7fb60025ee
Reviewed-by: johnc, ysr
955 lines
36 KiB
C++
955 lines
36 KiB
C++
/*
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* Copyright (c) 2001, 2012, 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 "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
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#include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp"
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#include "gc_implementation/parallelScavenge/psScavenge.hpp"
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#include "gc_implementation/parallelScavenge/psYoungGen.hpp"
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#include "gc_implementation/shared/gcUtil.hpp"
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#include "gc_implementation/shared/mutableNUMASpace.hpp"
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#include "gc_implementation/shared/spaceDecorator.hpp"
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#include "oops/oop.inline.hpp"
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#include "runtime/java.hpp"
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PSYoungGen::PSYoungGen(size_t initial_size,
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size_t min_size,
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size_t max_size) :
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_init_gen_size(initial_size),
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_min_gen_size(min_size),
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_max_gen_size(max_size)
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{}
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void PSYoungGen::initialize_virtual_space(ReservedSpace rs, size_t alignment) {
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assert(_init_gen_size != 0, "Should have a finite size");
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_virtual_space = new PSVirtualSpace(rs, alignment);
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if (!virtual_space()->expand_by(_init_gen_size)) {
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vm_exit_during_initialization("Could not reserve enough space for "
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"object heap");
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}
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}
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void PSYoungGen::initialize(ReservedSpace rs, size_t alignment) {
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initialize_virtual_space(rs, alignment);
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initialize_work();
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}
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void PSYoungGen::initialize_work() {
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_reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
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(HeapWord*)virtual_space()->high_boundary());
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MemRegion cmr((HeapWord*)virtual_space()->low(),
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(HeapWord*)virtual_space()->high());
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Universe::heap()->barrier_set()->resize_covered_region(cmr);
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if (ZapUnusedHeapArea) {
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// Mangle newly committed space immediately because it
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// can be done here more simply that after the new
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// spaces have been computed.
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SpaceMangler::mangle_region(cmr);
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}
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if (UseNUMA) {
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_eden_space = new MutableNUMASpace(virtual_space()->alignment());
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} else {
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_eden_space = new MutableSpace(virtual_space()->alignment());
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}
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_from_space = new MutableSpace(virtual_space()->alignment());
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_to_space = new MutableSpace(virtual_space()->alignment());
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if (_eden_space == NULL || _from_space == NULL || _to_space == NULL) {
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vm_exit_during_initialization("Could not allocate a young gen space");
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}
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// Allocate the mark sweep views of spaces
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_eden_mark_sweep =
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new PSMarkSweepDecorator(_eden_space, NULL, MarkSweepDeadRatio);
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_from_mark_sweep =
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new PSMarkSweepDecorator(_from_space, NULL, MarkSweepDeadRatio);
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_to_mark_sweep =
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new PSMarkSweepDecorator(_to_space, NULL, MarkSweepDeadRatio);
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if (_eden_mark_sweep == NULL ||
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_from_mark_sweep == NULL ||
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_to_mark_sweep == NULL) {
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vm_exit_during_initialization("Could not complete allocation"
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" of the young generation");
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}
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// Generation Counters - generation 0, 3 subspaces
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_gen_counters = new PSGenerationCounters("new", 0, 3, _virtual_space);
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// Compute maximum space sizes for performance counters
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ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
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size_t alignment = heap->intra_heap_alignment();
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size_t size = virtual_space()->reserved_size();
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size_t max_survivor_size;
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size_t max_eden_size;
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if (UseAdaptiveSizePolicy) {
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max_survivor_size = size / MinSurvivorRatio;
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// round the survivor space size down to the nearest alignment
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// and make sure its size is greater than 0.
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max_survivor_size = align_size_down(max_survivor_size, alignment);
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max_survivor_size = MAX2(max_survivor_size, alignment);
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// set the maximum size of eden to be the size of the young gen
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// less two times the minimum survivor size. The minimum survivor
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// size for UseAdaptiveSizePolicy is one alignment.
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max_eden_size = size - 2 * alignment;
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} else {
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max_survivor_size = size / InitialSurvivorRatio;
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// round the survivor space size down to the nearest alignment
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// and make sure its size is greater than 0.
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max_survivor_size = align_size_down(max_survivor_size, alignment);
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max_survivor_size = MAX2(max_survivor_size, alignment);
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// set the maximum size of eden to be the size of the young gen
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// less two times the survivor size when the generation is 100%
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// committed. The minimum survivor size for -UseAdaptiveSizePolicy
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// is dependent on the committed portion (current capacity) of the
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// generation - the less space committed, the smaller the survivor
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// space, possibly as small as an alignment. However, we are interested
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// in the case where the young generation is 100% committed, as this
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// is the point where eden reachs its maximum size. At this point,
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// the size of a survivor space is max_survivor_size.
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max_eden_size = size - 2 * max_survivor_size;
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}
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_eden_counters = new SpaceCounters("eden", 0, max_eden_size, _eden_space,
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_gen_counters);
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_from_counters = new SpaceCounters("s0", 1, max_survivor_size, _from_space,
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_gen_counters);
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_to_counters = new SpaceCounters("s1", 2, max_survivor_size, _to_space,
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_gen_counters);
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compute_initial_space_boundaries();
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}
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void PSYoungGen::compute_initial_space_boundaries() {
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ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
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assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
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// Compute sizes
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size_t alignment = heap->intra_heap_alignment();
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size_t size = virtual_space()->committed_size();
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size_t survivor_size = size / InitialSurvivorRatio;
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survivor_size = align_size_down(survivor_size, alignment);
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// ... but never less than an alignment
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survivor_size = MAX2(survivor_size, alignment);
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// Young generation is eden + 2 survivor spaces
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size_t eden_size = size - (2 * survivor_size);
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// Now go ahead and set 'em.
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set_space_boundaries(eden_size, survivor_size);
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space_invariants();
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if (UsePerfData) {
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_eden_counters->update_capacity();
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_from_counters->update_capacity();
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_to_counters->update_capacity();
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}
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}
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void PSYoungGen::set_space_boundaries(size_t eden_size, size_t survivor_size) {
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assert(eden_size < virtual_space()->committed_size(), "just checking");
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assert(eden_size > 0 && survivor_size > 0, "just checking");
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// Initial layout is Eden, to, from. After swapping survivor spaces,
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// that leaves us with Eden, from, to, which is step one in our two
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// step resize-with-live-data procedure.
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char *eden_start = virtual_space()->low();
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char *to_start = eden_start + eden_size;
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char *from_start = to_start + survivor_size;
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char *from_end = from_start + survivor_size;
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assert(from_end == virtual_space()->high(), "just checking");
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assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
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assert(is_object_aligned((intptr_t)to_start), "checking alignment");
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assert(is_object_aligned((intptr_t)from_start), "checking alignment");
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MemRegion eden_mr((HeapWord*)eden_start, (HeapWord*)to_start);
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MemRegion to_mr ((HeapWord*)to_start, (HeapWord*)from_start);
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MemRegion from_mr((HeapWord*)from_start, (HeapWord*)from_end);
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eden_space()->initialize(eden_mr, true, ZapUnusedHeapArea);
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to_space()->initialize(to_mr , true, ZapUnusedHeapArea);
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from_space()->initialize(from_mr, true, ZapUnusedHeapArea);
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}
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#ifndef PRODUCT
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void PSYoungGen::space_invariants() {
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ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
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const size_t alignment = heap->intra_heap_alignment();
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// Currently, our eden size cannot shrink to zero
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guarantee(eden_space()->capacity_in_bytes() >= alignment, "eden too small");
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guarantee(from_space()->capacity_in_bytes() >= alignment, "from too small");
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guarantee(to_space()->capacity_in_bytes() >= alignment, "to too small");
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// Relationship of spaces to each other
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char* eden_start = (char*)eden_space()->bottom();
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char* eden_end = (char*)eden_space()->end();
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char* from_start = (char*)from_space()->bottom();
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char* from_end = (char*)from_space()->end();
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char* to_start = (char*)to_space()->bottom();
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char* to_end = (char*)to_space()->end();
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guarantee(eden_start >= virtual_space()->low(), "eden bottom");
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guarantee(eden_start < eden_end, "eden space consistency");
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guarantee(from_start < from_end, "from space consistency");
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guarantee(to_start < to_end, "to space consistency");
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// Check whether from space is below to space
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if (from_start < to_start) {
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// Eden, from, to
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guarantee(eden_end <= from_start, "eden/from boundary");
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guarantee(from_end <= to_start, "from/to boundary");
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guarantee(to_end <= virtual_space()->high(), "to end");
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} else {
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// Eden, to, from
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guarantee(eden_end <= to_start, "eden/to boundary");
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guarantee(to_end <= from_start, "to/from boundary");
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guarantee(from_end <= virtual_space()->high(), "from end");
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}
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// More checks that the virtual space is consistent with the spaces
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assert(virtual_space()->committed_size() >=
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(eden_space()->capacity_in_bytes() +
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to_space()->capacity_in_bytes() +
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from_space()->capacity_in_bytes()), "Committed size is inconsistent");
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assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
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"Space invariant");
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char* eden_top = (char*)eden_space()->top();
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char* from_top = (char*)from_space()->top();
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char* to_top = (char*)to_space()->top();
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assert(eden_top <= virtual_space()->high(), "eden top");
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assert(from_top <= virtual_space()->high(), "from top");
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assert(to_top <= virtual_space()->high(), "to top");
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virtual_space()->verify();
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}
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#endif
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void PSYoungGen::resize(size_t eden_size, size_t survivor_size) {
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// Resize the generation if needed. If the generation resize
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// reports false, do not attempt to resize the spaces.
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if (resize_generation(eden_size, survivor_size)) {
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// Then we lay out the spaces inside the generation
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resize_spaces(eden_size, survivor_size);
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space_invariants();
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if (PrintAdaptiveSizePolicy && Verbose) {
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gclog_or_tty->print_cr("Young generation size: "
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"desired eden: " SIZE_FORMAT " survivor: " SIZE_FORMAT
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" used: " SIZE_FORMAT " capacity: " SIZE_FORMAT
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" gen limits: " SIZE_FORMAT " / " SIZE_FORMAT,
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eden_size, survivor_size, used_in_bytes(), capacity_in_bytes(),
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_max_gen_size, min_gen_size());
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}
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}
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}
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bool PSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) {
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const size_t alignment = virtual_space()->alignment();
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size_t orig_size = virtual_space()->committed_size();
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bool size_changed = false;
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// There used to be this guarantee there.
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// guarantee ((eden_size + 2*survivor_size) <= _max_gen_size, "incorrect input arguments");
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// Code below forces this requirement. In addition the desired eden
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// size and disired survivor sizes are desired goals and may
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// exceed the total generation size.
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assert(min_gen_size() <= orig_size && orig_size <= max_size(), "just checking");
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// Adjust new generation size
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const size_t eden_plus_survivors =
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align_size_up(eden_size + 2 * survivor_size, alignment);
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size_t desired_size = MAX2(MIN2(eden_plus_survivors, max_size()),
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min_gen_size());
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assert(desired_size <= max_size(), "just checking");
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if (desired_size > orig_size) {
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// Grow the generation
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size_t change = desired_size - orig_size;
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assert(change % alignment == 0, "just checking");
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HeapWord* prev_high = (HeapWord*) virtual_space()->high();
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if (!virtual_space()->expand_by(change)) {
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return false; // Error if we fail to resize!
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}
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if (ZapUnusedHeapArea) {
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// Mangle newly committed space immediately because it
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// can be done here more simply that after the new
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// spaces have been computed.
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HeapWord* new_high = (HeapWord*) virtual_space()->high();
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MemRegion mangle_region(prev_high, new_high);
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SpaceMangler::mangle_region(mangle_region);
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}
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size_changed = true;
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} else if (desired_size < orig_size) {
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size_t desired_change = orig_size - desired_size;
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assert(desired_change % alignment == 0, "just checking");
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desired_change = limit_gen_shrink(desired_change);
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if (desired_change > 0) {
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virtual_space()->shrink_by(desired_change);
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reset_survivors_after_shrink();
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size_changed = true;
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}
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} else {
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if (Verbose && PrintGC) {
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if (orig_size == gen_size_limit()) {
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gclog_or_tty->print_cr("PSYoung generation size at maximum: "
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SIZE_FORMAT "K", orig_size/K);
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} else if (orig_size == min_gen_size()) {
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gclog_or_tty->print_cr("PSYoung generation size at minium: "
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SIZE_FORMAT "K", orig_size/K);
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}
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}
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}
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if (size_changed) {
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post_resize();
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if (Verbose && PrintGC) {
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size_t current_size = virtual_space()->committed_size();
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gclog_or_tty->print_cr("PSYoung generation size changed: "
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SIZE_FORMAT "K->" SIZE_FORMAT "K",
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orig_size/K, current_size/K);
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}
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}
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guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
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virtual_space()->committed_size() == max_size(), "Sanity");
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return true;
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}
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#ifndef PRODUCT
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// In the numa case eden is not mangled so a survivor space
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// moving into a region previously occupied by a survivor
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// may find an unmangled region. Also in the PS case eden
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// to-space and from-space may not touch (i.e., there may be
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// gaps between them due to movement while resizing the
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// spaces). Those gaps must be mangled.
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void PSYoungGen::mangle_survivors(MutableSpace* s1,
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MemRegion s1MR,
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MutableSpace* s2,
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MemRegion s2MR) {
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// Check eden and gap between eden and from-space, in deciding
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// what to mangle in from-space. Check the gap between from-space
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// and to-space when deciding what to mangle.
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//
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// +--------+ +----+ +---+
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// | eden | |s1 | |s2 |
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// +--------+ +----+ +---+
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// +-------+ +-----+
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// |s1MR | |s2MR |
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// +-------+ +-----+
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// All of survivor-space is properly mangled so find the
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// upper bound on the mangling for any portion above current s1.
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HeapWord* delta_end = MIN2(s1->bottom(), s1MR.end());
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MemRegion delta1_left;
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if (s1MR.start() < delta_end) {
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delta1_left = MemRegion(s1MR.start(), delta_end);
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s1->mangle_region(delta1_left);
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}
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// Find any portion to the right of the current s1.
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HeapWord* delta_start = MAX2(s1->end(), s1MR.start());
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MemRegion delta1_right;
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if (delta_start < s1MR.end()) {
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delta1_right = MemRegion(delta_start, s1MR.end());
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s1->mangle_region(delta1_right);
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}
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// Similarly for the second survivor space except that
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// any of the new region that overlaps with the current
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// region of the first survivor space has already been
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// mangled.
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delta_end = MIN2(s2->bottom(), s2MR.end());
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delta_start = MAX2(s2MR.start(), s1->end());
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MemRegion delta2_left;
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if (s2MR.start() < delta_end) {
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delta2_left = MemRegion(s2MR.start(), delta_end);
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s2->mangle_region(delta2_left);
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}
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delta_start = MAX2(s2->end(), s2MR.start());
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MemRegion delta2_right;
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if (delta_start < s2MR.end()) {
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s2->mangle_region(delta2_right);
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}
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if (TraceZapUnusedHeapArea) {
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// s1
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gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") "
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"New region: [" PTR_FORMAT ", " PTR_FORMAT ")",
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s1->bottom(), s1->end(), s1MR.start(), s1MR.end());
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gclog_or_tty->print_cr(" Mangle before: [" PTR_FORMAT ", "
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PTR_FORMAT ") Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")",
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delta1_left.start(), delta1_left.end(), delta1_right.start(),
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delta1_right.end());
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// s2
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gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") "
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"New region: [" PTR_FORMAT ", " PTR_FORMAT ")",
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s2->bottom(), s2->end(), s2MR.start(), s2MR.end());
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gclog_or_tty->print_cr(" Mangle before: [" PTR_FORMAT ", "
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PTR_FORMAT ") Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")",
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delta2_left.start(), delta2_left.end(), delta2_right.start(),
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delta2_right.end());
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}
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}
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#endif // NOT PRODUCT
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void PSYoungGen::resize_spaces(size_t requested_eden_size,
|
|
size_t requested_survivor_size) {
|
|
assert(UseAdaptiveSizePolicy, "sanity check");
|
|
assert(requested_eden_size > 0 && requested_survivor_size > 0,
|
|
"just checking");
|
|
|
|
// We require eden and to space to be empty
|
|
if ((!eden_space()->is_empty()) || (!to_space()->is_empty())) {
|
|
return;
|
|
}
|
|
|
|
if (PrintAdaptiveSizePolicy && Verbose) {
|
|
gclog_or_tty->print_cr("PSYoungGen::resize_spaces(requested_eden_size: "
|
|
SIZE_FORMAT
|
|
", requested_survivor_size: " SIZE_FORMAT ")",
|
|
requested_eden_size, requested_survivor_size);
|
|
gclog_or_tty->print_cr(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") "
|
|
SIZE_FORMAT,
|
|
eden_space()->bottom(),
|
|
eden_space()->end(),
|
|
pointer_delta(eden_space()->end(),
|
|
eden_space()->bottom(),
|
|
sizeof(char)));
|
|
gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") "
|
|
SIZE_FORMAT,
|
|
from_space()->bottom(),
|
|
from_space()->end(),
|
|
pointer_delta(from_space()->end(),
|
|
from_space()->bottom(),
|
|
sizeof(char)));
|
|
gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") "
|
|
SIZE_FORMAT,
|
|
to_space()->bottom(),
|
|
to_space()->end(),
|
|
pointer_delta( to_space()->end(),
|
|
to_space()->bottom(),
|
|
sizeof(char)));
|
|
}
|
|
|
|
// There's nothing to do if the new sizes are the same as the current
|
|
if (requested_survivor_size == to_space()->capacity_in_bytes() &&
|
|
requested_survivor_size == from_space()->capacity_in_bytes() &&
|
|
requested_eden_size == eden_space()->capacity_in_bytes()) {
|
|
if (PrintAdaptiveSizePolicy && Verbose) {
|
|
gclog_or_tty->print_cr(" capacities are the right sizes, returning");
|
|
}
|
|
return;
|
|
}
|
|
|
|
char* eden_start = (char*)eden_space()->bottom();
|
|
char* eden_end = (char*)eden_space()->end();
|
|
char* from_start = (char*)from_space()->bottom();
|
|
char* from_end = (char*)from_space()->end();
|
|
char* to_start = (char*)to_space()->bottom();
|
|
char* to_end = (char*)to_space()->end();
|
|
|
|
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
const size_t alignment = heap->intra_heap_alignment();
|
|
const bool maintain_minimum =
|
|
(requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
|
|
|
|
bool eden_from_to_order = from_start < to_start;
|
|
// Check whether from space is below to space
|
|
if (eden_from_to_order) {
|
|
// Eden, from, to
|
|
eden_from_to_order = true;
|
|
if (PrintAdaptiveSizePolicy && Verbose) {
|
|
gclog_or_tty->print_cr(" Eden, from, to:");
|
|
}
|
|
|
|
// Set eden
|
|
// "requested_eden_size" is a goal for the size of eden
|
|
// and may not be attainable. "eden_size" below is
|
|
// calculated based on the location of from-space and
|
|
// the goal for the size of eden. from-space is
|
|
// fixed in place because it contains live data.
|
|
// The calculation is done this way to avoid 32bit
|
|
// overflow (i.e., eden_start + requested_eden_size
|
|
// may too large for representation in 32bits).
|
|
size_t eden_size;
|
|
if (maintain_minimum) {
|
|
// Only make eden larger than the requested size if
|
|
// the minimum size of the generation has to be maintained.
|
|
// This could be done in general but policy at a higher
|
|
// level is determining a requested size for eden and that
|
|
// should be honored unless there is a fundamental reason.
|
|
eden_size = pointer_delta(from_start,
|
|
eden_start,
|
|
sizeof(char));
|
|
} else {
|
|
eden_size = MIN2(requested_eden_size,
|
|
pointer_delta(from_start, eden_start, sizeof(char)));
|
|
}
|
|
|
|
eden_end = eden_start + eden_size;
|
|
assert(eden_end >= eden_start, "addition overflowed");
|
|
|
|
// To may resize into from space as long as it is clear of live data.
|
|
// From space must remain page aligned, though, so we need to do some
|
|
// extra calculations.
|
|
|
|
// First calculate an optimal to-space
|
|
to_end = (char*)virtual_space()->high();
|
|
to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
|
|
sizeof(char));
|
|
|
|
// Does the optimal to-space overlap from-space?
|
|
if (to_start < (char*)from_space()->end()) {
|
|
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
|
|
|
|
// Calculate the minimum offset possible for from_end
|
|
size_t from_size = pointer_delta(from_space()->top(), from_start, sizeof(char));
|
|
|
|
// Should we be in this method if from_space is empty? Why not the set_space method? FIX ME!
|
|
if (from_size == 0) {
|
|
from_size = alignment;
|
|
} else {
|
|
from_size = align_size_up(from_size, alignment);
|
|
}
|
|
|
|
from_end = from_start + from_size;
|
|
assert(from_end > from_start, "addition overflow or from_size problem");
|
|
|
|
guarantee(from_end <= (char*)from_space()->end(), "from_end moved to the right");
|
|
|
|
// Now update to_start with the new from_end
|
|
to_start = MAX2(from_end, to_start);
|
|
}
|
|
|
|
guarantee(to_start != to_end, "to space is zero sized");
|
|
|
|
if (PrintAdaptiveSizePolicy && Verbose) {
|
|
gclog_or_tty->print_cr(" [eden_start .. eden_end): "
|
|
"[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
|
|
eden_start,
|
|
eden_end,
|
|
pointer_delta(eden_end, eden_start, sizeof(char)));
|
|
gclog_or_tty->print_cr(" [from_start .. from_end): "
|
|
"[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
|
|
from_start,
|
|
from_end,
|
|
pointer_delta(from_end, from_start, sizeof(char)));
|
|
gclog_or_tty->print_cr(" [ to_start .. to_end): "
|
|
"[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
|
|
to_start,
|
|
to_end,
|
|
pointer_delta( to_end, to_start, sizeof(char)));
|
|
}
|
|
} else {
|
|
// Eden, to, from
|
|
if (PrintAdaptiveSizePolicy && Verbose) {
|
|
gclog_or_tty->print_cr(" Eden, to, from:");
|
|
}
|
|
|
|
// To space gets priority over eden resizing. Note that we position
|
|
// to space as if we were able to resize from space, even though from
|
|
// space is not modified.
|
|
// Giving eden priority was tried and gave poorer performance.
|
|
to_end = (char*)pointer_delta(virtual_space()->high(),
|
|
(char*)requested_survivor_size,
|
|
sizeof(char));
|
|
to_end = MIN2(to_end, from_start);
|
|
to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
|
|
sizeof(char));
|
|
// if the space sizes are to be increased by several times then
|
|
// 'to_start' will point beyond the young generation. In this case
|
|
// 'to_start' should be adjusted.
|
|
to_start = MAX2(to_start, eden_start + alignment);
|
|
|
|
// Compute how big eden can be, then adjust end.
|
|
// See comments above on calculating eden_end.
|
|
size_t eden_size;
|
|
if (maintain_minimum) {
|
|
eden_size = pointer_delta(to_start, eden_start, sizeof(char));
|
|
} else {
|
|
eden_size = MIN2(requested_eden_size,
|
|
pointer_delta(to_start, eden_start, sizeof(char)));
|
|
}
|
|
eden_end = eden_start + eden_size;
|
|
assert(eden_end >= eden_start, "addition overflowed");
|
|
|
|
// Could choose to not let eden shrink
|
|
// to_start = MAX2(to_start, eden_end);
|
|
|
|
// Don't let eden shrink down to 0 or less.
|
|
eden_end = MAX2(eden_end, eden_start + alignment);
|
|
to_start = MAX2(to_start, eden_end);
|
|
|
|
if (PrintAdaptiveSizePolicy && Verbose) {
|
|
gclog_or_tty->print_cr(" [eden_start .. eden_end): "
|
|
"[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
|
|
eden_start,
|
|
eden_end,
|
|
pointer_delta(eden_end, eden_start, sizeof(char)));
|
|
gclog_or_tty->print_cr(" [ to_start .. to_end): "
|
|
"[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
|
|
to_start,
|
|
to_end,
|
|
pointer_delta( to_end, to_start, sizeof(char)));
|
|
gclog_or_tty->print_cr(" [from_start .. from_end): "
|
|
"[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
|
|
from_start,
|
|
from_end,
|
|
pointer_delta(from_end, from_start, sizeof(char)));
|
|
}
|
|
}
|
|
|
|
|
|
guarantee((HeapWord*)from_start <= from_space()->bottom(),
|
|
"from start moved to the right");
|
|
guarantee((HeapWord*)from_end >= from_space()->top(),
|
|
"from end moved into live data");
|
|
assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
|
|
assert(is_object_aligned((intptr_t)from_start), "checking alignment");
|
|
assert(is_object_aligned((intptr_t)to_start), "checking alignment");
|
|
|
|
MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end);
|
|
MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end);
|
|
MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end);
|
|
|
|
// Let's make sure the call to initialize doesn't reset "top"!
|
|
HeapWord* old_from_top = from_space()->top();
|
|
|
|
// For PrintAdaptiveSizePolicy block below
|
|
size_t old_from = from_space()->capacity_in_bytes();
|
|
size_t old_to = to_space()->capacity_in_bytes();
|
|
|
|
if (ZapUnusedHeapArea) {
|
|
// NUMA is a special case because a numa space is not mangled
|
|
// in order to not prematurely bind its address to memory to
|
|
// the wrong memory (i.e., don't want the GC thread to first
|
|
// touch the memory). The survivor spaces are not numa
|
|
// spaces and are mangled.
|
|
if (UseNUMA) {
|
|
if (eden_from_to_order) {
|
|
mangle_survivors(from_space(), fromMR, to_space(), toMR);
|
|
} else {
|
|
mangle_survivors(to_space(), toMR, from_space(), fromMR);
|
|
}
|
|
}
|
|
|
|
// If not mangling the spaces, do some checking to verify that
|
|
// the spaces are already mangled.
|
|
// The spaces should be correctly mangled at this point so
|
|
// do some checking here. Note that they are not being mangled
|
|
// in the calls to initialize().
|
|
// Must check mangling before the spaces are reshaped. Otherwise,
|
|
// the bottom or end of one space may have moved into an area
|
|
// covered by another space and a failure of the check may
|
|
// not correctly indicate which space is not properly mangled.
|
|
HeapWord* limit = (HeapWord*) virtual_space()->high();
|
|
eden_space()->check_mangled_unused_area(limit);
|
|
from_space()->check_mangled_unused_area(limit);
|
|
to_space()->check_mangled_unused_area(limit);
|
|
}
|
|
// When an existing space is being initialized, it is not
|
|
// mangled because the space has been previously mangled.
|
|
eden_space()->initialize(edenMR,
|
|
SpaceDecorator::Clear,
|
|
SpaceDecorator::DontMangle);
|
|
to_space()->initialize(toMR,
|
|
SpaceDecorator::Clear,
|
|
SpaceDecorator::DontMangle);
|
|
from_space()->initialize(fromMR,
|
|
SpaceDecorator::DontClear,
|
|
SpaceDecorator::DontMangle);
|
|
|
|
assert(from_space()->top() == old_from_top, "from top changed!");
|
|
|
|
if (PrintAdaptiveSizePolicy) {
|
|
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
|
|
|
|
gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: "
|
|
"collection: %d "
|
|
"(" SIZE_FORMAT ", " SIZE_FORMAT ") -> "
|
|
"(" SIZE_FORMAT ", " SIZE_FORMAT ") ",
|
|
heap->total_collections(),
|
|
old_from, old_to,
|
|
from_space()->capacity_in_bytes(),
|
|
to_space()->capacity_in_bytes());
|
|
gclog_or_tty->cr();
|
|
}
|
|
}
|
|
|
|
void PSYoungGen::swap_spaces() {
|
|
MutableSpace* s = from_space();
|
|
_from_space = to_space();
|
|
_to_space = s;
|
|
|
|
// Now update the decorators.
|
|
PSMarkSweepDecorator* md = from_mark_sweep();
|
|
_from_mark_sweep = to_mark_sweep();
|
|
_to_mark_sweep = md;
|
|
|
|
assert(from_mark_sweep()->space() == from_space(), "Sanity");
|
|
assert(to_mark_sweep()->space() == to_space(), "Sanity");
|
|
}
|
|
|
|
size_t PSYoungGen::capacity_in_bytes() const {
|
|
return eden_space()->capacity_in_bytes()
|
|
+ from_space()->capacity_in_bytes(); // to_space() is only used during scavenge
|
|
}
|
|
|
|
|
|
size_t PSYoungGen::used_in_bytes() const {
|
|
return eden_space()->used_in_bytes()
|
|
+ from_space()->used_in_bytes(); // to_space() is only used during scavenge
|
|
}
|
|
|
|
|
|
size_t PSYoungGen::free_in_bytes() const {
|
|
return eden_space()->free_in_bytes()
|
|
+ from_space()->free_in_bytes(); // to_space() is only used during scavenge
|
|
}
|
|
|
|
size_t PSYoungGen::capacity_in_words() const {
|
|
return eden_space()->capacity_in_words()
|
|
+ from_space()->capacity_in_words(); // to_space() is only used during scavenge
|
|
}
|
|
|
|
|
|
size_t PSYoungGen::used_in_words() const {
|
|
return eden_space()->used_in_words()
|
|
+ from_space()->used_in_words(); // to_space() is only used during scavenge
|
|
}
|
|
|
|
|
|
size_t PSYoungGen::free_in_words() const {
|
|
return eden_space()->free_in_words()
|
|
+ from_space()->free_in_words(); // to_space() is only used during scavenge
|
|
}
|
|
|
|
void PSYoungGen::object_iterate(ObjectClosure* blk) {
|
|
eden_space()->object_iterate(blk);
|
|
from_space()->object_iterate(blk);
|
|
to_space()->object_iterate(blk);
|
|
}
|
|
|
|
void PSYoungGen::precompact() {
|
|
eden_mark_sweep()->precompact();
|
|
from_mark_sweep()->precompact();
|
|
to_mark_sweep()->precompact();
|
|
}
|
|
|
|
void PSYoungGen::adjust_pointers() {
|
|
eden_mark_sweep()->adjust_pointers();
|
|
from_mark_sweep()->adjust_pointers();
|
|
to_mark_sweep()->adjust_pointers();
|
|
}
|
|
|
|
void PSYoungGen::compact() {
|
|
eden_mark_sweep()->compact(ZapUnusedHeapArea);
|
|
from_mark_sweep()->compact(ZapUnusedHeapArea);
|
|
// Mark sweep stores preserved markOops in to space, don't disturb!
|
|
to_mark_sweep()->compact(false);
|
|
}
|
|
|
|
void PSYoungGen::print() const { print_on(tty); }
|
|
void PSYoungGen::print_on(outputStream* st) const {
|
|
st->print(" %-15s", "PSYoungGen");
|
|
if (PrintGCDetails && Verbose) {
|
|
st->print(" total " SIZE_FORMAT ", used " SIZE_FORMAT,
|
|
capacity_in_bytes(), used_in_bytes());
|
|
} else {
|
|
st->print(" total " SIZE_FORMAT "K, used " SIZE_FORMAT "K",
|
|
capacity_in_bytes()/K, used_in_bytes()/K);
|
|
}
|
|
virtual_space()->print_space_boundaries_on(st);
|
|
st->print(" eden"); eden_space()->print_on(st);
|
|
st->print(" from"); from_space()->print_on(st);
|
|
st->print(" to "); to_space()->print_on(st);
|
|
}
|
|
|
|
// Note that a space is not printed before the [NAME:
|
|
void PSYoungGen::print_used_change(size_t prev_used) const {
|
|
gclog_or_tty->print("[%s:", name());
|
|
gclog_or_tty->print(" " SIZE_FORMAT "K"
|
|
"->" SIZE_FORMAT "K"
|
|
"(" SIZE_FORMAT "K)",
|
|
prev_used / K, used_in_bytes() / K,
|
|
capacity_in_bytes() / K);
|
|
gclog_or_tty->print("]");
|
|
}
|
|
|
|
size_t PSYoungGen::available_for_expansion() {
|
|
ShouldNotReachHere();
|
|
return 0;
|
|
}
|
|
|
|
size_t PSYoungGen::available_for_contraction() {
|
|
ShouldNotReachHere();
|
|
return 0;
|
|
}
|
|
|
|
size_t PSYoungGen::available_to_min_gen() {
|
|
assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant");
|
|
return virtual_space()->committed_size() - min_gen_size();
|
|
}
|
|
|
|
// This method assumes that from-space has live data and that
|
|
// any shrinkage of the young gen is limited by location of
|
|
// from-space.
|
|
size_t PSYoungGen::available_to_live() {
|
|
size_t delta_in_survivor = 0;
|
|
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
const size_t space_alignment = heap->intra_heap_alignment();
|
|
const size_t gen_alignment = heap->young_gen_alignment();
|
|
|
|
MutableSpace* space_shrinking = NULL;
|
|
if (from_space()->end() > to_space()->end()) {
|
|
space_shrinking = from_space();
|
|
} else {
|
|
space_shrinking = to_space();
|
|
}
|
|
|
|
// Include any space that is committed but not included in
|
|
// the survivor spaces.
|
|
assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(),
|
|
"Survivor space beyond high end");
|
|
size_t unused_committed = pointer_delta(virtual_space()->high(),
|
|
space_shrinking->end(), sizeof(char));
|
|
|
|
if (space_shrinking->is_empty()) {
|
|
// Don't let the space shrink to 0
|
|
assert(space_shrinking->capacity_in_bytes() >= space_alignment,
|
|
"Space is too small");
|
|
delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment;
|
|
} else {
|
|
delta_in_survivor = pointer_delta(space_shrinking->end(),
|
|
space_shrinking->top(),
|
|
sizeof(char));
|
|
}
|
|
|
|
size_t delta_in_bytes = unused_committed + delta_in_survivor;
|
|
delta_in_bytes = align_size_down(delta_in_bytes, gen_alignment);
|
|
return delta_in_bytes;
|
|
}
|
|
|
|
// Return the number of bytes available for resizing down the young
|
|
// generation. This is the minimum of
|
|
// input "bytes"
|
|
// bytes to the minimum young gen size
|
|
// bytes to the size currently being used + some small extra
|
|
size_t PSYoungGen::limit_gen_shrink(size_t bytes) {
|
|
// Allow shrinkage into the current eden but keep eden large enough
|
|
// to maintain the minimum young gen size
|
|
bytes = MIN3(bytes, available_to_min_gen(), available_to_live());
|
|
return align_size_down(bytes, virtual_space()->alignment());
|
|
}
|
|
|
|
void PSYoungGen::reset_after_change() {
|
|
ShouldNotReachHere();
|
|
}
|
|
|
|
void PSYoungGen::reset_survivors_after_shrink() {
|
|
_reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
|
|
(HeapWord*)virtual_space()->high_boundary());
|
|
PSScavenge::reference_processor()->set_span(_reserved);
|
|
|
|
MutableSpace* space_shrinking = NULL;
|
|
if (from_space()->end() > to_space()->end()) {
|
|
space_shrinking = from_space();
|
|
} else {
|
|
space_shrinking = to_space();
|
|
}
|
|
|
|
HeapWord* new_end = (HeapWord*)virtual_space()->high();
|
|
assert(new_end >= space_shrinking->bottom(), "Shrink was too large");
|
|
// Was there a shrink of the survivor space?
|
|
if (new_end < space_shrinking->end()) {
|
|
MemRegion mr(space_shrinking->bottom(), new_end);
|
|
space_shrinking->initialize(mr,
|
|
SpaceDecorator::DontClear,
|
|
SpaceDecorator::Mangle);
|
|
}
|
|
}
|
|
|
|
// This method currently does not expect to expand into eden (i.e.,
|
|
// the virtual space boundaries is expected to be consistent
|
|
// with the eden boundaries..
|
|
void PSYoungGen::post_resize() {
|
|
assert_locked_or_safepoint(Heap_lock);
|
|
assert((eden_space()->bottom() < to_space()->bottom()) &&
|
|
(eden_space()->bottom() < from_space()->bottom()),
|
|
"Eden is assumed to be below the survivor spaces");
|
|
|
|
MemRegion cmr((HeapWord*)virtual_space()->low(),
|
|
(HeapWord*)virtual_space()->high());
|
|
Universe::heap()->barrier_set()->resize_covered_region(cmr);
|
|
space_invariants();
|
|
}
|
|
|
|
|
|
|
|
void PSYoungGen::update_counters() {
|
|
if (UsePerfData) {
|
|
_eden_counters->update_all();
|
|
_from_counters->update_all();
|
|
_to_counters->update_all();
|
|
_gen_counters->update_all();
|
|
}
|
|
}
|
|
|
|
void PSYoungGen::verify() {
|
|
eden_space()->verify();
|
|
from_space()->verify();
|
|
to_space()->verify();
|
|
}
|
|
|
|
#ifndef PRODUCT
|
|
void PSYoungGen::record_spaces_top() {
|
|
assert(ZapUnusedHeapArea, "Not mangling unused space");
|
|
eden_space()->set_top_for_allocations();
|
|
from_space()->set_top_for_allocations();
|
|
to_space()->set_top_for_allocations();
|
|
}
|
|
#endif
|