1 #ifdef USE_PRAGMA_IDENT_SRC
2 #pragma ident "@(#)oopMapCache.cpp 1.86 08/11/24 12:22:25 JVM"
3 #endif
4 /*
5 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 *
8 * This code is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
24 * have any questions.
25 *
26 */
27
28 # include "incls/_precompiled.incl"
29 # include "incls/_oopMapCache.cpp.incl"
30
31 class OopMapCacheEntry: private InterpreterOopMap {
32 friend class InterpreterOopMap;
33 friend class OopMapForCacheEntry;
34 friend class OopMapCache;
35 friend class VerifyClosure;
36
37 protected:
38 // Initialization
39 void fill(methodHandle method, int bci);
40 // fills the bit mask for native calls
41 void fill_for_native(methodHandle method);
42 void set_mask(CellTypeState* vars, CellTypeState* stack, int stack_top);
43
44 // Deallocate bit masks and initialize fields
45 void flush();
46
47 private:
48 void allocate_bit_mask(); // allocates the bit mask on C heap f necessary
49 void deallocate_bit_mask(); // allocates the bit mask on C heap f necessary
50 bool verify_mask(CellTypeState *vars, CellTypeState *stack, int max_locals, int stack_top);
51
52 public:
53 OopMapCacheEntry() : InterpreterOopMap() {
54 #ifdef ASSERT
55 _resource_allocate_bit_mask = false;
56 #endif
57 }
58 };
59
60
61 // Implementation of OopMapForCacheEntry
62 // (subclass of GenerateOopMap, initializes an OopMapCacheEntry for a given method and bci)
63
64 class OopMapForCacheEntry: public GenerateOopMap {
65 OopMapCacheEntry *_entry;
66 int _bci;
67 int _stack_top;
68
69 virtual bool report_results() const { return false; }
70 virtual bool possible_gc_point (BytecodeStream *bcs);
71 virtual void fill_stackmap_prolog (int nof_gc_points);
72 virtual void fill_stackmap_epilog ();
73 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
74 CellTypeState* vars,
75 CellTypeState* stack,
76 int stack_top);
77 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars);
78
79 public:
80 OopMapForCacheEntry(methodHandle method, int bci, OopMapCacheEntry *entry);
81
82 // Computes stack map for (method,bci) and initialize entry
83 void compute_map(TRAPS);
84 int size();
85 };
86
87
88 OopMapForCacheEntry::OopMapForCacheEntry(methodHandle method, int bci, OopMapCacheEntry* entry) : GenerateOopMap(method) {
89 _bci = bci;
90 _entry = entry;
91 _stack_top = -1;
92 }
93
94
95 void OopMapForCacheEntry::compute_map(TRAPS) {
96 assert(!method()->is_native(), "cannot compute oop map for native methods");
97 // First check if it is a method where the stackmap is always empty
98 if (method()->code_size() == 0 || method()->max_locals() + method()->max_stack() == 0) {
99 _entry->set_mask_size(0);
100 } else {
101 ResourceMark rm;
102 GenerateOopMap::compute_map(CATCH);
103 result_for_basicblock(_bci);
104 }
105 }
106
107
108 bool OopMapForCacheEntry::possible_gc_point(BytecodeStream *bcs) {
109 return false; // We are not reporting any result. We call result_for_basicblock directly
110 }
111
112
113 void OopMapForCacheEntry::fill_stackmap_prolog(int nof_gc_points) {
114 // Do nothing
115 }
116
117
118 void OopMapForCacheEntry::fill_stackmap_epilog() {
119 // Do nothing
120 }
121
122
123 void OopMapForCacheEntry::fill_init_vars(GrowableArray<intptr_t> *init_vars) {
124 // Do nothing
125 }
126
127
128 void OopMapForCacheEntry::fill_stackmap_for_opcodes(BytecodeStream *bcs,
129 CellTypeState* vars,
130 CellTypeState* stack,
131 int stack_top) {
132 // Only interested in one specific bci
133 if (bcs->bci() == _bci) {
134 _entry->set_mask(vars, stack, stack_top);
135 _stack_top = stack_top;
136 }
137 }
138
139
140 int OopMapForCacheEntry::size() {
141 assert(_stack_top != -1, "compute_map must be called first");
142 return ((method()->is_static()) ? 0 : 1) + method()->max_locals() + _stack_top;
143 }
144
145
146 // Implementation of InterpreterOopMap and OopMapCacheEntry
147
148 class VerifyClosure : public OffsetClosure {
149 private:
150 OopMapCacheEntry* _entry;
151 bool _failed;
152
153 public:
154 VerifyClosure(OopMapCacheEntry* entry) { _entry = entry; _failed = false; }
155 void offset_do(int offset) { if (!_entry->is_oop(offset)) _failed = true; }
156 bool failed() const { return _failed; }
157 };
158
159 InterpreterOopMap::InterpreterOopMap() {
160 initialize();
161 #ifdef ASSERT
162 _resource_allocate_bit_mask = true;
163 #endif
164 }
165
166 InterpreterOopMap::~InterpreterOopMap() {
167 // The expection is that the bit mask was allocated
168 // last in this resource area. That would make the free of the
169 // bit_mask effective (see how FREE_RESOURCE_ARRAY does a free).
170 // If it was not allocated last, there is not a correctness problem
171 // but the space for the bit_mask is not freed.
172 assert(_resource_allocate_bit_mask, "Trying to free C heap space");
173 if (mask_size() > small_mask_limit) {
174 FREE_RESOURCE_ARRAY(uintptr_t, _bit_mask[0], mask_word_size());
175 }
176 }
177
178 bool InterpreterOopMap::is_empty() {
179 bool result = _method == NULL;
180 assert(_method != NULL || (_bci == 0 &&
181 (_mask_size == 0 || _mask_size == USHRT_MAX) &&
182 _bit_mask[0] == 0), "Should be completely empty");
183 return result;
184 }
185
186 void InterpreterOopMap::initialize() {
187 _method = NULL;
188 _mask_size = USHRT_MAX; // This value should cause a failure quickly
189 _bci = 0;
190 _expression_stack_size = 0;
191 for (int i = 0; i < N; i++) _bit_mask[i] = 0;
192 }
193
194
195 void InterpreterOopMap::oop_iterate(OopClosure *blk) {
196 if (method() != NULL) {
197 blk->do_oop((oop*) &_method);
198 }
199 }
200
201 void InterpreterOopMap::oop_iterate(OopClosure *blk, MemRegion mr) {
202 if (method() != NULL && mr.contains(&_method)) {
203 blk->do_oop((oop*) &_method);
204 }
205 }
206
207
208
209 void InterpreterOopMap::iterate_oop(OffsetClosure* oop_closure) {
210 int n = number_of_entries();
211 int word_index = 0;
212 uintptr_t value = 0;
213 uintptr_t mask = 0;
214 // iterate over entries
215 for (int i = 0; i < n; i++, mask <<= bits_per_entry) {
216 // get current word
217 if (mask == 0) {
218 value = bit_mask()[word_index++];
219 mask = 1;
220 }
221 // test for oop
222 if ((value & (mask << oop_bit_number)) != 0) oop_closure->offset_do(i);
223 }
224 }
225
226 void InterpreterOopMap::verify() {
227 // If we are doing mark sweep _method may not have a valid header
228 // $$$ This used to happen only for m/s collections; we might want to
229 // think of an appropriate generalization of this distinction.
230 guarantee(Universe::heap()->is_gc_active() ||
231 _method->is_oop_or_null(), "invalid oop in oopMapCache")
232 }
233
234 #ifdef ENABLE_ZAP_DEAD_LOCALS
235
236 void InterpreterOopMap::iterate_all(OffsetClosure* oop_closure, OffsetClosure* value_closure, OffsetClosure* dead_closure) {
237 int n = number_of_entries();
238 int word_index = 0;
239 uintptr_t value = 0;
240 uintptr_t mask = 0;
241 // iterate over entries
242 for (int i = 0; i < n; i++, mask <<= bits_per_entry) {
243 // get current word
244 if (mask == 0) {
245 value = bit_mask()[word_index++];
246 mask = 1;
247 }
248 // test for dead values & oops, and for live values
249 if ((value & (mask << dead_bit_number)) != 0) dead_closure->offset_do(i); // call this for all dead values or oops
250 else if ((value & (mask << oop_bit_number)) != 0) oop_closure->offset_do(i); // call this for all live oops
251 else value_closure->offset_do(i); // call this for all live values
252 }
253 }
254
255 #endif
256
257
258 void InterpreterOopMap::print() {
259 int n = number_of_entries();
260 tty->print("oop map for ");
261 method()->print_value();
262 tty->print(" @ %d = [%d] { ", bci(), n);
263 for (int i = 0; i < n; i++) {
264 #ifdef ENABLE_ZAP_DEAD_LOCALS
265 if (is_dead(i)) tty->print("%d+ ", i);
266 else
267 #endif
268 if (is_oop(i)) tty->print("%d ", i);
269 }
270 tty->print_cr("}");
271 }
272
273 class MaskFillerForNative: public NativeSignatureIterator {
274 private:
275 uintptr_t * _mask; // the bit mask to be filled
276 int _size; // the mask size in bits
277
278 void set_one(int i) {
279 i *= InterpreterOopMap::bits_per_entry;
280 assert(0 <= i && i < _size, "offset out of bounds");
281 _mask[i / BitsPerWord] |= (((uintptr_t) 1 << InterpreterOopMap::oop_bit_number) << (i % BitsPerWord));
282 }
283
284 public:
285 void pass_int() { /* ignore */ }
286 void pass_long() { /* ignore */ }
287 #ifdef _LP64
288 void pass_float() { /* ignore */ }
289 #endif
290 void pass_double() { /* ignore */ }
291 void pass_object() { set_one(offset()); }
292
293 MaskFillerForNative(methodHandle method, uintptr_t* mask, int size) : NativeSignatureIterator(method) {
294 _mask = mask;
295 _size = size;
296 // initialize with 0
297 int i = (size + BitsPerWord - 1) / BitsPerWord;
298 while (i-- > 0) _mask[i] = 0;
299 }
300
301 void generate() {
302 NativeSignatureIterator::iterate();
303 }
304 };
305
306 bool OopMapCacheEntry::verify_mask(CellTypeState* vars, CellTypeState* stack, int max_locals, int stack_top) {
307 // Check mask includes map
308 VerifyClosure blk(this);
309 iterate_oop(&blk);
310 if (blk.failed()) return false;
311
312 // Check if map is generated correctly
313 // (Use ?: operator to make sure all 'true' & 'false' are represented exactly the same so we can use == afterwards)
314 if (TraceOopMapGeneration && Verbose) tty->print("Locals (%d): ", max_locals);
315
316 for(int i = 0; i < max_locals; i++) {
317 bool v1 = is_oop(i) ? true : false;
318 bool v2 = vars[i].is_reference() ? true : false;
319 assert(v1 == v2, "locals oop mask generation error");
320 if (TraceOopMapGeneration && Verbose) tty->print("%d", v1 ? 1 : 0);
321 #ifdef ENABLE_ZAP_DEAD_LOCALS
322 bool v3 = is_dead(i) ? true : false;
323 bool v4 = !vars[i].is_live() ? true : false;
324 assert(v3 == v4, "locals live mask generation error");
325 assert(!(v1 && v3), "dead value marked as oop");
326 #endif
327 }
328
329 if (TraceOopMapGeneration && Verbose) { tty->cr(); tty->print("Stack (%d): ", stack_top); }
330 for(int j = 0; j < stack_top; j++) {
331 bool v1 = is_oop(max_locals + j) ? true : false;
332 bool v2 = stack[j].is_reference() ? true : false;
333 assert(v1 == v2, "stack oop mask generation error");
334 if (TraceOopMapGeneration && Verbose) tty->print("%d", v1 ? 1 : 0);
335 #ifdef ENABLE_ZAP_DEAD_LOCALS
336 bool v3 = is_dead(max_locals + j) ? true : false;
337 bool v4 = !stack[j].is_live() ? true : false;
338 assert(v3 == v4, "stack live mask generation error");
339 assert(!(v1 && v3), "dead value marked as oop");
340 #endif
341 }
342 if (TraceOopMapGeneration && Verbose) tty->cr();
343 return true;
344 }
345
346 void OopMapCacheEntry::allocate_bit_mask() {
347 if (mask_size() > small_mask_limit) {
348 assert(_bit_mask[0] == 0, "bit mask should be new or just flushed");
349 _bit_mask[0] = (intptr_t)
350 NEW_C_HEAP_ARRAY(uintptr_t, mask_word_size());
351 }
352 }
353
354 void OopMapCacheEntry::deallocate_bit_mask() {
355 if (mask_size() > small_mask_limit && _bit_mask[0] != 0) {
356 assert(!Thread::current()->resource_area()->contains((void*)_bit_mask[0]),
357 "This bit mask should not be in the resource area");
358 FREE_C_HEAP_ARRAY(uintptr_t, _bit_mask[0]);
359 debug_only(_bit_mask[0] = 0;)
360 }
361 }
362
363
364 void OopMapCacheEntry::fill_for_native(methodHandle mh) {
365 assert(mh->is_native(), "method must be native method");
366 set_mask_size(mh->size_of_parameters() * bits_per_entry);
367 allocate_bit_mask();
368 // fill mask for parameters
369 MaskFillerForNative mf(mh, bit_mask(), mask_size());
370 mf.generate();
371 }
372
373
374 void OopMapCacheEntry::fill(methodHandle method, int bci) {
375 HandleMark hm;
376 // Flush entry to deallocate an existing entry
377 flush();
378 set_method(method());
379 set_bci(bci);
380 if (method->is_native()) {
381 // Native method activations have oops only among the parameters and one
382 // extra oop following the parameters (the mirror for static native methods).
383 fill_for_native(method);
384 } else {
385 EXCEPTION_MARK;
386 OopMapForCacheEntry gen(method, bci, this);
387 gen.compute_map(CATCH);
388 }
389 #ifdef ASSERT
390 verify();
391 #endif
392 }
393
394
395 void OopMapCacheEntry::set_mask(CellTypeState *vars, CellTypeState *stack, int stack_top) {
396 // compute bit mask size
397 int max_locals = method()->max_locals();
398 int n_entries = max_locals + stack_top;
399 set_mask_size(n_entries * bits_per_entry);
400 allocate_bit_mask();
401 set_expression_stack_size(stack_top);
402
403 // compute bits
404 int word_index = 0;
405 uintptr_t value = 0;
406 uintptr_t mask = 1;
407
408 CellTypeState* cell = vars;
409 for (int entry_index = 0; entry_index < n_entries; entry_index++, mask <<= bits_per_entry, cell++) {
410 // store last word
411 if (mask == 0) {
412 bit_mask()[word_index++] = value;
413 value = 0;
414 mask = 1;
415 }
416
417 // switch to stack when done with locals
418 if (entry_index == max_locals) {
419 cell = stack;
420 }
421
422 // set oop bit
423 if ( cell->is_reference()) {
424 value |= (mask << oop_bit_number );
425 }
426
427 #ifdef ENABLE_ZAP_DEAD_LOCALS
428 // set dead bit
429 if (!cell->is_live()) {
430 value |= (mask << dead_bit_number);
431 assert(!cell->is_reference(), "dead value marked as oop");
432 }
433 #endif
434 }
435
436 // make sure last word is stored
437 bit_mask()[word_index] = value;
438
439 // verify bit mask
440 assert(verify_mask(vars, stack, max_locals, stack_top), "mask could not be verified");
441
442
443 }
444
445 void OopMapCacheEntry::flush() {
446 deallocate_bit_mask();
447 initialize();
448 }
449
450
451 // Implementation of OopMapCache
452
453 #ifndef PRODUCT
454
455 static long _total_memory_usage = 0;
456
457 long OopMapCache::memory_usage() {
458 return _total_memory_usage;
459 }
460
461 #endif
462
463 void InterpreterOopMap::resource_copy(OopMapCacheEntry* from) {
464 assert(_resource_allocate_bit_mask,
465 "Should not resource allocate the _bit_mask");
466 assert(from->method()->is_oop(), "MethodOop is bad");
467
468 set_method(from->method());
469 set_bci(from->bci());
470 set_mask_size(from->mask_size());
471 set_expression_stack_size(from->expression_stack_size());
472
473 // Is the bit mask contained in the entry?
474 if (from->mask_size() <= small_mask_limit) {
475 memcpy((void *)_bit_mask, (void *)from->_bit_mask,
476 mask_word_size() * BytesPerWord);
477 } else {
478 // The expectation is that this InterpreterOopMap is a recently created
479 // and empty. It is used to get a copy of a cached entry.
480 // If the bit mask has a value, it should be in the
481 // resource area.
482 assert(_bit_mask[0] == 0 ||
483 Thread::current()->resource_area()->contains((void*)_bit_mask[0]),
484 "The bit mask should have been allocated from a resource area");
485 // Allocate the bit_mask from a Resource area for performance. Allocating
486 // from the C heap as is done for OopMapCache has a significant
487 // performance impact.
488 _bit_mask[0] = (uintptr_t) NEW_RESOURCE_ARRAY(uintptr_t, mask_word_size());
489 assert(_bit_mask[0] != 0, "bit mask was not allocated");
490 memcpy((void*) _bit_mask[0], (void*) from->_bit_mask[0],
491 mask_word_size() * BytesPerWord);
492 }
493 }
494
495 inline unsigned int OopMapCache::hash_value_for(methodHandle method, int bci) {
496 // We use method->code_size() rather than method->identity_hash() below since
497 // the mark may not be present if a pointer to the method is already reversed.
498 return ((unsigned int) bci)
499 ^ ((unsigned int) method->max_locals() << 2)
500 ^ ((unsigned int) method->code_size() << 4)
501 ^ ((unsigned int) method->size_of_parameters() << 6);
502 }
503
504
505 OopMapCache::OopMapCache() :
506 _mut(Mutex::leaf, "An OopMapCache lock", true)
507 {
508 _array = NEW_C_HEAP_ARRAY(OopMapCacheEntry, _size);
509 // Cannot call flush for initialization, since flush
510 // will check if memory should be deallocated
511 for(int i = 0; i < _size; i++) _array[i].initialize();
512 NOT_PRODUCT(_total_memory_usage += sizeof(OopMapCache) + (sizeof(OopMapCacheEntry) * _size);)
513 }
514
515
516 OopMapCache::~OopMapCache() {
517 assert(_array != NULL, "sanity check");
518 // Deallocate oop maps that are allocated out-of-line
519 flush();
520 // Deallocate array
521 NOT_PRODUCT(_total_memory_usage -= sizeof(OopMapCache) + (sizeof(OopMapCacheEntry) * _size);)
522 FREE_C_HEAP_ARRAY(OopMapCacheEntry, _array);
523 }
524
525 OopMapCacheEntry* OopMapCache::entry_at(int i) const {
526 return &_array[i % _size];
527 }
528
529 void OopMapCache::flush() {
530 for (int i = 0; i < _size; i++) _array[i].flush();
531 }
532
533 void OopMapCache::flush_obsolete_entries() {
534 for (int i = 0; i < _size; i++)
535 if (!_array[i].is_empty() && _array[i].method()->is_old()) {
536 // Cache entry is occupied by an old redefined method and we don't want
537 // to pin it down so flush the entry.
538 RC_TRACE(0x08000000, ("flush: %s(%s): cached entry @%d",
539 _array[i].method()->name()->as_C_string(),
540 _array[i].method()->signature()->as_C_string(), i));
541
542 _array[i].flush();
543 }
544 }
545
546 void OopMapCache::oop_iterate(OopClosure *blk) {
547 for (int i = 0; i < _size; i++) _array[i].oop_iterate(blk);
548 }
549
550 void OopMapCache::oop_iterate(OopClosure *blk, MemRegion mr) {
551 for (int i = 0; i < _size; i++) _array[i].oop_iterate(blk, mr);
552 }
553
554 void OopMapCache::verify() {
555 for (int i = 0; i < _size; i++) _array[i].verify();
556 }
557
558 void OopMapCache::lookup(methodHandle method,
559 int bci,
560 InterpreterOopMap* entry_for) {
561 MutexLocker x(&_mut);
562
563 OopMapCacheEntry* entry = NULL;
564 int probe = hash_value_for(method, bci);
565
566 // Search hashtable for match
567 int i;
568 for(i = 0; i < _probe_depth; i++) {
569 entry = entry_at(probe + i);
570 if (entry->match(method, bci)) {
571 entry_for->resource_copy(entry);
572 assert(!entry_for->is_empty(), "A non-empty oop map should be returned");
573 return;
574 }
575 }
576
577 if (TraceOopMapGeneration) {
578 static int count = 0;
579 ResourceMark rm;
580 tty->print("%d - Computing oopmap at bci %d for ", ++count, bci);
581 method->print_value(); tty->cr();
582 }
583
584 // Entry is not in hashtable.
585 // Compute entry and return it
586
587 if (method->should_not_be_cached()) {
588 // It is either not safe or not a good idea to cache this methodOop
589 // at this time. We give the caller of lookup() a copy of the
590 // interesting info via parameter entry_for, but we don't add it to
591 // the cache. See the gory details in methodOop.cpp.
592 compute_one_oop_map(method, bci, entry_for);
593 return;
594 }
595
596 // First search for an empty slot
597 for(i = 0; i < _probe_depth; i++) {
598 entry = entry_at(probe + i);
599 if (entry->is_empty()) {
600 entry->fill(method, bci);
601 entry_for->resource_copy(entry);
602 assert(!entry_for->is_empty(), "A non-empty oop map should be returned");
603 return;
604 }
605 }
606
607 if (TraceOopMapGeneration) {
608 ResourceMark rm;
609 tty->print_cr("*** collision in oopmap cache - flushing item ***");
610 }
611
612 // No empty slot (uncommon case). Use (some approximation of a) LRU algorithm
613 //entry_at(probe + _probe_depth - 1)->flush();
614 //for(i = _probe_depth - 1; i > 0; i--) {
615 // // Coping entry[i] = entry[i-1];
616 // OopMapCacheEntry *to = entry_at(probe + i);
617 // OopMapCacheEntry *from = entry_at(probe + i - 1);
618 // to->copy(from);
619 // }
620
621 assert(method->is_method(), "gaga");
622
623 entry = entry_at(probe + 0);
624 entry->fill(method, bci);
625
626 // Copy the newly cached entry to input parameter
627 entry_for->resource_copy(entry);
628
629 if (TraceOopMapGeneration) {
630 ResourceMark rm;
631 tty->print("Done with ");
632 method->print_value(); tty->cr();
633 }
634 assert(!entry_for->is_empty(), "A non-empty oop map should be returned");
635
636 return;
637 }
638
639 void OopMapCache::compute_one_oop_map(methodHandle method, int bci, InterpreterOopMap* entry) {
640 // Due to the invariants above it's tricky to allocate a temporary OopMapCacheEntry on the stack
641 OopMapCacheEntry* tmp = NEW_C_HEAP_ARRAY(OopMapCacheEntry, 1);
642 tmp->initialize();
643 tmp->fill(method, bci);
644 entry->resource_copy(tmp);
645 FREE_C_HEAP_ARRAY(OopMapCacheEntry, tmp);
646 }