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8055816: Remove dead code in g1BlockOffsetTable

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Reviewed-by: tschatzl, mgerdin
This commit is contained in:
Bengt Rutisson 2014-08-27 10:51:08 +02:00
parent 9086b5795f
commit bbe82cb85b
5 changed files with 13 additions and 374 deletions
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135
hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp
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@ -109,7 +109,12 @@ public:
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 @@ private:
// 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 @@ private:
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 @@ public:
// 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 @@ private:
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 @@ private:
// 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 @@ private:
// 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 @@ protected:
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 @@ public:
// 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 @@ class G1BlockOffsetArrayContigSpace: public G1BlockOffsetArray {
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);