1 /*
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  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  *
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 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
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 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 "oops/array.hpp"
 31 #include "oops/oop.hpp"
 32 #include "utilities/debug.hpp"
 33 #include "utilities/globalDefinitions.hpp"
 34 #include "utilities/ostream.hpp"
 35 #include "utilities/powerOfTwo.hpp"
 36 
 37 // A growable array.
 38 
 39 /*************************************************************************/
 40 /*                                                                       */
 41 /*     WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING   */
 42 /*                                                                       */
 43 /* Should you use GrowableArrays to contain handles you must be certain  */
 44 /* that the GrowableArray does not outlive the HandleMark that contains  */
 45 /* the handles. Since GrowableArrays are typically resource allocated    */
 46 /* the following is an example of INCORRECT CODE,                        */
 47 /*                                                                       */
 48 /* ResourceMark rm;                                                      */
 49 /* GrowableArray<Handle>* arr = new GrowableArray<Handle>(size);         */
 50 /* if (blah) {                                                           */
 51 /*    while (...) {                                                      */
 52 /*      HandleMark hm;                                                   */
 53 /*      ...                                                              */
 54 /*      Handle h(THREAD, some_oop);                                      */
 55 /*      arr->append(h);                                                  */
 56 /*    }                                                                  */
 57 /* }                                                                     */
 58 /* if (arr->length() != 0 ) {                                            */
 59 /*    oop bad_oop = arr->at(0)(); // Handle is BAD HERE.                 */
 60 /*    ...                                                                */
 61 /* }                                                                     */
 62 /*                                                                       */
 63 /* If the GrowableArrays you are creating is C_Heap allocated then it    */
 64 /* should not hold handles since the handles could trivially try and     */
 65 /* outlive their HandleMark. In some situations you might need to do     */
 66 /* this and it would be legal but be very careful and see if you can do  */
 67 /* the code in some other manner.                                        */
 68 /*                                                                       */
 69 /*************************************************************************/
 70 
 71 // Non-template base class responsible for handling the length and max.
 72 
 73 
 74 class GrowableArrayBase : public AnyObj {
 75   friend class VMStructs;
 76 
 77 protected:
 78   // Current number of accessible elements
 79   int _len;
 80   // Current number of allocated elements
 81   int _capacity;
 82 
 83   GrowableArrayBase(int capacity, int initial_len) :
 84       _len(initial_len),
 85       _capacity(capacity) {
 86     assert(_len >= 0 && _len <= _capacity, "initial_len too big");
 87   }
 88 
 89   ~GrowableArrayBase() {}
 90 
 91 public:
 92   int   length() const          { return _len; }
 93   int   capacity() const        { return _capacity; }
 94 
 95   bool  is_empty() const        { return _len == 0; }
 96   bool  is_nonempty() const     { return _len != 0; }
 97   bool  is_full() const         { return _len == _capacity; }
 98 };
 99 
100 template <typename E> class GrowableArrayIterator;
101 template <typename E, typename UnaryPredicate> class GrowableArrayFilterIterator;
102 
103 // Extends GrowableArrayBase with a typed data array.
104 //
105 // E: Element type
106 //
107 // The "view" adds function that don't grow or deallocate
108 // the _data array, so there's no need for an allocator.
109 //
110 // The "view" can be used to type erase the allocator classes
111 // of GrowableArrayWithAllocator.
112 template <typename E>
113 class GrowableArrayView : public GrowableArrayBase {
114 protected:
115   E* _data; // data array
116 
117   GrowableArrayView(E* data, int capacity, int initial_len) :
118       GrowableArrayBase(capacity, initial_len), _data(data) {}
119 
120   ~GrowableArrayView() {}
121 
122 public:
123   bool operator==(const GrowableArrayView& rhs) const {
124     if (_len != rhs._len)
125       return false;
126     for (int i = 0; i < _len; i++) {
127       if (at(i) != rhs.at(i)) {
128         return false;
129       }
130     }
131     return true;
132   }
133 
134   bool operator!=(const GrowableArrayView& rhs) const {
135     return !(*this == rhs);
136   }
137 
138   E& at(int i) {
139     assert(0 <= i && i < _len, "illegal index %d for length %d", i, _len);
140     return _data[i];
141   }
142 
143   E const& at(int i) const {
144     assert(0 <= i && i < _len, "illegal index %d for length %d", i, _len);
145     return _data[i];
146   }
147 
148   E* adr_at(int i) const {
149     assert(0 <= i && i < _len, "illegal index %d for length %d", i, _len);
150     return &_data[i];
151   }
152 
153   E& first() {
154     assert(_len > 0, "empty");
155     return _data[0];
156   }
157 
158   E const& first() const {
159     assert(_len > 0, "empty");
160     return _data[0];
161   }
162 
163   E& top() {
164     assert(_len > 0, "empty");
165     return _data[_len - 1];
166   }
167 
168   E const& top() const {
169     assert(_len > 0, "empty");
170     return _data[_len - 1];
171   }
172 
173   E& last() {
174     return top();
175   }
176 
177   E const& 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   void at_put(int i, const E& elem) {
190     assert(0 <= i && i < _len, "illegal index %d for length %d", i, _len);
191     _data[i] = elem;
192   }
193 
194   bool contains(const E& elem) const {
195     for (int i = 0; i < _len; i++) {
196       if (_data[i] == elem) return true;
197     }
198     return false;
199   }
200 
201   int  find(const E& elem) const {
202     for (int i = 0; i < _len; i++) {
203       if (_data[i] == elem) return i;
204     }
205     return -1;
206   }
207 
208   int  find_from_end(const E& elem) const {
209     for (int i = _len-1; i >= 0; i--) {
210       if (_data[i] == elem) return i;
211     }
212     return -1;
213   }
214 
215   // Find first element that matches the given predicate.
216   //
217   // Predicate: bool predicate(const E& elem)
218   //
219   // Returns the index of the element or -1 if no element matches the predicate
220   template<typename Predicate>
221   int find_if(Predicate predicate) const {
222     for (int i = 0; i < _len; i++) {
223       if (predicate(_data[i])) return i;
224     }
225     return -1;
226   }
227 
228   // Find last element that matches the given predicate.
229   //
230   // Predicate: bool predicate(const E& elem)
231   //
232   // Returns the index of the element or -1 if no element matches the predicate
233   template<typename Predicate>
234   int find_from_end_if(Predicate predicate) const {
235     // start at the end of the array
236     for (int i = _len-1; i >= 0; i--) {
237       if (predicate(_data[i])) return i;
238     }
239     return -1;
240   }
241 
242   void sort(int f(E*, E*)) {
243     if (_data == nullptr) return;
244     qsort(_data, length(), sizeof(E), (_sort_Fn)f);
245   }
246   // sort by fixed-stride sub arrays:
247   void sort(int f(E*, E*), int stride) {
248     if (_data == nullptr) return;
249     qsort(_data, length() / stride, sizeof(E) * stride, (_sort_Fn)f);
250   }
251 
252   template <typename K, int compare(const K&, const E&)> int find_sorted(const K& key, bool& found) const {
253     found = false;
254     int min = 0;
255     int max = length() - 1;
256 
257     while (max >= min) {
258       int mid = (int)(((uint)max + min) / 2);
259       E value = at(mid);
260       int diff = compare(key, value);
261       if (diff > 0) {
262         min = mid + 1;
263       } else if (diff < 0) {
264         max = mid - 1;
265       } else {
266         found = true;
267         return mid;
268       }
269     }
270     return min;
271   }
272 
273   template <typename K>
274   int find_sorted(CompareClosure<E>* cc, const K& key, bool& found) {
275     found = false;
276     int min = 0;
277     int max = length() - 1;
278 
279     while (max >= min) {
280       int mid = (int)(((uint)max + min) / 2);
281       E value = at(mid);
282       int diff = cc->do_compare(key, value);
283       if (diff > 0) {
284         min = mid + 1;
285       } else if (diff < 0) {
286         max = mid - 1;
287       } else {
288         found = true;
289         return mid;
290       }
291     }
292     return min;
293   }
294 
295   void print() const {
296     tty->print("Growable Array " PTR_FORMAT, p2i(this));
297     tty->print(": length %d (capacity %d) { ", _len, _capacity);
298     for (int i = 0; i < _len; i++) {
299       tty->print(INTPTR_FORMAT " ", *(intptr_t*)&(_data[i]));
300     }
301     tty->print("}\n");
302   }
303 };
304 
305 template <typename E>
306 class GrowableArrayFromArray : public GrowableArrayView<E> {
307 public:
308 
309   GrowableArrayFromArray(E* data, int len) :
310     GrowableArrayView<E>(data, len, len) {}
311 };
312 
313 // GrowableArrayWithAllocator extends the "view" with
314 // the capability to grow and deallocate the data array.
315 //
316 // The allocator responsibility is delegated to the sub-class.
317 //
318 // Derived: The sub-class responsible for allocation / deallocation
319 //  - E* Derived::allocate()       - member function responsible for allocation
320 //  - void Derived::deallocate(E*) - member function responsible for deallocation
321 template <typename E, typename Derived>
322 class GrowableArrayWithAllocator : public GrowableArrayView<E> {
323   void expand_to(int j);
324   void grow(int j);
325 
326 protected:
327   GrowableArrayWithAllocator(E* data, int capacity) :
328       GrowableArrayView<E>(data, capacity, 0) {
329     for (int i = 0; i < capacity; i++) {
330       ::new ((void*)&data[i]) E();
331     }
332   }
333 
334   GrowableArrayWithAllocator(E* data, int capacity, int initial_len, const E& filler) :
335       GrowableArrayView<E>(data, capacity, initial_len) {
336     int i = 0;
337     for (; i < initial_len; i++) {
338       ::new ((void*)&data[i]) E(filler);
339     }
340     for (; i < capacity; i++) {
341       ::new ((void*)&data[i]) E();
342     }
343   }
344 
345   GrowableArrayWithAllocator(E* data, int capacity, int initial_len) :
346     GrowableArrayView<E>(data, capacity, initial_len) {}
347 
348   ~GrowableArrayWithAllocator() {}
349 
350 public:
351   int append(const E& elem) {
352     if (this->_len == this->_capacity) grow(this->_len);
353     int idx = this->_len++;
354     this->_data[idx] = elem;
355     return idx;
356   }
357 
358   bool append_if_missing(const E& elem) {
359     // Returns TRUE if elem is added.
360     bool missed = !this->contains(elem);
361     if (missed) append(elem);
362     return missed;
363   }
364 
365   void push(const E& elem) { append(elem); }
366 
367   E pop() {
368     assert(this->_len > 0, "empty list");
369     return this->_data[--this->_len];
370   }
371 
372   E& at_grow(int i, const E& fill = E()) {
373     assert(0 <= i, "negative index %d", i);
374     if (i >= this->_len) {
375       if (i >= this->_capacity) grow(i);
376       for (int j = this->_len; j <= i; j++)
377         this->_data[j] = fill;
378       this->_len = i+1;
379     }
380     return this->_data[i];
381   }
382 
383   void at_put_grow(int i, const E& elem, const E& fill = E()) {
384     assert(0 <= i, "negative index %d", i);
385     if (i >= this->_len) {
386       if (i >= this->_capacity) grow(i);
387       for (int j = this->_len; j < i; j++)
388         this->_data[j] = fill;
389       this->_len = i+1;
390     }
391     this->_data[i] = elem;
392   }
393 
394   // inserts the given element before the element at index i
395   void insert_before(const int idx, const E& elem) {
396     assert(0 <= idx && idx <= this->_len, "illegal index %d for length %d", idx, this->_len);
397     if (this->_len == this->_capacity) grow(this->_len);
398     for (int j = this->_len - 1; j >= idx; j--) {
399       this->_data[j + 1] = this->_data[j];
400     }
401     this->_len++;
402     this->_data[idx] = elem;
403   }
404 
405   void insert_before(const int idx, const GrowableArrayView<E>* array) {
406     assert(0 <= idx && idx <= this->_len, "illegal index %d for length %d", idx, this->_len);
407     int array_len = array->length();
408     int new_len = this->_len + array_len;
409     if (new_len >= this->_capacity) grow(new_len);
410 
411     for (int j = this->_len - 1; j >= idx; j--) {
412       this->_data[j + array_len] = this->_data[j];
413     }
414 
415     for (int j = 0; j < array_len; j++) {
416       this->_data[idx + j] = array->at(j);
417     }
418 
419     this->_len += array_len;
420   }
421 
422   void appendAll(const GrowableArrayView<E>* l) {
423     for (int i = 0; i < l->length(); i++) {
424       this->at_put_grow(this->_len, l->at(i), E());
425     }
426   }
427 
428   void appendAll(const Array<E>* l) {
429     for (int i = 0; i < l->length(); i++) {
430       this->at_put_grow(this->_len, l->at(i), E());
431     }
432   }
433 
434   // Binary search and insertion utility.  Search array for element
435   // matching key according to the static compare function.  Insert
436   // that element if not already in the list.  Assumes the list is
437   // already sorted according to compare function.
438   template <int compare(const E&, const E&)> E insert_sorted(const E& key) {
439     bool found;
440     int location = GrowableArrayView<E>::template find_sorted<E, compare>(key, found);
441     if (!found) {
442       insert_before(location, key);
443     }
444     return this->at(location);
445   }
446 
447   E insert_sorted(CompareClosure<E>* cc, const E& key) {
448     bool found;
449     int location = find_sorted(cc, key, found);
450     if (!found) {
451       insert_before(location, key);
452     }
453     return this->at(location);
454   }
455 
456   void swap(GrowableArrayWithAllocator* other) {
457     ::swap(this->_data, other->_data);
458     ::swap(this->_len, other->_len);
459     ::swap(this->_capacity, other->_capacity);
460   }
461 
462   // Ensure capacity is at least new_capacity.
463   void reserve(int new_capacity);
464 
465   void trunc_to(int length) {
466     assert(length <= this->_len,"cannot increase length");
467     this->_len = length;
468   }
469 
470   // Order preserving remove operations.
471 
472   void remove_at(int index) {
473     assert(0 <= index && index < this->_len,
474            "illegal index %d for length %d", index, this->_len);
475     for (int j = index + 1; j < this->_len; j++) {
476       this->_data[j-1] = this->_data[j];
477     }
478     this->_len--;
479   }
480 
481   void remove(const E& elem) {
482     // Assuming that element does exist.
483     bool removed = this->remove_if_existing(elem);
484     if (removed) return;
485     ShouldNotReachHere();
486   }
487 
488   bool remove_if_existing(const E& elem) {
489     // Returns TRUE if elem is removed.
490     for (int i = 0; i < this->_len; i++) {
491       if (this->_data[i] == elem) {
492         this->remove_at(i);
493         return true;
494       }
495     }
496     return false;
497   }
498 
499   // Remove all elements up to the index (exclusive). The order is preserved.
500   void remove_till(int idx) {
501     remove_range(0, idx);
502   }
503 
504   // Remove all elements in the range [start - end). The order is preserved.
505   void remove_range(int start, int end) {
506     assert(0 <= start, "illegal start index %d", start);
507     assert(start < end && end <= this->_len,
508            "erase called with invalid range (%d, %d) for length %d",
509            start, end, this->_len);
510 
511     for (int i = start, j = end; j < this->length(); i++, j++) {
512       this->at_put(i, this->at(j));
513     }
514     this->_len -= (end - start);
515   }
516 
517   // Replaces the designated element with the last element and shrinks by 1.
518   void delete_at(int index) {
519     assert(0 <= index && index < this->_len, "illegal index %d for length %d", index, this->_len);
520     if (index < --this->_len) {
521       // Replace removed element with last one.
522       this->_data[index] = this->_data[this->_len];
523     }
524   }
525 
526   // Reduce capacity to length.
527   void shrink_to_fit();
528 
529   void clear() { this->_len = 0; }
530   void clear_and_deallocate();
531 };
532 
533 template <typename E, typename Derived>
534 void GrowableArrayWithAllocator<E, Derived>::expand_to(int new_capacity) {
535   int old_capacity = this->_capacity;
536   assert(new_capacity > old_capacity,
537          "expected growth but %d <= %d", new_capacity, old_capacity);
538   this->_capacity = new_capacity;
539   E* newData = static_cast<Derived*>(this)->allocate();
540   int i = 0;
541   for (     ; i < this->_len; i++) ::new ((void*)&newData[i]) E(this->_data[i]);
542   for (     ; i < this->_capacity; i++) ::new ((void*)&newData[i]) E();
543   for (i = 0; i < old_capacity; i++) this->_data[i].~E();
544   if (this->_data != nullptr) {
545     static_cast<Derived*>(this)->deallocate(this->_data);
546   }
547   this->_data = newData;
548 }
549 
550 template <typename E, typename Derived>
551 void GrowableArrayWithAllocator<E, Derived>::grow(int j) {
552   // grow the array by increasing _capacity to the first power of two larger than the size we need
553   expand_to(next_power_of_2(j));
554 }
555 
556 template <typename E, typename Derived>
557 void GrowableArrayWithAllocator<E, Derived>::reserve(int new_capacity) {
558   if (new_capacity > this->_capacity) {
559     expand_to(new_capacity);
560   }
561 }
562 
563 template <typename E, typename Derived>
564 void GrowableArrayWithAllocator<E, Derived>::shrink_to_fit() {
565   int old_capacity = this->_capacity;
566   int len = this->_len;
567   assert(len <= old_capacity, "invariant");
568 
569   // If already at full capacity, nothing to do.
570   if (len == old_capacity) {
571     return;
572   }
573 
574   // If not empty, allocate new, smaller, data, and copy old data to it.
575   E* old_data = this->_data;
576   E* new_data = nullptr;
577   this->_capacity = len;        // Must preceed allocate().
578   if (len > 0) {
579     new_data = static_cast<Derived*>(this)->allocate();
580     for (int i = 0; i < len; ++i) ::new (&new_data[i]) E(old_data[i]);
581   }
582   // Destroy contents of old data, and deallocate it.
583   for (int i = 0; i < old_capacity; ++i) old_data[i].~E();
584   if (old_data != nullptr) {
585     static_cast<Derived*>(this)->deallocate(old_data);
586   }
587   // Install new data, which might be nullptr.
588   this->_data = new_data;
589 }
590 
591 template <typename E, typename Derived>
592 void GrowableArrayWithAllocator<E, Derived>::clear_and_deallocate() {
593   this->clear();
594   this->shrink_to_fit();
595 }
596 
597 class GrowableArrayResourceAllocator {
598 public:
599   static void* allocate(int max, int element_size);
600 };
601 
602 // Arena allocator
603 class GrowableArrayArenaAllocator {
604 public:
605   static void* allocate(int max, int element_size, Arena* arena);
606 };
607 
608 // CHeap allocator
609 class GrowableArrayCHeapAllocator {
610 public:
611   static void* allocate(int max, int element_size, MemTag mem_tag);
612   static void deallocate(void* mem);
613 };
614 
615 #ifdef ASSERT
616 
617 // Checks resource allocation nesting
618 class GrowableArrayNestingCheck {
619   // resource area nesting at creation
620   int _nesting;
621 
622 public:
623   GrowableArrayNestingCheck(bool on_resource_area);
624   GrowableArrayNestingCheck(Arena* arena);
625 
626   void on_resource_area_alloc() const;
627   void on_arena_alloc(Arena* arena) const;
628 };
629 
630 #endif // ASSERT
631 
632 // Encodes where the backing array is allocated
633 // and performs necessary checks.
634 class GrowableArrayMetadata {
635   uintptr_t _bits;
636 
637   // resource area nesting at creation
638   DEBUG_ONLY(GrowableArrayNestingCheck _nesting_check;)
639 
640   // Resource allocation
641   static uintptr_t bits() {
642     return 0;
643   }
644 
645   // CHeap allocation
646   static uintptr_t bits(MemTag mem_tag) {
647     assert(mem_tag != mtNone, "Must provide a proper MemTag");
648     return (uintptr_t(mem_tag) << 1) | 1;
649   }
650 
651   // Arena allocation
652   static uintptr_t bits(Arena* arena) {
653     assert((uintptr_t(arena) & 1) == 0, "Required for on_C_heap() to work");
654     return uintptr_t(arena);
655   }
656 
657 public:
658   // Resource allocation
659   GrowableArrayMetadata() :
660       _bits(bits())
661       DEBUG_ONLY(COMMA _nesting_check(true)) {
662   }
663 
664   // Arena allocation
665   GrowableArrayMetadata(Arena* arena) :
666       _bits(bits(arena))
667       DEBUG_ONLY(COMMA _nesting_check(arena)) {
668   }
669 
670   // CHeap allocation
671   GrowableArrayMetadata(MemTag mem_tag) :
672       _bits(bits(mem_tag))
673       DEBUG_ONLY(COMMA _nesting_check(false)) {
674   }
675 
676 #ifdef ASSERT
677   GrowableArrayMetadata(const GrowableArrayMetadata& other) :
678       _bits(other._bits),
679       _nesting_check(other._nesting_check) {
680     assert(!on_C_heap(), "Copying of CHeap arrays not supported");
681     assert(!other.on_C_heap(), "Copying of CHeap arrays not supported");
682   }
683 
684   GrowableArrayMetadata& operator=(const GrowableArrayMetadata& other) {
685     _bits = other._bits;
686     _nesting_check = other._nesting_check;
687     assert(!on_C_heap(), "Assignment of CHeap arrays not supported");
688     assert(!other.on_C_heap(), "Assignment of CHeap arrays not supported");
689     return *this;
690   }
691 
692   void init_checks(const GrowableArrayBase* array) const;
693   void on_resource_area_alloc_check() const;
694   void on_arena_alloc_check() const;
695 #endif // ASSERT
696 
697   bool on_C_heap() const        { return (_bits & 1) == 1; }
698   bool on_resource_area() const { return _bits == 0; }
699   bool on_arena() const         { return (_bits & 1) == 0 && _bits != 0; }
700 
701   Arena* arena() const      { return (Arena*)_bits; }
702   MemTag mem_tag() const { return MemTag(_bits >> 1); }
703 };
704 
705 // THE GrowableArray.
706 //
707 // Supports multiple allocation strategies:
708 //  - Resource stack allocation: if no extra argument is provided
709 //  - CHeap allocation: if mem_tag is provided
710 //  - Arena allocation: if an arena is provided
711 //
712 // There are some drawbacks of using GrowableArray, that are removed in some
713 // of the other implementations of GrowableArrayWithAllocator sub-classes:
714 //
715 // Memory overhead: The multiple allocation strategies uses extra metadata
716 //  embedded in the instance.
717 //
718 // Strict allocation locations: There are rules about where the GrowableArray
719 //  instance is allocated, that depends on where the data array is allocated.
720 //  See: init_checks.
721 
722 template <typename E>
723 class GrowableArray : public GrowableArrayWithAllocator<E, GrowableArray<E>> {
724   friend class VMStructs;
725   friend class GrowableArrayWithAllocator<E, GrowableArray>;
726   friend class GrowableArrayTest;
727 
728   static E* allocate(int max) {
729     return (E*)GrowableArrayResourceAllocator::allocate(max, sizeof(E));
730   }
731 
732   static E* allocate(int max, MemTag mem_tag) {
733     return (E*)GrowableArrayCHeapAllocator::allocate(max, sizeof(E), mem_tag);
734   }
735 
736   static E* allocate(int max, Arena* arena) {
737     return (E*)GrowableArrayArenaAllocator::allocate(max, sizeof(E), arena);
738   }
739 
740   GrowableArrayMetadata _metadata;
741 
742   void init_checks() const { DEBUG_ONLY(_metadata.init_checks(this);) }
743 
744   // Where are we going to allocate memory?
745   bool on_C_heap() const        { return _metadata.on_C_heap(); }
746   bool on_resource_area() const { return _metadata.on_resource_area(); }
747   bool on_arena() const         { return _metadata.on_arena(); }
748 
749   E* allocate() {
750     if (on_resource_area()) {
751       DEBUG_ONLY(_metadata.on_resource_area_alloc_check());
752       return allocate(this->_capacity);
753     }
754 
755     if (on_C_heap()) {
756       return allocate(this->_capacity, _metadata.mem_tag());
757     }
758 
759     assert(on_arena(), "Sanity");
760     DEBUG_ONLY(_metadata.on_arena_alloc_check());
761     return allocate(this->_capacity, _metadata.arena());
762   }
763 
764   void deallocate(E* mem) {
765     if (on_C_heap()) {
766       GrowableArrayCHeapAllocator::deallocate(mem);
767     }
768   }
769 
770 public:
771   GrowableArray() : GrowableArray(2 /* initial_capacity */) {}
772 
773   explicit GrowableArray(int initial_capacity) :
774       GrowableArrayWithAllocator<E, GrowableArray>(
775           allocate(initial_capacity),
776           initial_capacity),
777       _metadata() {
778     init_checks();
779   }
780 
781   GrowableArray(int initial_capacity, MemTag mem_tag) :
782       GrowableArrayWithAllocator<E, GrowableArray>(
783           allocate(initial_capacity, mem_tag),
784           initial_capacity),
785       _metadata(mem_tag) {
786     init_checks();
787   }
788 
789   GrowableArray(int initial_capacity, int initial_len, const E& filler) :
790       GrowableArrayWithAllocator<E, GrowableArray>(
791           allocate(initial_capacity),
792           initial_capacity, initial_len, filler),
793       _metadata() {
794     init_checks();
795   }
796 
797   // This constructor performs no default initialization, so be careful.
798   GrowableArray(int initial_capacity, int initial_len, MemTag mem_tag) :
799     GrowableArrayWithAllocator<E, GrowableArray>(
800       allocate(initial_capacity, mem_tag),
801       initial_capacity, initial_len),
802     _metadata(mem_tag) {
803     init_checks();
804   }
805 
806   GrowableArray(int initial_capacity, int initial_len, const E& filler, MemTag mem_tag) :
807       GrowableArrayWithAllocator<E, GrowableArray>(
808           allocate(initial_capacity, mem_tag),
809           initial_capacity, initial_len, filler),
810       _metadata(mem_tag) {
811     init_checks();
812   }
813 
814   GrowableArray(Arena* arena, int initial_capacity, int initial_len, const E& filler) :
815       GrowableArrayWithAllocator<E, GrowableArray>(
816           allocate(initial_capacity, arena),
817           initial_capacity, initial_len, filler),
818       _metadata(arena) {
819     init_checks();
820   }
821 
822   ~GrowableArray() {
823     if (on_C_heap()) {
824       this->clear_and_deallocate();
825     }
826   }
827 };
828 
829 // Leaner GrowableArray for CHeap backed data arrays, with compile-time decided MemTag.
830 template <typename E, MemTag MT>
831 class GrowableArrayCHeap : public GrowableArrayWithAllocator<E, GrowableArrayCHeap<E, MT> > {
832   friend class GrowableArrayWithAllocator<E, GrowableArrayCHeap<E, MT> >;
833 
834   STATIC_ASSERT(MT != mtNone);
835 
836   static E* allocate(int max, MemTag mem_tag) {
837     return (E*)GrowableArrayCHeapAllocator::allocate(max, sizeof(E), mem_tag);
838   }
839 
840   NONCOPYABLE(GrowableArrayCHeap);
841 
842   E* allocate() {
843     return allocate(this->_capacity, MT);
844   }
845 
846   void deallocate(E* mem) {
847     GrowableArrayCHeapAllocator::deallocate(mem);
848   }
849 
850 public:
851   GrowableArrayCHeap(int initial_capacity = 0) :
852       GrowableArrayWithAllocator<E, GrowableArrayCHeap<E, MT> >(
853           allocate(initial_capacity, MT),
854           initial_capacity) {}
855 
856   GrowableArrayCHeap(int initial_capacity, int initial_len, const E& filler) :
857       GrowableArrayWithAllocator<E, GrowableArrayCHeap<E, MT> >(
858           allocate(initial_capacity, MT),
859           initial_capacity, initial_len, filler) {}
860 
861   ~GrowableArrayCHeap() {
862     this->clear_and_deallocate();
863   }
864 
865   void* operator new(size_t size) {
866     return AnyObj::operator new(size, MT);
867   }
868 
869   void* operator new(size_t size, const std::nothrow_t&  nothrow_constant) throw() {
870     return AnyObj::operator new(size, nothrow_constant, MT);
871   }
872   void operator delete(void *p) {
873     AnyObj::operator delete(p);
874   }
875 };
876 
877 // Custom STL-style iterator to iterate over GrowableArrays
878 // It is constructed by invoking GrowableArray::begin() and GrowableArray::end()
879 template <typename E>
880 class GrowableArrayIterator : public StackObj {
881   friend class GrowableArrayView<E>;
882   template <typename F, typename UnaryPredicate> friend class GrowableArrayFilterIterator;
883 
884  private:
885   const GrowableArrayView<E>* _array; // GrowableArray we iterate over
886   int _position;                      // The current position in the GrowableArray
887 
888   // Private constructor used in GrowableArray::begin() and GrowableArray::end()
889   GrowableArrayIterator(const GrowableArrayView<E>* array, int position) : _array(array), _position(position) {
890     assert(0 <= position && position <= _array->length(), "illegal position");
891   }
892 
893  public:
894   GrowableArrayIterator() : _array(nullptr), _position(0) { }
895   GrowableArrayIterator& operator++() { ++_position; return *this; }
896   E operator*()                       { return _array->at(_position); }
897 
898   bool operator==(const GrowableArrayIterator& rhs)  {
899     assert(_array == rhs._array, "iterator belongs to different array");
900     return _position == rhs._position;
901   }
902 
903   bool operator!=(const GrowableArrayIterator& rhs)  {
904     assert(_array == rhs._array, "iterator belongs to different array");
905     return _position != rhs._position;
906   }
907 };
908 
909 // Custom STL-style iterator to iterate over elements of a GrowableArray that satisfy a given predicate
910 template <typename E, class UnaryPredicate>
911 class GrowableArrayFilterIterator : public StackObj {
912   friend class GrowableArrayView<E>;
913 
914  private:
915   const GrowableArrayView<E>* _array; // GrowableArray we iterate over
916   int _position;                      // Current position in the GrowableArray
917   UnaryPredicate _predicate;          // Unary predicate the elements of the GrowableArray should satisfy
918 
919  public:
920   GrowableArrayFilterIterator(const GrowableArray<E>* array, UnaryPredicate filter_predicate) :
921       _array(array), _position(0), _predicate(filter_predicate) {
922     // Advance to first element satisfying the predicate
923     while(!at_end() && !_predicate(_array->at(_position))) {
924       ++_position;
925     }
926   }
927 
928   GrowableArrayFilterIterator<E, UnaryPredicate>& operator++() {
929     do {
930       // Advance to next element satisfying the predicate
931       ++_position;
932     } while(!at_end() && !_predicate(_array->at(_position)));
933     return *this;
934   }
935 
936   E operator*() { return _array->at(_position); }
937 
938   bool operator==(const GrowableArrayIterator<E>& rhs)  {
939     assert(_array == rhs._array, "iterator belongs to different array");
940     return _position == rhs._position;
941   }
942 
943   bool operator!=(const GrowableArrayIterator<E>& rhs)  {
944     assert(_array == rhs._array, "iterator belongs to different array");
945     return _position != rhs._position;
946   }
947 
948   bool operator==(const GrowableArrayFilterIterator<E, UnaryPredicate>& rhs)  {
949     assert(_array == rhs._array, "iterator belongs to different array");
950     return _position == rhs._position;
951   }
952 
953   bool operator!=(const GrowableArrayFilterIterator<E, UnaryPredicate>& rhs)  {
954     assert(_array == rhs._array, "iterator belongs to different array");
955     return _position != rhs._position;
956   }
957 
958   bool at_end() const {
959     return _array == nullptr || _position == _array->end()._position;
960   }
961 };
962 
963 // Arrays for basic types
964 typedef GrowableArray<int> intArray;
965 typedef GrowableArray<int> intStack;
966 typedef GrowableArray<bool> boolArray;
967 
968 #endif // SHARE_UTILITIES_GROWABLEARRAY_HPP