1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "cds/cds_globals.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/filemap.hpp"
29 #include "cds/heapShared.hpp"
30 #include "classfile/classFileStream.hpp"
31 #include "classfile/classLoader.inline.hpp"
32 #include "classfile/classLoaderData.inline.hpp"
33 #include "classfile/classLoaderExt.hpp"
34 #include "classfile/classLoadInfo.hpp"
35 #include "classfile/javaClasses.hpp"
36 #include "classfile/klassFactory.hpp"
37 #include "classfile/moduleEntry.hpp"
38 #include "classfile/modules.hpp"
39 #include "classfile/packageEntry.hpp"
40 #include "classfile/symbolTable.hpp"
41 #include "classfile/systemDictionary.hpp"
42 #include "classfile/systemDictionaryShared.hpp"
43 #include "classfile/vmClasses.hpp"
44 #include "classfile/vmSymbols.hpp"
45 #include "compiler/compileBroker.hpp"
46 #include "interpreter/bytecodeStream.hpp"
47 #include "interpreter/oopMapCache.hpp"
48 #include "jimage.hpp"
49 #include "jvm.h"
50 #include "logging/log.hpp"
51 #include "logging/logStream.hpp"
52 #include "logging/logTag.hpp"
53 #include "memory/allocation.inline.hpp"
54 #include "memory/oopFactory.hpp"
55 #include "memory/resourceArea.hpp"
56 #include "memory/universe.hpp"
57 #include "oops/instanceKlass.hpp"
58 #include "oops/instanceRefKlass.hpp"
59 #include "oops/klass.inline.hpp"
60 #include "oops/method.inline.hpp"
61 #include "oops/objArrayOop.inline.hpp"
62 #include "oops/oop.inline.hpp"
63 #include "oops/symbol.hpp"
64 #include "prims/jvm_misc.hpp"
65 #include "runtime/arguments.hpp"
66 #include "runtime/handles.inline.hpp"
67 #include "runtime/init.hpp"
68 #include "runtime/interfaceSupport.inline.hpp"
69 #include "runtime/java.hpp"
70 #include "runtime/javaCalls.hpp"
71 #include "runtime/os.hpp"
72 #include "runtime/perfData.hpp"
73 #include "runtime/threadCritical.hpp"
74 #include "runtime/timer.hpp"
75 #include "runtime/vm_version.hpp"
76 #include "services/management.hpp"
77 #include "services/threadService.hpp"
78 #include "utilities/checkedCast.hpp"
79 #include "utilities/classpathStream.hpp"
80 #include "utilities/events.hpp"
81 #include "utilities/macros.hpp"
82 #include "utilities/ostream.hpp"
83 #include "utilities/utf8.hpp"
84
85 #include <stdlib.h>
86 #include <ctype.h>
87
88 // Entry point in java.dll for path canonicalization
89
90 typedef int (*canonicalize_fn_t)(const char *orig, char *out, int len);
91
92 static canonicalize_fn_t CanonicalizeEntry = nullptr;
93
94 // Entry points for jimage.dll for loading jimage file entries
95
96 static JImageOpen_t JImageOpen = nullptr;
97 static JImageClose_t JImageClose = nullptr;
98 static JImageFindResource_t JImageFindResource = nullptr;
99 static JImageGetResource_t JImageGetResource = nullptr;
100
101 // JimageFile pointer, or null if exploded JDK build.
102 static JImageFile* JImage_file = nullptr;
103
104 // Globals
105
106 PerfCounter* ClassLoader::_perf_accumulated_time = nullptr;
107 PerfCounter* ClassLoader::_perf_classes_inited = nullptr;
108 PerfCounter* ClassLoader::_perf_class_init_time = nullptr;
109 PerfCounter* ClassLoader::_perf_class_init_selftime = nullptr;
110 PerfCounter* ClassLoader::_perf_classes_verified = nullptr;
111 PerfCounter* ClassLoader::_perf_class_verify_time = nullptr;
112 PerfCounter* ClassLoader::_perf_class_verify_selftime = nullptr;
113 PerfCounter* ClassLoader::_perf_classes_linked = nullptr;
114 PerfCounter* ClassLoader::_perf_class_link_time = nullptr;
115 PerfCounter* ClassLoader::_perf_class_link_selftime = nullptr;
116 PerfCounter* ClassLoader::_perf_shared_classload_time = nullptr;
117 PerfCounter* ClassLoader::_perf_sys_classload_time = nullptr;
118 PerfCounter* ClassLoader::_perf_app_classload_time = nullptr;
119 PerfCounter* ClassLoader::_perf_app_classload_selftime = nullptr;
120 PerfCounter* ClassLoader::_perf_app_classload_count = nullptr;
121 PerfCounter* ClassLoader::_perf_define_appclasses = nullptr;
122 PerfCounter* ClassLoader::_perf_define_appclass_time = nullptr;
123 PerfCounter* ClassLoader::_perf_define_appclass_selftime = nullptr;
124 PerfCounter* ClassLoader::_perf_app_classfile_bytes_read = nullptr;
125 PerfCounter* ClassLoader::_perf_sys_classfile_bytes_read = nullptr;
126 PerfCounter* ClassLoader::_perf_ik_link_methods_time = nullptr;
127 PerfCounter* ClassLoader::_perf_method_adapters_time = nullptr;
128 PerfCounter* ClassLoader::_perf_ik_link_methods_count = nullptr;
129 PerfCounter* ClassLoader::_perf_method_adapters_count = nullptr;
130 PerfCounter* ClassLoader::_unsafe_defineClassCallCounter = nullptr;
131 PerfCounter* ClassLoader::_perf_secondary_hash_time = nullptr;
132
133 PerfCounter* ClassLoader::_perf_resolve_indy_time = nullptr;
134 PerfCounter* ClassLoader::_perf_resolve_invokehandle_time = nullptr;
135 PerfCounter* ClassLoader::_perf_resolve_mh_time = nullptr;
136 PerfCounter* ClassLoader::_perf_resolve_mt_time = nullptr;
137
138 PerfCounter* ClassLoader::_perf_resolve_indy_count = nullptr;
139 PerfCounter* ClassLoader::_perf_resolve_invokehandle_count = nullptr;
140 PerfCounter* ClassLoader::_perf_resolve_mh_count = nullptr;
141 PerfCounter* ClassLoader::_perf_resolve_mt_count = nullptr;
142
143 void ClassLoader::print_counters(outputStream *st) {
144 st->print_cr("ClassLoader:");
145 st->print_cr(" clinit: " JLONG_FORMAT "ms / " JLONG_FORMAT " events", ClassLoader::class_init_time_ms(), ClassLoader::class_init_count());
146 st->print_cr(" link methods: " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_ik_link_methods_time->get_value()) , _perf_ik_link_methods_count->get_value());
147 st->print_cr(" method adapters: " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_method_adapters_time->get_value()) , _perf_method_adapters_count->get_value());
148 st->print_cr(" resolve...");
149 st->print_cr(" invokedynamic: " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_resolve_indy_time->get_value()) , _perf_resolve_indy_count->get_value());
150 st->print_cr(" invokehandle: " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_resolve_invokehandle_time->get_value()) , _perf_resolve_invokehandle_count->get_value());
151 st->print_cr(" CP_MethodHandle: " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_resolve_mh_time->get_value()) , _perf_resolve_mh_count->get_value());
152 st->print_cr(" CP_MethodType: " JLONG_FORMAT "ms / " JLONG_FORMAT " events", Management::ticks_to_ms(_perf_resolve_mt_time->get_value()) , _perf_resolve_mt_count->get_value());
153 st->cr();
154 }
155
156 GrowableArray<ModuleClassPathList*>* ClassLoader::_patch_mod_entries = nullptr;
157 GrowableArray<ModuleClassPathList*>* ClassLoader::_exploded_entries = nullptr;
158 ClassPathEntry* ClassLoader::_jrt_entry = nullptr;
159
160 ClassPathEntry* volatile ClassLoader::_first_append_entry_list = nullptr;
161 ClassPathEntry* volatile ClassLoader::_last_append_entry = nullptr;
162 #if INCLUDE_CDS
163 ClassPathEntry* ClassLoader::_app_classpath_entries = nullptr;
164 ClassPathEntry* ClassLoader::_last_app_classpath_entry = nullptr;
165 ClassPathEntry* ClassLoader::_module_path_entries = nullptr;
166 ClassPathEntry* ClassLoader::_last_module_path_entry = nullptr;
167 #endif
168
169 // helper routines
170 #if INCLUDE_CDS
171 static bool string_starts_with(const char* str, const char* str_to_find) {
172 size_t str_len = strlen(str);
173 size_t str_to_find_len = strlen(str_to_find);
174 if (str_to_find_len > str_len) {
175 return false;
176 }
177 return (strncmp(str, str_to_find, str_to_find_len) == 0);
178 }
179 #endif
180
181 static const char* get_jimage_version_string() {
182 static char version_string[10] = "";
183 if (version_string[0] == '\0') {
184 jio_snprintf(version_string, sizeof(version_string), "%d.%d",
185 VM_Version::vm_major_version(), VM_Version::vm_minor_version());
186 }
187 return (const char*)version_string;
188 }
189
190 bool ClassLoader::string_ends_with(const char* str, const char* str_to_find) {
191 size_t str_len = strlen(str);
192 size_t str_to_find_len = strlen(str_to_find);
193 if (str_to_find_len > str_len) {
194 return false;
195 }
196 return (strncmp(str + (str_len - str_to_find_len), str_to_find, str_to_find_len) == 0);
197 }
198
199 // Used to obtain the package name from a fully qualified class name.
200 Symbol* ClassLoader::package_from_class_name(const Symbol* name, bool* bad_class_name) {
201 if (name == nullptr) {
202 if (bad_class_name != nullptr) {
203 *bad_class_name = true;
204 }
205 return nullptr;
206 }
207
208 int utf_len = name->utf8_length();
209 const jbyte* base = (const jbyte*)name->base();
210 const jbyte* start = base;
211 const jbyte* end = UTF8::strrchr(start, utf_len, JVM_SIGNATURE_SLASH);
212 if (end == nullptr) {
213 return nullptr;
214 }
215 // Skip over '['s
216 if (*start == JVM_SIGNATURE_ARRAY) {
217 do {
218 start++;
219 } while (start < end && *start == JVM_SIGNATURE_ARRAY);
220
221 // Fully qualified class names should not contain a 'L'.
222 // Set bad_class_name to true to indicate that the package name
223 // could not be obtained due to an error condition.
224 // In this situation, is_same_class_package returns false.
225 if (*start == JVM_SIGNATURE_CLASS) {
226 if (bad_class_name != nullptr) {
227 *bad_class_name = true;
228 }
229 return nullptr;
230 }
231 }
232 // A class name could have just the slash character in the name,
233 // in which case start > end
234 if (start >= end) {
235 // No package name
236 if (bad_class_name != nullptr) {
237 *bad_class_name = true;
238 }
239 return nullptr;
240 }
241 return SymbolTable::new_symbol(name, pointer_delta_as_int(start, base), pointer_delta_as_int(end, base));
242 }
243
244 // Given a fully qualified package name, find its defining package in the class loader's
245 // package entry table.
246 PackageEntry* ClassLoader::get_package_entry(Symbol* pkg_name, ClassLoaderData* loader_data) {
247 if (pkg_name == nullptr) {
248 return nullptr;
249 }
250 PackageEntryTable* pkgEntryTable = loader_data->packages();
251 return pkgEntryTable->lookup_only(pkg_name);
252 }
253
254 const char* ClassPathEntry::copy_path(const char* path) {
255 char* copy = NEW_C_HEAP_ARRAY(char, strlen(path)+1, mtClass);
256 strcpy(copy, path);
257 return copy;
258 }
259
260 ClassPathDirEntry::~ClassPathDirEntry() {
261 FREE_C_HEAP_ARRAY(char, _dir);
262 }
263
264 ClassFileStream* ClassPathDirEntry::open_stream(JavaThread* current, const char* name) {
265 // construct full path name
266 assert((_dir != nullptr) && (name != nullptr), "sanity");
267 size_t path_len = strlen(_dir) + strlen(name) + strlen(os::file_separator()) + 1;
268 char* path = NEW_RESOURCE_ARRAY_IN_THREAD(current, char, path_len);
269 int len = jio_snprintf(path, path_len, "%s%s%s", _dir, os::file_separator(), name);
270 assert(len == (int)(path_len - 1), "sanity");
271 // check if file exists
272 struct stat st;
273 if (os::stat(path, &st) == 0) {
274 // found file, open it
275 int file_handle = os::open(path, 0, 0);
276 if (file_handle != -1) {
277 // read contents into resource array
278 u1* buffer = NEW_RESOURCE_ARRAY_IN_THREAD(current, u1, st.st_size);
279 size_t num_read = ::read(file_handle, (char*) buffer, st.st_size);
280 // close file
281 ::close(file_handle);
282 // construct ClassFileStream
283 if (num_read == (size_t)st.st_size) {
284 if (UsePerfData) {
285 ClassLoader::perf_sys_classfile_bytes_read()->inc(num_read);
286 }
287 #ifdef ASSERT
288 // Freeing path is a no-op here as buffer prevents it from being reclaimed. But we keep it for
289 // debug builds so that we guard against use-after-free bugs.
290 FREE_RESOURCE_ARRAY_IN_THREAD(current, char, path, path_len);
291 #endif
292 // We don't verify the length of the classfile stream fits in an int, but this is the
293 // bootloader so we have control of this.
294 // Resource allocated
295 return new ClassFileStream(buffer,
296 checked_cast<int>(st.st_size),
297 _dir);
298 }
299 }
300 }
301 FREE_RESOURCE_ARRAY_IN_THREAD(current, char, path, path_len);
302 return nullptr;
303 }
304
305 ClassPathZipEntry::ClassPathZipEntry(jzfile* zip, const char* zip_name,
306 bool is_boot_append, bool from_class_path_attr) : ClassPathEntry() {
307 _zip = zip;
308 _zip_name = copy_path(zip_name);
309 _from_class_path_attr = from_class_path_attr;
310 }
311
312 ClassPathZipEntry::~ClassPathZipEntry() {
313 ZipLibrary::close(_zip);
314 FREE_C_HEAP_ARRAY(char, _zip_name);
315 }
316
317 u1* ClassPathZipEntry::open_entry(JavaThread* current, const char* name, jint* filesize, bool nul_terminate) {
318 // enable call to C land
319 ThreadToNativeFromVM ttn(current);
320 // check whether zip archive contains name
321 jint name_len;
322 jzentry* entry = ZipLibrary::find_entry(_zip, name, filesize, &name_len);
323 if (entry == nullptr) return nullptr;
324 u1* buffer;
325 char name_buf[128];
326 char* filename;
327 if (name_len < 128) {
328 filename = name_buf;
329 } else {
330 filename = NEW_RESOURCE_ARRAY(char, name_len + 1);
331 }
332
333 // read contents into resource array
334 size_t size = (uint32_t)(*filesize);
335 if (nul_terminate) {
336 if (sizeof(size) == sizeof(uint32_t) && size == UINT_MAX) {
337 return nullptr; // 32-bit integer overflow will occur.
338 }
339 size++;
340 }
341 buffer = NEW_RESOURCE_ARRAY(u1, size);
342 if (!ZipLibrary::read_entry(_zip, entry, buffer, filename)) {
343 return nullptr;
344 }
345
346 // return result
347 if (nul_terminate) {
348 buffer[size - 1] = 0;
349 }
350 return buffer;
351 }
352
353 ClassFileStream* ClassPathZipEntry::open_stream(JavaThread* current, const char* name) {
354 jint filesize;
355 u1* buffer = open_entry(current, name, &filesize, false);
356 if (buffer == nullptr) {
357 return nullptr;
358 }
359 if (UsePerfData) {
360 ClassLoader::perf_sys_classfile_bytes_read()->inc(filesize);
361 }
362 // Resource allocated
363 return new ClassFileStream(buffer,
364 filesize,
365 _zip_name);
366 }
367
368 DEBUG_ONLY(ClassPathImageEntry* ClassPathImageEntry::_singleton = nullptr;)
369
370 JImageFile* ClassPathImageEntry::jimage() const {
371 return JImage_file;
372 }
373
374 JImageFile* ClassPathImageEntry::jimage_non_null() const {
375 assert(ClassLoader::has_jrt_entry(), "must be");
376 assert(jimage() != nullptr, "should have been opened by ClassLoader::lookup_vm_options "
377 "and remained throughout normal JVM lifetime");
378 return jimage();
379 }
380
381 void ClassPathImageEntry::close_jimage() {
382 if (jimage() != nullptr) {
383 (*JImageClose)(jimage());
384 JImage_file = nullptr;
385 }
386 }
387
388 ClassPathImageEntry::ClassPathImageEntry(JImageFile* jimage, const char* name) :
389 ClassPathEntry() {
390 guarantee(jimage != nullptr, "jimage file is null");
391 guarantee(name != nullptr, "jimage file name is null");
392 assert(_singleton == nullptr, "VM supports only one jimage");
393 DEBUG_ONLY(_singleton = this);
394 size_t len = strlen(name) + 1;
395 _name = copy_path(name);
396 }
397
398 ClassFileStream* ClassPathImageEntry::open_stream(JavaThread* current, const char* name) {
399 return open_stream_for_loader(current, name, ClassLoaderData::the_null_class_loader_data());
400 }
401
402 // For a class in a named module, look it up in the jimage file using this syntax:
403 // /<module-name>/<package-name>/<base-class>
404 //
405 // Assumptions:
406 // 1. There are no unnamed modules in the jimage file.
407 // 2. A package is in at most one module in the jimage file.
