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.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
27
28 #include "classfile/classFileStream.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/symbol.hpp"
32 #include "runtime/java.hpp"
33 #include "runtime/reflectionUtils.hpp"
34 #include "utilities/hashtable.hpp"
35 #include "utilities/hashtable.inline.hpp"
36
37
38 // The system dictionary stores all loaded classes and maps:
39 //
40 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass*
41 //
42 // Classes are loaded lazily. The default VM class loader is
43 // represented as NULL.
44
45 // The underlying data structure is an open hash table with a fixed number
46 // of buckets. During loading the loader object is locked, (for the VM loader
47 // a private lock object is used). Class loading can thus be done concurrently,
48 // but only by different loaders.
49 //
50 // During loading a placeholder (name, loader) is temporarily placed in
51 // a side data structure, and is used to detect ClassCircularityErrors
52 // and to perform verification during GC. A GC can occur in the midst
53 // of class loading, as we call out to Java, have to take locks, etc.
54 //
55 // When class loading is finished, a new entry is added to the system
56 // dictionary and the place holder is removed. Note that the protection
57 // domain field of the system dictionary has not yet been filled in when
58 // the "real" system dictionary entry is created.
59 //
60 // Clients of this class who are interested in finding if a class has
61 // been completely loaded -- not classes in the process of being loaded --
62 // can read the SystemDictionary unlocked. This is safe because
63 // - entries are only deleted at safepoints
64 // - readers cannot come to a safepoint while actively examining
65 // an entry (an entry cannot be deleted from under a reader)
66 // - entries must be fully formed before they are available to concurrent
67 // readers (we must ensure write ordering)
68 //
69 // Note that placeholders are deleted at any time, as they are removed
70 // when a class is completely loaded. Therefore, readers as well as writers
71 // of placeholders must hold the SystemDictionary_lock.
72 //
73
74 class Dictionary;
75 class PlaceholderTable;
76 class LoaderConstraintTable;
77 template <MEMFLAGS F> class HashtableBucket;
78 class ResolutionErrorTable;
79 class SymbolPropertyTable;
80 class Ticks;
81
82 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
83 // They are all "well-known", in the sense that no class loader is allowed
84 // to provide a different definition.
85 //
86 // These klasses must all have names defined in vmSymbols.
87
88 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
89
90 // Each well-known class has a short klass name (like object_klass),
91 // a vmSymbol name (like java_lang_Object), and a flag word
92 // that makes some minor distinctions, like whether the klass
93 // is preloaded, optional, release-specific, etc.
94 // The order of these definitions is significant; it is the order in which
95 // preloading is actually performed by initialize_preloaded_classes.
96
97 #define WK_KLASSES_DO(do_klass) \
98 /* well-known classes */ \
99 do_klass(Object_klass, java_lang_Object, Pre ) \
100 do_klass(String_klass, java_lang_String, Pre ) \
101 do_klass(Class_klass, java_lang_Class, Pre ) \
102 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \
103 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \
104 do_klass(Serializable_klass, java_io_Serializable, Pre ) \
105 do_klass(System_klass, java_lang_System, Pre ) \
106 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \
107 do_klass(Error_klass, java_lang_Error, Pre ) \
108 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \
109 do_klass(Exception_klass, java_lang_Exception, Pre ) \
110 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \
111 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \
112 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \
113 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \
114 do_klass(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_Module_klass, java_lang_reflect_Module, Pre ) \
140 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \
141 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \
142 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \
143 \
144 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
145 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
146 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \
147 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Pre ) \
148 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Pre ) \
149 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \
150 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt ) \
151 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt ) \
152 do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \
153 \
154 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
155 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \
156 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \
157 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \
158 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \
159 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \
160 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \
161 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \
162 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \
163 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \
164 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \
165 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \
166 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \
167 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \
168 \
169 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \
170 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \
171 do_klass(misc_Unsafe_klass, sun_misc_Unsafe, Pre ) \
172 do_klass(misc_Modules_klass, jdk_internal_misc_Modules, Pre ) \
173 \
174 /* support for CDS */ \
175 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \
176 do_klass(File_klass, java_io_File, Pre ) \
177 do_klass(URL_klass, java_net_URL, Pre ) \
178 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \
179 do_klass(jdk_internal_misc_ClassLoaders_AppClassLoader_klass, jdk_internal_misc_ClassLoaders_AppClassLoader, Pre ) \
180 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \
181 do_klass(ParseUtil_klass, sun_net_www_ParseUtil, Pre ) \
182 \
183 /* It's NULL in non-1.4 JDKs. */ \
184 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \
185 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
186 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \
187 \
188 /* Preload boxing klasses */ \
189 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \
190 do_klass(Character_klass, java_lang_Character, Pre ) \
191 do_klass(Float_klass, java_lang_Float, Pre ) \
192 do_klass(Double_klass, java_lang_Double, Pre ) \
193 do_klass(Byte_klass, java_lang_Byte, Pre ) \
194 do_klass(Short_klass, java_lang_Short, Pre ) \
195 do_klass(Integer_klass, java_lang_Integer, Pre ) \
196 do_klass(Long_klass, java_lang_Long, Pre ) \
197 /*end*/
198
199
200 class SystemDictionary : AllStatic {
201 friend class VMStructs;
202 friend class SystemDictionaryHandles;
203
204 public:
205 enum WKID {
206 NO_WKID = 0,
207
208 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
209 WK_KLASSES_DO(WK_KLASS_ENUM)
210 #undef WK_KLASS_ENUM
211
212 WKID_LIMIT,
213
214 FIRST_WKID = NO_WKID + 1
215 };
216
217 enum InitOption {
218 Pre, // preloaded; error if not present
219
220 // Order is significant. Options before this point require resolve_or_fail.
221 // Options after this point will use resolve_or_null instead.
222
223 Opt, // preload tried; NULL if not present
224 OPTION_LIMIT,
225 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
226 };
227
228
229 // Returns a class with a given class name and class loader. Loads the
230 // class if needed. If not found a NoClassDefFoundError or a
231 // ClassNotFoundException is thrown, depending on the value on the
232 // throw_error flag. For most uses the throw_error argument should be set
233 // to true.
234
235 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
236 // Convenient call for null loader and protection domain.
237 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
238 protected:
239 // handle error translation for resolve_or_null results
240 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, KlassHandle klass_h, TRAPS);
241
242 public:
243
244 // Returns a class with a given class name and class loader.
245 // Loads the class if needed. If not found NULL is returned.
246 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
247 // Version with null loader and protection domain
248 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
249
250 // Resolve a superclass or superinterface. Called from ClassFileParser,
251 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
252 // "child_name" is the class whose super class or interface is being resolved.
253 static Klass* resolve_super_or_fail(Symbol* child_name,
254 Symbol* class_name,
255 Handle class_loader,
256 Handle protection_domain,
257 bool is_superclass,
258 TRAPS);
259
260 // Parse new stream. This won't update the system dictionary or
261 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
262 static Klass* parse_stream(Symbol* class_name,
263 Handle class_loader,
264 Handle protection_domain,
265 ClassFileStream* st,
266 TRAPS) {
267 KlassHandle nullHandle;
268 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
269 }
270 static Klass* parse_stream(Symbol* class_name,
271 Handle class_loader,
272 Handle protection_domain,
273 ClassFileStream* st,
274 KlassHandle host_klass,
275 GrowableArray<Handle>* cp_patches,
276 TRAPS);
277
278 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
279 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
280 Handle protection_domain,
281 ClassFileStream* st, bool verify, TRAPS);
282
283 // Lookup an already loaded class. If not found NULL is returned.
284 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
285
286 // Lookup an already loaded instance or array class.
287 // Do not make any queries to class loaders; consult only the cache.
288 // If not found NULL is returned.
289 static Klass* find_instance_or_array_klass(Symbol* class_name,
290 Handle class_loader,
291 Handle protection_domain,
292 TRAPS);
293
294 // Lookup an instance or array class that has already been loaded
295 // either into the given class loader, or else into another class
296 // loader that is constrained (via loader constraints) to produce
297 // a consistent class. Do not take protection domains into account.
298 // Do not make any queries to class loaders; consult only the cache.
299 // Return NULL if the class is not found.
300 //
301 // This function is a strict superset of find_instance_or_array_klass.
302 // This function (the unchecked version) makes a conservative prediction
303 // of the result of the checked version, assuming successful lookup.
304 // If both functions return non-null, they must return the same value.
305 // Also, the unchecked version may sometimes be non-null where the
306 // checked version is null. This can occur in several ways:
307 // 1. No query has yet been made to the class loader.
308 // 2. The class loader was queried, but chose not to delegate.
309 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
310 // 4. Loading was attempted, but there was a linkage error of some sort.
311 // In all of these cases, the loader constraints on this type are
312 // satisfied, and it is safe for classes in the given class loader
313 // to manipulate strongly-typed values of the found class, subject
314 // to local linkage and access checks.
315 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
316 Handle class_loader,
317 TRAPS);
318
319 // Iterate over all klasses in dictionary
320 // Just the classes from defining class loaders
321 static void classes_do(void f(Klass*));
322 // Added for initialize_itable_for_klass to handle exceptions
323 static void classes_do(void f(Klass*, TRAPS), TRAPS);
324 // All classes, and their class loaders
325 static void classes_do(void f(Klass*, ClassLoaderData*));
326
327 static void placeholders_do(void f(Symbol*));
328
329 // Iterate over all methods in all klasses in dictionary
330 static void methods_do(void f(Method*));
331
332 // Garbage collection support
333
334 // This method applies "blk->do_oop" to all the pointers to "system"
335 // classes and loaders.
336 static void always_strong_oops_do(OopClosure* blk);
337 static void always_strong_classes_do(KlassClosure* closure);
338
339 // Unload (that is, break root links to) all unmarked classes and
340 // loaders. Returns "true" iff something was unloaded.
341 static bool do_unloading(BoolObjectClosure* is_alive,
342 bool clean_previous_versions = true);
343
344 // Used by DumpSharedSpaces only to remove classes that failed verification
345 static void remove_classes_in_error_state();
346
347 static int calculate_systemdictionary_size(int loadedclasses);
348
349 // Applies "f->do_oop" to all root oops in the system dictionary.
350 static void oops_do(OopClosure* f);
351 static void roots_oops_do(OopClosure* strong, OopClosure* weak);
352
353 // System loader lock
354 static oop system_loader_lock() { return _system_loader_lock_obj; }
355
356 protected:
357 // Extended Redefine classes support (tbi)
358 static void preloaded_classes_do(KlassClosure* f);
359 static void lazily_loaded_classes_do(KlassClosure* f);
360 public:
361 // Sharing support.
362 static void reorder_dictionary();
363 static void copy_buckets(char** top, char* end);
364 static void copy_table(char** top, char* end);
365 static void reverse();
366 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
367 int number_of_entries);
368 // Printing
369 static void print(bool details = true);
370 static void print_shared(bool details = true);
371 static void print_class_statistics() PRODUCT_RETURN;
372 static void print_method_statistics() PRODUCT_RETURN;
373
374 // Number of contained klasses
375 // This is both fully loaded classes and classes in the process
376 // of being loaded
377 static int number_of_classes();
378
379 // Monotonically increasing counter which grows as classes are
380 // loaded or modifications such as hot-swapping or setting/removing
381 // of breakpoints are performed
382 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
383 // Needed by evolution and breakpoint code
384 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
385
386 // Verification
387 static void verify();
388
389 #ifdef ASSERT
390 static bool is_internal_format(Symbol* class_name);
391 #endif
392
393 // Initialization
394 static void initialize(TRAPS);
395
396 // Fast access to commonly used classes (preloaded)
397 static Klass* check_klass(Klass* k) {
398 assert(k != NULL, "preloaded klass not initialized");
399 return k;
400 }
401
402 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); }
403 static Klass* check_klass_Opt( Klass* k) { return k; }
404
405 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
406 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
407 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
408 int limit = (int)end_id + 1;
409 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
410 }
411
412 public:
413 #define WK_KLASS_DECLARE(name, symbol, option) \
414 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
415 static Klass** name##_addr() { \
416 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
417 }
418 WK_KLASSES_DO(WK_KLASS_DECLARE);
419 #undef WK_KLASS_DECLARE
420
421 static Klass* well_known_klass(WKID id) {
422 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
423 return _well_known_klasses[id];
424 }
425
426 static Klass** well_known_klass_addr(WKID id) {
427 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
428 return &_well_known_klasses[id];
429 }
430
431 // Local definition for direct access to the private array:
432 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
433
434 static Klass* box_klass(BasicType t) {
435 assert((uint)t < T_VOID+1, "range check");
436 return check_klass(_box_klasses[t]);
437 }
438 static BasicType box_klass_type(Klass* k); // inverse of box_klass
439
440 // methods returning lazily loaded klasses
441 // The corresponding method to load the class must be called before calling them.
442 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
443
444 static void load_abstract_ownable_synchronizer_klass(TRAPS);
445
446 protected:
447 // Tells whether ClassLoader.loadClassInternal is present
448 static bool has_loadClassInternal() { return _has_loadClassInternal; }
449
450 // Returns the class loader data to be used when looking up/updating the
451 // system dictionary.
452 static ClassLoaderData *class_loader_data(Handle class_loader) {
453 return ClassLoaderData::class_loader_data(class_loader());
454 }
455
456 public:
457 // Tells whether ClassLoader.checkPackageAccess is present
458 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
459
460 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
461 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
462 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
463 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
464 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
465
466 // Returns default system loader
467 static oop java_system_loader();
468
469 // Compute the default system loader
470 static void compute_java_system_loader(TRAPS);
471
472 // Register a new class loader
473 static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
474 protected:
475 // Mirrors for primitive classes (created eagerly)
476 static oop check_mirror(oop m) {
477 assert(m != NULL, "mirror not initialized");
478 return m;
479 }
480
481 public:
482 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
483
484 // Check class loader constraints
485 static bool add_loader_constraint(Symbol* name, Handle loader1,
486 Handle loader2, TRAPS);
487 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
488 Handle loader2, bool is_method, TRAPS);
489
490 // JSR 292
491 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
492 // (asks Java to compute it if necessary, except in a compiler thread)
493 static methodHandle find_method_handle_invoker(Symbol* name,
494 Symbol* signature,
495 KlassHandle accessing_klass,
496 Handle *appendix_result,
497 Handle *method_type_result,
498 TRAPS);
499 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
500 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
501 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
502 Symbol* signature,
503 TRAPS);
504 // find a java.lang.invoke.MethodType object for a given signature
505 // (asks Java to compute it if necessary, except in a compiler thread)
506 static Handle find_method_handle_type(Symbol* signature,
507 KlassHandle accessing_klass,
508 TRAPS);
509
510 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
511 static Handle link_method_handle_constant(KlassHandle caller,
512 int ref_kind, //e.g., JVM_REF_invokeVirtual
513 KlassHandle callee,
514 Symbol* name,
515 Symbol* signature,
516 TRAPS);
517
518 // ask Java to create a dynamic call site, while linking an invokedynamic op
519 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
520 Handle bootstrap_method,
521 Symbol* name,
522 Symbol* type,
523 Handle *appendix_result,
524 Handle *method_type_result,
525 TRAPS);
526
527 // Utility for printing loader "name" as part of tracing constraints
528 static const char* loader_name(oop loader) {
529 return ((loader) == NULL ? "<bootloader>" :
530 InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
531 }
532 static const char* loader_name(ClassLoaderData* loader_data) {
533 return (loader_data->class_loader() == NULL ? "<bootloader>" :
534 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
535 }
536
537 // Record the error when the first attempt to resolve a reference from a constant
538 // pool entry to a class fails.
539 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error,
540 Symbol* message);
541 static void delete_resolution_error(ConstantPool* pool);
542 static Symbol* find_resolution_error(constantPoolHandle pool, int which,
543 Symbol** message);
544
545 protected:
546
547 enum Constants {
548 _loader_constraint_size = 107, // number of entries in constraint table
549 _resolution_error_size = 107, // number of entries in resolution error table
550 _invoke_method_size = 139, // number of entries in invoke method table
551 _nof_buckets = 1009, // number of buckets in hash table for placeholders
552 _old_default_sdsize = 1009, // backward compat for system dictionary size
553 _prime_array_size = 8, // array of primes for system dictionary size
554 _average_depth_goal = 3 // goal for lookup length
555 };
556
557
558 // Static variables
559
560 // hashtable sizes for system dictionary to allow growth
561 // prime numbers for system dictionary size
562 static int _sdgeneration;
563 static const int _primelist[_prime_array_size];
564
565 // Hashtable holding loaded classes.
566 static Dictionary* _dictionary;
567
568 // Hashtable holding placeholders for classes being loaded.
569 static PlaceholderTable* _placeholders;
570
571 // Hashtable holding classes from the shared archive.
572 static Dictionary* _shared_dictionary;
573
574 // Monotonically increasing counter which grows with
575 // _number_of_classes as well as hot-swapping and breakpoint setting
576 // and removal.
577 static int _number_of_modifications;
578
579 // Lock object for system class loader
580 static oop _system_loader_lock_obj;
581
582 // Constraints on class loaders
583 static LoaderConstraintTable* _loader_constraints;
584
585 // Resolution errors
586 static ResolutionErrorTable* _resolution_errors;
587
588 // Invoke methods (JSR 292)
589 static SymbolPropertyTable* _invoke_method_table;
590
591 public:
592 // for VM_CounterDecay iteration support
593 friend class CounterDecay;
594 static Klass* try_get_next_class();
595
596 protected:
597 static void validate_protection_domain(instanceKlassHandle klass,
598 Handle class_loader,
599 Handle protection_domain, TRAPS);
600
601 friend class VM_PopulateDumpSharedSpace;
602 friend class TraversePlaceholdersClosure;
603 static Dictionary* dictionary() { return _dictionary; }
604 static Dictionary* shared_dictionary() { return _shared_dictionary; }
605 static PlaceholderTable* placeholders() { return _placeholders; }
606 static LoaderConstraintTable* constraints() { return _loader_constraints; }
607 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
608 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
609
610 // Basic loading operations
611 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
612 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
613 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
614 // Wait on SystemDictionary_lock; unlocks lockObject before
615 // waiting; relocks lockObject with correct recursion count
616 // after waiting, but before reentering SystemDictionary_lock
617 // to preserve lock order semantics.
618 static void double_lock_wait(Handle lockObject, TRAPS);
619 static void define_instance_class(instanceKlassHandle k, TRAPS);
620 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
621 Handle class_loader,
622 instanceKlassHandle k, TRAPS);
623 static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
624 Handle class_loader,
625 Handle protection_domain,
626 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 instanceKlassHandle load_shared_class(Symbol* class_name,
635 Handle class_loader,
636 TRAPS);
637 static bool is_ext_class_loader(Handle class_loader);
638
639 protected:
640 static Klass* find_shared_class(Symbol* class_name);
641
642 // Setup link to hierarchy
643 static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
644
645 // event based tracing
646 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k,
647 Handle initiating_loader);
648 // We pass in the hashtable index so we can calculate it outside of
649 // the SystemDictionary_lock.
650
651 // Basic find on loaded classes
652 static Klass* find_class(int index, unsigned int hash,
653 Symbol* name, ClassLoaderData* loader_data);
654 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
655
656 // Basic find on classes in the midst of being loaded
657 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
658
659 // Updating entry in dictionary
660 // Add a completely loaded class
661 static void add_klass(int index, Symbol* class_name,
662 ClassLoaderData* loader_data, KlassHandle obj);
663
664 // Add a placeholder for a class being loaded
665 static void add_placeholder(int index,
666 Symbol* class_name,
667 ClassLoaderData* loader_data);
668 static void remove_placeholder(int index,
669 Symbol* class_name,
670 ClassLoaderData* loader_data);
671
672 // Performs cleanups after resolve_super_or_fail. This typically needs
673 // to be called on failure.
674 // Won't throw, but can block.
675 static void resolution_cleanups(Symbol* class_name,
676 ClassLoaderData* loader_data,
677 TRAPS);
678
679 // Initialization
680 static void initialize_preloaded_classes(TRAPS);
681
682 // Class loader constraints
683 static void check_constraints(int index, unsigned int hash,
684 instanceKlassHandle k, Handle loader,
685 bool defining, TRAPS);
686 static void update_dictionary(int d_index, unsigned int d_hash,
687 int p_index, unsigned int p_hash,
688 instanceKlassHandle k, Handle loader,
689 TRAPS);
690
691 // Variables holding commonly used klasses (preloaded)
692 static Klass* _well_known_klasses[];
693
694 // Lazily loaded klasses
695 static Klass* volatile _abstract_ownable_synchronizer_klass;
696
697 // table of box klasses (int_klass, etc.)
698 static Klass* _box_klasses[T_VOID+1];
699
700 static oop _java_system_loader;
701
702 static bool _has_loadClassInternal;
703 static bool _has_checkPackageAccess;
704 };
705
706 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP