1 /*
2 * Copyright 1997-2008 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 */
24
25 # include "incls/_precompiled.incl"
26 # include "incls/_oopMapCache.cpp.incl"
27
28 class OopMapCacheEntry: private InterpreterOopMap {
29 friend class InterpreterOopMap;
30 friend class OopMapForCacheEntry;
31 friend class OopMapCache;
32 friend class VerifyClosure;
33
34 protected:
35 // Initialization
36 void fill(methodHandle method, int bci);
37 // fills the bit mask for native calls
38 void fill_for_native(methodHandle method);
39 void set_mask(CellTypeState* vars, CellTypeState* stack, int stack_top);
40
41 // Deallocate bit masks and initialize fields
42 void flush();
43
44 private:
45 void allocate_bit_mask(); // allocates the bit mask on C heap f necessary
46 void deallocate_bit_mask(); // allocates the bit mask on C heap f necessary
47 bool verify_mask(CellTypeState *vars, CellTypeState *stack, int max_locals, int stack_top);
48
49 public:
50 OopMapCacheEntry() : InterpreterOopMap() {
51 #ifdef ASSERT
52 _resource_allocate_bit_mask = false;
53 #endif
54 }
55 };
56
57
58 // Implementation of OopMapForCacheEntry
59 // (subclass of GenerateOopMap, initializes an OopMapCacheEntry for a given method and bci)
60
61 class OopMapForCacheEntry: public GenerateOopMap {
62 OopMapCacheEntry *_entry;
63 int _bci;
64 int _stack_top;
65
66 virtual bool report_results() const { return false; }
67 virtual bool possible_gc_point (BytecodeStream *bcs);
68 virtual void fill_stackmap_prolog (int nof_gc_points);
69 virtual void fill_stackmap_epilog ();
70 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
71 CellTypeState* vars,
72 CellTypeState* stack,
73 int stack_top);
74 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars);
75
76 public:
77 OopMapForCacheEntry(methodHandle method, int bci, OopMapCacheEntry *entry);
78
79 // Computes stack map for (method,bci) and initialize entry
80 void compute_map(TRAPS);
81 int size();
82 };
83
84
85 OopMapForCacheEntry::OopMapForCacheEntry(methodHandle method, int bci, OopMapCacheEntry* entry) : GenerateOopMap(method) {
86 _bci = bci;
87 _entry = entry;
88 _stack_top = -1;
89 }
90
91
92 void OopMapForCacheEntry::compute_map(TRAPS) {
93 assert(!method()->is_native(), "cannot compute oop map for native methods");
94 // First check if it is a method where the stackmap is always empty
95 if (method()->code_size() == 0 || method()->max_locals() + method()->max_stack() == 0) {
96 _entry->set_mask_size(0);
97 } else {
98 ResourceMark rm;
99 GenerateOopMap::compute_map(CATCH);
100 result_for_basicblock(_bci);
101 }
102 }
103
104
105 bool OopMapForCacheEntry::possible_gc_point(BytecodeStream *bcs) {
106 return false; // We are not reporting any result. We call result_for_basicblock directly
107 }
108
109
110 void OopMapForCacheEntry::fill_stackmap_prolog(int nof_gc_points) {
111 // Do nothing
112 }
113
114
115 void OopMapForCacheEntry::fill_stackmap_epilog() {
116 // Do nothing
117 }
118
119
120 void OopMapForCacheEntry::fill_init_vars(GrowableArray<intptr_t> *init_vars) {
121 // Do nothing
122 }
123
124
125 void OopMapForCacheEntry::fill_stackmap_for_opcodes(BytecodeStream *bcs,
126 CellTypeState* vars,
127 CellTypeState* stack,
128 int stack_top) {
129 // Only interested in one specific bci
130 if (bcs->bci() == _bci) {
131 _entry->set_mask(vars, stack, stack_top);
132 _stack_top = stack_top;
133 }
134 }
135
136
137 int OopMapForCacheEntry::size() {
138 assert(_stack_top != -1, "compute_map must be called first");
139 return ((method()->is_static()) ? 0 : 1) + method()->max_locals() + _stack_top;
140 }
141
142
143 // Implementation of InterpreterOopMap and OopMapCacheEntry
144
145 class VerifyClosure : public OffsetClosure {
146 private:
147 OopMapCacheEntry* _entry;
148 bool _failed;
149
150 public:
151 VerifyClosure(OopMapCacheEntry* entry) { _entry = entry; _failed = false; }
152 void offset_do(int offset) { if (!_entry->is_oop(offset)) _failed = true; }
153 bool failed() const { return _failed; }
154 };
155
156 InterpreterOopMap::InterpreterOopMap() {
157 initialize();
158 #ifdef ASSERT
159 _resource_allocate_bit_mask = true;
160 #endif
161 }
162
163 InterpreterOopMap::~InterpreterOopMap() {
164 // The expection is that the bit mask was allocated
165 // last in this resource area. That would make the free of the
166 // bit_mask effective (see how FREE_RESOURCE_ARRAY does a free).
167 // If it was not allocated last, there is not a correctness problem
168 // but the space for the bit_mask is not freed.
169 assert(_resource_allocate_bit_mask, "Trying to free C heap space");
170 if (mask_size() > small_mask_limit) {
171 FREE_RESOURCE_ARRAY(uintptr_t, _bit_mask[0], mask_word_size());
172 }
173 }
174
175 bool InterpreterOopMap::is_empty() {
176 bool result = _method == NULL;
177 assert(_method != NULL || (_bci == 0 &&
178 (_mask_size == 0 || _mask_size == USHRT_MAX) &&
179 _bit_mask[0] == 0), "Should be completely empty");
180 return result;
181 }
182
183 void InterpreterOopMap::initialize() {
184 _method = NULL;
185 _mask_size = USHRT_MAX; // This value should cause a failure quickly
186 _bci = 0;
187 _expression_stack_size = 0;
188 for (int i = 0; i < N; i++) _bit_mask[i] = 0;
189 }
190
191
192 void InterpreterOopMap::oop_iterate(OopClosure *blk) {
193 if (method() != NULL) {
194 blk->do_oop((oop*) &_method);
195 }
196 }
197
198 void InterpreterOopMap::oop_iterate(OopClosure *blk, MemRegion mr) {
199 if (method() != NULL && mr.contains(&_method)) {
200 blk->do_oop((oop*) &_method);
201 }
202 }
203
204
205
206 void InterpreterOopMap::iterate_oop(OffsetClosure* oop_closure) {
207 int n = number_of_entries();
208 int word_index = 0;
209 uintptr_t value = 0;
210 uintptr_t mask = 0;
211 // iterate over entries
212 for (int i = 0; i < n; i++, mask <<= bits_per_entry) {
213 // get current word
214 if (mask == 0) {
215 value = bit_mask()[word_index++];
216 mask = 1;
217 }
218 // test for oop
219 if ((value & (mask << oop_bit_number)) != 0) oop_closure->offset_do(i);
220 }
221 }
222
223 void InterpreterOopMap::verify() {
224 // If we are doing mark sweep _method may not have a valid header
225 // $$$ This used to happen only for m/s collections; we might want to
226 // think of an appropriate generalization of this distinction.
227 guarantee(Universe::heap()->is_gc_active() ||
228 _method->is_oop_or_null(), "invalid oop in oopMapCache")
229 }
230
231 #ifdef ENABLE_ZAP_DEAD_LOCALS
232
233 void InterpreterOopMap::iterate_all(OffsetClosure* oop_closure, OffsetClosure* value_closure, OffsetClosure* dead_closure) {
234 int n = number_of_entries();
235 int word_index = 0;
236 uintptr_t value = 0;
237 uintptr_t mask = 0;
238 // iterate over entries
239 for (int i = 0; i < n; i++, mask <<= bits_per_entry) {
240 // get current word
241 if (mask == 0) {
242 value = bit_mask()[word_index++];
243 mask = 1;
244 }
245 // test for dead values & oops, and for live values
246 if ((value & (mask << dead_bit_number)) != 0) dead_closure->offset_do(i); // call this for all dead values or oops
247 else if ((value & (mask << oop_bit_number)) != 0) oop_closure->offset_do(i); // call this for all live oops
248 else value_closure->offset_do(i); // call this for all live values
249 }
250 }
251
252 #endif
253
254
255 void InterpreterOopMap::print() {
256 int n = number_of_entries();
257 tty->print("oop map for ");
258 method()->print_value();
259 tty->print(" @ %d = [%d] { ", bci(), n);
260 for (int i = 0; i < n; i++) {
261 #ifdef ENABLE_ZAP_DEAD_LOCALS
262 if (is_dead(i)) tty->print("%d+ ", i);
263 else
264 #endif
265 if (is_oop(i)) tty->print("%d ", i);
266 }
267 tty->print_cr("}");
268 }
269
270 class MaskFillerForNative: public NativeSignatureIterator {
271 private:
272 uintptr_t * _mask; // the bit mask to be filled
273 int _size; // the mask size in bits
274
275 void set_one(int i) {
276 i *= InterpreterOopMap::bits_per_entry;
277 assert(0 <= i && i < _size, "offset out of bounds");
278 _mask[i / BitsPerWord] |= (((uintptr_t) 1 << InterpreterOopMap::oop_bit_number) << (i % BitsPerWord));
279 }
280
281 public:
282 void pass_int() { /* ignore */ }
283 void pass_long() { /* ignore */ }
284 #if defined(_LP64) || defined(ZERO)
285 void pass_float() { /* ignore */ }
286 #endif
287 void pass_double() { /* ignore */ }
288 void pass_object() { set_one(offset()); }
289
290 MaskFillerForNative(methodHandle method, uintptr_t* mask, int size) : NativeSignatureIterator(method) {
291 _mask = mask;
292 _size = size;
293 // initialize with 0
294 int i = (size + BitsPerWord - 1) / BitsPerWord;
295 while (i-- > 0) _mask[i] = 0;
296 }
297
298 void generate() {
299 NativeSignatureIterator::iterate();
300 }
301 };
302
303 bool OopMapCacheEntry::verify_mask(CellTypeState* vars, CellTypeState* stack, int max_locals, int stack_top) {
304 // Check mask includes map
305 VerifyClosure blk(this);
306 iterate_oop(&blk);
307 if (blk.failed()) return false;
308
309 // Check if map is generated correctly
310 // (Use ?: operator to make sure all 'true' & 'false' are represented exactly the same so we can use == afterwards)
311 if (TraceOopMapGeneration && Verbose) tty->print("Locals (%d): ", max_locals);
312
313 for(int i = 0; i < max_locals; i++) {
314 bool v1 = is_oop(i) ? true : false;
315 bool v2 = vars[i].is_reference() ? true : false;
316 assert(v1 == v2, "locals oop mask generation error");
317 if (TraceOopMapGeneration && Verbose) tty->print("%d", v1 ? 1 : 0);
318 #ifdef ENABLE_ZAP_DEAD_LOCALS
319 bool v3 = is_dead(i) ? true : false;
320 bool v4 = !vars[i].is_live() ? true : false;
321 assert(v3 == v4, "locals live mask generation error");
322 assert(!(v1 && v3), "dead value marked as oop");
323 #endif
324 }
325
326 if (TraceOopMapGeneration && Verbose) { tty->cr(); tty->print("Stack (%d): ", stack_top); }
327 for(int j = 0; j < stack_top; j++) {
328 bool v1 = is_oop(max_locals + j) ? true : false;
329 bool v2 = stack[j].is_reference() ? true : false;
330 assert(v1 == v2, "stack oop mask generation error");
331 if (TraceOopMapGeneration && Verbose) tty->print("%d", v1 ? 1 : 0);
332 #ifdef ENABLE_ZAP_DEAD_LOCALS
333 bool v3 = is_dead(max_locals + j) ? true : false;
334 bool v4 = !stack[j].is_live() ? true : false;
335 assert(v3 == v4, "stack live mask generation error");
336 assert(!(v1 && v3), "dead value marked as oop");
337 #endif
338 }
339 if (TraceOopMapGeneration && Verbose) tty->cr();
340 return true;
341 }
342
343 void OopMapCacheEntry::allocate_bit_mask() {
344 if (mask_size() > small_mask_limit) {
345 assert(_bit_mask[0] == 0, "bit mask should be new or just flushed");
346 _bit_mask[0] = (intptr_t)
347 NEW_C_HEAP_ARRAY(uintptr_t, mask_word_size());
348 }
349 }
350
351 void OopMapCacheEntry::deallocate_bit_mask() {
352 if (mask_size() > small_mask_limit && _bit_mask[0] != 0) {
353 assert(!Thread::current()->resource_area()->contains((void*)_bit_mask[0]),
354 "This bit mask should not be in the resource area");
355 FREE_C_HEAP_ARRAY(uintptr_t, _bit_mask[0]);
356 debug_only(_bit_mask[0] = 0;)
357 }
358 }
359
360
361 void OopMapCacheEntry::fill_for_native(methodHandle mh) {
362 assert(mh->is_native(), "method must be native method");
363 set_mask_size(mh->size_of_parameters() * bits_per_entry);
364 allocate_bit_mask();
365 // fill mask for parameters
366 MaskFillerForNative mf(mh, bit_mask(), mask_size());
367 mf.generate();
368 }
369
370
371 void OopMapCacheEntry::fill(methodHandle method, int bci) {
372 HandleMark hm;
373 // Flush entry to deallocate an existing entry
374 flush();
375 set_method(method());
376 set_bci(bci);
377 if (method->is_native()) {
378 // Native method activations have oops only among the parameters and one
379 // extra oop following the parameters (the mirror for static native methods).
380 fill_for_native(method);
381 } else {
382 EXCEPTION_MARK;
383 OopMapForCacheEntry gen(method, bci, this);
384 gen.compute_map(CATCH);
385 }
386 #ifdef ASSERT
387 verify();
388 #endif
389 }
390
391
392 void OopMapCacheEntry::set_mask(CellTypeState *vars, CellTypeState *stack, int stack_top) {
393 // compute bit mask size
394 int max_locals = method()->max_locals();
395 int n_entries = max_locals + stack_top;
396 set_mask_size(n_entries * bits_per_entry);
397 allocate_bit_mask();
398 set_expression_stack_size(stack_top);
399
400 // compute bits
401 int word_index = 0;
402 uintptr_t value = 0;
403 uintptr_t mask = 1;
404
405 CellTypeState* cell = vars;
406 for (int entry_index = 0; entry_index < n_entries; entry_index++, mask <<= bits_per_entry, cell++) {
407 // store last word
408 if (mask == 0) {
409 bit_mask()[word_index++] = value;
410 value = 0;
411 mask = 1;
412 }
413
414 // switch to stack when done with locals
415 if (entry_index == max_locals) {
416 cell = stack;
417 }
418
419 // set oop bit
420 if ( cell->is_reference()) {
421 value |= (mask << oop_bit_number );
422 }
423
424 #ifdef ENABLE_ZAP_DEAD_LOCALS
425 // set dead bit
426 if (!cell->is_live()) {
427 value |= (mask << dead_bit_number);
428 assert(!cell->is_reference(), "dead value marked as oop");
429 }
430 #endif
431 }
432
433 // make sure last word is stored
434 bit_mask()[word_index] = value;
435
436 // verify bit mask
437 assert(verify_mask(vars, stack, max_locals, stack_top), "mask could not be verified");
438
439
440 }
441
442 void OopMapCacheEntry::flush() {
443 deallocate_bit_mask();
444 initialize();
445 }
446
447
448 // Implementation of OopMapCache
449
450 #ifndef PRODUCT
451
452 static long _total_memory_usage = 0;
453
454 long OopMapCache::memory_usage() {
455 return _total_memory_usage;
456 }
457
458 #endif
459
460 void InterpreterOopMap::resource_copy(OopMapCacheEntry* from) {
461 assert(_resource_allocate_bit_mask,
462 "Should not resource allocate the _bit_mask");
463 assert(from->method()->is_oop(), "MethodOop is bad");
464
465 set_method(from->method());
466 set_bci(from->bci());
467 set_mask_size(from->mask_size());
468 set_expression_stack_size(from->expression_stack_size());
469
470 // Is the bit mask contained in the entry?
471 if (from->mask_size() <= small_mask_limit) {
472 memcpy((void *)_bit_mask, (void *)from->_bit_mask,
473 mask_word_size() * BytesPerWord);
474 } else {
475 // The expectation is that this InterpreterOopMap is a recently created
476 // and empty. It is used to get a copy of a cached entry.
477 // If the bit mask has a value, it should be in the
478 // resource area.
479 assert(_bit_mask[0] == 0 ||
480 Thread::current()->resource_area()->contains((void*)_bit_mask[0]),
481 "The bit mask should have been allocated from a resource area");
482 // Allocate the bit_mask from a Resource area for performance. Allocating
483 // from the C heap as is done for OopMapCache has a significant
484 // performance impact.
485 _bit_mask[0] = (uintptr_t) NEW_RESOURCE_ARRAY(uintptr_t, mask_word_size());
486 assert(_bit_mask[0] != 0, "bit mask was not allocated");
487 memcpy((void*) _bit_mask[0], (void*) from->_bit_mask[0],
488 mask_word_size() * BytesPerWord);
489 }
490 }
491
492 inline unsigned int OopMapCache::hash_value_for(methodHandle method, int bci) {
493 // We use method->code_size() rather than method->identity_hash() below since
494 // the mark may not be present if a pointer to the method is already reversed.
495 return ((unsigned int) bci)
496 ^ ((unsigned int) method->max_locals() << 2)
497 ^ ((unsigned int) method->code_size() << 4)
498 ^ ((unsigned int) method->size_of_parameters() << 6);
499 }
500
501
502 OopMapCache::OopMapCache() :
503 _mut(Mutex::leaf, "An OopMapCache lock", true)
504 {
505 _array = NEW_C_HEAP_ARRAY(OopMapCacheEntry, _size);
506 // Cannot call flush for initialization, since flush
507 // will check if memory should be deallocated
508 for(int i = 0; i < _size; i++) _array[i].initialize();
509 NOT_PRODUCT(_total_memory_usage += sizeof(OopMapCache) + (sizeof(OopMapCacheEntry) * _size);)
510 }
511
512
513 OopMapCache::~OopMapCache() {
514 assert(_array != NULL, "sanity check");
515 // Deallocate oop maps that are allocated out-of-line
516 flush();
517 // Deallocate array
518 NOT_PRODUCT(_total_memory_usage -= sizeof(OopMapCache) + (sizeof(OopMapCacheEntry) * _size);)
519 FREE_C_HEAP_ARRAY(OopMapCacheEntry, _array);
520 }
521
522 OopMapCacheEntry* OopMapCache::entry_at(int i) const {
523 return &_array[i % _size];
524 }
525
526 void OopMapCache::flush() {
527 for (int i = 0; i < _size; i++) _array[i].flush();
528 }
529
530 void OopMapCache::flush_obsolete_entries() {
531 for (int i = 0; i < _size; i++)
532 if (!_array[i].is_empty() && _array[i].method()->is_old()) {
533 // Cache entry is occupied by an old redefined method and we don't want
534 // to pin it down so flush the entry.
535 RC_TRACE(0x08000000, ("flush: %s(%s): cached entry @%d",
536 _array[i].method()->name()->as_C_string(),
537 _array[i].method()->signature()->as_C_string(), i));
538
539 _array[i].flush();
540 }
541 }
542
543 void OopMapCache::oop_iterate(OopClosure *blk) {
544 for (int i = 0; i < _size; i++) _array[i].oop_iterate(blk);
545 }
546
547 void OopMapCache::oop_iterate(OopClosure *blk, MemRegion mr) {
548 for (int i = 0; i < _size; i++) _array[i].oop_iterate(blk, mr);
549 }
550
551 void OopMapCache::verify() {
552 for (int i = 0; i < _size; i++) _array[i].verify();
553 }
554
555 void OopMapCache::lookup(methodHandle method,
556 int bci,
557 InterpreterOopMap* entry_for) {
558 MutexLocker x(&_mut);
559
560 OopMapCacheEntry* entry = NULL;
561 int probe = hash_value_for(method, bci);
562
563 // Search hashtable for match
564 int i;
565 for(i = 0; i < _probe_depth; i++) {
566 entry = entry_at(probe + i);
567 if (entry->match(method, bci)) {
568 entry_for->resource_copy(entry);
569 assert(!entry_for->is_empty(), "A non-empty oop map should be returned");
570 return;
571 }
572 }
573
574 if (TraceOopMapGeneration) {
575 static int count = 0;
576 ResourceMark rm;
577 tty->print("%d - Computing oopmap at bci %d for ", ++count, bci);
578 method->print_value(); tty->cr();
579 }
580
581 // Entry is not in hashtable.
582 // Compute entry and return it
583
584 if (method->should_not_be_cached()) {
585 // It is either not safe or not a good idea to cache this methodOop
586 // at this time. We give the caller of lookup() a copy of the
587 // interesting info via parameter entry_for, but we don't add it to
588 // the cache. See the gory details in methodOop.cpp.
589 compute_one_oop_map(method, bci, entry_for);
590 return;
591 }
592
593 // First search for an empty slot
594 for(i = 0; i < _probe_depth; i++) {
595 entry = entry_at(probe + i);
596 if (entry->is_empty()) {
597 entry->fill(method, bci);
598 entry_for->resource_copy(entry);
599 assert(!entry_for->is_empty(), "A non-empty oop map should be returned");
600 return;
601 }
602 }
603
604 if (TraceOopMapGeneration) {
605 ResourceMark rm;
606 tty->print_cr("*** collision in oopmap cache - flushing item ***");
607 }
608
609 // No empty slot (uncommon case). Use (some approximation of a) LRU algorithm
610 //entry_at(probe + _probe_depth - 1)->flush();
611 //for(i = _probe_depth - 1; i > 0; i--) {
612 // // Coping entry[i] = entry[i-1];
613 // OopMapCacheEntry *to = entry_at(probe + i);
614 // OopMapCacheEntry *from = entry_at(probe + i - 1);
615 // to->copy(from);
616 // }
617
618 assert(method->is_method(), "gaga");
619
620 entry = entry_at(probe + 0);
621 entry->fill(method, bci);
622
623 // Copy the newly cached entry to input parameter
624 entry_for->resource_copy(entry);
625
626 if (TraceOopMapGeneration) {
627 ResourceMark rm;
628 tty->print("Done with ");
629 method->print_value(); tty->cr();
630 }
631 assert(!entry_for->is_empty(), "A non-empty oop map should be returned");
632
633 return;
634 }
635
636 void OopMapCache::compute_one_oop_map(methodHandle method, int bci, InterpreterOopMap* entry) {
637 // Due to the invariants above it's tricky to allocate a temporary OopMapCacheEntry on the stack
638 OopMapCacheEntry* tmp = NEW_C_HEAP_ARRAY(OopMapCacheEntry, 1);
639 tmp->initialize();
640 tmp->fill(method, bci);
641 entry->resource_copy(tmp);
642 FREE_C_HEAP_ARRAY(OopMapCacheEntry, tmp);
643 }