1 /*
2 * Copyright (c) 1997, 2015, 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 // Class path entry (directory or zip file)
37
38 class ClassPathEntry: public CHeapObj<mtClass> {
39 private:
40 ClassPathEntry* _next;
41 public:
42 // Next entry in class path
43 ClassPathEntry* next() { return _next; }
44 void set_next(ClassPathEntry* next) {
45 // may have unlocked readers, so write atomically.
46 OrderAccess::release_store_ptr(&_next, next);
47 }
48 virtual bool is_jar_file() = 0;
49 virtual const char* name() = 0;
50 virtual bool is_lazy();
51 // Constructor
52 ClassPathEntry();
53 // Attempt to locate file_name through this class path entry.
54 // Returns a class file parsing stream if successfull.
55 virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0;
56 // Debugging
57 NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;)
58 NOT_PRODUCT(virtual bool is_jrt() = 0;)
59 };
60
61
62 class ClassPathDirEntry: public ClassPathEntry {
63 private:
64 const char* _dir; // Name of directory
65 public:
66 bool is_jar_file() { return false; }
67 const char* name() { return _dir; }
68 ClassPathDirEntry(const char* dir);
69 ClassFileStream* open_stream(const char* name, TRAPS);
70 // Debugging
71 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
72 NOT_PRODUCT(bool is_jrt();)
73 };
74
75
76 // Type definitions for zip file and zip file entry
77 typedef void* jzfile;
78 typedef struct {
79 char *name; /* entry name */
80 jlong time; /* modification time */
81 jlong size; /* size of uncompressed data */
82 jlong csize; /* size of compressed data (zero if uncompressed) */
83 jint crc; /* crc of uncompressed data */
84 char *comment; /* optional zip file comment */
85 jbyte *extra; /* optional extra data */
86 jlong pos; /* position of LOC header (if negative) or data */
87 } jzentry;
88
89
90 class ClassPathZipEntry: public ClassPathEntry {
91 private:
92 jzfile* _zip; // The zip archive
93 const char* _zip_name; // Name of zip archive
94 public:
95 bool is_jar_file() { return true; }
96 const char* name() { return _zip_name; }
97 ClassPathZipEntry(jzfile* zip, const char* zip_name);
98 ~ClassPathZipEntry();
99 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
100 ClassFileStream* open_stream(const char* name, TRAPS);
101 void contents_do(void f(const char* name, void* context), void* context);
102 // Debugging
103 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
104 NOT_PRODUCT(bool is_jrt();)
105 };
106
107
108 // For lazier loading of boot class path entries
109 class LazyClassPathEntry: public ClassPathEntry {
110 private:
111 const char* _path; // dir or file
112 struct stat _st;
113 bool _has_error;
114 bool _throw_exception;
115 volatile ClassPathEntry* _resolved_entry;
116 ClassPathEntry* resolve_entry(TRAPS);
117 public:
118 bool is_jar_file();
119 const char* name() { return _path; }
120 LazyClassPathEntry(const char* path, const struct stat* st, bool throw_exception);
121 virtual ~LazyClassPathEntry();
122 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
123
124 ClassFileStream* open_stream(const char* name, TRAPS);
125 virtual bool is_lazy();
126 // Debugging
127 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
128 NOT_PRODUCT(bool is_jrt();)
129 };
130
131 // For java image files
132 class ImageFile;
133 class ClassPathImageEntry: public ClassPathEntry {
134 private:
135 ImageFile *_image;
136 public:
137 bool is_jar_file() { return false; }
138 bool is_open() { return _image != NULL; }
139 const char* name();
140 ClassPathImageEntry(char* name);
141 ~ClassPathImageEntry();
142 ClassFileStream* open_stream(const char* name, TRAPS);
143
144 // Debugging
145 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
146 NOT_PRODUCT(bool is_jrt();)
147 };
148
149 class PackageHashtable;
150 class PackageInfo;
151 class SharedPathsMiscInfo;
152 template <MEMFLAGS F> class HashtableBucket;
153
154 class ClassLoader: AllStatic {
155 public:
156 enum SomeConstants {
157 package_hash_table_size = 31 // Number of buckets
158 };
159 protected:
160 friend class LazyClassPathEntry;
161
162 // Performance counters
163 static PerfCounter* _perf_accumulated_time;
164 static PerfCounter* _perf_classes_inited;
165 static PerfCounter* _perf_class_init_time;
166 static PerfCounter* _perf_class_init_selftime;
167 static PerfCounter* _perf_classes_verified;
168 static PerfCounter* _perf_class_verify_time;
169 static PerfCounter* _perf_class_verify_selftime;
170 static PerfCounter* _perf_classes_linked;
171 static PerfCounter* _perf_class_link_time;
172 static PerfCounter* _perf_class_link_selftime;
173 static PerfCounter* _perf_class_parse_time;
174 static PerfCounter* _perf_class_parse_selftime;
175 static PerfCounter* _perf_sys_class_lookup_time;
176 static PerfCounter* _perf_shared_classload_time;
177 static PerfCounter* _perf_sys_classload_time;
178 static PerfCounter* _perf_app_classload_time;
179 static PerfCounter* _perf_app_classload_selftime;
180 static PerfCounter* _perf_app_classload_count;
181 static PerfCounter* _perf_define_appclasses;
182 static PerfCounter* _perf_define_appclass_time;
183 static PerfCounter* _perf_define_appclass_selftime;
184 static PerfCounter* _perf_app_classfile_bytes_read;
185 static PerfCounter* _perf_sys_classfile_bytes_read;
186
187 static PerfCounter* _sync_systemLoaderLockContentionRate;
188 static PerfCounter* _sync_nonSystemLoaderLockContentionRate;
189 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter;
190 static PerfCounter* _sync_JVMDefineClassLockFreeCounter;
191 static PerfCounter* _sync_JNIDefineClassLockFreeCounter;
192
193 static PerfCounter* _unsafe_defineClassCallCounter;
194 static PerfCounter* _isUnsyncloadClass;
195 static PerfCounter* _load_instance_class_failCounter;
196
197 // First entry in linked list of ClassPathEntry instances
198 static ClassPathEntry* _first_entry;
199 // Last entry in linked list of ClassPathEntry instances
200 static ClassPathEntry* _last_entry;
201 static int _num_entries;
202
203 // Hash table used to keep track of loaded packages
204 static PackageHashtable* _package_hash_table;
205 static const char* _shared_archive;
206
207 // Info used by CDS
208 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;)
209
210 // Hash function
211 static unsigned int hash(const char *s, int n);
212 // Returns the package file name corresponding to the specified package
213 // or class name, or null if not found.
214 static PackageInfo* lookup_package(const char *pkgname);
215 // Adds a new package entry for the specified class or package name and
216 // corresponding directory or jar file name.
217 static bool add_package(const char *pkgname, int classpath_index, TRAPS);
218
219 // Initialization
220 static void setup_bootstrap_search_path();
221 static void setup_search_path(const char *class_path);
222
223 static void load_zip_library();
224 static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st,
225 bool lazy, bool throw_exception, TRAPS);
226
227 // Canonicalizes path names, so strcmp will work properly. This is mainly
228 // to avoid confusing the zip library
229 static bool get_canonical_path(const char* orig, char* out, int len);
230 public:
231 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg);
232 static int crc32(int crc, const char* buf, int len);
233 static bool update_class_path_entry_list(const char *path,
234 bool check_for_duplicates,
235 bool throw_exception=true);
236 static void print_bootclasspath();
237
238 // Timing
239 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; }
240 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; }
241 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; }
242 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; }
243 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; }
244 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; }
245 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; }
246 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; }
247 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; }
248 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; }
249 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; }
250 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; }
251 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; }
252 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; }
253 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; }
254 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; }
255 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; }
256 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; }
257 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; }
258 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; }
259 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; }
260 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; }
261 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; }
262
263 // Record how often system loader lock object is contended
264 static PerfCounter* sync_systemLoaderLockContentionRate() {
265 return _sync_systemLoaderLockContentionRate;
266 }
267
268 // Record how often non system loader lock object is contended
269 static PerfCounter* sync_nonSystemLoaderLockContentionRate() {
270 return _sync_nonSystemLoaderLockContentionRate;
271 }
272
273 // Record how many calls to JVM_FindLoadedClass w/o holding a lock
274 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() {
275 return _sync_JVMFindLoadedClassLockFreeCounter;
276 }
277
278 // Record how many calls to JVM_DefineClass w/o holding a lock
279 static PerfCounter* sync_JVMDefineClassLockFreeCounter() {
280 return _sync_JVMDefineClassLockFreeCounter;
281 }
282
283 // Record how many calls to jni_DefineClass w/o holding a lock
284 static PerfCounter* sync_JNIDefineClassLockFreeCounter() {
285 return _sync_JNIDefineClassLockFreeCounter;
286 }
287
288 // Record how many calls to Unsafe_DefineClass
289 static PerfCounter* unsafe_defineClassCallCounter() {
290 return _unsafe_defineClassCallCounter;
291 }
292
293 // Record how many times SystemDictionary::load_instance_class call
294 // fails with linkageError when Unsyncloadclass flag is set.
295 static PerfCounter* load_instance_class_failCounter() {
296 return _load_instance_class_failCounter;
297 }
298
299 // Load individual .class file
300 static instanceKlassHandle load_classfile(Symbol* h_name, TRAPS);
301
302 // If the specified package has been loaded by the system, then returns
303 // the name of the directory or ZIP file that the package was loaded from.
304 // Returns null if the package was not loaded.
305 // Note: The specified name can either be the name of a class or package.
306 // If a package name is specified, then it must be "/"-separator and also
307 // end with a trailing "/".
308 static oop get_system_package(const char* name, TRAPS);
309
310 // Returns an array of Java strings representing all of the currently
311 // loaded system packages.
312 // Note: The package names returned are "/"-separated and end with a
313 // trailing "/".
314 static objArrayOop get_system_packages(TRAPS);
315
316 // Initialization
317 static void initialize();
318 CDS_ONLY(static void initialize_shared_path();)
319 static void create_package_info_table();
320 static void create_package_info_table(HashtableBucket<mtClass> *t, int length,
321 int number_of_entries);
322 static int compute_Object_vtable();
323
324 static ClassPathEntry* classpath_entry(int n) {
325 ClassPathEntry* e = ClassLoader::_first_entry;
326 while (--n >= 0) {
327 assert(e != NULL, "Not that many classpath entries.");
328 e = e->next();
329 }
330 return e;
331 }
332
333 #if INCLUDE_CDS
334 // Sharing dump and restore
335 static void copy_package_info_buckets(char** top, char* end);
336 static void copy_package_info_table(char** top, char* end);
337
338 static void check_shared_classpath(const char *path);
339 static void finalize_shared_paths_misc_info();
340 static int get_shared_paths_misc_info_size();
341 static void* get_shared_paths_misc_info();
342 static bool check_shared_paths_misc_info(void* info, int size);
343 static void exit_with_path_failure(const char* error, const char* message);
344 #endif
345
346 static void trace_class_path(const char* msg, const char* name = NULL);
347
348 // VM monitoring and management support
349 static jlong classloader_time_ms();
350 static jlong class_method_total_size();
351 static jlong class_init_count();
352 static jlong class_init_time_ms();
353 static jlong class_verify_time_ms();
354 static jlong class_link_count();
355 static jlong class_link_time_ms();
356
357 // indicates if class path already contains a entry (exact match by name)
358 static bool contains_entry(ClassPathEntry* entry);
359
360 // adds a class path list
361 static void add_to_list(ClassPathEntry* new_entry);
362
363 // creates a class path zip entry (returns NULL if JAR file cannot be opened)
364 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath);
365
366 // Debugging
367 static void verify() PRODUCT_RETURN;
368
369 // Force compilation of all methods in all classes in bootstrap class path (stress test)
370 #ifndef PRODUCT
371 protected:
372 static int _compile_the_world_class_counter;
373 static int _compile_the_world_method_counter;
374 public:
375 static void compile_the_world();
376 static void compile_the_world_in(char* name, Handle loader, TRAPS);
377 static int compile_the_world_counter() { return _compile_the_world_class_counter; }
378 #endif //PRODUCT
379 };
380
381 // PerfClassTraceTime is used to measure time for class loading related events.
382 // This class tracks cumulative time and exclusive time for specific event types.
383 // During the execution of one event, other event types (e.g. class loading and
384 // resolution) as well as recursive calls of the same event type could happen.
385 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive)
386 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime
387 // instances have been created as multiple events are happening.
388 class PerfClassTraceTime {
389 public:
390 enum {
391 CLASS_LOAD = 0,
392 PARSE_CLASS = 1,
393 CLASS_LINK = 2,
394 CLASS_VERIFY = 3,
395 CLASS_CLINIT = 4,
396 DEFINE_CLASS = 5,
397 EVENT_TYPE_COUNT = 6
398 };
399 protected:
400 // _t tracks time from initialization to destruction of this timer instance
401 // including time for all other event types, and recursive calls of this type.
402 // When a timer is called recursively, the elapsedTimer _t would not be used.
403 elapsedTimer _t;
404 PerfLongCounter* _timep;
405 PerfLongCounter* _selftimep;
406 PerfLongCounter* _eventp;
407 // pointer to thread-local recursion counter and timer array
408 // The thread_local timers track cumulative time for specific event types
409 // exclusive of time for other event types, but including recursive calls
410 // of the same type.
411 int* _recursion_counters;
412 elapsedTimer* _timers;
413 int _event_type;
414 int _prev_active_event;
415
416 public:
417
418 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
419 PerfLongCounter* selftimep, /* counter incremented with exclusive time */
420 PerfLongCounter* eventp, /* event counter */
421 int* recursion_counters, /* thread-local recursion counter array */
422 elapsedTimer* timers, /* thread-local timer array */
423 int type /* event type */ ) :
424 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) {
425 initialize();
426 }
427
428 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
429 elapsedTimer* timers, /* thread-local timer array */
430 int type /* event type */ ) :
431 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) {
432 initialize();
433 }
434
435 inline void suspend() { _t.stop(); _timers[_event_type].stop(); }
436 inline void resume() { _t.start(); _timers[_event_type].start(); }
437
438 ~PerfClassTraceTime();
439 void initialize();
440 };
441
442 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP