1 /*
2 * Copyright (c) 1997, 2011, 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.
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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
36 // The system dictionary stores all loaded classes and maps:
37 //
38 // [class name,class loader] -> class i.e. [Symbol*,oop] -> klassOop
39 //
40 // Classes are loaded lazily. The default VM class loader is
41 // represented as NULL.
42
43 // The underlying data structure is an open hash table with a fixed number
44 // of buckets. During loading the loader object is locked, (for the VM loader
45 // a private lock object is used). Class loading can thus be done concurrently,
46 // but only by different loaders.
47 //
48 // During loading a placeholder (name, loader) is temporarily placed in
49 // a side data structure, and is used to detect ClassCircularityErrors
50 // and to perform verification during GC. A GC can occur in the midst
51 // of class loading, as we call out to Java, have to take locks, etc.
52 //
53 // When class loading is finished, a new entry is added to the system
54 // dictionary and the place holder is removed. Note that the protection
55 // domain field of the system dictionary has not yet been filled in when
56 // the "real" system dictionary entry is created.
57 //
58 // Clients of this class who are interested in finding if a class has
59 // been completely loaded -- not classes in the process of being loaded --
60 // can read the SystemDictionary unlocked. This is safe because
61 // - entries are only deleted at safepoints
62 // - readers cannot come to a safepoint while actively examining
63 // an entry (an entry cannot be deleted from under a reader)
64 // - entries must be fully formed before they are available to concurrent
65 // readers (we must ensure write ordering)
66 //
67 // Note that placeholders are deleted at any time, as they are removed
68 // when a class is completely loaded. Therefore, readers as well as writers
69 // of placeholders must hold the SystemDictionary_lock.
70 //
71
72 class Dictionary;
73 class PlaceholderTable;
74 class LoaderConstraintTable;
75 class HashtableBucket;
76 class ResolutionErrorTable;
77 class SymbolPropertyTable;
78
79 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
80 // They are all "well-known", in the sense that no class loader is allowed
81 // to provide a different definition.
82 //
83 // These klasses must all have names defined in vmSymbols.
84
85 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
86
87 // Each well-known class has a short klass name (like object_klass),
88 // a vmSymbol name (like java_lang_Object), and a flag word
89 // that makes some minor distinctions, like whether the klass
90 // is preloaded, optional, release-specific, etc.
91 // The order of these definitions is significant; it is the order in which
92 // preloading is actually performed by initialize_preloaded_classes.
93
94 #define WK_KLASSES_DO(template) \
95 /* well-known classes */ \
96 template(Object_klass, java_lang_Object, Pre) \
97 template(String_klass, java_lang_String, Pre) \
98 template(Class_klass, java_lang_Class, Pre) \
99 template(Cloneable_klass, java_lang_Cloneable, Pre) \
100 template(ClassLoader_klass, java_lang_ClassLoader, Pre) \
101 template(Serializable_klass, java_io_Serializable, Pre) \
102 template(System_klass, java_lang_System, Pre) \
103 template(Throwable_klass, java_lang_Throwable, Pre) \
104 template(Error_klass, java_lang_Error, Pre) \
105 template(ThreadDeath_klass, java_lang_ThreadDeath, Pre) \
106 template(Exception_klass, java_lang_Exception, Pre) \
107 template(RuntimeException_klass, java_lang_RuntimeException, Pre) \
108 template(ProtectionDomain_klass, java_security_ProtectionDomain, Pre) \
109 template(AccessControlContext_klass, java_security_AccessControlContext, Pre) \
110 template(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre) \
111 template(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre) \
112 template(LinkageError_klass, java_lang_LinkageError, Pre) \
113 template(ClassCastException_klass, java_lang_ClassCastException, Pre) \
114 template(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre) \
115 template(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre) \
116 template(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre) \
117 template(StackOverflowError_klass, java_lang_StackOverflowError, Pre) \
118 template(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre) \
119 template(Reference_klass, java_lang_ref_Reference, Pre) \
120 \
121 /* Preload ref klasses and set reference types */ \
122 template(SoftReference_klass, java_lang_ref_SoftReference, Pre) \
123 template(WeakReference_klass, java_lang_ref_WeakReference, Pre) \
124 template(FinalReference_klass, java_lang_ref_FinalReference, Pre) \
125 template(PhantomReference_klass, java_lang_ref_PhantomReference, Pre) \
126 template(Finalizer_klass, java_lang_ref_Finalizer, Pre) \
127 \
128 template(Thread_klass, java_lang_Thread, Pre) \
129 template(ThreadGroup_klass, java_lang_ThreadGroup, Pre) \
130 template(Properties_klass, java_util_Properties, Pre) \
131 template(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre) \
132 template(reflect_Field_klass, java_lang_reflect_Field, Pre) \
133 template(reflect_Method_klass, java_lang_reflect_Method, Pre) \
134 template(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre) \
135 \
136 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
137 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
138 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
139 template(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt) \
140 template(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \
141 template(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \
142 template(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt) \
143 template(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15) \
144 template(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15) \
145 \
146 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
147 template(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre_JSR292) \
148 template(MemberName_klass, java_lang_invoke_MemberName, Pre_JSR292) \
149 template(MethodHandleImpl_klass, sun_dyn_MethodHandleImpl, Opt) /* AllowTransitionalJSR292 ONLY */ \
150 template(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre_JSR292) \
151 template(AdapterMethodHandle_klass, java_lang_invoke_AdapterMethodHandle, Pre_JSR292) \
152 template(BoundMethodHandle_klass, java_lang_invoke_BoundMethodHandle, Pre_JSR292) \
153 template(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Pre_JSR292) \
154 template(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292) \
155 template(MethodTypeForm_klass, java_lang_invoke_MethodTypeForm, Pre_JSR292) \
156 template(WrongMethodTypeException_klass, java_lang_invoke_WrongMethodTypeException, Pre_JSR292) \
157 template(Linkage_klass, java_lang_invoke_Linkage, Opt) /* AllowTransitionalJSR292 ONLY */ \
158 template(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292) \
159 /* Note: MethodHandle must be first, and CallSite last in group */ \
160 \
161 template(StringBuffer_klass, java_lang_StringBuffer, Pre) \
162 template(StringBuilder_klass, java_lang_StringBuilder, Pre) \
163 \
164 /* It's NULL in non-1.4 JDKs. */ \
165 template(StackTraceElement_klass, java_lang_StackTraceElement, Opt) \
166 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \
167 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
168 template(java_nio_Buffer_klass, java_nio_Buffer, Opt) \
169 \
170 /* If this class isn't present, it won't be referenced. */ \
171 template(sun_misc_AtomicLongCSImpl_klass, sun_misc_AtomicLongCSImpl, Opt) \
172 \
173 template(sun_jkernel_DownloadManager_klass, sun_jkernel_DownloadManager, Opt_Kernel) \
174 \
175 template(sun_misc_PostVMInitHook_klass, sun_misc_PostVMInitHook, Opt) \
176 \
177 /* Preload boxing klasses */ \
178 template(Boolean_klass, java_lang_Boolean, Pre) \
179 template(Character_klass, java_lang_Character, Pre) \
180 template(Float_klass, java_lang_Float, Pre) \
181 template(Double_klass, java_lang_Double, Pre) \
182 template(Byte_klass, java_lang_Byte, Pre) \
183 template(Short_klass, java_lang_Short, Pre) \
184 template(Integer_klass, java_lang_Integer, Pre) \
185 template(Long_klass, java_lang_Long, Pre) \
186 /*end*/
187
188
189 class SystemDictionary : AllStatic {
190 friend class VMStructs;
191 friend class CompactingPermGenGen;
192 friend class SystemDictionaryHandles;
193 NOT_PRODUCT(friend class instanceKlassKlass;)
194
195 public:
196 enum WKID {
197 NO_WKID = 0,
198
199 #define WK_KLASS_ENUM(name, ignore_s, ignore_o) WK_KLASS_ENUM_NAME(name),
200 WK_KLASSES_DO(WK_KLASS_ENUM)
201 #undef WK_KLASS_ENUM
202
203 WKID_LIMIT,
204
205 FIRST_WKID = NO_WKID + 1
206 };
207
208 enum InitOption {
209 Pre, // preloaded; error if not present
210 Pre_JSR292, // preloaded if EnableMethodHandles
211
212 // Order is significant. Options before this point require resolve_or_fail.
213 // Options after this point will use resolve_or_null instead.
214
215 Opt, // preload tried; NULL if not present
216 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection
217 Opt_Only_JDK15, // preload tried; use only with JDK1.5+
218 Opt_Kernel, // preload tried only #ifdef KERNEL
219 OPTION_LIMIT,
220 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
221 };
222
223
224 // Returns a class with a given class name and class loader. Loads the
225 // class if needed. If not found a NoClassDefFoundError or a
226 // ClassNotFoundException is thrown, depending on the value on the
227 // throw_error flag. For most uses the throw_error argument should be set
228 // to true.
229
230 static klassOop resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
231 // Convenient call for null loader and protection domain.
232 static klassOop resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
233 private:
234 // handle error translation for resolve_or_null results
235 static klassOop handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
236
237 public:
238
239 // Returns a class with a given class name and class loader.
240 // Loads the class if needed. If not found NULL is returned.
241 static klassOop resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
242 // Version with null loader and protection domain
243 static klassOop resolve_or_null(Symbol* class_name, TRAPS);
244
245 // Resolve a superclass or superinterface. Called from ClassFileParser,
246 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
247 // "child_name" is the class whose super class or interface is being resolved.
248 static klassOop resolve_super_or_fail(Symbol* child_name,
249 Symbol* class_name,
250 Handle class_loader,
251 Handle protection_domain,
252 bool is_superclass,
253 TRAPS);
254
255 // Parse new stream. This won't update the system dictionary or
256 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
257 static klassOop parse_stream(Symbol* class_name,
258 Handle class_loader,
259 Handle protection_domain,
260 ClassFileStream* st,
261 TRAPS) {
262 KlassHandle nullHandle;
263 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
264 }
265 static klassOop parse_stream(Symbol* class_name,
266 Handle class_loader,
267 Handle protection_domain,
268 ClassFileStream* st,
269 KlassHandle host_klass,
270 GrowableArray<Handle>* cp_patches,
271 TRAPS);
272
273 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
274 static klassOop resolve_from_stream(Symbol* class_name, Handle class_loader,
275 Handle protection_domain,
276 ClassFileStream* st, bool verify, TRAPS);
277
278 // Lookup an already loaded class. If not found NULL is returned.
279 static klassOop find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
280
281 // Lookup an already loaded instance or array class.
282 // Do not make any queries to class loaders; consult only the cache.
283 // If not found NULL is returned.
284 static klassOop find_instance_or_array_klass(Symbol* class_name,
285 Handle class_loader,
286 Handle protection_domain,
287 TRAPS);
288
289 // If the given name is known to vmSymbols, return the well-know klass:
290 static klassOop find_well_known_klass(Symbol* class_name);
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 klassOop 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(klassOop));
320 // Added for initialize_itable_for_klass to handle exceptions
321 static void classes_do(void f(klassOop, TRAPS), TRAPS);
322 // All classes, and their class loaders
323 static void classes_do(void f(klassOop, oop));
324 // All classes, and their class loaders
325 // (added for helpers that use HandleMarks and ResourceMarks)
326 static void classes_do(void f(klassOop, oop, TRAPS), TRAPS);
327 // All entries in the placeholder table and their class loaders
328 static void placeholders_do(void f(Symbol*, oop));
329
330 // Iterate over all methods in all klasses in dictionary
331 static void methods_do(void f(methodOop));
332
333 // Garbage collection support
334
335 // This method applies "blk->do_oop" to all the pointers to "system"
336 // classes and loaders.
337 static void always_strong_oops_do(OopClosure* blk);
338 static void always_strong_classes_do(OopClosure* blk);
339 // This method applies "blk->do_oop" to all the placeholders.
340 static void placeholders_do(OopClosure* blk);
341
342 // Unload (that is, break root links to) all unmarked classes and
343 // loaders. Returns "true" iff something was unloaded.
344 static bool do_unloading(BoolObjectClosure* is_alive);
345
346 // Applies "f->do_oop" to all root oops in the system dictionary.
347 static void oops_do(OopClosure* f);
348
349 // System loader lock
350 static oop system_loader_lock() { return _system_loader_lock_obj; }
351
352 private:
353 // Traverses preloaded oops: various system classes. These are
354 // guaranteed to be in the perm gen.
355 static void preloaded_oops_do(OopClosure* f);
356 static void lazily_loaded_oops_do(OopClosure* f);
357
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* t, int length,
365 int number_of_entries);
366 // Printing
367 static void print() PRODUCT_RETURN;
368 static void print_class_statistics() PRODUCT_RETURN;
369 static void print_method_statistics() PRODUCT_RETURN;
370
371 // Number of contained klasses
372 // This is both fully loaded classes and classes in the process
373 // of being loaded
374 static int number_of_classes();
375
376 // Monotonically increasing counter which grows as classes are
377 // loaded or modifications such as hot-swapping or setting/removing
378 // of breakpoints are performed
379 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
380 // Needed by evolution and breakpoint code
381 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
382
383 // Verification
384 static void verify();
385
386 #ifdef ASSERT
387 static bool is_internal_format(Symbol* class_name);
388 #endif
389
390 // Verify class is in dictionary
391 static void verify_obj_klass_present(Handle obj,
392 Symbol* class_name,
393 Handle class_loader);
394
395 // Initialization
396 static void initialize(TRAPS);
397
398 // Fast access to commonly used classes (preloaded)
399 static klassOop check_klass(klassOop k) {
400 assert(k != NULL, "preloaded klass not initialized");
401 return k;
402 }
403
404 static klassOop check_klass_Pre(klassOop k) { return check_klass(k); }
405 static klassOop check_klass_Pre_JSR292(klassOop k) { return EnableInvokeDynamic ? check_klass(k) : k; }
406 static klassOop check_klass_Opt(klassOop k) { return k; }
407 static klassOop check_klass_Opt_Kernel(klassOop k) { return k; } //== Opt
408 static klassOop check_klass_Opt_Only_JDK15(klassOop k) {
409 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
410 return k;
411 }
412 static klassOop check_klass_Opt_Only_JDK14NewRef(klassOop k) {
413 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
414 // despite the optional loading, if you use this it must be present:
415 return check_klass(k);
416 }
417
418 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
419 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
420 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
421 int limit = (int)end_id + 1;
422 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
423 }
424
425 static Symbol* find_backup_symbol(Symbol* symbol, const char* from_prefix, const char* to_prefix);
426
427 public:
428 #define WK_KLASS_DECLARE(name, ignore_symbol, option) \
429 static klassOop name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); }
430 WK_KLASSES_DO(WK_KLASS_DECLARE);
431 #undef WK_KLASS_DECLARE
432
433 // Local definition for direct access to the private array:
434 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
435
436 static klassOop box_klass(BasicType t) {
437 assert((uint)t < T_VOID+1, "range check");
438 return check_klass(_box_klasses[t]);
439 }
440 static BasicType box_klass_type(klassOop k); // inverse of box_klass
441
442 // methods returning lazily loaded klasses
443 // The corresponding method to load the class must be called before calling them.
444 static klassOop abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
445
446 static void load_abstract_ownable_synchronizer_klass(TRAPS);
447
448 static Symbol* find_backup_class_name(Symbol* class_name_symbol);
449 static Symbol* find_backup_signature(Symbol* signature_symbol);
450
451 private:
452 // Tells whether ClassLoader.loadClassInternal is present
453 static bool has_loadClassInternal() { return _has_loadClassInternal; }
454
455 public:
456 // Tells whether ClassLoader.checkPackageAccess is present
457 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
458
459 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
460 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
461
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 private:
469 // Mirrors for primitive classes (created eagerly)
470 static oop check_mirror(oop m) {
471 assert(m != NULL, "mirror not initialized");
472 return m;
473 }
474
475 public:
476 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
477
478 // Check class loader constraints
479 static bool add_loader_constraint(Symbol* name, Handle loader1,
480 Handle loader2, TRAPS);
481 static char* check_signature_loaders(Symbol* signature, Handle loader1,
482 Handle loader2, bool is_method, TRAPS);
483
484 // JSR 292
485 // find the java.lang.invoke.MethodHandles::invoke method for a given signature
486 static methodOop find_method_handle_invoke(Symbol* name,
487 Symbol* signature,
488 KlassHandle accessing_klass,
489 TRAPS);
490 // ask Java to compute a java.lang.invoke.MethodType object for a given signature
491 static Handle find_method_handle_type(Symbol* signature,
492 KlassHandle accessing_klass,
493 bool for_invokeGeneric,
494 bool& return_bcp_flag,
495 TRAPS);
496 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
497 static Handle link_method_handle_constant(KlassHandle caller,
498 int ref_kind, //e.g., JVM_REF_invokeVirtual
499 KlassHandle callee,
500 Symbol* name,
501 Symbol* signature,
502 TRAPS);
503 // ask Java to create a dynamic call site, while linking an invokedynamic op
504 static Handle make_dynamic_call_site(Handle bootstrap_method,
505 // Callee information:
506 Symbol* name,
507 methodHandle signature_invoker,
508 Handle info,
509 // Caller information:
510 methodHandle caller_method,
511 int caller_bci,
512 TRAPS);
513
514 // coordinate with Java about bootstrap methods
515 static Handle find_bootstrap_method(methodHandle caller_method,
516 int caller_bci, // N.B. must be an invokedynamic
517 int cache_index, // must be corresponding main_entry
518 Handle &argument_info_result, // static BSM arguments, if any
519 TRAPS);
520
521 // Utility for printing loader "name" as part of tracing constraints
522 static const char* loader_name(oop loader) {
523 return ((loader) == NULL ? "<bootloader>" :
524 instanceKlass::cast((loader)->klass())->name()->as_C_string() );
525 }
526
527 // Record the error when the first attempt to resolve a reference from a constant
528 // pool entry to a class fails.
529 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error);
530 static Symbol* find_resolution_error(constantPoolHandle pool, int which);
531
532 private:
533
534 enum Constants {
535 _loader_constraint_size = 107, // number of entries in constraint table
536 _resolution_error_size = 107, // number of entries in resolution error table
537 _invoke_method_size = 139, // number of entries in invoke method table
538 _nof_buckets = 1009 // number of buckets in hash table
539 };
540
541
542 // Static variables
543
544 // Hashtable holding loaded classes.
545 static Dictionary* _dictionary;
546
547 // Hashtable holding placeholders for classes being loaded.
548 static PlaceholderTable* _placeholders;
549
550 // Hashtable holding classes from the shared archive.
551 static Dictionary* _shared_dictionary;
552
553 // Monotonically increasing counter which grows with
554 // _number_of_classes as well as hot-swapping and breakpoint setting
555 // and removal.
556 static int _number_of_modifications;
557
558 // Lock object for system class loader
559 static oop _system_loader_lock_obj;
560
561 // Constraints on class loaders
562 static LoaderConstraintTable* _loader_constraints;
563
564 // Resolution errors
565 static ResolutionErrorTable* _resolution_errors;
566
567 // Invoke methods (JSR 292)
568 static SymbolPropertyTable* _invoke_method_table;
569
570 public:
571 // for VM_CounterDecay iteration support
572 friend class CounterDecay;
573 static klassOop try_get_next_class();
574
575 private:
576 static void validate_protection_domain(instanceKlassHandle klass,
577 Handle class_loader,
578 Handle protection_domain, TRAPS);
579
580 friend class VM_PopulateDumpSharedSpace;
581 friend class TraversePlaceholdersClosure;
582 static Dictionary* dictionary() { return _dictionary; }
583 static Dictionary* shared_dictionary() { return _shared_dictionary; }
584 static PlaceholderTable* placeholders() { return _placeholders; }
585 static LoaderConstraintTable* constraints() { return _loader_constraints; }
586 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
587 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
588
589 // Basic loading operations
590 static klassOop resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
591 static klassOop resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
592 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
593 // Wait on SystemDictionary_lock; unlocks lockObject before
594 // waiting; relocks lockObject with correct recursion count
595 // after waiting, but before reentering SystemDictionary_lock
596 // to preserve lock order semantics.
597 static void double_lock_wait(Handle lockObject, TRAPS);
598 static void define_instance_class(instanceKlassHandle k, TRAPS);
599 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
600 Handle class_loader,
601 instanceKlassHandle k, TRAPS);
602 static instanceKlassHandle load_shared_class(Symbol* class_name,
603 Handle class_loader, TRAPS);
604 static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
605 Handle class_loader, TRAPS);
606 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
607 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
608 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
609 static bool is_parallelCapable(Handle class_loader);
610 static bool is_parallelDefine(Handle class_loader);
611
612 static klassOop find_shared_class(Symbol* class_name);
613
614 // Setup link to hierarchy
615 static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
616
617 private:
618 // We pass in the hashtable index so we can calculate it outside of
619 // the SystemDictionary_lock.
620
621 // Basic find on loaded classes
622 static klassOop find_class(int index, unsigned int hash,
623 Symbol* name, Handle loader);
624 static klassOop find_class(Symbol* class_name, Handle class_loader);
625
626 // Basic find on classes in the midst of being loaded
627 static Symbol* find_placeholder(Symbol* name, Handle loader);
628
629 // Updating entry in dictionary
630 // Add a completely loaded class
631 static void add_klass(int index, Symbol* class_name,
632 Handle class_loader, KlassHandle obj);
633
634 // Add a placeholder for a class being loaded
635 static void add_placeholder(int index,
636 Symbol* class_name,
637 Handle class_loader);
638 static void remove_placeholder(int index,
639 Symbol* class_name,
640 Handle class_loader);
641
642 // Performs cleanups after resolve_super_or_fail. This typically needs
643 // to be called on failure.
644 // Won't throw, but can block.
645 static void resolution_cleanups(Symbol* class_name,
646 Handle class_loader,
647 TRAPS);
648
649 // Initialization
650 static void initialize_preloaded_classes(TRAPS);
651
652 // Class loader constraints
653 static void check_constraints(int index, unsigned int hash,
654 instanceKlassHandle k, Handle loader,
655 bool defining, TRAPS);
656 static void update_dictionary(int d_index, unsigned int d_hash,
657 int p_index, unsigned int p_hash,
658 instanceKlassHandle k, Handle loader, TRAPS);
659
660 // Variables holding commonly used klasses (preloaded)
661 static klassOop _well_known_klasses[];
662
663 // Lazily loaded klasses
664 static volatile klassOop _abstract_ownable_synchronizer_klass;
665
666 // table of box klasses (int_klass, etc.)
667 static klassOop _box_klasses[T_VOID+1];
668
669 static oop _java_system_loader;
670
671 static bool _has_loadClassInternal;
672 static bool _has_checkPackageAccess;
673 };
674
675 class SystemDictionaryHandles : AllStatic {
676 public:
677 #define WK_KLASS_HANDLE_DECLARE(name, ignore_symbol, option) \
678 static KlassHandle name() { \
679 SystemDictionary::name(); \
680 klassOop* loc = &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
681 return KlassHandle(loc, true); \
682 }
683 WK_KLASSES_DO(WK_KLASS_HANDLE_DECLARE);
684 #undef WK_KLASS_HANDLE_DECLARE
685
686 static KlassHandle box_klass(BasicType t);
687 };
688
689 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP