1 /* 2 * Copyright (c) 1997, 2020, 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 #ifndef SHARE_UTILITIES_GROWABLEARRAY_HPP 26 #define SHARE_UTILITIES_GROWABLEARRAY_HPP 27 28 #include "memory/allocation.hpp" 29 #include "memory/iterator.hpp" 30 #include "utilities/debug.hpp" 31 #include "utilities/globalDefinitions.hpp" 32 #include "utilities/ostream.hpp" 33 #include "utilities/powerOfTwo.hpp" 34 35 // A growable array. 36 37 /*************************************************************************/ 38 /* */ 39 /* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING */ 40 /* */ 41 /* Should you use GrowableArrays to contain handles you must be certain */ 42 /* that the GrowableArray does not outlive the HandleMark that contains */ 43 /* the handles. Since GrowableArrays are typically resource allocated */ 44 /* the following is an example of INCORRECT CODE, */ 45 /* */ 46 /* ResourceMark rm; */ 47 /* GrowableArray<Handle>* arr = new GrowableArray<Handle>(size); */ 48 /* if (blah) { */ 49 /* while (...) { */ 50 /* HandleMark hm; */ 51 /* ... */ 52 /* Handle h(THREAD, some_oop); */ 53 /* arr->append(h); */ 54 /* } */ 55 /* } */ 56 /* if (arr->length() != 0 ) { */ 57 /* oop bad_oop = arr->at(0)(); // Handle is BAD HERE. */ 58 /* ... */ 59 /* } */ 60 /* */ 61 /* If the GrowableArrays you are creating is C_Heap allocated then it */ 62 /* should not hold handles since the handles could trivially try and */ 63 /* outlive their HandleMark. In some situations you might need to do */ 64 /* this and it would be legal but be very careful and see if you can do */ 65 /* the code in some other manner. */ 66 /* */ 67 /*************************************************************************/ 68 69 // Non-template base class responsible for handling the length and max. 70 71 72 class GrowableArrayBase : public ResourceObj { 73 friend class VMStructs; 74 75 protected: 76 // Current number of accessible elements 77 int _len; 78 // Current number of allocated elements 79 int _max; 80 81 GrowableArrayBase(int initial_max, int initial_len) : 82 _len(initial_len), 83 _max(initial_max) { 84 assert(_len >= 0 && _len <= _max, "initial_len too big"); 85 } 86 87 ~GrowableArrayBase() {} 88 89 public: 90 int length() const { return _len; } 91 int max_length() const { return _max; } 92 93 bool is_empty() const { return _len == 0; } 94 bool is_nonempty() const { return _len != 0; } 95 bool is_full() const { return _len == _max; } 96 97 void clear() { _len = 0; } 98 void trunc_to(int length) { 99 assert(length <= _len,"cannot increase length"); 100 _len = length; 101 } 102 }; 103 104 template <typename E> class GrowableArrayIterator; 105 template <typename E, typename UnaryPredicate> class GrowableArrayFilterIterator; 106 107 // Extends GrowableArrayBase with a typed data array. 108 // 109 // E: Element type 110 // 111 // The "view" adds function that don't grow or deallocate 112 // the _data array, so there's no need for an allocator. 113 // 114 // The "view" can be used to type erase the allocator classes 115 // of GrowableArrayWithAllocator. 116 template <typename E> 117 class GrowableArrayView : public GrowableArrayBase { 118 protected: 119 E* _data; // data array 120 121 GrowableArrayView<E>(E* data, int initial_max, int initial_len) : 122 GrowableArrayBase(initial_max, initial_len), _data(data) {} 123 124 ~GrowableArrayView() {} 125 126 public: 127 const static GrowableArrayView EMPTY; 128 129 bool operator==(const GrowableArrayView<E>& rhs) const { 130 if (_len != rhs._len) 131 return false; 132 for (int i = 0; i < _len; i++) { 133 if (at(i) != rhs.at(i)) { 134 return false; 135 } 136 } 137 return true; 138 } 139 140 bool operator!=(const GrowableArrayView<E>& rhs) const { 141 return !(*this == rhs); 142 } 143 144 E* data() { 145 return _data; 146 } 147 148 const E* data() const { 149 return _data; 150 } 151 152 E& at(int i) { 153 assert(0 <= i && i < _len, "illegal index"); 154 return _data[i]; 155 } 156 157 E const& at(int i) const { 158 assert(0 <= i && i < _len, "illegal index"); 159 return _data[i]; 160 } 161 162 E* adr_at(int i) const { 163 assert(0 <= i && i < _len, "illegal index"); 164 return &_data[i]; 165 } 166 167 E first() const { 168 assert(_len > 0, "empty list"); 169 return _data[0]; 170 } 171 172 E top() const { 173 assert(_len > 0, "empty list"); 174 return _data[_len-1]; 175 } 176 177 E last() const { 178 return top(); 179 } 180 181 GrowableArrayIterator<E> begin() const { 182 return GrowableArrayIterator<E>(this, 0); 183 } 184 185 GrowableArrayIterator<E> end() const { 186 return GrowableArrayIterator<E>(this, length()); 187 } 188 189 E pop() { 190 assert(_len > 0, "empty list"); 191 return _data[--_len]; 192 } 193 194 void at_put(int i, const E& elem) { 195 assert(0 <= i && i < _len, "illegal index"); 196 _data[i] = elem; 197 } 198 199 bool contains(const E& elem) const { 200 for (int i = 0; i < _len; i++) { 201 if (_data[i] == elem) return true; 202 } 203 return false; 204 } 205 206 int find(const E& elem) const { 207 for (int i = 0; i < _len; i++) { 208 if (_data[i] == elem) return i; 209 } 210 return -1; 211 } 212 213 int find_from_end(const E& elem) const { 214 for (int i = _len-1; i >= 0; i--) { 215 if (_data[i] == elem) return i; 216 } 217 return -1; 218 } 219 220 int find(void* token, bool f(void*, E)) const { 221 for (int i = 0; i < _len; i++) { 222 if (f(token, _data[i])) return i; 223 } 224 return -1; 225 } 226 227 int find_from_end(void* token, bool f(void*, E)) const { 228 // start at the end of the array 229 for (int i = _len-1; i >= 0; i--) { 230 if (f(token, _data[i])) return i; 231 } 232 return -1; 233 } 234 235 // Order preserving remove operations. 236 237 void remove(const E& elem) { 238 // Assuming that element does exist. 239 bool removed = remove_if_existing(elem); 240 if (removed) return; 241 ShouldNotReachHere(); 242 } 243 244 bool remove_if_existing(const E& elem) { 245 // Returns TRUE if elem is removed. 246 for (int i = 0; i < _len; i++) { 247 if (_data[i] == elem) { 248 remove_at(i); 249 return true; 250 } 251 } 252 return false; 253 } 254 255 void remove_at(int index) { 256 assert(0 <= index && index < _len, "illegal index"); 257 for (int j = index + 1; j < _len; j++) { 258 _data[j-1] = _data[j]; 259 } 260 _len--; 261 } 262 263 // Remove all elements up to the index (exclusive). The order is preserved. 264 void remove_till(int idx) { 265 for (int i = 0, j = idx; j < length(); i++, j++) { 266 at_put(i, at(j)); 267 } 268 trunc_to(length() - idx); 269 } 270 271 // The order is changed. 272 void delete_at(int index) { 273 assert(0 <= index && index < _len, "illegal index"); 274 if (index < --_len) { 275 // Replace removed element with last one. 276 _data[index] = _data[_len]; 277 } 278 } 279 280 void sort(int f(E*, E*)) { 281 qsort(_data, length(), sizeof(E), (_sort_Fn)f); 282 } 283 // sort by fixed-stride sub arrays: 284 void sort(int f(E*, E*), int stride) { 285 qsort(_data, length() / stride, sizeof(E) * stride, (_sort_Fn)f); 286 } 287 288 template <typename K, int compare(const K&, const E&)> int find_sorted(const K& key, bool& found) { 289 found = false; 290 int min = 0; 291 int max = length() - 1; 292 293 while (max >= min) { 294 int mid = (int)(((uint)max + min) / 2); 295 E value = at(mid); 296 int diff = compare(key, value); 297 if (diff > 0) { 298 min = mid + 1; 299 } else if (diff < 0) { 300 max = mid - 1; 301 } else { 302 found = true; 303 return mid; 304 } 305 } 306 return min; 307 } 308 309 template <typename K> 310 int find_sorted(CompareClosure<E>* cc, const K& key, bool& found) { 311 found = false; 312 int min = 0; 313 int max = length() - 1; 314 315 while (max >= min) { 316 int mid = (int)(((uint)max + min) / 2); 317 E value = at(mid); 318 int diff = cc->do_compare(key, value); 319 if (diff > 0) { 320 min = mid + 1; 321 } else if (diff < 0) { 322 max = mid - 1; 323 } else { 324 found = true; 325 return mid; 326 } 327 } 328 return min; 329 } 330 331 void truncate_to(int idx) { 332 for (int i = 0, j = idx; j < length(); i++, j++) { 333 at_put(i, at(j)); 334 } 335 trunc_to(length() - idx); 336 } 337 338 void truncate_from(int idx) { 339 trunc_to(idx); 340 } 341 342 size_t data_size_in_bytes() const { 343 return _len * sizeof(E); 344 } 345 346 void print() const { 347 tty->print("Growable Array " INTPTR_FORMAT, p2i(this)); 348 tty->print(": length %d (_max %d) { ", _len, _max); 349 for (int i = 0; i < _len; i++) { 350 tty->print(INTPTR_FORMAT " ", *(intptr_t*)&(_data[i])); 351 } 352 tty->print("}\n"); 353 } 354 }; 355 356 template<typename E> 357 const GrowableArrayView<E> GrowableArrayView<E>::EMPTY(nullptr, 0, 0); 358 359 // GrowableArrayWithAllocator extends the "view" with 360 // the capability to grow and deallocate the data array. 361 // 362 // The allocator responsibility is delegated to the sub-class. 363 // 364 // Derived: The sub-class responsible for allocation / deallocation 365 // - E* Derived::allocate() - member function responsible for allocation 366 // - void Derived::deallocate(E*) - member function responsible for deallocation 367 template <typename E, typename Derived> 368 class GrowableArrayWithAllocator : public GrowableArrayView<E> { 369 friend class VMStructs; 370 371 void grow(int j); 372 373 protected: 374 GrowableArrayWithAllocator(E* data, int initial_max) : 375 GrowableArrayView<E>(data, initial_max, 0) { 376 for (int i = 0; i < initial_max; i++) { 377 ::new ((void*)&data[i]) E(); 378 } 379 } 380 381 GrowableArrayWithAllocator(E* data, int initial_max, int initial_len, const E& filler) : 382 GrowableArrayView<E>(data, initial_max, initial_len) { 383 int i = 0; 384 for (; i < initial_len; i++) { 385 ::new ((void*)&data[i]) E(filler); 386 } 387 for (; i < initial_max; i++) { 388 ::new ((void*)&data[i]) E(); 389 } 390 } 391 392 ~GrowableArrayWithAllocator() {} 393 394 public: 395 int append(const E& elem) { 396 if (this->_len == this->_max) grow(this->_len); 397 int idx = this->_len++; 398 this->_data[idx] = elem; 399 return idx; 400 } 401 402 bool append_if_missing(const E& elem) { 403 // Returns TRUE if elem is added. 404 bool missed = !this->contains(elem); 405 if (missed) append(elem); 406 return missed; 407 } 408 409 void push(const E& elem) { append(elem); } 410 411 E at_grow(int i, const E& fill = E()) { 412 assert(0 <= i, "negative index"); 413 if (i >= this->_len) { 414 if (i >= this->_max) grow(i); 415 for (int j = this->_len; j <= i; j++) 416 this->_data[j] = fill; 417 this->_len = i+1; 418 } 419 return this->_data[i]; 420 } 421 422 void at_put_grow(int i, const E& elem, const E& fill = E()) { 423 assert(0 <= i, "negative index"); 424 if (i >= this->_len) { 425 if (i >= this->_max) grow(i); 426 for (int j = this->_len; j < i; j++) 427 this->_data[j] = fill; 428 this->_len = i+1; 429 } 430 this->_data[i] = elem; 431 } 432 433 // inserts the given element before the element at index i 434 void insert_before(const int idx, const E& elem) { 435 assert(0 <= idx && idx <= this->_len, "illegal index"); 436 if (this->_len == this->_max) grow(this->_len); 437 for (int j = this->_len - 1; j >= idx; j--) { 438 this->_data[j + 1] = this->_data[j]; 439 } 440 this->_len++; 441 this->_data[idx] = elem; 442 } 443 444 void insert_before(const int idx, const GrowableArrayView<E>* array) { 445 assert(0 <= idx && idx <= this->_len, "illegal index"); 446 int array_len = array->length(); 447 int new_len = this->_len + array_len; 448 if (new_len >= this->_max) grow(new_len); 449 450 for (int j = this->_len - 1; j >= idx; j--) { 451 this->_data[j + array_len] = this->_data[j]; 452 } 453 454 for (int j = 0; j < array_len; j++) { 455 this->_data[idx + j] = array->at(j); 456 } 457 458 this->_len += array_len; 459 } 460 461 void appendAll(const GrowableArrayView<E>* l) { 462 for (int i = 0; i < l->length(); i++) { 463 this->at_put_grow(this->_len, l->at(i), E()); 464 } 465 } 466 467 // Binary search and insertion utility. Search array for element 468 // matching key according to the static compare function. Insert 469 // that element if not already in the list. Assumes the list is 470 // already sorted according to compare function. 471 template <int compare(const E&, const E&)> E insert_sorted(const E& key) { 472 bool found; 473 int location = GrowableArrayView<E>::template find_sorted<E, compare>(key, found); 474 if (!found) { 475 insert_before(location, key); 476 } 477 return this->at(location); 478 } 479 480 E insert_sorted(CompareClosure<E>* cc, const E& key) { 481 bool found; 482 int location = find_sorted(cc, key, found); 483 if (!found) { 484 insert_before(location, key); 485 } 486 return this->at(location); 487 } 488 489 void swap(GrowableArrayWithAllocator<E, Derived>* other) { 490 ::swap(this->_data, other->_data); 491 ::swap(this->_len, other->_len); 492 ::swap(this->_max, other->_max); 493 } 494 495 void clear_and_deallocate(); 496 }; 497 498 template <typename E, typename Derived> 499 void GrowableArrayWithAllocator<E, Derived>::grow(int j) { 500 int old_max = this->_max; 501 // grow the array by increasing _max to the first power of two larger than the size we need 502 this->_max = next_power_of_2((uint32_t)j); 503 // j < _max 504 E* newData = static_cast<Derived*>(this)->allocate(); 505 int i = 0; 506 for ( ; i < this->_len; i++) ::new ((void*)&newData[i]) E(this->_data[i]); 507 for ( ; i < this->_max; i++) ::new ((void*)&newData[i]) E(); 508 for (i = 0; i < old_max; i++) this->_data[i].~E(); 509 if (this->_data != NULL) { 510 static_cast<Derived*>(this)->deallocate(this->_data); 511 } 512 this->_data = newData; 513 } 514 515 template <typename E, typename Derived> 516 void GrowableArrayWithAllocator<E, Derived>::clear_and_deallocate() { 517 if (this->_data != NULL) { 518 for (int i = 0; i < this->_max; i++) { 519 this->_data[i].~E(); 520 } 521 static_cast<Derived*>(this)->deallocate(this->_data); 522 this->_data = NULL; 523 } 524 this->_len = 0; 525 this->_max = 0; 526 } 527 528 class GrowableArrayResourceAllocator { 529 public: 530 static void* allocate(int max, int element_size); 531 }; 532 533 // Arena allocator 534 class GrowableArrayArenaAllocator { 535 public: 536 static void* allocate(int max, int element_size, Arena* arena); 537 }; 538 539 // CHeap allocator 540 class GrowableArrayCHeapAllocator { 541 public: 542 static void* allocate(int max, int element_size, MEMFLAGS memflags); 543 static void deallocate(void* mem); 544 }; 545 546 #ifdef ASSERT 547 548 // Checks resource allocation nesting 549 class GrowableArrayNestingCheck { 550 // resource area nesting at creation 551 int _nesting; 552 553 public: 554 GrowableArrayNestingCheck(bool on_stack); 555 556 void on_stack_alloc() const; 557 }; 558 559 #endif // ASSERT 560 561 // Encodes where the backing array is allocated 562 // and performs necessary checks. 563 class GrowableArrayMetadata { 564 uintptr_t _bits; 565 566 // resource area nesting at creation 567 debug_only(GrowableArrayNestingCheck _nesting_check;) 568 569 uintptr_t bits(MEMFLAGS memflags) const { 570 if (memflags == mtNone) { 571 // Stack allocation 572 return 0; 573 } 574 575 // CHeap allocation 576 return (uintptr_t(memflags) << 1) | 1; 577 } 578 579 uintptr_t bits(Arena* arena) const { 580 return uintptr_t(arena); 581 } 582 583 public: 584 GrowableArrayMetadata(Arena* arena) : 585 _bits(bits(arena)) 586 debug_only(COMMA _nesting_check(on_stack())) { 587 } 588 589 GrowableArrayMetadata(MEMFLAGS memflags) : 590 _bits(bits(memflags)) 591 debug_only(COMMA _nesting_check(on_stack())) { 592 } 593 594 #ifdef ASSERT 595 GrowableArrayMetadata(const GrowableArrayMetadata& other) : 596 _bits(other._bits), 597 _nesting_check(other._nesting_check) { 598 assert(!on_C_heap(), "Copying of CHeap arrays not supported"); 599 assert(!other.on_C_heap(), "Copying of CHeap arrays not supported"); 600 } 601 602 GrowableArrayMetadata& operator=(const GrowableArrayMetadata& other) { 603 _bits = other._bits; 604 _nesting_check = other._nesting_check; 605 assert(!on_C_heap(), "Assignment of CHeap arrays not supported"); 606 assert(!other.on_C_heap(), "Assignment of CHeap arrays not supported"); 607 return *this; 608 } 609 610 void init_checks(const GrowableArrayBase* array) const; 611 void on_stack_alloc_check() const; 612 #endif // ASSERT 613 614 bool on_C_heap() const { return (_bits & 1) == 1; } 615 bool on_stack () const { return _bits == 0; } 616 bool on_arena () const { return (_bits & 1) == 0 && _bits != 0; } 617 618 Arena* arena() const { return (Arena*)_bits; } 619 MEMFLAGS memflags() const { return MEMFLAGS(_bits >> 1); } 620 }; 621 622 // THE GrowableArray. 623 // 624 // Supports multiple allocation strategies: 625 // - Resource stack allocation: if memflags == mtNone 626 // - CHeap allocation: if memflags != mtNone 627 // - Arena allocation: if an arena is provided 628 // 629 // There are some drawbacks of using GrowableArray, that are removed in some 630 // of the other implementations of GrowableArrayWithAllocator sub-classes: 631 // 632 // Memory overhead: The multiple allocation strategies uses extra metadata 633 // embedded in the instance. 634 // 635 // Strict allocation locations: There are rules about where the GrowableArray 636 // instance is allocated, that depends on where the data array is allocated. 637 // See: init_checks. 638 639 template <typename E> 640 class GrowableArray : public GrowableArrayWithAllocator<E, GrowableArray<E> > { 641 friend class GrowableArrayWithAllocator<E, GrowableArray<E> >; 642 friend class GrowableArrayTest; 643 644 static E* allocate(int max) { 645 return (E*)GrowableArrayResourceAllocator::allocate(max, sizeof(E)); 646 } 647 648 static E* allocate(int max, MEMFLAGS memflags) { 649 if (memflags != mtNone) { 650 return (E*)GrowableArrayCHeapAllocator::allocate(max, sizeof(E), memflags); 651 } 652 653 return (E*)GrowableArrayResourceAllocator::allocate(max, sizeof(E)); 654 } 655 656 static E* allocate(int max, Arena* arena) { 657 return (E*)GrowableArrayArenaAllocator::allocate(max, sizeof(E), arena); 658 } 659 660 GrowableArrayMetadata _metadata; 661 662 void init_checks() const { debug_only(_metadata.init_checks(this);) } 663 664 // Where are we going to allocate memory? 665 bool on_C_heap() const { return _metadata.on_C_heap(); } 666 bool on_stack () const { return _metadata.on_stack(); } 667 bool on_arena () const { return _metadata.on_arena(); } 668 669 E* allocate() { 670 if (on_stack()) { 671 debug_only(_metadata.on_stack_alloc_check()); 672 return allocate(this->_max); 673 } 674 675 if (on_C_heap()) { 676 return allocate(this->_max, _metadata.memflags()); 677 } 678 679 assert(on_arena(), "Sanity"); 680 return allocate(this->_max, _metadata.arena()); 681 } 682 683 void deallocate(E* mem) { 684 if (on_C_heap()) { 685 GrowableArrayCHeapAllocator::deallocate(mem); 686 } 687 } 688 689 public: 690 GrowableArray(int initial_max = 2, MEMFLAGS memflags = mtNone) : 691 GrowableArrayWithAllocator<E, GrowableArray<E> >( 692 allocate(initial_max, memflags), 693 initial_max), 694 _metadata(memflags) { 695 init_checks(); 696 } 697 698 GrowableArray(int initial_max, int initial_len, const E& filler, MEMFLAGS memflags = mtNone) : 699 GrowableArrayWithAllocator<E, GrowableArray<E> >( 700 allocate(initial_max, memflags), 701 initial_max, initial_len, filler), 702 _metadata(memflags) { 703 init_checks(); 704 } 705 706 GrowableArray(Arena* arena, int initial_max, int initial_len, const E& filler) : 707 GrowableArrayWithAllocator<E, GrowableArray<E> >( 708 allocate(initial_max, arena), 709 initial_max, initial_len, filler), 710 _metadata(arena) { 711 init_checks(); 712 } 713 714 ~GrowableArray() { 715 if (on_C_heap()) { 716 this->clear_and_deallocate(); 717 } 718 } 719 }; 720 721 // Leaner GrowableArray for CHeap backed data arrays, with compile-time decided MEMFLAGS. 722 template <typename E, MEMFLAGS F> 723 class GrowableArrayCHeap : public GrowableArrayWithAllocator<E, GrowableArrayCHeap<E, F> > { 724 friend class GrowableArrayWithAllocator<E, GrowableArrayCHeap<E, F> >; 725 726 STATIC_ASSERT(F != mtNone); 727 728 static E* allocate(int max, MEMFLAGS flags) { 729 if (max == 0) { 730 return NULL; 731 } 732 733 return (E*)GrowableArrayCHeapAllocator::allocate(max, sizeof(E), flags); 734 } 735 736 NONCOPYABLE(GrowableArrayCHeap); 737 738 E* allocate() { 739 return allocate(this->_max, F); 740 } 741 742 void deallocate(E* mem) { 743 GrowableArrayCHeapAllocator::deallocate(mem); 744 } 745 746 public: 747 GrowableArrayCHeap(int initial_max = 0) : 748 GrowableArrayWithAllocator<E, GrowableArrayCHeap<E, F> >( 749 allocate(initial_max, F), 750 initial_max) {} 751 752 GrowableArrayCHeap(int initial_max, int initial_len, const E& filler) : 753 GrowableArrayWithAllocator<E, GrowableArrayCHeap<E, F> >( 754 allocate(initial_max, F), 755 initial_max, initial_len, filler) {} 756 757 ~GrowableArrayCHeap() { 758 this->clear_and_deallocate(); 759 } 760 761 void* operator new(size_t size) throw() { 762 return ResourceObj::operator new(size, ResourceObj::C_HEAP, F); 763 } 764 765 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() { 766 return ResourceObj::operator new(size, nothrow_constant, ResourceObj::C_HEAP, F); 767 } 768 }; 769 770 // Custom STL-style iterator to iterate over GrowableArrays 771 // It is constructed by invoking GrowableArray::begin() and GrowableArray::end() 772 template <typename E> 773 class GrowableArrayIterator : public StackObj { 774 friend class GrowableArrayView<E>; 775 template <typename F, typename UnaryPredicate> friend class GrowableArrayFilterIterator; 776 777 private: 778 const GrowableArrayView<E>* _array; // GrowableArray we iterate over 779 int _position; // The current position in the GrowableArray 780 781 // Private constructor used in GrowableArray::begin() and GrowableArray::end() 782 GrowableArrayIterator(const GrowableArrayView<E>* array, int position) : _array(array), _position(position) { 783 assert(0 <= position && position <= _array->length(), "illegal position"); 784 } 785 786 public: 787 GrowableArrayIterator() : _array(NULL), _position(0) { } 788 GrowableArrayIterator<E>& operator++() { ++_position; return *this; } 789 E operator*() { return _array->at(_position); } 790 791 bool operator==(const GrowableArrayIterator<E>& rhs) { 792 assert(_array == rhs._array, "iterator belongs to different array"); 793 return _position == rhs._position; 794 } 795 796 bool operator!=(const GrowableArrayIterator<E>& rhs) { 797 assert(_array == rhs._array, "iterator belongs to different array"); 798 return _position != rhs._position; 799 } 800 }; 801 802 // Custom STL-style iterator to iterate over elements of a GrowableArray that satisfy a given predicate 803 template <typename E, class UnaryPredicate> 804 class GrowableArrayFilterIterator : public StackObj { 805 friend class GrowableArrayView<E>; 806 807 private: 808 const GrowableArrayView<E>* _array; // GrowableArray we iterate over 809 int _position; // Current position in the GrowableArray 810 UnaryPredicate _predicate; // Unary predicate the elements of the GrowableArray should satisfy 811 812 public: 813 GrowableArrayFilterIterator(const GrowableArrayIterator<E>& begin, UnaryPredicate filter_predicate) : 814 _array(begin._array), _position(begin._position), _predicate(filter_predicate) { 815 // Advance to first element satisfying the predicate 816 while(_position != _array->length() && !_predicate(_array->at(_position))) { 817 ++_position; 818 } 819 } 820 821 GrowableArrayFilterIterator<E, UnaryPredicate>& operator++() { 822 do { 823 // Advance to next element satisfying the predicate 824 ++_position; 825 } while(_position != _array->length() && !_predicate(_array->at(_position))); 826 return *this; 827 } 828 829 E operator*() { return _array->at(_position); } 830 831 bool operator==(const GrowableArrayIterator<E>& rhs) { 832 assert(_array == rhs._array, "iterator belongs to different array"); 833 return _position == rhs._position; 834 } 835 836 bool operator!=(const GrowableArrayIterator<E>& rhs) { 837 assert(_array == rhs._array, "iterator belongs to different array"); 838 return _position != rhs._position; 839 } 840 841 bool operator==(const GrowableArrayFilterIterator<E, UnaryPredicate>& rhs) { 842 assert(_array == rhs._array, "iterator belongs to different array"); 843 return _position == rhs._position; 844 } 845 846 bool operator!=(const GrowableArrayFilterIterator<E, UnaryPredicate>& rhs) { 847 assert(_array == rhs._array, "iterator belongs to different array"); 848 return _position != rhs._position; 849 } 850 }; 851 852 // Arrays for basic types 853 typedef GrowableArray<int> intArray; 854 typedef GrowableArray<int> intStack; 855 typedef GrowableArray<bool> boolArray; 856 857 #endif // SHARE_UTILITIES_GROWABLEARRAY_HPP