1 /* 2 * Copyright (c) 1997, 2008, 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 */ 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() || _method->is_oop_or_null(), 228 "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 void pass_float() { /* ignore */ } 285 void pass_double() { /* ignore */ } 286 void pass_object() { set_one(offset()); } 287 288 MaskFillerForNative(methodHandle method, uintptr_t* mask, int size) : NativeSignatureIterator(method) { 289 _mask = mask; 290 _size = size; 291 // initialize with 0 292 int i = (size + BitsPerWord - 1) / BitsPerWord; 293 while (i-- > 0) _mask[i] = 0; 294 } 295 296 void generate() { 297 NativeSignatureIterator::iterate(); 298 } 299 }; 300 301 bool OopMapCacheEntry::verify_mask(CellTypeState* vars, CellTypeState* stack, int max_locals, int stack_top) { 302 // Check mask includes map 303 VerifyClosure blk(this); 304 iterate_oop(&blk); 305 if (blk.failed()) return false; 306 307 // Check if map is generated correctly 308 // (Use ?: operator to make sure all 'true' & 'false' are represented exactly the same so we can use == afterwards) 309 if (TraceOopMapGeneration && Verbose) tty->print("Locals (%d): ", max_locals); 310 311 for(int i = 0; i < max_locals; i++) { 312 bool v1 = is_oop(i) ? true : false; 313 bool v2 = vars[i].is_reference() ? true : false; 314 assert(v1 == v2, "locals oop mask generation error"); 315 if (TraceOopMapGeneration && Verbose) tty->print("%d", v1 ? 1 : 0); 316 #ifdef ENABLE_ZAP_DEAD_LOCALS 317 bool v3 = is_dead(i) ? true : false; 318 bool v4 = !vars[i].is_live() ? true : false; 319 assert(v3 == v4, "locals live mask generation error"); 320 assert(!(v1 && v3), "dead value marked as oop"); 321 #endif 322 } 323 324 if (TraceOopMapGeneration && Verbose) { tty->cr(); tty->print("Stack (%d): ", stack_top); } 325 for(int j = 0; j < stack_top; j++) { 326 bool v1 = is_oop(max_locals + j) ? true : false; 327 bool v2 = stack[j].is_reference() ? true : false; 328 assert(v1 == v2, "stack oop mask generation error"); 329 if (TraceOopMapGeneration && Verbose) tty->print("%d", v1 ? 1 : 0); 330 #ifdef ENABLE_ZAP_DEAD_LOCALS 331 bool v3 = is_dead(max_locals + j) ? true : false; 332 bool v4 = !stack[j].is_live() ? true : false; 333 assert(v3 == v4, "stack live mask generation error"); 334 assert(!(v1 && v3), "dead value marked as oop"); 335 #endif 336 } 337 if (TraceOopMapGeneration && Verbose) tty->cr(); 338 return true; 339 } 340 341 void OopMapCacheEntry::allocate_bit_mask() { 342 if (mask_size() > small_mask_limit) { 343 assert(_bit_mask[0] == 0, "bit mask should be new or just flushed"); 344 _bit_mask[0] = (intptr_t) 345 NEW_C_HEAP_ARRAY(uintptr_t, mask_word_size()); 346 } 347 } 348 349 void OopMapCacheEntry::deallocate_bit_mask() { 350 if (mask_size() > small_mask_limit && _bit_mask[0] != 0) { 351 assert(!Thread::current()->resource_area()->contains((void*)_bit_mask[0]), 352 "This bit mask should not be in the resource area"); 353 FREE_C_HEAP_ARRAY(uintptr_t, _bit_mask[0]); 354 debug_only(_bit_mask[0] = 0;) 355 } 356 } 357 358 359 void OopMapCacheEntry::fill_for_native(methodHandle mh) { 360 assert(mh->is_native(), "method must be native method"); 361 set_mask_size(mh->size_of_parameters() * bits_per_entry); 362 allocate_bit_mask(); 363 // fill mask for parameters 364 MaskFillerForNative mf(mh, bit_mask(), mask_size()); 365 mf.generate(); 366 } 367 368 369 void OopMapCacheEntry::fill(methodHandle method, int bci) { 370 HandleMark hm; 371 // Flush entry to deallocate an existing entry 372 flush(); 373 set_method(method()); 374 set_bci(bci); 375 if (method->is_native()) { 376 // Native method activations have oops only among the parameters and one 377 // extra oop following the parameters (the mirror for static native methods). 378 fill_for_native(method); 379 } else { 380 EXCEPTION_MARK; 381 OopMapForCacheEntry gen(method, bci, this); 382 gen.compute_map(CATCH); 383 } 384 #ifdef ASSERT 385 verify(); 386 #endif 387 } 388 389 390 void OopMapCacheEntry::set_mask(CellTypeState *vars, CellTypeState *stack, int stack_top) { 391 // compute bit mask size 392 int max_locals = method()->max_locals(); 393 int n_entries = max_locals + stack_top; 394 set_mask_size(n_entries * bits_per_entry); 395 allocate_bit_mask(); 396 set_expression_stack_size(stack_top); 397 398 // compute bits 399 int word_index = 0; 400 uintptr_t value = 0; 401 uintptr_t mask = 1; 402 403 CellTypeState* cell = vars; 404 for (int entry_index = 0; entry_index < n_entries; entry_index++, mask <<= bits_per_entry, cell++) { 405 // store last word 406 if (mask == 0) { 407 bit_mask()[word_index++] = value; 408 value = 0; 409 mask = 1; 410 } 411 412 // switch to stack when done with locals 413 if (entry_index == max_locals) { 414 cell = stack; 415 } 416 417 // set oop bit 418 if ( cell->is_reference()) { 419 value |= (mask << oop_bit_number ); 420 } 421 422 #ifdef ENABLE_ZAP_DEAD_LOCALS 423 // set dead bit 424 if (!cell->is_live()) { 425 value |= (mask << dead_bit_number); 426 assert(!cell->is_reference(), "dead value marked as oop"); 427 } 428 #endif 429 } 430 431 // make sure last word is stored 432 bit_mask()[word_index] = value; 433 434 // verify bit mask 435 assert(verify_mask(vars, stack, max_locals, stack_top), "mask could not be verified"); 436 437 438 } 439 440 void OopMapCacheEntry::flush() { 441 deallocate_bit_mask(); 442 initialize(); 443 } 444 445 446 // Implementation of OopMapCache 447 448 #ifndef PRODUCT 449 450 static long _total_memory_usage = 0; 451 452 long OopMapCache::memory_usage() { 453 return _total_memory_usage; 454 } 455 456 #endif 457 458 void InterpreterOopMap::resource_copy(OopMapCacheEntry* from) { 459 assert(_resource_allocate_bit_mask, 460 "Should not resource allocate the _bit_mask"); 461 assert(from->method()->is_oop(), "MethodOop is bad"); 462 463 set_method(from->method()); 464 set_bci(from->bci()); 465 set_mask_size(from->mask_size()); 466 set_expression_stack_size(from->expression_stack_size()); 467 468 // Is the bit mask contained in the entry? 469 if (from->mask_size() <= small_mask_limit) { 470 memcpy((void *)_bit_mask, (void *)from->_bit_mask, 471 mask_word_size() * BytesPerWord); 472 } else { 473 // The expectation is that this InterpreterOopMap is a recently created 474 // and empty. It is used to get a copy of a cached entry. 475 // If the bit mask has a value, it should be in the 476 // resource area. 477 assert(_bit_mask[0] == 0 || 478 Thread::current()->resource_area()->contains((void*)_bit_mask[0]), 479 "The bit mask should have been allocated from a resource area"); 480 // Allocate the bit_mask from a Resource area for performance. Allocating 481 // from the C heap as is done for OopMapCache has a significant 482 // performance impact. 483 _bit_mask[0] = (uintptr_t) NEW_RESOURCE_ARRAY(uintptr_t, mask_word_size()); 484 assert(_bit_mask[0] != 0, "bit mask was not allocated"); 485 memcpy((void*) _bit_mask[0], (void*) from->_bit_mask[0], 486 mask_word_size() * BytesPerWord); 487 } 488 } 489 490 inline unsigned int OopMapCache::hash_value_for(methodHandle method, int bci) { 491 // We use method->code_size() rather than method->identity_hash() below since 492 // the mark may not be present if a pointer to the method is already reversed. 493 return ((unsigned int) bci) 494 ^ ((unsigned int) method->max_locals() << 2) 495 ^ ((unsigned int) method->code_size() << 4) 496 ^ ((unsigned int) method->size_of_parameters() << 6); 497 } 498 499 500 OopMapCache::OopMapCache() : 501 _mut(Mutex::leaf, "An OopMapCache lock", true) 502 { 503 _array = NEW_C_HEAP_ARRAY(OopMapCacheEntry, _size); 504 // Cannot call flush for initialization, since flush 505 // will check if memory should be deallocated 506 for(int i = 0; i < _size; i++) _array[i].initialize(); 507 NOT_PRODUCT(_total_memory_usage += sizeof(OopMapCache) + (sizeof(OopMapCacheEntry) * _size);) 508 } 509 510 511 OopMapCache::~OopMapCache() { 512 assert(_array != NULL, "sanity check"); 513 // Deallocate oop maps that are allocated out-of-line 514 flush(); 515 // Deallocate array 516 NOT_PRODUCT(_total_memory_usage -= sizeof(OopMapCache) + (sizeof(OopMapCacheEntry) * _size);) 517 FREE_C_HEAP_ARRAY(OopMapCacheEntry, _array); 518 } 519 520 OopMapCacheEntry* OopMapCache::entry_at(int i) const { 521 return &_array[i % _size]; 522 } 523 524 void OopMapCache::flush() { 525 for (int i = 0; i < _size; i++) _array[i].flush(); 526 } 527 528 void OopMapCache::flush_obsolete_entries() { 529 for (int i = 0; i < _size; i++) 530 if (!_array[i].is_empty() && _array[i].method()->is_old()) { 531 // Cache entry is occupied by an old redefined method and we don't want 532 // to pin it down so flush the entry. 533 RC_TRACE(0x08000000, ("flush: %s(%s): cached entry @%d", 534 _array[i].method()->name()->as_C_string(), 535 _array[i].method()->signature()->as_C_string(), i)); 536 537 _array[i].flush(); 538 } 539 } 540 541 void OopMapCache::oop_iterate(OopClosure *blk) { 542 for (int i = 0; i < _size; i++) _array[i].oop_iterate(blk); 543 } 544 545 void OopMapCache::oop_iterate(OopClosure *blk, MemRegion mr) { 546 for (int i = 0; i < _size; i++) _array[i].oop_iterate(blk, mr); 547 } 548 549 void OopMapCache::verify() { 550 for (int i = 0; i < _size; i++) _array[i].verify(); 551 } 552 553 void OopMapCache::lookup(methodHandle method, 554 int bci, 555 InterpreterOopMap* entry_for) { 556 MutexLocker x(&_mut); 557 558 OopMapCacheEntry* entry = NULL; 559 int probe = hash_value_for(method, bci); 560 561 // Search hashtable for match 562 int i; 563 for(i = 0; i < _probe_depth; i++) { 564 entry = entry_at(probe + i); 565 if (entry->match(method, bci)) { 566 entry_for->resource_copy(entry); 567 assert(!entry_for->is_empty(), "A non-empty oop map should be returned"); 568 return; 569 } 570 } 571 572 if (TraceOopMapGeneration) { 573 static int count = 0; 574 ResourceMark rm; 575 tty->print("%d - Computing oopmap at bci %d for ", ++count, bci); 576 method->print_value(); tty->cr(); 577 } 578 579 // Entry is not in hashtable. 580 // Compute entry and return it 581 582 if (method->should_not_be_cached()) { 583 // It is either not safe or not a good idea to cache this methodOop 584 // at this time. We give the caller of lookup() a copy of the 585 // interesting info via parameter entry_for, but we don't add it to 586 // the cache. See the gory details in methodOop.cpp. 587 compute_one_oop_map(method, bci, entry_for); 588 return; 589 } 590 591 // First search for an empty slot 592 for(i = 0; i < _probe_depth; i++) { 593 entry = entry_at(probe + i); 594 if (entry->is_empty()) { 595 entry->fill(method, bci); 596 entry_for->resource_copy(entry); 597 assert(!entry_for->is_empty(), "A non-empty oop map should be returned"); 598 return; 599 } 600 } 601 602 if (TraceOopMapGeneration) { 603 ResourceMark rm; 604 tty->print_cr("*** collision in oopmap cache - flushing item ***"); 605 } 606 607 // No empty slot (uncommon case). Use (some approximation of a) LRU algorithm 608 //entry_at(probe + _probe_depth - 1)->flush(); 609 //for(i = _probe_depth - 1; i > 0; i--) { 610 // // Coping entry[i] = entry[i-1]; 611 // OopMapCacheEntry *to = entry_at(probe + i); 612 // OopMapCacheEntry *from = entry_at(probe + i - 1); 613 // to->copy(from); 614 // } 615 616 assert(method->is_method(), "gaga"); 617 618 entry = entry_at(probe + 0); 619 entry->fill(method, bci); 620 621 // Copy the newly cached entry to input parameter 622 entry_for->resource_copy(entry); 623 624 if (TraceOopMapGeneration) { 625 ResourceMark rm; 626 tty->print("Done with "); 627 method->print_value(); tty->cr(); 628 } 629 assert(!entry_for->is_empty(), "A non-empty oop map should be returned"); 630 631 return; 632 } 633 634 void OopMapCache::compute_one_oop_map(methodHandle method, int bci, InterpreterOopMap* entry) { 635 // Due to the invariants above it's tricky to allocate a temporary OopMapCacheEntry on the stack 636 OopMapCacheEntry* tmp = NEW_C_HEAP_ARRAY(OopMapCacheEntry, 1); 637 tmp->initialize(); 638 tmp->fill(method, bci); 639 entry->resource_copy(tmp); 640 FREE_C_HEAP_ARRAY(OopMapCacheEntry, tmp); 641 }