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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23 */
24
25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
27
28 #include "classfile/classLoader.hpp"
29 #include "classfile/systemDictionary_ext.hpp"
30 #include "jvmci/systemDictionary_jvmci.hpp"
31 #include "oops/objArrayOop.hpp"
32 #include "oops/symbol.hpp"
33 #include "runtime/java.hpp"
34 #include "runtime/reflectionUtils.hpp"
35 #include "runtime/signature.hpp"
36 #include "utilities/hashtable.hpp"
37
38 // The dictionary in each ClassLoaderData stores all loaded classes, either
39 // initiatied by its class loader or defined by its class loader:
40 //
41 // class loader -> ClassLoaderData -> [class, protection domain set]
42 //
43 // Classes are loaded lazily. The default VM class loader is
44 // represented as NULL.
45
46 // The underlying data structure is an open hash table (Dictionary) per
47 // ClassLoaderData with a fixed number of buckets. During loading the
48 // class loader object is locked, (for the VM loader a private lock object is used).
49 // The global SystemDictionary_lock is held for all additions into the ClassLoaderData
50 // dictionaries. TODO: fix lock granularity so that class loading can
51 // be done concurrently, but only by different loaders.
52 //
53 // During loading a placeholder (name, loader) is temporarily placed in
54 // a side data structure, and is used to detect ClassCircularityErrors
55 // and to perform verification during GC. A GC can occur in the midst
56 // of class loading, as we call out to Java, have to take locks, etc.
57 //
58 // When class loading is finished, a new entry is added to the dictionary
59 // of the class loader and the placeholder is removed. Note that the protection
60 // domain field of the dictionary entry has not yet been filled in when
61 // the "real" dictionary entry is created.
62 //
63 // Clients of this class who are interested in finding if a class has
64 // been completely loaded -- not classes in the process of being loaded --
65 // can read the dictionary unlocked. This is safe because
66 // - entries are only deleted at safepoints
67 // - readers cannot come to a safepoint while actively examining
68 // an entry (an entry cannot be deleted from under a reader)
69 // - entries must be fully formed before they are available to concurrent
70 // readers (we must ensure write ordering)
71 //
72 // Note that placeholders are deleted at any time, as they are removed
73 // when a class is completely loaded. Therefore, readers as well as writers
74 // of placeholders must hold the SystemDictionary_lock.
75 //
76
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
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 initialize_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(File_klass, java_io_File, Pre ) \
185 do_klass(URL_klass, java_net_URL, Pre ) \
186 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, 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 do_klass(ParseUtil_klass, sun_net_www_ParseUtil, Pre ) \
191 \
192 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \
193 \
194 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
195 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \
196 \
197 /* Stack Walking */ \
198 do_klass(StackWalker_klass, java_lang_StackWalker, Opt ) \
199 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker, Opt ) \
200 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo, Opt ) \
201 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo, Opt ) \
202 \
203 /* Preload boxing klasses */ \
204 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \
205 do_klass(Character_klass, java_lang_Character, Pre ) \
206 do_klass(Float_klass, java_lang_Float, Pre ) \
207 do_klass(Double_klass, java_lang_Double, Pre ) \
208 do_klass(Byte_klass, java_lang_Byte, Pre ) \
209 do_klass(Short_klass, java_lang_Short, Pre ) \
210 do_klass(Integer_klass, java_lang_Integer, Pre ) \
211 do_klass(Long_klass, java_lang_Long, Pre ) \
212 \
213 /* Extensions */ \
214 WK_KLASSES_DO_EXT(do_klass) \
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 friend class SharedClassUtil;
225
226 public:
227 enum WKID {
228 NO_WKID = 0,
229
230 #define WK_KLASS_ENUM(name, symbol, ignore_o) 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 #if INCLUDE_JVMCI
237 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(JVMCI_klass),
238 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass),
239 #endif
240
241 FIRST_WKID = NO_WKID + 1
242 };
243
244 enum InitOption {
245 Pre, // preloaded; error if not present
246
247 // Order is significant. Options before this point require resolve_or_fail.
248 // Options after this point will use resolve_or_null instead.
249
250 Opt, // preload tried; NULL if not present
251 #if INCLUDE_JVMCI
252 Jvmci, // preload tried; error if not present if JVMCI enabled
253 #endif
254 OPTION_LIMIT,
255 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
256 };
257
258
259 // Returns a class with a given class name and class loader. Loads the
260 // class if needed. If not found a NoClassDefFoundError or a
261 // ClassNotFoundException is thrown, depending on the value on the
262 // throw_error flag. For most uses the throw_error argument should be set
263 // to true.
264
265 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
266 // Convenient call for null loader and protection domain.
267 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
268 protected:
269 // handle error translation for resolve_or_null results
270 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, TRAPS);
271
272 public:
273
274 // Returns a class with a given class name and class loader.
275 // Loads the class if needed. If not found NULL is returned.
276 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
277 // Version with null loader and protection domain
278 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
279
280 // Resolve a superclass or superinterface. Called from ClassFileParser,
281 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
282 // "child_name" is the class whose super class or interface is being resolved.
283 static Klass* resolve_super_or_fail(Symbol* child_name,
284 Symbol* class_name,
285 Handle class_loader,
286 Handle protection_domain,
287 bool is_superclass,
288 TRAPS);
289
290 // Parse new stream. This won't update the dictionary or
291 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
292 // Also used by Unsafe_DefineAnonymousClass
293 static InstanceKlass* parse_stream(Symbol* class_name,
294 Handle class_loader,
295 Handle protection_domain,
296 ClassFileStream* st,
297 TRAPS) {
298 return parse_stream(class_name,
299 class_loader,
300 protection_domain,
301 st,
302 NULL, // host klass
303 NULL, // cp_patches
304 THREAD);
305 }
306 static InstanceKlass* parse_stream(Symbol* class_name,
307 Handle class_loader,
308 Handle protection_domain,
309 ClassFileStream* st,
310 const InstanceKlass* host_klass,
311 GrowableArray<Handle>* cp_patches,
312 TRAPS);
313
314 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
315 static InstanceKlass* resolve_from_stream(Symbol* class_name,
316 Handle class_loader,
317 Handle protection_domain,
318 ClassFileStream* st,
319 TRAPS);
320
321 // Lookup an already loaded class. If not found NULL is returned.
322 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
323
324 // Lookup an already loaded instance or array class.
325 // Do not make any queries to class loaders; consult only the cache.
326 // If not found NULL is returned.
327 static Klass* find_instance_or_array_klass(Symbol* class_name,
328 Handle class_loader,
329 Handle protection_domain,
330 TRAPS);
331
332 // Lookup an instance or array class that has already been loaded
333 // either into the given class loader, or else into another class
334 // loader that is constrained (via loader constraints) to produce
335 // a consistent class. Do not take protection domains into account.
336 // Do not make any queries to class loaders; consult only the cache.
337 // Return NULL if the class is not found.
338 //
339 // This function is a strict superset of find_instance_or_array_klass.
340 // This function (the unchecked version) makes a conservative prediction
341 // of the result of the checked version, assuming successful lookup.
342 // If both functions return non-null, they must return the same value.
343 // Also, the unchecked version may sometimes be non-null where the
344 // checked version is null. This can occur in several ways:
345 // 1. No query has yet been made to the class loader.
346 // 2. The class loader was queried, but chose not to delegate.
347 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
348 // 4. Loading was attempted, but there was a linkage error of some sort.
349 // In all of these cases, the loader constraints on this type are
350 // satisfied, and it is safe for classes in the given class loader
351 // to manipulate strongly-typed values of the found class, subject
352 // to local linkage and access checks.
353 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
354 Handle class_loader,
355 TRAPS);
356
357 static void classes_do(MetaspaceClosure* it);
358 // Iterate over all methods in all klasses
359
360 static void methods_do(void f(Method*));
361
362 // Garbage collection support
363
364 // This method applies "blk->do_oop" to all the pointers to "system"
365 // classes and loaders.
366 static void always_strong_oops_do(OopClosure* blk);
367
368 // Unload (that is, break root links to) all unmarked classes and
369 // loaders. Returns "true" iff something was unloaded.
370 static bool do_unloading(BoolObjectClosure* is_alive,
371 GCTimer* gc_timer,
372 bool do_cleaning = true);
373
374 // Used by DumpSharedSpaces only to remove classes that failed verification
375 static void remove_classes_in_error_state();
376
377 static int calculate_systemdictionary_size(int loadedclasses);
378
379 // Applies "f->do_oop" to all root oops in the system dictionary.
380 static void oops_do(OopClosure* f);
381 static void roots_oops_do(OopClosure* strong, OopClosure* weak);
382
383 // System loader lock
384 static oop system_loader_lock() { return _system_loader_lock_obj; }
385
386 public:
387 // Sharing support.
388 static void reorder_dictionary_for_sharing() NOT_CDS_RETURN;
389 static void combine_shared_dictionaries();
390 static size_t count_bytes_for_buckets();
391 static size_t count_bytes_for_table();
392 static void copy_buckets(char* top, char* end);
393 static void copy_table(char* top, char* end);
394 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
395 int number_of_entries);
396 // Printing
397 static void print() { return print_on(tty); }
398 static void print_on(outputStream* st);
399 static void print_shared(outputStream* st);
400 static void dump(outputStream* st, bool verbose);
401
402 // Monotonically increasing counter which grows as classes are
403 // loaded or modifications such as hot-swapping or setting/removing
404 // of breakpoints are performed
405 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
406 // Needed by evolution and breakpoint code
407 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
408
409 // Verification
410 static void verify();
411
412 // Initialization
413 static void initialize(TRAPS);
414
415 // Checked fast access to commonly used classes - mostly preloaded
416 static InstanceKlass* check_klass(InstanceKlass* k) {
417 assert(k != NULL, "klass not loaded");
418 return k;
419 }
420
421 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); }
422 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; }
423
424 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; })
425
426 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
427 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
428 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
429 int limit = (int)end_id + 1;
430 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
431 }
432
433 public:
434 #define WK_KLASS_DECLARE(name, symbol, option) \
435 static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
436 static InstanceKlass** name##_addr() { \
437 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
438 }
439 WK_KLASSES_DO(WK_KLASS_DECLARE);
440 #undef WK_KLASS_DECLARE
441
442 static InstanceKlass* well_known_klass(WKID id) {
443 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
444 return _well_known_klasses[id];
445 }
446
447 static InstanceKlass** well_known_klass_addr(WKID id) {
448 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
449 return &_well_known_klasses[id];
450 }
451 static void well_known_klasses_do(MetaspaceClosure* it);
452
453 // Local definition for direct access to the private array:
454 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
455
456 static InstanceKlass* box_klass(BasicType t) {
457 assert((uint)t < T_VOID+1, "range check");
458 return check_klass(_box_klasses[t]);
459 }
460 static BasicType box_klass_type(Klass* k); // inverse of box_klass
461
462 // methods returning lazily loaded klasses
463 // The corresponding method to load the class must be called before calling them.
464 static InstanceKlass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
465
466 static void load_abstract_ownable_synchronizer_klass(TRAPS);
467
468 protected:
469 // Returns the class loader data to be used when looking up/updating the
470 // system dictionary.
471 static ClassLoaderData *class_loader_data(Handle class_loader) {
472 return ClassLoaderData::class_loader_data(class_loader());
473 }
474
475 public:
476 // Tells whether ClassLoader.checkPackageAccess is present
477 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
478
479 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
480 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
481 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
482 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
483 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
484
485 // Returns java system loader
486 static oop java_system_loader();
487
488 // Returns java platform loader
489 static oop java_platform_loader();
490
491 // Compute the java system and platform loaders
492 static void compute_java_loaders(TRAPS);
493
494 // Register a new class loader
495 static ClassLoaderData* register_loader(Handle class_loader);
496 protected:
497 // Mirrors for primitive classes (created eagerly)
498 static oop check_mirror(oop m) {
499 assert(m != NULL, "mirror not initialized");
500 return m;
501 }
502
503 public:
504 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
505
506 // Check class loader constraints
507 static bool add_loader_constraint(Symbol* name, Handle loader1,
508 Handle loader2, TRAPS);
509 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
510 Handle loader2, bool is_method, TRAPS);
511
512 // JSR 292
513 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
514 // (asks Java to compute it if necessary, except in a compiler thread)
515 static methodHandle find_method_handle_invoker(Klass* klass,
516 Symbol* name,
517 Symbol* signature,
518 Klass* accessing_klass,
519 Handle *appendix_result,
520 Handle *method_type_result,
521 TRAPS);
522 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
523 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
524 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
525 Symbol* signature,
526 TRAPS);
527
528 // compute java_mirror (java.lang.Class instance) for a type ("I", "[[B", "LFoo;", etc.)
529 // Either the accessing_klass or the CL/PD can be non-null, but not both.
530 static Handle find_java_mirror_for_type(Symbol* signature,
531 Klass* accessing_klass,
532 Handle class_loader,
533 Handle protection_domain,
534 SignatureStream::FailureMode failure_mode,
535 TRAPS);
536 static Handle find_java_mirror_for_type(Symbol* signature,
537 Klass* accessing_klass,
538 SignatureStream::FailureMode failure_mode,
539 TRAPS) {
540 // callee will fill in CL/PD from AK, if they are needed
541 return find_java_mirror_for_type(signature, accessing_klass, Handle(), Handle(),
542 failure_mode, THREAD);
543 }
544
545
546 // fast short-cut for the one-character case:
547 static oop find_java_mirror_for_type(char signature_char);
548
549 // find a java.lang.invoke.MethodType object for a given signature
550 // (asks Java to compute it if necessary, except in a compiler thread)
551 static Handle find_method_handle_type(Symbol* signature,
552 Klass* accessing_klass,
553 TRAPS);
554
555 // find a java.lang.Class object for a given signature
556 static Handle find_field_handle_type(Symbol* signature,
557 Klass* accessing_klass,
558 TRAPS);
559
560 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
561 static Handle link_method_handle_constant(Klass* caller,
562 int ref_kind, //e.g., JVM_REF_invokeVirtual
563 Klass* callee,
564 Symbol* name,
565 Symbol* signature,
566 TRAPS);
567
568 // ask Java to compute a constant by invoking a BSM given a Dynamic_info CP entry
569 static Handle link_dynamic_constant(Klass* caller,
570 int condy_index,
571 Handle bootstrap_specifier,
572 Symbol* name,
573 Symbol* type,
574 TRAPS);
575
576 // ask Java to create a dynamic call site, while linking an invokedynamic op
577 static methodHandle find_dynamic_call_site_invoker(Klass* caller,
578 int indy_index,
579 Handle bootstrap_method,
580 Symbol* name,
581 Symbol* type,
582 Handle *appendix_result,
583 Handle *method_type_result,
584 TRAPS);
585
586 // Utility for printing loader "name" as part of tracing constraints
587 static const char* loader_name(const oop loader);
588 static const char* loader_name(const ClassLoaderData* loader_data);
589
590 // Record the error when the first attempt to resolve a reference from a constant
591 // pool entry to a class fails.
592 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error,
593 Symbol* message);
594 static void delete_resolution_error(ConstantPool* pool);
595 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which,
596 Symbol** message);
597
598
599 static ProtectionDomainCacheEntry* cache_get(Handle protection_domain);
600
601 protected:
602
603 enum Constants {
604 _loader_constraint_size = 107, // number of entries in constraint table
605 _resolution_error_size = 107, // number of entries in resolution error table
606 _invoke_method_size = 139, // number of entries in invoke method table
607 _shared_dictionary_size = 1009, // number of entries in shared dictionary
608 _placeholder_table_size = 1009 // number of entries in hash table for placeholders
609 };
610
611
612 // Static tables owned by the SystemDictionary
613
614 // Hashtable holding placeholders for classes being loaded.
615 static PlaceholderTable* _placeholders;
616
617 // Hashtable holding classes from the shared archive.
618 static Dictionary* _shared_dictionary;
619
620 // Monotonically increasing counter which grows with
621 // loading classes as well as hot-swapping and breakpoint setting
622 // and removal.
623 static int _number_of_modifications;
624
625 // Lock object for system class loader
626 static oop _system_loader_lock_obj;
627
628 // Constraints on class loaders
629 static LoaderConstraintTable* _loader_constraints;
630
631 // Resolution errors
632 static ResolutionErrorTable* _resolution_errors;
633
634 // Invoke methods (JSR 292)
635 static SymbolPropertyTable* _invoke_method_table;
636
637 // ProtectionDomain cache
638 static ProtectionDomainCacheTable* _pd_cache_table;
639
640 protected:
641 static void validate_protection_domain(InstanceKlass* klass,
642 Handle class_loader,
643 Handle protection_domain, TRAPS);
644
645 friend class VM_PopulateDumpSharedSpace;
646 friend class TraversePlaceholdersClosure;
647 static Dictionary* shared_dictionary() { return _shared_dictionary; }
648 static PlaceholderTable* placeholders() { return _placeholders; }
649 static LoaderConstraintTable* constraints() { return _loader_constraints; }
650 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
651 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
652
653 // Basic loading operations
654 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
655 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
656 static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
657 // Wait on SystemDictionary_lock; unlocks lockObject before
658 // waiting; relocks lockObject with correct recursion count
659 // after waiting, but before reentering SystemDictionary_lock
660 // to preserve lock order semantics.
661 static void double_lock_wait(Handle lockObject, TRAPS);
662 static void define_instance_class(InstanceKlass* k, TRAPS);
663 static InstanceKlass* find_or_define_instance_class(Symbol* class_name,
664 Handle class_loader,
665 InstanceKlass* k, TRAPS);
666 static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik,
667 Handle class_loader, TRAPS);
668 static InstanceKlass* load_shared_class(InstanceKlass* ik,
669 Handle class_loader,
670 Handle protection_domain,
671 TRAPS);
672 static InstanceKlass* load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
673 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
674 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
675 static bool is_parallelCapable(Handle class_loader);
676 static bool is_parallelDefine(Handle class_loader);
677
678 public:
679 static InstanceKlass* load_shared_class(Symbol* class_name,
680 Handle class_loader,
681 TRAPS);
682 static bool is_system_class_loader(oop class_loader);
683 static bool is_platform_class_loader(oop class_loader);
684 static void clear_invoke_method_table();
685
686 // Returns TRUE if the method is a non-public member of class java.lang.Object.
687 static bool is_nonpublic_Object_method(Method* m) {
688 assert(m != NULL, "Unexpected NULL Method*");
689 return !m->is_public() && m->method_holder() == SystemDictionary::Object_klass();
690 }
691
692 protected:
693 static InstanceKlass* find_shared_class(Symbol* class_name);
694
695 // Setup link to hierarchy
696 static void add_to_hierarchy(InstanceKlass* k, TRAPS);
697
698 // Basic find on loaded classes
699 static InstanceKlass* find_class(unsigned int hash,
700 Symbol* name, Dictionary* dictionary);
701 static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
702
703 // Basic find on classes in the midst of being loaded
704 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
705
706 // Add a placeholder for a class being loaded
707 static void add_placeholder(int index,
708 Symbol* class_name,
709 ClassLoaderData* loader_data);
710 static void remove_placeholder(int index,
711 Symbol* class_name,
712 ClassLoaderData* loader_data);
713
714 // Performs cleanups after resolve_super_or_fail. This typically needs
715 // to be called on failure.
716 // Won't throw, but can block.
717 static void resolution_cleanups(Symbol* class_name,
718 ClassLoaderData* loader_data,
719 TRAPS);
720
721 // Initialization
722 static void initialize_preloaded_classes(TRAPS);
723
724 // Class loader constraints
725 static void check_constraints(unsigned int hash,
726 InstanceKlass* k, Handle loader,
727 bool defining, TRAPS);
728 static void update_dictionary(unsigned int d_hash,
729 int p_index, unsigned int p_hash,
730 InstanceKlass* k, Handle loader,
731 TRAPS);
732
733 // Variables holding commonly used klasses (preloaded)
734 static InstanceKlass* _well_known_klasses[];
735
736 // Lazily loaded klasses
737 static InstanceKlass* volatile _abstract_ownable_synchronizer_klass;
738
739 // table of box klasses (int_klass, etc.)
740 static InstanceKlass* _box_klasses[T_VOID+1];
741
742 static oop _java_system_loader;
743 static oop _java_platform_loader;
744
745 static bool _has_checkPackageAccess;
746 };
747
748 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP