1 /*
2 * Copyright (c) 1997, 2018, 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 #ifndef SHARE_VM_CLASSFILE_CLASSLOADER_HPP
26 #define SHARE_VM_CLASSFILE_CLASSLOADER_HPP
27
28 #include "jimage.hpp"
29 #include "runtime/handles.hpp"
30 #include "runtime/perfData.hpp"
31 #include "utilities/exceptions.hpp"
32 #include "utilities/macros.hpp"
33
34 // The VM class loader.
35 #include <sys/stat.h>
36
37 // Name of boot "modules" image
38 #define MODULES_IMAGE_NAME "modules"
39
40 // Class path entry (directory or zip file)
41
42 class JImageFile;
43 class ClassFileStream;
44 class PackageEntry;
45 template <typename T> class GrowableArray;
46
47 class ClassPathEntry : public CHeapObj<mtClass> {
48 private:
49 ClassPathEntry* volatile _next;
50 public:
51 ClassPathEntry* next() const;
52 virtual ~ClassPathEntry() {}
53 void set_next(ClassPathEntry* next);
54 virtual bool is_modules_image() const = 0;
55 virtual bool is_jar_file() const = 0;
56 virtual const char* name() const = 0;
57 virtual JImageFile* jimage() const = 0;
58 // Constructor
59 ClassPathEntry() : _next(NULL) {}
60 // Attempt to locate file_name through this class path entry.
61 // Returns a class file parsing stream if successfull.
62 virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0;
63 // Debugging
64 NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;)
65 };
66
67 class ClassPathDirEntry: public ClassPathEntry {
68 private:
69 const char* _dir; // Name of directory
70 public:
71 bool is_modules_image() const { return false; }
72 bool is_jar_file() const { return false; }
73 const char* name() const { return _dir; }
74 JImageFile* jimage() const { return NULL; }
75 ClassPathDirEntry(const char* dir);
76 virtual ~ClassPathDirEntry() {}
77 ClassFileStream* open_stream(const char* name, TRAPS);
78 // Debugging
79 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
80 };
81
82
83 // Type definitions for zip file and zip file entry
84 typedef void* jzfile;
85 typedef struct {
86 char *name; /* entry name */
87 jlong time; /* modification time */
88 jlong size; /* size of uncompressed data */
89 jlong csize; /* size of compressed data (zero if uncompressed) */
90 jint crc; /* crc of uncompressed data */
91 char *comment; /* optional zip file comment */
92 jbyte *extra; /* optional extra data */
93 jlong pos; /* position of LOC header (if negative) or data */
94 } jzentry;
95
96 class ClassPathZipEntry: public ClassPathEntry {
97 enum {
98 _unknown = 0,
99 _yes = 1,
100 _no = 2
101 };
102 private:
103 jzfile* _zip; // The zip archive
104 const char* _zip_name; // Name of zip archive
105 bool _is_boot_append; // entry coming from -Xbootclasspath/a
106 u1 _multi_versioned; // indicates if the jar file has multi-versioned entries.
107 // It can have value of "_unknown", "_yes", or "_no"
108 public:
109 bool is_modules_image() const { return false; }
110 bool is_jar_file() const { return true; }
111 const char* name() const { return _zip_name; }
112 JImageFile* jimage() const { return NULL; }
113 ClassPathZipEntry(jzfile* zip, const char* zip_name, bool is_boot_append);
114 virtual ~ClassPathZipEntry();
115 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
116 u1* open_versioned_entry(const char* name, jint* filesize, TRAPS) NOT_CDS_RETURN_(NULL);
117 ClassFileStream* open_stream(const char* name, TRAPS);
118 void contents_do(void f(const char* name, void* context), void* context);
119 bool is_multiple_versioned(TRAPS) NOT_CDS_RETURN_(false);
120 // Debugging
121 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
122 };
123
124
125 // For java image files
126 class ClassPathImageEntry: public ClassPathEntry {
127 private:
128 JImageFile* _jimage;
129 const char* _name;
130 public:
131 bool is_modules_image() const;
132 bool is_jar_file() const { return false; }
133 bool is_open() const { return _jimage != NULL; }
134 const char* name() const { return _name == NULL ? "" : _name; }
135 JImageFile* jimage() const { return _jimage; }
136 ClassPathImageEntry(JImageFile* jimage, const char* name);
137 virtual ~ClassPathImageEntry();
138 ClassFileStream* open_stream(const char* name, TRAPS);
139
140 // Debugging
141 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
142 };
143
144 // ModuleClassPathList contains a linked list of ClassPathEntry's
145 // that have been specified for a specific module. Currently,
146 // the only way to specify a module/path pair is via the --patch-module
147 // command line option.
148 class ModuleClassPathList : public CHeapObj<mtClass> {
149 private:
150 Symbol* _module_name;
151 // First and last entries of class path entries for a specific module
152 ClassPathEntry* _module_first_entry;
153 ClassPathEntry* _module_last_entry;
154 public:
155 Symbol* module_name() const { return _module_name; }
156 ClassPathEntry* module_first_entry() const { return _module_first_entry; }
157 ModuleClassPathList(Symbol* module_name);
158 ~ModuleClassPathList();
159 void add_to_list(ClassPathEntry* new_entry);
160 };
161
162 class SharedPathsMiscInfo;
163
164 class ClassLoader: AllStatic {
165 public:
166 enum ClassLoaderType {
167 BOOT_LOADER = 1, /* boot loader */
168 PLATFORM_LOADER = 2, /* PlatformClassLoader */
169 APP_LOADER = 3 /* AppClassLoader */
170 };
171 protected:
172
173 // Performance counters
174 static PerfCounter* _perf_accumulated_time;
175 static PerfCounter* _perf_classes_inited;
176 static PerfCounter* _perf_class_init_time;
177 static PerfCounter* _perf_class_init_selftime;
178 static PerfCounter* _perf_classes_verified;
179 static PerfCounter* _perf_class_verify_time;
180 static PerfCounter* _perf_class_verify_selftime;
181 static PerfCounter* _perf_classes_linked;
182 static PerfCounter* _perf_class_link_time;
183 static PerfCounter* _perf_class_link_selftime;
184 static PerfCounter* _perf_class_parse_time;
185 static PerfCounter* _perf_class_parse_selftime;
186 static PerfCounter* _perf_sys_class_lookup_time;
187 static PerfCounter* _perf_shared_classload_time;
188 static PerfCounter* _perf_sys_classload_time;
189 static PerfCounter* _perf_app_classload_time;
190 static PerfCounter* _perf_app_classload_selftime;
191 static PerfCounter* _perf_app_classload_count;
192 static PerfCounter* _perf_define_appclasses;
193 static PerfCounter* _perf_define_appclass_time;
194 static PerfCounter* _perf_define_appclass_selftime;
195 static PerfCounter* _perf_app_classfile_bytes_read;
196 static PerfCounter* _perf_sys_classfile_bytes_read;
197
198 static PerfCounter* _sync_systemLoaderLockContentionRate;
199 static PerfCounter* _sync_nonSystemLoaderLockContentionRate;
200 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter;
201 static PerfCounter* _sync_JVMDefineClassLockFreeCounter;
202 static PerfCounter* _sync_JNIDefineClassLockFreeCounter;
203
204 static PerfCounter* _unsafe_defineClassCallCounter;
205 static PerfCounter* _load_instance_class_failCounter;
206
207 // The boot class path consists of 3 ordered pieces:
208 // 1. the module/path pairs specified to --patch-module
209 // --patch-module=<module>=<file>(<pathsep><file>)*
210 // 2. the base piece
211 // [jimage | build with exploded modules]
212 // 3. boot loader append path
213 // [-Xbootclasspath/a]; [jvmti appended entries]
214 //
215 // The boot loader must obey this order when attempting
216 // to load a class.
217
218 // 1. Contains the module/path pairs specified to --patch-module
219 static GrowableArray<ModuleClassPathList*>* _patch_mod_entries;
220
221 // 2. the base piece
222 // Contains the ClassPathEntry of the modular java runtime image.
223 // If no java runtime image is present, this indicates a
224 // build with exploded modules is being used instead.
225 static ClassPathEntry* _jrt_entry;
226 static GrowableArray<ModuleClassPathList*>* _exploded_entries;
227 enum { EXPLODED_ENTRY_SIZE = 80 }; // Initial number of exploded modules
228
229 // 3. the boot loader's append path
230 // [-Xbootclasspath/a]; [jvmti appended entries]
231 // Note: boot loader append path does not support named modules.
232 static ClassPathEntry* _first_append_entry;
233 // Last entry in linked list of appended ClassPathEntry instances
234 static ClassPathEntry* _last_append_entry;
235
236 // Info used by CDS
237 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;)
238
239 CDS_ONLY(static ClassPathEntry* _app_classpath_entries;)
240 CDS_ONLY(static ClassPathEntry* _last_app_classpath_entry;)
241 CDS_ONLY(static ClassPathEntry* _module_path_entries;)
242 CDS_ONLY(static ClassPathEntry* _last_module_path_entry;)
243 CDS_ONLY(static void setup_app_search_path(const char* class_path);)
244 CDS_ONLY(static void setup_module_search_path(const char* path, TRAPS);)
245 static void add_to_app_classpath_entries(const char* path,
246 ClassPathEntry* entry,
247 bool check_for_duplicates);
248 CDS_ONLY(static void add_to_module_path_entries(const char* path,
249 ClassPathEntry* entry);)
250 public:
251 CDS_ONLY(static ClassPathEntry* app_classpath_entries() {return _app_classpath_entries;})
252 CDS_ONLY(static ClassPathEntry* module_path_entries() {return _module_path_entries;})
253
254 protected:
255 // Initialization:
256 // - setup the boot loader's system class path
257 // - setup the boot loader's patch mod entries, if present
258 // - create the ModuleEntry for java.base
259 static void setup_bootstrap_search_path();
260 static void setup_boot_search_path(const char *class_path);
261 static void setup_patch_mod_entries();
262 static void create_javabase();
263
264 static void load_zip_library();
265 static void load_jimage_library();
266 static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st,
267 bool throw_exception,
268 bool is_boot_append, TRAPS);
269
270 public:
271
272 // If the package for the fully qualified class name is in the boot
273 // loader's package entry table then add_package() sets the classpath_index
274 // field so that get_system_package() will know to return a non-null value
275 // for the package's location. And, so that the package will be added to
276 // the list of packages returned by get_system_packages().
277 // For packages whose classes are loaded from the boot loader class path, the
278 // classpath_index indicates which entry on the boot loader class path.
279 static bool add_package(const char *fullq_class_name, s2 classpath_index, TRAPS);
280
281 // Canonicalizes path names, so strcmp will work properly. This is mainly
282 // to avoid confusing the zip library
283 static bool get_canonical_path(const char* orig, char* out, int len);
284 static const char* file_name_for_class_name(const char* class_name,
285 int class_name_len);
286 static PackageEntry* get_package_entry(const char* class_name, ClassLoaderData* loader_data, TRAPS);
287
288 public:
289 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg);
290 static int crc32(int crc, const char* buf, int len);
291 static bool update_class_path_entry_list(const char *path,
292 bool check_for_duplicates,
293 bool is_boot_append,
294 bool throw_exception=true);
295 CDS_ONLY(static void update_module_path_entry_list(const char *path, TRAPS);)
296 static void print_bootclasspath();
297
298 // Timing
299 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; }
300 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; }
301 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; }
302 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; }
303 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; }
304 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; }
305 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; }
306 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; }
307 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; }
308 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; }
309 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; }
310 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; }
311 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; }
312 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; }
313 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; }
314 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; }
315 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; }
316 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; }
317 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; }
318 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; }
319 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; }
320 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; }
321 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; }
322
323 // Record how often system loader lock object is contended
324 static PerfCounter* sync_systemLoaderLockContentionRate() {
325 return _sync_systemLoaderLockContentionRate;
326 }
327
328 // Record how often non system loader lock object is contended
329 static PerfCounter* sync_nonSystemLoaderLockContentionRate() {
330 return _sync_nonSystemLoaderLockContentionRate;
331 }
332
333 // Record how many calls to JVM_FindLoadedClass w/o holding a lock
334 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() {
335 return _sync_JVMFindLoadedClassLockFreeCounter;
336 }
337
338 // Record how many calls to JVM_DefineClass w/o holding a lock
339 static PerfCounter* sync_JVMDefineClassLockFreeCounter() {
340 return _sync_JVMDefineClassLockFreeCounter;
341 }
342
343 // Record how many calls to jni_DefineClass w/o holding a lock
344 static PerfCounter* sync_JNIDefineClassLockFreeCounter() {
345 return _sync_JNIDefineClassLockFreeCounter;
346 }
347
348 // Record how many calls to Unsafe_DefineClass
349 static PerfCounter* unsafe_defineClassCallCounter() {
350 return _unsafe_defineClassCallCounter;
351 }
352
353 // Record how many times SystemDictionary::load_instance_class call
354 // fails with linkageError when Unsyncloadclass flag is set.
355 static PerfCounter* load_instance_class_failCounter() {
356 return _load_instance_class_failCounter;
357 }
358
359 // Modular java runtime image is present vs. a build with exploded modules
360 static bool has_jrt_entry() { return (_jrt_entry != NULL); }
361 static ClassPathEntry* get_jrt_entry() { return _jrt_entry; }
362
363 // Add a module's exploded directory to the boot loader's exploded module build list
364 static void add_to_exploded_build_list(Symbol* module_name, TRAPS);
365
366 // Attempt load of individual class from either the patched or exploded modules build lists
367 static ClassFileStream* search_module_entries(const GrowableArray<ModuleClassPathList*>* const module_list,
368 const char* const class_name,
369 const char* const file_name, TRAPS);
370
371 // Load individual .class file
372 static InstanceKlass* load_class(Symbol* class_name, bool search_append_only, TRAPS);
373
374 // If the specified package has been loaded by the system, then returns
375 // the name of the directory or ZIP file that the package was loaded from.
376 // Returns null if the package was not loaded.
377 // Note: The specified name can either be the name of a class or package.
378 // If a package name is specified, then it must be "/"-separator and also
379 // end with a trailing "/".
380 static oop get_system_package(const char* name, TRAPS);
381
382 // Returns an array of Java strings representing all of the currently
383 // loaded system packages.
384 // Note: The package names returned are "/"-separated and end with a
385 // trailing "/".
386 static objArrayOop get_system_packages(TRAPS);
387
388 // Initialization
389 static void initialize();
390 static void classLoader_init2(TRAPS);
391 CDS_ONLY(static void initialize_shared_path();)
392 CDS_ONLY(static void initialize_module_path(TRAPS);)
393
394 static int compute_Object_vtable();
395
396 static ClassPathEntry* classpath_entry(int n);
397
398 static bool is_in_patch_mod_entries(Symbol* module_name);
399
400 #if INCLUDE_CDS
401 // Sharing dump and restore
402
403 // Helper function used by CDS code to get the number of boot classpath
404 // entries during shared classpath setup time.
405 static int num_boot_classpath_entries();
406
407 static ClassPathEntry* get_next_boot_classpath_entry(ClassPathEntry* e);
408
409 // Helper function used by CDS code to get the number of app classpath
410 // entries during shared classpath setup time.
411 static int num_app_classpath_entries();
412
413 // Helper function used by CDS code to get the number of module path
414 // entries during shared classpath setup time.
415 static int num_module_path_entries() {
416 assert(DumpSharedSpaces, "Should only be called at CDS dump time");
417 int num_entries = 0;
418 ClassPathEntry* e= ClassLoader::_module_path_entries;
419 while (e != NULL) {
420 num_entries ++;
421 e = e->next();
422 }
423 return num_entries;
424 }
425 static void finalize_shared_paths_misc_info();
426 static int get_shared_paths_misc_info_size();
427 static void* get_shared_paths_misc_info();
428 static bool check_shared_paths_misc_info(void* info, int size);
429 static int get_module_paths_misc_info_size();
430 static void* get_module_paths_misc_info();
431 static void exit_with_path_failure(const char* error, const char* message);
432 static char* skip_uri_protocol(char* source);
433 static void record_result(InstanceKlass* ik, const ClassFileStream* stream, TRAPS);
434 #endif
435 static JImageLocationRef jimage_find_resource(JImageFile* jf, const char* module_name,
436 const char* file_name, jlong &size);
437
438 static void trace_class_path(const char* msg, const char* name = NULL);
439
440 // VM monitoring and management support
441 static jlong classloader_time_ms();
442 static jlong class_method_total_size();
443 static jlong class_init_count();
444 static jlong class_init_time_ms();
445 static jlong class_verify_time_ms();
446 static jlong class_link_count();
447 static jlong class_link_time_ms();
448
449 // indicates if class path already contains a entry (exact match by name)
450 static bool contains_append_entry(const char* name);
451
452 // adds a class path to the boot append entries
453 static void add_to_boot_append_entries(ClassPathEntry* new_entry);
454
455 // creates a class path zip entry (returns NULL if JAR file cannot be opened)
456 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath, bool is_boot_append);
457
458 static bool string_ends_with(const char* str, const char* str_to_find);
459
460 // obtain package name from a fully qualified class name
461 // *bad_class_name is set to true if there's a problem with parsing class_name, to
462 // distinguish from a class_name with no package name, as both cases have a NULL return value
463 static const char* package_from_name(const char* const class_name, bool* bad_class_name = NULL);
464
465 static bool is_modules_image(const char* name) { return string_ends_with(name, MODULES_IMAGE_NAME); }
466
467 // Debugging
468 static void verify() PRODUCT_RETURN;
469
470 // Force compilation of all methods in all classes in bootstrap class path (stress test)
471 #ifndef PRODUCT
472 protected:
473 static int _compile_the_world_class_counter;
474 static int _compile_the_world_method_counter;
475 public:
476 static void compile_the_world();
477 static void compile_the_world_in(char* name, Handle loader, TRAPS);
478 static int compile_the_world_counter() { return _compile_the_world_class_counter; }
479 #endif //PRODUCT
480 };
481
482 // PerfClassTraceTime is used to measure time for class loading related events.
483 // This class tracks cumulative time and exclusive time for specific event types.
484 // During the execution of one event, other event types (e.g. class loading and
485 // resolution) as well as recursive calls of the same event type could happen.
486 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive)
487 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime
488 // instances have been created as multiple events are happening.
489 class PerfClassTraceTime {
490 public:
491 enum {
492 CLASS_LOAD = 0,
493 PARSE_CLASS = 1,
494 CLASS_LINK = 2,
495 CLASS_VERIFY = 3,
496 CLASS_CLINIT = 4,
497 DEFINE_CLASS = 5,
498 EVENT_TYPE_COUNT = 6
499 };
500 protected:
501 // _t tracks time from initialization to destruction of this timer instance
502 // including time for all other event types, and recursive calls of this type.
503 // When a timer is called recursively, the elapsedTimer _t would not be used.
504 elapsedTimer _t;
505 PerfLongCounter* _timep;
506 PerfLongCounter* _selftimep;
507 PerfLongCounter* _eventp;
508 // pointer to thread-local recursion counter and timer array
509 // The thread_local timers track cumulative time for specific event types
510 // exclusive of time for other event types, but including recursive calls
511 // of the same type.
512 int* _recursion_counters;
513 elapsedTimer* _timers;
514 int _event_type;
515 int _prev_active_event;
516
517 public:
518
519 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
520 PerfLongCounter* selftimep, /* counter incremented with exclusive time */
521 PerfLongCounter* eventp, /* event counter */
522 int* recursion_counters, /* thread-local recursion counter array */
523 elapsedTimer* timers, /* thread-local timer array */
524 int type /* event type */ ) :
525 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) {
526 initialize();
527 }
528
529 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
530 elapsedTimer* timers, /* thread-local timer array */
531 int type /* event type */ ) :
532 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) {
533 initialize();
534 }
535
536 inline void suspend() { _t.stop(); _timers[_event_type].stop(); }
537 inline void resume() { _t.start(); _timers[_event_type].start(); }
538
539 ~PerfClassTraceTime();
540 void initialize();
541 };
542
543 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP