jdk8-mips64-public/hotspot: comparison src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp

--1:000000000000
+:f90c822e73f8
+/*
+* Copyright (c) 2005, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+* or visit www.oracle.com if you need additional information or have any
+* questions.
+*
+*/
+#ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPARALLELCOMPACT_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPARALLELCOMPACT_HPP
+#include "gc_implementation/parallelScavenge/objectStartArray.hpp"
+#include "gc_implementation/parallelScavenge/parMarkBitMap.hpp"
+#include "gc_implementation/parallelScavenge/psCompactionManager.hpp"
+#include "gc_implementation/shared/collectorCounters.hpp"
+#include "gc_implementation/shared/markSweep.hpp"
+#include "gc_implementation/shared/mutableSpace.hpp"
+#include "memory/sharedHeap.hpp"
+#include "oops/oop.hpp"
+class ParallelScavengeHeap;
+class PSAdaptiveSizePolicy;
+class PSYoungGen;
+class PSOldGen;
+class ParCompactionManager;
+class ParallelTaskTerminator;
+class PSParallelCompact;
+class GCTaskManager;
+class GCTaskQueue;
+class PreGCValues;
+class MoveAndUpdateClosure;
+class RefProcTaskExecutor;
+class ParallelOldTracer;
+class STWGCTimer;
+// The SplitInfo class holds the information needed to 'split' a source region
+// so that the live data can be copied to two destination *spaces*.  Normally,
+// all the live data in a region is copied to a single destination space (e.g.,
+// everything live in a region in eden is copied entirely into the old gen).
+// However, when the heap is nearly full, all the live data in eden may not fit
+// into the old gen.  Copying only some of the regions from eden to old gen
+// requires finding a region that does not contain a partial object (i.e., no
+// live object crosses the region boundary) somewhere near the last object that
+// does fit into the old gen.  Since it's not always possible to find such a
+// region, splitting is necessary for predictable behavior.
+//
+// A region is always split at the end of the partial object.  This avoids
+// additional tests when calculating the new location of a pointer, which is a
+// very hot code path.  The partial object and everything to its left will be
+// copied to another space (call it dest_space_1).  The live data to the right
+// of the partial object will be copied either within the space itself, or to a
+// different destination space (distinct from dest_space_1).
+//
+// Split points are identified during the summary phase, when region
+// destinations are computed:  data about the split, including the
+// partial_object_size, is recorded in a SplitInfo record and the
+// partial_object_size field in the summary data is set to zero.  The zeroing is
+// possible (and necessary) since the partial object will move to a different
+// destination space than anything to its right, thus the partial object should
+// not affect the locations of any objects to its right.
+//
+// The recorded data is used during the compaction phase, but only rarely:  when
+// the partial object on the split region will be copied across a destination
+// region boundary.  This test is made once each time a region is filled, and is
+// a simple address comparison, so the overhead is negligible (see
+// PSParallelCompact::first_src_addr()).
+//
+// Notes:
+//
+// Only regions with partial objects are split; a region without a partial
+// object does not need any extra bookkeeping.
+//
+// At most one region is split per space, so the amount of data required is
+// constant.
+//
+// A region is split only when the destination space would overflow.  Once that
+// happens, the destination space is abandoned and no other data (even from
+// other source spaces) is targeted to that destination space.  Abandoning the
+// destination space may leave a somewhat large unused area at the end, if a
+// large object caused the overflow.
+//
+// Future work:
+//
+// More bookkeeping would be required to continue to use the destination space.
+// The most general solution would allow data from regions in two different
+// source spaces to be "joined" in a single destination region.  At the very
+// least, additional code would be required in next_src_region() to detect the
+// join and skip to an out-of-order source region.  If the join region was also
+// the last destination region to which a split region was copied (the most
+// likely case), then additional work would be needed to get fill_region() to
+// stop iteration and switch to a new source region at the right point.  Basic
+// idea would be to use a fake value for the top of the source space.  It is
+// doable, if a bit tricky.
+//
+// A simpler (but less general) solution would fill the remainder of the
+// destination region with a dummy object and continue filling the next
+// destination region.
+class SplitInfo
+{
+public:
+// Return true if this split info is valid (i.e., if a split has been
+// recorded).  The very first region cannot have a partial object and thus is
+// never split, so 0 is the 'invalid' value.
+bool is_valid() const { return _src_region_idx > 0; }
+// Return true if this split holds data for the specified source region.
+inline bool is_split(size_t source_region) const;
+// The index of the split region, the size of the partial object on that
+// region and the destination of the partial object.
+size_t    src_region_idx() const   { return _src_region_idx; }
+size_t    partial_obj_size() const { return _partial_obj_size; }
+HeapWord* destination() const      { return _destination; }
+// The destination count of the partial object referenced by this split
+// (either 1 or 2).  This must be added to the destination count of the
+// remainder of the source region.
+unsigned int destination_count() const { return _destination_count; }
+// If a word within the partial object will be written to the first word of a
+// destination region, this is the address of the destination region;
+// otherwise this is NULL.
+HeapWord* dest_region_addr() const     { return _dest_region_addr; }
+// If a word within the partial object will be written to the first word of a
+// destination region, this is the address of that word within the partial
+// object; otherwise this is NULL.
+HeapWord* first_src_addr() const       { return _first_src_addr; }
+// Record the data necessary to split the region src_region_idx.
+void record(size_t src_region_idx, size_t partial_obj_size,
+HeapWord* destination);
+void clear();
+DEBUG_ONLY(void verify_clear();)
+private:
+size_t       _src_region_idx;
+size_t       _partial_obj_size;
+HeapWord*    _destination;
+unsigned int _destination_count;
+HeapWord*    _dest_region_addr;
+HeapWord*    _first_src_addr;
+};
+inline bool SplitInfo::is_split(size_t region_idx) const
+{
+return _src_region_idx == region_idx && is_valid();
+}
+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; }
+SplitInfo& split_info() { return _split_info; }
+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; }
+void publish_new_top() const              { _space->set_top(_new_top); }
+private:
+MutableSpace*     _space;
+HeapWord*         _new_top;
+HeapWord*         _min_dense_prefix;
+HeapWord*         _dense_prefix;
+ObjectStartArray* _start_array;
+SplitInfo         _split_info;
+};
+class ParallelCompactData
+{
+public:
+// Sizes are in HeapWords, unless indicated otherwise.
+static const size_t Log2RegionSize;
+static const size_t RegionSize;
+static const size_t RegionSizeBytes;
+// Mask for the bits in a size_t to get an offset within a region.
+static const size_t RegionSizeOffsetMask;
+// Mask for the bits in a pointer to get an offset within a region.
+static const size_t RegionAddrOffsetMask;
+// Mask for the bits in a pointer to get the address of the start of a region.
+static const size_t RegionAddrMask;
+static const size_t Log2BlockSize;
+static const size_t BlockSize;
+static const size_t BlockSizeBytes;
+static const size_t BlockSizeOffsetMask;
+static const size_t BlockAddrOffsetMask;
+static const size_t BlockAddrMask;
+static const size_t BlocksPerRegion;
+static const size_t Log2BlocksPerRegion;
+class RegionData
+{
+public:
+// Destination address of the region.
+HeapWord* destination() const { return _destination; }
+// The first region containing data destined for this region.
+size_t source_region() const { return _source_region; }
+// The object (if any) starting in this region and ending in a different
+// region that could not be updated during the main (parallel) compaction
+// phase.  This is different from _partial_obj_addr, which is an object that
+// extends onto a source region.  However, the two uses do not overlap in
+// time, so the same field is used to save space.
+HeapWord* deferred_obj_addr() const { return _partial_obj_addr; }
+// The starting address of the partial object extending onto the region.
+HeapWord* partial_obj_addr() const { return _partial_obj_addr; }
+// Size of the partial object extending onto the region (words).
+size_t partial_obj_size() const { return _partial_obj_size; }
+// Size of live data that lies within this region due to objects that start
+// in this region (words).  This does not include the partial object
+// extending onto the region (if any), or the part of an object that extends
+// onto the next region (if any).
+size_t live_obj_size() const { return _dc_and_los & los_mask; }
+// Total live data that lies within the region (words).
+size_t data_size() const { return partial_obj_size() + live_obj_size(); }
+// The destination_count is the number of other regions to which data from
+// this region will be copied.  At the end of the summary phase, the valid
+// values of destination_count are
+//
+// 0 - data from the region will be compacted completely into itself, or the
+//     region is empty.  The region can be claimed and then filled.
+// 1 - data from the region will be compacted into 1 other region; some
+//     data from the region may also be compacted into the region itself.
+// 2 - data from the region will be copied to 2 other regions.
+//
+// During compaction as regions are emptied, the destination_count is
+// decremented (atomically) and when it reaches 0, it can be claimed and
+// then filled.
+//
+// A region is claimed for processing by atomically changing the
+// destination_count to the claimed value (dc_claimed).  After a region has
+// been filled, the destination_count should be set to the completed value
+// (dc_completed).
+inline uint destination_count() const;
+inline uint destination_count_raw() const;
+// Whether the block table for this region has been filled.
+inline bool blocks_filled() const;
+// Number of times the block table was filled.
+DEBUG_ONLY(inline size_t blocks_filled_count() const;)
+// The location of the java heap data that corresponds to this region.
+inline HeapWord* data_location() const;
+// The highest address referenced by objects in this region.
+inline HeapWord* highest_ref() const;
+// Whether this region is available to be claimed, has been claimed, or has
+// been completed.
+//
+// Minor subtlety:  claimed() returns true if the region is marked
+// completed(), which is desirable since a region must be claimed before it
+// can be completed.
+bool available() const { return _dc_and_los < dc_one; }
+bool claimed() const   { return _dc_and_los >= dc_claimed; }
+bool completed() const { return _dc_and_los >= dc_completed; }
+// These are not atomic.
+void set_destination(HeapWord* addr)       { _destination = addr; }
+void set_source_region(size_t region)      { _source_region = region; }
+void set_deferred_obj_addr(HeapWord* addr) { _partial_obj_addr = addr; }
+void set_partial_obj_addr(HeapWord* addr)  { _partial_obj_addr = addr; }
+void set_partial_obj_size(size_t words)    {
+_partial_obj_size = (region_sz_t) words;
+}
+inline void set_blocks_filled();
+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 region.
+typedef uint region_sz_t;
+// Constants for manipulating the _dc_and_los field, which holds both the
+// destination count and live obj size.  The live obj size lives at the
+// least significant end so no masking is necessary when adding.
+static const region_sz_t dc_shift;           // Shift amount.
+static const region_sz_t dc_mask;            // Mask for destination count.
+static const region_sz_t dc_one;             // 1, shifted appropriately.
+static const region_sz_t dc_claimed;         // Region has been claimed.
+static const region_sz_t dc_completed;       // Region has been completed.
+static const region_sz_t los_mask;           // Mask for live obj size.
+HeapWord*            _destination;
+size_t               _source_region;
+HeapWord*            _partial_obj_addr;
+region_sz_t          _partial_obj_size;
+region_sz_t volatile _dc_and_los;
+bool                 _blocks_filled;
+#ifdef ASSERT
+size_t               _blocks_filled_count;   // Number of block table fills.
+// 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 region is pushed onto a 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 Region to the left
+// of the first live object that starts in the Block.
+class BlockData
+{
+public:
+typedef unsigned short int blk_ofs_t;
+blk_ofs_t offset() const    { return _offset; }
+void set_offset(size_t val) { _offset = (blk_ofs_t)val; }
+private:
+blk_ofs_t _offset;
+};
+public:
+ParallelCompactData();
+bool initialize(MemRegion covered_region);
+size_t region_count() const { return _region_count; }
+size_t reserved_byte_size() const { return _reserved_byte_size; }
+// Convert region indices to/from RegionData pointers.
+inline RegionData* region(size_t region_idx) const;
+inline size_t     region(const RegionData* const region_ptr) const;
+size_t block_count() const { return _block_count; }
+inline BlockData* block(size_t block_idx) const;
+inline size_t     block(const BlockData* block_ptr) const;
+void add_obj(HeapWord* addr, size_t len);
+void add_obj(oop p, size_t len) { add_obj((HeapWord*)p, len); }
+// Fill in the regions covering [beg, end) so that no data moves; i.e., the
+// destination of region n is simply the start of region n.  The argument beg
+// must be region-aligned; end need not be.
+void summarize_dense_prefix(HeapWord* beg, HeapWord* end);
+HeapWord* summarize_split_space(size_t src_region, SplitInfo& split_info,
+HeapWord* destination, HeapWord* target_end,
+HeapWord** target_next);
+bool summarize(SplitInfo& split_info,
+HeapWord* source_beg, HeapWord* source_end,
+HeapWord** source_next,
+HeapWord* target_beg, HeapWord* target_end,
+HeapWord** target_next);
+void clear();
+void clear_range(size_t beg_region, size_t end_region);
+void clear_range(HeapWord* beg, HeapWord* end) {
+clear_range(addr_to_region_idx(beg), addr_to_region_idx(end));
+}
+// Return the number of words between addr and the start of the region
+// containing addr.
+inline size_t     region_offset(const HeapWord* addr) const;
+// Convert addresses to/from a region index or region pointer.
+inline size_t     addr_to_region_idx(const HeapWord* addr) const;
+inline RegionData* addr_to_region_ptr(const HeapWord* addr) const;
+inline HeapWord*  region_to_addr(size_t region) const;
+inline HeapWord*  region_to_addr(size_t region, size_t offset) const;
+inline HeapWord*  region_to_addr(const RegionData* region) const;
+inline HeapWord*  region_align_down(HeapWord* addr) const;
+inline HeapWord*  region_align_up(HeapWord* addr) const;
+inline bool       is_region_aligned(HeapWord* addr) const;
+// Analogous to region_offset() for blocks.
+size_t     block_offset(const HeapWord* addr) const;
+size_t     addr_to_block_idx(const HeapWord* addr) const;
+size_t     addr_to_block_idx(const oop obj) const {
+return addr_to_block_idx((HeapWord*) obj);
+}
+inline BlockData* addr_to_block_ptr(const HeapWord* addr) const;
+inline HeapWord*  block_to_addr(size_t block) const;
+inline size_t     region_to_block_idx(size_t region) const;
+inline HeapWord*  block_align_down(HeapWord* addr) const;
+inline HeapWord*  block_align_up(HeapWord* addr) const;
+inline bool       is_block_aligned(HeapWord* addr) const;
+// Return the address one past the end of the partial object.
+HeapWord* partial_obj_end(size_t region_idx) const;
+// Return the location of the object after compaction.
+HeapWord* calc_new_pointer(HeapWord* addr);
+HeapWord* calc_new_pointer(oop p) {
+return calc_new_pointer((HeapWord*) p);
+}
+#ifdef  ASSERT
+void verify_clear(const PSVirtualSpace* vspace);
+void verify_clear();
+#endif  // #ifdef ASSERT
+private:
+bool initialize_block_data();
+bool initialize_region_data(size_t region_size);
+PSVirtualSpace* create_vspace(size_t count, size_t element_size);
+private:
+HeapWord*       _region_start;
+#ifdef  ASSERT
+HeapWord*       _region_end;
+#endif  // #ifdef ASSERT
+PSVirtualSpace* _region_vspace;
+size_t          _reserved_byte_size;
+RegionData*     _region_data;
+size_t          _region_count;
+PSVirtualSpace* _block_vspace;
+BlockData*      _block_data;
+size_t          _block_count;
+};
+inline uint
+ParallelCompactData::RegionData::destination_count_raw() const
+{
+return _dc_and_los & dc_mask;
+}
+inline uint
+ParallelCompactData::RegionData::destination_count() const
+{
+return destination_count_raw() >> dc_shift;
+}
+inline bool
+ParallelCompactData::RegionData::blocks_filled() const
+{
+return _blocks_filled;
+}
+#ifdef ASSERT
+inline size_t
+ParallelCompactData::RegionData::blocks_filled_count() const
+{
+return _blocks_filled_count;
+}
+#endif // #ifdef ASSERT
+inline void
+ParallelCompactData::RegionData::set_blocks_filled()
+{
+_blocks_filled = true;
+// Debug builds count the number of times the table was filled.
+DEBUG_ONLY(Atomic::inc_ptr(&_blocks_filled_count));
+}
+inline void
+ParallelCompactData::RegionData::set_destination_count(uint count)
+{
+assert(count <= (dc_completed >> dc_shift), "count too large");
+const region_sz_t live_sz = (region_sz_t) live_obj_size();
+_dc_and_los = (count << dc_shift) | live_sz;
+}
+inline void ParallelCompactData::RegionData::set_live_obj_size(size_t words)
+{
+assert(words <= los_mask, "would overflow");
+_dc_and_los = destination_count_raw() | (region_sz_t)words;
+}
+inline void ParallelCompactData::RegionData::decrement_destination_count()
+{
+assert(_dc_and_los < dc_claimed, "already claimed");
+assert(_dc_and_los >= dc_one, "count would go negative");
+Atomic::add((int)dc_mask, (volatile int*)&_dc_and_los);
+}
+inline HeapWord* ParallelCompactData::RegionData::data_location() const
+{
+DEBUG_ONLY(return _data_location;)
+NOT_DEBUG(return NULL;)
+}
+inline HeapWord* ParallelCompactData::RegionData::highest_ref() const
+{
+DEBUG_ONLY(return _highest_ref;)
+NOT_DEBUG(return NULL;)
+}
+inline void ParallelCompactData::RegionData::set_data_location(HeapWord* addr)
+{
+DEBUG_ONLY(_data_location = addr;)
+}
+inline void ParallelCompactData::RegionData::set_completed()
+{
+assert(claimed(), "must be claimed first");
+_dc_and_los = dc_completed | (region_sz_t) live_obj_size();
+}
+// MT-unsafe claiming of a region.  Should only be used during single threaded
+// execution.
+inline bool ParallelCompactData::RegionData::claim_unsafe()
+{
+if (available()) {
+_dc_and_los |= dc_claimed;
+return true;
+}
+return false;
+}
+inline void ParallelCompactData::RegionData::add_live_obj(size_t words)
+{
+assert(words <= (size_t)los_mask - live_obj_size(), "overflow");
+Atomic::add((int) words, (volatile int*) &_dc_and_los);
+}
+inline void ParallelCompactData::RegionData::set_highest_ref(HeapWord* addr)
+{
+#ifdef ASSERT
+HeapWord* tmp = _highest_ref;
+while (addr > tmp) {
+tmp = (HeapWord*)Atomic::cmpxchg_ptr(addr, &_highest_ref, tmp);
+}
+#endif  // #ifdef ASSERT
+}
+inline bool ParallelCompactData::RegionData::claim()
+{
+const int los = (int) live_obj_size();
+const int old = Atomic::cmpxchg(dc_claimed | los,
+(volatile int*) &_dc_and_los, los);
+return old == los;
+}
+inline ParallelCompactData::RegionData*
+ParallelCompactData::region(size_t region_idx) const
+{
+assert(region_idx <= region_count(), "bad arg");
+return _region_data + region_idx;
+}
+inline size_t
+ParallelCompactData::region(const RegionData* const region_ptr) const
+{
+assert(region_ptr >= _region_data, "bad arg");
+assert(region_ptr <= _region_data + region_count(), "bad arg");
+return pointer_delta(region_ptr, _region_data, sizeof(RegionData));
+}
+inline ParallelCompactData::BlockData*
+ParallelCompactData::block(size_t n) const {
+assert(n < block_count(), "bad arg");
+return _block_data + n;
+}
+inline size_t
+ParallelCompactData::region_offset(const HeapWord* addr) const
+{
+assert(addr >= _region_start, "bad addr");
+assert(addr <= _region_end, "bad addr");
+return (size_t(addr) & RegionAddrOffsetMask) >> LogHeapWordSize;
+}
+inline size_t
+ParallelCompactData::addr_to_region_idx(const HeapWord* addr) const
+{
+assert(addr >= _region_start, "bad addr");
+assert(addr <= _region_end, "bad addr");
+return pointer_delta(addr, _region_start) >> Log2RegionSize;
+}
+inline ParallelCompactData::RegionData*
+ParallelCompactData::addr_to_region_ptr(const HeapWord* addr) const
+{
+return region(addr_to_region_idx(addr));
+}
+inline HeapWord*
+ParallelCompactData::region_to_addr(size_t region) const
+{
+assert(region <= _region_count, "region out of range");
+return _region_start + (region << Log2RegionSize);
+}
+inline HeapWord*
+ParallelCompactData::region_to_addr(const RegionData* region) const
+{
+return region_to_addr(pointer_delta(region, _region_data,
+sizeof(RegionData)));
+}
+inline HeapWord*
+ParallelCompactData::region_to_addr(size_t region, size_t offset) const
+{
+assert(region <= _region_count, "region out of range");
+assert(offset < RegionSize, "offset too big");  // This may be too strict.
+return region_to_addr(region) + offset;
+}
+inline HeapWord*
+ParallelCompactData::region_align_down(HeapWord* addr) const
+{
+assert(addr >= _region_start, "bad addr");
+assert(addr < _region_end + RegionSize, "bad addr");
+return (HeapWord*)(size_t(addr) & RegionAddrMask);
+}
+inline HeapWord*
+ParallelCompactData::region_align_up(HeapWord* addr) const
+{
+assert(addr >= _region_start, "bad addr");
+assert(addr <= _region_end, "bad addr");
+return region_align_down(addr + RegionSizeOffsetMask);
+}
+inline bool
+ParallelCompactData::is_region_aligned(HeapWord* addr) const
+{
+return region_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 (size_t(addr) & BlockAddrOffsetMask) >> LogHeapWordSize;
+}
+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);
+}
+inline size_t
+ParallelCompactData::region_to_block_idx(size_t region) const
+{
+return region << Log2BlocksPerRegion;
+}
+inline HeapWord*
+ParallelCompactData::block_align_down(HeapWord* addr) const
+{
+assert(addr >= _region_start, "bad addr");
+assert(addr < _region_end + RegionSize, "bad addr");
+return (HeapWord*)(size_t(addr) & BlockAddrMask);
+}
+inline HeapWord*
+ParallelCompactData::block_align_up(HeapWord* addr) const
+{
+assert(addr >= _region_start, "bad addr");
+assert(addr <= _region_end, "bad addr");
+return block_align_down(addr + BlockSizeOffsetMask);
+}
+inline bool
+ParallelCompactData::is_block_aligned(HeapWord* addr) const
+{
+return block_offset(addr) == 0;
+}
+// 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;
+}
+// The UseParallelOldGC collector is a stop-the-world garbage collector that
+// does parts of the collection using parallel threads.  The collection includes
+// the tenured generation and the young generation.  The permanent generation is
+// collected at the same time as the other two generations but the permanent
+// generation is collect by a single GC thread.  The permanent generation is
+// collected serially because of the requirement that during the processing of a
+// klass AAA, any objects reference by AAA must already have been processed.
+// This requirement is enforced by a left (lower address) to right (higher
+// address) sliding compaction.
+//
+// There are four phases of the collection.
+//
+//      - marking phase
+//      - summary phase
+//      - compacting phase
+//      - clean up phase
+//
+// Roughly speaking these phases correspond, respectively, to
+//      - mark all the live objects
+//      - calculate the destination of each object at the end of the collection
+//      - move the objects to their destination
+//      - update some references and reinitialize some variables
+//
+// These three phases are invoked in PSParallelCompact::invoke_no_policy().  The
+// marking phase is implemented in PSParallelCompact::marking_phase() and does a
+// complete marking of the heap.  The summary phase is implemented in
+// PSParallelCompact::summary_phase().  The move and update phase is implemented
+// in PSParallelCompact::compact().
+//
+// A space that is being collected is divided into regions and with each region
+// is associated an object of type ParallelCompactData.  Each region is of a
+// fixed size and typically will contain more than 1 object and may have parts
+// of objects at the front and back of the region.
+//
+// region            -----+---------------------+----------
+// objects covered   [ AAA  )[ BBB )[ CCC   )[ DDD     )
+//
+// The marking phase does a complete marking of all live objects in the heap.
+// The marking also compiles the size of the data for all live objects covered
+// by the region.  This size includes the part of any live object spanning onto
+// the region (part of AAA if it is live) from the front, all live objects
+// contained in the region (BBB and/or CCC if they are live), and the part of
+// any live objects covered by the region that extends off the region (part of
+// DDD if it is live).  The marking phase uses multiple GC threads and marking
+// is done in a bit array of type ParMarkBitMap.  The marking of the bit map is
+// done atomically as is the accumulation of the size of the live objects
+// covered by a region.
+//
+// The summary phase calculates the total live data to the left of each region
+// XXX.  Based on that total and the bottom of the space, it can calculate the
+// starting location of the live data in XXX.  The summary phase calculates for
+// each region XXX quantites such as
+//
+//      - the amount of live data at the beginning of a region from an object
+//        entering the region.
+//      - the location of the first live data on the region
+//      - a count of the number of regions receiving live data from XXX.
+//
+// See ParallelCompactData for precise details.  The summary phase also
+// calculates the dense prefix for the compaction.  The dense prefix is a
+// portion at the beginning of the space that is not moved.  The objects in the
+// dense prefix do need to have their object references updated.  See method
+// summarize_dense_prefix().
+//
+// The summary phase is done using 1 GC thread.
+//
+// The compaction phase moves objects to their new location and updates all
+// references in the object.
+//
+// A current exception is that objects that cross a region boundary are moved
+// but do not have their references updated.  References are not updated because
+// it cannot easily be determined if the klass pointer KKK for the object AAA
+// has been updated.  KKK likely resides in a region to the left of the region
+// containing AAA.  These AAA's have there references updated at the end in a
+// clean up phase.  See the method PSParallelCompact::update_deferred_objects().
+// An alternate strategy is being investigated for this deferral of updating.
+//
+// Compaction is done on a region basis.  A region that is ready to be filled is
+// put on a ready list and GC threads take region off the list and fill them.  A
+// region is ready to be filled if it empty of live objects.  Such a region may
+// have been initially empty (only contained dead objects) or may have had all
+// its live objects copied out already.  A region that compacts into itself is
+// also ready for filling.  The ready list is initially filled with empty
+// regions and regions compacting into themselves.  There is always at least 1
+// region that can be put on the ready list.  The regions are atomically added
+// and removed from the ready list.
+class PSParallelCompact : AllStatic {
+public:
+// Convenient access to type names.
+typedef ParMarkBitMap::idx_t idx_t;
+typedef ParallelCompactData::RegionData RegionData;
+typedef ParallelCompactData::BlockData BlockData;
+typedef enum {
+old_space_id, eden_space_id,
+from_space_id, to_space_id, last_space_id
+} SpaceId;
+public:
+// Inline closure decls
+//
+class IsAliveClosure: public BoolObjectClosure {
+public:
+virtual bool do_object_b(oop p);
+};
+class KeepAliveClosure: public OopClosure {
+private:
+ParCompactionManager* _compaction_manager;
+protected:
+template <class T> inline void do_oop_work(T* p);
+public:
+KeepAliveClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
+virtual void do_oop(oop* p);
+virtual void do_oop(narrowOop* p);
+};
+class FollowStackClosure: public VoidClosure {
+private:
+ParCompactionManager* _compaction_manager;
+public:
+FollowStackClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
+virtual void do_void();
+};
+class AdjustPointerClosure: public OopClosure {
+public:
+virtual void do_oop(oop* p);
+virtual void do_oop(narrowOop* p);
+// do not walk from thread stacks to the code cache on this phase
+virtual void do_code_blob(CodeBlob* cb) const { }
+};
+class AdjustKlassClosure : public KlassClosure {
+public:
+void do_klass(Klass* klass);
+};
+friend class KeepAliveClosure;
+friend class FollowStackClosure;
+friend class AdjustPointerClosure;
+friend class AdjustKlassClosure;
+friend class FollowKlassClosure;
+friend class InstanceClassLoaderKlass;
+friend class RefProcTaskProxy;
+private:
+static STWGCTimer           _gc_timer;
+static ParallelOldTracer    _gc_tracer;
+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_pointer_closure;
+static AdjustKlassClosure   _adjust_klass_closure;
+// Reference processing (used in ...follow_contents)
+static ReferenceProcessor*  _ref_processor;
+// Updated location of intArrayKlassObj.
+static Klass* _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:
+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,
+ParallelOldTracer *gc_tracer);
+template <class T>
+static inline void follow_root(ParCompactionManager* cm, T* 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) region in the range [beg, end) that has at least
+// dead_words of dead space to the left.  The argument beg must be the first
+// region in the space that is not completely live.
+static RegionData* dead_wood_limit_region(const RegionData* beg,
+const RegionData* end,
+size_t dead_words);
+// Return a pointer to the first region in the range [beg, end) that is not
+// completely full.
+static RegionData* first_dead_space_region(const RegionData* beg,
+const RegionData* end);
+// Return a value indicating the benefit or 'yield' if the compacted region
+// were to start (or equivalently if the dense prefix were to end) at the
+// candidate region.  Higher values are better.
+//
+// The value is based on the amount of space reclaimed vs. the costs of (a)
+// updating references in the dense prefix plus (b) copying objects and
+// updating references in the compacted region.
+static inline double reclaimed_ratio(const RegionData* const candidate,
+HeapWord* const bottom,
+HeapWord* const top,
+HeapWord* const new_top);
+// Compute the dense prefix for the designated space.
+static HeapWord* compute_dense_prefix(const SpaceId id,
+bool maximum_compaction);
+// Return true if dead space crosses onto the specified Region; bit must be
+// the bit index corresponding to the first word of the Region.
+static inline bool dead_space_crosses_boundary(const RegionData* region,
+idx_t bit);
+// Summary phase utility routine to fill dead space (if any) at the dense
+// prefix boundary.  Should only be called if the the dense prefix is
+// non-empty.
+static void fill_dense_prefix_end(SpaceId id);
+// Clear the summary data source_region field for the specified addresses.
+static void clear_source_region(HeapWord* beg_addr, HeapWord* end_addr);
+#ifndef PRODUCT
+// Routines to provoke splitting a young gen space (ParallelOldGCSplitALot).
+// Fill the region [start, start + words) with live object(s).  Only usable
+// for the old and permanent generations.
+static void fill_with_live_objects(SpaceId id, HeapWord* const start,
+size_t words);
+// Include the new objects in the summary data.
+static void summarize_new_objects(SpaceId id, HeapWord* start);
+// Add live objects to a survivor space since it's rare that both survivors
+// are non-empty.
+static void provoke_split_fill_survivor(SpaceId id);
+// Add live objects and/or choose the dense prefix to provoke splitting.
+static void provoke_split(bool & maximum_compaction);
+#endif
+static void summarize_spaces_quick();
+static void summarize_space(SpaceId id, bool maximum_compaction);
+static void summary_phase(ParCompactionManager* cm, bool maximum_compaction);
+// Adjust addresses in roots.  Does not adjust addresses in heap.
+static void adjust_roots();
+DEBUG_ONLY(static void write_block_fill_histogram(outputStream* const out);)
+// Move objects to new locations.
+static void compact_perm(ParCompactionManager* cm);
+static void compact();
+// Add available regions to the stack and draining tasks to the task queue.
+static void enqueue_region_draining_tasks(GCTaskQueue* q,
+uint parallel_gc_threads);
+// Add dense prefix update tasks to the task queue.
+static void enqueue_dense_prefix_tasks(GCTaskQueue* q,
+uint parallel_gc_threads);
+// Add region stealing tasks to the task queue.
+static void enqueue_region_stealing_tasks(
+GCTaskQueue* q,
+ParallelTaskTerminator* terminator_ptr,
+uint parallel_gc_threads);
+// 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();
+public:
+class MarkAndPushClosure: public OopClosure {
+private:
+ParCompactionManager* _compaction_manager;
+public:
+MarkAndPushClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
+virtual void do_oop(oop* p);
+virtual void do_oop(narrowOop* p);
+};
+// The one and only place to start following the classes.
+// Should only be applied to the ClassLoaderData klasses list.
+class FollowKlassClosure : public KlassClosure {
+private:
+MarkAndPushClosure* _mark_and_push_closure;
+public:
+FollowKlassClosure(MarkAndPushClosure* mark_and_push_closure) :
+_mark_and_push_closure(mark_and_push_closure) { }
+void do_klass(Klass* klass);
+};
+PSParallelCompact();
+// Convenient accessor for Universe::heap().
+static ParallelScavengeHeap* gc_heap() {
+return (ParallelScavengeHeap*)Universe::heap();
+}
+static void invoke(bool maximum_heap_compaction);
+static bool 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();
+// Closure accessors
+static OopClosure* adjust_pointer_closure()      { return (OopClosure*)&_adjust_pointer_closure; }
+static KlassClosure* adjust_klass_closure()      { return (KlassClosure*)&_adjust_klass_closure; }
+static BoolObjectClosure* is_alive_closure()     { return (BoolObjectClosure*)&_is_alive_closure; }
+// 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 Klass* updated_int_array_klass_obj() {
+return _updated_int_array_klass_obj;
+}
+// Marking support
+static inline bool mark_obj(oop obj);
+static inline bool is_marked(oop obj);
+// Check mark and maybe push on marking stack
+template <class T> static inline void mark_and_push(ParCompactionManager* cm,
+T* p);
+template <class T> static inline void adjust_pointer(T* p);
+static inline void follow_klass(ParCompactionManager* cm, Klass* klass);
+static void follow_class_loader(ParCompactionManager* cm,
+ClassLoaderData* klass);
+// 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);
+// 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 region range in the dense prefix.
+// This includes saving any object not updated.
+static void dense_prefix_regions_epilogue(ParCompactionManager* cm,
+size_t region_start_index,
+size_t region_end_index,
+idx_t exiting_object_offset,
+idx_t region_offset_start,
+idx_t region_offset_end);
+// Update a region in the dense prefix.  For each live object
+// in the region, update it's interior references.  For each
+// dead object, fill it with deadwood. Dead space at the end
+// of a region range will be filled to the start of the next
+// live object regardless of the region_index_end.  None of the
+// objects in the dense prefix move and dead space is dead
+// (holds only dead objects that don't need any processing), so
+// dead space can be filled in any order.
+static void update_and_deadwood_in_dense_prefix(ParCompactionManager* cm,
+SpaceId space_id,
+size_t region_index_start,
+size_t region_index_end);
+// Return the address of the count + 1st live word in the range [beg, end).
+static HeapWord* skip_live_words(HeapWord* beg, HeapWord* end, size_t count);
+// Return the address of the word to be copied to dest_addr, which must be
+// aligned to a region boundary.
+static HeapWord* first_src_addr(HeapWord* const dest_addr,
+SpaceId src_space_id,
+size_t src_region_idx);
+// Determine the next source region, set closure.source() to the start of the
+// new region return the region index.  Parameter end_addr is the address one
+// beyond the end of source range just processed.  If necessary, switch to a
+// new source space and set src_space_id (in-out parameter) and src_space_top
+// (out parameter) accordingly.
+static size_t next_src_region(MoveAndUpdateClosure& closure,
+SpaceId& src_space_id,
+HeapWord*& src_space_top,
+HeapWord* end_addr);
+// Decrement the destination count for each non-empty source region in the
+// range [beg_region, region(region_align_up(end_addr))).  If the destination
+// count for a region goes to 0 and it needs to be filled, enqueue it.
+static void decrement_destination_counts(ParCompactionManager* cm,
+SpaceId src_space_id,
+size_t beg_region,
+HeapWord* end_addr);
+// Fill a region, copying objects from one or more source regions.
+static void fill_region(ParCompactionManager* cm, size_t region_idx);
+static void fill_and_update_region(ParCompactionManager* cm, size_t region) {
+fill_region(cm, region);
+}
+// Fill in the block table for the specified region.
+static void fill_blocks(size_t region_idx);
+// Update the deferred objects in the space.
+static void update_deferred_objects(ParCompactionManager* cm, SpaceId id);
+static ParMarkBitMap* mark_bitmap() { return &_mark_bitmap; }
+static ParallelCompactData& summary_data() { return _summary_data; }
+// Reference Processing
+static ReferenceProcessor* const ref_processor() { return _ref_processor; }
+static STWGCTimer* gc_timer() { return &_gc_timer; }
+// 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();
+static void print_on_error(outputStream* st);
+#ifndef PRODUCT
+// Debugging support.
+static const char* space_names[last_space_id];
+static void print_region_ranges();
+static void print_dense_prefix_stats(const char* const algorithm,
+const SpaceId id,
+const bool maximum_compaction,
+HeapWord* const addr);
+static void summary_phase_msg(SpaceId dst_space_id,
+HeapWord* dst_beg, HeapWord* dst_end,
+SpaceId src_space_id,
+HeapWord* src_beg, HeapWord* src_end);
+#endif  // #ifndef PRODUCT
+#ifdef  ASSERT
+// Sanity check the new location of a word in the heap.
+static inline void check_new_location(HeapWord* old_addr, HeapWord* new_addr);
+// Verify that all the regions have been emptied.
+static void verify_complete(SpaceId space_id);
+#endif  // #ifdef ASSERT
+};
+inline bool PSParallelCompact::mark_obj(oop obj) {
+const 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::is_marked(oop obj) {
+return mark_bitmap()->is_marked(obj);
+}
+template <class T>
+inline void PSParallelCompact::follow_root(ParCompactionManager* cm, T* p) {
+assert(!Universe::heap()->is_in_reserved(p),
+"roots shouldn't be things within the heap");
+T heap_oop = oopDesc::load_heap_oop(p);
+if (!oopDesc::is_null(heap_oop)) {
+oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
+if (mark_bitmap()->is_unmarked(obj)) {
+if (mark_obj(obj)) {
+obj->follow_contents(cm);
+}
+}
+}
+cm->follow_marking_stacks();
+}
+template <class T>
+inline void PSParallelCompact::mark_and_push(ParCompactionManager* cm, T* p) {
+T heap_oop = oopDesc::load_heap_oop(p);
+if (!oopDesc::is_null(heap_oop)) {
+oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
+if (mark_bitmap()->is_unmarked(obj) && mark_obj(obj)) {
+cm->push(obj);
+}
+}
+}
+template <class T>
+inline void PSParallelCompact::adjust_pointer(T* p) {
+T heap_oop = oopDesc::load_heap_oop(p);
+if (!oopDesc::is_null(heap_oop)) {
+oop obj     = oopDesc::decode_heap_oop_not_null(heap_oop);
+oop new_obj = (oop)summary_data().calc_new_pointer(obj);
+assert(new_obj != NULL,                    // is forwarding ptr?
+"should be forwarded");
+// Just always do the update unconditionally?
+if (new_obj != NULL) {
+assert(Universe::heap()->is_in_reserved(new_obj),
+"should be in object space");
+oopDesc::encode_store_heap_oop_not_null(p, new_obj);
+}
+}
+}
+inline void PSParallelCompact::follow_klass(ParCompactionManager* cm, Klass* klass) {
+oop holder = klass->klass_holder();
+PSParallelCompact::mark_and_push(cm, &holder);
+}
+template <class T>
+inline void PSParallelCompact::KeepAliveClosure::do_oop_work(T* p) {
+mark_and_push(_compaction_manager, p);
+}
+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 RegionData* region,
+idx_t bit)
+{
+assert(bit > 0, "cannot call this for the first bit/region");
+assert(_summary_data.region_to_addr(region) == _mark_bitmap.bit_to_addr(bit),
+"sanity check");
+// Dead space crosses the boundary if (1) a partial object does not extend
+// onto the region, (2) an object does not start at the beginning of the
+// region, and (3) an object does not end at the end of the prior region.
+return region->partial_obj_size() == 0 &&
+!_mark_bitmap.is_obj_beg(bit) &&
+!_mark_bitmap.is_obj_end(bit - 1);
+}
+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();
+}
+#ifdef ASSERT
+inline void
+PSParallelCompact::check_new_location(HeapWord* old_addr, HeapWord* new_addr)
+{
+assert(old_addr >= new_addr || space_id(old_addr) != space_id(new_addr),
+"must move left or to a different space");
+assert(is_object_aligned((intptr_t)old_addr) && is_object_aligned((intptr_t)new_addr),
+"checking alignment");
+}
+#endif // ASSERT
+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),
+_start_array(PSParallelCompact::start_array(space_id))
+{
+assert(space_id == PSParallelCompact::old_space_id,
+"cannot use FillClosure in the young gen");
+}
+virtual IterationStatus do_addr(HeapWord* addr, size_t size) {
+CollectedHeap::fill_with_objects(addr, size);
+HeapWord* const end = addr + size;
+do {
+_start_array->allocate_block(addr);
+addr += oop(addr)->size();
+} while (addr < end);
+return ParMarkBitMap::incomplete;
+}
+private:
+ObjectStartArray* const _start_array;
+};
+#endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPARALLELCOMPACT_HPP

Mercurial > jdk8-mips64-public > hotspot / file comparison

comparison: src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp

src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp