1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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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.
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23 */
24
25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
27
28 #include "classfile/classFileStream.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/symbol.hpp"
32 #include "runtime/java.hpp"
33 #include "runtime/reflectionUtils.hpp"
34 #include "utilities/hashtable.hpp"
35 #include "utilities/hashtable.inline.hpp"
36
37
38 // The system dictionary stores all loaded classes and maps:
39 //
40 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass*
41 //
42 // Classes are loaded lazily. The default VM class loader is
43 // represented as NULL.
44
45 // The underlying data structure is an open hash table with a fixed number
46 // of buckets. During loading the loader object is locked, (for the VM loader
47 // a private lock object is used). Class loading can thus be done concurrently,
48 // but only by different loaders.
49 //
50 // During loading a placeholder (name, loader) is temporarily placed in
51 // a side data structure, and is used to detect ClassCircularityErrors
52 // and to perform verification during GC. A GC can occur in the midst
53 // of class loading, as we call out to Java, have to take locks, etc.
54 //
55 // When class loading is finished, a new entry is added to the system
56 // dictionary and the place holder is removed. Note that the protection
57 // domain field of the system dictionary has not yet been filled in when
58 // the "real" system dictionary entry is created.
59 //
60 // Clients of this class who are interested in finding if a class has
61 // been completely loaded -- not classes in the process of being loaded --
62 // can read the SystemDictionary unlocked. This is safe because
63 // - entries are only deleted at safepoints
64 // - readers cannot come to a safepoint while actively examining
65 // an entry (an entry cannot be deleted from under a reader)
66 // - entries must be fully formed before they are available to concurrent
67 // readers (we must ensure write ordering)
68 //
69 // Note that placeholders are deleted at any time, as they are removed
70 // when a class is completely loaded. Therefore, readers as well as writers
71 // of placeholders must hold the SystemDictionary_lock.
72 //
73
74 class Dictionary;
75 class PlaceholderTable;
76 class LoaderConstraintTable;
77 template <MEMFLAGS F> class HashtableBucket;
78 class ResolutionErrorTable;
79 class SymbolPropertyTable;
80 class Ticks;
81
82 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
83 // They are all "well-known", in the sense that no class loader is allowed
84 // to provide a different definition.
85 //
86 // These klasses must all have names defined in vmSymbols.
87
88 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
89
90 // Each well-known class has a short klass name (like object_klass),
91 // a vmSymbol name (like java_lang_Object), and a flag word
92 // that makes some minor distinctions, like whether the klass
93 // is preloaded, optional, release-specific, etc.
94 // The order of these definitions is significant; it is the order in which
95 // preloading is actually performed by initialize_preloaded_classes.
96
97 #define WK_KLASSES_DO(do_klass) \
98 /* well-known classes */ \
99 do_klass(Object_klass, java_lang_Object, Pre ) \
100 do_klass(String_klass, java_lang_String, Pre ) \
101 do_klass(Class_klass, java_lang_Class, Pre ) \
102 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \
103 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \
104 do_klass(Serializable_klass, java_io_Serializable, Pre ) \
105 do_klass(System_klass, java_lang_System, Pre ) \
106 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \
107 do_klass(Error_klass, java_lang_Error, Pre ) \
108 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \
109 do_klass(Exception_klass, java_lang_Exception, Pre ) \
110 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \
111 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \
112 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \
113 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \
114 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \
115 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \
116 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \
117 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \
118 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \
119 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \
120 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \
121 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \
122 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \
123 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \
124 \
125 /* Preload ref klasses and set reference types */ \
126 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \
127 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \
128 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \
129 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \
130 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \
131 \
132 do_klass(Thread_klass, java_lang_Thread, Pre ) \
133 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \
134 do_klass(Properties_klass, java_util_Properties, Pre ) \
135 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \
136 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \
137 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \
138 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \
139 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \
140 \
141 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
142 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
143 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \
144 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Pre ) \
145 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Pre ) \
146 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \
147 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt ) \
148 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt ) \
149 do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \
150 \
151 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
152 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \
153 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \
154 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \
155 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \
156 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \
157 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \
158 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \
159 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \
160 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \
161 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \
162 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \
163 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \
164 \
165 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \
166 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \
167 do_klass(misc_Unsafe_klass, sun_misc_Unsafe, Pre ) \
168 \
169 /* It's NULL in non-1.4 JDKs. */ \
170 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \
171 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
172 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \
173 \
174 /* Preload boxing klasses */ \
175 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \
176 do_klass(Character_klass, java_lang_Character, Pre ) \
177 do_klass(Float_klass, java_lang_Float, Pre ) \
178 do_klass(Double_klass, java_lang_Double, Pre ) \
179 do_klass(Byte_klass, java_lang_Byte, Pre ) \
180 do_klass(Short_klass, java_lang_Short, Pre ) \
181 do_klass(Integer_klass, java_lang_Integer, Pre ) \
182 do_klass(Long_klass, java_lang_Long, Pre ) \
183 /*end*/
184
185
186 class SystemDictionary : AllStatic {
187 friend class VMStructs;
188 friend class SystemDictionaryHandles;
189
190 public:
191 enum WKID {
192 NO_WKID = 0,
193
194 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
195 WK_KLASSES_DO(WK_KLASS_ENUM)
196 #undef WK_KLASS_ENUM
197
198 WKID_LIMIT,
199
200 FIRST_WKID = NO_WKID + 1
201 };
202
203 enum InitOption {
204 Pre, // preloaded; error if not present
205
206 // Order is significant. Options before this point require resolve_or_fail.
207 // Options after this point will use resolve_or_null instead.
208
209 Opt, // preload tried; NULL if not present
210 OPTION_LIMIT,
211 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
212 };
213
214
215 // Returns a class with a given class name and class loader. Loads the
216 // class if needed. If not found a NoClassDefFoundError or a
217 // ClassNotFoundException is thrown, depending on the value on the
218 // throw_error flag. For most uses the throw_error argument should be set
219 // to true.
220
221 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
222 // Convenient call for null loader and protection domain.
223 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
224 private:
225 // handle error translation for resolve_or_null results
226 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, KlassHandle klass_h, TRAPS);
227
228 public:
229
230 // Returns a class with a given class name and class loader.
231 // Loads the class if needed. If not found NULL is returned.
232 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
233 // Version with null loader and protection domain
234 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
235
236 // Resolve a superclass or superinterface. Called from ClassFileParser,
237 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
238 // "child_name" is the class whose super class or interface is being resolved.
239 static Klass* resolve_super_or_fail(Symbol* child_name,
240 Symbol* class_name,
241 Handle class_loader,
242 Handle protection_domain,
243 bool is_superclass,
244 TRAPS);
245
246 // Parse new stream. This won't update the system dictionary or
247 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
248 static Klass* parse_stream(Symbol* class_name,
249 Handle class_loader,
250 Handle protection_domain,
251 ClassFileStream* st,
252 TRAPS) {
253 KlassHandle nullHandle;
254 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
255 }
256 static Klass* parse_stream(Symbol* class_name,
257 Handle class_loader,
258 Handle protection_domain,
259 ClassFileStream* st,
260 KlassHandle host_klass,
261 GrowableArray<Handle>* cp_patches,
262 TRAPS);
263
264 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
265 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
266 Handle protection_domain,
267 ClassFileStream* st, bool verify, TRAPS);
268
269 // Lookup an already loaded class. If not found NULL is returned.
270 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
271
272 // Lookup an already loaded instance or array class.
273 // Do not make any queries to class loaders; consult only the cache.
274 // If not found NULL is returned.
275 static Klass* find_instance_or_array_klass(Symbol* class_name,
276 Handle class_loader,
277 Handle protection_domain,
278 TRAPS);
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 Klass* find_constrained_instance_or_array_klass(Symbol* 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(Klass*));
308 // Added for initialize_itable_for_klass to handle exceptions
309 static void classes_do(void f(Klass*, TRAPS), TRAPS);
310 // All classes, and their class loaders
311 static void classes_do(void f(Klass*, ClassLoaderData*));
312
313 static void placeholders_do(void f(Symbol*));
314
315 // Iterate over all methods in all klasses in dictionary
316 static void methods_do(void f(Method*));
317
318 // Garbage collection support
319
320 // This method applies "blk->do_oop" to all the pointers to "system"
321 // classes and loaders.
322 static void always_strong_oops_do(OopClosure* blk);
323 static void always_strong_classes_do(KlassClosure* closure);
324
325 // Unload (that is, break root links to) all unmarked classes and
326 // loaders. Returns "true" iff something was unloaded.
327 static bool do_unloading(BoolObjectClosure* is_alive);
328
329 static int calculate_systemdictionary_size(int loadedclasses);
330
331 // Applies "f->do_oop" to all root oops in the system dictionary.
332 static void oops_do(OopClosure* f);
333 static void roots_oops_do(OopClosure* strong, OopClosure* weak);
334
335 // System loader lock
336 static oop system_loader_lock() { return _system_loader_lock_obj; }
337
338 private:
339 // Extended Redefine classes support (tbi)
340 static void preloaded_classes_do(KlassClosure* f);
341 static void lazily_loaded_classes_do(KlassClosure* f);
342 public:
343 // Sharing support.
344 static void reorder_dictionary();
345 static void copy_buckets(char** top, char* end);
346 static void copy_table(char** top, char* end);
347 static void reverse();
348 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
349 int number_of_entries);
350 // Printing
351 static void print() PRODUCT_RETURN;
352 static void print_class_statistics() PRODUCT_RETURN;
353 static void print_method_statistics() PRODUCT_RETURN;
354
355 // Number of contained klasses
356 // This is both fully loaded classes and classes in the process
357 // of being loaded
358 static int number_of_classes();
359
360 // Monotonically increasing counter which grows as classes are
361 // loaded or modifications such as hot-swapping or setting/removing
362 // of breakpoints are performed
363 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
364 // Needed by evolution and breakpoint code
365 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
366
367 // Verification
368 static void verify();
369
370 #ifdef ASSERT
371 static bool is_internal_format(Symbol* class_name);
372 #endif
373
374 // Initialization
375 static void initialize(TRAPS);
376
377 // Fast access to commonly used classes (preloaded)
378 static Klass* check_klass(Klass* k) {
379 assert(k != NULL, "preloaded klass not initialized");
380 return k;
381 }
382
383 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); }
384 static Klass* check_klass_Opt( Klass* k) { return k; }
385
386 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
387 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
388 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
389 int limit = (int)end_id + 1;
390 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
391 }
392
393 public:
394 #define WK_KLASS_DECLARE(name, symbol, option) \
395 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
396 static Klass** name##_addr() { \
397 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
398 }
399 WK_KLASSES_DO(WK_KLASS_DECLARE);
400 #undef WK_KLASS_DECLARE
401
402 static Klass* well_known_klass(WKID id) {
403 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
404 return _well_known_klasses[id];
405 }
406
407 static Klass** well_known_klass_addr(WKID id) {
408 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
409 return &_well_known_klasses[id];
410 }
411
412 // Local definition for direct access to the private array:
413 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
414
415 static Klass* box_klass(BasicType t) {
416 assert((uint)t < T_VOID+1, "range check");
417 return check_klass(_box_klasses[t]);
418 }
419 static BasicType box_klass_type(Klass* k); // inverse of box_klass
420
421 // methods returning lazily loaded klasses
422 // The corresponding method to load the class must be called before calling them.
423 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
424
425 static void load_abstract_ownable_synchronizer_klass(TRAPS);
426
427 private:
428 // Tells whether ClassLoader.loadClassInternal is present
429 static bool has_loadClassInternal() { return _has_loadClassInternal; }
430
431 // Returns the class loader data to be used when looking up/updating the
432 // system dictionary.
433 static ClassLoaderData *class_loader_data(Handle class_loader) {
434 return ClassLoaderData::class_loader_data(class_loader());
435 }
436
437 public:
438 // Tells whether ClassLoader.checkPackageAccess is present
439 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
440
441 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
442 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
443 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
444 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
445 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
446
447 // Returns default system loader
448 static oop java_system_loader();
449
450 // Compute the default system loader
451 static void compute_java_system_loader(TRAPS);
452
453 // Register a new class loader
454 static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
455 private:
456 // Mirrors for primitive classes (created eagerly)
457 static oop check_mirror(oop m) {
458 assert(m != NULL, "mirror not initialized");
459 return m;
460 }
461
462 public:
463 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
464
465 // Check class loader constraints
466 static bool add_loader_constraint(Symbol* name, Handle loader1,
467 Handle loader2, TRAPS);
468 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
469 Handle loader2, bool is_method, TRAPS);
470
471 // JSR 292
472 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
473 // (asks Java to compute it if necessary, except in a compiler thread)
474 static methodHandle find_method_handle_invoker(Symbol* name,
475 Symbol* signature,
476 KlassHandle accessing_klass,
477 Handle *appendix_result,
478 Handle *method_type_result,
479 TRAPS);
480 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
481 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
482 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
483 Symbol* signature,
484 TRAPS);
485 // find a java.lang.invoke.MethodType object for a given signature
486 // (asks Java to compute it if necessary, except in a compiler thread)
487 static Handle find_method_handle_type(Symbol* signature,
488 KlassHandle accessing_klass,
489 TRAPS);
490
491 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
492 static Handle link_method_handle_constant(KlassHandle caller,
493 int ref_kind, //e.g., JVM_REF_invokeVirtual
494 KlassHandle callee,
495 Symbol* name,
496 Symbol* signature,
497 TRAPS);
498
499 // ask Java to create a dynamic call site, while linking an invokedynamic op
500 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
501 Handle bootstrap_method,
502 Symbol* name,
503 Symbol* type,
504 Handle *appendix_result,
505 Handle *method_type_result,
506 TRAPS);
507
508 // Utility for printing loader "name" as part of tracing constraints
509 static const char* loader_name(oop loader) {
510 return ((loader) == NULL ? "<bootloader>" :
511 InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
512 }
513 static const char* loader_name(ClassLoaderData* loader_data) {
514 return (loader_data->class_loader() == NULL ? "<bootloader>" :
515 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
516 }
517
518 // Record the error when the first attempt to resolve a reference from a constant
519 // pool entry to a class fails.
520 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error,
521 Symbol* message);
522 static void delete_resolution_error(ConstantPool* pool);
523 static Symbol* find_resolution_error(constantPoolHandle pool, int which,
524 Symbol** message);
525
526 private:
527
528 enum Constants {
529 _loader_constraint_size = 107, // number of entries in constraint table
530 _resolution_error_size = 107, // number of entries in resolution error table
531 _invoke_method_size = 139, // number of entries in invoke method table
532 _nof_buckets = 1009, // number of buckets in hash table for placeholders
533 _old_default_sdsize = 1009, // backward compat for system dictionary size
534 _prime_array_size = 8, // array of primes for system dictionary size
535 _average_depth_goal = 3 // goal for lookup length
536 };
537
538
539 // Static variables
540
541 // hashtable sizes for system dictionary to allow growth
542 // prime numbers for system dictionary size
543 static int _sdgeneration;
544 static const int _primelist[_prime_array_size];
545
546 // Hashtable holding loaded classes.
547 static Dictionary* _dictionary;
548
549 // Hashtable holding placeholders for classes being loaded.
550 static PlaceholderTable* _placeholders;
551
552 // Hashtable holding classes from the shared archive.
553 static Dictionary* _shared_dictionary;
554
555 // Monotonically increasing counter which grows with
556 // _number_of_classes as well as hot-swapping and breakpoint setting
557 // and removal.
558 static int _number_of_modifications;
559
560 // Lock object for system class loader
561 static oop _system_loader_lock_obj;
562
563 // Constraints on class loaders
564 static LoaderConstraintTable* _loader_constraints;
565
566 // Resolution errors
567 static ResolutionErrorTable* _resolution_errors;
568
569 // Invoke methods (JSR 292)
570 static SymbolPropertyTable* _invoke_method_table;
571
572 public:
573 // for VM_CounterDecay iteration support
574 friend class CounterDecay;
575 static Klass* try_get_next_class();
576
577 private:
578 static void validate_protection_domain(instanceKlassHandle klass,
579 Handle class_loader,
580 Handle protection_domain, TRAPS);
581
582 friend class VM_PopulateDumpSharedSpace;
583 friend class TraversePlaceholdersClosure;
584 static Dictionary* dictionary() { return _dictionary; }
585 static Dictionary* shared_dictionary() { return _shared_dictionary; }
586 static PlaceholderTable* placeholders() { return _placeholders; }
587 static LoaderConstraintTable* constraints() { return _loader_constraints; }
588 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
589 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
590
591 // Basic loading operations
592 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
593 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
594 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
595 // Wait on SystemDictionary_lock; unlocks lockObject before
596 // waiting; relocks lockObject with correct recursion count
597 // after waiting, but before reentering SystemDictionary_lock
598 // to preserve lock order semantics.
599 static void double_lock_wait(Handle lockObject, TRAPS);
600 static void define_instance_class(instanceKlassHandle k, TRAPS);
601 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
602 Handle class_loader,
603 instanceKlassHandle k, TRAPS);
604 static instanceKlassHandle load_shared_class(Symbol* class_name,
605 Handle class_loader, TRAPS);
606 static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
607 Handle class_loader, TRAPS);
608 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
609 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
610 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
611 static bool is_parallelCapable(Handle class_loader);
612 static bool is_parallelDefine(Handle class_loader);
613
614 public:
615 static bool is_ext_class_loader(Handle class_loader);
616
617 private:
618 static Klass* find_shared_class(Symbol* class_name);
619
620 // Setup link to hierarchy
621 static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
622
623 // event based tracing
624 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k,
625 Handle initiating_loader);
626 // We pass in the hashtable index so we can calculate it outside of
627 // the SystemDictionary_lock.
628
629 // Basic find on loaded classes
630 static Klass* find_class(int index, unsigned int hash,
631 Symbol* name, ClassLoaderData* loader_data);
632 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
633
634 // Basic find on classes in the midst of being loaded
635 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
636
637 // Updating entry in dictionary
638 // Add a completely loaded class
639 static void add_klass(int index, Symbol* class_name,
640 ClassLoaderData* loader_data, KlassHandle obj);
641
642 // Add a placeholder for a class being loaded
643 static void add_placeholder(int index,
644 Symbol* class_name,
645 ClassLoaderData* loader_data);
646 static void remove_placeholder(int index,
647 Symbol* class_name,
648 ClassLoaderData* loader_data);
649
650 // Performs cleanups after resolve_super_or_fail. This typically needs
651 // to be called on failure.
652 // Won't throw, but can block.
653 static void resolution_cleanups(Symbol* class_name,
654 ClassLoaderData* loader_data,
655 TRAPS);
656
657 // Initialization
658 static void initialize_preloaded_classes(TRAPS);
659
660 // Class loader constraints
661 static void check_constraints(int index, unsigned int hash,
662 instanceKlassHandle k, Handle loader,
663 bool defining, TRAPS);
664 static void update_dictionary(int d_index, unsigned int d_hash,
665 int p_index, unsigned int p_hash,
666 instanceKlassHandle k, Handle loader,
667 TRAPS);
668
669 // Variables holding commonly used klasses (preloaded)
670 static Klass* _well_known_klasses[];
671
672 // Lazily loaded klasses
673 static Klass* volatile _abstract_ownable_synchronizer_klass;
674
675 // table of box klasses (int_klass, etc.)
676 static Klass* _box_klasses[T_VOID+1];
677
678 static oop _java_system_loader;
679
680 static bool _has_loadClassInternal;
681 static bool _has_checkPackageAccess;
682 };
683
684 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP