Wed, 09 Jun 2010 18:50:45 -0700
6939203: JSR 292 needs method handle constants
Summary: Add new CP types CONSTANT_MethodHandle, CONSTANT_MethodType; extend 'ldc' bytecode.
Reviewed-by: twisti, never
1 /*
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25 // A ConstantPoolCacheEntry describes an individual entry of the constant
26 // pool cache. There's 2 principal kinds of entries: field entries for in-
27 // stance & static field access, and method entries for invokes. Some of
28 // the entry layout is shared and looks as follows:
29 //
30 // bit number |31 0|
31 // bit length |-8--|-8--|---16----|
32 // --------------------------------
33 // _indices [ b2 | b1 | index ]
34 // _f1 [ entry specific ]
35 // _f2 [ entry specific ]
36 // _flags [t|f|vf|v|m|h|unused|field_index] (for field entries)
37 // bit length |4|1|1 |1|1|0|---7--|----16-----]
38 // _flags [t|f|vf|v|m|h|unused|eidx|psze] (for method entries)
39 // bit length |4|1|1 |1|1|1|---7--|-8--|-8--]
41 // --------------------------------
42 //
43 // with:
44 // index = original constant pool index
45 // b1 = bytecode 1
46 // b2 = bytecode 2
47 // psze = parameters size (method entries only)
48 // eidx = interpreter entry index (method entries only)
49 // field_index = index into field information in holder instanceKlass
50 // The index max is 0xffff (max number of fields in constant pool)
51 // and is multiplied by (instanceKlass::next_offset) when accessing.
52 // t = TosState (see below)
53 // f = field is marked final (see below)
54 // vf = virtual, final (method entries only : is_vfinal())
55 // v = field is volatile (see below)
56 // m = invokeinterface used for method in class Object (see below)
57 // h = RedefineClasses/Hotswap bit (see below)
58 //
59 // The flags after TosState have the following interpretation:
60 // bit 27: f flag true if field is marked final
61 // bit 26: vf flag true if virtual final method
62 // bit 25: v flag true if field is volatile (only for fields)
63 // bit 24: m flag true if invokeinterface used for method in class Object
64 // bit 23: 0 for fields, 1 for methods
65 //
66 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 8 with the
67 // following mapping to the TosState states:
68 //
69 // btos: 0
70 // ctos: 1
71 // stos: 2
72 // itos: 3
73 // ltos: 4
74 // ftos: 5
75 // dtos: 6
76 // atos: 7
77 // vtos: 8
78 //
79 // Entry specific: field entries:
80 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index
81 // _f1 = field holder
82 // _f2 = field offset in words
83 // _flags = field type information, original field index in field holder
84 // (field_index section)
85 //
86 // Entry specific: method entries:
87 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section),
88 // original constant pool index
89 // _f1 = method for all but virtual calls, unused by virtual calls
90 // (note: for interface calls, which are essentially virtual,
91 // contains klassOop for the corresponding interface.
92 // for invokedynamic, f1 contains the CallSite object for the invocation
93 // _f2 = method/vtable index for virtual calls only, unused by all other
94 // calls. The vf flag indicates this is a method pointer not an
95 // index.
96 // _flags = field type info (f section),
97 // virtual final entry (vf),
98 // interpreter entry index (eidx section),
99 // parameter size (psze section)
100 //
101 // Note: invokevirtual & invokespecial bytecodes can share the same constant
102 // pool entry and thus the same constant pool cache entry. All invoke
103 // bytecodes but invokevirtual use only _f1 and the corresponding b1
104 // bytecode, while invokevirtual uses only _f2 and the corresponding
105 // b2 bytecode. The value of _flags is shared for both types of entries.
106 //
107 // The fields are volatile so that they are stored in the order written in the
108 // source code. The _indices field with the bytecode must be written last.
110 class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {
111 friend class VMStructs;
112 friend class constantPoolCacheKlass;
113 friend class constantPoolOopDesc; //resolve_constant_at_impl => set_f1
115 private:
116 volatile intx _indices; // constant pool index & rewrite bytecodes
117 volatile oop _f1; // entry specific oop field
118 volatile intx _f2; // entry specific int/oop field
119 volatile intx _flags; // flags
122 #ifdef ASSERT
123 bool same_methodOop(oop cur_f1, oop f1);
124 #endif
126 void set_bytecode_1(Bytecodes::Code code);
127 void set_bytecode_2(Bytecodes::Code code);
128 void set_f1(oop f1) {
129 oop existing_f1 = _f1; // read once
130 assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
131 oop_store(&_f1, f1);
132 }
133 void set_f2(intx f2) { assert(_f2 == 0 || _f2 == f2, "illegal field change"); _f2 = f2; }
134 int as_flags(TosState state, bool is_final, bool is_vfinal, bool is_volatile,
135 bool is_method_interface, bool is_method);
136 void set_flags(intx flags) { _flags = flags; }
138 public:
139 // specific bit values in flag field
140 // Note: the interpreter knows this layout!
141 enum FlagBitValues {
142 hotSwapBit = 23,
143 methodInterface = 24,
144 volatileField = 25,
145 vfinalMethod = 26,
146 finalField = 27
147 };
149 enum { field_index_mask = 0xFFFF };
151 // start of type bits in flags
152 // Note: the interpreter knows this layout!
153 enum FlagValues {
154 tosBits = 28
155 };
157 // Initialization
158 void initialize_entry(int original_index); // initialize primary entry
159 void initialize_secondary_entry(int main_index); // initialize secondary entry
161 void set_field( // sets entry to resolved field state
162 Bytecodes::Code get_code, // the bytecode used for reading the field
163 Bytecodes::Code put_code, // the bytecode used for writing the field
164 KlassHandle field_holder, // the object/klass holding the field
165 int orig_field_index, // the original field index in the field holder
166 int field_offset, // the field offset in words in the field holder
167 TosState field_type, // the (machine) field type
168 bool is_final, // the field is final
169 bool is_volatile // the field is volatile
170 );
172 void set_method( // sets entry to resolved method entry
173 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
174 methodHandle method, // the method/prototype if any (NULL, otherwise)
175 int vtable_index // the vtable index if any, else negative
176 );
178 void set_interface_call(
179 methodHandle method, // Resolved method
180 int index // Method index into interface
181 );
183 void set_dynamic_call(
184 Handle call_site, // Resolved java.dyn.CallSite (f1)
185 methodHandle signature_invoker // determines signature information
186 );
188 void set_parameter_size(int value) {
189 assert(parameter_size() == 0 || parameter_size() == value,
190 "size must not change");
191 // Setting the parameter size by itself is only safe if the
192 // current value of _flags is 0, otherwise another thread may have
193 // updated it and we don't want to overwrite that value. Don't
194 // bother trying to update it once it's nonzero but always make
195 // sure that the final parameter size agrees with what was passed.
196 if (_flags == 0) {
197 Atomic::cmpxchg_ptr((value & 0xFF), &_flags, 0);
198 }
199 guarantee(parameter_size() == value, "size must not change");
200 }
202 // Which bytecode number (1 or 2) in the index field is valid for this bytecode?
203 // Returns -1 if neither is valid.
204 static int bytecode_number(Bytecodes::Code code) {
205 switch (code) {
206 case Bytecodes::_getstatic : // fall through
207 case Bytecodes::_getfield : // fall through
208 case Bytecodes::_invokespecial : // fall through
209 case Bytecodes::_invokestatic : // fall through
210 case Bytecodes::_invokeinterface : return 1;
211 case Bytecodes::_putstatic : // fall through
212 case Bytecodes::_putfield : // fall through
213 case Bytecodes::_invokevirtual : return 2;
214 default : break;
215 }
216 return -1;
217 }
219 // Has this bytecode been resolved? Only valid for invokes and get/put field/static.
220 bool is_resolved(Bytecodes::Code code) const {
221 switch (bytecode_number(code)) {
222 case 1: return (bytecode_1() == code);
223 case 2: return (bytecode_2() == code);
224 }
225 return false; // default: not resolved
226 }
228 // Accessors
229 bool is_secondary_entry() const { return (_indices & 0xFFFF) == 0; }
230 int constant_pool_index() const { assert((_indices & 0xFFFF) != 0, "must be main entry");
231 return (_indices & 0xFFFF); }
232 int main_entry_index() const { assert((_indices & 0xFFFF) == 0, "must be secondary entry");
233 return ((uintx)_indices >> 16); }
234 Bytecodes::Code bytecode_1() const { return Bytecodes::cast((_indices >> 16) & 0xFF); }
235 Bytecodes::Code bytecode_2() const { return Bytecodes::cast((_indices >> 24) & 0xFF); }
236 volatile oop f1() const { return _f1; }
237 intx f2() const { return _f2; }
238 int field_index() const;
239 int parameter_size() const { return _flags & 0xFF; }
240 bool is_vfinal() const { return ((_flags & (1 << vfinalMethod)) == (1 << vfinalMethod)); }
241 bool is_volatile() const { return ((_flags & (1 << volatileField)) == (1 << volatileField)); }
242 bool is_methodInterface() const { return ((_flags & (1 << methodInterface)) == (1 << methodInterface)); }
243 bool is_byte() const { return (((uintx) _flags >> tosBits) == btos); }
244 bool is_char() const { return (((uintx) _flags >> tosBits) == ctos); }
245 bool is_short() const { return (((uintx) _flags >> tosBits) == stos); }
246 bool is_int() const { return (((uintx) _flags >> tosBits) == itos); }
247 bool is_long() const { return (((uintx) _flags >> tosBits) == ltos); }
248 bool is_float() const { return (((uintx) _flags >> tosBits) == ftos); }
249 bool is_double() const { return (((uintx) _flags >> tosBits) == dtos); }
250 bool is_object() const { return (((uintx) _flags >> tosBits) == atos); }
251 TosState flag_state() const { assert( ( (_flags >> tosBits) & 0x0F ) < number_of_states, "Invalid state in as_flags");
252 return (TosState)((_flags >> tosBits) & 0x0F); }
254 // Code generation support
255 static WordSize size() { return in_WordSize(sizeof(ConstantPoolCacheEntry) / HeapWordSize); }
256 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
257 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
258 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
259 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
260 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
262 // GC Support
263 void oops_do(void f(oop*));
264 void oop_iterate(OopClosure* blk);
265 void oop_iterate_m(OopClosure* blk, MemRegion mr);
266 void follow_contents();
267 void adjust_pointers();
269 #ifndef SERIALGC
270 // Parallel Old
271 void follow_contents(ParCompactionManager* cm);
272 #endif // SERIALGC
274 void update_pointers();
275 void update_pointers(HeapWord* beg_addr, HeapWord* end_addr);
277 // RedefineClasses() API support:
278 // If this constantPoolCacheEntry refers to old_method then update it
279 // to refer to new_method.
280 // trace_name_printed is set to true if the current call has
281 // printed the klass name so that other routines in the adjust_*
282 // group don't print the klass name.
283 bool adjust_method_entry(methodOop old_method, methodOop new_method,
284 bool * trace_name_printed);
285 bool is_interesting_method_entry(klassOop k);
286 bool is_field_entry() const { return (_flags & (1 << hotSwapBit)) == 0; }
287 bool is_method_entry() const { return (_flags & (1 << hotSwapBit)) != 0; }
289 // Debugging & Printing
290 void print (outputStream* st, int index) const;
291 void verify(outputStream* st) const;
293 static void verify_tosBits() {
294 assert(tosBits == 28, "interpreter now assumes tosBits is 28");
295 }
296 };
299 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache
300 // holds interpreter runtime information for all field access and invoke bytecodes. The cache
301 // is created and initialized before a class is actively used (i.e., initialized), the indivi-
302 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).
304 class constantPoolCacheOopDesc: public oopDesc {
305 friend class VMStructs;
306 private:
307 int _length;
308 constantPoolOop _constant_pool; // the corresponding constant pool
309 // If true, safe for concurrent GC processing,
310 // Set unconditionally in constantPoolCacheKlass::allocate()
311 volatile bool _is_conc_safe;
313 // Sizing
314 debug_only(friend class ClassVerifier;)
315 int length() const { return _length; }
316 void set_length(int length) { _length = length; }
318 static int header_size() { return sizeof(constantPoolCacheOopDesc) / HeapWordSize; }
319 static int object_size(int length) { return align_object_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
320 int object_size() { return object_size(length()); }
322 // Helpers
323 constantPoolOop* constant_pool_addr() { return &_constant_pool; }
324 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
326 friend class constantPoolCacheKlass;
327 friend class ConstantPoolCacheEntry;
329 public:
330 // Initialization
331 void initialize(intArray& inverse_index_map);
333 // Secondary indexes.
334 // They must look completely different from normal indexes.
335 // The main reason is that byte swapping is sometimes done on normal indexes.
336 // Also, some of the CP accessors do different things for secondary indexes.
337 // Finally, it is helpful for debugging to tell the two apart.
338 static bool is_secondary_index(int i) { return (i < 0); }
339 static int decode_secondary_index(int i) { assert(is_secondary_index(i), ""); return ~i; }
340 static int encode_secondary_index(int i) { assert(!is_secondary_index(i), ""); return ~i; }
342 // Accessors
343 void set_constant_pool(constantPoolOop pool) { oop_store_without_check((oop*)&_constant_pool, (oop)pool); }
344 constantPoolOop constant_pool() const { return _constant_pool; }
345 // Fetches the entry at the given index.
346 // The entry may be either primary or secondary.
347 // In either case the index must not be encoded or byte-swapped in any way.
348 ConstantPoolCacheEntry* entry_at(int i) const {
349 assert(0 <= i && i < length(), "index out of bounds");
350 return base() + i;
351 }
352 // Fetches the secondary entry referred to by index.
353 // The index may be a secondary index, and must not be byte-swapped.
354 ConstantPoolCacheEntry* secondary_entry_at(int i) const {
355 int raw_index = i;
356 if (is_secondary_index(i)) { // correct these on the fly
357 raw_index = decode_secondary_index(i);
358 }
359 assert(entry_at(raw_index)->is_secondary_entry(), "not a secondary entry");
360 return entry_at(raw_index);
361 }
362 // Given a primary or secondary index, fetch the corresponding primary entry.
363 // Indirect through the secondary entry, if the index is encoded as a secondary index.
364 // The index must not be byte-swapped.
365 ConstantPoolCacheEntry* main_entry_at(int i) const {
366 int primary_index = i;
367 if (is_secondary_index(i)) {
368 // run through an extra level of indirection:
369 int raw_index = decode_secondary_index(i);
370 primary_index = entry_at(raw_index)->main_entry_index();
371 }
372 assert(!entry_at(primary_index)->is_secondary_entry(), "only one level of indirection");
373 return entry_at(primary_index);
374 }
376 // GC support
377 // If the _length field has not been set, the size of the
378 // constantPoolCache cannot be correctly calculated.
379 bool is_conc_safe() { return _is_conc_safe; }
380 void set_is_conc_safe(bool v) { _is_conc_safe = v; }
382 // Code generation
383 static ByteSize base_offset() { return in_ByteSize(sizeof(constantPoolCacheOopDesc)); }
384 static ByteSize entry_offset(int raw_index) {
385 int index = raw_index;
386 if (is_secondary_index(raw_index))
387 index = decode_secondary_index(raw_index);
388 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
389 }
391 // RedefineClasses() API support:
392 // If any entry of this constantPoolCache points to any of
393 // old_methods, replace it with the corresponding new_method.
394 // trace_name_printed is set to true if the current call has
395 // printed the klass name so that other routines in the adjust_*
396 // group don't print the klass name.
397 void adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
398 int methods_length, bool * trace_name_printed);
399 };