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 do_klass(PostVMInitHook_klass, sun_misc_PostVMInitHook, Opt ) \
177 \
178 /* Preload boxing klasses */ \
179 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \
180 do_klass(Character_klass, java_lang_Character, Pre ) \
181 do_klass(Float_klass, java_lang_Float, Pre ) \
182 do_klass(Double_klass, java_lang_Double, Pre ) \
183 do_klass(Byte_klass, java_lang_Byte, Pre ) \
184 do_klass(Short_klass, java_lang_Short, Pre ) \
185 do_klass(Integer_klass, java_lang_Integer, Pre ) \
186 do_klass(Long_klass, java_lang_Long, Pre ) \
187 /*end*/
188
189
190 class SystemDictionary : AllStatic {
191 friend class VMStructs;
192 friend class SystemDictionaryHandles;
193
194 public:
195 enum WKID {
196 NO_WKID = 0,
197
198 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
199 WK_KLASSES_DO(WK_KLASS_ENUM)
200 #undef WK_KLASS_ENUM
201
202 WKID_LIMIT,
203
204 FIRST_WKID = NO_WKID + 1
205 };
206
207 enum InitOption {
208 Pre, // preloaded; error if not present
209 Pre_JSR292, // preloaded if EnableInvokeDynamic
210
211 // Order is significant. Options before this point require resolve_or_fail.
212 // Options after this point will use resolve_or_null instead.
213
214 Opt, // preload tried; NULL if not present
215 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection
216 Opt_Only_JDK15, // preload tried; use only with JDK1.5+
217 OPTION_LIMIT,
218 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
219 };
220
221
222 // Returns a class with a given class name and class loader. Loads the
223 // class if needed. If not found a NoClassDefFoundError or a
224 // ClassNotFoundException is thrown, depending on the value on the
225 // throw_error flag. For most uses the throw_error argument should be set
226 // to true.
227
228 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
229 // Convenient call for null loader and protection domain.
230 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
231 private:
232 // handle error translation for resolve_or_null results
233 static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
234
235 public:
236
237 // Returns a class with a given class name and class loader.
238 // Loads the class if needed. If not found NULL is returned.
239 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
240 // Version with null loader and protection domain
241 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
242
243 // Resolve a superclass or superinterface. Called from ClassFileParser,
244 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
245 // "child_name" is the class whose super class or interface is being resolved.
246 static Klass* resolve_super_or_fail(Symbol* child_name,
247 Symbol* class_name,
248 Handle class_loader,
249 Handle protection_domain,
250 bool is_superclass,
251 TRAPS);
252
253 // Parse new stream. This won't update the system dictionary or
254 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
255 static Klass* parse_stream(Symbol* class_name,
256 Handle class_loader,
257 Handle protection_domain,
258 ClassFileStream* st,
259 TRAPS) {
260 KlassHandle nullHandle;
261 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
262 }
263 static Klass* parse_stream(Symbol* class_name,
264 Handle class_loader,
265 Handle protection_domain,
266 ClassFileStream* st,
267 KlassHandle host_klass,
268 GrowableArray<Handle>* cp_patches,
269 TRAPS);
270
271 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
272 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
273 Handle protection_domain,
274 ClassFileStream* st, bool verify, TRAPS);
275
276 // Lookup an already loaded class. If not found NULL is returned.
277 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
278
279 // Lookup an already loaded instance or array class.
280 // Do not make any queries to class loaders; consult only the cache.
281 // If not found NULL is returned.
282 static Klass* find_instance_or_array_klass(Symbol* class_name,
283 Handle class_loader,
284 Handle protection_domain,
285 TRAPS);
286
287 // Lookup an instance or array class that has already been loaded
288 // either into the given class loader, or else into another class
289 // loader that is constrained (via loader constraints) to produce
290 // a consistent class. Do not take protection domains into account.
291 // Do not make any queries to class loaders; consult only the cache.
292 // Return NULL if the class is not found.
293 //
294 // This function is a strict superset of find_instance_or_array_klass.
295 // This function (the unchecked version) makes a conservative prediction
296 // of the result of the checked version, assuming successful lookup.
297 // If both functions return non-null, they must return the same value.
298 // Also, the unchecked version may sometimes be non-null where the
299 // checked version is null. This can occur in several ways:
300 // 1. No query has yet been made to the class loader.
301 // 2. The class loader was queried, but chose not to delegate.
302 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
303 // 4. Loading was attempted, but there was a linkage error of some sort.
304 // In all of these cases, the loader constraints on this type are
305 // satisfied, and it is safe for classes in the given class loader
306 // to manipulate strongly-typed values of the found class, subject
307 // to local linkage and access checks.
308 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
309 Handle class_loader,
310 TRAPS);
311
312 // Iterate over all klasses in dictionary
313 // Just the classes from defining class loaders
314 static void classes_do(void f(Klass*));
315 // Added for initialize_itable_for_klass to handle exceptions
316 static void classes_do(void f(Klass*, TRAPS), TRAPS);
317 // All classes, and their class loaders
318 static void classes_do(void f(Klass*, ClassLoaderData*));
319
320 static void placeholders_do(void f(Symbol*));
321
322 // Iterate over all methods in all klasses in dictionary
323 static void methods_do(void f(Method*));
324
325 // Garbage collection support
326
327 // This method applies "blk->do_oop" to all the pointers to "system"
328 // classes and loaders.
329 static void always_strong_oops_do(OopClosure* blk);
330 static void always_strong_classes_do(KlassClosure* closure);
331
332 // Unload (that is, break root links to) all unmarked classes and
333 // loaders. Returns "true" iff something was unloaded.
334 static bool do_unloading(BoolObjectClosure* is_alive);
335
336 static int calculate_systemdictionary_size(int loadedclasses);
337
338 // Applies "f->do_oop" to all root oops in the system dictionary.
339 static void oops_do(OopClosure* f);
340
341 // System loader lock
342 static oop system_loader_lock() { return _system_loader_lock_obj; }
343
344 private:
345 // Extended Redefine classes support (tbi)
346 static void preloaded_classes_do(KlassClosure* f);
347 static void lazily_loaded_classes_do(KlassClosure* f);
348 public:
349 // Sharing support.
350 static void reorder_dictionary();
351 static void copy_buckets(char** top, char* end);
352 static void copy_table(char** top, char* end);
353 static void reverse();
354 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
355 int number_of_entries);
356 // Printing
357 static void print() PRODUCT_RETURN;
358 static void print_class_statistics() PRODUCT_RETURN;
359 static void print_method_statistics() PRODUCT_RETURN;
360
361 // Number of contained klasses
362 // This is both fully loaded classes and classes in the process
363 // of being loaded
364 static int number_of_classes();
365
366 // Monotonically increasing counter which grows as classes are
367 // loaded or modifications such as hot-swapping or setting/removing
368 // of breakpoints are performed
369 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
370 // Needed by evolution and breakpoint code
371 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
372
373 // Verification
374 static void verify();
375
376 #ifdef ASSERT
377 static bool is_internal_format(Symbol* class_name);
378 #endif
379
380 // Verify class is in dictionary
381 static void verify_obj_klass_present(Symbol* class_name,
382 ClassLoaderData* loader_data);
383
384 // Initialization
385 static void initialize(TRAPS);
386
387 // Fast access to commonly used classes (preloaded)
388 static Klass* check_klass(Klass* k) {
389 assert(k != NULL, "preloaded klass not initialized");
390 return k;
391 }
392
393 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); }
394 static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; }
395 static Klass* check_klass_Opt( Klass* k) { return k; }
396 static Klass* check_klass_Opt_Only_JDK15(Klass* k) {
397 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
398 return k;
399 }
400 static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) {
401 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
402 // despite the optional loading, if you use this it must be present:
403 return check_klass(k);
404 }
405
406 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
407 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
408 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
409 int limit = (int)end_id + 1;
410 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
411 }
412
413 public:
414 #define WK_KLASS_DECLARE(name, symbol, option) \
415 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
416 static Klass** name##_addr() { \
417 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
418 }
419 WK_KLASSES_DO(WK_KLASS_DECLARE);
420 #undef WK_KLASS_DECLARE
421
422 static Klass* well_known_klass(WKID id) {
423 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
424 return _well_known_klasses[id];
425 }
426
427 static Klass** well_known_klass_addr(WKID id) {
428 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
429 return &_well_known_klasses[id];
430 }
431
432 // Local definition for direct access to the private array:
433 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
434
435 static Klass* box_klass(BasicType t) {
436 assert((uint)t < T_VOID+1, "range check");
437 return check_klass(_box_klasses[t]);
438 }
439 static BasicType box_klass_type(Klass* k); // inverse of box_klass
440
441 // methods returning lazily loaded klasses
442 // The corresponding method to load the class must be called before calling them.
443 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
444
445 static void load_abstract_ownable_synchronizer_klass(TRAPS);
446
447 private:
448 // Tells whether ClassLoader.loadClassInternal is present
449 static bool has_loadClassInternal() { return _has_loadClassInternal; }
450
451 // Returns the class loader data to be used when looking up/updating the
452 // system dictionary.
453 static ClassLoaderData *class_loader_data(Handle class_loader) {
454 return ClassLoaderData::class_loader_data(class_loader());
455 }
456
457 public:
458 // Tells whether ClassLoader.checkPackageAccess is present
459 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
460
461 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
462 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
463 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
464 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
465 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
466
467 // Returns default system loader
468 static oop java_system_loader();
469
470 // Compute the default system loader
471 static void compute_java_system_loader(TRAPS);
472
473 // Register a new class loader
474 static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
475 private:
476 // Mirrors for primitive classes (created eagerly)
477 static oop check_mirror(oop m) {
478 assert(m != NULL, "mirror not initialized");
479 return m;
480 }
481
482 public:
483 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
484
485 // Check class loader constraints
486 static bool add_loader_constraint(Symbol* name, Handle loader1,
487 Handle loader2, TRAPS);
488 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
489 Handle loader2, bool is_method, TRAPS);
490
491 // JSR 292
492 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
493 // (asks Java to compute it if necessary, except in a compiler thread)
494 static methodHandle find_method_handle_invoker(Symbol* name,
495 Symbol* signature,
496 KlassHandle accessing_klass,
497 Handle *appendix_result,
498 Handle *method_type_result,
499 TRAPS);
500 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
501 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
502 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
503 Symbol* signature,
504 TRAPS);
505 // find a java.lang.invoke.MethodType object for a given signature
506 // (asks Java to compute it if necessary, except in a compiler thread)
507 static Handle find_method_handle_type(Symbol* signature,
508 KlassHandle accessing_klass,
509 TRAPS);
510
511 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
512 static Handle link_method_handle_constant(KlassHandle caller,
513 int ref_kind, //e.g., JVM_REF_invokeVirtual
514 KlassHandle callee,
515 Symbol* name,
516 Symbol* signature,
517 TRAPS);
518
519 // ask Java to create a dynamic call site, while linking an invokedynamic op
520 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
521 Handle bootstrap_method,
522 Symbol* name,
523 Symbol* type,
524 Handle *appendix_result,
525 Handle *method_type_result,
526 TRAPS);
527
528 // Utility for printing loader "name" as part of tracing constraints
529 static const char* loader_name(oop loader) {
530 return ((loader) == NULL ? "<bootloader>" :
531 InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
532 }
533 static const char* loader_name(ClassLoaderData* loader_data) {
534 return (loader_data->class_loader() == NULL ? "<bootloader>" :
535 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
536 }
537
538 // Record the error when the first attempt to resolve a reference from a constant
539 // pool entry to a class fails.
540 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error);
541 static void delete_resolution_error(ConstantPool* pool);
542 static Symbol* find_resolution_error(constantPoolHandle pool, int which);
543
544 private:
545
546 enum Constants {
547 _loader_constraint_size = 107, // number of entries in constraint table
548 _resolution_error_size = 107, // number of entries in resolution error table
549 _invoke_method_size = 139, // number of entries in invoke method table
550 _nof_buckets = 1009, // number of buckets in hash table for placeholders
551 _old_default_sdsize = 1009, // backward compat for system dictionary size
552 _prime_array_size = 8, // array of primes for system dictionary size
553 _average_depth_goal = 3 // goal for lookup length
554 };
555
556
557 // Static variables
558
559 // hashtable sizes for system dictionary to allow growth
560 // prime numbers for system dictionary size
561 static int _sdgeneration;
562 static const int _primelist[_prime_array_size];
563
564 // Hashtable holding loaded classes.
565 static Dictionary* _dictionary;
566
567 // Hashtable holding placeholders for classes being loaded.
568 static PlaceholderTable* _placeholders;
569
570 // Hashtable holding classes from the shared archive.
571 static Dictionary* _shared_dictionary;
572
573 // Monotonically increasing counter which grows with
574 // _number_of_classes as well as hot-swapping and breakpoint setting
575 // and removal.
576 static int _number_of_modifications;
577
578 // Lock object for system class loader
579 static oop _system_loader_lock_obj;
580
581 // Constraints on class loaders
582 static LoaderConstraintTable* _loader_constraints;
583
584 // Resolution errors
585 static ResolutionErrorTable* _resolution_errors;
586
587 // Invoke methods (JSR 292)
588 static SymbolPropertyTable* _invoke_method_table;
589
590 public:
591 // for VM_CounterDecay iteration support
592 friend class CounterDecay;
593 static Klass* try_get_next_class();
594
595 private:
596 static void validate_protection_domain(instanceKlassHandle klass,
597 Handle class_loader,
598 Handle protection_domain, TRAPS);
599
600 friend class VM_PopulateDumpSharedSpace;
601 friend class TraversePlaceholdersClosure;
602 static Dictionary* dictionary() { return _dictionary; }
603 static Dictionary* shared_dictionary() { return _shared_dictionary; }
604 static PlaceholderTable* placeholders() { return _placeholders; }
605 static LoaderConstraintTable* constraints() { return _loader_constraints; }
606 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
607 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
608
609 // Basic loading operations
610 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
611 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
612 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
613 // Wait on SystemDictionary_lock; unlocks lockObject before
614 // waiting; relocks lockObject with correct recursion count
615 // after waiting, but before reentering SystemDictionary_lock
616 // to preserve lock order semantics.
617 static void double_lock_wait(Handle lockObject, TRAPS);
618 static void define_instance_class(instanceKlassHandle k, TRAPS);
619 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
620 Handle class_loader,
621 instanceKlassHandle k, TRAPS);
622 static instanceKlassHandle load_shared_class(Symbol* class_name,
623 Handle class_loader, TRAPS);
624 static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
625 Handle class_loader, TRAPS);
626 static void clean_up_shared_class(instanceKlassHandle ik, Handle class_loader, TRAPS);
627 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
628 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
629 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
630 static bool is_parallelCapable(Handle class_loader);
631 static bool is_parallelDefine(Handle class_loader);
632
633 public:
634 static bool is_ext_class_loader(Handle class_loader);
635
636 private:
637 static Klass* find_shared_class(Symbol* class_name);
638
639 // Setup link to hierarchy
640 static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
641
642 // event based tracing
643 static void post_class_load_event(TracingTime start_time, instanceKlassHandle k,
644 Handle initiating_loader);
645 // We pass in the hashtable index so we can calculate it outside of
646 // the SystemDictionary_lock.
647
648 // Basic find on loaded classes
649 static Klass* find_class(int index, unsigned int hash,
650 Symbol* name, ClassLoaderData* loader_data);
651 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
652
653 // Basic find on classes in the midst of being loaded
654 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
655
656 // Updating entry in dictionary
657 // Add a completely loaded class
658 static void add_klass(int index, Symbol* class_name,
659 ClassLoaderData* loader_data, KlassHandle obj);
660
661 // Add a placeholder for a class being loaded
662 static void add_placeholder(int index,
663 Symbol* class_name,
664 ClassLoaderData* loader_data);
665 static void remove_placeholder(int index,
666 Symbol* class_name,
667 ClassLoaderData* loader_data);
668
669 // Performs cleanups after resolve_super_or_fail. This typically needs
670 // to be called on failure.
671 // Won't throw, but can block.
672 static void resolution_cleanups(Symbol* class_name,
673 ClassLoaderData* loader_data,
674 TRAPS);
675
676 // Initialization
677 static void initialize_preloaded_classes(TRAPS);
678
679 // Class loader constraints
680 static void check_constraints(int index, unsigned int hash,
681 instanceKlassHandle k, Handle loader,
682 bool defining, TRAPS);
683 static void update_dictionary(int d_index, unsigned int d_hash,
684 int p_index, unsigned int p_hash,
685 instanceKlassHandle k, Handle loader,
686 TRAPS);
687
688 // Variables holding commonly used klasses (preloaded)
689 static Klass* _well_known_klasses[];
690
691 // Lazily loaded klasses
692 static Klass* volatile _abstract_ownable_synchronizer_klass;
693
694 // table of box klasses (int_klass, etc.)
695 static Klass* _box_klasses[T_VOID+1];
696
697 static oop _java_system_loader;
698
699 static bool _has_loadClassInternal;
700 static bool _has_checkPackageAccess;
701 };
702
703 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP