1 /*
2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
27
28 #include "classfile/classFileStream.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/symbol.hpp"
32 #include "runtime/java.hpp"
33 #include "runtime/reflectionUtils.hpp"
34 #include "utilities/hashtable.hpp"
35 #include "utilities/hashtable.inline.hpp"
36
37
38 // The system dictionary stores all loaded classes and maps:
39 //
40 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass*
41 //
42 // Classes are loaded lazily. The default VM class loader is
43 // represented as NULL.
44
45 // The underlying data structure is an open hash table with a fixed number
46 // of buckets. During loading the loader object is locked, (for the VM loader
47 // a private lock object is used). Class loading can thus be done concurrently,
48 // but only by different loaders.
49 //
50 // During loading a placeholder (name, loader) is temporarily placed in
51 // a side data structure, and is used to detect ClassCircularityErrors
52 // and to perform verification during GC. A GC can occur in the midst
53 // of class loading, as we call out to Java, have to take locks, etc.
54 //
55 // When class loading is finished, a new entry is added to the system
56 // dictionary and the place holder is removed. Note that the protection
57 // domain field of the system dictionary has not yet been filled in when
58 // the "real" system dictionary entry is created.
59 //
60 // Clients of this class who are interested in finding if a class has
61 // been completely loaded -- not classes in the process of being loaded --
62 // can read the SystemDictionary unlocked. This is safe because
63 // - entries are only deleted at safepoints
64 // - readers cannot come to a safepoint while actively examining
65 // an entry (an entry cannot be deleted from under a reader)
66 // - entries must be fully formed before they are available to concurrent
67 // readers (we must ensure write ordering)
68 //
69 // Note that placeholders are deleted at any time, as they are removed
70 // when a class is completely loaded. Therefore, readers as well as writers
71 // of placeholders must hold the SystemDictionary_lock.
72 //
73
74 class Dictionary;
75 class PlaceholderTable;
76 class LoaderConstraintTable;
77 template <MEMFLAGS F> class HashtableBucket;
78 class ResolutionErrorTable;
79 class SymbolPropertyTable;
80 class Ticks;
81
82 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
83 // They are all "well-known", in the sense that no class loader is allowed
84 // to provide a different definition.
85 //
86 // These klasses must all have names defined in vmSymbols.
87
88 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
89
90 // Each well-known class has a short klass name (like object_klass),
91 // a vmSymbol name (like java_lang_Object), and a flag word
92 // that makes some minor distinctions, like whether the klass
93 // is preloaded, optional, release-specific, etc.
94 // The order of these definitions is significant; it is the order in which
95 // preloading is actually performed by initialize_preloaded_classes.
96
97 #define WK_KLASSES_DO(do_klass) \
98 /* well-known classes */ \
99 do_klass(Object_klass, java_lang_Object, Pre ) \
100 do_klass(String_klass, java_lang_String, Pre ) \
101 do_klass(Class_klass, java_lang_Class, Pre ) \
102 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \
103 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \
104 do_klass(Serializable_klass, java_io_Serializable, Pre ) \
105 do_klass(System_klass, java_lang_System, Pre ) \
106 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \
107 do_klass(Error_klass, java_lang_Error, Pre ) \
108 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \
109 do_klass(Exception_klass, java_lang_Exception, Pre ) \
110 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \
111 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \
112 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \
113 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \
114 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \
115 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \
116 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \
117 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \
118 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \
119 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \
120 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \
121 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \
122 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \
123 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \
124 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \
125 \
126 /* Preload ref klasses and set reference types */ \
127 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \
128 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \
129 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \
130 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \
131 do_klass(Cleaner_klass, sun_misc_Cleaner, Pre ) \
132 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \
133 \
134 do_klass(Thread_klass, java_lang_Thread, Pre ) \
135 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \
136 do_klass(Properties_klass, java_util_Properties, Pre ) \
137 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \
138 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \
139 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \
140 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \
141 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \
142 \
143 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
144 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
145 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \
146 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Pre ) \
147 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Pre ) \
148 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \
149 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt ) \
150 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt ) \
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 ) \
156 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \
157 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \
158 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \
159 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \
160 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \
161 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \
162 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \
163 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \
164 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \
165 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \
166 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \
167 \
168 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \
169 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \
170 do_klass(misc_Unsafe_klass, sun_misc_Unsafe, Pre ) \
171 \
172 /* support for CDS */ \
173 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \
174 do_klass(File_klass, java_io_File, Pre ) \
175 do_klass(URLClassLoader_klass, java_net_URLClassLoader, Pre ) \
176 do_klass(URL_klass, java_net_URL, Pre ) \
177 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \
178 do_klass(sun_misc_Launcher_klass, sun_misc_Launcher, Pre ) \
179 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \
180 \
181 /* It's NULL in non-1.4 JDKs. */ \
182 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \
183 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
184 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \
185 \
186 /* Preload boxing klasses */ \
187 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \
188 do_klass(Character_klass, java_lang_Character, Pre ) \
189 do_klass(Float_klass, java_lang_Float, Pre ) \
190 do_klass(Double_klass, java_lang_Double, Pre ) \
191 do_klass(Byte_klass, java_lang_Byte, Pre ) \
192 do_klass(Short_klass, java_lang_Short, Pre ) \
193 do_klass(Integer_klass, java_lang_Integer, Pre ) \
194 do_klass(Long_klass, java_lang_Long, Pre ) \
195 /*end*/
196
197
198 class SystemDictionary : AllStatic {
199 friend class VMStructs;
200 friend class SystemDictionaryHandles;
201
202 public:
203 enum WKID {
204 NO_WKID = 0,
205
206 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
207 WK_KLASSES_DO(WK_KLASS_ENUM)
208 #undef WK_KLASS_ENUM
209
210 WKID_LIMIT,
211
212 FIRST_WKID = NO_WKID + 1
213 };
214
215 enum InitOption {
216 Pre, // preloaded; error if not present
217
218 // Order is significant. Options before this point require resolve_or_fail.
219 // Options after this point will use resolve_or_null instead.
220
221 Opt, // preload tried; NULL if not present
222 OPTION_LIMIT,
223 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
224 };
225
226
227 // Returns a class with a given class name and class loader. Loads the
228 // class if needed. If not found a NoClassDefFoundError or a
229 // ClassNotFoundException is thrown, depending on the value on the
230 // throw_error flag. For most uses the throw_error argument should be set
231 // to true.
232
233 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
234 // Convenient call for null loader and protection domain.
235 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
236 protected:
237 // handle error translation for resolve_or_null results
238 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, KlassHandle klass_h, TRAPS);
239
240 public:
241
242 // Returns a class with a given class name and class loader.
243 // Loads the class if needed. If not found NULL is returned.
244 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
245 // Version with null loader and protection domain
246 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
247
248 // Resolve a superclass or superinterface. Called from ClassFileParser,
249 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
250 // "child_name" is the class whose super class or interface is being resolved.
251 static Klass* resolve_super_or_fail(Symbol* child_name,
252 Symbol* class_name,
253 Handle class_loader,
254 Handle protection_domain,
255 bool is_superclass,
256 TRAPS);
257
258 // Parse new stream. This won't update the system dictionary or
259 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
260 static Klass* parse_stream(Symbol* class_name,
261 Handle class_loader,
262 Handle protection_domain,
263 ClassFileStream* st,
264 TRAPS) {
265 KlassHandle nullHandle;
266 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
267 }
268 static Klass* parse_stream(Symbol* class_name,
269 Handle class_loader,
270 Handle protection_domain,
271 ClassFileStream* st,
272 KlassHandle host_klass,
273 GrowableArray<Handle>* cp_patches,
274 TRAPS);
275
276 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
277 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
278 Handle protection_domain,
279 ClassFileStream* st, bool verify, TRAPS);
280
281 // Lookup an already loaded class. If not found NULL is returned.
282 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
283
284 // Lookup an already loaded instance or array class.
285 // Do not make any queries to class loaders; consult only the cache.
286 // If not found NULL is returned.
287 static Klass* find_instance_or_array_klass(Symbol* class_name,
288 Handle class_loader,
289 Handle protection_domain,
290 TRAPS);
291
292 // Lookup an instance or array class that has already been loaded
293 // either into the given class loader, or else into another class
294 // loader that is constrained (via loader constraints) to produce
295 // a consistent class. Do not take protection domains into account.
296 // Do not make any queries to class loaders; consult only the cache.
297 // Return NULL if the class is not found.
298 //
299 // This function is a strict superset of find_instance_or_array_klass.
300 // This function (the unchecked version) makes a conservative prediction
301 // of the result of the checked version, assuming successful lookup.
302 // If both functions return non-null, they must return the same value.
303 // Also, the unchecked version may sometimes be non-null where the
304 // checked version is null. This can occur in several ways:
305 // 1. No query has yet been made to the class loader.
306 // 2. The class loader was queried, but chose not to delegate.
307 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
308 // 4. Loading was attempted, but there was a linkage error of some sort.
309 // In all of these cases, the loader constraints on this type are
310 // satisfied, and it is safe for classes in the given class loader
311 // to manipulate strongly-typed values of the found class, subject
312 // to local linkage and access checks.
313 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
314 Handle class_loader,
315 TRAPS);
316
317 // Iterate over all klasses in dictionary
318 // Just the classes from defining class loaders
319 static void classes_do(void f(Klass*));
320 // Added for initialize_itable_for_klass to handle exceptions
321 static void classes_do(void f(Klass*, TRAPS), TRAPS);
322 // All classes, and their class loaders
323 static void classes_do(void f(Klass*, ClassLoaderData*));
324
325 static void placeholders_do(void f(Symbol*));
326
327 // Iterate over all methods in all klasses in dictionary
328 static void methods_do(void f(Method*));
329
330 // Garbage collection support
331
332 // This method applies "blk->do_oop" to all the pointers to "system"
333 // classes and loaders.
334 static void always_strong_oops_do(OopClosure* blk);
335 static void always_strong_classes_do(KlassClosure* closure);
336
337 // Unload (that is, break root links to) all unmarked classes and
338 // loaders. Returns "true" iff something was unloaded.
339 static bool do_unloading(BoolObjectClosure* is_alive,
340 bool clean_previous_versions = true);
341
342 // Used by DumpSharedSpaces only to remove classes that failed verification
343 static void remove_classes_in_error_state();
344
345 static int calculate_systemdictionary_size(int loadedclasses);
346
347 // Applies "f->do_oop" to all root oops in the system dictionary.
348 static void oops_do(OopClosure* f);
349 static void roots_oops_do(OopClosure* strong, OopClosure* weak);
350
351 // System loader lock
352 static oop system_loader_lock() { return _system_loader_lock_obj; }
353
354 protected:
355 // Extended Redefine classes support (tbi)
356 static void preloaded_classes_do(KlassClosure* f);
357 static void lazily_loaded_classes_do(KlassClosure* f);
358 public:
359 // Sharing support.
360 static void reorder_dictionary();
361 static void copy_buckets(char** top, char* end);
362 static void copy_table(char** top, char* end);
363 static void reverse();
364 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
365 int number_of_entries);
366 // Printing
367 static void print(bool details = true);
368 static void print_shared(bool details = true);
369
370 // Number of contained klasses
371 // This is both fully loaded classes and classes in the process
372 // of being loaded
373 static int number_of_classes();
374
375 // Monotonically increasing counter which grows as classes are
376 // loaded or modifications such as hot-swapping or setting/removing
377 // of breakpoints are performed
378 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
379 // Needed by evolution and breakpoint code
380 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
381
382 // Verification
383 static void verify();
384
385 #ifdef ASSERT
386 static bool is_internal_format(Symbol* class_name);
387 #endif
388
389 // Initialization
390 static void initialize(TRAPS);
391
392 // Fast access to commonly used classes (preloaded)
393 static Klass* check_klass(Klass* k) {
394 assert(k != NULL, "preloaded klass not initialized");
395 return k;
396 }
397
398 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); }
399 static Klass* check_klass_Opt( Klass* k) { return k; }
400
401 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
402 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
403 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
404 int limit = (int)end_id + 1;
405 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
406 }
407
408 public:
409 #define WK_KLASS_DECLARE(name, symbol, option) \
410 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
411 static Klass** name##_addr() { \
412 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
413 }
414 WK_KLASSES_DO(WK_KLASS_DECLARE);
415 #undef WK_KLASS_DECLARE
416
417 static Klass* well_known_klass(WKID id) {
418 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
419 return _well_known_klasses[id];
420 }
421
422 static Klass** well_known_klass_addr(WKID id) {
423 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
424 return &_well_known_klasses[id];
425 }
426
427 // Local definition for direct access to the private array:
428 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
429
430 static Klass* box_klass(BasicType t) {
431 assert((uint)t < T_VOID+1, "range check");
432 return check_klass(_box_klasses[t]);
433 }
434 static BasicType box_klass_type(Klass* k); // inverse of box_klass
435
436 // methods returning lazily loaded klasses
437 // The corresponding method to load the class must be called before calling them.
438 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
439
440 static void load_abstract_ownable_synchronizer_klass(TRAPS);
441
442 protected:
443 // Tells whether ClassLoader.loadClassInternal is present
444 static bool has_loadClassInternal() { return _has_loadClassInternal; }
445
446 // Returns the class loader data to be used when looking up/updating the
447 // system dictionary.
448 static ClassLoaderData *class_loader_data(Handle class_loader) {
449 return ClassLoaderData::class_loader_data(class_loader());
450 }
451
452 public:
453 // Tells whether ClassLoader.checkPackageAccess is present
454 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
455
456 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
457 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
458 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
459 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
460 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
461
462 // Returns default system loader
463 static oop java_system_loader();
464
465 // Compute the default system loader
466 static void compute_java_system_loader(TRAPS);
467
468 // Register a new class loader
469 static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
470 protected:
471 // Mirrors for primitive classes (created eagerly)
472 static oop check_mirror(oop m) {
473 assert(m != NULL, "mirror not initialized");
474 return m;
475 }
476
477 public:
478 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
479
480 // Check class loader constraints
481 static bool add_loader_constraint(Symbol* name, Handle loader1,
482 Handle loader2, TRAPS);
483 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
484 Handle loader2, bool is_method, TRAPS);
485
486 // JSR 292
487 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
488 // (asks Java to compute it if necessary, except in a compiler thread)
489 static methodHandle find_method_handle_invoker(Symbol* name,
490 Symbol* signature,
491 KlassHandle accessing_klass,
492 Handle *appendix_result,
493 Handle *method_type_result,
494 TRAPS);
495 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
496 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
497 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
498 Symbol* signature,
499 TRAPS);
500 // find a java.lang.invoke.MethodType object for a given signature
501 // (asks Java to compute it if necessary, except in a compiler thread)
502 static Handle find_method_handle_type(Symbol* signature,
503 KlassHandle accessing_klass,
504 TRAPS);
505
506 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
507 static Handle link_method_handle_constant(KlassHandle caller,
508 int ref_kind, //e.g., JVM_REF_invokeVirtual
509 KlassHandle callee,
510 Symbol* name,
511 Symbol* signature,
512 TRAPS);
513
514 // ask Java to create a dynamic call site, while linking an invokedynamic op
515 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
516 Handle bootstrap_method,
517 Symbol* name,
518 Symbol* type,
519 Handle *appendix_result,
520 Handle *method_type_result,
521 TRAPS);
522
523 // Utility for printing loader "name" as part of tracing constraints
524 static const char* loader_name(oop loader) {
525 return ((loader) == NULL ? "<bootloader>" :
526 InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
527 }
528 static const char* loader_name(ClassLoaderData* loader_data) {
529 return (loader_data->class_loader() == NULL ? "<bootloader>" :
530 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
531 }
532
533 // Record the error when the first attempt to resolve a reference from a constant
534 // pool entry to a class fails.
535 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error,
536 Symbol* message);
537 static void delete_resolution_error(ConstantPool* pool);
538 static Symbol* find_resolution_error(constantPoolHandle pool, int which,
539 Symbol** message);
540
541 protected:
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 protected:
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(instanceKlassHandle ik,
620 Handle class_loader,
621 Handle protection_domain,
622 TRAPS);
623 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
624 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
625 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
626 static bool is_parallelCapable(Handle class_loader);
627 static bool is_parallelDefine(Handle class_loader);
628
629 public:
630 static instanceKlassHandle load_shared_class(Symbol* class_name,
631 Handle class_loader,
632 TRAPS);
633 static bool is_ext_class_loader(Handle class_loader);
634
635 protected:
636 static Klass* find_shared_class(Symbol* class_name);
637
638 // Setup link to hierarchy
639 static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
640
641 // event based tracing
642 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k,
643 Handle initiating_loader);
644 // We pass in the hashtable index so we can calculate it outside of
645 // the SystemDictionary_lock.
646
647 // Basic find on loaded classes
648 static Klass* find_class(int index, unsigned int hash,
649 Symbol* name, ClassLoaderData* loader_data);
650 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
651
652 // Basic find on classes in the midst of being loaded
653 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
654
655 // Updating entry in dictionary
656 // Add a completely loaded class
657 static void add_klass(int index, Symbol* class_name,
658 ClassLoaderData* loader_data, KlassHandle obj);
659
660 // Add a placeholder for a class being loaded
661 static void add_placeholder(int index,
662 Symbol* class_name,
663 ClassLoaderData* loader_data);
664 static void remove_placeholder(int index,
665 Symbol* class_name,
666 ClassLoaderData* loader_data);
667
668 // Performs cleanups after resolve_super_or_fail. This typically needs
669 // to be called on failure.
670 // Won't throw, but can block.
671 static void resolution_cleanups(Symbol* class_name,
672 ClassLoaderData* loader_data,
673 TRAPS);
674
675 // Initialization
676 static void initialize_preloaded_classes(TRAPS);
677
678 // Class loader constraints
679 static void check_constraints(int index, unsigned int hash,
680 instanceKlassHandle k, Handle loader,
681 bool defining, TRAPS);
682 static void update_dictionary(int d_index, unsigned int d_hash,
683 int p_index, unsigned int p_hash,
684 instanceKlassHandle k, Handle loader,
685 TRAPS);
686
687 // Variables holding commonly used klasses (preloaded)
688 static Klass* _well_known_klasses[];
689
690 // Lazily loaded klasses
691 static Klass* volatile _abstract_ownable_synchronizer_klass;
692
693 // table of box klasses (int_klass, etc.)
694 static Klass* _box_klasses[T_VOID+1];
695
696 static oop _java_system_loader;
697
698 static bool _has_loadClassInternal;
699 static bool _has_checkPackageAccess;
700 };
701
702 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP