1 /*
2 * Copyright 1997-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 // The system dictionary stores all loaded classes and maps:
26 //
27 // [class name,class loader] -> class i.e. [symbolOop,oop] -> klassOop
28 //
29 // Classes are loaded lazily. The default VM class loader is
30 // represented as NULL.
31
32 // The underlying data structure is an open hash table with a fixed number
33 // of buckets. During loading the loader object is locked, (for the VM loader
34 // a private lock object is used). Class loading can thus be done concurrently,
35 // but only by different loaders.
36 //
37 // During loading a placeholder (name, loader) is temporarily placed in
38 // a side data structure, and is used to detect ClassCircularityErrors
39 // and to perform verification during GC. A GC can occur in the midst
40 // of class loading, as we call out to Java, have to take locks, etc.
41 //
42 // When class loading is finished, a new entry is added to the system
43 // dictionary and the place holder is removed. Note that the protection
44 // domain field of the system dictionary has not yet been filled in when
45 // the "real" system dictionary entry is created.
46 //
47 // Clients of this class who are interested in finding if a class has
48 // been completely loaded -- not classes in the process of being loaded --
49 // can read the SystemDictionary unlocked. This is safe because
50 // - entries are only deleted at safepoints
51 // - readers cannot come to a safepoint while actively examining
52 // an entry (an entry cannot be deleted from under a reader)
53 // - entries must be fully formed before they are available to concurrent
54 // readers (we must ensure write ordering)
55 //
56 // Note that placeholders are deleted at any time, as they are removed
57 // when a class is completely loaded. Therefore, readers as well as writers
58 // of placeholders must hold the SystemDictionary_lock.
59 //
60
61 class Dictionary;
62 class PlaceholderTable;
63 class LoaderConstraintTable;
64 class HashtableBucket;
65 class ResolutionErrorTable;
66 class SymbolPropertyTable;
67
68 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
69 // They are all "well-known", in the sense that no class loader is allowed
70 // to provide a different definition.
71 //
72 // These klasses must all have names defined in vmSymbols.
73
74 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
75
76 // Each well-known class has a short klass name (like object_klass),
77 // a vmSymbol name (like java_lang_Object), and a flag word
78 // that makes some minor distinctions, like whether the klass
79 // is preloaded, optional, release-specific, etc.
80 // The order of these definitions is significant; it is the order in which
81 // preloading is actually performed by initialize_preloaded_classes.
82
83 #define WK_KLASSES_DO(template) \
84 /* well-known classes */ \
85 template(object_klass, java_lang_Object, Pre) \
86 template(string_klass, java_lang_String, Pre) \
87 template(class_klass, java_lang_Class, Pre) \
88 template(cloneable_klass, java_lang_Cloneable, Pre) \
89 template(classloader_klass, java_lang_ClassLoader, Pre) \
90 template(serializable_klass, java_io_Serializable, Pre) \
91 template(system_klass, java_lang_System, Pre) \
92 template(throwable_klass, java_lang_Throwable, Pre) \
93 template(error_klass, java_lang_Error, Pre) \
94 template(threaddeath_klass, java_lang_ThreadDeath, Pre) \
95 template(exception_klass, java_lang_Exception, Pre) \
96 template(runtime_exception_klass, java_lang_RuntimeException, Pre) \
97 template(protectionDomain_klass, java_security_ProtectionDomain, Pre) \
98 template(AccessControlContext_klass, java_security_AccessControlContext, Pre) \
99 template(classNotFoundException_klass, java_lang_ClassNotFoundException, Pre) \
100 template(noClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre) \
101 template(linkageError_klass, java_lang_LinkageError, Pre) \
102 template(ClassCastException_klass, java_lang_ClassCastException, Pre) \
103 template(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre) \
104 template(virtualMachineError_klass, java_lang_VirtualMachineError, Pre) \
105 template(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre) \
106 template(StackOverflowError_klass, java_lang_StackOverflowError, Pre) \
107 template(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre) \
108 template(reference_klass, java_lang_ref_Reference, Pre) \
109 \
110 /* Preload ref klasses and set reference types */ \
111 template(soft_reference_klass, java_lang_ref_SoftReference, Pre) \
112 template(weak_reference_klass, java_lang_ref_WeakReference, Pre) \
113 template(final_reference_klass, java_lang_ref_FinalReference, Pre) \
114 template(phantom_reference_klass, java_lang_ref_PhantomReference, Pre) \
115 template(finalizer_klass, java_lang_ref_Finalizer, Pre) \
116 \
117 template(thread_klass, java_lang_Thread, Pre) \
118 template(threadGroup_klass, java_lang_ThreadGroup, Pre) \
119 template(properties_klass, java_util_Properties, Pre) \
120 template(reflect_accessible_object_klass, java_lang_reflect_AccessibleObject, Pre) \
121 template(reflect_field_klass, java_lang_reflect_Field, Pre) \
122 template(reflect_method_klass, java_lang_reflect_Method, Pre) \
123 template(reflect_constructor_klass, java_lang_reflect_Constructor, Pre) \
124 \
125 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
126 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
127 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
128 template(reflect_magic_klass, sun_reflect_MagicAccessorImpl, Opt) \
129 template(reflect_method_accessor_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \
130 template(reflect_constructor_accessor_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \
131 template(reflect_delegating_classloader_klass, sun_reflect_DelegatingClassLoader, Opt) \
132 template(reflect_constant_pool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15) \
133 template(reflect_unsafe_static_field_accessor_impl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15) \
134 \
135 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
136 template(MethodHandle_klass, java_dyn_MethodHandle, Opt) \
137 template(MemberName_klass, sun_dyn_MemberName, Opt) \
138 template(MethodHandleImpl_klass, sun_dyn_MethodHandleImpl, Opt) \
139 template(AdapterMethodHandle_klass, sun_dyn_AdapterMethodHandle, Opt) \
140 template(BoundMethodHandle_klass, sun_dyn_BoundMethodHandle, Opt) \
141 template(DirectMethodHandle_klass, sun_dyn_DirectMethodHandle, Opt) \
142 template(MethodType_klass, java_dyn_MethodType, Opt) \
143 template(MethodTypeForm_klass, java_dyn_MethodTypeForm, Opt) \
144 template(WrongMethodTypeException_klass, java_dyn_WrongMethodTypeException, Opt) \
145 template(Linkage_klass, java_dyn_Linkage, Opt) \
146 template(CallSite_klass, java_dyn_CallSite, Opt) \
147 template(Dynamic_klass, java_dyn_Dynamic, Opt) \
148 /* Note: MethodHandle must be first, and Dynamic last in group */ \
149 \
150 template(vector_klass, java_util_Vector, Pre) \
151 template(hashtable_klass, java_util_Hashtable, Pre) \
152 template(stringBuffer_klass, java_lang_StringBuffer, Pre) \
153 template(StringBuilder_klass, java_lang_StringBuilder, Pre) \
154 \
155 /* It's NULL in non-1.4 JDKs. */ \
156 template(stackTraceElement_klass, java_lang_StackTraceElement, Opt) \
157 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
158 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
159 template(java_nio_Buffer_klass, java_nio_Buffer, Opt) \
160 \
161 /* If this class isn't present, it won't be referenced. */ \
162 template(sun_misc_AtomicLongCSImpl_klass, sun_misc_AtomicLongCSImpl, Opt) \
163 \
164 template(sun_jkernel_DownloadManager_klass, sun_jkernel_DownloadManager, Opt_Kernel) \
165 \
166 /* Preload boxing klasses */ \
167 template(boolean_klass, java_lang_Boolean, Pre) \
168 template(char_klass, java_lang_Character, Pre) \
169 template(float_klass, java_lang_Float, Pre) \
170 template(double_klass, java_lang_Double, Pre) \
171 template(byte_klass, java_lang_Byte, Pre) \
172 template(short_klass, java_lang_Short, Pre) \
173 template(int_klass, java_lang_Integer, Pre) \
174 template(long_klass, java_lang_Long, Pre) \
175 /*end*/
176
177
178 class SystemDictionary : AllStatic {
179 friend class VMStructs;
180 friend class CompactingPermGenGen;
181 friend class SystemDictionaryHandles;
182 NOT_PRODUCT(friend class instanceKlassKlass;)
183
184 public:
185 enum WKID {
186 NO_WKID = 0,
187
188 #define WK_KLASS_ENUM(name, ignore_s, ignore_o) WK_KLASS_ENUM_NAME(name),
189 WK_KLASSES_DO(WK_KLASS_ENUM)
190 #undef WK_KLASS_ENUM
191
192 WKID_LIMIT,
193
194 FIRST_WKID = NO_WKID + 1
195 };
196
197 enum InitOption {
198 Pre, // preloaded; error if not present
199
200 // Order is significant. Options before this point require resolve_or_fail.
201 // Options after this point will use resolve_or_null instead.
202
203 Opt, // preload tried; NULL if not present
204 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection
205 Opt_Only_JDK15, // preload tried; use only with JDK1.5+
206 Opt_Kernel, // preload tried only #ifdef KERNEL
207 OPTION_LIMIT,
208 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
209 };
210
211
212 // Returns a class with a given class name and class loader. Loads the
213 // class if needed. If not found a NoClassDefFoundError or a
214 // ClassNotFoundException is thrown, depending on the value on the
215 // throw_error flag. For most uses the throw_error argument should be set
216 // to true.
217
218 static klassOop resolve_or_fail(symbolHandle class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
219 // Convenient call for null loader and protection domain.
220 static klassOop resolve_or_fail(symbolHandle class_name, bool throw_error, TRAPS);
221 private:
222 // handle error translation for resolve_or_null results
223 static klassOop handle_resolution_exception(symbolHandle class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
224
225 public:
226
227 // Returns a class with a given class name and class loader.
228 // Loads the class if needed. If not found NULL is returned.
229 static klassOop resolve_or_null(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS);
230 // Version with null loader and protection domain
231 static klassOop resolve_or_null(symbolHandle class_name, TRAPS);
232
233 // Resolve a superclass or superinterface. Called from ClassFileParser,
234 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
235 // "child_name" is the class whose super class or interface is being resolved.
236 static klassOop resolve_super_or_fail(symbolHandle child_name,
237 symbolHandle class_name,
238 Handle class_loader,
239 Handle protection_domain,
240 bool is_superclass,
241 TRAPS);
242
243 // Parse new stream. This won't update the system dictionary or
244 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
245 static klassOop parse_stream(symbolHandle class_name,
246 Handle class_loader,
247 Handle protection_domain,
248 ClassFileStream* st,
249 TRAPS) {
250 KlassHandle nullHandle;
251 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
252 }
253 static klassOop parse_stream(symbolHandle class_name,
254 Handle class_loader,
255 Handle protection_domain,
256 ClassFileStream* st,
257 KlassHandle host_klass,
258 GrowableArray<Handle>* cp_patches,
259 TRAPS);
260
261 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
262 static klassOop resolve_from_stream(symbolHandle class_name, Handle class_loader,
263 Handle protection_domain,
264 ClassFileStream* st, bool verify, TRAPS);
265
266 // Lookup an already loaded class. If not found NULL is returned.
267 static klassOop find(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS);
268
269 // Lookup an already loaded instance or array class.
270 // Do not make any queries to class loaders; consult only the cache.
271 // If not found NULL is returned.
272 static klassOop find_instance_or_array_klass(symbolHandle class_name,
273 Handle class_loader,
274 Handle protection_domain,
275 TRAPS);
276
277 // If the given name is known to vmSymbols, return the well-know klass:
278 static klassOop find_well_known_klass(symbolOop class_name);
279
280 // Lookup an instance or array class that has already been loaded
281 // either into the given class loader, or else into another class
282 // loader that is constrained (via loader constraints) to produce
283 // a consistent class. Do not take protection domains into account.
284 // Do not make any queries to class loaders; consult only the cache.
285 // Return NULL if the class is not found.
286 //
287 // This function is a strict superset of find_instance_or_array_klass.
288 // This function (the unchecked version) makes a conservative prediction
289 // of the result of the checked version, assuming successful lookup.
290 // If both functions return non-null, they must return the same value.
291 // Also, the unchecked version may sometimes be non-null where the
292 // checked version is null. This can occur in several ways:
293 // 1. No query has yet been made to the class loader.
294 // 2. The class loader was queried, but chose not to delegate.
295 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
296 // 4. Loading was attempted, but there was a linkage error of some sort.
297 // In all of these cases, the loader constraints on this type are
298 // satisfied, and it is safe for classes in the given class loader
299 // to manipulate strongly-typed values of the found class, subject
300 // to local linkage and access checks.
301 static klassOop find_constrained_instance_or_array_klass(symbolHandle class_name,
302 Handle class_loader,
303 TRAPS);
304
305 // Iterate over all klasses in dictionary
306 // Just the classes from defining class loaders
307 static void classes_do(void f(klassOop));
308 // Added for initialize_itable_for_klass to handle exceptions
309 static void classes_do(void f(klassOop, TRAPS), TRAPS);
310 // All classes, and their class loaders
311 static void classes_do(void f(klassOop, oop));
312 // All classes, and their class loaders
313 // (added for helpers that use HandleMarks and ResourceMarks)
314 static void classes_do(void f(klassOop, oop, TRAPS), TRAPS);
315 // All entries in the placeholder table and their class loaders
316 static void placeholders_do(void f(symbolOop, oop));
317
318 // Iterate over all methods in all klasses in dictionary
319 static void methods_do(void f(methodOop));
320
321 // Garbage collection support
322
323 // This method applies "blk->do_oop" to all the pointers to "system"
324 // classes and loaders.
325 static void always_strong_oops_do(OopClosure* blk);
326 static void always_strong_classes_do(OopClosure* blk);
327 // This method applies "blk->do_oop" to all the placeholders.
328 static void placeholders_do(OopClosure* blk);
329
330 // Unload (that is, break root links to) all unmarked classes and
331 // loaders. Returns "true" iff something was unloaded.
332 static bool do_unloading(BoolObjectClosure* is_alive);
333
334 // Applies "f->do_oop" to all root oops in the system dictionary.
335 static void oops_do(OopClosure* f);
336
337 // System loader lock
338 static oop system_loader_lock() { return _system_loader_lock_obj; }
339
340 private:
341 // Traverses preloaded oops: various system classes. These are
342 // guaranteed to be in the perm gen.
343 static void preloaded_oops_do(OopClosure* f);
344 static void lazily_loaded_oops_do(OopClosure* f);
345
346 public:
347 // Sharing support.
348 static void reorder_dictionary();
349 static void copy_buckets(char** top, char* end);
350 static void copy_table(char** top, char* end);
351 static void reverse();
352 static void set_shared_dictionary(HashtableBucket* t, int length,
353 int number_of_entries);
354 // Printing
355 static void print() PRODUCT_RETURN;
356 static void print_class_statistics() PRODUCT_RETURN;
357 static void print_method_statistics() PRODUCT_RETURN;
358
359 // Number of contained klasses
360 // This is both fully loaded classes and classes in the process
361 // of being loaded
362 static int number_of_classes();
363
364 // Monotonically increasing counter which grows as classes are
365 // loaded or modifications such as hot-swapping or setting/removing
366 // of breakpoints are performed
367 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
368 // Needed by evolution and breakpoint code
369 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
370
371 // Verification
372 static void verify();
373
374 #ifdef ASSERT
375 static bool is_internal_format(symbolHandle class_name);
376 #endif
377
378 // Verify class is in dictionary
379 static void verify_obj_klass_present(Handle obj,
380 symbolHandle class_name,
381 Handle class_loader);
382
383 // Initialization
384 static void initialize(TRAPS);
385
386 // Fast access to commonly used classes (preloaded)
387 static klassOop check_klass(klassOop k) {
388 assert(k != NULL, "preloaded klass not initialized");
389 return k;
390 }
391
392 static klassOop check_klass_Pre(klassOop k) { return check_klass(k); }
393 static klassOop check_klass_Opt(klassOop k) { return k; }
394 static klassOop check_klass_Opt_Kernel(klassOop k) { return k; } //== Opt
395 static klassOop check_klass_Opt_Only_JDK15(klassOop k) {
396 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
397 return k;
398 }
399 static klassOop check_klass_Opt_Only_JDK14NewRef(klassOop k) {
400 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
401 // despite the optional loading, if you use this it must be present:
402 return check_klass(k);
403 }
404
405 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
406 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
407 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
408 int limit = (int)end_id + 1;
409 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
410 }
411
412 public:
413 #define WK_KLASS_DECLARE(name, ignore_symbol, option) \
414 static klassOop name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); }
415 WK_KLASSES_DO(WK_KLASS_DECLARE);
416 #undef WK_KLASS_DECLARE
417
418 // Local definition for direct access to the private array:
419 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
420
421 static klassOop box_klass(BasicType t) {
422 assert((uint)t < T_VOID+1, "range check");
423 return check_klass(_box_klasses[t]);
424 }
425 static BasicType box_klass_type(klassOop k); // inverse of box_klass
426
427 // methods returning lazily loaded klasses
428 // The corresponding method to load the class must be called before calling them.
429 static klassOop abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
430
431 static void load_abstract_ownable_synchronizer_klass(TRAPS);
432
433 private:
434 // Tells whether ClassLoader.loadClassInternal is present
435 static bool has_loadClassInternal() { return _has_loadClassInternal; }
436
437 public:
438 // Tells whether ClassLoader.checkPackageAccess is present
439 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
440
441 static bool class_klass_loaded() { return WK_KLASS(class_klass) != NULL; }
442 static bool cloneable_klass_loaded() { return WK_KLASS(cloneable_klass) != NULL; }
443
444 // Returns default system loader
445 static oop java_system_loader();
446
447 // Compute the default system loader
448 static void compute_java_system_loader(TRAPS);
449
450 private:
451 // Mirrors for primitive classes (created eagerly)
452 static oop check_mirror(oop m) {
453 assert(m != NULL, "mirror not initialized");
454 return m;
455 }
456
457 public:
458 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
459
460 // Check class loader constraints
461 static bool add_loader_constraint(symbolHandle name, Handle loader1,
462 Handle loader2, TRAPS);
463 static char* check_signature_loaders(symbolHandle signature, Handle loader1,
464 Handle loader2, bool is_method, TRAPS);
465
466 // JSR 292
467 // find the java.dyn.MethodHandles::invoke method for a given signature
468 static methodOop find_method_handle_invoke(symbolHandle signature,
469 Handle class_loader,
470 Handle protection_domain,
471 TRAPS);
472 // ask Java to compute the java.dyn.MethodType object for a given signature
473 static Handle compute_method_handle_type(symbolHandle signature,
474 Handle class_loader,
475 Handle protection_domain,
476 TRAPS);
477 // ask Java to create a dynamic call site, while linking an invokedynamic op
478 static Handle make_dynamic_call_site(KlassHandle caller,
479 int caller_method_idnum,
480 int caller_bci,
481 symbolHandle name,
482 methodHandle mh_invoke,
483 TRAPS);
484
485 // coordinate with Java about bootstrap methods
486 static Handle find_bootstrap_method(KlassHandle caller,
487 // This argument is non-null only when a
488 // classfile attribute has been found:
489 KlassHandle search_bootstrap_klass,
490 TRAPS);
491
492 // Utility for printing loader "name" as part of tracing constraints
493 static const char* loader_name(oop loader) {
494 return ((loader) == NULL ? "<bootloader>" :
495 instanceKlass::cast((loader)->klass())->name()->as_C_string() );
496 }
497
498 // Record the error when the first attempt to resolve a reference from a constant
499 // pool entry to a class fails.
500 static void add_resolution_error(constantPoolHandle pool, int which, symbolHandle error);
501 static symbolOop find_resolution_error(constantPoolHandle pool, int which);
502
503 private:
504
505 enum Constants {
506 _loader_constraint_size = 107, // number of entries in constraint table
507 _resolution_error_size = 107, // number of entries in resolution error table
508 _invoke_method_size = 139, // number of entries in invoke method table
509 _nof_buckets = 1009 // number of buckets in hash table
510 };
511
512
513 // Static variables
514
515 // Hashtable holding loaded classes.
516 static Dictionary* _dictionary;
517
518 // Hashtable holding placeholders for classes being loaded.
519 static PlaceholderTable* _placeholders;
520
521 // Hashtable holding classes from the shared archive.
522 static Dictionary* _shared_dictionary;
523
524 // Monotonically increasing counter which grows with
525 // _number_of_classes as well as hot-swapping and breakpoint setting
526 // and removal.
527 static int _number_of_modifications;
528
529 // Lock object for system class loader
530 static oop _system_loader_lock_obj;
531
532 // Constraints on class loaders
533 static LoaderConstraintTable* _loader_constraints;
534
535 // Resolution errors
536 static ResolutionErrorTable* _resolution_errors;
537
538 // Invoke methods (JSR 292)
539 static SymbolPropertyTable* _invoke_method_table;
540
541 public:
542 // for VM_CounterDecay iteration support
543 friend class CounterDecay;
544 static klassOop try_get_next_class();
545
546 private:
547 static void validate_protection_domain(instanceKlassHandle klass,
548 Handle class_loader,
549 Handle protection_domain, TRAPS);
550
551 friend class VM_PopulateDumpSharedSpace;
552 friend class TraversePlaceholdersClosure;
553 static Dictionary* dictionary() { return _dictionary; }
554 static Dictionary* shared_dictionary() { return _shared_dictionary; }
555 static PlaceholderTable* placeholders() { return _placeholders; }
556 static LoaderConstraintTable* constraints() { return _loader_constraints; }
557 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
558 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
559
560 // Basic loading operations
561 static klassOop resolve_instance_class_or_null(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS);
562 static klassOop resolve_array_class_or_null(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS);
563 static instanceKlassHandle handle_parallel_super_load(symbolHandle class_name, symbolHandle supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
564 // Wait on SystemDictionary_lock; unlocks lockObject before
565 // waiting; relocks lockObject with correct recursion count
566 // after waiting, but before reentering SystemDictionary_lock
567 // to preserve lock order semantics.
568 static void double_lock_wait(Handle lockObject, TRAPS);
569 static void define_instance_class(instanceKlassHandle k, TRAPS);
570 static instanceKlassHandle find_or_define_instance_class(symbolHandle class_name,
571 Handle class_loader,
572 instanceKlassHandle k, TRAPS);
573 static instanceKlassHandle load_shared_class(symbolHandle class_name,
574 Handle class_loader, TRAPS);
575 static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
576 Handle class_loader, TRAPS);
577 static instanceKlassHandle load_instance_class(symbolHandle class_name, Handle class_loader, TRAPS);
578 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
579 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
580 static bool is_parallelCapable(Handle class_loader);
581 static bool is_parallelDefine(Handle class_loader);
582
583 static klassOop find_shared_class(symbolHandle class_name);
584
585 // Setup link to hierarchy
586 static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
587
588 private:
589 // We pass in the hashtable index so we can calculate it outside of
590 // the SystemDictionary_lock.
591
592 // Basic find on loaded classes
593 static klassOop find_class(int index, unsigned int hash,
594 symbolHandle name, Handle loader);
595
596 // Basic find on classes in the midst of being loaded
597 static symbolOop find_placeholder(int index, unsigned int hash,
598 symbolHandle name, Handle loader);
599
600 // Basic find operation of loaded classes and classes in the midst
601 // of loading; used for assertions and verification only.
602 static oop find_class_or_placeholder(symbolHandle class_name,
603 Handle class_loader);
604
605 // Updating entry in dictionary
606 // Add a completely loaded class
607 static void add_klass(int index, symbolHandle class_name,
608 Handle class_loader, KlassHandle obj);
609
610 // Add a placeholder for a class being loaded
611 static void add_placeholder(int index,
612 symbolHandle class_name,
613 Handle class_loader);
614 static void remove_placeholder(int index,
615 symbolHandle class_name,
616 Handle class_loader);
617
618 // Performs cleanups after resolve_super_or_fail. This typically needs
619 // to be called on failure.
620 // Won't throw, but can block.
621 static void resolution_cleanups(symbolHandle class_name,
622 Handle class_loader,
623 TRAPS);
624
625 // Initialization
626 static void initialize_preloaded_classes(TRAPS);
627
628 // Class loader constraints
629 static void check_constraints(int index, unsigned int hash,
630 instanceKlassHandle k, Handle loader,
631 bool defining, TRAPS);
632 static void update_dictionary(int d_index, unsigned int d_hash,
633 int p_index, unsigned int p_hash,
634 instanceKlassHandle k, Handle loader, TRAPS);
635
636 // Variables holding commonly used klasses (preloaded)
637 static klassOop _well_known_klasses[];
638
639 // Lazily loaded klasses
640 static volatile klassOop _abstract_ownable_synchronizer_klass;
641
642 // table of box klasses (int_klass, etc.)
643 static klassOop _box_klasses[T_VOID+1];
644
645 static oop _java_system_loader;
646
647 static bool _has_loadClassInternal;
648 static bool _has_checkPackageAccess;
649 };
650
651 // Cf. vmSymbols vs. vmSymbolHandles
652 class SystemDictionaryHandles : AllStatic {
653 public:
654 #define WK_KLASS_HANDLE_DECLARE(name, ignore_symbol, option) \
655 static KlassHandle name() { \
656 SystemDictionary::name(); \
657 klassOop* loc = &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
658 return KlassHandle(loc, true); \
659 }
660 WK_KLASSES_DO(WK_KLASS_HANDLE_DECLARE);
661 #undef WK_KLASS_HANDLE_DECLARE
662
663 static KlassHandle box_klass(BasicType t);
664 };