
 825 // Note that at dump time, ClassLoader::_app_classpath_entries are NOT used for
 826 // loading app classes. Instead, the app class are loaded by the
 827 // jdk/internal/loader/ClassLoaders$AppClassLoader instance.
 828 bool ClassLoader::add_to_app_classpath_entries(JavaThread* current,
 829                                                ClassPathEntry* entry,
 830                                                bool check_for_duplicates) {
 831 #if INCLUDE_CDS
 832   assert(entry != nullptr, "ClassPathEntry should not be nullptr");
 833   ClassPathEntry* e = _app_classpath_entries;
 834   if (check_for_duplicates) {
 835     while (e != nullptr) {
 836       if (strcmp(e->name(), entry->name()) == 0 &&
 837           e->from_class_path_attr() == entry->from_class_path_attr()) {
 838         // entry already exists
 839         return false;
 840       }
 841       e = e->next();
 842     }
 843   }
 844 
 845   // The entry does not exist, add to the list
 846   if (_app_classpath_entries == nullptr) {
 847     assert(_last_app_classpath_entry == nullptr, "Sanity");
 848     _app_classpath_entries = _last_app_classpath_entry = entry;
 849   } else {
 850     _last_app_classpath_entry->set_next(entry);
 851     _last_app_classpath_entry = entry;
 852   }
 853 
 854   if (entry->is_jar_file()) {
 855     ClassLoaderExt::process_jar_manifest(current, entry);
 856   }
 857 #endif
 858   return true;
 859 }
 860 
 861 // Returns true IFF the file/dir exists and the entry was successfully created.
 862 bool ClassLoader::update_class_path_entry_list(JavaThread* current,
 863                                                const char *path,
 864                                                bool check_for_duplicates,
 865                                                bool is_boot_append,
 866                                                bool from_class_path_attr) {
 867   struct stat st;
 868   if (os::stat(path, &st) == 0) {
 869     // File or directory found
 870     ClassPathEntry* new_entry = nullptr;
 871     new_entry = create_class_path_entry(current, path, &st, is_boot_append, from_class_path_attr);
 872     if (new_entry == nullptr) {
 873       return false;
 874     }
 875 
 876     // Do not reorder the bootclasspath which would break get_system_package().
 877     // Add new entry to linked list
 878     if (is_boot_append) {
 879       add_to_boot_append_entries(new_entry);
 880     } else {
 881       if (!add_to_app_classpath_entries(current, new_entry, check_for_duplicates)) {
 882         // new_entry is not saved, free it now
 883         delete new_entry;
 884       }
 885     }
 886     return true;
 887   } else {
 888     return false;
 889   }
 890 }
 891 
 892 static void print_module_entry_table(const GrowableArray<ModuleClassPathList*>* const module_list) {
 893   ResourceMark rm;
 894   int num_of_entries = module_list->length();
 895   for (int i = 0; i < num_of_entries; i++) {
 896     ClassPathEntry* e;
 897     ModuleClassPathList* mpl = module_list->at(i);
 898     tty->print("%s=", mpl->module_name()->as_C_string());
 899     e = mpl->module_first_entry();
 900     while (e != nullptr) {
 901       tty->print("%s", e->name());
 902       e = e->next();
 903       if (e != nullptr) {
 904         tty->print("%s", os::path_separator());
 905       }
 906     }
 907     tty->print(" ;");
 908   }
 909 }
 910 
 911 void ClassLoader::print_bootclasspath() {
 912   ClassPathEntry* e;
 913   tty->print("[bootclasspath= ");
 914 
 915   // Print --patch-module module/path specifications first
 916   if (_patch_mod_entries != nullptr) {
 917     print_module_entry_table(_patch_mod_entries);
 918   }
 919 
 920   // [jimage | exploded modules build]
 921   if (has_jrt_entry()) {
 922     // Print the location of the java runtime image
 923     tty->print("%s ;", _jrt_entry->name());
 924   } else {
 925     // Print exploded module build path specifications
 926     if (_exploded_entries != nullptr) {
 927       print_module_entry_table(_exploded_entries);
 928     }
 929   }
 930 
 931   // appended entries
 932   e = first_append_entry();
 933   while (e != nullptr) {
 934     tty->print("%s ;", e->name());
 935     e = e->next();
 936   }
 937   tty->print_cr("]");
 938 }
 939 
 940 void* ClassLoader::dll_lookup(void* lib, const char* name, const char* path) {
 941   void* func = os::dll_lookup(lib, name);
 942   if (func == nullptr) {
 943     char msg[256] = "";
 944     jio_snprintf(msg, sizeof(msg), "Could not resolve \"%s\"", name);
 945     vm_exit_during_initialization(msg, path);
 946   }
 947   return func;
 948 }
 949 
 950 void ClassLoader::load_java_library() {
 951   assert(CanonicalizeEntry == nullptr, "should not load java library twice");
 952   void *javalib_handle = os::native_java_library();
 953   if (javalib_handle == nullptr) {
 954     vm_exit_during_initialization("Unable to load java library", nullptr);
 955   }
 956 
 957   CanonicalizeEntry = CAST_TO_FN_PTR(canonicalize_fn_t, dll_lookup(javalib_handle, "JDK_Canonicalize", nullptr));
 958 }
 959 
 960 void ClassLoader::load_jimage_library() {
 961   assert(JImageOpen == nullptr, "should not load jimage library twice");
 962   char path[JVM_MAXPATHLEN];
 963   char ebuf[1024];
 964   void* handle = nullptr;
 965   if (os::dll_locate_lib(path, sizeof(path), Arguments::get_dll_dir(), "jimage")) {
 966     handle = os::dll_load(path, ebuf, sizeof ebuf);
 967   }
 968   if (handle == nullptr) {
 969     vm_exit_during_initialization("Unable to load jimage library", path);
 970   }
 971 
 972   JImageOpen = CAST_TO_FN_PTR(JImageOpen_t, dll_lookup(handle, "JIMAGE_Open", path));
 973   JImageClose = CAST_TO_FN_PTR(JImageClose_t, dll_lookup(handle, "JIMAGE_Close", path));
 974   JImageFindResource = CAST_TO_FN_PTR(JImageFindResource_t, dll_lookup(handle, "JIMAGE_FindResource", path));
 975   JImageGetResource = CAST_TO_FN_PTR(JImageGetResource_t, dll_lookup(handle, "JIMAGE_GetResource", path));
 976 }
 977 
 978 int ClassLoader::crc32(int crc, const char* buf, int len) {
 979   return ZipLibrary::crc32(crc, (const jbyte*)buf, len);
 980 }
 981 
 982 oop ClassLoader::get_system_package(const char* name, TRAPS) {
 983   // Look up the name in the boot loader's package entry table.
 984   if (name != nullptr) {
 985     TempNewSymbol package_sym = SymbolTable::new_symbol(name);
 986     // Look for the package entry in the boot loader's package entry table.
 987     PackageEntry* package =
 988       ClassLoaderData::the_null_class_loader_data()->packages()->lookup_only(package_sym);
 989 
 990     // Return null if package does not exist or if no classes in that package
 991     // have been loaded.
 992     if (package != nullptr && package->has_loaded_class()) {
 993       ModuleEntry* module = package->module();
 994       if (module->location() != nullptr) {
 995         ResourceMark rm(THREAD);
 996         Handle ml = java_lang_String::create_from_str(
 997           module->location()->as_C_string(), THREAD);
 998         return ml();
 999       }
1000       // Return entry on boot loader class path.
1001       Handle cph = java_lang_String::create_from_str(
1002         ClassLoader::classpath_entry(package->classpath_index())->name(), THREAD);
1003       return cph();
1004     }
1005   }
1006   return nullptr;
1007 }
1008 
1009 objArrayOop ClassLoader::get_system_packages(TRAPS) {
1010   ResourceMark rm(THREAD);
1011   // List of pointers to PackageEntrys that have loaded classes.
1012   PackageEntryTable* pe_table =
1013       ClassLoaderData::the_null_class_loader_data()->packages();
1014   GrowableArray<PackageEntry*>* loaded_class_pkgs = pe_table->get_system_packages();
1015 
1016   // Allocate objArray and fill with java.lang.String
1017   objArrayOop r = oopFactory::new_objArray(vmClasses::String_klass(),
1018                                            loaded_class_pkgs->length(), CHECK_NULL);
1019   objArrayHandle result(THREAD, r);
1020   for (int x = 0; x < loaded_class_pkgs->length(); x++) {
1021     PackageEntry* package_entry = loaded_class_pkgs->at(x);
1022     Handle str = java_lang_String::create_from_symbol(package_entry->name(), CHECK_NULL);
1023     result->obj_at_put(x, str());
1024   }
1025   return result();
1026 }
1027 
1028 // caller needs ResourceMark
1029 const char* ClassLoader::file_name_for_class_name(const char* class_name,
1030                                                   int class_name_len) {
1031   assert(class_name != nullptr, "invariant");
1032   assert((int)strlen(class_name) == class_name_len, "invariant");
1033 
1034   static const char class_suffix[] = ".class";
1035   size_t class_suffix_len = sizeof(class_suffix);
1036 
1037   char* const file_name = NEW_RESOURCE_ARRAY(char,
1038                                              class_name_len +
1039                                              class_suffix_len); // includes term null
1040 
1041   strncpy(file_name, class_name, class_name_len);
1042   strncpy(&file_name[class_name_len], class_suffix, class_suffix_len);
1043 
1044   return file_name;
1045 }
1046 
1047 static ClassPathEntry* find_first_module_cpe(ModuleEntry* mod_entry,
1048                                              const GrowableArray<ModuleClassPathList*>* const module_list) {
1049   int num_of_entries = module_list->length();
1050   const Symbol* class_module_name = mod_entry->name();
1051 
1052   // Loop through all the modules in either the patch-module or exploded entries looking for module
1053   for (int i = 0; i < num_of_entries; i++) {
1054     ModuleClassPathList* module_cpl = module_list->at(i);
1055     Symbol* module_cpl_name = module_cpl->module_name();
1056 
1057     if (module_cpl_name->fast_compare(class_module_name) == 0) {
1058       // Class' module has been located.
