1 /*
   2  * Copyright (c) 1997, 2013, 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.
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  24 
  25 #ifndef SHARE_VM_UTILITIES_GROWABLEARRAY_HPP
  26 #define SHARE_VM_UTILITIES_GROWABLEARRAY_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "memory/allocation.inline.hpp"
  30 #include "utilities/debug.hpp"
  31 #include "utilities/globalDefinitions.hpp"
  32 #include "utilities/top.hpp"
  33 
  34 // A growable array.
  35 
  36 /*************************************************************************/
  37 /*                                                                       */
  38 /*     WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING   */
  39 /*                                                                       */
  40 /* Should you use GrowableArrays to contain handles you must be certain  */
  41 /* the the GrowableArray does not outlive the HandleMark that contains   */
  42 /* the handles. Since GrowableArrays are typically resource allocated    */
  43 /* the following is an example of INCORRECT CODE,                        */
  44 /*                                                                       */
  45 /* ResourceMark rm;                                                      */
  46 /* GrowableArray<Handle>* arr = new GrowableArray<Handle>(size);         */
  47 /* if (blah) {                                                           */
  48 /*    while (...) {                                                      */
  49 /*      HandleMark hm;                                                   */
  50 /*      ...                                                              */
  51 /*      Handle h(THREAD, some_oop);                                      */
  52 /*      arr->append(h);                                                  */
  53 /*    }                                                                  */
  54 /* }                                                                     */
  55 /* if (arr->length() != 0 ) {                                            */
  56 /*    oop bad_oop = arr->at(0)(); // Handle is BAD HERE.                 */
  57 /*    ...                                                                */
  58 /* }                                                                     */
  59 /*                                                                       */
  60 /* If the GrowableArrays you are creating is C_Heap allocated then it    */
  61 /* hould not old handles since the handles could trivially try and       */
  62 /* outlive their HandleMark. In some situations you might need to do     */
  63 /* this and it would be legal but be very careful and see if you can do  */
  64 /* the code in some other manner.                                        */
  65 /*                                                                       */
  66 /*************************************************************************/
  67 
  68 // To call default constructor the placement operator new() is used.
  69 // It should be empty (it only returns the passed void* pointer).
  70 // The definition of placement operator new(size_t, void*) in the <new>.
  71 
  72 #include <new>
  73 
  74 // Need the correct linkage to call qsort without warnings
  75 extern "C" {
  76   typedef int (*_sort_Fn)(const void *, const void *);
  77 }
  78 
  79 class GenericGrowableArray : public ResourceObj {
  80   friend class VMStructs;
  81 
  82  protected:
  83   int    _len;          // current length
  84   int    _max;          // maximum length
  85   Arena* _arena;        // Indicates where allocation occurs:
  86                         //   0 means default ResourceArea
  87                         //   1 means on C heap
  88                         //   otherwise, allocate in _arena
  89 
  90   MEMFLAGS   _memflags;   // memory type if allocation in C heap
  91 
  92 #ifdef ASSERT
  93   int    _nesting;      // resource area nesting at creation
  94   void   set_nesting();
  95   void   check_nesting();
  96 #else
  97 #define  set_nesting();
  98 #define  check_nesting();
  99 #endif
 100 
 101   // Where are we going to allocate memory?
 102   bool on_C_heap() { return _arena == (Arena*)1; }
 103   bool on_stack () { return _arena == NULL;      }
 104   bool on_arena () { return _arena >  (Arena*)1;  }
 105 
 106   // This GA will use the resource stack for storage if c_heap==false,
 107   // Else it will use the C heap.  Use clear_and_deallocate to avoid leaks.
 108   GenericGrowableArray(int initial_size, int initial_len, bool c_heap, MEMFLAGS flags = mtNone) {
 109     _len = initial_len;
 110     _max = initial_size;
 111     _memflags = flags;
 112 
 113     // memory type has to be specified for C heap allocation
 114     assert(!(c_heap && flags == mtNone), "memory type not specified for C heap object");
 115 
 116     assert(_len >= 0 && _len <= _max, "initial_len too big");
 117     _arena = (c_heap ? (Arena*)1 : NULL);
 118     set_nesting();
 119     assert(!on_C_heap() || allocated_on_C_heap(), "growable array must be on C heap if elements are");
 120     assert(!on_stack() ||
 121            (allocated_on_res_area() || allocated_on_stack()),
 122            "growable array must be on stack if elements are not on arena and not on C heap");
 123   }
 124 
 125   // This GA will use the given arena for storage.
 126   // Consider using new(arena) GrowableArray<T> to allocate the header.
 127   GenericGrowableArray(Arena* arena, int initial_size, int initial_len) {
 128     _len = initial_len;
 129     _max = initial_size;
 130     assert(_len >= 0 && _len <= _max, "initial_len too big");
 131     _arena = arena;
 132     _memflags = mtNone;
 133 
 134     assert(on_arena(), "arena has taken on reserved value 0 or 1");
 135     // Relax next assert to allow object allocation on resource area,
 136     // on stack or embedded into an other object.
 137     assert(allocated_on_arena() || allocated_on_stack(),
 138            "growable array must be on arena or on stack if elements are on arena");
 139   }
 140 
 141   void* raw_allocate(int elementSize);
 142 
 143   // some uses pass the Thread explicitly for speed (4990299 tuning)
 144   void* raw_allocate(Thread* thread, int elementSize) {
 145     assert(on_stack(), "fast ResourceObj path only");
 146     return (void*)resource_allocate_bytes(thread, elementSize * _max);
 147   }
 148 };
 149 
 150 template<class E> class GrowableArrayIterator;
 151 template<class E, class UnaryPredicate> class GrowableArrayFilterIterator;
 152 
 153 template<class E> class GrowableArray : public GenericGrowableArray {
 154   friend class VMStructs;
 155 
 156  private:
 157   E*     _data;         // data array
 158 
 159   void grow(int j);
 160   void raw_at_put_grow(int i, const E& p, const E& fill);
 161   void  clear_and_deallocate();
 162  public:
 163   GrowableArray(Thread* thread, int initial_size) : GenericGrowableArray(initial_size, 0, false) {
 164     _data = (E*)raw_allocate(thread, sizeof(E));
 165     for (int i = 0; i < _max; i++) ::new ((void*)&_data[i]) E();
 166   }
 167 
 168   GrowableArray(int initial_size, bool C_heap = false, MEMFLAGS F = mtInternal)
 169     : GenericGrowableArray(initial_size, 0, C_heap, F) {
 170     _data = (E*)raw_allocate(sizeof(E));
 171 // Needed for Visual Studio 2012 and older
 172 #ifdef _MSC_VER
 173 #pragma warning(suppress: 4345)
 174 #endif
 175     for (int i = 0; i < _max; i++) ::new ((void*)&_data[i]) E();
 176   }
 177 
 178   GrowableArray(int initial_size, int initial_len, const E& filler, bool C_heap = false, MEMFLAGS memflags = mtInternal)
 179     : GenericGrowableArray(initial_size, initial_len, C_heap, memflags) {
 180     _data = (E*)raw_allocate(sizeof(E));
 181     int i = 0;
 182     for (; i < _len; i++) ::new ((void*)&_data[i]) E(filler);
 183     for (; i < _max; i++) ::new ((void*)&_data[i]) E();
 184   }
 185 
 186   GrowableArray(Arena* arena, int initial_size, int initial_len, const E& filler) : GenericGrowableArray(arena, initial_size, initial_len) {
 187     _data = (E*)raw_allocate(sizeof(E));
 188     int i = 0;
 189     for (; i < _len; i++) ::new ((void*)&_data[i]) E(filler);
 190     for (; i < _max; i++) ::new ((void*)&_data[i]) E();
 191   }
 192 
 193   GrowableArray() : GenericGrowableArray(2, 0, false) {
 194     _data = (E*)raw_allocate(sizeof(E));
 195     ::new ((void*)&_data[0]) E();
 196     ::new ((void*)&_data[1]) E();
 197   }
 198 
 199                                 // Does nothing for resource and arena objects
 200   ~GrowableArray()              { if (on_C_heap()) clear_and_deallocate(); }
 201 
 202   void  clear()                 { _len = 0; }
 203   int   length() const          { return _len; }
 204   int   max_length() const      { return _max; }
 205   void  trunc_to(int l)         { assert(l <= _len,"cannot increase length"); _len = l; }
 206   bool  is_empty() const        { return _len == 0; }
 207   bool  is_nonempty() const     { return _len != 0; }
 208   bool  is_full() const         { return _len == _max; }
 209   DEBUG_ONLY(E* data_addr() const      { return _data; })
 210 
 211   void print();
 212 
 213   int append(const E& elem) {
 214     check_nesting();
 215     if (_len == _max) grow(_len);
 216     int idx = _len++;
 217     _data[idx] = elem;
 218     return idx;
 219   }
 220 
 221   bool append_if_missing(const E& elem) {
 222     // Returns TRUE if elem is added.
 223     bool missed = !contains(elem);
 224     if (missed) append(elem);
 225     return missed;
 226   }
 227 
 228   E& at(int i) {
 229     assert(0 <= i && i < _len, "illegal index");
 230     return _data[i];
 231   }
 232 
 233   E const& at(int i) const {
 234     assert(0 <= i && i < _len, "illegal index");
 235     return _data[i];
 236   }
 237 
 238   E* adr_at(int i) const {
 239     assert(0 <= i && i < _len, "illegal index");
 240     return &_data[i];
 241   }
 242 
 243   E first() const {
 244     assert(_len > 0, "empty list");
 245     return _data[0];
 246   }
 247 
 248   E top() const {
 249     assert(_len > 0, "empty list");
 250     return _data[_len-1];
 251   }
 252 
 253   GrowableArrayIterator<E> begin() const {
 254     return GrowableArrayIterator<E>(this, 0);
 255   }
 256 
 257   GrowableArrayIterator<E> end() const {
 258     return GrowableArrayIterator<E>(this, length());
 259   }
 260 
 261   void push(const E& elem) { append(elem); }
 262 
 263   E pop() {
 264     assert(_len > 0, "empty list");
 265     return _data[--_len];
 266   }
 267 
 268   void at_put(int i, const E& elem) {
 269     assert(0 <= i && i < _len, "illegal index");
 270     _data[i] = elem;
 271   }
 272 
 273   E at_grow(int i, const E& fill = E()) {
 274     assert(0 <= i, "negative index");
 275     check_nesting();
 276     if (i >= _len) {
 277       if (i >= _max) grow(i);
 278       for (int j = _len; j <= i; j++)
 279         _data[j] = fill;
 280       _len = i+1;
 281     }
 282     return _data[i];
 283   }
 284 
 285   void at_put_grow(int i, const E& elem, const E& fill = E()) {
 286     assert(0 <= i, "negative index");
 287     check_nesting();
 288     raw_at_put_grow(i, elem, fill);
 289   }
 290 
 291   bool contains(const E& elem) const {
 292     for (int i = 0; i < _len; i++) {
 293       if (_data[i] == elem) return true;
 294     }
 295     return false;
 296   }
 297 
 298   int  find(const E& elem) const {
 299     for (int i = 0; i < _len; i++) {
 300       if (_data[i] == elem) return i;
 301     }
 302     return -1;
 303   }
 304 
 305   int  find_from_end(const E& elem) const {
 306     for (int i = _len-1; i >= 0; i--) {
 307       if (_data[i] == elem) return i;
 308     }
 309     return -1;
 310   }
 311 
 312   int  find(void* token, bool f(void*, E)) const {
 313     for (int i = 0; i < _len; i++) {
 314       if (f(token, _data[i])) return i;
 315     }
 316     return -1;
 317   }
 318 
 319   int  find_from_end(void* token, bool f(void*, E)) const {
 320     // start at the end of the array
 321     for (int i = _len-1; i >= 0; i--) {
 322       if (f(token, _data[i])) return i;
 323     }
 324     return -1;
 325   }
 326 
 327   void remove(const E& elem) {
 328     for (int i = 0; i < _len; i++) {
 329       if (_data[i] == elem) {
 330         for (int j = i + 1; j < _len; j++) _data[j-1] = _data[j];
 331         _len--;
 332         return;
 333       }
 334     }
 335     ShouldNotReachHere();
 336   }
 337 
 338   // The order is preserved.
 339   void remove_at(int index) {
 340     assert(0 <= index && index < _len, "illegal index");
 341     for (int j = index + 1; j < _len; j++) _data[j-1] = _data[j];
 342     _len--;
 343   }
 344 
 345   // The order is changed.
 346   void delete_at(int index) {
 347     assert(0 <= index && index < _len, "illegal index");
 348     if (index < --_len) {
 349       // Replace removed element with last one.
 350       _data[index] = _data[_len];
 351     }
 352   }
 353 
 354   // inserts the given element before the element at index i
 355   void insert_before(const int idx, const E& elem) {
 356     assert(0 <= idx && idx <= _len, "illegal index");
 357     check_nesting();
 358     if (_len == _max) grow(_len);
 359     for (int j = _len - 1; j >= idx; j--) {
 360       _data[j + 1] = _data[j];
 361     }
 362     _len++;
 363     _data[idx] = elem;
 364   }
 365 
 366   void appendAll(const GrowableArray<E>* l) {
 367     for (int i = 0; i < l->_len; i++) {
 368       raw_at_put_grow(_len, l->_data[i], E());
 369     }
 370   }
 371 
 372   void sort(int f(E*,E*)) {
 373     qsort(_data, length(), sizeof(E), (_sort_Fn)f);
 374   }
 375   // sort by fixed-stride sub arrays:
 376   void sort(int f(E*,E*), int stride) {
 377     qsort(_data, length() / stride, sizeof(E) * stride, (_sort_Fn)f);
 378   }
 379 
 380   // Binary search and insertion utility.  Search array for element
 381   // matching key according to the static compare function.  Insert
 382   // that element is not already in the list.  Assumes the list is
 383   // already sorted according to compare function.
 384   template <int compare(const E&, const E&)> E insert_sorted(const E& key) {
 385     bool found;
 386     int location = find_sorted<E, compare>(key, found);
 387     if (!found) {
 388       insert_before(location, key);
 389     }
 390     return at(location);
 391   }
 392 
 393   template <typename K, int compare(const K&, const E&)> int find_sorted(const K& key, bool& found) {
 394     found = false;
 395     int min = 0;
 396     int max = length() - 1;
 397 
 398     while (max >= min) {
 399       int mid = (int)(((uint)max + min) / 2);
 400       E value = at(mid);
 401       int diff = compare(key, value);
 402       if (diff > 0) {
 403         min = mid + 1;
 404       } else if (diff < 0) {
 405         max = mid - 1;
 406       } else {
 407         found = true;
 408         return mid;
 409       }
 410     }
 411     return min;
 412   }
 413 };
 414 
 415 // Global GrowableArray methods (one instance in the library per each 'E' type).
 416 
 417 template<class E> void GrowableArray<E>::grow(int j) {
 418     // grow the array by doubling its size (amortized growth)
 419     int old_max = _max;
 420     if (_max == 0) _max = 1; // prevent endless loop
 421     while (j >= _max) _max = _max*2;
 422     // j < _max
 423     E* newData = (E*)raw_allocate(sizeof(E));
 424     int i = 0;
 425     for (     ; i < _len; i++) ::new ((void*)&newData[i]) E(_data[i]);
 426 // Needed for Visual Studio 2012 and older
 427 #ifdef _MSC_VER
 428 #pragma warning(suppress: 4345)
 429 #endif
 430     for (     ; i < _max; i++) ::new ((void*)&newData[i]) E();
 431     for (i = 0; i < old_max; i++) _data[i].~E();
 432     if (on_C_heap() && _data != NULL) {
 433       FreeHeap(_data);
 434     }
 435     _data = newData;
 436 }
 437 
 438 template<class E> void GrowableArray<E>::raw_at_put_grow(int i, const E& p, const E& fill) {
 439     if (i >= _len) {
 440       if (i >= _max) grow(i);
 441       for (int j = _len; j < i; j++)
 442         _data[j] = fill;
 443       _len = i+1;
 444     }
 445     _data[i] = p;
 446 }
 447 
 448 // This function clears and deallocate the data in the growable array that
 449 // has been allocated on the C heap.  It's not public - called by the
 450 // destructor.
 451 template<class E> void GrowableArray<E>::clear_and_deallocate() {
 452     assert(on_C_heap(),
 453            "clear_and_deallocate should only be called when on C heap");
 454     clear();
 455     if (_data != NULL) {
 456       for (int i = 0; i < _max; i++) _data[i].~E();
 457       FreeHeap(_data);
 458       _data = NULL;
 459     }
 460 }
 461 
 462 template<class E> void GrowableArray<E>::print() {
 463     tty->print("Growable Array " INTPTR_FORMAT, this);
 464     tty->print(": length %ld (_max %ld) { ", _len, _max);
 465     for (int i = 0; i < _len; i++) tty->print(INTPTR_FORMAT " ", *(intptr_t*)&(_data[i]));
 466     tty->print("}\n");
 467 }
 468 
 469 // Custom STL-style iterator to iterate over GrowableArrays
 470 // It is constructed by invoking GrowableArray::begin() and GrowableArray::end()
 471 template<class E> class GrowableArrayIterator : public StackObj {
 472   friend class GrowableArray<E>;
 473   template<class F, class UnaryPredicate> friend class GrowableArrayFilterIterator;
 474 
 475  private:
 476   const GrowableArray<E>* _array; // GrowableArray we iterate over
 477   int _position;                  // The current position in the GrowableArray
 478 
 479   // Private constructor used in GrowableArray::begin() and GrowableArray::end()
 480   GrowableArrayIterator(const GrowableArray<E>* array, int position) : _array(array), _position(position) {
 481     assert(0 <= position && position <= _array->length(), "illegal position");
 482   }
 483 
 484  public:
 485   GrowableArrayIterator<E>& operator++()  { ++_position; return *this; }
 486   E operator*()                           { return _array->at(_position); }
 487 
 488   bool operator==(const GrowableArrayIterator<E>& rhs)  {
 489     assert(_array == rhs._array, "iterator belongs to different array");
 490     return _position == rhs._position;
 491   }
 492 
 493   bool operator!=(const GrowableArrayIterator<E>& rhs)  {
 494     assert(_array == rhs._array, "iterator belongs to different array");
 495     return _position != rhs._position;
 496   }
 497 };
 498 
 499 // Custom STL-style iterator to iterate over elements of a GrowableArray that satisfy a given predicate
 500 template<class E, class UnaryPredicate> class GrowableArrayFilterIterator : public StackObj {
 501   friend class GrowableArray<E>;
 502 
 503  private:
 504   const GrowableArray<E>* _array;   // GrowableArray we iterate over
 505   int _position;                    // Current position in the GrowableArray
 506   UnaryPredicate _predicate;        // Unary predicate the elements of the GrowableArray should satisfy
 507 
 508  public:
 509   GrowableArrayFilterIterator(const GrowableArrayIterator<E>& begin, UnaryPredicate filter_predicate)
 510    : _array(begin._array), _position(begin._position), _predicate(filter_predicate) {
 511     // Advance to first element satisfying the predicate
 512     while(_position != _array->length() && !_predicate(_array->at(_position))) {
 513       ++_position;
 514     }
 515   }
 516 
 517   GrowableArrayFilterIterator<E, UnaryPredicate>& operator++() {
 518     do {
 519       // Advance to next element satisfying the predicate
 520       ++_position;
 521     } while(_position != _array->length() && !_predicate(_array->at(_position)));
 522     return *this;
 523   }
 524 
 525   E operator*()   { return _array->at(_position); }
 526 
 527   bool operator==(const GrowableArrayIterator<E>& rhs)  {
 528     assert(_array == rhs._array, "iterator belongs to different array");
 529     return _position == rhs._position;
 530   }
 531 
 532   bool operator!=(const GrowableArrayIterator<E>& rhs)  {
 533     assert(_array == rhs._array, "iterator belongs to different array");
 534     return _position != rhs._position;
 535   }
 536 
 537   bool operator==(const GrowableArrayFilterIterator<E, UnaryPredicate>& rhs)  {
 538     assert(_array == rhs._array, "iterator belongs to different array");
 539     return _position == rhs._position;
 540   }
 541 
 542   bool operator!=(const GrowableArrayFilterIterator<E, UnaryPredicate>& rhs)  {
 543     assert(_array == rhs._array, "iterator belongs to different array");
 544     return _position != rhs._position;
 545   }
 546 };
 547 
 548 #endif // SHARE_VM_UTILITIES_GROWABLEARRAY_HPP
--- EOF ---