--- a/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp Tue Aug 26 09:36:53 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp Wed Aug 27 10:51:08 2014 +0200
@@ -32,13 +32,6 @@
-void G1BlockOffsetSharedArrayMappingChangedListener::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.
-}
-
//////////////////////////////////////////////////////////////////////
// G1BlockOffsetSharedArray
//////////////////////////////////////////////////////////////////////
@@ -72,26 +65,16 @@
return (delta & right_n_bits(LogN_words)) == (size_t)NoBits;
}
-void G1BlockOffsetSharedArray::set_offset_array(HeapWord* left, HeapWord* right, u_char offset) {
- set_offset_array(index_for(left), index_for(right -1), offset);
-}
-
//////////////////////////////////////////////////////////////////////
// G1BlockOffsetArray
//////////////////////////////////////////////////////////////////////
G1BlockOffsetArray::G1BlockOffsetArray(G1BlockOffsetSharedArray* array,
- MemRegion mr, bool init_to_zero) :
+ MemRegion mr) :
G1BlockOffsetTable(mr.start(), mr.end()),
_unallocated_block(_bottom),
- _array(array), _gsp(NULL),
- _init_to_zero(init_to_zero) {
+ _array(array), _gsp(NULL) {
assert(_bottom <= _end, "arguments out of order");
- if (!_init_to_zero) {
- // initialize cards to point back to mr.start()
- set_remainder_to_point_to_start(mr.start() + N_words, mr.end());
- _array->set_offset_array(0, 0); // set first card to 0
- }
}
void G1BlockOffsetArray::set_space(G1OffsetTableContigSpace* sp) {
@@ -181,93 +164,6 @@
DEBUG_ONLY(check_all_cards(start_card, end_card);)
}
-// The block [blk_start, blk_end) has been allocated;
-// adjust the block offset table to represent this information;
-// right-open interval: [blk_start, blk_end)
-void
-G1BlockOffsetArray::alloc_block(HeapWord* blk_start, HeapWord* blk_end) {
- mark_block(blk_start, blk_end);
- allocated(blk_start, blk_end);
-}
-
-// Adjust BOT to show that a previously whole block has been split
-// into two.
-void G1BlockOffsetArray::split_block(HeapWord* blk, size_t blk_size,
- size_t left_blk_size) {
- // Verify that the BOT shows [blk, blk + blk_size) to be one block.
- verify_single_block(blk, blk_size);
- // Update the BOT to indicate that [blk + left_blk_size, blk + blk_size)
- // is one single block.
- mark_block(blk + left_blk_size, blk + blk_size);
-}
-
-
-// Action_mark - update the BOT for the block [blk_start, blk_end).
-// Current typical use is for splitting a block.
-// Action_single - update the BOT for an allocation.
-// Action_verify - BOT verification.
-void G1BlockOffsetArray::do_block_internal(HeapWord* blk_start,
- HeapWord* blk_end,
- Action action) {
- assert(Universe::heap()->is_in_reserved(blk_start),
- "reference must be into the heap");
- assert(Universe::heap()->is_in_reserved(blk_end-1),
- "limit must be within the heap");
- // This is optimized to make the test fast, assuming we only rarely
- // cross boundaries.
- uintptr_t end_ui = (uintptr_t)(blk_end - 1);
- uintptr_t start_ui = (uintptr_t)blk_start;
- // Calculate the last card boundary preceding end of blk
- intptr_t boundary_before_end = (intptr_t)end_ui;
- clear_bits(boundary_before_end, right_n_bits(LogN));
- if (start_ui <= (uintptr_t)boundary_before_end) {
- // blk starts at or crosses a boundary
- // Calculate index of card on which blk begins
- size_t start_index = _array->index_for(blk_start);
- // Index of card on which blk ends
- size_t end_index = _array->index_for(blk_end - 1);
- // Start address of card on which blk begins
- HeapWord* boundary = _array->address_for_index(start_index);
- assert(boundary <= blk_start, "blk should start at or after boundary");
- if (blk_start != boundary) {
- // blk starts strictly after boundary
- // adjust card boundary and start_index forward to next card
- boundary += N_words;
- start_index++;
- }
- assert(start_index <= end_index, "monotonicity of index_for()");
- assert(boundary <= (HeapWord*)boundary_before_end, "tautology");
- switch (action) {
- case Action_mark: {
- if (init_to_zero()) {
- _array->set_offset_array(start_index, boundary, blk_start);
- break;
- } // Else fall through to the next case
- }
- case Action_single: {
- _array->set_offset_array(start_index, boundary, blk_start);
- // We have finished marking the "offset card". We need to now
- // mark the subsequent cards that this blk spans.
- if (start_index < end_index) {
- HeapWord* rem_st = _array->address_for_index(start_index) + N_words;
- HeapWord* rem_end = _array->address_for_index(end_index) + N_words;
- set_remainder_to_point_to_start(rem_st, rem_end);
- }
- break;
- }
- case Action_check: {
- _array->check_offset_array(start_index, boundary, blk_start);
- // We have finished checking the "offset card". We need to now
- // check the subsequent cards that this blk spans.
- check_all_cards(start_index + 1, end_index);
- break;
- }
- default:
- ShouldNotReachHere();
- }
- }
-}
-
// The card-interval [start_card, end_card] is a closed interval; this
// is an expensive check -- use with care and only under protection of
// suitable flag.
@@ -306,25 +202,6 @@
}
}
-// The range [blk_start, blk_end) represents a single contiguous block
-// of storage; modify the block offset table to represent this
-// information; Right-open interval: [blk_start, blk_end)
-// NOTE: this method does _not_ adjust _unallocated_block.
-void
-G1BlockOffsetArray::single_block(HeapWord* blk_start, HeapWord* blk_end) {
- do_block_internal(blk_start, blk_end, Action_single);
-}
-
-// Mark the BOT such that if [blk_start, blk_end) straddles a card
-// boundary, the card following the first such boundary is marked
-// with the appropriate offset.
-// NOTE: this method does _not_ adjust _unallocated_block or
-// any cards subsequent to the first one.
-void
-G1BlockOffsetArray::mark_block(HeapWord* blk_start, HeapWord* blk_end) {
- do_block_internal(blk_start, blk_end, Action_mark);
-}
-
HeapWord* G1BlockOffsetArray::block_start_unsafe(const void* addr) {
assert(_bottom <= addr && addr < _end,
"addr must be covered by this Array");
@@ -397,57 +274,13 @@
return forward_to_block_containing_addr_const(q, n, addr);
}
-HeapWord* G1BlockOffsetArray::block_start_careful(const void* addr) const {
- assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
-
- assert(_bottom <= addr && addr < _end,
- "addr must be covered by this Array");
- // Must read this exactly once because it can be modified by parallel
- // allocation.
- HeapWord* ub = _unallocated_block;
- if (BlockOffsetArrayUseUnallocatedBlock && addr >= ub) {
- assert(ub < _end, "tautology (see above)");
- return ub;
- }
-
- // Otherwise, find the block start using the table, but taking
- // care (cf block_start_unsafe() above) not to parse any objects/blocks
- // on the cards themselves.
- size_t index = _array->index_for(addr);
- assert(_array->address_for_index(index) == addr,
- "arg should be start of card");
-
- HeapWord* q = (HeapWord*)addr;
- uint offset;
- do {
- offset = _array->offset_array(index--);
- q -= offset;
- } while (offset == N_words);
- assert(q <= addr, "block start should be to left of arg");
- return q;
-}
-
// Note that the committed size of the covered space may have changed,
// so the table size might also wish to change.
void G1BlockOffsetArray::resize(size_t new_word_size) {
HeapWord* new_end = _bottom + new_word_size;
- if (_end < new_end && !init_to_zero()) {
- // verify that the old and new boundaries are also card boundaries
- assert(_array->is_card_boundary(_end),
- "_end not a card boundary");
- assert(_array->is_card_boundary(new_end),
- "new _end would not be a card boundary");
- // set all the newly added cards
- _array->set_offset_array(_end, new_end, N_words);
- }
_end = new_end; // update _end
}
-void G1BlockOffsetArray::set_region(MemRegion mr) {
- _bottom = mr.start();
- _end = mr.end();
-}
-
//
// threshold_
// | _index_
@@ -606,7 +439,7 @@
G1BlockOffsetArrayContigSpace::
G1BlockOffsetArrayContigSpace(G1BlockOffsetSharedArray* array,
MemRegion mr) :
- G1BlockOffsetArray(array, mr, true)
+ G1BlockOffsetArray(array, mr)
{
_next_offset_threshold = NULL;
_next_offset_index = 0;
@@ -641,15 +474,6 @@
return _next_offset_threshold;
}
-void G1BlockOffsetArrayContigSpace::zero_bottom_entry() {
- assert(!Universe::heap()->is_in_reserved(_array->_offset_array),
- "just checking");
- size_t bottom_index = _array->index_for(_bottom);
- assert(_array->address_for_index(bottom_index) == _bottom,
- "Precondition of call");
- _array->set_offset_array(bottom_index, 0);
-}
-
void
G1BlockOffsetArrayContigSpace::set_for_starts_humongous(HeapWord* new_top) {
assert(new_top <= _end, "_end should have already been updated");
--- a/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp Tue Aug 26 09:36:53 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp Wed Aug 27 10:51:08 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);
--- a/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp Tue Aug 26 09:36:53 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp Wed Aug 27 10:51:08 2014 +0200
@@ -91,13 +91,6 @@
}
}
-void G1BlockOffsetSharedArray::check_offset_array(size_t index, HeapWord* high, HeapWord* low) const {
- check_index(index, "index out of range");
- assert(high >= low, "addresses out of order");
- check_offset(pointer_delta(high, low), "offset too large");
- assert(_offset_array[index] == pointer_delta(high, low), "Wrong offset");
-}
-
// Variant of index_for that does not check the index for validity.
inline size_t G1BlockOffsetSharedArray::index_for_raw(const void* p) const {
return pointer_delta((char*)p, _reserved.start(), sizeof(char)) >> LogN;
@@ -193,28 +186,4 @@
return q;
}
-//////////////////////////////////////////////////////////////////////////
-// BlockOffsetArrayNonContigSpace inlines
-//////////////////////////////////////////////////////////////////////////
-inline void G1BlockOffsetArray::freed(HeapWord* blk_start, HeapWord* blk_end) {
- // Verify that the BOT shows [blk_start, blk_end) to be one block.
- verify_single_block(blk_start, blk_end);
- // adjust _unallocated_block upward or downward
- // as appropriate
- if (BlockOffsetArrayUseUnallocatedBlock) {
- assert(_unallocated_block <= _end,
- "Inconsistent value for _unallocated_block");
- if (blk_end >= _unallocated_block && blk_start <= _unallocated_block) {
- // CMS-specific note: a block abutting _unallocated_block to
- // its left is being freed, a new block is being added or
- // we are resetting following a compaction
- _unallocated_block = blk_start;
- }
- }
-}
-
-inline void G1BlockOffsetArray::freed(HeapWord* blk, size_t size) {
- freed(blk, blk + size);
-}
-
#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp Tue Aug 26 09:36:53 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp Wed Aug 27 10:51:08 2014 +0200
@@ -322,29 +322,6 @@
return false;
}
-HeapWord* HeapRegion::next_block_start_careful(HeapWord* addr) {
- HeapWord* low = addr;
- HeapWord* high = end();
- while (low < high) {
- size_t diff = pointer_delta(high, low);
- // Must add one below to bias toward the high amount. Otherwise, if
- // "high" were at the desired value, and "low" were one less, we
- // would not converge on "high". This is not symmetric, because
- // we set "high" to a block start, which might be the right one,
- // which we don't do for "low".
- HeapWord* middle = low + (diff+1)/2;
- if (middle == high) return high;
- HeapWord* mid_bs = block_start_careful(middle);
- if (mid_bs < addr) {
- low = middle;
- } else {
- high = mid_bs;
- }
- }
- assert(low == high && low >= addr, "Didn't work.");
- return low;
-}
-
HeapRegion::HeapRegion(uint hrm_index,
G1BlockOffsetSharedArray* sharedOffsetArray,
MemRegion mr) :
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Tue Aug 26 09:36:53 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Wed Aug 27 10:51:08 2014 +0200
@@ -206,10 +206,6 @@
_offsets.reset_bot();
}
- void update_bot_for_object(HeapWord* start, size_t word_size) {
- _offsets.alloc_block(start, word_size);
- }
-
void print_bot_on(outputStream* out) {
_offsets.print_on(out);
}
@@ -737,18 +733,6 @@
bool filter_young,
jbyte* card_ptr);
- // A version of block start that is guaranteed to find *some* block
- // boundary at or before "p", but does not object iteration, and may
- // therefore be used safely when the heap is unparseable.
- HeapWord* block_start_careful(const void* p) const {
- return _offsets.block_start_careful(p);
- }
-
- // Requires that "addr" is within the region. Returns the start of the
- // first ("careful") block that starts at or after "addr", or else the
- // "end" of the region if there is no such block.
- HeapWord* next_block_start_careful(HeapWord* addr);
-
size_t recorded_rs_length() const { return _recorded_rs_length; }
double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; }
size_t predicted_bytes_to_copy() const { return _predicted_bytes_to_copy; }