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.
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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
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23 */
24
25 #ifndef SHARE_CLASSFILE_SYSTEMDICTIONARY_HPP
26 #define SHARE_CLASSFILE_SYSTEMDICTIONARY_HPP
27
28 #include "classfile/classLoaderData.hpp"
29 #include "oops/objArrayOop.hpp"
30 #include "oops/symbol.hpp"
31 #include "runtime/java.hpp"
32 #include "runtime/mutexLocker.hpp"
33 #include "runtime/reflectionUtils.hpp"
34 #include "runtime/signature.hpp"
35 #include "utilities/hashtable.hpp"
36
37 // The dictionary in each ClassLoaderData stores all loaded classes, either
38 // initiatied by its class loader or defined by its class loader:
39 //
40 // class loader -> ClassLoaderData -> [class, protection domain set]
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 (Dictionary) per
46 // ClassLoaderData with a fixed number of buckets. During loading the
47 // class loader object is locked, (for the VM loader a private lock object is used).
48 // The global SystemDictionary_lock is held for all additions into the ClassLoaderData
49 // dictionaries. TODO: fix lock granularity so that class loading can
50 // be done concurrently, but only by different loaders.
51 //
52 // During loading a placeholder (name, loader) is temporarily placed in
53 // a side data structure, and is used to detect ClassCircularityErrors
54 // and to perform verification during GC. A GC can occur in the midst
55 // of class loading, as we call out to Java, have to take locks, etc.
56 //
57 // When class loading is finished, a new entry is added to the dictionary
58 // of the class loader and the placeholder is removed. Note that the protection
59 // domain field of the dictionary entry has not yet been filled in when
60 // the "real" dictionary entry is created.
61 //
62 // Clients of this class who are interested in finding if a class has
63 // been completely loaded -- not classes in the process of being loaded --
64 // can read the dictionary unlocked. This is safe because
65 // - entries are only deleted at safepoints
66 // - readers cannot come to a safepoint while actively examining
67 // an entry (an entry cannot be deleted from under a reader)
68 // - entries must be fully formed before they are available to concurrent
69 // readers (we must ensure write ordering)
70 //
71 // Note that placeholders are deleted at any time, as they are removed
72 // when a class is completely loaded. Therefore, readers as well as writers
73 // of placeholders must hold the SystemDictionary_lock.
74 //
75
76 class BootstrapInfo;
77 class ClassFileStream;
78 class Dictionary;
79 class PlaceholderTable;
80 class LoaderConstraintTable;
81 template <MEMFLAGS F> class HashtableBucket;
82 class ResolutionErrorTable;
83 class SymbolPropertyTable;
84 class ProtectionDomainCacheTable;
85 class ProtectionDomainCacheEntry;
86 class GCTimer;
87 class OopStorage;
88
89 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
90
91 // Certain classes, such as java.lang.Object and java.lang.String,
92 // are "well-known", in the sense that no class loader is allowed
93 // to provide a different definition.
94 //
95 // Each well-known class has a short klass name (like object_klass),
96 // and a vmSymbol name (like java_lang_Object).
97 //
98 // The order of these definitions is significant: the classes are
99 // resolved during early VM start-up by resolve_well_known_classes
100 // in this order. Changing the order may require careful restructuring
101 // of the VM start-up sequence.
102 //
103 #define WK_KLASSES_DO(do_klass) \
104 /* well-known classes */ \
105 do_klass(Object_klass, java_lang_Object ) \
106 do_klass(String_klass, java_lang_String ) \
107 do_klass(Class_klass, java_lang_Class ) \
108 do_klass(Cloneable_klass, java_lang_Cloneable ) \
109 do_klass(ClassLoader_klass, java_lang_ClassLoader ) \
110 do_klass(Serializable_klass, java_io_Serializable ) \
111 do_klass(System_klass, java_lang_System ) \
112 do_klass(Throwable_klass, java_lang_Throwable ) \
113 do_klass(Error_klass, java_lang_Error ) \
114 do_klass(ThreadDeath_klass, java_lang_ThreadDeath ) \
115 do_klass(Exception_klass, java_lang_Exception ) \
116 do_klass(RuntimeException_klass, java_lang_RuntimeException ) \
117 do_klass(SecurityManager_klass, java_lang_SecurityManager ) \
118 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain ) \
119 do_klass(AccessControlContext_klass, java_security_AccessControlContext ) \
120 do_klass(AccessController_klass, java_security_AccessController ) \
121 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader ) \
122 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException ) \
123 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError ) \
124 do_klass(LinkageError_klass, java_lang_LinkageError ) \
125 do_klass(ClassCastException_klass, java_lang_ClassCastException ) \
126 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException ) \
127 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError ) \
128 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError ) \
129 do_klass(StackOverflowError_klass, java_lang_StackOverflowError ) \
130 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException ) \
131 do_klass(Reference_klass, java_lang_ref_Reference ) \
132 do_klass(Iterator_klass, java_util_Iterator ) \
133 \
134 /* ref klasses and set reference types */ \
135 do_klass(SoftReference_klass, java_lang_ref_SoftReference ) \
136 do_klass(WeakReference_klass, java_lang_ref_WeakReference ) \
137 do_klass(FinalReference_klass, java_lang_ref_FinalReference ) \
138 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference ) \
139 do_klass(Finalizer_klass, java_lang_ref_Finalizer ) \
140 \
141 do_klass(Thread_klass, java_lang_Thread ) \
142 do_klass(ThreadGroup_klass, java_lang_ThreadGroup ) \
143 do_klass(Properties_klass, java_util_Properties ) \
144 do_klass(Module_klass, java_lang_Module ) \
145 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject ) \
146 do_klass(reflect_Field_klass, java_lang_reflect_Field ) \
147 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter ) \
148 do_klass(reflect_Method_klass, java_lang_reflect_Method ) \
149 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor ) \
150 \
151 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
152 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
153 do_klass(reflect_MagicAccessorImpl_klass, reflect_MagicAccessorImpl ) \
154 do_klass(reflect_MethodAccessorImpl_klass, reflect_MethodAccessorImpl ) \
155 do_klass(reflect_ConstructorAccessorImpl_klass, reflect_ConstructorAccessorImpl ) \
156 do_klass(reflect_DelegatingClassLoader_klass, reflect_DelegatingClassLoader ) \
157 do_klass(reflect_ConstantPool_klass, reflect_ConstantPool ) \
158 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl ) \
159 do_klass(reflect_CallerSensitive_klass, reflect_CallerSensitive ) \
160 \
161 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
162 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle ) \
163 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle ) \
164 do_klass(VarHandle_klass, java_lang_invoke_VarHandle ) \
165 do_klass(MemberName_klass, java_lang_invoke_MemberName ) \
166 do_klass(ResolvedMethodName_klass, java_lang_invoke_ResolvedMethodName ) \
167 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives ) \
168 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm ) \
169 do_klass(MethodType_klass, java_lang_invoke_MethodType ) \
170 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError ) \
171 do_klass(CallSite_klass, java_lang_invoke_CallSite ) \
172 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext ) \
173 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite ) \
174 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite ) \
175 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite ) \
176 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \
177 \
178 do_klass(AssertionStatusDirectives_klass, java_lang_AssertionStatusDirectives ) \
179 do_klass(StringBuffer_klass, java_lang_StringBuffer ) \
180 do_klass(StringBuilder_klass, java_lang_StringBuilder ) \
181 do_klass(UnsafeConstants_klass, jdk_internal_misc_UnsafeConstants ) \
182 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe ) \
183 do_klass(module_Modules_klass, jdk_internal_module_Modules ) \
184 \
185 /* support for CDS */ \
186 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream ) \
187 do_klass(URL_klass, java_net_URL ) \
188 do_klass(Jar_Manifest_klass, java_util_jar_Manifest ) \
189 do_klass(jdk_internal_loader_ClassLoaders_klass, jdk_internal_loader_ClassLoaders ) \
190 do_klass(jdk_internal_loader_ClassLoaders_AppClassLoader_klass, jdk_internal_loader_ClassLoaders_AppClassLoader) \
191 do_klass(jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass, jdk_internal_loader_ClassLoaders_PlatformClassLoader) \
192 do_klass(CodeSource_klass, java_security_CodeSource ) \
193 \
194 do_klass(StackTraceElement_klass, java_lang_StackTraceElement ) \
195 \
196 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
197 do_klass(nio_Buffer_klass, java_nio_Buffer ) \
198 \
199 /* Stack Walking */ \
200 do_klass(StackWalker_klass, java_lang_StackWalker ) \
201 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker ) \
202 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo ) \
203 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo ) \
204 \
205 /* support for stack dump lock analysis */ \
206 do_klass(java_util_concurrent_locks_AbstractOwnableSynchronizer_klass, java_util_concurrent_locks_AbstractOwnableSynchronizer) \
207 \
208 /* boxing klasses */ \
209 do_klass(Boolean_klass, java_lang_Boolean ) \
210 do_klass(Character_klass, java_lang_Character ) \
211 do_klass(Float_klass, java_lang_Float ) \
212 do_klass(Double_klass, java_lang_Double ) \
213 do_klass(Byte_klass, java_lang_Byte ) \
214 do_klass(Short_klass, java_lang_Short ) \
215 do_klass(Integer_klass, java_lang_Integer ) \
216 do_klass(Long_klass, java_lang_Long ) \
217 \
218 /*end*/
219
220
221 class SystemDictionary : AllStatic {
222 friend class BootstrapInfo;
223 friend class VMStructs;
224 friend class SystemDictionaryHandles;
225
226 public:
227 enum WKID {
228 NO_WKID = 0,
229
230 #define WK_KLASS_ENUM(name, symbol) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
231 WK_KLASSES_DO(WK_KLASS_ENUM)
232 #undef WK_KLASS_ENUM
233
234 WKID_LIMIT,
235
236 FIRST_WKID = NO_WKID + 1
237 };
238
239 // Returns a class with a given class name and class loader. Loads the
240 // class if needed. If not found a NoClassDefFoundError or a
241 // ClassNotFoundException is thrown, depending on the value on the
242 // throw_error flag. For most uses the throw_error argument should be set
243 // to true.
244
245 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
246 // Convenient call for null loader and protection domain.
247 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
248 protected:
249 // handle error translation for resolve_or_null results
250 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, TRAPS);
251
252 public:
253
254 // Returns a class with a given class name and class loader.
255 // Loads the class if needed. If not found NULL is returned.
256 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
257 // Version with null loader and protection domain
258 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
259
260 // Resolve a superclass or superinterface. Called from ClassFileParser,
261 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
262 // "child_name" is the class whose super class or interface is being resolved.
263 static InstanceKlass* resolve_super_or_fail(Symbol* child_name,
264 Symbol* class_name,
265 Handle class_loader,
266 Handle protection_domain,
267 bool is_superclass,
268 TRAPS);
269
270 // Parse new stream. This won't update the dictionary or
271 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
272 // Also used by Unsafe_DefineAnonymousClass
273 static InstanceKlass* parse_stream(Symbol* class_name,
274 Handle class_loader,
275 Handle protection_domain,
276 ClassFileStream* st,
277 TRAPS) {
278 return parse_stream(class_name,
279 class_loader,
280 protection_domain,
281 st,
282 NULL, // unsafe_anonymous_host
283 NULL, // cp_patches
284 THREAD);
285 }
286 static InstanceKlass* parse_stream(Symbol* class_name,
287 Handle class_loader,
288 Handle protection_domain,
289 ClassFileStream* st,
290 const InstanceKlass* unsafe_anonymous_host,
291 GrowableArray<Handle>* cp_patches,
292 TRAPS);
293
294 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
295 static InstanceKlass* resolve_from_stream(Symbol* class_name,
296 Handle class_loader,
297 Handle protection_domain,
298 ClassFileStream* st,
299 TRAPS);
300
301 // Lookup an already loaded class. If not found NULL is returned.
302 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
303
304 // Lookup an already loaded instance or array class.
305 // Do not make any queries to class loaders; consult only the cache.
306 // If not found NULL is returned.
307 static Klass* find_instance_or_array_klass(Symbol* class_name,
308 Handle class_loader,
309 Handle protection_domain,
310 TRAPS);
311
312 // Lookup an instance or array class that has already been loaded
313 // either into the given class loader, or else into another class
314 // loader that is constrained (via loader constraints) to produce
315 // a consistent class. Do not take protection domains into account.
316 // Do not make any queries to class loaders; consult only the cache.
317 // Return NULL if the class is not found.
318 //
319 // This function is a strict superset of find_instance_or_array_klass.
320 // This function (the unchecked version) makes a conservative prediction
321 // of the result of the checked version, assuming successful lookup.
322 // If both functions return non-null, they must return the same value.
323 // Also, the unchecked version may sometimes be non-null where the
324 // checked version is null. This can occur in several ways:
325 // 1. No query has yet been made to the class loader.
326 // 2. The class loader was queried, but chose not to delegate.
327 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
328 // 4. Loading was attempted, but there was a linkage error of some sort.
329 // In all of these cases, the loader constraints on this type are
330 // satisfied, and it is safe for classes in the given class loader
331 // to manipulate strongly-typed values of the found class, subject
332 // to local linkage and access checks.
333 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
334 Handle class_loader,
335 TRAPS);
336
337 static void classes_do(MetaspaceClosure* it);
338 // Iterate over all methods in all klasses
339
340 static void methods_do(void f(Method*));
341
342 // Garbage collection support
343
344 // Unload (that is, break root links to) all unmarked classes and
345 // loaders. Returns "true" iff something was unloaded.
346 static bool do_unloading(GCTimer* gc_timer);
347
348 // Applies "f->do_oop" to all root oops in the system dictionary.
349 static void oops_do(OopClosure* f);
350
351 // System loader lock
352 static oop system_loader_lock() { return _system_loader_lock_obj; }
353
354 // Protection Domain Table
355 static ProtectionDomainCacheTable* pd_cache_table() { return _pd_cache_table; }
356
357 public:
358 // Printing
359 static void print() { return print_on(tty); }
360 static void print_on(outputStream* st);
361 static void dump(outputStream* st, bool verbose);
362
363 // Monotonically increasing counter which grows as classes are
364 // loaded or modifications such as hot-swapping or setting/removing
365 // of breakpoints are performed
366 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
367 // Needed by evolution and breakpoint code
368 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
369
370 // Verification
371 static void verify();
372
373 // Initialization
374 static void initialize(TRAPS);
375
376 // Checked fast access to the well-known classes -- so that you don't try to use them
377 // before they are resolved.
378 static InstanceKlass* check_klass(InstanceKlass* k) {
379 assert(k != NULL, "klass not loaded");
380 return k;
381 }
382
383 static bool resolve_wk_klass(WKID id, TRAPS);
384 static void resolve_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
385 static void resolve_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
386 int limit = (int)end_id + 1;
387 resolve_wk_klasses_until((WKID) limit, start_id, THREAD);
388 }
389
390 public:
391 #define WK_KLASS_DECLARE(name, symbol) \
392 static InstanceKlass* name() { return check_klass(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
393 static InstanceKlass** name##_addr() { \
394 return &_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
395 } \
396 static bool name##_is_loaded() { \
397 return _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] != NULL; \
398 }
399 WK_KLASSES_DO(WK_KLASS_DECLARE);
400 #undef WK_KLASS_DECLARE
401
402 static InstanceKlass* 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 InstanceKlass** 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 static void well_known_klasses_do(MetaspaceClosure* it);
412
413 // Local definition for direct access to the private array:
414 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
415
416 static InstanceKlass* box_klass(BasicType t) {
417 assert((uint)t < T_VOID+1, "range check");
418 return check_klass(_box_klasses[t]);
419 }
420 static BasicType box_klass_type(Klass* k); // inverse of box_klass
421 #ifdef ASSERT
422 static bool is_well_known_klass(Klass* k) {
423 return is_well_known_klass(k->name());
424 }
425 static bool is_well_known_klass(Symbol* class_name);
426 #endif
427
428 protected:
429 // Returns the class loader data to be used when looking up/updating the
430 // system dictionary.
431 static ClassLoaderData *class_loader_data(Handle class_loader) {
432 return ClassLoaderData::class_loader_data(class_loader());
433 }
434
435 public:
436 // Tells whether ClassLoader.checkPackageAccess is present
437 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
438
439 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
440 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
441 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
442 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
443 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
444
445 // Returns java system loader
446 static oop java_system_loader();
447
448 // Returns java platform loader
449 static oop java_platform_loader();
450
451 // Compute the java system and platform loaders
452 static void compute_java_loaders(TRAPS);
453
454 // Register a new class loader
455 static ClassLoaderData* register_loader(Handle class_loader);
456 protected:
457 // Mirrors for primitive classes (created eagerly)
458 static oop check_mirror(oop m) {
459 assert(m != NULL, "mirror not initialized");
460 return m;
461 }
462
463 public:
464 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
465
466 // Check class loader constraints
467 static bool add_loader_constraint(Symbol* name, Handle loader1,
468 Handle loader2, TRAPS);
469 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
470 Handle loader2, bool is_method, TRAPS);
471
472 // JSR 292
473 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
474 // (asks Java to compute it if necessary, except in a compiler thread)
475 static methodHandle find_method_handle_invoker(Klass* klass,
476 Symbol* name,
477 Symbol* signature,
478 Klass* accessing_klass,
479 Handle *appendix_result,
480 TRAPS);
481 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
482 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
483 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
484 Symbol* signature,
485 TRAPS);
486
487 // compute java_mirror (java.lang.Class instance) for a type ("I", "[[B", "LFoo;", etc.)
488 // Either the accessing_klass or the CL/PD can be non-null, but not both.
489 static Handle find_java_mirror_for_type(Symbol* signature,
490 Klass* accessing_klass,
491 Handle class_loader,
492 Handle protection_domain,
493 SignatureStream::FailureMode failure_mode,
494 TRAPS);
495 static Handle find_java_mirror_for_type(Symbol* signature,
496 Klass* accessing_klass,
497 SignatureStream::FailureMode failure_mode,
498 TRAPS) {
499 // callee will fill in CL/PD from AK, if they are needed
500 return find_java_mirror_for_type(signature, accessing_klass, Handle(), Handle(),
501 failure_mode, THREAD);
502 }
503
504
505 // fast short-cut for the one-character case:
506 static oop find_java_mirror_for_type(char signature_char);
507
508 // find a java.lang.invoke.MethodType object for a given signature
509 // (asks Java to compute it if necessary, except in a compiler thread)
510 static Handle find_method_handle_type(Symbol* signature,
511 Klass* accessing_klass,
512 TRAPS);
513
514 // find a java.lang.Class object for a given signature
515 static Handle find_field_handle_type(Symbol* signature,
516 Klass* accessing_klass,
517 TRAPS);
518
519 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
520 static Handle link_method_handle_constant(Klass* caller,
521 int ref_kind, //e.g., JVM_REF_invokeVirtual
522 Klass* callee,
523 Symbol* name,
524 Symbol* signature,
525 TRAPS);
526
527 // ask Java to compute a constant by invoking a BSM given a Dynamic_info CP entry
528 static void invoke_bootstrap_method(BootstrapInfo& bootstrap_specifier, TRAPS);
529
530 // Record the error when the first attempt to resolve a reference from a constant
531 // pool entry to a class fails.
532 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error,
533 Symbol* message);
534 static void delete_resolution_error(ConstantPool* pool);
535 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which,
536 Symbol** message);
537
538
539 static ProtectionDomainCacheEntry* cache_get(Handle protection_domain);
540
541 protected:
542
543 enum Constants {
544 _loader_constraint_size = 107, // number of entries in constraint table
545 _resolution_error_size = 107, // number of entries in resolution error table
546 _invoke_method_size = 139, // number of entries in invoke method table
547 _placeholder_table_size = 1009 // number of entries in hash table for placeholders
548 };
549
550
551 // Static tables owned by the SystemDictionary
552
553 // Hashtable holding placeholders for classes being loaded.
554 static PlaceholderTable* _placeholders;
555
556 // Monotonically increasing counter which grows with
557 // loading classes as well as hot-swapping and breakpoint setting
558 // and removal.
559 static int _number_of_modifications;
560
561 // Lock object for system class loader
562 static oop _system_loader_lock_obj;
563
564 // Constraints on class loaders
565 static LoaderConstraintTable* _loader_constraints;
566
567 // Resolution errors
568 static ResolutionErrorTable* _resolution_errors;
569
570 // Invoke methods (JSR 292)
571 static SymbolPropertyTable* _invoke_method_table;
572
573 // ProtectionDomain cache
574 static ProtectionDomainCacheTable* _pd_cache_table;
575
576 // VM weak OopStorage object.
577 static OopStorage* _vm_weak_oop_storage;
578
579 protected:
580 static void validate_protection_domain(InstanceKlass* klass,
581 Handle class_loader,
582 Handle protection_domain, TRAPS);
583
584 friend class VM_PopulateDumpSharedSpace;
585 friend class TraversePlaceholdersClosure;
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 InstanceKlass* resolve_instance_class_or_null_helper(Symbol* name,
593 Handle class_loader,
594 Handle protection_domain,
595 TRAPS);
596 static InstanceKlass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
597 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
598 static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
599 // Wait on SystemDictionary_lock; unlocks lockObject before
600 // waiting; relocks lockObject with correct recursion count
601 // after waiting, but before reentering SystemDictionary_lock
602 // to preserve lock order semantics.
603 static void double_lock_wait(Handle lockObject, TRAPS);
604 static void define_instance_class(InstanceKlass* k, TRAPS);
605 static InstanceKlass* find_or_define_instance_class(Symbol* class_name,
606 Handle class_loader,
607 InstanceKlass* k, TRAPS);
608 static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik,
609 Handle class_loader, TRAPS);
610 static InstanceKlass* load_shared_class(InstanceKlass* ik,
611 Handle class_loader,
612 Handle protection_domain,
613 const ClassFileStream *cfs,
614 TRAPS);
615 static InstanceKlass* load_shared_boot_class(Symbol* class_name,
616 TRAPS);
617 static InstanceKlass* load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
618 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
619 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
620 static bool is_parallelCapable(Handle class_loader);
621 static bool is_parallelDefine(Handle class_loader);
622
623 public:
624 static bool is_system_class_loader(oop class_loader);
625 static bool is_platform_class_loader(oop class_loader);
626
627 // Returns TRUE if the method is a non-public member of class java.lang.Object.
628 static bool is_nonpublic_Object_method(Method* m) {
629 assert(m != NULL, "Unexpected NULL Method*");
630 return !m->is_public() && m->method_holder() == SystemDictionary::Object_klass();
631 }
632
633 static void initialize_oop_storage();
634 static OopStorage* vm_weak_oop_storage();
635
636 protected:
637 // Setup link to hierarchy
638 static void add_to_hierarchy(InstanceKlass* k, TRAPS);
639
640 // Basic find on loaded classes
641 static InstanceKlass* find_class(unsigned int hash,
642 Symbol* name, Dictionary* dictionary);
643 static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
644
645 // Basic find on classes in the midst of being loaded
646 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
647
648 // Add a placeholder for a class being loaded
649 static void add_placeholder(int index,
650 Symbol* class_name,
651 ClassLoaderData* loader_data);
652 static void remove_placeholder(int index,
653 Symbol* class_name,
654 ClassLoaderData* loader_data);
655
656 // Performs cleanups after resolve_super_or_fail. This typically needs
657 // to be called on failure.
658 // Won't throw, but can block.
659 static void resolution_cleanups(Symbol* class_name,
660 ClassLoaderData* loader_data,
661 TRAPS);
662
663 // Resolve well-known classes so they can be used like SystemDictionary::String_klass()
664 static void resolve_well_known_classes(TRAPS);
665
666 // Class loader constraints
667 static void check_constraints(unsigned int hash,
668 InstanceKlass* k, Handle loader,
669 bool defining, TRAPS);
670 static void update_dictionary(unsigned int d_hash,
671 int p_index, unsigned int p_hash,
672 InstanceKlass* k, Handle loader,
673 TRAPS);
674
675 static InstanceKlass* _well_known_klasses[];
676
677 // table of box klasses (int_klass, etc.)
678 static InstanceKlass* _box_klasses[T_VOID+1];
679
680 private:
681 static oop _java_system_loader;
682 static oop _java_platform_loader;
683
684 static bool _has_checkPackageAccess;
685 };
686
687 #endif // SHARE_CLASSFILE_SYSTEMDICTIONARY_HPP