--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1368 @@
+/*
+ * Copyright 2005-2007 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+class ParallelScavengeHeap;
+class PSAdaptiveSizePolicy;
+class PSYoungGen;
+class PSOldGen;
+class PSPermGen;
+class ParCompactionManager;
+class ParallelTaskTerminator;
+class PSParallelCompact;
+class GCTaskManager;
+class GCTaskQueue;
+class PreGCValues;
+class MoveAndUpdateClosure;
+class RefProcTaskExecutor;
+
+class SpaceInfo
+{
+ public:
+ MutableSpace* space() const { return _space; }
+
+ // Where the free space will start after the collection. Valid only after the
+ // summary phase completes.
+ HeapWord* new_top() const { return _new_top; }
+
+ // Allows new_top to be set.
+ HeapWord** new_top_addr() { return &_new_top; }
+
+ // Where the smallest allowable dense prefix ends (used only for perm gen).
+ HeapWord* min_dense_prefix() const { return _min_dense_prefix; }
+
+ // Where the dense prefix ends, or the compacted region begins.
+ HeapWord* dense_prefix() const { return _dense_prefix; }
+
+ // The start array for the (generation containing the) space, or NULL if there
+ // is no start array.
+ ObjectStartArray* start_array() const { return _start_array; }
+
+ void set_space(MutableSpace* s) { _space = s; }
+ void set_new_top(HeapWord* addr) { _new_top = addr; }
+ void set_min_dense_prefix(HeapWord* addr) { _min_dense_prefix = addr; }
+ void set_dense_prefix(HeapWord* addr) { _dense_prefix = addr; }
+ void set_start_array(ObjectStartArray* s) { _start_array = s; }
+
+ private:
+ MutableSpace* _space;
+ HeapWord* _new_top;
+ HeapWord* _min_dense_prefix;
+ HeapWord* _dense_prefix;
+ ObjectStartArray* _start_array;
+};
+
+class ParallelCompactData
+{
+public:
+ // Sizes are in HeapWords, unless indicated otherwise.
+ static const size_t Log2ChunkSize;
+ static const size_t ChunkSize;
+ static const size_t ChunkSizeBytes;
+
+ // 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;
+
+ 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;
+
+ class ChunkData
+ {
+ public:
+ // Destination address of the chunk.
+ HeapWord* destination() const { return _destination; }
+
+ // The first chunk containing data destined for this chunk.
+ size_t source_chunk() const { return _source_chunk; }
+
+ // The object (if any) starting in this chunk and ending in a different
+ // chunk 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
+ // 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.
+ HeapWord* partial_obj_addr() const { return _partial_obj_addr; }
+
+ // Size of the partial object extending onto the chunk (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_t live_obj_size() const { return _dc_and_los & los_mask; }
+
+ // Total live data that lies within the chunk (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
+ // 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.
+ //
+ // During compaction as chunks 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
+ // 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.
+ inline HeapWord* data_location() const;
+
+ // The highest address referenced by objects in this chunk.
+ inline HeapWord* highest_ref() const;
+
+ // Whether this chunk 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
+ // 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_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;
+ }
+
+ 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_completed();
+ inline bool claim_unsafe();
+
+ // These are atomic.
+ inline void add_live_obj(size_t words);
+ 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.
+ typedef uint chunk_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.
+
+ HeapWord* _destination;
+ size_t _source_chunk;
+ HeapWord* _partial_obj_addr;
+ chunk_sz_t _partial_obj_size;
+ chunk_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;
+#endif // #ifdef ASSERT
+
+#ifdef ASSERT
+ public:
+ uint _pushed; // 0 until chunk 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
+ // 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.
+ //
+ // 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.
+ class BlockData
+ {
+ public:
+ typedef short int blk_ofs_t;
+
+ blk_ofs_t offset() const { return _offset >= 0 ? _offset : -_offset; }
+ blk_ofs_t raw_offset() const { return _offset; }
+ void set_first_is_start_bit(bool v) { _first_is_start_bit = v; }
+
+#if 0
+ // The need for this method was anticipated but it is
+ // never actually used. Do not include it for now. If
+ // it is needed, consider the problem of what is passed
+ // as "v". To avoid warning errors the method set_start_bit_offset()
+ // was changed to take a size_t as the parameter and to do the
+ // check for the possible overflow. Doing the cast in these
+ // methods better limits the potential problems because of
+ // the size of the field to this class.
+ void set_raw_offset(blk_ofs_t v) { _offset = v; }
+#endif
+ void set_start_bit_offset(size_t val) {
+ assert(val >= 0, "sanity");
+ _offset = (blk_ofs_t) val;
+ assert(val == (size_t) _offset, "Value is too large");
+ _first_is_start_bit = true;
+ }
+ void set_end_bit_offset(size_t val) {
+ assert(val >= 0, "sanity");
+ _offset = (blk_ofs_t) val;
+ assert(val == (size_t) _offset, "Value is too large");
+ _offset = - _offset;
+ _first_is_start_bit = false;
+ }
+ bool first_is_start_bit() {
+ assert(_set_phase > 0, "Not initialized");
+ return _first_is_start_bit;
+ }
+ bool first_is_end_bit() {
+ assert(_set_phase > 0, "Not initialized");
+ return !_first_is_start_bit;
+ }
+
+ private:
+ blk_ofs_t _offset;
+ // This is temporary until the mark_bitmap is separated into
+ // a start bit array and an end bit array.
+ bool _first_is_start_bit;
+#ifdef ASSERT
+ short _set_phase;
+ static short _cur_phase;
+ public:
+ static void set_cur_phase(short v) { _cur_phase = v; }
+#endif
+ };
+
+public:
+ ParallelCompactData();
+ bool initialize(MemRegion covered_region);
+
+ size_t chunk_count() const { return _chunk_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;
+
+ // Returns true if the given address is contained within the chunk
+ bool chunk_contains(size_t chunk_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);
+
+ 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.
+ 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(HeapWord* beg, HeapWord* end) {
+ clear_range(addr_to_chunk_idx(beg), addr_to_chunk_idx(end));
+ }
+
+ // Return the number of words between addr and the start of the chunk
+ // containing addr.
+ inline size_t chunk_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;
+
+ inline HeapWord* chunk_align_down(HeapWord* addr) const;
+ inline HeapWord* chunk_align_up(HeapWord* addr) const;
+ inline bool is_chunk_aligned(HeapWord* addr) const;
+
+ // Analogous to chunk_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;
+
+ // 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.
+ HeapWord* chunk_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
+ // 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);
+
+#ifdef ASSERT
+ void verify_clear(const PSVirtualSpace* vspace);
+ void verify_clear();
+#endif // #ifdef ASSERT
+
+private:
+ bool initialize_block_data(size_t region_size);
+ bool initialize_chunk_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;
+ ChunkData* _chunk_data;
+ size_t _chunk_count;
+
+ PSVirtualSpace* _block_vspace;
+ BlockData* _block_data;
+ size_t _block_count;
+};
+
+inline uint
+ParallelCompactData::ChunkData::destination_count_raw() const
+{
+ return _dc_and_los & dc_mask;
+}
+
+inline uint
+ParallelCompactData::ChunkData::destination_count() const
+{
+ return destination_count_raw() >> dc_shift;
+}
+
+inline void
+ParallelCompactData::ChunkData::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();
+ _dc_and_los = (count << dc_shift) | live_sz;
+}
+
+inline void ParallelCompactData::ChunkData::set_live_obj_size(size_t words)
+{
+ assert(words <= los_mask, "would overflow");
+ _dc_and_los = destination_count_raw() | (chunk_sz_t)words;
+}
+
+inline void ParallelCompactData::ChunkData::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
+{
+ DEBUG_ONLY(return _data_location;)
+ NOT_DEBUG(return NULL;)
+}
+
+inline HeapWord* ParallelCompactData::ChunkData::highest_ref() const
+{
+ DEBUG_ONLY(return _highest_ref;)
+ NOT_DEBUG(return NULL;)
+}
+
+inline void ParallelCompactData::ChunkData::set_data_location(HeapWord* addr)
+{
+ DEBUG_ONLY(_data_location = addr;)
+}
+
+inline void ParallelCompactData::ChunkData::set_completed()
+{
+ assert(claimed(), "must be claimed first");
+ _dc_and_los = dc_completed | (chunk_sz_t) live_obj_size();
+}
+
+// MT-unsafe claiming of a chunk. Should only be used during single threaded
+// execution.
+inline bool ParallelCompactData::ChunkData::claim_unsafe()
+{
+ if (available()) {
+ _dc_and_los |= dc_claimed;
+ return true;
+ }
+ return false;
+}
+
+inline void ParallelCompactData::ChunkData::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)
+{
+#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()
+{
+ 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*
+ParallelCompactData::chunk(size_t chunk_idx) const
+{
+ assert(chunk_idx <= chunk_count(), "bad arg");
+ return _chunk_data + chunk_idx;
+}
+
+inline size_t
+ParallelCompactData::chunk(const ChunkData* const chunk_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));
+}
+
+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
+{
+ assert(addr >= _region_start, "bad addr");
+ assert(addr <= _region_end, "bad addr");
+ return (size_t(addr) & ChunkAddrOffsetMask) >> LogHeapWordSize;
+}
+
+inline size_t
+ParallelCompactData::addr_to_chunk_idx(const HeapWord* addr) const
+{
+ assert(addr >= _region_start, "bad addr");
+ assert(addr <= _region_end, "bad addr");
+ return pointer_delta(addr, _region_start) >> Log2ChunkSize;
+}
+
+inline ParallelCompactData::ChunkData*
+ParallelCompactData::addr_to_chunk_ptr(const HeapWord* addr) const
+{
+ return chunk(addr_to_chunk_idx(addr));
+}
+
+inline HeapWord*
+ParallelCompactData::chunk_to_addr(size_t chunk) const
+{
+ assert(chunk <= _chunk_count, "chunk out of range");
+ return _region_start + (chunk << Log2ChunkSize);
+}
+
+inline HeapWord*
+ParallelCompactData::chunk_to_addr(const ChunkData* chunk) const
+{
+ return chunk_to_addr(pointer_delta(chunk, _chunk_data, sizeof(ChunkData)));
+}
+
+inline HeapWord*
+ParallelCompactData::chunk_to_addr(size_t chunk, 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;
+}
+
+inline HeapWord*
+ParallelCompactData::chunk_align_down(HeapWord* addr) const
+{
+ assert(addr >= _region_start, "bad addr");
+ assert(addr < _region_end + ChunkSize, "bad addr");
+ return (HeapWord*)(size_t(addr) & ChunkAddrMask);
+}
+
+inline HeapWord*
+ParallelCompactData::chunk_align_up(HeapWord* addr) const
+{
+ assert(addr >= _region_start, "bad addr");
+ assert(addr <= _region_end, "bad addr");
+ return chunk_align_down(addr + ChunkSizeOffsetMask);
+}
+
+inline bool
+ParallelCompactData::is_chunk_aligned(HeapWord* addr) const
+{
+ return chunk_offset(addr) == 0;
+}
+
+inline size_t
+ParallelCompactData::block_offset(const HeapWord* addr) const
+{
+ assert(addr >= _region_start, "bad addr");
+ assert(addr <= _region_end, "bad addr");
+ return pointer_delta(addr, _region_start) & BlockOffsetMask;
+}
+
+inline size_t
+ParallelCompactData::addr_to_block_idx(const HeapWord* addr) const
+{
+ assert(addr >= _region_start, "bad addr");
+ assert(addr <= _region_end, "bad addr");
+ return pointer_delta(addr, _region_start) >> Log2BlockSize;
+}
+
+inline ParallelCompactData::BlockData*
+ParallelCompactData::addr_to_block_ptr(const HeapWord* addr) const
+{
+ return block(addr_to_block_idx(addr));
+}
+
+inline HeapWord*
+ParallelCompactData::block_to_addr(size_t block) const
+{
+ assert(block < _block_count, "block out of range");
+ return _region_start + (block << Log2BlockSize);
+}
+
+// Abstract closure for use with ParMarkBitMap::iterate(), which will invoke the
+// do_addr() method.
+//
+// The closure is initialized with the number of heap words to process
+// (words_remaining()), and becomes 'full' when it reaches 0. The do_addr()
+// methods in subclasses should update the total as words are processed. Since
+// only one subclass actually uses this mechanism to terminate iteration, the
+// default initial value is > 0. The implementation is here and not in the
+// single subclass that uses it to avoid making is_full() virtual, and thus
+// adding a virtual call per live object.
+
+class ParMarkBitMapClosure: public StackObj {
+ public:
+ typedef ParMarkBitMap::idx_t idx_t;
+ typedef ParMarkBitMap::IterationStatus IterationStatus;
+
+ public:
+ inline ParMarkBitMapClosure(ParMarkBitMap* mbm, ParCompactionManager* cm,
+ size_t words = max_uintx);
+
+ inline ParCompactionManager* compaction_manager() const;
+ inline ParMarkBitMap* bitmap() const;
+ inline size_t words_remaining() const;
+ inline bool is_full() const;
+ inline HeapWord* source() const;
+
+ inline void set_source(HeapWord* addr);
+
+ virtual IterationStatus do_addr(HeapWord* addr, size_t words) = 0;
+
+ protected:
+ inline void decrement_words_remaining(size_t words);
+
+ private:
+ ParMarkBitMap* const _bitmap;
+ ParCompactionManager* const _compaction_manager;
+ DEBUG_ONLY(const size_t _initial_words_remaining;) // Useful in debugger.
+ size_t _words_remaining; // Words left to copy.
+
+ protected:
+ HeapWord* _source; // Next addr that would be read.
+};
+
+inline
+ParMarkBitMapClosure::ParMarkBitMapClosure(ParMarkBitMap* bitmap,
+ ParCompactionManager* cm,
+ size_t words):
+ _bitmap(bitmap), _compaction_manager(cm)
+#ifdef ASSERT
+ , _initial_words_remaining(words)
+#endif
+{
+ _words_remaining = words;
+ _source = NULL;
+}
+
+inline ParCompactionManager* ParMarkBitMapClosure::compaction_manager() const {
+ return _compaction_manager;
+}
+
+inline ParMarkBitMap* ParMarkBitMapClosure::bitmap() const {
+ return _bitmap;
+}
+
+inline size_t ParMarkBitMapClosure::words_remaining() const {
+ return _words_remaining;
+}
+
+inline bool ParMarkBitMapClosure::is_full() const {
+ return words_remaining() == 0;
+}
+
+inline HeapWord* ParMarkBitMapClosure::source() const {
+ return _source;
+}
+
+inline void ParMarkBitMapClosure::set_source(HeapWord* addr) {
+ _source = addr;
+}
+
+inline void ParMarkBitMapClosure::decrement_words_remaining(size_t words) {
+ assert(_words_remaining >= words, "processed too many words");
+ _words_remaining -= words;
+}
+
+// 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* _chunk_end;
+ size_t _chunk_index;
+
+ public:
+ BitBlockUpdateClosure(ParMarkBitMap* mbm,
+ ParCompactionManager* cm,
+ size_t chunk_index);
+
+ size_t cur_block() { return _cur_block; }
+ size_t chunk_index() { return _chunk_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();
+
+ // Set the chunk index and related chunk values for
+ // a new chunk.
+ void reset_chunk(size_t chunk_index);
+
+ virtual IterationStatus do_addr(HeapWord* addr, size_t words);
+};
+
+class PSParallelCompact : AllStatic {
+ public:
+ // Convenient access to type names.
+ typedef ParMarkBitMap::idx_t idx_t;
+ typedef ParallelCompactData::ChunkData ChunkData;
+ typedef ParallelCompactData::BlockData BlockData;
+
+ typedef enum {
+ perm_space_id, old_space_id, eden_space_id,
+ from_space_id, to_space_id, last_space_id
+ } SpaceId;
+
+ public:
+ // In line closure decls
+ //
+
+ class IsAliveClosure: public BoolObjectClosure {
+ public:
+ void do_object(oop p) { assert(false, "don't call"); }
+ bool do_object_b(oop p) { return mark_bitmap()->is_marked(p); }
+ };
+
+ class KeepAliveClosure: public OopClosure {
+ ParCompactionManager* _compaction_manager;
+ public:
+ KeepAliveClosure(ParCompactionManager* cm) {
+ _compaction_manager = cm;
+ }
+ void do_oop(oop* p);
+ };
+
+ class FollowRootClosure: public OopsInGenClosure{
+ ParCompactionManager* _compaction_manager;
+ public:
+ FollowRootClosure(ParCompactionManager* cm) {
+ _compaction_manager = cm;
+ }
+ void do_oop(oop* p) { follow_root(_compaction_manager, p); }
+ virtual const bool do_nmethods() const { return true; }
+ };
+
+ class FollowStackClosure: public VoidClosure {
+ ParCompactionManager* _compaction_manager;
+ public:
+ FollowStackClosure(ParCompactionManager* cm) {
+ _compaction_manager = cm;
+ }
+ void do_void() { follow_stack(_compaction_manager); }
+ };
+
+ class AdjustPointerClosure: public OopsInGenClosure {
+ bool _is_root;
+ public:
+ AdjustPointerClosure(bool is_root) : _is_root(is_root) {}
+ void do_oop(oop* p) { adjust_pointer(p, _is_root); }
+ };
+
+ // Closure for verifying update of pointers. Does not
+ // have any side effects.
+ class VerifyUpdateClosure: public ParMarkBitMapClosure {
+ const MutableSpace* _space; // Is this ever used?
+
+ public:
+ VerifyUpdateClosure(ParCompactionManager* cm, const MutableSpace* sp) :
+ ParMarkBitMapClosure(PSParallelCompact::mark_bitmap(), cm), _space(sp)
+ { }
+
+ virtual IterationStatus do_addr(HeapWord* addr, size_t words);
+
+ const MutableSpace* space() { return _space; }
+ };
+
+ // Closure for updating objects altered for debug checking
+ class ResetObjectsClosure: public ParMarkBitMapClosure {
+ public:
+ ResetObjectsClosure(ParCompactionManager* cm):
+ ParMarkBitMapClosure(PSParallelCompact::mark_bitmap(), cm)
+ { }
+
+ virtual IterationStatus do_addr(HeapWord* addr, size_t words);
+ };
+
+ friend class KeepAliveClosure;
+ friend class FollowStackClosure;
+ friend class AdjustPointerClosure;
+ friend class FollowRootClosure;
+ friend class instanceKlassKlass;
+ friend class RefProcTaskProxy;
+
+ static void mark_and_push_internal(ParCompactionManager* cm, oop* p);
+
+ private:
+ static elapsedTimer _accumulated_time;
+ static unsigned int _total_invocations;
+ static unsigned int _maximum_compaction_gc_num;
+ static jlong _time_of_last_gc; // ms
+ static CollectorCounters* _counters;
+ static ParMarkBitMap _mark_bitmap;
+ static ParallelCompactData _summary_data;
+ static IsAliveClosure _is_alive_closure;
+ static SpaceInfo _space_info[last_space_id];
+ static bool _print_phases;
+ static AdjustPointerClosure _adjust_root_pointer_closure;
+ static AdjustPointerClosure _adjust_pointer_closure;
+
+ // Reference processing (used in ...follow_contents)
+ static ReferenceProcessor* _ref_processor;
+
+ // Updated location of intArrayKlassObj.
+ static klassOop _updated_int_array_klass_obj;
+
+ // Values computed at initialization and used by dead_wood_limiter().
+ static double _dwl_mean;
+ static double _dwl_std_dev;
+ static double _dwl_first_term;
+ static double _dwl_adjustment;
+#ifdef ASSERT
+ static bool _dwl_initialized;
+#endif // #ifdef ASSERT
+
+ private:
+ // Closure accessors
+ static OopClosure* adjust_pointer_closure() { return (OopClosure*)&_adjust_pointer_closure; }
+ static OopClosure* adjust_root_pointer_closure() { return (OopClosure*)&_adjust_root_pointer_closure; }
+ static BoolObjectClosure* is_alive_closure() { return (BoolObjectClosure*)&_is_alive_closure; }
+
+ static void initialize_space_info();
+
+ // Return true if details about individual phases should be printed.
+ static inline bool print_phases();
+
+ // Clear the marking bitmap and summary data that cover the specified space.
+ static void clear_data_covering_space(SpaceId id);
+
+ static void pre_compact(PreGCValues* pre_gc_values);
+ static void post_compact();
+
+ // Mark live objects
+ static void marking_phase(ParCompactionManager* cm,
+ bool maximum_heap_compaction);
+ static void follow_stack(ParCompactionManager* cm);
+ static void follow_weak_klass_links(ParCompactionManager* cm);
+
+ static void adjust_pointer(oop* p, bool is_root);
+ static void adjust_root_pointer(oop* p) { adjust_pointer(p, true); }
+
+ static void follow_root(ParCompactionManager* cm, oop* p);
+
+ // Compute the dense prefix for the designated space. This is an experimental
+ // implementation currently not used in production.
+ static HeapWord* compute_dense_prefix_via_density(const SpaceId id,
+ bool maximum_compaction);
+
+ // Methods used to compute the dense prefix.
+
+ // Compute the value of the normal distribution at x = density. The mean and
+ // standard deviation are values saved by initialize_dead_wood_limiter().
+ static inline double normal_distribution(double density);
+
+ // Initialize the static vars used by dead_wood_limiter().
+ static void initialize_dead_wood_limiter();
+
+ // 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
+ // 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);
+
+ // Return a pointer to the first chunk in the range [beg, end) that is not
+ // completely full.
+ static ChunkData* first_dead_space_chunk(const ChunkData* beg,
+ const ChunkData* 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.
+ //
+ // 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,
+ 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
+ // bit index corresponding to the first word of the Chunk.
+ static inline bool dead_space_crosses_boundary(const ChunkData* chunk,
+ 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.
+ static void fill_dense_prefix_end(SpaceId id);
+
+ static void summarize_spaces_quick();
+ static void summarize_space(SpaceId id, bool maximum_compaction);
+ static void summary_phase(ParCompactionManager* cm, bool maximum_compaction);
+
+ static bool block_first_offset(size_t block_index, idx_t* block_offset_ptr);
+
+ // Fill in the BlockData
+ static void summarize_blocks(ParCompactionManager* cm,
+ SpaceId first_compaction_space_id);
+
+ // The space that is compacted after space_id.
+ static SpaceId next_compaction_space_id(SpaceId space_id);
+
+ // Adjust addresses in roots. Does not adjust addresses in heap.
+ static void adjust_roots();
+
+ // Serial code executed in preparation for the compaction phase.
+ static void compact_prologue();
+
+ // 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.
+ static void enqueue_chunk_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(
+ GCTaskQueue* q,
+ ParallelTaskTerminator* terminator_ptr,
+ uint parallel_gc_threads);
+
+ // For debugging only - compacts the old gen serially
+ static void compact_serial(ParCompactionManager* cm);
+
+ // If objects are left in eden after a collection, try to move the boundary
+ // and absorb them into the old gen. Returns true if eden was emptied.
+ static bool absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy,
+ PSYoungGen* young_gen,
+ PSOldGen* old_gen);
+
+ // Reset time since last full gc
+ static void reset_millis_since_last_gc();
+
+ protected:
+#ifdef VALIDATE_MARK_SWEEP
+ static GrowableArray<oop*>* _root_refs_stack;
+ static GrowableArray<oop> * _live_oops;
+ static GrowableArray<oop> * _live_oops_moved_to;
+ static GrowableArray<size_t>* _live_oops_size;
+ static size_t _live_oops_index;
+ static size_t _live_oops_index_at_perm;
+ static GrowableArray<oop*>* _other_refs_stack;
+ static GrowableArray<oop*>* _adjusted_pointers;
+ static bool _pointer_tracking;
+ static bool _root_tracking;
+
+ // The following arrays are saved since the time of the last GC and
+ // assist in tracking down problems where someone has done an errant
+ // store into the heap, usually to an oop that wasn't properly
+ // handleized across a GC. If we crash or otherwise fail before the
+ // next GC, we can query these arrays to find out the object we had
+ // intended to do the store to (assuming it is still alive) and the
+ // offset within that object. Covered under RecordMarkSweepCompaction.
+ static GrowableArray<HeapWord*> * _cur_gc_live_oops;
+ static GrowableArray<HeapWord*> * _cur_gc_live_oops_moved_to;
+ static GrowableArray<size_t>* _cur_gc_live_oops_size;
+ static GrowableArray<HeapWord*> * _last_gc_live_oops;
+ static GrowableArray<HeapWord*> * _last_gc_live_oops_moved_to;
+ static GrowableArray<size_t>* _last_gc_live_oops_size;
+#endif
+
+ public:
+ class MarkAndPushClosure: public OopClosure {
+ ParCompactionManager* _compaction_manager;
+ public:
+ MarkAndPushClosure(ParCompactionManager* cm) {
+ _compaction_manager = cm;
+ }
+ void do_oop(oop* p) { mark_and_push(_compaction_manager, p); }
+ virtual const bool do_nmethods() const { return true; }
+ };
+
+ PSParallelCompact();
+
+ // Convenient accessor for Universe::heap().
+ static ParallelScavengeHeap* gc_heap() {
+ return (ParallelScavengeHeap*)Universe::heap();
+ }
+
+ static void invoke(bool maximum_heap_compaction);
+ static void invoke_no_policy(bool maximum_heap_compaction);
+
+ static void post_initialize();
+ // Perform initialization for PSParallelCompact that requires
+ // allocations. This should be called during the VM initialization
+ // at a pointer where it would be appropriate to return a JNI_ENOMEM
+ // in the event of a failure.
+ static bool initialize();
+
+ // Public accessors
+ static elapsedTimer* accumulated_time() { return &_accumulated_time; }
+ static unsigned int total_invocations() { return _total_invocations; }
+ static CollectorCounters* counters() { return _counters; }
+
+ // Used to add tasks
+ static GCTaskManager* const gc_task_manager();
+ static klassOop updated_int_array_klass_obj() {
+ return _updated_int_array_klass_obj;
+ }
+
+ // Marking support
+ static inline bool mark_obj(oop obj);
+ static bool mark_obj(oop* p) {
+ if (*p != NULL) {
+ return mark_obj(*p);
+ } else {
+ return false;
+ }
+ }
+ static void mark_and_push(ParCompactionManager* cm, oop* p) {
+ // Check mark and maybe push on
+ // marking stack
+ oop m = *p;
+ if (m != NULL && mark_bitmap()->is_unmarked(m)) {
+ mark_and_push_internal(cm, p);
+ }
+ }
+
+ // Compaction support.
+ // Return true if p is in the range [beg_addr, end_addr).
+ static inline bool is_in(HeapWord* p, HeapWord* beg_addr, HeapWord* end_addr);
+ static inline bool is_in(oop* p, HeapWord* beg_addr, HeapWord* end_addr);
+
+ // Convenience wrappers for per-space data kept in _space_info.
+ static inline MutableSpace* space(SpaceId space_id);
+ static inline HeapWord* new_top(SpaceId space_id);
+ static inline HeapWord* dense_prefix(SpaceId space_id);
+ static inline ObjectStartArray* start_array(SpaceId space_id);
+
+ // Return true if the klass should be updated.
+ 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.
+ // 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);
+
+ // Update a chunk in the dense prefix. For each live object
+ // in the chunk, 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
+ // 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);
+
+ // 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.
+ static HeapWord* first_src_addr(HeapWord* const dest_addr,
+ size_t src_chunk_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
+ // 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);
+
+ // Decrement the destination count for each non-empty source chunk in the
+ // range [beg_chunk, chunk(chunk_align_up(end_addr))).
+ static void decrement_destination_counts(ParCompactionManager* cm,
+ size_t beg_chunk,
+ 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);
+ }
+
+ // Update the deferred objects in the space.
+ static void update_deferred_objects(ParCompactionManager* cm, SpaceId id);
+
+ // Mark pointer and follow contents.
+ static void mark_and_follow(ParCompactionManager* cm, oop* p);
+
+ static ParMarkBitMap* mark_bitmap() { return &_mark_bitmap; }
+ static ParallelCompactData& summary_data() { return _summary_data; }
+
+ static inline void adjust_pointer(oop* p) { adjust_pointer(p, false); }
+ static inline void adjust_pointer(oop* p,
+ HeapWord* beg_addr,
+ HeapWord* end_addr);
+
+ // Reference Processing
+ static ReferenceProcessor* const ref_processor() { return _ref_processor; }
+
+ // Return the SpaceId for the given address.
+ static SpaceId space_id(HeapWord* addr);
+
+ // Time since last full gc (in milliseconds).
+ static jlong millis_since_last_gc();
+
+#ifdef VALIDATE_MARK_SWEEP
+ static void track_adjusted_pointer(oop* p, oop newobj, bool isroot);
+ static void check_adjust_pointer(oop* p); // Adjust this pointer
+ static void track_interior_pointers(oop obj);
+ static void check_interior_pointers();
+
+ static void reset_live_oop_tracking(bool at_perm);
+ static void register_live_oop(oop p, size_t size);
+ static void validate_live_oop(oop p, size_t size);
+ static void live_oop_moved_to(HeapWord* q, size_t size, HeapWord* compaction_top);
+ static void compaction_complete();
+
+ // Querying operation of RecordMarkSweepCompaction results.
+ // Finds and prints the current base oop and offset for a word
+ // within an oop that was live during the last GC. Helpful for
+ // tracking down heap stomps.
+ static void print_new_location_of_heap_address(HeapWord* q);
+#endif // #ifdef VALIDATE_MARK_SWEEP
+
+ // Call backs for class unloading
+ // Update subklass/sibling/implementor links at end of marking.
+ 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_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.
+ static void verify_complete(SpaceId space_id);
+#endif // #ifdef ASSERT
+};
+
+bool PSParallelCompact::mark_obj(oop obj) {
+ const int obj_size = obj->size();
+ if (mark_bitmap()->mark_obj(obj, obj_size)) {
+ _summary_data.add_obj(obj, obj_size);
+ return true;
+ } else {
+ return false;
+ }
+}
+
+inline bool PSParallelCompact::print_phases()
+{
+ return _print_phases;
+}
+
+inline double PSParallelCompact::normal_distribution(double density)
+{
+ assert(_dwl_initialized, "uninitialized");
+ 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,
+ 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),
+ "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 &&
+ !_mark_bitmap.is_obj_beg(bit) &&
+ !_mark_bitmap.is_obj_end(bit - 1);
+}
+
+inline bool
+PSParallelCompact::is_in(HeapWord* p, HeapWord* beg_addr, HeapWord* end_addr) {
+ return p >= beg_addr && p < end_addr;
+}
+
+inline bool
+PSParallelCompact::is_in(oop* p, HeapWord* beg_addr, HeapWord* end_addr) {
+ return is_in((HeapWord*)p, beg_addr, end_addr);
+}
+
+inline MutableSpace* PSParallelCompact::space(SpaceId id) {
+ assert(id < last_space_id, "id out of range");
+ return _space_info[id].space();
+}
+
+inline HeapWord* PSParallelCompact::new_top(SpaceId id) {
+ assert(id < last_space_id, "id out of range");
+ return _space_info[id].new_top();
+}
+
+inline HeapWord* PSParallelCompact::dense_prefix(SpaceId id) {
+ assert(id < last_space_id, "id out of range");
+ return _space_info[id].dense_prefix();
+}
+
+inline ObjectStartArray* PSParallelCompact::start_array(SpaceId id) {
+ assert(id < last_space_id, "id out of range");
+ return _space_info[id].start_array();
+}
+
+inline bool PSParallelCompact::should_update_klass(klassOop k) {
+ return ((HeapWord*) k) >= dense_prefix(perm_space_id);
+}
+
+inline void PSParallelCompact::adjust_pointer(oop* p,
+ HeapWord* beg_addr,
+ HeapWord* end_addr) {
+ if (is_in(p, beg_addr, end_addr)) {
+ adjust_pointer(p);
+ }
+}
+
+class MoveAndUpdateClosure: public ParMarkBitMapClosure {
+ public:
+ inline MoveAndUpdateClosure(ParMarkBitMap* bitmap, ParCompactionManager* cm,
+ ObjectStartArray* start_array,
+ HeapWord* destination, size_t words);
+
+ // Accessors.
+ HeapWord* destination() const { return _destination; }
+
+ // If the object will fit (size <= words_remaining()), copy it to the current
+ // destination, update the interior oops and the start array and return either
+ // full (if the closure is full) or incomplete. If the object will not fit,
+ // return would_overflow.
+ virtual IterationStatus do_addr(HeapWord* addr, size_t size);
+
+ // Copy enough words to fill this closure, starting at source(). Interior
+ // oops and the start array are not updated. Return full.
+ IterationStatus copy_until_full();
+
+ // Copy enough words to fill this closure or to the end of an object,
+ // whichever is smaller, starting at source(). Interior oops and the start
+ // array are not updated.
+ void copy_partial_obj();
+
+ protected:
+ // Update variables to indicate that word_count words were processed.
+ inline void update_state(size_t word_count);
+
+ protected:
+ ObjectStartArray* const _start_array;
+ HeapWord* _destination; // Next addr to be written.
+};
+
+inline
+MoveAndUpdateClosure::MoveAndUpdateClosure(ParMarkBitMap* bitmap,
+ ParCompactionManager* cm,
+ ObjectStartArray* start_array,
+ HeapWord* destination,
+ size_t words) :
+ ParMarkBitMapClosure(bitmap, cm, words), _start_array(start_array)
+{
+ _destination = destination;
+}
+
+inline void MoveAndUpdateClosure::update_state(size_t words)
+{
+ decrement_words_remaining(words);
+ _source += words;
+ _destination += words;
+}
+
+class UpdateOnlyClosure: public ParMarkBitMapClosure {
+ private:
+ const PSParallelCompact::SpaceId _space_id;
+ ObjectStartArray* const _start_array;
+
+ public:
+ UpdateOnlyClosure(ParMarkBitMap* mbm,
+ ParCompactionManager* cm,
+ PSParallelCompact::SpaceId space_id);
+
+ // Update the object.
+ virtual IterationStatus do_addr(HeapWord* addr, size_t words);
+
+ inline void do_addr(HeapWord* addr);
+};
+
+inline void UpdateOnlyClosure::do_addr(HeapWord* addr) {
+ _start_array->allocate_block(addr);
+ oop(addr)->update_contents(compaction_manager());
+}
+
+class FillClosure: public ParMarkBitMapClosure {
+public:
+ FillClosure(ParCompactionManager* cm, PSParallelCompact::SpaceId space_id):
+ ParMarkBitMapClosure(PSParallelCompact::mark_bitmap(), cm),
+ _space_id(space_id),
+ _start_array(PSParallelCompact::start_array(space_id))
+ {
+ assert(_space_id == PSParallelCompact::perm_space_id ||
+ _space_id == PSParallelCompact::old_space_id,
+ "cannot use FillClosure in the young gen");
+ assert(bitmap() != NULL, "need a bitmap");
+ assert(_start_array != NULL, "need a start array");
+ }
+
+ void fill_region(HeapWord* addr, size_t size) {
+ MemRegion region(addr, size);
+ SharedHeap::fill_region_with_object(region);
+ _start_array->allocate_block(addr);
+ }
+
+ virtual IterationStatus do_addr(HeapWord* addr, size_t size) {
+ fill_region(addr, size);
+ return ParMarkBitMap::incomplete;
+ }
+
+private:
+ const PSParallelCompact::SpaceId _space_id;
+ ObjectStartArray* const _start_array;
+};