1 /*
2 * Copyright (c) 1997, 2014, 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 "classfile/classFileParser.hpp"
29 #include "runtime/perfData.hpp"
30 #include "utilities/macros.hpp"
31
32 // The VM class loader.
33 #include <sys/stat.h>
34
35
36 // Meta-index (optional, to be able to skip opening boot classpath jar files)
37 class MetaIndex: public CHeapObj<mtClass> {
38 private:
39 char** _meta_package_names;
40 int _num_meta_package_names;
41 public:
42 MetaIndex(char** meta_package_names, int num_meta_package_names);
43 ~MetaIndex();
44 bool may_contain(const char* class_name);
45 };
46
47
48 // Class path entry (directory or zip file)
49
50 class ClassPathEntry: public CHeapObj<mtClass> {
51 private:
52 ClassPathEntry* _next;
53 public:
54 // Next entry in class path
55 ClassPathEntry* next() { return _next; }
56 void set_next(ClassPathEntry* next) {
57 // may have unlocked readers, so write atomically.
58 OrderAccess::release_store_ptr(&_next, next);
59 }
60 virtual bool is_jar_file() = 0;
61 virtual const char* name() = 0;
62 virtual bool is_lazy();
63 // Constructor
64 ClassPathEntry();
65 // Attempt to locate file_name through this class path entry.
66 // Returns a class file parsing stream if successfull.
67 virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0;
68 // Debugging
69 NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;)
70 NOT_PRODUCT(virtual bool is_jrt() = 0;)
71 };
72
73
74 class ClassPathDirEntry: public ClassPathEntry {
75 private:
76 const char* _dir; // Name of directory
77 public:
78 bool is_jar_file() { return false; }
79 const char* name() { return _dir; }
80 ClassPathDirEntry(const char* dir);
81 ClassFileStream* open_stream(const char* name, TRAPS);
82 // Debugging
83 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
84 NOT_PRODUCT(bool is_jrt();)
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
102 class ClassPathZipEntry: public ClassPathEntry {
103 private:
104 jzfile* _zip; // The zip archive
105 const char* _zip_name; // Name of zip archive
106 public:
107 bool is_jar_file() { return true; }
108 const char* name() { return _zip_name; }
109 ClassPathZipEntry(jzfile* zip, const char* zip_name);
110 ~ClassPathZipEntry();
111 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
112 ClassFileStream* open_stream(const char* name, TRAPS);
113 void contents_do(void f(const char* name, void* context), void* context);
114 // Debugging
115 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
116 NOT_PRODUCT(bool is_jrt();)
117 };
118
119
120 // For lazier loading of boot class path entries
121 class LazyClassPathEntry: public ClassPathEntry {
122 private:
123 const char* _path; // dir or file
124 struct stat _st;
125 MetaIndex* _meta_index;
126 bool _has_error;
127 bool _throw_exception;
128 volatile ClassPathEntry* _resolved_entry;
129 ClassPathEntry* resolve_entry(TRAPS);
130 public:
131 bool is_jar_file();
132 const char* name() { return _path; }
133 LazyClassPathEntry(const char* path, const struct stat* st, bool throw_exception);
134 virtual ~LazyClassPathEntry();
135 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
136
137 ClassFileStream* open_stream(const char* name, TRAPS);
138 void set_meta_index(MetaIndex* meta_index) { _meta_index = meta_index; }
139 virtual bool is_lazy();
140 // Debugging
141 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
142 NOT_PRODUCT(bool is_jrt();)
143 };
144
145 // For java image files
146 class ImageFile;
147 class ClassPathImageEntry: public ClassPathEntry {
148 private:
149 ImageFile *_image;
150 public:
151 bool is_jar_file() { return false; }
152 bool is_open() { return _image != NULL; }
153 const char* name();
154 ClassPathImageEntry(char* name);
155 ~ClassPathImageEntry();
156 ClassFileStream* open_stream(const char* name, TRAPS);
157
158 // Debugging
159 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
160 NOT_PRODUCT(bool is_jrt();)
161 };
162
163 class PackageHashtable;
164 class PackageInfo;
165 class SharedPathsMiscInfo;
166 template <MEMFLAGS F> class HashtableBucket;
167
168 class ClassLoader: AllStatic {
169 public:
170 enum SomeConstants {
171 package_hash_table_size = 31 // Number of buckets
172 };
173 protected:
174 friend class LazyClassPathEntry;
175
176 // Performance counters
177 static PerfCounter* _perf_accumulated_time;
178 static PerfCounter* _perf_classes_inited;
179 static PerfCounter* _perf_class_init_time;
180 static PerfCounter* _perf_class_init_selftime;
181 static PerfCounter* _perf_classes_verified;
182 static PerfCounter* _perf_class_verify_time;
183 static PerfCounter* _perf_class_verify_selftime;
184 static PerfCounter* _perf_classes_linked;
185 static PerfCounter* _perf_class_link_time;
186 static PerfCounter* _perf_class_link_selftime;
187 static PerfCounter* _perf_class_parse_time;
188 static PerfCounter* _perf_class_parse_selftime;
189 static PerfCounter* _perf_sys_class_lookup_time;
190 static PerfCounter* _perf_shared_classload_time;
191 static PerfCounter* _perf_sys_classload_time;
192 static PerfCounter* _perf_app_classload_time;
193 static PerfCounter* _perf_app_classload_selftime;
194 static PerfCounter* _perf_app_classload_count;
195 static PerfCounter* _perf_define_appclasses;
196 static PerfCounter* _perf_define_appclass_time;
197 static PerfCounter* _perf_define_appclass_selftime;
198 static PerfCounter* _perf_app_classfile_bytes_read;
199 static PerfCounter* _perf_sys_classfile_bytes_read;
200
201 static PerfCounter* _sync_systemLoaderLockContentionRate;
202 static PerfCounter* _sync_nonSystemLoaderLockContentionRate;
203 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter;
204 static PerfCounter* _sync_JVMDefineClassLockFreeCounter;
205 static PerfCounter* _sync_JNIDefineClassLockFreeCounter;
206
207 static PerfCounter* _unsafe_defineClassCallCounter;
208 static PerfCounter* _isUnsyncloadClass;
209 static PerfCounter* _load_instance_class_failCounter;
210
211 // First entry in linked list of ClassPathEntry instances
212 static ClassPathEntry* _first_entry;
213 // Last entry in linked list of ClassPathEntry instances
214 static ClassPathEntry* _last_entry;
215 static int _num_entries;
216
217 // Hash table used to keep track of loaded packages
218 static PackageHashtable* _package_hash_table;
219 static const char* _shared_archive;
220
221 // Info used by CDS
222 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;)
223
224 // Hash function
225 static unsigned int hash(const char *s, int n);
226 // Returns the package file name corresponding to the specified package
227 // or class name, or null if not found.
228 static PackageInfo* lookup_package(const char *pkgname);
229 // Adds a new package entry for the specified class or package name and
230 // corresponding directory or jar file name.
231 static bool add_package(const char *pkgname, int classpath_index, TRAPS);
232
233 // Initialization
234 static void setup_bootstrap_meta_index();
235 static void setup_meta_index(const char* meta_index_path, const char* meta_index_dir,
236 int start_index);
237 static void setup_bootstrap_search_path();
238 static void setup_search_path(const char *class_path);
239
240 static void load_zip_library();
241 static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st,
242 bool lazy, bool throw_exception, TRAPS);
243
244 // Canonicalizes path names, so strcmp will work properly. This is mainly
245 // to avoid confusing the zip library
246 static bool get_canonical_path(const char* orig, char* out, int len);
247 public:
248 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg);
249 static int crc32(int crc, const char* buf, int len);
250 static bool update_class_path_entry_list(const char *path,
251 bool check_for_duplicates,
252 bool throw_exception=true);
253 static void print_bootclasspath();
254
255 // Timing
256 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; }
257 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; }
258 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; }
259 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; }
260 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; }
261 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; }
262 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; }
263 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; }
264 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; }
265 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; }
266 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; }
267 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; }
268 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; }
269 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; }
270 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; }
271 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; }
272 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; }
273 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; }
274 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; }
275 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; }
276 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; }
277 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; }
278 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; }
279
280 // Record how often system loader lock object is contended
281 static PerfCounter* sync_systemLoaderLockContentionRate() {
282 return _sync_systemLoaderLockContentionRate;
283 }
284
285 // Record how often non system loader lock object is contended
286 static PerfCounter* sync_nonSystemLoaderLockContentionRate() {
287 return _sync_nonSystemLoaderLockContentionRate;
288 }
289
290 // Record how many calls to JVM_FindLoadedClass w/o holding a lock
291 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() {
292 return _sync_JVMFindLoadedClassLockFreeCounter;
293 }
294
295 // Record how many calls to JVM_DefineClass w/o holding a lock
296 static PerfCounter* sync_JVMDefineClassLockFreeCounter() {
297 return _sync_JVMDefineClassLockFreeCounter;
298 }
299
300 // Record how many calls to jni_DefineClass w/o holding a lock
301 static PerfCounter* sync_JNIDefineClassLockFreeCounter() {
302 return _sync_JNIDefineClassLockFreeCounter;
303 }
304
305 // Record how many calls to Unsafe_DefineClass
306 static PerfCounter* unsafe_defineClassCallCounter() {
307 return _unsafe_defineClassCallCounter;
308 }
309
310 // Record how many times SystemDictionary::load_instance_class call
311 // fails with linkageError when Unsyncloadclass flag is set.
312 static PerfCounter* load_instance_class_failCounter() {
313 return _load_instance_class_failCounter;
314 }
315
316 // Load individual .class file
317 static instanceKlassHandle load_classfile(Symbol* h_name, TRAPS);
318
319 // If the specified package has been loaded by the system, then returns
320 // the name of the directory or ZIP file that the package was loaded from.
321 // Returns null if the package was not loaded.
322 // Note: The specified name can either be the name of a class or package.
323 // If a package name is specified, then it must be "/"-separator and also
324 // end with a trailing "/".
325 static oop get_system_package(const char* name, TRAPS);
326
327 // Returns an array of Java strings representing all of the currently
328 // loaded system packages.
329 // Note: The package names returned are "/"-separated and end with a
330 // trailing "/".
331 static objArrayOop get_system_packages(TRAPS);
332
333 // Initialization
334 static void initialize();
335 CDS_ONLY(static void initialize_shared_path();)
336 static void create_package_info_table();
337 static void create_package_info_table(HashtableBucket<mtClass> *t, int length,
338 int number_of_entries);
339 static int compute_Object_vtable();
340
341 static ClassPathEntry* classpath_entry(int n) {
342 ClassPathEntry* e = ClassLoader::_first_entry;
343 while (--n >= 0) {
344 assert(e != NULL, "Not that many classpath entries.");
345 e = e->next();
346 }
347 return e;
348 }
349
350 #if INCLUDE_CDS
351 // Sharing dump and restore
352 static void copy_package_info_buckets(char** top, char* end);
353 static void copy_package_info_table(char** top, char* end);
354
355 static void check_shared_classpath(const char *path);
356 static void finalize_shared_paths_misc_info();
357 static int get_shared_paths_misc_info_size();
358 static void* get_shared_paths_misc_info();
359 static bool check_shared_paths_misc_info(void* info, int size);
360 static void exit_with_path_failure(const char* error, const char* message);
361 #endif
362
363 static void trace_class_path(const char* msg, const char* name = NULL);
364
365 // VM monitoring and management support
366 static jlong classloader_time_ms();
367 static jlong class_method_total_size();
368 static jlong class_init_count();
369 static jlong class_init_time_ms();
370 static jlong class_verify_time_ms();
371 static jlong class_link_count();
372 static jlong class_link_time_ms();
373
374 // indicates if class path already contains a entry (exact match by name)
375 static bool contains_entry(ClassPathEntry* entry);
376
377 // adds a class path list
378 static void add_to_list(ClassPathEntry* new_entry);
379
380 // creates a class path zip entry (returns NULL if JAR file cannot be opened)
381 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath);
382
383 // Debugging
384 static void verify() PRODUCT_RETURN;
385
386 // Force compilation of all methods in all classes in bootstrap class path (stress test)
387 #ifndef PRODUCT
388 protected:
389 static int _compile_the_world_class_counter;
390 static int _compile_the_world_method_counter;
391 public:
392 static void compile_the_world();
393 static void compile_the_world_in(char* name, Handle loader, TRAPS);
394 static int compile_the_world_counter() { return _compile_the_world_class_counter; }
395 #endif //PRODUCT
396 };
397
398 // PerfClassTraceTime is used to measure time for class loading related events.
399 // This class tracks cumulative time and exclusive time for specific event types.
400 // During the execution of one event, other event types (e.g. class loading and
401 // resolution) as well as recursive calls of the same event type could happen.
402 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive)
403 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime
404 // instances have been created as multiple events are happening.
405 class PerfClassTraceTime {
406 public:
407 enum {
408 CLASS_LOAD = 0,
409 PARSE_CLASS = 1,
410 CLASS_LINK = 2,
411 CLASS_VERIFY = 3,
412 CLASS_CLINIT = 4,
413 DEFINE_CLASS = 5,
414 EVENT_TYPE_COUNT = 6
415 };
416 protected:
417 // _t tracks time from initialization to destruction of this timer instance
418 // including time for all other event types, and recursive calls of this type.
419 // When a timer is called recursively, the elapsedTimer _t would not be used.
420 elapsedTimer _t;
421 PerfLongCounter* _timep;
422 PerfLongCounter* _selftimep;
423 PerfLongCounter* _eventp;
424 // pointer to thread-local recursion counter and timer array
425 // The thread_local timers track cumulative time for specific event types
426 // exclusive of time for other event types, but including recursive calls
427 // of the same type.
428 int* _recursion_counters;
429 elapsedTimer* _timers;
430 int _event_type;
431 int _prev_active_event;
432
433 public:
434
435 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
436 PerfLongCounter* selftimep, /* counter incremented with exclusive time */
437 PerfLongCounter* eventp, /* event counter */
438 int* recursion_counters, /* thread-local recursion counter array */
439 elapsedTimer* timers, /* thread-local timer array */
440 int type /* event type */ ) :
441 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) {
442 initialize();
443 }
444
445 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
446 elapsedTimer* timers, /* thread-local timer array */
447 int type /* event type */ ) :
448 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) {
449 initialize();
450 }
451
452 inline void suspend() { _t.stop(); _timers[_event_type].stop(); }
453 inline void resume() { _t.start(); _timers[_event_type].start(); }
454
455 ~PerfClassTraceTime();
456 void initialize();
457 };
458
459 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP