truffle: src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp comparison

comparison src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp @ 0:a61af66fc99e jdk7-b24

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author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	82db0859acbe c0492d52d55b

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--1:000000000000
+:a61af66fc99e
+/*
+* 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.
+*
+*/
+#include "incls/_precompiled.incl"
+#include "incls/_psParallelCompact.cpp.incl"
+#include <math.h>
+// All sizes are in HeapWords.
+const size_t ParallelCompactData::Log2ChunkSize  = 9; // 512 words
+const size_t ParallelCompactData::ChunkSize      = (size_t)1 << Log2ChunkSize;
+const size_t ParallelCompactData::ChunkSizeBytes = ChunkSize << LogHeapWordSize;
+const size_t ParallelCompactData::ChunkSizeOffsetMask = ChunkSize - 1;
+const size_t ParallelCompactData::ChunkAddrOffsetMask = ChunkSizeBytes - 1;
+const size_t ParallelCompactData::ChunkAddrMask  = ~ChunkAddrOffsetMask;
+// 32-bit:  128 words covers 4 bitmap words
+// 64-bit:  128 words covers 2 bitmap words
+const size_t ParallelCompactData::Log2BlockSize   = 7; // 128 words
+const size_t ParallelCompactData::BlockSize       = (size_t)1 << Log2BlockSize;
+const size_t ParallelCompactData::BlockOffsetMask = BlockSize - 1;
+const size_t ParallelCompactData::BlockMask       = ~BlockOffsetMask;
+const size_t ParallelCompactData::BlocksPerChunk = ChunkSize / BlockSize;
+const ParallelCompactData::ChunkData::chunk_sz_t
+ParallelCompactData::ChunkData::dc_shift = 27;
+const ParallelCompactData::ChunkData::chunk_sz_t
+ParallelCompactData::ChunkData::dc_mask = ~0U << dc_shift;
+const ParallelCompactData::ChunkData::chunk_sz_t
+ParallelCompactData::ChunkData::dc_one = 0x1U << dc_shift;
+const ParallelCompactData::ChunkData::chunk_sz_t
+ParallelCompactData::ChunkData::los_mask = ~dc_mask;
+const ParallelCompactData::ChunkData::chunk_sz_t
+ParallelCompactData::ChunkData::dc_claimed = 0x8U << dc_shift;
+const ParallelCompactData::ChunkData::chunk_sz_t
+ParallelCompactData::ChunkData::dc_completed = 0xcU << dc_shift;
+#ifdef ASSERT
+short   ParallelCompactData::BlockData::_cur_phase = 0;
+#endif
+SpaceInfo PSParallelCompact::_space_info[PSParallelCompact::last_space_id];
+bool      PSParallelCompact::_print_phases = false;
+ReferenceProcessor* PSParallelCompact::_ref_processor = NULL;
+klassOop            PSParallelCompact::_updated_int_array_klass_obj = NULL;
+double PSParallelCompact::_dwl_mean;
+double PSParallelCompact::_dwl_std_dev;
+double PSParallelCompact::_dwl_first_term;
+double PSParallelCompact::_dwl_adjustment;
+#ifdef  ASSERT
+bool   PSParallelCompact::_dwl_initialized = false;
+#endif  // #ifdef ASSERT
+#ifdef VALIDATE_MARK_SWEEP
+GrowableArray<oop*>*    PSParallelCompact::_root_refs_stack = NULL;
+GrowableArray<oop> *    PSParallelCompact::_live_oops = NULL;
+GrowableArray<oop> *    PSParallelCompact::_live_oops_moved_to = NULL;
+GrowableArray<size_t>*  PSParallelCompact::_live_oops_size = NULL;
+size_t                  PSParallelCompact::_live_oops_index = 0;
+size_t                  PSParallelCompact::_live_oops_index_at_perm = 0;
+GrowableArray<oop*>*    PSParallelCompact::_other_refs_stack = NULL;
+GrowableArray<oop*>*    PSParallelCompact::_adjusted_pointers = NULL;
+bool                    PSParallelCompact::_pointer_tracking = false;
+bool                    PSParallelCompact::_root_tracking = true;
+GrowableArray<HeapWord*>* PSParallelCompact::_cur_gc_live_oops = NULL;
+GrowableArray<HeapWord*>* PSParallelCompact::_cur_gc_live_oops_moved_to = NULL;
+GrowableArray<size_t>   * PSParallelCompact::_cur_gc_live_oops_size = NULL;
+GrowableArray<HeapWord*>* PSParallelCompact::_last_gc_live_oops = NULL;
+GrowableArray<HeapWord*>* PSParallelCompact::_last_gc_live_oops_moved_to = NULL;
+GrowableArray<size_t>   * PSParallelCompact::_last_gc_live_oops_size = NULL;
+#endif
+// XXX beg - verification code; only works while we also mark in object headers
+static void
+verify_mark_bitmap(ParMarkBitMap& _mark_bitmap)
+{
+ParallelScavengeHeap* heap = PSParallelCompact::gc_heap();
+PSPermGen* perm_gen = heap->perm_gen();
+PSOldGen* old_gen = heap->old_gen();
+PSYoungGen* young_gen = heap->young_gen();
+MutableSpace* perm_space = perm_gen->object_space();
+MutableSpace* old_space = old_gen->object_space();
+MutableSpace* eden_space = young_gen->eden_space();
+MutableSpace* from_space = young_gen->from_space();
+MutableSpace* to_space = young_gen->to_space();
+// 'from_space' here is the survivor space at the lower address.
+if (to_space->bottom() < from_space->bottom()) {
+from_space = to_space;
+to_space = young_gen->from_space();
+}
+HeapWord* boundaries[12];
+unsigned int bidx = 0;
+const unsigned int bidx_max = sizeof(boundaries) / sizeof(boundaries[0]);
+boundaries[0] = perm_space->bottom();
+boundaries[1] = perm_space->top();
+boundaries[2] = old_space->bottom();
+boundaries[3] = old_space->top();
+boundaries[4] = eden_space->bottom();
+boundaries[5] = eden_space->top();
+boundaries[6] = from_space->bottom();
+boundaries[7] = from_space->top();
+boundaries[8] = to_space->bottom();
+boundaries[9] = to_space->top();
+boundaries[10] = to_space->end();
+boundaries[11] = to_space->end();
+BitMap::idx_t beg_bit = 0;
+BitMap::idx_t end_bit;
+BitMap::idx_t tmp_bit;
+const BitMap::idx_t last_bit = _mark_bitmap.size();
+do {
+HeapWord* addr = _mark_bitmap.bit_to_addr(beg_bit);
+if (_mark_bitmap.is_marked(beg_bit)) {
+oop obj = (oop)addr;
+assert(obj->is_gc_marked(), "obj header is not marked");
+end_bit = _mark_bitmap.find_obj_end(beg_bit, last_bit);
+const size_t size = _mark_bitmap.obj_size(beg_bit, end_bit);
+assert(size == (size_t)obj->size(), "end bit wrong?");
+beg_bit = _mark_bitmap.find_obj_beg(beg_bit + 1, last_bit);
+assert(beg_bit > end_bit, "bit set in middle of an obj");
+} else {
+if (addr >= boundaries[bidx] && addr < boundaries[bidx + 1]) {
+// a dead object in the current space.
+oop obj = (oop)addr;
+end_bit = _mark_bitmap.addr_to_bit(addr + obj->size());
+assert(!obj->is_gc_marked(), "obj marked in header, not in bitmap");
+tmp_bit = beg_bit + 1;
+beg_bit = _mark_bitmap.find_obj_beg(tmp_bit, end_bit);
+assert(beg_bit == end_bit, "beg bit set in unmarked obj");
+beg_bit = _mark_bitmap.find_obj_end(tmp_bit, end_bit);
+assert(beg_bit == end_bit, "end bit set in unmarked obj");
+} else if (addr < boundaries[bidx + 2]) {
+// addr is between top in the current space and bottom in the next.
+end_bit = beg_bit + pointer_delta(boundaries[bidx + 2], addr);
+tmp_bit = beg_bit;
+beg_bit = _mark_bitmap.find_obj_beg(tmp_bit, end_bit);
+assert(beg_bit == end_bit, "beg bit set above top");
+beg_bit = _mark_bitmap.find_obj_end(tmp_bit, end_bit);
+assert(beg_bit == end_bit, "end bit set above top");
+bidx += 2;
+} else if (bidx < bidx_max - 2) {
+bidx += 2; // ???
+} else {
+tmp_bit = beg_bit;
+beg_bit = _mark_bitmap.find_obj_beg(tmp_bit, last_bit);
+assert(beg_bit == last_bit, "beg bit set outside heap");
+beg_bit = _mark_bitmap.find_obj_end(tmp_bit, last_bit);
+assert(beg_bit == last_bit, "end bit set outside heap");
+}
+}
+} while (beg_bit < last_bit);
+}
+// XXX end - verification code; only works while we also mark in object headers
+#ifndef PRODUCT
+const char* PSParallelCompact::space_names[] = {
+"perm", "old ", "eden", "from", "to  "
+};
+void PSParallelCompact::print_chunk_ranges()
+{
+tty->print_cr("space  bottom     top        end        new_top");
+tty->print_cr("------ ---------- ---------- ---------- ----------");
+for (unsigned int id = 0; id < last_space_id; ++id) {
+const MutableSpace* space = _space_info[id].space();
+tty->print_cr("%u %s "
+SIZE_FORMAT_W("10") " " SIZE_FORMAT_W("10") " "
+SIZE_FORMAT_W("10") " " SIZE_FORMAT_W("10") " ",
+id, space_names[id],
+summary_data().addr_to_chunk_idx(space->bottom()),
+summary_data().addr_to_chunk_idx(space->top()),
+summary_data().addr_to_chunk_idx(space->end()),
+summary_data().addr_to_chunk_idx(_space_info[id].new_top()));
+}
+}
+void
+print_generic_summary_chunk(size_t i, const ParallelCompactData::ChunkData* c)
+{
+#define CHUNK_IDX_FORMAT        SIZE_FORMAT_W("7")
+#define CHUNK_DATA_FORMAT       SIZE_FORMAT_W("5")
+ParallelCompactData& sd = PSParallelCompact::summary_data();
+size_t dci = c->destination() ? sd.addr_to_chunk_idx(c->destination()) : 0;
+tty->print_cr(CHUNK_IDX_FORMAT " " PTR_FORMAT " "
+CHUNK_IDX_FORMAT " " PTR_FORMAT " "
+CHUNK_DATA_FORMAT " " CHUNK_DATA_FORMAT " "
+CHUNK_DATA_FORMAT " " CHUNK_IDX_FORMAT " %d",
+i, c->data_location(), dci, c->destination(),
+c->partial_obj_size(), c->live_obj_size(),
+c->data_size(), c->source_chunk(), c->destination_count());
+#undef  CHUNK_IDX_FORMAT
+#undef  CHUNK_DATA_FORMAT
+}
+void
+print_generic_summary_data(ParallelCompactData& summary_data,
+HeapWord* const beg_addr,
+HeapWord* const end_addr)
+{
+size_t total_words = 0;
+size_t i = summary_data.addr_to_chunk_idx(beg_addr);
+const size_t last = summary_data.addr_to_chunk_idx(end_addr);
+HeapWord* pdest = 0;
+while (i <= last) {
+ParallelCompactData::ChunkData* c = summary_data.chunk(i);
+if (c->data_size() != 0 || c->destination() != pdest) {
+print_generic_summary_chunk(i, c);
+total_words += c->data_size();
+pdest = c->destination();
+}
+++i;
+}
+tty->print_cr("summary_data_bytes=" SIZE_FORMAT, total_words * HeapWordSize);
+}
+void
+print_generic_summary_data(ParallelCompactData& summary_data,
+SpaceInfo* space_info)
+{
+for (unsigned int id = 0; id < PSParallelCompact::last_space_id; ++id) {
+const MutableSpace* space = space_info[id].space();
+print_generic_summary_data(summary_data, space->bottom(),
+MAX2(space->top(), space_info[id].new_top()));
+}
+}
+void
+print_initial_summary_chunk(size_t i,
+const ParallelCompactData::ChunkData* c,
+bool newline = true)
+{
+tty->print(SIZE_FORMAT_W("5") " " PTR_FORMAT " "
+SIZE_FORMAT_W("5") " " SIZE_FORMAT_W("5") " "
+SIZE_FORMAT_W("5") " " SIZE_FORMAT_W("5") " %d",
+i, c->destination(),
+c->partial_obj_size(), c->live_obj_size(),
+c->data_size(), c->source_chunk(), c->destination_count());
+if (newline) tty->cr();
+}
+void
+print_initial_summary_data(ParallelCompactData& summary_data,
+const MutableSpace* space) {
+if (space->top() == space->bottom()) {
+return;
+}
+const size_t chunk_size = ParallelCompactData::ChunkSize;
+HeapWord* const top_aligned_up = summary_data.chunk_align_up(space->top());
+const size_t end_chunk = summary_data.addr_to_chunk_idx(top_aligned_up);
+const ParallelCompactData::ChunkData* c = summary_data.chunk(end_chunk - 1);
+HeapWord* end_addr = c->destination() + c->data_size();
+const size_t live_in_space = pointer_delta(end_addr, space->bottom());
+// Print (and count) the full chunks at the beginning of the space.
+size_t full_chunk_count = 0;
+size_t i = summary_data.addr_to_chunk_idx(space->bottom());
+while (i < end_chunk && summary_data.chunk(i)->data_size() == chunk_size) {
+print_initial_summary_chunk(i, summary_data.chunk(i));
+++full_chunk_count;
+++i;
+}
+size_t live_to_right = live_in_space - full_chunk_count * chunk_size;
+double max_reclaimed_ratio = 0.0;
+size_t max_reclaimed_ratio_chunk = 0;
+size_t max_dead_to_right = 0;
+size_t max_live_to_right = 0;
+// Print the 'reclaimed ratio' for chunks while there is something live in the
+// chunk or to the right of it.  The remaining chunks are empty (and
+// uninteresting), and computing the ratio will result in division by 0.
+while (i < end_chunk && live_to_right > 0) {
+c = summary_data.chunk(i);
+HeapWord* const chunk_addr = summary_data.chunk_to_addr(i);
+const size_t used_to_right = pointer_delta(space->top(), chunk_addr);
+const size_t dead_to_right = used_to_right - live_to_right;
+const double reclaimed_ratio = double(dead_to_right) / live_to_right;
+if (reclaimed_ratio > max_reclaimed_ratio) {
+max_reclaimed_ratio = reclaimed_ratio;
+max_reclaimed_ratio_chunk = i;
+max_dead_to_right = dead_to_right;
+max_live_to_right = live_to_right;
+}
+print_initial_summary_chunk(i, c, false);
+tty->print_cr(" %12.10f " SIZE_FORMAT_W("10") " " SIZE_FORMAT_W("10"),
+reclaimed_ratio, dead_to_right, live_to_right);
+live_to_right -= c->data_size();
+++i;
+}
+// Any remaining chunks are empty.  Print one more if there is one.
+if (i < end_chunk) {
+print_initial_summary_chunk(i, summary_data.chunk(i));
+}
+tty->print_cr("max:  " SIZE_FORMAT_W("4") " d2r=" SIZE_FORMAT_W("10") " "
+"l2r=" SIZE_FORMAT_W("10") " max_ratio=%14.12f",
+max_reclaimed_ratio_chunk, max_dead_to_right,
+max_live_to_right, max_reclaimed_ratio);
+}
+void
+print_initial_summary_data(ParallelCompactData& summary_data,
+SpaceInfo* space_info) {
+unsigned int id = PSParallelCompact::perm_space_id;
+const MutableSpace* space;
+do {
+space = space_info[id].space();
+print_initial_summary_data(summary_data, space);
+} while (++id < PSParallelCompact::eden_space_id);
+do {
+space = space_info[id].space();
+print_generic_summary_data(summary_data, space->bottom(), space->top());
+} while (++id < PSParallelCompact::last_space_id);
+}
+#endif  // #ifndef PRODUCT
+#ifdef  ASSERT
+size_t add_obj_count;
+size_t add_obj_size;
+size_t mark_bitmap_count;
+size_t mark_bitmap_size;
+#endif  // #ifdef ASSERT
+ParallelCompactData::ParallelCompactData()
+{
+_region_start = 0;
+_chunk_vspace = 0;
+_chunk_data = 0;
+_chunk_count = 0;
+_block_vspace = 0;
+_block_data = 0;
+_block_count = 0;
+}
+bool ParallelCompactData::initialize(MemRegion covered_region)
+{
+_region_start = covered_region.start();
+const size_t region_size = covered_region.word_size();
+DEBUG_ONLY(_region_end = _region_start + region_size;)
+assert(chunk_align_down(_region_start) == _region_start,
+"region start not aligned");
+assert((region_size & ChunkSizeOffsetMask) == 0,
+"region size not a multiple of ChunkSize");
+bool result = initialize_chunk_data(region_size);
+// Initialize the block data if it will be used for updating pointers, or if
+// this is a debug build.
+if (!UseParallelOldGCChunkPointerCalc || trueInDebug) {
+result = result && initialize_block_data(region_size);
+}
+return result;
+}
+PSVirtualSpace*
+ParallelCompactData::create_vspace(size_t count, size_t element_size)
+{
+const size_t raw_bytes = count * element_size;
+const size_t page_sz = os::page_size_for_region(raw_bytes, raw_bytes, 10);
+const size_t granularity = os::vm_allocation_granularity();
+const size_t bytes = align_size_up(raw_bytes, MAX2(page_sz, granularity));
+const size_t rs_align = page_sz == (size_t) os::vm_page_size() ? 0 :
+MAX2(page_sz, granularity);
+ReservedSpace rs(bytes, rs_align, false);
+os::trace_page_sizes("par compact", raw_bytes, raw_bytes, page_sz, rs.base(),
+rs.size());
+PSVirtualSpace* vspace = new PSVirtualSpace(rs, page_sz);
+if (vspace != 0) {
+if (vspace->expand_by(bytes)) {
+return vspace;
+}
+delete vspace;
+}
+return 0;
+}
+bool ParallelCompactData::initialize_chunk_data(size_t region_size)
+{
+const size_t count = (region_size + ChunkSizeOffsetMask) >> Log2ChunkSize;
+_chunk_vspace = create_vspace(count, sizeof(ChunkData));
+if (_chunk_vspace != 0) {
+_chunk_data = (ChunkData*)_chunk_vspace->reserved_low_addr();
+_chunk_count = count;
+return true;
+}
+return false;
+}
+bool ParallelCompactData::initialize_block_data(size_t region_size)
+{
+const size_t count = (region_size + BlockOffsetMask) >> Log2BlockSize;
+_block_vspace = create_vspace(count, sizeof(BlockData));
+if (_block_vspace != 0) {
+_block_data = (BlockData*)_block_vspace->reserved_low_addr();
+_block_count = count;
+return true;
+}
+return false;
+}
+void ParallelCompactData::clear()
+{
+if (_block_data) {
+memset(_block_data, 0, _block_vspace->committed_size());
+}
+memset(_chunk_data, 0, _chunk_vspace->committed_size());
+}
+void ParallelCompactData::clear_range(size_t beg_chunk, size_t end_chunk) {
+assert(beg_chunk <= _chunk_count, "beg_chunk out of range");
+assert(end_chunk <= _chunk_count, "end_chunk out of range");
+assert(ChunkSize % BlockSize == 0, "ChunkSize not a multiple of BlockSize");
+const size_t chunk_cnt = end_chunk - beg_chunk;
+if (_block_data) {
+const size_t blocks_per_chunk = ChunkSize / BlockSize;
+const size_t beg_block = beg_chunk * blocks_per_chunk;
+const size_t block_cnt = chunk_cnt * blocks_per_chunk;
+memset(_block_data + beg_block, 0, block_cnt * sizeof(BlockData));
+}
+memset(_chunk_data + beg_chunk, 0, chunk_cnt * sizeof(ChunkData));
+}
+HeapWord* ParallelCompactData::partial_obj_end(size_t chunk_idx) const
+{
+const ChunkData* cur_cp = chunk(chunk_idx);
+const ChunkData* const end_cp = chunk(chunk_count() - 1);
+HeapWord* result = chunk_to_addr(chunk_idx);
+if (cur_cp < end_cp) {
+do {
+result += cur_cp->partial_obj_size();
+} while (cur_cp->partial_obj_size() == ChunkSize && ++cur_cp < end_cp);
+}
+return result;
+}
+void ParallelCompactData::add_obj(HeapWord* addr, size_t len)
+{
+const size_t obj_ofs = pointer_delta(addr, _region_start);
+const size_t beg_chunk = obj_ofs >> Log2ChunkSize;
+const size_t end_chunk = (obj_ofs + len - 1) >> Log2ChunkSize;
+DEBUG_ONLY(Atomic::inc_ptr(&add_obj_count);)
+DEBUG_ONLY(Atomic::add_ptr(len, &add_obj_size);)
+if (beg_chunk == end_chunk) {
+// All in one chunk.
+_chunk_data[beg_chunk].add_live_obj(len);
+return;
+}
+// First chunk.
+const size_t beg_ofs = chunk_offset(addr);
+_chunk_data[beg_chunk].add_live_obj(ChunkSize - beg_ofs);
+klassOop klass = ((oop)addr)->klass();
+// Middle chunks--completely spanned by this object.
+for (size_t chunk = beg_chunk + 1; chunk < end_chunk; ++chunk) {
+_chunk_data[chunk].set_partial_obj_size(ChunkSize);
+_chunk_data[chunk].set_partial_obj_addr(addr);
+}
+// Last chunk.
+const size_t end_ofs = chunk_offset(addr + len - 1);
+_chunk_data[end_chunk].set_partial_obj_size(end_ofs + 1);
+_chunk_data[end_chunk].set_partial_obj_addr(addr);
+}
+void
+ParallelCompactData::summarize_dense_prefix(HeapWord* beg, HeapWord* end)
+{
+assert(chunk_offset(beg) == 0, "not ChunkSize aligned");
+assert(chunk_offset(end) == 0, "not ChunkSize aligned");
+size_t cur_chunk = addr_to_chunk_idx(beg);
+const size_t end_chunk = addr_to_chunk_idx(end);
+HeapWord* addr = beg;
+while (cur_chunk < end_chunk) {
+_chunk_data[cur_chunk].set_destination(addr);
+_chunk_data[cur_chunk].set_destination_count(0);
+_chunk_data[cur_chunk].set_source_chunk(cur_chunk);
+_chunk_data[cur_chunk].set_data_location(addr);
+// Update live_obj_size so the chunk appears completely full.
+size_t live_size = ChunkSize - _chunk_data[cur_chunk].partial_obj_size();
+_chunk_data[cur_chunk].set_live_obj_size(live_size);
+++cur_chunk;
+addr += ChunkSize;
+}
+}
+bool ParallelCompactData::summarize(HeapWord* target_beg, HeapWord* target_end,
+HeapWord* source_beg, HeapWord* source_end,
+HeapWord** target_next,
+HeapWord** source_next) {
+// This is too strict.
+// assert(chunk_offset(source_beg) == 0, "not ChunkSize aligned");
+if (TraceParallelOldGCSummaryPhase) {
+tty->print_cr("tb=" PTR_FORMAT " te=" PTR_FORMAT " "
+"sb=" PTR_FORMAT " se=" PTR_FORMAT " "
+"tn=" PTR_FORMAT " sn=" PTR_FORMAT,
+target_beg, target_end,
+source_beg, source_end,
+target_next != 0 ? *target_next : (HeapWord*) 0,
+source_next != 0 ? *source_next : (HeapWord*) 0);
+}
+size_t cur_chunk = addr_to_chunk_idx(source_beg);
+const size_t end_chunk = addr_to_chunk_idx(chunk_align_up(source_end));
+HeapWord *dest_addr = target_beg;
+while (cur_chunk < end_chunk) {
+size_t words = _chunk_data[cur_chunk].data_size();
+#if     1
+assert(pointer_delta(target_end, dest_addr) >= words,
+"source region does not fit into target region");
+#else
+// XXX - need some work on the corner cases here.  If the chunk does not
+// fit, then must either make sure any partial_obj from the chunk fits, or
+// 'undo' the initial part of the partial_obj that is in the previous chunk.
+if (dest_addr + words >= target_end) {
+// Let the caller know where to continue.
+*target_next = dest_addr;
+*source_next = chunk_to_addr(cur_chunk);
+return false;
+}
+#endif  // #if 1
+_chunk_data[cur_chunk].set_destination(dest_addr);
+// Set the destination_count for cur_chunk, and if necessary, update
+// source_chunk for a destination chunk.  The source_chunk field is updated
+// if cur_chunk is the first (left-most) chunk to be copied to a destination
+// chunk.
+//
+// The destination_count calculation is a bit subtle.  A chunk that has data
+// that compacts into itself does not count itself as a destination.  This
+// maintains the invariant that a zero count means the chunk is available
+// and can be claimed and then filled.
+if (words > 0) {
+HeapWord* const last_addr = dest_addr + words - 1;
+const size_t dest_chunk_1 = addr_to_chunk_idx(dest_addr);
+const size_t dest_chunk_2 = addr_to_chunk_idx(last_addr);
+#if     0
+// Initially assume that the destination chunks will be the same and
+// adjust the value below if necessary.  Under this assumption, if
+// cur_chunk == dest_chunk_2, then cur_chunk will be compacted completely
+// into itself.
+uint destination_count = cur_chunk == dest_chunk_2 ? 0 : 1;
+if (dest_chunk_1 != dest_chunk_2) {
+// Destination chunks differ; adjust destination_count.
+destination_count += 1;
+// Data from cur_chunk will be copied to the start of dest_chunk_2.
+_chunk_data[dest_chunk_2].set_source_chunk(cur_chunk);
+} else if (chunk_offset(dest_addr) == 0) {
+// Data from cur_chunk will be copied to the start of the destination
+// chunk.
+_chunk_data[dest_chunk_1].set_source_chunk(cur_chunk);
+}
+#else
+// Initially assume that the destination chunks will be different and
+// adjust the value below if necessary.  Under this assumption, if
+// cur_chunk == dest_chunk2, then cur_chunk will be compacted partially
+// into dest_chunk_1 and partially into itself.
+uint destination_count = cur_chunk == dest_chunk_2 ? 1 : 2;
+if (dest_chunk_1 != dest_chunk_2) {
+// Data from cur_chunk will be copied to the start of dest_chunk_2.
+_chunk_data[dest_chunk_2].set_source_chunk(cur_chunk);
+} else {
+// Destination chunks are the same; adjust destination_count.
+destination_count -= 1;
+if (chunk_offset(dest_addr) == 0) {
+// Data from cur_chunk will be copied to the start of the destination
+// chunk.
+_chunk_data[dest_chunk_1].set_source_chunk(cur_chunk);
+}
+}
+#endif  // #if 0
+_chunk_data[cur_chunk].set_destination_count(destination_count);
+_chunk_data[cur_chunk].set_data_location(chunk_to_addr(cur_chunk));
+dest_addr += words;
+}
+++cur_chunk;
+}
+*target_next = dest_addr;
+return true;
+}
+bool ParallelCompactData::partial_obj_ends_in_block(size_t block_index) {
+HeapWord* block_addr = block_to_addr(block_index);
+HeapWord* block_end_addr = block_addr + BlockSize;
+size_t chunk_index = addr_to_chunk_idx(block_addr);
+HeapWord* partial_obj_end_addr = partial_obj_end(chunk_index);
+// An object that ends at the end of the block, ends
+// in the block (the last word of the object is to
+// the left of the end).
+if ((block_addr < partial_obj_end_addr) &&
+(partial_obj_end_addr <= block_end_addr)) {
+return true;
+}
+return false;
+}
+HeapWord* ParallelCompactData::calc_new_pointer(HeapWord* addr) {
+HeapWord* result = NULL;
+if (UseParallelOldGCChunkPointerCalc) {
+result = chunk_calc_new_pointer(addr);
+} else {
+result = block_calc_new_pointer(addr);
+}
+return result;
+}
+// This method is overly complicated (expensive) to be called
+// for every reference.
+// Try to restructure this so that a NULL is returned if
+// the object is dead.  But don't wast the cycles to explicitly check
+// that it is dead since only live objects should be passed in.
+HeapWord* ParallelCompactData::chunk_calc_new_pointer(HeapWord* addr) {
+assert(addr != NULL, "Should detect NULL oop earlier");
+assert(PSParallelCompact::gc_heap()->is_in(addr), "addr not in heap");
+#ifdef ASSERT
+if (PSParallelCompact::mark_bitmap()->is_unmarked(addr)) {
+gclog_or_tty->print_cr("calc_new_pointer:: addr " PTR_FORMAT, addr);
+}
+#endif
+assert(PSParallelCompact::mark_bitmap()->is_marked(addr), "obj not marked");
+// Chunk covering the object.
+size_t chunk_index = addr_to_chunk_idx(addr);
+const ChunkData* const chunk_ptr = chunk(chunk_index);
+HeapWord* const chunk_addr = chunk_align_down(addr);
+assert(addr < chunk_addr + ChunkSize, "Chunk does not cover object");
+assert(addr_to_chunk_ptr(chunk_addr) == chunk_ptr, "sanity check");
+HeapWord* result = chunk_ptr->destination();
+// If all the data in the chunk is live, then the new location of the object
+// can be calculated from the destination of the chunk plus the offset of the
+// object in the chunk.
+if (chunk_ptr->data_size() == ChunkSize) {
+result += pointer_delta(addr, chunk_addr);
+return result;
+}
+// The new location of the object is
+//    chunk destination +
+//    size of the partial object extending onto the chunk +
+//    sizes of the live objects in the Chunk that are to the left of addr
+const size_t partial_obj_size = chunk_ptr->partial_obj_size();
+HeapWord* const search_start = chunk_addr + partial_obj_size;
+const ParMarkBitMap* bitmap = PSParallelCompact::mark_bitmap();
+size_t live_to_left = bitmap->live_words_in_range(search_start, oop(addr));
+result += partial_obj_size + live_to_left;
+assert(result <= addr, "object cannot move to the right");
+return result;
+}
+HeapWord* ParallelCompactData::block_calc_new_pointer(HeapWord* addr) {
+assert(addr != NULL, "Should detect NULL oop earlier");
+assert(PSParallelCompact::gc_heap()->is_in(addr), "addr not in heap");
+#ifdef ASSERT
+if (PSParallelCompact::mark_bitmap()->is_unmarked(addr)) {
+gclog_or_tty->print_cr("calc_new_pointer:: addr " PTR_FORMAT, addr);
+}
+#endif
+assert(PSParallelCompact::mark_bitmap()->is_marked(addr), "obj not marked");
+// Chunk covering the object.
+size_t chunk_index = addr_to_chunk_idx(addr);
+const ChunkData* const chunk_ptr = chunk(chunk_index);
+HeapWord* const chunk_addr = chunk_align_down(addr);
+assert(addr < chunk_addr + ChunkSize, "Chunk does not cover object");
+assert(addr_to_chunk_ptr(chunk_addr) == chunk_ptr, "sanity check");
+HeapWord* result = chunk_ptr->destination();
+// If all the data in the chunk is live, then the new location of the object
+// can be calculated from the destination of the chunk plus the offset of the
+// object in the chunk.
+if (chunk_ptr->data_size() == ChunkSize) {
+result += pointer_delta(addr, chunk_addr);
+return result;
+}
+// The new location of the object is
+//    chunk destination +
+//    block offset +
+//    sizes of the live objects in the Block that are to the left of addr
+const size_t block_offset = addr_to_block_ptr(addr)->offset();
+HeapWord* const search_start = chunk_addr + block_offset;
+const ParMarkBitMap* bitmap = PSParallelCompact::mark_bitmap();
+size_t live_to_left = bitmap->live_words_in_range(search_start, oop(addr));
+result += block_offset + live_to_left;
+assert(result <= addr, "object cannot move to the right");
+assert(result == chunk_calc_new_pointer(addr), "Should match");
+return result;
+}
+klassOop ParallelCompactData::calc_new_klass(klassOop old_klass) {
+klassOop updated_klass;
+if (PSParallelCompact::should_update_klass(old_klass)) {
+updated_klass = (klassOop) calc_new_pointer(old_klass);
+} else {
+updated_klass = old_klass;
+}
+return updated_klass;
+}
+#ifdef  ASSERT
+void ParallelCompactData::verify_clear(const PSVirtualSpace* vspace)
+{
+const size_t* const beg = (const size_t*)vspace->committed_low_addr();
+const size_t* const end = (const size_t*)vspace->committed_high_addr();
+for (const size_t* p = beg; p < end; ++p) {
+assert(*p == 0, "not zero");
+}
+}
+void ParallelCompactData::verify_clear()
+{
+verify_clear(_chunk_vspace);
+verify_clear(_block_vspace);
+}
+#endif  // #ifdef ASSERT
+#ifdef NOT_PRODUCT
+ParallelCompactData::ChunkData* debug_chunk(size_t chunk_index) {
+ParallelCompactData& sd = PSParallelCompact::summary_data();
+return sd.chunk(chunk_index);
+}
+#endif
+elapsedTimer        PSParallelCompact::_accumulated_time;
+unsigned int        PSParallelCompact::_total_invocations = 0;
+unsigned int        PSParallelCompact::_maximum_compaction_gc_num = 0;
+jlong               PSParallelCompact::_time_of_last_gc = 0;
+CollectorCounters*  PSParallelCompact::_counters = NULL;
+ParMarkBitMap       PSParallelCompact::_mark_bitmap;
+ParallelCompactData PSParallelCompact::_summary_data;
+PSParallelCompact::IsAliveClosure PSParallelCompact::_is_alive_closure;
+PSParallelCompact::AdjustPointerClosure PSParallelCompact::_adjust_root_pointer_closure(true);
+PSParallelCompact::AdjustPointerClosure PSParallelCompact::_adjust_pointer_closure(false);
+void PSParallelCompact::KeepAliveClosure::do_oop(oop* p) {
+#ifdef VALIDATE_MARK_SWEEP
+if (ValidateMarkSweep) {
+if (!Universe::heap()->is_in_reserved(p)) {
+_root_refs_stack->push(p);
+} else {
+_other_refs_stack->push(p);
+}
+}
+#endif
+mark_and_push(_compaction_manager, p);
+}
+void PSParallelCompact::mark_and_follow(ParCompactionManager* cm,
+oop* p) {
+assert(Universe::heap()->is_in_reserved(p),
+"we should only be traversing objects here");
+oop m = *p;
+if (m != NULL && mark_bitmap()->is_unmarked(m)) {
+if (mark_obj(m)) {
+m->follow_contents(cm);  // Follow contents of the marked object
+}
+}
+}
+// Anything associated with this variable is temporary.
+void PSParallelCompact::mark_and_push_internal(ParCompactionManager* cm,
+oop* p) {
+// Push marked object, contents will be followed later
+oop m = *p;
+if (mark_obj(m)) {
+// This thread marked the object and
+// owns the subsequent processing of it.
+cm->save_for_scanning(m);
+}
+}
+void PSParallelCompact::post_initialize() {
+ParallelScavengeHeap* heap = gc_heap();
+assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+MemRegion mr = heap->reserved_region();
+_ref_processor = ReferenceProcessor::create_ref_processor(
+mr,                         // span
+true,                       // atomic_discovery
+true,                       // mt_discovery
+&_is_alive_closure,
+ParallelGCThreads,
+ParallelRefProcEnabled);
+_counters = new CollectorCounters("PSParallelCompact", 1);
+// Initialize static fields in ParCompactionManager.
+ParCompactionManager::initialize(mark_bitmap());
+}
+bool PSParallelCompact::initialize() {
+ParallelScavengeHeap* heap = gc_heap();
+assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+MemRegion mr = heap->reserved_region();
+// Was the old gen get allocated successfully?
+if (!heap->old_gen()->is_allocated()) {
+return false;
+}
+initialize_space_info();
+initialize_dead_wood_limiter();
+if (!_mark_bitmap.initialize(mr)) {
+vm_shutdown_during_initialization("Unable to allocate bit map for "
+"parallel garbage collection for the requested heap size.");
+return false;
+}
+if (!_summary_data.initialize(mr)) {
+vm_shutdown_during_initialization("Unable to allocate tables for "
+"parallel garbage collection for the requested heap size.");
+return false;
+}
+return true;
+}
+void PSParallelCompact::initialize_space_info()
+{
+memset(&_space_info, 0, sizeof(_space_info));
+ParallelScavengeHeap* heap = gc_heap();
+PSYoungGen* young_gen = heap->young_gen();
+MutableSpace* perm_space = heap->perm_gen()->object_space();
+_space_info[perm_space_id].set_space(perm_space);
+_space_info[old_space_id].set_space(heap->old_gen()->object_space());
+_space_info[eden_space_id].set_space(young_gen->eden_space());
+_space_info[from_space_id].set_space(young_gen->from_space());
+_space_info[to_space_id].set_space(young_gen->to_space());
+_space_info[perm_space_id].set_start_array(heap->perm_gen()->start_array());
+_space_info[old_space_id].set_start_array(heap->old_gen()->start_array());
+_space_info[perm_space_id].set_min_dense_prefix(perm_space->top());
+if (TraceParallelOldGCDensePrefix) {
+tty->print_cr("perm min_dense_prefix=" PTR_FORMAT,
+_space_info[perm_space_id].min_dense_prefix());
+}
+}
+void PSParallelCompact::initialize_dead_wood_limiter()
+{
+const size_t max = 100;
+_dwl_mean = double(MIN2(ParallelOldDeadWoodLimiterMean, max)) / 100.0;
+_dwl_std_dev = double(MIN2(ParallelOldDeadWoodLimiterStdDev, max)) / 100.0;
+_dwl_first_term = 1.0 / (sqrt(2.0 * M_PI) * _dwl_std_dev);
+DEBUG_ONLY(_dwl_initialized = true;)
+_dwl_adjustment = normal_distribution(1.0);
+}
+// Simple class for storing info about the heap at the start of GC, to be used
+// after GC for comparison/printing.
+class PreGCValues {
+public:
+PreGCValues() { }
+PreGCValues(ParallelScavengeHeap* heap) { fill(heap); }
+void fill(ParallelScavengeHeap* heap) {
+_heap_used      = heap->used();
+_young_gen_used = heap->young_gen()->used_in_bytes();
+_old_gen_used   = heap->old_gen()->used_in_bytes();
+_perm_gen_used  = heap->perm_gen()->used_in_bytes();
+};
+size_t heap_used() const      { return _heap_used; }
+size_t young_gen_used() const { return _young_gen_used; }
+size_t old_gen_used() const   { return _old_gen_used; }
+size_t perm_gen_used() const  { return _perm_gen_used; }
+private:
+size_t _heap_used;
+size_t _young_gen_used;
+size_t _old_gen_used;
+size_t _perm_gen_used;
+};
+void
+PSParallelCompact::clear_data_covering_space(SpaceId id)
+{
+// At this point, top is the value before GC, new_top() is the value that will
+// be set at the end of GC.  The marking bitmap is cleared to top; nothing
+// should be marked above top.  The summary data is cleared to the larger of
+// top & new_top.
+MutableSpace* const space = _space_info[id].space();
+HeapWord* const bot = space->bottom();
+HeapWord* const top = space->top();
+HeapWord* const max_top = MAX2(top, _space_info[id].new_top());
+const idx_t beg_bit = _mark_bitmap.addr_to_bit(bot);
+const idx_t end_bit = BitMap::word_align_up(_mark_bitmap.addr_to_bit(top));
+_mark_bitmap.clear_range(beg_bit, end_bit);
+const size_t beg_chunk = _summary_data.addr_to_chunk_idx(bot);
+const size_t end_chunk =
+_summary_data.addr_to_chunk_idx(_summary_data.chunk_align_up(max_top));
+_summary_data.clear_range(beg_chunk, end_chunk);
+}
+void PSParallelCompact::pre_compact(PreGCValues* pre_gc_values)
+{
+// Update the from & to space pointers in space_info, since they are swapped
+// at each young gen gc.  Do the update unconditionally (even though a
+// promotion failure does not swap spaces) because an unknown number of minor
+// collections will have swapped the spaces an unknown number of times.
+TraceTime tm("pre compact", print_phases(), true, gclog_or_tty);
+ParallelScavengeHeap* heap = gc_heap();
+_space_info[from_space_id].set_space(heap->young_gen()->from_space());
+_space_info[to_space_id].set_space(heap->young_gen()->to_space());
+pre_gc_values->fill(heap);
+ParCompactionManager::reset();
+NOT_PRODUCT(_mark_bitmap.reset_counters());
+DEBUG_ONLY(add_obj_count = add_obj_size = 0;)
+DEBUG_ONLY(mark_bitmap_count = mark_bitmap_size = 0;)
+// Increment the invocation count
+heap->increment_total_collections();
+// We need to track unique mark sweep invocations as well.
+_total_invocations++;
+if (PrintHeapAtGC) {
+Universe::print_heap_before_gc();
+}
+// Fill in TLABs
+heap->accumulate_statistics_all_tlabs();
+heap->ensure_parsability(true);  // retire TLABs
+if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) {
+HandleMark hm;  // Discard invalid handles created during verification
+gclog_or_tty->print(" VerifyBeforeGC:");
+Universe::verify(true);
+}
+// Verify object start arrays
+if (VerifyObjectStartArray &&
+VerifyBeforeGC) {
+heap->old_gen()->verify_object_start_array();
+heap->perm_gen()->verify_object_start_array();
+}
+DEBUG_ONLY(mark_bitmap()->verify_clear();)
+DEBUG_ONLY(summary_data().verify_clear();)
+}
+void PSParallelCompact::post_compact()
+{
+TraceTime tm("post compact", print_phases(), true, gclog_or_tty);
+// Clear the marking bitmap and summary data and update top() in each space.
+for (unsigned int id = perm_space_id; id < last_space_id; ++id) {
+clear_data_covering_space(SpaceId(id));
+_space_info[id].space()->set_top(_space_info[id].new_top());
+}
+MutableSpace* const eden_space = _space_info[eden_space_id].space();
+MutableSpace* const from_space = _space_info[from_space_id].space();
+MutableSpace* const to_space   = _space_info[to_space_id].space();
+ParallelScavengeHeap* heap = gc_heap();
+bool eden_empty = eden_space->is_empty();
+if (!eden_empty) {
+eden_empty = absorb_live_data_from_eden(heap->size_policy(),
+heap->young_gen(), heap->old_gen());
+}
+// Update heap occupancy information which is used as input to the soft ref
+// clearing policy at the next gc.
+Universe::update_heap_info_at_gc();
+bool young_gen_empty = eden_empty && from_space->is_empty() &&
+to_space->is_empty();
+BarrierSet* bs = heap->barrier_set();
+if (bs->is_a(BarrierSet::ModRef)) {
+ModRefBarrierSet* modBS = (ModRefBarrierSet*)bs;
+MemRegion old_mr = heap->old_gen()->reserved();
+MemRegion perm_mr = heap->perm_gen()->reserved();
+assert(perm_mr.end() <= old_mr.start(), "Generations out of order");
+if (young_gen_empty) {
+modBS->clear(MemRegion(perm_mr.start(), old_mr.end()));
+} else {
+modBS->invalidate(MemRegion(perm_mr.start(), old_mr.end()));
+}
+}
+Threads::gc_epilogue();
+CodeCache::gc_epilogue();
+COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
+ref_processor()->enqueue_discovered_references(NULL);
+// Update time of last GC
+reset_millis_since_last_gc();
+}
+HeapWord*
+PSParallelCompact::compute_dense_prefix_via_density(const SpaceId id,
+bool maximum_compaction)
+{
+const size_t chunk_size = ParallelCompactData::ChunkSize;
+const ParallelCompactData& sd = summary_data();
+const MutableSpace* const space = _space_info[id].space();
+HeapWord* const top_aligned_up = sd.chunk_align_up(space->top());
+const ChunkData* const beg_cp = sd.addr_to_chunk_ptr(space->bottom());
+const ChunkData* const end_cp = sd.addr_to_chunk_ptr(top_aligned_up);
+// Skip full chunks at the beginning of the space--they are necessarily part
+// of the dense prefix.
+size_t full_count = 0;
+const ChunkData* cp;
+for (cp = beg_cp; cp < end_cp && cp->data_size() == chunk_size; ++cp) {
+++full_count;
+}
+assert(total_invocations() >= _maximum_compaction_gc_num, "sanity");
+const size_t gcs_since_max = total_invocations() - _maximum_compaction_gc_num;
+const bool interval_ended = gcs_since_max > HeapMaximumCompactionInterval;
+if (maximum_compaction || cp == end_cp || interval_ended) {
+_maximum_compaction_gc_num = total_invocations();
+return sd.chunk_to_addr(cp);
+}
+HeapWord* const new_top = _space_info[id].new_top();
+const size_t space_live = pointer_delta(new_top, space->bottom());
+const size_t space_used = space->used_in_words();
+const size_t space_capacity = space->capacity_in_words();
+const double cur_density = double(space_live) / space_capacity;
+const double deadwood_density =
+(1.0 - cur_density) * (1.0 - cur_density) * cur_density * cur_density;
+const size_t deadwood_goal = size_t(space_capacity * deadwood_density);
+if (TraceParallelOldGCDensePrefix) {
+tty->print_cr("cur_dens=%5.3f dw_dens=%5.3f dw_goal=" SIZE_FORMAT,
+cur_density, deadwood_density, deadwood_goal);
+tty->print_cr("space_live=" SIZE_FORMAT " " "space_used=" SIZE_FORMAT " "
+"space_cap=" SIZE_FORMAT,
+space_live, space_used,
+space_capacity);
+}
+// XXX - Use binary search?
+HeapWord* dense_prefix = sd.chunk_to_addr(cp);
+const ChunkData* full_cp = cp;
+const ChunkData* const top_cp = sd.addr_to_chunk_ptr(space->top() - 1);
+while (cp < end_cp) {
+HeapWord* chunk_destination = cp->destination();
+const size_t cur_deadwood = pointer_delta(dense_prefix, chunk_destination);
+if (TraceParallelOldGCDensePrefix && Verbose) {
+tty->print_cr("c#=" SIZE_FORMAT_W("04") " dst=" PTR_FORMAT " "
+"dp=" SIZE_FORMAT_W("08") " " "cdw=" SIZE_FORMAT_W("08"),
+sd.chunk(cp), chunk_destination,
+dense_prefix, cur_deadwood);
+}
+if (cur_deadwood >= deadwood_goal) {
+// Found the chunk that has the correct amount of deadwood to the left.
+// This typically occurs after crossing a fairly sparse set of chunks, so
+// iterate backwards over those sparse chunks, looking for the chunk that
+// has the lowest density of live objects 'to the right.'
+size_t space_to_left = sd.chunk(cp) * chunk_size;
+size_t live_to_left = space_to_left - cur_deadwood;
+size_t space_to_right = space_capacity - space_to_left;
+size_t live_to_right = space_live - live_to_left;
+double density_to_right = double(live_to_right) / space_to_right;
+while (cp > full_cp) {
+--cp;
+const size_t prev_chunk_live_to_right = live_to_right - cp->data_size();
+const size_t prev_chunk_space_to_right = space_to_right + chunk_size;
+double prev_chunk_density_to_right =
+double(prev_chunk_live_to_right) / prev_chunk_space_to_right;
+if (density_to_right <= prev_chunk_density_to_right) {
+return dense_prefix;
+}
+if (TraceParallelOldGCDensePrefix && Verbose) {
+tty->print_cr("backing up from c=" SIZE_FORMAT_W("4") " d2r=%10.8f "
+"pc_d2r=%10.8f", sd.chunk(cp), density_to_right,
+prev_chunk_density_to_right);
+}
+dense_prefix -= chunk_size;
+live_to_right = prev_chunk_live_to_right;
+space_to_right = prev_chunk_space_to_right;
+density_to_right = prev_chunk_density_to_right;
+}
+return dense_prefix;
+}
+dense_prefix += chunk_size;
+++cp;
+}
+return dense_prefix;
+}
+#ifndef PRODUCT
+void PSParallelCompact::print_dense_prefix_stats(const char* const algorithm,
+const SpaceId id,
+const bool maximum_compaction,
+HeapWord* const addr)
+{
+const size_t chunk_idx = summary_data().addr_to_chunk_idx(addr);
+ChunkData* const cp = summary_data().chunk(chunk_idx);
+const MutableSpace* const space = _space_info[id].space();
+HeapWord* const new_top = _space_info[id].new_top();
+const size_t space_live = pointer_delta(new_top, space->bottom());
+const size_t dead_to_left = pointer_delta(addr, cp->destination());
+const size_t space_cap = space->capacity_in_words();
+const double dead_to_left_pct = double(dead_to_left) / space_cap;
+const size_t live_to_right = new_top - cp->destination();
+const size_t dead_to_right = space->top() - addr - live_to_right;
+tty->print_cr("%s=" PTR_FORMAT " dpc=" SIZE_FORMAT_W("05") " "
+"spl=" SIZE_FORMAT " "
+"d2l=" SIZE_FORMAT " d2l%%=%6.4f "
+"d2r=" SIZE_FORMAT " l2r=" SIZE_FORMAT
+" ratio=%10.8f",
+algorithm, addr, chunk_idx,
+space_live,
+dead_to_left, dead_to_left_pct,
+dead_to_right, live_to_right,
+double(dead_to_right) / live_to_right);
+}
+#endif  // #ifndef PRODUCT
+// Return a fraction indicating how much of the generation can be treated as
+// "dead wood" (i.e., not reclaimed).  The function uses a normal distribution
+// based on the density of live objects in the generation to determine a limit,
+// which is then adjusted so the return value is min_percent when the density is
+// 1.
+//
+// The following table shows some return values for a different values of the
+// standard deviation (ParallelOldDeadWoodLimiterStdDev); the mean is 0.5 and
+// min_percent is 1.
+//
+//                          fraction allowed as dead wood
+//         -----------------------------------------------------------------
+// density std_dev=70 std_dev=75 std_dev=80 std_dev=85 std_dev=90 std_dev=95
+// ------- ---------- ---------- ---------- ---------- ---------- ----------
+// 0.00000 0.01000000 0.01000000 0.01000000 0.01000000 0.01000000 0.01000000
+// 0.05000 0.03193096 0.02836880 0.02550828 0.02319280 0.02130337 0.01974941
+// 0.10000 0.05247504 0.04547452 0.03988045 0.03537016 0.03170171 0.02869272
+// 0.15000 0.07135702 0.06111390 0.05296419 0.04641639 0.04110601 0.03676066
+// 0.20000 0.08831616 0.07509618 0.06461766 0.05622444 0.04943437 0.04388975
+// 0.25000 0.10311208 0.08724696 0.07471205 0.06469760 0.05661313 0.05002313
+// 0.30000 0.11553050 0.09741183 0.08313394 0.07175114 0.06257797 0.05511132
+// 0.35000 0.12538832 0.10545958 0.08978741 0.07731366 0.06727491 0.05911289
+// 0.40000 0.13253818 0.11128511 0.09459590 0.08132834 0.07066107 0.06199500
+// 0.45000 0.13687208 0.11481163 0.09750361 0.08375387 0.07270534 0.06373386
+// 0.50000 0.13832410 0.11599237 0.09847664 0.08456518 0.07338887 0.06431510
+// 0.55000 0.13687208 0.11481163 0.09750361 0.08375387 0.07270534 0.06373386
+// 0.60000 0.13253818 0.11128511 0.09459590 0.08132834 0.07066107 0.06199500
+// 0.65000 0.12538832 0.10545958 0.08978741 0.07731366 0.06727491 0.05911289
+// 0.70000 0.11553050 0.09741183 0.08313394 0.07175114 0.06257797 0.05511132
+// 0.75000 0.10311208 0.08724696 0.07471205 0.06469760 0.05661313 0.05002313
+// 0.80000 0.08831616 0.07509618 0.06461766 0.05622444 0.04943437 0.04388975
+// 0.85000 0.07135702 0.06111390 0.05296419 0.04641639 0.04110601 0.03676066
+// 0.90000 0.05247504 0.04547452 0.03988045 0.03537016 0.03170171 0.02869272
+// 0.95000 0.03193096 0.02836880 0.02550828 0.02319280 0.02130337 0.01974941
+// 1.00000 0.01000000 0.01000000 0.01000000 0.01000000 0.01000000 0.01000000
+double PSParallelCompact::dead_wood_limiter(double density, size_t min_percent)
+{
+assert(_dwl_initialized, "uninitialized");
+// The raw limit is the value of the normal distribution at x = density.
+const double raw_limit = normal_distribution(density);
+// Adjust the raw limit so it becomes the minimum when the density is 1.
+//
+// First subtract the adjustment value (which is simply the precomputed value
+// normal_distribution(1.0)); this yields a value of 0 when the density is 1.
+// Then add the minimum value, so the minimum is returned when the density is
+// 1.  Finally, prevent negative values, which occur when the mean is not 0.5.
+const double min = double(min_percent) / 100.0;
+const double limit = raw_limit - _dwl_adjustment + min;
+return MAX2(limit, 0.0);
+}
+ParallelCompactData::ChunkData*
+PSParallelCompact::first_dead_space_chunk(const ChunkData* beg,
+const ChunkData* end)
+{
+const size_t chunk_size = ParallelCompactData::ChunkSize;
+ParallelCompactData& sd = summary_data();
+size_t left = sd.chunk(beg);
+size_t right = end > beg ? sd.chunk(end) - 1 : left;
+// Binary search.
+while (left < right) {
+// Equivalent to (left + right) / 2, but does not overflow.
+const size_t middle = left + (right - left) / 2;
+ChunkData* const middle_ptr = sd.chunk(middle);
+HeapWord* const dest = middle_ptr->destination();
+HeapWord* const addr = sd.chunk_to_addr(middle);
+assert(dest != NULL, "sanity");
+assert(dest <= addr, "must move left");
+if (middle > left && dest < addr) {
+right = middle - 1;
+} else if (middle < right && middle_ptr->data_size() == chunk_size) {
+left = middle + 1;
+} else {
+return middle_ptr;
+}
+}
+return sd.chunk(left);
+}
+ParallelCompactData::ChunkData*
+PSParallelCompact::dead_wood_limit_chunk(const ChunkData* beg,
+const ChunkData* end,
+size_t dead_words)
+{
+ParallelCompactData& sd = summary_data();
+size_t left = sd.chunk(beg);
+size_t right = end > beg ? sd.chunk(end) - 1 : left;
+// Binary search.
+while (left < right) {
+// Equivalent to (left + right) / 2, but does not overflow.
+const size_t middle = left + (right - left) / 2;
+ChunkData* const middle_ptr = sd.chunk(middle);
+HeapWord* const dest = middle_ptr->destination();
+HeapWord* const addr = sd.chunk_to_addr(middle);
+assert(dest != NULL, "sanity");
+assert(dest <= addr, "must move left");
+const size_t dead_to_left = pointer_delta(addr, dest);
+if (middle > left && dead_to_left > dead_words) {
+right = middle - 1;
+} else if (middle < right && dead_to_left < dead_words) {
+left = middle + 1;
+} else {
+return middle_ptr;
+}
+}
+return sd.chunk(left);
+}
+// The result is valid during the summary phase, after the initial summarization
+// of each space into itself, and before final summarization.
+inline double
+PSParallelCompact::reclaimed_ratio(const ChunkData* const cp,
+HeapWord* const bottom,
+HeapWord* const top,
+HeapWord* const new_top)
+{
+ParallelCompactData& sd = summary_data();
+assert(cp != NULL, "sanity");
+assert(bottom != NULL, "sanity");
+assert(top != NULL, "sanity");
+assert(new_top != NULL, "sanity");
+assert(top >= new_top, "summary data problem?");
+assert(new_top > bottom, "space is empty; should not be here");
+assert(new_top >= cp->destination(), "sanity");
+assert(top >= sd.chunk_to_addr(cp), "sanity");
+HeapWord* const destination = cp->destination();
+const size_t dense_prefix_live  = pointer_delta(destination, bottom);
+const size_t compacted_region_live = pointer_delta(new_top, destination);
+const size_t compacted_region_used = pointer_delta(top, sd.chunk_to_addr(cp));
+const size_t reclaimable = compacted_region_used - compacted_region_live;
+const double divisor = dense_prefix_live + 1.25 * compacted_region_live;
+return double(reclaimable) / divisor;
+}
+// Return the address of the end of the dense prefix, a.k.a. the start of the
+// compacted region.  The address is always on a chunk boundary.
+//
+// Completely full chunks at the left are skipped, since no compaction can occur
+// in those chunks.  Then the maximum amount of dead wood to allow is computed,
+// based on the density (amount live / capacity) of the generation; the chunk
+// with approximately that amount of dead space to the left is identified as the
+// limit chunk.  Chunks between the last completely full chunk and the limit
+// chunk are scanned and the one that has the best (maximum) reclaimed_ratio()
+// is selected.
+HeapWord*
+PSParallelCompact::compute_dense_prefix(const SpaceId id,
+bool maximum_compaction)
+{
+const size_t chunk_size = ParallelCompactData::ChunkSize;
+const ParallelCompactData& sd = summary_data();
+const MutableSpace* const space = _space_info[id].space();
+HeapWord* const top = space->top();
+HeapWord* const top_aligned_up = sd.chunk_align_up(top);
+HeapWord* const new_top = _space_info[id].new_top();
+HeapWord* const new_top_aligned_up = sd.chunk_align_up(new_top);
+HeapWord* const bottom = space->bottom();
+const ChunkData* const beg_cp = sd.addr_to_chunk_ptr(bottom);
+const ChunkData* const top_cp = sd.addr_to_chunk_ptr(top_aligned_up);
+const ChunkData* const new_top_cp = sd.addr_to_chunk_ptr(new_top_aligned_up);
+// Skip full chunks at the beginning of the space--they are necessarily part
+// of the dense prefix.
+const ChunkData* const full_cp = first_dead_space_chunk(beg_cp, new_top_cp);
+assert(full_cp->destination() == sd.chunk_to_addr(full_cp) ||
+space->is_empty(), "no dead space allowed to the left");
+assert(full_cp->data_size() < chunk_size || full_cp == new_top_cp - 1,
+"chunk must have dead space");
+// The gc number is saved whenever a maximum compaction is done, and used to
+// determine when the maximum compaction interval has expired.  This avoids
+// successive max compactions for different reasons.
+assert(total_invocations() >= _maximum_compaction_gc_num, "sanity");
+const size_t gcs_since_max = total_invocations() - _maximum_compaction_gc_num;
+const bool interval_ended = gcs_since_max > HeapMaximumCompactionInterval ||
+total_invocations() == HeapFirstMaximumCompactionCount;
+if (maximum_compaction || full_cp == top_cp || interval_ended) {
+_maximum_compaction_gc_num = total_invocations();
+return sd.chunk_to_addr(full_cp);
+}
+const size_t space_live = pointer_delta(new_top, bottom);
+const size_t space_used = space->used_in_words();
+const size_t space_capacity = space->capacity_in_words();
+const double density = double(space_live) / double(space_capacity);
+const size_t min_percent_free =
+id == perm_space_id ? PermMarkSweepDeadRatio : MarkSweepDeadRatio;
+const double limiter = dead_wood_limiter(density, min_percent_free);
+const size_t dead_wood_max = space_used - space_live;
+const size_t dead_wood_limit = MIN2(size_t(space_capacity * limiter),
+dead_wood_max);
+if (TraceParallelOldGCDensePrefix) {
+tty->print_cr("space_live=" SIZE_FORMAT " " "space_used=" SIZE_FORMAT " "
+"space_cap=" SIZE_FORMAT,
+space_live, space_used,
+space_capacity);
+tty->print_cr("dead_wood_limiter(%6.4f, %d)=%6.4f "
+"dead_wood_max=" SIZE_FORMAT " dead_wood_limit=" SIZE_FORMAT,
+density, min_percent_free, limiter,
+dead_wood_max, dead_wood_limit);
+}
+// Locate the chunk with the desired amount of dead space to the left.
+const ChunkData* const limit_cp =
+dead_wood_limit_chunk(full_cp, top_cp, dead_wood_limit);
+// Scan from the first chunk with dead space to the limit chunk and find the
+// one with the best (largest) reclaimed ratio.
+double best_ratio = 0.0;
+const ChunkData* best_cp = full_cp;
+for (const ChunkData* cp = full_cp; cp < limit_cp; ++cp) {
+double tmp_ratio = reclaimed_ratio(cp, bottom, top, new_top);
+if (tmp_ratio > best_ratio) {
+best_cp = cp;
+best_ratio = tmp_ratio;
+}
+}
+#if     0
+// Something to consider:  if the chunk with the best ratio is 'close to' the
+// first chunk w/free space, choose the first chunk with free space
+// ("first-free").  The first-free chunk is usually near the start of the
+// heap, which means we are copying most of the heap already, so copy a bit
+// more to get complete compaction.
+if (pointer_delta(best_cp, full_cp, sizeof(ChunkData)) < 4) {
+_maximum_compaction_gc_num = total_invocations();
+best_cp = full_cp;
+}
+#endif  // #if 0
+return sd.chunk_to_addr(best_cp);
+}
+void PSParallelCompact::summarize_spaces_quick()
+{
+for (unsigned int i = 0; i < last_space_id; ++i) {
+const MutableSpace* space = _space_info[i].space();
+bool result = _summary_data.summarize(space->bottom(), space->end(),
+space->bottom(), space->top(),
+_space_info[i].new_top_addr());
+assert(result, "should never fail");
+_space_info[i].set_dense_prefix(space->bottom());
+}
+}
+void PSParallelCompact::fill_dense_prefix_end(SpaceId id)
+{
+HeapWord* const dense_prefix_end = dense_prefix(id);
+const ChunkData* chunk = _summary_data.addr_to_chunk_ptr(dense_prefix_end);
+const idx_t dense_prefix_bit = _mark_bitmap.addr_to_bit(dense_prefix_end);
+if (dead_space_crosses_boundary(chunk, dense_prefix_bit)) {
+// Only enough dead space is filled so that any remaining dead space to the
+// left is larger than the minimum filler object.  (The remainder is filled
+// during the copy/update phase.)
+//
+// The size of the dead space to the right of the boundary is not a
+// concern, since compaction will be able to use whatever space is
+// available.
+//
+// Here '||' is the boundary, 'x' represents a don't care bit and a box
+// surrounds the space to be filled with an object.
+//
+// In the 32-bit VM, each bit represents two 32-bit words:
+//                              +---+
+// a) beg_bits:  ...  x   x   x | 0 | ||   0   x  x  ...
+//    end_bits:  ...  x   x   x | 0 | ||   0   x  x  ...
+//                              +---+
+//
+// In the 64-bit VM, each bit represents one 64-bit word:
+//                              +------------+
+// b) beg_bits:  ...  x   x   x | 0   ||   0 | x  x  ...
+//    end_bits:  ...  x   x   1 | 0   ||   0 | x  x  ...
+//                              +------------+
+//                          +-------+
+// c) beg_bits:  ...  x   x | 0   0 | ||   0   x  x  ...
+//    end_bits:  ...  x   1 | 0   0 | ||   0   x  x  ...
+//                          +-------+
+//                      +-----------+
+// d) beg_bits:  ...  x | 0   0   0 | ||   0   x  x  ...
+//    end_bits:  ...  1 | 0   0   0 | ||   0   x  x  ...
+//                      +-----------+
+//                          +-------+
+// e) beg_bits:  ...  0   0 | 0   0 | ||   0   x  x  ...
+//    end_bits:  ...  0   0 | 0   0 | ||   0   x  x  ...
+//                          +-------+
+// Initially assume case a, c or e will apply.
+size_t obj_len = (size_t)oopDesc::header_size();
+HeapWord* obj_beg = dense_prefix_end - obj_len;
+#ifdef  _LP64
+if (_mark_bitmap.is_obj_end(dense_prefix_bit - 2)) {
+// Case b above.
+obj_beg = dense_prefix_end - 1;
+} else if (!_mark_bitmap.is_obj_end(dense_prefix_bit - 3) &&
+_mark_bitmap.is_obj_end(dense_prefix_bit - 4)) {
+// Case d above.
+obj_beg = dense_prefix_end - 3;
+obj_len = 3;
+}
+#endif  // #ifdef _LP64
+MemRegion region(obj_beg, obj_len);
+SharedHeap::fill_region_with_object(region);
+_mark_bitmap.mark_obj(obj_beg, obj_len);
+_summary_data.add_obj(obj_beg, obj_len);
+assert(start_array(id) != NULL, "sanity");
+start_array(id)->allocate_block(obj_beg);
+}
+}
+void
+PSParallelCompact::summarize_space(SpaceId id, bool maximum_compaction)
+{
+assert(id < last_space_id, "id out of range");
+const MutableSpace* space = _space_info[id].space();
+HeapWord** new_top_addr = _space_info[id].new_top_addr();
+HeapWord* dense_prefix_end = compute_dense_prefix(id, maximum_compaction);
+_space_info[id].set_dense_prefix(dense_prefix_end);
+#ifndef PRODUCT
+if (TraceParallelOldGCDensePrefix) {
+print_dense_prefix_stats("ratio", id, maximum_compaction, dense_prefix_end);
+HeapWord* addr = compute_dense_prefix_via_density(id, maximum_compaction);
+print_dense_prefix_stats("density", id, maximum_compaction, addr);
+}
+#endif  // #ifndef PRODUCT
+// If dead space crosses the dense prefix boundary, it is (at least partially)
+// filled with a dummy object, marked live and added to the summary data.
+// This simplifies the copy/update phase and must be done before the final
+// locations of objects are determined, to prevent leaving a fragment of dead
+// space that is too small to fill with an object.
+if (!maximum_compaction && dense_prefix_end != space->bottom()) {
+fill_dense_prefix_end(id);
+}
+// Compute the destination of each Chunk, and thus each object.
+_summary_data.summarize_dense_prefix(space->bottom(), dense_prefix_end);
+_summary_data.summarize(dense_prefix_end, space->end(),
+dense_prefix_end, space->top(),
+new_top_addr);
+if (TraceParallelOldGCSummaryPhase) {
+const size_t chunk_size = ParallelCompactData::ChunkSize;
+const size_t dp_chunk = _summary_data.addr_to_chunk_idx(dense_prefix_end);
+const size_t dp_words = pointer_delta(dense_prefix_end, space->bottom());
+const HeapWord* nt_aligned_up = _summary_data.chunk_align_up(*new_top_addr);
+const size_t cr_words = pointer_delta(nt_aligned_up, dense_prefix_end);
+tty->print_cr("id=%d cap=" SIZE_FORMAT " dp=" PTR_FORMAT " "
+"dp_chunk=" SIZE_FORMAT " " "dp_count=" SIZE_FORMAT " "
+"cr_count=" SIZE_FORMAT " " "nt=" PTR_FORMAT,
+id, space->capacity_in_words(), dense_prefix_end,
+dp_chunk, dp_words / chunk_size,
+cr_words / chunk_size, *new_top_addr);
+}
+}
+void PSParallelCompact::summary_phase(ParCompactionManager* cm,
+bool maximum_compaction)
+{
+EventMark m("2 summarize");
+TraceTime tm("summary phase", print_phases(), true, gclog_or_tty);
+// trace("2");
+#ifdef  ASSERT
+if (VerifyParallelOldWithMarkSweep  &&
+(PSParallelCompact::total_invocations() %
+VerifyParallelOldWithMarkSweepInterval) == 0) {
+verify_mark_bitmap(_mark_bitmap);
+}
+if (TraceParallelOldGCMarkingPhase) {
+tty->print_cr("add_obj_count=" SIZE_FORMAT " "
+"add_obj_bytes=" SIZE_FORMAT,
+add_obj_count, add_obj_size * HeapWordSize);
+tty->print_cr("mark_bitmap_count=" SIZE_FORMAT " "
+"mark_bitmap_bytes=" SIZE_FORMAT,
+mark_bitmap_count, mark_bitmap_size * HeapWordSize);
+}
+#endif  // #ifdef ASSERT
+// Quick summarization of each space into itself, to see how much is live.
+summarize_spaces_quick();
+if (TraceParallelOldGCSummaryPhase) {
+tty->print_cr("summary_phase:  after summarizing each space to self");
+Universe::print();
+NOT_PRODUCT(print_chunk_ranges());
+if (Verbose) {
+NOT_PRODUCT(print_initial_summary_data(_summary_data, _space_info));
+}
+}
+// The amount of live data that will end up in old space (assuming it fits).
+size_t old_space_total_live = 0;
+unsigned int id;
+for (id = old_space_id; id < last_space_id; ++id) {
+old_space_total_live += pointer_delta(_space_info[id].new_top(),
+_space_info[id].space()->bottom());
+}
+const MutableSpace* old_space = _space_info[old_space_id].space();
+if (old_space_total_live > old_space->capacity_in_words()) {
+// XXX - should also try to expand
+maximum_compaction = true;
+} else if (!UseParallelOldGCDensePrefix) {
+maximum_compaction = true;
+}
+// Permanent and Old generations.
+summarize_space(perm_space_id, maximum_compaction);
+summarize_space(old_space_id, maximum_compaction);
+// Summarize the remaining spaces (those in the young gen) into old space.  If
+// the live data from a space doesn't fit, the existing summarization is left
+// intact, so the data is compacted down within the space itself.
+HeapWord** new_top_addr = _space_info[old_space_id].new_top_addr();
+HeapWord* const target_space_end = old_space->end();
+for (id = eden_space_id; id < last_space_id; ++id) {
+const MutableSpace* space = _space_info[id].space();
+const size_t live = pointer_delta(_space_info[id].new_top(),
+space->bottom());
+const size_t available = pointer_delta(target_space_end, *new_top_addr);
+if (live <= available) {
+// All the live data will fit.
+if (TraceParallelOldGCSummaryPhase) {
+tty->print_cr("summarizing %d into old_space @ " PTR_FORMAT,
+id, *new_top_addr);
+}
+_summary_data.summarize(*new_top_addr, target_space_end,
+space->bottom(), space->top(),
+new_top_addr);
+// Reset the new_top value for the space.
+_space_info[id].set_new_top(space->bottom());
+// Clear the source_chunk field for each chunk in the space.
+ChunkData* beg_chunk = _summary_data.addr_to_chunk_ptr(space->bottom());
+ChunkData* end_chunk = _summary_data.addr_to_chunk_ptr(space->top() - 1);
+while (beg_chunk <= end_chunk) {
+beg_chunk->set_source_chunk(0);
+++beg_chunk;
+}
+}
+}
+// Fill in the block data after any changes to the chunks have
+// been made.
+#ifdef  ASSERT
+summarize_blocks(cm, perm_space_id);
+summarize_blocks(cm, old_space_id);
+#else
+if (!UseParallelOldGCChunkPointerCalc) {
+summarize_blocks(cm, perm_space_id);
+summarize_blocks(cm, old_space_id);
+}
+#endif
+if (TraceParallelOldGCSummaryPhase) {
+tty->print_cr("summary_phase:  after final summarization");
+Universe::print();
+NOT_PRODUCT(print_chunk_ranges());
+if (Verbose) {
+NOT_PRODUCT(print_generic_summary_data(_summary_data, _space_info));
+}
+}
+}
+// Fill in the BlockData.
+// Iterate over the spaces and within each space iterate over
+// the chunks and fill in the BlockData for each chunk.
+void PSParallelCompact::summarize_blocks(ParCompactionManager* cm,
+SpaceId first_compaction_space_id) {
+#if     0
+DEBUG_ONLY(ParallelCompactData::BlockData::set_cur_phase(1);)
+for (SpaceId cur_space_id = first_compaction_space_id;
+cur_space_id != last_space_id;
+cur_space_id = next_compaction_space_id(cur_space_id)) {
+// Iterate over the chunks in the space
+size_t start_chunk_index =
+_summary_data.addr_to_chunk_idx(space(cur_space_id)->bottom());
+BitBlockUpdateClosure bbu(mark_bitmap(),
+cm,
+start_chunk_index);
+// Iterate over blocks.
+for (size_t chunk_index =  start_chunk_index;
+chunk_index < _summary_data.chunk_count() &&
+_summary_data.chunk_to_addr(chunk_index) < space(cur_space_id)->top();
+chunk_index++) {
+// Reset the closure for the new chunk.  Note that the closure
+// maintains some data that does not get reset for each chunk
+// so a new instance of the closure is no appropriate.
+bbu.reset_chunk(chunk_index);
+// Start the iteration with the first live object.  This
+// may return the end of the chunk.  That is acceptable since
+// it will properly limit the iterations.
+ParMarkBitMap::idx_t left_offset = mark_bitmap()->addr_to_bit(
+_summary_data.first_live_or_end_in_chunk(chunk_index));
+// End the iteration at the end of the chunk.
+HeapWord* chunk_addr = _summary_data.chunk_to_addr(chunk_index);
+HeapWord* chunk_end = chunk_addr + ParallelCompactData::ChunkSize;
+ParMarkBitMap::idx_t right_offset =
+mark_bitmap()->addr_to_bit(chunk_end);
+// Blocks that have not objects starting in them can be
+// skipped because their data will never be used.
+if (left_offset < right_offset) {
+// Iterate through the objects in the chunk.
+ParMarkBitMap::idx_t last_offset =
+mark_bitmap()->pair_iterate(&bbu, left_offset, right_offset);
+// If last_offset is less than right_offset, then the iterations
+// terminated while it was looking for an end bit.  "last_offset"
+// is then the offset for the last start bit.  In this situation
+// the "offset" field for the next block to the right (_cur_block + 1)
+// will not have been update although there may be live data
+// to the left of the chunk.
+size_t cur_block_plus_1 = bbu.cur_block() + 1;
+HeapWord* cur_block_plus_1_addr =
+_summary_data.block_to_addr(bbu.cur_block()) +
+ParallelCompactData::BlockSize;
+HeapWord* last_offset_addr = mark_bitmap()->bit_to_addr(last_offset);
+#if 1  // This code works.  The else doesn't but should.  Why does it?
+// The current block (cur_block()) has already been updated.
+// The last block that may need to be updated is either the
+// next block (current block + 1) or the block where the
+// last object starts (which can be greater than the
+// next block if there were no objects found in intervening
+// blocks).
+size_t last_block =
+MAX2(bbu.cur_block() + 1,
+_summary_data.addr_to_block_idx(last_offset_addr));
+#else
+// The current block has already been updated.  The only block
+// that remains to be updated is the block where the last
+// object in the chunk starts.
+size_t last_block = _summary_data.addr_to_block_idx(last_offset_addr);
+#endif
+assert_bit_is_start(last_offset);
+assert((last_block == _summary_data.block_count()) ||
+(_summary_data.block(last_block)->raw_offset() == 0),
+"Should not have been set");
+// Is the last block still in the current chunk?  If still
+// in this chunk, update the last block (the counting that
+// included the current block is meant for the offset of the last
+// block).  If not in this chunk, do nothing.  Should not
+// update a block in the next chunk.
+if (ParallelCompactData::chunk_contains_block(bbu.chunk_index(),
+last_block)) {
+if (last_offset < right_offset) {
+// The last object started in this chunk but ends beyond
+// this chunk.  Update the block for this last object.
+assert(mark_bitmap()->is_marked(last_offset), "Should be marked");
+// No end bit was found.  The closure takes care of
+// the cases where
+//   an objects crosses over into the next block
+//   an objects starts and ends in the next block
+// It does not handle the case where an object is
+// the first object in a later block and extends
+// past the end of the chunk (i.e., the closure
+// only handles complete objects that are in the range
+// it is given).  That object is handed back here
+// for any special consideration necessary.
+//
+// Is the first bit in the last block a start or end bit?
+//
+// If the partial object ends in the last block L,
+// then the 1st bit in L may be an end bit.
+//
+// Else does the last object start in a block after the current
+// block? A block AA will already have been updated if an
+// object ends in the next block AA+1.  An object found to end in
+// the AA+1 is the trigger that updates AA.  Objects are being
+// counted in the current block for updaing a following
+// block.  An object may start in later block
+// block but may extend beyond the last block in the chunk.
+// Updates are only done when the end of an object has been
+// found. If the last object (covered by block L) starts
+// beyond the current block, then no object ends in L (otherwise
+// L would be the current block).  So the first bit in L is
+// a start bit.
+//
+// Else the last objects start in the current block and ends
+// beyond the chunk.  The current block has already been
+// updated and there is no later block (with an object
+// starting in it) that needs to be updated.
+//
+if (_summary_data.partial_obj_ends_in_block(last_block)) {
+_summary_data.block(last_block)->set_end_bit_offset(
+bbu.live_data_left());
+} else if (last_offset_addr >= cur_block_plus_1_addr) {
+//   The start of the object is on a later block
+// (to the right of the current block and there are no
+// complete live objects to the left of this last object
+// within the chunk.
+//   The first bit in the block is for the start of the
+// last object.
+_summary_data.block(last_block)->set_start_bit_offset(
+bbu.live_data_left());
+} else {
+//   The start of the last object was found in
+// the current chunk (which has already
+// been updated).
+assert(bbu.cur_block() ==
+_summary_data.addr_to_block_idx(last_offset_addr),
+"Should be a block already processed");
+}
+#ifdef ASSERT
+// Is there enough block information to find this object?
+// The destination of the chunk has not been set so the
+// values returned by calc_new_pointer() and
+// block_calc_new_pointer() will only be
+// offsets.  But they should agree.
+HeapWord* moved_obj_with_chunks =
+_summary_data.chunk_calc_new_pointer(last_offset_addr);
+HeapWord* moved_obj_with_blocks =
+_summary_data.calc_new_pointer(last_offset_addr);
+assert(moved_obj_with_chunks == moved_obj_with_blocks,
+"Block calculation is wrong");
+#endif
+} else if (last_block < _summary_data.block_count()) {
+// Iterations ended looking for a start bit (but
+// did not run off the end of the block table).
+_summary_data.block(last_block)->set_start_bit_offset(
+bbu.live_data_left());
+}
+}
+#ifdef ASSERT
+// Is there enough block information to find this object?
+HeapWord* left_offset_addr = mark_bitmap()->bit_to_addr(left_offset);
+HeapWord* moved_obj_with_chunks =
+_summary_data.calc_new_pointer(left_offset_addr);
+HeapWord* moved_obj_with_blocks =
+_summary_data.calc_new_pointer(left_offset_addr);
+assert(moved_obj_with_chunks == moved_obj_with_blocks,
+"Block calculation is wrong");
+#endif
+// Is there another block after the end of this chunk?
+#ifdef ASSERT
+if (last_block < _summary_data.block_count()) {
+// No object may have been found in a block.  If that
+// block is at the end of the chunk, the iteration will
+// terminate without incrementing the current block so
+// that the current block is not the last block in the
+// chunk.  That situation precludes asserting that the
+// current block is the last block in the chunk.  Assert
+// the lesser condition that the current block does not
+// exceed the chunk.
+assert(_summary_data.block_to_addr(last_block) <=
+(_summary_data.chunk_to_addr(chunk_index) +
+ParallelCompactData::ChunkSize),
+"Chunk and block inconsistency");
+assert(last_offset <= right_offset, "Iteration over ran end");
+}
+#endif
+}
+#ifdef ASSERT
+if (PrintGCDetails && Verbose) {
+if (_summary_data.chunk(chunk_index)->partial_obj_size() == 1) {
+size_t first_block =
+chunk_index / ParallelCompactData::BlocksPerChunk;
+gclog_or_tty->print_cr("first_block " PTR_FORMAT
+" _offset " PTR_FORMAT
+"_first_is_start_bit %d",
+first_block,
+_summary_data.block(first_block)->raw_offset(),
+_summary_data.block(first_block)->first_is_start_bit());
+}
+}
+#endif
+}
+}
+DEBUG_ONLY(ParallelCompactData::BlockData::set_cur_phase(16);)
+#endif  // #if 0
+}
+// This method should contain all heap-specific policy for invoking a full
+// collection.  invoke_no_policy() will only attempt to compact the heap; it
+// will do nothing further.  If we need to bail out for policy reasons, scavenge
+// before full gc, or any other specialized behavior, it needs to be added here.
+//
+// Note that this method should only be called from the vm_thread while at a
+// safepoint.
+void PSParallelCompact::invoke(bool maximum_heap_compaction) {
+assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
+assert(Thread::current() == (Thread*)VMThread::vm_thread(),
+"should be in vm thread");
+ParallelScavengeHeap* heap = gc_heap();
+GCCause::Cause gc_cause = heap->gc_cause();
+assert(!heap->is_gc_active(), "not reentrant");
+PSAdaptiveSizePolicy* policy = heap->size_policy();
+// Before each allocation/collection attempt, find out from the
+// policy object if GCs are, on the whole, taking too long. If so,
+// bail out without attempting a collection.  The exceptions are
+// for explicitly requested GC's.
+if (!policy->gc_time_limit_exceeded() ||
+GCCause::is_user_requested_gc(gc_cause) ||
+GCCause::is_serviceability_requested_gc(gc_cause)) {
+IsGCActiveMark mark;
+if (ScavengeBeforeFullGC) {
+PSScavenge::invoke_no_policy();
+}
+PSParallelCompact::invoke_no_policy(maximum_heap_compaction);
+}
+}
+bool ParallelCompactData::chunk_contains(size_t chunk_index, HeapWord* addr) {
+size_t addr_chunk_index = addr_to_chunk_idx(addr);
+return chunk_index == addr_chunk_index;
+}
+bool ParallelCompactData::chunk_contains_block(size_t chunk_index,
+size_t block_index) {
+size_t first_block_in_chunk = chunk_index * BlocksPerChunk;
+size_t last_block_in_chunk = (chunk_index + 1) * BlocksPerChunk - 1;
+return (first_block_in_chunk <= block_index) &&
+(block_index <= last_block_in_chunk);
+}
+// This method contains no policy. You should probably
+// be calling invoke() instead.
+void PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
+assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
+assert(ref_processor() != NULL, "Sanity");
+if (GC_locker::is_active()) {
+return;
+}
+TimeStamp marking_start;
+TimeStamp compaction_start;
+TimeStamp collection_exit;
+// "serial_CM" is needed until the parallel implementation
+// of the move and update is done.
+ParCompactionManager* serial_CM = new ParCompactionManager();
+// Don't initialize more than once.
+// serial_CM->initialize(&summary_data(), mark_bitmap());
+ParallelScavengeHeap* heap = gc_heap();
+GCCause::Cause gc_cause = heap->gc_cause();
+PSYoungGen* young_gen = heap->young_gen();
+PSOldGen* old_gen = heap->old_gen();
+PSPermGen* perm_gen = heap->perm_gen();
+PSAdaptiveSizePolicy* size_policy = heap->size_policy();
+_print_phases = PrintGCDetails && PrintParallelOldGCPhaseTimes;
+// Make sure data structures are sane, make the heap parsable, and do other
+// miscellaneous bookkeeping.
+PreGCValues pre_gc_values;
+pre_compact(&pre_gc_values);
+// Place after pre_compact() where the number of invocations is incremented.
+AdaptiveSizePolicyOutput(size_policy, heap->total_collections());
+{
+ResourceMark rm;
+HandleMark hm;
+const bool is_system_gc = gc_cause == GCCause::_java_lang_system_gc;
+// This is useful for debugging but don't change the output the
+// the customer sees.
+const char* gc_cause_str = "Full GC";
+if (is_system_gc && PrintGCDetails) {
+gc_cause_str = "Full GC (System)";
+}
+gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
+TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
+TraceTime t1(gc_cause_str, PrintGC, !PrintGCDetails, gclog_or_tty);
+TraceCollectorStats tcs(counters());
+TraceMemoryManagerStats tms(true /* Full GC */);
+if (TraceGen1Time) accumulated_time()->start();
+// Let the size policy know we're starting
+size_policy->major_collection_begin();
+// When collecting the permanent generation methodOops may be moving,
+// so we either have to flush all bcp data or convert it into bci.
+CodeCache::gc_prologue();
+Threads::gc_prologue();
+NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
+COMPILER2_PRESENT(DerivedPointerTable::clear());
+ref_processor()->enable_discovery();
+bool marked_for_unloading = false;
+marking_start.update();
+marking_phase(serial_CM, maximum_heap_compaction);
+#ifndef PRODUCT
+if (TraceParallelOldGCMarkingPhase) {
+gclog_or_tty->print_cr("marking_phase: cas_tries %d  cas_retries %d "
+"cas_by_another %d",
+mark_bitmap()->cas_tries(), mark_bitmap()->cas_retries(),
+mark_bitmap()->cas_by_another());
+}
+#endif  // #ifndef PRODUCT
+#ifdef ASSERT
+if (VerifyParallelOldWithMarkSweep &&
+(PSParallelCompact::total_invocations() %
+VerifyParallelOldWithMarkSweepInterval) == 0) {
+gclog_or_tty->print_cr("Verify marking with mark_sweep_phase1()");
+if (PrintGCDetails && Verbose) {
+gclog_or_tty->print_cr("mark_sweep_phase1:");
+}
+// Clear the discovered lists so that discovered objects
+// don't look like they have been discovered twice.
+ref_processor()->clear_discovered_references();
+PSMarkSweep::allocate_stacks();
+MemRegion mr = Universe::heap()->reserved_region();
+PSMarkSweep::ref_processor()->enable_discovery();
+PSMarkSweep::mark_sweep_phase1(maximum_heap_compaction);
+}
+#endif
+bool max_on_system_gc = UseMaximumCompactionOnSystemGC && is_system_gc;
+summary_phase(serial_CM, maximum_heap_compaction || max_on_system_gc);
+#ifdef ASSERT
+if (VerifyParallelOldWithMarkSweep &&
+(PSParallelCompact::total_invocations() %
+VerifyParallelOldWithMarkSweepInterval) == 0) {
+if (PrintGCDetails && Verbose) {
+gclog_or_tty->print_cr("mark_sweep_phase2:");
+}
+PSMarkSweep::mark_sweep_phase2();
+}
+#endif
+COMPILER2_PRESENT(assert(DerivedPointerTable::is_active(), "Sanity"));
+COMPILER2_PRESENT(DerivedPointerTable::set_active(false));
+// adjust_roots() updates Universe::_intArrayKlassObj which is
+// needed by the compaction for filling holes in the dense prefix.
+adjust_roots();
+#ifdef ASSERT
+if (VerifyParallelOldWithMarkSweep &&
+(PSParallelCompact::total_invocations() %
+VerifyParallelOldWithMarkSweepInterval) == 0) {
+// Do a separate verify phase so that the verify
+// code can use the the forwarding pointers to
+// check the new pointer calculation.  The restore_marks()
+// has to be done before the real compact.
+serial_CM->set_action(ParCompactionManager::VerifyUpdate);
+compact_perm(serial_CM);
+compact_serial(serial_CM);
+serial_CM->set_action(ParCompactionManager::ResetObjects);
+compact_perm(serial_CM);
+compact_serial(serial_CM);
+serial_CM->set_action(ParCompactionManager::UpdateAndCopy);
+// For debugging only
+PSMarkSweep::restore_marks();
+PSMarkSweep::deallocate_stacks();
+}
+#endif
+compaction_start.update();
+// Does the perm gen always have to be done serially because
+// klasses are used in the update of an object?
+compact_perm(serial_CM);
+if (UseParallelOldGCCompacting) {
+compact();
+} else {
+compact_serial(serial_CM);
+}
+delete serial_CM;
+// Reset the mark bitmap, summary data, and do other bookkeeping.  Must be
+// done before resizing.
+post_compact();
+// Let the size policy know we're done
+size_policy->major_collection_end(old_gen->used_in_bytes(), gc_cause);
+if (UseAdaptiveSizePolicy) {
+if (PrintAdaptiveSizePolicy) {
+gclog_or_tty->print("AdaptiveSizeStart: ");
+gclog_or_tty->stamp();
+gclog_or_tty->print_cr(" collection: %d ",
+heap->total_collections());
+if (Verbose) {
+gclog_or_tty->print("old_gen_capacity: %d young_gen_capacity: %d"
+" perm_gen_capacity: %d ",
+old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes(),
+perm_gen->capacity_in_bytes());
+}
+}
+// Don't check if the size_policy is ready here.  Let
+// the size_policy check that internally.
+if (UseAdaptiveGenerationSizePolicyAtMajorCollection &&
+((gc_cause != GCCause::_java_lang_system_gc) ||
+UseAdaptiveSizePolicyWithSystemGC)) {
+// Calculate optimal free space amounts
+assert(young_gen->max_size() >
+young_gen->from_space()->capacity_in_bytes() +
+young_gen->to_space()->capacity_in_bytes(),
+"Sizes of space in young gen are out-of-bounds");
+size_t max_eden_size = young_gen->max_size() -
+young_gen->from_space()->capacity_in_bytes() -
+young_gen->to_space()->capacity_in_bytes();
+size_policy->compute_generation_free_space(young_gen->used_in_bytes(),
+young_gen->eden_space()->used_in_bytes(),
+old_gen->used_in_bytes(),
+perm_gen->used_in_bytes(),
+young_gen->eden_space()->capacity_in_bytes(),
+old_gen->max_gen_size(),
+max_eden_size,
+true /* full gc*/,
+gc_cause);
+heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes());
+// Don't resize the young generation at an major collection.  A
+// desired young generation size may have been calculated but
+// resizing the young generation complicates the code because the
+// resizing of the old generation may have moved the boundary
+// between the young generation and the old generation.  Let the
+// young generation resizing happen at the minor collections.
+}
+if (PrintAdaptiveSizePolicy) {
+gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ",
+heap->total_collections());
+}
+}
+if (UsePerfData) {
+PSGCAdaptivePolicyCounters* const counters = heap->gc_policy_counters();
+counters->update_counters();
+counters->update_old_capacity(old_gen->capacity_in_bytes());
+counters->update_young_capacity(young_gen->capacity_in_bytes());
+}
+heap->resize_all_tlabs();
+// We collected the perm gen, so we'll resize it here.
+perm_gen->compute_new_size(pre_gc_values.perm_gen_used());
+if (TraceGen1Time) accumulated_time()->stop();
+if (PrintGC) {
+if (PrintGCDetails) {
+// No GC timestamp here.  This is after GC so it would be confusing.
+young_gen->print_used_change(pre_gc_values.young_gen_used());
+old_gen->print_used_change(pre_gc_values.old_gen_used());
+heap->print_heap_change(pre_gc_values.heap_used());
+// Print perm gen last (print_heap_change() excludes the perm gen).
+perm_gen->print_used_change(pre_gc_values.perm_gen_used());
+} else {
+heap->print_heap_change(pre_gc_values.heap_used());
+}
+}
+// Track memory usage and detect low memory
+MemoryService::track_memory_usage();
+heap->update_counters();
+if (PrintGCDetails) {
+if (size_policy->print_gc_time_limit_would_be_exceeded()) {
+if (size_policy->gc_time_limit_exceeded()) {
+gclog_or_tty->print_cr("      GC time is exceeding GCTimeLimit "
+"of %d%%", GCTimeLimit);
+} else {
+gclog_or_tty->print_cr("      GC time would exceed GCTimeLimit "
+"of %d%%", GCTimeLimit);
+}
+}
+size_policy->set_print_gc_time_limit_would_be_exceeded(false);
+}
+}
+if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
+HandleMark hm;  // Discard invalid handles created during verification
+gclog_or_tty->print(" VerifyAfterGC:");
+Universe::verify(false);
+}
+// Re-verify object start arrays
+if (VerifyObjectStartArray &&
+VerifyAfterGC) {
+old_gen->verify_object_start_array();
+perm_gen->verify_object_start_array();
+}
+NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
+collection_exit.update();
+if (PrintHeapAtGC) {
+Universe::print_heap_after_gc();
+}
+if (PrintGCTaskTimeStamps) {
+gclog_or_tty->print_cr("VM-Thread " INT64_FORMAT " " INT64_FORMAT " "
+INT64_FORMAT,
+marking_start.ticks(), compaction_start.ticks(),
+collection_exit.ticks());
+gc_task_manager()->print_task_time_stamps();
+}
+}
+bool PSParallelCompact::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy,
+PSYoungGen* young_gen,
+PSOldGen* old_gen) {
+MutableSpace* const eden_space = young_gen->eden_space();
+assert(!eden_space->is_empty(), "eden must be non-empty");
+assert(young_gen->virtual_space()->alignment() ==
+old_gen->virtual_space()->alignment(), "alignments do not match");
+if (!(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary)) {
+return false;
+}
+// Both generations must be completely committed.
+if (young_gen->virtual_space()->uncommitted_size() != 0) {
+return false;
+}
+if (old_gen->virtual_space()->uncommitted_size() != 0) {
+return false;
+}
+// Figure out how much to take from eden.  Include the average amount promoted
+// in the total; otherwise the next young gen GC will simply bail out to a
+// full GC.
+const size_t alignment = old_gen->virtual_space()->alignment();
+const size_t eden_used = eden_space->used_in_bytes();
+const size_t promoted = (size_t)size_policy->avg_promoted()->padded_average();
+const size_t absorb_size = align_size_up(eden_used + promoted, alignment);
+const size_t eden_capacity = eden_space->capacity_in_bytes();
+if (absorb_size >= eden_capacity) {
+return false; // Must leave some space in eden.
+}
+const size_t new_young_size = young_gen->capacity_in_bytes() - absorb_size;
+if (new_young_size < young_gen->min_gen_size()) {
+return false; // Respect young gen minimum size.
+}
+if (TraceAdaptiveGCBoundary && Verbose) {
+gclog_or_tty->print(" absorbing " SIZE_FORMAT "K:  "
+"eden " SIZE_FORMAT "K->" SIZE_FORMAT "K "
+"from " SIZE_FORMAT "K, to " SIZE_FORMAT "K "
+"young_gen " SIZE_FORMAT "K->" SIZE_FORMAT "K ",
+absorb_size / K,
+eden_capacity / K, (eden_capacity - absorb_size) / K,
+young_gen->from_space()->used_in_bytes() / K,
+young_gen->to_space()->used_in_bytes() / K,
+young_gen->capacity_in_bytes() / K, new_young_size / K);
+}
+// Fill the unused part of the old gen.
+MutableSpace* const old_space = old_gen->object_space();
+MemRegion old_gen_unused(old_space->top(), old_space->end());
+if (!old_gen_unused.is_empty()) {
+SharedHeap::fill_region_with_object(old_gen_unused);
+}
+// Take the live data from eden and set both top and end in the old gen to
+// eden top.  (Need to set end because reset_after_change() mangles the region
+// from end to virtual_space->high() in debug builds).
+HeapWord* const new_top = eden_space->top();
+old_gen->virtual_space()->expand_into(young_gen->virtual_space(),
+absorb_size);
+young_gen->reset_after_change();
+old_space->set_top(new_top);
+old_space->set_end(new_top);
+old_gen->reset_after_change();
+// Update the object start array for the filler object and the data from eden.
+ObjectStartArray* const start_array = old_gen->start_array();
+HeapWord* const start = old_gen_unused.start();
+for (HeapWord* addr = start; addr < new_top; addr += oop(addr)->size()) {
+start_array->allocate_block(addr);
+}
+// Could update the promoted average here, but it is not typically updated at
+// full GCs and the value to use is unclear.  Something like
+//
+// cur_promoted_avg + absorb_size / number_of_scavenges_since_last_full_gc.
+size_policy->set_bytes_absorbed_from_eden(absorb_size);
+return true;
+}
+GCTaskManager* const PSParallelCompact::gc_task_manager() {
+assert(ParallelScavengeHeap::gc_task_manager() != NULL,
+"shouldn't return NULL");
+return ParallelScavengeHeap::gc_task_manager();
+}
+void PSParallelCompact::marking_phase(ParCompactionManager* cm,
+bool maximum_heap_compaction) {
+// Recursively traverse all live objects and mark them
+EventMark m("1 mark object");
+TraceTime tm("marking phase", print_phases(), true, gclog_or_tty);
+ParallelScavengeHeap* heap = gc_heap();
+uint parallel_gc_threads = heap->gc_task_manager()->workers();
+TaskQueueSetSuper* qset = ParCompactionManager::chunk_array();
+ParallelTaskTerminator terminator(parallel_gc_threads, qset);
+PSParallelCompact::MarkAndPushClosure mark_and_push_closure(cm);
+PSParallelCompact::FollowStackClosure follow_stack_closure(cm);
+{
+TraceTime tm_m("par mark", print_phases(), true, gclog_or_tty);
+GCTaskQueue* q = GCTaskQueue::create();
+q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::universe));
+q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::jni_handles));
+// We scan the thread roots in parallel
+Threads::create_thread_roots_marking_tasks(q);
+q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::object_synchronizer));
+q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::flat_profiler));
+q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::management));
+q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::system_dictionary));
+q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::jvmti));
+q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::vm_symbols));
+if (parallel_gc_threads > 1) {
+for (uint j = 0; j < parallel_gc_threads; j++) {
+q->enqueue(new StealMarkingTask(&terminator));
+}
+}
+WaitForBarrierGCTask* fin = WaitForBarrierGCTask::create();
+q->enqueue(fin);
+gc_task_manager()->add_list(q);
+fin->wait_for();
+// We have to release the barrier tasks!
+WaitForBarrierGCTask::destroy(fin);
+}
+// Process reference objects found during marking
+{
+TraceTime tm_r("reference processing", print_phases(), true, gclog_or_tty);
+ReferencePolicy *soft_ref_policy;
+if (maximum_heap_compaction) {
+soft_ref_policy = new AlwaysClearPolicy();
+} else {
+#ifdef COMPILER2
+soft_ref_policy = new LRUMaxHeapPolicy();
+#else
+soft_ref_policy = new LRUCurrentHeapPolicy();
+#endif // COMPILER2
+}
+assert(soft_ref_policy != NULL, "No soft reference policy");
+if (ref_processor()->processing_is_mt()) {
+RefProcTaskExecutor task_executor;
+ref_processor()->process_discovered_references(
+soft_ref_policy, is_alive_closure(), &mark_and_push_closure,
+&follow_stack_closure, &task_executor);
+} else {
+ref_processor()->process_discovered_references(
+soft_ref_policy, is_alive_closure(), &mark_and_push_closure,
+&follow_stack_closure, NULL);
+}
+}
+TraceTime tm_c("class unloading", print_phases(), true, gclog_or_tty);
+// Follow system dictionary roots and unload classes.
+bool purged_class = SystemDictionary::do_unloading(is_alive_closure());
+// Follow code cache roots.
+CodeCache::do_unloading(is_alive_closure(), &mark_and_push_closure,
+purged_class);
+follow_stack(cm); // Flush marking stack.
+// Update subklass/sibling/implementor links of live klasses
+// revisit_klass_stack is used in follow_weak_klass_links().
+follow_weak_klass_links(cm);
+// Visit symbol and interned string tables and delete unmarked oops
+SymbolTable::unlink(is_alive_closure());
+StringTable::unlink(is_alive_closure());
+assert(cm->marking_stack()->size() == 0, "stack should be empty by now");
+assert(cm->overflow_stack()->is_empty(), "stack should be empty by now");
+}
+// This should be moved to the shared markSweep code!
+class PSAlwaysTrueClosure: public BoolObjectClosure {
+public:
+void do_object(oop p) { ShouldNotReachHere(); }
+bool do_object_b(oop p) { return true; }
+};
+static PSAlwaysTrueClosure always_true;
+void PSParallelCompact::adjust_roots() {
+// Adjust the pointers to reflect the new locations
+EventMark m("3 adjust roots");
+TraceTime tm("adjust roots", print_phases(), true, gclog_or_tty);
+// General strong roots.
+Universe::oops_do(adjust_root_pointer_closure());
+ReferenceProcessor::oops_do(adjust_root_pointer_closure());
+JNIHandles::oops_do(adjust_root_pointer_closure());   // Global (strong) JNI handles
+Threads::oops_do(adjust_root_pointer_closure());
+ObjectSynchronizer::oops_do(adjust_root_pointer_closure());
+FlatProfiler::oops_do(adjust_root_pointer_closure());
+Management::oops_do(adjust_root_pointer_closure());
+JvmtiExport::oops_do(adjust_root_pointer_closure());
+// SO_AllClasses
+SystemDictionary::oops_do(adjust_root_pointer_closure());
+vmSymbols::oops_do(adjust_root_pointer_closure());
+// Now adjust pointers in remaining weak roots.  (All of which should
+// have been cleared if they pointed to non-surviving objects.)
+// Global (weak) JNI handles
+JNIHandles::weak_oops_do(&always_true, adjust_root_pointer_closure());
+CodeCache::oops_do(adjust_pointer_closure());
+SymbolTable::oops_do(adjust_root_pointer_closure());
+StringTable::oops_do(adjust_root_pointer_closure());
+ref_processor()->weak_oops_do(adjust_root_pointer_closure());
+// Roots were visited so references into the young gen in roots
+// may have been scanned.  Process them also.
+// Should the reference processor have a span that excludes
+// young gen objects?
+PSScavenge::reference_processor()->weak_oops_do(
+adjust_root_pointer_closure());
+}
+void PSParallelCompact::compact_perm(ParCompactionManager* cm) {
+EventMark m("4 compact perm");
+TraceTime tm("compact perm gen", print_phases(), true, gclog_or_tty);
+// trace("4");
+gc_heap()->perm_gen()->start_array()->reset();
+move_and_update(cm, perm_space_id);
+}
+void PSParallelCompact::enqueue_chunk_draining_tasks(GCTaskQueue* q,
+uint parallel_gc_threads) {
+TraceTime tm("drain task setup", print_phases(), true, gclog_or_tty);
+const unsigned int task_count = MAX2(parallel_gc_threads, 1U);
+for (unsigned int j = 0; j < task_count; j++) {
+q->enqueue(new DrainStacksCompactionTask());
+}
+// Find all chunks that are available (can be filled immediately) and
+// distribute them to the thread stacks.  The iteration is done in reverse
+// order (high to low) so the chunks will be removed in ascending order.
+const ParallelCompactData& sd = PSParallelCompact::summary_data();
+size_t fillable_chunks = 0;   // A count for diagnostic purposes.
+unsigned int which = 0;       // The worker thread number.
+for (unsigned int id = to_space_id; id > perm_space_id; --id) {
+SpaceInfo* const space_info = _space_info + id;
+MutableSpace* const space = space_info->space();
+HeapWord* const new_top = space_info->new_top();
+const size_t beg_chunk = sd.addr_to_chunk_idx(space_info->dense_prefix());
+const size_t end_chunk = sd.addr_to_chunk_idx(sd.chunk_align_up(new_top));
+assert(end_chunk > 0, "perm gen cannot be empty");
+for (size_t cur = end_chunk - 1; cur >= beg_chunk; --cur) {
+if (sd.chunk(cur)->claim_unsafe()) {
+ParCompactionManager* cm = ParCompactionManager::manager_array(which);
+cm->save_for_processing(cur);
+if (TraceParallelOldGCCompactionPhase && Verbose) {
+const size_t count_mod_8 = fillable_chunks & 7;
+if (count_mod_8 == 0) gclog_or_tty->print("fillable: ");
+gclog_or_tty->print(" " SIZE_FORMAT_W("7"), cur);
+if (count_mod_8 == 7) gclog_or_tty->cr();
+}
+NOT_PRODUCT(++fillable_chunks;)
+// Assign chunks to threads in round-robin fashion.
+if (++which == task_count) {
+which = 0;
+}
+}
+}
+}
+if (TraceParallelOldGCCompactionPhase) {
+if (Verbose && (fillable_chunks & 7) != 0) gclog_or_tty->cr();
+gclog_or_tty->print_cr("%u initially fillable chunks", fillable_chunks);
+}
+}
+#define PAR_OLD_DENSE_PREFIX_OVER_PARTITIONING 4
+void PSParallelCompact::enqueue_dense_prefix_tasks(GCTaskQueue* q,
+uint parallel_gc_threads) {
+TraceTime tm("dense prefix task setup", print_phases(), true, gclog_or_tty);
+ParallelCompactData& sd = PSParallelCompact::summary_data();
+// Iterate over all the spaces adding tasks for updating
+// chunks in the dense prefix.  Assume that 1 gc thread
+// will work on opening the gaps and the remaining gc threads
+// will work on the dense prefix.
+SpaceId space_id = old_space_id;
+while (space_id != last_space_id) {
+HeapWord* const dense_prefix_end = _space_info[space_id].dense_prefix();
+const MutableSpace* const space = _space_info[space_id].space();
+if (dense_prefix_end == space->bottom()) {
+// There is no dense prefix for this space.
+space_id = next_compaction_space_id(space_id);
+continue;
+}
+// The dense prefix is before this chunk.
+size_t chunk_index_end_dense_prefix =
+sd.addr_to_chunk_idx(dense_prefix_end);
+ChunkData* const dense_prefix_cp = sd.chunk(chunk_index_end_dense_prefix);
+assert(dense_prefix_end == space->end() ||
+dense_prefix_cp->available() ||
+dense_prefix_cp->claimed(),
+"The chunk after the dense prefix should always be ready to fill");
+size_t chunk_index_start = sd.addr_to_chunk_idx(space->bottom());
+// Is there dense prefix work?
+size_t total_dense_prefix_chunks =
+chunk_index_end_dense_prefix - chunk_index_start;
+// How many chunks of the dense prefix should be given to
+// each thread?
+if (total_dense_prefix_chunks > 0) {
+uint tasks_for_dense_prefix = 1;
+if (UseParallelDensePrefixUpdate) {
+if (total_dense_prefix_chunks <=
+(parallel_gc_threads * PAR_OLD_DENSE_PREFIX_OVER_PARTITIONING)) {
+// Don't over partition.  This assumes that
+// PAR_OLD_DENSE_PREFIX_OVER_PARTITIONING is a small integer value
+// so there are not many chunks to process.
+tasks_for_dense_prefix = parallel_gc_threads;
+} else {
+// Over partition
+tasks_for_dense_prefix = parallel_gc_threads *
+PAR_OLD_DENSE_PREFIX_OVER_PARTITIONING;
+}
+}
+size_t chunks_per_thread = total_dense_prefix_chunks /
+tasks_for_dense_prefix;
+// Give each thread at least 1 chunk.
+if (chunks_per_thread == 0) {
+chunks_per_thread = 1;
+}
+for (uint k = 0; k < tasks_for_dense_prefix; k++) {
+if (chunk_index_start >= chunk_index_end_dense_prefix) {
+break;
+}
+// chunk_index_end is not processed
+size_t chunk_index_end = MIN2(chunk_index_start + chunks_per_thread,
+chunk_index_end_dense_prefix);
+q->enqueue(new UpdateDensePrefixTask(
+space_id,
+chunk_index_start,
+chunk_index_end));
+chunk_index_start = chunk_index_end;
+}
+}
+// This gets any part of the dense prefix that did not
+// fit evenly.
+if (chunk_index_start < chunk_index_end_dense_prefix) {
+q->enqueue(new UpdateDensePrefixTask(
+space_id,
+chunk_index_start,
+chunk_index_end_dense_prefix));
+}
+space_id = next_compaction_space_id(space_id);
+}  // End tasks for dense prefix
+}
+void PSParallelCompact::enqueue_chunk_stealing_tasks(
+GCTaskQueue* q,
+ParallelTaskTerminator* terminator_ptr,
+uint parallel_gc_threads) {
+TraceTime tm("steal task setup", print_phases(), true, gclog_or_tty);
+// Once a thread has drained it's stack, it should try to steal chunks from
+// other threads.
+if (parallel_gc_threads > 1) {
+for (uint j = 0; j < parallel_gc_threads; j++) {
+q->enqueue(new StealChunkCompactionTask(terminator_ptr));
+}
+}
+}
+void PSParallelCompact::compact() {
+EventMark m("5 compact");
+// trace("5");
+TraceTime tm("compaction phase", print_phases(), true, gclog_or_tty);
+ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+PSOldGen* old_gen = heap->old_gen();
+old_gen->start_array()->reset();
+uint parallel_gc_threads = heap->gc_task_manager()->workers();
+TaskQueueSetSuper* qset = ParCompactionManager::chunk_array();
+ParallelTaskTerminator terminator(parallel_gc_threads, qset);
+GCTaskQueue* q = GCTaskQueue::create();
+enqueue_chunk_draining_tasks(q, parallel_gc_threads);
+enqueue_dense_prefix_tasks(q, parallel_gc_threads);
+enqueue_chunk_stealing_tasks(q, &terminator, parallel_gc_threads);
+{
+TraceTime tm_pc("par compact", print_phases(), true, gclog_or_tty);
+WaitForBarrierGCTask* fin = WaitForBarrierGCTask::create();
+q->enqueue(fin);
+gc_task_manager()->add_list(q);
+fin->wait_for();
+// We have to release the barrier tasks!
+WaitForBarrierGCTask::destroy(fin);
+#ifdef  ASSERT
+// Verify that all chunks have been processed before the deferred updates.
+// Note that perm_space_id is skipped; this type of verification is not
+// valid until the perm gen is compacted by chunks.
+for (unsigned int id = old_space_id; id < last_space_id; ++id) {
+verify_complete(SpaceId(id));
+}
+#endif
+}
+{
+// Update the deferred objects, if any.  Any compaction manager can be used.
+TraceTime tm_du("deferred updates", print_phases(), true, gclog_or_tty);
+ParCompactionManager* cm = ParCompactionManager::manager_array(0);
+for (unsigned int id = old_space_id; id < last_space_id; ++id) {
+update_deferred_objects(cm, SpaceId(id));
+}
+}
+}
+#ifdef  ASSERT
+void PSParallelCompact::verify_complete(SpaceId space_id) {
+// All Chunks between space bottom() to new_top() should be marked as filled
+// and all Chunks between new_top() and top() should be available (i.e.,
+// should have been emptied).
+ParallelCompactData& sd = summary_data();
+SpaceInfo si = _space_info[space_id];
+HeapWord* new_top_addr = sd.chunk_align_up(si.new_top());
+HeapWord* old_top_addr = sd.chunk_align_up(si.space()->top());
+const size_t beg_chunk = sd.addr_to_chunk_idx(si.space()->bottom());
+const size_t new_top_chunk = sd.addr_to_chunk_idx(new_top_addr);
+const size_t old_top_chunk = sd.addr_to_chunk_idx(old_top_addr);
+bool issued_a_warning = false;
+size_t cur_chunk;
+for (cur_chunk = beg_chunk; cur_chunk < new_top_chunk; ++cur_chunk) {
+const ChunkData* const c = sd.chunk(cur_chunk);
+if (!c->completed()) {
+warning("chunk " SIZE_FORMAT " not filled:  "
+"destination_count=" SIZE_FORMAT,
+cur_chunk, c->destination_count());
+issued_a_warning = true;
+}
+}
+for (cur_chunk = new_top_chunk; cur_chunk < old_top_chunk; ++cur_chunk) {
+const ChunkData* const c = sd.chunk(cur_chunk);
+if (!c->available()) {
+warning("chunk " SIZE_FORMAT " not empty:   "
+"destination_count=" SIZE_FORMAT,
+cur_chunk, c->destination_count());
+issued_a_warning = true;
+}
+}
+if (issued_a_warning) {
+print_chunk_ranges();
+}
+}
+#endif  // #ifdef ASSERT
+void PSParallelCompact::compact_serial(ParCompactionManager* cm) {
+EventMark m("5 compact serial");
+TraceTime tm("compact serial", print_phases(), true, gclog_or_tty);
+ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+PSYoungGen* young_gen = heap->young_gen();
+PSOldGen* old_gen = heap->old_gen();
+old_gen->start_array()->reset();
+old_gen->move_and_update(cm);
+young_gen->move_and_update(cm);
+}
+void PSParallelCompact::follow_root(ParCompactionManager* cm, oop* p) {
+assert(!Universe::heap()->is_in_reserved(p),
+"roots shouldn't be things within the heap");
+#ifdef VALIDATE_MARK_SWEEP
+if (ValidateMarkSweep) {
+guarantee(!_root_refs_stack->contains(p), "should only be in here once");
+_root_refs_stack->push(p);
+}
+#endif
+oop m = *p;
+if (m != NULL && mark_bitmap()->is_unmarked(m)) {
+if (mark_obj(m)) {
+m->follow_contents(cm);  // Follow contents of the marked object
+}
+}
+follow_stack(cm);
+}
+void PSParallelCompact::follow_stack(ParCompactionManager* cm) {
+while(!cm->overflow_stack()->is_empty()) {
+oop obj = cm->overflow_stack()->pop();
+obj->follow_contents(cm);
+}
+oop obj;
+// obj is a reference!!!
+while (cm->marking_stack()->pop_local(obj)) {
+// It would be nice to assert about the type of objects we might
+// pop, but they can come from anywhere, unfortunately.
+obj->follow_contents(cm);
+}
+}
+void
+PSParallelCompact::follow_weak_klass_links(ParCompactionManager* serial_cm) {
+// All klasses on the revisit stack are marked at this point.
+// Update and follow all subklass, sibling and implementor links.
+for (uint i = 0; i < ParallelGCThreads+1; i++) {
+ParCompactionManager* cm = ParCompactionManager::manager_array(i);
+KeepAliveClosure keep_alive_closure(cm);
+for (int i = 0; i < cm->revisit_klass_stack()->length(); i++) {
+cm->revisit_klass_stack()->at(i)->follow_weak_klass_links(
+is_alive_closure(),
+&keep_alive_closure);
+}
+follow_stack(cm);
+}
+}
+void
+PSParallelCompact::revisit_weak_klass_link(ParCompactionManager* cm, Klass* k) {
+cm->revisit_klass_stack()->push(k);
+}
+#ifdef VALIDATE_MARK_SWEEP
+void PSParallelCompact::track_adjusted_pointer(oop* p, oop newobj, bool isroot) {
+if (!ValidateMarkSweep)
+return;
+if (!isroot) {
+if (_pointer_tracking) {
+guarantee(_adjusted_pointers->contains(p), "should have seen this pointer");
+_adjusted_pointers->remove(p);
+}
+} else {
+ptrdiff_t index = _root_refs_stack->find(p);
+if (index != -1) {
+int l = _root_refs_stack->length();
+if (l > 0 && l - 1 != index) {
+oop* last = _root_refs_stack->pop();
+assert(last != p, "should be different");
+_root_refs_stack->at_put(index, last);
+} else {
+_root_refs_stack->remove(p);
+}
+}
+}
+}
+void PSParallelCompact::check_adjust_pointer(oop* p) {
+_adjusted_pointers->push(p);
+}
+class AdjusterTracker: public OopClosure {
+public:
+AdjusterTracker() {};
+void do_oop(oop* o)   { PSParallelCompact::check_adjust_pointer(o); }
+};
+void PSParallelCompact::track_interior_pointers(oop obj) {
+if (ValidateMarkSweep) {
+_adjusted_pointers->clear();
+_pointer_tracking = true;
+AdjusterTracker checker;
+obj->oop_iterate(&checker);
+}
+}
+void PSParallelCompact::check_interior_pointers() {
+if (ValidateMarkSweep) {
+_pointer_tracking = false;
+guarantee(_adjusted_pointers->length() == 0, "should have processed the same pointers");
+}
+}
+void PSParallelCompact::reset_live_oop_tracking(bool at_perm) {
+if (ValidateMarkSweep) {
+guarantee((size_t)_live_oops->length() == _live_oops_index, "should be at end of live oops");
+_live_oops_index = at_perm ? _live_oops_index_at_perm : 0;
+}
+}
+void PSParallelCompact::register_live_oop(oop p, size_t size) {
+if (ValidateMarkSweep) {
+_live_oops->push(p);
+_live_oops_size->push(size);
+_live_oops_index++;
+}
+}
+void PSParallelCompact::validate_live_oop(oop p, size_t size) {
+if (ValidateMarkSweep) {
+oop obj = _live_oops->at((int)_live_oops_index);
+guarantee(obj == p, "should be the same object");
+guarantee(_live_oops_size->at((int)_live_oops_index) == size, "should be the same size");
+_live_oops_index++;
+}
+}
+void PSParallelCompact::live_oop_moved_to(HeapWord* q, size_t size,
+HeapWord* compaction_top) {
+assert(oop(q)->forwardee() == NULL || oop(q)->forwardee() == oop(compaction_top),
+"should be moved to forwarded location");
+if (ValidateMarkSweep) {
+PSParallelCompact::validate_live_oop(oop(q), size);
+_live_oops_moved_to->push(oop(compaction_top));
+}
+if (RecordMarkSweepCompaction) {
+_cur_gc_live_oops->push(q);
+_cur_gc_live_oops_moved_to->push(compaction_top);
+_cur_gc_live_oops_size->push(size);
+}
+}
+void PSParallelCompact::compaction_complete() {
+if (RecordMarkSweepCompaction) {
+GrowableArray<HeapWord*>* _tmp_live_oops          = _cur_gc_live_oops;
+GrowableArray<HeapWord*>* _tmp_live_oops_moved_to = _cur_gc_live_oops_moved_to;
+GrowableArray<size_t>   * _tmp_live_oops_size     = _cur_gc_live_oops_size;
+_cur_gc_live_oops           = _last_gc_live_oops;
+_cur_gc_live_oops_moved_to  = _last_gc_live_oops_moved_to;
+_cur_gc_live_oops_size      = _last_gc_live_oops_size;
+_last_gc_live_oops          = _tmp_live_oops;
+_last_gc_live_oops_moved_to = _tmp_live_oops_moved_to;
+_last_gc_live_oops_size     = _tmp_live_oops_size;
+}
+}
+void PSParallelCompact::print_new_location_of_heap_address(HeapWord* q) {
+if (!RecordMarkSweepCompaction) {
+tty->print_cr("Requires RecordMarkSweepCompaction to be enabled");
+return;
+}
+if (_last_gc_live_oops == NULL) {
+tty->print_cr("No compaction information gathered yet");
+return;
+}
+for (int i = 0; i < _last_gc_live_oops->length(); i++) {
+HeapWord* old_oop = _last_gc_live_oops->at(i);
+size_t    sz      = _last_gc_live_oops_size->at(i);
+if (old_oop <= q && q < (old_oop + sz)) {
+HeapWord* new_oop = _last_gc_live_oops_moved_to->at(i);
+size_t offset = (q - old_oop);
+tty->print_cr("Address " PTR_FORMAT, q);
+tty->print_cr(" Was in oop " PTR_FORMAT ", size %d, at offset %d", old_oop, sz, offset);
+tty->print_cr(" Now in oop " PTR_FORMAT ", actual address " PTR_FORMAT, new_oop, new_oop + offset);
+return;
+}
+}
+tty->print_cr("Address " PTR_FORMAT " not found in live oop information from last GC", q);
+}
+#endif //VALIDATE_MARK_SWEEP
+void PSParallelCompact::adjust_pointer(oop* p, bool isroot) {
+oop obj = *p;
+VALIDATE_MARK_SWEEP_ONLY(oop saved_new_pointer = NULL);
+if (obj != NULL) {
+oop new_pointer = (oop) summary_data().calc_new_pointer(obj);
+assert(new_pointer != NULL ||                     // is forwarding ptr?
+obj->is_shared(),                          // never forwarded?
+"should have a new location");
+// Just always do the update unconditionally?
+if (new_pointer != NULL) {
+*p = new_pointer;
+assert(Universe::heap()->is_in_reserved(new_pointer),
+"should be in object space");
+VALIDATE_MARK_SWEEP_ONLY(saved_new_pointer = new_pointer);
+}
+}
+VALIDATE_MARK_SWEEP_ONLY(track_adjusted_pointer(p, saved_new_pointer, isroot));
+}
+// Update interior oops in the ranges of chunks [beg_chunk, end_chunk).
+void
+PSParallelCompact::update_and_deadwood_in_dense_prefix(ParCompactionManager* cm,
+SpaceId space_id,
+size_t beg_chunk,
+size_t end_chunk) {
+ParallelCompactData& sd = summary_data();
+ParMarkBitMap* const mbm = mark_bitmap();
+HeapWord* beg_addr = sd.chunk_to_addr(beg_chunk);
+HeapWord* const end_addr = sd.chunk_to_addr(end_chunk);
+assert(beg_chunk <= end_chunk, "bad chunk range");
+assert(end_addr <= dense_prefix(space_id), "not in the dense prefix");
+#ifdef  ASSERT
+// Claim the chunks to avoid triggering an assert when they are marked as
+// filled.
+for (size_t claim_chunk = beg_chunk; claim_chunk < end_chunk; ++claim_chunk) {
+assert(sd.chunk(claim_chunk)->claim_unsafe(), "claim() failed");
+}
+#endif  // #ifdef ASSERT
+if (beg_addr != space(space_id)->bottom()) {
+// Find the first live object or block of dead space that *starts* in this
+// range of chunks.  If a partial object crosses onto the chunk, skip it; it
+// will be marked for 'deferred update' when the object head is processed.
+// If dead space crosses onto the chunk, it is also skipped; it will be
+// filled when the prior chunk is processed.  If neither of those apply, the
+// first word in the chunk is the start of a live object or dead space.
+assert(beg_addr > space(space_id)->bottom(), "sanity");
+const ChunkData* const cp = sd.chunk(beg_chunk);
+if (cp->partial_obj_size() != 0) {
+beg_addr = sd.partial_obj_end(beg_chunk);
+} else if (dead_space_crosses_boundary(cp, mbm->addr_to_bit(beg_addr))) {
+beg_addr = mbm->find_obj_beg(beg_addr, end_addr);
+}
+}
+if (beg_addr < end_addr) {
+// A live object or block of dead space starts in this range of Chunks.
+HeapWord* const dense_prefix_end = dense_prefix(space_id);
+// Create closures and iterate.
+UpdateOnlyClosure update_closure(mbm, cm, space_id);
+FillClosure fill_closure(cm, space_id);
+ParMarkBitMap::IterationStatus status;
+status = mbm->iterate(&update_closure, &fill_closure, beg_addr, end_addr,
+dense_prefix_end);
+if (status == ParMarkBitMap::incomplete) {
+update_closure.do_addr(update_closure.source());
+}
+}
+// Mark the chunks as filled.
+ChunkData* const beg_cp = sd.chunk(beg_chunk);
+ChunkData* const end_cp = sd.chunk(end_chunk);
+for (ChunkData* cp = beg_cp; cp < end_cp; ++cp) {
+cp->set_completed();
+}
+}
+// Return the SpaceId for the space containing addr.  If addr is not in the
+// heap, last_space_id is returned.  In debug mode it expects the address to be
+// in the heap and asserts such.
+PSParallelCompact::SpaceId PSParallelCompact::space_id(HeapWord* addr) {
+assert(Universe::heap()->is_in_reserved(addr), "addr not in the heap");
+for (unsigned int id = perm_space_id; id < last_space_id; ++id) {
+if (_space_info[id].space()->contains(addr)) {
+return SpaceId(id);
+}
+}
+assert(false, "no space contains the addr");
+return last_space_id;
+}
+void PSParallelCompact::update_deferred_objects(ParCompactionManager* cm,
+SpaceId id) {
+assert(id < last_space_id, "bad space id");
+ParallelCompactData& sd = summary_data();
+const SpaceInfo* const space_info = _space_info + id;
+ObjectStartArray* const start_array = space_info->start_array();
+const MutableSpace* const space = space_info->space();
+assert(space_info->dense_prefix() >= space->bottom(), "dense_prefix not set");
+HeapWord* const beg_addr = space_info->dense_prefix();
+HeapWord* const end_addr = sd.chunk_align_up(space_info->new_top());
+const ChunkData* const beg_chunk = sd.addr_to_chunk_ptr(beg_addr);
+const ChunkData* const end_chunk = sd.addr_to_chunk_ptr(end_addr);
+const ChunkData* cur_chunk;
+for (cur_chunk = beg_chunk; cur_chunk < end_chunk; ++cur_chunk) {
+HeapWord* const addr = cur_chunk->deferred_obj_addr();
+if (addr != NULL) {
+if (start_array != NULL) {
+start_array->allocate_block(addr);
+}
+oop(addr)->update_contents(cm);
+assert(oop(addr)->is_oop_or_null(), "should be an oop now");
+}
+}
+}
+// Skip over count live words starting from beg, and return the address of the
+// next live word.  Unless marked, the word corresponding to beg is assumed to
+// be dead.  Callers must either ensure beg does not correspond to the middle of
+// an object, or account for those live words in some other way.  Callers must
+// also ensure that there are enough live words in the range [beg, end) to skip.
+HeapWord*
+PSParallelCompact::skip_live_words(HeapWord* beg, HeapWord* end, size_t count)
+{
+assert(count > 0, "sanity");
+ParMarkBitMap* m = mark_bitmap();
+idx_t bits_to_skip = m->words_to_bits(count);
+idx_t cur_beg = m->addr_to_bit(beg);
+const idx_t search_end = BitMap::word_align_up(m->addr_to_bit(end));
+do {
+cur_beg = m->find_obj_beg(cur_beg, search_end);
+idx_t cur_end = m->find_obj_end(cur_beg, search_end);
+const size_t obj_bits = cur_end - cur_beg + 1;
+if (obj_bits > bits_to_skip) {
+return m->bit_to_addr(cur_beg + bits_to_skip);
+}
+bits_to_skip -= obj_bits;
+cur_beg = cur_end + 1;
+} while (bits_to_skip > 0);
+// Skipping the desired number of words landed just past the end of an object.
+// Find the start of the next object.
+cur_beg = m->find_obj_beg(cur_beg, search_end);
+assert(cur_beg < m->addr_to_bit(end), "not enough live words to skip");
+return m->bit_to_addr(cur_beg);
+}
+HeapWord*
+PSParallelCompact::first_src_addr(HeapWord* const dest_addr,
+size_t src_chunk_idx)
+{
+ParMarkBitMap* const bitmap = mark_bitmap();
+const ParallelCompactData& sd = summary_data();
+const size_t ChunkSize = ParallelCompactData::ChunkSize;
+assert(sd.is_chunk_aligned(dest_addr), "not aligned");
+const ChunkData* const src_chunk_ptr = sd.chunk(src_chunk_idx);
+const size_t partial_obj_size = src_chunk_ptr->partial_obj_size();
+HeapWord* const src_chunk_destination = src_chunk_ptr->destination();
+assert(dest_addr >= src_chunk_destination, "wrong src chunk");
+assert(src_chunk_ptr->data_size() > 0, "src chunk cannot be empty");
+HeapWord* const src_chunk_beg = sd.chunk_to_addr(src_chunk_idx);
+HeapWord* const src_chunk_end = src_chunk_beg + ChunkSize;
+HeapWord* addr = src_chunk_beg;
+if (dest_addr == src_chunk_destination) {
+// Return the first live word in the source chunk.
+if (partial_obj_size == 0) {
+addr = bitmap->find_obj_beg(addr, src_chunk_end);
+assert(addr < src_chunk_end, "no objects start in src chunk");
+}
+return addr;
+}
+// Must skip some live data.
+size_t words_to_skip = dest_addr - src_chunk_destination;
+assert(src_chunk_ptr->data_size() > words_to_skip, "wrong src chunk");
+if (partial_obj_size >= words_to_skip) {
+// All the live words to skip are part of the partial object.
+addr += words_to_skip;
+if (partial_obj_size == words_to_skip) {
+// Find the first live word past the partial object.
+addr = bitmap->find_obj_beg(addr, src_chunk_end);
+assert(addr < src_chunk_end, "wrong src chunk");
+}
+return addr;
+}
+// Skip over the partial object (if any).
+if (partial_obj_size != 0) {
+words_to_skip -= partial_obj_size;
+addr += partial_obj_size;
+}
+// Skip over live words due to objects that start in the chunk.
+addr = skip_live_words(addr, src_chunk_end, words_to_skip);
+assert(addr < src_chunk_end, "wrong src chunk");
+return addr;
+}
+void PSParallelCompact::decrement_destination_counts(ParCompactionManager* cm,
+size_t beg_chunk,
+HeapWord* end_addr)
+{
+ParallelCompactData& sd = summary_data();
+ChunkData* const beg = sd.chunk(beg_chunk);
+HeapWord* const end_addr_aligned_up = sd.chunk_align_up(end_addr);
+ChunkData* const end = sd.addr_to_chunk_ptr(end_addr_aligned_up);
+size_t cur_idx = beg_chunk;
+for (ChunkData* cur = beg; cur < end; ++cur, ++cur_idx) {
+assert(cur->data_size() > 0, "chunk must have live data");
+cur->decrement_destination_count();
+if (cur_idx <= cur->source_chunk() && cur->available() && cur->claim()) {
+cm->save_for_processing(cur_idx);
+}
+}
+}
+size_t PSParallelCompact::next_src_chunk(MoveAndUpdateClosure& closure,
+SpaceId& src_space_id,
+HeapWord*& src_space_top,
+HeapWord* end_addr)
+{
+typedef ParallelCompactData::ChunkData ChunkData;
+ParallelCompactData& sd = PSParallelCompact::summary_data();
+const size_t chunk_size = ParallelCompactData::ChunkSize;
+size_t src_chunk_idx = 0;
+// Skip empty chunks (if any) up to the top of the space.
+HeapWord* const src_aligned_up = sd.chunk_align_up(end_addr);
+ChunkData* src_chunk_ptr = sd.addr_to_chunk_ptr(src_aligned_up);
+HeapWord* const top_aligned_up = sd.chunk_align_up(src_space_top);
+const ChunkData* const top_chunk_ptr = sd.addr_to_chunk_ptr(top_aligned_up);
+while (src_chunk_ptr < top_chunk_ptr && src_chunk_ptr->data_size() == 0) {
+++src_chunk_ptr;
+}
+if (src_chunk_ptr < top_chunk_ptr) {
+// The next source chunk is in the current space.  Update src_chunk_idx and
+// the source address to match src_chunk_ptr.
+src_chunk_idx = sd.chunk(src_chunk_ptr);
+HeapWord* const src_chunk_addr = sd.chunk_to_addr(src_chunk_idx);
+if (src_chunk_addr > closure.source()) {
+closure.set_source(src_chunk_addr);
+}
+return src_chunk_idx;
+}
+// Switch to a new source space and find the first non-empty chunk.
+unsigned int space_id = src_space_id + 1;
+assert(space_id < last_space_id, "not enough spaces");
+HeapWord* const destination = closure.destination();
+do {
+MutableSpace* space = _space_info[space_id].space();
+HeapWord* const bottom = space->bottom();
+const ChunkData* const bottom_cp = sd.addr_to_chunk_ptr(bottom);
+// Iterate over the spaces that do not compact into themselves.
+if (bottom_cp->destination() != bottom) {
+HeapWord* const top_aligned_up = sd.chunk_align_up(space->top());
+const ChunkData* const top_cp = sd.addr_to_chunk_ptr(top_aligned_up);
+for (const ChunkData* src_cp = bottom_cp; src_cp < top_cp; ++src_cp) {
+if (src_cp->live_obj_size() > 0) {
+// Found it.
+assert(src_cp->destination() == destination,
+"first live obj in the space must match the destination");
+assert(src_cp->partial_obj_size() == 0,
+"a space cannot begin with a partial obj");
+src_space_id = SpaceId(space_id);
+src_space_top = space->top();
+const size_t src_chunk_idx = sd.chunk(src_cp);
+closure.set_source(sd.chunk_to_addr(src_chunk_idx));
+return src_chunk_idx;
+} else {
+assert(src_cp->data_size() == 0, "sanity");
+}
+}
+}
+} while (++space_id < last_space_id);
+assert(false, "no source chunk was found");
+return 0;
+}
+void PSParallelCompact::fill_chunk(ParCompactionManager* cm, size_t chunk_idx)
+{
+typedef ParMarkBitMap::IterationStatus IterationStatus;
+const size_t ChunkSize = ParallelCompactData::ChunkSize;
+ParMarkBitMap* const bitmap = mark_bitmap();
+ParallelCompactData& sd = summary_data();
+ChunkData* const chunk_ptr = sd.chunk(chunk_idx);
+// Get the items needed to construct the closure.
+HeapWord* dest_addr = sd.chunk_to_addr(chunk_idx);
+SpaceId dest_space_id = space_id(dest_addr);
+ObjectStartArray* start_array = _space_info[dest_space_id].start_array();
+HeapWord* new_top = _space_info[dest_space_id].new_top();
+assert(dest_addr < new_top, "sanity");
+const size_t words = MIN2(pointer_delta(new_top, dest_addr), ChunkSize);
+// Get the source chunk and related info.
+size_t src_chunk_idx = chunk_ptr->source_chunk();
+SpaceId src_space_id = space_id(sd.chunk_to_addr(src_chunk_idx));
+HeapWord* src_space_top = _space_info[src_space_id].space()->top();
+MoveAndUpdateClosure closure(bitmap, cm, start_array, dest_addr, words);
+closure.set_source(first_src_addr(dest_addr, src_chunk_idx));
+// Adjust src_chunk_idx to prepare for decrementing destination counts (the
+// destination count is not decremented when a chunk is copied to itself).
+if (src_chunk_idx == chunk_idx) {
+src_chunk_idx += 1;
+}
+if (bitmap->is_unmarked(closure.source())) {
+// The first source word is in the middle of an object; copy the remainder
+// of the object or as much as will fit.  The fact that pointer updates were
+// deferred will be noted when the object header is processed.
+HeapWord* const old_src_addr = closure.source();
+closure.copy_partial_obj();
+if (closure.is_full()) {
+decrement_destination_counts(cm, src_chunk_idx, closure.source());
+chunk_ptr->set_deferred_obj_addr(NULL);
+chunk_ptr->set_completed();
+return;
+}
+HeapWord* const end_addr = sd.chunk_align_down(closure.source());
+if (sd.chunk_align_down(old_src_addr) != end_addr) {
+// The partial object was copied from more than one source chunk.
+decrement_destination_counts(cm, src_chunk_idx, end_addr);
+// Move to the next source chunk, possibly switching spaces as well.  All
+// args except end_addr may be modified.
+src_chunk_idx = next_src_chunk(closure, src_space_id, src_space_top,
+end_addr);
+}
+}
+do {
+HeapWord* const cur_addr = closure.source();
+HeapWord* const end_addr = MIN2(sd.chunk_align_up(cur_addr + 1),
+src_space_top);
+IterationStatus status = bitmap->iterate(&closure, cur_addr, end_addr);
+if (status == ParMarkBitMap::incomplete) {
+// The last obj that starts in the source chunk does not end in the chunk.
+assert(closure.source() < end_addr, "sanity")
+HeapWord* const obj_beg = closure.source();
+HeapWord* const range_end = MIN2(obj_beg + closure.words_remaining(),
+src_space_top);
+HeapWord* const obj_end = bitmap->find_obj_end(obj_beg, range_end);
+if (obj_end < range_end) {
+// The end was found; the entire object will fit.
+status = closure.do_addr(obj_beg, bitmap->obj_size(obj_beg, obj_end));
+assert(status != ParMarkBitMap::would_overflow, "sanity");
+} else {
+// The end was not found; the object will not fit.
+assert(range_end < src_space_top, "obj cannot cross space boundary");
+status = ParMarkBitMap::would_overflow;
+}
+}
+if (status == ParMarkBitMap::would_overflow) {
+// The last object did not fit.  Note that interior oop updates were
+// deferred, then copy enough of the object to fill the chunk.
+chunk_ptr->set_deferred_obj_addr(closure.destination());
+status = closure.copy_until_full(); // copies from closure.source()
+decrement_destination_counts(cm, src_chunk_idx, closure.source());
+chunk_ptr->set_completed();
+return;
+}
+if (status == ParMarkBitMap::full) {
+decrement_destination_counts(cm, src_chunk_idx, closure.source());
+chunk_ptr->set_deferred_obj_addr(NULL);
+chunk_ptr->set_completed();
+return;
+}
+decrement_destination_counts(cm, src_chunk_idx, end_addr);
+// Move to the next source chunk, possibly switching spaces as well.  All
+// args except end_addr may be modified.
+src_chunk_idx = next_src_chunk(closure, src_space_id, src_space_top,
+end_addr);
+} while (true);
+}
+void
+PSParallelCompact::move_and_update(ParCompactionManager* cm, SpaceId space_id) {
+const MutableSpace* sp = space(space_id);
+if (sp->is_empty()) {
+return;
+}
+ParallelCompactData& sd = PSParallelCompact::summary_data();
+ParMarkBitMap* const bitmap = mark_bitmap();
+HeapWord* const dp_addr = dense_prefix(space_id);
+HeapWord* beg_addr = sp->bottom();
+HeapWord* end_addr = sp->top();
+#ifdef ASSERT
+assert(beg_addr <= dp_addr && dp_addr <= end_addr, "bad dense prefix");
+if (cm->should_verify_only()) {
+VerifyUpdateClosure verify_update(cm, sp);
+bitmap->iterate(&verify_update, beg_addr, end_addr);
+return;
+}
+if (cm->should_reset_only()) {
+ResetObjectsClosure reset_objects(cm);
+bitmap->iterate(&reset_objects, beg_addr, end_addr);
+return;
+}
+#endif
+const size_t beg_chunk = sd.addr_to_chunk_idx(beg_addr);
+const size_t dp_chunk = sd.addr_to_chunk_idx(dp_addr);
+if (beg_chunk < dp_chunk) {
+update_and_deadwood_in_dense_prefix(cm, space_id, beg_chunk, dp_chunk);
+}
+// The destination of the first live object that starts in the chunk is one
+// past the end of the partial object entering the chunk (if any).
+HeapWord* const dest_addr = sd.partial_obj_end(dp_chunk);
+HeapWord* const new_top = _space_info[space_id].new_top();
+assert(new_top >= dest_addr, "bad new_top value");
+const size_t words = pointer_delta(new_top, dest_addr);
+if (words > 0) {
+ObjectStartArray* start_array = _space_info[space_id].start_array();
+MoveAndUpdateClosure closure(bitmap, cm, start_array, dest_addr, words);
+ParMarkBitMap::IterationStatus status;
+status = bitmap->iterate(&closure, dest_addr, end_addr);
+assert(status == ParMarkBitMap::full, "iteration not complete");
+assert(bitmap->find_obj_beg(closure.source(), end_addr) == end_addr,
+"live objects skipped because closure is full");
+}
+}
+jlong PSParallelCompact::millis_since_last_gc() {
+jlong ret_val = os::javaTimeMillis() - _time_of_last_gc;
+// XXX See note in genCollectedHeap::millis_since_last_gc().
+if (ret_val < 0) {
+NOT_PRODUCT(warning("time warp: %d", ret_val);)
+return 0;
+}
+return ret_val;
+}
+void PSParallelCompact::reset_millis_since_last_gc() {
+_time_of_last_gc = os::javaTimeMillis();
+}
+ParMarkBitMap::IterationStatus MoveAndUpdateClosure::copy_until_full()
+{
+if (source() != destination()) {
+assert(source() > destination(), "must copy to the left");
+Copy::aligned_conjoint_words(source(), destination(), words_remaining());
+}
+update_state(words_remaining());
+assert(is_full(), "sanity");
+return ParMarkBitMap::full;
+}
+void MoveAndUpdateClosure::copy_partial_obj()
+{
+size_t words = words_remaining();
+HeapWord* const range_end = MIN2(source() + words, bitmap()->region_end());
+HeapWord* const end_addr = bitmap()->find_obj_end(source(), range_end);
+if (end_addr < range_end) {
+words = bitmap()->obj_size(source(), end_addr);
+}
+// This test is necessary; if omitted, the pointer updates to a partial object
+// that crosses the dense prefix boundary could be overwritten.
+if (source() != destination()) {
+assert(source() > destination(), "must copy to the left");
+Copy::aligned_conjoint_words(source(), destination(), words);
+}
+update_state(words);
+}
+ParMarkBitMapClosure::IterationStatus
+MoveAndUpdateClosure::do_addr(HeapWord* addr, size_t words) {
+assert(destination() != NULL, "sanity");
+assert(bitmap()->obj_size(addr) == words, "bad size");
+_source = addr;
+assert(PSParallelCompact::summary_data().calc_new_pointer(source()) ==
+destination(), "wrong destination");
+if (words > words_remaining()) {
+return ParMarkBitMap::would_overflow;
+}
+// The start_array must be updated even if the object is not moving.
+if (_start_array != NULL) {
+_start_array->allocate_block(destination());
+}
+if (destination() != source()) {
+assert(destination() < source(), "must copy to the left");
+Copy::aligned_conjoint_words(source(), destination(), words);
+}
+oop moved_oop = (oop) destination();
+moved_oop->update_contents(compaction_manager());
+assert(moved_oop->is_oop_or_null(), "Object should be whole at this point");
+update_state(words);
+assert(destination() == (HeapWord*)moved_oop + moved_oop->size(), "sanity");
+return is_full() ? ParMarkBitMap::full : ParMarkBitMap::incomplete;
+}
+UpdateOnlyClosure::UpdateOnlyClosure(ParMarkBitMap* mbm,
+ParCompactionManager* cm,
+PSParallelCompact::SpaceId space_id) :
+ParMarkBitMapClosure(mbm, cm),
+_space_id(space_id),
+_start_array(PSParallelCompact::start_array(space_id))
+{
+}
+// Updates the references in the object to their new values.
+ParMarkBitMapClosure::IterationStatus
+UpdateOnlyClosure::do_addr(HeapWord* addr, size_t words) {
+do_addr(addr);
+return ParMarkBitMap::incomplete;
+}
+BitBlockUpdateClosure::BitBlockUpdateClosure(ParMarkBitMap* mbm,
+ParCompactionManager* cm,
+size_t chunk_index) :
+ParMarkBitMapClosure(mbm, cm),
+_live_data_left(0),
+_cur_block(0) {
+_chunk_start =
+PSParallelCompact::summary_data().chunk_to_addr(chunk_index);
+_chunk_end =
+PSParallelCompact::summary_data().chunk_to_addr(chunk_index) +
+ParallelCompactData::ChunkSize;
+_chunk_index = chunk_index;
+_cur_block =
+PSParallelCompact::summary_data().addr_to_block_idx(_chunk_start);
+}
+bool BitBlockUpdateClosure::chunk_contains_cur_block() {
+return ParallelCompactData::chunk_contains_block(_chunk_index, _cur_block);
+}
+void BitBlockUpdateClosure::reset_chunk(size_t chunk_index) {
+DEBUG_ONLY(ParallelCompactData::BlockData::set_cur_phase(7);)
+ParallelCompactData& sd = PSParallelCompact::summary_data();
+_chunk_index = chunk_index;
+_live_data_left = 0;
+_chunk_start = sd.chunk_to_addr(chunk_index);
+_chunk_end = sd.chunk_to_addr(chunk_index) + ParallelCompactData::ChunkSize;
+// The first block in this chunk
+size_t first_block =  sd.addr_to_block_idx(_chunk_start);
+size_t partial_live_size = sd.chunk(chunk_index)->partial_obj_size();
+// Set the offset to 0. By definition it should have that value
+// but it may have been written while processing an earlier chunk.
+if (partial_live_size == 0) {
+// No live object extends onto the chunk.  The first bit
+// in the bit map for the first chunk must be a start bit.
+// Although there may not be any marked bits, it is safe
+// to set it as a start bit.
+sd.block(first_block)->set_start_bit_offset(0);
+sd.block(first_block)->set_first_is_start_bit(true);
+} else if (sd.partial_obj_ends_in_block(first_block)) {
+sd.block(first_block)->set_end_bit_offset(0);
+sd.block(first_block)->set_first_is_start_bit(false);
+} else {
+// The partial object extends beyond the first block.
+// There is no object starting in the first block
+// so the offset and bit parity are not needed.
+// Set the the bit parity to start bit so assertions
+// work when not bit is found.
+sd.block(first_block)->set_end_bit_offset(0);
+sd.block(first_block)->set_first_is_start_bit(false);
+}
+_cur_block = first_block;
+#ifdef ASSERT
+if (sd.block(first_block)->first_is_start_bit()) {
+assert(!sd.partial_obj_ends_in_block(first_block),
+"Partial object cannot end in first block");
+}
+if (PrintGCDetails && Verbose) {
+if (partial_live_size == 1) {
+gclog_or_tty->print_cr("first_block " PTR_FORMAT
+" _offset " PTR_FORMAT
+" _first_is_start_bit %d",
+first_block,
+sd.block(first_block)->raw_offset(),
+sd.block(first_block)->first_is_start_bit());
+}
+}
+#endif
+DEBUG_ONLY(ParallelCompactData::BlockData::set_cur_phase(17);)
+}
+// This method is called when a object has been found (both beginning
+// and end of the object) in the range of iteration.  This method is
+// calculating the words of live data to the left of a block.  That live
+// data includes any object starting to the left of the block (i.e.,
+// the live-data-to-the-left of block AAA will include the full size
+// of any object entering AAA).
+ParMarkBitMapClosure::IterationStatus
+BitBlockUpdateClosure::do_addr(HeapWord* addr, size_t words) {
+// add the size to the block data.
+HeapWord* obj = addr;
+ParallelCompactData& sd = PSParallelCompact::summary_data();
+assert(bitmap()->obj_size(obj) == words, "bad size");
+assert(_chunk_start <= obj, "object is not in chunk");
+assert(obj + words <= _chunk_end, "object is not in chunk");
+// Update the live data to the left
+size_t prev_live_data_left = _live_data_left;
+_live_data_left = _live_data_left + words;
+// Is this object in the current block.
+size_t block_of_obj = sd.addr_to_block_idx(obj);
+size_t block_of_obj_last = sd.addr_to_block_idx(obj + words - 1);
+HeapWord* block_of_obj_last_addr = sd.block_to_addr(block_of_obj_last);
+if (_cur_block < block_of_obj) {
+//
+// No object crossed the block boundary and this object was found
+// on the other side of the block boundary.  Update the offset for
+// the new block with the data size that does not include this object.
+//
+// The first bit in block_of_obj is a start bit except in the
+// case where the partial object for the chunk extends into
+// this block.
+if (sd.partial_obj_ends_in_block(block_of_obj)) {
+sd.block(block_of_obj)->set_end_bit_offset(prev_live_data_left);
+} else {
+sd.block(block_of_obj)->set_start_bit_offset(prev_live_data_left);
+}
+// Does this object pass beyond the its block?
+if (block_of_obj < block_of_obj_last) {
+// Object crosses block boundary.  Two blocks need to be udpated:
+//        the current block where the object started
+//        the block where the object ends
+//
+// The offset for blocks with no objects starting in them
+// (e.g., blocks between _cur_block and  block_of_obj_last)
+// should not be needed.
+// Note that block_of_obj_last may be in another chunk.  If so,
+// it should be overwritten later.  This is a problem (writting
+// into a block in a later chunk) for parallel execution.
+assert(obj < block_of_obj_last_addr,
+"Object should start in previous block");
+// obj is crossing into block_of_obj_last so the first bit
+// is and end bit.
+sd.block(block_of_obj_last)->set_end_bit_offset(_live_data_left);
+_cur_block = block_of_obj_last;
+} else {
+// _first_is_start_bit has already been set correctly
+// in the if-then-else above so don't reset it here.
+_cur_block = block_of_obj;
+}
+} else {
+// The current block only changes if the object extends beyound
+// the block it starts in.
+//
+// The object starts in the current block.
+// Does this object pass beyond the end of it?
+if (block_of_obj < block_of_obj_last) {
+// Object crosses block boundary.
+// See note above on possible blocks between block_of_obj and
+// block_of_obj_last
+assert(obj < block_of_obj_last_addr,
+"Object should start in previous block");
+sd.block(block_of_obj_last)->set_end_bit_offset(_live_data_left);
+_cur_block = block_of_obj_last;
+}
+}
+// Return incomplete if there are more blocks to be done.
+if (chunk_contains_cur_block()) {
+return ParMarkBitMap::incomplete;
+}
+return ParMarkBitMap::complete;
+}
+// Verify the new location using the forwarding pointer
+// from MarkSweep::mark_sweep_phase2().  Set the mark_word
+// to the initial value.
+ParMarkBitMapClosure::IterationStatus
+PSParallelCompact::VerifyUpdateClosure::do_addr(HeapWord* addr, size_t words) {
+// The second arg (words) is not used.
+oop obj = (oop) addr;
+HeapWord* forwarding_ptr = (HeapWord*) obj->mark()->decode_pointer();
+HeapWord* new_pointer = summary_data().calc_new_pointer(obj);
+if (forwarding_ptr == NULL) {
+// The object is dead or not moving.
+assert(bitmap()->is_unmarked(obj) || (new_pointer == (HeapWord*) obj),
+"Object liveness is wrong.");
+return ParMarkBitMap::incomplete;
+}
+assert(UseParallelOldGCDensePrefix ||
+(HeapMaximumCompactionInterval > 1) ||
+(MarkSweepAlwaysCompactCount > 1) ||
+(forwarding_ptr == new_pointer),
+"Calculation of new location is incorrect");
+return ParMarkBitMap::incomplete;
+}
+// Reset objects modified for debug checking.
+ParMarkBitMapClosure::IterationStatus
+PSParallelCompact::ResetObjectsClosure::do_addr(HeapWord* addr, size_t words) {
+// The second arg (words) is not used.
+oop obj = (oop) addr;
+obj->init_mark();
+return ParMarkBitMap::incomplete;
+}
+// Prepare for compaction.  This method is executed once
+// (i.e., by a single thread) before compaction.
+// Save the updated location of the intArrayKlassObj for
+// filling holes in the dense prefix.
+void PSParallelCompact::compact_prologue() {
+_updated_int_array_klass_obj = (klassOop)
+summary_data().calc_new_pointer(Universe::intArrayKlassObj());
+}
+// The initial implementation of this method created a field
+// _next_compaction_space_id in SpaceInfo and initialized
+// that field in SpaceInfo::initialize_space_info().  That
+// required that _next_compaction_space_id be declared a
+// SpaceId in SpaceInfo and that would have required that
+// either SpaceId be declared in a separate class or that
+// it be declared in SpaceInfo.  It didn't seem consistent
+// to declare it in SpaceInfo (didn't really fit logically).
+// Alternatively, defining a separate class to define SpaceId
+// seem excessive.  This implementation is simple and localizes
+// the knowledge.
+PSParallelCompact::SpaceId
+PSParallelCompact::next_compaction_space_id(SpaceId id) {
+assert(id < last_space_id, "id out of range");
+switch (id) {
+case perm_space_id :
+return last_space_id;
+case old_space_id :
+return eden_space_id;
+case eden_space_id :
+return from_space_id;
+case from_space_id :
+return to_space_id;
+case to_space_id :
+return last_space_id;
+default:
+assert(false, "Bad space id");
+return last_space_id;
+}
+}
+// Here temporarily for debugging
+#ifdef ASSERT
+size_t ParallelCompactData::block_idx(BlockData* block) {
+size_t index = pointer_delta(block,
+PSParallelCompact::summary_data()._block_data, sizeof(BlockData));
+return index;
+}
+#endif

Mercurial > hg > truffle

comparison src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp @ 0:a61af66fc99e jdk7-b24