408 //
409 ClassFileStream* ClassPathImageEntry::open_stream_for_loader(JavaThread* current, const char* name, ClassLoaderData* loader_data) {
410 jlong size;
411 JImageLocationRef location = (*JImageFindResource)(jimage_non_null(), "", get_jimage_version_string(), name, &size);
412
413 if (location == 0) {
414 TempNewSymbol class_name = SymbolTable::new_symbol(name);
415 TempNewSymbol pkg_name = ClassLoader::package_from_class_name(class_name);
416
417 if (pkg_name != nullptr) {
418 if (!Universe::is_module_initialized()) {
419 location = (*JImageFindResource)(jimage_non_null(), JAVA_BASE_NAME, get_jimage_version_string(), name, &size);
420 } else {
421 PackageEntry* package_entry = ClassLoader::get_package_entry(pkg_name, loader_data);
422 if (package_entry != nullptr) {
423 ResourceMark rm(current);
424 // Get the module name
425 ModuleEntry* module = package_entry->module();
426 assert(module != nullptr, "Boot classLoader package missing module");
427 assert(module->is_named(), "Boot classLoader package is in unnamed module");
428 const char* module_name = module->name()->as_C_string();
429 if (module_name != nullptr) {
430 location = (*JImageFindResource)(jimage_non_null(), module_name, get_jimage_version_string(), name, &size);
431 }
432 }
433 }
434 }
435 }
436 if (location != 0) {
437 if (UsePerfData) {
438 ClassLoader::perf_sys_classfile_bytes_read()->inc(size);
439 }
440 char* data = NEW_RESOURCE_ARRAY(char, size);
441 (*JImageGetResource)(jimage_non_null(), location, data, size);
442 // Resource allocated
443 assert(this == (ClassPathImageEntry*)ClassLoader::get_jrt_entry(), "must be");
444 return new ClassFileStream((u1*)data,
445 checked_cast<int>(size),
446 _name,
447 true); // from_boot_loader_modules_image
448 }
449
450 return nullptr;
451 }
452
453 JImageLocationRef ClassLoader::jimage_find_resource(JImageFile* jf,
454 const char* module_name,
455 const char* file_name,
456 jlong &size) {
457 return ((*JImageFindResource)(jf, module_name, get_jimage_version_string(), file_name, &size));
458 }
459
460 bool ClassPathImageEntry::is_modules_image() const {
461 assert(this == _singleton, "VM supports a single jimage");
462 assert(this == (ClassPathImageEntry*)ClassLoader::get_jrt_entry(), "must be used for jrt entry");
463 return true;
464 }
465
466 #if INCLUDE_CDS
467 void ClassLoader::exit_with_path_failure(const char* error, const char* message) {
468 assert(CDSConfig::is_dumping_archive(), "sanity");
469 tty->print_cr("Hint: enable -Xlog:class+path=info to diagnose the failure");
470 vm_exit_during_cds_dumping(error, message);
471 }
472 #endif
473
474 ModuleClassPathList::ModuleClassPathList(Symbol* module_name) {
475 _module_name = module_name;
476 _module_first_entry = nullptr;
477 _module_last_entry = nullptr;
478 }
479
480 ModuleClassPathList::~ModuleClassPathList() {
481 // Clean out each ClassPathEntry on list
482 ClassPathEntry* e = _module_first_entry;
483 while (e != nullptr) {
484 ClassPathEntry* next_entry = e->next();
485 delete e;
486 e = next_entry;
487 }
488 }
489
490 void ModuleClassPathList::add_to_list(ClassPathEntry* new_entry) {
491 if (new_entry != nullptr) {
492 if (_module_last_entry == nullptr) {
493 _module_first_entry = _module_last_entry = new_entry;
494 } else {
495 _module_last_entry->set_next(new_entry);
496 _module_last_entry = new_entry;
497 }
498 }
499 }
500
501 void ClassLoader::trace_class_path(const char* msg, const char* name) {
502 LogTarget(Info, class, path) lt;
503 if (lt.is_enabled()) {
504 LogStream ls(lt);
505 if (msg) {
506 ls.print("%s", msg);
507 }
508 if (name) {
509 if (strlen(name) < 256) {
510 ls.print("%s", name);
511 } else {
512 // For very long paths, we need to print each character separately,
513 // as print_cr() has a length limit
514 while (name[0] != '\0') {
515 ls.print("%c", name[0]);
516 name++;
517 }
518 }
519 }
520 ls.cr();
521 }
522 }
523
524 void ClassLoader::setup_bootstrap_search_path(JavaThread* current) {
525 const char* bootcp = Arguments::get_boot_class_path();
526 assert(bootcp != nullptr, "Boot class path must not be nullptr");
527 if (PrintSharedArchiveAndExit) {
528 // Don't print bootcp - this is the bootcp of this current VM process, not necessarily
529 // the same as the boot classpath of the shared archive.
530 } else {
531 trace_class_path("bootstrap loader class path=", bootcp);
532 }
533 setup_bootstrap_search_path_impl(current, bootcp);
534 }
535
536 #if INCLUDE_CDS
537 void ClassLoader::setup_app_search_path(JavaThread* current, const char *class_path) {
538 assert(CDSConfig::is_dumping_archive(), "sanity");
539
540 ResourceMark rm(current);
541 ClasspathStream cp_stream(class_path);
542
543 while (cp_stream.has_next()) {
544 const char* path = cp_stream.get_next();
545 update_class_path_entry_list(current, path, /* check_for_duplicates */ true,
546 /* is_boot_append */ false, /* from_class_path_attr */ false);
547 }
548 }
549
550 void ClassLoader::add_to_module_path_entries(const char* path,
551 ClassPathEntry* entry) {
552 assert(entry != nullptr, "ClassPathEntry should not be nullptr");
553 assert(CDSConfig::is_dumping_archive(), "sanity");
554
555 // The entry does not exist, add to the list
556 if (_module_path_entries == nullptr) {
557 assert(_last_module_path_entry == nullptr, "Sanity");
558 _module_path_entries = _last_module_path_entry = entry;
559 } else {
560 _last_module_path_entry->set_next(entry);
561 _last_module_path_entry = entry;
562 }
563 }
564
565 // Add a module path to the _module_path_entries list.
566 void ClassLoader::setup_module_search_path(JavaThread* current, const char* path) {
567 assert(CDSConfig::is_dumping_archive(), "sanity");
568 struct stat st;
569 if (os::stat(path, &st) != 0) {
570 tty->print_cr("os::stat error %d (%s). CDS dump aborted (path was \"%s\").",
571 errno, os::errno_name(errno), path);
572 vm_exit_during_initialization();
573 }
574 // File or directory found
575 ClassPathEntry* new_entry = nullptr;
576 new_entry = create_class_path_entry(current, path, &st,
577 false /*is_boot_append */, false /* from_class_path_attr */);
578 if (new_entry != nullptr) {
579 // ClassLoaderExt::process_module_table() filters out non-jar entries before calling this function.
580 assert(new_entry->is_jar_file(), "module path entry %s is not a jar file", new_entry->name());
581 add_to_module_path_entries(path, new_entry);
582 }
583 }
584
585 #endif // INCLUDE_CDS
586
587 void ClassLoader::close_jrt_image() {
588 // Not applicable for exploded builds
589 if (!ClassLoader::has_jrt_entry()) return;
590 _jrt_entry->close_jimage();
591 }
592
593 // Construct the array of module/path pairs as specified to --patch-module
594 // for the boot loader to search ahead of the jimage, if the class being
595 // loaded is defined to a module that has been specified to --patch-module.
596 void ClassLoader::setup_patch_mod_entries() {
597 JavaThread* current = JavaThread::current();
598 GrowableArray<ModulePatchPath*>* patch_mod_args = Arguments::get_patch_mod_prefix();
599 int num_of_entries = patch_mod_args->length();
600
601 // Set up the boot loader's _patch_mod_entries list
602 _patch_mod_entries = new (mtModule) GrowableArray<ModuleClassPathList*>(num_of_entries, mtModule);
603
604 for (int i = 0; i < num_of_entries; i++) {
605 const char* module_name = (patch_mod_args->at(i))->module_name();
606 Symbol* const module_sym = SymbolTable::new_symbol(module_name);
607 assert(module_sym != nullptr, "Failed to obtain Symbol for module name");
608 ModuleClassPathList* module_cpl = new ModuleClassPathList(module_sym);
609
610 char* class_path = (patch_mod_args->at(i))->path_string();
611 ResourceMark rm(current);
612 ClasspathStream cp_stream(class_path);
613
614 while (cp_stream.has_next()) {
615 const char* path = cp_stream.get_next();
616 struct stat st;
617 if (os::stat(path, &st) == 0) {
618 // File or directory found
619 ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
620 // If the path specification is valid, enter it into this module's list
621 if (new_entry != nullptr) {
622 module_cpl->add_to_list(new_entry);
623 }
624 }
625 }
626
627 // Record the module into the list of --patch-module entries only if
628 // valid ClassPathEntrys have been created
629 if (module_cpl->module_first_entry() != nullptr) {
630 _patch_mod_entries->push(module_cpl);
631 }
632 }
633 }
634
635 // Determine whether the module has been patched via the command-line
636 // option --patch-module
637 bool ClassLoader::is_in_patch_mod_entries(Symbol* module_name) {
638 if (_patch_mod_entries != nullptr && _patch_mod_entries->is_nonempty()) {
639 int table_len = _patch_mod_entries->length();
640 for (int i = 0; i < table_len; i++) {
641 ModuleClassPathList* patch_mod = _patch_mod_entries->at(i);
642 if (module_name->fast_compare(patch_mod->module_name()) == 0) {
643 return true;
644 }
645 }
646 }
647 return false;
648 }
649
650 // Set up the _jrt_entry if present and boot append path
651 void ClassLoader::setup_bootstrap_search_path_impl(JavaThread* current, const char *class_path) {
652 ResourceMark rm(current);
653 ClasspathStream cp_stream(class_path);
654 bool set_base_piece = true;
655
656 #if INCLUDE_CDS
657 if (CDSConfig::is_dumping_archive()) {
658 if (!Arguments::has_jimage()) {
659 vm_exit_during_initialization("CDS is not supported in exploded JDK build", nullptr);
660 }
661 }
662 #endif
663
664 while (cp_stream.has_next()) {
665 const char* path = cp_stream.get_next();
666
667 if (set_base_piece) {
668 // The first time through the bootstrap_search setup, it must be determined
669 // what the base or core piece of the boot loader search is. Either a java runtime
670 // image is present or this is an exploded module build situation.
671 assert(string_ends_with(path, MODULES_IMAGE_NAME) || string_ends_with(path, JAVA_BASE_NAME),
672 "Incorrect boot loader search path, no java runtime image or " JAVA_BASE_NAME " exploded build");
673 struct stat st;
674 if (os::stat(path, &st) == 0) {
675 // Directory found
676 if (JImage_file != nullptr) {
677 assert(Arguments::has_jimage(), "sanity check");
678 const char* canonical_path = get_canonical_path(path, current);
679 assert(canonical_path != nullptr, "canonical_path issue");
680
681 _jrt_entry = new ClassPathImageEntry(JImage_file, canonical_path);
682 assert(_jrt_entry != nullptr && _jrt_entry->is_modules_image(), "No java runtime image present");
683 assert(_jrt_entry->jimage() != nullptr, "No java runtime image");
684 } // else it's an exploded build.
685 } else {
686 // If path does not exist, exit
687 vm_exit_during_initialization("Unable to establish the boot loader search path", path);
688 }
689 set_base_piece = false;
690 } else {
691 // Every entry on the boot class path after the initial base piece,
692 // which is set by os::set_boot_path(), is considered an appended entry.
693 update_class_path_entry_list(current, path, /* check_for_duplicates */ false,
694 /* is_boot_append */ true, /* from_class_path_attr */ false);
695 }
696 }
697 }
698
699 // Gets the exploded path for the named module. The memory for the path
700 // is allocated on the C heap if `c_heap` is true otherwise in the resource area.
701 static const char* get_exploded_module_path(const char* module_name, bool c_heap) {
702 const char *home = Arguments::get_java_home();
703 const char file_sep = os::file_separator()[0];
704 // 10 represents the length of "modules" + 2 file separators + \0
705 size_t len = strlen(home) + strlen(module_name) + 10;
706 char *path = c_heap ? NEW_C_HEAP_ARRAY(char, len, mtModule) : NEW_RESOURCE_ARRAY(char, len);
707 jio_snprintf(path, len, "%s%cmodules%c%s", home, file_sep, file_sep, module_name);
708 return path;
709 }
710
711 // During an exploded modules build, each module defined to the boot loader
712 // will be added to the ClassLoader::_exploded_entries array.
713 void ClassLoader::add_to_exploded_build_list(JavaThread* current, Symbol* module_sym) {
714 assert(!ClassLoader::has_jrt_entry(), "Exploded build not applicable");
715 assert(_exploded_entries != nullptr, "_exploded_entries was not initialized");
716
717 // Find the module's symbol
718 ResourceMark rm(current);
719 const char *module_name = module_sym->as_C_string();
720 const char *path = get_exploded_module_path(module_name, false);
721
722 struct stat st;
723 if (os::stat(path, &st) == 0) {
724 // Directory found
725 ClassPathEntry* new_entry = create_class_path_entry(current, path, &st, false, false);
726
727 // If the path specification is valid, enter it into this module's list.
728 // There is no need to check for duplicate modules in the exploded entry list,
729 // since no two modules with the same name can be defined to the boot loader.
730 // This is checked at module definition time in Modules::define_module.
731 if (new_entry != nullptr) {
732 ModuleClassPathList* module_cpl = new ModuleClassPathList(module_sym);
733 module_cpl->add_to_list(new_entry);
734 {
735 MutexLocker ml(current, Module_lock);
736 _exploded_entries->push(module_cpl);
737 }
738 log_info(class, load)("path: %s", path);
739 }
740 }
741 }
742
743 jzfile* ClassLoader::open_zip_file(const char* canonical_path, char** error_msg, JavaThread* thread) {
744 // enable call to C land
745 ThreadToNativeFromVM ttn(thread);
746 HandleMark hm(thread);
747 return ZipLibrary::open(canonical_path, error_msg);
748 }
749
750 ClassPathEntry* ClassLoader::create_class_path_entry(JavaThread* current,
751 const char *path, const struct stat* st,
752 bool is_boot_append,
753 bool from_class_path_attr) {
754 ClassPathEntry* new_entry = nullptr;
755 if ((st->st_mode & S_IFMT) == S_IFREG) {
756 ResourceMark rm(current);
757 // Regular file, should be a zip file
758 // Canonicalized filename
759 const char* canonical_path = get_canonical_path(path, current);
760 if (canonical_path == nullptr) {
761 return nullptr;
762 }
763 char* error_msg = nullptr;
764 jzfile* zip = open_zip_file(canonical_path, &error_msg, current);
765 if (zip != nullptr && error_msg == nullptr) {
766 new_entry = new ClassPathZipEntry(zip, path, is_boot_append, from_class_path_attr);
767 } else {
768 #if INCLUDE_CDS
769 ClassLoaderExt::set_has_non_jar_in_classpath();
770 #endif
771 return nullptr;
772 }
773 log_info(class, path)("opened: %s", path);
774 log_info(class, load)("opened: %s", path);
775 } else {
776 // Directory
777 new_entry = new ClassPathDirEntry(path);
778 log_info(class, load)("path: %s", path);
779 }
780 return new_entry;
781 }
782
783
784 // Create a class path zip entry for a given path (return null if not found
785 // or zip/JAR file cannot be opened)
786 ClassPathZipEntry* ClassLoader::create_class_path_zip_entry(const char *path, bool is_boot_append) {
787 // check for a regular file
788 struct stat st;
789 if (os::stat(path, &st) == 0) {
790 if ((st.st_mode & S_IFMT) == S_IFREG) {
791 JavaThread* thread = JavaThread::current();
792 ResourceMark rm(thread);
793 const char* canonical_path = get_canonical_path(path, thread);
794 if (canonical_path != nullptr) {
795 char* error_msg = nullptr;
796 jzfile* zip = open_zip_file(canonical_path, &error_msg, thread);
797 if (zip != nullptr && error_msg == nullptr) {
798 // create using canonical path
799 return new ClassPathZipEntry(zip, canonical_path, is_boot_append, false);
800 }
801 }
802 }
803 }
804 return nullptr;
805 }
806
807 // The boot append entries are added with a lock, and read lock free.
808 void ClassLoader::add_to_boot_append_entries(ClassPathEntry *new_entry) {
809 if (new_entry != nullptr) {
810 MutexLocker ml(Bootclasspath_lock, Mutex::_no_safepoint_check_flag);
811 if (_last_append_entry == nullptr) {
812 _last_append_entry = new_entry;
813 assert(first_append_entry() == nullptr, "boot loader's append class path entry list not empty");
814 Atomic::release_store(&_first_append_entry_list, new_entry);
815 } else {
816 _last_append_entry->set_next(new_entry);
817 _last_append_entry = new_entry;
818 }
819 }
820 }
821
822 // Record the path entries specified in -cp during dump time. The recorded
823 // information will be used at runtime for loading the archived app classes.
824 //
825 // Note that at dump time, ClassLoader::_app_classpath_entries are NOT used for
826 // loading app classes. Instead, the app class are loaded by the
827 // jdk/internal/loader/ClassLoaders$AppClassLoader instance.
828 bool ClassLoader::add_to_app_classpath_entries(JavaThread* current,
829 ClassPathEntry* entry,
830 bool check_for_duplicates) {
831 #if INCLUDE_CDS
832 assert(entry != nullptr, "ClassPathEntry should not be nullptr");
833 ClassPathEntry* e = _app_classpath_entries;
834 if (check_for_duplicates) {
835 while (e != nullptr) {
836 if (strcmp(e->name(), entry->name()) == 0 &&
837 e->from_class_path_attr() == entry->from_class_path_attr()) {
838 // entry already exists
839 return false;
840 }
841 e = e->next();
842 }
843 }
844
845 // The entry does not exist, add to the list
846 if (_app_classpath_entries == nullptr) {
847 assert(_last_app_classpath_entry == nullptr, "Sanity");
848 _app_classpath_entries = _last_app_classpath_entry = entry;
849 } else {
850 _last_app_classpath_entry->set_next(entry);
851 _last_app_classpath_entry = entry;
852 }
853
854 if (entry->is_jar_file()) {
855 ClassLoaderExt::process_jar_manifest(current, entry);
856 }
857 #endif
858 return true;
859 }
860
861 // Returns true IFF the file/dir exists and the entry was successfully created.
862 bool ClassLoader::update_class_path_entry_list(JavaThread* current,
863 const char *path,
864 bool check_for_duplicates,
865 bool is_boot_append,
866 bool from_class_path_attr) {
867 struct stat st;
868 if (os::stat(path, &st) == 0) {
869 // File or directory found
870 ClassPathEntry* new_entry = nullptr;
871 new_entry = create_class_path_entry(current, path, &st, is_boot_append, from_class_path_attr);
872 if (new_entry == nullptr) {
873 return false;
874 }
875
876 // Do not reorder the bootclasspath which would break get_system_package().
877 // Add new entry to linked list
878 if (is_boot_append) {
879 add_to_boot_append_entries(new_entry);
880 } else {
881 if (!add_to_app_classpath_entries(current, new_entry, check_for_duplicates)) {
882 // new_entry is not saved, free it now
883 delete new_entry;
884 }
885 }
886 return true;
887 } else {
888 return false;
889 }
890 }
891
892 static void print_module_entry_table(const GrowableArray<ModuleClassPathList*>* const module_list) {
893 ResourceMark rm;
894 int num_of_entries = module_list->length();
895 for (int i = 0; i < num_of_entries; i++) {
896 ClassPathEntry* e;
897 ModuleClassPathList* mpl = module_list->at(i);
898 tty->print("%s=", mpl->module_name()->as_C_string());
899 e = mpl->module_first_entry();
900 while (e != nullptr) {
901 tty->print("%s", e->name());
902 e = e->next();
903 if (e != nullptr) {
904 tty->print("%s", os::path_separator());
905 }
906 }
907 tty->print(" ;");
908 }
909 }
910
911 void ClassLoader::print_bootclasspath() {
912 ClassPathEntry* e;
913 tty->print("[bootclasspath= ");
914
915 // Print --patch-module module/path specifications first
916 if (_patch_mod_entries != nullptr) {
917 print_module_entry_table(_patch_mod_entries);
918 }
919
920 // [jimage | exploded modules build]
921 if (has_jrt_entry()) {
922 // Print the location of the java runtime image
923 tty->print("%s ;", _jrt_entry->name());
924 } else {
925 // Print exploded module build path specifications
926 if (_exploded_entries != nullptr) {
927 print_module_entry_table(_exploded_entries);
928 }
929 }
930
931 // appended entries
932 e = first_append_entry();
933 while (e != nullptr) {
934 tty->print("%s ;", e->name());
935 e = e->next();
936 }
937 tty->print_cr("]");
938 }
939
940 void* ClassLoader::dll_lookup(void* lib, const char* name, const char* path) {
941 void* func = os::dll_lookup(lib, name);
942 if (func == nullptr) {
943 char msg[256] = "";
944 jio_snprintf(msg, sizeof(msg), "Could not resolve \"%s\"", name);
945 vm_exit_during_initialization(msg, path);
946 }
947 return func;
948 }
949
950 void ClassLoader::load_java_library() {
951 assert(CanonicalizeEntry == nullptr, "should not load java library twice");
952 void *javalib_handle = os::native_java_library();
953 if (javalib_handle == nullptr) {
954 vm_exit_during_initialization("Unable to load java library", nullptr);
955 }
956
957 CanonicalizeEntry = CAST_TO_FN_PTR(canonicalize_fn_t, dll_lookup(javalib_handle, "JDK_Canonicalize", nullptr));
958 }
959
960 void ClassLoader::load_jimage_library() {
961 assert(JImageOpen == nullptr, "should not load jimage library twice");
962 char path[JVM_MAXPATHLEN];
963 char ebuf[1024];
964 void* handle = nullptr;
965 if (os::dll_locate_lib(path, sizeof(path), Arguments::get_dll_dir(), "jimage")) {
966 handle = os::dll_load(path, ebuf, sizeof ebuf);
967 }
968 if (handle == nullptr) {
969 vm_exit_during_initialization("Unable to load jimage library", path);
970 }
971
972 JImageOpen = CAST_TO_FN_PTR(JImageOpen_t, dll_lookup(handle, "JIMAGE_Open", path));
973 JImageClose = CAST_TO_FN_PTR(JImageClose_t, dll_lookup(handle, "JIMAGE_Close", path));
974 JImageFindResource = CAST_TO_FN_PTR(JImageFindResource_t, dll_lookup(handle, "JIMAGE_FindResource", path));
975 JImageGetResource = CAST_TO_FN_PTR(JImageGetResource_t, dll_lookup(handle, "JIMAGE_GetResource", path));
976 }
977
978 int ClassLoader::crc32(int crc, const char* buf, int len) {
979 return ZipLibrary::crc32(crc, (const jbyte*)buf, len);
980 }
981
982 oop ClassLoader::get_system_package(const char* name, TRAPS) {
983 // Look up the name in the boot loader's package entry table.
984 if (name != nullptr) {
985 TempNewSymbol package_sym = SymbolTable::new_symbol(name);
986 // Look for the package entry in the boot loader's package entry table.
987 PackageEntry* package =
988 ClassLoaderData::the_null_class_loader_data()->packages()->lookup_only(package_sym);
989
990 // Return null if package does not exist or if no classes in that package
991 // have been loaded.
992 if (package != nullptr && package->has_loaded_class()) {
993 ModuleEntry* module = package->module();
994 if (module->location() != nullptr) {
995 ResourceMark rm(THREAD);
996 Handle ml = java_lang_String::create_from_str(
997 module->location()->as_C_string(), THREAD);
998 return ml();
999 }
1000 // Return entry on boot loader class path.
1001 Handle cph = java_lang_String::create_from_str(
1002 ClassLoader::classpath_entry(package->classpath_index())->name(), THREAD);
1003 return cph();
1004 }
1005 }
1006 return nullptr;
1007 }
1008
1009 objArrayOop ClassLoader::get_system_packages(TRAPS) {
1010 ResourceMark rm(THREAD);
1011 // List of pointers to PackageEntrys that have loaded classes.
1012 PackageEntryTable* pe_table =
1013 ClassLoaderData::the_null_class_loader_data()->packages();
1014 GrowableArray<PackageEntry*>* loaded_class_pkgs = pe_table->get_system_packages();
1015
1016 // Allocate objArray and fill with java.lang.String
1017 objArrayOop r = oopFactory::new_objArray(vmClasses::String_klass(),
1018 loaded_class_pkgs->length(), CHECK_NULL);
1019 objArrayHandle result(THREAD, r);
1020 for (int x = 0; x < loaded_class_pkgs->length(); x++) {
1021 PackageEntry* package_entry = loaded_class_pkgs->at(x);
1022 Handle str = java_lang_String::create_from_symbol(package_entry->name(), CHECK_NULL);
1023 result->obj_at_put(x, str());
1024 }
1025 return result();
1026 }
1027
1028 // caller needs ResourceMark
1029 const char* ClassLoader::file_name_for_class_name(const char* class_name,
1030 int class_name_len) {
1031 assert(class_name != nullptr, "invariant");
1032 assert((int)strlen(class_name) == class_name_len, "invariant");
1033
1034 static const char class_suffix[] = ".class";
1035 size_t class_suffix_len = sizeof(class_suffix);
1036
1037 char* const file_name = NEW_RESOURCE_ARRAY(char,
1038 class_name_len +
1039 class_suffix_len); // includes term null
1040
1041 strncpy(file_name, class_name, class_name_len);
1042 strncpy(&file_name[class_name_len], class_suffix, class_suffix_len);
1043
1044 return file_name;
1045 }
1046
1047 static ClassPathEntry* find_first_module_cpe(ModuleEntry* mod_entry,
1048 const GrowableArray<ModuleClassPathList*>* const module_list) {
1049 int num_of_entries = module_list->length();
1050 const Symbol* class_module_name = mod_entry->name();
1051
1052 // Loop through all the modules in either the patch-module or exploded entries looking for module
1053 for (int i = 0; i < num_of_entries; i++) {
1054 ModuleClassPathList* module_cpl = module_list->at(i);
1055 Symbol* module_cpl_name = module_cpl->module_name();
1056
1057 if (module_cpl_name->fast_compare(class_module_name) == 0) {
1058 // Class' module has been located.
1059 return module_cpl->module_first_entry();
1060 }
1061 }
1062 return nullptr;
1063 }
1064
1065
1066 // Search the module list for the class file stream based on the file name and java package
1067 ClassFileStream* ClassLoader::search_module_entries(JavaThread* current,
1068 const GrowableArray<ModuleClassPathList*>* const module_list,
1069 PackageEntry* pkg_entry, // Java package entry derived from the class name
1070 const char* const file_name) {
1071 ClassFileStream* stream = nullptr;
1072
1073 // Find the defining module in the boot loader's module entry table
1074 ModuleEntry* mod_entry = (pkg_entry != nullptr) ? pkg_entry->module() : nullptr;
1075
1076 // If the module system has not defined java.base yet, then
1077 // classes loaded are assumed to be defined to java.base.
1078 // When java.base is eventually defined by the module system,
1079 // all packages of classes that have been previously loaded
1080 // are verified in ModuleEntryTable::verify_javabase_packages().
1081 if (!Universe::is_module_initialized() &&
1082 !ModuleEntryTable::javabase_defined() &&
1083 mod_entry == nullptr) {
1084 mod_entry = ModuleEntryTable::javabase_moduleEntry();
1085 }
1086
1087 // The module must be a named module
1088 ClassPathEntry* e = nullptr;
1089 if (mod_entry != nullptr && mod_entry->is_named()) {
1090 if (module_list == _exploded_entries) {
1091 // The exploded build entries can be added to at any time so a lock is
1092 // needed when searching them.
1093 assert(!ClassLoader::has_jrt_entry(), "Must be exploded build");
1094 MutexLocker ml(current, Module_lock);
1095 e = find_first_module_cpe(mod_entry, module_list);
1096 } else {
1097 e = find_first_module_cpe(mod_entry, module_list);
1098 }
1099 }
1100
1101 // Try to load the class from the module's ClassPathEntry list.
1102 while (e != nullptr) {
1103 stream = e->open_stream(current, file_name);
1104 // No context.check is required since CDS is not supported
1105 // for an exploded modules build or if --patch-module is specified.
1106 if (nullptr != stream) {
1107 return stream;
1108 }
1109 e = e->next();
1110 }
1111 // If the module was located, break out even if the class was not
1112 // located successfully from that module's ClassPathEntry list.
1113 // There will not be another valid entry for that module.
1114 return nullptr;
1115 }
1116
1117 // Called by the boot classloader to load classes
1118 InstanceKlass* ClassLoader::load_class(Symbol* name, PackageEntry* pkg_entry, bool search_append_only, TRAPS) {
1119 assert(name != nullptr, "invariant");
1120
1121 ResourceMark rm(THREAD);
1122 HandleMark hm(THREAD);
1123
1124 const char* const class_name = name->as_C_string();
1125
1126 EventMarkClassLoading m("Loading class %s", class_name);
1127
1128 const char* const file_name = file_name_for_class_name(class_name,
1129 name->utf8_length());
1130 assert(file_name != nullptr, "invariant");
1131
1132 // Lookup stream for parsing .class file
1133 ClassFileStream* stream = nullptr;
1134 s2 classpath_index = 0;
1135 ClassPathEntry* e = nullptr;
1136
1137 // If search_append_only is true, boot loader visibility boundaries are
1138 // set to be _first_append_entry to the end. This includes:
1139 // [-Xbootclasspath/a]; [jvmti appended entries]
1140 //
1141 // If search_append_only is false, boot loader visibility boundaries are
1142 // set to be the --patch-module entries plus the base piece. This includes:
1143 // [--patch-module=<module>=<file>(<pathsep><file>)*]; [jimage | exploded module build]
1144 //
1145
1146 // Load Attempt #1: --patch-module
1147 // Determine the class' defining module. If it appears in the _patch_mod_entries,
1148 // attempt to load the class from those locations specific to the module.
1149 // Specifications to --patch-module can contain a partial number of classes
1150 // that are part of the overall module definition. So if a particular class is not
1151 // found within its module specification, the search should continue to Load Attempt #2.
1152 // Note: The --patch-module entries are never searched if the boot loader's
1153 // visibility boundary is limited to only searching the append entries.
1154 if (_patch_mod_entries != nullptr && !search_append_only) {
1155 assert(!CDSConfig::is_dumping_archive(), "CDS doesn't support --patch-module during dumping");
1156 stream = search_module_entries(THREAD, _patch_mod_entries, pkg_entry, file_name);
1157 }
1158
1159 // Load Attempt #2: [jimage | exploded build]
1160 if (!search_append_only && (nullptr == stream)) {
1161 if (has_jrt_entry()) {
1162 e = _jrt_entry;
1163 stream = _jrt_entry->open_stream(THREAD, file_name);
1164 } else {
1165 // Exploded build - attempt to locate class in its defining module's location.
1166 assert(_exploded_entries != nullptr, "No exploded build entries present");
1167 assert(!CDSConfig::is_dumping_archive(), "CDS dumping doesn't support exploded build");
1168 stream = search_module_entries(THREAD, _exploded_entries, pkg_entry, file_name);
1169 }
1170 }
1171
1172 // Load Attempt #3: [-Xbootclasspath/a]; [jvmti appended entries]
1173 if (search_append_only && (nullptr == stream)) {
1174 // For the boot loader append path search, the starting classpath_index
1175 // for the appended piece is always 1 to account for either the
1176 // _jrt_entry or the _exploded_entries.
1177 assert(classpath_index == 0, "The classpath_index has been incremented incorrectly");
1178 classpath_index = 1;
1179
1180 e = first_append_entry();
1181 while (e != nullptr) {
1182 stream = e->open_stream(THREAD, file_name);
1183 if (nullptr != stream) {
1184 break;
1185 }
1186 e = e->next();
1187 ++classpath_index;
1188 }
1189 }
1190
1191 if (nullptr == stream) {
1192 return nullptr;
1193 }
1194
1195 ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
1196 Handle protection_domain;
1197 ClassLoadInfo cl_info(protection_domain);
1198
1199 InstanceKlass* result = KlassFactory::create_from_stream(stream,
1200 name,
1201 loader_data,
1202 cl_info,
1203 CHECK_NULL);
1204 result->set_classpath_index(classpath_index);
1205 return result;
1206 }
1207
1208 #if INCLUDE_CDS
1209 static const char* skip_uri_protocol(const char* source) {
1210 if (strncmp(source, "file:", 5) == 0) {
1211 // file: protocol path could start with file:/ or file:///
1212 // locate the char after all the forward slashes
1213 int offset = 5;
1214 while (*(source + offset) == '/') {
1215 offset++;
1216 }
1217 source += offset;
1218 // for non-windows platforms, move back one char as the path begins with a '/'
1219 #ifndef _WINDOWS
1220 source -= 1;
1221 #endif
1222 } else if (strncmp(source, "jrt:/", 5) == 0) {
1223 source += 5;
1224 }
1225 return source;
1226 }
1227
1228 static char decode_percent_encoded(const char *str, size_t& index) {
1229 if (str[index] == '%'
1230 && isxdigit(str[index + 1])
1231 && isxdigit(str[index + 2])) {
1232 char hex[3];
1233 hex[0] = str[index + 1];
1234 hex[1] = str[index + 2];
1235 hex[2] = '\0';
1236 index += 2;
1237 return (char) strtol(hex, nullptr, 16);
1238 }
1239 return str[index];
1240 }
1241
1242 char* ClassLoader::uri_to_path(const char* uri) {
1243 const size_t len = strlen(uri) + 1;
1244 char* path = NEW_RESOURCE_ARRAY(char, len);
1245
1246 uri = skip_uri_protocol(uri);
1247
1248 if (strncmp(uri, "//", 2) == 0) {
1249 // Skip the empty "authority" part
1250 uri += 2;
1251 }
1252
1253 #ifdef _WINDOWS
1254 if (uri[0] == '/') {
1255 // Absolute path name on Windows does not begin with a slash
1256 uri += 1;
1257 }
1258 #endif
1259
1260 size_t path_index = 0;
1261 for (size_t i = 0; i < strlen(uri); ++i) {
1262 char decoded = decode_percent_encoded(uri, i);
1263 path[path_index++] = decoded;
1264 }
1265 path[path_index] = '\0';
1266 return path;
1267 }
1268
1269 // Record the shared classpath index and loader type for classes loaded
1270 // by the builtin loaders at dump time.
1271 void ClassLoader::record_result(JavaThread* current, InstanceKlass* ik,
1272 const ClassFileStream* stream, bool redefined) {
1273 assert(CDSConfig::is_dumping_archive(), "sanity");
1274 assert(stream != nullptr, "sanity");
1275
1276 if (ik->is_hidden()) {
1277 record_hidden_class(ik);
1278 return;
1279 }
1280
1281 oop loader = ik->class_loader();
1282 char* src = (char*)stream->source();
1283 if (src == nullptr) {
1284 if (loader == nullptr) {
1285 // JFR classes
1286 ik->set_shared_classpath_index(0);
1287 ik->set_shared_class_loader_type(ClassLoader::BOOT_LOADER);
1288 }
1289 return;
1290 }
1291
1292 assert(has_jrt_entry(), "CDS dumping does not support exploded JDK build");
1293
1294 ResourceMark rm(current);
1295 int classpath_index = -1;
1296 PackageEntry* pkg_entry = ik->package();
1297
1298 if (FileMapInfo::get_number_of_shared_paths() > 0) {
1299 // Save the path from the file: protocol or the module name from the jrt: protocol
1300 // if no protocol prefix is found, path is the same as stream->source(). This path
1301 // must be valid since the class has been successfully parsed.
1302 const char* path = ClassLoader::uri_to_path(src);
1303 assert(path != nullptr, "sanity");
1304 for (int i = 0; i < FileMapInfo::get_number_of_shared_paths(); i++) {
1305 SharedClassPathEntry* ent = FileMapInfo::shared_path(i);
1306 // A shared path has been validated during its creation in ClassLoader::create_class_path_entry(),
1307 // it must be valid here.
1308 assert(ent->name() != nullptr, "sanity");
1309 // If the path (from the class stream source) is the same as the shared
1310 // class or module path, then we have a match.
1311 // src may come from the App/Platform class loaders, which would canonicalize
1312 // the file name. We cannot use strcmp to check for equality against ent->name().
1313 // We must use os::same_files (which is faster than canonicalizing ent->name()).
1314 if (os::same_files(ent->name(), path)) {
1315 // null pkg_entry and pkg_entry in an unnamed module implies the class
1316 // is from the -cp or boot loader append path which consists of -Xbootclasspath/a
1317 // and jvmti appended entries.
1318 if ((pkg_entry == nullptr) || (pkg_entry->in_unnamed_module())) {
1319 // Ensure the index is within the -cp range before assigning
1320 // to the classpath_index.
1321 if (SystemDictionary::is_system_class_loader(loader) &&
1322 (i >= ClassLoaderExt::app_class_paths_start_index()) &&
1323 (i < ClassLoaderExt::app_module_paths_start_index())) {
1324 classpath_index = i;
1325 break;
1326 } else {
1327 if ((i >= 1) &&
1328 (i < ClassLoaderExt::app_class_paths_start_index())) {
1329 // The class must be from boot loader append path which consists of
1330 // -Xbootclasspath/a and jvmti appended entries.
1331 assert(loader == nullptr, "sanity");
1332 classpath_index = i;
1333 break;
1334 }
1335 }
1336 } else {
1337 // A class from a named module from the --module-path. Ensure the index is
1338 // within the --module-path range before assigning to the classpath_index.
1339 if ((pkg_entry != nullptr) && !(pkg_entry->in_unnamed_module()) && (i > 0)) {
1340 if (i >= ClassLoaderExt::app_module_paths_start_index() &&
1341 i < FileMapInfo::get_number_of_shared_paths()) {
1342 classpath_index = i;
1343 break;
1344 }
1345 }
1346 }
1347 }
1348 // for index 0 and the stream->source() is the modules image or has the jrt: protocol.
1349 // The class must be from the runtime modules image.
1350 if (i == 0 && (stream->from_boot_loader_modules_image() || string_starts_with(src, "jrt:"))) {
1351 classpath_index = i;
1352 break;
1353 }
1354 }
1355
1356 // No path entry found for this class: most likely a shared class loaded by the
1357 // user defined classloader.
1358 if (classpath_index < 0 && !SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
1359 assert(ik->shared_classpath_index() < 0, "not assigned yet");
1360 ik->set_shared_classpath_index(UNREGISTERED_INDEX);
1361 SystemDictionaryShared::set_shared_class_misc_info(ik, (ClassFileStream*)stream);
1362 return;
1363 }
1364 } else {
1365 // The shared path table is set up after module system initialization.
1366 // The path table contains no entry before that. Any classes loaded prior
1367 // to the setup of the shared path table must be from the modules image.
1368 assert(stream->from_boot_loader_modules_image(), "stream must be loaded by boot loader from modules image");
1369 assert(FileMapInfo::get_number_of_shared_paths() == 0, "shared path table must not have been setup");
1370 classpath_index = 0;
1371 }
1372
1373 const char* const class_name = ik->name()->as_C_string();
1374 const char* const file_name = file_name_for_class_name(class_name,
1375 ik->name()->utf8_length());
1376 assert(file_name != nullptr, "invariant");
1377 ClassLoaderExt::record_result(checked_cast<s2>(classpath_index), ik, redefined);
1378 }
1379
1380 void ClassLoader::record_hidden_class(InstanceKlass* ik) {
1381 assert(ik->is_hidden(), "must be");
1382
1383 s2 classloader_type;
1384 if (HeapShared::is_lambda_form_klass(ik)) {
1385 classloader_type = ClassLoader::BOOT_LOADER;
1386 } else {
1387 oop loader = ik->class_loader();
1388
1389 if (loader == nullptr) {
1390 classloader_type = ClassLoader::BOOT_LOADER;
1391 } else if (SystemDictionary::is_platform_class_loader(loader)) {
1392 classloader_type = ClassLoader::PLATFORM_LOADER;
1393 } else if (SystemDictionary::is_system_class_loader(loader)) {
1394 classloader_type = ClassLoader::APP_LOADER;
1395 } else {
1396 // This class won't be archived, so no need to update its
1397 // classloader_type/classpath_index.
1398 return;
1399 }
1400 }
1401 ik->set_shared_class_loader_type(classloader_type);
1402
1403 if (HeapShared::is_lambda_proxy_klass(ik)) {
1404 InstanceKlass* nest_host = ik->nest_host_not_null();
1405 ik->set_shared_classpath_index(nest_host->shared_classpath_index());
1406 } else if (HeapShared::is_lambda_form_klass(ik)) {
1407 ik->set_shared_classpath_index(0);
1408 } else {
1409 // Generated invoker classes.
1410 if (classloader_type == ClassLoader::APP_LOADER) {
1411 ik->set_shared_classpath_index(ClassLoaderExt::app_class_paths_start_index());
1412 } else {
1413 ik->set_shared_classpath_index(0);
1414 }
1415 }
1416 }
1417 #endif // INCLUDE_CDS
1418
1419 // Initialize the class loader's access to methods in libzip. Parse and
1420 // process the boot classpath into a list ClassPathEntry objects. Once
1421 // this list has been created, it must not change order (see class PackageInfo)
1422 // it can be appended to and is by jvmti.
1423
1424 void ClassLoader::initialize(TRAPS) {
1425 if (UsePerfData) {
1426 // jvmstat performance counters
1427 NEWPERFTICKCOUNTER(_perf_accumulated_time, SUN_CLS, "time");
1428 NEWPERFTICKCOUNTER(_perf_class_init_time, SUN_CLS, "classInitTime");
1429 NEWPERFTICKCOUNTER(_perf_class_init_selftime, SUN_CLS, "classInitTime.self");
1430 NEWPERFTICKCOUNTER(_perf_class_verify_time, SUN_CLS, "classVerifyTime");
1431 NEWPERFTICKCOUNTER(_perf_class_verify_selftime, SUN_CLS, "classVerifyTime.self");
1432 NEWPERFTICKCOUNTER(_perf_class_link_time, SUN_CLS, "classLinkedTime");
1433 NEWPERFTICKCOUNTER(_perf_class_link_selftime, SUN_CLS, "classLinkedTime.self");
1434 NEWPERFEVENTCOUNTER(_perf_classes_inited, SUN_CLS, "initializedClasses");
1435 NEWPERFEVENTCOUNTER(_perf_classes_linked, SUN_CLS, "linkedClasses");
1436 NEWPERFEVENTCOUNTER(_perf_classes_verified, SUN_CLS, "verifiedClasses");
1437
1438 NEWPERFTICKCOUNTER(_perf_shared_classload_time, SUN_CLS, "sharedClassLoadTime");
1439 NEWPERFTICKCOUNTER(_perf_sys_classload_time, SUN_CLS, "sysClassLoadTime");
1440 NEWPERFTICKCOUNTER(_perf_app_classload_time, SUN_CLS, "appClassLoadTime");
1441 NEWPERFTICKCOUNTER(_perf_app_classload_selftime, SUN_CLS, "appClassLoadTime.self");
1442 NEWPERFEVENTCOUNTER(_perf_app_classload_count, SUN_CLS, "appClassLoadCount");
1443 NEWPERFTICKCOUNTER(_perf_define_appclasses, SUN_CLS, "defineAppClasses");
1444 NEWPERFTICKCOUNTER(_perf_define_appclass_time, SUN_CLS, "defineAppClassTime");
1445 NEWPERFTICKCOUNTER(_perf_define_appclass_selftime, SUN_CLS, "defineAppClassTime.self");
1446 NEWPERFBYTECOUNTER(_perf_app_classfile_bytes_read, SUN_CLS, "appClassBytes");
1447 NEWPERFBYTECOUNTER(_perf_sys_classfile_bytes_read, SUN_CLS, "sysClassBytes");
1448 NEWPERFEVENTCOUNTER(_unsafe_defineClassCallCounter, SUN_CLS, "unsafeDefineClassCalls");
1449 NEWPERFTICKCOUNTER(_perf_secondary_hash_time, SUN_CLS, "secondarySuperHashTime");
1450
1451 if (log_is_enabled(Info, perf, class, link)) {
1452 NEWPERFTICKCOUNTER(_perf_ik_link_methods_time, SUN_CLS, "linkMethodsTime");
1453 NEWPERFTICKCOUNTER(_perf_method_adapters_time, SUN_CLS, "makeAdaptersTime");
1454 NEWPERFEVENTCOUNTER(_perf_ik_link_methods_count, SUN_CLS, "linkMethodsCount");
1455 NEWPERFEVENTCOUNTER(_perf_method_adapters_count, SUN_CLS, "makeAdaptersCount");
1456
1457 NEWPERFTICKCOUNTER(_perf_resolve_indy_time, SUN_CLS, "resolve_invokedynamic_time");
1458 NEWPERFTICKCOUNTER(_perf_resolve_invokehandle_time, SUN_CLS, "resolve_invokehandle_time");
1459 NEWPERFTICKCOUNTER(_perf_resolve_mh_time, SUN_CLS, "resolve_MethodHandle_time");
1460 NEWPERFTICKCOUNTER(_perf_resolve_mt_time, SUN_CLS, "resolve_MethodType_time");
1461
1462 NEWPERFEVENTCOUNTER(_perf_resolve_indy_count, SUN_CLS, "resolve_invokedynamic_count");
1463 NEWPERFEVENTCOUNTER(_perf_resolve_invokehandle_count, SUN_CLS, "resolve_invokehandle_count");
1464 NEWPERFEVENTCOUNTER(_perf_resolve_mh_count, SUN_CLS, "resolve_MethodHandle_count");
1465 NEWPERFEVENTCOUNTER(_perf_resolve_mt_count, SUN_CLS, "resolve_MethodType_count");
1466 }
1467 }
1468
1469 // lookup java library entry points
1470 load_java_library();
1471 // jimage library entry points are loaded below, in lookup_vm_options
1472 setup_bootstrap_search_path(THREAD);
1473 }
1474
1475 static char* lookup_vm_resource(JImageFile *jimage, const char *jimage_version, const char *path) {
1476 jlong size;
1477 JImageLocationRef location = (*JImageFindResource)(jimage, "java.base", jimage_version, path, &size);
1478 if (location == 0)
1479 return nullptr;
1480 char *val = NEW_C_HEAP_ARRAY(char, size+1, mtClass);
1481 (*JImageGetResource)(jimage, location, val, size);
1482 val[size] = '\0';
1483 return val;
1484 }
1485
1486 // Lookup VM options embedded in the modules jimage file
1487 char* ClassLoader::lookup_vm_options() {
1488 jint error;
1489 char modules_path[JVM_MAXPATHLEN];
1490 const char* fileSep = os::file_separator();
1491
1492 // Initialize jimage library entry points
1493 load_jimage_library();
1494
1495 jio_snprintf(modules_path, JVM_MAXPATHLEN, "%s%slib%smodules", Arguments::get_java_home(), fileSep, fileSep);
1496 JImage_file =(*JImageOpen)(modules_path, &error);
1497 if (JImage_file == nullptr) {
1498 return nullptr;
1499 }
1500
1501 const char *jimage_version = get_jimage_version_string();
1502 char *options = lookup_vm_resource(JImage_file, jimage_version, "jdk/internal/vm/options");
1503 return options;
1504 }
1505
1506 bool ClassLoader::is_module_observable(const char* module_name) {
1507 assert(JImageOpen != nullptr, "jimage library should have been opened");
1508 if (JImage_file == nullptr) {
1509 struct stat st;
1510 const char *path = get_exploded_module_path(module_name, true);
1511 bool res = os::stat(path, &st) == 0;
1512 FREE_C_HEAP_ARRAY(char, path);
1513 return res;
1514 }
1515 jlong size;
1516 const char *jimage_version = get_jimage_version_string();
1517 return (*JImageFindResource)(JImage_file, module_name, jimage_version, "module-info.class", &size) != 0;
1518 }
1519
1520 #if INCLUDE_CDS
1521 void ClassLoader::initialize_shared_path(JavaThread* current) {
1522 if (CDSConfig::is_dumping_archive()) {
1523 ClassLoaderExt::setup_search_paths(current);
1524 }
1525 }
1526
1527 void ClassLoader::initialize_module_path(TRAPS) {
1528 if (CDSConfig::is_dumping_archive()) {
1529 ClassLoaderExt::setup_module_paths(THREAD);
1530 FileMapInfo::allocate_shared_path_table(CHECK);
1531 }
1532 }
1533
1534 // Helper function used by CDS code to get the number of module path
1535 // entries during shared classpath setup time.
1536 int ClassLoader::num_module_path_entries() {
1537 assert(CDSConfig::is_dumping_archive(), "sanity");
1538 int num_entries = 0;
1539 ClassPathEntry* e= ClassLoader::_module_path_entries;
1540 while (e != nullptr) {
1541 num_entries ++;
1542 e = e->next();
1543 }
1544 return num_entries;
1545 }
1546 #endif
1547
1548 jlong ClassLoader::classloader_time_ms() {
1549 return UsePerfData ?
1550 Management::ticks_to_ms(_perf_accumulated_time->get_value()) : -1;
1551 }
1552
1553 jlong ClassLoader::class_init_count() {
1554 return UsePerfData ? _perf_classes_inited->get_value() : -1;
1555 }
1556
1557 jlong ClassLoader::class_init_time_ms() {
1558 return UsePerfData ?
1559 Management::ticks_to_ms(_perf_class_init_time->get_value()) : -1;
1560 }
1561
1562 jlong ClassLoader::class_verify_time_ms() {
1563 return UsePerfData ?
1564 Management::ticks_to_ms(_perf_class_verify_time->get_value()) : -1;
1565 }
1566
1567 jlong ClassLoader::class_link_count() {
1568 return UsePerfData ? _perf_classes_linked->get_value() : -1;
1569 }
1570
1571 jlong ClassLoader::class_link_time_ms() {
1572 return UsePerfData ?
1573 Management::ticks_to_ms(_perf_class_link_time->get_value()) : -1;
1574 }
1575
1576 int ClassLoader::compute_Object_vtable() {
1577 // hardwired for JDK1.2 -- would need to duplicate class file parsing
1578 // code to determine actual value from file
1579 // Would be value '11' if finals were in vtable
1580 int JDK_1_2_Object_vtable_size = 5;
1581 return JDK_1_2_Object_vtable_size * vtableEntry::size();
1582 }
1583
1584
1585 void classLoader_init1() {
1586 EXCEPTION_MARK;
1587 ClassLoader::initialize(THREAD);
1588 if (HAS_PENDING_EXCEPTION) {
1589 vm_exit_during_initialization("ClassLoader::initialize() failed unexpectedly");
1590 }
1591 }
1592
1593 // Complete the ClassPathEntry setup for the boot loader
1594 void ClassLoader::classLoader_init2(JavaThread* current) {
1595 // Setup the list of module/path pairs for --patch-module processing
1596 // This must be done after the SymbolTable is created in order
1597 // to use fast_compare on module names instead of a string compare.
1598 if (Arguments::get_patch_mod_prefix() != nullptr) {
1599 setup_patch_mod_entries();
1600 }
1601
1602 // Create the ModuleEntry for java.base (must occur after setup_patch_mod_entries
1603 // to successfully determine if java.base has been patched)
1604 create_javabase();
1605
1606 // Setup the initial java.base/path pair for the exploded build entries.
1607 // As more modules are defined during module system initialization, more
1608 // entries will be added to the exploded build array.
1609 if (!has_jrt_entry()) {
1610 assert(!CDSConfig::is_dumping_archive(), "not supported with exploded module builds");
1611 assert(!CDSConfig::is_using_archive(), "UsedSharedSpaces not supported with exploded module builds");
1612 // Set up the boot loader's _exploded_entries list. Note that this gets
1613 // done before loading any classes, by the same thread that will
1614 // subsequently do the first class load. So, no lock is needed for this.
1615 assert(_exploded_entries == nullptr, "Should only get initialized once");
1616 _exploded_entries = new (mtModule)
1617 GrowableArray<ModuleClassPathList*>(EXPLODED_ENTRY_SIZE, mtModule);
1618 add_to_exploded_build_list(current, vmSymbols::java_base());
1619 }
1620 }
1621
1622 char* ClassLoader::get_canonical_path(const char* orig, Thread* thread) {
1623 assert(orig != nullptr, "bad arguments");
1624 // caller needs to allocate ResourceMark for the following output buffer
1625 char* canonical_path = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, JVM_MAXPATHLEN);
1626 ResourceMark rm(thread);
1627 // os::native_path writes into orig_copy
1628 char* orig_copy = NEW_RESOURCE_ARRAY_IN_THREAD(thread, char, strlen(orig)+1);
1629 strcpy(orig_copy, orig);
1630 if ((CanonicalizeEntry)(os::native_path(orig_copy), canonical_path, JVM_MAXPATHLEN) < 0) {
1631 return nullptr;
1632 }
1633 return canonical_path;
1634 }
1635
1636 void ClassLoader::create_javabase() {
1637 JavaThread* current = JavaThread::current();
1638
1639 // Create java.base's module entry for the boot
1640 // class loader prior to loading j.l.Object.
1641 ClassLoaderData* null_cld = ClassLoaderData::the_null_class_loader_data();
1642
1643 // Get module entry table
1644 ModuleEntryTable* null_cld_modules = null_cld->modules();
1645 if (null_cld_modules == nullptr) {
1646 vm_exit_during_initialization("No ModuleEntryTable for the boot class loader");
1647 }
1648
1649 {
1650 MutexLocker ml(current, Module_lock);
1651 if (ModuleEntryTable::javabase_moduleEntry() == nullptr) { // may have been inited by CDS.
1652 ModuleEntry* jb_module = null_cld_modules->locked_create_entry(Handle(),
1653 false, vmSymbols::java_base(), nullptr, nullptr, null_cld);
1654 if (jb_module == nullptr) {
1655 vm_exit_during_initialization("Unable to create ModuleEntry for " JAVA_BASE_NAME);
1656 }
1657 ModuleEntryTable::set_javabase_moduleEntry(jb_module);
1658 }
1659 }
1660 }
1661
1662 // Please keep following two functions at end of this file. With them placed at top or in middle of the file,
1663 // they could get inlined by aggressive compiler, an unknown trick, see bug 6966589.
1664 void PerfClassTraceTime::initialize() {
1665 if (!UsePerfData) return;
1666
1667 if (_eventp != nullptr) {
1668 // increment the event counter
1669 _eventp->inc();
1670 }
1671
1672 // stop the current active thread-local timer to measure inclusive time
1673 _prev_active_event = -1;
1674 for (int i=0; i < EVENT_TYPE_COUNT; i++) {
1675 if (_timers[i].is_active()) {
1676 assert(_prev_active_event == -1, "should have only one active timer");
1677 _prev_active_event = i;
1678 _timers[i].stop();
1679 }
1680 }
1681
1682 if (_recursion_counters == nullptr || (_recursion_counters[_event_type])++ == 0) {
1683 // start the inclusive timer if not recursively called
1684 _t.start();
1685 }
1686
1687 // start thread-local timer of the given event type
1688 if (!_timers[_event_type].is_active()) {
1689 _timers[_event_type].start();
1690 }
1691 }
1692
1693 PerfClassTraceTime::~PerfClassTraceTime() {
1694 if (!UsePerfData) return;
1695
1696 // stop the thread-local timer as the event completes
1697 // and resume the thread-local timer of the event next on the stack
1698 _timers[_event_type].stop();
1699 jlong selftime = _timers[_event_type].ticks();
1700
1701 if (_prev_active_event >= 0) {
1702 _timers[_prev_active_event].start();
1703 }
1704
1705 if (_recursion_counters != nullptr && --(_recursion_counters[_event_type]) > 0) return;
1706
1707 // increment the counters only on the leaf call
1708 _t.stop();
1709 _timep->inc(_t.ticks());
1710 if (_selftimep != nullptr) {
1711 _selftimep->inc(selftime);
1712 }
1713 // add all class loading related event selftime to the accumulated time counter
1714 ClassLoader::perf_accumulated_time()->inc(selftime);
1715
1716 // reset the timer
1717 _timers[_event_type].reset();
1718 }