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