--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp Tue Sep 30 11:49:31 2008 -0700
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp Tue Sep 30 12:20:22 2008 -0700
@@ -76,87 +76,87 @@
{
public:
// Sizes are in HeapWords, unless indicated otherwise.
- static const size_t Log2ChunkSize;
- static const size_t ChunkSize;
- static const size_t ChunkSizeBytes;
+ static const size_t Log2RegionSize;
+ static const size_t RegionSize;
+ static const size_t RegionSizeBytes;
- // Mask for the bits in a size_t to get an offset within a chunk.
- static const size_t ChunkSizeOffsetMask;
- // Mask for the bits in a pointer to get an offset within a chunk.
- static const size_t ChunkAddrOffsetMask;
- // Mask for the bits in a pointer to get the address of the start of a chunk.
- static const size_t ChunkAddrMask;
+ // Mask for the bits in a size_t to get an offset within a region.
+ static const size_t RegionSizeOffsetMask;
+ // Mask for the bits in a pointer to get an offset within a region.
+ static const size_t RegionAddrOffsetMask;
+ // Mask for the bits in a pointer to get the address of the start of a region.
+ 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.
- size_t source_chunk() const { return _source_chunk; }
+ // The first region containing data destined for this region.
+ size_t source_region() const { return _source_region; }
- // The object (if any) starting in this chunk and ending in a different
- // chunk that could not be updated during the main (parallel) compaction
+ // The object (if any) starting in this region and ending in a different
+ // 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
- // in this chunk (words). This does not include the partial object
- // extending onto the chunk (if any), or the part of an object that extends
- // onto the next chunk (if any).
+ // Size of live data that lies within this region due to objects that start
+ // in this region (words). This does not include the partial object
+ // extending onto the region (if any), or the part of an object that extends
+ // 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
- // this chunk will be copied. At the end of the summary phase, the valid
+ // The destination_count is the number of other regions to which data from
+ // 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
- // chunk is empty. The chunk can be claimed and then filled.
- // 1 - data from the chunk will be compacted into 1 other chunk; some
- // data from the chunk may also be compacted into the chunk itself.
- // 2 - data from the chunk will be copied to 2 other chunks.
+ // 0 - data from the region will be compacted completely into itself, or the
+ // region is empty. The region can be claimed and then filled.
+ // 1 - data from the region will be compacted into 1 other region; some
+ // data from the region may also be compacted into the region itself.
+ // 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
- // destination_count to the claimed value (dc_claimed). After a chunk has
+ // A region is claimed for processing by atomically changing the
+ // 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
- // completed(), which is desirable since a chunk must be claimed before it
+ // Minor subtlety: claimed() returns true if the region is marked
+ // 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; }
@@ -164,11 +164,11 @@
// 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);
@@ -184,44 +184,44 @@
inline bool claim();
private:
- // The type used to represent object sizes within a chunk.
- typedef uint chunk_sz_t;
+ // The type used to represent object sizes within a region.
+ 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 chunk_sz_t dc_mask; // Mask for destination count.
- static const chunk_sz_t dc_one; // 1, shifted appropriately.
- static const chunk_sz_t dc_claimed; // Chunk has been claimed.
- static const chunk_sz_t dc_completed; // Chunk has been completed.
- static const chunk_sz_t los_mask; // Mask for live obj size.
+ static const region_sz_t dc_shift; // Shift amount.
+ static const region_sz_t dc_mask; // Mask for destination count.
+ static const region_sz_t dc_one; // 1, shifted appropriately.
+ static const region_sz_t dc_claimed; // Region has been claimed.
+ static const region_sz_t dc_completed; // Region has been completed.
+ static const region_sz_t los_mask; // Mask for live obj size.
- HeapWord* _destination;
- size_t _source_chunk;
- HeapWord* _partial_obj_addr;
- chunk_sz_t _partial_obj_size;
- chunk_sz_t volatile _dc_and_los;
+ HeapWord* _destination;
+ size_t _source_region;
+ HeapWord* _partial_obj_addr;
+ region_sz_t _partial_obj_size;
+ 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* _highest_ref;
+ HeapWord* _data_location;
+ 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
- // the chunk.
+ // a region does not include any partial object extending into the
+ // the region.
//
// The offset also encodes the
// 'parity' of the first 1 bit in the Block: a positive offset means the
@@ -286,27 +286,27 @@
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.
- inline ChunkData* chunk(size_t chunk_idx) const;
- inline size_t chunk(const ChunkData* const chunk_ptr) const;
+ // Convert region indices to/from RegionData pointers.
+ inline RegionData* region(size_t region_idx) const;
+ inline size_t region(const RegionData* const region_ptr) const;
- // Returns true if the given address is contained within the chunk
- bool chunk_contains(size_t chunk_index, HeapWord* addr);
+ // Returns true if the given address is contained within the region
+ 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.
- static bool chunk_contains_block(size_t chunk_index, size_t block_index);
+ // Returns true if the given block is in the given region.
+ 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
- // destination of chunk n is simply the start of chunk n. The argument beg
- // must be chunk-aligned; end need not be.
+ // Fill in the regions covering [beg, end) so that no data moves; i.e., the
+ // destination of region n is simply the start of region n. The argument beg
+ // must be region-aligned; end need not be.
void summarize_dense_prefix(HeapWord* beg, HeapWord* end);
bool summarize(HeapWord* target_beg, HeapWord* target_end,
@@ -314,27 +314,27 @@
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.
- inline size_t addr_to_chunk_idx(const HeapWord* addr) const;
- inline ChunkData* addr_to_chunk_ptr(const HeapWord* addr) const;
- inline HeapWord* chunk_to_addr(size_t chunk) const;
- inline HeapWord* chunk_to_addr(size_t chunk, size_t offset) const;
- inline HeapWord* chunk_to_addr(const ChunkData* chunk) const;
+ // Convert addresses to/from a region index or region pointer.
+ inline size_t addr_to_region_idx(const HeapWord* addr) const;
+ inline RegionData* addr_to_region_ptr(const HeapWord* addr) const;
+ inline HeapWord* region_to_addr(size_t region) const;
+ inline HeapWord* region_to_addr(size_t region, size_t offset) const;
+ inline HeapWord* region_to_addr(const RegionData* region) const;
- inline HeapWord* chunk_align_down(HeapWord* addr) const;
- inline HeapWord* chunk_align_up(HeapWord* addr) const;
- inline bool is_chunk_aligned(HeapWord* addr) const;
+ inline HeapWord* region_align_down(HeapWord* addr) const;
+ inline HeapWord* region_align_up(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 {
@@ -344,7 +344,7 @@
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.
@@ -353,8 +353,8 @@
// Same as calc_new_pointer() using blocks.
HeapWord* block_calc_new_pointer(HeapWord* addr);
- // Same as calc_new_pointer() using chunks.
- HeapWord* chunk_calc_new_pointer(HeapWord* addr);
+ // Same as calc_new_pointer() using regions.
+ HeapWord* region_calc_new_pointer(HeapWord* addr);
HeapWord* calc_new_pointer(oop p) {
return calc_new_pointer((HeapWord*) p);
@@ -364,7 +364,7 @@
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);
@@ -378,7 +378,7 @@
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:
@@ -387,9 +387,9 @@
HeapWord* _region_end;
#endif // #ifdef ASSERT
- PSVirtualSpace* _chunk_vspace;
- ChunkData* _chunk_data;
- size_t _chunk_count;
+ PSVirtualSpace* _region_vspace;
+ RegionData* _region_data;
+ size_t _region_count;
PSVirtualSpace* _block_vspace;
BlockData* _block_data;
@@ -397,64 +397,64 @@
};
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;
@@ -463,13 +463,13 @@
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;
@@ -479,7 +479,7 @@
#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,
@@ -487,19 +487,19 @@
return old == los;
}
-inline ParallelCompactData::ChunkData*
-ParallelCompactData::chunk(size_t chunk_idx) const
+inline ParallelCompactData::RegionData*
+ParallelCompactData::region(size_t region_idx) const
{
- assert(chunk_idx <= chunk_count(), "bad arg");
- return _chunk_data + chunk_idx;
+ assert(region_idx <= region_count(), "bad arg");
+ 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(chunk_ptr <= _chunk_data + chunk_count(), "bad arg");
- return pointer_delta(chunk_ptr, _chunk_data, sizeof(ChunkData));
+ assert(region_ptr >= _region_data, "bad arg");
+ assert(region_ptr <= _region_data + region_count(), "bad arg");
+ return pointer_delta(region_ptr, _region_data, sizeof(RegionData));
}
inline ParallelCompactData::BlockData*
@@ -509,68 +509,69 @@
}
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*
-ParallelCompactData::addr_to_chunk_ptr(const HeapWord* addr) const
+inline ParallelCompactData::RegionData*
+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");
- return _region_start + (chunk << Log2ChunkSize);
+ assert(region <= _region_count, "region out of range");
+ 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(offset < ChunkSize, "offset too big"); // This may be too strict.
- return chunk_to_addr(chunk) + offset;
+ assert(region <= _region_count, "region out of range");
+ assert(offset < RegionSize, "offset too big"); // This may be too strict.
+ 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");
- return (HeapWord*)(size_t(addr) & ChunkAddrMask);
+ assert(addr < _region_end + RegionSize, "bad addr");
+ 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
@@ -692,40 +693,39 @@
// ParallelCompactData::BlockData::blk_ofs_t _live_data_left;
size_t _live_data_left;
size_t _cur_block;
- HeapWord* _chunk_start;
- HeapWord* _chunk_end;
- size_t _chunk_index;
+ HeapWord* _region_start;
+ HeapWord* _region_end;
+ 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;
- bool chunk_contains_cur_block();
+ // Returns true if the current block is within the region for the closure;
+ bool region_contains_cur_block();
- // Set the chunk index and related chunk values for
- // a new chunk.
- void reset_chunk(size_t chunk_index);
+ // Set the region index and related region values for
+ // a new region.
+ 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
-// collector that does parts of the collection using parallel threads.
-// The collection includes the tenured generation and the young
-// generation. The permanent generation is collected at the same
-// time as the other two generations but the permanent generation
-// is collect by a single GC thread. The permanent generation is
-// collected serially because of the requirement that during the
-// processing of a klass AAA, any objects reference by AAA must
-// already have been processed. This requirement is enforced by
-// a left (lower address) to right (higher address) sliding compaction.
+// The UseParallelOldGC collector is a stop-the-world garbage collector that
+// does parts of the collection using parallel threads. The collection includes
+// the tenured generation and the young generation. The permanent generation is
+// collected at the same time as the other two generations but the permanent
+// generation is collect by a single GC thread. The permanent generation is
+// collected serially because of the requirement that during the processing of a
+// klass AAA, any objects reference by AAA must already have been processed.
+// This requirement is enforced by a left (lower address) to right (higher
+// address) sliding compaction.
//
// There are four phases of the collection.
//
@@ -740,80 +740,75 @@
// - move the objects to their destination
// - update some references and reinitialize some variables
//
-// These three phases are invoked in PSParallelCompact::invoke_no_policy().
-// The marking phase is implemented in PSParallelCompact::marking_phase()
-// and does a complete marking of the heap.
-// The summary phase is implemented in PSParallelCompact::summary_phase().
-// The move and update phase is implemented in PSParallelCompact::compact().
+// These three phases are invoked in PSParallelCompact::invoke_no_policy(). The
+// marking phase is implemented in PSParallelCompact::marking_phase() and does a
+// complete marking of the heap. The summary phase is implemented in
+// PSParallelCompact::summary_phase(). The move and update phase is implemented
+// in PSParallelCompact::compact().
//
-// A space that is being collected is divided into chunks and with
-// each chunk is associated an object of type ParallelCompactData.
-// Each chunk is of a fixed size and typically will contain more than
-// 1 object and may have parts of objects at the front and back of the
-// chunk.
+// A space that is being collected is divided into regions and with each region
+// is associated an object of type ParallelCompactData. Each region is of a
+// fixed size and typically will contain more than 1 object and may have parts
+// of objects at the front and back of the region.
//
-// chunk -----+---------------------+----------
+// region -----+---------------------+----------
// objects covered [ AAA )[ BBB )[ CCC )[ DDD )
//
-// The marking phase does a complete marking of all live objects in the
-// heap. The marking also compiles the size of the data for
-// all live objects covered by the chunk. This size includes the
-// part of any live object spanning onto the chunk (part of AAA
-// if it is live) from the front, all live objects contained in the chunk
-// (BBB and/or CCC if they are live), and the part of any live objects
-// covered by the chunk that extends off the chunk (part of DDD if it is
-// live). The marking phase uses multiple GC threads and marking is
-// done in a bit array of type ParMarkBitMap. The marking of the
-// bit map is done atomically as is the accumulation of the size of the
-// live objects covered by a chunk.
+// The marking phase does a complete marking of all live objects in the heap.
+// The marking also compiles the size of the data for all live objects covered
+// by the region. This size includes the part of any live object spanning onto
+// the region (part of AAA if it is live) from the front, all live objects
+// contained in the region (BBB and/or CCC if they are live), and the part of
+// any live objects covered by the region that extends off the region (part of
+// DDD if it is live). The marking phase uses multiple GC threads and marking
+// is done in a bit array of type ParMarkBitMap. The marking of the bit map is
+// done atomically as is the accumulation of the size of the live objects
+// covered by a region.
//
-// The summary phase calculates the total live data to the left of
-// each chunk XXX. Based on that total and the bottom of the space,
-// it can calculate the starting location of the live data in XXX.
-// The summary phase calculates for each chunk XXX quantites such as
+// The summary phase calculates the total live data to the left of each region
+// XXX. Based on that total and the bottom of the space, it can calculate the
+// starting location of the live data in XXX. The summary phase calculates for
+// each region XXX quantites such as
//
-// - the amount of live data at the beginning of a chunk from an object
-// entering the chunk.
-// - the location of the first live data on the chunk
-// - a count of the number of chunks receiving live data from XXX.
+// - the amount of live data at the beginning of a region from an object
+// entering the region.
+// - the location of the first live data on the region
+// - 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
-// is a portion at the beginning of the space that is not moved. The
-// objects in the dense prefix do need to have their object references
-// updated. See method summarize_dense_prefix().
+// calculates the dense prefix for the compaction. The dense prefix is a
+// portion at the beginning of the space that is not moved. The objects in the
+// dense prefix do need to have their object references updated. See method
+// summarize_dense_prefix().
//
// The summary phase is done using 1 GC thread.
//
-// The compaction phase moves objects to their new location and updates
-// all references in the object.
+// The compaction phase moves objects to their new location and updates all
+// references in the object.
//
-// A current exception is that objects that cross a chunk boundary
-// are moved but do not have their references updated. References are
-// not updated because it cannot easily be determined if the klass
-// pointer KKK for the object AAA has been updated. KKK likely resides
-// in a chunk to the left of the chunk containing AAA. These AAA's
-// have there references updated at the end in a clean up phase.
-// See the method PSParallelCompact::update_deferred_objects(). An
-// alternate strategy is being investigated for this deferral of updating.
+// A current exception is that objects that cross a region boundary are moved
+// but do not have their references updated. References are not updated because
+// it cannot easily be determined if the klass pointer KKK for the object AAA
+// has been updated. KKK likely resides in a region to the left of the region
+// containing AAA. These AAA's have there references updated at the end in a
+// clean up phase. See the method PSParallelCompact::update_deferred_objects().
+// An alternate strategy is being investigated for this deferral of updating.
//
-// Compaction is done on a chunk basis. A chunk that is ready to be
-// filled is put on a ready list and GC threads take chunk off the list
-// and fill them. A chunk is ready to be filled if it
-// empty of live objects. Such a chunk may have been initially
-// empty (only contained
-// dead objects) or may have had all its live objects copied out already.
-// A chunk that compacts into itself is also ready for filling. The
-// ready list is initially filled with empty chunks and chunks compacting
-// into themselves. There is always at least 1 chunk that can be put on
-// the ready list. The chunks are atomically added and removed from
-// the ready list.
-//
+// Compaction is done on a region basis. A region that is ready to be filled is
+// put on a ready list and GC threads take region off the list and fill them. A
+// region is ready to be filled if it empty of live objects. Such a region may
+// have been initially empty (only contained dead objects) or may have had all
+// its live objects copied out already. A region that compacts into itself is
+// also ready for filling. The ready list is initially filled with empty
+// regions and regions compacting into themselves. There is always at least 1
+// region that can be put on the ready list. The regions 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 {
@@ -977,26 +972,26 @@
// 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.
- static ChunkData* dead_wood_limit_chunk(const ChunkData* beg,
- const ChunkData* end,
- size_t dead_words);
+ // region in the space that is not completely live.
+ static RegionData* dead_wood_limit_region(const RegionData* beg,
+ 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,
- const ChunkData* end);
+ static RegionData* first_dead_space_region(const RegionData* beg,
+ 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);
@@ -1005,9 +1000,9 @@
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
- // bit index corresponding to the first word of the Chunk.
- static inline bool dead_space_crosses_boundary(const ChunkData* chunk,
+ // Return true if dead space crosses onto the specified Region; bit must be
+ // the bit index corresponding to the first word of the Region.
+ 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
@@ -1038,16 +1033,16 @@
static void compact_perm(ParCompactionManager* cm);
static void compact();
- // Add available chunks to the stack and draining tasks to the task queue.
- static void enqueue_chunk_draining_tasks(GCTaskQueue* q,
- uint parallel_gc_threads);
+ // Add available regions to the stack and draining tasks to the task queue.
+ 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.
- static void enqueue_chunk_stealing_tasks(
+ // Add region stealing tasks to the task queue.
+ static void enqueue_region_stealing_tasks(
GCTaskQueue* q,
ParallelTaskTerminator* terminator_ptr,
uint parallel_gc_threads);
@@ -1154,56 +1149,56 @@
// 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,
- size_t chunk_start_index,
- size_t chunk_end_index,
- idx_t exiting_object_offset,
- idx_t chunk_offset_start,
- idx_t chunk_offset_end);
+ static void dense_prefix_regions_epilogue(ParCompactionManager* cm,
+ size_t region_start_index,
+ size_t region_end_index,
+ idx_t exiting_object_offset,
+ idx_t region_offset_start,
+ idx_t region_offset_end);
- // Update a chunk in the dense prefix. For each live object
- // in the chunk, update it's interior references. For each
+ // Update a region in the dense prefix. For each live object
+ // 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
- // live object regardless of the chunk_index_end. None of the
+ // of a region range will be filled to the start of the next
+ // 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 chunk_index_end);
+ size_t region_index_start,
+ 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
- // new chunk return the chunk index. Parameter end_addr is the address one
+ // Determine the next source region, set closure.source() to the start of the
+ // 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,
- SpaceId& src_space_id,
- HeapWord*& src_space_top,
- HeapWord* end_addr);
+ 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
- // range [beg_chunk, chunk(chunk_align_up(end_addr))).
+ // Decrement the destination count for each non-empty source region in the
+ // 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.
- static void fill_chunk(ParCompactionManager* cm, size_t chunk_idx);
- static void fill_and_update_chunk(ParCompactionManager* cm, size_t chunk) {
- fill_chunk(cm, chunk);
+ // Fill a region, copying objects from one or more source regions.
+ static void fill_region(ParCompactionManager* cm, size_t region_idx);
+ static void fill_and_update_region(ParCompactionManager* cm, size_t region) {
+ fill_region(cm, region);
}
// Update the deferred objects in the space.
@@ -1259,7 +1254,7 @@
#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,
@@ -1267,7 +1262,7 @@
#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
};
@@ -1376,17 +1371,17 @@
}
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(_summary_data.chunk_to_addr(chunk) == _mark_bitmap.bit_to_addr(bit),
+ assert(bit > 0, "cannot call this for the first bit/region");
+ 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,
- // and (3) an object does not end at the end of the prior chunk.
- return chunk->partial_obj_size() == 0 &&
+ // onto the region, (2) an object does not start at the beginning of the
+ // region, and (3) an object does not end at the end of the prior region.
+ return region->partial_obj_size() == 0 &&
!_mark_bitmap.is_obj_beg(bit) &&
!_mark_bitmap.is_obj_end(bit - 1);
}