--- a/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp	Mon Sep 29 09:59:23 2014 +0200
+++ b/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp	Fri Oct 10 15:45:45 2014 +0200
@@ -109,7 +109,12 @@
 
 class G1BlockOffsetSharedArrayMappingChangedListener : public G1MappingChangedListener {
  public:
-  virtual void on_commit(uint start_idx, size_t num_regions);
+  virtual void on_commit(uint start_idx, size_t num_regions) {
+    // Nothing to do. The BOT is hard-wired to be part of the HeapRegion, and we cannot
+    // retrieve it here since this would cause firing of several asserts. The code
+    // executed after commit of a region already needs to do some re-initialization of
+    // the HeapRegion, so we combine that.
+  }
 };
 
 // This implementation of "G1BlockOffsetTable" divides the covered region
@@ -153,8 +158,6 @@
   // For performance these have to devolve to array accesses in product builds.
   inline u_char offset_array(size_t index) const;
 
-  void set_offset_array(HeapWord* left, HeapWord* right, u_char offset);
-
   void set_offset_array_raw(size_t index, u_char offset) {
     _offset_array[index] = offset;
   }
@@ -165,8 +168,6 @@
 
   inline void set_offset_array(size_t left, size_t right, u_char offset);
 
-  inline void check_offset_array(size_t index, HeapWord* high, HeapWord* low) const;
-
   bool is_card_boundary(HeapWord* p) const;
 
 public:
@@ -193,8 +194,6 @@
   // G1BlockOffsetTable(s) to initialize cards.
   G1BlockOffsetSharedArray(MemRegion heap, G1RegionToSpaceMapper* storage);
 
-  void set_bottom(HeapWord* new_bottom);
-
   // Return the appropriate index into "_offset_array" for "p".
   inline size_t index_for(const void* p) const;
   inline size_t index_for_raw(const void* p) const;
@@ -220,14 +219,6 @@
     LogN    = G1BlockOffsetSharedArray::LogN
   };
 
-  // The following enums are used by do_block_helper
-  enum Action {
-    Action_single,      // BOT records a single block (see single_block())
-    Action_mark,        // BOT marks the start of a block (see mark_block())
-    Action_check        // Check that BOT records block correctly
-                        // (see verify_single_block()).
-  };
-
   // This is the array, which can be shared by several BlockOffsetArray's
   // servicing different
   G1BlockOffsetSharedArray* _array;
@@ -235,10 +226,6 @@
   // The space that owns this subregion.
   G1OffsetTableContigSpace* _gsp;
 
-  // If true, array entries are initialized to 0; otherwise, they are
-  // initialized to point backwards to the beginning of the covered region.
-  bool _init_to_zero;
-
   // The portion [_unallocated_block, _sp.end()) of the space that
   // is a single block known not to contain any objects.
   // NOTE: See BlockOffsetArrayUseUnallocatedBlock flag.
@@ -253,9 +240,6 @@
   // that is closed: [start_index, end_index]
   void set_remainder_to_point_to_start_incl(size_t start, size_t end);
 
-  // A helper function for BOT adjustment/verification work
-  void do_block_internal(HeapWord* blk_start, HeapWord* blk_end, Action action);
-
 protected:
 
   G1OffsetTableContigSpace* gsp() const { return _gsp; }
@@ -303,11 +287,9 @@
 
 public:
   // The space may not have it's bottom and top set yet, which is why the
-  // region is passed as a parameter.  If "init_to_zero" is true, the
-  // elements of the array are initialized to zero.  Otherwise, they are
-  // initialized to point backwards to the beginning.
-  G1BlockOffsetArray(G1BlockOffsetSharedArray* array, MemRegion mr,
-                     bool init_to_zero);
+  // region is passed as a parameter. The elements of the array are
+  // initialized to zero.
+  G1BlockOffsetArray(G1BlockOffsetSharedArray* array, MemRegion mr);
 
   // Note: this ought to be part of the constructor, but that would require
   // "this" to be passed as a parameter to a member constructor for
@@ -315,114 +297,19 @@
   // This would be legal C++, but MS VC++ doesn't allow it.
   void set_space(G1OffsetTableContigSpace* sp);
 
-  // Resets the covered region to the given "mr".
-  void set_region(MemRegion mr);
-
   // Resets the covered region to one with the same _bottom as before but
   // the "new_word_size".
   void resize(size_t new_word_size);
 
-  // These must be guaranteed to work properly (i.e., do nothing)
-  // when "blk_start" ("blk" for second version) is "NULL".
-  virtual void alloc_block(HeapWord* blk_start, HeapWord* blk_end);
-  virtual void alloc_block(HeapWord* blk, size_t size) {
-    alloc_block(blk, blk + size);
-  }
-
-  // The following methods are useful and optimized for a
-  // general, non-contiguous space.
-
-  // Given a block [blk_start, blk_start + full_blk_size), and
-  // a left_blk_size < full_blk_size, adjust the BOT to show two
-  // blocks [blk_start, blk_start + left_blk_size) and
-  // [blk_start + left_blk_size, blk_start + full_blk_size).
-  // It is assumed (and verified in the non-product VM) that the
-  // BOT was correct for the original block.
-  void split_block(HeapWord* blk_start, size_t full_blk_size,
-                           size_t left_blk_size);
-
-  // Adjust the BOT to show that it has a single block in the
-  // range [blk_start, blk_start + size). All necessary BOT
-  // cards are adjusted, but _unallocated_block isn't.
-  void single_block(HeapWord* blk_start, HeapWord* blk_end);
-  void single_block(HeapWord* blk, size_t size) {
-    single_block(blk, blk + size);
-  }
-
-  // Adjust BOT to show that it has a block in the range
-  // [blk_start, blk_start + size). Only the first card
-  // of BOT is touched. It is assumed (and verified in the
-  // non-product VM) that the remaining cards of the block
-  // are correct.
-  void mark_block(HeapWord* blk_start, HeapWord* blk_end);
-  void mark_block(HeapWord* blk, size_t size) {
-    mark_block(blk, blk + size);
-  }
-
-  // Adjust _unallocated_block to indicate that a particular
-  // block has been newly allocated or freed. It is assumed (and
-  // verified in the non-product VM) that the BOT is correct for
-  // the given block.
-  inline void allocated(HeapWord* blk_start, HeapWord* blk_end) {
-    // Verify that the BOT shows [blk, blk + blk_size) to be one block.
-    verify_single_block(blk_start, blk_end);
-    if (BlockOffsetArrayUseUnallocatedBlock) {
-      _unallocated_block = MAX2(_unallocated_block, blk_end);
-    }
-  }
-
-  inline void allocated(HeapWord* blk, size_t size) {
-    allocated(blk, blk + size);
-  }
-
-  inline void freed(HeapWord* blk_start, HeapWord* blk_end);
-
-  inline void freed(HeapWord* blk, size_t size);
-
   virtual HeapWord* block_start_unsafe(const void* addr);
   virtual HeapWord* block_start_unsafe_const(const void* addr) const;
 
-  // Requires "addr" to be the start of a card and returns the
-  // start of the block that contains the given address.
-  HeapWord* block_start_careful(const void* addr) const;
-
-  // If true, initialize array slots with no allocated blocks to zero.
-  // Otherwise, make them point back to the front.
-  bool init_to_zero() { return _init_to_zero; }
-
-  // Verification & debugging - ensure that the offset table reflects the fact
-  // that the block [blk_start, blk_end) or [blk, blk + size) is a
-  // single block of storage. NOTE: can;t const this because of
-  // call to non-const do_block_internal() below.
-  inline void verify_single_block(HeapWord* blk_start, HeapWord* blk_end) {
-    if (VerifyBlockOffsetArray) {
-      do_block_internal(blk_start, blk_end, Action_check);
-    }
-  }
-
-  inline void verify_single_block(HeapWord* blk, size_t size) {
-    verify_single_block(blk, blk + size);
-  }
-
   // Used by region verification. Checks that the contents of the
   // BOT reflect that there's a single object that spans the address
   // range [obj_start, obj_start + word_size); returns true if this is
   // the case, returns false if it's not.
   bool verify_for_object(HeapWord* obj_start, size_t word_size) const;
 
-  // Verify that the given block is before _unallocated_block
-  inline void verify_not_unallocated(HeapWord* blk_start,
-                                     HeapWord* blk_end) const {
-    if (BlockOffsetArrayUseUnallocatedBlock) {
-      assert(blk_start < blk_end, "Block inconsistency?");
-      assert(blk_end <= _unallocated_block, "_unallocated_block problem");
-    }
-  }
-
-  inline void verify_not_unallocated(HeapWord* blk, size_t size) const {
-    verify_not_unallocated(blk, blk + size);
-  }
-
   void check_all_cards(size_t left_card, size_t right_card) const;
 
   virtual void print_on(outputStream* out) PRODUCT_RETURN;
@@ -445,14 +332,12 @@
                       blk_start, blk_end);
   }
 
-  // Variant of zero_bottom_entry that does not check for availability of the
+  // Zero out the entry for _bottom (offset will be zero). Does not check for availability of the
   // memory first.
   void zero_bottom_entry_raw();
   // Variant of initialize_threshold that does not check for availability of the
   // memory first.
   HeapWord* initialize_threshold_raw();
-  // Zero out the entry for _bottom (offset will be zero).
-  void zero_bottom_entry();
  public:
   G1BlockOffsetArrayContigSpace(G1BlockOffsetSharedArray* array, MemRegion mr);