1 /*
2 * Copyright (c) 1997, 2019, 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_CLASSFILE_CLASSLOADER_HPP
26 #define SHARE_CLASSFILE_CLASSLOADER_HPP
27
28 #include "jimage.hpp"
29 #include "runtime/handles.hpp"
30 #include "runtime/perfData.hpp"
31 #include "utilities/exceptions.hpp"
32 #include "utilities/macros.hpp"
33
34 // The VM class loader.
35 #include <sys/stat.h>
36
37 // Name of boot "modules" image
38 #define MODULES_IMAGE_NAME "modules"
39
40 // Class path entry (directory or zip file)
41
42 class JImageFile;
43 class ClassFileStream;
44 class PackageEntry;
45 template <typename T> class GrowableArray;
46
47 class ClassPathEntry : public CHeapObj<mtClass> {
48 private:
49 ClassPathEntry* volatile _next;
50 public:
51 ClassPathEntry* next() const;
52 virtual ~ClassPathEntry() {}
53 void set_next(ClassPathEntry* next);
54 virtual bool is_modules_image() const = 0;
55 virtual bool is_jar_file() const = 0;
56 virtual const char* name() const = 0;
57 virtual JImageFile* jimage() const = 0;
58 virtual void close_jimage() = 0;
59 // Constructor
60 ClassPathEntry() : _next(NULL) {}
61 // Attempt to locate file_name through this class path entry.
62 // Returns a class file parsing stream if successfull.
63 virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0;
64 };
65
66 class ClassPathDirEntry: public ClassPathEntry {
67 private:
68 const char* _dir; // Name of directory
69 public:
70 bool is_modules_image() const { return false; }
71 bool is_jar_file() const { return false; }
72 const char* name() const { return _dir; }
73 JImageFile* jimage() const { return NULL; }
74 void close_jimage() {}
75 ClassPathDirEntry(const char* dir);
76 virtual ~ClassPathDirEntry() {}
77 ClassFileStream* open_stream(const char* name, TRAPS);
78 };
79
80
81 // Type definitions for zip file and zip file entry
82 typedef void* jzfile;
83 typedef struct {
84 char *name; /* entry name */
85 jlong time; /* modification time */
86 jlong size; /* size of uncompressed data */
87 jlong csize; /* size of compressed data (zero if uncompressed) */
88 jint crc; /* crc of uncompressed data */
89 char *comment; /* optional zip file comment */
90 jbyte *extra; /* optional extra data */
91 jlong pos; /* position of LOC header (if negative) or data */
92 } jzentry;
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_modules_image() const { return false; }
100 bool is_jar_file() const { return true; }
101 const char* name() const { return _zip_name; }
102 JImageFile* jimage() const { return NULL; }
103 void close_jimage() {}
104 ClassPathZipEntry(jzfile* zip, const char* zip_name, bool is_boot_append);
105 virtual ~ClassPathZipEntry();
106 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS);
107 ClassFileStream* open_stream(const char* name, TRAPS);
108 void contents_do(void f(const char* name, void* context), void* context);
109 };
110
111
112 // For java image files
113 class ClassPathImageEntry: public ClassPathEntry {
114 private:
115 JImageFile* _jimage;
116 const char* _name;
117 public:
118 bool is_modules_image() const;
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 void close_jimage();
124 ClassPathImageEntry(JImageFile* jimage, const char* name);
125 virtual ~ClassPathImageEntry();
126 ClassFileStream* open_stream(const char* name, TRAPS);
127 };
128
129 // ModuleClassPathList contains a linked list of ClassPathEntry's
130 // that have been specified for a specific module. Currently,
131 // the only way to specify a module/path pair is via the --patch-module
132 // command line option.
133 class ModuleClassPathList : public CHeapObj<mtClass> {
134 private:
135 Symbol* _module_name;
136 // First and last entries of class path entries for a specific module
137 ClassPathEntry* _module_first_entry;
138 ClassPathEntry* _module_last_entry;
139 public:
140 Symbol* module_name() const { return _module_name; }
141 ClassPathEntry* module_first_entry() const { return _module_first_entry; }
142 ModuleClassPathList(Symbol* module_name);
143 ~ModuleClassPathList();
144 void add_to_list(ClassPathEntry* new_entry);
145 };
146
147 class SharedPathsMiscInfo;
148
149 class ClassLoader: AllStatic {
150 public:
151 enum ClassLoaderType {
152 BOOT_LOADER = 1, /* boot loader */
153 PLATFORM_LOADER = 2, /* PlatformClassLoader */
154 APP_LOADER = 3 /* AppClassLoader */
155 };
156 protected:
157
158 // Performance counters
159 static PerfCounter* _perf_accumulated_time;
160 static PerfCounter* _perf_classes_inited;
161 static PerfCounter* _perf_class_init_time;
162 static PerfCounter* _perf_class_init_selftime;
163 static PerfCounter* _perf_classes_verified;
164 static PerfCounter* _perf_class_verify_time;
165 static PerfCounter* _perf_class_verify_selftime;
166 static PerfCounter* _perf_classes_linked;
167 static PerfCounter* _perf_class_link_time;
168 static PerfCounter* _perf_class_link_selftime;
169 static PerfCounter* _perf_class_parse_time;
170 static PerfCounter* _perf_class_parse_selftime;
171 static PerfCounter* _perf_sys_class_lookup_time;
172 static PerfCounter* _perf_shared_classload_time;
173 static PerfCounter* _perf_sys_classload_time;
174 static PerfCounter* _perf_app_classload_time;
175 static PerfCounter* _perf_app_classload_selftime;
176 static PerfCounter* _perf_app_classload_count;
177 static PerfCounter* _perf_define_appclasses;
178 static PerfCounter* _perf_define_appclass_time;
179 static PerfCounter* _perf_define_appclass_selftime;
180 static PerfCounter* _perf_app_classfile_bytes_read;
181 static PerfCounter* _perf_sys_classfile_bytes_read;
182
183 static PerfCounter* _sync_systemLoaderLockContentionRate;
184 static PerfCounter* _sync_nonSystemLoaderLockContentionRate;
185 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter;
186 static PerfCounter* _sync_JVMDefineClassLockFreeCounter;
187 static PerfCounter* _sync_JNIDefineClassLockFreeCounter;
188
189 static PerfCounter* _unsafe_defineClassCallCounter;
190
191 // The boot class path consists of 3 ordered pieces:
192 // 1. the module/path pairs specified to --patch-module
193 // --patch-module=<module>=<file>(<pathsep><file>)*
194 // 2. the base piece
195 // [jimage | build with exploded modules]
196 // 3. boot loader append path
197 // [-Xbootclasspath/a]; [jvmti appended entries]
198 //
199 // The boot loader must obey this order when attempting
200 // to load a class.
201
202 // 1. Contains the module/path pairs specified to --patch-module
203 static GrowableArray<ModuleClassPathList*>* _patch_mod_entries;
204
205 // 2. the base piece
206 // Contains the ClassPathEntry of the modular java runtime image.
207 // If no java runtime image is present, this indicates a
208 // build with exploded modules is being used instead.
209 static ClassPathEntry* _jrt_entry;
210 static GrowableArray<ModuleClassPathList*>* _exploded_entries;
211 enum { EXPLODED_ENTRY_SIZE = 80 }; // Initial number of exploded modules
212
213 // 3. the boot loader's append path
214 // [-Xbootclasspath/a]; [jvmti appended entries]
215 // Note: boot loader append path does not support named modules.
216 static ClassPathEntry* _first_append_entry;
217 // Last entry in linked list of appended ClassPathEntry instances
218 static ClassPathEntry* _last_append_entry;
219
220 // Info used by CDS
221 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;)
222
223 CDS_ONLY(static ClassPathEntry* _app_classpath_entries;)
224 CDS_ONLY(static ClassPathEntry* _last_app_classpath_entry;)
225 CDS_ONLY(static ClassPathEntry* _module_path_entries;)
226 CDS_ONLY(static ClassPathEntry* _last_module_path_entry;)
227 CDS_ONLY(static void setup_app_search_path(const char* class_path);)
228 CDS_ONLY(static void setup_module_search_path(const char* path, TRAPS);)
229 static void add_to_app_classpath_entries(const char* path,
230 ClassPathEntry* entry,
231 bool check_for_duplicates);
232 CDS_ONLY(static void add_to_module_path_entries(const char* path,
233 ClassPathEntry* entry);)
234 public:
235 CDS_ONLY(static ClassPathEntry* app_classpath_entries() {return _app_classpath_entries;})
236 CDS_ONLY(static ClassPathEntry* module_path_entries() {return _module_path_entries;})
237
238 protected:
239 // Initialization:
240 // - setup the boot loader's system class path
241 // - setup the boot loader's patch mod entries, if present
242 // - create the ModuleEntry for java.base
243 static void setup_bootstrap_search_path();
244 static void setup_boot_search_path(const char *class_path);
245 static void setup_patch_mod_entries();
246 static void create_javabase();
247
248 static void load_zip_library();
249 static void load_jimage_library();
250
251 public:
252 static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st,
253 bool throw_exception,
254 bool is_boot_append, TRAPS);
255
256 // If the package for the fully qualified class name is in the boot
257 // loader's package entry table then add_package() sets the classpath_index
258 // field so that get_system_package() will know to return a non-null value
259 // for the package's location. And, so that the package will be added to
260 // the list of packages returned by get_system_packages().
261 // For packages whose classes are loaded from the boot loader class path, the
262 // classpath_index indicates which entry on the boot loader class path.
263 static bool add_package(const char *fullq_class_name, s2 classpath_index, TRAPS);
264
265 // Canonicalizes path names, so strcmp will work properly. This is mainly
266 // to avoid confusing the zip library
267 static bool get_canonical_path(const char* orig, char* out, int len);
268 static const char* file_name_for_class_name(const char* class_name,
269 int class_name_len);
270 static PackageEntry* get_package_entry(const char* class_name, ClassLoaderData* loader_data, TRAPS);
271
272 public:
273 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg);
274 static int crc32(int crc, const char* buf, int len);
275 static bool update_class_path_entry_list(const char *path,
276 bool check_for_duplicates,
277 bool is_boot_append,
278 bool throw_exception=true);
279 CDS_ONLY(static void update_module_path_entry_list(const char *path, TRAPS);)
280 static void print_bootclasspath();
281
282 // Timing
283 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; }
284 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; }
285 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; }
286 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; }
287 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; }
288 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; }
289 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; }
290 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; }
291 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; }
292 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; }
293 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; }
294 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; }
295 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; }
296 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; }
297 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; }
298 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; }
299 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; }
300 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; }
301 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; }
302 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; }
303 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; }
304 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; }
305 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; }
306
307 // Record how often system loader lock object is contended
308 static PerfCounter* sync_systemLoaderLockContentionRate() {
309 return _sync_systemLoaderLockContentionRate;
310 }
311
312 // Record how often non system loader lock object is contended
313 static PerfCounter* sync_nonSystemLoaderLockContentionRate() {
314 return _sync_nonSystemLoaderLockContentionRate;
315 }
316
317 // Record how many calls to JVM_FindLoadedClass w/o holding a lock
318 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() {
319 return _sync_JVMFindLoadedClassLockFreeCounter;
320 }
321
322 // Record how many calls to JVM_DefineClass w/o holding a lock
323 static PerfCounter* sync_JVMDefineClassLockFreeCounter() {
324 return _sync_JVMDefineClassLockFreeCounter;
325 }
326
327 // Record how many calls to jni_DefineClass w/o holding a lock
328 static PerfCounter* sync_JNIDefineClassLockFreeCounter() {
329 return _sync_JNIDefineClassLockFreeCounter;
330 }
331
332 // Record how many calls to Unsafe_DefineClass
333 static PerfCounter* unsafe_defineClassCallCounter() {
334 return _unsafe_defineClassCallCounter;
335 }
336
337 // Modular java runtime image is present vs. a build with exploded modules
338 static bool has_jrt_entry() { return (_jrt_entry != NULL); }
339 static ClassPathEntry* get_jrt_entry() { return _jrt_entry; }
340 static void close_jrt_image();
341
342 // Add a module's exploded directory to the boot loader's exploded module build list
343 static void add_to_exploded_build_list(Symbol* module_name, TRAPS);
344
345 // Attempt load of individual class from either the patched or exploded modules build lists
346 static ClassFileStream* search_module_entries(const GrowableArray<ModuleClassPathList*>* const module_list,
347 const char* const class_name,
348 const char* const file_name, TRAPS);
349
350 // Load individual .class file
351 static InstanceKlass* load_class(Symbol* class_name, bool search_append_only, TRAPS);
352
353 // If the specified package has been loaded by the system, then returns
354 // the name of the directory or ZIP file that the package was loaded from.
355 // Returns null if the package was not loaded.
356 // Note: The specified name can either be the name of a class or package.
357 // If a package name is specified, then it must be "/"-separator and also
358 // end with a trailing "/".
359 static oop get_system_package(const char* name, TRAPS);
360
361 // Returns an array of Java strings representing all of the currently
362 // loaded system packages.
363 // Note: The package names returned are "/"-separated and end with a
364 // trailing "/".
365 static objArrayOop get_system_packages(TRAPS);
366
367 // Initialization
368 static void initialize();
369 static void classLoader_init2(TRAPS);
370 CDS_ONLY(static void initialize_shared_path();)
371 CDS_ONLY(static void initialize_module_path(TRAPS);)
372
373 static int compute_Object_vtable();
374
375 static ClassPathEntry* classpath_entry(int n);
376
377 static bool is_in_patch_mod_entries(Symbol* module_name);
378
379 #if INCLUDE_CDS
380 // Sharing dump and restore
381
382 // Helper function used by CDS code to get the number of boot classpath
383 // entries during shared classpath setup time.
384 static int num_boot_classpath_entries();
385
386 static ClassPathEntry* get_next_boot_classpath_entry(ClassPathEntry* e);
387
388 // Helper function used by CDS code to get the number of app classpath
389 // entries during shared classpath setup time.
390 static int num_app_classpath_entries();
391
392 // Helper function used by CDS code to get the number of module path
393 // entries during shared classpath setup time.
394 static int num_module_path_entries() {
395 assert(DumpSharedSpaces, "Should only be called at CDS dump time");
396 int num_entries = 0;
397 ClassPathEntry* e= ClassLoader::_module_path_entries;
398 while (e != NULL) {
399 num_entries ++;
400 e = e->next();
401 }
402 return num_entries;
403 }
404 static void finalize_shared_paths_misc_info();
405 static int get_shared_paths_misc_info_size();
406 static void* get_shared_paths_misc_info();
407 static bool check_shared_paths_misc_info(void* info, int size);
408 static void exit_with_path_failure(const char* error, const char* message);
409 static char* skip_uri_protocol(char* source);
410 static void record_result(InstanceKlass* ik, const ClassFileStream* stream, TRAPS);
411 #endif
412 static JImageLocationRef jimage_find_resource(JImageFile* jf, const char* module_name,
413 const char* file_name, jlong &size);
414
415 static void trace_class_path(const char* msg, const char* name = NULL);
416
417 // VM monitoring and management support
418 static jlong classloader_time_ms();
419 static jlong class_method_total_size();
420 static jlong class_init_count();
421 static jlong class_init_time_ms();
422 static jlong class_verify_time_ms();
423 static jlong class_link_count();
424 static jlong class_link_time_ms();
425
426 // indicates if class path already contains a entry (exact match by name)
427 static bool contains_append_entry(const char* name);
428
429 // adds a class path to the boot append entries
430 static void add_to_boot_append_entries(ClassPathEntry* new_entry);
431
432 // creates a class path zip entry (returns NULL if JAR file cannot be opened)
433 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath, bool is_boot_append);
434
435 static bool string_ends_with(const char* str, const char* str_to_find);
436
437 // obtain package name from a fully qualified class name
438 // *bad_class_name is set to true if there's a problem with parsing class_name, to
439 // distinguish from a class_name with no package name, as both cases have a NULL return value
440 static const char* package_from_name(const char* const class_name, bool* bad_class_name = NULL);
441
442 static bool is_modules_image(const char* name) { return string_ends_with(name, MODULES_IMAGE_NAME); }
443
444 // Debugging
445 static void verify() PRODUCT_RETURN;
446 };
447
448 // PerfClassTraceTime is used to measure time for class loading related events.
449 // This class tracks cumulative time and exclusive time for specific event types.
450 // During the execution of one event, other event types (e.g. class loading and
451 // resolution) as well as recursive calls of the same event type could happen.
452 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive)
453 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime
454 // instances have been created as multiple events are happening.
455 class PerfClassTraceTime {
456 public:
457 enum {
458 CLASS_LOAD = 0,
459 PARSE_CLASS = 1,
460 CLASS_LINK = 2,
461 CLASS_VERIFY = 3,
462 CLASS_CLINIT = 4,
463 DEFINE_CLASS = 5,
464 EVENT_TYPE_COUNT = 6
465 };
466 protected:
467 // _t tracks time from initialization to destruction of this timer instance
468 // including time for all other event types, and recursive calls of this type.
469 // When a timer is called recursively, the elapsedTimer _t would not be used.
470 elapsedTimer _t;
471 PerfLongCounter* _timep;
472 PerfLongCounter* _selftimep;
473 PerfLongCounter* _eventp;
474 // pointer to thread-local recursion counter and timer array
475 // The thread_local timers track cumulative time for specific event types
476 // exclusive of time for other event types, but including recursive calls
477 // of the same type.
478 int* _recursion_counters;
479 elapsedTimer* _timers;
480 int _event_type;
481 int _prev_active_event;
482
483 public:
484
485 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
486 PerfLongCounter* selftimep, /* counter incremented with exclusive time */
487 PerfLongCounter* eventp, /* event counter */
488 int* recursion_counters, /* thread-local recursion counter array */
489 elapsedTimer* timers, /* thread-local timer array */
490 int type /* event type */ ) :
491 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) {
492 initialize();
493 }
494
495 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */
496 elapsedTimer* timers, /* thread-local timer array */
497 int type /* event type */ ) :
498 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) {
499 initialize();
500 }
501
502 inline void suspend() { _t.stop(); _timers[_event_type].stop(); }
503 inline void resume() { _t.start(); _timers[_event_type].start(); }
504
505 ~PerfClassTraceTime();
506 void initialize();
507 };
508
509 #endif // SHARE_CLASSFILE_CLASSLOADER_HPP