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