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