Fri, 25 Jan 2013 15:06:18 -0500
6479360: PrintClassHistogram improvements
Summary: jcmd <pid> GC.class_stats (UnlockDiagnosticVMOptions)
Reviewed-by: coleenp, hseigel, sla, acorn
Contributed-by: ioi.lam@oracle.com
1 /*
2 * Copyright (c) 1997, 2013, 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 */
25 #ifndef SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
26 #define SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
28 #include "oops/arrayOop.hpp"
29 #include "oops/cpCache.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/symbol.hpp"
32 #include "oops/typeArrayOop.hpp"
33 #include "runtime/handles.hpp"
34 #include "utilities/constantTag.hpp"
35 #ifdef TARGET_ARCH_x86
36 # include "bytes_x86.hpp"
37 #endif
38 #ifdef TARGET_ARCH_sparc
39 # include "bytes_sparc.hpp"
40 #endif
41 #ifdef TARGET_ARCH_zero
42 # include "bytes_zero.hpp"
43 #endif
44 #ifdef TARGET_ARCH_arm
45 # include "bytes_arm.hpp"
46 #endif
47 #ifdef TARGET_ARCH_ppc
48 # include "bytes_ppc.hpp"
49 #endif
51 // A constantPool is an array containing class constants as described in the
52 // class file.
53 //
54 // Most of the constant pool entries are written during class parsing, which
55 // is safe. For klass types, the constant pool entry is
56 // modified when the entry is resolved. If a klass constant pool
57 // entry is read without a lock, only the resolved state guarantees that
58 // the entry in the constant pool is a klass object and not a Symbol*.
60 class SymbolHashMap;
62 class CPSlot VALUE_OBJ_CLASS_SPEC {
63 intptr_t _ptr;
64 public:
65 CPSlot(intptr_t ptr): _ptr(ptr) {}
66 CPSlot(Klass* ptr): _ptr((intptr_t)ptr) {}
67 CPSlot(Symbol* ptr): _ptr((intptr_t)ptr | 1) {}
69 intptr_t value() { return _ptr; }
70 bool is_resolved() { return (_ptr & 1) == 0; }
71 bool is_unresolved() { return (_ptr & 1) == 1; }
73 Symbol* get_symbol() {
74 assert(is_unresolved(), "bad call");
75 return (Symbol*)(_ptr & ~1);
76 }
77 Klass* get_klass() {
78 assert(is_resolved(), "bad call");
79 return (Klass*)_ptr;
80 }
81 };
83 class KlassSizeStats;
84 class ConstantPool : public Metadata {
85 friend class VMStructs;
86 friend class BytecodeInterpreter; // Directly extracts an oop in the pool for fast instanceof/checkcast
87 friend class Universe; // For null constructor
88 private:
89 Array<u1>* _tags; // the tag array describing the constant pool's contents
90 ConstantPoolCache* _cache; // the cache holding interpreter runtime information
91 InstanceKlass* _pool_holder; // the corresponding class
92 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
94 // Array of resolved objects from the constant pool and map from resolved
95 // object index to original constant pool index
96 jobject _resolved_references;
97 Array<u2>* _reference_map;
99 enum {
100 _has_invokedynamic = 1, // Flags
101 _has_pseudo_string = 2,
102 _has_preresolution = 4,
103 _on_stack = 8
104 };
106 int _flags; // old fashioned bit twiddling
107 int _length; // number of elements in the array
109 union {
110 // set for CDS to restore resolved references
111 int _resolved_reference_length;
112 // keeps version number for redefined classes (used in backtrace)
113 int _version;
114 } _saved;
116 Monitor* _lock;
118 void set_tags(Array<u1>* tags) { _tags = tags; }
119 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); }
120 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
122 void set_operands(Array<u2>* operands) { _operands = operands; }
124 int flags() const { return _flags; }
125 void set_flags(int f) { _flags = f; }
127 private:
128 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
130 CPSlot slot_at(int which) {
131 assert(is_within_bounds(which), "index out of bounds");
132 // Uses volatile because the klass slot changes without a lock.
133 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which));
134 assert(adr != 0 || which == 0, "cp entry for klass should not be zero");
135 return CPSlot(adr);
136 }
138 void slot_at_put(int which, CPSlot s) const {
139 assert(is_within_bounds(which), "index out of bounds");
140 assert(s.value() != 0, "Caught something");
141 *(intptr_t*)&base()[which] = s.value();
142 }
143 intptr_t* obj_at_addr_raw(int which) const {
144 assert(is_within_bounds(which), "index out of bounds");
145 return (intptr_t*) &base()[which];
146 }
148 jint* int_at_addr(int which) const {
149 assert(is_within_bounds(which), "index out of bounds");
150 return (jint*) &base()[which];
151 }
153 jlong* long_at_addr(int which) const {
154 assert(is_within_bounds(which), "index out of bounds");
155 return (jlong*) &base()[which];
156 }
158 jfloat* float_at_addr(int which) const {
159 assert(is_within_bounds(which), "index out of bounds");
160 return (jfloat*) &base()[which];
161 }
163 jdouble* double_at_addr(int which) const {
164 assert(is_within_bounds(which), "index out of bounds");
165 return (jdouble*) &base()[which];
166 }
168 ConstantPool(Array<u1>* tags);
169 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
170 public:
171 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
173 bool is_constantPool() const volatile { return true; }
175 Array<u1>* tags() const { return _tags; }
176 Array<u2>* operands() const { return _operands; }
178 bool has_invokedynamic() const { return (_flags & _has_invokedynamic) != 0; }
179 void set_has_invokedynamic() { _flags |= _has_invokedynamic; }
181 bool has_pseudo_string() const { return (_flags & _has_pseudo_string) != 0; }
182 void set_has_pseudo_string() { _flags |= _has_pseudo_string; }
184 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
185 void set_has_preresolution() { _flags |= _has_preresolution; }
187 // Redefine classes support. If a method refering to this constant pool
188 // is on the executing stack, or as a handle in vm code, this constant pool
189 // can't be removed from the set of previous versions saved in the instance
190 // class.
191 bool on_stack() const { return (_flags &_on_stack) != 0; }
192 void set_on_stack(const bool value);
194 // Klass holding pool
195 InstanceKlass* pool_holder() const { return _pool_holder; }
196 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
197 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
199 // Interpreter runtime support
200 ConstantPoolCache* cache() const { return _cache; }
201 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
203 // Create object cache in the constant pool
204 void initialize_resolved_references(ClassLoaderData* loader_data,
205 intStack reference_map,
206 int constant_pool_map_length,
207 TRAPS);
209 // resolved strings, methodHandles and callsite objects from the constant pool
210 objArrayOop resolved_references() const;
211 // mapping resolved object array indexes to cp indexes and back.
212 int object_to_cp_index(int index) { return _reference_map->at(index); }
213 int cp_to_object_index(int index);
215 // Invokedynamic indexes.
216 // They must look completely different from normal indexes.
217 // The main reason is that byte swapping is sometimes done on normal indexes.
218 // Finally, it is helpful for debugging to tell the two apart.
219 static bool is_invokedynamic_index(int i) { return (i < 0); }
220 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
221 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
224 // The invokedynamic points at a CP cache entry. This entry points back
225 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry
226 // in the resolved_references array (which provides the appendix argument).
227 int invokedynamic_cp_cache_index(int index) const {
228 assert (is_invokedynamic_index(index), "should be a invokedynamic index");
229 int cache_index = decode_invokedynamic_index(index);
230 return cache_index;
231 }
232 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const {
233 // decode index that invokedynamic points to.
234 int cp_cache_index = invokedynamic_cp_cache_index(index);
235 return cache()->entry_at(cp_cache_index);
236 }
238 // Assembly code support
239 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); }
240 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); }
241 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); }
242 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPool, _resolved_references); }
243 static int reference_map_offset_in_bytes() { return offset_of(ConstantPool, _reference_map); }
245 // Storing constants
247 void klass_at_put(int which, Klass* k) {
248 assert(k != NULL, "resolved class shouldn't be null");
249 assert(is_within_bounds(which), "index out of bounds");
250 OrderAccess::release_store_ptr((Klass* volatile *)obj_at_addr_raw(which), k);
251 // The interpreter assumes when the tag is stored, the klass is resolved
252 // and the Klass* is a klass rather than a Symbol*, so we need
253 // hardware store ordering here.
254 release_tag_at_put(which, JVM_CONSTANT_Class);
255 }
257 // For temporary use while constructing constant pool
258 void klass_index_at_put(int which, int name_index) {
259 tag_at_put(which, JVM_CONSTANT_ClassIndex);
260 *int_at_addr(which) = name_index;
261 }
263 // Temporary until actual use
264 void unresolved_klass_at_put(int which, Symbol* s) {
265 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
266 slot_at_put(which, s);
267 }
269 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
270 tag_at_put(which, JVM_CONSTANT_MethodHandle);
271 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
272 }
274 void method_type_index_at_put(int which, int ref_index) {
275 tag_at_put(which, JVM_CONSTANT_MethodType);
276 *int_at_addr(which) = ref_index;
277 }
279 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
280 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
281 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
282 }
284 void unresolved_string_at_put(int which, Symbol* s) {
285 release_tag_at_put(which, JVM_CONSTANT_String);
286 *symbol_at_addr(which) = s;
287 }
289 void int_at_put(int which, jint i) {
290 tag_at_put(which, JVM_CONSTANT_Integer);
291 *int_at_addr(which) = i;
292 }
294 void long_at_put(int which, jlong l) {
295 tag_at_put(which, JVM_CONSTANT_Long);
296 // *long_at_addr(which) = l;
297 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
298 }
300 void float_at_put(int which, jfloat f) {
301 tag_at_put(which, JVM_CONSTANT_Float);
302 *float_at_addr(which) = f;
303 }
305 void double_at_put(int which, jdouble d) {
306 tag_at_put(which, JVM_CONSTANT_Double);
307 // *double_at_addr(which) = d;
308 // u8 temp = *(u8*) &d;
309 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
310 }
312 Symbol** symbol_at_addr(int which) const {
313 assert(is_within_bounds(which), "index out of bounds");
314 return (Symbol**) &base()[which];
315 }
317 void symbol_at_put(int which, Symbol* s) {
318 assert(s->refcount() != 0, "should have nonzero refcount");
319 tag_at_put(which, JVM_CONSTANT_Utf8);
320 *symbol_at_addr(which) = s;
321 }
323 void string_at_put(int which, int obj_index, oop str) {
324 resolved_references()->obj_at_put(obj_index, str);
325 }
327 void set_object_tag_at(int which) {
328 release_tag_at_put(which, JVM_CONSTANT_Object);
329 }
331 void object_at_put(int which, oop obj) {
332 resolved_references()->obj_at_put(cp_to_object_index(which), obj);
333 }
335 // For temporary use while constructing constant pool
336 void string_index_at_put(int which, int string_index) {
337 tag_at_put(which, JVM_CONSTANT_StringIndex);
338 *int_at_addr(which) = string_index;
339 }
341 void field_at_put(int which, int class_index, int name_and_type_index) {
342 tag_at_put(which, JVM_CONSTANT_Fieldref);
343 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
344 }
346 void method_at_put(int which, int class_index, int name_and_type_index) {
347 tag_at_put(which, JVM_CONSTANT_Methodref);
348 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
349 }
351 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
352 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
353 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
354 }
356 void name_and_type_at_put(int which, int name_index, int signature_index) {
357 tag_at_put(which, JVM_CONSTANT_NameAndType);
358 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
359 }
361 // Tag query
363 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
365 // Fetching constants
367 Klass* klass_at(int which, TRAPS) {
368 constantPoolHandle h_this(THREAD, this);
369 return klass_at_impl(h_this, which, CHECK_NULL);
370 }
372 Symbol* klass_name_at(int which); // Returns the name, w/o resolving.
374 Klass* resolved_klass_at(int which) { // Used by Compiler
375 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
376 // Must do an acquire here in case another thread resolved the klass
377 // behind our back, lest we later load stale values thru the oop.
378 return CPSlot((Klass*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_klass();
379 }
381 // This method should only be used with a cpool lock or during parsing or gc
382 Symbol* unresolved_klass_at(int which) { // Temporary until actual use
383 Symbol* s = CPSlot((Symbol*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_symbol();
384 // check that the klass is still unresolved.
385 assert(tag_at(which).is_unresolved_klass(), "Corrupted constant pool");
386 return s;
387 }
389 // RedefineClasses() API support:
390 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
392 jint int_at(int which) {
393 assert(tag_at(which).is_int(), "Corrupted constant pool");
394 return *int_at_addr(which);
395 }
397 jlong long_at(int which) {
398 assert(tag_at(which).is_long(), "Corrupted constant pool");
399 // return *long_at_addr(which);
400 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
401 return *((jlong*)&tmp);
402 }
404 jfloat float_at(int which) {
405 assert(tag_at(which).is_float(), "Corrupted constant pool");
406 return *float_at_addr(which);
407 }
409 jdouble double_at(int which) {
410 assert(tag_at(which).is_double(), "Corrupted constant pool");
411 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
412 return *((jdouble*)&tmp);
413 }
415 Symbol* symbol_at(int which) {
416 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
417 return *symbol_at_addr(which);
418 }
420 oop string_at(int which, int obj_index, TRAPS) {
421 constantPoolHandle h_this(THREAD, this);
422 return string_at_impl(h_this, which, obj_index, THREAD);
423 }
424 oop string_at(int which, TRAPS) {
425 int obj_index = cp_to_object_index(which);
426 return string_at(which, obj_index, THREAD);
427 }
429 // Version that can be used before string oop array is created.
430 oop uncached_string_at(int which, TRAPS);
432 oop object_at(int which) {
433 assert(tag_at(which).is_object(), "Corrupted constant pool");
434 int obj_index = cp_to_object_index(which);
435 return resolved_references()->obj_at(obj_index);
436 }
438 // A "pseudo-string" is an non-string oop that has found is way into
439 // a String entry.
440 // Under EnableInvokeDynamic this can happen if the user patches a live
441 // object into a CONSTANT_String entry of an anonymous class.
442 // Method oops internally created for method handles may also
443 // use pseudo-strings to link themselves to related metaobjects.
445 bool is_pseudo_string_at(int which) {
446 // A pseudo string is a string that doesn't have a symbol in the cpSlot
447 return unresolved_string_at(which) == NULL;
448 }
450 oop pseudo_string_at(int which, int obj_index) {
451 assert(tag_at(which).is_string(), "Corrupted constant pool");
452 assert(unresolved_string_at(which) == NULL, "shouldn't have symbol");
453 oop s = resolved_references()->obj_at(obj_index);
454 return s;
455 }
457 void pseudo_string_at_put(int which, int obj_index, oop x) {
458 assert(EnableInvokeDynamic, "");
459 set_has_pseudo_string(); // mark header
460 assert(tag_at(which).is_string(), "Corrupted constant pool");
461 string_at_put(which, obj_index, x); // this works just fine
462 }
464 // only called when we are sure a string entry is already resolved (via an
465 // earlier string_at call.
466 oop resolved_string_at(int which) {
467 assert(tag_at(which).is_string(), "Corrupted constant pool");
468 // Must do an acquire here in case another thread resolved the klass
469 // behind our back, lest we later load stale values thru the oop.
470 // we might want a volatile_obj_at in ObjArrayKlass.
471 int obj_index = cp_to_object_index(which);
472 return resolved_references()->obj_at(obj_index);
473 }
475 Symbol* unresolved_string_at(int which) {
476 assert(tag_at(which).is_string(), "Corrupted constant pool");
477 Symbol* s = *symbol_at_addr(which);
478 return s;
479 }
481 // Returns an UTF8 for a CONSTANT_String entry at a given index.
482 // UTF8 char* representation was chosen to avoid conversion of
483 // java_lang_Strings at resolved entries into Symbol*s
484 // or vice versa.
485 // Caller is responsible for checking for pseudo-strings.
486 char* string_at_noresolve(int which);
488 jint name_and_type_at(int which) {
489 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
490 return *int_at_addr(which);
491 }
493 int method_handle_ref_kind_at(int which) {
494 assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
495 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
496 }
497 int method_handle_index_at(int which) {
498 assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
499 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
500 }
501 int method_type_index_at(int which) {
502 assert(tag_at(which).is_method_type(), "Corrupted constant pool");
503 return *int_at_addr(which);
504 }
505 // Derived queries:
506 Symbol* method_handle_name_ref_at(int which) {
507 int member = method_handle_index_at(which);
508 return impl_name_ref_at(member, true);
509 }
510 Symbol* method_handle_signature_ref_at(int which) {
511 int member = method_handle_index_at(which);
512 return impl_signature_ref_at(member, true);
513 }
514 int method_handle_klass_index_at(int which) {
515 int member = method_handle_index_at(which);
516 return impl_klass_ref_index_at(member, true);
517 }
518 Symbol* method_type_signature_at(int which) {
519 int sym = method_type_index_at(which);
520 return symbol_at(sym);
521 }
523 int invoke_dynamic_name_and_type_ref_index_at(int which) {
524 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
525 return extract_high_short_from_int(*int_at_addr(which));
526 }
527 int invoke_dynamic_bootstrap_specifier_index(int which) {
528 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool");
529 return extract_low_short_from_int(*int_at_addr(which));
530 }
531 int invoke_dynamic_operand_base(int which) {
532 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
533 return operand_offset_at(operands(), bootstrap_specifier_index);
534 }
535 // The first part of the operands array consists of an index into the second part.
536 // Extract a 32-bit index value from the first part.
537 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) {
538 int n = (bootstrap_specifier_index * 2);
539 assert(n >= 0 && n+2 <= operands->length(), "oob");
540 // The first 32-bit index points to the beginning of the second part
541 // of the operands array. Make sure this index is in the first part.
542 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
543 operands->at(1)));
544 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
545 int offset = build_int_from_shorts(operands->at(n+0),
546 operands->at(n+1));
547 // The offset itself must point into the second part of the array.
548 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
549 return offset;
550 }
551 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) {
552 int n = bootstrap_specifier_index * 2;
553 assert(n >= 0 && n+2 <= operands->length(), "oob");
554 operands->at_put(n+0, extract_low_short_from_int(offset));
555 operands->at_put(n+1, extract_high_short_from_int(offset));
556 }
557 static int operand_array_length(Array<u2>* operands) {
558 if (operands == NULL || operands->length() == 0) return 0;
559 int second_part = operand_offset_at(operands, 0);
560 return (second_part / 2);
561 }
563 #ifdef ASSERT
564 // operand tuples fit together exactly, end to end
565 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) {
566 int nextidx = bootstrap_specifier_index + 1;
567 if (nextidx == operand_array_length(operands))
568 return operands->length();
569 else
570 return operand_offset_at(operands, nextidx);
571 }
572 int invoke_dynamic_operand_limit(int which) {
573 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
574 return operand_limit_at(operands(), bootstrap_specifier_index);
575 }
576 #endif //ASSERT
578 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array):
579 enum {
580 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
581 _indy_argc_offset = 1, // u2 argc
582 _indy_argv_offset = 2 // u2 argv[argc]
583 };
584 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
585 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
586 int op_base = invoke_dynamic_operand_base(which);
587 return operands()->at(op_base + _indy_bsm_offset);
588 }
589 int invoke_dynamic_argument_count_at(int which) {
590 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
591 int op_base = invoke_dynamic_operand_base(which);
592 int argc = operands()->at(op_base + _indy_argc_offset);
593 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
594 int next_offset = invoke_dynamic_operand_limit(which));
595 assert(end_offset == next_offset, "matched ending");
596 return argc;
597 }
598 int invoke_dynamic_argument_index_at(int which, int j) {
599 int op_base = invoke_dynamic_operand_base(which);
600 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
601 assert((uint)j < (uint)argc, "oob");
602 return operands()->at(op_base + _indy_argv_offset + j);
603 }
605 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
606 // name_and_type_ref_index_at) all expect to be passed indices obtained
607 // directly from the bytecode.
608 // If the indices are meant to refer to fields or methods, they are
609 // actually rewritten constant pool cache indices.
610 // The routine remap_instruction_operand_from_cache manages the adjustment
611 // of these values back to constant pool indices.
613 // There are also "uncached" versions which do not adjust the operand index; see below.
615 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
616 // In a few cases (the verifier) there are uses before a cpcache has been built,
617 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
618 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
620 // Lookup for entries consisting of (klass_index, name_and_type index)
621 Klass* klass_ref_at(int which, TRAPS);
622 Symbol* klass_ref_at_noresolve(int which);
623 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
624 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
626 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
627 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
629 // Lookup for entries consisting of (name_index, signature_index)
630 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
631 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
633 BasicType basic_type_for_signature_at(int which);
635 // Resolve string constants (to prevent allocation during compilation)
636 void resolve_string_constants(TRAPS) {
637 constantPoolHandle h_this(THREAD, this);
638 resolve_string_constants_impl(h_this, CHECK);
639 }
641 // CDS support
642 void remove_unshareable_info();
643 void restore_unshareable_info(TRAPS);
644 bool resolve_class_constants(TRAPS);
645 // The ConstantPool vtable is restored by this call when the ConstantPool is
646 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
647 // all the gory details. SA, dtrace and pstack helpers distinguish metadata
648 // by their vtable.
649 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
651 private:
652 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
653 public:
655 // Resolve late bound constants.
656 oop resolve_constant_at(int index, TRAPS) {
657 constantPoolHandle h_this(THREAD, this);
658 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD);
659 }
661 oop resolve_cached_constant_at(int cache_index, TRAPS) {
662 constantPoolHandle h_this(THREAD, this);
663 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD);
664 }
666 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
667 constantPoolHandle h_this(THREAD, this);
668 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD);
669 }
671 oop resolve_bootstrap_specifier_at(int index, TRAPS) {
672 constantPoolHandle h_this(THREAD, this);
673 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD);
674 }
676 // Klass name matches name at offset
677 bool klass_name_at_matches(instanceKlassHandle k, int which);
679 // Sizing
680 int length() const { return _length; }
681 void set_length(int length) { _length = length; }
683 // Tells whether index is within bounds.
684 bool is_within_bounds(int index) const {
685 return 0 <= index && index < length();
686 }
688 // Sizing (in words)
689 static int header_size() { return sizeof(ConstantPool)/HeapWordSize; }
690 static int size(int length) { return align_object_size(header_size() + length); }
691 int size() const { return size(length()); }
692 #if INCLUDE_SERVICES
693 void collect_statistics(KlassSizeStats *sz) const;
694 #endif
696 friend class ClassFileParser;
697 friend class SystemDictionary;
699 // Used by compiler to prevent classloading.
700 static Method* method_at_if_loaded (constantPoolHandle this_oop, int which);
701 static bool has_appendix_at_if_loaded (constantPoolHandle this_oop, int which);
702 static oop appendix_at_if_loaded (constantPoolHandle this_oop, int which);
703 static bool has_method_type_at_if_loaded (constantPoolHandle this_oop, int which);
704 static oop method_type_at_if_loaded (constantPoolHandle this_oop, int which);
705 static Klass* klass_at_if_loaded (constantPoolHandle this_oop, int which);
706 static Klass* klass_ref_at_if_loaded (constantPoolHandle this_oop, int which);
707 // Same as above - but does LinkResolving.
708 static Klass* klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int which, TRAPS);
710 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
711 // future by other Java code. These take constant pool indices rather than
712 // constant pool cache indices as do the peer methods above.
713 Symbol* uncached_klass_ref_at_noresolve(int which);
714 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
715 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
716 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
717 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
719 // Sharing
720 int pre_resolve_shared_klasses(TRAPS);
722 // Debugging
723 const char* printable_name_at(int which) PRODUCT_RETURN0;
725 #ifdef ASSERT
726 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
727 #else
728 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
729 #endif //ASSERT
731 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
732 if (invokedynamic_ok && is_invokedynamic_index(raw_index))
733 return decode_invokedynamic_index(raw_index);
734 else
735 return raw_index - CPCACHE_INDEX_TAG;
736 }
738 private:
740 void set_resolved_references(jobject s) { _resolved_references = s; }
741 Array<u2>* reference_map() const { return _reference_map; }
742 void set_reference_map(Array<u2>* o) { _reference_map = o; }
744 // patch JSR 292 resolved references after the class is linked.
745 void patch_resolved_references(GrowableArray<Handle>* cp_patches);
747 Symbol* impl_name_ref_at(int which, bool uncached);
748 Symbol* impl_signature_ref_at(int which, bool uncached);
749 int impl_klass_ref_index_at(int which, bool uncached);
750 int impl_name_and_type_ref_index_at(int which, bool uncached);
752 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
754 // Used while constructing constant pool (only by ClassFileParser)
755 jint klass_index_at(int which) {
756 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
757 return *int_at_addr(which);
758 }
760 jint string_index_at(int which) {
761 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
762 return *int_at_addr(which);
763 }
765 // Performs the LinkResolver checks
766 static void verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle klass, TRAPS);
768 // Implementation of methods that needs an exposed 'this' pointer, in order to
769 // handle GC while executing the method
770 static Klass* klass_at_impl(constantPoolHandle this_oop, int which, TRAPS);
771 static oop string_at_impl(constantPoolHandle this_oop, int which, int obj_index, TRAPS);
773 // Resolve string constants (to prevent allocation during compilation)
774 static void resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS);
776 static oop resolve_constant_at_impl(constantPoolHandle this_oop, int index, int cache_index, TRAPS);
777 static void save_and_throw_exception(constantPoolHandle this_oop, int which, int tag_value, TRAPS);
778 static oop resolve_bootstrap_specifier_at_impl(constantPoolHandle this_oop, int index, TRAPS);
780 public:
781 // Merging ConstantPool* support:
782 bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS);
783 void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS) {
784 constantPoolHandle h_this(THREAD, this);
785 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
786 }
787 static void copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS);
788 static void copy_entry_to(constantPoolHandle from_cp, int from_i, constantPoolHandle to_cp, int to_i, TRAPS);
789 int find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS);
790 int version() const { return _saved._version; }
791 void set_version(int version) { _saved._version = version; }
792 void increment_and_save_version(int version) {
793 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
794 }
796 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
797 int resolved_reference_length() const { return _saved._resolved_reference_length; }
798 void set_lock(Monitor* lock) { _lock = lock; }
799 Monitor* lock() { return _lock; }
801 // Decrease ref counts of symbols that are in the constant pool
802 // when the holder class is unloaded
803 void unreference_symbols();
805 // Deallocate constant pool for RedefineClasses
806 void deallocate_contents(ClassLoaderData* loader_data);
807 void release_C_heap_structures();
809 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
810 friend class JvmtiConstantPoolReconstituter;
812 private:
813 jint cpool_entry_size(jint idx);
814 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
816 // Copy cpool bytes into byte array.
817 // Returns:
818 // int > 0, count of the raw cpool bytes that have been copied
819 // 0, OutOfMemory error
820 // -1, Internal error
821 int copy_cpool_bytes(int cpool_size,
822 SymbolHashMap* tbl,
823 unsigned char *bytes);
825 public:
826 // Verify
827 void verify_on(outputStream* st);
829 // Printing
830 void print_on(outputStream* st) const;
831 void print_value_on(outputStream* st) const;
832 void print_entry_on(int index, outputStream* st);
834 const char* internal_name() const { return "{constant pool}"; }
836 #ifndef PRODUCT
837 // Compile the world support
838 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS);
839 #endif
840 };
842 class SymbolHashMapEntry : public CHeapObj<mtSymbol> {
843 private:
844 unsigned int _hash; // 32-bit hash for item
845 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
846 Symbol* _symbol; // 1-st part of the mapping: symbol => value
847 u2 _value; // 2-nd part of the mapping: symbol => value
849 public:
850 unsigned int hash() const { return _hash; }
851 void set_hash(unsigned int hash) { _hash = hash; }
853 SymbolHashMapEntry* next() const { return _next; }
854 void set_next(SymbolHashMapEntry* next) { _next = next; }
856 Symbol* symbol() const { return _symbol; }
857 void set_symbol(Symbol* sym) { _symbol = sym; }
859 u2 value() const { return _value; }
860 void set_value(u2 value) { _value = value; }
862 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
863 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
865 }; // End SymbolHashMapEntry class
868 class SymbolHashMapBucket : public CHeapObj<mtSymbol> {
870 private:
871 SymbolHashMapEntry* _entry;
873 public:
874 SymbolHashMapEntry* entry() const { return _entry; }
875 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
876 void clear() { _entry = NULL; }
878 }; // End SymbolHashMapBucket class
881 class SymbolHashMap: public CHeapObj<mtSymbol> {
883 private:
884 // Default number of entries in the table
885 enum SymbolHashMap_Constants {
886 _Def_HashMap_Size = 256
887 };
889 int _table_size;
890 SymbolHashMapBucket* _buckets;
892 void initialize_table(int table_size) {
893 _table_size = table_size;
894 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol);
895 for (int index = 0; index < table_size; index++) {
896 _buckets[index].clear();
897 }
898 }
900 public:
902 int table_size() const { return _table_size; }
904 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
905 SymbolHashMap(int table_size) { initialize_table(table_size); }
907 // hash P(31) from Kernighan & Ritchie
908 static unsigned int compute_hash(const char* str, int len) {
909 unsigned int hash = 0;
910 while (len-- > 0) {
911 hash = 31*hash + (unsigned) *str;
912 str++;
913 }
914 return hash;
915 }
917 SymbolHashMapEntry* bucket(int i) {
918 return _buckets[i].entry();
919 }
921 void add_entry(Symbol* sym, u2 value);
922 SymbolHashMapEntry* find_entry(Symbol* sym);
924 u2 symbol_to_value(Symbol* sym) {
925 SymbolHashMapEntry *entry = find_entry(sym);
926 return (entry == NULL) ? 0 : entry->value();
927 }
929 ~SymbolHashMap() {
930 SymbolHashMapEntry* next;
931 for (int i = 0; i < _table_size; i++) {
932 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
933 next = cur->next();
934 delete(cur);
935 }
936 }
937 delete _buckets;
938 }
939 }; // End SymbolHashMap class
941 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP