| /* |
| * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "incls/_precompiled.incl" |
| #include "incls/_psParallelCompact.cpp.incl" |
| |
| #include <math.h> |
| |
| // All sizes are in HeapWords. |
| const size_t ParallelCompactData::Log2RegionSize = 9; // 512 words |
| const size_t ParallelCompactData::RegionSize = (size_t)1 << Log2RegionSize; |
| const size_t ParallelCompactData::RegionSizeBytes = |
| RegionSize << LogHeapWordSize; |
| const size_t ParallelCompactData::RegionSizeOffsetMask = RegionSize - 1; |
| const size_t ParallelCompactData::RegionAddrOffsetMask = RegionSizeBytes - 1; |
| const size_t ParallelCompactData::RegionAddrMask = ~RegionAddrOffsetMask; |
| |
| const ParallelCompactData::RegionData::region_sz_t |
| ParallelCompactData::RegionData::dc_shift = 27; |
| |
| const ParallelCompactData::RegionData::region_sz_t |
| ParallelCompactData::RegionData::dc_mask = ~0U << dc_shift; |
| |
| const ParallelCompactData::RegionData::region_sz_t |
| ParallelCompactData::RegionData::dc_one = 0x1U << dc_shift; |
| |
| const ParallelCompactData::RegionData::region_sz_t |
| ParallelCompactData::RegionData::los_mask = ~dc_mask; |
| |
| const ParallelCompactData::RegionData::region_sz_t |
| ParallelCompactData::RegionData::dc_claimed = 0x8U << dc_shift; |
| |
| const ParallelCompactData::RegionData::region_sz_t |
| ParallelCompactData::RegionData::dc_completed = 0xcU << dc_shift; |
| |
| 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<void*>* 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<void*>* PSParallelCompact::_other_refs_stack = NULL; |
| GrowableArray<void*>* 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 |
| |
| void SplitInfo::record(size_t src_region_idx, size_t partial_obj_size, |
| HeapWord* destination) |
| { |
| assert(src_region_idx != 0, "invalid src_region_idx"); |
| assert(partial_obj_size != 0, "invalid partial_obj_size argument"); |
| assert(destination != NULL, "invalid destination argument"); |
| |
| _src_region_idx = src_region_idx; |
| _partial_obj_size = partial_obj_size; |
| _destination = destination; |
| |
| // These fields may not be updated below, so make sure they're clear. |
| assert(_dest_region_addr == NULL, "should have been cleared"); |
| assert(_first_src_addr == NULL, "should have been cleared"); |
| |
| // Determine the number of destination regions for the partial object. |
| HeapWord* const last_word = destination + partial_obj_size - 1; |
| const ParallelCompactData& sd = PSParallelCompact::summary_data(); |
| HeapWord* const beg_region_addr = sd.region_align_down(destination); |
| HeapWord* const end_region_addr = sd.region_align_down(last_word); |
| |
| if (beg_region_addr == end_region_addr) { |
| // One destination region. |
| _destination_count = 1; |
| if (end_region_addr == destination) { |
| // The destination falls on a region boundary, thus the first word of the |
| // partial object will be the first word copied to the destination region. |
| _dest_region_addr = end_region_addr; |
| _first_src_addr = sd.region_to_addr(src_region_idx); |
| } |
| } else { |
| // Two destination regions. When copied, the partial object will cross a |
| // destination region boundary, so a word somewhere within the partial |
| // object will be the first word copied to the second destination region. |
| _destination_count = 2; |
| _dest_region_addr = end_region_addr; |
| const size_t ofs = pointer_delta(end_region_addr, destination); |
| assert(ofs < _partial_obj_size, "sanity"); |
| _first_src_addr = sd.region_to_addr(src_region_idx) + ofs; |
| } |
| } |
| |
| void SplitInfo::clear() |
| { |
| _src_region_idx = 0; |
| _partial_obj_size = 0; |
| _destination = NULL; |
| _destination_count = 0; |
| _dest_region_addr = NULL; |
| _first_src_addr = NULL; |
| assert(!is_valid(), "sanity"); |
| } |
| |
| #ifdef ASSERT |
| void SplitInfo::verify_clear() |
| { |
| assert(_src_region_idx == 0, "not clear"); |
| assert(_partial_obj_size == 0, "not clear"); |
| assert(_destination == NULL, "not clear"); |
| assert(_destination_count == 0, "not clear"); |
| assert(_dest_region_addr == NULL, "not clear"); |
| assert(_first_src_addr == NULL, "not clear"); |
| } |
| #endif // #ifdef ASSERT |
| |
| |
| #ifndef PRODUCT |
| const char* PSParallelCompact::space_names[] = { |
| "perm", "old ", "eden", "from", "to " |
| }; |
| |
| void PSParallelCompact::print_region_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_region_idx(space->bottom()), |
| summary_data().addr_to_region_idx(space->top()), |
| summary_data().addr_to_region_idx(space->end()), |
| summary_data().addr_to_region_idx(_space_info[id].new_top())); |
| } |
| } |
| |
| void |
| print_generic_summary_region(size_t i, const ParallelCompactData::RegionData* c) |
| { |
| #define REGION_IDX_FORMAT SIZE_FORMAT_W(7) |
| #define REGION_DATA_FORMAT SIZE_FORMAT_W(5) |
| |
| ParallelCompactData& sd = PSParallelCompact::summary_data(); |
| size_t dci = c->destination() ? sd.addr_to_region_idx(c->destination()) : 0; |
| tty->print_cr(REGION_IDX_FORMAT " " PTR_FORMAT " " |
| REGION_IDX_FORMAT " " PTR_FORMAT " " |
| REGION_DATA_FORMAT " " REGION_DATA_FORMAT " " |
| REGION_DATA_FORMAT " " REGION_IDX_FORMAT " %d", |
| i, c->data_location(), dci, c->destination(), |
| c->partial_obj_size(), c->live_obj_size(), |
| c->data_size(), c->source_region(), c->destination_count()); |
| |
| #undef REGION_IDX_FORMAT |
| #undef REGION_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_region_idx(beg_addr); |
| const size_t last = summary_data.addr_to_region_idx(end_addr); |
| HeapWord* pdest = 0; |
| |
| while (i <= last) { |
| ParallelCompactData::RegionData* c = summary_data.region(i); |
| if (c->data_size() != 0 || c->destination() != pdest) { |
| print_generic_summary_region(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_region(size_t i, |
| const ParallelCompactData::RegionData* 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_region(), 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 region_size = ParallelCompactData::RegionSize; |
| typedef ParallelCompactData::RegionData RegionData; |
| HeapWord* const top_aligned_up = summary_data.region_align_up(space->top()); |
| const size_t end_region = summary_data.addr_to_region_idx(top_aligned_up); |
| const RegionData* c = summary_data.region(end_region - 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 regions at the beginning of the space. |
| size_t full_region_count = 0; |
| size_t i = summary_data.addr_to_region_idx(space->bottom()); |
| while (i < end_region && summary_data.region(i)->data_size() == region_size) { |
| print_initial_summary_region(i, summary_data.region(i)); |
| ++full_region_count; |
| ++i; |
| } |
| |
| size_t live_to_right = live_in_space - full_region_count * region_size; |
| |
| double max_reclaimed_ratio = 0.0; |
| size_t max_reclaimed_ratio_region = 0; |
| size_t max_dead_to_right = 0; |
| size_t max_live_to_right = 0; |
| |
| // Print the 'reclaimed ratio' for regions while there is something live in |
| // the region or to the right of it. The remaining regions are empty (and |
| // uninteresting), and computing the ratio will result in division by 0. |
| while (i < end_region && live_to_right > 0) { |
| c = summary_data.region(i); |
| HeapWord* const region_addr = summary_data.region_to_addr(i); |
| const size_t used_to_right = pointer_delta(space->top(), region_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_region = i; |
| max_dead_to_right = dead_to_right; |
| max_live_to_right = live_to_right; |
| } |
| |
| print_initial_summary_region(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 regions are empty. Print one more if there is one. |
| if (i < end_region) { |
| print_initial_summary_region(i, summary_data.region(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_region, 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; |
| |
| _region_vspace = 0; |
| _region_data = 0; |
| _region_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(region_align_down(_region_start) == _region_start, |
| "region start not aligned"); |
| assert((region_size & RegionSizeOffsetMask) == 0, |
| "region size not a multiple of RegionSize"); |
| |
| bool result = initialize_region_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, rs_align > 0); |
| 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; |
| // Release memory reserved in the space. |
| rs.release(); |
| } |
| |
| return 0; |
| } |
| |
| bool ParallelCompactData::initialize_region_data(size_t region_size) |
| { |
| const size_t count = (region_size + RegionSizeOffsetMask) >> Log2RegionSize; |
| _region_vspace = create_vspace(count, sizeof(RegionData)); |
| if (_region_vspace != 0) { |
| _region_data = (RegionData*)_region_vspace->reserved_low_addr(); |
| _region_count = count; |
| return true; |
| } |
| return false; |
| } |
| |
| void ParallelCompactData::clear() |
| { |
| memset(_region_data, 0, _region_vspace->committed_size()); |
| } |
| |
| void ParallelCompactData::clear_range(size_t beg_region, size_t end_region) { |
| assert(beg_region <= _region_count, "beg_region out of range"); |
| assert(end_region <= _region_count, "end_region out of range"); |
| |
| const size_t region_cnt = end_region - beg_region; |
| memset(_region_data + beg_region, 0, region_cnt * sizeof(RegionData)); |
| } |
| |
| HeapWord* ParallelCompactData::partial_obj_end(size_t region_idx) const |
| { |
| const RegionData* cur_cp = region(region_idx); |
| const RegionData* const end_cp = region(region_count() - 1); |
| |
| HeapWord* result = region_to_addr(region_idx); |
| if (cur_cp < end_cp) { |
| do { |
| result += cur_cp->partial_obj_size(); |
| } while (cur_cp->partial_obj_size() == RegionSize && ++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_region = obj_ofs >> Log2RegionSize; |
| const size_t end_region = (obj_ofs + len - 1) >> Log2RegionSize; |
| |
| DEBUG_ONLY(Atomic::inc_ptr(&add_obj_count);) |
| DEBUG_ONLY(Atomic::add_ptr(len, &add_obj_size);) |
| |
| if (beg_region == end_region) { |
| // All in one region. |
| _region_data[beg_region].add_live_obj(len); |
| return; |
| } |
| |
| // First region. |
| const size_t beg_ofs = region_offset(addr); |
| _region_data[beg_region].add_live_obj(RegionSize - beg_ofs); |
| |
| klassOop klass = ((oop)addr)->klass(); |
| // Middle regions--completely spanned by this object. |
| for (size_t region = beg_region + 1; region < end_region; ++region) { |
| _region_data[region].set_partial_obj_size(RegionSize); |
| _region_data[region].set_partial_obj_addr(addr); |
| } |
| |
| // Last region. |
| const size_t end_ofs = region_offset(addr + len - 1); |
| _region_data[end_region].set_partial_obj_size(end_ofs + 1); |
| _region_data[end_region].set_partial_obj_addr(addr); |
| } |
| |
| void |
| ParallelCompactData::summarize_dense_prefix(HeapWord* beg, HeapWord* end) |
| { |
| assert(region_offset(beg) == 0, "not RegionSize aligned"); |
| assert(region_offset(end) == 0, "not RegionSize aligned"); |
| |
| size_t cur_region = addr_to_region_idx(beg); |
| const size_t end_region = addr_to_region_idx(end); |
| HeapWord* addr = beg; |
| while (cur_region < end_region) { |
| _region_data[cur_region].set_destination(addr); |
| _region_data[cur_region].set_destination_count(0); |
| _region_data[cur_region].set_source_region(cur_region); |
| _region_data[cur_region].set_data_location(addr); |
| |
| // Update live_obj_size so the region appears completely full. |
| size_t live_size = RegionSize - _region_data[cur_region].partial_obj_size(); |
| _region_data[cur_region].set_live_obj_size(live_size); |
| |
| ++cur_region; |
| addr += RegionSize; |
| } |
| } |
| |
| // Find the point at which a space can be split and, if necessary, record the |
| // split point. |
| // |
| // If the current src region (which overflowed the destination space) doesn't |
| // have a partial object, the split point is at the beginning of the current src |
| // region (an "easy" split, no extra bookkeeping required). |
| // |
| // If the current src region has a partial object, the split point is in the |
| // region where that partial object starts (call it the split_region). If |
| // split_region has a partial object, then the split point is just after that |
| // partial object (a "hard" split where we have to record the split data and |
| // zero the partial_obj_size field). With a "hard" split, we know that the |
| // partial_obj ends within split_region because the partial object that caused |
| // the overflow starts in split_region. If split_region doesn't have a partial |
| // obj, then the split is at the beginning of split_region (another "easy" |
| // split). |
| HeapWord* |
| ParallelCompactData::summarize_split_space(size_t src_region, |
| SplitInfo& split_info, |
| HeapWord* destination, |
| HeapWord* target_end, |
| HeapWord** target_next) |
| { |
| assert(destination <= target_end, "sanity"); |
| assert(destination + _region_data[src_region].data_size() > target_end, |
| "region should not fit into target space"); |
| assert(is_region_aligned(target_end), "sanity"); |
| |
| size_t split_region = src_region; |
| HeapWord* split_destination = destination; |
| size_t partial_obj_size = _region_data[src_region].partial_obj_size(); |
| |
| if (destination + partial_obj_size > target_end) { |
| // The split point is just after the partial object (if any) in the |
| // src_region that contains the start of the object that overflowed the |
| // destination space. |
| // |
| // Find the start of the "overflow" object and set split_region to the |
| // region containing it. |
| HeapWord* const overflow_obj = _region_data[src_region].partial_obj_addr(); |
| split_region = addr_to_region_idx(overflow_obj); |
| |
| // Clear the source_region field of all destination regions whose first word |
| // came from data after the split point (a non-null source_region field |
| // implies a region must be filled). |
| // |
| // An alternative to the simple loop below: clear during post_compact(), |
| // which uses memcpy instead of individual stores, and is easy to |
| // parallelize. (The downside is that it clears the entire RegionData |
| // object as opposed to just one field.) |
| // |
| // post_compact() would have to clear the summary data up to the highest |
| // address that was written during the summary phase, which would be |
| // |
| // max(top, max(new_top, clear_top)) |
| // |
| // where clear_top is a new field in SpaceInfo. Would have to set clear_top |
| // to target_end. |
| const RegionData* const sr = region(split_region); |
| const size_t beg_idx = |
| addr_to_region_idx(region_align_up(sr->destination() + |
| sr->partial_obj_size())); |
| const size_t end_idx = addr_to_region_idx(target_end); |
| |
| if (TraceParallelOldGCSummaryPhase) { |
| gclog_or_tty->print_cr("split: clearing source_region field in [" |
| SIZE_FORMAT ", " SIZE_FORMAT ")", |
| beg_idx, end_idx); |
| } |
| for (size_t idx = beg_idx; idx < end_idx; ++idx) { |
| _region_data[idx].set_source_region(0); |
| } |
| |
| // Set split_destination and partial_obj_size to reflect the split region. |
| split_destination = sr->destination(); |
| partial_obj_size = sr->partial_obj_size(); |
| } |
| |
| // The split is recorded only if a partial object extends onto the region. |
| if (partial_obj_size != 0) { |
| _region_data[split_region].set_partial_obj_size(0); |
| split_info.record(split_region, partial_obj_size, split_destination); |
| } |
| |
| // Setup the continuation addresses. |
| *target_next = split_destination + partial_obj_size; |
| HeapWord* const source_next = region_to_addr(split_region) + partial_obj_size; |
| |
| if (TraceParallelOldGCSummaryPhase) { |
| const char * split_type = partial_obj_size == 0 ? "easy" : "hard"; |
| gclog_or_tty->print_cr("%s split: src=" PTR_FORMAT " src_c=" SIZE_FORMAT |
| " pos=" SIZE_FORMAT, |
| split_type, source_next, split_region, |
| partial_obj_size); |
| gclog_or_tty->print_cr("%s split: dst=" PTR_FORMAT " dst_c=" SIZE_FORMAT |
| " tn=" PTR_FORMAT, |
| split_type, split_destination, |
| addr_to_region_idx(split_destination), |
| *target_next); |
| |
| if (partial_obj_size != 0) { |
| HeapWord* const po_beg = split_info.destination(); |
| HeapWord* const po_end = po_beg + split_info.partial_obj_size(); |
| gclog_or_tty->print_cr("%s split: " |
| "po_beg=" PTR_FORMAT " " SIZE_FORMAT " " |
| "po_end=" PTR_FORMAT " " SIZE_FORMAT, |
| split_type, |
| po_beg, addr_to_region_idx(po_beg), |
| po_end, addr_to_region_idx(po_end)); |
| } |
| } |
| |
| return source_next; |
| } |
| |
| bool ParallelCompactData::summarize(SplitInfo& split_info, |
| HeapWord* source_beg, HeapWord* source_end, |
| HeapWord** source_next, |
| HeapWord* target_beg, HeapWord* target_end, |
| HeapWord** target_next) |
| { |
| if (TraceParallelOldGCSummaryPhase) { |
| HeapWord* const source_next_val = source_next == NULL ? NULL : *source_next; |
| tty->print_cr("sb=" PTR_FORMAT " se=" PTR_FORMAT " sn=" PTR_FORMAT |
| "tb=" PTR_FORMAT " te=" PTR_FORMAT " tn=" PTR_FORMAT, |
| source_beg, source_end, source_next_val, |
| target_beg, target_end, *target_next); |
| } |
| |
| size_t cur_region = addr_to_region_idx(source_beg); |
| const size_t end_region = addr_to_region_idx(region_align_up(source_end)); |
| |
| HeapWord *dest_addr = target_beg; |
| while (cur_region < end_region) { |
| // The destination must be set even if the region has no data. |
| _region_data[cur_region].set_destination(dest_addr); |
| |
| size_t words = _region_data[cur_region].data_size(); |
| if (words > 0) { |
| // If cur_region does not fit entirely into the target space, find a point |
| // at which the source space can be 'split' so that part is copied to the |
| // target space and the rest is copied elsewhere. |
| if (dest_addr + words > target_end) { |
| assert(source_next != NULL, "source_next is NULL when splitting"); |
| *source_next = summarize_split_space(cur_region, split_info, dest_addr, |
| target_end, target_next); |
| return false; |
| } |
| |
| // Compute the destination_count for cur_region, and if necessary, update |
| // source_region for a destination region. The source_region field is |
| // updated if cur_region is the first (left-most) region to be copied to a |
| // destination region. |
| // |
| // The destination_count calculation is a bit subtle. A region that has |
| // data that compacts into itself does not count itself as a destination. |
| // This maintains the invariant that a zero count means the region is |
| // available and can be claimed and then filled. |
| uint destination_count = 0; |
| if (split_info.is_split(cur_region)) { |
| // The current region has been split: the partial object will be copied |
| // to one destination space and the remaining data will be copied to |
| // another destination space. Adjust the initial destination_count and, |
| // if necessary, set the source_region field if the partial object will |
| // cross a destination region boundary. |
| destination_count = split_info.destination_count(); |
| if (destination_count == 2) { |
| size_t dest_idx = addr_to_region_idx(split_info.dest_region_addr()); |
| _region_data[dest_idx].set_source_region(cur_region); |
| } |
| } |
| |
| HeapWord* const last_addr = dest_addr + words - 1; |
| const size_t dest_region_1 = addr_to_region_idx(dest_addr); |
| const size_t dest_region_2 = addr_to_region_idx(last_addr); |
| |
| // Initially assume that the destination regions will be the same and |
| // adjust the value below if necessary. Under this assumption, if |
| // cur_region == dest_region_2, then cur_region will be compacted |
| // completely into itself. |
| destination_count += cur_region == dest_region_2 ? 0 : 1; |
| if (dest_region_1 != dest_region_2) { |
| // Destination regions differ; adjust destination_count. |
| destination_count += 1; |
| // Data from cur_region will be copied to the start of dest_region_2. |
| _region_data[dest_region_2].set_source_region(cur_region); |
| } else if (region_offset(dest_addr) == 0) { |
| // Data from cur_region will be copied to the start of the destination |
| // region. |
| _region_data[dest_region_1].set_source_region(cur_region); |
| } |
| |
| _region_data[cur_region].set_destination_count(destination_count); |
| _region_data[cur_region].set_data_location(region_to_addr(cur_region)); |
| dest_addr += words; |
| } |
| |
| ++cur_region; |
| } |
| |
| *target_next = dest_addr; |
| return true; |
| } |
| |
| HeapWord* ParallelCompactData::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"); |
| |
| // Region covering the object. |
| size_t region_index = addr_to_region_idx(addr); |
| const RegionData* const region_ptr = region(region_index); |
| HeapWord* const region_addr = region_align_down(addr); |
| |
| assert(addr < region_addr + RegionSize, "Region does not cover object"); |
| assert(addr_to_region_ptr(region_addr) == region_ptr, "sanity check"); |
| |
| HeapWord* result = region_ptr->destination(); |
| |
| // If all the data in the region is live, then the new location of the object |
| // can be calculated from the destination of the region plus the offset of the |
| // object in the region. |
| if (region_ptr->data_size() == RegionSize) { |
| result += pointer_delta(addr, region_addr); |
| DEBUG_ONLY(PSParallelCompact::check_new_location(addr, result);) |
| return result; |
| } |
| |
| // The new location of the object is |
| // region destination + |
| // size of the partial object extending onto the region + |
| // sizes of the live objects in the Region that are to the left of addr |
| const size_t partial_obj_size = region_ptr->partial_obj_size(); |
| HeapWord* const search_start = region_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; |
| DEBUG_ONLY(PSParallelCompact::check_new_location(addr, result);) |
| 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(_region_vspace); |
| } |
| #endif // #ifdef ASSERT |
| |
| #ifdef NOT_PRODUCT |
| ParallelCompactData::RegionData* debug_region(size_t region_index) { |
| ParallelCompactData& sd = PSParallelCompact::summary_data(); |
| return sd.region(region_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; |
| |
| void PSParallelCompact::IsAliveClosure::do_object(oop p) { ShouldNotReachHere(); } |
| bool PSParallelCompact::IsAliveClosure::do_object_b(oop p) { return mark_bitmap()->is_marked(p); } |
| |
| void PSParallelCompact::KeepAliveClosure::do_oop(oop* p) { PSParallelCompact::KeepAliveClosure::do_oop_work(p); } |
| void PSParallelCompact::KeepAliveClosure::do_oop(narrowOop* p) { PSParallelCompact::KeepAliveClosure::do_oop_work(p); } |
| |
| PSParallelCompact::AdjustPointerClosure PSParallelCompact::_adjust_root_pointer_closure(true); |
| PSParallelCompact::AdjustPointerClosure PSParallelCompact::_adjust_pointer_closure(false); |
| |
| void PSParallelCompact::AdjustPointerClosure::do_oop(oop* p) { adjust_pointer(p, _is_root); } |
| void PSParallelCompact::AdjustPointerClosure::do_oop(narrowOop* p) { adjust_pointer(p, _is_root); } |
| |
| void PSParallelCompact::FollowStackClosure::do_void() { _compaction_manager->follow_marking_stacks(); } |
| |
| void PSParallelCompact::MarkAndPushClosure::do_oop(oop* p) { mark_and_push(_compaction_manager, p); } |
| void PSParallelCompact::MarkAndPushClosure::do_oop(narrowOop* p) { mark_and_push(_compaction_manager, p); } |
| |
| 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_region = _summary_data.addr_to_region_idx(bot); |
| const size_t end_region = |
| _summary_data.addr_to_region_idx(_summary_data.region_align_up(max_top)); |
| _summary_data.clear_range(beg_region, end_region); |
| |
| // Clear the data used to 'split' regions. |
| SplitInfo& split_info = _space_info[id].split_info(); |
| if (split_info.is_valid()) { |
| split_info.clear(); |
| } |
| DEBUG_ONLY(split_info.verify_clear();) |
| } |
| |
| 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(true); |
| |
| // 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();) |
| |
| // Have worker threads release resources the next time they run a task. |
| gc_task_manager()->release_all_resources(); |
| } |
| |
| void PSParallelCompact::post_compact() |
| { |
| TraceTime tm("post compact", print_phases(), true, gclog_or_tty); |
| |
| for (unsigned int id = perm_space_id; id < last_space_id; ++id) { |
| // Clear the marking bitmap, summary data and split info. |
| clear_data_covering_space(SpaceId(id)); |
| // Update top(). Must be done after clearing the bitmap and summary data. |
| _space_info[id].publish_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); |
| |
| if (ZapUnusedHeapArea) { |
| heap->gen_mangle_unused_area(); |
| } |
| |
| // 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 region_size = ParallelCompactData::RegionSize; |
| const ParallelCompactData& sd = summary_data(); |
| |
| const MutableSpace* const space = _space_info[id].space(); |
| HeapWord* const top_aligned_up = sd.region_align_up(space->top()); |
| const RegionData* const beg_cp = sd.addr_to_region_ptr(space->bottom()); |
| const RegionData* const end_cp = sd.addr_to_region_ptr(top_aligned_up); |
| |
| // Skip full regions at the beginning of the space--they are necessarily part |
| // of the dense prefix. |
| size_t full_count = 0; |
| const RegionData* cp; |
| for (cp = beg_cp; cp < end_cp && cp->data_size() == region_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.region_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.region_to_addr(cp); |
| const RegionData* full_cp = cp; |
| const RegionData* const top_cp = sd.addr_to_region_ptr(space->top() - 1); |
| while (cp < end_cp) { |
| HeapWord* region_destination = cp->destination(); |
| const size_t cur_deadwood = pointer_delta(dense_prefix, region_destination); |
| if (TraceParallelOldGCDensePrefix && Verbose) { |
| tty->print_cr("c#=" SIZE_FORMAT_W(4) " dst=" PTR_FORMAT " " |
| "dp=" SIZE_FORMAT_W(8) " " "cdw=" SIZE_FORMAT_W(8), |
| sd.region(cp), region_destination, |
| dense_prefix, cur_deadwood); |
| } |
| |
| if (cur_deadwood >= deadwood_goal) { |
| // Found the region that has the correct amount of deadwood to the left. |
| // This typically occurs after crossing a fairly sparse set of regions, so |
| // iterate backwards over those sparse regions, looking for the region |
| // that has the lowest density of live objects 'to the right.' |
| size_t space_to_left = sd.region(cp) * region_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_region_live_to_right = live_to_right - |
| cp->data_size(); |
| const size_t prev_region_space_to_right = space_to_right + region_size; |
| double prev_region_density_to_right = |
| double(prev_region_live_to_right) / prev_region_space_to_right; |
| if (density_to_right <= prev_region_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.region(cp), density_to_right, |
| prev_region_density_to_right); |
| } |
| dense_prefix -= region_size; |
| live_to_right = prev_region_live_to_right; |
| space_to_right = prev_region_space_to_right; |
| density_to_right = prev_region_density_to_right; |
| } |
| return dense_prefix; |
| } |
| |
| dense_prefix += region_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 region_idx = summary_data().addr_to_region_idx(addr); |
| RegionData* const cp = summary_data().region(region_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(5) " " |
| "spl=" SIZE_FORMAT " " |
| "d2l=" SIZE_FORMAT " d2l%%=%6.4f " |
| "d2r=" SIZE_FORMAT " l2r=" SIZE_FORMAT |
| " ratio=%10.8f", |
| algorithm, addr, region_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::RegionData* |
| PSParallelCompact::first_dead_space_region(const RegionData* beg, |
| const RegionData* end) |
| { |
| const size_t region_size = ParallelCompactData::RegionSize; |
| ParallelCompactData& sd = summary_data(); |
| size_t left = sd.region(beg); |
| size_t right = end > beg ? sd.region(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; |
| RegionData* const middle_ptr = sd.region(middle); |
| HeapWord* const dest = middle_ptr->destination(); |
| HeapWord* const addr = sd.region_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() == region_size) { |
| left = middle + 1; |
| } else { |
| return middle_ptr; |
| } |
| } |
| return sd.region(left); |
| } |
| |
| ParallelCompactData::RegionData* |
| PSParallelCompact::dead_wood_limit_region(const RegionData* beg, |
| const RegionData* end, |
| size_t dead_words) |
| { |
| ParallelCompactData& sd = summary_data(); |
| size_t left = sd.region(beg); |
| size_t right = end > beg ? sd.region(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; |
| RegionData* const middle_ptr = sd.region(middle); |
| HeapWord* const dest = middle_ptr->destination(); |
| HeapWord* const addr = sd.region_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.region(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 RegionData* 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.region_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.region_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 region boundary. |
| // |
| // Completely full regions at the left are skipped, since no compaction can |
| // occur in those regions. Then the maximum amount of dead wood to allow is |
| // computed, based on the density (amount live / capacity) of the generation; |
| // the region with approximately that amount of dead space to the left is |
| // identified as the limit region. Regions between the last completely full |
| // region and the limit region 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) |
| { |
| if (ParallelOldGCSplitALot) { |
| if (_space_info[id].dense_prefix() != _space_info[id].space()->bottom()) { |
| // The value was chosen to provoke splitting a young gen space; use it. |
| return _space_info[id].dense_prefix(); |
| } |
| } |
| |
| const size_t region_size = ParallelCompactData::RegionSize; |
| const ParallelCompactData& sd = summary_data(); |
| |
| const MutableSpace* const space = _space_info[id].space(); |
| HeapWord* const top = space->top(); |
| HeapWord* const top_aligned_up = sd.region_align_up(top); |
| HeapWord* const new_top = _space_info[id].new_top(); |
| HeapWord* const new_top_aligned_up = sd.region_align_up(new_top); |
| HeapWord* const bottom = space->bottom(); |
| const RegionData* const beg_cp = sd.addr_to_region_ptr(bottom); |
| const RegionData* const top_cp = sd.addr_to_region_ptr(top_aligned_up); |
| const RegionData* const new_top_cp = |
| sd.addr_to_region_ptr(new_top_aligned_up); |
| |
| // Skip full regions at the beginning of the space--they are necessarily part |
| // of the dense prefix. |
| const RegionData* const full_cp = first_dead_space_region(beg_cp, new_top_cp); |
| assert(full_cp->destination() == sd.region_to_addr(full_cp) || |
| space->is_empty(), "no dead space allowed to the left"); |
| assert(full_cp->data_size() < region_size || full_cp == new_top_cp - 1, |
| "region 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.region_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 region with the desired amount of dead space to the left. |
| const RegionData* const limit_cp = |
| dead_wood_limit_region(full_cp, top_cp, dead_wood_limit); |
| |
| // Scan from the first region with dead space to the limit region and find the |
| // one with the best (largest) reclaimed ratio. |
| double best_ratio = 0.0; |
| const RegionData* best_cp = full_cp; |
| for (const RegionData* 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 region with the best ratio is 'close to' the |
| // first region w/free space, choose the first region with free space |
| // ("first-free"). The first-free region 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(RegionData)) < 4) { |
| _maximum_compaction_gc_num = total_invocations(); |
| best_cp = full_cp; |
| } |
| #endif // #if 0 |
| |
| return sd.region_to_addr(best_cp); |
| } |
| |
| #ifndef PRODUCT |
| void |
| PSParallelCompact::fill_with_live_objects(SpaceId id, HeapWord* const start, |
| size_t words) |
| { |
| if (TraceParallelOldGCSummaryPhase) { |
| tty->print_cr("fill_with_live_objects [" PTR_FORMAT " " PTR_FORMAT ") " |
| SIZE_FORMAT, start, start + words, words); |
| } |
| |
| ObjectStartArray* const start_array = _space_info[id].start_array(); |
| CollectedHeap::fill_with_objects(start, words); |
| for (HeapWord* p = start; p < start + words; p += oop(p)->size()) { |
| _mark_bitmap.mark_obj(p, words); |
| _summary_data.add_obj(p, words); |
| start_array->allocate_block(p); |
| } |
| } |
| |
| void |
| PSParallelCompact::summarize_new_objects(SpaceId id, HeapWord* start) |
| { |
| ParallelCompactData& sd = summary_data(); |
| MutableSpace* space = _space_info[id].space(); |
| |
| // Find the source and destination start addresses. |
| HeapWord* const src_addr = sd.region_align_down(start); |
| HeapWord* dst_addr; |
| if (src_addr < start) { |
| dst_addr = sd.addr_to_region_ptr(src_addr)->destination(); |
| } else if (src_addr > space->bottom()) { |
| // The start (the original top() value) is aligned to a region boundary so |
| // the associated region does not have a destination. Compute the |
| // destination from the previous region. |
| RegionData* const cp = sd.addr_to_region_ptr(src_addr) - 1; |
| dst_addr = cp->destination() + cp->data_size(); |
| } else { |
| // Filling the entire space. |
| dst_addr = space->bottom(); |
| } |
| assert(dst_addr != NULL, "sanity"); |
| |
| // Update the summary data. |
| bool result = _summary_data.summarize(_space_info[id].split_info(), |
| src_addr, space->top(), NULL, |
| dst_addr, space->end(), |
| _space_info[id].new_top_addr()); |
| assert(result, "should not fail: bad filler object size"); |
| } |
| |
| void |
| PSParallelCompact::provoke_split_fill_survivor(SpaceId id) |
| { |
| if (total_invocations() % (ParallelOldGCSplitInterval * 3) != 0) { |
| return; |
| } |
| |
| MutableSpace* const space = _space_info[id].space(); |
| if (space->is_empty()) { |
| HeapWord* b = space->bottom(); |
| HeapWord* t = b + space->capacity_in_words() / 2; |
| space->set_top(t); |
| if (ZapUnusedHeapArea) { |
| space->set_top_for_allocations(); |
| } |
| |
| size_t min_size = CollectedHeap::min_fill_size(); |
| size_t obj_len = min_size; |
| while (b + obj_len <= t) { |
| CollectedHeap::fill_with_object(b, obj_len); |
| mark_bitmap()->mark_obj(b, obj_len); |
| summary_data().add_obj(b, obj_len); |
| b += obj_len; |
| obj_len = (obj_len & (min_size*3)) + min_size; // 8 16 24 32 8 16 24 32 ... |
| } |
| if (b < t) { |
| // The loop didn't completely fill to t (top); adjust top downward. |
| space->set_top(b); |
| if (ZapUnusedHeapArea) { |
| space->set_top_for_allocations(); |
| } |
| } |
| |
| HeapWord** nta = _space_info[id].new_top_addr(); |
| bool result = summary_data().summarize(_space_info[id].split_info(), |
| space->bottom(), space->top(), NULL, |
| space->bottom(), space->end(), nta); |
| assert(result, "space must fit into itself"); |
| } |
| } |
| |
| void |
| PSParallelCompact::provoke_split(bool & max_compaction) |
| { |
| if (total_invocations() % ParallelOldGCSplitInterval != 0) { |
| return; |
| } |
| |
| const size_t region_size = ParallelCompactData::RegionSize; |
| ParallelCompactData& sd = summary_data(); |
| |
| MutableSpace* const eden_space = _space_info[eden_space_id].space(); |
| MutableSpace* const from_space = _space_info[from_space_id].space(); |
| const size_t eden_live = pointer_delta(eden_space->top(), |
| _space_info[eden_space_id].new_top()); |
| const size_t from_live = pointer_delta(from_space->top(), |
| _space_info[from_space_id].new_top()); |
| |
| const size_t min_fill_size = CollectedHeap::min_fill_size(); |
| const size_t eden_free = pointer_delta(eden_space->end(), eden_space->top()); |
| const size_t eden_fillable = eden_free >= min_fill_size ? eden_free : 0; |
| const size_t from_free = pointer_delta(from_space->end(), from_space->top()); |
| const size_t from_fillable = from_free >= min_fill_size ? from_free : 0; |
| |
| // Choose the space to split; need at least 2 regions live (or fillable). |
| SpaceId id; |
| MutableSpace* space; |
| size_t live_words; |
| size_t fill_words; |
| if (eden_live + eden_fillable >= region_size * 2) { |
| id = eden_space_id; |
| space = eden_space; |
| live_words = eden_live; |
| fill_words = eden_fillable; |
| } else if (from_live + from_fillable >= region_size * 2) { |
| id = from_space_id; |
| space = from_space; |
| live_words = from_live; |
| fill_words = from_fillable; |
| } else { |
| return; // Give up. |
| } |
| assert(fill_words == 0 || fill_words >= min_fill_size, "sanity"); |
| |
| if (live_words < region_size * 2) { |
| // Fill from top() to end() w/live objects of mixed sizes. |
| HeapWord* const fill_start = space->top(); |
| live_words += fill_words; |
| |
| space->set_top(fill_start + fill_words); |
| if (ZapUnusedHeapArea) { |
| space->set_top_for_allocations(); |
| } |
| |
| HeapWord* cur_addr = fill_start; |
| while (fill_words > 0) { |
| const size_t r = (size_t)os::random() % (region_size / 2) + min_fill_size; |
| size_t cur_size = MIN2(align_object_size_(r), fill_words); |
| if (fill_words - cur_size < min_fill_size) { |
| cur_size = fill_words; // Avoid leaving a fragment too small to fill. |
| } |
| |
| CollectedHeap::fill_with_object(cur_addr, cur_size); |
| mark_bitmap()->mark_obj(cur_addr, cur_size); |
| sd.add_obj(cur_addr, cur_size); |
| |
| cur_addr += cur_size; |
| fill_words -= cur_size; |
| } |
| |
| summarize_new_objects(id, fill_start); |
| } |
| |
| max_compaction = false; |
| |
| // Manipulate the old gen so that it has room for about half of the live data |
| // in the target young gen space (live_words / 2). |
| id = old_space_id; |
| space = _space_info[id].space(); |
| const size_t free_at_end = space->free_in_words(); |
| const size_t free_target = align_object_size(live_words / 2); |
| const size_t dead = pointer_delta(space->top(), _space_info[id].new_top()); |
| |
| if (free_at_end >= free_target + min_fill_size) { |
| // Fill space above top() and set the dense prefix so everything survives. |
| HeapWord* const fill_start = space->top(); |
| const size_t fill_size = free_at_end - free_target; |
| space->set_top(space->top() + fill_size); |
| if (ZapUnusedHeapArea) { |
| space->set_top_for_allocations(); |
| } |
| fill_with_live_objects(id, fill_start, fill_size); |
| summarize_new_objects(id, fill_start); |
| _space_info[id].set_dense_prefix(sd.region_align_down(space->top())); |
| } else if (dead + free_at_end > free_target) { |
| // Find a dense prefix that makes the right amount of space available. |
| HeapWord* cur = sd.region_align_down(space->top()); |
| HeapWord* cur_destination = sd.addr_to_region_ptr(cur)->destination(); |
| size_t dead_to_right = pointer_delta(space->end(), cur_destination); |
| while (dead_to_right < free_target) { |
| cur -= region_size; |
| cur_destination = sd.addr_to_region_ptr(cur)->destination(); |
| dead_to_right = pointer_delta(space->end(), cur_destination); |
| } |
| _space_info[id].set_dense_prefix(cur); |
| } |
| } |
| #endif // #ifndef PRODUCT |
| |
| void PSParallelCompact::summarize_spaces_quick() |
| { |
| for (unsigned int i = 0; i < last_space_id; ++i) { |
| const MutableSpace* space = _space_info[i].space(); |
| HeapWord** nta = _space_info[i].new_top_addr(); |
| bool result = _summary_data.summarize(_space_info[i].split_info(), |
| space->bottom(), space->top(), NULL, |
| space->bottom(), space->end(), nta); |
| assert(result, "space must fit into itself"); |
| _space_info[i].set_dense_prefix(space->bottom()); |
| } |
| |
| #ifndef PRODUCT |
| if (ParallelOldGCSplitALot) { |
| provoke_split_fill_survivor(to_space_id); |
| } |
| #endif // #ifndef PRODUCT |
| } |
| |
| void PSParallelCompact::fill_dense_prefix_end(SpaceId id) |
| { |
| HeapWord* const dense_prefix_end = dense_prefix(id); |
| const RegionData* region = _summary_data.addr_to_region_ptr(dense_prefix_end); |
| const idx_t dense_prefix_bit = _mark_bitmap.addr_to_bit(dense_prefix_end); |
| if (dead_space_crosses_boundary(region, 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 = CollectedHeap::min_fill_size(); |
| HeapWord* obj_beg = dense_prefix_end - obj_len; |
| |
| #ifdef _LP64 |
| if (MinObjAlignment > 1) { // object alignment > heap word size |
| // Cases a, c or e. |
| } else 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 |
| |
| CollectedHeap::fill_with_object(obj_beg, obj_len); |
| _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::clear_source_region(HeapWord* beg_addr, HeapWord* end_addr) |
| { |
| RegionData* const beg_ptr = _summary_data.addr_to_region_ptr(beg_addr); |
| HeapWord* const end_aligned_up = _summary_data.region_align_up(end_addr); |
| RegionData* const end_ptr = _summary_data.addr_to_region_ptr(end_aligned_up); |
| for (RegionData* cur = beg_ptr; cur < end_ptr; ++cur) { |
| cur->set_source_region(0); |
| } |
| } |
| |
| void |
| PSParallelCompact::summarize_space(SpaceId id, bool maximum_compaction) |
| { |
| assert(id < last_space_id, "id out of range"); |
| assert(_space_info[id].dense_prefix() == _space_info[id].space()->bottom() || |
| ParallelOldGCSplitALot && id == old_space_id, |
| "should have been reset in summarize_spaces_quick()"); |
| |
| const MutableSpace* space = _space_info[id].space(); |
| if (_space_info[id].new_top() != space->bottom()) { |
| 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 |
| |
| // Recompute the summary data, taking into account the dense prefix. If |
| // every last byte will be reclaimed, then the existing summary data which |
| // compacts everything can be left in place. |
| if (!maximum_compaction && dense_prefix_end != space->bottom()) { |
| // 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. |
| fill_dense_prefix_end(id); |
| |
| // Compute the destination of each Region, and thus each object. |
| _summary_data.summarize_dense_prefix(space->bottom(), dense_prefix_end); |
| _summary_data.summarize(_space_info[id].split_info(), |
| dense_prefix_end, space->top(), NULL, |
| dense_prefix_end, space->end(), |
| _space_info[id].new_top_addr()); |
| } |
| } |
| |
| if (TraceParallelOldGCSummaryPhase) { |
| const size_t region_size = ParallelCompactData::RegionSize; |
| HeapWord* const dense_prefix_end = _space_info[id].dense_prefix(); |
| const size_t dp_region = _summary_data.addr_to_region_idx(dense_prefix_end); |
| const size_t dp_words = pointer_delta(dense_prefix_end, space->bottom()); |
| HeapWord* const new_top = _space_info[id].new_top(); |
| const HeapWord* nt_aligned_up = _summary_data.region_align_up(new_top); |
| 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_region=" SIZE_FORMAT " " "dp_count=" SIZE_FORMAT " " |
| "cr_count=" SIZE_FORMAT " " "nt=" PTR_FORMAT, |
| id, space->capacity_in_words(), dense_prefix_end, |
| dp_region, dp_words / region_size, |
| cr_words / region_size, new_top); |
| } |
| } |
| |
| #ifndef PRODUCT |
| void PSParallelCompact::summary_phase_msg(SpaceId dst_space_id, |
| HeapWord* dst_beg, HeapWord* dst_end, |
| SpaceId src_space_id, |
| HeapWord* src_beg, HeapWord* src_end) |
| { |
| if (TraceParallelOldGCSummaryPhase) { |
| tty->print_cr("summarizing %d [%s] into %d [%s]: " |
| "src=" PTR_FORMAT "-" PTR_FORMAT " " |
| SIZE_FORMAT "-" SIZE_FORMAT " " |
| "dst=" PTR_FORMAT "-" PTR_FORMAT " " |
| SIZE_FORMAT "-" SIZE_FORMAT, |
| src_space_id, space_names[src_space_id], |
| dst_space_id, space_names[dst_space_id], |
| src_beg, src_end, |
| _summary_data.addr_to_region_idx(src_beg), |
| _summary_data.addr_to_region_idx(src_end), |
| dst_beg, dst_end, |
| _summary_data.addr_to_region_idx(dst_beg), |
| _summary_data.addr_to_region_idx(dst_end)); |
| } |
| } |
| #endif // #ifndef PRODUCT |
| |
| 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 (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_region_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; |
| assert(perm_space_id < old_space_id, "should not count perm data here"); |
| for (unsigned int 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()); |
| } |
| |
| MutableSpace* const old_space = _space_info[old_space_id].space(); |
| const size_t old_capacity = old_space->capacity_in_words(); |
| if (old_space_total_live > old_capacity) { |
| // XXX - should also try to expand |
| maximum_compaction = true; |
| } |
| #ifndef PRODUCT |
| if (ParallelOldGCSplitALot && old_space_total_live < old_capacity) { |
| provoke_split(maximum_compaction); |
| } |
| #endif // #ifndef PRODUCT |
| |
| // Permanent and Old generations. |
| summarize_space(perm_space_id, maximum_compaction); |
| summarize_space(old_space_id, maximum_compaction); |
| |
| // Summarize the remaining spaces in the young gen. The initial target space |
| // is the old gen. If a space does not fit entirely into the target, then the |
| // remainder is compacted into the space itself and that space becomes the new |
| // target. |
| SpaceId dst_space_id = old_space_id; |
| HeapWord* dst_space_end = old_space->end(); |
| HeapWord** new_top_addr = _space_info[dst_space_id].new_top_addr(); |
| for (unsigned int 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(dst_space_end, *new_top_addr); |
| |
| NOT_PRODUCT(summary_phase_msg(dst_space_id, *new_top_addr, dst_space_end, |
| SpaceId(id), space->bottom(), space->top());) |
| if (live > 0 && live <= available) { |
| // All the live data will fit. |
| bool done = _summary_data.summarize(_space_info[id].split_info(), |
| space->bottom(), space->top(), |
| NULL, |
| *new_top_addr, dst_space_end, |
| new_top_addr); |
| assert(done, "space must fit into old gen"); |
| |
| // Reset the new_top value for the space. |
| _space_info[id].set_new_top(space->bottom()); |
| } else if (live > 0) { |
| // Attempt to fit part of the source space into the target space. |
| HeapWord* next_src_addr = NULL; |
| bool done = _summary_data.summarize(_space_info[id].split_info(), |
| space->bottom(), space->top(), |
| &next_src_addr, |
| *new_top_addr, dst_space_end, |
| new_top_addr); |
| assert(!done, "space should not fit into old gen"); |
| assert(next_src_addr != NULL, "sanity"); |
| |
| // The source space becomes the new target, so the remainder is compacted |
| // within the space itself. |
| dst_space_id = SpaceId(id); |
| dst_space_end = space->end(); |
| new_top_addr = _space_info[id].new_top_addr(); |
| NOT_PRODUCT(summary_phase_msg(dst_space_id, |
| space->bottom(), dst_space_end, |
| SpaceId(id), next_src_addr, space->top());) |
| done = _summary_data.summarize(_space_info[id].split_info(), |
| next_src_addr, space->top(), |
| NULL, |
| space->bottom(), dst_space_end, |
| new_top_addr); |
| assert(done, "space must fit when compacted into itself"); |
| assert(*new_top_addr <= space->top(), "usage should not grow"); |
| } |
| } |
| |
| if (TraceParallelOldGCSummaryPhase) { |
| tty->print_cr("summary_phase: after final summarization"); |
| Universe::print(); |
| NOT_PRODUCT(print_region_ranges()); |
| if (Verbose) { |
| NOT_PRODUCT(print_generic_summary_data(_summary_data, _space_info)); |
| } |
| } |
| } |
| |
| // 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. |
| // |
| // Note that the all_soft_refs_clear flag in the collector policy |
| // may be true because this method can be called without intervening |
| // activity. For example when the heap space is tight and full measure |
| // are being taken to free space. |
| 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(); |
| IsGCActiveMark mark; |
| |
| if (ScavengeBeforeFullGC) { |
| PSScavenge::invoke_no_policy(); |
| } |
| |
| const bool clear_all_soft_refs = |
| heap->collector_policy()->should_clear_all_soft_refs(); |
| |
| PSParallelCompact::invoke_no_policy(clear_all_soft_refs || |
| maximum_heap_compaction); |
| } |
| |
| bool ParallelCompactData::region_contains(size_t region_index, HeapWord* addr) { |
| size_t addr_region_index = addr_to_region_idx(addr); |
| return region_index == addr_region_index; |
| } |
| |
| // 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::check_active_before_gc()) { |
| return; |
| } |
| |
| TimeStamp marking_start; |
| TimeStamp compaction_start; |
| TimeStamp collection_exit; |
| |
| 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(); |
| |
| // The scope of casr should end after code that can change |
| // CollectorPolicy::_should_clear_all_soft_refs. |
| ClearedAllSoftRefs casr(maximum_heap_compaction, |
| heap->collector_policy()); |
| |
| if (ZapUnusedHeapArea) { |
| // Save information needed to minimize mangling |
| heap->record_gen_tops_before_GC(); |
| } |
| |
| heap->pre_full_gc_dump(); |
| |
| _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); |
| |
| // Get the compaction manager reserved for the VM thread. |
| ParCompactionManager* const vmthread_cm = |
| ParCompactionManager::manager_array(gc_task_manager()->workers()); |
| |
| // 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(); |
| ref_processor()->setup_policy(maximum_heap_compaction); |
| |
| bool marked_for_unloading = false; |
| |
| marking_start.update(); |
| marking_phase(vmthread_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 |
| |
| bool max_on_system_gc = UseMaximumCompactionOnSystemGC && is_system_gc; |
| summary_phase(vmthread_cm, maximum_heap_compaction || max_on_system_gc); |
| |
| 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(); |
| |
| 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(vmthread_cm); |
| |
| if (UseParallelOldGCCompacting) { |
| compact(); |
| } else { |
| compact_serial(vmthread_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->collector_policy()); |
| |
| 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 (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(); |
| } |
| |
| if (ZapUnusedHeapArea) { |
| old_gen->object_space()->check_mangled_unused_area_complete(); |
| perm_gen->object_space()->check_mangled_unused_area_complete(); |
| } |
| |
| 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(); |
| } |
| |
| heap->post_full_gc_dump(); |
| |
| #ifdef TRACESPINNING |
| ParallelTaskTerminator::print_termination_counts(); |
| #endif |
| } |
| |
| 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(); |
| HeapWord* const unused_start = old_space->top(); |
| size_t const unused_words = pointer_delta(old_space->end(), unused_start); |
| |
| if (unused_words > 0) { |
| if (unused_words < CollectedHeap::min_fill_size()) { |
| return false; // If the old gen cannot be filled, must give up. |
| } |
| CollectedHeap::fill_with_objects(unused_start, unused_words); |
| } |
| |
| // 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(); |
| for (HeapWord* p = unused_start; p < new_top; p += oop(p)->size()) { |
| start_array->allocate_block(p); |
| } |
| |
| // 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::region_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); |
| ParallelScavengeHeap::ParStrongRootsScope psrs; |
| |
| 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)); |
| q->enqueue(new MarkFromRootsTask(MarkFromRootsTask::code_cache)); |
| |
| 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); |
| if (ref_processor()->processing_is_mt()) { |
| RefProcTaskExecutor task_executor; |
| ref_processor()->process_discovered_references( |
| is_alive_closure(), &mark_and_push_closure, &follow_stack_closure, |
| &task_executor); |
| } else { |
| ref_processor()->process_discovered_references( |
| 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); |
| cm->follow_marking_stacks(); // 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(); |
| |
| // Revisit memoized MDO's and clear any unmarked weak refs |
| follow_mdo_weak_refs(); |
| |
| // Visit symbol and interned string tables and delete unmarked oops |
| SymbolTable::unlink(is_alive_closure()); |
| StringTable::unlink(is_alive_closure()); |
| |
| assert(cm->marking_stacks_empty(), "marking stacks should be empty"); |
| } |
| |
| // 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(), NULL); |
| 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_region_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 regions 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 regions will be removed in ascending order. |
| |
| const ParallelCompactData& sd = PSParallelCompact::summary_data(); |
| |
| size_t fillable_regions = 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_region = sd.addr_to_region_idx(space_info->dense_prefix()); |
| const size_t end_region = |
| sd.addr_to_region_idx(sd.region_align_up(new_top)); |
| assert(end_region > 0, "perm gen cannot be empty"); |
| |
| for (size_t cur = end_region - 1; cur >= beg_region; --cur) { |
| if (sd.region(cur)->claim_unsafe()) { |
| ParCompactionManager* cm = ParCompactionManager::manager_array(which); |
| cm->push_region(cur); |
| |
| if (TraceParallelOldGCCompactionPhase && Verbose) { |
| const size_t count_mod_8 = fillable_regions & 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_regions;) |
| |
| // Assign regions to threads in round-robin fashion. |
| if (++which == task_count) { |
| which = 0; |
| } |
| } |
| } |
| } |
| |
| if (TraceParallelOldGCCompactionPhase) { |
| if (Verbose && (fillable_regions & 7) != 0) gclog_or_tty->cr(); |
| gclog_or_tty->print_cr("%u initially fillable regions", fillable_regions); |
| } |
| } |
| |
| #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 |
| // regions 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. |
| unsigned int space_id; |
| for (space_id = old_space_id; space_id < last_space_id; ++ 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. |
| continue; |
| } |
| |
| // The dense prefix is before this region. |
| size_t region_index_end_dense_prefix = |
| sd.addr_to_region_idx(dense_prefix_end); |
| RegionData* const dense_prefix_cp = |
| sd.region(region_index_end_dense_prefix); |
| assert(dense_prefix_end == space->end() || |
| dense_prefix_cp->available() || |
| dense_prefix_cp->claimed(), |
| "The region after the dense prefix should always be ready to fill"); |
| |
| size_t region_index_start = sd.addr_to_region_idx(space->bottom()); |
| |
| // Is there dense prefix work? |
| size_t total_dense_prefix_regions = |
| region_index_end_dense_prefix - region_index_start; |
| // How many regions of the dense prefix should be given to |
| // each thread? |
| if (total_dense_prefix_regions > 0) { |
| uint tasks_for_dense_prefix = 1; |
| if (UseParallelDensePrefixUpdate) { |
| if (total_dense_prefix_regions <= |
| (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 regions 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 regions_per_thread = total_dense_prefix_regions / |
| tasks_for_dense_prefix; |
| // Give each thread at least 1 region. |
| if (regions_per_thread == 0) { |
| regions_per_thread = 1; |
| } |
| |
| for (uint k = 0; k < tasks_for_dense_prefix; k++) { |
| if (region_index_start >= region_index_end_dense_prefix) { |
| break; |
| } |
| // region_index_end is not processed |
| size_t region_index_end = MIN2(region_index_start + regions_per_thread, |
| region_index_end_dense_prefix); |
| q->enqueue(new UpdateDensePrefixTask(SpaceId(space_id), |
| region_index_start, |
| region_index_end)); |
| region_index_start = region_index_end; |
| } |
| } |
| // This gets any part of the dense prefix that did not |
| // fit evenly. |
| if (region_index_start < region_index_end_dense_prefix) { |
| q->enqueue(new UpdateDensePrefixTask(SpaceId(space_id), |
| region_index_start, |
| region_index_end_dense_prefix)); |
| } |
| } |
| } |
| |
| void PSParallelCompact::enqueue_region_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 regions from |
| // other threads. |
| if (parallel_gc_threads > 1) { |
| for (uint j = 0; j < parallel_gc_threads; j++) { |
| q->enqueue(new StealRegionCompactionTask(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::region_array(); |
| ParallelTaskTerminator terminator(parallel_gc_threads, qset); |
| |
| GCTaskQueue* q = GCTaskQueue::create(); |
| enqueue_region_draining_tasks(q, parallel_gc_threads); |
| enqueue_dense_prefix_tasks(q, parallel_gc_threads); |
| enqueue_region_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 regions 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 regions. |
| 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 Regions between space bottom() to new_top() should be marked as filled |
| // and all Regions 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.region_align_up(si.new_top()); |
| HeapWord* old_top_addr = sd.region_align_up(si.space()->top()); |
| const size_t beg_region = sd.addr_to_region_idx(si.space()->bottom()); |
| const size_t new_top_region = sd.addr_to_region_idx(new_top_addr); |
| const size_t old_top_region = sd.addr_to_region_idx(old_top_addr); |
| |
| bool issued_a_warning = false; |
| |
| size_t cur_region; |
| for (cur_region = beg_region; cur_region < new_top_region; ++cur_region) { |
| const RegionData* const c = sd.region(cur_region); |
| if (!c->completed()) { |
| warning("region " SIZE_FORMAT " not filled: " |
| "destination_count=" SIZE_FORMAT, |
| cur_region, c->destination_count()); |
| issued_a_warning = true; |
| } |
| } |
| |
| for (cur_region = new_top_region; cur_region < old_top_region; ++cur_region) { |
| const RegionData* const c = sd.region(cur_region); |
| if (!c->available()) { |
| warning("region " SIZE_FORMAT " not empty: " |
| "destination_count=" SIZE_FORMAT, |
| cur_region, c->destination_count()); |
| issued_a_warning = true; |
| } |
| } |
| |
| if (issued_a_warning) { |
| print_region_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_weak_klass_links() { |
| // All klasses on the revisit stack are marked at this point. |
| // Update and follow all subklass, sibling and implementor links. |
| if (PrintRevisitStats) { |
| gclog_or_tty->print_cr("#classes in system dictionary = %d", SystemDictionary::number_of_classes()); |
| } |
| for (uint i = 0; i < ParallelGCThreads + 1; i++) { |
| ParCompactionManager* cm = ParCompactionManager::manager_array(i); |
| KeepAliveClosure keep_alive_closure(cm); |
| int length = cm->revisit_klass_stack()->length(); |
| if (PrintRevisitStats) { |
| gclog_or_tty->print_cr("Revisit klass stack[%d] length = %d", i, length); |
| } |
| for (int j = 0; j < length; j++) { |
| cm->revisit_klass_stack()->at(j)->follow_weak_klass_links( |
| is_alive_closure(), |
| &keep_alive_closure); |
| } |
| // revisit_klass_stack is cleared in reset() |
| cm->follow_marking_stacks(); |
| } |
| } |
| |
| void |
| PSParallelCompact::revisit_weak_klass_link(ParCompactionManager* cm, Klass* k) { |
| cm->revisit_klass_stack()->push(k); |
| } |
| |
| void PSParallelCompact::revisit_mdo(ParCompactionManager* cm, DataLayout* p) { |
| cm->revisit_mdo_stack()->push(p); |
| } |
| |
| void PSParallelCompact::follow_mdo_weak_refs() { |
| // All strongly reachable oops have been marked at this point; |
| // we can visit and clear any weak references from MDO's which |
| // we memoized during the strong marking phase. |
| if (PrintRevisitStats) { |
| gclog_or_tty->print_cr("#classes in system dictionary = %d", SystemDictionary::number_of_classes()); |
| } |
| for (uint i = 0; i < ParallelGCThreads + 1; i++) { |
| ParCompactionManager* cm = ParCompactionManager::manager_array(i); |
| GrowableArray<DataLayout*>* rms = cm->revisit_mdo_stack(); |
| int length = rms->length(); |
| if (PrintRevisitStats) { |
| gclog_or_tty->print_cr("Revisit MDO stack[%d] length = %d", i, length); |
| } |
| for (int j = 0; j < length; j++) { |
| rms->at(j)->follow_weak_refs(is_alive_closure()); |
| } |
| // revisit_mdo_stack is cleared in reset() |
| cm->follow_marking_stacks(); |
| } |
| } |
| |
| |
| #ifdef VALIDATE_MARK_SWEEP |
| |
| void PSParallelCompact::track_adjusted_pointer(void* p, 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) { |
| void* 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(void* p) { |
| _adjusted_pointers->push(p); |
| } |
| |
| |
| class AdjusterTracker: public OopClosure { |
| public: |
| AdjusterTracker() {}; |
| void do_oop(oop* o) { PSParallelCompact::check_adjust_pointer(o); } |
| void do_oop(narrowOop* 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 |
| |
| // Update interior oops in the ranges of regions [beg_region, end_region). |
| void |
| PSParallelCompact::update_and_deadwood_in_dense_prefix(ParCompactionManager* cm, |
| SpaceId space_id, |
| size_t beg_region, |
| size_t end_region) { |
| ParallelCompactData& sd = summary_data(); |
| ParMarkBitMap* const mbm = mark_bitmap(); |
| |
| HeapWord* beg_addr = sd.region_to_addr(beg_region); |
| HeapWord* const end_addr = sd.region_to_addr(end_region); |
| assert(beg_region <= end_region, "bad region range"); |
| assert(end_addr <= dense_prefix(space_id), "not in the dense prefix"); |
| |
| #ifdef ASSERT |
| // Claim the regions to avoid triggering an assert when they are marked as |
| // filled. |
| for (size_t claim_region = beg_region; claim_region < end_region; ++claim_region) { |
| assert(sd.region(claim_region)->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 regions. If a partial object crosses onto the region, skip it; |
| // it will be marked for 'deferred update' when the object head is |
| // processed. If dead space crosses onto the region, it is also skipped; it |
| // will be filled when the prior region is processed. If neither of those |
| // apply, the first word in the region is the start of a live object or dead |
| // space. |
| assert(beg_addr > space(space_id)->bottom(), "sanity"); |
| const RegionData* const cp = sd.region(beg_region); |
| if (cp->partial_obj_size() != 0) { |
| beg_addr = sd.partial_obj_end(beg_region); |
| } 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 Regions. |
| 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 regions as filled. |
| RegionData* const beg_cp = sd.region(beg_region); |
| RegionData* const end_cp = sd.region(end_region); |
| for (RegionData* 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.region_align_up(space_info->new_top()); |
| |
| const RegionData* const beg_region = sd.addr_to_region_ptr(beg_addr); |
| const RegionData* const end_region = sd.addr_to_region_ptr(end_addr); |
| const RegionData* cur_region; |
| for (cur_region = beg_region; cur_region < end_region; ++cur_region) { |
| HeapWord* const addr = cur_region->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, |
| SpaceId src_space_id, |
| size_t src_region_idx) |
| { |
| assert(summary_data().is_region_aligned(dest_addr), "not aligned"); |
| |
| const SplitInfo& split_info = _space_info[src_space_id].split_info(); |
| if (split_info.dest_region_addr() == dest_addr) { |
| // The partial object ending at the split point contains the first word to |
| // be copied to dest_addr. |
| return split_info.first_src_addr(); |
| } |
| |
| const ParallelCompactData& sd = summary_data(); |
| ParMarkBitMap* const bitmap = mark_bitmap(); |
| const size_t RegionSize = ParallelCompactData::RegionSize; |
| |
| assert(sd.is_region_aligned(dest_addr), "not aligned"); |
| const RegionData* const src_region_ptr = sd.region(src_region_idx); |
| const size_t partial_obj_size = src_region_ptr->partial_obj_size(); |
| HeapWord* const src_region_destination = src_region_ptr->destination(); |
| |
| assert(dest_addr >= src_region_destination, "wrong src region"); |
| assert(src_region_ptr->data_size() > 0, "src region cannot be empty"); |
| |
| HeapWord* const src_region_beg = sd.region_to_addr(src_region_idx); |
| HeapWord* const src_region_end = src_region_beg + RegionSize; |
| |
| HeapWord* addr = src_region_beg; |
| if (dest_addr == src_region_destination) { |
| // Return the first live word in the source region. |
| if (partial_obj_size == 0) { |
| addr = bitmap->find_obj_beg(addr, src_region_end); |
| assert(addr < src_region_end, "no objects start in src region"); |
| } |
| return addr; |
| } |
| |
| // Must skip some live data. |
| size_t words_to_skip = dest_addr - src_region_destination; |
| assert(src_region_ptr->data_size() > words_to_skip, "wrong src region"); |
| |
| 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_region_end); |
| assert(addr < src_region_end, "wrong src region"); |
| } |
| 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 region. |
| addr = skip_live_words(addr, src_region_end, words_to_skip); |
| assert(addr < src_region_end, "wrong src region"); |
| return addr; |
| } |
| |
| void PSParallelCompact::decrement_destination_counts(ParCompactionManager* cm, |
| SpaceId src_space_id, |
| size_t beg_region, |
| HeapWord* end_addr) |
| { |
| ParallelCompactData& sd = summary_data(); |
| |
| #ifdef ASSERT |
| MutableSpace* const src_space = _space_info[src_space_id].space(); |
| HeapWord* const beg_addr = sd.region_to_addr(beg_region); |
| assert(src_space->contains(beg_addr) || beg_addr == src_space->end(), |
| "src_space_id does not match beg_addr"); |
| assert(src_space->contains(end_addr) || end_addr == src_space->end(), |
| "src_space_id does not match end_addr"); |
| #endif // #ifdef ASSERT |
| |
| RegionData* const beg = sd.region(beg_region); |
| RegionData* const end = sd.addr_to_region_ptr(sd.region_align_up(end_addr)); |
| |
| // Regions up to new_top() are enqueued if they become available. |
| HeapWord* const new_top = _space_info[src_space_id].new_top(); |
| RegionData* const enqueue_end = |
| sd.addr_to_region_ptr(sd.region_align_up(new_top)); |
| |
| for (RegionData* cur = beg; cur < end; ++cur) { |
| assert(cur->data_size() > 0, "region must have live data"); |
| cur->decrement_destination_count(); |
| if (cur < enqueue_end && cur->available() && cur->claim()) { |
| cm->push_region(sd.region(cur)); |
| } |
| } |
| } |
| |
| size_t PSParallelCompact::next_src_region(MoveAndUpdateClosure& closure, |
| SpaceId& src_space_id, |
| HeapWord*& src_space_top, |
| HeapWord* end_addr) |
| { |
| typedef ParallelCompactData::RegionData RegionData; |
| |
| ParallelCompactData& sd = PSParallelCompact::summary_data(); |
| const size_t region_size = ParallelCompactData::RegionSize; |
| |
| size_t src_region_idx = 0; |
| |
| // Skip empty regions (if any) up to the top of the space. |
| HeapWord* const src_aligned_up = sd.region_align_up(end_addr); |
| RegionData* src_region_ptr = sd.addr_to_region_ptr(src_aligned_up); |
| HeapWord* const top_aligned_up = sd.region_align_up(src_space_top); |
| const RegionData* const top_region_ptr = |
| sd.addr_to_region_ptr(top_aligned_up); |
| while (src_region_ptr < top_region_ptr && src_region_ptr->data_size() == 0) { |
| ++src_region_ptr; |
| } |
| |
| if (src_region_ptr < top_region_ptr) { |
| // The next source region is in the current space. Update src_region_idx |
| // and the source address to match src_region_ptr. |
| src_region_idx = sd.region(src_region_ptr); |
| HeapWord* const src_region_addr = sd.region_to_addr(src_region_idx); |
| if (src_region_addr > closure.source()) { |
| closure.set_source(src_region_addr); |
| } |
| return src_region_idx; |
| } |
| |
| // Switch to a new source space and find the first non-empty region. |
| 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 RegionData* const bottom_cp = sd.addr_to_region_ptr(bottom); |
| |
| // Iterate over the spaces that do not compact into themselves. |
| if (bottom_cp->destination() != bottom) { |
| HeapWord* const top_aligned_up = sd.region_align_up(space->top()); |
| const RegionData* const top_cp = sd.addr_to_region_ptr(top_aligned_up); |
| |
| for (const RegionData* 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_region_idx = sd.region(src_cp); |
| closure.set_source(sd.region_to_addr(src_region_idx)); |
| return src_region_idx; |
| } else { |
| assert(src_cp->data_size() == 0, "sanity"); |
| } |
| } |
| } |
| } while (++space_id < last_space_id); |
| |
| assert(false, "no source region was found"); |
| return 0; |
| } |
| |
| void PSParallelCompact::fill_region(ParCompactionManager* cm, size_t region_idx) |
| { |
| typedef ParMarkBitMap::IterationStatus IterationStatus; |
| const size_t RegionSize = ParallelCompactData::RegionSize; |
| ParMarkBitMap* const bitmap = mark_bitmap(); |
| ParallelCompactData& sd = summary_data(); |
| RegionData* const region_ptr = sd.region(region_idx); |
| |
| // Get the items needed to construct the closure. |
| HeapWord* dest_addr = sd.region_to_addr(region_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), RegionSize); |
| |
| // Get the source region and related info. |
| size_t src_region_idx = region_ptr->source_region(); |
| SpaceId src_space_id = space_id(sd.region_to_addr(src_region_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_space_id, src_region_idx)); |
| |
| // Adjust src_region_idx to prepare for decrementing destination counts (the |
| // destination count is not decremented when a region is copied to itself). |
| if (src_region_idx == region_idx) { |
| src_region_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_space_id, src_region_idx, |
| closure.source()); |
| region_ptr->set_deferred_obj_addr(NULL); |
| region_ptr->set_completed(); |
| return; |
| } |
| |
| HeapWord* const end_addr = sd.region_align_down(closure.source()); |
| if (sd.region_align_down(old_src_addr) != end_addr) { |
| // The partial object was copied from more than one source region. |
| decrement_destination_counts(cm, src_space_id, src_region_idx, end_addr); |
| |
| // Move to the next source region, possibly switching spaces as well. All |
| // args except end_addr may be modified. |
| src_region_idx = next_src_region(closure, src_space_id, src_space_top, |
| end_addr); |
| } |
| } |
| |
| do { |
| HeapWord* const cur_addr = closure.source(); |
| HeapWord* const end_addr = MIN2(sd.region_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 region does not end in the |
| // region. |
| 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 region. |
| region_ptr->set_deferred_obj_addr(closure.destination()); |
| status = closure.copy_until_full(); // copies from closure.source() |
| |
| decrement_destination_counts(cm, src_space_id, src_region_idx, |
| closure.source()); |
| region_ptr->set_completed(); |
| return; |
| } |
| |
| if (status == ParMarkBitMap::full) { |
| decrement_destination_counts(cm, src_space_id, src_region_idx, |
| closure.source()); |
| region_ptr->set_deferred_obj_addr(NULL); |
| region_ptr->set_completed(); |
| return; |
| } |
| |
| decrement_destination_counts(cm, src_space_id, src_region_idx, end_addr); |
| |
| // Move to the next source region, possibly switching spaces as well. All |
| // args except end_addr may be modified. |
| src_region_idx = next_src_region(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_region = sd.addr_to_region_idx(beg_addr); |
| const size_t dp_region = sd.addr_to_region_idx(dp_addr); |
| if (beg_region < dp_region) { |
| update_and_deadwood_in_dense_prefix(cm, space_id, beg_region, dp_region); |
| } |
| |
| // The destination of the first live object that starts in the region is one |
| // past the end of the partial object entering the region (if any). |
| HeapWord* const dest_addr = sd.partial_obj_end(dp_region); |
| 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()) { |
| DEBUG_ONLY(PSParallelCompact::check_new_location(source(), destination());) |
| 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()) { |
| DEBUG_ONLY(PSParallelCompact::check_new_location(source(), destination());) |
| 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()) { |
| DEBUG_ONLY(PSParallelCompact::check_new_location(source(), destination());) |
| 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; |
| } |
| |
| // 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()); |
| } |
| |