1 /*
   2  * Copyright (c) 1997, 2023, 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/filemap.hpp"
  28 #include "classfile/classFileStream.hpp"
  29 #include "classfile/classLoader.inline.hpp"
  30 #include "classfile/classLoaderData.inline.hpp"
  31 #include "classfile/classLoaderExt.hpp"
  32 #include "classfile/classLoadInfo.hpp"
  33 #include "classfile/javaClasses.hpp"
  34 #include "classfile/moduleEntry.hpp"
  35 #include "classfile/modules.hpp"
  36 #include "classfile/packageEntry.hpp"
  37 #include "classfile/klassFactory.hpp"
  38 #include "classfile/symbolTable.hpp"
  39 #include "classfile/systemDictionary.hpp"
  40 #include "classfile/systemDictionaryShared.hpp"
  41 #include "classfile/vmClasses.hpp"
  42 #include "classfile/vmSymbols.hpp"
  43 #include "compiler/compileBroker.hpp"
  44 #include "interpreter/bytecodeStream.hpp"
  45 #include "interpreter/oopMapCache.hpp"
  46 #include "jimage.hpp"
  47 #include "jvm.h"
  48 #include "logging/log.hpp"
  49 #include "logging/logStream.hpp"
  50 #include "logging/logTag.hpp"
  51 #include "memory/allocation.inline.hpp"
  52 #include "memory/oopFactory.hpp"
  53 #include "memory/resourceArea.hpp"
  54 #include "memory/universe.hpp"
  55 #include "oops/instanceKlass.hpp"
  56 #include "oops/instanceRefKlass.hpp"
  57 #include "oops/klass.inline.hpp"
  58 #include "oops/method.inline.hpp"
  59 #include "oops/objArrayOop.inline.hpp"
  60 #include "oops/oop.inline.hpp"
  61 #include "oops/symbol.hpp"
  62 #include "prims/jvm_misc.hpp"
  63 #include "runtime/arguments.hpp"
  64 #include "runtime/handles.inline.hpp"
  65 #include "runtime/init.hpp"
  66 #include "runtime/interfaceSupport.inline.hpp"
  67 #include "runtime/java.hpp"
  68 #include "runtime/javaCalls.hpp"
  69 #include "runtime/os.hpp"
  70 #include "runtime/perfData.hpp"
  71 #include "runtime/threadCritical.hpp"
  72 #include "runtime/timer.hpp"
  73 #include "runtime/vm_version.hpp"
  74 #include "services/management.hpp"
  75 #include "services/threadService.hpp"
  76 #include "utilities/checkedCast.hpp"
  77 #include "utilities/classpathStream.hpp"
  78 #include "utilities/events.hpp"
  79 #include "utilities/macros.hpp"
  80 #include "utilities/utf8.hpp"
  81 
  82 // Entry point in java.dll for path canonicalization
  83 
  84 typedef int (*canonicalize_fn_t)(const char *orig, char *out, int len);
  85 
  86 static canonicalize_fn_t CanonicalizeEntry  = nullptr;
  87 
  88 // Entry points in zip.dll for loading zip/jar file entries
  89 
  90 typedef void * * (*ZipOpen_t)(const char *name, char **pmsg);
  91 typedef void     (*ZipClose_t)(jzfile *zip);
  92 typedef jzentry* (*FindEntry_t)(jzfile *zip, const char *name, jint *sizeP, jint *nameLen);
  93 typedef jboolean (*ReadEntry_t)(jzfile *zip, jzentry *entry, unsigned char *buf, char *namebuf);
  94 typedef jint     (*Crc32_t)(jint crc, const jbyte *buf, jint len);
  95 
  96 static ZipOpen_t         ZipOpen            = nullptr;
  97 static ZipClose_t        ZipClose           = nullptr;
  98 static FindEntry_t       FindEntry          = nullptr;
  99 static ReadEntry_t       ReadEntry          = nullptr;
 100 static Crc32_t           Crc32              = nullptr;
 101 int    ClassLoader::_libzip_loaded          = 0;
 102 void*  ClassLoader::_zip_handle             = nullptr;
 103 
 104 // Entry points for jimage.dll for loading jimage file entries
 105 
 106 static JImageOpen_t                    JImageOpen             = nullptr;
 107 static JImageClose_t                   JImageClose            = nullptr;
 108 static JImageFindResource_t            JImageFindResource     = nullptr;
 109 static JImageGetResource_t             JImageGetResource      = nullptr;
 110 
 111 // JimageFile pointer, or null if exploded JDK build.
 112 static JImageFile*                     JImage_file            = nullptr;
 113 
 114 // Globals
 115 
 116 PerfCounter*    ClassLoader::_perf_accumulated_time = nullptr;
 117 PerfCounter*    ClassLoader::_perf_classes_inited = nullptr;
 118 PerfCounter*    ClassLoader::_perf_class_init_time = nullptr;
 119 PerfCounter*    ClassLoader::_perf_class_init_selftime = nullptr;
 120 PerfCounter*    ClassLoader::_perf_classes_verified = nullptr;
 121 PerfCounter*    ClassLoader::_perf_class_verify_time = nullptr;
 122 PerfCounter*    ClassLoader::_perf_class_verify_selftime = nullptr;
 123 PerfCounter*    ClassLoader::_perf_classes_linked = nullptr;
 124 PerfCounter*    ClassLoader::_perf_class_link_time = nullptr;
 125 PerfCounter*    ClassLoader::_perf_class_link_selftime = nullptr;
 126 PerfCounter*    ClassLoader::_perf_sys_class_lookup_time = nullptr;
 127 PerfCounter*    ClassLoader::_perf_shared_classload_time = nullptr;
 128 PerfCounter*    ClassLoader::_perf_sys_classload_time = nullptr;
 129 PerfCounter*    ClassLoader::_perf_app_classload_time = nullptr;
 130 PerfCounter*    ClassLoader::_perf_app_classload_selftime = nullptr;
 131 PerfCounter*    ClassLoader::_perf_app_classload_count = nullptr;
 132 PerfCounter*    ClassLoader::_perf_define_appclasses = nullptr;
 133 PerfCounter*    ClassLoader::_perf_define_appclass_time = nullptr;
 134 PerfCounter*    ClassLoader::_perf_define_appclass_selftime = nullptr;
 135 PerfCounter*    ClassLoader::_perf_app_classfile_bytes_read = nullptr;
 136 PerfCounter*    ClassLoader::_perf_sys_classfile_bytes_read = nullptr;
 137 PerfCounter*    ClassLoader::_unsafe_defineClassCallCounter = nullptr;
 138 
 139 GrowableArray<ModuleClassPathList*>* ClassLoader::_patch_mod_entries = nullptr;
 140 GrowableArray<ModuleClassPathList*>* ClassLoader::_exploded_entries = nullptr;
 141 ClassPathEntry* ClassLoader::_jrt_entry = nullptr;
 142 
 143 ClassPathEntry* volatile ClassLoader::_first_append_entry_list = nullptr;
 144 ClassPathEntry* volatile ClassLoader::_last_append_entry  = nullptr;
 145 #if INCLUDE_CDS
 146 ClassPathEntry* ClassLoader::_app_classpath_entries = nullptr;
 147 ClassPathEntry* ClassLoader::_last_app_classpath_entry = nullptr;
 148 ClassPathEntry* ClassLoader::_module_path_entries = nullptr;
 149 ClassPathEntry* ClassLoader::_last_module_path_entry = nullptr;
 150 #endif
 151 
 152 // helper routines
 153 bool string_starts_with(const char* str, const char* str_to_find) {
 154   size_t str_len = strlen(str);
 155   size_t str_to_find_len = strlen(str_to_find);
 156   if (str_to_find_len > str_len) {
 157     return false;
 158   }
 159   return (strncmp(str, str_to_find, str_to_find_len) == 0);
 160 }
 161 
 162 static const char* get_jimage_version_string() {
 163   static char version_string[10] = "";
 164   if (version_string[0] == '\0') {
 165     jio_snprintf(version_string, sizeof(version_string), "%d.%d",
 166                  VM_Version::vm_major_version(), VM_Version::vm_minor_version());
 167   }
 168   return (const char*)version_string;
 169 }
 170 
 171 bool ClassLoader::string_ends_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_len - str_to_find_len), str_to_find, str_to_find_len) == 0);
 178 }
 179 
 180 // Used to obtain the package name from a fully qualified class name.
 181 Symbol* ClassLoader::package_from_class_name(const Symbol* name, bool* bad_class_name) {
 182   if (name == nullptr) {
 183     if (bad_class_name != nullptr) {
 184       *bad_class_name = true;
 185     }
 186     return nullptr;
 187   }
 188 
 189   int utf_len = name->utf8_length();
 190   const jbyte* base = (const jbyte*)name->base();
 191   const jbyte* start = base;
 192   const jbyte* end = UTF8::strrchr(start, utf_len, JVM_SIGNATURE_SLASH);
 193   if (end == nullptr) {
 194     return nullptr;
 195   }
 196   // Skip over '['s
 197   if (*start == JVM_SIGNATURE_ARRAY) {
 198     do {
 199       start++;
 200     } while (start < end && *start == JVM_SIGNATURE_ARRAY);
 201 
 202     // Fully qualified class names should not contain a 'L'.
