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
31 // The VM class loader.
32 #include <sys/stat.h>
33
34
35 // Meta-index (optional, to be able to skip opening boot classpath jar files)
36 class MetaIndex: public CHeapObj<mtClass> {
37 private:
38 char** _meta_package_names;
39 int _num_meta_package_names;
40 public:
41 MetaIndex(char** meta_package_names, int num_meta_package_names);
42 ~MetaIndex();
43 bool may_contain(const char* class_name);
44 };
45
46
47 // Class path entry (directory or zip file)
48
49 class ClassPathEntry: public CHeapObj<mtClass> {
50 private:
51 ClassPathEntry* _next;
52 public:
53 // Next entry in class path
54 ClassPathEntry* next() { return _next; }
55 void set_next(ClassPathEntry* next) {
56 // may have unlocked readers, so write atomically.
57 OrderAccess::release_store_ptr(&_next, next);
58 }
59 virtual bool is_jar_file() = 0;
60 virtual const char* name() = 0;
61 virtual bool is_lazy();
62 // Constructor
63 ClassPathEntry();
64 // Attempt to locate file_name through this class path entry.
65 // Returns a class file parsing stream if successfull.
66 virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0;
67 // Debugging
68 NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;)
69 NOT_PRODUCT(virtual bool is_rt_jar() = 0;)
70 };
71
72
73 class ClassPathDirEntry: public ClassPathEntry {
74 private:
75 char* _dir; // Name of directory
76 public:
77 bool is_jar_file() { return false; }
78 const char* name() { return _dir; }
79 ClassPathDirEntry(char* dir);
80 ClassFileStream* open_stream(const char* name, TRAPS);
81 // Debugging
82 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
83 NOT_PRODUCT(bool is_rt_jar();)
84 };
85
86
87 // Type definitions for zip file and zip file entry
88 typedef void* jzfile;
89 typedef struct {
90 char *name; /* entry name */
91 jlong time; /* modification time */
92 jlong size; /* size of uncompressed data */
93 jlong csize; /* size of compressed data (zero if uncompressed) */
94 jint crc; /* crc of uncompressed data */
95 char *comment; /* optional zip file comment */
96 jbyte *extra; /* optional extra data */
97 jlong pos; /* position of LOC header (if negative) or data */
98 } jzentry;
99
100
101 class ClassPathZipEntry: public ClassPathEntry {
102 private:
103 jzfile* _zip; // The zip archive
104 char* _zip_name; // Name of zip archive
105 public:
106 bool is_jar_file() { return true; }
107 const char* name() { return _zip_name; }
108 ClassPathZipEntry(jzfile* zip, const char* zip_name);
109 ~ClassPathZipEntry();
110 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
111 ClassFileStream* open_stream(const char* name, TRAPS);
112 void contents_do(void f(const char* name, void* context), void* context);
113 // Debugging
114 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
115 NOT_PRODUCT(bool is_rt_jar();)
116 };
117
118
119 // For lazier loading of boot class path entries
120 class LazyClassPathEntry: public ClassPathEntry {
121 private:
122 char* _path; // dir or file
123 struct stat _st;
124 MetaIndex* _meta_index;
125 bool _has_error;
126 bool _throw_exception;
127 volatile ClassPathEntry* _resolved_entry;
128 ClassPathEntry* resolve_entry(TRAPS);
129 public:
130 bool is_jar_file();
131 const char* name() { return _path; }
132 LazyClassPathEntry(char* path, const struct stat* st, bool throw_exception);
133 virtual ~LazyClassPathEntry();
134 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
135
136 ClassFileStream* open_stream(const char* name, TRAPS);
137 void set_meta_index(MetaIndex* meta_index) { _meta_index = meta_index; }
138 virtual bool is_lazy();
139 // Debugging
140 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
141 NOT_PRODUCT(bool is_rt_jar();)
142 };
143
144 class PackageHashtable;
145 class PackageInfo;
146 class SharedPathsMiscInfo;
147 template <MEMFLAGS F> class HashtableBucket;
148
149 class ClassLoader: AllStatic {
150 public:
151 enum SomeConstants {
152 package_hash_table_size = 31 // Number of buckets
153 };
154 protected:
155 friend class LazyClassPathEntry;
156
157 // Performance counters
158 static PerfCounter* _perf_accumulated_time;
159 static PerfCounter* _perf_classes_inited;
160 static PerfCounter* _perf_class_init_time;
161 static PerfCounter* _perf_class_init_selftime;
162 static PerfCounter* _perf_classes_verified;
163 static PerfCounter* _perf_class_verify_time;
164 static PerfCounter* _perf_class_verify_selftime;
165 static PerfCounter* _perf_classes_linked;
166 static PerfCounter* _perf_class_link_time;
167 static PerfCounter* _perf_class_link_selftime;
168 static PerfCounter* _perf_class_parse_time;
169 static PerfCounter* _perf_class_parse_selftime;
170 static PerfCounter* _perf_sys_class_lookup_time;
171 static PerfCounter* _perf_shared_classload_time;
172 static PerfCounter* _perf_sys_classload_time;
173 static PerfCounter* _perf_app_classload_time;
174 static PerfCounter* _perf_app_classload_selftime;
175 static PerfCounter* _perf_app_classload_count;
176 static PerfCounter* _perf_define_appclasses;
177 static PerfCounter* _perf_define_appclass_time;
178 static PerfCounter* _perf_define_appclass_selftime;
179 static PerfCounter* _perf_app_classfile_bytes_read;
180 static PerfCounter* _perf_sys_classfile_bytes_read;
181
182 static PerfCounter* _sync_systemLoaderLockContentionRate;
183 static PerfCounter* _sync_nonSystemLoaderLockContentionRate;
184 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter;
185 static PerfCounter* _sync_JVMDefineClassLockFreeCounter;
186 static PerfCounter* _sync_JNIDefineClassLockFreeCounter;
187
188 static PerfCounter* _unsafe_defineClassCallCounter;
189 static PerfCounter* _isUnsyncloadClass;
190 static PerfCounter* _load_instance_class_failCounter;
191
192 // First entry in linked list of ClassPathEntry instances
193 static ClassPathEntry* _first_entry;
194 // Last entry in linked list of ClassPathEntry instances
195 static ClassPathEntry* _last_entry;
196 static int _num_entries;
197
198 // Hash table used to keep track of loaded packages
199 static PackageHashtable* _package_hash_table;
200 static const char* _shared_archive;
201
202 // Info used by CDS
203 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;)
204
205 // Hash function
206 static unsigned int hash(const char *s, int n);
207 // Returns the package file name corresponding to the specified package
208 // or class name, or null if not found.
209 static PackageInfo* lookup_package(const char *pkgname);
210 // Adds a new package entry for the specified class or package name and
211 // corresponding directory or jar file name.
212 static bool add_package(const char *pkgname, int classpath_index, TRAPS);
213
214 // Initialization
215 static void setup_bootstrap_meta_index();
216 static void setup_meta_index(const char* meta_index_path, const char* meta_index_dir,
217 int start_index);
218 static void setup_bootstrap_search_path();
219 static void setup_search_path(char *class_path);
220
221 static void load_zip_library();
222 static ClassPathEntry* create_class_path_entry(char *path, const struct stat* st,
223 bool lazy, bool throw_exception, TRAPS);
224
225 // Canonicalizes path names, so strcmp will work properly. This is mainly
226 // to avoid confusing the zip library
227 static bool get_canonical_path(char* orig, char* out, int len);
228 public:
229 static bool update_class_path_entry_list(char *path,
230 bool check_for_duplicates,
231 bool throw_exception=true);
232 static void print_bootclasspath();
233
234 // Timing
235 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; }
236 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; }
237 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; }
238 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; }
239 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; }
240 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; }
241 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; }
242 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; }
243 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; }
244 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; }
245 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; }
246 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; }
247 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; }
248 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; }
249 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; }
250 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; }
251 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; }
252 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; }
253 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; }
254 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; }
255 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; }
256 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; }
257 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; }
258
259 // Record how often system loader lock object is contended
260 static PerfCounter* sync_systemLoaderLockContentionRate() {
261 return _sync_systemLoaderLockContentionRate;
262 }
263
264 // Record how often non system loader lock object is contended
265 static PerfCounter* sync_nonSystemLoaderLockContentionRate() {
266 return _sync_nonSystemLoaderLockContentionRate;
267 }
268
269 // Record how many calls to JVM_FindLoadedClass w/o holding a lock
270 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() {
271 return _sync_JVMFindLoadedClassLockFreeCounter;
272 }
273
274 // Record how many calls to JVM_DefineClass w/o holding a lock
275 static PerfCounter* sync_JVMDefineClassLockFreeCounter() {
276 return _sync_JVMDefineClassLockFreeCounter;
277 }
278
279 // Record how many calls to jni_DefineClass w/o holding a lock
280 static PerfCounter* sync_JNIDefineClassLockFreeCounter() {
281 return _sync_JNIDefineClassLockFreeCounter;
282 }
283
284 // Record how many calls to Unsafe_DefineClass
285 static PerfCounter* unsafe_defineClassCallCounter() {
286 return _unsafe_defineClassCallCounter;
287 }
288
289 // Record how many times SystemDictionary::load_instance_class call
290 // fails with linkageError when Unsyncloadclass flag is set.
291 static PerfCounter* load_instance_class_failCounter() {
292 return _load_instance_class_failCounter;
293 }
294
295 // Load individual .class file
296 static instanceKlassHandle load_classfile(Symbol* h_name, TRAPS);
297
298 // If the specified package has been loaded by the system, then returns
299 // the name of the directory or ZIP file that the package was loaded from.
300 // Returns null if the package was not loaded.
301 // Note: The specified name can either be the name of a class or package.
302 // If a package name is specified, then it must be "/"-separator and also
303 // end with a trailing "/".
304 static oop get_system_package(const char* name, TRAPS);
305
306 // Returns an array of Java strings representing all of the currently
307 // loaded system packages.
308 // Note: The package names returned are "/"-separated and end with a
309 // trailing "/".
310 static objArrayOop get_system_packages(TRAPS);
311
312 // Initialization
313 static void initialize();
314 CDS_ONLY(static void initialize_shared_path();)
315 static void create_package_info_table();
316 static void create_package_info_table(HashtableBucket<mtClass> *t, int length,
317 int number_of_entries);
318 static int compute_Object_vtable();
319
320 static ClassPathEntry* classpath_entry(int n) {
321 ClassPathEntry* e = ClassLoader::_first_entry;
322 while (--n >= 0) {
323 assert(e != NULL, "Not that many classpath entries.");
324 e = e->next();
325 }
326 return e;
327 }
328
329 #if INCLUDE_CDS
330 // Sharing dump and restore
331 static void copy_package_info_buckets(char** top, char* end);
332 static void copy_package_info_table(char** top, char* end);
333
334 static void check_shared_classpath(const char *path);
335 static void finalize_shared_paths_misc_info();
336 static int get_shared_paths_misc_info_size();
337 static void* get_shared_paths_misc_info();
338 static bool check_shared_paths_misc_info(void* info, int size);
339 static void exit_with_path_failure(const char* error, const char* message);
340 #endif
341
342 static void trace_class_path(const char* msg, const char* name = NULL);
343
344 // VM monitoring and management support
345 static jlong classloader_time_ms();
346 static jlong class_method_total_size();
347 static jlong class_init_count();
348 static jlong class_init_time_ms();
349 static jlong class_verify_time_ms();
350 static jlong class_link_count();
351 static jlong class_link_time_ms();
352
353 // indicates if class path already contains a entry (exact match by name)
354 static bool contains_entry(ClassPathEntry* entry);
355
356 // adds a class path list
357 static void add_to_list(ClassPathEntry* new_entry);
358
359 // creates a class path zip entry (returns NULL if JAR file cannot be opened)
360 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath);
361
362 // Debugging
363 static void verify() PRODUCT_RETURN;
364
365 // Force compilation of all methods in all classes in bootstrap class path (stress test)
366 #ifndef PRODUCT
367 protected:
368 static int _compile_the_world_class_counter;
369 static int _compile_the_world_method_counter;
370 public:
371 static void compile_the_world();
372 static void compile_the_world_in(char* name, Handle loader, TRAPS);
373 static int compile_the_world_counter() { return _compile_the_world_class_counter; }
374 #endif //PRODUCT
375 };
376
377 // PerfClassTraceTime is used to measure time for class loading related events.
378 // This class tracks cumulative time and exclusive time for specific event types.
379 // During the execution of one event, other event types (e.g. class loading and
380 // resolution) as well as recursive calls of the same event type could happen.
381 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive)
382 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime
383 // instances have been created as multiple events are happening.
384 class PerfClassTraceTime {
385 public:
386 enum {
387 CLASS_LOAD = 0,
388 PARSE_CLASS = 1,
389 CLASS_LINK = 2,
390 CLASS_VERIFY = 3,
391 CLASS_CLINIT = 4,
392 DEFINE_CLASS = 5,
393 EVENT_TYPE_COUNT = 6
394 };
395 protected:
396 // _t tracks time from initialization to destruction of this timer instance
397 // including time for all other event types, and recursive calls of this type.
398 // When a timer is called recursively, the elapsedTimer _t would not be used.
399 elapsedTimer _t;
400 PerfLongCounter* _timep;
401 PerfLongCounter* _selftimep;
402 PerfLongCounter* _eventp;
403 // pointer to thread-local recursion counter and timer array
404 // The thread_local timers track cumulative time for specific event types
405 // exclusive of time for other event types, but including recursive calls
406 // of the same type.
407 int* _recursion_counters;
408 elapsedTimer* _timers;
409 int _event_type;
410 int _prev_active_event;
411
412 public:
413
414 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
415 PerfLongCounter* selftimep, /* counter incremented with exclusive time */
416 PerfLongCounter* eventp, /* event counter */
417 int* recursion_counters, /* thread-local recursion counter array */
418 elapsedTimer* timers, /* thread-local timer array */
419 int type /* event type */ ) :
420 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) {
421 initialize();
422 }
423
424 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
425 elapsedTimer* timers, /* thread-local timer array */
426 int type /* event type */ ) :
427 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) {
428 initialize();
429 }
430
431 inline void suspend() { _t.stop(); _timers[_event_type].stop(); }
432 inline void resume() { _t.start(); _timers[_event_type].start(); }
433
434 ~PerfClassTraceTime();
435 void initialize();
436 };
437
438 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP