mirror of
https://github.com/openjdk/jdk.git
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694acedf18
Reviewed-by: coleenp, erikj, stefank, iignatyev, dholmes, aph, shade, iklam, mchung, iveresov
3328 lines
130 KiB
C++
3328 lines
130 KiB
C++
/*
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* Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*
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*/
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#include "precompiled.hpp"
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#include "classfile/classLoaderDataGraph.hpp"
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#include "classfile/javaClasses.inline.hpp"
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#include "classfile/stringTable.hpp"
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#include "classfile/symbolTable.hpp"
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#include "classfile/systemDictionary.hpp"
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#include "code/codeCache.hpp"
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#include "compiler/oopMap.hpp"
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#include "gc/parallel/parallelArguments.hpp"
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#include "gc/parallel/parallelScavengeHeap.inline.hpp"
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#include "gc/parallel/parMarkBitMap.inline.hpp"
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#include "gc/parallel/psAdaptiveSizePolicy.hpp"
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#include "gc/parallel/psCompactionManager.inline.hpp"
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#include "gc/parallel/psOldGen.hpp"
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#include "gc/parallel/psParallelCompact.inline.hpp"
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#include "gc/parallel/psPromotionManager.inline.hpp"
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#include "gc/parallel/psRootType.hpp"
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#include "gc/parallel/psScavenge.hpp"
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#include "gc/parallel/psYoungGen.hpp"
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#include "gc/shared/gcCause.hpp"
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#include "gc/shared/gcHeapSummary.hpp"
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#include "gc/shared/gcId.hpp"
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#include "gc/shared/gcLocker.hpp"
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#include "gc/shared/gcTimer.hpp"
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#include "gc/shared/gcTrace.hpp"
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#include "gc/shared/gcTraceTime.inline.hpp"
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#include "gc/shared/isGCActiveMark.hpp"
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#include "gc/shared/oopStorage.inline.hpp"
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#include "gc/shared/oopStorageSet.inline.hpp"
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#include "gc/shared/oopStorageSetParState.inline.hpp"
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#include "gc/shared/referencePolicy.hpp"
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#include "gc/shared/referenceProcessor.hpp"
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#include "gc/shared/referenceProcessorPhaseTimes.hpp"
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#include "gc/shared/spaceDecorator.inline.hpp"
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#include "gc/shared/taskTerminator.hpp"
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#include "gc/shared/weakProcessor.inline.hpp"
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#include "gc/shared/workerPolicy.hpp"
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#include "gc/shared/workgroup.hpp"
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#include "logging/log.hpp"
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#include "memory/iterator.inline.hpp"
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#include "memory/metaspaceUtils.hpp"
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#include "memory/resourceArea.hpp"
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#include "memory/universe.hpp"
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#include "oops/access.inline.hpp"
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#include "oops/instanceClassLoaderKlass.inline.hpp"
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#include "oops/instanceKlass.inline.hpp"
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#include "oops/instanceMirrorKlass.inline.hpp"
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#include "oops/methodData.hpp"
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#include "oops/objArrayKlass.inline.hpp"
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#include "oops/oop.inline.hpp"
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#include "runtime/atomic.hpp"
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#include "runtime/handles.inline.hpp"
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#include "runtime/java.hpp"
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#include "runtime/safepoint.hpp"
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#include "runtime/vmThread.hpp"
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#include "services/memTracker.hpp"
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#include "services/memoryService.hpp"
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#include "utilities/align.hpp"
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#include "utilities/debug.hpp"
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#include "utilities/events.hpp"
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#include "utilities/formatBuffer.hpp"
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#include "utilities/macros.hpp"
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#include "utilities/stack.inline.hpp"
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#if INCLUDE_JVMCI
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#include "jvmci/jvmci.hpp"
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#endif
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#include <math.h>
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// All sizes are in HeapWords.
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const size_t ParallelCompactData::Log2RegionSize = 16; // 64K words
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const size_t ParallelCompactData::RegionSize = (size_t)1 << Log2RegionSize;
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const size_t ParallelCompactData::RegionSizeBytes =
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RegionSize << LogHeapWordSize;
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const size_t ParallelCompactData::RegionSizeOffsetMask = RegionSize - 1;
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const size_t ParallelCompactData::RegionAddrOffsetMask = RegionSizeBytes - 1;
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const size_t ParallelCompactData::RegionAddrMask = ~RegionAddrOffsetMask;
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const size_t ParallelCompactData::Log2BlockSize = 7; // 128 words
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const size_t ParallelCompactData::BlockSize = (size_t)1 << Log2BlockSize;
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const size_t ParallelCompactData::BlockSizeBytes =
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BlockSize << LogHeapWordSize;
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const size_t ParallelCompactData::BlockSizeOffsetMask = BlockSize - 1;
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const size_t ParallelCompactData::BlockAddrOffsetMask = BlockSizeBytes - 1;
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const size_t ParallelCompactData::BlockAddrMask = ~BlockAddrOffsetMask;
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const size_t ParallelCompactData::BlocksPerRegion = RegionSize / BlockSize;
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const size_t ParallelCompactData::Log2BlocksPerRegion =
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Log2RegionSize - Log2BlockSize;
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const ParallelCompactData::RegionData::region_sz_t
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ParallelCompactData::RegionData::dc_shift = 27;
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const ParallelCompactData::RegionData::region_sz_t
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ParallelCompactData::RegionData::dc_mask = ~0U << dc_shift;
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const ParallelCompactData::RegionData::region_sz_t
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ParallelCompactData::RegionData::dc_one = 0x1U << dc_shift;
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const ParallelCompactData::RegionData::region_sz_t
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ParallelCompactData::RegionData::los_mask = ~dc_mask;
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const ParallelCompactData::RegionData::region_sz_t
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ParallelCompactData::RegionData::dc_claimed = 0x8U << dc_shift;
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const ParallelCompactData::RegionData::region_sz_t
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ParallelCompactData::RegionData::dc_completed = 0xcU << dc_shift;
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SpaceInfo PSParallelCompact::_space_info[PSParallelCompact::last_space_id];
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SpanSubjectToDiscoveryClosure PSParallelCompact::_span_based_discoverer;
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ReferenceProcessor* PSParallelCompact::_ref_processor = NULL;
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double PSParallelCompact::_dwl_mean;
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double PSParallelCompact::_dwl_std_dev;
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double PSParallelCompact::_dwl_first_term;
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double PSParallelCompact::_dwl_adjustment;
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#ifdef ASSERT
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bool PSParallelCompact::_dwl_initialized = false;
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#endif // #ifdef ASSERT
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void SplitInfo::record(size_t src_region_idx, size_t partial_obj_size,
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HeapWord* destination)
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{
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assert(src_region_idx != 0, "invalid src_region_idx");
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assert(partial_obj_size != 0, "invalid partial_obj_size argument");
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assert(destination != NULL, "invalid destination argument");
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_src_region_idx = src_region_idx;
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_partial_obj_size = partial_obj_size;
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_destination = destination;
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// These fields may not be updated below, so make sure they're clear.
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assert(_dest_region_addr == NULL, "should have been cleared");
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assert(_first_src_addr == NULL, "should have been cleared");
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// Determine the number of destination regions for the partial object.
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HeapWord* const last_word = destination + partial_obj_size - 1;
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const ParallelCompactData& sd = PSParallelCompact::summary_data();
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HeapWord* const beg_region_addr = sd.region_align_down(destination);
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HeapWord* const end_region_addr = sd.region_align_down(last_word);
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if (beg_region_addr == end_region_addr) {
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// One destination region.
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_destination_count = 1;
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if (end_region_addr == destination) {
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// The destination falls on a region boundary, thus the first word of the
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// partial object will be the first word copied to the destination region.
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_dest_region_addr = end_region_addr;
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_first_src_addr = sd.region_to_addr(src_region_idx);
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}
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} else {
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// Two destination regions. When copied, the partial object will cross a
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// destination region boundary, so a word somewhere within the partial
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// object will be the first word copied to the second destination region.
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_destination_count = 2;
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_dest_region_addr = end_region_addr;
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const size_t ofs = pointer_delta(end_region_addr, destination);
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assert(ofs < _partial_obj_size, "sanity");
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_first_src_addr = sd.region_to_addr(src_region_idx) + ofs;
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}
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}
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void SplitInfo::clear()
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{
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_src_region_idx = 0;
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_partial_obj_size = 0;
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_destination = NULL;
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_destination_count = 0;
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_dest_region_addr = NULL;
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_first_src_addr = NULL;
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assert(!is_valid(), "sanity");
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}
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#ifdef ASSERT
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void SplitInfo::verify_clear()
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{
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assert(_src_region_idx == 0, "not clear");
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assert(_partial_obj_size == 0, "not clear");
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assert(_destination == NULL, "not clear");
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assert(_destination_count == 0, "not clear");
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assert(_dest_region_addr == NULL, "not clear");
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assert(_first_src_addr == NULL, "not clear");
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}
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#endif // #ifdef ASSERT
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void PSParallelCompact::print_on_error(outputStream* st) {
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_mark_bitmap.print_on_error(st);
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}
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#ifndef PRODUCT
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const char* PSParallelCompact::space_names[] = {
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"old ", "eden", "from", "to "
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};
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void PSParallelCompact::print_region_ranges() {
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if (!log_develop_is_enabled(Trace, gc, compaction)) {
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return;
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}
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Log(gc, compaction) log;
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ResourceMark rm;
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LogStream ls(log.trace());
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Universe::print_on(&ls);
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log.trace("space bottom top end new_top");
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log.trace("------ ---------- ---------- ---------- ----------");
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for (unsigned int id = 0; id < last_space_id; ++id) {
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const MutableSpace* space = _space_info[id].space();
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log.trace("%u %s "
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SIZE_FORMAT_W(10) " " SIZE_FORMAT_W(10) " "
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SIZE_FORMAT_W(10) " " SIZE_FORMAT_W(10) " ",
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id, space_names[id],
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summary_data().addr_to_region_idx(space->bottom()),
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summary_data().addr_to_region_idx(space->top()),
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summary_data().addr_to_region_idx(space->end()),
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summary_data().addr_to_region_idx(_space_info[id].new_top()));
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}
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}
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void
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print_generic_summary_region(size_t i, const ParallelCompactData::RegionData* c)
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{
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#define REGION_IDX_FORMAT SIZE_FORMAT_W(7)
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#define REGION_DATA_FORMAT SIZE_FORMAT_W(5)
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ParallelCompactData& sd = PSParallelCompact::summary_data();
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size_t dci = c->destination() ? sd.addr_to_region_idx(c->destination()) : 0;
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log_develop_trace(gc, compaction)(
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REGION_IDX_FORMAT " " PTR_FORMAT " "
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REGION_IDX_FORMAT " " PTR_FORMAT " "
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REGION_DATA_FORMAT " " REGION_DATA_FORMAT " "
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REGION_DATA_FORMAT " " REGION_IDX_FORMAT " %d",
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i, p2i(c->data_location()), dci, p2i(c->destination()),
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c->partial_obj_size(), c->live_obj_size(),
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c->data_size(), c->source_region(), c->destination_count());
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#undef REGION_IDX_FORMAT
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#undef REGION_DATA_FORMAT
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}
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void
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print_generic_summary_data(ParallelCompactData& summary_data,
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HeapWord* const beg_addr,
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HeapWord* const end_addr)
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{
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size_t total_words = 0;
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size_t i = summary_data.addr_to_region_idx(beg_addr);
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const size_t last = summary_data.addr_to_region_idx(end_addr);
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HeapWord* pdest = 0;
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while (i < last) {
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ParallelCompactData::RegionData* c = summary_data.region(i);
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if (c->data_size() != 0 || c->destination() != pdest) {
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print_generic_summary_region(i, c);
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total_words += c->data_size();
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pdest = c->destination();
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}
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++i;
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}
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log_develop_trace(gc, compaction)("summary_data_bytes=" SIZE_FORMAT, total_words * HeapWordSize);
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}
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void
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PSParallelCompact::print_generic_summary_data(ParallelCompactData& summary_data,
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HeapWord* const beg_addr,
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HeapWord* const end_addr) {
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::print_generic_summary_data(summary_data,beg_addr, end_addr);
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}
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void
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print_generic_summary_data(ParallelCompactData& summary_data,
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SpaceInfo* space_info)
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{
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if (!log_develop_is_enabled(Trace, gc, compaction)) {
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return;
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}
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for (unsigned int id = 0; id < PSParallelCompact::last_space_id; ++id) {
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const MutableSpace* space = space_info[id].space();
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print_generic_summary_data(summary_data, space->bottom(),
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MAX2(space->top(), space_info[id].new_top()));
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}
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}
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void
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print_initial_summary_data(ParallelCompactData& summary_data,
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const MutableSpace* space) {
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if (space->top() == space->bottom()) {
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return;
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}
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const size_t region_size = ParallelCompactData::RegionSize;
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typedef ParallelCompactData::RegionData RegionData;
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HeapWord* const top_aligned_up = summary_data.region_align_up(space->top());
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const size_t end_region = summary_data.addr_to_region_idx(top_aligned_up);
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const RegionData* c = summary_data.region(end_region - 1);
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HeapWord* end_addr = c->destination() + c->data_size();
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const size_t live_in_space = pointer_delta(end_addr, space->bottom());
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// Print (and count) the full regions at the beginning of the space.
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size_t full_region_count = 0;
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size_t i = summary_data.addr_to_region_idx(space->bottom());
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while (i < end_region && summary_data.region(i)->data_size() == region_size) {
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ParallelCompactData::RegionData* c = summary_data.region(i);
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log_develop_trace(gc, compaction)(
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SIZE_FORMAT_W(5) " " PTR_FORMAT " " SIZE_FORMAT_W(5) " " SIZE_FORMAT_W(5) " " SIZE_FORMAT_W(5) " " SIZE_FORMAT_W(5) " %d",
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i, p2i(c->destination()),
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c->partial_obj_size(), c->live_obj_size(),
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c->data_size(), c->source_region(), c->destination_count());
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++full_region_count;
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++i;
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}
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size_t live_to_right = live_in_space - full_region_count * region_size;
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double max_reclaimed_ratio = 0.0;
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size_t max_reclaimed_ratio_region = 0;
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size_t max_dead_to_right = 0;
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size_t max_live_to_right = 0;
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// Print the 'reclaimed ratio' for regions while there is something live in
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// the region or to the right of it. The remaining regions are empty (and
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// uninteresting), and computing the ratio will result in division by 0.
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while (i < end_region && live_to_right > 0) {
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c = summary_data.region(i);
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HeapWord* const region_addr = summary_data.region_to_addr(i);
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const size_t used_to_right = pointer_delta(space->top(), region_addr);
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const size_t dead_to_right = used_to_right - live_to_right;
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const double reclaimed_ratio = double(dead_to_right) / live_to_right;
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if (reclaimed_ratio > max_reclaimed_ratio) {
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max_reclaimed_ratio = reclaimed_ratio;
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max_reclaimed_ratio_region = i;
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max_dead_to_right = dead_to_right;
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max_live_to_right = live_to_right;
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}
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ParallelCompactData::RegionData* c = summary_data.region(i);
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log_develop_trace(gc, compaction)(
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SIZE_FORMAT_W(5) " " PTR_FORMAT " " SIZE_FORMAT_W(5) " " SIZE_FORMAT_W(5) " " SIZE_FORMAT_W(5) " " SIZE_FORMAT_W(5) " %d"
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"%12.10f " SIZE_FORMAT_W(10) " " SIZE_FORMAT_W(10),
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i, p2i(c->destination()),
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c->partial_obj_size(), c->live_obj_size(),
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c->data_size(), c->source_region(), c->destination_count(),
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reclaimed_ratio, dead_to_right, live_to_right);
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live_to_right -= c->data_size();
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++i;
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}
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// Any remaining regions are empty. Print one more if there is one.
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if (i < end_region) {
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ParallelCompactData::RegionData* c = summary_data.region(i);
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log_develop_trace(gc, compaction)(
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SIZE_FORMAT_W(5) " " PTR_FORMAT " " SIZE_FORMAT_W(5) " " SIZE_FORMAT_W(5) " " SIZE_FORMAT_W(5) " " SIZE_FORMAT_W(5) " %d",
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i, p2i(c->destination()),
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c->partial_obj_size(), c->live_obj_size(),
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c->data_size(), c->source_region(), c->destination_count());
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}
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log_develop_trace(gc, compaction)("max: " SIZE_FORMAT_W(4) " d2r=" SIZE_FORMAT_W(10) " l2r=" SIZE_FORMAT_W(10) " max_ratio=%14.12f",
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max_reclaimed_ratio_region, max_dead_to_right, max_live_to_right, max_reclaimed_ratio);
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}
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void
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print_initial_summary_data(ParallelCompactData& summary_data,
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SpaceInfo* space_info) {
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if (!log_develop_is_enabled(Trace, gc, compaction)) {
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return;
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}
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unsigned int id = PSParallelCompact::old_space_id;
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const MutableSpace* space;
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do {
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space = space_info[id].space();
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print_initial_summary_data(summary_data, space);
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} while (++id < PSParallelCompact::eden_space_id);
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do {
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space = space_info[id].space();
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print_generic_summary_data(summary_data, space->bottom(), space->top());
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} while (++id < PSParallelCompact::last_space_id);
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}
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#endif // #ifndef PRODUCT
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ParallelCompactData::ParallelCompactData() :
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_region_start(NULL),
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DEBUG_ONLY(_region_end(NULL) COMMA)
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_region_vspace(NULL),
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_reserved_byte_size(0),
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_region_data(NULL),
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_region_count(0),
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_block_vspace(NULL),
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_block_data(NULL),
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_block_count(0) {}
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bool ParallelCompactData::initialize(MemRegion covered_region)
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{
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_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) && initialize_block_data();
|
|
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_aligned(raw_bytes, 10);
|
|
const size_t granularity = os::vm_allocation_granularity();
|
|
_reserved_byte_size = align_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(_reserved_byte_size, rs_align, rs_align > 0);
|
|
os::trace_page_sizes("Parallel Compact Data", raw_bytes, raw_bytes, page_sz, rs.base(),
|
|
rs.size());
|
|
|
|
MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);
|
|
|
|
PSVirtualSpace* vspace = new PSVirtualSpace(rs, page_sz);
|
|
if (vspace != 0) {
|
|
if (vspace->expand_by(_reserved_byte_size)) {
|
|
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;
|
|
}
|
|
|
|
bool ParallelCompactData::initialize_block_data()
|
|
{
|
|
assert(_region_count != 0, "region data must be initialized first");
|
|
const size_t count = _region_count << Log2BlocksPerRegion;
|
|
_block_vspace = create_vspace(count, sizeof(BlockData));
|
|
if (_block_vspace != 0) {
|
|
_block_data = (BlockData*)_block_vspace->reserved_low_addr();
|
|
_block_count = count;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void ParallelCompactData::clear()
|
|
{
|
|
memset(_region_data, 0, _region_vspace->committed_size());
|
|
memset(_block_data, 0, _block_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");
|
|
assert(RegionSize % BlockSize == 0, "RegionSize not a multiple of BlockSize");
|
|
|
|
const size_t region_cnt = end_region - beg_region;
|
|
memset(_region_data + beg_region, 0, region_cnt * sizeof(RegionData));
|
|
|
|
const size_t beg_block = beg_region * BlocksPerRegion;
|
|
const size_t block_cnt = region_cnt * BlocksPerRegion;
|
|
memset(_block_data + beg_block, 0, block_cnt * sizeof(BlockData));
|
|
}
|
|
|
|
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;
|
|
// end_region is inclusive
|
|
const size_t end_region = (obj_ofs + len - 1) >> Log2RegionSize;
|
|
|
|
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);
|
|
|
|
// 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(is_region_aligned(beg), "not RegionSize aligned");
|
|
assert(is_region_aligned(end), "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);
|
|
|
|
log_develop_trace(gc, compaction)("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 (log_develop_is_enabled(Trace, gc, compaction)) {
|
|
const char * split_type = partial_obj_size == 0 ? "easy" : "hard";
|
|
log_develop_trace(gc, compaction)("%s split: src=" PTR_FORMAT " src_c=" SIZE_FORMAT " pos=" SIZE_FORMAT,
|
|
split_type, p2i(source_next), split_region, partial_obj_size);
|
|
log_develop_trace(gc, compaction)("%s split: dst=" PTR_FORMAT " dst_c=" SIZE_FORMAT " tn=" PTR_FORMAT,
|
|
split_type, p2i(split_destination),
|
|
addr_to_region_idx(split_destination),
|
|
p2i(*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();
|
|
log_develop_trace(gc, compaction)("%s split: po_beg=" PTR_FORMAT " " SIZE_FORMAT " po_end=" PTR_FORMAT " " SIZE_FORMAT,
|
|
split_type,
|
|
p2i(po_beg), addr_to_region_idx(po_beg),
|
|
p2i(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)
|
|
{
|
|
HeapWord* const source_next_val = source_next == NULL ? NULL : *source_next;
|
|
log_develop_trace(gc, compaction)(
|
|
"sb=" PTR_FORMAT " se=" PTR_FORMAT " sn=" PTR_FORMAT
|
|
"tb=" PTR_FORMAT " te=" PTR_FORMAT " tn=" PTR_FORMAT,
|
|
p2i(source_beg), p2i(source_end), p2i(source_next_val),
|
|
p2i(target_beg), p2i(target_end), p2i(*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 (is_region_aligned(dest_addr)) {
|
|
// 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, ParCompactionManager* cm) const {
|
|
assert(addr != NULL, "Should detect NULL oop earlier");
|
|
assert(ParallelScavengeHeap::heap()->is_in(addr), "not in heap");
|
|
assert(PSParallelCompact::mark_bitmap()->is_marked(addr), "not marked");
|
|
|
|
// Region covering the object.
|
|
RegionData* const region_ptr = addr_to_region_ptr(addr);
|
|
HeapWord* result = region_ptr->destination();
|
|
|
|
// If the entire Region is live, the new location is region->destination + the
|
|
// offset of the object within in the Region.
|
|
|
|
// Run some performance tests to determine if this special case pays off. It
|
|
// is worth it for pointers into the dense prefix. If the optimization to
|
|
// avoid pointer updates in regions that only point to the dense prefix is
|
|
// ever implemented, this should be revisited.
|
|
if (region_ptr->data_size() == RegionSize) {
|
|
result += region_offset(addr);
|
|
return result;
|
|
}
|
|
|
|
// Otherwise, the new location is region->destination + block offset + the
|
|
// number of live words in the Block that are (a) to the left of addr and (b)
|
|
// due to objects that start in the Block.
|
|
|
|
// Fill in the block table if necessary. This is unsynchronized, so multiple
|
|
// threads may fill the block table for a region (harmless, since it is
|
|
// idempotent).
|
|
if (!region_ptr->blocks_filled()) {
|
|
PSParallelCompact::fill_blocks(addr_to_region_idx(addr));
|
|
region_ptr->set_blocks_filled();
|
|
}
|
|
|
|
HeapWord* const search_start = block_align_down(addr);
|
|
const size_t block_offset = addr_to_block_ptr(addr)->offset();
|
|
|
|
const ParMarkBitMap* bitmap = PSParallelCompact::mark_bitmap();
|
|
const size_t live = bitmap->live_words_in_range(cm, search_start, cast_to_oop(addr));
|
|
result += block_offset + live;
|
|
DEBUG_ONLY(PSParallelCompact::check_new_location(addr, result));
|
|
return result;
|
|
}
|
|
|
|
#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);
|
|
verify_clear(_block_vspace);
|
|
}
|
|
#endif // #ifdef ASSERT
|
|
|
|
STWGCTimer PSParallelCompact::_gc_timer;
|
|
ParallelOldTracer PSParallelCompact::_gc_tracer;
|
|
elapsedTimer PSParallelCompact::_accumulated_time;
|
|
unsigned int PSParallelCompact::_total_invocations = 0;
|
|
unsigned int PSParallelCompact::_maximum_compaction_gc_num = 0;
|
|
CollectorCounters* PSParallelCompact::_counters = NULL;
|
|
ParMarkBitMap PSParallelCompact::_mark_bitmap;
|
|
ParallelCompactData PSParallelCompact::_summary_data;
|
|
|
|
PSParallelCompact::IsAliveClosure PSParallelCompact::_is_alive_closure;
|
|
|
|
bool PSParallelCompact::IsAliveClosure::do_object_b(oop p) { return mark_bitmap()->is_marked(p); }
|
|
|
|
class PCReferenceProcessor: public ReferenceProcessor {
|
|
public:
|
|
PCReferenceProcessor(
|
|
BoolObjectClosure* is_subject_to_discovery,
|
|
BoolObjectClosure* is_alive_non_header) :
|
|
ReferenceProcessor(is_subject_to_discovery,
|
|
ParallelGCThreads, // mt processing degree
|
|
true, // mt discovery
|
|
ParallelGCThreads, // mt discovery degree
|
|
true, // atomic_discovery
|
|
is_alive_non_header) {
|
|
}
|
|
|
|
template<typename T> bool discover(oop obj, ReferenceType type) {
|
|
T* referent_addr = (T*) java_lang_ref_Reference::referent_addr_raw(obj);
|
|
T heap_oop = RawAccess<>::oop_load(referent_addr);
|
|
oop referent = CompressedOops::decode_not_null(heap_oop);
|
|
return PSParallelCompact::mark_bitmap()->is_unmarked(referent)
|
|
&& ReferenceProcessor::discover_reference(obj, type);
|
|
}
|
|
virtual bool discover_reference(oop obj, ReferenceType type) {
|
|
if (UseCompressedOops) {
|
|
return discover<narrowOop>(obj, type);
|
|
} else {
|
|
return discover<oop>(obj, type);
|
|
}
|
|
}
|
|
};
|
|
|
|
void PSParallelCompact::post_initialize() {
|
|
ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
|
|
_span_based_discoverer.set_span(heap->reserved_region());
|
|
_ref_processor =
|
|
new PCReferenceProcessor(&_span_based_discoverer,
|
|
&_is_alive_closure); // non-header is alive closure
|
|
|
|
_counters = new CollectorCounters("Parallel full collection pauses", 1);
|
|
|
|
// Initialize static fields in ParCompactionManager.
|
|
ParCompactionManager::initialize(mark_bitmap());
|
|
}
|
|
|
|
bool PSParallelCompact::initialize() {
|
|
ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
|
|
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(
|
|
err_msg("Unable to allocate " SIZE_FORMAT "KB bitmaps for parallel "
|
|
"garbage collection for the requested " SIZE_FORMAT "KB heap.",
|
|
_mark_bitmap.reserved_byte_size()/K, mr.byte_size()/K));
|
|
return false;
|
|
}
|
|
|
|
if (!_summary_data.initialize(mr)) {
|
|
vm_shutdown_during_initialization(
|
|
err_msg("Unable to allocate " SIZE_FORMAT "KB card tables for parallel "
|
|
"garbage collection for the requested " SIZE_FORMAT "KB heap.",
|
|
_summary_data.reserved_byte_size()/K, mr.byte_size()/K));
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void PSParallelCompact::initialize_space_info()
|
|
{
|
|
memset(&_space_info, 0, sizeof(_space_info));
|
|
|
|
ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
|
|
PSYoungGen* young_gen = heap->young_gen();
|
|
|
|
_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[old_space_id].set_start_array(heap->old_gen()->start_array());
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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 = _mark_bitmap.align_range_end(_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()
|
|
{
|
|
// 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 young
|
|
// collections will have swapped the spaces an unknown number of times.
|
|
GCTraceTime(Debug, gc, phases) tm("Pre Compact", &_gc_timer);
|
|
ParallelScavengeHeap* heap = ParallelScavengeHeap::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());
|
|
|
|
// Increment the invocation count
|
|
heap->increment_total_collections(true);
|
|
|
|
// We need to track unique mark sweep invocations as well.
|
|
_total_invocations++;
|
|
|
|
heap->print_heap_before_gc();
|
|
heap->trace_heap_before_gc(&_gc_tracer);
|
|
|
|
// Fill in TLABs
|
|
heap->ensure_parsability(true); // retire TLABs
|
|
|
|
if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) {
|
|
Universe::verify("Before GC");
|
|
}
|
|
|
|
// Verify object start arrays
|
|
if (VerifyObjectStartArray &&
|
|
VerifyBeforeGC) {
|
|
heap->old_gen()->verify_object_start_array();
|
|
}
|
|
|
|
DEBUG_ONLY(mark_bitmap()->verify_clear();)
|
|
DEBUG_ONLY(summary_data().verify_clear();)
|
|
|
|
ParCompactionManager::reset_all_bitmap_query_caches();
|
|
}
|
|
|
|
void PSParallelCompact::post_compact()
|
|
{
|
|
GCTraceTime(Info, gc, phases) tm("Post Compact", &_gc_timer);
|
|
ParCompactionManager::remove_all_shadow_regions();
|
|
|
|
for (unsigned int id = old_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 = ParallelScavengeHeap::heap();
|
|
bool eden_empty = eden_space->is_empty();
|
|
|
|
// Update heap occupancy information which is used as input to the soft ref
|
|
// clearing policy at the next gc.
|
|
Universe::heap()->update_capacity_and_used_at_gc();
|
|
|
|
bool young_gen_empty = eden_empty && from_space->is_empty() &&
|
|
to_space->is_empty();
|
|
|
|
PSCardTable* ct = heap->card_table();
|
|
MemRegion old_mr = heap->old_gen()->reserved();
|
|
if (young_gen_empty) {
|
|
ct->clear(MemRegion(old_mr.start(), old_mr.end()));
|
|
} else {
|
|
ct->invalidate(MemRegion(old_mr.start(), old_mr.end()));
|
|
}
|
|
|
|
// Delete metaspaces for unloaded class loaders and clean up loader_data graph
|
|
ClassLoaderDataGraph::purge(/*at_safepoint*/true);
|
|
DEBUG_ONLY(MetaspaceUtils::verify();)
|
|
|
|
heap->prune_scavengable_nmethods();
|
|
|
|
#if COMPILER2_OR_JVMCI
|
|
DerivedPointerTable::update_pointers();
|
|
#endif
|
|
|
|
if (ZapUnusedHeapArea) {
|
|
heap->gen_mangle_unused_area();
|
|
}
|
|
|
|
// Signal that we have completed a visit to all live objects.
|
|
Universe::heap()->record_whole_heap_examined_timestamp();
|
|
}
|
|
|
|
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);
|
|
|
|
log_develop_debug(gc, compaction)(
|
|
"cur_dens=%5.3f dw_dens=%5.3f dw_goal=" SIZE_FORMAT,
|
|
cur_density, deadwood_density, deadwood_goal);
|
|
log_develop_debug(gc, compaction)(
|
|
"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);
|
|
|
|
log_develop_trace(gc, compaction)(
|
|
"c#=" SIZE_FORMAT_W(4) " dst=" PTR_FORMAT " "
|
|
"dp=" PTR_FORMAT " cdw=" SIZE_FORMAT_W(8),
|
|
sd.region(cp), p2i(region_destination),
|
|
p2i(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;
|
|
}
|
|
|
|
log_develop_trace(gc, compaction)(
|
|
"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;
|
|
|
|
log_develop_debug(gc, compaction)(
|
|
"%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, p2i(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)
|
|
{
|
|
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 = 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);
|
|
|
|
log_develop_debug(gc, compaction)(
|
|
"space_live=" SIZE_FORMAT " space_used=" SIZE_FORMAT " "
|
|
"space_cap=" SIZE_FORMAT,
|
|
space_live, space_used,
|
|
space_capacity);
|
|
log_develop_debug(gc, compaction)(
|
|
"dead_wood_limiter(%6.4f, " SIZE_FORMAT ")=%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;
|
|
}
|
|
}
|
|
|
|
return sd.region_to_addr(best_cp);
|
|
}
|
|
|
|
void PSParallelCompact::summarize_spaces_quick()
|
|
{
|
|
for (unsigned int i = 0; i < last_space_id; ++i) {
|
|
const MutableSpace* space = _space_info[i].space();
|
|
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());
|
|
}
|
|
}
|
|
|
|
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::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(),
|
|
"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 (log_is_enabled(Debug, gc, compaction)) {
|
|
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 (log_develop_is_enabled(Trace, gc, compaction)) {
|
|
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);
|
|
log_develop_trace(gc, compaction)(
|
|
"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(), p2i(dense_prefix_end),
|
|
dp_region, dp_words / region_size,
|
|
cr_words / region_size, p2i(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)
|
|
{
|
|
log_develop_trace(gc, compaction)(
|
|
"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],
|
|
p2i(src_beg), p2i(src_end),
|
|
_summary_data.addr_to_region_idx(src_beg),
|
|
_summary_data.addr_to_region_idx(src_end),
|
|
p2i(dst_beg), p2i(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)
|
|
{
|
|
GCTraceTime(Info, gc, phases) tm("Summary Phase", &_gc_timer);
|
|
|
|
// Quick summarization of each space into itself, to see how much is live.
|
|
summarize_spaces_quick();
|
|
|
|
log_develop_trace(gc, compaction)("summary phase: after summarizing each space to self");
|
|
NOT_PRODUCT(print_region_ranges());
|
|
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;
|
|
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;
|
|
}
|
|
|
|
// Old generations.
|
|
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");
|
|
}
|
|
}
|
|
|
|
log_develop_trace(gc, compaction)("Summary_phase: after final summarization");
|
|
NOT_PRODUCT(print_region_ranges());
|
|
NOT_PRODUCT(print_initial_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 soft ref 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 = ParallelScavengeHeap::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->soft_ref_policy()->should_clear_all_soft_refs();
|
|
|
|
PSParallelCompact::invoke_no_policy(clear_all_soft_refs ||
|
|
maximum_heap_compaction);
|
|
}
|
|
|
|
// This method contains no policy. You should probably
|
|
// be calling invoke() instead.
|
|
bool PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
|
|
assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
|
|
assert(ref_processor() != NULL, "Sanity");
|
|
|
|
if (GCLocker::check_active_before_gc()) {
|
|
return false;
|
|
}
|
|
|
|
ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
|
|
|
|
GCIdMark gc_id_mark;
|
|
_gc_timer.register_gc_start();
|
|
_gc_tracer.report_gc_start(heap->gc_cause(), _gc_timer.gc_start());
|
|
|
|
TimeStamp marking_start;
|
|
TimeStamp compaction_start;
|
|
TimeStamp collection_exit;
|
|
|
|
GCCause::Cause gc_cause = heap->gc_cause();
|
|
PSYoungGen* young_gen = heap->young_gen();
|
|
PSOldGen* old_gen = heap->old_gen();
|
|
PSAdaptiveSizePolicy* size_policy = heap->size_policy();
|
|
|
|
// The scope of casr should end after code that can change
|
|
// SoftRefPolicy::_should_clear_all_soft_refs.
|
|
ClearedAllSoftRefs casr(maximum_heap_compaction,
|
|
heap->soft_ref_policy());
|
|
|
|
if (ZapUnusedHeapArea) {
|
|
// Save information needed to minimize mangling
|
|
heap->record_gen_tops_before_GC();
|
|
}
|
|
|
|
// Make sure data structures are sane, make the heap parsable, and do other
|
|
// miscellaneous bookkeeping.
|
|
pre_compact();
|
|
|
|
const PreGenGCValues pre_gc_values = heap->get_pre_gc_values();
|
|
|
|
// Get the compaction manager reserved for the VM thread.
|
|
ParCompactionManager* const vmthread_cm = ParCompactionManager::get_vmthread_cm();
|
|
|
|
{
|
|
const uint active_workers =
|
|
WorkerPolicy::calc_active_workers(ParallelScavengeHeap::heap()->workers().total_workers(),
|
|
ParallelScavengeHeap::heap()->workers().active_workers(),
|
|
Threads::number_of_non_daemon_threads());
|
|
ParallelScavengeHeap::heap()->workers().update_active_workers(active_workers);
|
|
|
|
GCTraceCPUTime tcpu;
|
|
GCTraceTime(Info, gc) tm("Pause Full", NULL, gc_cause, true);
|
|
|
|
heap->pre_full_gc_dump(&_gc_timer);
|
|
|
|
TraceCollectorStats tcs(counters());
|
|
TraceMemoryManagerStats tms(heap->old_gc_manager(), gc_cause);
|
|
|
|
if (log_is_enabled(Debug, gc, heap, exit)) {
|
|
accumulated_time()->start();
|
|
}
|
|
|
|
// Let the size policy know we're starting
|
|
size_policy->major_collection_begin();
|
|
|
|
#if COMPILER2_OR_JVMCI
|
|
DerivedPointerTable::clear();
|
|
#endif
|
|
|
|
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, &_gc_tracer);
|
|
|
|
bool max_on_system_gc = UseMaximumCompactionOnSystemGC
|
|
&& GCCause::is_user_requested_gc(gc_cause);
|
|
summary_phase(vmthread_cm, maximum_heap_compaction || max_on_system_gc);
|
|
|
|
#if COMPILER2_OR_JVMCI
|
|
assert(DerivedPointerTable::is_active(), "Sanity");
|
|
DerivedPointerTable::set_active(false);
|
|
#endif
|
|
|
|
// adjust_roots() updates Universe::_intArrayKlassObj which is
|
|
// needed by the compaction for filling holes in the dense prefix.
|
|
adjust_roots();
|
|
|
|
compaction_start.update();
|
|
compact();
|
|
|
|
ParCompactionManager::verify_all_region_stack_empty();
|
|
|
|
// 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) {
|
|
log_debug(gc, ergo)("AdaptiveSizeStart: collection: %d ", heap->total_collections());
|
|
log_trace(gc, ergo)("old_gen_capacity: " SIZE_FORMAT " young_gen_capacity: " SIZE_FORMAT,
|
|
old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes());
|
|
|
|
// Don't check if the size_policy is ready here. Let
|
|
// the size_policy check that internally.
|
|
if (UseAdaptiveGenerationSizePolicyAtMajorCollection &&
|
|
AdaptiveSizePolicy::should_update_promo_stats(gc_cause)) {
|
|
// Swap the survivor spaces if from_space is empty. The
|
|
// resize_young_gen() called below is normally used after
|
|
// a successful young GC and swapping of survivor spaces;
|
|
// otherwise, it will fail to resize the young gen with
|
|
// the current implementation.
|
|
if (young_gen->from_space()->is_empty()) {
|
|
young_gen->from_space()->clear(SpaceDecorator::Mangle);
|
|
young_gen->swap_spaces();
|
|
}
|
|
|
|
// Calculate optimal free space amounts
|
|
assert(young_gen->max_gen_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 young_live = young_gen->used_in_bytes();
|
|
size_t eden_live = young_gen->eden_space()->used_in_bytes();
|
|
size_t old_live = old_gen->used_in_bytes();
|
|
size_t cur_eden = young_gen->eden_space()->capacity_in_bytes();
|
|
size_t max_old_gen_size = old_gen->max_gen_size();
|
|
size_t max_eden_size = young_gen->max_gen_size() -
|
|
young_gen->from_space()->capacity_in_bytes() -
|
|
young_gen->to_space()->capacity_in_bytes();
|
|
|
|
// Used for diagnostics
|
|
size_policy->clear_generation_free_space_flags();
|
|
|
|
size_policy->compute_generations_free_space(young_live,
|
|
eden_live,
|
|
old_live,
|
|
cur_eden,
|
|
max_old_gen_size,
|
|
max_eden_size,
|
|
true /* full gc*/);
|
|
|
|
size_policy->check_gc_overhead_limit(eden_live,
|
|
max_old_gen_size,
|
|
max_eden_size,
|
|
true /* full gc*/,
|
|
gc_cause,
|
|
heap->soft_ref_policy());
|
|
|
|
size_policy->decay_supplemental_growth(true /* full gc*/);
|
|
|
|
heap->resize_old_gen(
|
|
size_policy->calculated_old_free_size_in_bytes());
|
|
|
|
heap->resize_young_gen(size_policy->calculated_eden_size_in_bytes(),
|
|
size_policy->calculated_survivor_size_in_bytes());
|
|
}
|
|
|
|
log_debug(gc, ergo)("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();
|
|
|
|
// Resize the metaspace capacity after a collection
|
|
MetaspaceGC::compute_new_size();
|
|
|
|
if (log_is_enabled(Debug, gc, heap, exit)) {
|
|
accumulated_time()->stop();
|
|
}
|
|
|
|
heap->print_heap_change(pre_gc_values);
|
|
|
|
// Track memory usage and detect low memory
|
|
MemoryService::track_memory_usage();
|
|
heap->update_counters();
|
|
|
|
heap->post_full_gc_dump(&_gc_timer);
|
|
}
|
|
|
|
if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
|
|
Universe::verify("After GC");
|
|
}
|
|
|
|
// Re-verify object start arrays
|
|
if (VerifyObjectStartArray &&
|
|
VerifyAfterGC) {
|
|
old_gen->verify_object_start_array();
|
|
}
|
|
|
|
if (ZapUnusedHeapArea) {
|
|
old_gen->object_space()->check_mangled_unused_area_complete();
|
|
}
|
|
|
|
NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
|
|
|
|
collection_exit.update();
|
|
|
|
heap->print_heap_after_gc();
|
|
heap->trace_heap_after_gc(&_gc_tracer);
|
|
|
|
log_debug(gc, task, time)("VM-Thread " JLONG_FORMAT " " JLONG_FORMAT " " JLONG_FORMAT,
|
|
marking_start.ticks(), compaction_start.ticks(),
|
|
collection_exit.ticks());
|
|
|
|
AdaptiveSizePolicyOutput::print(size_policy, heap->total_collections());
|
|
|
|
_gc_timer.register_gc_end();
|
|
|
|
_gc_tracer.report_dense_prefix(dense_prefix(old_space_id));
|
|
_gc_tracer.report_gc_end(_gc_timer.gc_end(), _gc_timer.time_partitions());
|
|
|
|
return true;
|
|
}
|
|
|
|
class PCAddThreadRootsMarkingTaskClosure : public ThreadClosure {
|
|
private:
|
|
uint _worker_id;
|
|
|
|
public:
|
|
PCAddThreadRootsMarkingTaskClosure(uint worker_id) : _worker_id(worker_id) { }
|
|
void do_thread(Thread* thread) {
|
|
assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");
|
|
|
|
ResourceMark rm;
|
|
|
|
ParCompactionManager* cm = ParCompactionManager::gc_thread_compaction_manager(_worker_id);
|
|
|
|
PCMarkAndPushClosure mark_and_push_closure(cm);
|
|
MarkingCodeBlobClosure mark_and_push_in_blobs(&mark_and_push_closure, !CodeBlobToOopClosure::FixRelocations);
|
|
|
|
thread->oops_do(&mark_and_push_closure, &mark_and_push_in_blobs);
|
|
|
|
// Do the real work
|
|
cm->follow_marking_stacks();
|
|
}
|
|
};
|
|
|
|
static void mark_from_roots_work(ParallelRootType::Value root_type, uint worker_id) {
|
|
assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");
|
|
|
|
ParCompactionManager* cm =
|
|
ParCompactionManager::gc_thread_compaction_manager(worker_id);
|
|
PCMarkAndPushClosure mark_and_push_closure(cm);
|
|
|
|
switch (root_type) {
|
|
case ParallelRootType::class_loader_data:
|
|
{
|
|
CLDToOopClosure cld_closure(&mark_and_push_closure, ClassLoaderData::_claim_strong);
|
|
ClassLoaderDataGraph::always_strong_cld_do(&cld_closure);
|
|
}
|
|
break;
|
|
|
|
case ParallelRootType::code_cache:
|
|
// Do not treat nmethods as strong roots for mark/sweep, since we can unload them.
|
|
//ScavengableNMethods::scavengable_nmethods_do(CodeBlobToOopClosure(&mark_and_push_closure));
|
|
break;
|
|
|
|
case ParallelRootType::sentinel:
|
|
DEBUG_ONLY(default:) // DEBUG_ONLY hack will create compile error on release builds (-Wswitch) and runtime check on debug builds
|
|
fatal("Bad enumeration value: %u", root_type);
|
|
break;
|
|
}
|
|
|
|
// Do the real work
|
|
cm->follow_marking_stacks();
|
|
}
|
|
|
|
static void steal_marking_work(TaskTerminator& terminator, uint worker_id) {
|
|
assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");
|
|
|
|
ParCompactionManager* cm =
|
|
ParCompactionManager::gc_thread_compaction_manager(worker_id);
|
|
|
|
oop obj = NULL;
|
|
ObjArrayTask task;
|
|
do {
|
|
while (ParCompactionManager::steal_objarray(worker_id, task)) {
|
|
cm->follow_array((objArrayOop)task.obj(), task.index());
|
|
cm->follow_marking_stacks();
|
|
}
|
|
while (ParCompactionManager::steal(worker_id, obj)) {
|
|
cm->follow_contents(obj);
|
|
cm->follow_marking_stacks();
|
|
}
|
|
} while (!terminator.offer_termination());
|
|
}
|
|
|
|
class MarkFromRootsTask : public AbstractGangTask {
|
|
typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask;
|
|
StrongRootsScope _strong_roots_scope; // needed for Threads::possibly_parallel_threads_do
|
|
OopStorageSetStrongParState<false /* concurrent */, false /* is_const */> _oop_storage_set_par_state;
|
|
SequentialSubTasksDone _subtasks;
|
|
TaskTerminator _terminator;
|
|
uint _active_workers;
|
|
|
|
public:
|
|
MarkFromRootsTask(uint active_workers) :
|
|
AbstractGangTask("MarkFromRootsTask"),
|
|
_strong_roots_scope(active_workers),
|
|
_subtasks(ParallelRootType::sentinel),
|
|
_terminator(active_workers, ParCompactionManager::oop_task_queues()),
|
|
_active_workers(active_workers) {
|
|
}
|
|
|
|
virtual void work(uint worker_id) {
|
|
for (uint task = 0; _subtasks.try_claim_task(task); /*empty*/ ) {
|
|
mark_from_roots_work(static_cast<ParallelRootType::Value>(task), worker_id);
|
|
}
|
|
|
|
PCAddThreadRootsMarkingTaskClosure closure(worker_id);
|
|
Threads::possibly_parallel_threads_do(true /*parallel */, &closure);
|
|
|
|
// Mark from OopStorages
|
|
{
|
|
ParCompactionManager* cm = ParCompactionManager::gc_thread_compaction_manager(worker_id);
|
|
PCMarkAndPushClosure closure(cm);
|
|
_oop_storage_set_par_state.oops_do(&closure);
|
|
// Do the real work
|
|
cm->follow_marking_stacks();
|
|
}
|
|
|
|
if (_active_workers > 1) {
|
|
steal_marking_work(_terminator, worker_id);
|
|
}
|
|
}
|
|
};
|
|
|
|
class PCRefProcTask : public AbstractGangTask {
|
|
typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask;
|
|
ProcessTask& _task;
|
|
uint _ergo_workers;
|
|
TaskTerminator _terminator;
|
|
|
|
public:
|
|
PCRefProcTask(ProcessTask& task, uint ergo_workers) :
|
|
AbstractGangTask("PCRefProcTask"),
|
|
_task(task),
|
|
_ergo_workers(ergo_workers),
|
|
_terminator(_ergo_workers, ParCompactionManager::oop_task_queues()) {
|
|
}
|
|
|
|
virtual void work(uint worker_id) {
|
|
ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
|
|
assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");
|
|
|
|
ParCompactionManager* cm =
|
|
ParCompactionManager::gc_thread_compaction_manager(worker_id);
|
|
PCMarkAndPushClosure mark_and_push_closure(cm);
|
|
ParCompactionManager::FollowStackClosure follow_stack_closure(cm);
|
|
_task.work(worker_id, *PSParallelCompact::is_alive_closure(),
|
|
mark_and_push_closure, follow_stack_closure);
|
|
|
|
steal_marking_work(_terminator, worker_id);
|
|
}
|
|
};
|
|
|
|
class RefProcTaskExecutor: public AbstractRefProcTaskExecutor {
|
|
void execute(ProcessTask& process_task, uint ergo_workers) {
|
|
assert(ParallelScavengeHeap::heap()->workers().active_workers() == ergo_workers,
|
|
"Ergonomically chosen workers (%u) must be equal to active workers (%u)",
|
|
ergo_workers, ParallelScavengeHeap::heap()->workers().active_workers());
|
|
|
|
PCRefProcTask task(process_task, ergo_workers);
|
|
ParallelScavengeHeap::heap()->workers().run_task(&task);
|
|
}
|
|
};
|
|
|
|
void PSParallelCompact::marking_phase(ParCompactionManager* cm,
|
|
bool maximum_heap_compaction,
|
|
ParallelOldTracer *gc_tracer) {
|
|
// Recursively traverse all live objects and mark them
|
|
GCTraceTime(Info, gc, phases) tm("Marking Phase", &_gc_timer);
|
|
|
|
ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
|
|
uint active_gc_threads = ParallelScavengeHeap::heap()->workers().active_workers();
|
|
|
|
PCMarkAndPushClosure mark_and_push_closure(cm);
|
|
ParCompactionManager::FollowStackClosure follow_stack_closure(cm);
|
|
|
|
// Need new claim bits before marking starts.
|
|
ClassLoaderDataGraph::clear_claimed_marks();
|
|
|
|
{
|
|
GCTraceTime(Debug, gc, phases) tm("Par Mark", &_gc_timer);
|
|
|
|
MarkFromRootsTask task(active_gc_threads);
|
|
ParallelScavengeHeap::heap()->workers().run_task(&task);
|
|
}
|
|
|
|
// Process reference objects found during marking
|
|
{
|
|
GCTraceTime(Debug, gc, phases) tm("Reference Processing", &_gc_timer);
|
|
|
|
ReferenceProcessorStats stats;
|
|
ReferenceProcessorPhaseTimes pt(&_gc_timer, ref_processor()->max_num_queues());
|
|
|
|
if (ref_processor()->processing_is_mt()) {
|
|
ref_processor()->set_active_mt_degree(active_gc_threads);
|
|
|
|
RefProcTaskExecutor task_executor;
|
|
stats = ref_processor()->process_discovered_references(
|
|
is_alive_closure(), &mark_and_push_closure, &follow_stack_closure,
|
|
&task_executor, &pt);
|
|
} else {
|
|
stats = ref_processor()->process_discovered_references(
|
|
is_alive_closure(), &mark_and_push_closure, &follow_stack_closure, NULL,
|
|
&pt);
|
|
}
|
|
|
|
gc_tracer->report_gc_reference_stats(stats);
|
|
pt.print_all_references();
|
|
}
|
|
|
|
// This is the point where the entire marking should have completed.
|
|
ParCompactionManager::verify_all_marking_stack_empty();
|
|
|
|
{
|
|
GCTraceTime(Debug, gc, phases) tm("Weak Processing", &_gc_timer);
|
|
WeakProcessor::weak_oops_do(is_alive_closure(), &do_nothing_cl);
|
|
}
|
|
|
|
{
|
|
GCTraceTime(Debug, gc, phases) tm_m("Class Unloading", &_gc_timer);
|
|
|
|
// Follow system dictionary roots and unload classes.
|
|
bool purged_class = SystemDictionary::do_unloading(&_gc_timer);
|
|
|
|
// Unload nmethods.
|
|
CodeCache::do_unloading(is_alive_closure(), purged_class);
|
|
|
|
// Prune dead klasses from subklass/sibling/implementor lists.
|
|
Klass::clean_weak_klass_links(purged_class);
|
|
|
|
// Clean JVMCI metadata handles.
|
|
JVMCI_ONLY(JVMCI::do_unloading(purged_class));
|
|
}
|
|
|
|
_gc_tracer.report_object_count_after_gc(is_alive_closure());
|
|
}
|
|
|
|
#ifdef ASSERT
|
|
void PCAdjustPointerClosure::verify_cm(ParCompactionManager* cm) {
|
|
assert(cm != NULL, "associate ParCompactionManage should not be NULL");
|
|
auto vmthread_cm = ParCompactionManager::get_vmthread_cm();
|
|
if (Thread::current()->is_VM_thread()) {
|
|
assert(cm == vmthread_cm, "VM threads should use ParCompactionManager from get_vmthread_cm()");
|
|
} else {
|
|
assert(Thread::current()->is_GC_task_thread(), "Must be a GC thread");
|
|
assert(cm != vmthread_cm, "GC threads should use ParCompactionManager from gc_thread_compaction_manager()");
|
|
}
|
|
}
|
|
#endif
|
|
|
|
class PSAdjustTask final : public AbstractGangTask {
|
|
SubTasksDone _sub_tasks;
|
|
WeakProcessor::Task _weak_proc_task;
|
|
OopStorageSetStrongParState<false, false> _oop_storage_iter;
|
|
uint _nworkers;
|
|
|
|
enum PSAdjustSubTask {
|
|
PSAdjustSubTask_code_cache,
|
|
PSAdjustSubTask_old_ref_process,
|
|
PSAdjustSubTask_young_ref_process,
|
|
|
|
PSAdjustSubTask_num_elements
|
|
};
|
|
|
|
public:
|
|
PSAdjustTask(uint nworkers) :
|
|
AbstractGangTask("PSAdjust task"),
|
|
_sub_tasks(PSAdjustSubTask_num_elements),
|
|
_weak_proc_task(nworkers),
|
|
_nworkers(nworkers) {
|
|
// Need new claim bits when tracing through and adjusting pointers.
|
|
ClassLoaderDataGraph::clear_claimed_marks();
|
|
if (nworkers > 1) {
|
|
Threads::change_thread_claim_token();
|
|
}
|
|
}
|
|
|
|
~PSAdjustTask() {
|
|
Threads::assert_all_threads_claimed();
|
|
}
|
|
|
|
void work(uint worker_id) {
|
|
ParCompactionManager* cm = ParCompactionManager::gc_thread_compaction_manager(worker_id);
|
|
PCAdjustPointerClosure adjust(cm);
|
|
{
|
|
ResourceMark rm;
|
|
Threads::possibly_parallel_oops_do(_nworkers > 1, &adjust, nullptr);
|
|
}
|
|
_oop_storage_iter.oops_do(&adjust);
|
|
{
|
|
CLDToOopClosure cld_closure(&adjust, ClassLoaderData::_claim_strong);
|
|
ClassLoaderDataGraph::cld_do(&cld_closure);
|
|
}
|
|
{
|
|
AlwaysTrueClosure always_alive;
|
|
_weak_proc_task.work(worker_id, &always_alive, &adjust);
|
|
}
|
|
if (_sub_tasks.try_claim_task(PSAdjustSubTask_code_cache)) {
|
|
CodeBlobToOopClosure adjust_code(&adjust, CodeBlobToOopClosure::FixRelocations);
|
|
CodeCache::blobs_do(&adjust_code);
|
|
}
|
|
if (_sub_tasks.try_claim_task(PSAdjustSubTask_old_ref_process)) {
|
|
PSParallelCompact::ref_processor()->weak_oops_do(&adjust);
|
|
}
|
|
if (_sub_tasks.try_claim_task(PSAdjustSubTask_young_ref_process)) {
|
|
// 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);
|
|
}
|
|
_sub_tasks.all_tasks_claimed();
|
|
}
|
|
};
|
|
|
|
void PSParallelCompact::adjust_roots() {
|
|
// Adjust the pointers to reflect the new locations
|
|
GCTraceTime(Info, gc, phases) tm("Adjust Roots", &_gc_timer);
|
|
uint nworkers = ParallelScavengeHeap::heap()->workers().active_workers();
|
|
PSAdjustTask task(nworkers);
|
|
ParallelScavengeHeap::heap()->workers().run_task(&task);
|
|
}
|
|
|
|
// Helper class to print 8 region numbers per line and then print the total at the end.
|
|
class FillableRegionLogger : public StackObj {
|
|
private:
|
|
Log(gc, compaction) log;
|
|
static const int LineLength = 8;
|
|
size_t _regions[LineLength];
|
|
int _next_index;
|
|
bool _enabled;
|
|
size_t _total_regions;
|
|
public:
|
|
FillableRegionLogger() : _next_index(0), _enabled(log_develop_is_enabled(Trace, gc, compaction)), _total_regions(0) { }
|
|
~FillableRegionLogger() {
|
|
log.trace(SIZE_FORMAT " initially fillable regions", _total_regions);
|
|
}
|
|
|
|
void print_line() {
|
|
if (!_enabled || _next_index == 0) {
|
|
return;
|
|
}
|
|
FormatBuffer<> line("Fillable: ");
|
|
for (int i = 0; i < _next_index; i++) {
|
|
line.append(" " SIZE_FORMAT_W(7), _regions[i]);
|
|
}
|
|
log.trace("%s", line.buffer());
|
|
_next_index = 0;
|
|
}
|
|
|
|
void handle(size_t region) {
|
|
if (!_enabled) {
|
|
return;
|
|
}
|
|
_regions[_next_index++] = region;
|
|
if (_next_index == LineLength) {
|
|
print_line();
|
|
}
|
|
_total_regions++;
|
|
}
|
|
};
|
|
|
|
void PSParallelCompact::prepare_region_draining_tasks(uint parallel_gc_threads)
|
|
{
|
|
GCTraceTime(Trace, gc, phases) tm("Drain Task Setup", &_gc_timer);
|
|
|
|
// Find the threads that are active
|
|
uint worker_id = 0;
|
|
|
|
// 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();
|
|
|
|
// id + 1 is used to test termination so unsigned can
|
|
// be used with an old_space_id == 0.
|
|
FillableRegionLogger region_logger;
|
|
for (unsigned int id = to_space_id; id + 1 > old_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));
|
|
|
|
for (size_t cur = end_region - 1; cur + 1 > beg_region; --cur) {
|
|
if (sd.region(cur)->claim_unsafe()) {
|
|
ParCompactionManager* cm = ParCompactionManager::gc_thread_compaction_manager(worker_id);
|
|
bool result = sd.region(cur)->mark_normal();
|
|
assert(result, "Must succeed at this point.");
|
|
cm->region_stack()->push(cur);
|
|
region_logger.handle(cur);
|
|
// Assign regions to tasks in round-robin fashion.
|
|
if (++worker_id == parallel_gc_threads) {
|
|
worker_id = 0;
|
|
}
|
|
}
|
|
}
|
|
region_logger.print_line();
|
|
}
|
|
}
|
|
|
|
class TaskQueue : StackObj {
|
|
volatile uint _counter;
|
|
uint _size;
|
|
uint _insert_index;
|
|
PSParallelCompact::UpdateDensePrefixTask* _backing_array;
|
|
public:
|
|
explicit TaskQueue(uint size) : _counter(0), _size(size), _insert_index(0), _backing_array(NULL) {
|
|
_backing_array = NEW_C_HEAP_ARRAY(PSParallelCompact::UpdateDensePrefixTask, _size, mtGC);
|
|
}
|
|
~TaskQueue() {
|
|
assert(_counter >= _insert_index, "not all queue elements were claimed");
|
|
FREE_C_HEAP_ARRAY(T, _backing_array);
|
|
}
|
|
|
|
void push(const PSParallelCompact::UpdateDensePrefixTask& value) {
|
|
assert(_insert_index < _size, "too small backing array");
|
|
_backing_array[_insert_index++] = value;
|
|
}
|
|
|
|
bool try_claim(PSParallelCompact::UpdateDensePrefixTask& reference) {
|
|
uint claimed = Atomic::fetch_and_add(&_counter, 1u);
|
|
if (claimed < _insert_index) {
|
|
reference = _backing_array[claimed];
|
|
return true;
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
};
|
|
|
|
#define PAR_OLD_DENSE_PREFIX_OVER_PARTITIONING 4
|
|
|
|
void PSParallelCompact::enqueue_dense_prefix_tasks(TaskQueue& task_queue,
|
|
uint parallel_gc_threads) {
|
|
GCTraceTime(Trace, gc, phases) tm("Dense Prefix Task Setup", &_gc_timer);
|
|
|
|
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 (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);
|
|
task_queue.push(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) {
|
|
task_queue.push(UpdateDensePrefixTask(SpaceId(space_id),
|
|
region_index_start,
|
|
region_index_end_dense_prefix));
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef ASSERT
|
|
// Write a histogram of the number of times the block table was filled for a
|
|
// region.
|
|
void PSParallelCompact::write_block_fill_histogram()
|
|
{
|
|
if (!log_develop_is_enabled(Trace, gc, compaction)) {
|
|
return;
|
|
}
|
|
|
|
Log(gc, compaction) log;
|
|
ResourceMark rm;
|
|
LogStream ls(log.trace());
|
|
outputStream* out = &ls;
|
|
|
|
typedef ParallelCompactData::RegionData rd_t;
|
|
ParallelCompactData& sd = summary_data();
|
|
|
|
for (unsigned int id = old_space_id; id < last_space_id; ++id) {
|
|
MutableSpace* const spc = _space_info[id].space();
|
|
if (spc->bottom() != spc->top()) {
|
|
const rd_t* const beg = sd.addr_to_region_ptr(spc->bottom());
|
|
HeapWord* const top_aligned_up = sd.region_align_up(spc->top());
|
|
const rd_t* const end = sd.addr_to_region_ptr(top_aligned_up);
|
|
|
|
size_t histo[5] = { 0, 0, 0, 0, 0 };
|
|
const size_t histo_len = sizeof(histo) / sizeof(size_t);
|
|
const size_t region_cnt = pointer_delta(end, beg, sizeof(rd_t));
|
|
|
|
for (const rd_t* cur = beg; cur < end; ++cur) {
|
|
++histo[MIN2(cur->blocks_filled_count(), histo_len - 1)];
|
|
}
|
|
out->print("Block fill histogram: %u %-4s" SIZE_FORMAT_W(5), id, space_names[id], region_cnt);
|
|
for (size_t i = 0; i < histo_len; ++i) {
|
|
out->print(" " SIZE_FORMAT_W(5) " %5.1f%%",
|
|
histo[i], 100.0 * histo[i] / region_cnt);
|
|
}
|
|
out->cr();
|
|
}
|
|
}
|
|
}
|
|
#endif // #ifdef ASSERT
|
|
|
|
static void compaction_with_stealing_work(TaskTerminator* terminator, uint worker_id) {
|
|
assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");
|
|
|
|
ParCompactionManager* cm =
|
|
ParCompactionManager::gc_thread_compaction_manager(worker_id);
|
|
|
|
// Drain the stacks that have been preloaded with regions
|
|
// that are ready to fill.
|
|
|
|
cm->drain_region_stacks();
|
|
|
|
guarantee(cm->region_stack()->is_empty(), "Not empty");
|
|
|
|
size_t region_index = 0;
|
|
|
|
while (true) {
|
|
if (ParCompactionManager::steal(worker_id, region_index)) {
|
|
PSParallelCompact::fill_and_update_region(cm, region_index);
|
|
cm->drain_region_stacks();
|
|
} else if (PSParallelCompact::steal_unavailable_region(cm, region_index)) {
|
|
// Fill and update an unavailable region with the help of a shadow region
|
|
PSParallelCompact::fill_and_update_shadow_region(cm, region_index);
|
|
cm->drain_region_stacks();
|
|
} else {
|
|
if (terminator->offer_termination()) {
|
|
break;
|
|
}
|
|
// Go around again.
|
|
}
|
|
}
|
|
}
|
|
|
|
class UpdateDensePrefixAndCompactionTask: public AbstractGangTask {
|
|
typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask;
|
|
TaskQueue& _tq;
|
|
TaskTerminator _terminator;
|
|
uint _active_workers;
|
|
|
|
public:
|
|
UpdateDensePrefixAndCompactionTask(TaskQueue& tq, uint active_workers) :
|
|
AbstractGangTask("UpdateDensePrefixAndCompactionTask"),
|
|
_tq(tq),
|
|
_terminator(active_workers, ParCompactionManager::region_task_queues()),
|
|
_active_workers(active_workers) {
|
|
}
|
|
virtual void work(uint worker_id) {
|
|
ParCompactionManager* cm = ParCompactionManager::gc_thread_compaction_manager(worker_id);
|
|
|
|
for (PSParallelCompact::UpdateDensePrefixTask task; _tq.try_claim(task); /* empty */) {
|
|
PSParallelCompact::update_and_deadwood_in_dense_prefix(cm,
|
|
task._space_id,
|
|
task._region_index_start,
|
|
task._region_index_end);
|
|
}
|
|
|
|
// Once a thread has drained it's stack, it should try to steal regions from
|
|
// other threads.
|
|
compaction_with_stealing_work(&_terminator, worker_id);
|
|
}
|
|
};
|
|
|
|
void PSParallelCompact::compact() {
|
|
GCTraceTime(Info, gc, phases) tm("Compaction Phase", &_gc_timer);
|
|
|
|
ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
|
|
PSOldGen* old_gen = heap->old_gen();
|
|
old_gen->start_array()->reset();
|
|
uint active_gc_threads = ParallelScavengeHeap::heap()->workers().active_workers();
|
|
|
|
// for [0..last_space_id)
|
|
// for [0..active_gc_threads * PAR_OLD_DENSE_PREFIX_OVER_PARTITIONING)
|
|
// push
|
|
// push
|
|
//
|
|
// max push count is thus: last_space_id * (active_gc_threads * PAR_OLD_DENSE_PREFIX_OVER_PARTITIONING + 1)
|
|
TaskQueue task_queue(last_space_id * (active_gc_threads * PAR_OLD_DENSE_PREFIX_OVER_PARTITIONING + 1));
|
|
initialize_shadow_regions(active_gc_threads);
|
|
prepare_region_draining_tasks(active_gc_threads);
|
|
enqueue_dense_prefix_tasks(task_queue, active_gc_threads);
|
|
|
|
{
|
|
GCTraceTime(Trace, gc, phases) tm("Par Compact", &_gc_timer);
|
|
|
|
UpdateDensePrefixAndCompactionTask task(task_queue, active_gc_threads);
|
|
ParallelScavengeHeap::heap()->workers().run_task(&task);
|
|
|
|
#ifdef ASSERT
|
|
// Verify that all regions have been processed before the deferred updates.
|
|
for (unsigned int id = old_space_id; id < last_space_id; ++id) {
|
|
verify_complete(SpaceId(id));
|
|
}
|
|
#endif
|
|
}
|
|
|
|
{
|
|
GCTraceTime(Trace, gc, phases) tm("Deferred Updates", &_gc_timer);
|
|
// Update the deferred objects, if any. In principle, any compaction
|
|
// manager can be used. However, since the current thread is VM thread, we
|
|
// use the rightful one to keep the verification logic happy.
|
|
ParCompactionManager* cm = ParCompactionManager::get_vmthread_cm();
|
|
for (unsigned int id = old_space_id; id < last_space_id; ++id) {
|
|
update_deferred_objects(cm, SpaceId(id));
|
|
}
|
|
}
|
|
|
|
DEBUG_ONLY(write_block_fill_histogram());
|
|
}
|
|
|
|
#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()) {
|
|
log_warning(gc)("region " SIZE_FORMAT " not filled: destination_count=%u",
|
|
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()) {
|
|
log_warning(gc)("region " SIZE_FORMAT " not empty: destination_count=%u",
|
|
cur_region, c->destination_count());
|
|
issued_a_warning = true;
|
|
}
|
|
}
|
|
|
|
if (issued_a_warning) {
|
|
print_region_ranges();
|
|
}
|
|
}
|
|
#endif // #ifdef ASSERT
|
|
|
|
inline void UpdateOnlyClosure::do_addr(HeapWord* addr) {
|
|
_start_array->allocate_block(addr);
|
|
compaction_manager()->update_contents(cast_to_oop(addr));
|
|
}
|
|
|
|
// 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(ParallelScavengeHeap::heap()->is_in_reserved(addr), "addr not in the heap");
|
|
|
|
for (unsigned int id = old_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);
|
|
}
|
|
cm->update_contents(cast_to_oop(addr));
|
|
assert(oopDesc::is_oop_or_null(cast_to_oop(addr)), "Expected an oop or NULL at " PTR_FORMAT, p2i(cast_to_oop(addr)));
|
|
}
|
|
}
|
|
}
|
|
|
|
// 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 = m->align_range_end(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()) {
|
|
if (cur->mark_normal()) {
|
|
cm->push_region(sd.region(cur));
|
|
} else if (cur->mark_copied()) {
|
|
// Try to copy the content of the shadow region back to its corresponding
|
|
// heap region if the shadow region is filled. Otherwise, the GC thread
|
|
// fills the shadow region will copy the data back (see
|
|
// MoveAndUpdateShadowClosure::complete_region).
|
|
copy_back(sd.region_to_addr(cur->shadow_region()), sd.region_to_addr(cur));
|
|
ParCompactionManager::push_shadow_region_mt_safe(cur->shadow_region());
|
|
cur->set_completed();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
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, MoveAndUpdateClosure& closure, size_t region_idx)
|
|
{
|
|
typedef ParMarkBitMap::IterationStatus IterationStatus;
|
|
ParMarkBitMap* const bitmap = mark_bitmap();
|
|
ParallelCompactData& sd = summary_data();
|
|
RegionData* const region_ptr = sd.region(region_idx);
|
|
|
|
// 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();
|
|
HeapWord* dest_addr = sd.region_to_addr(region_idx);
|
|
|
|
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);
|
|
closure.complete_region(cm, dest_addr, region_ptr);
|
|
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());
|
|
closure.complete_region(cm, dest_addr, region_ptr);
|
|
return;
|
|
}
|
|
|
|
if (status == ParMarkBitMap::full) {
|
|
decrement_destination_counts(cm, src_space_id, src_region_idx,
|
|
closure.source());
|
|
region_ptr->set_deferred_obj_addr(NULL);
|
|
closure.complete_region(cm, dest_addr, region_ptr);
|
|
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::fill_and_update_region(ParCompactionManager* cm, size_t region_idx)
|
|
{
|
|
MoveAndUpdateClosure cl(mark_bitmap(), cm, region_idx);
|
|
fill_region(cm, cl, region_idx);
|
|
}
|
|
|
|
void PSParallelCompact::fill_and_update_shadow_region(ParCompactionManager* cm, size_t region_idx)
|
|
{
|
|
// Get a shadow region first
|
|
ParallelCompactData& sd = summary_data();
|
|
RegionData* const region_ptr = sd.region(region_idx);
|
|
size_t shadow_region = ParCompactionManager::pop_shadow_region_mt_safe(region_ptr);
|
|
// The InvalidShadow return value indicates the corresponding heap region is available,
|
|
// so use MoveAndUpdateClosure to fill the normal region. Otherwise, use
|
|
// MoveAndUpdateShadowClosure to fill the acquired shadow region.
|
|
if (shadow_region == ParCompactionManager::InvalidShadow) {
|
|
MoveAndUpdateClosure cl(mark_bitmap(), cm, region_idx);
|
|
region_ptr->shadow_to_normal();
|
|
return fill_region(cm, cl, region_idx);
|
|
} else {
|
|
MoveAndUpdateShadowClosure cl(mark_bitmap(), cm, region_idx, shadow_region);
|
|
return fill_region(cm, cl, region_idx);
|
|
}
|
|
}
|
|
|
|
void PSParallelCompact::copy_back(HeapWord *shadow_addr, HeapWord *region_addr)
|
|
{
|
|
Copy::aligned_conjoint_words(shadow_addr, region_addr, _summary_data.RegionSize);
|
|
}
|
|
|
|
bool PSParallelCompact::steal_unavailable_region(ParCompactionManager* cm, size_t ®ion_idx)
|
|
{
|
|
size_t next = cm->next_shadow_region();
|
|
ParallelCompactData& sd = summary_data();
|
|
size_t old_new_top = sd.addr_to_region_idx(_space_info[old_space_id].new_top());
|
|
uint active_gc_threads = ParallelScavengeHeap::heap()->workers().active_workers();
|
|
|
|
while (next < old_new_top) {
|
|
if (sd.region(next)->mark_shadow()) {
|
|
region_idx = next;
|
|
return true;
|
|
}
|
|
next = cm->move_next_shadow_region_by(active_gc_threads);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// The shadow region is an optimization to address region dependencies in full GC. The basic
|
|
// idea is making more regions available by temporally storing their live objects in empty
|
|
// shadow regions to resolve dependencies between them and the destination regions. Therefore,
|
|
// GC threads need not wait destination regions to be available before processing sources.
|
|
//
|
|
// A typical workflow would be:
|
|
// After draining its own stack and failing to steal from others, a GC worker would pick an
|
|
// unavailable region (destination count > 0) and get a shadow region. Then the worker fills
|
|
// the shadow region by copying live objects from source regions of the unavailable one. Once
|
|
// the unavailable region becomes available, the data in the shadow region will be copied back.
|
|
// Shadow regions are empty regions in the to-space and regions between top and end of other spaces.
|
|
//
|
|
// For more details, please refer to §4.2 of the VEE'19 paper:
|
|
// Haoyu Li, Mingyu Wu, Binyu Zang, and Haibo Chen. 2019. ScissorGC: scalable and efficient
|
|
// compaction for Java full garbage collection. In Proceedings of the 15th ACM SIGPLAN/SIGOPS
|
|
// International Conference on Virtual Execution Environments (VEE 2019). ACM, New York, NY, USA,
|
|
// 108-121. DOI: https://doi.org/10.1145/3313808.3313820
|
|
void PSParallelCompact::initialize_shadow_regions(uint parallel_gc_threads)
|
|
{
|
|
const ParallelCompactData& sd = PSParallelCompact::summary_data();
|
|
|
|
for (unsigned int id = old_space_id; id < last_space_id; ++id) {
|
|
SpaceInfo* const space_info = _space_info + id;
|
|
MutableSpace* const space = space_info->space();
|
|
|
|
const size_t beg_region =
|
|
sd.addr_to_region_idx(sd.region_align_up(MAX2(space_info->new_top(), space->top())));
|
|
const size_t end_region =
|
|
sd.addr_to_region_idx(sd.region_align_down(space->end()));
|
|
|
|
for (size_t cur = beg_region; cur < end_region; ++cur) {
|
|
ParCompactionManager::push_shadow_region(cur);
|
|
}
|
|
}
|
|
|
|
size_t beg_region = sd.addr_to_region_idx(_space_info[old_space_id].dense_prefix());
|
|
for (uint i = 0; i < parallel_gc_threads; i++) {
|
|
ParCompactionManager *cm = ParCompactionManager::gc_thread_compaction_manager(i);
|
|
cm->set_next_shadow_region(beg_region + i);
|
|
}
|
|
}
|
|
|
|
void PSParallelCompact::fill_blocks(size_t region_idx)
|
|
{
|
|
// Fill in the block table elements for the specified region. Each block
|
|
// table element holds the number of live words in the region that are to the
|
|
// left of the first object that starts in the block. Thus only blocks in
|
|
// which an object starts need to be filled.
|
|
//
|
|
// The algorithm scans the section of the bitmap that corresponds to the
|
|
// region, keeping a running total of the live words. When an object start is
|
|
// found, if it's the first to start in the block that contains it, the
|
|
// current total is written to the block table element.
|
|
const size_t Log2BlockSize = ParallelCompactData::Log2BlockSize;
|
|
const size_t Log2RegionSize = ParallelCompactData::Log2RegionSize;
|
|
const size_t RegionSize = ParallelCompactData::RegionSize;
|
|
|
|
ParallelCompactData& sd = summary_data();
|
|
const size_t partial_obj_size = sd.region(region_idx)->partial_obj_size();
|
|
if (partial_obj_size >= RegionSize) {
|
|
return; // No objects start in this region.
|
|
}
|
|
|
|
// Ensure the first loop iteration decides that the block has changed.
|
|
size_t cur_block = sd.block_count();
|
|
|
|
const ParMarkBitMap* const bitmap = mark_bitmap();
|
|
|
|
const size_t Log2BitsPerBlock = Log2BlockSize - LogMinObjAlignment;
|
|
assert((size_t)1 << Log2BitsPerBlock ==
|
|
bitmap->words_to_bits(ParallelCompactData::BlockSize), "sanity");
|
|
|
|
size_t beg_bit = bitmap->words_to_bits(region_idx << Log2RegionSize);
|
|
const size_t range_end = beg_bit + bitmap->words_to_bits(RegionSize);
|
|
size_t live_bits = bitmap->words_to_bits(partial_obj_size);
|
|
beg_bit = bitmap->find_obj_beg(beg_bit + live_bits, range_end);
|
|
while (beg_bit < range_end) {
|
|
const size_t new_block = beg_bit >> Log2BitsPerBlock;
|
|
if (new_block != cur_block) {
|
|
cur_block = new_block;
|
|
sd.block(cur_block)->set_offset(bitmap->bits_to_words(live_bits));
|
|
}
|
|
|
|
const size_t end_bit = bitmap->find_obj_end(beg_bit, range_end);
|
|
if (end_bit < range_end - 1) {
|
|
live_bits += end_bit - beg_bit + 1;
|
|
beg_bit = bitmap->find_obj_beg(end_bit + 1, range_end);
|
|
} else {
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
ParMarkBitMap::IterationStatus MoveAndUpdateClosure::copy_until_full()
|
|
{
|
|
if (source() != copy_destination()) {
|
|
DEBUG_ONLY(PSParallelCompact::check_new_location(source(), destination());)
|
|
Copy::aligned_conjoint_words(source(), copy_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() != copy_destination()) {
|
|
DEBUG_ONLY(PSParallelCompact::check_new_location(source(), destination());)
|
|
Copy::aligned_conjoint_words(source(), copy_destination(), words);
|
|
}
|
|
update_state(words);
|
|
}
|
|
|
|
void MoveAndUpdateClosure::complete_region(ParCompactionManager *cm, HeapWord *dest_addr,
|
|
PSParallelCompact::RegionData *region_ptr) {
|
|
assert(region_ptr->shadow_state() == ParallelCompactData::RegionData::NormalRegion, "Region should be finished");
|
|
region_ptr->set_completed();
|
|
}
|
|
|
|
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(), compaction_manager()) ==
|
|
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 (copy_destination() != source()) {
|
|
DEBUG_ONLY(PSParallelCompact::check_new_location(source(), destination());)
|
|
Copy::aligned_conjoint_words(source(), copy_destination(), words);
|
|
}
|
|
|
|
oop moved_oop = cast_to_oop(copy_destination());
|
|
compaction_manager()->update_contents(moved_oop);
|
|
assert(oopDesc::is_oop_or_null(moved_oop), "Expected an oop or NULL at " PTR_FORMAT, p2i(moved_oop));
|
|
|
|
update_state(words);
|
|
assert(copy_destination() == cast_from_oop<HeapWord*>(moved_oop) + moved_oop->size(), "sanity");
|
|
return is_full() ? ParMarkBitMap::full : ParMarkBitMap::incomplete;
|
|
}
|
|
|
|
void MoveAndUpdateShadowClosure::complete_region(ParCompactionManager *cm, HeapWord *dest_addr,
|
|
PSParallelCompact::RegionData *region_ptr) {
|
|
assert(region_ptr->shadow_state() == ParallelCompactData::RegionData::ShadowRegion, "Region should be shadow");
|
|
// Record the shadow region index
|
|
region_ptr->set_shadow_region(_shadow);
|
|
// Mark the shadow region as filled to indicate the data is ready to be
|
|
// copied back
|
|
region_ptr->mark_filled();
|
|
// Try to copy the content of the shadow region back to its corresponding
|
|
// heap region if available; the GC thread that decreases the destination
|
|
// count to zero will do the copying otherwise (see
|
|
// PSParallelCompact::decrement_destination_counts).
|
|
if (((region_ptr->available() && region_ptr->claim()) || region_ptr->claimed()) && region_ptr->mark_copied()) {
|
|
region_ptr->set_completed();
|
|
PSParallelCompact::copy_back(PSParallelCompact::summary_data().region_to_addr(_shadow), dest_addr);
|
|
ParCompactionManager::push_shadow_region_mt_safe(_shadow);
|
|
}
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
FillClosure::FillClosure(ParCompactionManager* cm, PSParallelCompact::SpaceId space_id) :
|
|
ParMarkBitMapClosure(PSParallelCompact::mark_bitmap(), cm),
|
|
_start_array(PSParallelCompact::start_array(space_id))
|
|
{
|
|
assert(space_id == PSParallelCompact::old_space_id,
|
|
"cannot use FillClosure in the young gen");
|
|
}
|
|
|
|
ParMarkBitMapClosure::IterationStatus
|
|
FillClosure::do_addr(HeapWord* addr, size_t size) {
|
|
CollectedHeap::fill_with_objects(addr, size);
|
|
HeapWord* const end = addr + size;
|
|
do {
|
|
_start_array->allocate_block(addr);
|
|
addr += cast_to_oop(addr)->size();
|
|
} while (addr < end);
|
|
return ParMarkBitMap::incomplete;
|
|
}
|