 203     // Set bad_class_name to true to indicate that the package name
 204     // could not be obtained due to an error condition.
 205     // In this situation, is_same_class_package returns false.
 206     if (*start == JVM_SIGNATURE_CLASS) {
 207       if (bad_class_name != nullptr) {
 208         *bad_class_name = true;
 209       }
 210       return nullptr;
 211     }
 212   }
 213   // A class name could have just the slash character in the name,
 214   // in which case start > end
 215   if (start >= end) {
 216     // No package name
 217     if (bad_class_name != nullptr) {
 218       *bad_class_name = true;
 219     }
 220     return nullptr;
 221   }
 222   return SymbolTable::new_symbol(name, pointer_delta_as_int(start, base), pointer_delta_as_int(end, base));
 223 }
 224 
 225 // Given a fully qualified package name, find its defining package in the class loader's
 226 // package entry table.
 227 PackageEntry* ClassLoader::get_package_entry(Symbol* pkg_name, ClassLoaderData* loader_data) {
 228   if (pkg_name == nullptr) {
 229     return nullptr;
 230   }
 231   PackageEntryTable* pkgEntryTable = loader_data->packages();
 232   return pkgEntryTable->lookup_only(pkg_name);
 233 }
 234 
 235 const char* ClassPathEntry::copy_path(const char* path) {
 236   char* copy = NEW_C_HEAP_ARRAY(char, strlen(path)+1, mtClass);
 237   strcpy(copy, path);
 238   return copy;
 239 }
 240 
 241 ClassPathDirEntry::~ClassPathDirEntry() {
 242   FREE_C_HEAP_ARRAY(char, _dir);
 243 }
 244 
 245 ClassFileStream* ClassPathDirEntry::open_stream(JavaThread* current, const char* name) {
 246   // construct full path name
 247   assert((_dir != nullptr) && (name != nullptr), "sanity");
 248   size_t path_len = strlen(_dir) + strlen(name) + strlen(os::file_separator()) + 1;
 249   char* path = NEW_RESOURCE_ARRAY_IN_THREAD(current, char, path_len);
 250   int len = jio_snprintf(path, path_len, "%s%s%s", _dir, os::file_separator(), name);
 251   assert(len == (int)(path_len - 1), "sanity");
 252   // check if file exists
 253   struct stat st;
 254   if (os::stat(path, &st) == 0) {
 255     // found file, open it
 256     int file_handle = os::open(path, 0, 0);
 257     if (file_handle != -1) {
 258       // read contents into resource array
 259       u1* buffer = NEW_RESOURCE_ARRAY_IN_THREAD(current, u1, st.st_size);
 260       size_t num_read = ::read(file_handle, (char*) buffer, st.st_size);
 261       // close file
 262       ::close(file_handle);
 263       // construct ClassFileStream
 264       if (num_read == (size_t)st.st_size) {
 265         if (UsePerfData) {
 266           ClassLoader::perf_sys_classfile_bytes_read()->inc(num_read);
 267         }
 268 #ifdef ASSERT
 269         // Freeing path is a no-op here as buffer prevents it from being reclaimed. But we keep it for
 270         // debug builds so that we guard against use-after-free bugs.
 271         FREE_RESOURCE_ARRAY_IN_THREAD(current, char, path, path_len);
 272 #endif
 273         // We don't verify the length of the classfile stream fits in an int, but this is the
 274         // bootloader so we have control of this.
 275         // Resource allocated
 276         return new ClassFileStream(buffer,
 277                                    checked_cast<int>(st.st_size),
 278                                    _dir,
 279                                    ClassFileStream::verify);
 280       }
 281     }
 282   }
 283   FREE_RESOURCE_ARRAY_IN_THREAD(current, char, path, path_len);
 284   return nullptr;
 285 }
 286 
 287 ClassPathZipEntry::ClassPathZipEntry(jzfile* zip, const char* zip_name,
 288                                      bool is_boot_append, bool from_class_path_attr) : ClassPathEntry() {
 289   _zip = zip;
 290   _zip_name = copy_path(zip_name);
 291   _from_class_path_attr = from_class_path_attr;
 292 }
 293 
 294 ClassPathZipEntry::~ClassPathZipEntry() {
 295   (*ZipClose)(_zip);
 296   FREE_C_HEAP_ARRAY(char, _zip_name);
 297 }
 298 
 299 u1* ClassPathZipEntry::open_entry(JavaThread* current, const char* name, jint* filesize, bool nul_terminate) {
 300   // enable call to C land
 301   ThreadToNativeFromVM ttn(current);
 302   // check whether zip archive contains name
 303   jint name_len;
 304   jzentry* entry = (*FindEntry)(_zip, name, filesize, &name_len);
 305   if (entry == nullptr) return nullptr;
 306   u1* buffer;
 307   char name_buf[128];
 308   char* filename;
 309   if (name_len < 128) {
 310     filename = name_buf;
 311   } else {
 312     filename = NEW_RESOURCE_ARRAY(char, name_len + 1);
 313   }
 314 
 315   // read contents into resource array
 316   size_t size = (uint32_t)(*filesize);
 317   if (nul_terminate) {
 318     if (sizeof(size) == sizeof(uint32_t) && size == UINT_MAX) {
 319       return nullptr; // 32-bit integer overflow will occur.
 320     }
 321     size++;
 322   }
 323   buffer = NEW_RESOURCE_ARRAY(u1, size);
 324   if (!(*ReadEntry)(_zip, entry, buffer, filename)) return nullptr;
 325 
 326   // return result
 327   if (nul_terminate) {
 328     buffer[size - 1] = 0;
 329   }
 330   return buffer;
 331 }
 332 
 333 ClassFileStream* ClassPathZipEntry::open_stream(JavaThread* current, const char* name) {
 334   jint filesize;
 335   u1* buffer = open_entry(current, name, &filesize, false);
 336   if (buffer == nullptr) {
 337     return nullptr;
 338   }
 339   if (UsePerfData) {
 340     ClassLoader::perf_sys_classfile_bytes_read()->inc(filesize);
 341   }
 342   // Resource allocated
 343   return new ClassFileStream(buffer,
 344                              filesize,
 345                              _zip_name,
 346                              ClassFileStream::verify);
 347 }
 348 
 349 DEBUG_ONLY(ClassPathImageEntry* ClassPathImageEntry::_singleton = nullptr;)
 350 
 351 JImageFile* ClassPathImageEntry::jimage() const {
 352   return JImage_file;
 353 }
 354 
 355 JImageFile* ClassPathImageEntry::jimage_non_null() const {
 356   assert(ClassLoader::has_jrt_entry(), "must be");
 357   assert(jimage() != nullptr, "should have been opened by ClassLoader::lookup_vm_options "
 358                            "and remained throughout normal JVM lifetime");
 359   return jimage();
 360 }
 361 
 362 void ClassPathImageEntry::close_jimage() {
 363   if (jimage() != nullptr) {
 364     (*JImageClose)(jimage());
 365     JImage_file = nullptr;
 366   }
 367 }
 368 
 369 ClassPathImageEntry::ClassPathImageEntry(JImageFile* jimage, const char* name) :
 370   ClassPathEntry() {
 371   guarantee(jimage != nullptr, "jimage file is null");
 372   guarantee(name != nullptr, "jimage file name is null");
 373   assert(_singleton == nullptr, "VM supports only one jimage");
 374   DEBUG_ONLY(_singleton = this);
 375   size_t len = strlen(name) + 1;
 376   _name = copy_path(name);
 377 }
 378 
 379 ClassFileStream* ClassPathImageEntry::open_stream(JavaThread* current, const char* name) {
 380   return open_stream_for_loader(current, name, ClassLoaderData::the_null_class_loader_data());
 381 }
 382 
 383 // For a class in a named module, look it up in the jimage file using this syntax:
 384 //    /<module-name>/<package-name>/<base-class>
 385 //
 386 // Assumptions:
 387 //     1. There are no unnamed modules in the jimage file.
 388 //     2. A package is in at most one module in the jimage file.
 389 //
 390 ClassFileStream* ClassPathImageEntry::open_stream_for_loader(JavaThread* current, const char* name, ClassLoaderData* loader_data) {
 391   jlong size;
 392   JImageLocationRef location = (*JImageFindResource)(jimage_non_null(), "", get_jimage_version_string(), name, &size);
 393 
 394   if (location == 0) {
 395     TempNewSymbol class_name = SymbolTable::new_symbol(name);
 396     TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
 397 
 398     if (pkg_name != nullptr) {
 399       if (!Universe::is_module_initialized()) {
 400         location = (*JImageFindResource)(jimage_non_null(), JAVA_BASE_NAME, get_jimage_version_string(), name, &size);
 401       } else {
 402         PackageEntry* package_entry = ClassLoader::get_package_entry(pkg_name, loader_data);
 403         if (package_entry != nullptr) {
 404           ResourceMark rm(current);
 405           // Get the module name
 406           ModuleEntry* module = package_entry->module();
 407           assert(module != nullptr, "Boot classLoader package missing module");
 408           assert(module->is_named(), "Boot classLoader package is in unnamed module");
 409           const char* module_name = module->name()->as_C_string();
 410           if (module_name != nullptr) {
 411             location = (*JImageFindResource)(jimage_non_null(), module_name, get_jimage_version_string(), name, &size);
 412           }
 413         }
 414       }
 415     }
 416   }
 417   if (location != 0) {
 418     if (UsePerfData) {
 419       ClassLoader::perf_sys_classfile_bytes_read()->inc(size);
 420     }
 421     char* data = NEW_RESOURCE_ARRAY(char, size);
 422     (*JImageGetResource)(jimage_non_null(), location, data, size);
 423     // Resource allocated
 424     assert(this == (ClassPathImageEntry*)ClassLoader::get_jrt_entry(), "must be");
 425     return new ClassFileStream((u1*)data,
 426                                checked_cast<int>(size),
 427                                _name,
 428                                ClassFileStream::verify,
 429                                true); // from_boot_loader_modules_image
 430   }
 431 
 432   return nullptr;
 433 }
 434 
 435 JImageLocationRef ClassLoader::jimage_find_resource(JImageFile* jf,
 436                                                     const char* module_name,
 437                                                     const char* file_name,
 438                                                     jlong &size) {
 439   return ((*JImageFindResource)(jf, module_name, get_jimage_version_string(), file_name, &size));
 440 }
 441 
 442 bool ClassPathImageEntry::is_modules_image() const {
 443   assert(this == _singleton, "VM supports a single jimage");
 444   assert(this == (ClassPathImageEntry*)ClassLoader::get_jrt_entry(), "must be used for jrt entry");
 445   return true;
 446 }
 447 
 448 #if INCLUDE_CDS
 449 void ClassLoader::exit_with_path_failure(const char* error, const char* message) {
 450   Arguments::assert_is_dumping_archive();
 451   tty->print_cr("Hint: enable -Xlog:class+path=info to diagnose the failure");
 452   vm_exit_during_initialization(error, message);
 453 }
 454 #endif
 455 
 456 ModuleClassPathList::ModuleClassPathList(Symbol* module_name) {
 457   _module_name = module_name;
 458   _module_first_entry = nullptr;
 459   _module_last_entry = nullptr;
 460 }
 461 
 462 ModuleClassPathList::~ModuleClassPathList() {
 463   // Clean out each ClassPathEntry on list
 464   ClassPathEntry* e = _module_first_entry;
 465   while (e != nullptr) {
 466     ClassPathEntry* next_entry = e->next();
 467     delete e;
 468     e = next_entry;
 469   }
 470 }
 471 
 472 void ModuleClassPathList::add_to_list(ClassPathEntry* new_entry) {
 473   if (new_entry != nullptr) {
 474     if (_module_last_entry == nullptr) {
 475       _module_first_entry = _module_last_entry = new_entry;
 476     } else {
 477       _module_last_entry->set_next(new_entry);
 478       _module_last_entry = new_entry;
 479     }
 480   }
 481 }
 482 
 483 void ClassLoader::trace_class_path(const char* msg, const char* name) {
 484   LogTarget(Info, class, path) lt;
 485   if (lt.is_enabled()) {
 486     LogStream ls(lt);
 487     if (msg) {
 488       ls.print("%s", msg);
 489     }
 490     if (name) {
 491       if (strlen(name) < 256) {
 492         ls.print("%s", name);
 493       } else {
 494         // For very long paths, we need to print each character separately,
 495         // as print_cr() has a length limit
 496         while (name[0] != '\0') {
 497           ls.print("%c", name[0]);
 498           name++;
 499         }
 500       }
 501     }
 502     ls.cr();
 503   }
 504 }
 505 
 506 void ClassLoader::setup_bootstrap_search_path(JavaThread* current) {
 507   const char* bootcp = Arguments::get_boot_class_path();
 508   assert(bootcp != nullptr, "Boot class path must not be nullptr");
 509   if (PrintSharedArchiveAndExit) {
 510     // Don't print bootcp - this is the bootcp of this current VM process, not necessarily
 511     // the same as the boot classpath of the shared archive.
 512   } else {
 513     trace_class_path("bootstrap loader class path=", bootcp);
 514   }
 515   setup_bootstrap_search_path_impl(current, bootcp);
 516 }
 517 
 518 #if INCLUDE_CDS
 519 void ClassLoader::setup_app_search_path(JavaThread* current, const char *class_path) {
 520   Arguments::assert_is_dumping_archive();
 521 
 522   ResourceMark rm(current);
 523   ClasspathStream cp_stream(class_path);
 524 
 525   while (cp_stream.has_next()) {
 526     const char* path = cp_stream.get_next();
 527     update_class_path_entry_list(current, path, /* check_for_duplicates */ true,
 528                                  /* is_boot_append */ false, /* from_class_path_attr */ false);
 529   }
 530 }
 531 
 532 void ClassLoader::add_to_module_path_entries(const char* path,
 533                                              ClassPathEntry* entry) {
 534   assert(entry != nullptr, "ClassPathEntry should not be nullptr");
 535   Arguments::assert_is_dumping_archive();
 536 
 537   // The entry does not exist, add to the list
 538   if (_module_path_entries == nullptr) {
 539     assert(_last_module_path_entry == nullptr, "Sanity");
 540     _module_path_entries = _last_module_path_entry = entry;
 541   } else {
 542     _last_module_path_entry->set_next(entry);
 543     _last_module_path_entry = entry;
 544   }
 545 }
 546 
 547 // Add a module path to the _module_path_entries list.
 548 void ClassLoader::setup_module_search_path(JavaThread* current, const char* path) {
 549   Arguments::assert_is_dumping_archive();
 550   struct stat st;
 551   if (os::stat(path, &st) != 0) {
 552     tty->print_cr("os::stat error %d (%s). CDS dump aborted (path was \"%s\").",
 553       errno, os::errno_name(errno), path);
 554     vm_exit_during_initialization();
 555   }
 556   // File or directory found
 557   ClassPathEntry* new_entry = nullptr;
 558   new_entry = create_class_path_entry(current, path, &st,
 559                                       false /*is_boot_append */, false /* from_class_path_attr */);
 560   if (new_entry != nullptr) {
 561     add_to_module_path_entries(path, new_entry);
 562   }
 563 }
 564 
 565 #endif // INCLUDE_CDS
 566 
 567 void ClassLoader::close_jrt_image() {
 568   // Not applicable for exploded builds
 569   if (!ClassLoader::has_jrt_entry()) return;
 570   _jrt_entry->close_jimage();
 571 }
 572 
 573 // Construct the array of module/path pairs as specified to --patch-module
 574 // for the boot loader to search ahead of the jimage, if the class being
 575 // loaded is defined to a module that has been specified to --patch-module.
 576 void ClassLoader::setup_patch_mod_entries() {
 577   JavaThread* current = JavaThread::current();
 578   GrowableArray<ModulePatchPath*>* patch_mod_args = Arguments::get_patch_mod_prefix();
 579   int num_of_entries = patch_mod_args->length();
 580 
 581   // Set up the boot loader's _patch_mod_entries list
 582   _patch_mod_entries = new (mtModule) GrowableArray<ModuleClassPathList*>(num_of_entries, mtModule);
 583 
 584   for (int i = 0; i < num_of_entries; i++) {
 585     const char* module_name = (patch_mod_args->at(i))->module_name();
 586     Symbol* const module_sym = SymbolTable::new_symbol(module_name);
 587     assert(module_sym != nullptr, "Failed to obtain Symbol for module name");
 588     ModuleClassPathList* module_cpl = new ModuleClassPathList(module_sym);
 589 
 590     char* class_path = (patch_mod_args->at(i))->path_string();
 591     ResourceMark rm(current);
 592     ClasspathStream cp_stream(class_path);
 593 
 594     while (cp_stream.has_next()) {
 595       const char* path = cp_stream.get_next();
 596       struct stat st;
 597       if (os::stat(path, &st) == 0) {
 598         // File or directory found
 599         ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
 600         // If the path specification is valid, enter it into this module's list
 601         if (new_entry != nullptr) {
 602           module_cpl->add_to_list(new_entry);
 603         }
 604       }
 605     }
 606 
 607     // Record the module into the list of --patch-module entries only if
 608     // valid ClassPathEntrys have been created
 609     if (module_cpl->module_first_entry() != nullptr) {
 610       _patch_mod_entries->push(module_cpl);
 611     }
 612   }
 613 }
 614 
 615 // Determine whether the module has been patched via the command-line
 616 // option --patch-module
 617 bool ClassLoader::is_in_patch_mod_entries(Symbol* module_name) {
 618   if (_patch_mod_entries != nullptr && _patch_mod_entries->is_nonempty()) {
 619     int table_len = _patch_mod_entries->length();
 620     for (int i = 0; i < table_len; i++) {
 621       ModuleClassPathList* patch_mod = _patch_mod_entries->at(i);
 622       if (module_name->fast_compare(patch_mod->module_name()) == 0) {
 623         return true;
 624       }
 625     }
 626   }
 627   return false;
 628 }
 629 
 630 // Set up the _jrt_entry if present and boot append path
 631 void ClassLoader::setup_bootstrap_search_path_impl(JavaThread* current, const char *class_path) {
 632   ResourceMark rm(current);
 633   ClasspathStream cp_stream(class_path);
 634   bool set_base_piece = true;
 635 
 636 #if INCLUDE_CDS
 637   if (Arguments::is_dumping_archive()) {
 638     if (!Arguments::has_jimage()) {
 639       vm_exit_during_initialization("CDS is not supported in exploded JDK build", nullptr);
 640     }
 641   }
 642 #endif
 643 
 644   while (cp_stream.has_next()) {
 645     const char* path = cp_stream.get_next();
 646 
 647     if (set_base_piece) {
 648       // The first time through the bootstrap_search setup, it must be determined
 649       // what the base or core piece of the boot loader search is.  Either a java runtime
 650       // image is present or this is an exploded module build situation.
 651       assert(string_ends_with(path, MODULES_IMAGE_NAME) || string_ends_with(path, JAVA_BASE_NAME),
 652              "Incorrect boot loader search path, no java runtime image or " JAVA_BASE_NAME " exploded build");
 653       struct stat st;
 654       if (os::stat(path, &st) == 0) {
 655         // Directory found
 656         if (JImage_file != nullptr) {
 657           assert(Arguments::has_jimage(), "sanity check");
 658           const char* canonical_path = get_canonical_path(path, current);
 659           assert(canonical_path != nullptr, "canonical_path issue");
 660 
 661           _jrt_entry = new ClassPathImageEntry(JImage_file, canonical_path);
 662           assert(_jrt_entry != nullptr && _jrt_entry->is_modules_image(), "No java runtime image present");
 663           assert(_jrt_entry->jimage() != nullptr, "No java runtime image");
 664         } // else it's an exploded build.
 665       } else {
 666         // If path does not exist, exit
 667         vm_exit_during_initialization("Unable to establish the boot loader search path", path);
 668       }
 669       set_base_piece = false;
 670     } else {
 671       // Every entry on the boot class path after the initial base piece,
 672       // which is set by os::set_boot_path(), is considered an appended entry.
 673       update_class_path_entry_list(current, path, /* check_for_duplicates */ false,
 674                                     /* is_boot_append */ true, /* from_class_path_attr */ false);
 675     }
 676   }
 677 }
 678 
 679 // Gets the exploded path for the named module. The memory for the path
 680 // is allocated on the C heap if `c_heap` is true otherwise in the resource area.
 681 static const char* get_exploded_module_path(const char* module_name, bool c_heap) {
 682   const char *home = Arguments::get_java_home();
 683   const char file_sep = os::file_separator()[0];
 684   // 10 represents the length of "modules" + 2 file separators + \0
 685   size_t len = strlen(home) + strlen(module_name) + 10;
 686   char *path = c_heap ? NEW_C_HEAP_ARRAY(char, len, mtModule) : NEW_RESOURCE_ARRAY(char, len);
 687   jio_snprintf(path, len, "%s%cmodules%c%s", home, file_sep, file_sep, module_name);
 688   return path;
 689 }
 690 
 691 // During an exploded modules build, each module defined to the boot loader
 692 // will be added to the ClassLoader::_exploded_entries array.
 693 void ClassLoader::add_to_exploded_build_list(JavaThread* current, Symbol* module_sym) {
 694   assert(!ClassLoader::has_jrt_entry(), "Exploded build not applicable");
 695   assert(_exploded_entries != nullptr, "_exploded_entries was not initialized");
 696 
 697   // Find the module's symbol
 698   ResourceMark rm(current);
 699   const char *module_name = module_sym->as_C_string();
 700   const char *path = get_exploded_module_path(module_name, false);
 701 
 702   struct stat st;
 703   if (os::stat(path, &st) == 0) {
 704     // Directory found
 705     ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
 706 
 707     // If the path specification is valid, enter it into this module's list.
 708     // There is no need to check for duplicate modules in the exploded entry list,
 709     // since no two modules with the same name can be defined to the boot loader.
 710     // This is checked at module definition time in Modules::define_module.
 711     if (new_entry != nullptr) {
 712       ModuleClassPathList* module_cpl = new ModuleClassPathList(module_sym);
 713       module_cpl->add_to_list(new_entry);
 714       {
 715         MutexLocker ml(current, Module_lock);
 716         _exploded_entries->push(module_cpl);
 717       }
 718       log_info(class, load)("path: %s", path);
 719     }
 720   }
 721 }
 722 
 723 jzfile* ClassLoader::open_zip_file(const char* canonical_path, char** error_msg, JavaThread* thread) {
 724   // enable call to C land
 725   ThreadToNativeFromVM ttn(thread);
 726   HandleMark hm(thread);
 727   load_zip_library_if_needed();
 728   return (*ZipOpen)(canonical_path, error_msg);
 729 }
 730 
 731 ClassPathEntry* ClassLoader::create_class_path_entry(JavaThread* current,
 732                                                      const char *path, const struct stat* st,
 733                                                      bool is_boot_append,
 734                                                      bool from_class_path_attr) {
 735   ClassPathEntry* new_entry = nullptr;
 736   if ((st->st_mode & S_IFMT) == S_IFREG) {
 737     ResourceMark rm(current);
 738     // Regular file, should be a zip file
 739     // Canonicalized filename
 740     const char* canonical_path = get_canonical_path(path, current);
 741     if (canonical_path == nullptr) {
 742       return nullptr;
 743     }
 744     char* error_msg = nullptr;
 745     jzfile* zip = open_zip_file(canonical_path, &error_msg, current);
 746     if (zip != nullptr && error_msg == nullptr) {
 747       new_entry = new ClassPathZipEntry(zip, path, is_boot_append, from_class_path_attr);
 748     } else {
 749 #if INCLUDE_CDS
 750       ClassLoaderExt::set_has_non_jar_in_classpath();
 751 #endif
 752       return nullptr;
 753     }
 754     log_info(class, path)("opened: %s", path);
 755     log_info(class, load)("opened: %s", path);
 756   } else {
 757     // Directory
 758     new_entry = new ClassPathDirEntry(path);
 759     log_info(class, load)("path: %s", path);
 760   }
 761   return new_entry;
 762 }
 763 
 764 
 765 // Create a class path zip entry for a given path (return null if not found
 766 // or zip/JAR file cannot be opened)
 767 ClassPathZipEntry* ClassLoader::create_class_path_zip_entry(const char *path, bool is_boot_append) {
 768   // check for a regular file
 769   struct stat st;
 770   if (os::stat(path, &st) == 0) {
 771     if ((st.st_mode & S_IFMT) == S_IFREG) {
 772       JavaThread* thread = JavaThread::current();
 773       ResourceMark rm(thread);
 774       const char* canonical_path = get_canonical_path(path, thread);
 775       if (canonical_path != nullptr) {
 776         char* error_msg = nullptr;
 777         jzfile* zip = open_zip_file(canonical_path, &error_msg, thread);
 778         if (zip != nullptr && error_msg == nullptr) {
 779           // create using canonical path
 780           return new ClassPathZipEntry(zip, canonical_path, is_boot_append, false);
 781         }
 782       }
 783     }
 784   }
 785   return nullptr;
 786 }
 787 
 788 // The boot append entries are added with a lock, and read lock free.
 789 void ClassLoader::add_to_boot_append_entries(ClassPathEntry *new_entry) {
 790   if (new_entry != nullptr) {
 791     MutexLocker ml(Bootclasspath_lock, Mutex::_no_safepoint_check_flag);
 792     if (_last_append_entry == nullptr) {
 793       _last_append_entry = new_entry;
 794       assert(first_append_entry() == nullptr, "boot loader's append class path entry list not empty");
 795       Atomic::release_store(&_first_append_entry_list, new_entry);
 796     } else {
 797       _last_append_entry->set_next(new_entry);
 798       _last_append_entry = new_entry;
 799     }
 800   }
 801 }
 802 
 803 // Record the path entries specified in -cp during dump time. The recorded
 804 // information will be used at runtime for loading the archived app classes.
 805 //
 806 // Note that at dump time, ClassLoader::_app_classpath_entries are NOT used for
 807 // loading app classes. Instead, the app class are loaded by the
 808 // jdk/internal/loader/ClassLoaders$AppClassLoader instance.
 809 bool ClassLoader::add_to_app_classpath_entries(JavaThread* current,
 810                                                ClassPathEntry* entry,
 811                                                bool check_for_duplicates) {
 812 #if INCLUDE_CDS
 813   assert(entry != nullptr, "ClassPathEntry should not be nullptr");
 814   ClassPathEntry* e = _app_classpath_entries;
 815   if (check_for_duplicates) {
 816     while (e != nullptr) {
 817       if (strcmp(e->name(), entry->name()) == 0) {
 818         // entry already exists
 819         return false;
 820       }
 821       e = e->next();
 822     }
 823   }
 824 
 825   // The entry does not exist, add to the list
 826   if (_app_classpath_entries == nullptr) {
 827     assert(_last_app_classpath_entry == nullptr, "Sanity");
 828     _app_classpath_entries = _last_app_classpath_entry = entry;
 829   } else {
 830     _last_app_classpath_entry->set_next(entry);
 831     _last_app_classpath_entry = entry;
 832   }
 833 
 834   if (entry->is_jar_file()) {
 835     ClassLoaderExt::process_jar_manifest(current, entry);
 836   }
 837 #endif
 838   return true;
 839 }
 840 
 841 // Returns true IFF the file/dir exists and the entry was successfully created.
 842 bool ClassLoader::update_class_path_entry_list(JavaThread* current,
 843                                                const char *path,
 844                                                bool check_for_duplicates,
 845                                                bool is_boot_append,
 846                                                bool from_class_path_attr) {
 847   struct stat st;
 848   if (os::stat(path, &st) == 0) {
 849     // File or directory found
 850     ClassPathEntry* new_entry = nullptr;
 851     new_entry = create_class_path_entry(current, path, &st, is_boot_append, from_class_path_attr);
 852     if (new_entry == nullptr) {
 853       return false;
 854     }
 855 
 856     // Do not reorder the bootclasspath which would break get_system_package().
 857     // Add new entry to linked list
 858     if (is_boot_append) {
 859       add_to_boot_append_entries(new_entry);
 860     } else {
 861       if (!add_to_app_classpath_entries(current, new_entry, check_for_duplicates)) {
 862         // new_entry is not saved, free it now
 863         delete new_entry;
 864       }
 865     }
 866     return true;
 867   } else {
 868     return false;
 869   }
 870 }
 871 
 872 static void print_module_entry_table(const GrowableArray<ModuleClassPathList*>* const module_list) {
 873   ResourceMark rm;
 874   int num_of_entries = module_list->length();
 875   for (int i = 0; i < num_of_entries; i++) {
 876     ClassPathEntry* e;
 877     ModuleClassPathList* mpl = module_list->at(i);
 878     tty->print("%s=", mpl->module_name()->as_C_string());
 879     e = mpl->module_first_entry();
 880     while (e != nullptr) {
 881       tty->print("%s", e->name());
 882       e = e->next();
 883       if (e != nullptr) {
 884         tty->print("%s", os::path_separator());
 885       }
 886     }
 887     tty->print(" ;");
 888   }
 889 }
 890 
 891 void ClassLoader::print_bootclasspath() {
 892   ClassPathEntry* e;
 893   tty->print("[bootclasspath= ");
 894 
 895   // Print --patch-module module/path specifications first
 896   if (_patch_mod_entries != nullptr) {
 897     print_module_entry_table(_patch_mod_entries);
 898   }
 899 
 900   // [jimage | exploded modules build]
 901   if (has_jrt_entry()) {
 902     // Print the location of the java runtime image
 903     tty->print("%s ;", _jrt_entry->name());
 904   } else {
 905     // Print exploded module build path specifications
 906     if (_exploded_entries != nullptr) {
 907       print_module_entry_table(_exploded_entries);
 908     }
 909   }
 910 
 911   // appended entries
 912   e = first_append_entry();
 913   while (e != nullptr) {
 914     tty->print("%s ;", e->name());
 915     e = e->next();
 916   }
 917   tty->print_cr("]");
 918 }
 919 
 920 void* ClassLoader::dll_lookup(void* lib, const char* name, const char* path) {
 921   void* func = os::dll_lookup(lib, name);
 922   if (func == nullptr) {
 923     char msg[256] = "";
 924     jio_snprintf(msg, sizeof(msg), "Could not resolve \"%s\"", name);
 925     vm_exit_during_initialization(msg, path);
 926   }
 927   return func;
 928 }
 929 
 930 void ClassLoader::load_java_library() {
 931   assert(CanonicalizeEntry == nullptr, "should not load java library twice");
 932   void *javalib_handle = os::native_java_library();
 933   if (javalib_handle == nullptr) {
 934     vm_exit_during_initialization("Unable to load java library", nullptr);
 935   }
 936 
 937   CanonicalizeEntry = CAST_TO_FN_PTR(canonicalize_fn_t, dll_lookup(javalib_handle, "JDK_Canonicalize", nullptr));
 938 }
 939 
 940 void ClassLoader::release_load_zip_library() {
 941   ConditionalMutexLocker locker(Zip_lock, Zip_lock != nullptr, Monitor::_no_safepoint_check_flag);
 942   if (_libzip_loaded == 0) {
 943     load_zip_library();
 944     Atomic::release_store(&_libzip_loaded, 1);
 945   }
 946 }
 947 
 948 void ClassLoader::load_zip_library() {
 949   assert(ZipOpen == nullptr, "should not load zip library twice");
 950   char path[JVM_MAXPATHLEN];
 951   char ebuf[1024];
 952   if (os::dll_locate_lib(path, sizeof(path), Arguments::get_dll_dir(), "zip")) {
 953     _zip_handle = os::dll_load(path, ebuf, sizeof ebuf);
 954   }
 955   if (_zip_handle == nullptr) {
 956     vm_exit_during_initialization("Unable to load zip library", path);
 957   }
 958 
 959   ZipOpen = CAST_TO_FN_PTR(ZipOpen_t, dll_lookup(_zip_handle, "ZIP_Open", path));
 960   ZipClose = CAST_TO_FN_PTR(ZipClose_t, dll_lookup(_zip_handle, "ZIP_Close", path));
 961   FindEntry = CAST_TO_FN_PTR(FindEntry_t, dll_lookup(_zip_handle, "ZIP_FindEntry", path));
 962   ReadEntry = CAST_TO_FN_PTR(ReadEntry_t, dll_lookup(_zip_handle, "ZIP_ReadEntry", path));
 963   Crc32 = CAST_TO_FN_PTR(Crc32_t, dll_lookup(_zip_handle, "ZIP_CRC32", path));
 964 }
 965 
 966 void ClassLoader::load_jimage_library() {
 967   assert(JImageOpen == nullptr, "should not load jimage library twice");
 968   char path[JVM_MAXPATHLEN];
 969   char ebuf[1024];
 970   void* handle = nullptr;
 971   if (os::dll_locate_lib(path, sizeof(path), Arguments::get_dll_dir(), "jimage")) {
 972     handle = os::dll_load(path, ebuf, sizeof ebuf);
 973   }
 974   if (handle == nullptr) {
 975     vm_exit_during_initialization("Unable to load jimage library", path);
 976   }
 977 
 978   JImageOpen = CAST_TO_FN_PTR(JImageOpen_t, dll_lookup(handle, "JIMAGE_Open", path));
 979   JImageClose = CAST_TO_FN_PTR(JImageClose_t, dll_lookup(handle, "JIMAGE_Close", path));
 980   JImageFindResource = CAST_TO_FN_PTR(JImageFindResource_t, dll_lookup(handle, "JIMAGE_FindResource", path));
 981   JImageGetResource = CAST_TO_FN_PTR(JImageGetResource_t, dll_lookup(handle, "JIMAGE_GetResource", path));
 982 }
 983 
 984 int ClassLoader::crc32(int crc, const char* buf, int len) {
 985   load_zip_library_if_needed();
 986   return (*Crc32)(crc, (const jbyte*)buf, len);
 987 }
 988 
 989 oop ClassLoader::get_system_package(const char* name, TRAPS) {
 990   // Look up the name in the boot loader's package entry table.
 991   if (name != nullptr) {
 992     TempNewSymbol package_sym = SymbolTable::new_symbol(name);
 993     // Look for the package entry in the boot loader's package entry table.
 994     PackageEntry* package =
 995       ClassLoaderData::the_null_class_loader_data()->packages()->lookup_only(package_sym);
 996 
 997     // Return null if package does not exist or if no classes in that package
 998     // have been loaded.
 999     if (package != nullptr && package->has_loaded_class()) {
1000       ModuleEntry* module = package->module();
1001       if (module->location() != nullptr) {
1002         ResourceMark rm(THREAD);
1003         Handle ml = java_lang_String::create_from_str(
1004           module->location()->as_C_string(), THREAD);
1005         return ml();
1006       }
1007       // Return entry on boot loader class path.
1008       Handle cph = java_lang_String::create_from_str(
1009         ClassLoader::classpath_entry(package->classpath_index())->name(), THREAD);
1010       return cph();
1011     }
1012   }
1013   return nullptr;
1014 }
1015 
1016 objArrayOop ClassLoader::get_system_packages(TRAPS) {
1017   ResourceMark rm(THREAD);
1018   // List of pointers to PackageEntrys that have loaded classes.
1019   PackageEntryTable* pe_table =
1020       ClassLoaderData::the_null_class_loader_data()->packages();
1021   GrowableArray<PackageEntry*>* loaded_class_pkgs = pe_table->get_system_packages();
1022 
1023   // Allocate objArray and fill with java.lang.String
1024   objArrayOop r = oopFactory::new_objArray(vmClasses::String_klass(),
1025                                            loaded_class_pkgs->length(), CHECK_NULL);
1026   objArrayHandle result(THREAD, r);
1027   for (int x = 0; x < loaded_class_pkgs->length(); x++) {
1028     PackageEntry* package_entry = loaded_class_pkgs->at(x);
1029     Handle str = java_lang_String::create_from_symbol(package_entry->name(), CHECK_NULL);
1030     result->obj_at_put(x, str());
1031   }
1032   return result();
1033 }
1034 
1035 // caller needs ResourceMark
1036 const char* ClassLoader::file_name_for_class_name(const char* class_name,
1037                                                   int class_name_len) {
1038   assert(class_name != nullptr, "invariant");
1039   assert((int)strlen(class_name) == class_name_len, "invariant");
1040 
1041   static const char class_suffix[] = ".class";
1042   size_t class_suffix_len = sizeof(class_suffix);
1043 
1044   char* const file_name = NEW_RESOURCE_ARRAY(char,
1045                                              class_name_len +
1046                                              class_suffix_len); // includes term null
1047 
1048   strncpy(file_name, class_name, class_name_len);
1049   strncpy(&file_name[class_name_len], class_suffix, class_suffix_len);
1050 
1051   return file_name;
1052 }
1053 
1054 ClassPathEntry* find_first_module_cpe(ModuleEntry* mod_entry,
1055                                       const GrowableArray<ModuleClassPathList*>* const module_list) {
1056   int num_of_entries = module_list->length();
1057   const Symbol* class_module_name = mod_entry->name();
1058 
1059   // Loop through all the modules in either the patch-module or exploded entries looking for module
1060   for (int i = 0; i < num_of_entries; i++) {
1061     ModuleClassPathList* module_cpl = module_list->at(i);
1062     Symbol* module_cpl_name = module_cpl->module_name();
1063 
1064     if (module_cpl_name->fast_compare(class_module_name) == 0) {
1065       // Class' module has been located.
1066       return module_cpl->module_first_entry();
1067     }
1068   }
1069   return nullptr;
1070 }
1071 
1072 
1073 // Search either the patch-module or exploded build entries for class.
1074 ClassFileStream* ClassLoader::search_module_entries(JavaThread* current,
1075                                                     const GrowableArray<ModuleClassPathList*>* const module_list,
1076                                                     const char* const class_name,
1077                                                     const char* const file_name) {
1078   ClassFileStream* stream = nullptr;
1079 
1080   // Find the class' defining module in the boot loader's module entry table
1081   TempNewSymbol class_name_symbol = SymbolTable::new_symbol(class_name);
1082   TempNewSymbol pkg_name = package_from_class_name(class_name_symbol);
1083   PackageEntry* pkg_entry = get_package_entry(pkg_name, ClassLoaderData::the_null_class_loader_data());
1084   ModuleEntry* mod_entry = (pkg_entry != nullptr) ? pkg_entry->module() : nullptr;
1085 
1086   // If the module system has not defined java.base yet, then
1087   // classes loaded are assumed to be defined to java.base.
1088   // When java.base is eventually defined by the module system,
1089   // all packages of classes that have been previously loaded
1090   // are verified in ModuleEntryTable::verify_javabase_packages().
1091   if (!Universe::is_module_initialized() &&
1092       !ModuleEntryTable::javabase_defined() &&
1093       mod_entry == nullptr) {
1094     mod_entry = ModuleEntryTable::javabase_moduleEntry();
1095   }
1096 
1097   // The module must be a named module
1098   ClassPathEntry* e = nullptr;
1099   if (mod_entry != nullptr && mod_entry->is_named()) {
1100     if (module_list == _exploded_entries) {
1101       // The exploded build entries can be added to at any time so a lock is
1102       // needed when searching them.
1103       assert(!ClassLoader::has_jrt_entry(), "Must be exploded build");
1104       MutexLocker ml(current, Module_lock);
1105       e = find_first_module_cpe(mod_entry, module_list);
1106     } else {
1107       e = find_first_module_cpe(mod_entry, module_list);
1108     }
1109   }
1110 
1111   // Try to load the class from the module's ClassPathEntry list.
1112   while (e != nullptr) {
1113     stream = e->open_stream(current, file_name);
1114     // No context.check is required since CDS is not supported
1115     // for an exploded modules build or if --patch-module is specified.
1116     if (nullptr != stream) {
1117       return stream;
1118     }
1119     e = e->next();
1120   }
1121   // If the module was located, break out even if the class was not
1122   // located successfully from that module's ClassPathEntry list.
1123   // There will not be another valid entry for that module.
1124   return nullptr;
1125 }
1126 
1127 // Called by the boot classloader to load classes
1128 InstanceKlass* ClassLoader::load_class(Symbol* name, bool search_append_only, TRAPS) {
1129   assert(name != nullptr, "invariant");
1130 
1131   ResourceMark rm(THREAD);
1132   HandleMark hm(THREAD);
1133 
1134   const char* const class_name = name->as_C_string();
1135 
1136   EventMarkClassLoading m("Loading class %s", class_name);
1137 
1138   const char* const file_name = file_name_for_class_name(class_name,
1139                                                          name->utf8_length());
1140   assert(file_name != nullptr, "invariant");
1141 
1142   // Lookup stream for parsing .class file
1143   ClassFileStream* stream = nullptr;
1144   s2 classpath_index = 0;
1145   ClassPathEntry* e = nullptr;
1146 
1147   // If search_append_only is true, boot loader visibility boundaries are
1148   // set to be _first_append_entry to the end. This includes:
1149   //   [-Xbootclasspath/a]; [jvmti appended entries]
1150   //
1151   // If search_append_only is false, boot loader visibility boundaries are
1152   // set to be the --patch-module entries plus the base piece. This includes:
1153   //   [--patch-module=<module>=<file>(<pathsep><file>)*]; [jimage | exploded module build]
1154   //
1155 
1156   // Load Attempt #1: --patch-module
1157   // Determine the class' defining module.  If it appears in the _patch_mod_entries,
1158   // attempt to load the class from those locations specific to the module.
1159   // Specifications to --patch-module can contain a partial number of classes
1160   // that are part of the overall module definition.  So if a particular class is not
1161   // found within its module specification, the search should continue to Load Attempt #2.
1162   // Note: The --patch-module entries are never searched if the boot loader's
1163   //       visibility boundary is limited to only searching the append entries.
1164   if (_patch_mod_entries != nullptr && !search_append_only) {
1165     // At CDS dump time, the --patch-module entries are ignored. That means a
1166     // class is still loaded from the runtime image even if it might
1167     // appear in the _patch_mod_entries. The runtime shared class visibility
1168     // check will determine if a shared class is visible based on the runtime
1169     // environment, including the runtime --patch-module setting.
1170     //
1171     // DynamicDumpSharedSpaces requires UseSharedSpaces to be enabled. Since --patch-module
1172     // is not supported with UseSharedSpaces, it is not supported with DynamicDumpSharedSpaces.
1173     assert(!DynamicDumpSharedSpaces, "sanity");
1174     if (!DumpSharedSpaces) {
1175       stream = search_module_entries(THREAD, _patch_mod_entries, class_name, file_name);
1176     }
1177   }
1178 
1179   // Load Attempt #2: [jimage | exploded build]
1180   if (!search_append_only && (nullptr == stream)) {
1181     if (has_jrt_entry()) {
1182       e = _jrt_entry;
1183       stream = _jrt_entry->open_stream(THREAD, file_name);
1184     } else {
1185       // Exploded build - attempt to locate class in its defining module's location.
1186       assert(_exploded_entries != nullptr, "No exploded build entries present");
1187       stream = search_module_entries(THREAD, _exploded_entries, class_name, file_name);
1188     }
1189   }
1190 
1191   // Load Attempt #3: [-Xbootclasspath/a]; [jvmti appended entries]
1192   if (search_append_only && (nullptr == stream)) {
1193     // For the boot loader append path search, the starting classpath_index
1194     // for the appended piece is always 1 to account for either the
1195     // _jrt_entry or the _exploded_entries.
1196     assert(classpath_index == 0, "The classpath_index has been incremented incorrectly");
1197     classpath_index = 1;
1198 
1199     e = first_append_entry();
1200     while (e != nullptr) {
1201       stream = e->open_stream(THREAD, file_name);
1202       if (nullptr != stream) {
1203         break;
1204       }
1205       e = e->next();
1206       ++classpath_index;
1207     }
1208   }
1209 
1210   if (nullptr == stream) {
1211     return nullptr;
1212   }
1213 
1214   stream->set_verify(ClassLoaderExt::should_verify(classpath_index));
1215 
1216   ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
1217   Handle protection_domain;
1218   ClassLoadInfo cl_info(protection_domain);
1219 
1220   InstanceKlass* result = KlassFactory::create_from_stream(stream,
1221                                                            name,
1222                                                            loader_data,
1223                                                            cl_info,
1224                                                            CHECK_NULL);
1225   result->set_classpath_index(classpath_index);
1226   return result;
1227 }
1228 
1229 #if INCLUDE_CDS
1230 char* ClassLoader::skip_uri_protocol(char* source) {
1231   if (strncmp(source, "file:", 5) == 0) {
1232     // file: protocol path could start with file:/ or file:///
1233     // locate the char after all the forward slashes
1234     int offset = 5;
1235     while (*(source + offset) == '/') {
1236         offset++;
1237     }
1238     source += offset;
1239   // for non-windows platforms, move back one char as the path begins with a '/'
1240 #ifndef _WINDOWS
1241     source -= 1;
1242 #endif
1243   } else if (strncmp(source, "jrt:/", 5) == 0) {
1244     source += 5;
1245   }
1246   return source;
1247 }
1248 
1249 // Record the shared classpath index and loader type for classes loaded
1250 // by the builtin loaders at dump time.
1251 void ClassLoader::record_result(JavaThread* current, InstanceKlass* ik,
1252                                 const ClassFileStream* stream, bool redefined) {
1253   Arguments::assert_is_dumping_archive();
1254   assert(stream != nullptr, "sanity");
1255 
1256   if (ik->is_hidden()) {
1257     // We do not archive hidden classes.
1258     return;
1259   }
1260 
1261   oop loader = ik->class_loader();
1262   char* src = (char*)stream->source();
1263   if (src == nullptr) {
1264     if (loader == nullptr) {
1265       // JFR classes
1266       ik->set_shared_classpath_index(0);
1267       ik->set_shared_class_loader_type(ClassLoader::BOOT_LOADER);
1268     }
1269     return;
1270   }
1271 
1272   assert(has_jrt_entry(), "CDS dumping does not support exploded JDK build");
1273 
1274   ResourceMark rm(current);
1275   int classpath_index = -1;
1276   PackageEntry* pkg_entry = ik->package();
1277 
1278   if (FileMapInfo::get_number_of_shared_paths() > 0) {
1279     // Save the path from the file: protocol or the module name from the jrt: protocol
1280     // if no protocol prefix is found, path is the same as stream->source(). This path
1281     // must be valid since the class has been successfully parsed.
1282     char* path = skip_uri_protocol(src);
1283     assert(path != nullptr, "sanity");
1284     for (int i = 0; i < FileMapInfo::get_number_of_shared_paths(); i++) {
1285       SharedClassPathEntry* ent = FileMapInfo::shared_path(i);
1286       // A shared path has been validated during its creation in ClassLoader::create_class_path_entry(),
1287       // it must be valid here.
1288       assert(ent->name() != nullptr, "sanity");
1289       // If the path (from the class stream source) is the same as the shared
1290       // class or module path, then we have a match.
1291       // src may come from the App/Platform class loaders, which would canonicalize
1292       // the file name. We cannot use strcmp to check for equality against ent->name().
1293       // We must use os::same_files (which is faster than canonicalizing ent->name()).
1294       if (os::same_files(ent->name(), path)) {
1295         // null pkg_entry and pkg_entry in an unnamed module implies the class
1296         // is from the -cp or boot loader append path which consists of -Xbootclasspath/a
1297         // and jvmti appended entries.
1298         if ((pkg_entry == nullptr) || (pkg_entry->in_unnamed_module())) {
1299           // Ensure the index is within the -cp range before assigning
1300           // to the classpath_index.
1301           if (SystemDictionary::is_system_class_loader(loader) &&
1302               (i >= ClassLoaderExt::app_class_paths_start_index()) &&
1303               (i < ClassLoaderExt::app_module_paths_start_index())) {
1304             classpath_index = i;
1305             break;
1306           } else {
1307             if ((i >= 1) &&
1308                 (i < ClassLoaderExt::app_class_paths_start_index())) {
1309               // The class must be from boot loader append path which consists of
1310               // -Xbootclasspath/a and jvmti appended entries.
1311               assert(loader == nullptr, "sanity");
1312               classpath_index = i;
1313               break;
1314             }
1315           }
1316         } else {
1317           // A class from a named module from the --module-path. Ensure the index is
1318           // within the --module-path range before assigning to the classpath_index.
1319           if ((pkg_entry != nullptr) && !(pkg_entry->in_unnamed_module()) && (i > 0)) {
1320             if (i >= ClassLoaderExt::app_module_paths_start_index() &&
1321                 i < FileMapInfo::get_number_of_shared_paths()) {
1322               classpath_index = i;
1323               break;
1324             }
1325           }
1326         }
1327       }
1328       // for index 0 and the stream->source() is the modules image or has the jrt: protocol.
1329       // The class must be from the runtime modules image.
1330       if (i == 0 && (stream->from_boot_loader_modules_image() || string_starts_with(src, "jrt:"))) {
1331         classpath_index = i;
1332         break;
1333       }
1334     }
1335 
1336     // No path entry found for this class: most likely a shared class loaded by the
1337     // user defined classloader.
1338     if (classpath_index < 0 && !SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
1339       assert(ik->shared_classpath_index() < 0, "not assigned yet");
1340       ik->set_shared_classpath_index(UNREGISTERED_INDEX);
1341       SystemDictionaryShared::set_shared_class_misc_info(ik, (ClassFileStream*)stream);
1342       return;
1343     }
1344   } else {
1345     // The shared path table is set up after module system initialization.
1346     // The path table contains no entry before that. Any classes loaded prior
1347     // to the setup of the shared path table must be from the modules image.
1348     assert(stream->from_boot_loader_modules_image(), "stream must be loaded by boot loader from modules image");
1349     assert(FileMapInfo::get_number_of_shared_paths() == 0, "shared path table must not have been setup");
1350     classpath_index = 0;
1351   }
1352 
1353   const char* const class_name = ik->name()->as_C_string();
1354   const char* const file_name = file_name_for_class_name(class_name,
1355                                                          ik->name()->utf8_length());
1356   assert(file_name != nullptr, "invariant");
1357   ClassLoaderExt::record_result(checked_cast<s2>(classpath_index), ik, redefined);
1358 }
1359 #endif // INCLUDE_CDS
1360 
1361 // Initialize the class loader's access to methods in libzip.  Parse and
1362 // process the boot classpath into a list ClassPathEntry objects.  Once
1363 // this list has been created, it must not change order (see class PackageInfo)
1364 // it can be appended to and is by jvmti.
1365 
1366 void ClassLoader::initialize(TRAPS) {
1367   if (UsePerfData) {
1368     // jvmstat performance counters
1369     NEWPERFTICKCOUNTER(_perf_accumulated_time, SUN_CLS, "time");
1370     NEWPERFTICKCOUNTER(_perf_class_init_time, SUN_CLS, "classInitTime");
1371     NEWPERFTICKCOUNTER(_perf_class_init_selftime, SUN_CLS, "classInitTime.self");
1372     NEWPERFTICKCOUNTER(_perf_class_verify_time, SUN_CLS, "classVerifyTime");
1373     NEWPERFTICKCOUNTER(_perf_class_verify_selftime, SUN_CLS, "classVerifyTime.self");
1374     NEWPERFTICKCOUNTER(_perf_class_link_time, SUN_CLS, "classLinkedTime");
1375     NEWPERFTICKCOUNTER(_perf_class_link_selftime, SUN_CLS, "classLinkedTime.self");
1376     NEWPERFEVENTCOUNTER(_perf_classes_inited, SUN_CLS, "initializedClasses");
1377     NEWPERFEVENTCOUNTER(_perf_classes_linked, SUN_CLS, "linkedClasses");
1378     NEWPERFEVENTCOUNTER(_perf_classes_verified, SUN_CLS, "verifiedClasses");
1379 
1380     NEWPERFTICKCOUNTER(_perf_sys_class_lookup_time, SUN_CLS, "lookupSysClassTime");
1381     NEWPERFTICKCOUNTER(_perf_shared_classload_time, SUN_CLS, "sharedClassLoadTime");
1382     NEWPERFTICKCOUNTER(_perf_sys_classload_time, SUN_CLS, "sysClassLoadTime");
1383     NEWPERFTICKCOUNTER(_perf_app_classload_time, SUN_CLS, "appClassLoadTime");
1384     NEWPERFTICKCOUNTER(_perf_app_classload_selftime, SUN_CLS, "appClassLoadTime.self");
1385     NEWPERFEVENTCOUNTER(_perf_app_classload_count, SUN_CLS, "appClassLoadCount");
1386     NEWPERFTICKCOUNTER(_perf_define_appclasses, SUN_CLS, "defineAppClasses");
1387     NEWPERFTICKCOUNTER(_perf_define_appclass_time, SUN_CLS, "defineAppClassTime");
1388     NEWPERFTICKCOUNTER(_perf_define_appclass_selftime, SUN_CLS, "defineAppClassTime.self");
1389     NEWPERFBYTECOUNTER(_perf_app_classfile_bytes_read, SUN_CLS, "appClassBytes");
1390     NEWPERFBYTECOUNTER(_perf_sys_classfile_bytes_read, SUN_CLS, "sysClassBytes");
1391 
1392     NEWPERFEVENTCOUNTER(_unsafe_defineClassCallCounter, SUN_CLS, "unsafeDefineClassCalls");
1393   }
1394 
1395   // lookup java library entry points
1396   load_java_library();
1397   // jimage library entry points are loaded below, in lookup_vm_options
1398   setup_bootstrap_search_path(THREAD);
1399 }
1400 
1401 char* lookup_vm_resource(JImageFile *jimage, const char *jimage_version, const char *path) {
1402   jlong size;
1403   JImageLocationRef location = (*JImageFindResource)(jimage, "java.base", jimage_version, path, &size);
1404   if (location == 0)
1405     return nullptr;
1406   char *val = NEW_C_HEAP_ARRAY(char, size+1, mtClass);
1407   (*JImageGetResource)(jimage, location, val, size);
1408   val[size] = '\0';
1409   return val;
1410 }
1411 
1412 // Lookup VM options embedded in the modules jimage file
1413 char* ClassLoader::lookup_vm_options() {
1414   jint error;
1415   char modules_path[JVM_MAXPATHLEN];
1416   const char* fileSep = os::file_separator();
1417 
1418   // Initialize jimage library entry points
1419   load_jimage_library();
1420 
1421   jio_snprintf(modules_path, JVM_MAXPATHLEN, "%s%slib%smodules", Arguments::get_java_home(), fileSep, fileSep);
1422   JImage_file =(*JImageOpen)(modules_path, &error);
1423   if (JImage_file == nullptr) {
1424     return nullptr;
1425   }
1426 
1427   const char *jimage_version = get_jimage_version_string();
1428   char *options = lookup_vm_resource(JImage_file, jimage_version, "jdk/internal/vm/options");
1429   return options;
1430 }
1431 
1432 bool ClassLoader::is_module_observable(const char* module_name) {
1433   assert(JImageOpen != nullptr, "jimage library should have been opened");
1434   if (JImage_file == nullptr) {
1435     struct stat st;
1436     const char *path = get_exploded_module_path(module_name, true);
1437     bool res = os::stat(path, &st) == 0;
1438     FREE_C_HEAP_ARRAY(char, path);
1439     return res;
1440   }
1441   jlong size;
1442   const char *jimage_version = get_jimage_version_string();
1443   return (*JImageFindResource)(JImage_file, module_name, jimage_version, "module-info.class", &size) != 0;
1444 }
1445 
1446 #if INCLUDE_CDS
1447 void ClassLoader::initialize_shared_path(JavaThread* current) {
1448   if (Arguments::is_dumping_archive()) {
1449     ClassLoaderExt::setup_search_paths(current);
1450   }
1451 }
1452 
1453 void ClassLoader::initialize_module_path(TRAPS) {
1454   if (Arguments::is_dumping_archive()) {
1455     ClassLoaderExt::setup_module_paths(THREAD);
1456     FileMapInfo::allocate_shared_path_table(CHECK);
1457   }
1458 }
1459 
1460 // Helper function used by CDS code to get the number of module path
1461 // entries during shared classpath setup time.
1462 int ClassLoader::num_module_path_entries() {
1463   Arguments::assert_is_dumping_archive();
1464   int num_entries = 0;
1465   ClassPathEntry* e= ClassLoader::_module_path_entries;
1466   while (e != nullptr) {
1467     num_entries ++;
1468     e = e->next();
1469   }
1470   return num_entries;
1471 }
1472 #endif
1473 
1474 jlong ClassLoader::classloader_time_ms() {
1475   return UsePerfData ?
1476     Management::ticks_to_ms(_perf_accumulated_time->get_value()) : -1;
1477 }
1478 
1479 jlong ClassLoader::class_init_count() {
1480   return UsePerfData ? _perf_classes_inited->get_value() : -1;
1481 }
1482 
1483 jlong ClassLoader::class_init_time_ms() {
1484   return UsePerfData ?
1485     Management::ticks_to_ms(_perf_class_init_time->get_value()) : -1;
1486 }
1487 
1488 jlong ClassLoader::class_verify_time_ms() {
1489   return UsePerfData ?
1490     Management::ticks_to_ms(_perf_class_verify_time->get_value()) : -1;
1491 }
1492 
1493 jlong ClassLoader::class_link_count() {
1494   return UsePerfData ? _perf_classes_linked->get_value() : -1;
1495 }
1496 
1497 jlong ClassLoader::class_link_time_ms() {
1498   return UsePerfData ?
1499     Management::ticks_to_ms(_perf_class_link_time->get_value()) : -1;
1500 }
1501 
1502 int ClassLoader::compute_Object_vtable() {
1503   // hardwired for JDK1.2 -- would need to duplicate class file parsing
1504   // code to determine actual value from file
1505   // Would be value '11' if finals were in vtable
1506   int JDK_1_2_Object_vtable_size = 5;
1507   return JDK_1_2_Object_vtable_size * vtableEntry::size();
1508 }
1509 
1510 
1511 void classLoader_init1() {
1512   EXCEPTION_MARK;
1513   ClassLoader::initialize(THREAD);
1514   if (HAS_PENDING_EXCEPTION) {
1515     vm_exit_during_initialization("ClassLoader::initialize() failed unexpectedly");
1516   }
1517 }
1518 
1519 // Complete the ClassPathEntry setup for the boot loader
1520 void ClassLoader::classLoader_init2(JavaThread* current) {
1521   // Setup the list of module/path pairs for --patch-module processing
1522   // This must be done after the SymbolTable is created in order
1523   // to use fast_compare on module names instead of a string compare.
1524   if (Arguments::get_patch_mod_prefix() != nullptr) {
1525     setup_patch_mod_entries();
1526   }
1527 
1528   // Create the ModuleEntry for java.base (must occur after setup_patch_mod_entries
1529   // to successfully determine if java.base has been patched)
1530   create_javabase();
1531 
1532   // Setup the initial java.base/path pair for the exploded build entries.
1533   // As more modules are defined during module system initialization, more
1534   // entries will be added to the exploded build array.
1535   if (!has_jrt_entry()) {
1536     assert(!DumpSharedSpaces, "DumpSharedSpaces not supported with exploded module builds");
1537     assert(!DynamicDumpSharedSpaces, "DynamicDumpSharedSpaces not supported with exploded module builds");
1538     assert(!UseSharedSpaces, "UsedSharedSpaces not supported with exploded module builds");
1539     // Set up the boot loader's _exploded_entries list.  Note that this gets
1540     // done before loading any classes, by the same thread that will
1541     // subsequently do the first class load. So, no lock is needed for this.
1542     assert(_exploded_entries == nullptr, "Should only get initialized once");
1543     _exploded_entries = new (mtModule)
1544       GrowableArray<ModuleClassPathList*>(EXPLODED_ENTRY_SIZE, mtModule);
1545     add_to_exploded_build_list(current, vmSymbols::java_base());
1546   }
1547 }
1548 
1549 char* ClassLoader::get_canonical_path(const char* orig, Thread* thread) {
1550   assert(orig != nullptr, "bad arguments");
1551   // caller needs to allocate ResourceMark for the following output buffer
1552   char* canonical_path = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, JVM_MAXPATHLEN);
1553   ResourceMark rm(thread);
1554   // os::native_path writes into orig_copy
1555   char* orig_copy = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, strlen(orig)+1);
1556   strcpy(orig_copy, orig);
1557   if ((CanonicalizeEntry)(os::native_path(orig_copy), canonical_path, JVM_MAXPATHLEN) < 0) {
1558     return nullptr;
1559   }
1560   return canonical_path;
1561 }
1562 
1563 void ClassLoader::create_javabase() {
1564   JavaThread* current = JavaThread::current();
1565 
1566   // Create java.base's module entry for the boot
1567   // class loader prior to loading j.l.Object.
1568   ClassLoaderData* null_cld = ClassLoaderData::the_null_class_loader_data();
1569 
1570   // Get module entry table
1571   ModuleEntryTable* null_cld_modules = null_cld->modules();
1572   if (null_cld_modules == nullptr) {
1573     vm_exit_during_initialization("No ModuleEntryTable for the boot class loader");
1574   }
1575 
1576   {
1577     MutexLocker ml(current, Module_lock);
1578     if (ModuleEntryTable::javabase_moduleEntry() == nullptr) {  // may have been inited by CDS.
1579       ModuleEntry* jb_module = null_cld_modules->locked_create_entry(Handle(),
1580                                false, vmSymbols::java_base(), nullptr, nullptr, null_cld);
1581       if (jb_module == nullptr) {
1582         vm_exit_during_initialization("Unable to create ModuleEntry for " JAVA_BASE_NAME);
1583       }
1584       ModuleEntryTable::set_javabase_moduleEntry(jb_module);
1585     }
1586   }
1587 }
1588 
1589 // Please keep following two functions at end of this file. With them placed at top or in middle of the file,
1590 // they could get inlined by aggressive compiler, an unknown trick, see bug 6966589.
1591 void PerfClassTraceTime::initialize() {
1592   if (!UsePerfData) return;
1593 
1594   if (_eventp != nullptr) {
1595     // increment the event counter
1596     _eventp->inc();
1597   }
1598 
1599   // stop the current active thread-local timer to measure inclusive time
1600   _prev_active_event = -1;
1601   for (int i=0; i < EVENT_TYPE_COUNT; i++) {
1602      if (_timers[i].is_active()) {
1603        assert(_prev_active_event == -1, "should have only one active timer");
1604        _prev_active_event = i;
1605        _timers[i].stop();
1606      }
1607   }
1608 
1609   if (_recursion_counters == nullptr || (_recursion_counters[_event_type])++ == 0) {
1610     // start the inclusive timer if not recursively called
1611     _t.start();
1612   }
1613 
1614   // start thread-local timer of the given event type
1615    if (!_timers[_event_type].is_active()) {
1616     _timers[_event_type].start();
1617   }
1618 }
1619 
1620 PerfClassTraceTime::~PerfClassTraceTime() {
1621   if (!UsePerfData) return;
1622 
1623   // stop the thread-local timer as the event completes
1624   // and resume the thread-local timer of the event next on the stack
1625   _timers[_event_type].stop();
1626   jlong selftime = _timers[_event_type].ticks();
1627 
1628   if (_prev_active_event >= 0) {
1629     _timers[_prev_active_event].start();
1630   }
1631 
1632   if (_recursion_counters != nullptr && --(_recursion_counters[_event_type]) > 0) return;
1633 
1634   // increment the counters only on the leaf call
1635   _t.stop();
1636   _timep->inc(_t.ticks());
1637   if (_selftimep != nullptr) {
1638     _selftimep->inc(selftime);
1639   }
1640   // add all class loading related event selftime to the accumulated time counter
1641   ClassLoader::perf_accumulated_time()->inc(selftime);
1642 
1643   // reset the timer
1644   _timers[_event_type].reset();
1645 }