Wed, 17 Mar 2010 11:01:05 +0100
6935224: Adding new DTrace probes to work with Palantir
Summary: Adding probes related to thread scheduling and class initialization
Reviewed-by: kamg, never
1 /*
2 * Copyright 1998-2009 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 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;
114 private:
115 volatile intx _indices; // constant pool index & rewrite bytecodes
116 volatile oop _f1; // entry specific oop field
117 volatile intx _f2; // entry specific int/oop field
118 volatile intx _flags; // flags
121 #ifdef ASSERT
122 bool same_methodOop(oop cur_f1, oop f1);
123 #endif
125 void set_bytecode_1(Bytecodes::Code code);
126 void set_bytecode_2(Bytecodes::Code code);
127 void set_f1(oop f1) {
128 oop existing_f1 = _f1; // read once
129 assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
130 oop_store(&_f1, f1);
131 }
132 void set_f2(intx f2) { assert(_f2 == 0 || _f2 == f2, "illegal field change"); _f2 = f2; }
133 int as_flags(TosState state, bool is_final, bool is_vfinal, bool is_volatile,
134 bool is_method_interface, bool is_method);
135 void set_flags(intx flags) { _flags = flags; }
137 public:
138 // specific bit values in flag field
139 // Note: the interpreter knows this layout!
140 enum FlagBitValues {
141 hotSwapBit = 23,
142 methodInterface = 24,
143 volatileField = 25,
144 vfinalMethod = 26,
145 finalField = 27
146 };
148 enum { field_index_mask = 0xFFFF };
150 // start of type bits in flags
151 // Note: the interpreter knows this layout!
152 enum FlagValues {
153 tosBits = 28
154 };
156 // Initialization
157 void initialize_entry(int original_index); // initialize primary entry
158 void initialize_secondary_entry(int main_index); // initialize secondary entry
160 void set_field( // sets entry to resolved field state
161 Bytecodes::Code get_code, // the bytecode used for reading the field
162 Bytecodes::Code put_code, // the bytecode used for writing the field
163 KlassHandle field_holder, // the object/klass holding the field
164 int orig_field_index, // the original field index in the field holder
165 int field_offset, // the field offset in words in the field holder
166 TosState field_type, // the (machine) field type
167 bool is_final, // the field is final
168 bool is_volatile // the field is volatile
169 );
171 void set_method( // sets entry to resolved method entry
172 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
173 methodHandle method, // the method/prototype if any (NULL, otherwise)
174 int vtable_index // the vtable index if any, else negative
175 );
177 void set_interface_call(
178 methodHandle method, // Resolved method
179 int index // Method index into interface
180 );
182 void set_dynamic_call(
183 Handle call_site, // Resolved java.dyn.CallSite (f1)
184 int extra_data // (f2)
185 );
187 void set_parameter_size(int value) {
188 assert(parameter_size() == 0 || parameter_size() == value,
189 "size must not change");
190 // Setting the parameter size by itself is only safe if the
191 // current value of _flags is 0, otherwise another thread may have
192 // updated it and we don't want to overwrite that value. Don't
193 // bother trying to update it once it's nonzero but always make
194 // sure that the final parameter size agrees with what was passed.
195 if (_flags == 0) {
196 Atomic::cmpxchg_ptr((value & 0xFF), &_flags, 0);
197 }
198 guarantee(parameter_size() == value, "size must not change");
199 }
201 // Which bytecode number (1 or 2) in the index field is valid for this bytecode?
202 // Returns -1 if neither is valid.
203 static int bytecode_number(Bytecodes::Code code) {
204 switch (code) {
205 case Bytecodes::_getstatic : // fall through
206 case Bytecodes::_getfield : // fall through
207 case Bytecodes::_invokespecial : // fall through
208 case Bytecodes::_invokestatic : // fall through
209 case Bytecodes::_invokeinterface : return 1;
210 case Bytecodes::_putstatic : // fall through
211 case Bytecodes::_putfield : // fall through
212 case Bytecodes::_invokevirtual : return 2;
213 default : break;
214 }
215 return -1;
216 }
218 // Has this bytecode been resolved? Only valid for invokes and get/put field/static.
219 bool is_resolved(Bytecodes::Code code) const {
220 switch (bytecode_number(code)) {
221 case 1: return (bytecode_1() == code);
222 case 2: return (bytecode_2() == code);
223 }
224 return false; // default: not resolved
225 }
227 // Accessors
228 bool is_secondary_entry() const { return (_indices & 0xFFFF) == 0; }
229 int constant_pool_index() const { assert((_indices & 0xFFFF) != 0, "must be main entry");
230 return (_indices & 0xFFFF); }
231 int main_entry_index() const { assert((_indices & 0xFFFF) == 0, "must be secondary entry");
232 return ((uintx)_indices >> 16); }
233 Bytecodes::Code bytecode_1() const { return Bytecodes::cast((_indices >> 16) & 0xFF); }
234 Bytecodes::Code bytecode_2() const { return Bytecodes::cast((_indices >> 24) & 0xFF); }
235 volatile oop f1() const { return _f1; }
236 intx f2() const { return _f2; }
237 int field_index() const;
238 int parameter_size() const { return _flags & 0xFF; }
239 bool is_vfinal() const { return ((_flags & (1 << vfinalMethod)) == (1 << vfinalMethod)); }
240 bool is_volatile() const { return ((_flags & (1 << volatileField)) == (1 << volatileField)); }
241 bool is_methodInterface() const { return ((_flags & (1 << methodInterface)) == (1 << methodInterface)); }
242 bool is_byte() const { return (((uintx) _flags >> tosBits) == btos); }
243 bool is_char() const { return (((uintx) _flags >> tosBits) == ctos); }
244 bool is_short() const { return (((uintx) _flags >> tosBits) == stos); }
245 bool is_int() const { return (((uintx) _flags >> tosBits) == itos); }
246 bool is_long() const { return (((uintx) _flags >> tosBits) == ltos); }
247 bool is_float() const { return (((uintx) _flags >> tosBits) == ftos); }
248 bool is_double() const { return (((uintx) _flags >> tosBits) == dtos); }
249 bool is_object() const { return (((uintx) _flags >> tosBits) == atos); }
250 TosState flag_state() const { assert( ( (_flags >> tosBits) & 0x0F ) < number_of_states, "Invalid state in as_flags");
251 return (TosState)((_flags >> tosBits) & 0x0F); }
253 // Code generation support
254 static WordSize size() { return in_WordSize(sizeof(ConstantPoolCacheEntry) / HeapWordSize); }
255 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
256 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
257 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
258 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
259 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
261 // GC Support
262 void oops_do(void f(oop*));
263 void oop_iterate(OopClosure* blk);
264 void oop_iterate_m(OopClosure* blk, MemRegion mr);
265 void follow_contents();
266 void adjust_pointers();
268 #ifndef SERIALGC
269 // Parallel Old
270 void follow_contents(ParCompactionManager* cm);
271 #endif // SERIALGC
273 void update_pointers();
274 void update_pointers(HeapWord* beg_addr, HeapWord* end_addr);
276 // RedefineClasses() API support:
277 // If this constantPoolCacheEntry refers to old_method then update it
278 // to refer to new_method.
279 // trace_name_printed is set to true if the current call has
280 // printed the klass name so that other routines in the adjust_*
281 // group don't print the klass name.
282 bool adjust_method_entry(methodOop old_method, methodOop new_method,
283 bool * trace_name_printed);
284 bool is_interesting_method_entry(klassOop k);
285 bool is_field_entry() const { return (_flags & (1 << hotSwapBit)) == 0; }
286 bool is_method_entry() const { return (_flags & (1 << hotSwapBit)) != 0; }
288 // Debugging & Printing
289 void print (outputStream* st, int index) const;
290 void verify(outputStream* st) const;
292 static void verify_tosBits() {
293 assert(tosBits == 28, "interpreter now assumes tosBits is 28");
294 }
295 };
298 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache
299 // holds interpreter runtime information for all field access and invoke bytecodes. The cache
300 // is created and initialized before a class is actively used (i.e., initialized), the indivi-
301 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).
303 class constantPoolCacheOopDesc: public oopDesc {
304 friend class VMStructs;
305 private:
306 int _length;
307 constantPoolOop _constant_pool; // the corresponding constant pool
308 // If true, safe for concurrent GC processing,
309 // Set unconditionally in constantPoolCacheKlass::allocate()
310 volatile bool _is_conc_safe;
312 // Sizing
313 debug_only(friend class ClassVerifier;)
314 int length() const { return _length; }
315 void set_length(int length) { _length = length; }
317 static int header_size() { return sizeof(constantPoolCacheOopDesc) / HeapWordSize; }
318 static int object_size(int length) { return align_object_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
319 int object_size() { return object_size(length()); }
321 // Helpers
322 constantPoolOop* constant_pool_addr() { return &_constant_pool; }
323 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
325 friend class constantPoolCacheKlass;
326 friend class ConstantPoolCacheEntry;
328 public:
329 // Initialization
330 void initialize(intArray& inverse_index_map);
332 // Secondary indexes.
333 // They must look completely different from normal indexes.
334 // The main reason is that byte swapping is sometimes done on normal indexes.
335 // Also, some of the CP accessors do different things for secondary indexes.
336 // Finally, it is helpful for debugging to tell the two apart.
337 static bool is_secondary_index(int i) { return (i < 0); }
338 static int decode_secondary_index(int i) { assert(is_secondary_index(i), ""); return ~i; }
339 static int encode_secondary_index(int i) { assert(!is_secondary_index(i), ""); return ~i; }
341 // Accessors
342 void set_constant_pool(constantPoolOop pool) { oop_store_without_check((oop*)&_constant_pool, (oop)pool); }
343 constantPoolOop constant_pool() const { return _constant_pool; }
344 // Fetches the entry at the given index.
345 // The entry may be either primary or secondary.
346 // In either case the index must not be encoded or byte-swapped in any way.
347 ConstantPoolCacheEntry* entry_at(int i) const {
348 assert(0 <= i && i < length(), "index out of bounds");
349 return base() + i;
350 }
351 // Fetches the secondary entry referred to by index.
352 // The index may be a secondary index, and must not be byte-swapped.
353 ConstantPoolCacheEntry* secondary_entry_at(int i) const {
354 int raw_index = i;
355 if (is_secondary_index(i)) { // correct these on the fly
356 raw_index = decode_secondary_index(i);
357 }
358 assert(entry_at(raw_index)->is_secondary_entry(), "not a secondary entry");
359 return entry_at(raw_index);
360 }
361 // Given a primary or secondary index, fetch the corresponding primary entry.
362 // Indirect through the secondary entry, if the index is encoded as a secondary index.
363 // The index must not be byte-swapped.
364 ConstantPoolCacheEntry* main_entry_at(int i) const {
365 int primary_index = i;
366 if (is_secondary_index(i)) {
367 // run through an extra level of indirection:
368 int raw_index = decode_secondary_index(i);
369 primary_index = entry_at(raw_index)->main_entry_index();
370 }
371 assert(!entry_at(primary_index)->is_secondary_entry(), "only one level of indirection");
372 return entry_at(primary_index);
373 }
375 // GC support
376 // If the _length field has not been set, the size of the
377 // constantPoolCache cannot be correctly calculated.
378 bool is_conc_safe() { return _is_conc_safe; }
379 void set_is_conc_safe(bool v) { _is_conc_safe = v; }
381 // Code generation
382 static ByteSize base_offset() { return in_ByteSize(sizeof(constantPoolCacheOopDesc)); }
383 static ByteSize entry_offset(int raw_index) {
384 int index = raw_index;
385 if (is_secondary_index(raw_index))
386 index = decode_secondary_index(raw_index);
387 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
388 }
390 // RedefineClasses() API support:
391 // If any entry of this constantPoolCache points to any of
392 // old_methods, replace it with the corresponding new_method.
393 // trace_name_printed is set to true if the current call has
394 // printed the klass name so that other routines in the adjust_*
395 // group don't print the klass name.
396 void adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
397 int methods_length, bool * trace_name_printed);
398 };