Mon, 05 Jan 2009 13:44:03 -0500
4670071: loadClassInternal is too restrictive.
Summary: VM support for deadlock fix. Library fix in 4735126. See API proposal.
Reviewed-by: dholmes, blacklion
1 /*
2 * Copyright 1997-2008 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 */
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.
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 //
61 class Dictionary;
62 class PlaceholderTable;
63 class LoaderConstraintTable;
64 class HashtableBucket;
65 class ResolutionErrorTable;
67 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
68 // They are all "well-known", in the sense that no class loader is allowed
69 // to provide a different definition.
70 //
71 // These klasses must all have names defined in vmSymbols.
73 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
75 // Each well-known class has a short klass name (like object_klass),
76 // a vmSymbol name (like java_lang_Object), and a flag word
77 // that makes some minor distinctions, like whether the klass
78 // is preloaded, optional, release-specific, etc.
79 // The order of these definitions is significant; it is the order in which
80 // preloading is actually performed by initialize_preloaded_classes.
82 #define WK_KLASSES_DO(template) \
83 /* well-known classes */ \
84 template(object_klass, java_lang_Object, Pre) \
85 template(string_klass, java_lang_String, Pre) \
86 template(class_klass, java_lang_Class, Pre) \
87 template(cloneable_klass, java_lang_Cloneable, Pre) \
88 template(classloader_klass, java_lang_ClassLoader, Pre) \
89 template(serializable_klass, java_io_Serializable, Pre) \
90 template(system_klass, java_lang_System, Pre) \
91 template(throwable_klass, java_lang_Throwable, Pre) \
92 template(error_klass, java_lang_Error, Pre) \
93 template(threaddeath_klass, java_lang_ThreadDeath, Pre) \
94 template(exception_klass, java_lang_Exception, Pre) \
95 template(runtime_exception_klass, java_lang_RuntimeException, Pre) \
96 template(protectionDomain_klass, java_security_ProtectionDomain, Pre) \
97 template(AccessControlContext_klass, java_security_AccessControlContext, Pre) \
98 template(classNotFoundException_klass, java_lang_ClassNotFoundException, Pre) \
99 template(noClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre) \
100 template(linkageError_klass, java_lang_LinkageError, Pre) \
101 template(ClassCastException_klass, java_lang_ClassCastException, Pre) \
102 template(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre) \
103 template(virtualMachineError_klass, java_lang_VirtualMachineError, Pre) \
104 template(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre) \
105 template(StackOverflowError_klass, java_lang_StackOverflowError, Pre) \
106 template(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre) \
107 template(reference_klass, java_lang_ref_Reference, Pre) \
108 \
109 /* Preload ref klasses and set reference types */ \
110 template(soft_reference_klass, java_lang_ref_SoftReference, Pre) \
111 template(weak_reference_klass, java_lang_ref_WeakReference, Pre) \
112 template(final_reference_klass, java_lang_ref_FinalReference, Pre) \
113 template(phantom_reference_klass, java_lang_ref_PhantomReference, Pre) \
114 template(finalizer_klass, java_lang_ref_Finalizer, Pre) \
115 \
116 template(thread_klass, java_lang_Thread, Pre) \
117 template(threadGroup_klass, java_lang_ThreadGroup, Pre) \
118 template(properties_klass, java_util_Properties, Pre) \
119 template(reflect_accessible_object_klass, java_lang_reflect_AccessibleObject, Pre) \
120 template(reflect_field_klass, java_lang_reflect_Field, Pre) \
121 template(reflect_method_klass, java_lang_reflect_Method, Pre) \
122 template(reflect_constructor_klass, java_lang_reflect_Constructor, Pre) \
123 \
124 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
125 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
126 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
127 template(reflect_magic_klass, sun_reflect_MagicAccessorImpl, Opt) \
128 template(reflect_method_accessor_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \
129 template(reflect_constructor_accessor_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \
130 template(reflect_delegating_classloader_klass, sun_reflect_DelegatingClassLoader, Opt) \
131 template(reflect_constant_pool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15) \
132 template(reflect_unsafe_static_field_accessor_impl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15) \
133 \
134 template(vector_klass, java_util_Vector, Pre) \
135 template(hashtable_klass, java_util_Hashtable, Pre) \
136 template(stringBuffer_klass, java_lang_StringBuffer, Pre) \
137 \
138 /* It's NULL in non-1.4 JDKs. */ \
139 template(stackTraceElement_klass, java_lang_StackTraceElement, Opt) \
140 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
141 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
142 template(java_nio_Buffer_klass, java_nio_Buffer, Opt) \
143 \
144 /* If this class isn't present, it won't be referenced. */ \
145 template(sun_misc_AtomicLongCSImpl_klass, sun_misc_AtomicLongCSImpl, Opt) \
146 \
147 template(sun_jkernel_DownloadManager_klass, sun_jkernel_DownloadManager, Opt_Kernel) \
148 \
149 /* Preload boxing klasses */ \
150 template(boolean_klass, java_lang_Boolean, Pre) \
151 template(char_klass, java_lang_Character, Pre) \
152 template(float_klass, java_lang_Float, Pre) \
153 template(double_klass, java_lang_Double, Pre) \
154 template(byte_klass, java_lang_Byte, Pre) \
155 template(short_klass, java_lang_Short, Pre) \
156 template(int_klass, java_lang_Integer, Pre) \
157 template(long_klass, java_lang_Long, Pre) \
158 /*end*/
161 class SystemDictionary : AllStatic {
162 friend class VMStructs;
163 friend class CompactingPermGenGen;
164 NOT_PRODUCT(friend class instanceKlassKlass;)
166 public:
167 enum WKID {
168 NO_WKID = 0,
170 #define WK_KLASS_ENUM(name, ignore_s, ignore_o) WK_KLASS_ENUM_NAME(name),
171 WK_KLASSES_DO(WK_KLASS_ENUM)
172 #undef WK_KLASS_ENUM
174 WKID_LIMIT,
176 FIRST_WKID = NO_WKID + 1
177 };
179 enum InitOption {
180 Pre, // preloaded; error if not present
182 // Order is significant. Options before this point require resolve_or_fail.
183 // Options after this point will use resolve_or_null instead.
185 Opt, // preload tried; NULL if not present
186 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection
187 Opt_Only_JDK15, // preload tried; use only with JDK1.5+
188 Opt_Kernel, // preload tried only #ifdef KERNEL
189 OPTION_LIMIT,
190 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
191 };
194 // Returns a class with a given class name and class loader. Loads the
195 // class if needed. If not found a NoClassDefFoundError or a
196 // ClassNotFoundException is thrown, depending on the value on the
197 // throw_error flag. For most uses the throw_error argument should be set
198 // to true.
200 static klassOop resolve_or_fail(symbolHandle class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
201 // Convenient call for null loader and protection domain.
202 static klassOop resolve_or_fail(symbolHandle class_name, bool throw_error, TRAPS);
203 private:
204 // handle error translation for resolve_or_null results
205 static klassOop handle_resolution_exception(symbolHandle class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
207 public:
209 // Returns a class with a given class name and class loader.
210 // Loads the class if needed. If not found NULL is returned.
211 static klassOop resolve_or_null(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS);
212 // Version with null loader and protection domain
213 static klassOop resolve_or_null(symbolHandle class_name, TRAPS);
215 // Resolve a superclass or superinterface. Called from ClassFileParser,
216 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
217 // "child_name" is the class whose super class or interface is being resolved.
218 static klassOop resolve_super_or_fail(symbolHandle child_name,
219 symbolHandle class_name,
220 Handle class_loader,
221 Handle protection_domain,
222 bool is_superclass,
223 TRAPS);
225 // Parse new stream. This won't update the system dictionary or
226 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
227 static klassOop parse_stream(symbolHandle class_name,
228 Handle class_loader,
229 Handle protection_domain,
230 ClassFileStream* st,
231 TRAPS) {
232 KlassHandle nullHandle;
233 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
234 }
235 static klassOop parse_stream(symbolHandle class_name,
236 Handle class_loader,
237 Handle protection_domain,
238 ClassFileStream* st,
239 KlassHandle host_klass,
240 GrowableArray<Handle>* cp_patches,
241 TRAPS);
243 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
244 static klassOop resolve_from_stream(symbolHandle class_name, Handle class_loader, Handle protection_domain, ClassFileStream* st, TRAPS);
246 // Lookup an already loaded class. If not found NULL is returned.
247 static klassOop find(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS);
249 // Lookup an already loaded instance or array class.
250 // Do not make any queries to class loaders; consult only the cache.
251 // If not found NULL is returned.
252 static klassOop find_instance_or_array_klass(symbolHandle class_name,
253 Handle class_loader,
254 Handle protection_domain,
255 TRAPS);
257 // If the given name is known to vmSymbols, return the well-know klass:
258 static klassOop find_well_known_klass(symbolOop class_name);
260 // Lookup an instance or array class that has already been loaded
261 // either into the given class loader, or else into another class
262 // loader that is constrained (via loader constraints) to produce
263 // a consistent class. Do not take protection domains into account.
264 // Do not make any queries to class loaders; consult only the cache.
265 // Return NULL if the class is not found.
266 //
267 // This function is a strict superset of find_instance_or_array_klass.
268 // This function (the unchecked version) makes a conservative prediction
269 // of the result of the checked version, assuming successful lookup.
270 // If both functions return non-null, they must return the same value.
271 // Also, the unchecked version may sometimes be non-null where the
272 // checked version is null. This can occur in several ways:
273 // 1. No query has yet been made to the class loader.
274 // 2. The class loader was queried, but chose not to delegate.
275 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
276 // 4. Loading was attempted, but there was a linkage error of some sort.
277 // In all of these cases, the loader constraints on this type are
278 // satisfied, and it is safe for classes in the given class loader
279 // to manipulate strongly-typed values of the found class, subject
280 // to local linkage and access checks.
281 static klassOop find_constrained_instance_or_array_klass(symbolHandle class_name,
282 Handle class_loader,
283 TRAPS);
285 // Iterate over all klasses in dictionary
286 // Just the classes from defining class loaders
287 static void classes_do(void f(klassOop));
288 // Added for initialize_itable_for_klass to handle exceptions
289 static void classes_do(void f(klassOop, TRAPS), TRAPS);
290 // All classes, and their class loaders
291 static void classes_do(void f(klassOop, oop));
292 // All classes, and their class loaders
293 // (added for helpers that use HandleMarks and ResourceMarks)
294 static void classes_do(void f(klassOop, oop, TRAPS), TRAPS);
295 // All entries in the placeholder table and their class loaders
296 static void placeholders_do(void f(symbolOop, oop));
298 // Iterate over all methods in all klasses in dictionary
299 static void methods_do(void f(methodOop));
301 // Garbage collection support
303 // This method applies "blk->do_oop" to all the pointers to "system"
304 // classes and loaders.
305 static void always_strong_oops_do(OopClosure* blk);
306 static void always_strong_classes_do(OopClosure* blk);
307 // This method applies "blk->do_oop" to all the placeholders.
308 static void placeholders_do(OopClosure* blk);
310 // Unload (that is, break root links to) all unmarked classes and
311 // loaders. Returns "true" iff something was unloaded.
312 static bool do_unloading(BoolObjectClosure* is_alive);
314 // Applies "f->do_oop" to all root oops in the system dictionary.
315 static void oops_do(OopClosure* f);
317 // System loader lock
318 static oop system_loader_lock() { return _system_loader_lock_obj; }
320 private:
321 // Traverses preloaded oops: various system classes. These are
322 // guaranteed to be in the perm gen.
323 static void preloaded_oops_do(OopClosure* f);
324 static void lazily_loaded_oops_do(OopClosure* f);
326 public:
327 // Sharing support.
328 static void reorder_dictionary();
329 static void copy_buckets(char** top, char* end);
330 static void copy_table(char** top, char* end);
331 static void reverse();
332 static void set_shared_dictionary(HashtableBucket* t, int length,
333 int number_of_entries);
334 // Printing
335 static void print() PRODUCT_RETURN;
336 static void print_class_statistics() PRODUCT_RETURN;
337 static void print_method_statistics() PRODUCT_RETURN;
339 // Number of contained klasses
340 // This is both fully loaded classes and classes in the process
341 // of being loaded
342 static int number_of_classes();
344 // Monotonically increasing counter which grows as classes are
345 // loaded or modifications such as hot-swapping or setting/removing
346 // of breakpoints are performed
347 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
348 // Needed by evolution and breakpoint code
349 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
351 // Verification
352 static void verify();
354 #ifdef ASSERT
355 static bool is_internal_format(symbolHandle class_name);
356 #endif
358 // Verify class is in dictionary
359 static void verify_obj_klass_present(Handle obj,
360 symbolHandle class_name,
361 Handle class_loader);
363 // Initialization
364 static void initialize(TRAPS);
366 // Fast access to commonly used classes (preloaded)
367 static klassOop check_klass(klassOop k) {
368 assert(k != NULL, "preloaded klass not initialized");
369 return k;
370 }
372 static klassOop check_klass_Pre(klassOop k) { return check_klass(k); }
373 static klassOop check_klass_Opt(klassOop k) { return k; }
374 static klassOop check_klass_Opt_Kernel(klassOop k) { return k; } //== Opt
375 static klassOop check_klass_Opt_Only_JDK15(klassOop k) {
376 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
377 return k;
378 }
379 static klassOop check_klass_Opt_Only_JDK14NewRef(klassOop k) {
380 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
381 // despite the optional loading, if you use this it must be present:
382 return check_klass(k);
383 }
385 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
386 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
387 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
388 int limit = (int)end_id + 1;
389 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
390 }
392 public:
393 #define WK_KLASS_DECLARE(name, ignore_symbol, option) \
394 static klassOop name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); }
395 WK_KLASSES_DO(WK_KLASS_DECLARE);
396 #undef WK_KLASS_DECLARE
398 // Local definition for direct access to the private array:
399 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
401 static klassOop box_klass(BasicType t) {
402 assert((uint)t < T_VOID+1, "range check");
403 return check_klass(_box_klasses[t]);
404 }
405 static BasicType box_klass_type(klassOop k); // inverse of box_klass
407 // methods returning lazily loaded klasses
408 // The corresponding method to load the class must be called before calling them.
409 static klassOop abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
411 static void load_abstract_ownable_synchronizer_klass(TRAPS);
413 private:
414 // Tells whether ClassLoader.loadClassInternal is present
415 static bool has_loadClassInternal() { return _has_loadClassInternal; }
417 public:
418 // Tells whether ClassLoader.checkPackageAccess is present
419 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
421 static bool class_klass_loaded() { return WK_KLASS(class_klass) != NULL; }
422 static bool cloneable_klass_loaded() { return WK_KLASS(cloneable_klass) != NULL; }
424 // Returns default system loader
425 static oop java_system_loader();
427 // Compute the default system loader
428 static void compute_java_system_loader(TRAPS);
430 private:
431 // Mirrors for primitive classes (created eagerly)
432 static oop check_mirror(oop m) {
433 assert(m != NULL, "mirror not initialized");
434 return m;
435 }
437 public:
438 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
440 // Check class loader constraints
441 static bool add_loader_constraint(symbolHandle name, Handle loader1,
442 Handle loader2, TRAPS);
443 static char* check_signature_loaders(symbolHandle signature, Handle loader1,
444 Handle loader2, bool is_method, TRAPS);
446 // Utility for printing loader "name" as part of tracing constraints
447 static const char* loader_name(oop loader) {
448 return ((loader) == NULL ? "<bootloader>" :
449 instanceKlass::cast((loader)->klass())->name()->as_C_string() );
450 }
452 // Record the error when the first attempt to resolve a reference from a constant
453 // pool entry to a class fails.
454 static void add_resolution_error(constantPoolHandle pool, int which, symbolHandle error);
455 static symbolOop find_resolution_error(constantPoolHandle pool, int which);
457 private:
459 enum Constants {
460 _loader_constraint_size = 107, // number of entries in constraint table
461 _resolution_error_size = 107, // number of entries in resolution error table
462 _nof_buckets = 1009 // number of buckets in hash table
463 };
466 // Static variables
468 // Hashtable holding loaded classes.
469 static Dictionary* _dictionary;
471 // Hashtable holding placeholders for classes being loaded.
472 static PlaceholderTable* _placeholders;
474 // Hashtable holding classes from the shared archive.
475 static Dictionary* _shared_dictionary;
477 // Monotonically increasing counter which grows with
478 // _number_of_classes as well as hot-swapping and breakpoint setting
479 // and removal.
480 static int _number_of_modifications;
482 // Lock object for system class loader
483 static oop _system_loader_lock_obj;
485 // Constraints on class loaders
486 static LoaderConstraintTable* _loader_constraints;
488 // Resolution errors
489 static ResolutionErrorTable* _resolution_errors;
491 public:
492 // for VM_CounterDecay iteration support
493 friend class CounterDecay;
494 static klassOop try_get_next_class();
496 private:
497 static void validate_protection_domain(instanceKlassHandle klass,
498 Handle class_loader,
499 Handle protection_domain, TRAPS);
501 friend class VM_PopulateDumpSharedSpace;
502 friend class TraversePlaceholdersClosure;
503 static Dictionary* dictionary() { return _dictionary; }
504 static Dictionary* shared_dictionary() { return _shared_dictionary; }
505 static PlaceholderTable* placeholders() { return _placeholders; }
506 static LoaderConstraintTable* constraints() { return _loader_constraints; }
507 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
509 // Basic loading operations
510 static klassOop resolve_instance_class_or_null(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS);
511 static klassOop resolve_array_class_or_null(symbolHandle class_name, Handle class_loader, Handle protection_domain, TRAPS);
512 static instanceKlassHandle handle_parallel_super_load(symbolHandle class_name, symbolHandle supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
513 // Wait on SystemDictionary_lock; unlocks lockObject before
514 // waiting; relocks lockObject with correct recursion count
515 // after waiting, but before reentering SystemDictionary_lock
516 // to preserve lock order semantics.
517 static void double_lock_wait(Handle lockObject, TRAPS);
518 static void define_instance_class(instanceKlassHandle k, TRAPS);
519 static instanceKlassHandle find_or_define_instance_class(symbolHandle class_name,
520 Handle class_loader,
521 instanceKlassHandle k, TRAPS);
522 static instanceKlassHandle load_shared_class(symbolHandle class_name,
523 Handle class_loader, TRAPS);
524 static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
525 Handle class_loader, TRAPS);
526 static instanceKlassHandle load_instance_class(symbolHandle class_name, Handle class_loader, TRAPS);
527 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
528 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
529 static bool is_parallelCapable(Handle class_loader);
531 static klassOop find_shared_class(symbolHandle class_name);
533 // Setup link to hierarchy
534 static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
536 private:
537 // We pass in the hashtable index so we can calculate it outside of
538 // the SystemDictionary_lock.
540 // Basic find on loaded classes
541 static klassOop find_class(int index, unsigned int hash,
542 symbolHandle name, Handle loader);
544 // Basic find on classes in the midst of being loaded
545 static symbolOop find_placeholder(int index, unsigned int hash,
546 symbolHandle name, Handle loader);
548 // Basic find operation of loaded classes and classes in the midst
549 // of loading; used for assertions and verification only.
550 static oop find_class_or_placeholder(symbolHandle class_name,
551 Handle class_loader);
553 // Updating entry in dictionary
554 // Add a completely loaded class
555 static void add_klass(int index, symbolHandle class_name,
556 Handle class_loader, KlassHandle obj);
558 // Add a placeholder for a class being loaded
559 static void add_placeholder(int index,
560 symbolHandle class_name,
561 Handle class_loader);
562 static void remove_placeholder(int index,
563 symbolHandle class_name,
564 Handle class_loader);
566 // Performs cleanups after resolve_super_or_fail. This typically needs
567 // to be called on failure.
568 // Won't throw, but can block.
569 static void resolution_cleanups(symbolHandle class_name,
570 Handle class_loader,
571 TRAPS);
573 // Initialization
574 static void initialize_preloaded_classes(TRAPS);
576 // Class loader constraints
577 static void check_constraints(int index, unsigned int hash,
578 instanceKlassHandle k, Handle loader,
579 bool defining, TRAPS);
580 static void update_dictionary(int d_index, unsigned int d_hash,
581 int p_index, unsigned int p_hash,
582 instanceKlassHandle k, Handle loader, TRAPS);
584 // Variables holding commonly used klasses (preloaded)
585 static klassOop _well_known_klasses[];
587 // Lazily loaded klasses
588 static volatile klassOop _abstract_ownable_synchronizer_klass;
590 // table of box klasses (int_klass, etc.)
591 static klassOop _box_klasses[T_VOID+1];
593 static oop _java_system_loader;
595 static bool _has_loadClassInternal;
596 static bool _has_checkPackageAccess;
597 };