1059       return module_cpl->module_first_entry();
1060     }
1061   }
1062   return nullptr;
1063 }
1064 
1065 
1066 // Search the module list for the class file stream based on the file name and java package
1067 ClassFileStream* ClassLoader::search_module_entries(JavaThread* current,
1068                                                     const GrowableArray<ModuleClassPathList*>* const module_list,
1069                                                     PackageEntry* pkg_entry, // Java package entry derived from the class name
1070                                                     const char* const file_name) {
1071   ClassFileStream* stream = nullptr;
1072 
1073   // Find the defining module in the boot loader's module entry table
1074   ModuleEntry* mod_entry = (pkg_entry != nullptr) ? pkg_entry->module() : nullptr;
1075 
1076   // If the module system has not defined java.base yet, then
1077   // classes loaded are assumed to be defined to java.base.
1078   // When java.base is eventually defined by the module system,
1079   // all packages of classes that have been previously loaded
1080   // are verified in ModuleEntryTable::verify_javabase_packages().
1081   if (!Universe::is_module_initialized() &&
1082       !ModuleEntryTable::javabase_defined() &&
1083       mod_entry == nullptr) {
1084     mod_entry = ModuleEntryTable::javabase_moduleEntry();
1085   }
1086 
1087   // The module must be a named module
1088   ClassPathEntry* e = nullptr;
1089   if (mod_entry != nullptr && mod_entry->is_named()) {
1090     if (module_list == _exploded_entries) {
1091       // The exploded build entries can be added to at any time so a lock is
1092       // needed when searching them.
1093       assert(!ClassLoader::has_jrt_entry(), "Must be exploded build");
1094       MutexLocker ml(current, Module_lock);
1095       e = find_first_module_cpe(mod_entry, module_list);
1096     } else {
1097       e = find_first_module_cpe(mod_entry, module_list);
1098     }
1099   }
1100 
1101   // Try to load the class from the module's ClassPathEntry list.
1102   while (e != nullptr) {
1103     stream = e->open_stream(current, file_name);
1104     // No context.check is required since CDS is not supported
1105     // for an exploded modules build or if --patch-module is specified.
1106     if (nullptr != stream) {
1107       return stream;
1108     }
1109     e = e->next();
1110   }
1111   // If the module was located, break out even if the class was not
1112   // located successfully from that module's ClassPathEntry list.
1113   // There will not be another valid entry for that module.
1114   return nullptr;
1115 }
1116 
1117 // Called by the boot classloader to load classes
1118 InstanceKlass* ClassLoader::load_class(Symbol* name, PackageEntry* pkg_entry, bool search_append_only, TRAPS) {
1119   assert(name != nullptr, "invariant");
1120 
1121   ResourceMark rm(THREAD);
1122   HandleMark hm(THREAD);
1123 
1124   const char* const class_name = name->as_C_string();
1125 
1126   EventMarkClassLoading m("Loading class %s", class_name);
1127 
1128   const char* const file_name = file_name_for_class_name(class_name,
1129                                                          name->utf8_length());
1130   assert(file_name != nullptr, "invariant");
1131 
1132   // Lookup stream for parsing .class file
1133   ClassFileStream* stream = nullptr;
1134   s2 classpath_index = 0;
1135   ClassPathEntry* e = nullptr;
1136 
1137   // If search_append_only is true, boot loader visibility boundaries are
1138   // set to be _first_append_entry to the end. This includes:
1139   //   [-Xbootclasspath/a]; [jvmti appended entries]
1140   //
1141   // If search_append_only is false, boot loader visibility boundaries are
1142   // set to be the --patch-module entries plus the base piece. This includes:
1143   //   [--patch-module=<module>=<file>(<pathsep><file>)*]; [jimage | exploded module build]
1144   //
1145 
1146   // Load Attempt #1: --patch-module
1147   // Determine the class' defining module.  If it appears in the _patch_mod_entries,
1148   // attempt to load the class from those locations specific to the module.
1149   // Specifications to --patch-module can contain a partial number of classes
1150   // that are part of the overall module definition.  So if a particular class is not
1151   // found within its module specification, the search should continue to Load Attempt #2.
1152   // Note: The --patch-module entries are never searched if the boot loader's
1153   //       visibility boundary is limited to only searching the append entries.
1154   if (_patch_mod_entries != nullptr && !search_append_only) {
1155     assert(!CDSConfig::is_dumping_archive(), "CDS doesn't support --patch-module during dumping");
1156     stream = search_module_entries(THREAD, _patch_mod_entries, pkg_entry, file_name);
1157   }
1158 
1159   // Load Attempt #2: [jimage | exploded build]
1160   if (!search_append_only && (nullptr == stream)) {
1161     if (has_jrt_entry()) {
1162       e = _jrt_entry;
1163       stream = _jrt_entry->open_stream(THREAD, file_name);
1164     } else {
1165       // Exploded build - attempt to locate class in its defining module's location.
1166       assert(_exploded_entries != nullptr, "No exploded build entries present");
1167       assert(!CDSConfig::is_dumping_archive(), "CDS dumping doesn't support exploded build");
1168       stream = search_module_entries(THREAD, _exploded_entries, pkg_entry, file_name);
1169     }
1170   }
1171 
1172   // Load Attempt #3: [-Xbootclasspath/a]; [jvmti appended entries]
1173   if (search_append_only && (nullptr == stream)) {
1174     // For the boot loader append path search, the starting classpath_index
1175     // for the appended piece is always 1 to account for either the
1176     // _jrt_entry or the _exploded_entries.
1177     assert(classpath_index == 0, "The classpath_index has been incremented incorrectly");
1178     classpath_index = 1;
1179 
1180     e = first_append_entry();
1181     while (e != nullptr) {
1182       stream = e->open_stream(THREAD, file_name);
1183       if (nullptr != stream) {
1184         break;
1185       }
1186       e = e->next();
1187       ++classpath_index;
1188     }
1189   }
1190 
1191   if (nullptr == stream) {
1192     return nullptr;
1193   }
1194 
1195   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
1196   Handle protection_domain;
1197   ClassLoadInfo cl_info(protection_domain);
1198 
1199   InstanceKlass* result = KlassFactory::create_from_stream(stream,
1200                                                            name,
1201                                                            loader_data,
1202                                                            cl_info,
1203                                                            CHECK_NULL);
1204   result->set_classpath_index(classpath_index);
1205   return result;
1206 }
1207 
1208 #if INCLUDE_CDS
1209 static const char* skip_uri_protocol(const char* source) {
1210   if (strncmp(source, "file:", 5) == 0) {
1211     // file: protocol path could start with file:/ or file:///
1212     // locate the char after all the forward slashes
1213     int offset = 5;
1214     while (*(source + offset) == '/') {
1215         offset++;
1216     }
1217     source += offset;
1218   // for non-windows platforms, move back one char as the path begins with a '/'
1219 #ifndef _WINDOWS
1220     source -= 1;
1221 #endif
1222   } else if (strncmp(source, "jrt:/", 5) == 0) {
1223     source += 5;
1224   }
1225   return source;
1226 }
1227 
1228 static char decode_percent_encoded(const char *str, size_t& index) {
1229   if (str[index] == '%'
1230       && isxdigit(str[index + 1])
1231       && isxdigit(str[index + 2])) {
1232     char hex[3];
1233     hex[0] = str[index + 1];
1234     hex[1] = str[index + 2];
1235     hex[2] = '\0';
1236     index += 2;
1237     return (char) strtol(hex, nullptr, 16);
1238   }
1239   return str[index];
1240 }
1241 
1242 char* ClassLoader::uri_to_path(const char* uri) {
1243   const size_t len = strlen(uri) + 1;
1244   char* path = NEW_RESOURCE_ARRAY(char, len);
1245 
1246   uri = skip_uri_protocol(uri);
1247 
1248   if (strncmp(uri, "//", 2) == 0) {
1249     // Skip the empty "authority" part
1250     uri += 2;
1251   }
1252 
1253 #ifdef _WINDOWS
1254   if (uri[0] == '/') {
1255     // Absolute path name on Windows does not begin with a slash
1256     uri += 1;
1257   }
1258 #endif
1259 
1260   size_t path_index = 0;
1261   for (size_t i = 0; i < strlen(uri); ++i) {
1262     char decoded = decode_percent_encoded(uri, i);
1263     path[path_index++] = decoded;
1264   }
1265   path[path_index] = '\0';
1266   return path;
1267 }
1268 
1269 // Record the shared classpath index and loader type for classes loaded
1270 // by the builtin loaders at dump time.
1271 void ClassLoader::record_result(JavaThread* current, InstanceKlass* ik,
1272                                 const ClassFileStream* stream, bool redefined) {
1273   assert(CDSConfig::is_dumping_archive(), "sanity");
1274   assert(stream != nullptr, "sanity");
1275 
1276   if (ik->is_hidden()) {
1277     record_hidden_class(ik);
1278     return;
1279   }
1280 
1281   oop loader = ik->class_loader();
1282   char* src = (char*)stream->source();
1283   if (src == nullptr) {
1284     if (loader == nullptr) {
1285       // JFR classes
1286       ik->set_shared_classpath_index(0);
1287       ik->set_shared_class_loader_type(ClassLoader::BOOT_LOADER);
1288     }
1289     return;
1290   }
1291 
1292   assert(has_jrt_entry(), "CDS dumping does not support exploded JDK build");
1293 
1294   ResourceMark rm(current);
1295   int classpath_index = -1;
1296   PackageEntry* pkg_entry = ik->package();
1297 
1298   if (FileMapInfo::get_number_of_shared_paths() > 0) {
1299     // Save the path from the file: protocol or the module name from the jrt: protocol
1300     // if no protocol prefix is found, path is the same as stream->source(). This path
1301     // must be valid since the class has been successfully parsed.
1302     const char* path = ClassLoader::uri_to_path(src);
1303     assert(path != nullptr, "sanity");
1304     for (int i = 0; i < FileMapInfo::get_number_of_shared_paths(); i++) {
1305       SharedClassPathEntry* ent = FileMapInfo::shared_path(i);
1306       // A shared path has been validated during its creation in ClassLoader::create_class_path_entry(),
1307       // it must be valid here.
1308       assert(ent->name() != nullptr, "sanity");
1309       // If the path (from the class stream source) is the same as the shared
1310       // class or module path, then we have a match.
1311       // src may come from the App/Platform class loaders, which would canonicalize
1312       // the file name. We cannot use strcmp to check for equality against ent->name().
1313       // We must use os::same_files (which is faster than canonicalizing ent->name()).
1314       if (os::same_files(ent->name(), path)) {
1315         // null pkg_entry and pkg_entry in an unnamed module implies the class
1316         // is from the -cp or boot loader append path which consists of -Xbootclasspath/a
1317         // and jvmti appended entries.
1318         if ((pkg_entry == nullptr) || (pkg_entry->in_unnamed_module())) {
1319           // Ensure the index is within the -cp range before assigning
1320           // to the classpath_index.
1321           if (SystemDictionary::is_system_class_loader(loader) &&
1322               (i >= ClassLoaderExt::app_class_paths_start_index()) &&
1323               (i < ClassLoaderExt::app_module_paths_start_index())) {
1324             classpath_index = i;
1325             break;
1326           } else {
1327             if ((i >= 1) &&
1328                 (i < ClassLoaderExt::app_class_paths_start_index())) {
1329               // The class must be from boot loader append path which consists of
1330               // -Xbootclasspath/a and jvmti appended entries.
1331               assert(loader == nullptr, "sanity");
1332               classpath_index = i;
1333               break;
1334             }
1335           }
1336         } else {
1337           // A class from a named module from the --module-path. Ensure the index is
1338           // within the --module-path range before assigning to the classpath_index.
1339           if ((pkg_entry != nullptr) && !(pkg_entry->in_unnamed_module()) && (i > 0)) {
1340             if (i >= ClassLoaderExt::app_module_paths_start_index() &&
1341                 i < FileMapInfo::get_number_of_shared_paths()) {
1342               classpath_index = i;
1343               break;
1344             }
1345           }
1346         }
1347       }
1348       // for index 0 and the stream->source() is the modules image or has the jrt: protocol.
1349       // The class must be from the runtime modules image.
1350       if (i == 0 && (stream->from_boot_loader_modules_image() || string_starts_with(src, "jrt:"))) {
1351         classpath_index = i;
1352         break;
1353       }
1354     }
1355 
1356     // No path entry found for this class: most likely a shared class loaded by the
1357     // user defined classloader.
1358     if (classpath_index < 0 && !SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
1359       assert(ik->shared_classpath_index() < 0, "not assigned yet");
1360       ik->set_shared_classpath_index(UNREGISTERED_INDEX);
1361       SystemDictionaryShared::set_shared_class_misc_info(ik, (ClassFileStream*)stream);
1362       return;
1363     }
1364   } else {
1365     // The shared path table is set up after module system initialization.
1366     // The path table contains no entry before that. Any classes loaded prior
1367     // to the setup of the shared path table must be from the modules image.
1368     assert(stream->from_boot_loader_modules_image(), "stream must be loaded by boot loader from modules image");
1369     assert(FileMapInfo::get_number_of_shared_paths() == 0, "shared path table must not have been setup");
1370     classpath_index = 0;
1371   }
1372 
1373   const char* const class_name = ik->name()->as_C_string();
1374   const char* const file_name = file_name_for_class_name(class_name,
1375                                                          ik->name()->utf8_length());
1376   assert(file_name != nullptr, "invariant");
1377   ClassLoaderExt::record_result(checked_cast<s2>(classpath_index), ik, redefined);
1378 }
1379 
1380 void ClassLoader::record_hidden_class(InstanceKlass* ik) {
1381   assert(ik->is_hidden(), "must be");
1382 
1383   s2 classloader_type;
1384   if (HeapShared::is_lambda_form_klass(ik)) {
1385     classloader_type = ClassLoader::BOOT_LOADER;
1386   } else {
1387     oop loader = ik->class_loader();
1388 
1389     if (loader == nullptr) {
1390       classloader_type = ClassLoader::BOOT_LOADER;
1391     } else if (SystemDictionary::is_platform_class_loader(loader)) {
1392       classloader_type = ClassLoader::PLATFORM_LOADER;
1393     } else if (SystemDictionary::is_system_class_loader(loader)) {
1394       classloader_type = ClassLoader::APP_LOADER;
1395     } else {
1396       // This class won't be archived, so no need to update its
1397       // classloader_type/classpath_index.
1398       return;
1399     }
1400   }
1401   ik->set_shared_class_loader_type(classloader_type);
1402 
1403   if (HeapShared::is_lambda_proxy_klass(ik)) {
1404     InstanceKlass* nest_host = ik->nest_host_not_null();
1405     ik->set_shared_classpath_index(nest_host->shared_classpath_index());
1406   } else if (HeapShared::is_lambda_form_klass(ik)) {
1407     ik->set_shared_classpath_index(0);
1408   } else {
1409     // Generated invoker classes.
1410     if (classloader_type == ClassLoader::APP_LOADER) {
1411       ik->set_shared_classpath_index(ClassLoaderExt::app_class_paths_start_index());
1412     } else {
1413       ik->set_shared_classpath_index(0);
1414     }
1415   }
1416 }
1417 #endif // INCLUDE_CDS
1418 
1419 // Initialize the class loader's access to methods in libzip.  Parse and
1420 // process the boot classpath into a list ClassPathEntry objects.  Once
1421 // this list has been created, it must not change order (see class PackageInfo)
1422 // it can be appended to and is by jvmti.
1423 
1424 void ClassLoader::initialize(TRAPS) {
1425   if (UsePerfData) {
1426     // jvmstat performance counters
1427     NEWPERFTICKCOUNTER(_perf_accumulated_time, SUN_CLS, "time");
1428     NEWPERFTICKCOUNTER(_perf_class_init_time, SUN_CLS, "classInitTime");
1429     NEWPERFTICKCOUNTER(_perf_class_init_selftime, SUN_CLS, "classInitTime.self");
1430     NEWPERFTICKCOUNTER(_perf_class_verify_time, SUN_CLS, "classVerifyTime");
1431     NEWPERFTICKCOUNTER(_perf_class_verify_selftime, SUN_CLS, "classVerifyTime.self");
1432     NEWPERFTICKCOUNTER(_perf_class_link_time, SUN_CLS, "classLinkedTime");
1433     NEWPERFTICKCOUNTER(_perf_class_link_selftime, SUN_CLS, "classLinkedTime.self");
1434     NEWPERFEVENTCOUNTER(_perf_classes_inited, SUN_CLS, "initializedClasses");
1435     NEWPERFEVENTCOUNTER(_perf_classes_linked, SUN_CLS, "linkedClasses");
1436     NEWPERFEVENTCOUNTER(_perf_classes_verified, SUN_CLS, "verifiedClasses");
1437 
1438     NEWPERFTICKCOUNTER(_perf_shared_classload_time, SUN_CLS, "sharedClassLoadTime");
1439     NEWPERFTICKCOUNTER(_perf_sys_classload_time, SUN_CLS, "sysClassLoadTime");
1440     NEWPERFTICKCOUNTER(_perf_app_classload_time, SUN_CLS, "appClassLoadTime");
1441     NEWPERFTICKCOUNTER(_perf_app_classload_selftime, SUN_CLS, "appClassLoadTime.self");
1442     NEWPERFEVENTCOUNTER(_perf_app_classload_count, SUN_CLS, "appClassLoadCount");
1443     NEWPERFTICKCOUNTER(_perf_define_appclasses, SUN_CLS, "defineAppClasses");
1444     NEWPERFTICKCOUNTER(_perf_define_appclass_time, SUN_CLS, "defineAppClassTime");
1445     NEWPERFTICKCOUNTER(_perf_define_appclass_selftime, SUN_CLS, "defineAppClassTime.self");
1446     NEWPERFBYTECOUNTER(_perf_app_classfile_bytes_read, SUN_CLS, "appClassBytes");
1447     NEWPERFBYTECOUNTER(_perf_sys_classfile_bytes_read, SUN_CLS, "sysClassBytes");
1448     NEWPERFEVENTCOUNTER(_unsafe_defineClassCallCounter, SUN_CLS, "unsafeDefineClassCalls");
1449     NEWPERFTICKCOUNTER(_perf_secondary_hash_time, SUN_CLS, "secondarySuperHashTime");
1450 
1451     if (log_is_enabled(Info, perf, class, link)) {
1452       NEWPERFTICKCOUNTER(_perf_ik_link_methods_time, SUN_CLS, "linkMethodsTime");
1453       NEWPERFTICKCOUNTER(_perf_method_adapters_time, SUN_CLS, "makeAdaptersTime");
1454       NEWPERFEVENTCOUNTER(_perf_ik_link_methods_count, SUN_CLS, "linkMethodsCount");
1455       NEWPERFEVENTCOUNTER(_perf_method_adapters_count, SUN_CLS, "makeAdaptersCount");
1456 
1457       NEWPERFTICKCOUNTER(_perf_resolve_indy_time, SUN_CLS, "resolve_invokedynamic_time");
1458       NEWPERFTICKCOUNTER(_perf_resolve_invokehandle_time, SUN_CLS, "resolve_invokehandle_time");
1459       NEWPERFTICKCOUNTER(_perf_resolve_mh_time, SUN_CLS, "resolve_MethodHandle_time");
1460       NEWPERFTICKCOUNTER(_perf_resolve_mt_time, SUN_CLS, "resolve_MethodType_time");
1461 
1462       NEWPERFEVENTCOUNTER(_perf_resolve_indy_count, SUN_CLS, "resolve_invokedynamic_count");
1463       NEWPERFEVENTCOUNTER(_perf_resolve_invokehandle_count, SUN_CLS, "resolve_invokehandle_count");
1464       NEWPERFEVENTCOUNTER(_perf_resolve_mh_count, SUN_CLS, "resolve_MethodHandle_count");
1465       NEWPERFEVENTCOUNTER(_perf_resolve_mt_count, SUN_CLS, "resolve_MethodType_count");
1466     }
1467   }
1468 
1469   // lookup java library entry points
1470   load_java_library();
1471   // jimage library entry points are loaded below, in lookup_vm_options
1472   setup_bootstrap_search_path(THREAD);
1473 }
1474 
1475 static char* lookup_vm_resource(JImageFile *jimage, const char *jimage_version, const char *path) {
1476   jlong size;
1477   JImageLocationRef location = (*JImageFindResource)(jimage, "java.base", jimage_version, path, &size);
1478   if (location == 0)
1479     return nullptr;
1480   char *val = NEW_C_HEAP_ARRAY(char, size+1, mtClass);
1481   (*JImageGetResource)(jimage, location, val, size);
1482   val[size] = '\0';
1483   return val;
1484 }
1485 
1486 // Lookup VM options embedded in the modules jimage file
1487 char* ClassLoader::lookup_vm_options() {
1488   jint error;
1489   char modules_path[JVM_MAXPATHLEN];
1490   const char* fileSep = os::file_separator();
1491 
1492   // Initialize jimage library entry points
1493   load_jimage_library();
1494 
1495   jio_snprintf(modules_path, JVM_MAXPATHLEN, "%s%slib%smodules", Arguments::get_java_home(), fileSep, fileSep);
1496   JImage_file =(*JImageOpen)(modules_path, &error);
1497   if (JImage_file == nullptr) {
1498     return nullptr;
1499   }
1500 
1501   const char *jimage_version = get_jimage_version_string();
1502   char *options = lookup_vm_resource(JImage_file, jimage_version, "jdk/internal/vm/options");
1503   return options;
1504 }
1505 
1506 bool ClassLoader::is_module_observable(const char* module_name) {
1507   assert(JImageOpen != nullptr, "jimage library should have been opened");
1508   if (JImage_file == nullptr) {
1509     struct stat st;
1510     const char *path = get_exploded_module_path(module_name, true);
1511     bool res = os::stat(path, &st) == 0;
1512     FREE_C_HEAP_ARRAY(char, path);
1513     return res;
1514   }
1515   jlong size;
1516   const char *jimage_version = get_jimage_version_string();
1517   return (*JImageFindResource)(JImage_file, module_name, jimage_version, "module-info.class", &size) != 0;
1518 }
1519 
1520 #if INCLUDE_CDS
1521 void ClassLoader::initialize_shared_path(JavaThread* current) {
1522   if (CDSConfig::is_dumping_archive()) {
1523     ClassLoaderExt::setup_search_paths(current);
1524   }
1525 }
1526 
1527 void ClassLoader::initialize_module_path(TRAPS) {
1528   if (CDSConfig::is_dumping_archive()) {
1529     ClassLoaderExt::setup_module_paths(THREAD);
1530     FileMapInfo::allocate_shared_path_table(CHECK);
1531   }
1532 }
1533 
1534 // Helper function used by CDS code to get the number of module path
1535 // entries during shared classpath setup time.
1536 int ClassLoader::num_module_path_entries() {
1537   assert(CDSConfig::is_dumping_archive(), "sanity");
1538   int num_entries = 0;
1539   ClassPathEntry* e= ClassLoader::_module_path_entries;
1540   while (e != nullptr) {
1541     num_entries ++;
1542     e = e->next();
1543   }
1544   return num_entries;
1545 }
1546 #endif
1547 
1548 jlong ClassLoader::classloader_time_ms() {
1549   return UsePerfData ?
1550     Management::ticks_to_ms(_perf_accumulated_time->get_value()) : -1;
1551 }
1552 
1553 jlong ClassLoader::class_init_count() {
1554   return UsePerfData ? _perf_classes_inited->get_value() : -1;
1555 }
1556 
1557 jlong ClassLoader::class_init_time_ms() {
1558   return UsePerfData ?
1559     Management::ticks_to_ms(_perf_class_init_time->get_value()) : -1;
1560 }
1561 
1562 jlong ClassLoader::class_verify_time_ms() {
1563   return UsePerfData ?
1564     Management::ticks_to_ms(_perf_class_verify_time->get_value()) : -1;
1565 }
1566 
1567 jlong ClassLoader::class_link_count() {
1568   return UsePerfData ? _perf_classes_linked->get_value() : -1;
1569 }
1570 
1571 jlong ClassLoader::class_link_time_ms() {
1572   return UsePerfData ?
1573     Management::ticks_to_ms(_perf_class_link_time->get_value()) : -1;
1574 }
1575 
1576 int ClassLoader::compute_Object_vtable() {
1577   // hardwired for JDK1.2 -- would need to duplicate class file parsing
1578   // code to determine actual value from file
1579   // Would be value '11' if finals were in vtable
1580   int JDK_1_2_Object_vtable_size = 5;
1581   return JDK_1_2_Object_vtable_size * vtableEntry::size();
1582 }
1583 
1584 
1585 void classLoader_init1() {
1586   EXCEPTION_MARK;
1587   ClassLoader::initialize(THREAD);
1588   if (HAS_PENDING_EXCEPTION) {
1589     vm_exit_during_initialization("ClassLoader::initialize() failed unexpectedly");
1590   }
1591 }
1592 
1593 // Complete the ClassPathEntry setup for the boot loader
1594 void ClassLoader::classLoader_init2(JavaThread* current) {
1595   // Setup the list of module/path pairs for --patch-module processing
1596   // This must be done after the SymbolTable is created in order
1597   // to use fast_compare on module names instead of a string compare.
1598   if (Arguments::get_patch_mod_prefix() != nullptr) {
1599     setup_patch_mod_entries();
1600   }
1601 
1602   // Create the ModuleEntry for java.base (must occur after setup_patch_mod_entries
1603   // to successfully determine if java.base has been patched)
1604   create_javabase();
1605 
1606   // Setup the initial java.base/path pair for the exploded build entries.
1607   // As more modules are defined during module system initialization, more
1608   // entries will be added to the exploded build array.
1609   if (!has_jrt_entry()) {
1610     assert(!CDSConfig::is_dumping_archive(), "not supported with exploded module builds");
1611     assert(!CDSConfig::is_using_archive(), "UsedSharedSpaces not supported with exploded module builds");
1612     // Set up the boot loader's _exploded_entries list.  Note that this gets
1613     // done before loading any classes, by the same thread that will
1614     // subsequently do the first class load. So, no lock is needed for this.
1615     assert(_exploded_entries == nullptr, "Should only get initialized once");
1616     _exploded_entries = new (mtModule)
1617       GrowableArray<ModuleClassPathList*>(EXPLODED_ENTRY_SIZE, mtModule);
1618     add_to_exploded_build_list(current, vmSymbols::java_base());
1619   }
1620 }
1621 
1622 char* ClassLoader::get_canonical_path(const char* orig, Thread* thread) {
1623   assert(orig != nullptr, "bad arguments");
1624   // caller needs to allocate ResourceMark for the following output buffer
1625   char* canonical_path = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, JVM_MAXPATHLEN);
1626   ResourceMark rm(thread);
1627   // os::native_path writes into orig_copy
1628   char* orig_copy = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, strlen(orig)+1);
1629   strcpy(orig_copy, orig);
1630   if ((CanonicalizeEntry)(os::native_path(orig_copy), canonical_path, JVM_MAXPATHLEN) < 0) {
1631     return nullptr;
1632   }
1633   return canonical_path;
1634 }
1635 
1636 void ClassLoader::create_javabase() {
1637   JavaThread* current = JavaThread::current();
1638 
1639   // Create java.base's module entry for the boot
1640   // class loader prior to loading j.l.Object.
1641   ClassLoaderData* null_cld = ClassLoaderData::the_null_class_loader_data();
1642 
1643   // Get module entry table
1644   ModuleEntryTable* null_cld_modules = null_cld->modules();
1645   if (null_cld_modules == nullptr) {
1646     vm_exit_during_initialization("No ModuleEntryTable for the boot class loader");
1647   }
1648 
1649   {
1650     MutexLocker ml(current, Module_lock);
1651     if (ModuleEntryTable::javabase_moduleEntry() == nullptr) {  // may have been inited by CDS.
1652       ModuleEntry* jb_module = null_cld_modules->locked_create_entry(Handle(),
1653                                false, vmSymbols::java_base(), nullptr, nullptr, null_cld);
1654       if (jb_module == nullptr) {
1655         vm_exit_during_initialization("Unable to create ModuleEntry for " JAVA_BASE_NAME);
1656       }
1657       ModuleEntryTable::set_javabase_moduleEntry(jb_module);
1658     }
1659   }
1660 }
1661 
1662 // Please keep following two functions at end of this file. With them placed at top or in middle of the file,
1663 // they could get inlined by aggressive compiler, an unknown trick, see bug 6966589.
1664 void PerfClassTraceTime::initialize() {
1665   if (!UsePerfData) return;
1666 
1667   if (_eventp != nullptr) {
1668     // increment the event counter
1669     _eventp->inc();
1670   }
1671 
1672   // stop the current active thread-local timer to measure inclusive time
1673   _prev_active_event = -1;
1674   for (int i=0; i < EVENT_TYPE_COUNT; i++) {
1675      if (_timers[i].is_active()) {
1676        assert(_prev_active_event == -1, "should have only one active timer");
1677        _prev_active_event = i;
1678        _timers[i].stop();
1679      }
1680   }
1681 
1682   if (_recursion_counters == nullptr || (_recursion_counters[_event_type])++ == 0) {
1683     // start the inclusive timer if not recursively called
1684     _t.start();
1685   }
1686 
1687   // start thread-local timer of the given event type
1688    if (!_timers[_event_type].is_active()) {
1689     _timers[_event_type].start();
1690   }
1691 }
1692 
1693 PerfClassTraceTime::~PerfClassTraceTime() {
1694   if (!UsePerfData) return;
1695 
1696   // stop the thread-local timer as the event completes
1697   // and resume the thread-local timer of the event next on the stack
1698   _timers[_event_type].stop();
1699   jlong selftime = _timers[_event_type].ticks();
1700 
1701   if (_prev_active_event >= 0) {
1702     _timers[_prev_active_event].start();
1703   }
1704 
1705   if (_recursion_counters != nullptr && --(_recursion_counters[_event_type]) > 0) return;
1706 
1707   // increment the counters only on the leaf call
1708   _t.stop();
1709   _timep->inc(_t.ticks());
1710   if (_selftimep != nullptr) {
1711     _selftimep->inc(selftime);
1712   }
1713   // add all class loading related event selftime to the accumulated time counter
1714   ClassLoader::perf_accumulated_time()->inc(selftime);
1715 
1716   // reset the timer
1717   _timers[_event_type].reset();
1718 }