1 /*
2 * Copyright (c) 1997, 2019, 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_CLASSFILE_CLASSLOADER_HPP
26 #define SHARE_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 // Is this entry created from the "Class-path" attribute from a JAR Manifest?
57 virtual bool from_class_path_attr() const = 0;
58 virtual const char* name() const = 0;
59 virtual JImageFile* jimage() const = 0;
60 virtual void close_jimage() = 0;
61 // Constructor
62 ClassPathEntry() : _next(NULL) {}
63 // Attempt to locate file_name through this class path entry.
64 // Returns a class file parsing stream if successfull.
65 virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0;
66 // Open the stream for a specific class loader
67 virtual ClassFileStream* open_stream_for_loader(const char* name, ClassLoaderData* loader_data, TRAPS) {
68 return open_stream(name, THREAD);
69 }
70 };
71
72 class ClassPathDirEntry: public ClassPathEntry {
73 private:
74 const char* _dir; // Name of directory
75 public:
76 bool is_modules_image() const { return false; }
77 bool is_jar_file() const { return false; }
78 bool from_class_path_attr() const { return false; }
79 const char* name() const { return _dir; }
80 JImageFile* jimage() const { return NULL; }
81 void close_jimage() {}
82 ClassPathDirEntry(const char* dir);
83 virtual ~ClassPathDirEntry() {}
84 ClassFileStream* open_stream(const char* name, TRAPS);
85 };
86
87
88 // Type definitions for zip file and zip file entry
89 typedef void* jzfile;
90 typedef struct {
91 char *name; /* entry name */
92 jlong time; /* modification time */
93 jlong size; /* size of uncompressed data */
94 jlong csize; /* size of compressed data (zero if uncompressed) */
95 jint crc; /* crc of uncompressed data */
96 char *comment; /* optional zip file comment */
97 jbyte *extra; /* optional extra data */
98 jlong pos; /* position of LOC header (if negative) or data */
99 } jzentry;
100
101 class ClassPathZipEntry: public ClassPathEntry {
102 private:
103 jzfile* _zip; // The zip archive
104 const char* _zip_name; // Name of zip archive
105 bool _from_class_path_attr; // From the "Class-path" attribute of a jar file
106 public:
107 bool is_modules_image() const { return false; }
108 bool is_jar_file() const { return true; }
109 bool from_class_path_attr() const { return _from_class_path_attr; }
110 const char* name() const { return _zip_name; }
111 JImageFile* jimage() const { return NULL; }
112 void close_jimage() {}
113 ClassPathZipEntry(jzfile* zip, const char* zip_name, bool is_boot_append, bool from_class_path_attr);
114 virtual ~ClassPathZipEntry();
115 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
116 ClassFileStream* open_stream(const char* name, TRAPS);
117 void contents_do(void f(const char* name, void* context), void* context);
118 };
119
120
121 // For java image files
122 class ClassPathImageEntry: public ClassPathEntry {
123 private:
124 JImageFile* _jimage;
125 const char* _name;
126 DEBUG_ONLY(static ClassPathImageEntry* _singleton;)
127 public:
128 bool is_modules_image() const;
129 bool is_jar_file() const { return false; }
130 bool from_class_path_attr() const { return false; }
131 bool is_open() const { return _jimage != NULL; }
132 const char* name() const { return _name == NULL ? "" : _name; }
133 JImageFile* jimage() const { return _jimage; }
134 void close_jimage();
135 ClassPathImageEntry(JImageFile* jimage, const char* name);
136 virtual ~ClassPathImageEntry();
137 ClassFileStream* open_stream(const char* name, TRAPS);
138 ClassFileStream* open_stream_for_loader(const char* name, ClassLoaderData* loader_data, TRAPS);
139 };
140
141 // ModuleClassPathList contains a linked list of ClassPathEntry's
142 // that have been specified for a specific module. Currently,
143 // the only way to specify a module/path pair is via the --patch-module
144 // command line option.
145 class ModuleClassPathList : public CHeapObj<mtClass> {
146 private:
147 Symbol* _module_name;
148 // First and last entries of class path entries for a specific module
149 ClassPathEntry* _module_first_entry;
150 ClassPathEntry* _module_last_entry;
151 public:
152 Symbol* module_name() const { return _module_name; }
153 ClassPathEntry* module_first_entry() const { return _module_first_entry; }
154 ModuleClassPathList(Symbol* module_name);
155 ~ModuleClassPathList();
156 void add_to_list(ClassPathEntry* new_entry);
157 };
158
159 class SharedPathsMiscInfo;
160
161 class ClassLoader: AllStatic {
162 public:
163 enum ClassLoaderType {
164 BOOT_LOADER = 1, /* boot loader */
165 PLATFORM_LOADER = 2, /* PlatformClassLoader */
166 APP_LOADER = 3 /* AppClassLoader */
167 };
168 protected:
169
170 // Performance counters
171 static PerfCounter* _perf_accumulated_time;
172 static PerfCounter* _perf_classes_inited;
173 static PerfCounter* _perf_class_init_time;
174 static PerfCounter* _perf_class_init_selftime;
175 static PerfCounter* _perf_classes_verified;
176 static PerfCounter* _perf_class_verify_time;
177 static PerfCounter* _perf_class_verify_selftime;
178 static PerfCounter* _perf_classes_linked;
179 static PerfCounter* _perf_class_link_time;
180 static PerfCounter* _perf_class_link_selftime;
181 static PerfCounter* _perf_class_parse_time;
182 static PerfCounter* _perf_class_parse_selftime;
183 static PerfCounter* _perf_sys_class_lookup_time;
184 static PerfCounter* _perf_shared_classload_time;
185 static PerfCounter* _perf_sys_classload_time;
186 static PerfCounter* _perf_app_classload_time;
187 static PerfCounter* _perf_app_classload_selftime;
188 static PerfCounter* _perf_app_classload_count;
189 static PerfCounter* _perf_define_appclasses;
190 static PerfCounter* _perf_define_appclass_time;
191 static PerfCounter* _perf_define_appclass_selftime;
192 static PerfCounter* _perf_app_classfile_bytes_read;
193 static PerfCounter* _perf_sys_classfile_bytes_read;
194
195 static PerfCounter* _sync_systemLoaderLockContentionRate;
196 static PerfCounter* _sync_nonSystemLoaderLockContentionRate;
197 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter;
198 static PerfCounter* _sync_JVMDefineClassLockFreeCounter;
199 static PerfCounter* _sync_JNIDefineClassLockFreeCounter;
200
201 static PerfCounter* _unsafe_defineClassCallCounter;
202
203 // The boot class path consists of 3 ordered pieces:
204 // 1. the module/path pairs specified to --patch-module
205 // --patch-module=<module>=<file>(<pathsep><file>)*
206 // 2. the base piece
207 // [jimage | build with exploded modules]
208 // 3. boot loader append path
209 // [-Xbootclasspath/a]; [jvmti appended entries]
210 //
211 // The boot loader must obey this order when attempting
212 // to load a class.
213
214 // 1. Contains the module/path pairs specified to --patch-module
215 static GrowableArray<ModuleClassPathList*>* _patch_mod_entries;
216
217 // 2. the base piece
218 // Contains the ClassPathEntry of the modular java runtime image.
219 // If no java runtime image is present, this indicates a
220 // build with exploded modules is being used instead.
221 static ClassPathEntry* _jrt_entry;
222 static GrowableArray<ModuleClassPathList*>* _exploded_entries;
223 enum { EXPLODED_ENTRY_SIZE = 80 }; // Initial number of exploded modules
224
225 // 3. the boot loader's append path
226 // [-Xbootclasspath/a]; [jvmti appended entries]
227 // Note: boot loader append path does not support named modules.
228 static ClassPathEntry* _first_append_entry;
229 // Last entry in linked list of appended ClassPathEntry instances
230 static ClassPathEntry* _last_append_entry;
231
232 // Info used by CDS
233 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;)
234
235 CDS_ONLY(static ClassPathEntry* _app_classpath_entries;)
236 CDS_ONLY(static ClassPathEntry* _last_app_classpath_entry;)
237 CDS_ONLY(static ClassPathEntry* _module_path_entries;)
238 CDS_ONLY(static ClassPathEntry* _last_module_path_entry;)
239 CDS_ONLY(static void setup_app_search_path(const char* class_path);)
240 CDS_ONLY(static void setup_module_search_path(const char* path, TRAPS);)
241 static void add_to_app_classpath_entries(const char* path,
242 ClassPathEntry* entry,
243 bool check_for_duplicates);
244 CDS_ONLY(static void add_to_module_path_entries(const char* path,
245 ClassPathEntry* entry);)
246 public:
247 CDS_ONLY(static ClassPathEntry* app_classpath_entries() {return _app_classpath_entries;})
248 CDS_ONLY(static ClassPathEntry* module_path_entries() {return _module_path_entries;})
249
250 protected:
251 // Initialization:
252 // - setup the boot loader's system class path
253 // - setup the boot loader's patch mod entries, if present
254 // - create the ModuleEntry for java.base
255 static void setup_bootstrap_search_path();
256 static void setup_boot_search_path(const char *class_path);
257 static void setup_patch_mod_entries();
258 static void create_javabase();
259
260 static void load_zip_library();
261 static void load_jimage_library();
262
263 public:
264 static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st,
265 bool throw_exception,
266 bool is_boot_append,
267 bool from_class_path_attr, TRAPS);
268
269 // If the package for the fully qualified class name is in the boot
270 // loader's package entry table then add_package() sets the classpath_index
271 // field so that get_system_package() will know to return a non-null value
272 // for the package's location. And, so that the package will be added to
273 // the list of packages returned by get_system_packages().
