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/classLoader.hpp"
29 #include "jvmci/systemDictionary_jvmci.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 // The system dictionary stores all loaded classes and maps:
38 //
39 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass*
40 //
41 // Classes are loaded lazily. The default VM class loader is
42 // represented as NULL.
43
44 // The underlying data structure is an open hash table with a fixed number
45 // of buckets. During loading the loader object is locked, (for the VM loader
46 // a private lock object is used). Class loading can thus be done concurrently,
47 // but only by different loaders.
48 //
49 // During loading a placeholder (name, loader) is temporarily placed in
50 // a side data structure, and is used to detect ClassCircularityErrors
51 // and to perform verification during GC. A GC can occur in the midst
52 // of class loading, as we call out to Java, have to take locks, etc.
53 //
54 // When class loading is finished, a new entry is added to the system
55 // dictionary and the place holder is removed. Note that the protection
56 // domain field of the system dictionary has not yet been filled in when
57 // the "real" system dictionary entry is created.
58 //
59 // Clients of this class who are interested in finding if a class has
60 // been completely loaded -- not classes in the process of being loaded --
61 // can read the SystemDictionary unlocked. This is safe because
62 // - entries are only deleted at safepoints
63 // - readers cannot come to a safepoint while actively examining
64 // an entry (an entry cannot be deleted from under a reader)
65 // - entries must be fully formed before they are available to concurrent
66 // readers (we must ensure write ordering)
67 //
68 // Note that placeholders are deleted at any time, as they are removed
69 // when a class is completely loaded. Therefore, readers as well as writers
70 // of placeholders must hold the SystemDictionary_lock.
71 //
72
73 class ClassFileStream;
74 class Dictionary;
75 class PlaceholderTable;
76 class LoaderConstraintTable;
77 template <MEMFLAGS F> class HashtableBucket;
78 class ResolutionErrorTable;
79 class SymbolPropertyTable;
80
81 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
82 // They are all "well-known", in the sense that no class loader is allowed
83 // to provide a different definition.
84 //
85 // These klasses must all have names defined in vmSymbols.
86
87 #define WK_KLASS_ENUM_NAME(kname) kname##_knum
88
89 // Each well-known class has a short klass name (like object_klass),
90 // a vmSymbol name (like java_lang_Object), and a flag word
91 // that makes some minor distinctions, like whether the klass
92 // is preloaded, optional, release-specific, etc.
93 // The order of these definitions is significant; it is the order in which
94 // preloading is actually performed by initialize_preloaded_classes.
95
96 #define WK_KLASSES_DO(do_klass) \
97 /* well-known classes */ \
98 do_klass(Object_klass, java_lang_Object, Pre ) \
99 do_klass(String_klass, java_lang_String, Pre ) \
100 do_klass(Class_klass, java_lang_Class, Pre ) \
101 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \
102 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \
103 do_klass(Serializable_klass, java_io_Serializable, Pre ) \
104 do_klass(System_klass, java_lang_System, Pre ) \
105 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \
106 do_klass(Error_klass, java_lang_Error, Pre ) \
107 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \
108 do_klass(Exception_klass, java_lang_Exception, Pre ) \
109 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \
110 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \
111 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \
112 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \
113 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \
114 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \
115 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \
116 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \
117 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \
118 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \
119 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \
120 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \
121 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \
122 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \
123 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \
124 \
125 /* Preload ref klasses and set reference types */ \
126 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \
127 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \
128 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \
129 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \
130 do_klass(Cleaner_klass, sun_misc_Cleaner, Pre ) \
131 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \
132 \
133 do_klass(Thread_klass, java_lang_Thread, Pre ) \
134 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \
135 do_klass(Properties_klass, java_util_Properties, Pre ) \
136 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \
137 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \
138 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \
139 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \
140 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \
141 \
142 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \
143 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
144 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \
145 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Pre ) \
146 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Pre ) \
147 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \
148 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt ) \
149 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt ) \
150 do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \
151 \
152 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
153 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \
154 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \
155 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \
156 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \
157 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \
158 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \
159 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \
160 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \
161 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \
162 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \
163 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \
164 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \
165 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \
166 \
167 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \
168 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \
169 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe, Pre ) \
170 \
171 /* support for CDS */ \
172 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \
173 do_klass(File_klass, java_io_File, Pre ) \
174 do_klass(URLClassLoader_klass, java_net_URLClassLoader, Pre ) \
175 do_klass(URL_klass, java_net_URL, Pre ) \
176 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \
177 do_klass(sun_misc_Launcher_klass, sun_misc_Launcher, Pre ) \
178 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \
179 \
180 /* It's NULL in non-1.4 JDKs. */ \
181 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \
182 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \
183 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \
184 \
185 /* Preload boxing klasses */ \
186 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \
187 do_klass(Character_klass, java_lang_Character, Pre ) \
188 do_klass(Float_klass, java_lang_Float, Pre ) \
189 do_klass(Double_klass, java_lang_Double, Pre ) \
190 do_klass(Byte_klass, java_lang_Byte, Pre ) \
191 do_klass(Short_klass, java_lang_Short, Pre ) \
192 do_klass(Integer_klass, java_lang_Integer, Pre ) \
193 do_klass(Long_klass, java_lang_Long, Pre ) \
194 \
195 /* JVMCI classes. These are loaded on-demand. */ \
196 JVMCI_WK_KLASSES_DO(do_klass) \
197
198 /*end*/
199
200
201 class SystemDictionary : AllStatic {
202 friend class VMStructs;
203 friend class SystemDictionaryHandles;
204
205 public:
206 enum WKID {
207 NO_WKID = 0,
208
209 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
210 WK_KLASSES_DO(WK_KLASS_ENUM)
211 #undef WK_KLASS_ENUM
212
213 WKID_LIMIT,
214
215 #if INCLUDE_JVMCI
216 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(HotSpotCompiledCode_klass),
217 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass),
218 #endif
219
220 FIRST_WKID = NO_WKID + 1
221 };
222
223 enum InitOption {
224 Pre, // preloaded; error if not present
225
226 // Order is significant. Options before this point require resolve_or_fail.
227 // Options after this point will use resolve_or_null instead.
228
229 Opt, // preload tried; NULL if not present
230 #if INCLUDE_JVMCI
231 Jvmci, // preload tried; error if not present, use only with JVMCI
232 #endif
233 OPTION_LIMIT,
234 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
235 };
236
237
238 // Returns a class with a given class name and class loader. Loads the
239 // class if needed. If not found a NoClassDefFoundError or a
240 // ClassNotFoundException is thrown, depending on the value on the
241 // throw_error flag. For most uses the throw_error argument should be set
242 // to true.
243
244 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
245 // Convenient call for null loader and protection domain.
246 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
247 protected:
248 // handle error translation for resolve_or_null results
249 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, KlassHandle klass_h, TRAPS);
250
251 public:
252
253 // Returns a class with a given class name and class loader.
254 // Loads the class if needed. If not found NULL is returned.
255 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
256 // Version with null loader and protection domain
257 static Klass* resolve_or_null(Symbol* class_name, TRAPS);
258
259 // Resolve a superclass or superinterface. Called from ClassFileParser,
260 // parse_interfaces, resolve_instance_class_or_null, load_shared_class
261 // "child_name" is the class whose super class or interface is being resolved.
262 static Klass* resolve_super_or_fail(Symbol* child_name,
263 Symbol* class_name,
264 Handle class_loader,
265 Handle protection_domain,
266 bool is_superclass,
267 TRAPS);
268
269 // Parse new stream. This won't update the system dictionary or
270 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
271 static Klass* parse_stream(Symbol* class_name,
272 Handle class_loader,
273 Handle protection_domain,
274 ClassFileStream* st,
275 TRAPS) {
276 return parse_stream(class_name,
277 class_loader,
278 protection_domain,
279 st,
280 NULL, // host klass
281 NULL, // cp_patches
282 THREAD);
283 }
284 static Klass* parse_stream(Symbol* class_name,
285 Handle class_loader,
286 Handle protection_domain,
287 ClassFileStream* st,
288 const Klass* host_klass,
289 GrowableArray<Handle>* cp_patches,
290 TRAPS);
291
292 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
293 static Klass* resolve_from_stream(Symbol* class_name,
294 Handle class_loader,
295 Handle protection_domain,
296 ClassFileStream* st,
297 TRAPS);
298
299 // Lookup an already loaded class. If not found NULL is returned.
300 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
301
302 // Lookup an already loaded instance or array class.
303 // Do not make any queries to class loaders; consult only the cache.
304 // If not found NULL is returned.
305 static Klass* find_instance_or_array_klass(Symbol* class_name,
306 Handle class_loader,
307 Handle protection_domain,
308 TRAPS);
309
310 // Lookup an instance or array class that has already been loaded
311 // either into the given class loader, or else into another class
312 // loader that is constrained (via loader constraints) to produce
313 // a consistent class. Do not take protection domains into account.
314 // Do not make any queries to class loaders; consult only the cache.
315 // Return NULL if the class is not found.
316 //
317 // This function is a strict superset of find_instance_or_array_klass.
318 // This function (the unchecked version) makes a conservative prediction
319 // of the result of the checked version, assuming successful lookup.
320 // If both functions return non-null, they must return the same value.
321 // Also, the unchecked version may sometimes be non-null where the
322 // checked version is null. This can occur in several ways:
323 // 1. No query has yet been made to the class loader.
324 // 2. The class loader was queried, but chose not to delegate.
325 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
326 // 4. Loading was attempted, but there was a linkage error of some sort.
327 // In all of these cases, the loader constraints on this type are
328 // satisfied, and it is safe for classes in the given class loader
329 // to manipulate strongly-typed values of the found class, subject
330 // to local linkage and access checks.
331 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
332 Handle class_loader,
333 TRAPS);
334
335 // Iterate over all klasses in dictionary
336 // Just the classes from defining class loaders
337 static void classes_do(void f(Klass*));
338 // Added for initialize_itable_for_klass to handle exceptions
339 static void classes_do(void f(Klass*, TRAPS), TRAPS);
340 // All classes, and their class loaders
341 static void classes_do(void f(Klass*, ClassLoaderData*));
342
343 static void placeholders_do(void f(Symbol*));
344
345 // Iterate over all methods in all klasses in dictionary
346 static void methods_do(void f(Method*));
347
348 // Garbage collection support
349
350 // This method applies "blk->do_oop" to all the pointers to "system"
351 // classes and loaders.
352 static void always_strong_oops_do(OopClosure* blk);
353 static void always_strong_classes_do(KlassClosure* closure);
354
355 // Unload (that is, break root links to) all unmarked classes and
356 // loaders. Returns "true" iff something was unloaded.
357 static bool do_unloading(BoolObjectClosure* is_alive,
358 bool clean_previous_versions = true);
359
360 // Used by DumpSharedSpaces only to remove classes that failed verification
361 static void remove_classes_in_error_state();
362
363 static int calculate_systemdictionary_size(int loadedclasses);
364
365 // Applies "f->do_oop" to all root oops in the system dictionary.
366 static void oops_do(OopClosure* f);
367 static void roots_oops_do(OopClosure* strong, OopClosure* weak);
368
369 // System loader lock
370 static oop system_loader_lock() { return _system_loader_lock_obj; }
371
372 protected:
373 // Extended Redefine classes support (tbi)
374 static void preloaded_classes_do(KlassClosure* f);
375 static void lazily_loaded_classes_do(KlassClosure* f);
376 public:
377 // Sharing support.
378 static void reorder_dictionary();
379 static void copy_buckets(char** top, char* end);
380 static void copy_table(char** top, char* end);
381 static void reverse();
382 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
383 int number_of_entries);
384 // Printing
385 static void print(bool details = true);
386 static void print_shared(bool details = true);
387
388 // Number of contained klasses
389 // This is both fully loaded classes and classes in the process
390 // of being loaded
391 static int number_of_classes();
392
393 // Monotonically increasing counter which grows as classes are
394 // loaded or modifications such as hot-swapping or setting/removing
395 // of breakpoints are performed
396 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
397 // Needed by evolution and breakpoint code
398 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; }
399
400 // Verification
401 static void verify();
402
403 #ifdef ASSERT
404 static bool is_internal_format(Symbol* class_name);
405 #endif
406
407 // Initialization
408 static void initialize(TRAPS);
409
410 // Fast access to commonly used classes (preloaded)
411 static InstanceKlass* check_klass(InstanceKlass* k) {
412 assert(k != NULL, "preloaded klass not initialized");
413 return k;
414 }
415
416 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); }
417 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; }
418
419 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; })
420
421 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
422 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
423 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
424 int limit = (int)end_id + 1;
425 initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
426 }
427
428 public:
429 #define WK_KLASS_DECLARE(name, symbol, option) \
430 static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
431 static InstanceKlass** name##_addr() { \
432 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \
433 }
434 WK_KLASSES_DO(WK_KLASS_DECLARE);
435 #undef WK_KLASS_DECLARE
436
437 static InstanceKlass* well_known_klass(WKID id) {
438 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
439 return _well_known_klasses[id];
440 }
441
442 static InstanceKlass** well_known_klass_addr(WKID id) {
443 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
444 return &_well_known_klasses[id];
445 }
446
447 // Local definition for direct access to the private array:
448 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
449
450 static InstanceKlass* box_klass(BasicType t) {
451 assert((uint)t < T_VOID+1, "range check");
452 return check_klass(_box_klasses[t]);
453 }
454 static BasicType box_klass_type(Klass* k); // inverse of box_klass
455
456 // methods returning lazily loaded klasses
457 // The corresponding method to load the class must be called before calling them.
458 static InstanceKlass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
459
460 static void load_abstract_ownable_synchronizer_klass(TRAPS);
461
462 protected:
463 // Tells whether ClassLoader.loadClassInternal is present
464 static bool has_loadClassInternal() { return _has_loadClassInternal; }
465
466 // Returns the class loader data to be used when looking up/updating the
467 // system dictionary.
468 static ClassLoaderData *class_loader_data(Handle class_loader) {
469 return ClassLoaderData::class_loader_data(class_loader());
470 }
471
472 public:
473 // Tells whether ClassLoader.checkPackageAccess is present
474 static bool has_checkPackageAccess() { return _has_checkPackageAccess; }
475
476 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; }
477 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; }
478 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; }
479 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; }
480 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; }
481
482 // Returns default system loader
483 static oop java_system_loader();
484
485 // Compute the default system loader
486 static void compute_java_system_loader(TRAPS);
487
488 // Register a new class loader
489 static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
490 protected:
491 // Mirrors for primitive classes (created eagerly)
492 static oop check_mirror(oop m) {
493 assert(m != NULL, "mirror not initialized");
494 return m;
495 }
496
497 public:
498 // Note: java_lang_Class::primitive_type is the inverse of java_mirror
499
500 // Check class loader constraints
501 static bool add_loader_constraint(Symbol* name, Handle loader1,
502 Handle loader2, TRAPS);
503 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
504 Handle loader2, bool is_method, TRAPS);
505
506 // JSR 292
507 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
508 // (asks Java to compute it if necessary, except in a compiler thread)
509 static methodHandle find_method_handle_invoker(Symbol* name,
510 Symbol* signature,
511 KlassHandle accessing_klass,
512 Handle *appendix_result,
513 Handle *method_type_result,
514 TRAPS);
515 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
516 // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
517 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
518 Symbol* signature,
519 TRAPS);
520 // find a java.lang.invoke.MethodType object for a given signature
521 // (asks Java to compute it if necessary, except in a compiler thread)
522 static Handle find_method_handle_type(Symbol* signature,
523 KlassHandle accessing_klass,
524 TRAPS);
525
526 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
527 static Handle link_method_handle_constant(KlassHandle caller,
528 int ref_kind, //e.g., JVM_REF_invokeVirtual
529 KlassHandle callee,
530 Symbol* name,
531 Symbol* signature,
532 TRAPS);
533
534 // ask Java to create a dynamic call site, while linking an invokedynamic op
535 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
536 Handle bootstrap_method,
537 Symbol* name,
538 Symbol* type,
539 Handle *appendix_result,
540 Handle *method_type_result,
541 TRAPS);
542
543 // Utility for printing loader "name" as part of tracing constraints
544 static const char* loader_name(const oop loader);
545 static const char* loader_name(const ClassLoaderData* loader_data);
546
547 // Record the error when the first attempt to resolve a reference from a constant
548 // pool entry to a class fails.
549 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error,
550 Symbol* message);
551 static void delete_resolution_error(ConstantPool* pool);
552 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which,
553 Symbol** message);
554
555 protected:
556
557 enum Constants {
558 _loader_constraint_size = 107, // number of entries in constraint table
559 _resolution_error_size = 107, // number of entries in resolution error table
560 _invoke_method_size = 139, // number of entries in invoke method table
561 _nof_buckets = 1009, // number of buckets in hash table for placeholders
562 _old_default_sdsize = 1009, // backward compat for system dictionary size
563 _prime_array_size = 8, // array of primes for system dictionary size
564 _average_depth_goal = 3 // goal for lookup length
565 };
566
567
568 // Static variables
569
570 // hashtable sizes for system dictionary to allow growth
571 // prime numbers for system dictionary size
572 static int _sdgeneration;
573 static const int _primelist[_prime_array_size];
574
575 // Hashtable holding loaded classes.
576 static Dictionary* _dictionary;
577
578 // Hashtable holding placeholders for classes being loaded.
579 static PlaceholderTable* _placeholders;
580
581 // Hashtable holding classes from the shared archive.
582 static Dictionary* _shared_dictionary;
583
584 // Monotonically increasing counter which grows with
585 // _number_of_classes as well as hot-swapping and breakpoint setting
586 // and removal.
587 static int _number_of_modifications;
588
589 // Lock object for system class loader
590 static oop _system_loader_lock_obj;
591
592 // Constraints on class loaders
593 static LoaderConstraintTable* _loader_constraints;
594
595 // Resolution errors
596 static ResolutionErrorTable* _resolution_errors;
597
598 // Invoke methods (JSR 292)
599 static SymbolPropertyTable* _invoke_method_table;
600
601 public:
602 // for VM_CounterDecay iteration support
603 friend class CounterDecay;
604 static Klass* try_get_next_class();
605
606 protected:
607 static void validate_protection_domain(instanceKlassHandle klass,
608 Handle class_loader,
609 Handle protection_domain, TRAPS);
610
611 friend class VM_PopulateDumpSharedSpace;
612 friend class TraversePlaceholdersClosure;
613 static Dictionary* dictionary() { return _dictionary; }
614 static Dictionary* shared_dictionary() { return _shared_dictionary; }
615 static PlaceholderTable* placeholders() { return _placeholders; }
616 static LoaderConstraintTable* constraints() { return _loader_constraints; }
617 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
618 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
619
620 // Basic loading operations
621 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
622 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
623 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
624 // Wait on SystemDictionary_lock; unlocks lockObject before
625 // waiting; relocks lockObject with correct recursion count
626 // after waiting, but before reentering SystemDictionary_lock
627 // to preserve lock order semantics.
628 static void double_lock_wait(Handle lockObject, TRAPS);
629 static void define_instance_class(instanceKlassHandle k, TRAPS);
630 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
631 Handle class_loader,
632 instanceKlassHandle k, TRAPS);
633 static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
634 Handle class_loader,
635 Handle protection_domain,
636 TRAPS);
637 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
638 static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
639 static void check_loader_lock_contention(Handle loader_lock, TRAPS);
640 static bool is_parallelCapable(Handle class_loader);
641 static bool is_parallelDefine(Handle class_loader);
642
643 public:
644 static instanceKlassHandle load_shared_class(Symbol* class_name,
645 Handle class_loader,
646 TRAPS);
647 static bool is_ext_class_loader(Handle class_loader);
648
649 protected:
650 static Klass* find_shared_class(Symbol* class_name);
651
652 // Setup link to hierarchy
653 static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
654
655 // We pass in the hashtable index so we can calculate it outside of
656 // the SystemDictionary_lock.
657
658 // Basic find on loaded classes
659 static Klass* find_class(int index, unsigned int hash,
660 Symbol* name, ClassLoaderData* loader_data);
661 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
662
663 // Basic find on classes in the midst of being loaded
664 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
665
666 // Updating entry in dictionary
667 // Add a completely loaded class
668 static void add_klass(int index, Symbol* class_name,
669 ClassLoaderData* loader_data, KlassHandle obj);
670
671 // Add a placeholder for a class being loaded
672 static void add_placeholder(int index,
673 Symbol* class_name,
674 ClassLoaderData* loader_data);
675 static void remove_placeholder(int index,
676 Symbol* class_name,
677 ClassLoaderData* loader_data);
678
679 // Performs cleanups after resolve_super_or_fail. This typically needs
680 // to be called on failure.
681 // Won't throw, but can block.
682 static void resolution_cleanups(Symbol* class_name,
683 ClassLoaderData* loader_data,
684 TRAPS);
685
686 // Initialization
687 static void initialize_preloaded_classes(TRAPS);
688
689 // Class loader constraints
690 static void check_constraints(int index, unsigned int hash,
691 instanceKlassHandle k, Handle loader,
692 bool defining, TRAPS);
693 static void update_dictionary(int d_index, unsigned int d_hash,
694 int p_index, unsigned int p_hash,
695 instanceKlassHandle k, Handle loader,
696 TRAPS);
697
698 // Variables holding commonly used klasses (preloaded)
699 static InstanceKlass* _well_known_klasses[];
700
701 // Lazily loaded klasses
702 static InstanceKlass* volatile _abstract_ownable_synchronizer_klass;
703
704 // table of box klasses (int_klass, etc.)
705 static InstanceKlass* _box_klasses[T_VOID+1];
706
707 static oop _java_system_loader;
708
709 static bool _has_loadClassInternal;
710 static bool _has_checkPackageAccess;
711 };
712
713 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP