jdk-sandbox: comparison hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp

equal deleted inserted replaced

-:e5e2b519fc11
+:9006b01ba3fd
 class ParallelCompactData
 {
 public:
 // Sizes are in HeapWords, unless indicated otherwise.
-static const size_t Log2ChunkSize;
+static const size_t Log2RegionSize;
-static const size_t ChunkSize;
+static const size_t RegionSize;
-static const size_t ChunkSizeBytes;
+static const size_t RegionSizeBytes;
-// Mask for the bits in a size_t to get an offset within a chunk.
+// Mask for the bits in a size_t to get an offset within a region.
-static const size_t ChunkSizeOffsetMask;
+static const size_t RegionSizeOffsetMask;
-// Mask for the bits in a pointer to get an offset within a chunk.
+// Mask for the bits in a pointer to get an offset within a region.
-static const size_t ChunkAddrOffsetMask;
+static const size_t RegionAddrOffsetMask;
-// Mask for the bits in a pointer to get the address of the start of a chunk.
+// Mask for the bits in a pointer to get the address of the start of a region.
-static const size_t ChunkAddrMask;
+static const size_t RegionAddrMask;
 static const size_t Log2BlockSize;
 static const size_t BlockSize;
 static const size_t BlockOffsetMask;
 static const size_t BlockMask;
-static const size_t BlocksPerChunk;
+static const size_t BlocksPerRegion;
-class ChunkData
+class RegionData
 {
 public:
-// Destination address of the chunk.
+// Destination address of the region.
 HeapWord* destination() const { return _destination; }
-// The first chunk containing data destined for this chunk.
+// The first region containing data destined for this region.
-size_t source_chunk() const { return _source_chunk; }
+size_t source_region() const { return _source_region; }
-// The object (if any) starting in this chunk and ending in a different
+// The object (if any) starting in this region and ending in a different
-// chunk that could not be updated during the main (parallel) compaction
+// region that could not be updated during the main (parallel) compaction
 // phase.  This is different from _partial_obj_addr, which is an object that
-// extends onto a source chunk.  However, the two uses do not overlap in
+// extends onto a source region.  However, the two uses do not overlap in
 // time, so the same field is used to save space.
 HeapWord* deferred_obj_addr() const { return _partial_obj_addr; }
-// The starting address of the partial object extending onto the chunk.
+// The starting address of the partial object extending onto the region.
 HeapWord* partial_obj_addr() const { return _partial_obj_addr; }
-// Size of the partial object extending onto the chunk (words).
+// Size of the partial object extending onto the region (words).
 size_t partial_obj_size() const { return _partial_obj_size; }
-// Size of live data that lies within this chunk due to objects that start
+// Size of live data that lies within this region due to objects that start
-// in this chunk (words).  This does not include the partial object
+// in this region (words).  This does not include the partial object
-// extending onto the chunk (if any), or the part of an object that extends
+// extending onto the region (if any), or the part of an object that extends
-// onto the next chunk (if any).
+// onto the next region (if any).
 size_t live_obj_size() const { return _dc_and_los & los_mask; }
-// Total live data that lies within the chunk (words).
+// Total live data that lies within the region (words).
 size_t data_size() const { return partial_obj_size() + live_obj_size(); }
-// The destination_count is the number of other chunks to which data from
+// The destination_count is the number of other regions to which data from
-// this chunk will be copied.  At the end of the summary phase, the valid
+// this region will be copied.  At the end of the summary phase, the valid
 // values of destination_count are
 //
-// 0 - data from the chunk will be compacted completely into itself, or the
+// 0 - data from the region will be compacted completely into itself, or the
-//     chunk is empty.  The chunk can be claimed and then filled.
+//     region is empty.  The region can be claimed and then filled.
-// 1 - data from the chunk will be compacted into 1 other chunk; some
+// 1 - data from the region will be compacted into 1 other region; some
-//     data from the chunk may also be compacted into the chunk itself.
+//     data from the region may also be compacted into the region itself.
-// 2 - data from the chunk will be copied to 2 other chunks.
+// 2 - data from the region will be copied to 2 other regions.
 //
-// During compaction as chunks are emptied, the destination_count is
+// During compaction as regions are emptied, the destination_count is
 // decremented (atomically) and when it reaches 0, it can be claimed and
 // then filled.
 //
-// A chunk is claimed for processing by atomically changing the
+// A region is claimed for processing by atomically changing the
-// destination_count to the claimed value (dc_claimed).  After a chunk has
+// destination_count to the claimed value (dc_claimed).  After a region has
 // been filled, the destination_count should be set to the completed value
 // (dc_completed).
 inline uint destination_count() const;
 inline uint destination_count_raw() const;
-// The location of the java heap data that corresponds to this chunk.
+// The location of the java heap data that corresponds to this region.
 inline HeapWord* data_location() const;
-// The highest address referenced by objects in this chunk.
+// The highest address referenced by objects in this region.
 inline HeapWord* highest_ref() const;
-// Whether this chunk is available to be claimed, has been claimed, or has
+// Whether this region is available to be claimed, has been claimed, or has
 // been completed.
 //
-// Minor subtlety:  claimed() returns true if the chunk is marked
+// Minor subtlety:  claimed() returns true if the region is marked
-// completed(), which is desirable since a chunk must be claimed before it
+// completed(), which is desirable since a region must be claimed before it
 // can be completed.
 bool available() const { return _dc_and_los < dc_one; }
 bool claimed() const   { return _dc_and_los >= dc_claimed; }
 bool completed() const { return _dc_and_los >= dc_completed; }
 // These are not atomic.
 void set_destination(HeapWord* addr)       { _destination = addr; }
-void set_source_chunk(size_t chunk)        { _source_chunk = chunk; }
+void set_source_region(size_t region)      { _source_region = region; }
 void set_deferred_obj_addr(HeapWord* addr) { _partial_obj_addr = addr; }
 void set_partial_obj_addr(HeapWord* addr)  { _partial_obj_addr = addr; }
 void set_partial_obj_size(size_t words)    {
-_partial_obj_size = (chunk_sz_t) words;
+_partial_obj_size = (region_sz_t) words;
 }
 inline void set_destination_count(uint count);
 inline void set_live_obj_size(size_t words);
 inline void set_data_location(HeapWord* addr);
 inline void set_highest_ref(HeapWord* addr);
 inline void decrement_destination_count();
 inline bool claim();
 private:
-// The type used to represent object sizes within a chunk.
+// The type used to represent object sizes within a region.
-typedef uint chunk_sz_t;
+typedef uint region_sz_t;
 // Constants for manipulating the _dc_and_los field, which holds both the
 // destination count and live obj size.  The live obj size lives at the
 // least significant end so no masking is necessary when adding.
-static const chunk_sz_t dc_shift;           // Shift amount.
+static const region_sz_t dc_shift;           // Shift amount.
-static const chunk_sz_t dc_mask;            // Mask for destination count.
+static const region_sz_t dc_mask;            // Mask for destination count.
-static const chunk_sz_t dc_one;             // 1, shifted appropriately.
+static const region_sz_t dc_one;             // 1, shifted appropriately.
-static const chunk_sz_t dc_claimed;         // Chunk has been claimed.
+static const region_sz_t dc_claimed;         // Region has been claimed.
-static const chunk_sz_t dc_completed;       // Chunk has been completed.
+static const region_sz_t dc_completed;       // Region has been completed.
-static const chunk_sz_t los_mask;           // Mask for live obj size.
+static const region_sz_t los_mask;           // Mask for live obj size.
-HeapWord*           _destination;
+HeapWord*            _destination;
-size_t              _source_chunk;
+size_t               _source_region;
-HeapWord*           _partial_obj_addr;
+HeapWord*            _partial_obj_addr;
-chunk_sz_t          _partial_obj_size;
+region_sz_t          _partial_obj_size;
-chunk_sz_t volatile _dc_and_los;
+region_sz_t volatile _dc_and_los;
 #ifdef ASSERT
 // These enable optimizations that are only partially implemented.  Use
 // debug builds to prevent the code fragments from breaking.
-HeapWord*           _data_location;
+HeapWord*            _data_location;
-HeapWord*           _highest_ref;
+HeapWord*            _highest_ref;
 #endif  // #ifdef ASSERT
 #ifdef ASSERT
 public:
-uint            _pushed;    // 0 until chunk is pushed onto a worker's stack
+uint            _pushed;   // 0 until region is pushed onto a worker's stack
 private:
 #endif
 };
 // 'Blocks' allow shorter sections of the bitmap to be searched.  Each Block
-// holds an offset, which is the amount of live data in the Chunk to the left
+// holds an offset, which is the amount of live data in the Region to the left
 // of the first live object in the Block.  This amount of live data will
 // include any object extending into the block. The first block in
-// a chunk does not include any partial object extending into the
+// a region does not include any partial object extending into the
-// the chunk.
+// the region.
 //
 // The offset also encodes the
 // 'parity' of the first 1 bit in the Block:  a positive offset means the
 // first 1 bit marks the start of an object, a negative offset means the first
 // 1 bit marks the end of an object.
 public:
 ParallelCompactData();
 bool initialize(MemRegion covered_region);
-size_t chunk_count() const { return _chunk_count; }
+size_t region_count() const { return _region_count; }
-// Convert chunk indices to/from ChunkData pointers.
+// Convert region indices to/from RegionData pointers.
-inline ChunkData* chunk(size_t chunk_idx) const;
+inline RegionData* region(size_t region_idx) const;
-inline size_t     chunk(const ChunkData* const chunk_ptr) const;
+inline size_t     region(const RegionData* const region_ptr) const;
-// Returns true if the given address is contained within the chunk
+// Returns true if the given address is contained within the region
-bool chunk_contains(size_t chunk_index, HeapWord* addr);
+bool region_contains(size_t region_index, HeapWord* addr);
 size_t block_count() const { return _block_count; }
 inline BlockData* block(size_t n) const;
-// Returns true if the given block is in the given chunk.
+// Returns true if the given block is in the given region.
-static bool chunk_contains_block(size_t chunk_index, size_t block_index);
+static bool region_contains_block(size_t region_index, size_t block_index);
 void add_obj(HeapWord* addr, size_t len);
 void add_obj(oop p, size_t len) { add_obj((HeapWord*)p, len); }
-// Fill in the chunks covering [beg, end) so that no data moves; i.e., the
+// Fill in the regions covering [beg, end) so that no data moves; i.e., the
-// destination of chunk n is simply the start of chunk n.  The argument beg
+// destination of region n is simply the start of region n.  The argument beg
-// must be chunk-aligned; end need not be.
+// must be region-aligned; end need not be.
 void summarize_dense_prefix(HeapWord* beg, HeapWord* end);
 bool summarize(HeapWord* target_beg, HeapWord* target_end,
 HeapWord* source_beg, HeapWord* source_end,
 HeapWord** target_next, HeapWord** source_next = 0);
 void clear();
-void clear_range(size_t beg_chunk, size_t end_chunk);
+void clear_range(size_t beg_region, size_t end_region);
 void clear_range(HeapWord* beg, HeapWord* end) {
-clear_range(addr_to_chunk_idx(beg), addr_to_chunk_idx(end));
+clear_range(addr_to_region_idx(beg), addr_to_region_idx(end));
 }
-// Return the number of words between addr and the start of the chunk
+// Return the number of words between addr and the start of the region
 // containing addr.
-inline size_t     chunk_offset(const HeapWord* addr) const;
+inline size_t     region_offset(const HeapWord* addr) const;
-// Convert addresses to/from a chunk index or chunk pointer.
+// Convert addresses to/from a region index or region pointer.
-inline size_t     addr_to_chunk_idx(const HeapWord* addr) const;
+inline size_t     addr_to_region_idx(const HeapWord* addr) const;
-inline ChunkData* addr_to_chunk_ptr(const HeapWord* addr) const;
+inline RegionData* addr_to_region_ptr(const HeapWord* addr) const;
-inline HeapWord*  chunk_to_addr(size_t chunk) const;
+inline HeapWord*  region_to_addr(size_t region) const;
-inline HeapWord*  chunk_to_addr(size_t chunk, size_t offset) const;
+inline HeapWord*  region_to_addr(size_t region, size_t offset) const;
-inline HeapWord*  chunk_to_addr(const ChunkData* chunk) const;
+inline HeapWord*  region_to_addr(const RegionData* region) const;
-inline HeapWord*  chunk_align_down(HeapWord* addr) const;
+inline HeapWord*  region_align_down(HeapWord* addr) const;
-inline HeapWord*  chunk_align_up(HeapWord* addr) const;
+inline HeapWord*  region_align_up(HeapWord* addr) const;
-inline bool       is_chunk_aligned(HeapWord* addr) const;
+inline bool       is_region_aligned(HeapWord* addr) const;
-// Analogous to chunk_offset() for blocks.
+// Analogous to region_offset() for blocks.
 size_t     block_offset(const HeapWord* addr) const;
 size_t     addr_to_block_idx(const HeapWord* addr) const;
 size_t     addr_to_block_idx(const oop obj) const {
 return addr_to_block_idx((HeapWord*) obj);
 }
 inline BlockData* addr_to_block_ptr(const HeapWord* addr) const;
 inline HeapWord*  block_to_addr(size_t block) const;
 // Return the address one past the end of the partial object.
-HeapWord* partial_obj_end(size_t chunk_idx) const;
+HeapWord* partial_obj_end(size_t region_idx) const;
 // Return the new location of the object p after the
 // the compaction.
 HeapWord* calc_new_pointer(HeapWord* addr);
 // Same as calc_new_pointer() using blocks.
 HeapWord* block_calc_new_pointer(HeapWord* addr);
-// Same as calc_new_pointer() using chunks.
+// Same as calc_new_pointer() using regions.
-HeapWord* chunk_calc_new_pointer(HeapWord* addr);
+HeapWord* region_calc_new_pointer(HeapWord* addr);
 HeapWord* calc_new_pointer(oop p) {
 return calc_new_pointer((HeapWord*) p);
 }
 // Return the updated address for the given klass
 klassOop calc_new_klass(klassOop);
 // Given a block returns true if the partial object for the
-// corresponding chunk ends in the block.  Returns false, otherwise
+// corresponding region ends in the block.  Returns false, otherwise
 // If there is no partial object, returns false.
 bool partial_obj_ends_in_block(size_t block_index);
 // Returns the block index for the block
 static size_t block_idx(BlockData* block);
 void verify_clear();
 #endif  // #ifdef ASSERT
 private:
 bool initialize_block_data(size_t region_size);
-bool initialize_chunk_data(size_t region_size);
+bool initialize_region_data(size_t region_size);
 PSVirtualSpace* create_vspace(size_t count, size_t element_size);
 private:
 HeapWord*       _region_start;
 #ifdef  ASSERT
 HeapWord*       _region_end;
 #endif  // #ifdef ASSERT
-PSVirtualSpace* _chunk_vspace;
+PSVirtualSpace* _region_vspace;
-ChunkData*      _chunk_data;
+RegionData*     _region_data;
-size_t          _chunk_count;
+size_t          _region_count;
 PSVirtualSpace* _block_vspace;
 BlockData*      _block_data;
 size_t          _block_count;
 };
 inline uint
-ParallelCompactData::ChunkData::destination_count_raw() const
+ParallelCompactData::RegionData::destination_count_raw() const
 {
 return _dc_and_los & dc_mask;
 }
 inline uint
-ParallelCompactData::ChunkData::destination_count() const
+ParallelCompactData::RegionData::destination_count() const
 {
 return destination_count_raw() >> dc_shift;
 }
 inline void
-ParallelCompactData::ChunkData::set_destination_count(uint count)
+ParallelCompactData::RegionData::set_destination_count(uint count)
 {
 assert(count <= (dc_completed >> dc_shift), "count too large");
-const chunk_sz_t live_sz = (chunk_sz_t) live_obj_size();
+const region_sz_t live_sz = (region_sz_t) live_obj_size();
 _dc_and_los = (count << dc_shift) | live_sz;
 }
-inline void ParallelCompactData::ChunkData::set_live_obj_size(size_t words)
+inline void ParallelCompactData::RegionData::set_live_obj_size(size_t words)
 {
 assert(words <= los_mask, "would overflow");
-_dc_and_los = destination_count_raw() | (chunk_sz_t)words;
+_dc_and_los = destination_count_raw() | (region_sz_t)words;
 }
-inline void ParallelCompactData::ChunkData::decrement_destination_count()
+inline void ParallelCompactData::RegionData::decrement_destination_count()
 {
 assert(_dc_and_los < dc_claimed, "already claimed");
 assert(_dc_and_los >= dc_one, "count would go negative");
 Atomic::add((int)dc_mask, (volatile int*)&_dc_and_los);
 }
-inline HeapWord* ParallelCompactData::ChunkData::data_location() const
+inline HeapWord* ParallelCompactData::RegionData::data_location() const
 {
 DEBUG_ONLY(return _data_location;)
 NOT_DEBUG(return NULL;)
 }
-inline HeapWord* ParallelCompactData::ChunkData::highest_ref() const
+inline HeapWord* ParallelCompactData::RegionData::highest_ref() const
 {
 DEBUG_ONLY(return _highest_ref;)
 NOT_DEBUG(return NULL;)
 }
-inline void ParallelCompactData::ChunkData::set_data_location(HeapWord* addr)
+inline void ParallelCompactData::RegionData::set_data_location(HeapWord* addr)
 {
 DEBUG_ONLY(_data_location = addr;)
 }
-inline void ParallelCompactData::ChunkData::set_completed()
+inline void ParallelCompactData::RegionData::set_completed()
 {
 assert(claimed(), "must be claimed first");
-_dc_and_los = dc_completed | (chunk_sz_t) live_obj_size();
+_dc_and_los = dc_completed | (region_sz_t) live_obj_size();
 }
-// MT-unsafe claiming of a chunk.  Should only be used during single threaded
+// MT-unsafe claiming of a region.  Should only be used during single threaded
 // execution.
-inline bool ParallelCompactData::ChunkData::claim_unsafe()
+inline bool ParallelCompactData::RegionData::claim_unsafe()
 {
 if (available()) {
 _dc_and_los |= dc_claimed;
 return true;
 }
 return false;
 }
-inline void ParallelCompactData::ChunkData::add_live_obj(size_t words)
+inline void ParallelCompactData::RegionData::add_live_obj(size_t words)
 {
 assert(words <= (size_t)los_mask - live_obj_size(), "overflow");
 Atomic::add((int) words, (volatile int*) &_dc_and_los);
 }
-inline void ParallelCompactData::ChunkData::set_highest_ref(HeapWord* addr)
+inline void ParallelCompactData::RegionData::set_highest_ref(HeapWord* addr)
 {
 #ifdef ASSERT
 HeapWord* tmp = _highest_ref;
 while (addr > tmp) {
 tmp = (HeapWord*)Atomic::cmpxchg_ptr(addr, &_highest_ref, tmp);
 }
 #endif  // #ifdef ASSERT
 }
-inline bool ParallelCompactData::ChunkData::claim()
+inline bool ParallelCompactData::RegionData::claim()
 {
 const int los = (int) live_obj_size();
 const int old = Atomic::cmpxchg(dc_claimed | los,
 (volatile int*) &_dc_and_los, los);
 return old == los;
 }
-inline ParallelCompactData::ChunkData*
+inline ParallelCompactData::RegionData*
-ParallelCompactData::chunk(size_t chunk_idx) const
+ParallelCompactData::region(size_t region_idx) const
 {
-assert(chunk_idx <= chunk_count(), "bad arg");
+assert(region_idx <= region_count(), "bad arg");
-return _chunk_data + chunk_idx;
+return _region_data + region_idx;
 }
 inline size_t
-ParallelCompactData::chunk(const ChunkData* const chunk_ptr) const
+ParallelCompactData::region(const RegionData* const region_ptr) const
 {
-assert(chunk_ptr >= _chunk_data, "bad arg");
+assert(region_ptr >= _region_data, "bad arg");
-assert(chunk_ptr <= _chunk_data + chunk_count(), "bad arg");
+assert(region_ptr <= _region_data + region_count(), "bad arg");
-return pointer_delta(chunk_ptr, _chunk_data, sizeof(ChunkData));
+return pointer_delta(region_ptr, _region_data, sizeof(RegionData));
 }
 inline ParallelCompactData::BlockData*
 ParallelCompactData::block(size_t n) const {
 assert(n < block_count(), "bad arg");
 return _block_data + n;
 }
 inline size_t
-ParallelCompactData::chunk_offset(const HeapWord* addr) const
+ParallelCompactData::region_offset(const HeapWord* addr) const
 {
 assert(addr >= _region_start, "bad addr");
 assert(addr <= _region_end, "bad addr");
-return (size_t(addr) & ChunkAddrOffsetMask) >> LogHeapWordSize;
+return (size_t(addr) & RegionAddrOffsetMask) >> LogHeapWordSize;
 }
 inline size_t
-ParallelCompactData::addr_to_chunk_idx(const HeapWord* addr) const
+ParallelCompactData::addr_to_region_idx(const HeapWord* addr) const
 {
 assert(addr >= _region_start, "bad addr");
 assert(addr <= _region_end, "bad addr");
-return pointer_delta(addr, _region_start) >> Log2ChunkSize;
+return pointer_delta(addr, _region_start) >> Log2RegionSize;
 }
-inline ParallelCompactData::ChunkData*
+inline ParallelCompactData::RegionData*
-ParallelCompactData::addr_to_chunk_ptr(const HeapWord* addr) const
+ParallelCompactData::addr_to_region_ptr(const HeapWord* addr) const
 {
-return chunk(addr_to_chunk_idx(addr));
+return region(addr_to_region_idx(addr));
 }
 inline HeapWord*
-ParallelCompactData::chunk_to_addr(size_t chunk) const
+ParallelCompactData::region_to_addr(size_t region) const
 {
-assert(chunk <= _chunk_count, "chunk out of range");
+assert(region <= _region_count, "region out of range");
-return _region_start + (chunk << Log2ChunkSize);
+return _region_start + (region << Log2RegionSize);
 }
 inline HeapWord*
-ParallelCompactData::chunk_to_addr(const ChunkData* chunk) const
+ParallelCompactData::region_to_addr(const RegionData* region) const
 {
-return chunk_to_addr(pointer_delta(chunk, _chunk_data, sizeof(ChunkData)));
+return region_to_addr(pointer_delta(region, _region_data,
+sizeof(RegionData)));
 }
 inline HeapWord*
-ParallelCompactData::chunk_to_addr(size_t chunk, size_t offset) const
+ParallelCompactData::region_to_addr(size_t region, size_t offset) const
 {
-assert(chunk <= _chunk_count, "chunk out of range");
+assert(region <= _region_count, "region out of range");
-assert(offset < ChunkSize, "offset too big");  // This may be too strict.
+assert(offset < RegionSize, "offset too big");  // This may be too strict.
-return chunk_to_addr(chunk) + offset;
+return region_to_addr(region) + offset;
 }
 inline HeapWord*
-ParallelCompactData::chunk_align_down(HeapWord* addr) const
+ParallelCompactData::region_align_down(HeapWord* addr) const
 {
 assert(addr >= _region_start, "bad addr");
-assert(addr < _region_end + ChunkSize, "bad addr");
+assert(addr < _region_end + RegionSize, "bad addr");
-return (HeapWord*)(size_t(addr) & ChunkAddrMask);
+return (HeapWord*)(size_t(addr) & RegionAddrMask);
 }
 inline HeapWord*
-ParallelCompactData::chunk_align_up(HeapWord* addr) const
+ParallelCompactData::region_align_up(HeapWord* addr) const
 {
 assert(addr >= _region_start, "bad addr");
 assert(addr <= _region_end, "bad addr");
-return chunk_align_down(addr + ChunkSizeOffsetMask);
+return region_align_down(addr + RegionSizeOffsetMask);
 }
 inline bool
-ParallelCompactData::is_chunk_aligned(HeapWord* addr) const
+ParallelCompactData::is_region_aligned(HeapWord* addr) const
 {
-return chunk_offset(addr) == 0;
+return region_offset(addr) == 0;
 }
 inline size_t
 ParallelCompactData::block_offset(const HeapWord* addr) const
 {
 // Closure for updating the block data during the summary phase.
 class BitBlockUpdateClosure: public ParMarkBitMapClosure {
 // ParallelCompactData::BlockData::blk_ofs_t _live_data_left;
 size_t    _live_data_left;
 size_t    _cur_block;
-HeapWord* _chunk_start;
+HeapWord* _region_start;
-HeapWord* _chunk_end;
+HeapWord* _region_end;
-size_t    _chunk_index;
+size_t    _region_index;
 public:
 BitBlockUpdateClosure(ParMarkBitMap* mbm,
 ParCompactionManager* cm,
-size_t chunk_index);
+size_t region_index);
 size_t cur_block() { return _cur_block; }
-size_t chunk_index() { return _chunk_index; }
+size_t region_index() { return _region_index; }
 size_t live_data_left() { return _live_data_left; }
 // Returns true the first bit in the current block (cur_block) is
 // a start bit.
-// Returns true if the current block is within the chunk for the closure;
+// Returns true if the current block is within the region for the closure;
-bool chunk_contains_cur_block();
+bool region_contains_cur_block();
-// Set the chunk index and related chunk values for
+// Set the region index and related region values for
-// a new chunk.
+// a new region.
-void reset_chunk(size_t chunk_index);
+void reset_region(size_t region_index);
 virtual IterationStatus do_addr(HeapWord* addr, size_t words);
 };
-// The UseParallelOldGC collector is a stop-the-world garbage
+// The UseParallelOldGC collector is a stop-the-world garbage collector that
-// collector that does parts of the collection using parallel threads.
+// does parts of the collection using parallel threads.  The collection includes
-// The collection includes the tenured generation and the young
+// the tenured generation and the young generation.  The permanent generation is
-// generation.  The permanent generation is collected at the same
+// collected at the same time as the other two generations but the permanent
-// time as the other two generations but the permanent generation
+// generation is collect by a single GC thread.  The permanent generation is
-// is collect by a single GC thread.  The permanent generation is
+// collected serially because of the requirement that during the processing of a
-// collected serially because of the requirement that during the
+// klass AAA, any objects reference by AAA must already have been processed.
-// processing of a klass AAA, any objects reference by AAA must
+// This requirement is enforced by a left (lower address) to right (higher
-// already have been processed.  This requirement is enforced by
+// address) sliding compaction.
-// a left (lower address) to right (higher address) sliding compaction.
 //
 // There are four phases of the collection.
 //
 //      - marking phase
 //      - summary phase
 //      - mark all the live objects
 //      - calculate the destination of each object at the end of the collection
 //      - move the objects to their destination
 //      - update some references and reinitialize some variables
 //
-// These three phases are invoked in PSParallelCompact::invoke_no_policy().
+// These three phases are invoked in PSParallelCompact::invoke_no_policy().  The
-// The marking phase is implemented in PSParallelCompact::marking_phase()
+// marking phase is implemented in PSParallelCompact::marking_phase() and does a
-// and does a complete marking of the heap.
+// complete marking of the heap.  The summary phase is implemented in
-// The summary phase is implemented in PSParallelCompact::summary_phase().
+// PSParallelCompact::summary_phase().  The move and update phase is implemented
-// The move and update phase is implemented in PSParallelCompact::compact().
+// in PSParallelCompact::compact().
 //
-// A space that is being collected is divided into chunks and with
+// A space that is being collected is divided into regions and with each region
-// each chunk is associated an object of type ParallelCompactData.
+// is associated an object of type ParallelCompactData.  Each region is of a
-// Each chunk is of a fixed size and typically will contain more than
+// fixed size and typically will contain more than 1 object and may have parts
-// 1 object and may have parts of objects at the front and back of the
+// of objects at the front and back of the region.
-// chunk.
 //
-// chunk            -----+---------------------+----------
+// region            -----+---------------------+----------
 // objects covered   [ AAA  )[ BBB )[ CCC   )[ DDD     )
 //
-// The marking phase does a complete marking of all live objects in the
+// The marking phase does a complete marking of all live objects in the heap.
-// heap.  The marking also compiles the size of the data for
+// The marking also compiles the size of the data for all live objects covered
-// all live objects covered by the chunk.  This size includes the
+// by the region.  This size includes the part of any live object spanning onto
-// part of any live object spanning onto the chunk (part of AAA
+// the region (part of AAA if it is live) from the front, all live objects
-// if it is live) from the front, all live objects contained in the chunk
+// contained in the region (BBB and/or CCC if they are live), and the part of
-// (BBB and/or CCC if they are live), and the part of any live objects
+// any live objects covered by the region that extends off the region (part of
-// covered by the chunk that extends off the chunk (part of DDD if it is
+// DDD if it is live).  The marking phase uses multiple GC threads and marking
-// live).  The marking phase uses multiple GC threads and marking is
+// is done in a bit array of type ParMarkBitMap.  The marking of the bit map is
-// done in a bit array of type ParMarkBitMap.  The marking of the
+// done atomically as is the accumulation of the size of the live objects
-// bit map is done atomically as is the accumulation of the size of the
+// covered by a region.
-// live objects covered by a chunk.
 //
-// The summary phase calculates the total live data to the left of
+// The summary phase calculates the total live data to the left of each region
-// each chunk XXX.  Based on that total and the bottom of the space,
+// XXX.  Based on that total and the bottom of the space, it can calculate the
-// it can calculate the starting location of the live data in XXX.
+// starting location of the live data in XXX.  The summary phase calculates for
-// The summary phase calculates for each chunk XXX quantites such as
+// each region XXX quantites such as
 //
-//      - the amount of live data at the beginning of a chunk from an object
+//      - the amount of live data at the beginning of a region from an object
-//      entering the chunk.
+//        entering the region.
-//      - the location of the first live data on the chunk
+//      - the location of the first live data on the region
-//      - a count of the number of chunks receiving live data from XXX.
+//      - a count of the number of regions receiving live data from XXX.
 //
 // See ParallelCompactData for precise details.  The summary phase also
-// calculates the dense prefix for the compaction.  The dense prefix
+// calculates the dense prefix for the compaction.  The dense prefix is a
-// is a portion at the beginning of the space that is not moved.  The
+// portion at the beginning of the space that is not moved.  The objects in the
-// objects in the dense prefix do need to have their object references
+// dense prefix do need to have their object references updated.  See method
-// updated.  See method summarize_dense_prefix().
+// summarize_dense_prefix().
 //
 // The summary phase is done using 1 GC thread.
 //
-// The compaction phase moves objects to their new location and updates
+// The compaction phase moves objects to their new location and updates all
-// all references in the object.
+// references in the object.
 //
-// A current exception is that objects that cross a chunk boundary
+// A current exception is that objects that cross a region boundary are moved
-// are moved but do not have their references updated.  References are
+// but do not have their references updated.  References are not updated because
-// not updated because it cannot easily be determined if the klass
+// it cannot easily be determined if the klass pointer KKK for the object AAA
-// pointer KKK for the object AAA has been updated.  KKK likely resides
+// has been updated.  KKK likely resides in a region to the left of the region
-// in a chunk to the left of the chunk containing AAA.  These AAA's
+// containing AAA.  These AAA's have there references updated at the end in a
-// have there references updated at the end in a clean up phase.
+// clean up phase.  See the method PSParallelCompact::update_deferred_objects().
-// See the method PSParallelCompact::update_deferred_objects().  An
+// An alternate strategy is being investigated for this deferral of updating.
-// alternate strategy is being investigated for this deferral of updating.
 //
-// Compaction is done on a chunk basis.  A chunk that is ready to be
+// Compaction is done on a region basis.  A region that is ready to be filled is
-// filled is put on a ready list and GC threads take chunk off the list
+// put on a ready list and GC threads take region off the list and fill them.  A
-// and fill them.  A chunk is ready to be filled if it
+// region is ready to be filled if it empty of live objects.  Such a region may
-// empty of live objects.  Such a chunk may have been initially
+// have been initially empty (only contained dead objects) or may have had all
-// empty (only contained
+// its live objects copied out already.  A region that compacts into itself is
-// dead objects) or may have had all its live objects copied out already.
+// also ready for filling.  The ready list is initially filled with empty
-// A chunk that compacts into itself is also ready for filling.  The
+// regions and regions compacting into themselves.  There is always at least 1
-// ready list is initially filled with empty chunks and chunks compacting
+// region that can be put on the ready list.  The regions are atomically added
-// into themselves.  There is always at least 1 chunk that can be put on
+// and removed from the ready list.
-// the ready list.  The chunks are atomically added and removed from
-// the ready list.
-//
 class PSParallelCompact : AllStatic {
 public:
 // Convenient access to type names.
 typedef ParMarkBitMap::idx_t idx_t;
-typedef ParallelCompactData::ChunkData ChunkData;
+typedef ParallelCompactData::RegionData RegionData;
 typedef ParallelCompactData::BlockData BlockData;
 typedef enum {
 perm_space_id, old_space_id, eden_space_id,
 from_space_id, to_space_id, last_space_id
 // Return the percentage of space that can be treated as "dead wood" (i.e.,
 // not reclaimed).
 static double dead_wood_limiter(double density, size_t min_percent);
-// Find the first (left-most) chunk in the range [beg, end) that has at least
+// Find the first (left-most) region in the range [beg, end) that has at least
 // dead_words of dead space to the left.  The argument beg must be the first
-// chunk in the space that is not completely live.
+// region in the space that is not completely live.
-static ChunkData* dead_wood_limit_chunk(const ChunkData* beg,
+static RegionData* dead_wood_limit_region(const RegionData* beg,
-const ChunkData* end,
+const RegionData* end,
 size_t dead_words);
-// Return a pointer to the first chunk in the range [beg, end) that is not
+// Return a pointer to the first region in the range [beg, end) that is not
 // completely full.
-static ChunkData* first_dead_space_chunk(const ChunkData* beg,
+static RegionData* first_dead_space_region(const RegionData* beg,
-const ChunkData* end);
+const RegionData* end);
 // Return a value indicating the benefit or 'yield' if the compacted region
 // were to start (or equivalently if the dense prefix were to end) at the
-// candidate chunk.  Higher values are better.
+// candidate region.  Higher values are better.
 //
 // The value is based on the amount of space reclaimed vs. the costs of (a)
 // updating references in the dense prefix plus (b) copying objects and
 // updating references in the compacted region.
-static inline double reclaimed_ratio(const ChunkData* const candidate,
+static inline double reclaimed_ratio(const RegionData* const candidate,
 HeapWord* const bottom,
 HeapWord* const top,
 HeapWord* const new_top);
 // Compute the dense prefix for the designated space.
 static HeapWord* compute_dense_prefix(const SpaceId id,
 bool maximum_compaction);
-// Return true if dead space crosses onto the specified Chunk; bit must be the
+// Return true if dead space crosses onto the specified Region; bit must be
-// bit index corresponding to the first word of the Chunk.
+// the bit index corresponding to the first word of the Region.
-static inline bool dead_space_crosses_boundary(const ChunkData* chunk,
+static inline bool dead_space_crosses_boundary(const RegionData* region,
 idx_t bit);
 // Summary phase utility routine to fill dead space (if any) at the dense
 // prefix boundary.  Should only be called if the the dense prefix is
 // non-empty.
 // Move objects to new locations.
 static void compact_perm(ParCompactionManager* cm);
 static void compact();
-// Add available chunks to the stack and draining tasks to the task queue.
+// Add available regions to the stack and draining tasks to the task queue.
-static void enqueue_chunk_draining_tasks(GCTaskQueue* q,
+static void enqueue_region_draining_tasks(GCTaskQueue* q,
 uint parallel_gc_threads);
 // Add dense prefix update tasks to the task queue.
 static void enqueue_dense_prefix_tasks(GCTaskQueue* q,
 uint parallel_gc_threads);
-// Add chunk stealing tasks to the task queue.
+// Add region stealing tasks to the task queue.
-static void enqueue_chunk_stealing_tasks(
+static void enqueue_region_stealing_tasks(
 GCTaskQueue* q,
 ParallelTaskTerminator* terminator_ptr,
 uint parallel_gc_threads);
 // For debugging only - compacts the old gen serially
 static inline bool should_update_klass(klassOop k);
 // Move and update the live objects in the specified space.
 static void move_and_update(ParCompactionManager* cm, SpaceId space_id);
-// Process the end of the given chunk range in the dense prefix.
+// Process the end of the given region range in the dense prefix.
 // This includes saving any object not updated.
-static void dense_prefix_chunks_epilogue(ParCompactionManager* cm,
+static void dense_prefix_regions_epilogue(ParCompactionManager* cm,
-size_t chunk_start_index,
+size_t region_start_index,
-size_t chunk_end_index,
+size_t region_end_index,
 idx_t exiting_object_offset,
-idx_t chunk_offset_start,
+idx_t region_offset_start,
-idx_t chunk_offset_end);
+idx_t region_offset_end);
-// Update a chunk in the dense prefix.  For each live object
+// Update a region in the dense prefix.  For each live object
-// in the chunk, update it's interior references.  For each
+// in the region, update it's interior references.  For each
 // dead object, fill it with deadwood. Dead space at the end
-// of a chunk range will be filled to the start of the next
+// of a region range will be filled to the start of the next
-// live object regardless of the chunk_index_end.  None of the
+// live object regardless of the region_index_end.  None of the
 // objects in the dense prefix move and dead space is dead
 // (holds only dead objects that don't need any processing), so
 // dead space can be filled in any order.
 static void update_and_deadwood_in_dense_prefix(ParCompactionManager* cm,
 SpaceId space_id,
-size_t chunk_index_start,
+size_t region_index_start,
-size_t chunk_index_end);
+size_t region_index_end);
 // Return the address of the count + 1st live word in the range [beg, end).
 static HeapWord* skip_live_words(HeapWord* beg, HeapWord* end, size_t count);
 // Return the address of the word to be copied to dest_addr, which must be
-// aligned to a chunk boundary.
+// aligned to a region boundary.
 static HeapWord* first_src_addr(HeapWord* const dest_addr,
-size_t src_chunk_idx);
+size_t src_region_idx);
-// Determine the next source chunk, set closure.source() to the start of the
+// Determine the next source region, set closure.source() to the start of the
-// new chunk return the chunk index.  Parameter end_addr is the address one
+// new region return the region index.  Parameter end_addr is the address one
 // beyond the end of source range just processed.  If necessary, switch to a
 // new source space and set src_space_id (in-out parameter) and src_space_top
 // (out parameter) accordingly.
-static size_t next_src_chunk(MoveAndUpdateClosure& closure,
+static size_t next_src_region(MoveAndUpdateClosure& closure,
 SpaceId& src_space_id,
 HeapWord*& src_space_top,
 HeapWord* end_addr);
-// Decrement the destination count for each non-empty source chunk in the
+// Decrement the destination count for each non-empty source region in the
-// range [beg_chunk, chunk(chunk_align_up(end_addr))).
+// range [beg_region, region(region_align_up(end_addr))).
 static void decrement_destination_counts(ParCompactionManager* cm,
-size_t beg_chunk,
+size_t beg_region,
 HeapWord* end_addr);
-// Fill a chunk, copying objects from one or more source chunks.
+// Fill a region, copying objects from one or more source regions.
-static void fill_chunk(ParCompactionManager* cm, size_t chunk_idx);
+static void fill_region(ParCompactionManager* cm, size_t region_idx);
-static void fill_and_update_chunk(ParCompactionManager* cm, size_t chunk) {
+static void fill_and_update_region(ParCompactionManager* cm, size_t region) {
-fill_chunk(cm, chunk);
+fill_region(cm, region);
 }
 // Update the deferred objects in the space.
 static void update_deferred_objects(ParCompactionManager* cm, SpaceId id);
 static void revisit_weak_klass_link(ParCompactionManager* cm, Klass* k);
 #ifndef PRODUCT
 // Debugging support.
 static const char* space_names[last_space_id];
-static void print_chunk_ranges();
+static void print_region_ranges();
 static void print_dense_prefix_stats(const char* const algorithm,
 const SpaceId id,
 const bool maximum_compaction,
 HeapWord* const addr);
 #endif  // #ifndef PRODUCT
 #ifdef  ASSERT
-// Verify that all the chunks have been emptied.
+// Verify that all the regions have been emptied.
 static void verify_complete(SpaceId space_id);
 #endif  // #ifdef ASSERT
 };
 inline bool PSParallelCompact::mark_obj(oop obj) {
 const double squared_term = (density - _dwl_mean) / _dwl_std_dev;
 return _dwl_first_term * exp(-0.5 * squared_term * squared_term);
 }
 inline bool
-PSParallelCompact::dead_space_crosses_boundary(const ChunkData* chunk,
+PSParallelCompact::dead_space_crosses_boundary(const RegionData* region,
 idx_t bit)
 {
-assert(bit > 0, "cannot call this for the first bit/chunk");
+assert(bit > 0, "cannot call this for the first bit/region");
-assert(_summary_data.chunk_to_addr(chunk) == _mark_bitmap.bit_to_addr(bit),
+assert(_summary_data.region_to_addr(region) == _mark_bitmap.bit_to_addr(bit),
 "sanity check");
 // Dead space crosses the boundary if (1) a partial object does not extend
-// onto the chunk, (2) an object does not start at the beginning of the chunk,
+// onto the region, (2) an object does not start at the beginning of the
-// and (3) an object does not end at the end of the prior chunk.
+// region, and (3) an object does not end at the end of the prior region.
-return chunk->partial_obj_size() == 0 &&
+return region->partial_obj_size() == 0 &&
 !_mark_bitmap.is_obj_beg(bit) &&
 !_mark_bitmap.is_obj_end(bit - 1);
 }
 inline bool

changeset 1407	9006b01ba3fd
parent 977	b90650e2a9f7
child 1408	e9c4f37aed49