274 // For packages whose classes are loaded from the boot loader class path, the
275 // classpath_index indicates which entry on the boot loader class path.
276 static bool add_package(const char *fullq_class_name, s2 classpath_index, TRAPS);
277
278 // Canonicalizes path names, so strcmp will work properly. This is mainly
279 // to avoid confusing the zip library
280 static bool get_canonical_path(const char* orig, char* out, int len);
281 static const char* file_name_for_class_name(const char* class_name,
282 int class_name_len);
283 static PackageEntry* get_package_entry(const char* class_name, ClassLoaderData* loader_data, TRAPS);
284
285 public:
286 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg);
287 static int crc32(int crc, const char* buf, int len);
288 static bool update_class_path_entry_list(const char *path,
289 bool check_for_duplicates,
290 bool is_boot_append,
291 bool from_class_path_attr,
292 bool throw_exception=true);
293 CDS_ONLY(static void update_module_path_entry_list(const char *path, TRAPS);)
294 static void print_bootclasspath();
295
296 // Timing
297 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; }
298 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; }
299 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; }
300 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; }
301 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; }
302 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; }
303 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; }
304 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; }
305 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; }
306 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; }
307 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; }
308 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; }
309 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; }
310 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; }
311 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; }
312 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; }
313 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; }
314 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; }
315 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; }
316 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; }
317 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; }
318 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; }
319 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; }
320
321 // Record how often system loader lock object is contended
322 static PerfCounter* sync_systemLoaderLockContentionRate() {
323 return _sync_systemLoaderLockContentionRate;
324 }
325
326 // Record how often non system loader lock object is contended
327 static PerfCounter* sync_nonSystemLoaderLockContentionRate() {
328 return _sync_nonSystemLoaderLockContentionRate;
329 }
330
331 // Record how many calls to JVM_FindLoadedClass w/o holding a lock
332 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() {
333 return _sync_JVMFindLoadedClassLockFreeCounter;
334 }
335
336 // Record how many calls to JVM_DefineClass w/o holding a lock
337 static PerfCounter* sync_JVMDefineClassLockFreeCounter() {
338 return _sync_JVMDefineClassLockFreeCounter;
339 }
340
341 // Record how many calls to jni_DefineClass w/o holding a lock
342 static PerfCounter* sync_JNIDefineClassLockFreeCounter() {
343 return _sync_JNIDefineClassLockFreeCounter;
344 }
345
346 // Record how many calls to Unsafe_DefineClass
347 static PerfCounter* unsafe_defineClassCallCounter() {
348 return _unsafe_defineClassCallCounter;
349 }
350
351 // Modular java runtime image is present vs. a build with exploded modules
352 static bool has_jrt_entry() { return (_jrt_entry != NULL); }
353 static ClassPathEntry* get_jrt_entry() { return _jrt_entry; }
354 static void close_jrt_image();
355
356 // Add a module's exploded directory to the boot loader's exploded module build list
357 static void add_to_exploded_build_list(Symbol* module_name, TRAPS);
358
359 // Attempt load of individual class from either the patched or exploded modules build lists
360 static ClassFileStream* search_module_entries(const GrowableArray<ModuleClassPathList*>* const module_list,
361 const char* const class_name,
362 const char* const file_name, TRAPS);
363
364 // Load individual .class file
365 static InstanceKlass* load_class(Symbol* class_name, bool search_append_only, TRAPS);
366
367 // If the specified package has been loaded by the system, then returns
368 // the name of the directory or ZIP file that the package was loaded from.
369 // Returns null if the package was not loaded.
370 // Note: The specified name can either be the name of a class or package.
371 // If a package name is specified, then it must be "/"-separator and also
372 // end with a trailing "/".
373 static oop get_system_package(const char* name, TRAPS);
374
375 // Returns an array of Java strings representing all of the currently
376 // loaded system packages.
377 // Note: The package names returned are "/"-separated and end with a
378 // trailing "/".
379 static objArrayOop get_system_packages(TRAPS);
380
381 // Initialization
382 static void initialize();
383 static void classLoader_init2(TRAPS);
384 CDS_ONLY(static void initialize_shared_path();)
385 CDS_ONLY(static void initialize_module_path(TRAPS);)
386
387 static int compute_Object_vtable();
388
389 static ClassPathEntry* classpath_entry(int n);
390
391 static bool is_in_patch_mod_entries(Symbol* module_name);
392
393 #if INCLUDE_CDS
394 // Sharing dump and restore
395
396 // Helper function used by CDS code to get the number of boot classpath
397 // entries during shared classpath setup time.
398 static int num_boot_classpath_entries();
399
400 static ClassPathEntry* get_next_boot_classpath_entry(ClassPathEntry* e);
401
402 // Helper function used by CDS code to get the number of app classpath
403 // entries during shared classpath setup time.
404 static int num_app_classpath_entries();
405
406 // Helper function used by CDS code to get the number of module path
407 // entries during shared classpath setup time.
408 static int num_module_path_entries() {
409 assert(DumpSharedSpaces || DynamicDumpSharedSpaces,
410 "Should only be called at CDS dump time");
411 int num_entries = 0;
412 ClassPathEntry* e= ClassLoader::_module_path_entries;
413 while (e != NULL) {
414 num_entries ++;
415 e = e->next();
416 }
417 return num_entries;
418 }
419 static void finalize_shared_paths_misc_info();
420 static int get_shared_paths_misc_info_size();
421 static void* get_shared_paths_misc_info();
422 static bool check_shared_paths_misc_info(void* info, int size, bool is_static);
423 static void exit_with_path_failure(const char* error, const char* message);
424 static char* skip_uri_protocol(char* source);
425 static void record_result(InstanceKlass* ik, const ClassFileStream* stream, TRAPS);
426 #endif
427 static JImageLocationRef jimage_find_resource(JImageFile* jf, const char* module_name,
428 const char* file_name, jlong &size);
429
430 static void trace_class_path(const char* msg, const char* name = NULL);
431
432 // VM monitoring and management support
433 static jlong classloader_time_ms();
434 static jlong class_method_total_size();
435 static jlong class_init_count();
436 static jlong class_init_time_ms();
437 static jlong class_verify_time_ms();
438 static jlong class_link_count();
439 static jlong class_link_time_ms();
440
441 // indicates if class path already contains a entry (exact match by name)
442 static bool contains_append_entry(const char* name);
443
444 // adds a class path to the boot append entries
445 static void add_to_boot_append_entries(ClassPathEntry* new_entry);
446
447 // creates a class path zip entry (returns NULL if JAR file cannot be opened)
448 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath, bool is_boot_append);
449
450 static bool string_ends_with(const char* str, const char* str_to_find);
451
452 // obtain package name from a fully qualified class name
453 // *bad_class_name is set to true if there's a problem with parsing class_name, to
454 // distinguish from a class_name with no package name, as both cases have a NULL return value
455 static const char* package_from_name(const char* const class_name, bool* bad_class_name = NULL);
456
457 // Debugging
458 static void verify() PRODUCT_RETURN;
459 };
460
461 // PerfClassTraceTime is used to measure time for class loading related events.
462 // This class tracks cumulative time and exclusive time for specific event types.
463 // During the execution of one event, other event types (e.g. class loading and
464 // resolution) as well as recursive calls of the same event type could happen.
465 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive)
466 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime
467 // instances have been created as multiple events are happening.
468 class PerfClassTraceTime {
469 public:
470 enum {
471 CLASS_LOAD = 0,
472 PARSE_CLASS = 1,
473 CLASS_LINK = 2,
474 CLASS_VERIFY = 3,
475 CLASS_CLINIT = 4,
476 DEFINE_CLASS = 5,
477 EVENT_TYPE_COUNT = 6
478 };
479 protected:
480 // _t tracks time from initialization to destruction of this timer instance
481 // including time for all other event types, and recursive calls of this type.
482 // When a timer is called recursively, the elapsedTimer _t would not be used.
483 elapsedTimer _t;
484 PerfLongCounter* _timep;
485 PerfLongCounter* _selftimep;
486 PerfLongCounter* _eventp;
487 // pointer to thread-local recursion counter and timer array
488 // The thread_local timers track cumulative time for specific event types
489 // exclusive of time for other event types, but including recursive calls
490 // of the same type.
491 int* _recursion_counters;
492 elapsedTimer* _timers;
493 int _event_type;
494 int _prev_active_event;
495
496 public:
497
498 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
499 PerfLongCounter* selftimep, /* counter incremented with exclusive time */
500 PerfLongCounter* eventp, /* event counter */
501 int* recursion_counters, /* thread-local recursion counter array */
502 elapsedTimer* timers, /* thread-local timer array */
503 int type /* event type */ ) :
504 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) {
505 initialize();
506 }
507
508 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
509 elapsedTimer* timers, /* thread-local timer array */
510 int type /* event type */ ) :
511 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) {
512 initialize();
513 }
514
515 inline void suspend() { _t.stop(); _timers[_event_type].stop(); }
516 inline void resume() { _t.start(); _timers[_event_type].start(); }
517
518 ~PerfClassTraceTime();
519 void initialize();
520 };
521
522 #endif // SHARE_CLASSFILE_CLASSLOADER_HPP