1 /*
2 * Copyright (c) 1997, 2013, 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
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(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \
115 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \
116 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \
117 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \
118 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \
119 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \
120 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \
121 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \
122 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \
123 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \
124 \
125 /* Preload ref klasses and set reference types */ \
126 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \
127 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \
128 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \
129 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \
130 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \
131 \
132 do_klass(Thread_klass, java_lang_Thread, Pre ) \
133 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \
134 do_klass(Properties_klass, java_util_Properties, Pre ) \
135 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \
136 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \
137 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \
138 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \
139 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \
140 \
141 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
142 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
143 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
144 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \
145 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \
146 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \
147 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \
148 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15 ) \
149 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15 ) \
150 do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \
151 \
152 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
153 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \
154 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre_JSR292 ) \
155 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre_JSR292 ) \
156 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre_JSR292 ) \
157 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \
158 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292 ) \
159 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre_JSR292 ) \
160 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292 ) \
161 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre_JSR292 ) \
162 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre_JSR292 ) \
163 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre_JSR292 ) \
164 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \
165 \
166 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \
167 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \
168 \
169 /* It's NULL in non-1.4 JDKs. */ \
170 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \
171 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
172 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
173 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \
174 \
175 /* Preload boxing klasses */ \
176 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \
177 do_klass(Character_klass, java_lang_Character, Pre ) \
178 do_klass(Float_klass, java_lang_Float, Pre ) \
179 do_klass(Double_klass, java_lang_Double, Pre ) \
180 do_klass(Byte_klass, java_lang_Byte, Pre ) \
181 do_klass(Short_klass, java_lang_Short, Pre ) \
182 do_klass(Integer_klass, java_lang_Integer, Pre ) \
183 do_klass(Long_klass, java_lang_Long, Pre ) \
184 /*end*/
185
186
187 class SystemDictionary : AllStatic {
188 friend class VMStructs;
189 friend class SystemDictionaryHandles;
190
191 public:
192 enum WKID {
193 NO_WKID = 0,
194
195 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
196 WK_KLASSES_DO(WK_KLASS_ENUM)
197 #undef WK_KLASS_ENUM
198
199 WKID_LIMIT,
200
201 FIRST_WKID = NO_WKID + 1
202 };
203
204 enum InitOption {
205 Pre, // preloaded; error if not present
206 Pre_JSR292, // preloaded if EnableInvokeDynamic
207
208 // Order is significant. Options before this point require resolve_or_fail.
209 // Options after this point will use resolve_or_null instead.
210
211 Opt, // preload tried; NULL if not present
212 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection
213 Opt_Only_JDK15, // preload tried; use only with JDK1.5+
214 OPTION_LIMIT,
215 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
216 };
217
218
219 // Returns a class with a given class name and class loader. Loads the
220 // class if needed. If not found a NoClassDefFoundError or a
221 // ClassNotFoundException is thrown, depending on the value on the
222 // throw_error flag. For most uses the throw_error argument should be set
223 // to true.
224
225 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
226 // Convenient call for null loader and protection domain.
227 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
228 private:
229 // handle error translation for resolve_or_null results
230 static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
231
232 public:
233
234 // Returns a class with a given class name and class loader.
235 // Loads the class if needed. If not found NULL is returned.
236 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
237 // Version with null loader and protection domain
238 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
239
240 // Resolve a superclass or superinterface. Called from ClassFileParser,
241 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
242 // "child_name" is the class whose super class or interface is being resolved.
243 static Klass* resolve_super_or_fail(Symbol* child_name,
244 Symbol* class_name,
245 Handle class_loader,
246 Handle protection_domain,
247 bool is_superclass,
248 TRAPS);
249
250 // Parse new stream. This won't update the system dictionary or
251 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
252 static Klass* parse_stream(Symbol* class_name,
253 Handle class_loader,
254 Handle protection_domain,
255 ClassFileStream* st,
256 TRAPS) {
257 KlassHandle nullHandle;
258 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
259 }
260 static Klass* parse_stream(Symbol* class_name,
261 Handle class_loader,
262 Handle protection_domain,
263 ClassFileStream* st,
264 KlassHandle host_klass,
265 GrowableArray<Handle>* cp_patches,
266 TRAPS);
267
268 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
269 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
270 Handle protection_domain,
271 ClassFileStream* st, bool verify, TRAPS);
272
273 // Lookup an already loaded class. If not found NULL is returned.
274 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
275
276 // Lookup an already loaded instance or array class.
277 // Do not make any queries to class loaders; consult only the cache.
278 // If not found NULL is returned.
279 static Klass* find_instance_or_array_klass(Symbol* class_name,
280 Handle class_loader,
281 Handle protection_domain,
282 TRAPS);
283
284 // Lookup an instance or array class that has already been loaded
285 // either into the given class loader, or else into another class
286 // loader that is constrained (via loader constraints) to produce
287 // a consistent class. Do not take protection domains into account.
288 // Do not make any queries to class loaders; consult only the cache.
289 // Return NULL if the class is not found.
290 //
291 // This function is a strict superset of find_instance_or_array_klass.
292 // This function (the unchecked version) makes a conservative prediction
293 // of the result of the checked version, assuming successful lookup.
294 // If both functions return non-null, they must return the same value.
295 // Also, the unchecked version may sometimes be non-null where the
296 // checked version is null. This can occur in several ways:
297 // 1. No query has yet been made to the class loader.
298 // 2. The class loader was queried, but chose not to delegate.
299 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
300 // 4. Loading was attempted, but there was a linkage error of some sort.
301 // In all of these cases, the loader constraints on this type are
302 // satisfied, and it is safe for classes in the given class loader
303 // to manipulate strongly-typed values of the found class, subject
304 // to local linkage and access checks.
305 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
306 Handle class_loader,
307 TRAPS);
308
309 // Iterate over all klasses in dictionary
310 // Just the classes from defining class loaders
311 static void classes_do(void f(Klass*));
312 // Added for initialize_itable_for_klass to handle exceptions
313 static void classes_do(void f(Klass*, TRAPS), TRAPS);
314 // All classes, and their class loaders
315 static void classes_do(void f(Klass*, ClassLoaderData*));
316
317 static void placeholders_do(void f(Symbol*));
318
319 // Iterate over all methods in all klasses in dictionary
320 static void methods_do(void f(Method*));
321
322 // Garbage collection support
323
324 // This method applies "blk->do_oop" to all the pointers to "system"
325 // classes and loaders.
326 static void always_strong_oops_do(OopClosure* blk);
327 static void always_strong_classes_do(KlassClosure* closure);
328
329 // Unload (that is, break root links to) all unmarked classes and
330 // loaders. Returns "true" iff something was unloaded.
331 static bool do_unloading(BoolObjectClosure* is_alive);
332
333 static int calculate_systemdictionary_size(int loadedclasses);
334
335 // Applies "f->do_oop" to all root oops in the system dictionary.
336 static void oops_do(OopClosure* f);
337
338 // System loader lock
339 static oop system_loader_lock() { return _system_loader_lock_obj; }
340
341 private:
342 // Extended Redefine classes support (tbi)
343 static void preloaded_classes_do(KlassClosure* f);
344 static void lazily_loaded_classes_do(KlassClosure* f);
345 public:
346 // Sharing support.
347 static void reorder_dictionary();
348 static void copy_buckets(char** top, char* end);
349 static void copy_table(char** top, char* end);
350 static void reverse();
351 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
352 int number_of_entries);
353 // Printing
354 static void print() PRODUCT_RETURN;
355 static void print_class_statistics() PRODUCT_RETURN;
356 static void print_method_statistics() PRODUCT_RETURN;
357
358 // Number of contained klasses
359 // This is both fully loaded classes and classes in the process
360 // of being loaded
361 static int number_of_classes();
362
363 // Monotonically increasing counter which grows as classes are
364 // loaded or modifications such as hot-swapping or setting/removing
365 // of breakpoints are performed
366 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
367 // Needed by evolution and breakpoint code
368 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
369
370 // Verification
371 static void verify();
372
373 #ifdef ASSERT
374 static bool is_internal_format(Symbol* class_name);
375 #endif
376
377 // Verify class is in dictionary
378 static void verify_obj_klass_present(Symbol* class_name,
379 ClassLoaderData* loader_data);
380
381 // Initialization
382 static void initialize(TRAPS);
383
384 // Fast access to commonly used classes (preloaded)
385 static Klass* check_klass(Klass* k) {
386 assert(k != NULL, "preloaded klass not initialized");
387 return k;
388 }
389
390 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); }
391 static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; }
392 static Klass* check_klass_Opt( Klass* k) { return k; }
393 static Klass* check_klass_Opt_Only_JDK15(Klass* k) {
394 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
395 return k;
396 }
397 static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) {
398 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
399 // despite the optional loading, if you use this it must be present:
400 return check_klass(k);
401 }
402
403 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
404 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
405 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
406 int limit = (int)end_id + 1;
407 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
408 }
409
410 public:
411 #define WK_KLASS_DECLARE(name, symbol, option) \
412 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
413 static Klass** name##_addr() { \
414 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
415 }
416 WK_KLASSES_DO(WK_KLASS_DECLARE);
417 #undef WK_KLASS_DECLARE
418
419 static Klass* well_known_klass(WKID id) {
420 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
421 return _well_known_klasses[id];
422 }
423
424 static Klass** well_known_klass_addr(WKID id) {
425 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
426 return &_well_known_klasses[id];
427 }
428
429 // Local definition for direct access to the private array:
430 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
431
432 static Klass* box_klass(BasicType t) {
433 assert((uint)t < T_VOID+1, "range check");
434 return check_klass(_box_klasses[t]);
435 }
436 static BasicType box_klass_type(Klass* k); // inverse of box_klass
437
438 // methods returning lazily loaded klasses
439 // The corresponding method to load the class must be called before calling them.
440 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
441
442 static void load_abstract_ownable_synchronizer_klass(TRAPS);
443
444 private:
445 // Tells whether ClassLoader.loadClassInternal is present
446 static bool has_loadClassInternal() { return _has_loadClassInternal; }
447
448 // Returns the class loader data to be used when looking up/updating the
449 // system dictionary.
450 static ClassLoaderData *class_loader_data(Handle class_loader) {
451 return ClassLoaderData::class_loader_data(class_loader());
452 }
453
454 public:
455 // Tells whether ClassLoader.checkPackageAccess is present
456 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
457
458 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
459 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
460 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
461 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
462 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
463
464 // Returns default system loader
465 static oop java_system_loader();
466
467 // Compute the default system loader
468 static void compute_java_system_loader(TRAPS);
469
470 // Register a new class loader
471 static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
472 private:
473 // Mirrors for primitive classes (created eagerly)
474 static oop check_mirror(oop m) {
475 assert(m != NULL, "mirror not initialized");
476 return m;
477 }
478
479 public:
480 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
481
482 // Check class loader constraints
483 static bool add_loader_constraint(Symbol* name, Handle loader1,
484 Handle loader2, TRAPS);
485 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
486 Handle loader2, bool is_method, TRAPS);
487
488 // JSR 292
489 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
490 // (asks Java to compute it if necessary, except in a compiler thread)
491 static methodHandle find_method_handle_invoker(Symbol* name,
492 Symbol* signature,
493 KlassHandle accessing_klass,
494 Handle *appendix_result,
495 Handle *method_type_result,
496 TRAPS);
497 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
498 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
499 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
500 Symbol* signature,
501 TRAPS);
502 // find a java.lang.invoke.MethodType object for a given signature
503 // (asks Java to compute it if necessary, except in a compiler thread)
504 static Handle find_method_handle_type(Symbol* signature,
505 KlassHandle accessing_klass,
506 TRAPS);
507
508 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
509 static Handle link_method_handle_constant(KlassHandle caller,
510 int ref_kind, //e.g., JVM_REF_invokeVirtual
511 KlassHandle callee,
512 Symbol* name,
513 Symbol* signature,
514 TRAPS);
515
516 // ask Java to create a dynamic call site, while linking an invokedynamic op
517 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
518 Handle bootstrap_method,
519 Symbol* name,
520 Symbol* type,
521 Handle *appendix_result,
522 Handle *method_type_result,
523 TRAPS);
524
525 // Utility for printing loader "name" as part of tracing constraints
526 static const char* loader_name(oop loader) {
527 return ((loader) == NULL ? "<bootloader>" :
528 InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
529 }
530 static const char* loader_name(ClassLoaderData* loader_data) {
531 return (loader_data->class_loader() == NULL ? "<bootloader>" :
532 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
533 }
534
535 // Record the error when the first attempt to resolve a reference from a constant
536 // pool entry to a class fails.
537 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error);
538 static void delete_resolution_error(ConstantPool* pool);
539 static Symbol* find_resolution_error(constantPoolHandle pool, int which);
540
541 private:
542
543 enum Constants {
544 _loader_constraint_size = 107, // number of entries in constraint table
545 _resolution_error_size = 107, // number of entries in resolution error table
546 _invoke_method_size = 139, // number of entries in invoke method table
547 _nof_buckets = 1009, // number of buckets in hash table for placeholders
548 _old_default_sdsize = 1009, // backward compat for system dictionary size
549 _prime_array_size = 8, // array of primes for system dictionary size
550 _average_depth_goal = 3 // goal for lookup length
551 };
552
553
554 // Static variables
555
556 // hashtable sizes for system dictionary to allow growth
557 // prime numbers for system dictionary size
558 static int _sdgeneration;
559 static const int _primelist[_prime_array_size];
560
561 // Hashtable holding loaded classes.
562 static Dictionary* _dictionary;
563
564 // Hashtable holding placeholders for classes being loaded.
565 static PlaceholderTable* _placeholders;
566
567 // Hashtable holding classes from the shared archive.
568 static Dictionary* _shared_dictionary;
569
570 // Monotonically increasing counter which grows with
571 // _number_of_classes as well as hot-swapping and breakpoint setting
572 // and removal.
573 static int _number_of_modifications;
574
575 // Lock object for system class loader
576 static oop _system_loader_lock_obj;
577
578 // Constraints on class loaders
579 static LoaderConstraintTable* _loader_constraints;
580
581 // Resolution errors
582 static ResolutionErrorTable* _resolution_errors;
583
584 // Invoke methods (JSR 292)
585 static SymbolPropertyTable* _invoke_method_table;
586
587 public:
588 // for VM_CounterDecay iteration support
589 friend class CounterDecay;
590 static Klass* try_get_next_class();
591
592 private:
593 static void validate_protection_domain(instanceKlassHandle klass,
594 Handle class_loader,
595 Handle protection_domain, TRAPS);
596
597 friend class VM_PopulateDumpSharedSpace;
598 friend class TraversePlaceholdersClosure;
599 static Dictionary* dictionary() { return _dictionary; }
600 static Dictionary* shared_dictionary() { return _shared_dictionary; }
601 static PlaceholderTable* placeholders() { return _placeholders; }
602 static LoaderConstraintTable* constraints() { return _loader_constraints; }
603 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
604 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
605
606 // Basic loading operations
607 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
608 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
609 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
610 // Wait on SystemDictionary_lock; unlocks lockObject before
611 // waiting; relocks lockObject with correct recursion count
612 // after waiting, but before reentering SystemDictionary_lock
613 // to preserve lock order semantics.
614 static void double_lock_wait(Handle lockObject, TRAPS);
615 static void define_instance_class(instanceKlassHandle k, TRAPS);
616 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
617 Handle class_loader,
618 instanceKlassHandle k, TRAPS);
619 static instanceKlassHandle load_shared_class(Symbol* class_name,
620 Handle class_loader, TRAPS);
621 static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
622 Handle class_loader, TRAPS);
623 static void clean_up_shared_class(instanceKlassHandle ik, Handle class_loader, TRAPS);
624 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
625 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
626 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
627 static bool is_parallelCapable(Handle class_loader);
628 static bool is_parallelDefine(Handle class_loader);
629
630 public:
631 static bool is_ext_class_loader(Handle class_loader);
632
633 private:
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 // event based tracing
640 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k,
641 Handle initiating_loader);
642 // We pass in the hashtable index so we can calculate it outside of
643 // the SystemDictionary_lock.
644
645 // Basic find on loaded classes
646 static Klass* find_class(int index, unsigned int hash,
647 Symbol* name, ClassLoaderData* loader_data);
648 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
649
650 // Basic find on classes in the midst of being loaded
651 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
652
653 // Updating entry in dictionary
654 // Add a completely loaded class
655 static void add_klass(int index, Symbol* class_name,
656 ClassLoaderData* loader_data, KlassHandle obj);
657
658 // Add a placeholder for a class being loaded
659 static void add_placeholder(int index,
660 Symbol* class_name,
661 ClassLoaderData* loader_data);
662 static void remove_placeholder(int index,
663 Symbol* class_name,
664 ClassLoaderData* loader_data);
665
666 // Performs cleanups after resolve_super_or_fail. This typically needs
667 // to be called on failure.
668 // Won't throw, but can block.
669 static void resolution_cleanups(Symbol* class_name,
670 ClassLoaderData* loader_data,
671 TRAPS);
672
673 // Initialization
674 static void initialize_preloaded_classes(TRAPS);
675
676 // Class loader constraints
677 static void check_constraints(int index, unsigned int hash,
678 instanceKlassHandle k, Handle loader,
679 bool defining, TRAPS);
680 static void update_dictionary(int d_index, unsigned int d_hash,
681 int p_index, unsigned int p_hash,
682 instanceKlassHandle k, Handle loader,
683 TRAPS);
684
685 // Variables holding commonly used klasses (preloaded)
686 static Klass* _well_known_klasses[];
687
688 // Lazily loaded klasses
689 static Klass* volatile _abstract_ownable_synchronizer_klass;
690
691 // table of box klasses (int_klass, etc.)
692 static Klass* _box_klasses[T_VOID+1];
693
694 static oop _java_system_loader;
695
696 static bool _has_loadClassInternal;
697 static bool _has_checkPackageAccess;
698 };
699
700 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP