8042668: GC Support for shared heap ranges in CDS

Added "Archive Region" support to the G1 GC

Reviewed-by: tschatzl, brutisso

hotspot/src/share/vm/gc/g1/collectionSetChooser.cpp

@@ -107,7 +107,8 @@ void CollectionSetChooser::verify() {
     HeapRegion *curr = regions_at(index++);
     guarantee(curr != NULL, "Regions in _regions array cannot be NULL");
     guarantee(!curr->is_young(), "should not be young!");
-    guarantee(!curr->is_humongous(), "should not be humongous!");
+    guarantee(!curr->is_pinned(),
+              err_msg("Pinned region should not be in collection set (index %u)", curr->hrm_index()));
     if (prev != NULL) {
       guarantee(order_regions(prev, curr) != 1,
                 err_msg("GC eff prev: %1.4f GC eff curr: %1.4f",
@@ -149,8 +150,8 @@ void CollectionSetChooser::sort_regions() {
 
 
 void CollectionSetChooser::add_region(HeapRegion* hr) {
-  assert(!hr->is_humongous(),
+  assert(!hr->is_pinned(),
-         "Humongous regions shouldn't be added to the collection set");
+         err_msg("Pinned region shouldn't be added to the collection set (index %u)", hr->hrm_index()));
   assert(!hr->is_young(), "should not be young!");
   _regions.append(hr);
   _length++;

hotspot/src/share/vm/gc/g1/collectionSetChooser.hpp

@@ -103,13 +103,12 @@ public:
   void sort_regions();
 
   // Determine whether to add the given region to the CSet chooser or
-  // not. Currently, we skip humongous regions (we never add them to
+  // not. Currently, we skip pinned regions and regions whose live
-  // the CSet, we only reclaim them during cleanup) and regions whose
+  // bytes are over the threshold. Humongous regions may be reclaimed during cleanup.
-  // live bytes are over the threshold.
   bool should_add(HeapRegion* hr) {
     assert(hr->is_marked(), "pre-condition");
     assert(!hr->is_young(), "should never consider young regions");
-    return !hr->is_humongous() &&
+    return !hr->is_pinned() &&
             hr->live_bytes() < _region_live_threshold_bytes;
   }
 

hotspot/src/share/vm/gc/g1/concurrentMark.cpp

@@ -1784,7 +1784,7 @@ public:
   const HeapRegionSetCount& humongous_regions_removed() { return _humongous_regions_removed; }
 
   bool doHeapRegion(HeapRegion *hr) {
-    if (hr->is_continues_humongous()) {
+    if (hr->is_continues_humongous() || hr->is_archive()) {
       return false;
     }
     // We use a claim value of zero here because all regions

hotspot/src/share/vm/gc/g1/g1Allocator.cpp

@@ -26,6 +26,7 @@
 #include "gc/g1/g1Allocator.hpp"
 #include "gc/g1/g1CollectedHeap.inline.hpp"
 #include "gc/g1/g1CollectorPolicy.hpp"
+#include "gc/g1/g1MarkSweep.hpp"
 #include "gc/g1/heapRegion.inline.hpp"
 #include "gc/g1/heapRegionSet.inline.hpp"
 
@@ -44,6 +45,8 @@ void G1Allocator::reuse_retained_old_region(EvacuationInfo& evacuation_info,
                                             HeapRegion** retained_old) {
   HeapRegion* retained_region = *retained_old;
   *retained_old = NULL;
+  assert(retained_region == NULL || !retained_region->is_archive(),
+         err_msg("Archive region should not be alloc region (index %u)", retained_region->hrm_index()));
 
   // We will discard the current GC alloc region if:
   // a) it's in the collection set (it can happen!),
@@ -168,3 +171,153 @@ void G1DefaultParGCAllocator::waste(size_t& wasted, size_t& undo_wasted) {
     }
   }
 }
+
+G1ArchiveAllocator* G1ArchiveAllocator::create_allocator(G1CollectedHeap* g1h) {
+  // Create the archive allocator, and also enable archive object checking
+  // in mark-sweep, since we will be creating archive regions.
+  G1ArchiveAllocator* result =  new G1ArchiveAllocator(g1h);
+  G1MarkSweep::enable_archive_object_check();
+  return result;
+}
+
+bool G1ArchiveAllocator::alloc_new_region() {
+  // Allocate the highest free region in the reserved heap,
+  // and add it to our list of allocated regions. It is marked
+  // archive and added to the old set.
+  HeapRegion* hr = _g1h->alloc_highest_free_region();
+  if (hr == NULL) {
+    return false;
+  }
+  assert(hr->is_empty(), err_msg("expected empty region (index %u)", hr->hrm_index()));
+  hr->set_archive();
+  _g1h->_old_set.add(hr);
+  _g1h->_hr_printer.alloc(hr, G1HRPrinter::Archive);
+  _allocated_regions.append(hr);
+  _allocation_region = hr;
+
+  // Set up _bottom and _max to begin allocating in the lowest
+  // min_region_size'd chunk of the allocated G1 region.
+  _bottom = hr->bottom();
+  _max = _bottom + HeapRegion::min_region_size_in_words();
+
+  // Tell mark-sweep that objects in this region are not to be marked.
+  G1MarkSweep::mark_range_archive(MemRegion(_bottom, HeapRegion::GrainWords));
+
+  // Since we've modified the old set, call update_sizes.
+  _g1h->g1mm()->update_sizes();
+  return true;
+}
+
+HeapWord* G1ArchiveAllocator::archive_mem_allocate(size_t word_size) {
+  assert(word_size != 0, "size must not be zero");
+  if (_allocation_region == NULL) {
+    if (!alloc_new_region()) {
+      return NULL;
+    }
+  }
+  HeapWord* old_top = _allocation_region->top();
+  assert(_bottom >= _allocation_region->bottom(),
+         err_msg("inconsistent allocation state: " PTR_FORMAT " < " PTR_FORMAT,
+                 p2i(_bottom), p2i(_allocation_region->bottom())));
+  assert(_max <= _allocation_region->end(),
+         err_msg("inconsistent allocation state: " PTR_FORMAT " > " PTR_FORMAT,
+                 p2i(_max), p2i(_allocation_region->end())));
+  assert(_bottom <= old_top && old_top <= _max,
+         err_msg("inconsistent allocation state: expected "
+                 PTR_FORMAT " <= " PTR_FORMAT " <= " PTR_FORMAT,
+                 p2i(_bottom), p2i(old_top), p2i(_max)));
+
+  // Allocate the next word_size words in the current allocation chunk.
+  // If allocation would cross the _max boundary, insert a filler and begin
+  // at the base of the next min_region_size'd chunk. Also advance to the next
+  // chunk if we don't yet cross the boundary, but the remainder would be too
+  // small to fill.
+  HeapWord* new_top = old_top + word_size;
+  size_t remainder = pointer_delta(_max, new_top);
+  if ((new_top > _max) ||
+      ((new_top < _max) && (remainder < CollectedHeap::min_fill_size()))) {
+    if (old_top != _max) {
+      size_t fill_size = pointer_delta(_max, old_top);
+      CollectedHeap::fill_with_object(old_top, fill_size);
+      _summary_bytes_used += fill_size * HeapWordSize;
+    }
+    _allocation_region->set_top(_max);
+    old_top = _bottom = _max;
+
+    // Check if we've just used up the last min_region_size'd chunk
+    // in the current region, and if so, allocate a new one.
+    if (_bottom != _allocation_region->end()) {
+      _max = _bottom + HeapRegion::min_region_size_in_words();
+    } else {
+      if (!alloc_new_region()) {
+        return NULL;
+      }
+      old_top = _allocation_region->bottom();
+    }
+  }
+  _allocation_region->set_top(old_top + word_size);
+  _summary_bytes_used += word_size * HeapWordSize;
+
+  return old_top;
+}
+
+void G1ArchiveAllocator::complete_archive(GrowableArray<MemRegion>* ranges,
+                                          size_t end_alignment_in_bytes) {
+  assert((end_alignment_in_bytes >> LogHeapWordSize) < HeapRegion::min_region_size_in_words(),
+          err_msg("alignment " SIZE_FORMAT " too large", end_alignment_in_bytes));
+  assert(is_size_aligned(end_alignment_in_bytes, HeapWordSize),
+         err_msg("alignment " SIZE_FORMAT " is not HeapWord (%u) aligned", end_alignment_in_bytes, HeapWordSize));
+
+  // If we've allocated nothing, simply return.
+  if (_allocation_region == NULL) {
+    return;
+  }
+
+  // If an end alignment was requested, insert filler objects.
+  if (end_alignment_in_bytes != 0) {
+    HeapWord* currtop = _allocation_region->top();
+    HeapWord* newtop = (HeapWord*)align_pointer_up(currtop, end_alignment_in_bytes);
+    size_t fill_size = pointer_delta(newtop, currtop);
+    if (fill_size != 0) {
+      if (fill_size < CollectedHeap::min_fill_size()) {
+        // If the required fill is smaller than we can represent,
+        // bump up to the next aligned address. We know we won't exceed the current
+        // region boundary because the max supported alignment is smaller than the min
+        // region size, and because the allocation code never leaves space smaller than
+        // the min_fill_size at the top of the current allocation region.
+        newtop = (HeapWord*)align_pointer_up(currtop + CollectedHeap::min_fill_size(),
+                                             end_alignment_in_bytes);
+        fill_size = pointer_delta(newtop, currtop);
+      }
+      HeapWord* fill = archive_mem_allocate(fill_size);
+      CollectedHeap::fill_with_objects(fill, fill_size);
+    }
+  }
+
+  // Loop through the allocated regions, and create MemRegions summarizing
+  // the allocated address range, combining contiguous ranges. Add the
+  // MemRegions to the GrowableArray provided by the caller.
+  int index = _allocated_regions.length() - 1;
+  assert(_allocated_regions.at(index) == _allocation_region,
+         err_msg("expected region %u at end of array, found %u",
+                 _allocation_region->hrm_index(), _allocated_regions.at(index)->hrm_index()));
+  HeapWord* base_address = _allocation_region->bottom();
+  HeapWord* top = base_address;
+
+  while (index >= 0) {
+    HeapRegion* next = _allocated_regions.at(index);
+    HeapWord* new_base = next->bottom();
+    HeapWord* new_top = next->top();
+    if (new_base != top) {
+      ranges->append(MemRegion(base_address, pointer_delta(top, base_address)));
+      base_address = new_base;
+    }
+    top = new_top;
+    index = index - 1;
+  }
+
+  assert(top != base_address, err_msg("zero-sized range, address " PTR_FORMAT, p2i(base_address)));
+  ranges->append(MemRegion(base_address, pointer_delta(top, base_address)));
+  _allocated_regions.clear();
+  _allocation_region = NULL;
+};

hotspot/src/share/vm/gc/g1/g1Allocator.hpp

@@ -269,4 +269,72 @@ public:
   virtual void waste(size_t& wasted, size_t& undo_wasted);
 };
 
+// G1ArchiveAllocator is used to allocate memory in archive
+// regions. Such regions are not modifiable by GC, being neither
+// scavenged nor compacted, or even marked in the object header.
+// They can contain no pointers to non-archive heap regions,
+class G1ArchiveAllocator : public CHeapObj<mtGC> {
+
+protected:
+  G1CollectedHeap* _g1h;
+
+  // The current allocation region
+  HeapRegion* _allocation_region;
+
+  // Regions allocated for the current archive range.
+  GrowableArray<HeapRegion*> _allocated_regions;
+
+  // The number of bytes used in the current range.
+  size_t _summary_bytes_used;
+
+  // Current allocation window within the current region.
+  HeapWord* _bottom;
+  HeapWord* _top;
+  HeapWord* _max;
+
+  // Allocate a new region for this archive allocator.
+  // Allocation is from the top of the reserved heap downward.
+  bool alloc_new_region();
+
+public:
+  G1ArchiveAllocator(G1CollectedHeap* g1h) :
+    _g1h(g1h),
+    _allocation_region(NULL),
+    _allocated_regions((ResourceObj::set_allocation_type((address) &_allocated_regions,
+                                                         ResourceObj::C_HEAP),
+                        2), true /* C_Heap */),
+    _summary_bytes_used(0),
+    _bottom(NULL),
+    _top(NULL),
+    _max(NULL) { }
+
+  virtual ~G1ArchiveAllocator() {
+    assert(_allocation_region == NULL, "_allocation_region not NULL");
+  }
+
+  static G1ArchiveAllocator* create_allocator(G1CollectedHeap* g1h);
+
+  // Allocate memory for an individual object.
+  HeapWord* archive_mem_allocate(size_t word_size);
+
+  // Return the memory ranges used in the current archive, after
+  // aligning to the requested alignment.
+  void complete_archive(GrowableArray<MemRegion>* ranges,
+                        size_t end_alignment_in_bytes);
+
+  // The number of bytes allocated by this allocator.
+  size_t used() {
+    return _summary_bytes_used;
+  }
+
+  // Clear the count of bytes allocated in prior G1 regions. This
+  // must be done when recalculate_use is used to reset the counter
+  // for the generic allocator, since it counts bytes in all G1
+  // regions, including those still associated with this allocator.
+  void clear_used() {
+    _summary_bytes_used = 0;
+  }
+
+};
+
 #endif // SHARE_VM_GC_G1_G1ALLOCATOR_HPP

hotspot/src/share/vm/gc/g1/g1BiasedArray.hpp

@@ -128,6 +128,14 @@ public:
     return biased_base()[biased_index];
   }
 
+  // Return the index of the element of the given array that covers the given
+  // word in the heap.
+  idx_t get_index_by_address(HeapWord* value) const {
+    idx_t biased_index = ((uintptr_t)value) >> this->shift_by();
+    this->verify_biased_index(biased_index);
+    return biased_index - _bias;
+  }
+
   // Set the value of the array entry that corresponds to the given array.
   void set_by_address(HeapWord * address, T value) {
     idx_t biased_index = ((uintptr_t)address) >> this->shift_by();
@@ -135,6 +143,18 @@ public:
     biased_base()[biased_index] = value;
   }
 
+  // Set the value of all array entries that correspond to addresses
+  // in the specified MemRegion.
+  void set_by_address(MemRegion range, T value) {
+    idx_t biased_start = ((uintptr_t)range.start()) >> this->shift_by();
+    idx_t biased_last = ((uintptr_t)range.last()) >> this->shift_by();
+    this->verify_biased_index(biased_start);
+    this->verify_biased_index(biased_last);
+    for (idx_t i = biased_start; i <= biased_last; i++) {
+      biased_base()[i] = value;
+    }
+  }
+
 protected:
   // Returns the address of the element the given address maps to
   T* address_mapped_to(HeapWord* address) {

hotspot/src/share/vm/gc/g1/g1CollectedHeap.cpp

@@ -405,7 +405,7 @@ HeapRegion* G1CollectedHeap::pop_dirty_cards_region()
 // can move in an incremental collection.
 bool G1CollectedHeap::is_scavengable(const void* p) {
   HeapRegion* hr = heap_region_containing(p);
-  return !hr->is_humongous();
+  return !hr->is_pinned();
 }
 
 // Private methods.
@@ -908,6 +908,207 @@ HeapWord* G1CollectedHeap::attempt_allocation_slow(size_t word_size,
   return NULL;
 }
 
+void G1CollectedHeap::begin_archive_alloc_range() {
+  assert_at_safepoint(true /* should_be_vm_thread */);
+  if (_archive_allocator == NULL) {
+    _archive_allocator = G1ArchiveAllocator::create_allocator(this);
+  }
+}
+
+bool G1CollectedHeap::is_archive_alloc_too_large(size_t word_size) {
+  // Allocations in archive regions cannot be of a size that would be considered
+  // humongous even for a minimum-sized region, because G1 region sizes/boundaries
+  // may be different at archive-restore time.
+  return word_size >= humongous_threshold_for(HeapRegion::min_region_size_in_words());
+}
+
+HeapWord* G1CollectedHeap::archive_mem_allocate(size_t word_size) {
+  assert_at_safepoint(true /* should_be_vm_thread */);
+  assert(_archive_allocator != NULL, "_archive_allocator not initialized");
+  if (is_archive_alloc_too_large(word_size)) {
+    return NULL;
+  }
+  return _archive_allocator->archive_mem_allocate(word_size);
+}
+
+void G1CollectedHeap::end_archive_alloc_range(GrowableArray<MemRegion>* ranges,
+                                              size_t end_alignment_in_bytes) {
+  assert_at_safepoint(true /* should_be_vm_thread */);
+  assert(_archive_allocator != NULL, "_archive_allocator not initialized");
+
+  // Call complete_archive to do the real work, filling in the MemRegion
+  // array with the archive regions.
+  _archive_allocator->complete_archive(ranges, end_alignment_in_bytes);
+  delete _archive_allocator;
+  _archive_allocator = NULL;
+}
+
+bool G1CollectedHeap::check_archive_addresses(MemRegion* ranges, size_t count) {
+  assert(ranges != NULL, "MemRegion array NULL");
+  assert(count != 0, "No MemRegions provided");
+  MemRegion reserved = _hrm.reserved();
+  for (size_t i = 0; i < count; i++) {
+    if (!reserved.contains(ranges[i].start()) || !reserved.contains(ranges[i].last())) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool G1CollectedHeap::alloc_archive_regions(MemRegion* ranges, size_t count) {
+  assert(ranges != NULL, "MemRegion array NULL");
+  assert(count != 0, "No MemRegions provided");
+  MutexLockerEx x(Heap_lock);
+
+  MemRegion reserved = _hrm.reserved();
+  HeapWord* prev_last_addr = NULL;
+  HeapRegion* prev_last_region = NULL;
+
+  // Temporarily disable pretouching of heap pages. This interface is used
+  // when mmap'ing archived heap data in, so pre-touching is wasted.
+  FlagSetting fs(AlwaysPreTouch, false);
+
+  // Enable archive object checking in G1MarkSweep. We have to let it know
+  // about each archive range, so that objects in those ranges aren't marked.
+  G1MarkSweep::enable_archive_object_check();
+
+  // For each specified MemRegion range, allocate the corresponding G1
+  // regions and mark them as archive regions. We expect the ranges in
+  // ascending starting address order, without overlap.
+  for (size_t i = 0; i < count; i++) {
+    MemRegion curr_range = ranges[i];
+    HeapWord* start_address = curr_range.start();
+    size_t word_size = curr_range.word_size();
+    HeapWord* last_address = curr_range.last();
+    size_t commits = 0;
+
+    guarantee(reserved.contains(start_address) && reserved.contains(last_address),
+              err_msg("MemRegion outside of heap [" PTR_FORMAT ", " PTR_FORMAT "]",
+              p2i(start_address), p2i(last_address)));
+    guarantee(start_address > prev_last_addr,
+              err_msg("Ranges not in ascending order: " PTR_FORMAT " <= " PTR_FORMAT ,
+              p2i(start_address), p2i(prev_last_addr)));
+    prev_last_addr = last_address;
+
+    // Check for ranges that start in the same G1 region in which the previous
+    // range ended, and adjust the start address so we don't try to allocate
+    // the same region again. If the current range is entirely within that
+    // region, skip it, just adjusting the recorded top.
+    HeapRegion* start_region = _hrm.addr_to_region(start_address);
+    if ((prev_last_region != NULL) && (start_region == prev_last_region)) {
+      start_address = start_region->end();
+      if (start_address > last_address) {
+        _allocator->increase_used(word_size * HeapWordSize);
+        start_region->set_top(last_address + 1);
+        continue;
+      }
+      start_region->set_top(start_address);
+      curr_range = MemRegion(start_address, last_address + 1);
+      start_region = _hrm.addr_to_region(start_address);
+    }
+
+    // Perform the actual region allocation, exiting if it fails.
+    // Then note how much new space we have allocated.
+    if (!_hrm.allocate_containing_regions(curr_range, &commits)) {
+      return false;
+    }
+    _allocator->increase_used(word_size * HeapWordSize);
+    if (commits != 0) {
+      ergo_verbose1(ErgoHeapSizing,
+                    "attempt heap expansion",
+                    ergo_format_reason("allocate archive regions")
+                    ergo_format_byte("total size"),
+                    HeapRegion::GrainWords * HeapWordSize * commits);
+    }
+
+    // Mark each G1 region touched by the range as archive, add it to the old set,
+    // and set the allocation context and top.
+    HeapRegion* curr_region = _hrm.addr_to_region(start_address);
+    HeapRegion* last_region = _hrm.addr_to_region(last_address);
+    prev_last_region = last_region;
+
+    while (curr_region != NULL) {
+      assert(curr_region->is_empty() && !curr_region->is_pinned(),
+             err_msg("Region already in use (index %u)", curr_region->hrm_index()));
+      _hr_printer.alloc(curr_region, G1HRPrinter::Archive);
+      curr_region->set_allocation_context(AllocationContext::system());
+      curr_region->set_archive();
+      _old_set.add(curr_region);
+      if (curr_region != last_region) {
+        curr_region->set_top(curr_region->end());
+        curr_region = _hrm.next_region_in_heap(curr_region);
+      } else {
+        curr_region->set_top(last_address + 1);
+        curr_region = NULL;
+      }
+    }
+
+    // Notify mark-sweep of the archive range.
+    G1MarkSweep::mark_range_archive(curr_range);
+  }
+  return true;
+}
+
+void G1CollectedHeap::fill_archive_regions(MemRegion* ranges, size_t count) {
+  assert(ranges != NULL, "MemRegion array NULL");
+  assert(count != 0, "No MemRegions provided");
+  MemRegion reserved = _hrm.reserved();
+  HeapWord *prev_last_addr = NULL;
+  HeapRegion* prev_last_region = NULL;
+
+  // For each MemRegion, create filler objects, if needed, in the G1 regions
+  // that contain the address range. The address range actually within the
+  // MemRegion will not be modified. That is assumed to have been initialized
+  // elsewhere, probably via an mmap of archived heap data.
+  MutexLockerEx x(Heap_lock);
+  for (size_t i = 0; i < count; i++) {
+    HeapWord* start_address = ranges[i].start();
+    HeapWord* last_address = ranges[i].last();
+
+    assert(reserved.contains(start_address) && reserved.contains(last_address),
+           err_msg("MemRegion outside of heap [" PTR_FORMAT ", " PTR_FORMAT "]",
+                   p2i(start_address), p2i(last_address)));
+    assert(start_address > prev_last_addr,
+           err_msg("Ranges not in ascending order: " PTR_FORMAT " <= " PTR_FORMAT ,
+                   p2i(start_address), p2i(prev_last_addr)));
+
+    HeapRegion* start_region = _hrm.addr_to_region(start_address);
+    HeapRegion* last_region = _hrm.addr_to_region(last_address);
+    HeapWord* bottom_address = start_region->bottom();
+
+    // Check for a range beginning in the same region in which the
+    // previous one ended.
+    if (start_region == prev_last_region) {
+      bottom_address = prev_last_addr + 1;
+    }
+
+    // Verify that the regions were all marked as archive regions by
+    // alloc_archive_regions.
+    HeapRegion* curr_region = start_region;
+    while (curr_region != NULL) {
+      guarantee(curr_region->is_archive(),
+                err_msg("Expected archive region at index %u", curr_region->hrm_index()));
+      if (curr_region != last_region) {
+        curr_region = _hrm.next_region_in_heap(curr_region);
+      } else {
+        curr_region = NULL;
+      }
+    }
+
+    prev_last_addr = last_address;
+    prev_last_region = last_region;
+
+    // Fill the memory below the allocated range with dummy object(s),
+    // if the region bottom does not match the range start, or if the previous
+    // range ended within the same G1 region, and there is a gap.
+    if (start_address != bottom_address) {
+      size_t fill_size = pointer_delta(start_address, bottom_address);
+      G1CollectedHeap::fill_with_objects(bottom_address, fill_size);
+      _allocator->increase_used(fill_size * HeapWordSize);
+    }
+  }
+}
+
 HeapWord* G1CollectedHeap::attempt_allocation_humongous(size_t word_size,
                                                         uint* gc_count_before_ret,
                                                         uint* gclocker_retry_count_ret) {
@@ -1132,6 +1333,8 @@ public:
       }
     } else if (hr->is_continues_humongous()) {
       _hr_printer->post_compaction(hr, G1HRPrinter::ContinuesHumongous);
+    } else if (hr->is_archive()) {
+      _hr_printer->post_compaction(hr, G1HRPrinter::Archive);
     } else if (hr->is_old()) {
       _hr_printer->post_compaction(hr, G1HRPrinter::Old);
     } else {
@@ -1723,6 +1926,7 @@ G1CollectedHeap::G1CollectedHeap(G1CollectorPolicy* policy_) :
   _humongous_set("Master Humongous Set", true /* humongous */, new HumongousRegionSetMtSafeChecker()),
   _humongous_reclaim_candidates(),
   _has_humongous_reclaim_candidates(false),
+  _archive_allocator(NULL),
   _free_regions_coming(false),
   _young_list(new YoungList(this)),
   _gc_time_stamp(0),
@@ -1748,7 +1952,11 @@ G1CollectedHeap::G1CollectedHeap(G1CollectorPolicy* policy_) :
   _workers->initialize_workers();
 
   _allocator = G1Allocator::create_allocator(this);
-  _humongous_object_threshold_in_words = HeapRegion::GrainWords / 2;
+  _humongous_object_threshold_in_words = humongous_threshold_for(HeapRegion::GrainWords);
+
+  // Override the default _filler_array_max_size so that no humongous filler
+  // objects are created.
+  _filler_array_max_size = _humongous_object_threshold_in_words;
 
   uint n_queues = ParallelGCThreads;
   _task_queues = new RefToScanQueueSet(n_queues);
@@ -2163,7 +2371,11 @@ void G1CollectedHeap::iterate_dirty_card_closure(CardTableEntryClosure* cl,
 
 // Computes the sum of the storage used by the various regions.
 size_t G1CollectedHeap::used() const {
-  return _allocator->used();
+  size_t result = _allocator->used();
+  if (_archive_allocator != NULL) {
+    result += _archive_allocator->used();
+  }
+  return result;
 }
 
 size_t G1CollectedHeap::used_unlocked() const {
@@ -2576,7 +2788,7 @@ void G1CollectedHeap::collection_set_iterate_from(HeapRegion* r,
 
 HeapRegion* G1CollectedHeap::next_compaction_region(const HeapRegion* from) const {
   HeapRegion* result = _hrm.next_region_in_heap(from);
-  while (result != NULL && result->is_humongous()) {
+  while (result != NULL && result->is_pinned()) {
     result = _hrm.next_region_in_heap(result);
   }
   return result;
@@ -2884,6 +3096,31 @@ public:
   size_t live_bytes() { return _live_bytes; }
 };
 
+class VerifyArchiveOopClosure: public OopClosure {
+public:
+  VerifyArchiveOopClosure(HeapRegion *hr) { }
+  void do_oop(narrowOop *p) { do_oop_work(p); }
+  void do_oop(      oop *p) { do_oop_work(p); }
+
+  template <class T> void do_oop_work(T *p) {
+    oop obj = oopDesc::load_decode_heap_oop(p);
+    guarantee(obj == NULL || G1MarkSweep::in_archive_range(obj),
+              err_msg("Archive object at " PTR_FORMAT " references a non-archive object at " PTR_FORMAT,
+                      p2i(p), p2i(obj)));
+  }
+};
+
+class VerifyArchiveRegionClosure: public ObjectClosure {
+public:
+  VerifyArchiveRegionClosure(HeapRegion *hr) { }
+  // Verify that all object pointers are to archive regions.
+  void do_object(oop o) {
+    VerifyArchiveOopClosure checkOop(NULL);
+    assert(o != NULL, "Should not be here for NULL oops");
+    o->oop_iterate_no_header(&checkOop);
+  }
+};
+
 class VerifyRegionClosure: public HeapRegionClosure {
 private:
   bool             _par;
@@ -2903,6 +3140,13 @@ public:
   }
 
   bool doHeapRegion(HeapRegion* r) {
+    // For archive regions, verify there are no heap pointers to
+    // non-pinned regions. For all others, verify liveness info.
+    if (r->is_archive()) {
+      VerifyArchiveRegionClosure verify_oop_pointers(r);
+      r->object_iterate(&verify_oop_pointers);
+      return true;
+    }
     if (!r->is_continues_humongous()) {
       bool failures = false;
       r->verify(_vo, &failures);
@@ -3087,7 +3331,7 @@ bool G1CollectedHeap::is_obj_dead_cond(const oop obj,
   switch (vo) {
   case VerifyOption_G1UsePrevMarking: return is_obj_dead(obj, hr);
   case VerifyOption_G1UseNextMarking: return is_obj_ill(obj, hr);
-  case VerifyOption_G1UseMarkWord:    return !obj->is_gc_marked();
+  case VerifyOption_G1UseMarkWord:    return !obj->is_gc_marked() && !hr->is_archive();
   default:                            ShouldNotReachHere();
   }
   return false; // keep some compilers happy
@@ -3098,7 +3342,10 @@ bool G1CollectedHeap::is_obj_dead_cond(const oop obj,
   switch (vo) {
   case VerifyOption_G1UsePrevMarking: return is_obj_dead(obj);
   case VerifyOption_G1UseNextMarking: return is_obj_ill(obj);
-  case VerifyOption_G1UseMarkWord:    return !obj->is_gc_marked();
+  case VerifyOption_G1UseMarkWord: {
+    HeapRegion* hr = _hrm.addr_to_region((HeapWord*)obj);
+    return !obj->is_gc_marked() && !hr->is_archive();
+  }
   default:                            ShouldNotReachHere();
   }
   return false; // keep some compilers happy
@@ -3131,7 +3378,7 @@ void G1CollectedHeap::print_extended_on(outputStream* st) const {
   st->cr();
   st->print_cr("Heap Regions: (Y=young(eden), SU=young(survivor), "
                "HS=humongous(starts), HC=humongous(continues), "
-               "CS=collection set, F=free, TS=gc time stamp, "
+               "CS=collection set, F=free, A=archive, TS=gc time stamp, "
                "PTAMS=previous top-at-mark-start, "
                "NTAMS=next top-at-mark-start)");
   PrintRegionClosure blk(st);
@@ -3852,6 +4099,9 @@ G1CollectedHeap::do_collection_pause_at_safepoint(double target_pause_time_ms) {
 
         if (evacuation_failed()) {
           _allocator->set_used(recalculate_used());
+          if (_archive_allocator != NULL) {
+            _archive_allocator->clear_used();
+          }
           for (uint i = 0; i < ParallelGCThreads; i++) {
             if (_evacuation_failed_info_array[i].has_failed()) {
               _gc_tracer_stw->report_evacuation_failed(_evacuation_failed_info_array[i]);
@@ -6173,13 +6423,18 @@ public:
       assert(!r->is_young(), "we should not come across young regions");
 
       if (r->is_humongous()) {
-        // We ignore humongous regions, we left the humongous set unchanged
+        // We ignore humongous regions. We left the humongous set unchanged.
       } else {
         // Objects that were compacted would have ended up on regions
-        // that were previously old or free.
+        // that were previously old or free.  Archive regions (which are
+        // old) will not have been touched.
         assert(r->is_free() || r->is_old(), "invariant");
-        // We now consider them old, so register as such.
+        // We now consider them old, so register as such. Leave
+        // archive regions set that way, however, while still adding
+        // them to the old set.
+        if (!r->is_archive()) {
           r->set_old();
+        }
         _old_set->add(r);
       }
       _total_used += r->used();
@@ -6205,6 +6460,9 @@ void G1CollectedHeap::rebuild_region_sets(bool free_list_only) {
 
   if (!free_list_only) {
     _allocator->set_used(cl.total_used());
+    if (_archive_allocator != NULL) {
+      _archive_allocator->clear_used();
+    }
   }
   assert(_allocator->used_unlocked() == recalculate_used(),
          err_msg("inconsistent _allocator->used_unlocked(), "
@@ -6305,6 +6563,25 @@ void G1CollectedHeap::retire_gc_alloc_region(HeapRegion* alloc_region,
   _hr_printer.retire(alloc_region);
 }
 
+HeapRegion* G1CollectedHeap::alloc_highest_free_region() {
+  bool expanded = false;
+  uint index = _hrm.find_highest_free(&expanded);
+
+  if (index != G1_NO_HRM_INDEX) {
+    if (expanded) {
+      ergo_verbose1(ErgoHeapSizing,
+                    "attempt heap expansion",
+                    ergo_format_reason("requested address range outside heap bounds")
+                    ergo_format_byte("region size"),
+                    HeapRegion::GrainWords * HeapWordSize);
+    }
+    _hrm.allocate_free_regions_starting_at(index, 1);
+    return region_at(index);
+  }
+  return NULL;
+}
+
+
 // Heap region set verification
 
 class VerifyRegionListsClosure : public HeapRegionClosure {
@@ -6341,6 +6618,9 @@ public:
       assert(hr->containing_set() == _old_set, err_msg("Heap region %u is old but not in the old set.", hr->hrm_index()));
       _old_count.increment(1u, hr->capacity());
     } else {
+      // There are no other valid region types. Check for one invalid
+      // one we can identify: pinned without old or humongous set.
+      assert(!hr->is_pinned(), err_msg("Heap region %u is pinned but not old (archive) or humongous.", hr->hrm_index()));
       ShouldNotReachHere();
     }
     return false;

hotspot/src/share/vm/gc/g1/g1CollectedHeap.hpp

@@ -188,6 +188,7 @@ class G1CollectedHeap : public CollectedHeap {
   friend class SurvivorGCAllocRegion;
   friend class OldGCAllocRegion;
   friend class G1Allocator;
+  friend class G1ArchiveAllocator;
 
   // Closures used in implementation.
   friend class G1ParScanThreadState;
@@ -250,6 +251,9 @@ private:
   // Class that handles the different kinds of allocations.
   G1Allocator* _allocator;
 
+  // Class that handles archive allocation ranges.
+  G1ArchiveAllocator* _archive_allocator;
+
   // Statistics for each allocation context
   AllocationContextStats _allocation_context_stats;
 
@@ -576,6 +580,10 @@ protected:
   void retire_gc_alloc_region(HeapRegion* alloc_region,
                               size_t allocated_bytes, InCSetState dest);
 
+  // Allocate the highest free region in the reserved heap. This will commit
+  // regions as necessary.
+  HeapRegion* alloc_highest_free_region();
+
   // - if explicit_gc is true, the GC is for a System.gc() or a heap
   //   inspection request and should collect the entire heap
   // - if clear_all_soft_refs is true, all soft references should be
@@ -731,6 +739,44 @@ public:
   void free_humongous_region(HeapRegion* hr,
                              FreeRegionList* free_list,
                              bool par);
+
+  // Facility for allocating in 'archive' regions in high heap memory and
+  // recording the allocated ranges. These should all be called from the
+  // VM thread at safepoints, without the heap lock held. They can be used
+  // to create and archive a set of heap regions which can be mapped at the
+  // same fixed addresses in a subsequent JVM invocation.
+  void begin_archive_alloc_range();
+
+  // Check if the requested size would be too large for an archive allocation.
+  bool is_archive_alloc_too_large(size_t word_size);
+
+  // Allocate memory of the requested size from the archive region. This will
+  // return NULL if the size is too large or if no memory is available. It
+  // does not trigger a garbage collection.
+  HeapWord* archive_mem_allocate(size_t word_size);
+
+  // Optionally aligns the end address and returns the allocated ranges in
+  // an array of MemRegions in order of ascending addresses.
+  void end_archive_alloc_range(GrowableArray<MemRegion>* ranges,
+                               size_t end_alignment_in_bytes = 0);
+
+  // Facility for allocating a fixed range within the heap and marking
+  // the containing regions as 'archive'. For use at JVM init time, when the
+  // caller may mmap archived heap data at the specified range(s).
+  // Verify that the MemRegions specified in the argument array are within the
+  // reserved heap.
+  bool check_archive_addresses(MemRegion* range, size_t count);
+
+  // Commit the appropriate G1 regions containing the specified MemRegions
+  // and mark them as 'archive' regions. The regions in the array must be
+  // non-overlapping and in order of ascending address.
+  bool alloc_archive_regions(MemRegion* range, size_t count);
+
+  // Insert any required filler objects in the G1 regions around the specified
+  // ranges to make the regions parseable. This must be called after
+  // alloc_archive_regions, and after class loading has occurred.
+  void fill_archive_regions(MemRegion* range, size_t count);
+
 protected:
 
   // Shrink the garbage-first heap by at most the given size (in bytes!).
@@ -1395,6 +1441,11 @@ public:
     return word_size > _humongous_object_threshold_in_words;
   }
 
+  // Returns the humongous threshold for a specific region size
+  static size_t humongous_threshold_for(size_t region_size) {
+    return (region_size / 2);
+  }
+
   // Update mod union table with the set of dirty cards.
   void updateModUnion();
 
@@ -1441,21 +1492,23 @@ public:
 
   // Determine if an object is dead, given the object and also
   // the region to which the object belongs. An object is dead
-  // iff a) it was not allocated since the last mark and b) it
+  // iff a) it was not allocated since the last mark, b) it
-  // is not marked.
+  // is not marked, and c) it is not in an archive region.
   bool is_obj_dead(const oop obj, const HeapRegion* hr) const {
     return
       !hr->obj_allocated_since_prev_marking(obj) &&
-      !isMarkedPrev(obj);
+      !isMarkedPrev(obj) &&
+      !hr->is_archive();
   }
 
   // This function returns true when an object has been
   // around since the previous marking and hasn't yet
-  // been marked during this marking.
+  // been marked during this marking, and is not in an archive region.
   bool is_obj_ill(const oop obj, const HeapRegion* hr) const {
     return
       !hr->obj_allocated_since_next_marking(obj) &&
-      !isMarkedNext(obj);
+      !isMarkedNext(obj) &&
+      !hr->is_archive();
   }
 
   // Determine if an object is dead, given only the object itself.

hotspot/src/share/vm/gc/g1/g1EvacFailure.cpp

@@ -190,7 +190,7 @@ public:
     bool during_initial_mark = _g1h->collector_state()->during_initial_mark_pause();
     bool during_conc_mark = _g1h->collector_state()->mark_in_progress();
 
-    assert(!hr->is_humongous(), "sanity");
+    assert(!hr->is_pinned(), err_msg("Unexpected pinned region at index %u", hr->hrm_index()));
     assert(hr->in_collection_set(), "bad CS");
 
     if (_hrclaimer->claim_region(hr->hrm_index())) {

hotspot/src/share/vm/gc/g1/g1HRPrinter.cpp

@@ -54,6 +54,7 @@ const char* G1HRPrinter::region_type_name(RegionType type) {
     case SingleHumongous:    return "SingleH";
     case StartsHumongous:    return "StartsH";
     case ContinuesHumongous: return "ContinuesH";
+    case Archive:            return "Archive";
     default:                 ShouldNotReachHere();
   }
   // trying to keep the Windows compiler happy

hotspot/src/share/vm/gc/g1/g1HRPrinter.hpp

@@ -52,7 +52,8 @@ public:
     Old,
     SingleHumongous,
     StartsHumongous,
-    ContinuesHumongous
+    ContinuesHumongous,
+    Archive
   } RegionType;
 
   typedef enum {

hotspot/src/share/vm/gc/g1/g1MarkSweep.cpp

@@ -57,6 +57,9 @@
 
 class HeapRegion;
 
+bool G1MarkSweep::_archive_check_enabled = false;
+G1ArchiveRegionMap G1MarkSweep::_archive_region_map;
+
 void G1MarkSweep::invoke_at_safepoint(ReferenceProcessor* rp,
                                       bool clear_all_softrefs) {
   assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
@@ -212,7 +215,7 @@ class G1AdjustPointersClosure: public HeapRegionClosure {
         // point all the oops to the new location
         MarkSweep::adjust_pointers(obj);
       }
-    } else {
+    } else if (!r->is_pinned()) {
       // This really ought to be "as_CompactibleSpace"...
       r->adjust_pointers();
     }
@@ -275,7 +278,7 @@ public:
         }
         hr->reset_during_compaction();
       }
-    } else {
+    } else if (!hr->is_pinned()) {
       hr->compact();
     }
     return false;
@@ -298,6 +301,26 @@ void G1MarkSweep::mark_sweep_phase4() {
 
 }
 
+void G1MarkSweep::enable_archive_object_check() {
+  assert(!_archive_check_enabled, "archive range check already enabled");
+  _archive_check_enabled = true;
+  size_t length = Universe::heap()->max_capacity();
+  _archive_region_map.initialize((HeapWord*)Universe::heap()->base(),
+                                 (HeapWord*)Universe::heap()->base() + length,
+                                 HeapRegion::GrainBytes);
+}
+
+void G1MarkSweep::mark_range_archive(MemRegion range) {
+  assert(_archive_check_enabled, "archive range check not enabled");
+  _archive_region_map.set_by_address(range, true);
+}
+
+bool G1MarkSweep::in_archive_range(oop object) {
+  // This is the out-of-line part of is_archive_object test, done separately
+  // to avoid additional performance impact when the check is not enabled.
+  return _archive_region_map.get_by_address((HeapWord*)object);
+}
+
 void G1MarkSweep::prepare_compaction_work(G1PrepareCompactClosure* blk) {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   g1h->heap_region_iterate(blk);
@@ -357,7 +380,7 @@ bool G1PrepareCompactClosure::doHeapRegion(HeapRegion* hr) {
     } else {
       assert(hr->is_continues_humongous(), "Invalid humongous.");
     }
-  } else {
+  } else if (!hr->is_pinned()) {
     prepare_for_compaction(hr, hr->end());
   }
   return false;

hotspot/src/share/vm/gc/g1/g1MarkSweep.hpp

@@ -44,6 +44,7 @@ class ReferenceProcessor;
 //
 // Class unloading will only occur when a full gc is invoked.
 class G1PrepareCompactClosure;
+class G1ArchiveRegionMap;
 
 class G1MarkSweep : AllStatic {
  public:
@@ -54,7 +55,22 @@ class G1MarkSweep : AllStatic {
   static STWGCTimer* gc_timer() { return GenMarkSweep::_gc_timer; }
   static SerialOldTracer* gc_tracer() { return GenMarkSweep::_gc_tracer; }
 
+  // Create the _archive_region_map which is used to identify archive objects.
+  static void enable_archive_object_check();
+
+  // Mark the regions containing the specified address range as archive regions.
+  static void mark_range_archive(MemRegion range);
+
+  // Check if an object is in an archive region using the _archive_region_map.
+  static bool in_archive_range(oop object);
+
+  // Check if archive object checking is enabled, to avoid calling in_archive_range
+  // unnecessarily.
+  static bool archive_check_enabled() { return G1MarkSweep::_archive_check_enabled; }
+
  private:
+  static bool _archive_check_enabled;
+  static G1ArchiveRegionMap  _archive_region_map;
 
   // Mark live objects
   static void mark_sweep_phase1(bool& marked_for_deopt,
@@ -93,4 +109,12 @@ class G1PrepareCompactClosure : public HeapRegionClosure {
   bool doHeapRegion(HeapRegion* hr);
 };
 
+// G1ArchiveRegionMap is a boolean array used to mark G1 regions as
+// archive regions.  This allows a quick check for whether an object
+// should not be marked because it is in an archive region.
+class G1ArchiveRegionMap : public G1BiasedMappedArray<bool> {
+protected:
+  bool default_value() const { return false; }
+};
+
 #endif // SHARE_VM_GC_G1_G1MARKSWEEP_HPP

hotspot/src/share/vm/gc/g1/heapRegion.cpp

@@ -103,6 +103,10 @@ size_t HeapRegion::max_region_size() {
   return HeapRegionBounds::max_size();
 }
 
+size_t HeapRegion::min_region_size_in_words() {
+  return HeapRegionBounds::min_size() >> LogHeapWordSize;
+}
+
 void HeapRegion::setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size) {
   size_t region_size = G1HeapRegionSize;
   if (FLAG_IS_DEFAULT(G1HeapRegionSize)) {
@@ -716,7 +720,7 @@ public:
         HeapRegion* to   = _g1h->heap_region_containing(obj);
         if (from != NULL && to != NULL &&
             from != to &&
-            !to->is_humongous()) {
+            !to->is_pinned()) {
           jbyte cv_obj = *_bs->byte_for_const(_containing_obj);
           jbyte cv_field = *_bs->byte_for_const(p);
           const jbyte dirty = CardTableModRefBS::dirty_card_val();

hotspot/src/share/vm/gc/g1/heapRegion.hpp

@@ -331,6 +331,7 @@ class HeapRegion: public G1OffsetTableContigSpace {
   }
 
   static size_t max_region_size();
+  static size_t min_region_size_in_words();
 
   // It sets up the heap region size (GrainBytes / GrainWords), as
   // well as other related fields that are based on the heap region
@@ -417,6 +418,15 @@ class HeapRegion: public G1OffsetTableContigSpace {
 
   bool is_old() const { return _type.is_old(); }
 
+  // A pinned region contains objects which are not moved by garbage collections.
+  // Humongous regions and archive regions are pinned.
+  bool is_pinned() const { return _type.is_pinned(); }
+
+  // An archive region is a pinned region, also tagged as old, which
+  // should not be marked during mark/sweep. This allows the address
+  // space to be shared by JVM instances.
+  bool is_archive() const { return _type.is_archive(); }
+
   // For a humongous region, region in which it starts.
   HeapRegion* humongous_start_region() const {
     return _humongous_start_region;
@@ -670,6 +680,8 @@ class HeapRegion: public G1OffsetTableContigSpace {
 
   void set_old() { _type.set_old(); }
 
+  void set_archive() { _type.set_archive(); }
+
   // Determine if an object has been allocated since the last
   // mark performed by the collector. This returns true iff the object
   // is within the unmarked area of the region.

hotspot/src/share/vm/gc/g1/heapRegionManager.cpp

@@ -278,6 +278,55 @@ uint HeapRegionManager::find_unavailable_from_idx(uint start_idx, uint* res_idx)
   return num_regions;
 }
 
+uint HeapRegionManager::find_highest_free(bool* expanded) {
+  // Loop downwards from the highest region index, looking for an
+  // entry which is either free or not yet committed.  If not yet
+  // committed, expand_at that index.
+  uint curr = max_length() - 1;
+  while (true) {
+    HeapRegion *hr = _regions.get_by_index(curr);
+    if (hr == NULL) {
+      uint res = expand_at(curr, 1);
+      if (res == 1) {
+        *expanded = true;
+        return curr;
+      }
+    } else {
+      if (hr->is_free()) {
+        *expanded = false;
+        return curr;
+      }
+    }
+    if (curr == 0) {
+      return G1_NO_HRM_INDEX;
+    }
+    curr--;
+  }
+}
+
+bool HeapRegionManager::allocate_containing_regions(MemRegion range, size_t* commit_count) {
+  size_t commits = 0;
+  uint start_index = (uint)_regions.get_index_by_address(range.start());
+  uint last_index = (uint)_regions.get_index_by_address(range.last());
+
+  // Ensure that each G1 region in the range is free, returning false if not.
+  // Commit those that are not yet available, and keep count.
+  for (uint curr_index = start_index; curr_index <= last_index; curr_index++) {
+    if (!is_available(curr_index)) {
+      commits++;
+      expand_at(curr_index, 1);
+    }
+    HeapRegion* curr_region  = _regions.get_by_index(curr_index);
+    if (!curr_region->is_free()) {
+      return false;
+    }
+  }
+
+  allocate_free_regions_starting_at(start_index, (last_index - start_index) + 1);
+  *commit_count = commits;
+  return true;
+}
+
 void HeapRegionManager::par_iterate(HeapRegionClosure* blk, uint worker_id, HeapRegionClaimer* hrclaimer, bool concurrent) const {
   const uint start_index = hrclaimer->start_region_for_worker(worker_id);
 

hotspot/src/share/vm/gc/g1/heapRegionManager.hpp

@@ -221,6 +221,16 @@ public:
 
   HeapRegion* next_region_in_heap(const HeapRegion* r) const;
 
+  // Find the highest free or uncommitted region in the reserved heap,
+  // and if uncommitted, commit it. If none are available, return G1_NO_HRM_INDEX.
+  // Set the 'expanded' boolean true if a new region was committed.
+  uint find_highest_free(bool* expanded);
+
+  // Allocate the regions that contain the address range specified, committing the
+  // regions if necessary. Return false if any of the regions is already committed
+  // and not free, and return the number of regions newly committed in commit_count.
+  bool allocate_containing_regions(MemRegion range, size_t* commit_count);
+
   // Apply blk->doHeapRegion() on all committed regions in address order,
   // terminating the iteration early if doHeapRegion() returns true.
   void iterate(HeapRegionClosure* blk) const;

hotspot/src/share/vm/gc/g1/heapRegionSet.cpp

@@ -42,7 +42,8 @@ void HeapRegionSetBase::verify_region(HeapRegion* hr) {
   assert(hr->is_humongous() == regions_humongous(), err_msg("Wrong humongous state for region %u and set %s", hr->hrm_index(), name()));
   assert(hr->is_free() == regions_free(), err_msg("Wrong free state for region %u and set %s", hr->hrm_index(), name()));
   assert(!hr->is_free() || hr->is_empty(), err_msg("Free region %u is not empty for set %s", hr->hrm_index(), name()));
-  assert(!hr->is_empty() || hr->is_free(), err_msg("Empty region %u is not free for set %s", hr->hrm_index(), name()));
+  assert(!hr->is_empty() || hr->is_free() || hr->is_archive(),
+         err_msg("Empty region %u is not free or archive for set %s", hr->hrm_index(), name()));
   assert(hr->rem_set()->verify_ready_for_par_iteration(), err_msg("Wrong iteration state %u", hr->hrm_index()));
 }
 #endif

hotspot/src/share/vm/gc/g1/heapRegionType.cpp

@@ -33,6 +33,7 @@ bool HeapRegionType::is_valid(Tag tag) {
     case StartsHumongousTag:
     case ContinuesHumongousTag:
     case OldTag:
+    case ArchiveTag:
       return true;
   }
   return false;
@@ -47,6 +48,7 @@ const char* HeapRegionType::get_str() const {
     case StartsHumongousTag:    return "HUMS";
     case ContinuesHumongousTag: return "HUMC";
     case OldTag:                return "OLD";
+    case ArchiveTag:            return "ARC";
   }
   ShouldNotReachHere();
   // keep some compilers happy
@@ -62,6 +64,7 @@ const char* HeapRegionType::get_short_str() const {
     case StartsHumongousTag:    return "HS";
     case ContinuesHumongousTag: return "HC";
     case OldTag:                return "O";
+    case ArchiveTag:            return "A";
   }
   ShouldNotReachHere();
   // keep some compilers happy

hotspot/src/share/vm/gc/g1/heapRegionType.hpp

@@ -44,15 +44,18 @@ private:
   //
   // 0000 0 [ 0] Free
   //
-  // 0001 0      Young Mask
+  // 0001 0 [ 2] Young Mask
   // 0001 0 [ 2] Eden
   // 0001 1 [ 3] Survivor
   //
-  // 0010 0      Humongous Mask
+  // 0010 0 [ 4] Humongous Mask
-  // 0010 0 [ 4] Starts Humongous
+  // 0100 0 [ 8] Pinned Mask
-  // 0010 1 [ 5] Continues Humongous
+  // 0110 0 [12] Starts Humongous
+  // 0110 1 [13] Continues Humongous
   //
-  // 01000 [ 8] Old
+  // 1000 0 [16] Old Mask
+  //
+  // 1100 0 [24] Archive
   typedef enum {
     FreeTag               = 0,
 
@@ -61,10 +64,14 @@ private:
     SurvTag               = YoungMask + 1,
 
     HumongousMask         = 4,
-    StartsHumongousTag    = HumongousMask,
+    PinnedMask            = 8,
-    ContinuesHumongousTag = HumongousMask + 1,
+    StartsHumongousTag    = HumongousMask | PinnedMask,
+    ContinuesHumongousTag = HumongousMask | PinnedMask + 1,
 
-    OldTag                = 8
+    OldMask               = 16,
+    OldTag                = OldMask,
+
+    ArchiveTag            = PinnedMask | OldMask
   } Tag;
 
   volatile Tag _tag;
@@ -108,7 +115,13 @@ public:
   bool is_starts_humongous()    const { return get() == StartsHumongousTag;    }
   bool is_continues_humongous() const { return get() == ContinuesHumongousTag; }
 
-  bool is_old() const { return get() == OldTag; }
+  bool is_archive() const { return get() == ArchiveTag; }
+
+  // is_old regions may or may not also be pinned
+  bool is_old() const { return (get() & OldMask) != 0; }
+
+  // is_pinned regions may be archive or humongous
+  bool is_pinned() const { return (get() & PinnedMask) != 0; }
 
   // Setters
 
@@ -123,6 +136,8 @@ public:
 
   void set_old() { set(OldTag); }
 
+  void set_archive() { set_from(ArchiveTag, FreeTag); }
+
   // Misc
 
   const char* get_str() const;

hotspot/src/share/vm/gc/serial/markSweep.cpp

@@ -313,7 +313,7 @@ void MarkSweep::restore_marks() {
 
 MarkSweep::IsAliveClosure   MarkSweep::is_alive;
 
-bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked(); }
+bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked() || is_archive_object(p); }
 
 MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
 

hotspot/src/share/vm/gc/serial/markSweep.hpp

@@ -147,6 +147,9 @@ class MarkSweep : AllStatic {
   // Reference Processing
   static ReferenceProcessor* const ref_processor() { return _ref_processor; }
 
+  // Archive Object handling
+  static inline bool is_archive_object(oop object);
+
   static STWGCTimer* gc_timer() { return _gc_timer; }
   static SerialOldTracer* gc_tracer() { return _gc_tracer; }
 

hotspot/src/share/vm/gc/serial/markSweep.inline.hpp

@@ -37,6 +37,7 @@
 #include "utilities/stack.inline.hpp"
 #if INCLUDE_ALL_GCS
 #include "gc/g1/g1StringDedup.hpp"
+#include "gc/g1/g1MarkSweep.hpp"
 #endif // INCLUDE_ALL_GCS
 
 inline void MarkSweep::mark_object(oop obj) {
@@ -57,6 +58,15 @@ inline void MarkSweep::mark_object(oop obj) {
   }
 }
 
+inline bool MarkSweep::is_archive_object(oop object) {
+#if INCLUDE_ALL_GCS
+  return (G1MarkSweep::archive_check_enabled() &&
+          G1MarkSweep::in_archive_range(object));
+#else
+  return false;
+#endif
+}
+
 inline void MarkSweep::follow_klass(Klass* klass) {
   oop op = klass->klass_holder();
   MarkSweep::mark_and_push(&op);
@@ -74,7 +84,8 @@ template <class T> inline void MarkSweep::follow_root(T* p) {
   T heap_oop = oopDesc::load_heap_oop(p);
   if (!oopDesc::is_null(heap_oop)) {
     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
-    if (!obj->mark()->is_marked()) {
+    if (!obj->mark()->is_marked() &&
+        !is_archive_object(obj)) {
       mark_object(obj);
       follow_object(obj);
     }
@@ -87,7 +98,8 @@ template <class T> inline void MarkSweep::mark_and_push(T* p) {
   T heap_oop = oopDesc::load_heap_oop(p);
   if (!oopDesc::is_null(heap_oop)) {
     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
-    if (!obj->mark()->is_marked()) {
+    if (!obj->mark()->is_marked() &&
+        !is_archive_object(obj)) {
       mark_object(obj);
       _marking_stack.push(obj);
     }
@@ -111,18 +123,21 @@ template <class T> inline void MarkSweep::adjust_pointer(T* p) {
     assert(Universe::heap()->is_in(obj), "should be in heap");
 
     oop new_obj = oop(obj->mark()->decode_pointer());
-    assert(new_obj != NULL ||                         // is forwarding ptr?
+    assert(is_archive_object(obj) ||                  // no forwarding of archive objects
+           new_obj != NULL ||                         // is forwarding ptr?
            obj->mark() == markOopDesc::prototype() || // not gc marked?
            (UseBiasedLocking && obj->mark()->has_bias_pattern()),
            // not gc marked?
            "should be forwarded");
     if (new_obj != NULL) {
+      if (!is_archive_object(obj)) {
         assert(Universe::heap()->is_in_reserved(new_obj),
               "should be in object space");
         oopDesc::encode_store_heap_oop_not_null(p, new_obj);
       }
     }
   }
+}
 
 template <class T> inline void MarkSweep::KeepAliveClosure::do_oop_work(T* p) {
   mark_and_push(p);

hotspot/src/share/vm/gc/shared/collectedHeap.hpp

@@ -88,9 +88,6 @@ class CollectedHeap : public CHeapObj<mtInternal> {
   static int       _fire_out_of_memory_count;
 #endif
 
-  // Used for filler objects (static, but initialized in ctor).
-  static size_t _filler_array_max_size;
-
   GCHeapLog* _gc_heap_log;
 
   // Used in support of ReduceInitialCardMarks; only consulted if COMPILER2 is being used
@@ -102,6 +99,9 @@ class CollectedHeap : public CHeapObj<mtInternal> {
   BarrierSet* _barrier_set;
   bool _is_gc_active;
 
+  // Used for filler objects (static, but initialized in ctor).
+  static size_t _filler_array_max_size;
+
   unsigned int _total_collections;          // ... started
   unsigned int _total_full_collections;     // ... started
   NOT_PRODUCT(volatile size_t _promotion_failure_alot_count;)