1 /*
2 * Copyright (c) 1997, 2012, 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.
18 *
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.
22 *
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 // The system dictionary stores all loaded classes and maps:
38 //
39 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass*
40 //
41 // Classes are loaded lazily. The default VM class loader is
42 // represented as NULL.
43
44 // The underlying data structure is an open hash table with a fixed number
45 // of buckets. During loading the loader object is locked, (for the VM loader
46 // a private lock object is used). Class loading can thus be done concurrently,
47 // but only by different loaders.
48 //
49 // During loading a placeholder (name, loader) is temporarily placed in
50 // a side data structure, and is used to detect ClassCircularityErrors
51 // and to perform verification during GC. A GC can occur in the midst
52 // of class loading, as we call out to Java, have to take locks, etc.
53 //
54 // When class loading is finished, a new entry is added to the system
55 // dictionary and the place holder is removed. Note that the protection
56 // domain field of the system dictionary has not yet been filled in when
57 // the "real" system dictionary entry is created.
58 //
59 // Clients of this class who are interested in finding if a class has
60 // been completely loaded -- not classes in the process of being loaded --
61 // can read the SystemDictionary unlocked. This is safe because
62 // - entries are only deleted at safepoints
63 // - readers cannot come to a safepoint while actively examining
64 // an entry (an entry cannot be deleted from under a reader)
65 // - entries must be fully formed before they are available to concurrent
66 // readers (we must ensure write ordering)
67 //
68 // Note that placeholders are deleted at any time, as they are removed
69 // when a class is completely loaded. Therefore, readers as well as writers
70 // of placeholders must hold the SystemDictionary_lock.
71 //
72
73 class Dictionary;
74 class PlaceholderTable;
75 class LoaderConstraintTable;
76 template <MEMFLAGS F> class HashtableBucket;
77 class ResolutionErrorTable;
78 class SymbolPropertyTable;
79
80 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
81 // They are all "well-known", in the sense that no class loader is allowed
82 // to provide a different definition.
83 //
84 // These klasses must all have names defined in vmSymbols.
85
86 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
87
88 // Each well-known class has a short klass name (like object_klass),
89 // a vmSymbol name (like java_lang_Object), and a flag word
90 // that makes some minor distinctions, like whether the klass
91 // is preloaded, optional, release-specific, etc.
92 // The order of these definitions is significant; it is the order in which
93 // preloading is actually performed by initialize_preloaded_classes.
94
95 #define WK_KLASSES_DO(template) \
96 /* well-known classes */ \
97 template(Object_klass, java_lang_Object, Pre) \
98 template(String_klass, java_lang_String, Pre) \
99 template(Class_klass, java_lang_Class, Pre) \
100 template(Cloneable_klass, java_lang_Cloneable, Pre) \
101 template(ClassLoader_klass, java_lang_ClassLoader, Pre) \
102 template(Serializable_klass, java_io_Serializable, Pre) \
103 template(System_klass, java_lang_System, Pre) \
104 template(Throwable_klass, java_lang_Throwable, Pre) \
105 template(Error_klass, java_lang_Error, Pre) \
106 template(ThreadDeath_klass, java_lang_ThreadDeath, Pre) \
107 template(Exception_klass, java_lang_Exception, Pre) \
108 template(RuntimeException_klass, java_lang_RuntimeException, Pre) \
109 template(ProtectionDomain_klass, java_security_ProtectionDomain, Pre) \
110 template(AccessControlContext_klass, java_security_AccessControlContext, Pre) \
111 template(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre) \
112 template(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre) \
113 template(LinkageError_klass, java_lang_LinkageError, Pre) \
114 template(ClassCastException_klass, java_lang_ClassCastException, Pre) \
115 template(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre) \
116 template(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre) \
117 template(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre) \
118 template(StackOverflowError_klass, java_lang_StackOverflowError, Pre) \
119 template(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre) \
120 template(Reference_klass, java_lang_ref_Reference, Pre) \
121 \
122 /* Preload ref klasses and set reference types */ \
123 template(SoftReference_klass, java_lang_ref_SoftReference, Pre) \
124 template(WeakReference_klass, java_lang_ref_WeakReference, Pre) \
125 template(FinalReference_klass, java_lang_ref_FinalReference, Pre) \
126 template(PhantomReference_klass, java_lang_ref_PhantomReference, Pre) \
127 template(Finalizer_klass, java_lang_ref_Finalizer, Pre) \
128 \
129 template(Thread_klass, java_lang_Thread, Pre) \
130 template(ThreadGroup_klass, java_lang_ThreadGroup, Pre) \
131 template(Properties_klass, java_util_Properties, Pre) \
132 template(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre) \
133 template(reflect_Field_klass, java_lang_reflect_Field, Pre) \
134 template(reflect_Method_klass, java_lang_reflect_Method, Pre) \
135 template(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre) \
136 \
137 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
138 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
139 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
140 template(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt) \
141 template(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \
142 template(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \
143 template(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt) \
144 template(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15) \
145 template(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15) \
146 \
147 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
148 template(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre_JSR292) \
149 template(MemberName_klass, java_lang_invoke_MemberName, Pre_JSR292) \
150 template(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre_JSR292) \
151 template(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt) \
152 template(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292) \
153 template(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre_JSR292) \
154 template(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292) \
155 template(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre_JSR292) \
156 template(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre_JSR292) \
157 template(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre_JSR292) \
158 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \
159 \
160 template(StringBuffer_klass, java_lang_StringBuffer, Pre) \
161 template(StringBuilder_klass, java_lang_StringBuilder, Pre) \
162 \
163 /* It's NULL in non-1.4 JDKs. */ \
164 template(StackTraceElement_klass, java_lang_StackTraceElement, Opt) \
165 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
166 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
167 template(nio_Buffer_klass, java_nio_Buffer, Opt) \
168 \
169 template(DownloadManager_klass, sun_jkernel_DownloadManager, Opt_Kernel) \
170 \
171 template(PostVMInitHook_klass, sun_misc_PostVMInitHook, Opt) \
172 \
173 /* Preload boxing klasses */ \
174 template(Boolean_klass, java_lang_Boolean, Pre) \
175 template(Character_klass, java_lang_Character, Pre) \
176 template(Float_klass, java_lang_Float, Pre) \
177 template(Double_klass, java_lang_Double, Pre) \
178 template(Byte_klass, java_lang_Byte, Pre) \
179 template(Short_klass, java_lang_Short, Pre) \
180 template(Integer_klass, java_lang_Integer, Pre) \
181 template(Long_klass, java_lang_Long, Pre) \
182 /*end*/
183
184
185 class SystemDictionary : AllStatic {
186 friend class VMStructs;
187 friend class SystemDictionaryHandles;
188
189 public:
190 enum WKID {
191 NO_WKID = 0,
192
193 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
194 WK_KLASSES_DO(WK_KLASS_ENUM)
195 #undef WK_KLASS_ENUM
196
197 WKID_LIMIT,
198
199 FIRST_WKID = NO_WKID + 1
200 };
201
202 enum InitOption {
203 Pre, // preloaded; error if not present
204 Pre_JSR292, // preloaded if EnableInvokeDynamic
205
206 // Order is significant. Options before this point require resolve_or_fail.
207 // Options after this point will use resolve_or_null instead.
208
209 Opt, // preload tried; NULL if not present
210 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection
211 Opt_Only_JDK15, // preload tried; use only with JDK1.5+
212 Opt_Kernel, // preload tried only #ifdef KERNEL
213 OPTION_LIMIT,
214 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
215 };
216
217
218 // Returns a class with a given class name and class loader. Loads the
219 // class if needed. If not found a NoClassDefFoundError or a
220 // ClassNotFoundException is thrown, depending on the value on the
221 // throw_error flag. For most uses the throw_error argument should be set
222 // to true.
223
224 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
225 // Convenient call for null loader and protection domain.
226 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
227 private:
228 // handle error translation for resolve_or_null results
229 static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
230
231 public:
232
233 // Returns a class with a given class name and class loader.
234 // Loads the class if needed. If not found NULL is returned.
235 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
236 // Version with null loader and protection domain
237 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
238
239 // Resolve a superclass or superinterface. Called from ClassFileParser,
240 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
241 // "child_name" is the class whose super class or interface is being resolved.
242 static Klass* resolve_super_or_fail(Symbol* child_name,
243 Symbol* class_name,
244 Handle class_loader,
245 Handle protection_domain,
246 bool is_superclass,
247 TRAPS);
248
249 // Parse new stream. This won't update the system dictionary or
250 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
251 static Klass* parse_stream(Symbol* class_name,
252 Handle class_loader,
253 Handle protection_domain,
254 ClassFileStream* st,
255 TRAPS) {
256 KlassHandle nullHandle;
257 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
258 }
259 static Klass* parse_stream(Symbol* class_name,
260 Handle class_loader,
261 Handle protection_domain,
262 ClassFileStream* st,
263 KlassHandle host_klass,
264 GrowableArray<Handle>* cp_patches,
265 TRAPS);
266
267 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
268 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
269 Handle protection_domain,
270 ClassFileStream* st, bool verify, TRAPS);
271
272 // Lookup an already loaded class. If not found NULL is returned.
273 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
274
275 // Lookup an already loaded instance or array class.
276 // Do not make any queries to class loaders; consult only the cache.
277 // If not found NULL is returned.
278 static Klass* find_instance_or_array_klass(Symbol* class_name,
279 Handle class_loader,
280 Handle protection_domain,
281 TRAPS);
282
283 // If the given name is known to vmSymbols, return the well-know klass:
284 static Klass* find_well_known_klass(Symbol* class_name);
285
286 // Lookup an instance or array class that has already been loaded
287 // either into the given class loader, or else into another class
288 // loader that is constrained (via loader constraints) to produce
289 // a consistent class. Do not take protection domains into account.
290 // Do not make any queries to class loaders; consult only the cache.
291 // Return NULL if the class is not found.
292 //
293 // This function is a strict superset of find_instance_or_array_klass.
294 // This function (the unchecked version) makes a conservative prediction
295 // of the result of the checked version, assuming successful lookup.
296 // If both functions return non-null, they must return the same value.
297 // Also, the unchecked version may sometimes be non-null where the
298 // checked version is null. This can occur in several ways:
299 // 1. No query has yet been made to the class loader.
300 // 2. The class loader was queried, but chose not to delegate.
301 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
302 // 4. Loading was attempted, but there was a linkage error of some sort.
303 // In all of these cases, the loader constraints on this type are
304 // satisfied, and it is safe for classes in the given class loader
305 // to manipulate strongly-typed values of the found class, subject
306 // to local linkage and access checks.
307 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
308 Handle class_loader,
309 TRAPS);
310
311 // Iterate over all klasses in dictionary
312 // Just the classes from defining class loaders
313 static void classes_do(void f(Klass*));
314 // Added for initialize_itable_for_klass to handle exceptions
315 static void classes_do(void f(Klass*, TRAPS), TRAPS);
316 // All classes, and their class loaders
317 static void classes_do(void f(Klass*, ClassLoaderData*));
318 // All classes, and their class loaders
319 // (added for helpers that use HandleMarks and ResourceMarks)
320 static void classes_do(void f(Klass*, ClassLoaderData*, TRAPS), TRAPS);
321 // All entries in the placeholder table and their class loaders
322 static void placeholders_do(void f(Symbol*));
323
324 // Iterate over all methods in all klasses in dictionary
325 static void methods_do(void f(Method*));
326
327 // Garbage collection support
328
329 // This method applies "blk->do_oop" to all the pointers to "system"
330 // classes and loaders.
331 static void always_strong_oops_do(OopClosure* blk);
332 static void always_strong_classes_do(KlassClosure* closure);
333
334 // Unload (that is, break root links to) all unmarked classes and
335 // loaders. Returns "true" iff something was unloaded.
336 static bool do_unloading(BoolObjectClosure* is_alive);
337
338 static int calculate_systemdictionary_size(int loadedclasses);
339
340 // Applies "f->do_oop" to all root oops in the system dictionary.
341 static void oops_do(OopClosure* f);
342
343 // System loader lock
344 static oop system_loader_lock() { return _system_loader_lock_obj; }
345
346 private:
347 // Extended Redefine classes support (tbi)
348 static void preloaded_classes_do(KlassClosure* f);
349 static void lazily_loaded_classes_do(KlassClosure* f);
350 public:
351 // Sharing support.
352 static void reorder_dictionary();
353 static void copy_buckets(char** top, char* end);
354 static void copy_table(char** top, char* end);
355 static void reverse();
356 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
357 int number_of_entries);
358 // Printing
359 static void print() PRODUCT_RETURN;
360 static void print_class_statistics() PRODUCT_RETURN;
361 static void print_method_statistics() PRODUCT_RETURN;
362
363 // Number of contained klasses
364 // This is both fully loaded classes and classes in the process
365 // of being loaded
366 static int number_of_classes();
367
368 // Monotonically increasing counter which grows as classes are
369 // loaded or modifications such as hot-swapping or setting/removing
370 // of breakpoints are performed
371 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
372 // Needed by evolution and breakpoint code
373 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
374
375 // Verification
376 static void verify();
377
378 #ifdef ASSERT
379 static bool is_internal_format(Symbol* class_name);
380 #endif
381
382 // Verify class is in dictionary
383 static void verify_obj_klass_present(Symbol* class_name,
384 ClassLoaderData* loader_data);
385
386 // Initialization
387 static void initialize(TRAPS);
388
389 // Fast access to commonly used classes (preloaded)
390 static Klass* check_klass(Klass* k) {
391 assert(k != NULL, "preloaded klass not initialized");
392 return k;
393 }
394
395 static Klass* check_klass_Pre(Klass* k) { return check_klass(k); }
396 static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; }
397 static Klass* check_klass_Opt(Klass* k) { return k; }
398 static Klass* check_klass_Opt_Kernel(Klass* k) { return k; } //== Opt
399 static Klass* check_klass_Opt_Only_JDK15(Klass* k) {
400 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
401 return k;
402 }
403 static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) {
404 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
405 // despite the optional loading, if you use this it must be present:
406 return check_klass(k);
407 }
408
409 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
410 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
411 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
412 int limit = (int)end_id + 1;
413 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
414 }
415
416 public:
417 #define WK_KLASS_DECLARE(name, symbol, option) \
418 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
419 static Klass** name##_addr() { \
420 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
421 }
422 WK_KLASSES_DO(WK_KLASS_DECLARE);
423 #undef WK_KLASS_DECLARE
424
425 static Klass* well_known_klass(WKID id) {
426 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
427 return _well_known_klasses[id];
428 }
429
430 static Klass** well_known_klass_addr(WKID id) {
431 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
432 return &_well_known_klasses[id];
433 }
434
435 // Local definition for direct access to the private array:
436 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
437
438 static Klass* box_klass(BasicType t) {
439 assert((uint)t < T_VOID+1, "range check");
440 return check_klass(_box_klasses[t]);
441 }
442 static BasicType box_klass_type(Klass* k); // inverse of box_klass
443
444 // methods returning lazily loaded klasses
445 // The corresponding method to load the class must be called before calling them.
446 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
447
448 static void load_abstract_ownable_synchronizer_klass(TRAPS);
449
450 private:
451 // Tells whether ClassLoader.loadClassInternal is present
452 static bool has_loadClassInternal() { return _has_loadClassInternal; }
453
454 // Returns the class loader data to be used when looking up/updating the
455 // system dictionary.
456 static ClassLoaderData *class_loader_data(Handle class_loader) {
457 return ClassLoaderData::class_loader_data(class_loader());
458 }
459
460 public:
461 // Tells whether ClassLoader.checkPackageAccess is present
462 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
463
464 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
465 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
466 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
467 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
468
469 // Returns default system loader
470 static oop java_system_loader();
471
472 // Compute the default system loader
473 static void compute_java_system_loader(TRAPS);
474
475 // Register a new class loader
476 static ClassLoaderData* register_loader(Handle class_loader);
477 private:
478 // Mirrors for primitive classes (created eagerly)
479 static oop check_mirror(oop m) {
480 assert(m != NULL, "mirror not initialized");
481 return m;
482 }
483
484 public:
485 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
486
487 // Check class loader constraints
488 static bool add_loader_constraint(Symbol* name, Handle loader1,
489 Handle loader2, TRAPS);
490 static char* check_signature_loaders(Symbol* signature, Handle loader1,
491 Handle loader2, bool is_method, TRAPS);
492
493 // JSR 292
494 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
495 // (asks Java to compute it if necessary, except in a compiler thread)
496 static methodHandle find_method_handle_invoker(Symbol* name,
497 Symbol* signature,
498 KlassHandle accessing_klass,
499 Handle *appendix_result,
500 Handle *method_type_result,
501 TRAPS);
502 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
503 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
504 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
505 Symbol* signature,
506 TRAPS);
507 // find a java.lang.invoke.MethodType object for a given signature
508 // (asks Java to compute it if necessary, except in a compiler thread)
509 static Handle find_method_handle_type(Symbol* signature,
510 KlassHandle accessing_klass,
511 TRAPS);
512
513 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
514 static Handle link_method_handle_constant(KlassHandle caller,
515 int ref_kind, //e.g., JVM_REF_invokeVirtual
516 KlassHandle callee,
517 Symbol* name,
518 Symbol* signature,
519 TRAPS);
520
521 // ask Java to create a dynamic call site, while linking an invokedynamic op
522 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
523 Handle bootstrap_method,
524 Symbol* name,
525 Symbol* type,
526 Handle *appendix_result,
527 Handle *method_type_result,
528 TRAPS);
529
530 // Utility for printing loader "name" as part of tracing constraints
531 static const char* loader_name(oop loader) {
532 return ((loader) == NULL ? "<bootloader>" :
533 InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
534 }
535 static const char* loader_name(ClassLoaderData* loader_data) {
536 return (loader_data->is_the_null_class_loader_data() ? "<bootloader>" :
537 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
538 }
539
540 // Record the error when the first attempt to resolve a reference from a constant
541 // pool entry to a class fails.
542 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error);
543 static void delete_resolution_error(ConstantPool* pool);
544 static Symbol* find_resolution_error(constantPoolHandle pool, int which);
545
546 private:
547
548 enum Constants {
549 _loader_constraint_size = 107, // number of entries in constraint table
550 _resolution_error_size = 107, // number of entries in resolution error table
551 _invoke_method_size = 139, // number of entries in invoke method table
552 _nof_buckets = 1009, // number of buckets in hash table for placeholders
553 _old_default_sdsize = 1009, // backward compat for system dictionary size
554 _prime_array_size = 8, // array of primes for system dictionary size
555 _average_depth_goal = 3 // goal for lookup length
556 };
557
558
559 // Static variables
560
561 // hashtable sizes for system dictionary to allow growth
562 // prime numbers for system dictionary size
563 static int _sdgeneration;
564 static const int _primelist[_prime_array_size];
565
566 // Hashtable holding loaded classes.
567 static Dictionary* _dictionary;
568
569 // Hashtable holding placeholders for classes being loaded.
570 static PlaceholderTable* _placeholders;
571
572 // Hashtable holding classes from the shared archive.
573 static Dictionary* _shared_dictionary;
574
575 // Monotonically increasing counter which grows with
576 // _number_of_classes as well as hot-swapping and breakpoint setting
577 // and removal.
578 static int _number_of_modifications;
579
580 // Lock object for system class loader
581 static oop _system_loader_lock_obj;
582
583 // Constraints on class loaders
584 static LoaderConstraintTable* _loader_constraints;
585
586 // Resolution errors
587 static ResolutionErrorTable* _resolution_errors;
588
589 // Invoke methods (JSR 292)
590 static SymbolPropertyTable* _invoke_method_table;
591
592 public:
593 // for VM_CounterDecay iteration support
594 friend class CounterDecay;
595 static Klass* try_get_next_class();
596
597 private:
598 static void validate_protection_domain(instanceKlassHandle klass,
599 Handle class_loader,
600 Handle protection_domain, TRAPS);
601
602 friend class VM_PopulateDumpSharedSpace;
603 friend class TraversePlaceholdersClosure;
604 static Dictionary* dictionary() { return _dictionary; }
605 static Dictionary* shared_dictionary() { return _shared_dictionary; }
606 static PlaceholderTable* placeholders() { return _placeholders; }
607 static LoaderConstraintTable* constraints() { return _loader_constraints; }
608 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
609 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
610
611 // Basic loading operations
612 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
613 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
614 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
615 // Wait on SystemDictionary_lock; unlocks lockObject before
616 // waiting; relocks lockObject with correct recursion count
617 // after waiting, but before reentering SystemDictionary_lock
618 // to preserve lock order semantics.
619 static void double_lock_wait(Handle lockObject, TRAPS);
620 static void define_instance_class(instanceKlassHandle k, TRAPS);
621 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
622 Handle class_loader,
623 instanceKlassHandle k, TRAPS);
624 static instanceKlassHandle load_shared_class(Symbol* class_name,
625 Handle class_loader, TRAPS);
626 static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
627 Handle class_loader, TRAPS);
628 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
629 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
630 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
631 static bool is_parallelCapable(Handle class_loader);
632 static bool is_parallelDefine(Handle class_loader);
633
634 static Klass* find_shared_class(Symbol* class_name);
635
636 // Setup link to hierarchy
637 static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
638
639 private:
640 // We pass in the hashtable index so we can calculate it outside of
641 // the SystemDictionary_lock.
642
643 // Basic find on loaded classes
644 static Klass* find_class(int index, unsigned int hash,
645 Symbol* name, ClassLoaderData* loader_data);
646 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
647
648 // Basic find on classes in the midst of being loaded
649 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
650
651 // Updating entry in dictionary
652 // Add a completely loaded class
653 static void add_klass(int index, Symbol* class_name,
654 ClassLoaderData* loader_data, KlassHandle obj);
655
656 // Add a placeholder for a class being loaded
657 static void add_placeholder(int index,
658 Symbol* class_name,
659 ClassLoaderData* loader_data);
660 static void remove_placeholder(int index,
661 Symbol* class_name,
662 ClassLoaderData* loader_data);
663
664 // Performs cleanups after resolve_super_or_fail. This typically needs
665 // to be called on failure.
666 // Won't throw, but can block.
667 static void resolution_cleanups(Symbol* class_name,
668 ClassLoaderData* loader_data,
669 TRAPS);
670
671 // Initialization
672 static void initialize_preloaded_classes(TRAPS);
673
674 // Class loader constraints
675 static void check_constraints(int index, unsigned int hash,
676 instanceKlassHandle k, Handle loader,
677 bool defining, TRAPS);
678 static void update_dictionary(int d_index, unsigned int d_hash,
679 int p_index, unsigned int p_hash,
680 instanceKlassHandle k, Handle loader,
681 TRAPS);
682
683 // Variables holding commonly used klasses (preloaded)
684 static Klass* _well_known_klasses[];
685
686 // Lazily loaded klasses
687 static Klass* volatile _abstract_ownable_synchronizer_klass;
688
689 // table of box klasses (int_klass, etc.)
690 static Klass* _box_klasses[T_VOID+1];
691
692 static oop _java_system_loader;
693
694 static bool _has_loadClassInternal;
695 static bool _has_checkPackageAccess;
696 };
697
698 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP