1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "cds/cds_globals.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/filemap.hpp"
29 #include "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 "jimage.hpp"
48 #include "jvm.h"
49 #include "logging/log.hpp"
50 #include "logging/logStream.hpp"
51 #include "logging/logTag.hpp"
52 #include "memory/allocation.inline.hpp"
53 #include "memory/oopFactory.hpp"
54 #include "memory/resourceArea.hpp"
55 #include "memory/universe.hpp"
56 #include "oops/instanceKlass.hpp"
57 #include "oops/instanceRefKlass.hpp"
58 #include "oops/klass.inline.hpp"
59 #include "oops/method.inline.hpp"
60 #include "oops/objArrayOop.inline.hpp"
61 #include "oops/oop.inline.hpp"
62 #include "oops/symbol.hpp"
63 #include "prims/jvm_misc.hpp"
64 #include "runtime/arguments.hpp"
65 #include "runtime/handles.inline.hpp"
66 #include "runtime/init.hpp"
67 #include "runtime/interfaceSupport.inline.hpp"
68 #include "runtime/java.hpp"
69 #include "runtime/javaCalls.hpp"
70 #include "runtime/os.hpp"
71 #include "runtime/perfData.inline.hpp"
72 #include "runtime/threadCritical.hpp"
73 #include "runtime/timer.hpp"
74 #include "runtime/vm_version.hpp"
75 #include "services/management.hpp"
76 #include "services/threadService.hpp"
77 #include "utilities/checkedCast.hpp"
78 #include "utilities/classpathStream.hpp"
79 #include "utilities/events.hpp"
80 #include "utilities/macros.hpp"
81 #include "utilities/ostream.hpp"
82 #include "utilities/utf8.hpp"
83
84 // Entry point in java.dll for path canonicalization
85
86 typedef int (*canonicalize_fn_t)(const char *orig, char *out, int len);
87
88 static canonicalize_fn_t CanonicalizeEntry = nullptr;
89
90 // Entry points for jimage.dll for loading jimage file entries
91
92 static JImageOpen_t JImageOpen = nullptr;
93 static JImageClose_t JImageClose = nullptr;
94 static JImageFindResource_t JImageFindResource = nullptr;
95 static JImageGetResource_t JImageGetResource = nullptr;
96
97 // JimageFile pointer, or null if exploded JDK build.
98 static JImageFile* JImage_file = nullptr;
99
100 // Globals
101
102 PerfCounter* ClassLoader::_perf_accumulated_time = nullptr;
103 PerfCounter* ClassLoader::_perf_classes_inited = nullptr;
104 PerfCounter* ClassLoader::_perf_class_init_time = nullptr;
105 PerfCounter* ClassLoader::_perf_class_init_selftime = nullptr;
106 PerfCounter* ClassLoader::_perf_class_init_bytecodes_count = nullptr;
107 PerfCounter* ClassLoader::_perf_classes_verified = nullptr;
108 PerfCounter* ClassLoader::_perf_class_verify_time = nullptr;
109 PerfCounter* ClassLoader::_perf_class_verify_selftime = nullptr;
110 PerfCounter* ClassLoader::_perf_classes_linked = nullptr;
111 PerfCounter* ClassLoader::_perf_class_link_time = nullptr;
112 PerfCounter* ClassLoader::_perf_class_link_selftime = nullptr;
113 PerfCounter* ClassLoader::_perf_shared_classload_time = nullptr;
114 PerfCounter* ClassLoader::_perf_sys_classload_time = nullptr;
115 PerfCounter* ClassLoader::_perf_app_classload_time = nullptr;
116 PerfCounter* ClassLoader::_perf_app_classload_selftime = nullptr;
117 PerfCounter* ClassLoader::_perf_app_classload_count = nullptr;
118 PerfCounter* ClassLoader::_perf_define_appclasses = nullptr;
119 PerfCounter* ClassLoader::_perf_define_appclass_time = nullptr;
120 PerfCounter* ClassLoader::_perf_define_appclass_selftime = nullptr;
121 PerfCounter* ClassLoader::_perf_app_classfile_bytes_read = nullptr;
122 PerfCounter* ClassLoader::_perf_sys_classfile_bytes_read = nullptr;
123 PerfCounter* ClassLoader::_perf_preload_total_time = nullptr;
124 PerfCounter* ClassLoader::_perf_preload_time = nullptr;
125 PerfCounter* ClassLoader::_perf_prelink_time = nullptr;
126 PerfCounter* ClassLoader::_perf_preinit_time = nullptr;
127 PerfCounter* ClassLoader::_perf_preresolve_time = nullptr;
128 PerfCounter* ClassLoader::_perf_ik_link_methods_time = nullptr;
129 PerfCounter* ClassLoader::_perf_method_adapters_time = nullptr;
130 PerfCounter* ClassLoader::_perf_ik_link_methods_count = nullptr;
131 PerfCounter* ClassLoader::_perf_method_adapters_count = nullptr;
132 PerfCounter* ClassLoader::_unsafe_defineClassCallCounter = nullptr;
133 PerfCounter* ClassLoader::_perf_secondary_hash_time = nullptr;
134
135 PerfTickCounters* ClassLoader::_perf_resolve_indy_time = nullptr;
136 PerfTickCounters* ClassLoader::_perf_resolve_invokehandle_time = nullptr;
137 PerfTickCounters* ClassLoader::_perf_resolve_mh_time = nullptr;
138 PerfTickCounters* ClassLoader::_perf_resolve_mt_time = nullptr;
139
140 PerfCounter* ClassLoader::_perf_resolve_indy_count = nullptr;
141 PerfCounter* ClassLoader::_perf_resolve_invokehandle_count = nullptr;
142 PerfCounter* ClassLoader::_perf_resolve_mh_count = nullptr;
143 PerfCounter* ClassLoader::_perf_resolve_mt_count = nullptr;
144
145 void ClassLoader::print_counters(outputStream *st) {
146 // The counters are only active if the logging is enabled, but
147 // we print to the passed in outputStream as requested.
148 if (log_is_enabled(Info, perf, class, link)) {
149 st->print_cr("ClassLoader:");
150 st->print_cr( " clinit: " JLONG_FORMAT "ms / " JLONG_FORMAT " events",
151 ClassLoader::class_init_time_ms(), ClassLoader::class_init_count());
152 st->print_cr(" link methods: " JLONG_FORMAT "ms / " JLONG_FORMAT " events",
153 Management::ticks_to_ms(_perf_ik_link_methods_time->get_value()) , _perf_ik_link_methods_count->get_value());
154 st->print_cr(" method adapters: " JLONG_FORMAT "ms / " JLONG_FORMAT " events",
155 Management::ticks_to_ms(_perf_method_adapters_time->get_value()) , _perf_method_adapters_count->get_value());
156 if (CountBytecodes || CountBytecodesPerThread) {
157 st->print_cr("; executed " JLONG_FORMAT " bytecodes", ClassLoader::class_init_bytecodes_count());
158 }
159 st->print_cr(" resolve...");
160 st->print_cr(" invokedynamic: " JLONG_FORMAT "ms (elapsed) " JLONG_FORMAT "ms (thread) / " JLONG_FORMAT " events",
161 _perf_resolve_indy_time->elapsed_counter_value_ms(),
162 _perf_resolve_indy_time->thread_counter_value_ms(),
163 _perf_resolve_indy_count->get_value());
164 st->print_cr(" invokehandle: " JLONG_FORMAT "ms (elapsed) " JLONG_FORMAT "ms (thread) / " JLONG_FORMAT " events",
165 _perf_resolve_invokehandle_time->elapsed_counter_value_ms(),
166 _perf_resolve_invokehandle_time->thread_counter_value_ms(),
167 _perf_resolve_invokehandle_count->get_value());
168 st->print_cr(" CP_MethodHandle: " JLONG_FORMAT "ms (elapsed) " JLONG_FORMAT "ms (thread) / " JLONG_FORMAT " events",
169 _perf_resolve_mh_time->elapsed_counter_value_ms(),
170 _perf_resolve_mh_time->thread_counter_value_ms(),
171 _perf_resolve_mh_count->get_value());
172 st->print_cr(" CP_MethodType: " JLONG_FORMAT "ms (elapsed) " JLONG_FORMAT "ms (thread) / " JLONG_FORMAT " events",
173 _perf_resolve_mt_time->elapsed_counter_value_ms(),
174 _perf_resolve_mt_time->thread_counter_value_ms(),
175 _perf_resolve_mt_count->get_value());
176 }
177 }
178
179 GrowableArray<ModuleClassPathList*>* ClassLoader::_patch_mod_entries = nullptr;
180 GrowableArray<ModuleClassPathList*>* ClassLoader::_exploded_entries = nullptr;
181 ClassPathEntry* ClassLoader::_jrt_entry = nullptr;
182
183 ClassPathEntry* volatile ClassLoader::_first_append_entry_list = nullptr;
184 ClassPathEntry* volatile ClassLoader::_last_append_entry = nullptr;
185 #if INCLUDE_CDS
186 ClassPathEntry* ClassLoader::_app_classpath_entries = nullptr;
187 ClassPathEntry* ClassLoader::_last_app_classpath_entry = nullptr;
188 ClassPathEntry* ClassLoader::_module_path_entries = nullptr;
189 ClassPathEntry* ClassLoader::_last_module_path_entry = nullptr;
190 #endif
191
192 // helper routines
193 #if INCLUDE_CDS
194 static bool string_starts_with(const char* str, const char* str_to_find) {
195 size_t str_len = strlen(str);
196 size_t str_to_find_len = strlen(str_to_find);
197 if (str_to_find_len > str_len) {
198 return false;
199 }
200 return (strncmp(str, str_to_find, str_to_find_len) == 0);
201 }
202 #endif
203
204 static const char* get_jimage_version_string() {
205 static char version_string[10] = "";
206 if (version_string[0] == '\0') {
207 jio_snprintf(version_string, sizeof(version_string), "%d.%d",
208 VM_Version::vm_major_version(), VM_Version::vm_minor_version());
209 }
210 return (const char*)version_string;
211 }
212
213 bool ClassLoader::string_ends_with(const char* str, const char* str_to_find) {
214 size_t str_len = strlen(str);
215 size_t str_to_find_len = strlen(str_to_find);
216 if (str_to_find_len > str_len) {
217 return false;
218 }
219 return (strncmp(str + (str_len - str_to_find_len), str_to_find, str_to_find_len) == 0);
220 }
221
222 // Used to obtain the package name from a fully qualified class name.
223 Symbol* ClassLoader::package_from_class_name(const Symbol* name, bool* bad_class_name) {
224 if (name == nullptr) {
225 if (bad_class_name != nullptr) {
226 *bad_class_name = true;
227 }
228 return nullptr;
229 }
230
231 int utf_len = name->utf8_length();
232 const jbyte* base = (const jbyte*)name->base();
233 const jbyte* start = base;
234 const jbyte* end = UTF8::strrchr(start, utf_len, JVM_SIGNATURE_SLASH);
235 if (end == nullptr) {
236 return nullptr;
237 }
238 // Skip over '['s
239 if (*start == JVM_SIGNATURE_ARRAY) {
240 do {
241 start++;
242 } while (start < end && *start == JVM_SIGNATURE_ARRAY);
243
244 // Fully qualified class names should not contain a 'L'.
245 // Set bad_class_name to true to indicate that the package name
246 // could not be obtained due to an error condition.
247 // In this situation, is_same_class_package returns false.
248 if (*start == JVM_SIGNATURE_CLASS) {
249 if (bad_class_name != nullptr) {
250 *bad_class_name = true;
251 }
252 return nullptr;
253 }
254 }
255 // A class name could have just the slash character in the name,
256 // in which case start > end
257 if (start >= end) {
258 // No package name
259 if (bad_class_name != nullptr) {
260 *bad_class_name = true;
261 }
262 return nullptr;
263 }
264 return SymbolTable::new_symbol(name, pointer_delta_as_int(start, base), pointer_delta_as_int(end, base));
265 }
266
267 // Given a fully qualified package name, find its defining package in the class loader's
268 // package entry table.
269 PackageEntry* ClassLoader::get_package_entry(Symbol* pkg_name, ClassLoaderData* loader_data) {
270 if (pkg_name == nullptr) {
271 return nullptr;
272 }
273 PackageEntryTable* pkgEntryTable = loader_data->packages();
274 return pkgEntryTable->lookup_only(pkg_name);
275 }
276
277 const char* ClassPathEntry::copy_path(const char* path) {
278 char* copy = NEW_C_HEAP_ARRAY(char, strlen(path)+1, mtClass);
279 strcpy(copy, path);
280 return copy;
281 }
282
283 ClassPathDirEntry::~ClassPathDirEntry() {
284 FREE_C_HEAP_ARRAY(char, _dir);
285 }
286
287 ClassFileStream* ClassPathDirEntry::open_stream(JavaThread* current, const char* name) {
288 // construct full path name
289 assert((_dir != nullptr) && (name != nullptr), "sanity");
290 size_t path_len = strlen(_dir) + strlen(name) + strlen(os::file_separator()) + 1;
291 char* path = NEW_RESOURCE_ARRAY_IN_THREAD(current, char, path_len);
292 int len = jio_snprintf(path, path_len, "%s%s%s", _dir, os::file_separator(), name);
293 assert(len == (int)(path_len - 1), "sanity");
294 // check if file exists
295 struct stat st;
296 if (os::stat(path, &st) == 0) {
297 // found file, open it
298 int file_handle = os::open(path, 0, 0);
299 if (file_handle != -1) {
300 // read contents into resource array
301 u1* buffer = NEW_RESOURCE_ARRAY_IN_THREAD(current, u1, st.st_size);
302 size_t num_read = ::read(file_handle, (char*) buffer, st.st_size);
303 // close file
304 ::close(file_handle);
305 // construct ClassFileStream
306 if (num_read == (size_t)st.st_size) {
307 if (UsePerfData) {
308 ClassLoader::perf_sys_classfile_bytes_read()->inc(num_read);
309 }
310 #ifdef ASSERT
311 // Freeing path is a no-op here as buffer prevents it from being reclaimed. But we keep it for
312 // debug builds so that we guard against use-after-free bugs.
313 FREE_RESOURCE_ARRAY_IN_THREAD(current, char, path, path_len);
314 #endif
315 // We don't verify the length of the classfile stream fits in an int, but this is the
316 // bootloader so we have control of this.
317 // Resource allocated
318 return new ClassFileStream(buffer,
319 checked_cast<int>(st.st_size),
320 _dir,
321 ClassFileStream::verify);
322 }
323 }
324 }
325 FREE_RESOURCE_ARRAY_IN_THREAD(current, char, path, path_len);
326 return nullptr;
327 }
328
329 ClassPathZipEntry::ClassPathZipEntry(jzfile* zip, const char* zip_name,
330 bool from_class_path_attr) : ClassPathEntry() {
331 _zip = zip;
332 _zip_name = copy_path(zip_name);
333 _from_class_path_attr = from_class_path_attr;
334 }
335
336 ClassPathZipEntry::~ClassPathZipEntry() {
337 ZipLibrary::close(_zip);
338 FREE_C_HEAP_ARRAY(char, _zip_name);
339 }
340
341 bool ClassPathZipEntry::has_entry(JavaThread* current, const char* name) {
342 ThreadToNativeFromVM ttn(current);
343 // check whether zip archive contains name
344 jint name_len;
345 jint filesize;
346 jzentry* entry = ZipLibrary::find_entry(_zip, name, &filesize, &name_len);
347 if (entry == nullptr) {
348 return false;
349 } else {
350 ZipLibrary::free_entry(_zip, entry);
351 return true;
352 }
353 }
354
355 u1* ClassPathZipEntry::open_entry(JavaThread* current, const char* name, jint* filesize, bool nul_terminate) {
356 // enable call to C land
357 ThreadToNativeFromVM ttn(current);
358 // check whether zip archive contains name
359 jint name_len;
360 jzentry* entry = ZipLibrary::find_entry(_zip, name, filesize, &name_len);
361 if (entry == nullptr) return nullptr;
362 u1* buffer;
363 char name_buf[128];
364 char* filename;
365 if (name_len < 128) {
366 filename = name_buf;
367 } else {
368 filename = NEW_RESOURCE_ARRAY(char, name_len + 1);
369 }
370
371 // read contents into resource array
372 size_t size = (uint32_t)(*filesize);
373 if (nul_terminate) {
374 if (sizeof(size) == sizeof(uint32_t) && size == UINT_MAX) {
375 return nullptr; // 32-bit integer overflow will occur.
376 }
377 size++;
378 }
379
380 // ZIP_ReadEntry also frees zentry
381 buffer = NEW_RESOURCE_ARRAY(u1, size);
382 if (!ZipLibrary::read_entry(_zip, entry, buffer, filename)) {
383 return nullptr;
384 }
385
386 // return result
387 if (nul_terminate) {
388 buffer[size - 1] = 0;
389 }
390 return buffer;
391 }
392
393 ClassFileStream* ClassPathZipEntry::open_stream(JavaThread* current, const char* name) {
394 jint filesize;
395 u1* buffer = open_entry(current, name, &filesize, false);
396 if (buffer == nullptr) {
397 return nullptr;
398 }
399 if (UsePerfData) {
400 ClassLoader::perf_sys_classfile_bytes_read()->inc(filesize);
401 }
402 // Resource allocated
403 return new ClassFileStream(buffer,
404 filesize,
405 _zip_name,
406 ClassFileStream::verify);
407 }
408
409 DEBUG_ONLY(ClassPathImageEntry* ClassPathImageEntry::_singleton = nullptr;)
410
411 JImageFile* ClassPathImageEntry::jimage() const {
412 return JImage_file;
413 }
414
415 JImageFile* ClassPathImageEntry::jimage_non_null() const {
416 assert(ClassLoader::has_jrt_entry(), "must be");
417 assert(jimage() != nullptr, "should have been opened by ClassLoader::lookup_vm_options "
418 "and remained throughout normal JVM lifetime");
419 return jimage();
420 }
421
422 void ClassPathImageEntry::close_jimage() {
423 if (jimage() != nullptr) {
424 (*JImageClose)(jimage());
425 JImage_file = nullptr;
426 }
427 }
428
429 ClassPathImageEntry::ClassPathImageEntry(JImageFile* jimage, const char* name) :
430 ClassPathEntry() {
431 guarantee(jimage != nullptr, "jimage file is null");
432 guarantee(name != nullptr, "jimage file name is null");
433 assert(_singleton == nullptr, "VM supports only one jimage");
434 DEBUG_ONLY(_singleton = this);
435 size_t len = strlen(name) + 1;
436 _name = copy_path(name);
437 }
438
439 ClassFileStream* ClassPathImageEntry::open_stream(JavaThread* current, const char* name) {
440 return open_stream_for_loader(current, name, ClassLoaderData::the_null_class_loader_data());
441 }
442
443 // For a class in a named module, look it up in the jimage file using this syntax:
444 // /<module-name>/<package-name>/<base-class>
445 //
446 // Assumptions:
447 // 1. There are no unnamed modules in the jimage file.
448 // 2. A package is in at most one module in the jimage file.
449 //
450 ClassFileStream* ClassPathImageEntry::open_stream_for_loader(JavaThread* current, const char* name, ClassLoaderData* loader_data) {
451 jlong size;
452 JImageLocationRef location = (*JImageFindResource)(jimage_non_null(), "", get_jimage_version_string(), name, &size);
453
454 if (location == 0) {
455 TempNewSymbol class_name = SymbolTable::new_symbol(name);
456 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
457
458 if (pkg_name != nullptr) {
459 if (!Universe::is_module_initialized()) {
460 location = (*JImageFindResource)(jimage_non_null(), JAVA_BASE_NAME, get_jimage_version_string(), name, &size);
461 } else {
462 PackageEntry* package_entry = ClassLoader::get_package_entry(pkg_name, loader_data);
463 if (package_entry != nullptr) {
464 ResourceMark rm(current);
465 // Get the module name
466 ModuleEntry* module = package_entry->module();
467 assert(module != nullptr, "Boot classLoader package missing module");
468 assert(module->is_named(), "Boot classLoader package is in unnamed module");
469 const char* module_name = module->name()->as_C_string();
470 if (module_name != nullptr) {
471 location = (*JImageFindResource)(jimage_non_null(), module_name, get_jimage_version_string(), name, &size);
472 }
473 }
474 }
475 }
476 }
477 if (location != 0) {
478 if (UsePerfData) {
479 ClassLoader::perf_sys_classfile_bytes_read()->inc(size);
480 }
481 char* data = NEW_RESOURCE_ARRAY(char, size);
482 (*JImageGetResource)(jimage_non_null(), location, data, size);
483 // Resource allocated
484 assert(this == (ClassPathImageEntry*)ClassLoader::get_jrt_entry(), "must be");
485 return new ClassFileStream((u1*)data,
486 checked_cast<int>(size),
487 _name,
488 ClassFileStream::verify,
489 true); // from_boot_loader_modules_image
490 }
491
492 return nullptr;
493 }
494
495 JImageLocationRef ClassLoader::jimage_find_resource(JImageFile* jf,
496 const char* module_name,
497 const char* file_name,
498 jlong &size) {
499 return ((*JImageFindResource)(jf, module_name, get_jimage_version_string(), file_name, &size));
500 }
501
502 bool ClassPathImageEntry::is_modules_image() const {
503 assert(this == _singleton, "VM supports a single jimage");
504 assert(this == (ClassPathImageEntry*)ClassLoader::get_jrt_entry(), "must be used for jrt entry");
505 return true;
506 }
507
508 #if INCLUDE_CDS
509 void ClassLoader::exit_with_path_failure(const char* error, const char* message) {
510 assert(CDSConfig::is_dumping_archive(), "sanity");
511 tty->print_cr("Hint: enable -Xlog:class+path=info to diagnose the failure");
512 vm_exit_during_cds_dumping(error, message);
513 }
514 #endif
515
516 ModuleClassPathList::ModuleClassPathList(Symbol* module_name) {
517 _module_name = module_name;
518 _module_first_entry = nullptr;
519 _module_last_entry = nullptr;
520 }
521
522 ModuleClassPathList::~ModuleClassPathList() {
523 // Clean out each ClassPathEntry on list
524 ClassPathEntry* e = _module_first_entry;
525 while (e != nullptr) {
526 ClassPathEntry* next_entry = e->next();
527 delete e;
528 e = next_entry;
529 }
530 }
531
532 void ModuleClassPathList::add_to_list(ClassPathEntry* new_entry) {
533 if (new_entry != nullptr) {
534 if (_module_last_entry == nullptr) {
535 _module_first_entry = _module_last_entry = new_entry;
536 } else {
537 _module_last_entry->set_next(new_entry);
538 _module_last_entry = new_entry;
539 }
540 }
541 }
542
543 void ClassLoader::trace_class_path(const char* msg, const char* name) {
544 LogTarget(Info, class, path) lt;
545 if (lt.is_enabled()) {
546 LogStream ls(lt);
547 if (msg) {
548 ls.print("%s", msg);
549 }
550 if (name) {
551 if (strlen(name) < 256) {
552 ls.print("%s", name);
553 } else {
554 // For very long paths, we need to print each character separately,
555 // as print_cr() has a length limit
556 while (name[0] != '\0') {
557 ls.print("%c", name[0]);
558 name++;
559 }
560 }
561 }
562 ls.cr();
563 }
564 }
565
566 void ClassLoader::setup_bootstrap_search_path(JavaThread* current) {
567 const char* bootcp = Arguments::get_boot_class_path();
568 assert(bootcp != nullptr, "Boot class path must not be nullptr");
569 if (PrintSharedArchiveAndExit) {
570 // Don't print bootcp - this is the bootcp of this current VM process, not necessarily
571 // the same as the boot classpath of the shared archive.
572 } else {
573 trace_class_path("bootstrap loader class path=", bootcp);
574 }
575 setup_bootstrap_search_path_impl(current, bootcp);
576 }
577
578 #if INCLUDE_CDS
579 void ClassLoader::setup_app_search_path(JavaThread* current, const char *class_path) {
580 assert(CDSConfig::is_dumping_archive(), "sanity");
581
582 ResourceMark rm(current);
583 ClasspathStream cp_stream(class_path);
584
585 while (cp_stream.has_next()) {
586 const char* path = cp_stream.get_next();
587 update_class_path_entry_list(current, path, /* check_for_duplicates */ true,
588 /* is_boot_append */ false, /* from_class_path_attr */ false);
589 }
590 }
591
592 void ClassLoader::add_to_module_path_entries(const char* path,
593 ClassPathEntry* entry) {
594 assert(entry != nullptr, "ClassPathEntry should not be nullptr");
595 assert(CDSConfig::is_dumping_archive(), "sanity");
596
597 // The entry does not exist, add to the list
598 if (_module_path_entries == nullptr) {
599 assert(_last_module_path_entry == nullptr, "Sanity");
600 _module_path_entries = _last_module_path_entry = entry;
601 } else {
602 _last_module_path_entry->set_next(entry);
603 _last_module_path_entry = entry;
604 }
605 }
606
607 // Add a module path to the _module_path_entries list.
608 void ClassLoader::setup_module_search_path(JavaThread* current, const char* path) {
609 assert(CDSConfig::is_dumping_archive(), "sanity");
610 struct stat st;
611 if (os::stat(path, &st) != 0) {
612 tty->print_cr("os::stat error %d (%s). CDS dump aborted (path was \"%s\").",
613 errno, os::errno_name(errno), path);
614 vm_exit_during_initialization();
615 }
616 // File or directory found
617 ClassPathEntry* new_entry = nullptr;
618 new_entry = create_class_path_entry(current, path, &st,
619 false /*is_boot_append */, false /* from_class_path_attr */);
620 if (new_entry != nullptr) {
621 add_to_module_path_entries(path, new_entry);
622 }
623 }
624
625 #endif // INCLUDE_CDS
626
627 void ClassLoader::close_jrt_image() {
628 // Not applicable for exploded builds
629 if (!ClassLoader::has_jrt_entry()) return;
630 _jrt_entry->close_jimage();
631 }
632
633 // Construct the array of module/path pairs as specified to --patch-module
634 // for the boot loader to search ahead of the jimage, if the class being
635 // loaded is defined to a module that has been specified to --patch-module.
636 void ClassLoader::setup_patch_mod_entries() {
637 JavaThread* current = JavaThread::current();
638 GrowableArray<ModulePatchPath*>* patch_mod_args = Arguments::get_patch_mod_prefix();
639 int num_of_entries = patch_mod_args->length();
640
641 // Set up the boot loader's _patch_mod_entries list
642 _patch_mod_entries = new (mtModule) GrowableArray<ModuleClassPathList*>(num_of_entries, mtModule);
643
644 for (int i = 0; i < num_of_entries; i++) {
645 const char* module_name = (patch_mod_args->at(i))->module_name();
646 Symbol* const module_sym = SymbolTable::new_symbol(module_name);
647 assert(module_sym != nullptr, "Failed to obtain Symbol for module name");
648 ModuleClassPathList* module_cpl = new ModuleClassPathList(module_sym);
649
650 char* class_path = (patch_mod_args->at(i))->path_string();
651 ResourceMark rm(current);
652 ClasspathStream cp_stream(class_path);
653
654 while (cp_stream.has_next()) {
655 const char* path = cp_stream.get_next();
656 struct stat st;
657 if (os::stat(path, &st) == 0) {
658 // File or directory found
659 ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
660 // If the path specification is valid, enter it into this module's list
661 if (new_entry != nullptr) {
662 module_cpl->add_to_list(new_entry);
663 }
664 }
665 }
666
667 // Record the module into the list of --patch-module entries only if
668 // valid ClassPathEntrys have been created
669 if (module_cpl->module_first_entry() != nullptr) {
670 _patch_mod_entries->push(module_cpl);
671 }
672 }
673 }
674
675 // Determine whether the module has been patched via the command-line
676 // option --patch-module
677 bool ClassLoader::is_in_patch_mod_entries(Symbol* module_name) {
678 if (_patch_mod_entries != nullptr && _patch_mod_entries->is_nonempty()) {
679 int table_len = _patch_mod_entries->length();
680 for (int i = 0; i < table_len; i++) {
681 ModuleClassPathList* patch_mod = _patch_mod_entries->at(i);
682 if (module_name->fast_compare(patch_mod->module_name()) == 0) {
683 return true;
684 }
685 }
686 }
687 return false;
688 }
689
690 // Set up the _jrt_entry if present and boot append path
691 void ClassLoader::setup_bootstrap_search_path_impl(JavaThread* current, const char *class_path) {
692 ResourceMark rm(current);
693 ClasspathStream cp_stream(class_path);
694 bool set_base_piece = true;
695
696 #if INCLUDE_CDS
697 if (CDSConfig::is_dumping_archive()) {
698 if (!Arguments::has_jimage()) {
699 vm_exit_during_initialization("CDS is not supported in exploded JDK build", nullptr);
700 }
701 }
702 #endif
703
704 while (cp_stream.has_next()) {
705 const char* path = cp_stream.get_next();
706
707 if (set_base_piece) {
708 // The first time through the bootstrap_search setup, it must be determined
709 // what the base or core piece of the boot loader search is. Either a java runtime
710 // image is present or this is an exploded module build situation.
711 assert(string_ends_with(path, MODULES_IMAGE_NAME) || string_ends_with(path, JAVA_BASE_NAME),
712 "Incorrect boot loader search path, no java runtime image or " JAVA_BASE_NAME " exploded build");
713 struct stat st;
714 if (os::stat(path, &st) == 0) {
715 // Directory found
716 if (JImage_file != nullptr) {
717 assert(Arguments::has_jimage(), "sanity check");
718 const char* canonical_path = get_canonical_path(path, current);
719 assert(canonical_path != nullptr, "canonical_path issue");
720
721 _jrt_entry = new ClassPathImageEntry(JImage_file, canonical_path);
722 assert(_jrt_entry != nullptr && _jrt_entry->is_modules_image(), "No java runtime image present");
723 assert(_jrt_entry->jimage() != nullptr, "No java runtime image");
724 } // else it's an exploded build.
725 } else {
726 // If path does not exist, exit
727 vm_exit_during_initialization("Unable to establish the boot loader search path", path);
728 }
729 set_base_piece = false;
730 } else {
731 // Every entry on the boot class path after the initial base piece,
732 // which is set by os::set_boot_path(), is considered an appended entry.
733 update_class_path_entry_list(current, path, /* check_for_duplicates */ false,
734 /* is_boot_append */ true, /* from_class_path_attr */ false);
735 }
736 }
737 }
738
739 // Gets the exploded path for the named module. The memory for the path
740 // is allocated on the C heap if `c_heap` is true otherwise in the resource area.
741 static const char* get_exploded_module_path(const char* module_name, bool c_heap) {
742 const char *home = Arguments::get_java_home();
743 const char file_sep = os::file_separator()[0];
744 // 10 represents the length of "modules" + 2 file separators + \0
745 size_t len = strlen(home) + strlen(module_name) + 10;
746 char *path = c_heap ? NEW_C_HEAP_ARRAY(char, len, mtModule) : NEW_RESOURCE_ARRAY(char, len);
747 jio_snprintf(path, len, "%s%cmodules%c%s", home, file_sep, file_sep, module_name);
748 return path;
749 }
750
751 // During an exploded modules build, each module defined to the boot loader
752 // will be added to the ClassLoader::_exploded_entries array.
753 void ClassLoader::add_to_exploded_build_list(JavaThread* current, Symbol* module_sym) {
754 assert(!ClassLoader::has_jrt_entry(), "Exploded build not applicable");
755 assert(_exploded_entries != nullptr, "_exploded_entries was not initialized");
756
757 // Find the module's symbol
758 ResourceMark rm(current);
759 const char *module_name = module_sym->as_C_string();
760 const char *path = get_exploded_module_path(module_name, false);
761
762 struct stat st;
763 if (os::stat(path, &st) == 0) {
764 // Directory found
765 ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
766
767 // If the path specification is valid, enter it into this module's list.
768 // There is no need to check for duplicate modules in the exploded entry list,
769 // since no two modules with the same name can be defined to the boot loader.
770 // This is checked at module definition time in Modules::define_module.
771 if (new_entry != nullptr) {
772 ModuleClassPathList* module_cpl = new ModuleClassPathList(module_sym);
773 module_cpl->add_to_list(new_entry);
774 {
775 MutexLocker ml(current, Module_lock);
776 _exploded_entries->push(module_cpl);
777 }
778 log_info(class, load)("path: %s", path);
779 }
780 }
781 }
782
783 jzfile* ClassLoader::open_zip_file(const char* canonical_path, char** error_msg, JavaThread* thread) {
784 // enable call to C land
785 ThreadToNativeFromVM ttn(thread);
786 HandleMark hm(thread);
787 return ZipLibrary::open(canonical_path, error_msg);
788 }
789
790 ClassPathEntry* ClassLoader::create_class_path_entry(JavaThread* current,
791 const char *path, const struct stat* st,
792 bool is_boot_append,
793 bool from_class_path_attr) {
794 ClassPathEntry* new_entry = nullptr;
795 if ((st->st_mode & S_IFMT) == S_IFREG) {
796 ResourceMark rm(current);
797 // Regular file, should be a zip file
798 // Canonicalized filename
799 const char* canonical_path = get_canonical_path(path, current);
800 if (canonical_path == nullptr) {
801 return nullptr;
802 }
803 char* error_msg = nullptr;
804 jzfile* zip = open_zip_file(canonical_path, &error_msg, current);
805 if (zip != nullptr && error_msg == nullptr) {
806 new_entry = new ClassPathZipEntry(zip, path, from_class_path_attr);
807 } else {
808 #if INCLUDE_CDS
809 ClassLoaderExt::set_has_non_jar_in_classpath();
810 #endif
811 return nullptr;
812 }
813 log_info(class, path)("opened: %s", path);
814 log_info(class, load)("opened: %s", path);
815 } else {
816 // Directory
817 new_entry = new ClassPathDirEntry(path);
818 log_info(class, load)("path: %s", path);
819 }
820 return new_entry;
821 }
822
823
824 // Create a class path zip entry for a given path (return null if not found
825 // or zip/JAR file cannot be opened)
826 ClassPathZipEntry* ClassLoader::create_class_path_zip_entry(const char *path) {
827 // check for a regular file
828 struct stat st;
829 if (os::stat(path, &st) == 0) {
830 if ((st.st_mode & S_IFMT) == S_IFREG) {
831 JavaThread* thread = JavaThread::current();
832 ResourceMark rm(thread);
833 const char* canonical_path = get_canonical_path(path, thread);
834 if (canonical_path != nullptr) {
835 char* error_msg = nullptr;
836 jzfile* zip = open_zip_file(canonical_path, &error_msg, thread);
837 if (zip != nullptr && error_msg == nullptr) {
838 // create using canonical path
839 return new ClassPathZipEntry(zip, canonical_path, false);
840 }
841 }
842 }
843 }
844 return nullptr;
845 }
846
847 // The boot append entries are added with a lock, and read lock free.
848 void ClassLoader::add_to_boot_append_entries(ClassPathEntry *new_entry) {
849 if (new_entry != nullptr) {
850 MutexLocker ml(Bootclasspath_lock, Mutex::_no_safepoint_check_flag);
851 if (_last_append_entry == nullptr) {
852 _last_append_entry = new_entry;
853 assert(first_append_entry() == nullptr, "boot loader's append class path entry list not empty");
854 Atomic::release_store(&_first_append_entry_list, new_entry);
855 } else {
856 _last_append_entry->set_next(new_entry);
857 _last_append_entry = new_entry;
858 }
859 }
860 }
861
862 // Record the path entries specified in -cp during dump time. The recorded
863 // information will be used at runtime for loading the archived app classes.
864 //
865 // Note that at dump time, ClassLoader::_app_classpath_entries are NOT used for
866 // loading app classes. Instead, the app class are loaded by the
867 // jdk/internal/loader/ClassLoaders$AppClassLoader instance.
868 bool ClassLoader::add_to_app_classpath_entries(JavaThread* current,
869 ClassPathEntry* entry,
870 bool check_for_duplicates) {
871 #if INCLUDE_CDS
872 assert(entry != nullptr, "ClassPathEntry should not be nullptr");
873 ClassPathEntry* e = _app_classpath_entries;
874 if (check_for_duplicates) {
875 while (e != nullptr) {
876 if (strcmp(e->name(), entry->name()) == 0) {
877 // entry already exists
878 return false;
879 }
880 e = e->next();
881 }
882 }
883
884 // The entry does not exist, add to the list
885 if (_app_classpath_entries == nullptr) {
886 assert(_last_app_classpath_entry == nullptr, "Sanity");
887 _app_classpath_entries = _last_app_classpath_entry = entry;
888 } else {
889 _last_app_classpath_entry->set_next(entry);
890 _last_app_classpath_entry = entry;
891 }
892
893 if (entry->is_jar_file()) {
894 ClassLoaderExt::process_jar_manifest(current, entry);
895 }
896 #endif
897 return true;
898 }
899
900 // Returns true IFF the file/dir exists and the entry was successfully created.
901 bool ClassLoader::update_class_path_entry_list(JavaThread* current,
902 const char *path,
903 bool check_for_duplicates,
904 bool is_boot_append,
905 bool from_class_path_attr) {
906 struct stat st;
907 if (os::stat(path, &st) == 0) {
908 // File or directory found
909 ClassPathEntry* new_entry = nullptr;
910 new_entry = create_class_path_entry(current, path, &st, is_boot_append, from_class_path_attr);
911 if (new_entry == nullptr) {
912 return false;
913 }
914
915 // Do not reorder the bootclasspath which would break get_system_package().
916 // Add new entry to linked list
917 if (is_boot_append) {
918 add_to_boot_append_entries(new_entry);
919 } else {
920 if (!add_to_app_classpath_entries(current, new_entry, check_for_duplicates)) {
921 // new_entry is not saved, free it now
922 delete new_entry;
923 }
924 }
925 return true;
926 } else {
927 return false;
928 }
929 }
930
931 static void print_module_entry_table(const GrowableArray<ModuleClassPathList*>* const module_list) {
932 ResourceMark rm;
933 int num_of_entries = module_list->length();
934 for (int i = 0; i < num_of_entries; i++) {
935 ClassPathEntry* e;
936 ModuleClassPathList* mpl = module_list->at(i);
937 tty->print("%s=", mpl->module_name()->as_C_string());
938 e = mpl->module_first_entry();
939 while (e != nullptr) {
940 tty->print("%s", e->name());
941 e = e->next();
942 if (e != nullptr) {
943 tty->print("%s", os::path_separator());
944 }
945 }
946 tty->print(" ;");
947 }
948 }
949
950 void ClassLoader::print_bootclasspath() {
951 ClassPathEntry* e;
952 tty->print("[bootclasspath= ");
953
954 // Print --patch-module module/path specifications first
955 if (_patch_mod_entries != nullptr) {
956 print_module_entry_table(_patch_mod_entries);
957 }
958
959 // [jimage | exploded modules build]
960 if (has_jrt_entry()) {
961 // Print the location of the java runtime image
962 tty->print("%s ;", _jrt_entry->name());
963 } else {
964 // Print exploded module build path specifications
965 if (_exploded_entries != nullptr) {
966 print_module_entry_table(_exploded_entries);
967 }
968 }
969
970 // appended entries
971 e = first_append_entry();
972 while (e != nullptr) {
973 tty->print("%s ;", e->name());
974 e = e->next();
975 }
976 tty->print_cr("]");
977 }
978
979 void* ClassLoader::dll_lookup(void* lib, const char* name, const char* path) {
980 void* func = os::dll_lookup(lib, name);
981 if (func == nullptr) {
982 char msg[256] = "";
983 jio_snprintf(msg, sizeof(msg), "Could not resolve \"%s\"", name);
984 vm_exit_during_initialization(msg, path);
985 }
986 return func;
987 }
988
989 void ClassLoader::load_java_library() {
990 assert(CanonicalizeEntry == nullptr, "should not load java library twice");
991 void *javalib_handle = os::native_java_library();
992 if (javalib_handle == nullptr) {
993 vm_exit_during_initialization("Unable to load java library", nullptr);
994 }
995
996 CanonicalizeEntry = CAST_TO_FN_PTR(canonicalize_fn_t, dll_lookup(javalib_handle, "JDK_Canonicalize", nullptr));
997 }
998
999 void ClassLoader::load_jimage_library() {
1000 assert(JImageOpen == nullptr, "should not load jimage library twice");
1001 char path[JVM_MAXPATHLEN];
1002 char ebuf[1024];
1003 void* handle = nullptr;
1004 if (os::dll_locate_lib(path, sizeof(path), Arguments::get_dll_dir(), "jimage")) {
1005 handle = os::dll_load(path, ebuf, sizeof ebuf);
1006 }
1007 if (handle == nullptr) {
1008 vm_exit_during_initialization("Unable to load jimage library", path);
1009 }
1010
1011 JImageOpen = CAST_TO_FN_PTR(JImageOpen_t, dll_lookup(handle, "JIMAGE_Open", path));
1012 JImageClose = CAST_TO_FN_PTR(JImageClose_t, dll_lookup(handle, "JIMAGE_Close", path));
1013 JImageFindResource = CAST_TO_FN_PTR(JImageFindResource_t, dll_lookup(handle, "JIMAGE_FindResource", path));
1014 JImageGetResource = CAST_TO_FN_PTR(JImageGetResource_t, dll_lookup(handle, "JIMAGE_GetResource", path));
1015 }
1016
1017 int ClassLoader::crc32(int crc, const char* buf, int len) {
1018 return ZipLibrary::crc32(crc, (const jbyte*)buf, len);
1019 }
1020
1021 oop ClassLoader::get_system_package(const char* name, TRAPS) {
1022 // Look up the name in the boot loader's package entry table.
1023 if (name != nullptr) {
1024 TempNewSymbol package_sym = SymbolTable::new_symbol(name);
1025 // Look for the package entry in the boot loader's package entry table.
1026 PackageEntry* package =
1027 ClassLoaderData::the_null_class_loader_data()->packages()->lookup_only(package_sym);
1028
1029 // Return null if package does not exist or if no classes in that package
1030 // have been loaded.
1031 if (package != nullptr && package->has_loaded_class()) {
1032 ModuleEntry* module = package->module();
1033 if (module->location() != nullptr) {
1034 ResourceMark rm(THREAD);
1035 Handle ml = java_lang_String::create_from_str(
1036 module->location()->as_C_string(), THREAD);
1037 return ml();
1038 }
1039 // Return entry on boot loader class path.
1040 Handle cph = java_lang_String::create_from_str(
1041 ClassLoader::classpath_entry(package->classpath_index())->name(), THREAD);
1042 return cph();
1043 }
1044 }
1045 return nullptr;
1046 }
1047
1048 objArrayOop ClassLoader::get_system_packages(TRAPS) {
1049 ResourceMark rm(THREAD);
1050 // List of pointers to PackageEntrys that have loaded classes.
1051 PackageEntryTable* pe_table =
1052 ClassLoaderData::the_null_class_loader_data()->packages();
1053 GrowableArray<PackageEntry*>* loaded_class_pkgs = pe_table->get_system_packages();
1054
1055 // Allocate objArray and fill with java.lang.String
1056 objArrayOop r = oopFactory::new_objArray(vmClasses::String_klass(),
1057 loaded_class_pkgs->length(), CHECK_NULL);
1058 objArrayHandle result(THREAD, r);
1059 for (int x = 0; x < loaded_class_pkgs->length(); x++) {
1060 PackageEntry* package_entry = loaded_class_pkgs->at(x);
1061 Handle str = java_lang_String::create_from_symbol(package_entry->name(), CHECK_NULL);
1062 result->obj_at_put(x, str());
1063 }
1064 return result();
1065 }
1066
1067 // caller needs ResourceMark
1068 const char* ClassLoader::file_name_for_class_name(const char* class_name,
1069 int class_name_len) {
1070 assert(class_name != nullptr, "invariant");
1071 assert((int)strlen(class_name) == class_name_len, "invariant");
1072
1073 static const char class_suffix[] = ".class";
1074 size_t class_suffix_len = sizeof(class_suffix);
1075
1076 char* const file_name = NEW_RESOURCE_ARRAY(char,
1077 class_name_len +
1078 class_suffix_len); // includes term null
1079
1080 strncpy(file_name, class_name, class_name_len);
1081 strncpy(&file_name[class_name_len], class_suffix, class_suffix_len);
1082
1083 return file_name;
1084 }
1085
1086 static ClassPathEntry* find_first_module_cpe(ModuleEntry* mod_entry,
1087 const GrowableArray<ModuleClassPathList*>* const module_list) {
1088 int num_of_entries = module_list->length();
1089 const Symbol* class_module_name = mod_entry->name();
1090
1091 // Loop through all the modules in either the patch-module or exploded entries looking for module
1092 for (int i = 0; i < num_of_entries; i++) {
1093 ModuleClassPathList* module_cpl = module_list->at(i);
1094 Symbol* module_cpl_name = module_cpl->module_name();
1095
1096 if (module_cpl_name->fast_compare(class_module_name) == 0) {
1097 // Class' module has been located.
1098 return module_cpl->module_first_entry();
1099 }
1100 }
1101 return nullptr;
1102 }
1103
1104
1105 // Search the module list for the class file stream based on the file name and java package
1106 ClassFileStream* ClassLoader::search_module_entries(JavaThread* current,
1107 const GrowableArray<ModuleClassPathList*>* const module_list,
1108 PackageEntry* pkg_entry, // Java package entry derived from the class name
1109 const char* const file_name) {
1110 ClassFileStream* stream = nullptr;
1111
1112 // Find the defining module in the boot loader's module entry table
1113 ModuleEntry* mod_entry = (pkg_entry != nullptr) ? pkg_entry->module() : nullptr;
1114
1115 // If the module system has not defined java.base yet, then
1116 // classes loaded are assumed to be defined to java.base.
1117 // When java.base is eventually defined by the module system,
1118 // all packages of classes that have been previously loaded
1119 // are verified in ModuleEntryTable::verify_javabase_packages().
1120 if (!Universe::is_module_initialized() &&
1121 !ModuleEntryTable::javabase_defined() &&
1122 mod_entry == nullptr) {
1123 mod_entry = ModuleEntryTable::javabase_moduleEntry();
1124 }
1125
1126 // The module must be a named module
1127 ClassPathEntry* e = nullptr;
1128 if (mod_entry != nullptr && mod_entry->is_named()) {
1129 if (module_list == _exploded_entries) {
1130 // The exploded build entries can be added to at any time so a lock is
1131 // needed when searching them.
1132 assert(!ClassLoader::has_jrt_entry(), "Must be exploded build");
1133 MutexLocker ml(current, Module_lock);
1134 e = find_first_module_cpe(mod_entry, module_list);
1135 } else {
1136 e = find_first_module_cpe(mod_entry, module_list);
1137 }
1138 }
1139
1140 // Try to load the class from the module's ClassPathEntry list.
1141 while (e != nullptr) {
1142 stream = e->open_stream(current, file_name);
1143 // No context.check is required since CDS is not supported
1144 // for an exploded modules build or if --patch-module is specified.
1145 if (nullptr != stream) {
1146 return stream;
1147 }
1148 e = e->next();
1149 }
1150 // If the module was located, break out even if the class was not
1151 // located successfully from that module's ClassPathEntry list.
1152 // There will not be another valid entry for that module.
1153 return nullptr;
1154 }
1155
1156 // Called by the boot classloader to load classes
1157 InstanceKlass* ClassLoader::load_class(Symbol* name, PackageEntry* pkg_entry, bool search_append_only, TRAPS) {
1158 assert(name != nullptr, "invariant");
1159
1160 ResourceMark rm(THREAD);
1161 HandleMark hm(THREAD);
1162
1163 const char* const class_name = name->as_C_string();
1164
1165 EventMarkClassLoading m("Loading class %s", class_name);
1166
1167 const char* const file_name = file_name_for_class_name(class_name,
1168 name->utf8_length());
1169 assert(file_name != nullptr, "invariant");
1170
1171 // Lookup stream for parsing .class file
1172 ClassFileStream* stream = nullptr;
1173 s2 classpath_index = 0;
1174 ClassPathEntry* e = nullptr;
1175
1176 // If search_append_only is true, boot loader visibility boundaries are
1177 // set to be _first_append_entry to the end. This includes:
1178 // [-Xbootclasspath/a]; [jvmti appended entries]
1179 //
1180 // If search_append_only is false, boot loader visibility boundaries are
1181 // set to be the --patch-module entries plus the base piece. This includes:
1182 // [--patch-module=<module>=<file>(<pathsep><file>)*]; [jimage | exploded module build]
1183 //
1184
1185 // Load Attempt #1: --patch-module
1186 // Determine the class' defining module. If it appears in the _patch_mod_entries,
1187 // attempt to load the class from those locations specific to the module.
1188 // Specifications to --patch-module can contain a partial number of classes
1189 // that are part of the overall module definition. So if a particular class is not
1190 // found within its module specification, the search should continue to Load Attempt #2.
1191 // Note: The --patch-module entries are never searched if the boot loader's
1192 // visibility boundary is limited to only searching the append entries.
1193 if (_patch_mod_entries != nullptr && !search_append_only) {
1194 assert(!CDSConfig::is_dumping_archive(), "CDS doesn't support --patch-module during dumping");
1195 stream = search_module_entries(THREAD, _patch_mod_entries, pkg_entry, file_name);
1196 }
1197
1198 // Load Attempt #2: [jimage | exploded build]
1199 if (!search_append_only && (nullptr == stream)) {
1200 if (has_jrt_entry()) {
1201 e = _jrt_entry;
1202 stream = _jrt_entry->open_stream(THREAD, file_name);
1203 } else {
1204 // Exploded build - attempt to locate class in its defining module's location.
1205 assert(_exploded_entries != nullptr, "No exploded build entries present");
1206 assert(!CDSConfig::is_dumping_archive(), "CDS dumping doesn't support exploded build");
1207 stream = search_module_entries(THREAD, _exploded_entries, pkg_entry, file_name);
1208 }
1209 }
1210
1211 // Load Attempt #3: [-Xbootclasspath/a]; [jvmti appended entries]
1212 if (search_append_only && (nullptr == stream)) {
1213 // For the boot loader append path search, the starting classpath_index
1214 // for the appended piece is always 1 to account for either the
1215 // _jrt_entry or the _exploded_entries.
1216 assert(classpath_index == 0, "The classpath_index has been incremented incorrectly");
1217 classpath_index = 1;
1218
1219 e = first_append_entry();
1220 while (e != nullptr) {
1221 stream = e->open_stream(THREAD, file_name);
1222 if (nullptr != stream) {
1223 break;
1224 }
1225 e = e->next();
1226 ++classpath_index;
1227 }
1228 }
1229
1230 if (nullptr == stream) {
1231 return nullptr;
1232 }
1233
1234 stream->set_verify(ClassLoaderExt::should_verify(classpath_index));
1235
1236 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
1237 Handle protection_domain;
1238 ClassLoadInfo cl_info(protection_domain);
1239
1240 InstanceKlass* result = KlassFactory::create_from_stream(stream,
1241 name,
1242 loader_data,
1243 cl_info,
1244 CHECK_NULL);
1245 result->set_classpath_index(classpath_index);
1246 return result;
1247 }
1248
1249 #if INCLUDE_CDS
1250 char* ClassLoader::skip_uri_protocol(char* source) {
1251 if (strncmp(source, "file:", 5) == 0) {
1252 // file: protocol path could start with file:/ or file:///
1253 // locate the char after all the forward slashes
1254 int offset = 5;
1255 while (*(source + offset) == '/') {
1256 offset++;
1257 }
1258 source += offset;
1259 // for non-windows platforms, move back one char as the path begins with a '/'
1260 #ifndef _WINDOWS
1261 source -= 1;
1262 #endif
1263 } else if (strncmp(source, "jrt:/", 5) == 0) {
1264 source += 5;
1265 }
1266 return source;
1267 }
1268
1269 // Record the shared classpath index and loader type for classes loaded
1270 // by the builtin loaders at dump time.
1271 void ClassLoader::record_result(JavaThread* current, InstanceKlass* ik,
1272 const ClassFileStream* stream, bool redefined) {
1273 assert(CDSConfig::is_dumping_archive(), "sanity");
1274 assert(stream != nullptr, "sanity");
1275
1276 if (ik->is_hidden()) {
1277 // We do not archive hidden classes.
1278 return;
1279 }
1280
1281 oop loader = ik->class_loader();
1282 char* src = (char*)stream->source();
1283 if (src == nullptr) {
1284 if (loader == nullptr) {
1285 // JFR classes
1286 ik->set_shared_classpath_index(0);
1287 ik->set_shared_class_loader_type(ClassLoader::BOOT_LOADER);
1288 }
1289 return;
1290 }
1291
1292 assert(has_jrt_entry(), "CDS dumping does not support exploded JDK build");
1293
1294 ResourceMark rm(current);
1295 int classpath_index = -1;
1296 PackageEntry* pkg_entry = ik->package();
1297
1298 if (FileMapInfo::get_number_of_shared_paths() > 0) {
1299 // Save the path from the file: protocol or the module name from the jrt: protocol
1300 // if no protocol prefix is found, path is the same as stream->source(). This path
1301 // must be valid since the class has been successfully parsed.
1302 char* path = skip_uri_protocol(src);
1303 assert(path != nullptr, "sanity");
1304 for (int i = 0; i < FileMapInfo::get_number_of_shared_paths(); i++) {
1305 SharedClassPathEntry* ent = FileMapInfo::shared_path(i);
1306 // A shared path has been validated during its creation in ClassLoader::create_class_path_entry(),
1307 // it must be valid here.
1308 assert(ent->name() != nullptr, "sanity");
1309 // If the path (from the class stream source) is the same as the shared
1310 // class or module path, then we have a match.
1311 // src may come from the App/Platform class loaders, which would canonicalize
1312 // the file name. We cannot use strcmp to check for equality against ent->name().
1313 // We must use os::same_files (which is faster than canonicalizing ent->name()).
1314 if (os::same_files(ent->name(), path)) {
1315 // null pkg_entry and pkg_entry in an unnamed module implies the class
1316 // is from the -cp or boot loader append path which consists of -Xbootclasspath/a
1317 // and jvmti appended entries.
1318 if ((pkg_entry == nullptr) || (pkg_entry->in_unnamed_module())) {
1319 // Ensure the index is within the -cp range before assigning
1320 // to the classpath_index.
1321 if (SystemDictionary::is_system_class_loader(loader) &&
1322 (i >= ClassLoaderExt::app_class_paths_start_index()) &&
1323 (i < ClassLoaderExt::app_module_paths_start_index())) {
1324 classpath_index = i;
1325 break;
1326 } else {
1327 if ((i >= 1) &&
1328 (i < ClassLoaderExt::app_class_paths_start_index())) {
1329 // The class must be from boot loader append path which consists of
1330 // -Xbootclasspath/a and jvmti appended entries.
1331 assert(loader == nullptr, "sanity");
1332 classpath_index = i;
1333 break;
1334 }
1335 }
1336 } else {
1337 // A class from a named module from the --module-path. Ensure the index is
1338 // within the --module-path range before assigning to the classpath_index.
1339 if ((pkg_entry != nullptr) && !(pkg_entry->in_unnamed_module()) && (i > 0)) {
1340 if (i >= ClassLoaderExt::app_module_paths_start_index() &&
1341 i < FileMapInfo::get_number_of_shared_paths()) {
1342 classpath_index = i;
1343 break;
1344 }
1345 }
1346 }
1347 }
1348 // for index 0 and the stream->source() is the modules image or has the jrt: protocol.
1349 // The class must be from the runtime modules image.
1350 if (i == 0 && (stream->from_boot_loader_modules_image() || string_starts_with(src, "jrt:"))) {
1351 classpath_index = i;
1352 break;
1353 }
1354 }
1355
1356 // No path entry found for this class: most likely a shared class loaded by the
1357 // user defined classloader.
1358 if (classpath_index < 0 && !SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
1359 assert(ik->shared_classpath_index() < 0, "not assigned yet");
1360 ik->set_shared_classpath_index(UNREGISTERED_INDEX);
1361 SystemDictionaryShared::set_shared_class_misc_info(ik, (ClassFileStream*)stream);
1362 return;
1363 }
1364 } else {
1365 // The shared path table is set up after module system initialization.
1366 // The path table contains no entry before that. Any classes loaded prior
1367 // to the setup of the shared path table must be from the modules image.
1368 assert(stream->from_boot_loader_modules_image(), "stream must be loaded by boot loader from modules image");
1369 assert(FileMapInfo::get_number_of_shared_paths() == 0, "shared path table must not have been setup");
1370 classpath_index = 0;
1371 }
1372
1373 const char* const class_name = ik->name()->as_C_string();
1374 const char* const file_name = file_name_for_class_name(class_name,
1375 ik->name()->utf8_length());
1376 assert(file_name != nullptr, "invariant");
1377 ClassLoaderExt::record_result(checked_cast<s2>(classpath_index), ik, redefined);
1378 }
1379 #endif // INCLUDE_CDS
1380
1381 // Initialize the class loader's access to methods in libzip. Parse and
1382 // process the boot classpath into a list ClassPathEntry objects. Once
1383 // this list has been created, it must not change order (see class PackageInfo)
1384 // it can be appended to and is by jvmti.
1385
1386 void ClassLoader::initialize(TRAPS) {
1387 if (UsePerfData) {
1388 // jvmstat performance counters
1389 NEWPERFTICKCOUNTER(_perf_accumulated_time, SUN_CLS, "time");
1390 NEWPERFTICKCOUNTER(_perf_class_init_time, SUN_CLS, "classInitTime");
1391 NEWPERFTICKCOUNTER(_perf_class_init_selftime, SUN_CLS, "classInitTime.self");
1392 NEWPERFTICKCOUNTER(_perf_class_verify_time, SUN_CLS, "classVerifyTime");
1393 NEWPERFTICKCOUNTER(_perf_class_verify_selftime, SUN_CLS, "classVerifyTime.self");
1394 NEWPERFTICKCOUNTER(_perf_class_link_time, SUN_CLS, "classLinkedTime");
1395 NEWPERFTICKCOUNTER(_perf_class_link_selftime, SUN_CLS, "classLinkedTime.self");
1396 NEWPERFEVENTCOUNTER(_perf_classes_inited, SUN_CLS, "initializedClasses");
1397 NEWPERFEVENTCOUNTER(_perf_classes_linked, SUN_CLS, "linkedClasses");
1398 NEWPERFEVENTCOUNTER(_perf_classes_verified, SUN_CLS, "verifiedClasses");
1399 NEWPERFEVENTCOUNTER(_perf_class_init_bytecodes_count, SUN_CLS, "clinitBytecodesCount");
1400
1401 NEWPERFTICKCOUNTER(_perf_shared_classload_time, SUN_CLS, "sharedClassLoadTime");
1402 NEWPERFTICKCOUNTER(_perf_sys_classload_time, SUN_CLS, "sysClassLoadTime");
1403 NEWPERFTICKCOUNTER(_perf_app_classload_time, SUN_CLS, "appClassLoadTime");
1404 NEWPERFTICKCOUNTER(_perf_app_classload_selftime, SUN_CLS, "appClassLoadTime.self");
1405 NEWPERFEVENTCOUNTER(_perf_app_classload_count, SUN_CLS, "appClassLoadCount");
1406 NEWPERFTICKCOUNTER(_perf_define_appclasses, SUN_CLS, "defineAppClasses");
1407 NEWPERFTICKCOUNTER(_perf_define_appclass_time, SUN_CLS, "defineAppClassTime");
1408 NEWPERFTICKCOUNTER(_perf_define_appclass_selftime, SUN_CLS, "defineAppClassTime.self");
1409 NEWPERFBYTECOUNTER(_perf_app_classfile_bytes_read, SUN_CLS, "appClassBytes");
1410 NEWPERFBYTECOUNTER(_perf_sys_classfile_bytes_read, SUN_CLS, "sysClassBytes");
1411 NEWPERFEVENTCOUNTER(_unsafe_defineClassCallCounter, SUN_CLS, "unsafeDefineClassCalls");
1412 NEWPERFTICKCOUNTER(_perf_secondary_hash_time, SUN_CLS, "secondarySuperHashTime");
1413
1414 if (log_is_enabled(Info, perf, class, link)) {
1415 NEWPERFTICKCOUNTER(_perf_preload_total_time, SUN_CLS, "preloadTotalTime");
1416 NEWPERFTICKCOUNTER(_perf_preload_time, SUN_CLS, "preloadTime");
1417 NEWPERFTICKCOUNTER(_perf_prelink_time, SUN_CLS, "prelinkTime");
1418 NEWPERFTICKCOUNTER(_perf_preinit_time, SUN_CLS, "preinitTime");
1419 NEWPERFTICKCOUNTER(_perf_preresolve_time, SUN_CLS, "preresolveTime");
1420
1421 NEWPERFTICKCOUNTER(_perf_ik_link_methods_time, SUN_CLS, "linkMethodsTime");
1422 NEWPERFTICKCOUNTER(_perf_method_adapters_time, SUN_CLS, "makeAdaptersTime");
1423 NEWPERFEVENTCOUNTER(_perf_ik_link_methods_count, SUN_CLS, "linkMethodsCount");
1424 NEWPERFEVENTCOUNTER(_perf_method_adapters_count, SUN_CLS, "makeAdaptersCount");
1425
1426 NEWPERFTICKCOUNTERS(_perf_resolve_indy_time, SUN_CLS, "resolve_invokedynamic_time");
1427 NEWPERFTICKCOUNTERS(_perf_resolve_invokehandle_time, SUN_CLS, "resolve_invokehandle_time");
1428 NEWPERFTICKCOUNTERS(_perf_resolve_mh_time, SUN_CLS, "resolve_MethodHandle_time");
1429 NEWPERFTICKCOUNTERS(_perf_resolve_mt_time, SUN_CLS, "resolve_MethodType_time");
1430
1431 NEWPERFEVENTCOUNTER(_perf_resolve_indy_count, SUN_CLS, "resolve_invokedynamic_count");
1432 NEWPERFEVENTCOUNTER(_perf_resolve_invokehandle_count, SUN_CLS, "resolve_invokehandle_count");
1433 NEWPERFEVENTCOUNTER(_perf_resolve_mh_count, SUN_CLS, "resolve_MethodHandle_count");
1434 NEWPERFEVENTCOUNTER(_perf_resolve_mt_count, SUN_CLS, "resolve_MethodType_count");
1435 }
1436 }
1437
1438 // lookup java library entry points
1439 load_java_library();
1440 // jimage library entry points are loaded below, in lookup_vm_options
1441 setup_bootstrap_search_path(THREAD);
1442 }
1443
1444 static char* lookup_vm_resource(JImageFile *jimage, const char *jimage_version, const char *path) {
1445 jlong size;
1446 JImageLocationRef location = (*JImageFindResource)(jimage, "java.base", jimage_version, path, &size);
1447 if (location == 0)
1448 return nullptr;
1449 char *val = NEW_C_HEAP_ARRAY(char, size+1, mtClass);
1450 (*JImageGetResource)(jimage, location, val, size);
1451 val[size] = '\0';
1452 return val;
1453 }
1454
1455 // Lookup VM options embedded in the modules jimage file
1456 char* ClassLoader::lookup_vm_options() {
1457 jint error;
1458 char modules_path[JVM_MAXPATHLEN];
1459 const char* fileSep = os::file_separator();
1460
1461 // Initialize jimage library entry points
1462 load_jimage_library();
1463
1464 jio_snprintf(modules_path, JVM_MAXPATHLEN, "%s%slib%smodules", Arguments::get_java_home(), fileSep, fileSep);
1465 JImage_file =(*JImageOpen)(modules_path, &error);
1466 if (JImage_file == nullptr) {
1467 return nullptr;
1468 }
1469
1470 const char *jimage_version = get_jimage_version_string();
1471 char *options = lookup_vm_resource(JImage_file, jimage_version, "jdk/internal/vm/options");
1472 return options;
1473 }
1474
1475 bool ClassLoader::is_module_observable(const char* module_name) {
1476 assert(JImageOpen != nullptr, "jimage library should have been opened");
1477 if (JImage_file == nullptr) {
1478 struct stat st;
1479 const char *path = get_exploded_module_path(module_name, true);
1480 bool res = os::stat(path, &st) == 0;
1481 FREE_C_HEAP_ARRAY(char, path);
1482 return res;
1483 }
1484 jlong size;
1485 const char *jimage_version = get_jimage_version_string();
1486 return (*JImageFindResource)(JImage_file, module_name, jimage_version, "module-info.class", &size) != 0;
1487 }
1488
1489 #if INCLUDE_CDS
1490 void ClassLoader::initialize_shared_path(JavaThread* current) {
1491 if (CDSConfig::is_dumping_archive()) {
1492 ClassLoaderExt::setup_search_paths(current);
1493 }
1494 }
1495
1496 void ClassLoader::initialize_module_path(TRAPS) {
1497 if (CDSConfig::is_dumping_archive()) {
1498 ClassLoaderExt::setup_module_paths(THREAD);
1499 FileMapInfo::allocate_shared_path_table(CHECK);
1500 }
1501 }
1502
1503 // Helper function used by CDS code to get the number of module path
1504 // entries during shared classpath setup time.
1505 int ClassLoader::num_module_path_entries() {
1506 assert(CDSConfig::is_dumping_archive(), "sanity");
1507 int num_entries = 0;
1508 ClassPathEntry* e= ClassLoader::_module_path_entries;
1509 while (e != nullptr) {
1510 num_entries ++;
1511 e = e->next();
1512 }
1513 return num_entries;
1514 }
1515 #endif
1516
1517 jlong ClassLoader::classloader_time_ms() {
1518 return UsePerfData ?
1519 Management::ticks_to_ms(_perf_accumulated_time->get_value()) : -1;
1520 }
1521
1522 jlong ClassLoader::class_init_bytecodes_count() {
1523 return UsePerfData ? _perf_class_init_bytecodes_count->get_value() : -1;
1524 }
1525
1526 jlong ClassLoader::class_init_count() {
1527 return UsePerfData ? _perf_classes_inited->get_value() : -1;
1528 }
1529
1530 jlong ClassLoader::class_init_time_ms() {
1531 return UsePerfData ?
1532 Management::ticks_to_ms(_perf_class_init_time->get_value()) : -1;
1533 }
1534
1535 jlong ClassLoader::class_verify_time_ms() {
1536 return UsePerfData ?
1537 Management::ticks_to_ms(_perf_class_verify_time->get_value()) : -1;
1538 }
1539
1540 jlong ClassLoader::class_link_count() {
1541 return UsePerfData ? _perf_classes_linked->get_value() : -1;
1542 }
1543
1544 jlong ClassLoader::class_link_time_ms() {
1545 return UsePerfData ?
1546 Management::ticks_to_ms(_perf_class_link_time->get_value()) : -1;
1547 }
1548
1549 int ClassLoader::compute_Object_vtable() {
1550 // hardwired for JDK1.2 -- would need to duplicate class file parsing
1551 // code to determine actual value from file
1552 // Would be value '11' if finals were in vtable
1553 int JDK_1_2_Object_vtable_size = 5;
1554 return JDK_1_2_Object_vtable_size * vtableEntry::size();
1555 }
1556
1557
1558 void classLoader_init1() {
1559 EXCEPTION_MARK;
1560 ClassLoader::initialize(THREAD);
1561 if (HAS_PENDING_EXCEPTION) {
1562 vm_exit_during_initialization("ClassLoader::initialize() failed unexpectedly");
1563 }
1564 }
1565
1566 // Complete the ClassPathEntry setup for the boot loader
1567 void ClassLoader::classLoader_init2(JavaThread* current) {
1568 // Setup the list of module/path pairs for --patch-module processing
1569 // This must be done after the SymbolTable is created in order
1570 // to use fast_compare on module names instead of a string compare.
1571 if (Arguments::get_patch_mod_prefix() != nullptr) {
1572 setup_patch_mod_entries();
1573 }
1574
1575 // Create the ModuleEntry for java.base (must occur after setup_patch_mod_entries
1576 // to successfully determine if java.base has been patched)
1577 create_javabase();
1578
1579 // Setup the initial java.base/path pair for the exploded build entries.
1580 // As more modules are defined during module system initialization, more
1581 // entries will be added to the exploded build array.
1582 if (!has_jrt_entry()) {
1583 assert(!CDSConfig::is_dumping_archive(), "not supported with exploded module builds");
1584 assert(!CDSConfig::is_using_archive(), "UsedSharedSpaces not supported with exploded module builds");
1585 // Set up the boot loader's _exploded_entries list. Note that this gets
1586 // done before loading any classes, by the same thread that will
1587 // subsequently do the first class load. So, no lock is needed for this.
1588 assert(_exploded_entries == nullptr, "Should only get initialized once");
1589 _exploded_entries = new (mtModule)
1590 GrowableArray<ModuleClassPathList*>(EXPLODED_ENTRY_SIZE, mtModule);
1591 add_to_exploded_build_list(current, vmSymbols::java_base());
1592 }
1593 }
1594
1595 char* ClassLoader::get_canonical_path(const char* orig, Thread* thread) {
1596 assert(orig != nullptr, "bad arguments");
1597 // caller needs to allocate ResourceMark for the following output buffer
1598 char* canonical_path = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, JVM_MAXPATHLEN);
1599 ResourceMark rm(thread);
1600 // os::native_path writes into orig_copy
1601 char* orig_copy = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, strlen(orig)+1);
1602 strcpy(orig_copy, orig);
1603 if ((CanonicalizeEntry)(os::native_path(orig_copy), canonical_path, JVM_MAXPATHLEN) < 0) {
1604 return nullptr;
1605 }
1606 return canonical_path;
1607 }
1608
1609 void ClassLoader::create_javabase() {
1610 JavaThread* current = JavaThread::current();
1611
1612 // Create java.base's module entry for the boot
1613 // class loader prior to loading j.l.Object.
1614 ClassLoaderData* null_cld = ClassLoaderData::the_null_class_loader_data();
1615
1616 // Get module entry table
1617 ModuleEntryTable* null_cld_modules = null_cld->modules();
1618 if (null_cld_modules == nullptr) {
1619 vm_exit_during_initialization("No ModuleEntryTable for the boot class loader");
1620 }
1621
1622 {
1623 MutexLocker ml(current, Module_lock);
1624 if (ModuleEntryTable::javabase_moduleEntry() == nullptr) { // may have been inited by CDS.
1625 ModuleEntry* jb_module = null_cld_modules->locked_create_entry(Handle(),
1626 false, vmSymbols::java_base(), nullptr, nullptr, null_cld);
1627 if (jb_module == nullptr) {
1628 vm_exit_during_initialization("Unable to create ModuleEntry for " JAVA_BASE_NAME);
1629 }
1630 ModuleEntryTable::set_javabase_moduleEntry(jb_module);
1631 }
1632 }
1633 }
1634
1635 // Please keep following two functions at end of this file. With them placed at top or in middle of the file,
1636 // they could get inlined by aggressive compiler, an unknown trick, see bug 6966589.
1637 void PerfClassTraceTime::initialize() {
1638 if (!UsePerfData) return;
1639
1640 if (_eventp != nullptr) {
1641 // increment the event counter
1642 _eventp->inc();
1643 }
1644
1645 // stop the current active thread-local timer to measure inclusive time
1646 _prev_active_event = -1;
1647 for (int i=0; i < EVENT_TYPE_COUNT; i++) {
1648 if (_timers[i].is_active()) {
1649 assert(_prev_active_event == -1, "should have only one active timer");
1650 _prev_active_event = i;
1651 _timers[i].stop();
1652 }
1653 }
1654
1655 if (_recursion_counters == nullptr || (_recursion_counters[_event_type])++ == 0) {
1656 // start the inclusive timer if not recursively called
1657 _t.start();
1658 }
1659
1660 // start thread-local timer of the given event type
1661 if (!_timers[_event_type].is_active()) {
1662 _timers[_event_type].start();
1663 }
1664 }
1665
1666 PerfClassTraceTime::~PerfClassTraceTime() {
1667 if (!UsePerfData) return;
1668
1669 // stop the thread-local timer as the event completes
1670 // and resume the thread-local timer of the event next on the stack
1671 _timers[_event_type].stop();
1672 jlong selftime = _timers[_event_type].ticks();
1673
1674 if (_prev_active_event >= 0) {
1675 _timers[_prev_active_event].start();
1676 }
1677
1678 if (_recursion_counters != nullptr && --(_recursion_counters[_event_type]) > 0) return;
1679
1680 // increment the counters only on the leaf call
1681 _t.stop();
1682 _timep->inc(_t.ticks());
1683 if (_selftimep != nullptr) {
1684 _selftimep->inc(selftime);
1685 }
1686 // add all class loading related event selftime to the accumulated time counter
1687 ClassLoader::perf_accumulated_time()->inc(selftime);
1688
1689 // reset the timer
1690 _timers[_event_type].reset();
1691 }