1 /*
   2  * Copyright (c) 1997, 2014, 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 "precompiled.hpp"
  26 #include "memory/allocation.hpp"
  27 #include "memory/allocation.inline.hpp"
  28 #include "memory/genCollectedHeap.hpp"
  29 #include "memory/metaspaceShared.hpp"
  30 #include "memory/resourceArea.hpp"
  31 #include "memory/universe.hpp"
  32 #include "runtime/atomic.inline.hpp"
  33 #include "runtime/os.hpp"
  34 #include "runtime/task.hpp"
  35 #include "runtime/threadCritical.hpp"
  36 #include "services/memTracker.hpp"
  37 #include "utilities/ostream.hpp"
  38 
  39 void* StackObj::operator new(size_t size)     throw() { ShouldNotCallThis(); return 0; }
  40 void  StackObj::operator delete(void* p)              { ShouldNotCallThis(); }
  41 void* StackObj::operator new [](size_t size)  throw() { ShouldNotCallThis(); return 0; }
  42 void  StackObj::operator delete [](void* p)           { ShouldNotCallThis(); }
  43 
  44 void* _ValueObj::operator new(size_t size)    throw() { ShouldNotCallThis(); return 0; }
  45 void  _ValueObj::operator delete(void* p)             { ShouldNotCallThis(); }
  46 void* _ValueObj::operator new [](size_t size) throw() { ShouldNotCallThis(); return 0; }
  47 void  _ValueObj::operator delete [](void* p)          { ShouldNotCallThis(); }
  48 
  49 void* MetaspaceObj::operator new(size_t size, ClassLoaderData* loader_data,
  50                                  size_t word_size, bool read_only,
  51                                  MetaspaceObj::Type type, TRAPS) throw() {
  52   // Klass has it's own operator new
  53   return Metaspace::allocate(loader_data, word_size, read_only, type, THREAD);
  54 }
  55 
  56 bool MetaspaceObj::is_shared() const {
  57   return MetaspaceShared::is_in_shared_space(this);
  58 }
  59 
  60 bool MetaspaceObj::is_metaspace_object() const {
  61   return Metaspace::contains((void*)this);
  62 }
  63 
  64 void MetaspaceObj::print_address_on(outputStream* st) const {
  65   st->print(" {" INTPTR_FORMAT "}", p2i(this));
  66 }
  67 
  68 void* ResourceObj::operator new(size_t size, allocation_type type, MEMFLAGS flags) throw() {
  69   address res;
  70   switch (type) {
  71    case C_HEAP:
  72     res = (address)AllocateHeap(size, flags, CALLER_PC);
  73     DEBUG_ONLY(set_allocation_type(res, C_HEAP);)
  74     break;
  75    case RESOURCE_AREA:
  76     // new(size) sets allocation type RESOURCE_AREA.
  77     res = (address)operator new(size);
  78     break;
  79    default:
  80     ShouldNotReachHere();
  81   }
  82   return res;
  83 }
  84 
  85 void* ResourceObj::operator new [](size_t size, allocation_type type, MEMFLAGS flags) throw() {
  86   return (address) operator new(size, type, flags);
  87 }
  88 
  89 void* ResourceObj::operator new(size_t size, const std::nothrow_t&  nothrow_constant,
  90     allocation_type type, MEMFLAGS flags) throw() {
  91   //should only call this with std::nothrow, use other operator new() otherwise
  92   address res;
  93   switch (type) {
  94    case C_HEAP:
  95     res = (address)AllocateHeap(size, flags, CALLER_PC, AllocFailStrategy::RETURN_NULL);
  96     DEBUG_ONLY(if (res!= NULL) set_allocation_type(res, C_HEAP);)
  97     break;
  98    case RESOURCE_AREA:
  99     // new(size) sets allocation type RESOURCE_AREA.
 100     res = (address)operator new(size, std::nothrow);
 101     break;
 102    default:
 103     ShouldNotReachHere();
 104   }
 105   return res;
 106 }
 107 
 108 void* ResourceObj::operator new [](size_t size, const std::nothrow_t&  nothrow_constant,
 109     allocation_type type, MEMFLAGS flags) throw() {
 110   return (address)operator new(size, nothrow_constant, type, flags);
 111 }
 112 
 113 void ResourceObj::operator delete(void* p) {
 114   assert(((ResourceObj *)p)->allocated_on_C_heap(),
 115          "delete only allowed for C_HEAP objects");
 116   DEBUG_ONLY(((ResourceObj *)p)->_allocation_t[0] = (uintptr_t)badHeapOopVal;)
 117   FreeHeap(p);
 118 }
 119 
 120 void ResourceObj::operator delete [](void* p) {
 121   operator delete(p);
 122 }
 123 
 124 #ifdef ASSERT
 125 void ResourceObj::set_allocation_type(address res, allocation_type type) {
 126     // Set allocation type in the resource object
 127     uintptr_t allocation = (uintptr_t)res;
 128     assert((allocation & allocation_mask) == 0, err_msg("address should be aligned to 4 bytes at least: " INTPTR_FORMAT, p2i(res)));
 129     assert(type <= allocation_mask, "incorrect allocation type");
 130     ResourceObj* resobj = (ResourceObj *)res;
 131     resobj->_allocation_t[0] = ~(allocation + type);
 132     if (type != STACK_OR_EMBEDDED) {
 133       // Called from operator new() and CollectionSetChooser(),
 134       // set verification value.
 135       resobj->_allocation_t[1] = (uintptr_t)&(resobj->_allocation_t[1]) + type;
 136     }
 137 }
 138 
 139 ResourceObj::allocation_type ResourceObj::get_allocation_type() const {
 140     assert(~(_allocation_t[0] | allocation_mask) == (uintptr_t)this, "lost resource object");
 141     return (allocation_type)((~_allocation_t[0]) & allocation_mask);
 142 }
 143 
 144 bool ResourceObj::is_type_set() const {
 145     allocation_type type = (allocation_type)(_allocation_t[1] & allocation_mask);
 146     return get_allocation_type()  == type &&
 147            (_allocation_t[1] - type) == (uintptr_t)(&_allocation_t[1]);
 148 }
 149 
 150 ResourceObj::ResourceObj() { // default constructor
 151     if (~(_allocation_t[0] | allocation_mask) != (uintptr_t)this) {
 152       // Operator new() is not called for allocations
 153       // on stack and for embedded objects.
 154       set_allocation_type((address)this, STACK_OR_EMBEDDED);
 155     } else if (allocated_on_stack()) { // STACK_OR_EMBEDDED
 156       // For some reason we got a value which resembles
 157       // an embedded or stack object (operator new() does not
 158       // set such type). Keep it since it is valid value
 159       // (even if it was garbage).
 160       // Ignore garbage in other fields.
 161     } else if (is_type_set()) {
 162       // Operator new() was called and type was set.
 163       assert(!allocated_on_stack(),
 164              err_msg("not embedded or stack, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
 165                      p2i(this), get_allocation_type(), _allocation_t[0], _allocation_t[1]));
 166     } else {
 167       // Operator new() was not called.
 168       // Assume that it is embedded or stack object.
 169       set_allocation_type((address)this, STACK_OR_EMBEDDED);
 170     }
 171     _allocation_t[1] = 0; // Zap verification value
 172 }
 173 
 174 ResourceObj::ResourceObj(const ResourceObj& r) { // default copy constructor
 175     // Used in ClassFileParser::parse_constant_pool_entries() for ClassFileStream.
 176     // Note: garbage may resembles valid value.
 177     assert(~(_allocation_t[0] | allocation_mask) != (uintptr_t)this || !is_type_set(),
 178            err_msg("embedded or stack only, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
 179                    p2i(this), get_allocation_type(), _allocation_t[0], _allocation_t[1]));
 180     set_allocation_type((address)this, STACK_OR_EMBEDDED);
 181     _allocation_t[1] = 0; // Zap verification value
 182 }
 183 
 184 ResourceObj& ResourceObj::operator=(const ResourceObj& r) { // default copy assignment
 185     // Used in InlineTree::ok_to_inline() for WarmCallInfo.
 186     assert(allocated_on_stack(),
 187            err_msg("copy only into local, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
 188                    p2i(this), get_allocation_type(), _allocation_t[0], _allocation_t[1]));
 189     // Keep current _allocation_t value;
 190     return *this;
 191 }
 192 
 193 ResourceObj::~ResourceObj() {
 194     // allocated_on_C_heap() also checks that encoded (in _allocation) address == this.
 195     if (!allocated_on_C_heap()) { // ResourceObj::delete() will zap _allocation for C_heap.
 196       _allocation_t[0] = (uintptr_t)badHeapOopVal; // zap type
 197     }
 198 }
 199 #endif // ASSERT
 200 
 201 
 202 void trace_heap_malloc(size_t size, const char* name, void* p) {
 203   // A lock is not needed here - tty uses a lock internally
 204   tty->print_cr("Heap malloc " INTPTR_FORMAT " " SIZE_FORMAT " %s", p2i(p), size, name == NULL ? "" : name);
 205 }
 206 
 207 
 208 void trace_heap_free(void* p) {
 209   // A lock is not needed here - tty uses a lock internally
 210   tty->print_cr("Heap free   " INTPTR_FORMAT, p2i(p));
 211 }
 212 
 213 //--------------------------------------------------------------------------------------
 214 // ChunkPool implementation
 215 
 216 // MT-safe pool of chunks to reduce malloc/free thrashing
 217 // NB: not using Mutex because pools are used before Threads are initialized
 218 class ChunkPool: public CHeapObj<mtInternal> {
 219   Chunk*       _first;        // first cached Chunk; its first word points to next chunk
 220   size_t       _num_chunks;   // number of unused chunks in pool
 221   size_t       _num_used;     // number of chunks currently checked out
 222   const size_t _size;         // size of each chunk (must be uniform)
 223 
 224   // Our four static pools
 225   static ChunkPool* _large_pool;
 226   static ChunkPool* _medium_pool;
 227   static ChunkPool* _small_pool;
 228   static ChunkPool* _tiny_pool;
 229 
 230   // return first element or null
 231   void* get_first() {
 232     Chunk* c = _first;
 233     if (_first) {
 234       _first = _first->next();
 235       _num_chunks--;
 236     }
 237     return c;
 238   }
 239 
 240  public:
 241   // All chunks in a ChunkPool has the same size
 242    ChunkPool(size_t size) : _size(size) { _first = NULL; _num_chunks = _num_used = 0; }
 243 
 244   // Allocate a new chunk from the pool (might expand the pool)
 245   _NOINLINE_ void* allocate(size_t bytes, AllocFailType alloc_failmode) {
 246     assert(bytes == _size, "bad size");
 247     void* p = NULL;
 248     // No VM lock can be taken inside ThreadCritical lock, so os::malloc
 249     // should be done outside ThreadCritical lock due to NMT
 250     { ThreadCritical tc;
 251       _num_used++;
 252       p = get_first();
 253     }
 254     if (p == NULL) p = os::malloc(bytes, mtChunk, CURRENT_PC);
 255     if (p == NULL && alloc_failmode == AllocFailStrategy::EXIT_OOM) {
 256       vm_exit_out_of_memory(bytes, OOM_MALLOC_ERROR, "ChunkPool::allocate");
 257     }
 258     return p;
 259   }
 260 
 261   // Return a chunk to the pool
 262   void free(Chunk* chunk) {
 263     assert(chunk->length() + Chunk::aligned_overhead_size() == _size, "bad size");
 264     ThreadCritical tc;
 265     _num_used--;
 266 
 267     // Add chunk to list
 268     chunk->set_next(_first);
 269     _first = chunk;
 270     _num_chunks++;
 271   }
 272 
 273   // Prune the pool
 274   void free_all_but(size_t n) {
 275     Chunk* cur = NULL;
 276     Chunk* next;
 277     {
 278     // if we have more than n chunks, free all of them
 279     ThreadCritical tc;
 280     if (_num_chunks > n) {
 281       // free chunks at end of queue, for better locality
 282         cur = _first;
 283       for (size_t i = 0; i < (n - 1) && cur != NULL; i++) cur = cur->next();
 284 
 285       if (cur != NULL) {
 286           next = cur->next();
 287         cur->set_next(NULL);
 288         cur = next;
 289 
 290           _num_chunks = n;
 291         }
 292       }
 293     }
 294 
 295     // Free all remaining chunks, outside of ThreadCritical
 296     // to avoid deadlock with NMT
 297         while(cur != NULL) {
 298           next = cur->next();
 299       os::free(cur);
 300           cur = next;
 301         }
 302       }
 303 
 304   // Accessors to preallocated pool's
 305   static ChunkPool* large_pool()  { assert(_large_pool  != NULL, "must be initialized"); return _large_pool;  }
 306   static ChunkPool* medium_pool() { assert(_medium_pool != NULL, "must be initialized"); return _medium_pool; }
 307   static ChunkPool* small_pool()  { assert(_small_pool  != NULL, "must be initialized"); return _small_pool;  }
 308   static ChunkPool* tiny_pool()   { assert(_tiny_pool   != NULL, "must be initialized"); return _tiny_pool;   }
 309 
 310   static void initialize() {
 311     _large_pool  = new ChunkPool(Chunk::size        + Chunk::aligned_overhead_size());
 312     _medium_pool = new ChunkPool(Chunk::medium_size + Chunk::aligned_overhead_size());
 313     _small_pool  = new ChunkPool(Chunk::init_size   + Chunk::aligned_overhead_size());
 314     _tiny_pool   = new ChunkPool(Chunk::tiny_size   + Chunk::aligned_overhead_size());
 315   }
 316 
 317   static void clean() {
 318     enum { BlocksToKeep = 5 };
 319      _tiny_pool->free_all_but(BlocksToKeep);
 320      _small_pool->free_all_but(BlocksToKeep);
 321      _medium_pool->free_all_but(BlocksToKeep);
 322      _large_pool->free_all_but(BlocksToKeep);
 323   }
 324 };
 325 
 326 ChunkPool* ChunkPool::_large_pool  = NULL;
 327 ChunkPool* ChunkPool::_medium_pool = NULL;
 328 ChunkPool* ChunkPool::_small_pool  = NULL;
 329 ChunkPool* ChunkPool::_tiny_pool   = NULL;
 330 
 331 void chunkpool_init() {
 332   ChunkPool::initialize();
 333 }
 334 
 335 void
 336 Chunk::clean_chunk_pool() {
 337   ChunkPool::clean();
 338 }
 339 
 340 
 341 //--------------------------------------------------------------------------------------
 342 // ChunkPoolCleaner implementation
 343 //
 344 
 345 class ChunkPoolCleaner : public PeriodicTask {
 346   enum { CleaningInterval = 5000 };      // cleaning interval in ms
 347 
 348  public:
 349    ChunkPoolCleaner() : PeriodicTask(CleaningInterval) {}
 350    void task() {
 351      ChunkPool::clean();
 352    }
 353 };
 354 
 355 //--------------------------------------------------------------------------------------
 356 // Chunk implementation
 357 
 358 void* Chunk::operator new (size_t requested_size, AllocFailType alloc_failmode, size_t length) throw() {
 359   // requested_size is equal to sizeof(Chunk) but in order for the arena
 360   // allocations to come out aligned as expected the size must be aligned
 361   // to expected arena alignment.
 362   // expect requested_size but if sizeof(Chunk) doesn't match isn't proper size we must align it.
 363   assert(ARENA_ALIGN(requested_size) == aligned_overhead_size(), "Bad alignment");
 364   size_t bytes = ARENA_ALIGN(requested_size) + length;
 365   switch (length) {
 366    case Chunk::size:        return ChunkPool::large_pool()->allocate(bytes, alloc_failmode);
 367    case Chunk::medium_size: return ChunkPool::medium_pool()->allocate(bytes, alloc_failmode);
 368    case Chunk::init_size:   return ChunkPool::small_pool()->allocate(bytes, alloc_failmode);
 369    case Chunk::tiny_size:   return ChunkPool::tiny_pool()->allocate(bytes, alloc_failmode);
 370    default: {
 371      void* p = os::malloc(bytes, mtChunk, CALLER_PC);
 372      if (p == NULL && alloc_failmode == AllocFailStrategy::EXIT_OOM) {
 373        vm_exit_out_of_memory(bytes, OOM_MALLOC_ERROR, "Chunk::new");
 374      }
 375      return p;
 376    }
 377   }
 378 }
 379 
 380 void Chunk::operator delete(void* p) {
 381   Chunk* c = (Chunk*)p;
 382   switch (c->length()) {
 383    case Chunk::size:        ChunkPool::large_pool()->free(c); break;
 384    case Chunk::medium_size: ChunkPool::medium_pool()->free(c); break;
 385    case Chunk::init_size:   ChunkPool::small_pool()->free(c); break;
 386    case Chunk::tiny_size:   ChunkPool::tiny_pool()->free(c); break;
 387    default:                 os::free(c);
 388   }
 389 }
 390 
 391 Chunk::Chunk(size_t length) : _len(length) {
 392   _next = NULL;         // Chain on the linked list
 393 }
 394 
 395 
 396 void Chunk::chop() {
 397   Chunk *k = this;
 398   while( k ) {
 399     Chunk *tmp = k->next();
 400     // clear out this chunk (to detect allocation bugs)
 401     if (ZapResourceArea) memset(k->bottom(), badResourceValue, k->length());
 402     delete k;                   // Free chunk (was malloc'd)
 403     k = tmp;
 404   }
 405 }
 406 
 407 void Chunk::next_chop() {
 408   _next->chop();
 409   _next = NULL;
 410 }
 411 
 412 
 413 void Chunk::start_chunk_pool_cleaner_task() {
 414 #ifdef ASSERT
 415   static bool task_created = false;
 416   assert(!task_created, "should not start chuck pool cleaner twice");
 417   task_created = true;
 418 #endif
 419   ChunkPoolCleaner* cleaner = new ChunkPoolCleaner();
 420   cleaner->enroll();
 421 }
 422 
 423 //------------------------------Arena------------------------------------------
 424 
 425 Arena::Arena(MEMFLAGS flag, size_t init_size) : _flags(flag), _size_in_bytes(0)  {
 426   size_t round_size = (sizeof (char *)) - 1;
 427   init_size = (init_size+round_size) & ~round_size;
 428   _first = _chunk = new (AllocFailStrategy::EXIT_OOM, init_size) Chunk(init_size);
 429   _hwm = _chunk->bottom();      // Save the cached hwm, max
 430   _max = _chunk->top();
 431   MemTracker::record_new_arena(flag);
 432   set_size_in_bytes(init_size);
 433 }
 434 
 435 Arena::Arena(MEMFLAGS flag) : _flags(flag), _size_in_bytes(0) {
 436   _first = _chunk = new (AllocFailStrategy::EXIT_OOM, Chunk::init_size) Chunk(Chunk::init_size);
 437   _hwm = _chunk->bottom();      // Save the cached hwm, max
 438   _max = _chunk->top();
 439   MemTracker::record_new_arena(flag);
 440   set_size_in_bytes(Chunk::init_size);
 441 }
 442 
 443 Arena *Arena::move_contents(Arena *copy) {
 444   copy->destruct_contents();
 445   copy->_chunk = _chunk;
 446   copy->_hwm   = _hwm;
 447   copy->_max   = _max;
 448   copy->_first = _first;
 449 
 450   // workaround rare racing condition, which could double count
 451   // the arena size by native memory tracking
 452   size_t size = size_in_bytes();
 453   set_size_in_bytes(0);
 454   copy->set_size_in_bytes(size);
 455   // Destroy original arena
 456   reset();
 457   return copy;            // Return Arena with contents
 458 }
 459 
 460 Arena::~Arena() {
 461   destruct_contents();
 462   MemTracker::record_arena_free(_flags);
 463 }
 464 
 465 void* Arena::operator new(size_t size) throw() {
 466   assert(false, "Use dynamic memory type binding");
 467   return NULL;
 468 }
 469 
 470 void* Arena::operator new (size_t size, const std::nothrow_t&  nothrow_constant) throw() {
 471   assert(false, "Use dynamic memory type binding");
 472   return NULL;
 473 }
 474 
 475   // dynamic memory type binding
 476 void* Arena::operator new(size_t size, MEMFLAGS flags) throw() {
 477 #ifdef ASSERT
 478   void* p = (void*)AllocateHeap(size, flags, CALLER_PC);
 479   if (PrintMallocFree) trace_heap_malloc(size, "Arena-new", p);
 480   return p;
 481 #else
 482   return (void *) AllocateHeap(size, flags, CALLER_PC);
 483 #endif
 484 }
 485 
 486 void* Arena::operator new(size_t size, const std::nothrow_t& nothrow_constant, MEMFLAGS flags) throw() {
 487 #ifdef ASSERT
 488   void* p = os::malloc(size, flags, CALLER_PC);
 489   if (PrintMallocFree) trace_heap_malloc(size, "Arena-new", p);
 490   return p;
 491 #else
 492   return os::malloc(size, flags, CALLER_PC);
 493 #endif
 494 }
 495 
 496 void Arena::operator delete(void* p) {
 497   FreeHeap(p);
 498 }
 499 
 500 // Destroy this arenas contents and reset to empty
 501 void Arena::destruct_contents() {
 502   if (UseMallocOnly && _first != NULL) {
 503     char* end = _first->next() ? _first->top() : _hwm;
 504     free_malloced_objects(_first, _first->bottom(), end, _hwm);
 505   }
 506   // reset size before chop to avoid a rare racing condition
 507   // that can have total arena memory exceed total chunk memory
 508   set_size_in_bytes(0);
 509   _first->chop();
 510   reset();
 511 }
 512 
 513 // This is high traffic method, but many calls actually don't
 514 // change the size
 515 void Arena::set_size_in_bytes(size_t size) {
 516   if (_size_in_bytes != size) {
 517     long delta = (long)(size - size_in_bytes());
 518     _size_in_bytes = size;
 519     MemTracker::record_arena_size_change(delta, _flags);
 520   }
 521 }
 522 
 523 // Total of all Chunks in arena
 524 size_t Arena::used() const {
 525   size_t sum = _chunk->length() - (_max-_hwm); // Size leftover in this Chunk
 526   register Chunk *k = _first;
 527   while( k != _chunk) {         // Whilst have Chunks in a row
 528     sum += k->length();         // Total size of this Chunk
 529     k = k->next();              // Bump along to next Chunk
 530   }
 531   return sum;                   // Return total consumed space.
 532 }
 533 
 534 void Arena::signal_out_of_memory(size_t sz, const char* whence) const {
 535   vm_exit_out_of_memory(sz, OOM_MALLOC_ERROR, whence);
 536 }
 537 
 538 // Grow a new Chunk
 539 void* Arena::grow(size_t x, AllocFailType alloc_failmode) {
 540   // Get minimal required size.  Either real big, or even bigger for giant objs
 541   size_t len = MAX2(x, (size_t) Chunk::size);
 542 
 543   Chunk *k = _chunk;            // Get filled-up chunk address
 544   _chunk = new (alloc_failmode, len) Chunk(len);
 545 
 546   if (_chunk == NULL) {
 547     _chunk = k;                 // restore the previous value of _chunk
 548     return NULL;
 549   }
 550   if (k) k->set_next(_chunk);   // Append new chunk to end of linked list
 551   else _first = _chunk;
 552   _hwm  = _chunk->bottom();     // Save the cached hwm, max
 553   _max =  _chunk->top();
 554   set_size_in_bytes(size_in_bytes() + len);
 555   void* result = _hwm;
 556   _hwm += x;
 557   return result;
 558 }
 559 
 560 
 561 
 562 // Reallocate storage in Arena.
 563 void *Arena::Arealloc(void* old_ptr, size_t old_size, size_t new_size, AllocFailType alloc_failmode) {
 564   assert(new_size >= 0, "bad size");
 565   if (new_size == 0) return NULL;
 566 #ifdef ASSERT
 567   if (UseMallocOnly) {
 568     // always allocate a new object  (otherwise we'll free this one twice)
 569     char* copy = (char*)Amalloc(new_size, alloc_failmode);
 570     if (copy == NULL) {
 571       return NULL;
 572     }
 573     size_t n = MIN2(old_size, new_size);
 574     if (n > 0) memcpy(copy, old_ptr, n);
 575     Afree(old_ptr,old_size);    // Mostly done to keep stats accurate
 576     return copy;
 577   }
 578 #endif
 579   char *c_old = (char*)old_ptr; // Handy name
 580   // Stupid fast special case
 581   if( new_size <= old_size ) {  // Shrink in-place
 582     if( c_old+old_size == _hwm) // Attempt to free the excess bytes
 583       _hwm = c_old+new_size;    // Adjust hwm
 584     return c_old;
 585   }
 586 
 587   // make sure that new_size is legal
 588   size_t corrected_new_size = ARENA_ALIGN(new_size);
 589 
 590   // See if we can resize in-place
 591   if( (c_old+old_size == _hwm) &&       // Adjusting recent thing
 592       (c_old+corrected_new_size <= _max) ) {      // Still fits where it sits
 593     _hwm = c_old+corrected_new_size;      // Adjust hwm
 594     return c_old;               // Return old pointer
 595   }
 596 
 597   // Oops, got to relocate guts
 598   void *new_ptr = Amalloc(new_size, alloc_failmode);
 599   if (new_ptr == NULL) {
 600     return NULL;
 601   }
 602   memcpy( new_ptr, c_old, old_size );
 603   Afree(c_old,old_size);        // Mostly done to keep stats accurate
 604   return new_ptr;
 605 }
 606 
 607 
 608 // Determine if pointer belongs to this Arena or not.
 609 bool Arena::contains( const void *ptr ) const {
 610 #ifdef ASSERT
 611   if (UseMallocOnly) {
 612     // really slow, but not easy to make fast
 613     if (_chunk == NULL) return false;
 614     char** bottom = (char**)_chunk->bottom();
 615     for (char** p = (char**)_hwm - 1; p >= bottom; p--) {
 616       if (*p == ptr) return true;
 617     }
 618     for (Chunk *c = _first; c != NULL; c = c->next()) {
 619       if (c == _chunk) continue;  // current chunk has been processed
 620       char** bottom = (char**)c->bottom();
 621       for (char** p = (char**)c->top() - 1; p >= bottom; p--) {
 622         if (*p == ptr) return true;
 623       }
 624     }
 625     return false;
 626   }
 627 #endif
 628   if( (void*)_chunk->bottom() <= ptr && ptr < (void*)_hwm )
 629     return true;                // Check for in this chunk
 630   for (Chunk *c = _first; c; c = c->next()) {
 631     if (c == _chunk) continue;  // current chunk has been processed
 632     if ((void*)c->bottom() <= ptr && ptr < (void*)c->top()) {
 633       return true;              // Check for every chunk in Arena
 634     }
 635   }
 636   return false;                 // Not in any Chunk, so not in Arena
 637 }
 638 
 639 
 640 #ifdef ASSERT
 641 void* Arena::malloc(size_t size) {
 642   assert(UseMallocOnly, "shouldn't call");
 643   // use malloc, but save pointer in res. area for later freeing
 644   char** save = (char**)internal_malloc_4(sizeof(char*));
 645   return (*save = (char*)os::malloc(size, mtChunk));
 646 }
 647 
 648 // for debugging with UseMallocOnly
 649 void* Arena::internal_malloc_4(size_t x) {
 650   assert( (x&(sizeof(char*)-1)) == 0, "misaligned size" );
 651   check_for_overflow(x, "Arena::internal_malloc_4");
 652   if (_hwm + x > _max) {
 653     return grow(x);
 654   } else {
 655     char *old = _hwm;
 656     _hwm += x;
 657     return old;
 658   }
 659 }
 660 #endif
 661 
 662 
 663 //--------------------------------------------------------------------------------------
 664 // Non-product code
 665 
 666 #ifndef PRODUCT
 667 // The global operator new should never be called since it will usually indicate
 668 // a memory leak.  Use CHeapObj as the base class of such objects to make it explicit
 669 // that they're allocated on the C heap.
 670 // Commented out in product version to avoid conflicts with third-party C++ native code.
 671 //
 672 // In C++98/03 the throwing new operators are defined with the following signature:
 673 //
 674 // void* operator new(std::size_tsize) throw(std::bad_alloc);
 675 // void* operator new[](std::size_tsize) throw(std::bad_alloc);
 676 //
 677 // while all the other (non-throwing) new and delete operators are defined with an empty
 678 // throw clause (i.e. "operator delete(void* p) throw()") which means that they do not
 679 // throw any exceptions (see section 18.4 of the C++ standard).
 680 //
 681 // In the new C++11/14 standard, the signature of the throwing new operators was changed
 682 // by completely omitting the throw clause (which effectively means they could throw any
 683 // exception) while all the other new/delete operators where changed to have a 'nothrow'
 684 // clause instead of an empty throw clause.
 685 //
 686 // Unfortunately, the support for exception specifications among C++ compilers is still
 687 // very fragile. While some more strict compilers like AIX xlC or HP aCC reject to
 688 // override the default throwing new operator with a user operator with an empty throw()
 689 // clause, the MS Visual C++ compiler warns for every non-empty throw clause like
 690 // throw(std::bad_alloc) that it will ignore the exception specification. The following
 691 // operator definitions have been checked to correctly work with all currently supported
 692 // compilers and they should be upwards compatible with C++11/14. Therefore
 693 // PLEASE BE CAREFUL if you change the signature of the following operators!
 694 
 695 static void * zero = (void *) 0;
 696 
 697 void* operator new(size_t size) /* throw(std::bad_alloc) */ {
 698   fatal("Should not call global operator new");
 699   return zero;
 700 }
 701 
 702 void* operator new [](size_t size) /* throw(std::bad_alloc) */ {
 703   fatal("Should not call global operator new[]");
 704   return zero;
 705 }
 706 
 707 void* operator new(size_t size, const std::nothrow_t&  nothrow_constant) throw() {
 708   fatal("Should not call global operator new");
 709   return 0;
 710 }
 711 
 712 void* operator new [](size_t size, std::nothrow_t&  nothrow_constant) throw() {
 713   fatal("Should not call global operator new[]");
 714   return 0;
 715 }
 716 
 717 void operator delete(void* p) throw() {
 718   fatal("Should not call global delete");
 719 }
 720 
 721 void operator delete [](void* p) throw() {
 722   fatal("Should not call global delete []");
 723 }
 724 
 725 void AllocatedObj::print() const       { print_on(tty); }
 726 void AllocatedObj::print_value() const { print_value_on(tty); }
 727 
 728 void AllocatedObj::print_on(outputStream* st) const {
 729   st->print_cr("AllocatedObj(" INTPTR_FORMAT ")", p2i(this));
 730 }
 731 
 732 void AllocatedObj::print_value_on(outputStream* st) const {
 733   st->print("AllocatedObj(" INTPTR_FORMAT ")", p2i(this));
 734 }
 735 
 736 julong Arena::_bytes_allocated = 0;
 737 
 738 void Arena::inc_bytes_allocated(size_t x) { inc_stat_counter(&_bytes_allocated, x); }
 739 
 740 AllocStats::AllocStats() {
 741   start_mallocs      = os::num_mallocs;
 742   start_frees        = os::num_frees;
 743   start_malloc_bytes = os::alloc_bytes;
 744   start_mfree_bytes  = os::free_bytes;
 745   start_res_bytes    = Arena::_bytes_allocated;
 746 }
 747 
 748 julong  AllocStats::num_mallocs() { return os::num_mallocs - start_mallocs; }
 749 julong  AllocStats::alloc_bytes() { return os::alloc_bytes - start_malloc_bytes; }
 750 julong  AllocStats::num_frees()   { return os::num_frees - start_frees; }
 751 julong  AllocStats::free_bytes()  { return os::free_bytes - start_mfree_bytes; }
 752 julong  AllocStats::resource_bytes() { return Arena::_bytes_allocated - start_res_bytes; }
 753 void    AllocStats::print() {
 754   tty->print_cr(UINT64_FORMAT " mallocs (" UINT64_FORMAT "MB), "
 755                 UINT64_FORMAT" frees (" UINT64_FORMAT "MB), " UINT64_FORMAT "MB resrc",
 756                 num_mallocs(), alloc_bytes()/M, num_frees(), free_bytes()/M, resource_bytes()/M);
 757 }
 758 
 759 
 760 // debugging code
 761 inline void Arena::free_all(char** start, char** end) {
 762   for (char** p = start; p < end; p++) if (*p) os::free(*p);
 763 }
 764 
 765 void Arena::free_malloced_objects(Chunk* chunk, char* hwm, char* max, char* hwm2) {
 766   assert(UseMallocOnly, "should not call");
 767   // free all objects malloced since resource mark was created; resource area
 768   // contains their addresses
 769   if (chunk->next()) {
 770     // this chunk is full, and some others too
 771     for (Chunk* c = chunk->next(); c != NULL; c = c->next()) {
 772       char* top = c->top();
 773       if (c->next() == NULL) {
 774         top = hwm2;     // last junk is only used up to hwm2
 775         assert(c->contains(hwm2), "bad hwm2");
 776       }
 777       free_all((char**)c->bottom(), (char**)top);
 778     }
 779     assert(chunk->contains(hwm), "bad hwm");
 780     assert(chunk->contains(max), "bad max");
 781     free_all((char**)hwm, (char**)max);
 782   } else {
 783     // this chunk was partially used
 784     assert(chunk->contains(hwm), "bad hwm");
 785     assert(chunk->contains(hwm2), "bad hwm2");
 786     free_all((char**)hwm, (char**)hwm2);
 787   }
 788 }
 789 
 790 
 791 ReallocMark::ReallocMark() {
 792 #ifdef ASSERT
 793   Thread *thread = ThreadLocalStorage::get_thread_slow();
 794   _nesting = thread->resource_area()->nesting();
 795 #endif
 796 }
 797 
 798 void ReallocMark::check() {
 799 #ifdef ASSERT
 800   if (_nesting != Thread::current()->resource_area()->nesting()) {
 801     fatal("allocation bug: array could grow within nested ResourceMark");
 802   }
 803 #endif
 804 }
 805 
 806 #endif // Non-product