Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "runtime/mutexLocker.hpp"

 #include "utilities/decoder.hpp"

 #include "services/memBaseline.hpp"

 #include "services/memPtr.hpp"

 #include "services/memPtrArray.hpp"

 #include "services/memSnapshot.hpp"

 #include "services/memTracker.hpp"

 #ifdef ASSERT

 void decode_pointer_record(MemPointerRecord* rec) {

   tty->print("Pointer: [" PTR_FORMAT " - " PTR_FORMAT  "] size = %d bytes", rec->addr(),

     rec->addr() + rec->size(), (int)rec->size());

   tty->print(" type = %s", MemBaseline::type2name(FLAGS_TO_MEMORY_TYPE(rec->flags())));

   if (rec->is_vm_pointer()) {

     if (rec->is_allocation_record()) {

       tty->print_cr(" (reserve)");

     } else if (rec->is_commit_record()) {

       tty->print_cr(" (commit)");

     } else if (rec->is_uncommit_record()) {

       tty->print_cr(" (uncommit)");

     } else if (rec->is_deallocation_record()) {

       tty->print_cr(" (release)");

     } else {

       tty->print_cr(" (tag)");

     }

   } else {

     if (rec->is_arena_size_record()) {

       tty->print_cr(" (arena size)");

     } else if (rec->is_allocation_record()) {

       tty->print_cr(" (malloc)");

     } else {

       tty->print_cr(" (free)");

     }

   }

   if (MemTracker::track_callsite()) {

     char buf[1024];

     address pc = ((MemPointerRecordEx*)rec)->pc();

     if (pc != NULL && os::dll_address_to_function_name(pc, buf, sizeof(buf), NULL)) {

       tty->print_cr("\tfrom %s", buf);

     } else {

       tty->print_cr("\tcould not decode pc = " PTR_FORMAT "", pc);

     }

   }

 }

 void decode_vm_region_record(VMMemRegion* rec) {

   tty->print("VM Region [" PTR_FORMAT " - " PTR_FORMAT "]", rec->addr(),

     rec->addr() + rec->size());

   tty->print(" type = %s", MemBaseline::type2name(FLAGS_TO_MEMORY_TYPE(rec->flags())));

   if (rec->is_allocation_record()) {

     tty->print_cr(" (reserved)");

   } else if (rec->is_commit_record()) {

     tty->print_cr(" (committed)");

   } else {

     ShouldNotReachHere();

   }

   if (MemTracker::track_callsite()) {

     char buf[1024];

     address pc = ((VMMemRegionEx*)rec)->pc();

     if (pc != NULL && os::dll_address_to_function_name(pc, buf, sizeof(buf), NULL)) {

       tty->print_cr("\tfrom %s", buf);

     } else {

       tty->print_cr("\tcould not decode pc = " PTR_FORMAT "", pc);

     }

   }

 }

 #endif

 bool VMMemPointerIterator::insert_record(MemPointerRecord* rec) {

   VMMemRegionEx new_rec;

   assert(rec->is_allocation_record() || rec->is_commit_record(),

     "Sanity check");

   if (MemTracker::track_callsite()) {

     new_rec.init((MemPointerRecordEx*)rec);

   } else {

     new_rec.init(rec);

   }

   return insert(&new_rec);

 }

 bool VMMemPointerIterator::insert_record_after(MemPointerRecord* rec) {

   VMMemRegionEx new_rec;

   assert(rec->is_allocation_record() || rec->is_commit_record(),

     "Sanity check");

   if (MemTracker::track_callsite()) {

     new_rec.init((MemPointerRecordEx*)rec);

   } else {

     new_rec.init(rec);

   }

   return insert_after(&new_rec);

 }

 // we don't consolidate reserved regions, since they may be categorized

 // in different types.

 bool VMMemPointerIterator::add_reserved_region(MemPointerRecord* rec) {

   assert(rec->is_allocation_record(), "Sanity check");

   VMMemRegion* cur = (VMMemRegion*)current();

   // we don't have anything yet

   if (cur == NULL) {

     return insert_record(rec);

   }

   assert(cur->is_reserved_region(), "Sanity check");

   // duplicated records

   if (cur->is_same_region(rec)) {

     return true;

   }

   assert(cur->base() > rec->addr(), "Just check: locate()");

   assert(!cur->overlaps_region(rec), "overlapping reserved regions");

   return insert_record(rec);

 }

 // we do consolidate committed regions

 bool VMMemPointerIterator::add_committed_region(MemPointerRecord* rec) {

   assert(rec->is_commit_record(), "Sanity check");

   VMMemRegion* reserved_rgn = (VMMemRegion*)current();

   assert(reserved_rgn->is_reserved_region() && reserved_rgn->contains_region(rec),

     "Sanity check");

   // thread's native stack is always marked as "committed", ignore

   // the "commit" operation for creating stack guard pages

   if (FLAGS_TO_MEMORY_TYPE(reserved_rgn->flags()) == mtThreadStack &&

       FLAGS_TO_MEMORY_TYPE(rec->flags()) != mtThreadStack) {

     return true;

   }

   // if the reserved region has any committed regions

   VMMemRegion* committed_rgn  = (VMMemRegion*)next();

   while (committed_rgn != NULL && committed_rgn->is_committed_region()) {

     // duplicated commit records

     if(committed_rgn->contains_region(rec)) {

       return true;

     } else if (committed_rgn->overlaps_region(rec)) {

       // overlaps front part

       if (rec->addr() < committed_rgn->addr()) {

         committed_rgn->expand_region(rec->addr(),

           committed_rgn->addr() - rec->addr());

       } else {

         // overlaps tail part

         address committed_rgn_end = committed_rgn->addr() +

               committed_rgn->size();

         assert(committed_rgn_end < rec->addr() + rec->size(),

              "overlap tail part");

         committed_rgn->expand_region(committed_rgn_end,

           (rec->addr() + rec->size()) - committed_rgn_end);

       }

     } else if (committed_rgn->base() + committed_rgn->size() == rec->addr()) {

       // adjunct each other

       committed_rgn->expand_region(rec->addr(), rec->size());

       VMMemRegion* next_reg = (VMMemRegion*)next();

       // see if we can consolidate next committed region

       if (next_reg != NULL && next_reg->is_committed_region() &&

         next_reg->base() == committed_rgn->base() + committed_rgn->size()) {

           committed_rgn->expand_region(next_reg->base(), next_reg->size());

           // delete merged region

           remove();

       }

       return true;

     } else if (committed_rgn->base() > rec->addr()) {

       // found the location, insert this committed region

       return insert_record(rec);

     }

     committed_rgn = (VMMemRegion*)next();

   }

   return insert_record(rec);

 }

 bool VMMemPointerIterator::remove_uncommitted_region(MemPointerRecord* rec) {

   assert(rec->is_uncommit_record(), "sanity check");

   VMMemRegion* cur;

   cur = (VMMemRegion*)current();

   assert(cur->is_reserved_region() && cur->contains_region(rec),

     "Sanity check");

   // thread's native stack is always marked as "committed", ignore

   // the "commit" operation for creating stack guard pages

   if (FLAGS_TO_MEMORY_TYPE(cur->flags()) == mtThreadStack &&

       FLAGS_TO_MEMORY_TYPE(rec->flags()) != mtThreadStack) {

     return true;

   }

   cur = (VMMemRegion*)next();

   while (cur != NULL && cur->is_committed_region()) {

     // region already uncommitted, must be due to duplicated record

     if (cur->addr() >= rec->addr() + rec->size()) {

       break;

     } else if (cur->contains_region(rec)) {

       // uncommit whole region

       if (cur->is_same_region(rec)) {

         remove();

         break;

       } else if (rec->addr() == cur->addr() ||

         rec->addr() + rec->size() == cur->addr() + cur->size()) {

         // uncommitted from either end of current memory region.

         cur->exclude_region(rec->addr(), rec->size());

         break;

       } else { // split the committed region and release the middle

         address high_addr = cur->addr() + cur->size();

         size_t sz = high_addr - rec->addr();

         cur->exclude_region(rec->addr(), sz);

         sz = high_addr - (rec->addr() + rec->size());

         if (MemTracker::track_callsite()) {

           MemPointerRecordEx tmp(rec->addr() + rec->size(), cur->flags(), sz,

              ((VMMemRegionEx*)cur)->pc());

           return insert_record_after(&tmp);

         } else {

           MemPointerRecord tmp(rec->addr() + rec->size(), cur->flags(), sz);

           return insert_record_after(&tmp);

         }

       }

     }

     cur = (VMMemRegion*)next();

   }

   // we may not find committed record due to duplicated records

   return true;

 }

 bool VMMemPointerIterator::remove_released_region(MemPointerRecord* rec) {

   assert(rec->is_deallocation_record(), "Sanity check");

   VMMemRegion* cur = (VMMemRegion*)current();

   assert(cur->is_reserved_region() && cur->contains_region(rec),

     "Sanity check");

 #ifdef ASSERT

   VMMemRegion* next_reg = (VMMemRegion*)peek_next();

   // should not have any committed memory in this reserved region

   assert(next_reg == NULL || !next_reg->is_committed_region(), "Sanity check");

 #endif

   if (rec->is_same_region(cur)) {

     remove();

   } else if (rec->addr() == cur->addr() ||

     rec->addr() + rec->size() == cur->addr() + cur->size()) {

     // released region is at either end of this region

     cur->exclude_region(rec->addr(), rec->size());

   } else { // split the reserved region and release the middle

     address high_addr = cur->addr() + cur->size();

     size_t sz = high_addr - rec->addr();

     cur->exclude_region(rec->addr(), sz);

     sz = high_addr - rec->addr() - rec->size();

     if (MemTracker::track_callsite()) {

       MemPointerRecordEx tmp(rec->addr() + rec->size(), cur->flags(), sz,

         ((VMMemRegionEx*)cur)->pc());

       return insert_reserved_region(&tmp);

     } else {

       MemPointerRecord tmp(rec->addr() + rec->size(), cur->flags(), sz);

       return insert_reserved_region(&tmp);

     }

   }

   return true;

 }

 bool VMMemPointerIterator::insert_reserved_region(MemPointerRecord* rec) {

   // skip all 'commit' records associated with previous reserved region

   VMMemRegion* p = (VMMemRegion*)next();

   while (p != NULL && p->is_committed_region() &&

          p->base() + p->size() < rec->addr()) {

     p = (VMMemRegion*)next();

   }

   return insert_record(rec);

 }

 bool VMMemPointerIterator::split_reserved_region(VMMemRegion* rgn, address new_rgn_addr, size_t new_rgn_size) {

   assert(rgn->contains_region(new_rgn_addr, new_rgn_size), "Not fully contained");

   address pc = (MemTracker::track_callsite() ? ((VMMemRegionEx*)rgn)->pc() : NULL);

   if (rgn->base() == new_rgn_addr) { // new region is at the beginning of the region

     size_t sz = rgn->size() - new_rgn_size;

     // the original region becomes 'new' region

     rgn->exclude_region(new_rgn_addr + new_rgn_size, sz);

      // remaining becomes next region

     MemPointerRecordEx next_rgn(new_rgn_addr + new_rgn_size, rgn->flags(), sz, pc);

     return insert_reserved_region(&next_rgn);

   } else if (rgn->base() + rgn->size() == new_rgn_addr + new_rgn_size) {

     rgn->exclude_region(new_rgn_addr, new_rgn_size);

     MemPointerRecordEx next_rgn(new_rgn_addr, rgn->flags(), new_rgn_size, pc);

     return insert_reserved_region(&next_rgn);

   } else {

     // the orginal region will be split into three

     address rgn_high_addr = rgn->base() + rgn->size();

     // first region

     rgn->exclude_region(new_rgn_addr, (rgn_high_addr - new_rgn_addr));

     // the second region is the new region

     MemPointerRecordEx new_rgn(new_rgn_addr, rgn->flags(), new_rgn_size, pc);

     if (!insert_reserved_region(&new_rgn)) return false;

     // the remaining region

     MemPointerRecordEx rem_rgn(new_rgn_addr + new_rgn_size, rgn->flags(),

       rgn_high_addr - (new_rgn_addr + new_rgn_size), pc);

     return insert_reserved_region(&rem_rgn);

   }

 }

 static int sort_in_seq_order(const void* p1, const void* p2) {

   assert(p1 != NULL && p2 != NULL, "Sanity check");

   const MemPointerRecord* mp1 = (MemPointerRecord*)p1;

   const MemPointerRecord* mp2 = (MemPointerRecord*)p2;

   return (mp1->seq() - mp2->seq());

 }

 bool StagingArea::init() {

   if (MemTracker::track_callsite()) {

     _malloc_data = new (std::nothrow)MemPointerArrayImpl<SeqMemPointerRecordEx>();

     _vm_data = new (std::nothrow)MemPointerArrayImpl<SeqMemPointerRecordEx>();

   } else {

     _malloc_data = new (std::nothrow)MemPointerArrayImpl<SeqMemPointerRecord>();

     _vm_data = new (std::nothrow)MemPointerArrayImpl<SeqMemPointerRecord>();

   }

   if (_malloc_data != NULL && _vm_data != NULL &&

       !_malloc_data->out_of_memory() &&

       !_vm_data->out_of_memory()) {

     return true;

   } else {

     if (_malloc_data != NULL) delete _malloc_data;

     if (_vm_data != NULL) delete _vm_data;

     _malloc_data = NULL;

     _vm_data = NULL;

     return false;

   }

 }

 VMRecordIterator StagingArea::virtual_memory_record_walker() {

   MemPointerArray* arr = vm_data();

   // sort into seq number order

   arr->sort((FN_SORT)sort_in_seq_order);

   return VMRecordIterator(arr);

 }

 MemSnapshot::MemSnapshot() {

   if (MemTracker::track_callsite()) {

     _alloc_ptrs = new (std::nothrow) MemPointerArrayImpl<MemPointerRecordEx>();

     _vm_ptrs = new (std::nothrow)MemPointerArrayImpl<VMMemRegionEx>(64, true);

   } else {

     _alloc_ptrs = new (std::nothrow) MemPointerArrayImpl<MemPointerRecord>();

     _vm_ptrs = new (std::nothrow)MemPointerArrayImpl<VMMemRegion>(64, true);

   }

   _staging_area.init();

   _lock = new (std::nothrow) Mutex(Monitor::max_nonleaf - 1, "memSnapshotLock");

   NOT_PRODUCT(_untracked_count = 0;)

 }

 MemSnapshot::~MemSnapshot() {

   assert(MemTracker::shutdown_in_progress(), "native memory tracking still on");

   {

     MutexLockerEx locker(_lock);

     if (_alloc_ptrs != NULL) {

       delete _alloc_ptrs;

       _alloc_ptrs = NULL;

     }

     if (_vm_ptrs != NULL) {

       delete _vm_ptrs;

       _vm_ptrs = NULL;

     }

   }

   if (_lock != NULL) {

     delete _lock;

     _lock = NULL;

   }

 }

 void MemSnapshot::copy_pointer(MemPointerRecord* dest, const MemPointerRecord* src) {

   assert(dest != NULL && src != NULL, "Just check");

   assert(dest->addr() == src->addr(), "Just check");

   MEMFLAGS flags = dest->flags();

   if (MemTracker::track_callsite()) {

     *(MemPointerRecordEx*)dest = *(MemPointerRecordEx*)src;

   } else {

     *dest = *src;

   }

 }

 // merge a per-thread memory recorder to the staging area

 bool MemSnapshot::merge(MemRecorder* rec) {

   assert(rec != NULL && !rec->out_of_memory(), "Just check");

   SequencedRecordIterator itr(rec->pointer_itr());

   MutexLockerEx lock(_lock, true);

   MemPointerIterator malloc_staging_itr(_staging_area.malloc_data());

   MemPointerRecord *p1, *p2;

   p1 = (MemPointerRecord*) itr.current();

   while (p1 != NULL) {

     if (p1->is_vm_pointer()) {

       // we don't do anything with virtual memory records during merge

       if (!_staging_area.vm_data()->append(p1)) {

         return false;

       }

     } else {

       // locate matched record and/or also position the iterator to proper

       // location for this incoming record.

       p2 = (MemPointerRecord*)malloc_staging_itr.locate(p1->addr());

       // we have not seen this memory block, so just add to staging area

       if (p2 == NULL) {

         if (!malloc_staging_itr.insert(p1)) {

           return false;

         }

       } else if (p1->addr() == p2->addr()) {

         MemPointerRecord* staging_next = (MemPointerRecord*)malloc_staging_itr.peek_next();

         // a memory block can have many tagging records, find right one to replace or

         // right position to insert

         while (staging_next != NULL && staging_next->addr() == p1->addr()) {

           if ((staging_next->flags() & MemPointerRecord::tag_masks) <=

             (p1->flags() & MemPointerRecord::tag_masks)) {

             p2 = (MemPointerRecord*)malloc_staging_itr.next();

             staging_next = (MemPointerRecord*)malloc_staging_itr.peek_next();

           } else {

             break;

           }

         }

         int df = (p1->flags() & MemPointerRecord::tag_masks) -

           (p2->flags() & MemPointerRecord::tag_masks);

         if (df == 0) {

           assert(p1->seq() > 0, "not sequenced");

           assert(p2->seq() > 0, "not sequenced");

           if (p1->seq() > p2->seq()) {

             copy_pointer(p2, p1);

           }

         } else if (df < 0) {

           if (!malloc_staging_itr.insert(p1)) {

             return false;

           }

         } else {

           if (!malloc_staging_itr.insert_after(p1)) {

             return false;

           }

         }

       } else if (p1->addr() < p2->addr()) {

         if (!malloc_staging_itr.insert(p1)) {

           return false;

         }

       } else {

         if (!malloc_staging_itr.insert_after(p1)) {

           return false;

         }

       }

     }

     p1 = (MemPointerRecord*)itr.next();

   }

   NOT_PRODUCT(void check_staging_data();)

   return true;

 }

 // promote data to next generation

 bool MemSnapshot::promote() {

   assert(_alloc_ptrs != NULL && _vm_ptrs != NULL, "Just check");

   assert(_staging_area.malloc_data() != NULL && _staging_area.vm_data() != NULL,

          "Just check");

   MutexLockerEx lock(_lock, true);

   MallocRecordIterator  malloc_itr = _staging_area.malloc_record_walker();

   bool promoted = false;

   if (promote_malloc_records(&malloc_itr)) {

     VMRecordIterator vm_itr = _staging_area.virtual_memory_record_walker();

     if (promote_virtual_memory_records(&vm_itr)) {

       promoted = true;

     }

   }

   NOT_PRODUCT(check_malloc_pointers();)

   _staging_area.clear();

   return promoted;

 }

 bool MemSnapshot::promote_malloc_records(MemPointerArrayIterator* itr) {

   MemPointerIterator malloc_snapshot_itr(_alloc_ptrs);

   MemPointerRecord* new_rec = (MemPointerRecord*)itr->current();

   MemPointerRecord* matched_rec;

   while (new_rec != NULL) {

     matched_rec = (MemPointerRecord*)malloc_snapshot_itr.locate(new_rec->addr());

     // found matched memory block

     if (matched_rec != NULL && new_rec->addr() == matched_rec->addr()) {

       // snapshot already contains 'live' records

       assert(matched_rec->is_allocation_record() || matched_rec->is_arena_size_record(),

              "Sanity check");

       // update block states

       if (new_rec->is_allocation_record() || new_rec->is_arena_size_record()) {

         copy_pointer(matched_rec, new_rec);

       } else {

         // a deallocation record

         assert(new_rec->is_deallocation_record(), "Sanity check");

         // an arena record can be followed by a size record, we need to remove both

         if (matched_rec->is_arena_record()) {

           MemPointerRecord* next = (MemPointerRecord*)malloc_snapshot_itr.peek_next();

           if (next->is_arena_size_record()) {

             // it has to match the arena record

             assert(next->is_size_record_of_arena(matched_rec), "Sanity check");

             malloc_snapshot_itr.remove();

           }

         }

         // the memory is deallocated, remove related record(s)

         malloc_snapshot_itr.remove();

       }

     } else {

       // it is a new record, insert into snapshot

       if (new_rec->is_arena_size_record()) {

         MemPointerRecord* prev = (MemPointerRecord*)malloc_snapshot_itr.peek_prev();

         if (prev == NULL || !prev->is_arena_record() || !new_rec->is_size_record_of_arena(prev)) {

           // no matched arena record, ignore the size record

           new_rec = NULL;

         }

       }

       // only 'live' record can go into snapshot

       if (new_rec != NULL) {

         if  (new_rec->is_allocation_record() || new_rec->is_arena_size_record()) {

           if (matched_rec != NULL && new_rec->addr() > matched_rec->addr()) {

             if (!malloc_snapshot_itr.insert_after(new_rec)) {

               return false;

             }

           } else {

             if (!malloc_snapshot_itr.insert(new_rec)) {

               return false;

             }

           }

         }

 #ifndef PRODUCT

         else if (!has_allocation_record(new_rec->addr())) {

           // NMT can not track some startup memory, which is allocated before NMT is on

           _untracked_count ++;

         }

 #endif

       }

     }

     new_rec = (MemPointerRecord*)itr->next();

   }

   return true;

 }

 bool MemSnapshot::promote_virtual_memory_records(MemPointerArrayIterator* itr) {

   VMMemPointerIterator vm_snapshot_itr(_vm_ptrs);

   MemPointerRecord* new_rec = (MemPointerRecord*)itr->current();

   VMMemRegion*  reserved_rec;

   while (new_rec != NULL) {

     assert(new_rec->is_vm_pointer(), "Sanity check");

     // locate a reserved region that contains the specified address, or

     // the nearest reserved region has base address just above the specified

     // address

     reserved_rec = (VMMemRegion*)vm_snapshot_itr.locate(new_rec->addr());

     if (reserved_rec != NULL && reserved_rec->contains_region(new_rec)) {

       // snapshot can only have 'live' records

       assert(reserved_rec->is_reserved_region(), "Sanity check");

       if (new_rec->is_allocation_record()) {

         if (!reserved_rec->is_same_region(new_rec)) {

           // only deal with split a bigger reserved region into smaller regions.

           // So far, CDS is the only use case.

           if (!vm_snapshot_itr.split_reserved_region(reserved_rec, new_rec->addr(), new_rec->size())) {

             return false;

           }

         }

       } else if (new_rec->is_uncommit_record()) {

         if (!vm_snapshot_itr.remove_uncommitted_region(new_rec)) {

           return false;

         }

       } else if (new_rec->is_commit_record()) {

         // insert or expand existing committed region to cover this

         // newly committed region

         if (!vm_snapshot_itr.add_committed_region(new_rec)) {

           return false;

         }

       } else if (new_rec->is_deallocation_record()) {

         // release part or all memory region

         if (!vm_snapshot_itr.remove_released_region(new_rec)) {

           return false;

         }

       } else if (new_rec->is_type_tagging_record()) {

         // tag this reserved virtual memory range to a memory type. Can not re-tag a memory range

         // to different type.

         assert(FLAGS_TO_MEMORY_TYPE(reserved_rec->flags()) == mtNone ||

                FLAGS_TO_MEMORY_TYPE(reserved_rec->flags()) == FLAGS_TO_MEMORY_TYPE(new_rec->flags()),

                "Sanity check");

         reserved_rec->tag(new_rec->flags());

     } else {

         ShouldNotReachHere();

           }

         } else {

       /*

        * The assertion failure indicates mis-matched virtual memory records. The likely

        * scenario is, that some virtual memory operations are not going through os::xxxx_memory()

        * api, which have to be tracked manually. (perfMemory is an example).

       */

       assert(new_rec->is_allocation_record(), "Sanity check");

       if (!vm_snapshot_itr.add_reserved_region(new_rec)) {

             return false;

           }

   }

     new_rec = (MemPointerRecord*)itr->next();

   }

   return true;

 }

 #ifndef PRODUCT

 void MemSnapshot::print_snapshot_stats(outputStream* st) {

   st->print_cr("Snapshot:");

   st->print_cr("\tMalloced: %d/%d [%5.2f%%]  %dKB", _alloc_ptrs->length(), _alloc_ptrs->capacity(),

     (100.0 * (float)_alloc_ptrs->length()) / (float)_alloc_ptrs->capacity(), _alloc_ptrs->instance_size()/K);

   st->print_cr("\tVM: %d/%d [%5.2f%%] %dKB", _vm_ptrs->length(), _vm_ptrs->capacity(),

     (100.0 * (float)_vm_ptrs->length()) / (float)_vm_ptrs->capacity(), _vm_ptrs->instance_size()/K);

   st->print_cr("\tMalloc staging Area:     %d/%d [%5.2f%%] %dKB", _staging_area.malloc_data()->length(),

     _staging_area.malloc_data()->capacity(),

     (100.0 * (float)_staging_area.malloc_data()->length()) / (float)_staging_area.malloc_data()->capacity(),

     _staging_area.malloc_data()->instance_size()/K);

   st->print_cr("\tVirtual memory staging Area:     %d/%d [%5.2f%%] %dKB", _staging_area.vm_data()->length(),

     _staging_area.vm_data()->capacity(),

     (100.0 * (float)_staging_area.vm_data()->length()) / (float)_staging_area.vm_data()->capacity(),

     _staging_area.vm_data()->instance_size()/K);

   st->print_cr("\tUntracked allocation: %d", _untracked_count);

 }

 void MemSnapshot::check_malloc_pointers() {

   MemPointerArrayIteratorImpl mItr(_alloc_ptrs);

   MemPointerRecord* p = (MemPointerRecord*)mItr.current();

   MemPointerRecord* prev = NULL;

   while (p != NULL) {

     if (prev != NULL) {

       assert(p->addr() >= prev->addr(), "sorting order");

     }

     prev = p;

     p = (MemPointerRecord*)mItr.next();

   }

 }

 bool MemSnapshot::has_allocation_record(address addr) {

   MemPointerArrayIteratorImpl itr(_staging_area.malloc_data());

   MemPointerRecord* cur = (MemPointerRecord*)itr.current();

   while (cur != NULL) {

     if (cur->addr() == addr && cur->is_allocation_record()) {

       return true;

     }

     cur = (MemPointerRecord*)itr.next();

   }

   return false;

 }

 #endif // PRODUCT

 #ifdef ASSERT

 void MemSnapshot::check_staging_data() {

   MemPointerArrayIteratorImpl itr(_staging_area.malloc_data());

   MemPointerRecord* cur = (MemPointerRecord*)itr.current();

   MemPointerRecord* next = (MemPointerRecord*)itr.next();

   while (next != NULL) {

     assert((next->addr() > cur->addr()) ||

       ((next->flags() & MemPointerRecord::tag_masks) >

        (cur->flags() & MemPointerRecord::tag_masks)),

        "sorting order");

     cur = next;

     next = (MemPointerRecord*)itr.next();

   }

   MemPointerArrayIteratorImpl vm_itr(_staging_area.vm_data());

   cur = (MemPointerRecord*)vm_itr.current();

   while (cur != NULL) {

     assert(cur->is_vm_pointer(), "virtual memory pointer only");

     cur = (MemPointerRecord*)vm_itr.next();

   }

 }

 void MemSnapshot::dump_all_vm_pointers() {

   MemPointerArrayIteratorImpl itr(_vm_ptrs);

   VMMemRegion* ptr = (VMMemRegion*)itr.current();

   tty->print_cr("dump virtual memory pointers:");

   while (ptr != NULL) {

     if (ptr->is_committed_region()) {

       tty->print("\t");

     }

     tty->print("[" PTR_FORMAT " - " PTR_FORMAT "] [%x]", ptr->addr(),

       (ptr->addr() + ptr->size()), ptr->flags());

     if (MemTracker::track_callsite()) {

       VMMemRegionEx* ex = (VMMemRegionEx*)ptr;

       if (ex->pc() != NULL) {

         char buf[1024];

         if (os::dll_address_to_function_name(ex->pc(), buf, sizeof(buf), NULL)) {

           tty->print_cr("\t%s", buf);

         } else {

           tty->print_cr("");

         }

       }

     }

     ptr = (VMMemRegion*)itr.next();

   }

   tty->flush();

 }

 #endif // ASSERT