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).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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23 */
24
25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
27
28 #include "classfile/classFileStream.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/symbol.hpp"
32 #include "runtime/java.hpp"
33 #include "runtime/reflectionUtils.hpp"
34 #include "utilities/hashtable.hpp"
35 #include "utilities/hashtable.inline.hpp"
36
37
38 // The system dictionary stores all loaded classes and maps:
39 //
40 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass*
41 //
42 // Classes are loaded lazily. The default VM class loader is
43 // represented as NULL.
44
45 // The underlying data structure is an open hash table with a fixed number
46 // of buckets. During loading the loader object is locked, (for the VM loader
47 // a private lock object is used). Class loading can thus be done concurrently,
48 // but only by different loaders.
49 //
50 // During loading a placeholder (name, loader) is temporarily placed in
51 // a side data structure, and is used to detect ClassCircularityErrors
52 // and to perform verification during GC. A GC can occur in the midst
53 // of class loading, as we call out to Java, have to take locks, etc.
54 //
55 // When class loading is finished, a new entry is added to the system
56 // dictionary and the place holder is removed. Note that the protection
57 // domain field of the system dictionary has not yet been filled in when
58 // the "real" system dictionary entry is created.
59 //
60 // Clients of this class who are interested in finding if a class has
61 // been completely loaded -- not classes in the process of being loaded --
62 // can read the SystemDictionary unlocked. This is safe because
63 // - entries are only deleted at safepoints
64 // - readers cannot come to a safepoint while actively examining
65 // an entry (an entry cannot be deleted from under a reader)
66 // - entries must be fully formed before they are available to concurrent
67 // readers (we must ensure write ordering)
68 //
69 // Note that placeholders are deleted at any time, as they are removed
70 // when a class is completely loaded. Therefore, readers as well as writers
71 // of placeholders must hold the SystemDictionary_lock.
72 //
73
74 class Dictionary;
75 class PlaceholderTable;
76 class LoaderConstraintTable;
77 template <MEMFLAGS F> class HashtableBucket;
78 class ResolutionErrorTable;
79 class SymbolPropertyTable;
80 class Ticks;
81
82 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
83 // They are all "well-known", in the sense that no class loader is allowed
84 // to provide a different definition.
85 //
86 // These klasses must all have names defined in vmSymbols.
87
88 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
89
90 // Each well-known class has a short klass name (like object_klass),
91 // a vmSymbol name (like java_lang_Object), and a flag word
92 // that makes some minor distinctions, like whether the klass
93 // is preloaded, optional, release-specific, etc.
94 // The order of these definitions is significant; it is the order in which
95 // preloading is actually performed by initialize_preloaded_classes.
96
97 #define WK_KLASSES_DO(do_klass) \
98 /* well-known classes */ \
99 do_klass(Object_klass, java_lang_Object, Pre ) \
100 do_klass(String_klass, java_lang_String, Pre ) \
101 do_klass(Class_klass, java_lang_Class, Pre ) \
102 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \
103 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \
104 do_klass(Serializable_klass, java_io_Serializable, Pre ) \
105 do_klass(System_klass, java_lang_System, Pre ) \
106 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \
107 do_klass(Error_klass, java_lang_Error, Pre ) \
108 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \
109 do_klass(Exception_klass, java_lang_Exception, Pre ) \
110 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \
111 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \
112 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \
113 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \
114 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \
115 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \
116 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \
117 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \
118 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \
119 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \
120 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \
121 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \
122 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \
123 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \
124 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \
125 \
126 /* Preload ref klasses and set reference types */ \
127 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \
128 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \
129 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \
130 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \
131 do_klass(Cleaner_klass, sun_misc_Cleaner, Pre ) \
132 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \
133 do_klass(ReferenceQueue_klass, java_lang_ref_ReferenceQueue, Pre ) \
134 \
135 do_klass(Thread_klass, java_lang_Thread, Pre ) \
136 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \
137 do_klass(Properties_klass, java_util_Properties, Pre ) \
138 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \
139 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \
140 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \
141 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \
142 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \
143 \
144 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
145 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
146 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
147 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \
148 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \
149 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \
150 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \
151 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15 ) \
152 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15 ) \
153 do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \
154 \
155 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
156 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \
157 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre_JSR292 ) \
158 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre_JSR292 ) \
159 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre_JSR292 ) \
160 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \
161 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292 ) \
162 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre_JSR292 ) \
163 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292 ) \
164 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre_JSR292 ) \
165 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre_JSR292 ) \
166 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre_JSR292 ) \
167 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \
168 \
169 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \
170 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \
171 do_klass(misc_Unsafe_klass, sun_misc_Unsafe, Pre ) \
172 \
173 /* support for CDS */ \
174 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \
175 do_klass(File_klass, java_io_File, Pre ) \
176 do_klass(URLClassLoader_klass, java_net_URLClassLoader, Pre ) \
177 do_klass(URL_klass, java_net_URL, Pre ) \
178 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \
179 do_klass(sun_misc_Launcher_klass, sun_misc_Launcher, Pre ) \
180 do_klass(sun_misc_Launcher_AppClassLoader_klass, sun_misc_Launcher_AppClassLoader, Pre ) \
181 do_klass(sun_misc_Launcher_ExtClassLoader_klass, sun_misc_Launcher_ExtClassLoader, Pre ) \
182 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \
183 \
184 /* It's NULL in non-1.4 JDKs. */ \
185 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \
186 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
187 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
188 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \
189 \
190 /* Preload boxing klasses */ \
191 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \
192 do_klass(Character_klass, java_lang_Character, Pre ) \
193 do_klass(Float_klass, java_lang_Float, Pre ) \
194 do_klass(Double_klass, java_lang_Double, Pre ) \
195 do_klass(Byte_klass, java_lang_Byte, Pre ) \
196 do_klass(Short_klass, java_lang_Short, Pre ) \
197 do_klass(Integer_klass, java_lang_Integer, Pre ) \
198 do_klass(Long_klass, java_lang_Long, Pre ) \
199 /*end*/
200
201
202 class SystemDictionary : AllStatic {
203 friend class VMStructs;
204 friend class SystemDictionaryHandles;
205
206 public:
207 enum WKID {
208 NO_WKID = 0,
209
210 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
211 WK_KLASSES_DO(WK_KLASS_ENUM)
212 #undef WK_KLASS_ENUM
213
214 WKID_LIMIT,
215
216 FIRST_WKID = NO_WKID + 1
217 };
218
219 enum InitOption {
220 Pre, // preloaded; error if not present
221 Pre_JSR292, // preloaded if EnableInvokeDynamic
222
223 // Order is significant. Options before this point require resolve_or_fail.
224 // Options after this point will use resolve_or_null instead.
225
226 Opt, // preload tried; NULL if not present
227 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection
228 Opt_Only_JDK15, // preload tried; use only with JDK1.5+
229 OPTION_LIMIT,
230 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
231 };
232
233
234 // Returns a class with a given class name and class loader. Loads the
235 // class if needed. If not found a NoClassDefFoundError or a
236 // ClassNotFoundException is thrown, depending on the value on the
237 // throw_error flag. For most uses the throw_error argument should be set
238 // to true.
239
240 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
241 // Convenient call for null loader and protection domain.
242 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
243 protected:
244 // handle error translation for resolve_or_null results
245 static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
246
247 public:
248
249 // Returns a class with a given class name and class loader.
250 // Loads the class if needed. If not found NULL is returned.
251 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
252 // Version with null loader and protection domain
253 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
254
255 // Resolve a superclass or superinterface. Called from ClassFileParser,
256 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
257 // "child_name" is the class whose super class or interface is being resolved.
258 static Klass* resolve_super_or_fail(Symbol* child_name,
259 Symbol* class_name,
260 Handle class_loader,
261 Handle protection_domain,
262 bool is_superclass,
263 TRAPS);
264
265 // Parse new stream. This won't update the system dictionary or
266 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
267 static Klass* parse_stream(Symbol* class_name,
268 Handle class_loader,
269 Handle protection_domain,
270 ClassFileStream* st,
271 TRAPS) {
272 KlassHandle nullHandle;
273 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
274 }
275 static Klass* parse_stream(Symbol* class_name,
276 Handle class_loader,
277 Handle protection_domain,
278 ClassFileStream* st,
279 KlassHandle host_klass,
280 GrowableArray<Handle>* cp_patches,
281 TRAPS);
282
283 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
284 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
285 Handle protection_domain,
286 ClassFileStream* st, bool verify, TRAPS);
287
288 // Lookup an already loaded class. If not found NULL is returned.
289 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
290
291 // Lookup an already loaded instance or array class.
292 // Do not make any queries to class loaders; consult only the cache.
293 // If not found NULL is returned.
294 static Klass* find_instance_or_array_klass(Symbol* class_name,
295 Handle class_loader,
296 Handle protection_domain,
297 TRAPS);
298
299 // Lookup an instance or array class that has already been loaded
300 // either into the given class loader, or else into another class
301 // loader that is constrained (via loader constraints) to produce
302 // a consistent class. Do not take protection domains into account.
303 // Do not make any queries to class loaders; consult only the cache.
304 // Return NULL if the class is not found.
305 //
306 // This function is a strict superset of find_instance_or_array_klass.
307 // This function (the unchecked version) makes a conservative prediction
308 // of the result of the checked version, assuming successful lookup.
309 // If both functions return non-null, they must return the same value.
310 // Also, the unchecked version may sometimes be non-null where the
311 // checked version is null. This can occur in several ways:
312 // 1. No query has yet been made to the class loader.
313 // 2. The class loader was queried, but chose not to delegate.
314 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
315 // 4. Loading was attempted, but there was a linkage error of some sort.
316 // In all of these cases, the loader constraints on this type are
317 // satisfied, and it is safe for classes in the given class loader
318 // to manipulate strongly-typed values of the found class, subject
319 // to local linkage and access checks.
320 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
321 Handle class_loader,
322 TRAPS);
323
324 // Iterate over all klasses in dictionary
325 // Just the classes from defining class loaders
326 static void classes_do(void f(Klass*));
327 // Added for initialize_itable_for_klass to handle exceptions
328 static void classes_do(void f(Klass*, TRAPS), TRAPS);
329 // All classes, and their class loaders
330 static void classes_do(void f(Klass*, ClassLoaderData*));
331
332 static void placeholders_do(void f(Symbol*));
333
334 // Iterate over all methods in all klasses in dictionary
335 static void methods_do(void f(Method*));
336
337 // Garbage collection support
338
339 // This method applies "blk->do_oop" to all the pointers to "system"
340 // classes and loaders.
341 static void always_strong_oops_do(OopClosure* blk);
342 static void always_strong_classes_do(KlassClosure* closure);
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(BoolObjectClosure* is_alive, bool clean_alive = true);
347
348 // Used by DumpSharedSpaces only to remove classes that failed verification
349 static void remove_classes_in_error_state();
350
351 static int calculate_systemdictionary_size(int loadedclasses);
352
353 // Applies "f->do_oop" to all root oops in the system dictionary.
354 static void oops_do(OopClosure* f);
355 static void roots_oops_do(OopClosure* strong, OopClosure* weak);
356
357 // System loader lock
358 static oop system_loader_lock() { return _system_loader_lock_obj; }
359
360 protected:
361 // Extended Redefine classes support (tbi)
362 static void preloaded_classes_do(KlassClosure* f);
363 static void lazily_loaded_classes_do(KlassClosure* f);
364 public:
365 // Sharing support.
366 static void reorder_dictionary();
367 static void copy_buckets(char** top, char* end);
368 static void copy_table(char** top, char* end);
369 static void reverse();
370 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
371 int number_of_entries);
372 // Printing
373 static void print(bool details = true);
374 static void print_shared(bool details = true);
375 static void print_class_statistics() PRODUCT_RETURN;
376 static void print_method_statistics() PRODUCT_RETURN;
377
378 // Number of contained klasses
379 // This is both fully loaded classes and classes in the process
380 // of being loaded
381 static int number_of_classes();
382
383 // Monotonically increasing counter which grows as classes are
384 // loaded or modifications such as hot-swapping or setting/removing
385 // of breakpoints are performed
386 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
387 // Needed by evolution and breakpoint code
388 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
389
390 // Verification
391 static void verify();
392
393 #ifdef ASSERT
394 static bool is_internal_format(Symbol* class_name);
395 #endif
396
397 // Initialization
398 static void initialize(TRAPS);
399
400 // Fast access to commonly used classes (preloaded)
401 static Klass* check_klass(Klass* k) {
402 assert(k != NULL, "preloaded klass not initialized");
403 return k;
404 }
405
406 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); }
407 static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; }
408 static Klass* check_klass_Opt( Klass* k) { return k; }
409 static Klass* check_klass_Opt_Only_JDK15(Klass* k) {
410 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
411 return k;
412 }
413 static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) {
414 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
415 // despite the optional loading, if you use this it must be present:
416 return check_klass(k);
417 }
418
419 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
420 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
421 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
422 int limit = (int)end_id + 1;
423 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
424 }
425
426 public:
427 #define WK_KLASS_DECLARE(name, symbol, option) \
428 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
429 static Klass** name##_addr() { \
430 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
431 }
432 WK_KLASSES_DO(WK_KLASS_DECLARE);
433 #undef WK_KLASS_DECLARE
434
435 static Klass* well_known_klass(WKID id) {
436 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
437 return _well_known_klasses[id];
438 }
439
440 static Klass** well_known_klass_addr(WKID id) {
441 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
442 return &_well_known_klasses[id];
443 }
444
445 // Local definition for direct access to the private array:
446 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
447
448 static Klass* box_klass(BasicType t) {
449 assert((uint)t < T_VOID+1, "range check");
450 return check_klass(_box_klasses[t]);
451 }
452 static BasicType box_klass_type(Klass* k); // inverse of box_klass
453
454 // methods returning lazily loaded klasses
455 // The corresponding method to load the class must be called before calling them.
456 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
457
458 static void load_abstract_ownable_synchronizer_klass(TRAPS);
459
460 protected:
461 // Tells whether ClassLoader.loadClassInternal is present
462 static bool has_loadClassInternal() { return _has_loadClassInternal; }
463
464 // Returns the class loader data to be used when looking up/updating the
465 // system dictionary.
466 static ClassLoaderData *class_loader_data(Handle class_loader) {
467 return ClassLoaderData::class_loader_data(class_loader());
468 }
469
470 public:
471 // Tells whether ClassLoader.checkPackageAccess is present
472 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
473
474 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
475 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
476 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
477 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
478 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
479
480 // Returns default system loader
481 static oop java_system_loader();
482
483 // Compute the default system loader
484 static void compute_java_system_loader(TRAPS);
485
486 // Register a new class loader
487 static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
488 protected:
489 // Mirrors for primitive classes (created eagerly)
490 static oop check_mirror(oop m) {
491 assert(m != NULL, "mirror not initialized");
492 return m;
493 }
494
495 public:
496 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
497
498 // Check class loader constraints
499 static bool add_loader_constraint(Symbol* name, Handle loader1,
500 Handle loader2, TRAPS);
501 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
502 Handle loader2, bool is_method, TRAPS);
503
504 // JSR 292
505 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
506 // (asks Java to compute it if necessary, except in a compiler thread)
507 static methodHandle find_method_handle_invoker(Symbol* name,
508 Symbol* signature,
509 KlassHandle accessing_klass,
510 Handle *appendix_result,
511 Handle *method_type_result,
512 TRAPS);
513 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
514 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
515 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
516 Symbol* signature,
517 TRAPS);
518 // find a java.lang.invoke.MethodType object for a given signature
519 // (asks Java to compute it if necessary, except in a compiler thread)
520 static Handle find_method_handle_type(Symbol* signature,
521 KlassHandle accessing_klass,
522 TRAPS);
523
524 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
525 static Handle link_method_handle_constant(KlassHandle caller,
526 int ref_kind, //e.g., JVM_REF_invokeVirtual
527 KlassHandle callee,
528 Symbol* name,
529 Symbol* signature,
530 TRAPS);
531
532 // ask Java to create a dynamic call site, while linking an invokedynamic op
533 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
534 Handle bootstrap_method,
535 Symbol* name,
536 Symbol* type,
537 Handle *appendix_result,
538 Handle *method_type_result,
539 TRAPS);
540
541 // Utility for printing loader "name" as part of tracing constraints
542 static const char* loader_name(oop loader) {
543 return ((loader) == NULL ? "<bootloader>" :
544 InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
545 }
546 static const char* loader_name(ClassLoaderData* loader_data) {
547 return (loader_data->class_loader() == NULL ? "<bootloader>" :
548 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
549 }
550
551 // Record the error when the first attempt to resolve a reference from a constant
552 // pool entry to a class fails.
553 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error);
554 static void delete_resolution_error(ConstantPool* pool);
555 static Symbol* find_resolution_error(constantPoolHandle pool, int which);
556
557 protected:
558
559 enum Constants {
560 _loader_constraint_size = 107, // number of entries in constraint table
561 _resolution_error_size = 107, // number of entries in resolution error table
562 _invoke_method_size = 139, // number of entries in invoke method table
563 _nof_buckets = 1009, // number of buckets in hash table for placeholders
564 _old_default_sdsize = 1009, // backward compat for system dictionary size
565 _prime_array_size = 8, // array of primes for system dictionary size
566 _average_depth_goal = 3 // goal for lookup length
567 };
568
569
570 // Static variables
571
572 // hashtable sizes for system dictionary to allow growth
573 // prime numbers for system dictionary size
574 static int _sdgeneration;
575 static const int _primelist[_prime_array_size];
576
577 // Hashtable holding loaded classes.
578 static Dictionary* _dictionary;
579
580 // Hashtable holding placeholders for classes being loaded.
581 static PlaceholderTable* _placeholders;
582
583 // Hashtable holding classes from the shared archive.
584 static Dictionary* _shared_dictionary;
585
586 // Monotonically increasing counter which grows with
587 // _number_of_classes as well as hot-swapping and breakpoint setting
588 // and removal.
589 static int _number_of_modifications;
590
591 // Lock object for system class loader
592 static oop _system_loader_lock_obj;
593
594 // Constraints on class loaders
595 static LoaderConstraintTable* _loader_constraints;
596
597 // Resolution errors
598 static ResolutionErrorTable* _resolution_errors;
599
600 // Invoke methods (JSR 292)
601 static SymbolPropertyTable* _invoke_method_table;
602
603 public:
604 // for VM_CounterDecay iteration support
605 friend class CounterDecay;
606 static Klass* try_get_next_class();
607
608 protected:
609 static void validate_protection_domain(instanceKlassHandle klass,
610 Handle class_loader,
611 Handle protection_domain, TRAPS);
612
613 friend class VM_PopulateDumpSharedSpace;
614 friend class TraversePlaceholdersClosure;
615 static Dictionary* dictionary() { return _dictionary; }
616 static Dictionary* shared_dictionary() { return _shared_dictionary; }
617 static PlaceholderTable* placeholders() { return _placeholders; }
618 static LoaderConstraintTable* constraints() { return _loader_constraints; }
619 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
620 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
621
622 // Basic loading operations
623 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
624 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
625 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
626 // Wait on SystemDictionary_lock; unlocks lockObject before
627 // waiting; relocks lockObject with correct recursion count
628 // after waiting, but before reentering SystemDictionary_lock
629 // to preserve lock order semantics.
630 static void double_lock_wait(Handle lockObject, TRAPS);
631 static void define_instance_class(instanceKlassHandle k, TRAPS);
632 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
633 Handle class_loader,
634 instanceKlassHandle k, TRAPS);
635 static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
636 Handle class_loader,
637 Handle protection_domain,
638 TRAPS);
639 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
640 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
641 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
642 static bool is_parallelCapable(Handle class_loader);
643 static bool is_parallelDefine(Handle class_loader);
644
645 public:
646 static instanceKlassHandle load_shared_class(Symbol* class_name,
647 Handle class_loader,
648 TRAPS);
649 static bool is_ext_class_loader(Handle class_loader);
650
651 protected:
652 static Klass* find_shared_class(Symbol* class_name);
653
654 // Setup link to hierarchy
655 static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
656
657 // event based tracing
658 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k,
659 Handle initiating_loader);
660 // We pass in the hashtable index so we can calculate it outside of
661 // the SystemDictionary_lock.
662
663 // Basic find on loaded classes
664 static Klass* find_class(int index, unsigned int hash,
665 Symbol* name, ClassLoaderData* loader_data);
666 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
667
668 // Basic find on classes in the midst of being loaded
669 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
670
671 // Updating entry in dictionary
672 // Add a completely loaded class
673 static void add_klass(int index, Symbol* class_name,
674 ClassLoaderData* loader_data, KlassHandle obj);
675
676 // Add a placeholder for a class being loaded
677 static void add_placeholder(int index,
678 Symbol* class_name,
679 ClassLoaderData* loader_data);
680 static void remove_placeholder(int index,
681 Symbol* class_name,
682 ClassLoaderData* loader_data);
683
684 // Performs cleanups after resolve_super_or_fail. This typically needs
685 // to be called on failure.
686 // Won't throw, but can block.
687 static void resolution_cleanups(Symbol* class_name,
688 ClassLoaderData* loader_data,
689 TRAPS);
690
691 // Initialization
692 static void initialize_preloaded_classes(TRAPS);
693
694 // Class loader constraints
695 static void check_constraints(int index, unsigned int hash,
696 instanceKlassHandle k, Handle loader,
697 bool defining, TRAPS);
698 static void update_dictionary(int d_index, unsigned int d_hash,
699 int p_index, unsigned int p_hash,
700 instanceKlassHandle k, Handle loader,
701 TRAPS);
702
703 // Variables holding commonly used klasses (preloaded)
704 static Klass* _well_known_klasses[];
705
706 // Lazily loaded klasses
707 static Klass* volatile _abstract_ownable_synchronizer_klass;
708
709 // table of box klasses (int_klass, etc.)
710 static Klass* _box_klasses[T_VOID+1];
711
712 static oop _java_system_loader;
713
714 static bool _has_loadClassInternal;
715 static bool _has_checkPackageAccess;
716 };
717
718 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP