1 /*
2 * Copyright (c) 1997, 2016, 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 "runtime/orderAccess.hpp"
29 #include "runtime/perfData.hpp"
30 #include "utilities/exceptions.hpp"
31 #include "utilities/macros.hpp"
32
33 // The VM class loader.
34 #include <sys/stat.h>
35
36 // Name of boot module image
37 #define BOOT_IMAGE_NAME "bootmodules.jimage"
38
39 class JImageFile;
40 class ClassFileStream;
41
42 class ClassPathEntry : public CHeapObj<mtClass> {
43 private:
44 ClassPathEntry* _next;
45 public:
46 // Next entry in class path
47 ClassPathEntry* next() const { return _next; }
48 void set_next(ClassPathEntry* next) {
49 // may have unlocked readers, so write atomically.
50 OrderAccess::release_store_ptr(&_next, next);
51 }
52 virtual bool is_jar_file() const = 0;
53 virtual const char* name() const = 0;
54 virtual JImageFile* jimage() const = 0;
55 // Constructor
56 ClassPathEntry() : _next(NULL) {}
57 // Attempt to locate file_name through this class path entry.
58 // Returns a class file parsing stream if successfull.
59 virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0;
60 // Debugging
61 NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;)
62 NOT_PRODUCT(virtual bool is_jrt() = 0;)
63 };
64
65 class ClassPathDirEntry: public ClassPathEntry {
66 private:
67 const char* _dir; // Name of directory
68 public:
69 bool is_jar_file() const { return false; }
70 const char* name() const { return _dir; }
71 JImageFile* jimage() const { return NULL; }
72 ClassPathDirEntry(const char* dir);
73 ClassFileStream* open_stream(const char* name, TRAPS);
74 // Debugging
75 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
76 NOT_PRODUCT(bool is_jrt();)
77 };
78
79
80 // Type definitions for zip file and zip file entry
81 typedef void* jzfile;
82 typedef struct {
83 char *name; /* entry name */
84 jlong time; /* modification time */
85 jlong size; /* size of uncompressed data */
86 jlong csize; /* size of compressed data (zero if uncompressed) */
87 jint crc; /* crc of uncompressed data */
88 char *comment; /* optional zip file comment */
89 jbyte *extra; /* optional extra data */
90 jlong pos; /* position of LOC header (if negative) or data */
91 } jzentry;
92
93
94 class ClassPathZipEntry: public ClassPathEntry {
95 private:
96 jzfile* _zip; // The zip archive
97 const char* _zip_name; // Name of zip archive
98 public:
99 bool is_jar_file() const { return true; }
100 const char* name() const { return _zip_name; }
101 JImageFile* jimage() const { return NULL; }
102 ClassPathZipEntry(jzfile* zip, const char* zip_name);
103 ~ClassPathZipEntry();
104 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
105 ClassFileStream* open_stream(const char* name, TRAPS);
106 void contents_do(void f(const char* name, void* context), void* context);
107 // Debugging
108 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
109 NOT_PRODUCT(bool is_jrt();)
110 };
111
112
113 // For java image files
114 class ClassPathImageEntry: public ClassPathEntry {
115 private:
116 JImageFile* _jimage;
117 const char* _name;
118 public:
119 bool is_jar_file() const { return false; }
120 bool is_open() const { return _jimage != NULL; }
121 const char* name() const { return _name == NULL ? "" : _name; }
122 JImageFile* jimage() const { return _jimage; }
123 ClassPathImageEntry(JImageFile* jimage, const char* name);
124 ~ClassPathImageEntry();
125 static void name_to_package(const char* name, char* buffer, int length);
126 ClassFileStream* open_stream(const char* name, TRAPS);
127
128 // Debugging
129 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);)
130 NOT_PRODUCT(bool is_jrt();)
131 };
132
133 class PackageHashtable;
134 class PackageInfo;
135 class SharedPathsMiscInfo;
136 template <MEMFLAGS F> class HashtableBucket;
137
138 class ClassLoader: AllStatic {
139 public:
140 enum SomeConstants {
141 package_hash_table_size = 31 // Number of buckets
142 };
143 protected:
144
145 // Performance counters
146 static PerfCounter* _perf_accumulated_time;
147 static PerfCounter* _perf_classes_inited;
148 static PerfCounter* _perf_class_init_time;
149 static PerfCounter* _perf_class_init_selftime;
150 static PerfCounter* _perf_classes_verified;
151 static PerfCounter* _perf_class_verify_time;
152 static PerfCounter* _perf_class_verify_selftime;
153 static PerfCounter* _perf_classes_linked;
154 static PerfCounter* _perf_class_link_time;
155 static PerfCounter* _perf_class_link_selftime;
156 static PerfCounter* _perf_class_parse_time;
157 static PerfCounter* _perf_class_parse_selftime;
158 static PerfCounter* _perf_sys_class_lookup_time;
159 static PerfCounter* _perf_shared_classload_time;
160 static PerfCounter* _perf_sys_classload_time;
161 static PerfCounter* _perf_app_classload_time;
162 static PerfCounter* _perf_app_classload_selftime;
163 static PerfCounter* _perf_app_classload_count;
164 static PerfCounter* _perf_define_appclasses;
165 static PerfCounter* _perf_define_appclass_time;
166 static PerfCounter* _perf_define_appclass_selftime;
167 static PerfCounter* _perf_app_classfile_bytes_read;
168 static PerfCounter* _perf_sys_classfile_bytes_read;
169
170 static PerfCounter* _sync_systemLoaderLockContentionRate;
171 static PerfCounter* _sync_nonSystemLoaderLockContentionRate;
172 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter;
173 static PerfCounter* _sync_JVMDefineClassLockFreeCounter;
174 static PerfCounter* _sync_JNIDefineClassLockFreeCounter;
175
176 static PerfCounter* _unsafe_defineClassCallCounter;
177 static PerfCounter* _isUnsyncloadClass;
178 static PerfCounter* _load_instance_class_failCounter;
179
180 // First entry in linked list of ClassPathEntry instances
181 static ClassPathEntry* _first_entry;
182 // Last entry in linked list of ClassPathEntry instances
183 static ClassPathEntry* _last_entry;
184 static int _num_entries;
185
186 // Hash table used to keep track of loaded packages
187 static PackageHashtable* _package_hash_table;
188 static const char* _shared_archive;
189
190 // Info used by CDS
191 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;)
192
193 // Hash function
194 static unsigned int hash(const char *s, int n);
195 // Returns the package file name corresponding to the specified package
196 // or class name, or null if not found.
197 static PackageInfo* lookup_package(const char *pkgname);
198 // Adds a new package entry for the specified class or package name and
199 // corresponding directory or jar file name.
200 static bool add_package(const char *pkgname, int classpath_index, TRAPS);
201
202 // Initialization
203 static void setup_bootstrap_search_path();
204 static void setup_search_path(const char *class_path);
205
206 static void load_zip_library();
207 static void load_jimage_library();
208 static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st,
209 bool throw_exception, TRAPS);
210
211 // Canonicalizes path names, so strcmp will work properly. This is mainly
212 // to avoid confusing the zip library
213 static bool get_canonical_path(const char* orig, char* out, int len);
214
215 static const char* file_name_for_class_name(const char* class_name,
216 int class_name_len);
217
218 public:
219 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg);
220 static int crc32(int crc, const char* buf, int len);
221 static bool update_class_path_entry_list(const char *path,
222 bool check_for_duplicates,
223 bool throw_exception=true);
224 static void print_bootclasspath();
225
226 // Timing
227 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; }
228 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; }
229 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; }
230 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; }
231 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; }
232 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; }
233 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; }
234 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; }
235 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; }
236 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; }
237 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; }
238 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; }
239 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; }
240 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; }
241 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; }
242 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; }
243 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; }
244 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; }
245 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; }
246 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; }
247 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; }
248 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; }
249 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; }
250
251 // Record how often system loader lock object is contended
252 static PerfCounter* sync_systemLoaderLockContentionRate() {
253 return _sync_systemLoaderLockContentionRate;
254 }
255
256 // Record how often non system loader lock object is contended
257 static PerfCounter* sync_nonSystemLoaderLockContentionRate() {
258 return _sync_nonSystemLoaderLockContentionRate;
259 }
260
261 // Record how many calls to JVM_FindLoadedClass w/o holding a lock
262 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() {
263 return _sync_JVMFindLoadedClassLockFreeCounter;
264 }
265
266 // Record how many calls to JVM_DefineClass w/o holding a lock
267 static PerfCounter* sync_JVMDefineClassLockFreeCounter() {
268 return _sync_JVMDefineClassLockFreeCounter;
269 }
270
271 // Record how many calls to jni_DefineClass w/o holding a lock
272 static PerfCounter* sync_JNIDefineClassLockFreeCounter() {
273 return _sync_JNIDefineClassLockFreeCounter;
274 }
275
276 // Record how many calls to Unsafe_DefineClass
277 static PerfCounter* unsafe_defineClassCallCounter() {
278 return _unsafe_defineClassCallCounter;
279 }
280
281 // Record how many times SystemDictionary::load_instance_class call
282 // fails with linkageError when Unsyncloadclass flag is set.
283 static PerfCounter* load_instance_class_failCounter() {
284 return _load_instance_class_failCounter;
285 }
286
287 // Load individual .class file
288 static instanceKlassHandle load_class(Symbol* class_name, TRAPS);
289
290 // If the specified package has been loaded by the system, then returns
291 // the name of the directory or ZIP file that the package was loaded from.
292 // Returns null if the package was not loaded.
293 // Note: The specified name can either be the name of a class or package.
294 // If a package name is specified, then it must be "/"-separator and also
295 // end with a trailing "/".
296 static oop get_system_package(const char* name, TRAPS);
297
298 // Returns an array of Java strings representing all of the currently
299 // loaded system packages.
300 // Note: The package names returned are "/"-separated and end with a
301 // trailing "/".
302 static objArrayOop get_system_packages(TRAPS);
303
304 // Initialization
305 static void initialize();
306 CDS_ONLY(static void initialize_shared_path();)
307 static void create_package_info_table();
308 static void create_package_info_table(HashtableBucket<mtClass> *t, int length,
309 int number_of_entries);
310 static int compute_Object_vtable();
311
312 static ClassPathEntry* classpath_entry(int n) {
313 ClassPathEntry* e = ClassLoader::_first_entry;
314 while (--n >= 0) {
315 assert(e != NULL, "Not that many classpath entries.");
316 e = e->next();
317 }
318 return e;
319 }
320
321 #if INCLUDE_CDS
322 // Sharing dump and restore
323 static void copy_package_info_buckets(char** top, char* end);
324 static void copy_package_info_table(char** top, char* end);
325
326 static void check_shared_classpath(const char *path);
327 static void finalize_shared_paths_misc_info();
328 static int get_shared_paths_misc_info_size();
329 static void* get_shared_paths_misc_info();
330 static bool check_shared_paths_misc_info(void* info, int size);
331 static void exit_with_path_failure(const char* error, const char* message);
332 #endif
333
334 static void trace_class_path(const char* msg, const char* name = NULL);
335
336 // VM monitoring and management support
337 static jlong classloader_time_ms();
338 static jlong class_method_total_size();
339 static jlong class_init_count();
340 static jlong class_init_time_ms();
341 static jlong class_verify_time_ms();
342 static jlong class_link_count();
343 static jlong class_link_time_ms();
344
345 // indicates if class path already contains a entry (exact match by name)
346 static bool contains_entry(ClassPathEntry* entry);
347
348 // adds a class path list
349 static void add_to_list(ClassPathEntry* new_entry);
350
351 // creates a class path zip entry (returns NULL if JAR file cannot be opened)
352 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath);
353
354 // Debugging
355 static void verify() PRODUCT_RETURN;
356
357 // Force compilation of all methods in all classes in bootstrap class path (stress test)
358 #ifndef PRODUCT
359 protected:
360 static int _compile_the_world_class_counter;
361 static int _compile_the_world_method_counter;
362 public:
363 static void compile_the_world();
364 static void compile_the_world_in(char* name, Handle loader, TRAPS);
365 static int compile_the_world_counter() { return _compile_the_world_class_counter; }
366 #endif //PRODUCT
367 };
368
369 // PerfClassTraceTime is used to measure time for class loading related events.
370 // This class tracks cumulative time and exclusive time for specific event types.
371 // During the execution of one event, other event types (e.g. class loading and
372 // resolution) as well as recursive calls of the same event type could happen.
373 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive)
374 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime
375 // instances have been created as multiple events are happening.
376 class PerfClassTraceTime {
377 public:
378 enum {
379 CLASS_LOAD = 0,
380 PARSE_CLASS = 1,
381 CLASS_LINK = 2,
382 CLASS_VERIFY = 3,
383 CLASS_CLINIT = 4,
384 DEFINE_CLASS = 5,
385 EVENT_TYPE_COUNT = 6
386 };
387 protected:
388 // _t tracks time from initialization to destruction of this timer instance
389 // including time for all other event types, and recursive calls of this type.
390 // When a timer is called recursively, the elapsedTimer _t would not be used.
391 elapsedTimer _t;
392 PerfLongCounter* _timep;
393 PerfLongCounter* _selftimep;
394 PerfLongCounter* _eventp;
395 // pointer to thread-local recursion counter and timer array
396 // The thread_local timers track cumulative time for specific event types
397 // exclusive of time for other event types, but including recursive calls
398 // of the same type.
399 int* _recursion_counters;
400 elapsedTimer* _timers;
401 int _event_type;
402 int _prev_active_event;
403
404 public:
405
406 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
407 PerfLongCounter* selftimep, /* counter incremented with exclusive time */
408 PerfLongCounter* eventp, /* event counter */
409 int* recursion_counters, /* thread-local recursion counter array */
410 elapsedTimer* timers, /* thread-local timer array */
411 int type /* event type */ ) :
412 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) {
413 initialize();
414 }
415
416 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
417 elapsedTimer* timers, /* thread-local timer array */
418 int type /* event type */ ) :
419 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) {
420 initialize();
421 }
422
423 inline void suspend() { _t.stop(); _timers[_event_type].stop(); }
424 inline void resume() { _t.start(); _timers[_event_type].start(); }
425
426 ~PerfClassTraceTime();
427 void initialize();
428 };
429
430 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP