1 /*
2 * Copyright (c) 1997, 2018, 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).
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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,
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20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
27
28 #include "classfile/classLoader.hpp"
29 #include "jvmci/systemDictionary_jvmci.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/symbol.hpp"
32 #include "runtime/java.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 ClassFileStream;
77 class Dictionary;
78 class PlaceholderTable;
79 class LoaderConstraintTable;
80 template <MEMFLAGS F> class HashtableBucket;
81 class ResolutionErrorTable;
82 class SymbolPropertyTable;
83 class ProtectionDomainCacheTable;
84 class ProtectionDomainCacheEntry;
85 class GCTimer;
86 class OopStorage;
87
88 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
89 // They are all "well-known", in the sense that no class loader is allowed
90 // to provide a different definition.
91 //
92 // These klasses must all have names defined in vmSymbols.
93
94 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
95
96 // Each well-known class has a short klass name (like object_klass),
97 // a vmSymbol name (like java_lang_Object), and a flag word
98 // that makes some minor distinctions, like whether the klass
99 // is preloaded, optional, release-specific, etc.
100 // The order of these definitions is significant; it is the order in which
101 // preloading is actually performed by resolve_preloaded_classes.
102
103 #define WK_KLASSES_DO(do_klass) \
104 /* well-known classes */ \
105 do_klass(Object_klass, java_lang_Object, Pre ) \
106 do_klass(String_klass, java_lang_String, Pre ) \
107 do_klass(Class_klass, java_lang_Class, Pre ) \
108 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \
109 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \
110 do_klass(Serializable_klass, java_io_Serializable, Pre ) \
111 do_klass(System_klass, java_lang_System, Pre ) \
112 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \
113 do_klass(Error_klass, java_lang_Error, Pre ) \
114 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \
115 do_klass(Exception_klass, java_lang_Exception, Pre ) \
116 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \
117 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \
118 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \
119 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \
120 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \
121 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \
122 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \
123 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \
124 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \
125 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \
126 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \
127 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \
128 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \
129 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \
130 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \
131 \
132 /* Preload ref klasses and set reference types */ \
133 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \
134 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \
135 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \
136 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \
137 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \
138 \
139 do_klass(Thread_klass, java_lang_Thread, Pre ) \
140 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \
141 do_klass(Properties_klass, java_util_Properties, Pre ) \
142 do_klass(Module_klass, java_lang_Module, Pre ) \
143 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \
144 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \
145 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \
146 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \
147 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \
148 \
149 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
150 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
151 do_klass(reflect_MagicAccessorImpl_klass, reflect_MagicAccessorImpl, Opt ) \
152 do_klass(reflect_MethodAccessorImpl_klass, reflect_MethodAccessorImpl, Pre ) \
153 do_klass(reflect_ConstructorAccessorImpl_klass, reflect_ConstructorAccessorImpl, Pre ) \
154 do_klass(reflect_DelegatingClassLoader_klass, reflect_DelegatingClassLoader, Opt ) \
155 do_klass(reflect_ConstantPool_klass, reflect_ConstantPool, Opt ) \
156 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl, Opt ) \
157 do_klass(reflect_CallerSensitive_klass, reflect_CallerSensitive, Opt ) \
158 \
159 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
160 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \
161 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \
162 do_klass(VarHandle_klass, java_lang_invoke_VarHandle, Pre ) \
163 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \
164 do_klass(ResolvedMethodName_klass, java_lang_invoke_ResolvedMethodName, Pre ) \
165 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \
166 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \
167 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \
168 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \
169 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \
170 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \
171 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \
172 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \
173 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \
174 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \
175 \
176 do_klass(AssertionStatusDirectives_klass, java_lang_AssertionStatusDirectives, Pre ) \
177 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \
178 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \
179 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe, Pre ) \
180 do_klass(module_Modules_klass, jdk_internal_module_Modules, Pre ) \
181 \
182 /* support for CDS */ \
183 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \
184 do_klass(URL_klass, java_net_URL, Pre ) \
185 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \
186 do_klass(jdk_internal_loader_ClassLoaders_klass, jdk_internal_loader_ClassLoaders, Pre ) \
187 do_klass(jdk_internal_loader_ClassLoaders_AppClassLoader_klass, jdk_internal_loader_ClassLoaders_AppClassLoader, Pre ) \
188 do_klass(jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass, jdk_internal_loader_ClassLoaders_PlatformClassLoader, Pre ) \
189 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \
190 \
191 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \
192 \
193 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
194 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \
195 \
196 /* Stack Walking */ \
197 do_klass(StackWalker_klass, java_lang_StackWalker, Opt ) \
198 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker, Opt ) \
199 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo, Opt ) \
200 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo, Opt ) \
201 \
202 /* support for stack dump lock analysis */ \
203 do_klass(java_util_concurrent_locks_AbstractOwnableSynchronizer_klass, java_util_concurrent_locks_AbstractOwnableSynchronizer, Pre ) \
204 \
205 /* Preload boxing klasses */ \
206 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \
207 do_klass(Character_klass, java_lang_Character, Pre ) \
208 do_klass(Float_klass, java_lang_Float, Pre ) \
209 do_klass(Double_klass, java_lang_Double, Pre ) \
210 do_klass(Byte_klass, java_lang_Byte, Pre ) \
211 do_klass(Short_klass, java_lang_Short, Pre ) \
212 do_klass(Integer_klass, java_lang_Integer, Pre ) \
213 do_klass(Long_klass, java_lang_Long, Pre ) \
214 \
215 /* JVMCI classes. These are loaded on-demand. */ \
216 JVMCI_WK_KLASSES_DO(do_klass) \
217 \
218 /*end*/
219
220
221 class SystemDictionary : AllStatic {
222 friend class VMStructs;
223 friend class SystemDictionaryHandles;
224
225 public:
226 enum WKID {
227 NO_WKID = 0,
228
229 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
230 WK_KLASSES_DO(WK_KLASS_ENUM)
231 #undef WK_KLASS_ENUM
232
233 WKID_LIMIT,
234
235 #if INCLUDE_JVMCI
236 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(JVMCI_klass),
237 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass),
238 #endif
239
240 FIRST_WKID = NO_WKID + 1
241 };
242
243 enum InitOption {
244 Pre, // preloaded; error if not present
245
246 // Order is significant. Options before this point require resolve_or_fail.
247 // Options after this point will use resolve_or_null instead.
248
249 Opt, // preload tried; NULL if not present
250 #if INCLUDE_JVMCI
251 Jvmci, // preload tried; error if not present if JVMCI enabled
252 #endif
253 OPTION_LIMIT,
254 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
255 };
256
257
258 // Returns a class with a given class name and class loader. Loads the
259 // class if needed. If not found a NoClassDefFoundError or a
260 // ClassNotFoundException is thrown, depending on the value on the
261 // throw_error flag. For most uses the throw_error argument should be set
262 // to true.
263
264 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
265 // Convenient call for null loader and protection domain.
266 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
267 protected:
268 // handle error translation for resolve_or_null results
269 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, TRAPS);
270
271 public:
272
273 // Returns a class with a given class name and class loader.
274 // Loads the class if needed. If not found NULL is returned.
275 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
276 // Version with null loader and protection domain
277 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
278
279 // Resolve a superclass or superinterface. Called from ClassFileParser,
280 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
281 // "child_name" is the class whose super class or interface is being resolved.
