1 /*
   2  * Copyright (c) 1997, 2022, 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 "jvm.h"
  27 #include "jimage.hpp"
  28 #include "cds/filemap.hpp"
  29 #include "classfile/classFileStream.hpp"
  30 #include "classfile/classLoader.inline.hpp"
  31 #include "classfile/classLoaderData.inline.hpp"
  32 #include "classfile/classLoaderExt.hpp"
  33 #include "classfile/classLoadInfo.hpp"
  34 #include "classfile/javaClasses.hpp"
  35 #include "classfile/moduleEntry.hpp"
  36 #include "classfile/modules.hpp"
  37 #include "classfile/packageEntry.hpp"
  38 #include "classfile/klassFactory.hpp"
  39 #include "classfile/symbolTable.hpp"
  40 #include "classfile/systemDictionary.hpp"
  41 #include "classfile/systemDictionaryShared.hpp"
  42 #include "classfile/vmClasses.hpp"
  43 #include "classfile/vmSymbols.hpp"
  44 #include "compiler/compileBroker.hpp"
  45 #include "interpreter/bytecodeStream.hpp"
  46 #include "interpreter/oopMapCache.hpp"
  47 #include "logging/log.hpp"
  48 #include "logging/logStream.hpp"
  49 #include "logging/logTag.hpp"
  50 #include "memory/allocation.inline.hpp"
  51 #include "memory/oopFactory.hpp"
  52 #include "memory/resourceArea.hpp"
  53 #include "memory/universe.hpp"
  54 #include "oops/instanceKlass.hpp"
  55 #include "oops/instanceRefKlass.hpp"
  56 #include "oops/klass.inline.hpp"
  57 #include "oops/method.inline.hpp"
  58 #include "oops/objArrayOop.inline.hpp"
  59 #include "oops/oop.inline.hpp"
  60 #include "oops/symbol.hpp"
  61 #include "prims/jvm_misc.hpp"
  62 #include "runtime/arguments.hpp"
  63 #include "runtime/handles.inline.hpp"
  64 #include "runtime/init.hpp"
  65 #include "runtime/interfaceSupport.inline.hpp"
  66 #include "runtime/java.hpp"
  67 #include "runtime/javaCalls.hpp"
  68 #include "runtime/os.hpp"
  69 #include "runtime/perfData.hpp"
  70 #include "runtime/threadCritical.hpp"
  71 #include "runtime/timer.hpp"
  72 #include "runtime/vm_version.hpp"
  73 #include "services/management.hpp"
  74 #include "services/threadService.hpp"
  75 #include "utilities/classpathStream.hpp"
  76 #include "utilities/events.hpp"
  77 #include "utilities/hashtable.inline.hpp"
  78 #include "utilities/macros.hpp"
  79 #include "utilities/utf8.hpp"
  80 
  81 // Entry point in java.dll for path canonicalization
  82 
  83 typedef int (*canonicalize_fn_t)(const char *orig, char *out, int len);
  84 
  85 static canonicalize_fn_t CanonicalizeEntry  = NULL;
  86 
  87 // Entry points in zip.dll for loading zip/jar file entries
  88 
  89 typedef void * * (*ZipOpen_t)(const char *name, char **pmsg);
  90 typedef void     (*ZipClose_t)(jzfile *zip);
  91 typedef jzentry* (*FindEntry_t)(jzfile *zip, const char *name, jint *sizeP, jint *nameLen);
  92 typedef jboolean (*ReadEntry_t)(jzfile *zip, jzentry *entry, unsigned char *buf, char *namebuf);
  93 typedef jzentry* (*GetNextEntry_t)(jzfile *zip, jint n);
  94 typedef jint     (*Crc32_t)(jint crc, const jbyte *buf, jint len);
  95 
  96 static ZipOpen_t         ZipOpen            = NULL;
  97 static ZipClose_t        ZipClose           = NULL;
  98 static FindEntry_t       FindEntry          = NULL;
  99 static ReadEntry_t       ReadEntry          = NULL;
 100 static GetNextEntry_t    GetNextEntry       = NULL;
 101 static Crc32_t           Crc32              = NULL;
 102 int    ClassLoader::_libzip_loaded          = 0;
 103 void*  ClassLoader::_zip_handle             = NULL;
 104 
 105 // Entry points for jimage.dll for loading jimage file entries
 106 
 107 static JImageOpen_t                    JImageOpen             = NULL;
 108 static JImageClose_t                   JImageClose            = NULL;
 109 static JImageFindResource_t            JImageFindResource     = NULL;
 110 static JImageGetResource_t             JImageGetResource      = NULL;
 111 
 112 // JimageFile pointer, or null if exploded JDK build.
 113 static JImageFile*                     JImage_file            = NULL;
 114 
 115 // Globals
 116 
 117 PerfCounter*    ClassLoader::_perf_accumulated_time = NULL;
 118 PerfCounter*    ClassLoader::_perf_classes_inited = NULL;
 119 PerfCounter*    ClassLoader::_perf_class_init_time = NULL;
 120 PerfCounter*    ClassLoader::_perf_class_init_selftime = NULL;
 121 PerfCounter*    ClassLoader::_perf_classes_verified = NULL;
 122 PerfCounter*    ClassLoader::_perf_class_verify_time = NULL;
 123 PerfCounter*    ClassLoader::_perf_class_verify_selftime = NULL;
 124 PerfCounter*    ClassLoader::_perf_classes_linked = NULL;
 125 PerfCounter*    ClassLoader::_perf_class_link_time = NULL;
 126 PerfCounter*    ClassLoader::_perf_class_link_selftime = NULL;
 127 PerfCounter*    ClassLoader::_perf_sys_class_lookup_time = NULL;
 128 PerfCounter*    ClassLoader::_perf_shared_classload_time = NULL;
 129 PerfCounter*    ClassLoader::_perf_sys_classload_time = NULL;
 130 PerfCounter*    ClassLoader::_perf_app_classload_time = NULL;
 131 PerfCounter*    ClassLoader::_perf_app_classload_selftime = NULL;
 132 PerfCounter*    ClassLoader::_perf_app_classload_count = NULL;
 133 PerfCounter*    ClassLoader::_perf_define_appclasses = NULL;
 134 PerfCounter*    ClassLoader::_perf_define_appclass_time = NULL;
 135 PerfCounter*    ClassLoader::_perf_define_appclass_selftime = NULL;
 136 PerfCounter*    ClassLoader::_perf_app_classfile_bytes_read = NULL;
 137 PerfCounter*    ClassLoader::_perf_sys_classfile_bytes_read = NULL;
 138 PerfCounter*    ClassLoader::_unsafe_defineClassCallCounter = NULL;
 139 
 140 GrowableArray<ModuleClassPathList*>* ClassLoader::_patch_mod_entries = NULL;
 141 GrowableArray<ModuleClassPathList*>* ClassLoader::_exploded_entries = NULL;
 142 ClassPathEntry* ClassLoader::_jrt_entry = NULL;
 143 
 144 ClassPathEntry* volatile ClassLoader::_first_append_entry_list = NULL;
 145 ClassPathEntry* volatile ClassLoader::_last_append_entry  = NULL;
 146 #if INCLUDE_CDS
 147 ClassPathEntry* ClassLoader::_app_classpath_entries = NULL;
 148 ClassPathEntry* ClassLoader::_last_app_classpath_entry = NULL;
 149 ClassPathEntry* ClassLoader::_module_path_entries = NULL;
 150 ClassPathEntry* ClassLoader::_last_module_path_entry = NULL;
 151 #endif
 152 
 153 // helper routines
 154 bool string_starts_with(const char* str, const char* str_to_find) {
 155   size_t str_len = strlen(str);
 156   size_t str_to_find_len = strlen(str_to_find);
 157   if (str_to_find_len > str_len) {
 158     return false;
 159   }
 160   return (strncmp(str, str_to_find, str_to_find_len) == 0);
 161 }
 162 
 163 static const char* get_jimage_version_string() {
 164   static char version_string[10] = "";
 165   if (version_string[0] == '\0') {
 166     jio_snprintf(version_string, sizeof(version_string), "%d.%d",
 167                  VM_Version::vm_major_version(), VM_Version::vm_minor_version());
 168   }
 169   return (const char*)version_string;
 170 }
 171 
 172 bool ClassLoader::string_ends_with(const char* str, const char* str_to_find) {
 173   size_t str_len = strlen(str);
 174   size_t str_to_find_len = strlen(str_to_find);
 175   if (str_to_find_len > str_len) {
 176     return false;
 177   }
 178   return (strncmp(str + (str_len - str_to_find_len), str_to_find, str_to_find_len) == 0);
 179 }
 180 
 181 // Used to obtain the package name from a fully qualified class name.
 182 Symbol* ClassLoader::package_from_class_name(const Symbol* name, bool* bad_class_name) {
 183   if (name == NULL) {
 184     if (bad_class_name != NULL) {
 185       *bad_class_name = true;
 186     }
 187     return NULL;
 188   }
 189 
 190   int utf_len = name->utf8_length();
 191   const jbyte* base = (const jbyte*)name->base();
 192   const jbyte* start = base;
 193   const jbyte* end = UTF8::strrchr(start, utf_len, JVM_SIGNATURE_SLASH);
 194   if (end == NULL) {
 195     return NULL;
 196   }
 197   // Skip over '['s
 198   if (*start == JVM_SIGNATURE_ARRAY) {
 199     do {
 200       start++;
 201     } while (start < end && *start == JVM_SIGNATURE_ARRAY);
 202 
 203     // Fully qualified class names should not contain a 'L'.
 204     // Set bad_class_name to true to indicate that the package name
 205     // could not be obtained due to an error condition.
 206     // In this situation, is_same_class_package returns false.
 207     if (*start == JVM_SIGNATURE_CLASS) {
 208       if (bad_class_name != NULL) {
 209         *bad_class_name = true;
 210       }
 211       return NULL;
 212     }
 213   }
 214   // A class name could have just the slash character in the name,
 215   // in which case start > end
 216   if (start >= end) {
 217     // No package name
 218     if (bad_class_name != NULL) {
 219       *bad_class_name = true;
 220     }
 221     return NULL;
 222   }
 223   return SymbolTable::new_symbol(name, start - base, end - base);
 224 }
 225 
 226 // Given a fully qualified package name, find its defining package in the class loader's
 227 // package entry table.
 228 PackageEntry* ClassLoader::get_package_entry(Symbol* pkg_name, ClassLoaderData* loader_data) {
 229   if (pkg_name == NULL) {
 230     return NULL;
 231   }
 232   PackageEntryTable* pkgEntryTable = loader_data->packages();
 233   return pkgEntryTable->lookup_only(pkg_name);
 234 }
 235 
 236 const char* ClassPathEntry::copy_path(const char* path) {
 237   char* copy = NEW_C_HEAP_ARRAY(char, strlen(path)+1, mtClass);
 238   strcpy(copy, path);
 239   return copy;
 240 }
 241 
 242 ClassFileStream* ClassPathDirEntry::open_stream(JavaThread* current, const char* name) {
 243   // construct full path name
 244   assert((_dir != NULL) && (name != NULL), "sanity");
 245   size_t path_len = strlen(_dir) + strlen(name) + strlen(os::file_separator()) + 1;
 246   char* path = NEW_RESOURCE_ARRAY_IN_THREAD(current, char, path_len);
 247   int len = jio_snprintf(path, path_len, "%s%s%s", _dir, os::file_separator(), name);
 248   assert(len == (int)(path_len - 1), "sanity");
 249   // check if file exists
 250   struct stat st;
 251   if (os::stat(path, &st) == 0) {
 252     // found file, open it
 253     int file_handle = os::open(path, 0, 0);
 254     if (file_handle != -1) {
 255       // read contents into resource array
 256       u1* buffer = NEW_RESOURCE_ARRAY(u1, st.st_size);
 257       size_t num_read = ::read(file_handle, (char*) buffer, st.st_size);
 258       // close file
 259       ::close(file_handle);
 260       // construct ClassFileStream
 261       if (num_read == (size_t)st.st_size) {
 262         if (UsePerfData) {
 263           ClassLoader::perf_sys_classfile_bytes_read()->inc(num_read);
 264         }
 265         FREE_RESOURCE_ARRAY(char, path, path_len);
 266         // Resource allocated
 267         return new ClassFileStream(buffer,
 268                                    st.st_size,
 269                                    _dir,
 270                                    ClassFileStream::verify);
 271       }
 272     }
 273   }
 274   FREE_RESOURCE_ARRAY(char, path, path_len);
 275   return NULL;
 276 }
 277 
 278 ClassPathZipEntry::ClassPathZipEntry(jzfile* zip, const char* zip_name,
 279                                      bool is_boot_append, bool from_class_path_attr) : ClassPathEntry() {
 280   _zip = zip;
 281   _zip_name = copy_path(zip_name);
 282   _from_class_path_attr = from_class_path_attr;
 283 }
 284 
 285 ClassPathZipEntry::~ClassPathZipEntry() {
 286   (*ZipClose)(_zip);
 287   FREE_C_HEAP_ARRAY(char, _zip_name);
 288 }
 289 
 290 u1* ClassPathZipEntry::open_entry(JavaThread* current, const char* name, jint* filesize, bool nul_terminate) {
 291   // enable call to C land
 292   ThreadToNativeFromVM ttn(current);
 293   // check whether zip archive contains name
 294   jint name_len;
 295   jzentry* entry = (*FindEntry)(_zip, name, filesize, &name_len);
 296   if (entry == NULL) return NULL;
 297   u1* buffer;
 298   char name_buf[128];
 299   char* filename;
 300   if (name_len < 128) {
 301     filename = name_buf;
 302   } else {
 303     filename = NEW_RESOURCE_ARRAY(char, name_len + 1);
 304   }
 305 
 306   // read contents into resource array
 307   size_t size = (uint32_t)(*filesize);
 308   if (nul_terminate) {
 309     if (sizeof(size) == sizeof(uint32_t) && size == UINT_MAX) {
 310       return NULL; // 32-bit integer overflow will occur.
 311     }
 312     size++;
 313   }
 314   buffer = NEW_RESOURCE_ARRAY(u1, size);
 315   if (!(*ReadEntry)(_zip, entry, buffer, filename)) return NULL;
 316 
 317   // return result
 318   if (nul_terminate) {
 319     buffer[size - 1] = 0;
 320   }
 321   return buffer;
 322 }
 323 
 324 ClassFileStream* ClassPathZipEntry::open_stream(JavaThread* current, const char* name) {
 325   jint filesize;
 326   u1* buffer = open_entry(current, name, &filesize, false);
 327   if (buffer == NULL) {
 328     return NULL;
 329   }
 330   if (UsePerfData) {
 331     ClassLoader::perf_sys_classfile_bytes_read()->inc(filesize);
 332   }
 333   // Resource allocated
 334   return new ClassFileStream(buffer,
 335                              filesize,
 336                              _zip_name,
 337                              ClassFileStream::verify);
 338 }
 339 
 340 // invoke function for each entry in the zip file
 341 void ClassPathZipEntry::contents_do(void f(const char* name, void* context), void* context) {
 342   JavaThread* thread = JavaThread::current();
 343   HandleMark  handle_mark(thread);
 344   ThreadToNativeFromVM ttn(thread);
 345   for (int n = 0; ; n++) {
 346     jzentry * ze = ((*GetNextEntry)(_zip, n));
 347     if (ze == NULL) break;
 348     (*f)(ze->name, context);
 349   }
 350 }
 351 
 352 DEBUG_ONLY(ClassPathImageEntry* ClassPathImageEntry::_singleton = NULL;)
 353 
 354 JImageFile* ClassPathImageEntry::jimage() const {
 355   return JImage_file;
 356 }
 357 
 358 JImageFile* ClassPathImageEntry::jimage_non_null() const {
 359   assert(ClassLoader::has_jrt_entry(), "must be");
 360   assert(jimage() != NULL, "should have been opened by ClassLoader::lookup_vm_options "
 361                            "and remained throughout normal JVM lifetime");
 362   return jimage();
 363 }
 364 
 365 void ClassPathImageEntry::close_jimage() {
 366   if (jimage() != NULL) {
 367     (*JImageClose)(jimage());
 368     JImage_file = NULL;
 369   }
 370 }
 371 
 372 ClassPathImageEntry::ClassPathImageEntry(JImageFile* jimage, const char* name) :
 373   ClassPathEntry() {
 374   guarantee(jimage != NULL, "jimage file is null");
 375   guarantee(name != NULL, "jimage file name is null");
 376   assert(_singleton == NULL, "VM supports only one jimage");
 377   DEBUG_ONLY(_singleton = this);
 378   size_t len = strlen(name) + 1;
 379   _name = copy_path(name);
 380 }
 381 
 382 ClassFileStream* ClassPathImageEntry::open_stream(JavaThread* current, const char* name) {
 383   return open_stream_for_loader(current, name, ClassLoaderData::the_null_class_loader_data());
 384 }
 385 
 386 // For a class in a named module, look it up in the jimage file using this syntax:
 387 //    /<module-name>/<package-name>/<base-class>
 388 //
 389 // Assumptions:
 390 //     1. There are no unnamed modules in the jimage file.
 391 //     2. A package is in at most one module in the jimage file.
 392 //
 393 ClassFileStream* ClassPathImageEntry::open_stream_for_loader(JavaThread* current, const char* name, ClassLoaderData* loader_data) {
 394   jlong size;
 395   JImageLocationRef location = (*JImageFindResource)(jimage_non_null(), "", get_jimage_version_string(), name, &size);
 396 
 397   if (location == 0) {
 398     TempNewSymbol class_name = SymbolTable::new_symbol(name);
 399     TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
 400 
 401     if (pkg_name != NULL) {
 402       if (!Universe::is_module_initialized()) {
 403         location = (*JImageFindResource)(jimage_non_null(), JAVA_BASE_NAME, get_jimage_version_string(), name, &size);
 404       } else {
 405         PackageEntry* package_entry = ClassLoader::get_package_entry(pkg_name, loader_data);
 406         if (package_entry != NULL) {
 407           ResourceMark rm(current);
 408           // Get the module name
 409           ModuleEntry* module = package_entry->module();
 410           assert(module != NULL, "Boot classLoader package missing module");
 411           assert(module->is_named(), "Boot classLoader package is in unnamed module");
 412           const char* module_name = module->name()->as_C_string();
 413           if (module_name != NULL) {
 414             location = (*JImageFindResource)(jimage_non_null(), module_name, get_jimage_version_string(), name, &size);
 415           }
 416         }
 417       }
 418     }
 419   }
 420   if (location != 0) {
 421     if (UsePerfData) {
 422       ClassLoader::perf_sys_classfile_bytes_read()->inc(size);
 423     }
 424     char* data = NEW_RESOURCE_ARRAY(char, size);
 425     (*JImageGetResource)(jimage_non_null(), location, data, size);
 426     // Resource allocated
 427     assert(this == (ClassPathImageEntry*)ClassLoader::get_jrt_entry(), "must be");
 428     return new ClassFileStream((u1*)data,
 429                                (int)size,
 430                                _name,
 431                                ClassFileStream::verify,
 432                                true); // from_boot_loader_modules_image
 433   }
 434 
 435   return NULL;
 436 }
 437 
 438 JImageLocationRef ClassLoader::jimage_find_resource(JImageFile* jf,
 439                                                     const char* module_name,
 440                                                     const char* file_name,
 441                                                     jlong &size) {
 442   return ((*JImageFindResource)(jf, module_name, get_jimage_version_string(), file_name, &size));
 443 }
 444 
 445 bool ClassPathImageEntry::is_modules_image() const {
 446   assert(this == _singleton, "VM supports a single jimage");
 447   assert(this == (ClassPathImageEntry*)ClassLoader::get_jrt_entry(), "must be used for jrt entry");
 448   return true;
 449 }
 450 
 451 #if INCLUDE_CDS
 452 void ClassLoader::exit_with_path_failure(const char* error, const char* message) {
 453   Arguments::assert_is_dumping_archive();
 454   tty->print_cr("Hint: enable -Xlog:class+path=info to diagnose the failure");
 455   vm_exit_during_initialization(error, message);
 456 }
 457 #endif
 458 
 459 ModuleClassPathList::ModuleClassPathList(Symbol* module_name) {
 460   _module_name = module_name;
 461   _module_first_entry = NULL;
 462   _module_last_entry = NULL;
 463 }
 464 
 465 ModuleClassPathList::~ModuleClassPathList() {
 466   // Clean out each ClassPathEntry on list
 467   ClassPathEntry* e = _module_first_entry;
 468   while (e != NULL) {
 469     ClassPathEntry* next_entry = e->next();
 470     delete e;
 471     e = next_entry;
 472   }
 473 }
 474 
 475 void ModuleClassPathList::add_to_list(ClassPathEntry* new_entry) {
 476   if (new_entry != NULL) {
 477     if (_module_last_entry == NULL) {
 478       _module_first_entry = _module_last_entry = new_entry;
 479     } else {
 480       _module_last_entry->set_next(new_entry);
 481       _module_last_entry = new_entry;
 482     }
 483   }
 484 }
 485 
 486 void ClassLoader::trace_class_path(const char* msg, const char* name) {
 487   LogTarget(Info, class, path) lt;
 488   if (lt.is_enabled()) {
 489     LogStream ls(lt);
 490     if (msg) {
 491       ls.print("%s", msg);
 492     }
 493     if (name) {
 494       if (strlen(name) < 256) {
 495         ls.print("%s", name);
 496       } else {
 497         // For very long paths, we need to print each character separately,
 498         // as print_cr() has a length limit
 499         while (name[0] != '\0') {
 500           ls.print("%c", name[0]);
 501           name++;
 502         }
 503       }
 504     }
 505     ls.cr();
 506   }
 507 }
 508 
 509 void ClassLoader::setup_bootstrap_search_path(JavaThread* current) {
 510   const char* sys_class_path = Arguments::get_sysclasspath();
 511   assert(sys_class_path != NULL, "System boot class path must not be NULL");
 512   if (PrintSharedArchiveAndExit) {
 513     // Don't print sys_class_path - this is the bootcp of this current VM process, not necessarily
 514     // the same as the bootcp of the shared archive.
 515   } else {
 516     trace_class_path("bootstrap loader class path=", sys_class_path);
 517   }
 518   setup_bootstrap_search_path_impl(current, sys_class_path);
 519 }
 520 
 521 #if INCLUDE_CDS
 522 void ClassLoader::setup_app_search_path(JavaThread* current, const char *class_path) {
 523   Arguments::assert_is_dumping_archive();
 524 
 525   ResourceMark rm(current);
 526   ClasspathStream cp_stream(class_path);
 527 
 528   while (cp_stream.has_next()) {
 529     const char* path = cp_stream.get_next();
 530     update_class_path_entry_list(current, path, false, false, false);
 531   }
 532 }
 533 
 534 void ClassLoader::add_to_module_path_entries(const char* path,
 535                                              ClassPathEntry* entry) {
 536   assert(entry != NULL, "ClassPathEntry should not be NULL");
 537   Arguments::assert_is_dumping_archive();
 538 
 539   // The entry does not exist, add to the list
 540   if (_module_path_entries == NULL) {
 541     assert(_last_module_path_entry == NULL, "Sanity");
 542     _module_path_entries = _last_module_path_entry = entry;
 543   } else {
 544     _last_module_path_entry->set_next(entry);
 545     _last_module_path_entry = entry;
 546   }
 547 }
 548 
 549 // Add a module path to the _module_path_entries list.
 550 void ClassLoader::setup_module_search_path(JavaThread* current, const char* path) {
 551   Arguments::assert_is_dumping_archive();
 552   struct stat st;
 553   if (os::stat(path, &st) != 0) {
 554     tty->print_cr("os::stat error %d (%s). CDS dump aborted (path was \"%s\").",
 555       errno, os::errno_name(errno), path);
 556     vm_exit_during_initialization();
 557   }
 558   // File or directory found
 559   ClassPathEntry* new_entry = NULL;
 560   new_entry = create_class_path_entry(current, path, &st,
 561                                       false /*is_boot_append */, false /* from_class_path_attr */);
 562   if (new_entry != NULL) {
 563     add_to_module_path_entries(path, new_entry);
 564   }
 565 }
 566 
 567 #endif // INCLUDE_CDS
 568 
 569 void ClassLoader::close_jrt_image() {
 570   // Not applicable for exploded builds
 571   if (!ClassLoader::has_jrt_entry()) return;
 572   _jrt_entry->close_jimage();
 573 }
 574 
 575 // Construct the array of module/path pairs as specified to --patch-module
 576 // for the boot loader to search ahead of the jimage, if the class being
 577 // loaded is defined to a module that has been specified to --patch-module.
 578 void ClassLoader::setup_patch_mod_entries() {
 579   JavaThread* current = JavaThread::current();
 580   GrowableArray<ModulePatchPath*>* patch_mod_args = Arguments::get_patch_mod_prefix();
 581   int num_of_entries = patch_mod_args->length();
 582 
 583   // Set up the boot loader's _patch_mod_entries list
 584   _patch_mod_entries = new (ResourceObj::C_HEAP, mtModule) GrowableArray<ModuleClassPathList*>(num_of_entries, mtModule);
 585 
 586   for (int i = 0; i < num_of_entries; i++) {
 587     const char* module_name = (patch_mod_args->at(i))->module_name();
 588     Symbol* const module_sym = SymbolTable::new_symbol(module_name);
 589     assert(module_sym != NULL, "Failed to obtain Symbol for module name");
 590     ModuleClassPathList* module_cpl = new ModuleClassPathList(module_sym);
 591 
 592     char* class_path = (patch_mod_args->at(i))->path_string();
 593     ResourceMark rm(current);
 594     ClasspathStream cp_stream(class_path);
 595 
 596     while (cp_stream.has_next()) {
 597       const char* path = cp_stream.get_next();
 598       struct stat st;
 599       if (os::stat(path, &st) == 0) {
 600         // File or directory found
 601         ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
 602         // If the path specification is valid, enter it into this module's list
 603         if (new_entry != NULL) {
 604           module_cpl->add_to_list(new_entry);
 605         }
 606       }
 607     }
 608 
 609     // Record the module into the list of --patch-module entries only if
 610     // valid ClassPathEntrys have been created
 611     if (module_cpl->module_first_entry() != NULL) {
 612       _patch_mod_entries->push(module_cpl);
 613     }
 614   }
 615 }
 616 
 617 // Determine whether the module has been patched via the command-line
 618 // option --patch-module
 619 bool ClassLoader::is_in_patch_mod_entries(Symbol* module_name) {
 620   if (_patch_mod_entries != NULL && _patch_mod_entries->is_nonempty()) {
 621     int table_len = _patch_mod_entries->length();
 622     for (int i = 0; i < table_len; i++) {
 623       ModuleClassPathList* patch_mod = _patch_mod_entries->at(i);
 624       if (module_name->fast_compare(patch_mod->module_name()) == 0) {
 625         return true;
 626       }
 627     }
 628   }
 629   return false;
 630 }
 631 
 632 // Set up the _jrt_entry if present and boot append path
 633 void ClassLoader::setup_bootstrap_search_path_impl(JavaThread* current, const char *class_path) {
 634   ResourceMark rm(current);
 635   ClasspathStream cp_stream(class_path);
 636   bool set_base_piece = true;
 637 
 638 #if INCLUDE_CDS
 639   if (Arguments::is_dumping_archive()) {
 640     if (!Arguments::has_jimage()) {
 641       vm_exit_during_initialization("CDS is not supported in exploded JDK build", NULL);
 642     }
 643   }
 644 #endif
 645 
 646   while (cp_stream.has_next()) {
 647     const char* path = cp_stream.get_next();
 648 
 649     if (set_base_piece) {
 650       // The first time through the bootstrap_search setup, it must be determined
 651       // what the base or core piece of the boot loader search is.  Either a java runtime
 652       // image is present or this is an exploded module build situation.
 653       assert(string_ends_with(path, MODULES_IMAGE_NAME) || string_ends_with(path, JAVA_BASE_NAME),
 654              "Incorrect boot loader search path, no java runtime image or " JAVA_BASE_NAME " exploded build");
 655       struct stat st;
 656       if (os::stat(path, &st) == 0) {
 657         // Directory found
 658         if (JImage_file != NULL) {
 659           assert(Arguments::has_jimage(), "sanity check");
 660           const char* canonical_path = get_canonical_path(path, current);
 661           assert(canonical_path != NULL, "canonical_path issue");
 662 
 663           _jrt_entry = new ClassPathImageEntry(JImage_file, canonical_path);
 664           assert(_jrt_entry != NULL && _jrt_entry->is_modules_image(), "No java runtime image present");
 665           assert(_jrt_entry->jimage() != NULL, "No java runtime image");
 666         } else {
 667           // It's an exploded build.
 668           ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
 669         }
 670       } else {
 671         // If path does not exist, exit
 672         vm_exit_during_initialization("Unable to establish the boot loader search path", path);
 673       }
 674       set_base_piece = false;
 675     } else {
 676       // Every entry on the system boot class path after the initial base piece,
 677       // which is set by os::set_boot_path(), is considered an appended entry.
 678       update_class_path_entry_list(current, path, false, true, false);
 679     }
 680   }
 681 }
 682 
 683 // During an exploded modules build, each module defined to the boot loader
 684 // will be added to the ClassLoader::_exploded_entries array.
 685 void ClassLoader::add_to_exploded_build_list(JavaThread* current, Symbol* module_sym) {
 686   assert(!ClassLoader::has_jrt_entry(), "Exploded build not applicable");
 687   assert(_exploded_entries != NULL, "_exploded_entries was not initialized");
 688 
 689   // Find the module's symbol
 690   ResourceMark rm(current);
 691   const char *module_name = module_sym->as_C_string();
 692   const char *home = Arguments::get_java_home();
 693   const char file_sep = os::file_separator()[0];
 694   // 10 represents the length of "modules" + 2 file separators + \0
 695   size_t len = strlen(home) + strlen(module_name) + 10;
 696   char *path = NEW_RESOURCE_ARRAY(char, len);
 697   jio_snprintf(path, len, "%s%cmodules%c%s", home, file_sep, file_sep, module_name);
 698 
 699   struct stat st;
 700   if (os::stat(path, &st) == 0) {
 701     // Directory found
 702     ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
 703 
 704     // If the path specification is valid, enter it into this module's list.
 705     // There is no need to check for duplicate modules in the exploded entry list,
 706     // since no two modules with the same name can be defined to the boot loader.
 707     // This is checked at module definition time in Modules::define_module.
 708     if (new_entry != NULL) {
 709       ModuleClassPathList* module_cpl = new ModuleClassPathList(module_sym);
 710       module_cpl->add_to_list(new_entry);
 711       {
 712         MutexLocker ml(current, Module_lock);
 713         _exploded_entries->push(module_cpl);
 714       }
 715       log_info(class, load)("path: %s", path);
 716     }
 717   }
 718 }
 719 
 720 jzfile* ClassLoader::open_zip_file(const char* canonical_path, char** error_msg, JavaThread* thread) {
 721   // enable call to C land
 722   ThreadToNativeFromVM ttn(thread);
 723   HandleMark hm(thread);
 724   load_zip_library_if_needed();
 725   return (*ZipOpen)(canonical_path, error_msg);
 726 }
 727 
 728 ClassPathEntry* ClassLoader::create_class_path_entry(JavaThread* current,
 729                                                      const char *path, const struct stat* st,
 730                                                      bool is_boot_append,
 731                                                      bool from_class_path_attr) {
 732   ClassPathEntry* new_entry = NULL;
 733   if ((st->st_mode & S_IFMT) == S_IFREG) {
 734     ResourceMark rm(current);
 735     // Regular file, should be a zip file
 736     // Canonicalized filename
 737     const char* canonical_path = get_canonical_path(path, current);
 738     if (canonical_path == NULL) {
 739       return NULL;
 740     }
 741     char* error_msg = NULL;
 742     jzfile* zip = open_zip_file(canonical_path, &error_msg, current);
 743     if (zip != NULL && error_msg == NULL) {
 744       new_entry = new ClassPathZipEntry(zip, path, is_boot_append, from_class_path_attr);
 745     } else {
 746 #if INCLUDE_CDS
 747       ClassLoaderExt::set_has_non_jar_in_classpath();
 748 #endif
 749       return NULL;
 750     }
 751     log_info(class, path)("opened: %s", path);
 752     log_info(class, load)("opened: %s", path);
 753   } else {
 754     // Directory
 755     new_entry = new ClassPathDirEntry(path);
 756     log_info(class, load)("path: %s", path);
 757   }
 758   return new_entry;
 759 }
 760 
 761 
 762 // Create a class path zip entry for a given path (return NULL if not found
 763 // or zip/JAR file cannot be opened)
 764 ClassPathZipEntry* ClassLoader::create_class_path_zip_entry(const char *path, bool is_boot_append) {
 765   // check for a regular file
 766   struct stat st;
 767   if (os::stat(path, &st) == 0) {
 768     if ((st.st_mode & S_IFMT) == S_IFREG) {
 769       JavaThread* thread = JavaThread::current();
 770       ResourceMark rm(thread);
 771       const char* canonical_path = get_canonical_path(path, thread);
 772       if (canonical_path != NULL) {
 773         char* error_msg = NULL;
 774         jzfile* zip = open_zip_file(canonical_path, &error_msg, thread);
 775         if (zip != NULL && error_msg == NULL) {
 776           // create using canonical path
 777           return new ClassPathZipEntry(zip, canonical_path, is_boot_append, false);
 778         }
 779       }
 780     }
 781   }
 782   return NULL;
 783 }
 784 
 785 // The boot append entries are added with a lock, and read lock free.
 786 void ClassLoader::add_to_boot_append_entries(ClassPathEntry *new_entry) {
 787   if (new_entry != NULL) {
 788     MutexLocker ml(Bootclasspath_lock, Mutex::_no_safepoint_check_flag);
 789     if (_last_append_entry == NULL) {
 790       _last_append_entry = new_entry;
 791       assert(first_append_entry() == NULL, "boot loader's append class path entry list not empty");
 792       Atomic::release_store(&_first_append_entry_list, new_entry);
 793     } else {
 794       _last_append_entry->set_next(new_entry);
 795       _last_append_entry = new_entry;
 796     }
 797   }
 798 }
 799 
 800 // Record the path entries specified in -cp during dump time. The recorded
 801 // information will be used at runtime for loading the archived app classes.
 802 //
 803 // Note that at dump time, ClassLoader::_app_classpath_entries are NOT used for
 804 // loading app classes. Instead, the app class are loaded by the
 805 // jdk/internal/loader/ClassLoaders$AppClassLoader instance.
 806 void ClassLoader::add_to_app_classpath_entries(JavaThread* current,
 807                                                const char* path,
 808                                                ClassPathEntry* entry,
 809                                                bool check_for_duplicates) {
 810 #if INCLUDE_CDS
 811   assert(entry != NULL, "ClassPathEntry should not be NULL");
 812   ClassPathEntry* e = _app_classpath_entries;
 813   if (check_for_duplicates) {
 814     while (e != NULL) {
 815       if (strcmp(e->name(), entry->name()) == 0) {
 816         // entry already exists
 817         return;
 818       }
 819       e = e->next();
 820     }
 821   }
 822 
 823   // The entry does not exist, add to the list
 824   if (_app_classpath_entries == NULL) {
 825     assert(_last_app_classpath_entry == NULL, "Sanity");
 826     _app_classpath_entries = _last_app_classpath_entry = entry;
 827   } else {
 828     _last_app_classpath_entry->set_next(entry);
 829     _last_app_classpath_entry = entry;
 830   }
 831 
 832   if (entry->is_jar_file()) {
 833     ClassLoaderExt::process_jar_manifest(current, entry, check_for_duplicates);
 834   }
 835 #endif
 836 }
 837 
 838 // Returns true IFF the file/dir exists and the entry was successfully created.
 839 bool ClassLoader::update_class_path_entry_list(JavaThread* current,
 840                                                const char *path,
 841                                                bool check_for_duplicates,
 842                                                bool is_boot_append,
 843                                                bool from_class_path_attr) {
 844   struct stat st;
 845   if (os::stat(path, &st) == 0) {
 846     // File or directory found
 847     ClassPathEntry* new_entry = NULL;
 848     new_entry = create_class_path_entry(current, path, &st, is_boot_append, from_class_path_attr);
 849     if (new_entry == NULL) {
 850       return false;
 851     }
 852 
 853     // Do not reorder the bootclasspath which would break get_system_package().
 854     // Add new entry to linked list
 855     if (is_boot_append) {
 856       add_to_boot_append_entries(new_entry);
 857     } else {
 858       add_to_app_classpath_entries(current, path, new_entry, check_for_duplicates);
 859     }
 860     return true;
 861   } else {
 862     return false;
 863   }
 864 }
 865 
 866 static void print_module_entry_table(const GrowableArray<ModuleClassPathList*>* const module_list) {
 867   ResourceMark rm;
 868   int num_of_entries = module_list->length();
 869   for (int i = 0; i < num_of_entries; i++) {
 870     ClassPathEntry* e;
 871     ModuleClassPathList* mpl = module_list->at(i);
 872     tty->print("%s=", mpl->module_name()->as_C_string());
 873     e = mpl->module_first_entry();
 874     while (e != NULL) {
 875       tty->print("%s", e->name());
 876       e = e->next();
 877       if (e != NULL) {
 878         tty->print("%s", os::path_separator());
 879       }
 880     }
 881     tty->print(" ;");
 882   }
 883 }
 884 
 885 void ClassLoader::print_bootclasspath() {
 886   ClassPathEntry* e;
 887   tty->print("[bootclasspath= ");
 888 
 889   // Print --patch-module module/path specifications first
 890   if (_patch_mod_entries != NULL) {
 891     print_module_entry_table(_patch_mod_entries);
 892   }
 893 
 894   // [jimage | exploded modules build]
 895   if (has_jrt_entry()) {
 896     // Print the location of the java runtime image
 897     tty->print("%s ;", _jrt_entry->name());
 898   } else {
 899     // Print exploded module build path specifications
 900     if (_exploded_entries != NULL) {
 901       print_module_entry_table(_exploded_entries);
 902     }
 903   }
 904 
 905   // appended entries
 906   e = first_append_entry();
 907   while (e != NULL) {
 908     tty->print("%s ;", e->name());
 909     e = e->next();
 910   }
 911   tty->print_cr("]");
 912 }
 913 
 914 void* ClassLoader::dll_lookup(void* lib, const char* name, const char* path) {
 915   void* func = os::dll_lookup(lib, name);
 916   if (func == NULL) {
 917     char msg[256] = "";
 918     jio_snprintf(msg, sizeof(msg), "Could not resolve \"%s\"", name);
 919     vm_exit_during_initialization(msg, path);
 920   }
 921   return func;
 922 }
 923 
 924 void ClassLoader::load_java_library() {
 925   assert(CanonicalizeEntry == NULL, "should not load java library twice");
 926   void *javalib_handle = os::native_java_library();
 927   if (javalib_handle == NULL) {
 928     vm_exit_during_initialization("Unable to load java library", NULL);
 929   }
 930 
 931   CanonicalizeEntry = CAST_TO_FN_PTR(canonicalize_fn_t, dll_lookup(javalib_handle, "JDK_Canonicalize", NULL));
 932 }
 933 
 934 void ClassLoader::release_load_zip_library() {
 935   MutexLocker locker(Zip_lock, Monitor::_no_safepoint_check_flag);
 936   if (_libzip_loaded == 0) {
 937     load_zip_library();
 938     Atomic::release_store(&_libzip_loaded, 1);
 939   }
 940 }
 941 
 942 void ClassLoader::load_zip_library() {
 943   assert(ZipOpen == NULL, "should not load zip library twice");
 944   char path[JVM_MAXPATHLEN];
 945   char ebuf[1024];
 946   if (os::dll_locate_lib(path, sizeof(path), Arguments::get_dll_dir(), "zip")) {
 947     _zip_handle = os::dll_load(path, ebuf, sizeof ebuf);
 948   }
 949   if (_zip_handle == NULL) {
 950     vm_exit_during_initialization("Unable to load zip library", path);
 951   }
 952 
 953   ZipOpen = CAST_TO_FN_PTR(ZipOpen_t, dll_lookup(_zip_handle, "ZIP_Open", path));
 954   ZipClose = CAST_TO_FN_PTR(ZipClose_t, dll_lookup(_zip_handle, "ZIP_Close", path));
 955   FindEntry = CAST_TO_FN_PTR(FindEntry_t, dll_lookup(_zip_handle, "ZIP_FindEntry", path));
 956   ReadEntry = CAST_TO_FN_PTR(ReadEntry_t, dll_lookup(_zip_handle, "ZIP_ReadEntry", path));
 957   GetNextEntry = CAST_TO_FN_PTR(GetNextEntry_t, dll_lookup(_zip_handle, "ZIP_GetNextEntry", path));
 958   Crc32 = CAST_TO_FN_PTR(Crc32_t, dll_lookup(_zip_handle, "ZIP_CRC32", path));
 959 }
 960 
 961 void ClassLoader::load_jimage_library() {
 962   assert(JImageOpen == NULL, "should not load jimage library twice");
 963   char path[JVM_MAXPATHLEN];
 964   char ebuf[1024];
 965   void* handle = NULL;
 966   if (os::dll_locate_lib(path, sizeof(path), Arguments::get_dll_dir(), "jimage")) {
 967     handle = os::dll_load(path, ebuf, sizeof ebuf);
 968   }
 969   if (handle == NULL) {
 970     vm_exit_during_initialization("Unable to load jimage library", path);
 971   }
 972 
 973   JImageOpen = CAST_TO_FN_PTR(JImageOpen_t, dll_lookup(handle, "JIMAGE_Open", path));
 974   JImageClose = CAST_TO_FN_PTR(JImageClose_t, dll_lookup(handle, "JIMAGE_Close", path));
 975   JImageFindResource = CAST_TO_FN_PTR(JImageFindResource_t, dll_lookup(handle, "JIMAGE_FindResource", path));
 976   JImageGetResource = CAST_TO_FN_PTR(JImageGetResource_t, dll_lookup(handle, "JIMAGE_GetResource", path));
 977 }
 978 
 979 int ClassLoader::crc32(int crc, const char* buf, int len) {
 980   load_zip_library_if_needed();
 981   return (*Crc32)(crc, (const jbyte*)buf, len);
 982 }
 983 
 984 oop ClassLoader::get_system_package(const char* name, TRAPS) {
 985   // Look up the name in the boot loader's package entry table.
 986   if (name != NULL) {
 987     TempNewSymbol package_sym = SymbolTable::new_symbol(name);
 988     // Look for the package entry in the boot loader's package entry table.
 989     PackageEntry* package =
 990       ClassLoaderData::the_null_class_loader_data()->packages()->lookup_only(package_sym);
 991 
 992     // Return NULL if package does not exist or if no classes in that package
 993     // have been loaded.
 994     if (package != NULL && package->has_loaded_class()) {
 995       ModuleEntry* module = package->module();
 996       if (module->location() != NULL) {
 997         ResourceMark rm(THREAD);
 998         Handle ml = java_lang_String::create_from_str(
 999           module->location()->as_C_string(), THREAD);
1000         return ml();
1001       }
1002       // Return entry on boot loader class path.
1003       Handle cph = java_lang_String::create_from_str(
1004         ClassLoader::classpath_entry(package->classpath_index())->name(), THREAD);
1005       return cph();
1006     }
1007   }
1008   return NULL;
1009 }
1010 
1011 objArrayOop ClassLoader::get_system_packages(TRAPS) {
1012   ResourceMark rm(THREAD);
1013   // List of pointers to PackageEntrys that have loaded classes.
1014   GrowableArray<PackageEntry*>* loaded_class_pkgs = new GrowableArray<PackageEntry*>(50);
1015   {
1016     MutexLocker ml(THREAD, Module_lock);
1017 
1018     PackageEntryTable* pe_table =
1019       ClassLoaderData::the_null_class_loader_data()->packages();
1020 
1021     // Collect the packages that have at least one loaded class.
1022     for (int x = 0; x < pe_table->table_size(); x++) {
1023       for (PackageEntry* package_entry = pe_table->bucket(x);
1024            package_entry != NULL;
1025            package_entry = package_entry->next()) {
1026         if (package_entry->has_loaded_class()) {
1027           loaded_class_pkgs->append(package_entry);
1028         }
1029       }
1030     }
1031   }
1032 
1033 
1034   // Allocate objArray and fill with java.lang.String
1035   objArrayOop r = oopFactory::new_objArray(vmClasses::String_klass(),
1036                                            loaded_class_pkgs->length(), CHECK_NULL);
1037   objArrayHandle result(THREAD, r);
1038   for (int x = 0; x < loaded_class_pkgs->length(); x++) {
1039     PackageEntry* package_entry = loaded_class_pkgs->at(x);
1040     Handle str = java_lang_String::create_from_symbol(package_entry->name(), CHECK_NULL);
1041     result->obj_at_put(x, str());
1042   }
1043   return result();
1044 }
1045 
1046 // caller needs ResourceMark
1047 const char* ClassLoader::file_name_for_class_name(const char* class_name,
1048                                                   int class_name_len) {
1049   assert(class_name != NULL, "invariant");
1050   assert((int)strlen(class_name) == class_name_len, "invariant");
1051 
1052   static const char class_suffix[] = ".class";
1053   size_t class_suffix_len = sizeof(class_suffix);
1054 
1055   char* const file_name = NEW_RESOURCE_ARRAY(char,
1056                                              class_name_len +
1057                                              class_suffix_len); // includes term NULL
1058 
1059   strncpy(file_name, class_name, class_name_len);
1060   strncpy(&file_name[class_name_len], class_suffix, class_suffix_len);
1061 
1062   return file_name;
1063 }
1064 
1065 ClassPathEntry* find_first_module_cpe(ModuleEntry* mod_entry,
1066                                       const GrowableArray<ModuleClassPathList*>* const module_list) {
1067   int num_of_entries = module_list->length();
1068   const Symbol* class_module_name = mod_entry->name();
1069 
1070   // Loop through all the modules in either the patch-module or exploded entries looking for module
1071   for (int i = 0; i < num_of_entries; i++) {
1072     ModuleClassPathList* module_cpl = module_list->at(i);
1073     Symbol* module_cpl_name = module_cpl->module_name();
1074 
1075     if (module_cpl_name->fast_compare(class_module_name) == 0) {
1076       // Class' module has been located.
1077       return module_cpl->module_first_entry();
1078     }
1079   }
1080   return NULL;
1081 }
1082 
1083 
1084 // Search either the patch-module or exploded build entries for class.
1085 ClassFileStream* ClassLoader::search_module_entries(JavaThread* current,
1086                                                     const GrowableArray<ModuleClassPathList*>* const module_list,
1087                                                     const char* const class_name,
1088                                                     const char* const file_name) {
1089   ClassFileStream* stream = NULL;
1090 
1091   // Find the class' defining module in the boot loader's module entry table
1092   TempNewSymbol class_name_symbol = SymbolTable::new_symbol(class_name);
1093   TempNewSymbol pkg_name = package_from_class_name(class_name_symbol);
1094   PackageEntry* pkg_entry = get_package_entry(pkg_name, ClassLoaderData::the_null_class_loader_data());
1095   ModuleEntry* mod_entry = (pkg_entry != NULL) ? pkg_entry->module() : NULL;
1096 
1097   // If the module system has not defined java.base yet, then
1098   // classes loaded are assumed to be defined to java.base.
1099   // When java.base is eventually defined by the module system,
1100   // all packages of classes that have been previously loaded
1101   // are verified in ModuleEntryTable::verify_javabase_packages().
1102   if (!Universe::is_module_initialized() &&
1103       !ModuleEntryTable::javabase_defined() &&
1104       mod_entry == NULL) {
1105     mod_entry = ModuleEntryTable::javabase_moduleEntry();
1106   }
1107 
1108   // The module must be a named module
1109   ClassPathEntry* e = NULL;
1110   if (mod_entry != NULL && mod_entry->is_named()) {
1111     if (module_list == _exploded_entries) {
1112       // The exploded build entries can be added to at any time so a lock is
1113       // needed when searching them.
1114       assert(!ClassLoader::has_jrt_entry(), "Must be exploded build");
1115       MutexLocker ml(current, Module_lock);
1116       e = find_first_module_cpe(mod_entry, module_list);
1117     } else {
1118       e = find_first_module_cpe(mod_entry, module_list);
1119     }
1120   }
1121 
1122   // Try to load the class from the module's ClassPathEntry list.
1123   while (e != NULL) {
1124     stream = e->open_stream(current, file_name);
1125     // No context.check is required since CDS is not supported
1126     // for an exploded modules build or if --patch-module is specified.
1127     if (NULL != stream) {
1128       return stream;
1129     }
1130     e = e->next();
1131   }
1132   // If the module was located, break out even if the class was not
1133   // located successfully from that module's ClassPathEntry list.
1134   // There will not be another valid entry for that module.
1135   return NULL;
1136 }
1137 
1138 // Called by the boot classloader to load classes
1139 InstanceKlass* ClassLoader::load_class(Symbol* name, bool search_append_only, TRAPS) {
1140   assert(name != NULL, "invariant");
1141 
1142   ResourceMark rm(THREAD);
1143   HandleMark hm(THREAD);
1144 
1145   const char* const class_name = name->as_C_string();
1146 
1147   EventMarkClassLoading m("Loading class %s", class_name);
1148 
1149   const char* const file_name = file_name_for_class_name(class_name,
1150                                                          name->utf8_length());
1151   assert(file_name != NULL, "invariant");
1152 
1153   // Lookup stream for parsing .class file
1154   ClassFileStream* stream = NULL;
1155   s2 classpath_index = 0;
1156   ClassPathEntry* e = NULL;
1157 
1158   // If search_append_only is true, boot loader visibility boundaries are
1159   // set to be _first_append_entry to the end. This includes:
1160   //   [-Xbootclasspath/a]; [jvmti appended entries]
1161   //
1162   // If search_append_only is false, boot loader visibility boundaries are
1163   // set to be the --patch-module entries plus the base piece. This includes:
1164   //   [--patch-module=<module>=<file>(<pathsep><file>)*]; [jimage | exploded module build]
1165   //
1166 
1167   // Load Attempt #1: --patch-module
1168   // Determine the class' defining module.  If it appears in the _patch_mod_entries,
1169   // attempt to load the class from those locations specific to the module.
1170   // Specifications to --patch-module can contain a partial number of classes
1171   // that are part of the overall module definition.  So if a particular class is not
1172   // found within its module specification, the search should continue to Load Attempt #2.
1173   // Note: The --patch-module entries are never searched if the boot loader's
1174   //       visibility boundary is limited to only searching the append entries.
1175   if (_patch_mod_entries != NULL && !search_append_only) {
1176     // At CDS dump time, the --patch-module entries are ignored. That means a
1177     // class is still loaded from the runtime image even if it might
1178     // appear in the _patch_mod_entries. The runtime shared class visibility
1179     // check will determine if a shared class is visible based on the runtime
1180     // environemnt, including the runtime --patch-module setting.
1181     //
1182     // DynamicDumpSharedSpaces requires UseSharedSpaces to be enabled. Since --patch-module
1183     // is not supported with UseSharedSpaces, it is not supported with DynamicDumpSharedSpaces.
1184     assert(!DynamicDumpSharedSpaces, "sanity");
1185     if (!DumpSharedSpaces) {
1186       stream = search_module_entries(THREAD, _patch_mod_entries, class_name, file_name);
1187     }
1188   }
1189 
1190   // Load Attempt #2: [jimage | exploded build]
1191   if (!search_append_only && (NULL == stream)) {
1192     if (has_jrt_entry()) {
1193       e = _jrt_entry;
1194       stream = _jrt_entry->open_stream(THREAD, file_name);
1195     } else {
1196       // Exploded build - attempt to locate class in its defining module's location.
1197       assert(_exploded_entries != NULL, "No exploded build entries present");
1198       stream = search_module_entries(THREAD, _exploded_entries, class_name, file_name);
1199     }
1200   }
1201 
1202   // Load Attempt #3: [-Xbootclasspath/a]; [jvmti appended entries]
1203   if (search_append_only && (NULL == stream)) {
1204     // For the boot loader append path search, the starting classpath_index
1205     // for the appended piece is always 1 to account for either the
1206     // _jrt_entry or the _exploded_entries.
1207     assert(classpath_index == 0, "The classpath_index has been incremented incorrectly");
1208     classpath_index = 1;
1209 
1210     e = first_append_entry();
1211     while (e != NULL) {
1212       stream = e->open_stream(THREAD, file_name);
1213       if (NULL != stream) {
1214         break;
1215       }
1216       e = e->next();
1217       ++classpath_index;
1218     }
1219   }
1220 
1221   if (NULL == stream) {
1222     return NULL;
1223   }
1224 
1225   stream->set_verify(ClassLoaderExt::should_verify(classpath_index));
1226 
1227   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
1228   Handle protection_domain;
1229   ClassLoadInfo cl_info(protection_domain);
1230 
1231   InstanceKlass* result = KlassFactory::create_from_stream(stream,
1232                                                            name,
1233                                                            loader_data,
1234                                                            cl_info,
1235                                                            CHECK_NULL);
1236   result->set_classpath_index(classpath_index);
1237   return result;
1238 }
1239 
1240 #if INCLUDE_CDS
1241 char* ClassLoader::skip_uri_protocol(char* source) {
1242   if (strncmp(source, "file:", 5) == 0) {
1243     // file: protocol path could start with file:/ or file:///
1244     // locate the char after all the forward slashes
1245     int offset = 5;
1246     while (*(source + offset) == '/') {
1247         offset++;
1248     }
1249     source += offset;
1250   // for non-windows platforms, move back one char as the path begins with a '/'
1251 #ifndef _WINDOWS
1252     source -= 1;
1253 #endif
1254   } else if (strncmp(source, "jrt:/", 5) == 0) {
1255     source += 5;
1256   }
1257   return source;
1258 }
1259 
1260 // Record the shared classpath index and loader type for classes loaded
1261 // by the builtin loaders at dump time.
1262 void ClassLoader::record_result(JavaThread* current, InstanceKlass* ik,
1263                                 const ClassFileStream* stream, bool redefined) {
1264   Arguments::assert_is_dumping_archive();
1265   assert(stream != NULL, "sanity");
1266 
1267   if (ik->is_hidden()) {
1268     // We do not archive hidden classes.
1269     return;
1270   }
1271 
1272   oop loader = ik->class_loader();
1273   char* src = (char*)stream->source();
1274   if (src == NULL) {
1275     if (loader == NULL) {
1276       // JFR classes
1277       ik->set_shared_classpath_index(0);
1278       ik->set_shared_class_loader_type(ClassLoader::BOOT_LOADER);
1279     }
1280     return;
1281   }
1282 
1283   assert(has_jrt_entry(), "CDS dumping does not support exploded JDK build");
1284 
1285   ResourceMark rm(current);
1286   int classpath_index = -1;
1287   PackageEntry* pkg_entry = ik->package();
1288 
1289   if (FileMapInfo::get_number_of_shared_paths() > 0) {
1290     // Save the path from the file: protocol or the module name from the jrt: protocol
1291     // if no protocol prefix is found, path is the same as stream->source(). This path
1292     // must be valid since the class has been successfully parsed.
1293     char* path = skip_uri_protocol(src);
1294     assert(path != NULL, "sanity");
1295     for (int i = 0; i < FileMapInfo::get_number_of_shared_paths(); i++) {
1296       SharedClassPathEntry* ent = FileMapInfo::shared_path(i);
1297       // A shared path has been validated during its creation in ClassLoader::create_class_path_entry(),
1298       // it must be valid here.
1299       assert(ent->name() != NULL, "sanity");
1300       // If the path (from the class stream source) is the same as the shared
1301       // class or module path, then we have a match.
1302       // src may come from the App/Platform class loaders, which would canonicalize
1303       // the file name. We cannot use strcmp to check for equality against ent->name().
1304       // We must use os::same_files (which is faster than canonicalizing ent->name()).
1305       if (os::same_files(ent->name(), path)) {
1306         // NULL pkg_entry and pkg_entry in an unnamed module implies the class
1307         // is from the -cp or boot loader append path which consists of -Xbootclasspath/a
1308         // and jvmti appended entries.
1309         if ((pkg_entry == NULL) || (pkg_entry->in_unnamed_module())) {
1310           // Ensure the index is within the -cp range before assigning
1311           // to the classpath_index.
1312           if (SystemDictionary::is_system_class_loader(loader) &&
1313               (i >= ClassLoaderExt::app_class_paths_start_index()) &&
1314               (i < ClassLoaderExt::app_module_paths_start_index())) {
1315             classpath_index = i;
1316             break;
1317           } else {
1318             if ((i >= 1) &&
1319                 (i < ClassLoaderExt::app_class_paths_start_index())) {
1320               // The class must be from boot loader append path which consists of
1321               // -Xbootclasspath/a and jvmti appended entries.
1322               assert(loader == NULL, "sanity");
1323               classpath_index = i;
1324               break;
1325             }
1326           }
1327         } else {
1328           // A class from a named module from the --module-path. Ensure the index is
1329           // within the --module-path range before assigning to the classpath_index.
1330           if ((pkg_entry != NULL) && !(pkg_entry->in_unnamed_module()) && (i > 0)) {
1331             if (i >= ClassLoaderExt::app_module_paths_start_index() &&
1332                 i < FileMapInfo::get_number_of_shared_paths()) {
1333               classpath_index = i;
1334               break;
1335             }
1336           }
1337         }
1338       }
1339       // for index 0 and the stream->source() is the modules image or has the jrt: protocol.
1340       // The class must be from the runtime modules image.
1341       if (i == 0 && (stream->from_boot_loader_modules_image() || string_starts_with(src, "jrt:"))) {
1342         classpath_index = i;
1343         break;
1344       }
1345     }
1346 
1347     // No path entry found for this class: most likely a shared class loaded by the
1348     // user defined classloader.
1349     if (classpath_index < 0 && !SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
1350       assert(ik->shared_classpath_index() < 0, "not assigned yet");
1351       ik->set_shared_classpath_index(UNREGISTERED_INDEX);
1352       SystemDictionaryShared::set_shared_class_misc_info(ik, (ClassFileStream*)stream);
1353       return;
1354     }
1355   } else {
1356     // The shared path table is set up after module system initialization.
1357     // The path table contains no entry before that. Any classes loaded prior
1358     // to the setup of the shared path table must be from the modules image.
1359     assert(stream->from_boot_loader_modules_image(), "stream must be loaded by boot loader from modules image");
1360     assert(FileMapInfo::get_number_of_shared_paths() == 0, "shared path table must not have been setup");
1361     classpath_index = 0;
1362   }
1363 
1364   const char* const class_name = ik->name()->as_C_string();
1365   const char* const file_name = file_name_for_class_name(class_name,
1366                                                          ik->name()->utf8_length());
1367   assert(file_name != NULL, "invariant");
1368 
1369   ClassLoaderExt::record_result(classpath_index, ik, redefined);
1370 }
1371 #endif // INCLUDE_CDS
1372 
1373 // Initialize the class loader's access to methods in libzip.  Parse and
1374 // process the boot classpath into a list ClassPathEntry objects.  Once
1375 // this list has been created, it must not change order (see class PackageInfo)
1376 // it can be appended to and is by jvmti.
1377 
1378 void ClassLoader::initialize(TRAPS) {
1379   if (UsePerfData) {
1380     // jvmstat performance counters
1381     NEWPERFTICKCOUNTER(_perf_accumulated_time, SUN_CLS, "time");
1382     NEWPERFTICKCOUNTER(_perf_class_init_time, SUN_CLS, "classInitTime");
1383     NEWPERFTICKCOUNTER(_perf_class_init_selftime, SUN_CLS, "classInitTime.self");
1384     NEWPERFTICKCOUNTER(_perf_class_verify_time, SUN_CLS, "classVerifyTime");
1385     NEWPERFTICKCOUNTER(_perf_class_verify_selftime, SUN_CLS, "classVerifyTime.self");
1386     NEWPERFTICKCOUNTER(_perf_class_link_time, SUN_CLS, "classLinkedTime");
1387     NEWPERFTICKCOUNTER(_perf_class_link_selftime, SUN_CLS, "classLinkedTime.self");
1388     NEWPERFEVENTCOUNTER(_perf_classes_inited, SUN_CLS, "initializedClasses");
1389     NEWPERFEVENTCOUNTER(_perf_classes_linked, SUN_CLS, "linkedClasses");
1390     NEWPERFEVENTCOUNTER(_perf_classes_verified, SUN_CLS, "verifiedClasses");
1391 
1392     NEWPERFTICKCOUNTER(_perf_sys_class_lookup_time, SUN_CLS, "lookupSysClassTime");
1393     NEWPERFTICKCOUNTER(_perf_shared_classload_time, SUN_CLS, "sharedClassLoadTime");
1394     NEWPERFTICKCOUNTER(_perf_sys_classload_time, SUN_CLS, "sysClassLoadTime");
1395     NEWPERFTICKCOUNTER(_perf_app_classload_time, SUN_CLS, "appClassLoadTime");
1396     NEWPERFTICKCOUNTER(_perf_app_classload_selftime, SUN_CLS, "appClassLoadTime.self");
1397     NEWPERFEVENTCOUNTER(_perf_app_classload_count, SUN_CLS, "appClassLoadCount");
1398     NEWPERFTICKCOUNTER(_perf_define_appclasses, SUN_CLS, "defineAppClasses");
1399     NEWPERFTICKCOUNTER(_perf_define_appclass_time, SUN_CLS, "defineAppClassTime");
1400     NEWPERFTICKCOUNTER(_perf_define_appclass_selftime, SUN_CLS, "defineAppClassTime.self");
1401     NEWPERFBYTECOUNTER(_perf_app_classfile_bytes_read, SUN_CLS, "appClassBytes");
1402     NEWPERFBYTECOUNTER(_perf_sys_classfile_bytes_read, SUN_CLS, "sysClassBytes");
1403 
1404     NEWPERFEVENTCOUNTER(_unsafe_defineClassCallCounter, SUN_CLS, "unsafeDefineClassCalls");
1405   }
1406 
1407   // lookup java library entry points
1408   load_java_library();
1409   // jimage library entry points are loaded below, in lookup_vm_options
1410   setup_bootstrap_search_path(THREAD);
1411 }
1412 
1413 char* lookup_vm_resource(JImageFile *jimage, const char *jimage_version, const char *path) {
1414   jlong size;
1415   JImageLocationRef location = (*JImageFindResource)(jimage, "java.base", jimage_version, path, &size);
1416   if (location == 0)
1417     return NULL;
1418   char *val = NEW_C_HEAP_ARRAY(char, size+1, mtClass);
1419   (*JImageGetResource)(jimage, location, val, size);
1420   val[size] = '\0';
1421   return val;
1422 }
1423 
1424 // Lookup VM options embedded in the modules jimage file
1425 char* ClassLoader::lookup_vm_options() {
1426   jint error;
1427   char modules_path[JVM_MAXPATHLEN];
1428   const char* fileSep = os::file_separator();
1429 
1430   // Initialize jimage library entry points
1431   load_jimage_library();
1432 
1433   jio_snprintf(modules_path, JVM_MAXPATHLEN, "%s%slib%smodules", Arguments::get_java_home(), fileSep, fileSep);
1434   JImage_file =(*JImageOpen)(modules_path, &error);
1435   if (JImage_file == NULL) {
1436     return NULL;
1437   }
1438 
1439   const char *jimage_version = get_jimage_version_string();
1440   char *options = lookup_vm_resource(JImage_file, jimage_version, "jdk/internal/vm/options");
1441   return options;
1442 }
1443 
1444 #if INCLUDE_CDS
1445 void ClassLoader::initialize_shared_path(JavaThread* current) {
1446   if (Arguments::is_dumping_archive()) {
1447     ClassLoaderExt::setup_search_paths(current);
1448   }
1449 }
1450 
1451 void ClassLoader::initialize_module_path(TRAPS) {
1452   if (Arguments::is_dumping_archive()) {
1453     ClassLoaderExt::setup_module_paths(THREAD);
1454     FileMapInfo::allocate_shared_path_table(CHECK);
1455   }
1456 }
1457 
1458 // Helper function used by CDS code to get the number of module path
1459 // entries during shared classpath setup time.
1460 int ClassLoader::num_module_path_entries() {
1461   Arguments::assert_is_dumping_archive();
1462   int num_entries = 0;
1463   ClassPathEntry* e= ClassLoader::_module_path_entries;
1464   while (e != NULL) {
1465     num_entries ++;
1466     e = e->next();
1467   }
1468   return num_entries;
1469 }
1470 #endif
1471 
1472 jlong ClassLoader::classloader_time_ms() {
1473   return UsePerfData ?
1474     Management::ticks_to_ms(_perf_accumulated_time->get_value()) : -1;
1475 }
1476 
1477 jlong ClassLoader::class_init_count() {
1478   return UsePerfData ? _perf_classes_inited->get_value() : -1;
1479 }
1480 
1481 jlong ClassLoader::class_init_time_ms() {
1482   return UsePerfData ?
1483     Management::ticks_to_ms(_perf_class_init_time->get_value()) : -1;
1484 }
1485 
1486 jlong ClassLoader::class_verify_time_ms() {
1487   return UsePerfData ?
1488     Management::ticks_to_ms(_perf_class_verify_time->get_value()) : -1;
1489 }
1490 
1491 jlong ClassLoader::class_link_count() {
1492   return UsePerfData ? _perf_classes_linked->get_value() : -1;
1493 }
1494 
1495 jlong ClassLoader::class_link_time_ms() {
1496   return UsePerfData ?
1497     Management::ticks_to_ms(_perf_class_link_time->get_value()) : -1;
1498 }
1499 
1500 int ClassLoader::compute_Object_vtable() {
1501   // hardwired for JDK1.2 -- would need to duplicate class file parsing
1502   // code to determine actual value from file
1503   // Would be value '11' if finals were in vtable
1504   int JDK_1_2_Object_vtable_size = 5;
1505   return JDK_1_2_Object_vtable_size * vtableEntry::size();
1506 }
1507 
1508 
1509 void classLoader_init1() {
1510   EXCEPTION_MARK;
1511   ClassLoader::initialize(THREAD);
1512   if (HAS_PENDING_EXCEPTION) {
1513     vm_exit_during_initialization("ClassLoader::initialize() failed unexpectedly");
1514   }
1515 }
1516 
1517 // Complete the ClassPathEntry setup for the boot loader
1518 void ClassLoader::classLoader_init2(JavaThread* current) {
1519   // Setup the list of module/path pairs for --patch-module processing
1520   // This must be done after the SymbolTable is created in order
1521   // to use fast_compare on module names instead of a string compare.
1522   if (Arguments::get_patch_mod_prefix() != NULL) {
1523     setup_patch_mod_entries();
1524   }
1525 
1526   // Create the ModuleEntry for java.base (must occur after setup_patch_mod_entries
1527   // to successfully determine if java.base has been patched)
1528   create_javabase();
1529 
1530   // Setup the initial java.base/path pair for the exploded build entries.
1531   // As more modules are defined during module system initialization, more
1532   // entries will be added to the exploded build array.
1533   if (!has_jrt_entry()) {
1534     assert(!DumpSharedSpaces, "DumpSharedSpaces not supported with exploded module builds");
1535     assert(!DynamicDumpSharedSpaces, "DynamicDumpSharedSpaces not supported with exploded module builds");
1536     assert(!UseSharedSpaces, "UsedSharedSpaces not supported with exploded module builds");
1537     // Set up the boot loader's _exploded_entries list.  Note that this gets
1538     // done before loading any classes, by the same thread that will
1539     // subsequently do the first class load. So, no lock is needed for this.
1540     assert(_exploded_entries == NULL, "Should only get initialized once");
1541     _exploded_entries = new (ResourceObj::C_HEAP, mtModule)
1542       GrowableArray<ModuleClassPathList*>(EXPLODED_ENTRY_SIZE, mtModule);
1543     add_to_exploded_build_list(current, vmSymbols::java_base());
1544   }
1545 }
1546 
1547 char* ClassLoader::get_canonical_path(const char* orig, Thread* thread) {
1548   assert(orig != NULL, "bad arguments");
1549   // caller needs to allocate ResourceMark for the following output buffer
1550   char* canonical_path = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, JVM_MAXPATHLEN);
1551   ResourceMark rm(thread);
1552   // os::native_path writes into orig_copy
1553   char* orig_copy = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, strlen(orig)+1);
1554   strcpy(orig_copy, orig);
1555   if ((CanonicalizeEntry)(os::native_path(orig_copy), canonical_path, JVM_MAXPATHLEN) < 0) {
1556     return NULL;
1557   }
1558   return canonical_path;
1559 }
1560 
1561 void ClassLoader::create_javabase() {
1562   JavaThread* current = JavaThread::current();
1563 
1564   // Create java.base's module entry for the boot
1565   // class loader prior to loading j.l.Ojbect.
1566   ClassLoaderData* null_cld = ClassLoaderData::the_null_class_loader_data();
1567 
1568   // Get module entry table
1569   ModuleEntryTable* null_cld_modules = null_cld->modules();
1570   if (null_cld_modules == NULL) {
1571     vm_exit_during_initialization("No ModuleEntryTable for the boot class loader");
1572   }
1573 
1574   {
1575     MutexLocker ml(current, Module_lock);
1576     if (ModuleEntryTable::javabase_moduleEntry() == NULL) {  // may have been inited by CDS.
1577       ModuleEntry* jb_module = null_cld_modules->locked_create_entry(Handle(),
1578                                false, vmSymbols::java_base(), NULL, NULL, null_cld);
1579       if (jb_module == NULL) {
1580         vm_exit_during_initialization("Unable to create ModuleEntry for " JAVA_BASE_NAME);
1581       }
1582       ModuleEntryTable::set_javabase_moduleEntry(jb_module);
1583     }
1584   }
1585 }
1586 
1587 // Please keep following two functions at end of this file. With them placed at top or in middle of the file,
1588 // they could get inlined by agressive compiler, an unknown trick, see bug 6966589.
1589 void PerfClassTraceTime::initialize() {
1590   if (!UsePerfData) return;
1591 
1592   if (_eventp != NULL) {
1593     // increment the event counter
1594     _eventp->inc();
1595   }
1596 
1597   // stop the current active thread-local timer to measure inclusive time
1598   _prev_active_event = -1;
1599   for (int i=0; i < EVENT_TYPE_COUNT; i++) {
1600      if (_timers[i].is_active()) {
1601        assert(_prev_active_event == -1, "should have only one active timer");
1602        _prev_active_event = i;
1603        _timers[i].stop();
1604      }
1605   }
1606 
1607   if (_recursion_counters == NULL || (_recursion_counters[_event_type])++ == 0) {
1608     // start the inclusive timer if not recursively called
1609     _t.start();
1610   }
1611 
1612   // start thread-local timer of the given event type
1613    if (!_timers[_event_type].is_active()) {
1614     _timers[_event_type].start();
1615   }
1616 }
1617 
1618 PerfClassTraceTime::~PerfClassTraceTime() {
1619   if (!UsePerfData) return;
1620 
1621   // stop the thread-local timer as the event completes
1622   // and resume the thread-local timer of the event next on the stack
1623   _timers[_event_type].stop();
1624   jlong selftime = _timers[_event_type].ticks();
1625 
1626   if (_prev_active_event >= 0) {
1627     _timers[_prev_active_event].start();
1628   }
1629 
1630   if (_recursion_counters != NULL && --(_recursion_counters[_event_type]) > 0) return;
1631 
1632   // increment the counters only on the leaf call
1633   _t.stop();
1634   _timep->inc(_t.ticks());
1635   if (_selftimep != NULL) {
1636     _selftimep->inc(selftime);
1637   }
1638   // add all class loading related event selftime to the accumulated time counter
1639   ClassLoader::perf_accumulated_time()->inc(selftime);
1640 
1641   // reset the timer
1642   _timers[_event_type].reset();
1643 }