Mon, 09 Mar 2009 13:28:46 -0700
6814575: Update copyright year
Summary: Update copyright for files that have been modified in 2009, up to 03/09
Reviewed-by: katleman, tbell, ohair
1 /*
2 * Copyright 1997-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 // A constantPool is an array containing class constants as described in the
26 // class file.
27 //
28 // Most of the constant pool entries are written during class parsing, which
29 // is safe. For klass and string types, the constant pool entry is
30 // modified when the entry is resolved. If a klass or string constant pool
31 // entry is read without a lock, only the resolved state guarantees that
32 // the entry in the constant pool is a klass or String object and
33 // not a symbolOop.
35 class SymbolHashMap;
37 class constantPoolOopDesc : public oopDesc {
38 friend class VMStructs;
39 friend class BytecodeInterpreter; // Directly extracts an oop in the pool for fast instanceof/checkcast
40 private:
41 typeArrayOop _tags; // the tag array describing the constant pool's contents
42 constantPoolCacheOop _cache; // the cache holding interpreter runtime information
43 klassOop _pool_holder; // the corresponding class
44 int _flags; // a few header bits to describe contents for GC
45 int _length; // number of elements in the array
46 volatile bool _is_conc_safe; // if true, safe for concurrent
47 // GC processing
48 // only set to non-zero if constant pool is merged by RedefineClasses
49 int _orig_length;
51 void set_tags(typeArrayOop tags) { oop_store_without_check((oop*)&_tags, tags); }
52 void tag_at_put(int which, jbyte t) { tags()->byte_at_put(which, t); }
53 void release_tag_at_put(int which, jbyte t) { tags()->release_byte_at_put(which, t); }
55 enum FlagBit {
56 FB_has_pseudo_string = 2
57 };
59 int flags() const { return _flags; }
60 void set_flags(int f) { _flags = f; }
61 bool flag_at(FlagBit fb) const { return (_flags & (1 << (int)fb)) != 0; }
62 void set_flag_at(FlagBit fb);
63 // no clear_flag_at function; they only increase
65 private:
66 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(constantPoolOopDesc)); }
67 oop* tags_addr() { return (oop*)&_tags; }
68 oop* cache_addr() { return (oop*)&_cache; }
70 oop* obj_at_addr(int which) const {
71 assert(is_within_bounds(which), "index out of bounds");
72 return (oop*) &base()[which];
73 }
75 jint* int_at_addr(int which) const {
76 assert(is_within_bounds(which), "index out of bounds");
77 return (jint*) &base()[which];
78 }
80 jlong* long_at_addr(int which) const {
81 assert(is_within_bounds(which), "index out of bounds");
82 return (jlong*) &base()[which];
83 }
85 jfloat* float_at_addr(int which) const {
86 assert(is_within_bounds(which), "index out of bounds");
87 return (jfloat*) &base()[which];
88 }
90 jdouble* double_at_addr(int which) const {
91 assert(is_within_bounds(which), "index out of bounds");
92 return (jdouble*) &base()[which];
93 }
95 public:
96 typeArrayOop tags() const { return _tags; }
98 bool has_pseudo_string() const { return flag_at(FB_has_pseudo_string); }
99 void set_pseudo_string() { set_flag_at(FB_has_pseudo_string); }
101 // Klass holding pool
102 klassOop pool_holder() const { return _pool_holder; }
103 void set_pool_holder(klassOop k) { oop_store_without_check((oop*)&_pool_holder, (oop) k); }
104 oop* pool_holder_addr() { return (oop*)&_pool_holder; }
106 // Interpreter runtime support
107 constantPoolCacheOop cache() const { return _cache; }
108 void set_cache(constantPoolCacheOop cache){ oop_store((oop*)&_cache, cache); }
110 // Assembly code support
111 static int tags_offset_in_bytes() { return offset_of(constantPoolOopDesc, _tags); }
112 static int cache_offset_in_bytes() { return offset_of(constantPoolOopDesc, _cache); }
113 static int pool_holder_offset_in_bytes() { return offset_of(constantPoolOopDesc, _pool_holder); }
115 // Storing constants
117 void klass_at_put(int which, klassOop k) {
118 oop_store_without_check((volatile oop *)obj_at_addr(which), oop(k));
119 // The interpreter assumes when the tag is stored, the klass is resolved
120 // and the klassOop is a klass rather than a symbolOop, so we need
121 // hardware store ordering here.
122 release_tag_at_put(which, JVM_CONSTANT_Class);
123 if (UseConcMarkSweepGC) {
124 // In case the earlier card-mark was consumed by a concurrent
125 // marking thread before the tag was updated, redirty the card.
126 oop_store_without_check((volatile oop *)obj_at_addr(which), oop(k));
127 }
128 }
130 // For temporary use while constructing constant pool
131 void klass_index_at_put(int which, int name_index) {
132 tag_at_put(which, JVM_CONSTANT_ClassIndex);
133 *int_at_addr(which) = name_index;
134 }
136 // Temporary until actual use
137 void unresolved_klass_at_put(int which, symbolOop s) {
138 // Overwrite the old index with a GC friendly value so
139 // that if GC looks during the transition it won't try
140 // to treat a small integer as oop.
141 *obj_at_addr(which) = NULL;
142 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
143 oop_store_without_check(obj_at_addr(which), oop(s));
144 }
146 // Temporary until actual use
147 void unresolved_string_at_put(int which, symbolOop s) {
148 *obj_at_addr(which) = NULL;
149 release_tag_at_put(which, JVM_CONSTANT_UnresolvedString);
150 oop_store_without_check(obj_at_addr(which), oop(s));
151 }
153 void int_at_put(int which, jint i) {
154 tag_at_put(which, JVM_CONSTANT_Integer);
155 *int_at_addr(which) = i;
156 }
158 void long_at_put(int which, jlong l) {
159 tag_at_put(which, JVM_CONSTANT_Long);
160 // *long_at_addr(which) = l;
161 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
162 }
164 void float_at_put(int which, jfloat f) {
165 tag_at_put(which, JVM_CONSTANT_Float);
166 *float_at_addr(which) = f;
167 }
169 void double_at_put(int which, jdouble d) {
170 tag_at_put(which, JVM_CONSTANT_Double);
171 // *double_at_addr(which) = d;
172 // u8 temp = *(u8*) &d;
173 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
174 }
176 void symbol_at_put(int which, symbolOop s) {
177 tag_at_put(which, JVM_CONSTANT_Utf8);
178 oop_store_without_check(obj_at_addr(which), oop(s));
179 }
181 void string_at_put(int which, oop str) {
182 oop_store((volatile oop*)obj_at_addr(which), str);
183 release_tag_at_put(which, JVM_CONSTANT_String);
184 if (UseConcMarkSweepGC) {
185 // In case the earlier card-mark was consumed by a concurrent
186 // marking thread before the tag was updated, redirty the card.
187 oop_store_without_check((volatile oop *)obj_at_addr(which), str);
188 }
189 }
191 // For temporary use while constructing constant pool
192 void string_index_at_put(int which, int string_index) {
193 tag_at_put(which, JVM_CONSTANT_StringIndex);
194 *int_at_addr(which) = string_index;
195 }
197 void field_at_put(int which, int class_index, int name_and_type_index) {
198 tag_at_put(which, JVM_CONSTANT_Fieldref);
199 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
200 }
202 void method_at_put(int which, int class_index, int name_and_type_index) {
203 tag_at_put(which, JVM_CONSTANT_Methodref);
204 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
205 }
207 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
208 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
209 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
210 }
212 void name_and_type_at_put(int which, int name_index, int signature_index) {
213 tag_at_put(which, JVM_CONSTANT_NameAndType);
214 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
215 }
217 // Tag query
219 constantTag tag_at(int which) const { return (constantTag)tags()->byte_at_acquire(which); }
221 // Whether the entry is a pointer that must be GC'd.
222 bool is_pointer_entry(int which) {
223 constantTag tag = tag_at(which);
224 return tag.is_klass() ||
225 tag.is_unresolved_klass() ||
226 tag.is_symbol() ||
227 tag.is_unresolved_string() ||
228 tag.is_string();
229 }
231 // Fetching constants
233 klassOop klass_at(int which, TRAPS) {
234 constantPoolHandle h_this(THREAD, this);
235 return klass_at_impl(h_this, which, CHECK_NULL);
236 }
238 symbolOop klass_name_at(int which); // Returns the name, w/o resolving.
240 klassOop resolved_klass_at(int which) { // Used by Compiler
241 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
242 // Must do an acquire here in case another thread resolved the klass
243 // behind our back, lest we later load stale values thru the oop.
244 return klassOop((oop)OrderAccess::load_ptr_acquire(obj_at_addr(which)));
245 }
247 // This method should only be used with a cpool lock or during parsing or gc
248 symbolOop unresolved_klass_at(int which) { // Temporary until actual use
249 symbolOop s = symbolOop((oop)OrderAccess::load_ptr_acquire(obj_at_addr(which)));
250 // check that the klass is still unresolved.
251 assert(tag_at(which).is_unresolved_klass(), "Corrupted constant pool");
252 return s;
253 }
255 // RedefineClasses() API support:
256 symbolOop klass_at_noresolve(int which) { return klass_name_at(which); }
258 jint int_at(int which) {
259 assert(tag_at(which).is_int(), "Corrupted constant pool");
260 return *int_at_addr(which);
261 }
263 jlong long_at(int which) {
264 assert(tag_at(which).is_long(), "Corrupted constant pool");
265 // return *long_at_addr(which);
266 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
267 return *((jlong*)&tmp);
268 }
270 jfloat float_at(int which) {
271 assert(tag_at(which).is_float(), "Corrupted constant pool");
272 return *float_at_addr(which);
273 }
275 jdouble double_at(int which) {
276 assert(tag_at(which).is_double(), "Corrupted constant pool");
277 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
278 return *((jdouble*)&tmp);
279 }
281 symbolOop symbol_at(int which) {
282 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
283 return symbolOop(*obj_at_addr(which));
284 }
286 oop string_at(int which, TRAPS) {
287 constantPoolHandle h_this(THREAD, this);
288 return string_at_impl(h_this, which, CHECK_NULL);
289 }
291 // A "pseudo-string" is an non-string oop that has found is way into
292 // a String entry.
293 // Under AnonymousClasses this can happen if the user patches a live
294 // object into a CONSTANT_String entry of an anonymous class.
295 // Method oops internally created for method handles may also
296 // use pseudo-strings to link themselves to related metaobjects.
298 bool is_pseudo_string_at(int which);
300 oop pseudo_string_at(int which) {
301 assert(tag_at(which).is_string(), "Corrupted constant pool");
302 return *obj_at_addr(which);
303 }
305 void pseudo_string_at_put(int which, oop x) {
306 assert(AnonymousClasses, "");
307 set_pseudo_string(); // mark header
308 assert(tag_at(which).is_string() || tag_at(which).is_unresolved_string(), "Corrupted constant pool");
309 string_at_put(which, x); // this works just fine
310 }
312 // only called when we are sure a string entry is already resolved (via an
313 // earlier string_at call.
314 oop resolved_string_at(int which) {
315 assert(tag_at(which).is_string(), "Corrupted constant pool");
316 // Must do an acquire here in case another thread resolved the klass
317 // behind our back, lest we later load stale values thru the oop.
318 return (oop)OrderAccess::load_ptr_acquire(obj_at_addr(which));
319 }
321 // This method should only be used with a cpool lock or during parsing or gc
322 symbolOop unresolved_string_at(int which) { // Temporary until actual use
323 symbolOop s = symbolOop((oop)OrderAccess::load_ptr_acquire(obj_at_addr(which)));
324 // check that the string is still unresolved.
325 assert(tag_at(which).is_unresolved_string(), "Corrupted constant pool");
326 return s;
327 }
329 // Returns an UTF8 for a CONSTANT_String entry at a given index.
330 // UTF8 char* representation was chosen to avoid conversion of
331 // java_lang_Strings at resolved entries into symbolOops
332 // or vice versa.
333 // Caller is responsible for checking for pseudo-strings.
334 char* string_at_noresolve(int which);
336 jint name_and_type_at(int which) {
337 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
338 return *int_at_addr(which);
339 }
341 // The following methods (klass_ref_at, klass_ref_at_noresolve, name_ref_at,
342 // signature_ref_at, klass_ref_index_at, name_and_type_ref_index_at,
343 // name_ref_index_at, signature_ref_index_at) all expect constant pool indices
344 // from the bytecodes to be passed in, which are actually potentially byte-swapped
345 // contstant pool cache indices. See field_or_method_at.
347 // Lookup for entries consisting of (klass_index, name_and_type index)
348 klassOop klass_ref_at(int which, TRAPS);
349 symbolOop klass_ref_at_noresolve(int which);
350 symbolOop name_ref_at(int which);
351 symbolOop signature_ref_at(int which); // the type descriptor
353 int klass_ref_index_at(int which);
354 int name_and_type_ref_index_at(int which);
356 // Lookup for entries consisting of (name_index, signature_index)
357 int name_ref_index_at(int which);
358 int signature_ref_index_at(int which);
360 BasicType basic_type_for_signature_at(int which);
362 // Resolve string constants (to prevent allocation during compilation)
363 void resolve_string_constants(TRAPS) {
364 constantPoolHandle h_this(THREAD, this);
365 resolve_string_constants_impl(h_this, CHECK);
366 }
368 // Klass name matches name at offset
369 bool klass_name_at_matches(instanceKlassHandle k, int which);
371 // Sizing
372 int length() const { return _length; }
373 void set_length(int length) { _length = length; }
375 // Tells whether index is within bounds.
376 bool is_within_bounds(int index) const {
377 return 0 <= index && index < length();
378 }
380 static int header_size() { return sizeof(constantPoolOopDesc)/HeapWordSize; }
381 static int object_size(int length) { return align_object_size(header_size() + length); }
382 int object_size() { return object_size(length()); }
384 bool is_conc_safe() { return _is_conc_safe; }
385 void set_is_conc_safe(bool v) { _is_conc_safe = v; }
387 friend class constantPoolKlass;
388 friend class ClassFileParser;
389 friend class SystemDictionary;
391 // Used by compiler to prevent classloading.
392 static klassOop klass_at_if_loaded (constantPoolHandle this_oop, int which);
393 static klassOop klass_ref_at_if_loaded (constantPoolHandle this_oop, int which);
394 // Same as above - but does LinkResolving.
395 static klassOop klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int which, TRAPS);
397 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
398 // future by other Java code. These take constant pool indices rather than possibly-byte-swapped
399 // constant pool cache indices as do the peer methods above.
400 symbolOop uncached_name_ref_at(int which);
401 symbolOop uncached_signature_ref_at(int which);
402 int uncached_klass_ref_index_at(int which);
403 int uncached_name_and_type_ref_index_at(int which);
405 // Sharing
406 int pre_resolve_shared_klasses(TRAPS);
407 void shared_symbols_iterate(OopClosure* closure0);
408 void shared_tags_iterate(OopClosure* closure0);
409 void shared_strings_iterate(OopClosure* closure0);
411 // Debugging
412 const char* printable_name_at(int which) PRODUCT_RETURN0;
414 private:
416 // Takes either a constant pool cache index in possibly byte-swapped
417 // byte order (which comes from the bytecodes after rewriting) or,
418 // if "uncached" is true, a vanilla constant pool index
419 jint field_or_method_at(int which, bool uncached) {
420 int i = -1;
421 if (uncached || cache() == NULL) {
422 i = which;
423 } else {
424 // change byte-ordering and go via cache
425 i = cache()->entry_at(Bytes::swap_u2(which))->constant_pool_index();
426 }
427 assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
428 return *int_at_addr(i);
429 }
431 // Used while constructing constant pool (only by ClassFileParser)
432 jint klass_index_at(int which) {
433 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
434 return *int_at_addr(which);
435 }
437 jint string_index_at(int which) {
438 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
439 return *int_at_addr(which);
440 }
442 // Performs the LinkResolver checks
443 static void verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle klass, TRAPS);
445 // Implementation of methods that needs an exposed 'this' pointer, in order to
446 // handle GC while executing the method
447 static klassOop klass_at_impl(constantPoolHandle this_oop, int which, TRAPS);
448 static oop string_at_impl(constantPoolHandle this_oop, int which, TRAPS);
450 // Resolve string constants (to prevent allocation during compilation)
451 static void resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS);
453 public:
454 // Merging constantPoolOop support:
455 bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS);
456 void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i,
457 TRAPS);
458 void copy_entry_to(int from_i, constantPoolHandle to_cp, int to_i, TRAPS);
459 int find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS);
460 int orig_length() const { return _orig_length; }
461 void set_orig_length(int orig_length) { _orig_length = orig_length; }
464 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
465 friend class JvmtiConstantPoolReconstituter;
467 private:
468 jint cpool_entry_size(jint idx);
469 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
471 // Copy cpool bytes into byte array.
472 // Returns:
473 // int > 0, count of the raw cpool bytes that have been copied
474 // 0, OutOfMemory error
475 // -1, Internal error
476 int copy_cpool_bytes(int cpool_size,
477 SymbolHashMap* tbl,
478 unsigned char *bytes);
479 };
481 class SymbolHashMapEntry : public CHeapObj {
482 private:
483 unsigned int _hash; // 32-bit hash for item
484 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
485 symbolOop _symbol; // 1-st part of the mapping: symbol => value
486 u2 _value; // 2-nd part of the mapping: symbol => value
488 public:
489 unsigned int hash() const { return _hash; }
490 void set_hash(unsigned int hash) { _hash = hash; }
492 SymbolHashMapEntry* next() const { return _next; }
493 void set_next(SymbolHashMapEntry* next) { _next = next; }
495 symbolOop symbol() const { return _symbol; }
496 void set_symbol(symbolOop sym) { _symbol = sym; }
498 u2 value() const { return _value; }
499 void set_value(u2 value) { _value = value; }
501 SymbolHashMapEntry(unsigned int hash, symbolOop symbol, u2 value)
502 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
504 }; // End SymbolHashMapEntry class
507 class SymbolHashMapBucket : public CHeapObj {
509 private:
510 SymbolHashMapEntry* _entry;
512 public:
513 SymbolHashMapEntry* entry() const { return _entry; }
514 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
515 void clear() { _entry = NULL; }
517 }; // End SymbolHashMapBucket class
520 class SymbolHashMap: public CHeapObj {
522 private:
523 // Default number of entries in the table
524 enum SymbolHashMap_Constants {
525 _Def_HashMap_Size = 256
526 };
528 int _table_size;
529 SymbolHashMapBucket* _buckets;
531 void initialize_table(int table_size) {
532 _table_size = table_size;
533 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size);
534 for (int index = 0; index < table_size; index++) {
535 _buckets[index].clear();
536 }
537 }
539 public:
541 int table_size() const { return _table_size; }
543 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
544 SymbolHashMap(int table_size) { initialize_table(table_size); }
546 // hash P(31) from Kernighan & Ritchie
547 static unsigned int compute_hash(const char* str, int len) {
548 unsigned int hash = 0;
549 while (len-- > 0) {
550 hash = 31*hash + (unsigned) *str;
551 str++;
552 }
553 return hash;
554 }
556 SymbolHashMapEntry* bucket(int i) {
557 return _buckets[i].entry();
558 }
560 void add_entry(symbolOop sym, u2 value);
561 SymbolHashMapEntry* find_entry(symbolOop sym);
563 u2 symbol_to_value(symbolOop sym) {
564 SymbolHashMapEntry *entry = find_entry(sym);
565 return (entry == NULL) ? 0 : entry->value();
566 }
568 ~SymbolHashMap() {
569 SymbolHashMapEntry* next;
570 for (int i = 0; i < _table_size; i++) {
571 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
572 next = cur->next();
573 delete(cur);
574 }
575 }
576 delete _buckets;
577 }
578 }; // End SymbolHashMap class