282 static InstanceKlass* resolve_super_or_fail(Symbol* child_name,
283 Symbol* class_name,
284 Handle class_loader,
285 Handle protection_domain,
286 bool is_superclass,
287 TRAPS);
288
289 // Parse new stream. This won't update the dictionary or
290 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
291 // Also used by Unsafe_DefineAnonymousClass
292 static InstanceKlass* parse_stream(Symbol* class_name,
293 Handle class_loader,
294 Handle protection_domain,
295 ClassFileStream* st,
296 TRAPS) {
297 return parse_stream(class_name,
298 class_loader,
299 protection_domain,
300 st,
301 NULL, // unsafe_anonymous_host
302 NULL, // cp_patches
303 THREAD);
304 }
305 static InstanceKlass* parse_stream(Symbol* class_name,
306 Handle class_loader,
307 Handle protection_domain,
308 ClassFileStream* st,
309 const InstanceKlass* unsafe_anonymous_host,
310 GrowableArray<Handle>* cp_patches,
311 TRAPS);
312
313 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
314 static InstanceKlass* resolve_from_stream(Symbol* class_name,
315 Handle class_loader,
316 Handle protection_domain,
317 ClassFileStream* st,
318 TRAPS);
319
320 // Lookup an already loaded class. If not found NULL is returned.
321 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
322
323 // Lookup an already loaded instance or array class.
324 // Do not make any queries to class loaders; consult only the cache.
325 // If not found NULL is returned.
326 static Klass* find_instance_or_array_klass(Symbol* class_name,
327 Handle class_loader,
328 Handle protection_domain,
329 TRAPS);
330
331 // Lookup an instance or array class that has already been loaded
332 // either into the given class loader, or else into another class
333 // loader that is constrained (via loader constraints) to produce
334 // a consistent class. Do not take protection domains into account.
335 // Do not make any queries to class loaders; consult only the cache.
336 // Return NULL if the class is not found.
337 //
338 // This function is a strict superset of find_instance_or_array_klass.
339 // This function (the unchecked version) makes a conservative prediction
340 // of the result of the checked version, assuming successful lookup.
341 // If both functions return non-null, they must return the same value.
342 // Also, the unchecked version may sometimes be non-null where the
343 // checked version is null. This can occur in several ways:
344 // 1. No query has yet been made to the class loader.
345 // 2. The class loader was queried, but chose not to delegate.
346 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
347 // 4. Loading was attempted, but there was a linkage error of some sort.
348 // In all of these cases, the loader constraints on this type are
349 // satisfied, and it is safe for classes in the given class loader
350 // to manipulate strongly-typed values of the found class, subject
351 // to local linkage and access checks.
352 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
353 Handle class_loader,
354 TRAPS);
355
356 static void classes_do(MetaspaceClosure* it);
357 // Iterate over all methods in all klasses
358
359 static void methods_do(void f(Method*));
360
361 // Garbage collection support
362
363 // Unload (that is, break root links to) all unmarked classes and
364 // loaders. Returns "true" iff something was unloaded.
365 static bool do_unloading(GCTimer* gc_timer,
366 bool do_cleaning = true);
367
368 // Used by DumpSharedSpaces only to remove classes that failed verification
369 static void remove_classes_in_error_state();
370
371 static int calculate_systemdictionary_size(int loadedclasses);
372
373 // Applies "f->do_oop" to all root oops in the system dictionary.
374 static void oops_do(OopClosure* f);
375
376 // System loader lock
377 static oop system_loader_lock() { return _system_loader_lock_obj; }
378
379 // Protection Domain Table
380 static ProtectionDomainCacheTable* pd_cache_table() { return _pd_cache_table; }
381
382 public:
383 // Sharing support.
384 static void reorder_dictionary_for_sharing() NOT_CDS_RETURN;
385 static void combine_shared_dictionaries();
386 static size_t count_bytes_for_buckets();
387 static size_t count_bytes_for_table();
388 static void copy_buckets(char* top, char* end);
389 static void copy_table(char* top, char* end);
390 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
391 int number_of_entries);
392 // Printing
393 static void print() { return print_on(tty); }
394 static void print_on(outputStream* st);
395 static void print_shared(outputStream* st);
396 static void dump(outputStream* st, bool verbose);
397
398 // Monotonically increasing counter which grows as classes are
399 // loaded or modifications such as hot-swapping or setting/removing
400 // of breakpoints are performed
401 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
402 // Needed by evolution and breakpoint code
403 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
404
405 // Verification
406 static void verify();
407
408 // Initialization
409 static void initialize(TRAPS);
410
411 // Checked fast access to commonly used classes - mostly preloaded
412 static InstanceKlass* check_klass(InstanceKlass* k) {
413 assert(k != NULL, "klass not loaded");
414 return k;
415 }
416
417 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); }
418 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; }
419
420 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; })
421
422 static bool resolve_wk_klass(WKID id, int init_opt, TRAPS);
423 static void resolve_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
424 static void resolve_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
425 int limit = (int)end_id + 1;
426 resolve_wk_klasses_until((WKID) limit, start_id, THREAD);
427 }
428
429 public:
430 #define WK_KLASS_DECLARE(name, symbol, option) \
431 static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
432 static InstanceKlass** name##_addr() { \
433 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
434 }
435 WK_KLASSES_DO(WK_KLASS_DECLARE);
436 #undef WK_KLASS_DECLARE
437
438 static InstanceKlass* well_known_klass(WKID id) {
439 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
440 return _well_known_klasses[id];
441 }
442
443 static InstanceKlass** well_known_klass_addr(WKID id) {
444 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
445 return &_well_known_klasses[id];
446 }
447 static void well_known_klasses_do(MetaspaceClosure* it);
448
449 // Local definition for direct access to the private array:
450 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
451
452 static InstanceKlass* box_klass(BasicType t) {
453 assert((uint)t < T_VOID+1, "range check");
454 return check_klass(_box_klasses[t]);
455 }
456 static BasicType box_klass_type(Klass* k); // inverse of box_klass
457
458 protected:
459 // Returns the class loader data to be used when looking up/updating the
460 // system dictionary.
461 static ClassLoaderData *class_loader_data(Handle class_loader) {
462 return ClassLoaderData::class_loader_data(class_loader());
463 }
464
465 public:
466 // Tells whether ClassLoader.checkPackageAccess is present
467 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
468
469 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
470 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
471 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
472 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
473 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
474
475 // Returns java system loader
476 static oop java_system_loader();
477
478 // Returns java platform loader
479 static oop java_platform_loader();
480
481 // Compute the java system and platform loaders
482 static void compute_java_loaders(TRAPS);
483
484 // Register a new class loader
485 static ClassLoaderData* register_loader(Handle class_loader);
486 protected:
487 // Mirrors for primitive classes (created eagerly)
488 static oop check_mirror(oop m) {
489 assert(m != NULL, "mirror not initialized");
490 return m;
491 }
492
493 public:
494 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
495
496 // Check class loader constraints
497 static bool add_loader_constraint(Symbol* name, Handle loader1,
498 Handle loader2, TRAPS);
499 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
500 Handle loader2, bool is_method, TRAPS);
501
502 // JSR 292
503 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
504 // (asks Java to compute it if necessary, except in a compiler thread)
505 static methodHandle find_method_handle_invoker(Klass* klass,
506 Symbol* name,
507 Symbol* signature,
508 Klass* accessing_klass,
509 Handle *appendix_result,
510 Handle *method_type_result,
511 TRAPS);
512 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
513 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
514 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
515 Symbol* signature,
516 TRAPS);
517
518 // compute java_mirror (java.lang.Class instance) for a type ("I", "[[B", "LFoo;", etc.)
519 // Either the accessing_klass or the CL/PD can be non-null, but not both.
520 static Handle find_java_mirror_for_type(Symbol* signature,
521 Klass* accessing_klass,
522 Handle class_loader,
523 Handle protection_domain,
524 SignatureStream::FailureMode failure_mode,
525 TRAPS);
526 static Handle find_java_mirror_for_type(Symbol* signature,
527 Klass* accessing_klass,
528 SignatureStream::FailureMode failure_mode,
529 TRAPS) {
530 // callee will fill in CL/PD from AK, if they are needed
531 return find_java_mirror_for_type(signature, accessing_klass, Handle(), Handle(),
532 failure_mode, THREAD);
533 }
534
535
536 // fast short-cut for the one-character case:
537 static oop find_java_mirror_for_type(char signature_char);
538
539 // find a java.lang.invoke.MethodType object for a given signature
540 // (asks Java to compute it if necessary, except in a compiler thread)
541 static Handle find_method_handle_type(Symbol* signature,
542 Klass* accessing_klass,
543 TRAPS);
544
545 // find a java.lang.Class object for a given signature
546 static Handle find_field_handle_type(Symbol* signature,
547 Klass* accessing_klass,
548 TRAPS);
549
550 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
551 static Handle link_method_handle_constant(Klass* caller,
552 int ref_kind, //e.g., JVM_REF_invokeVirtual
553 Klass* callee,
554 Symbol* name,
555 Symbol* signature,
556 TRAPS);
557
558 // ask Java to compute a constant by invoking a BSM given a Dynamic_info CP entry
559 static Handle link_dynamic_constant(Klass* caller,
560 int condy_index,
561 Handle bootstrap_specifier,
562 Symbol* name,
563 Symbol* type,
564 TRAPS);
565
566 // ask Java to create a dynamic call site, while linking an invokedynamic op
567 static methodHandle find_dynamic_call_site_invoker(Klass* caller,
568 int indy_index,
569 Handle bootstrap_method,
570 Symbol* name,
571 Symbol* type,
572 Handle *appendix_result,
573 Handle *method_type_result,
574 TRAPS);
575
576 // Record the error when the first attempt to resolve a reference from a constant
577 // pool entry to a class fails.
578 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error,
579 Symbol* message);
580 static void delete_resolution_error(ConstantPool* pool);
581 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which,
582 Symbol** message);
583
584
585 static ProtectionDomainCacheEntry* cache_get(Handle protection_domain);
586
587 protected:
588
589 enum Constants {
590 _loader_constraint_size = 107, // number of entries in constraint table
591 _resolution_error_size = 107, // number of entries in resolution error table
592 _invoke_method_size = 139, // number of entries in invoke method table
593 _shared_dictionary_size = 1009, // number of entries in shared dictionary
594 _placeholder_table_size = 1009 // number of entries in hash table for placeholders
595 };
596
597
598 // Static tables owned by the SystemDictionary
599
600 // Hashtable holding placeholders for classes being loaded.
601 static PlaceholderTable* _placeholders;
602
603 // Hashtable holding classes from the shared archive.
604 static Dictionary* _shared_dictionary;
605
606 // Monotonically increasing counter which grows with
607 // loading classes as well as hot-swapping and breakpoint setting
608 // and removal.
609 static int _number_of_modifications;
610
611 // Lock object for system class loader
612 static oop _system_loader_lock_obj;
613
614 // Constraints on class loaders
615 static LoaderConstraintTable* _loader_constraints;
616
617 // Resolution errors
618 static ResolutionErrorTable* _resolution_errors;
619
620 // Invoke methods (JSR 292)
621 static SymbolPropertyTable* _invoke_method_table;
622
623 // ProtectionDomain cache
624 static ProtectionDomainCacheTable* _pd_cache_table;
625
626 // VM weak OopStorage object.
627 static OopStorage* _vm_weak_oop_storage;
628
629 protected:
630 static void validate_protection_domain(InstanceKlass* klass,
631 Handle class_loader,
632 Handle protection_domain, TRAPS);
633
634 friend class VM_PopulateDumpSharedSpace;
635 friend class TraversePlaceholdersClosure;
636 static Dictionary* shared_dictionary() { return _shared_dictionary; }
637 static PlaceholderTable* placeholders() { return _placeholders; }
638 static LoaderConstraintTable* constraints() { return _loader_constraints; }
639 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
640 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
641
642 // Basic loading operations
643 static InstanceKlass* resolve_instance_class_or_null_helper(Symbol* name,
644 Handle class_loader,
645 Handle protection_domain,
646 TRAPS);
647 static InstanceKlass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
648 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
649 static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
650 // Wait on SystemDictionary_lock; unlocks lockObject before
651 // waiting; relocks lockObject with correct recursion count
652 // after waiting, but before reentering SystemDictionary_lock
653 // to preserve lock order semantics.
654 static void double_lock_wait(Handle lockObject, TRAPS);
655 static void define_instance_class(InstanceKlass* k, TRAPS);
656 static InstanceKlass* find_or_define_instance_class(Symbol* class_name,
657 Handle class_loader,
658 InstanceKlass* k, TRAPS);
659 static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik,
660 Handle class_loader, TRAPS);
661 static InstanceKlass* load_shared_class(InstanceKlass* ik,
662 Handle class_loader,
663 Handle protection_domain,
664 TRAPS);
665 static InstanceKlass* load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
666 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
667 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
668 static bool is_parallelCapable(Handle class_loader);
669 static bool is_parallelDefine(Handle class_loader);
670
671 public:
672 static InstanceKlass* load_shared_class(Symbol* class_name,
673 Handle class_loader,
674 TRAPS);
675 static bool is_system_class_loader(oop class_loader);
676 static bool is_platform_class_loader(oop class_loader);
677 static void clear_invoke_method_table();
678
679 // Returns TRUE if the method is a non-public member of class java.lang.Object.
680 static bool is_nonpublic_Object_method(Method* m) {
681 assert(m != NULL, "Unexpected NULL Method*");
682 return !m->is_public() && m->method_holder() == SystemDictionary::Object_klass();
683 }
684
685 static void initialize_oop_storage();
686 static OopStorage* vm_weak_oop_storage();
687
688 protected:
689 static InstanceKlass* find_shared_class(Symbol* class_name);
690
691 // Setup link to hierarchy
692 static void add_to_hierarchy(InstanceKlass* k, TRAPS);
693
694 // Basic find on loaded classes
695 static InstanceKlass* find_class(unsigned int hash,
696 Symbol* name, Dictionary* dictionary);
697 static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
698
699 // Basic find on classes in the midst of being loaded
700 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
701
702 // Add a placeholder for a class being loaded
703 static void add_placeholder(int index,
704 Symbol* class_name,
705 ClassLoaderData* loader_data);
706 static void remove_placeholder(int index,
707 Symbol* class_name,
708 ClassLoaderData* loader_data);
709
710 // Performs cleanups after resolve_super_or_fail. This typically needs
711 // to be called on failure.
712 // Won't throw, but can block.
713 static void resolution_cleanups(Symbol* class_name,
714 ClassLoaderData* loader_data,
715 TRAPS);
716
717 // Resolve preloaded classes so they can be used like SystemDictionary::String_klass()
718 static void resolve_preloaded_classes(TRAPS);
719
720 // Class loader constraints
721 static void check_constraints(unsigned int hash,
722 InstanceKlass* k, Handle loader,
723 bool defining, TRAPS);
724 static void update_dictionary(unsigned int d_hash,
725 int p_index, unsigned int p_hash,
726 InstanceKlass* k, Handle loader,
727 TRAPS);
728
729 // Variables holding commonly used klasses (preloaded)
730 static InstanceKlass* _well_known_klasses[];
731
732 // table of box klasses (int_klass, etc.)
733 static InstanceKlass* _box_klasses[T_VOID+1];
734
735 private:
736 static oop _java_system_loader;
737 static oop _java_platform_loader;
738
739 static bool _has_checkPackageAccess;
740 };
741
742 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP