Mercurial > hg > graal-compiler
diff src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp @ 0:a61af66fc99e jdk7-b24
Initial load
author | duke |
---|---|
date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | ba764ed4b6f2 |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/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; +};