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/*
* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "gc_implementation/parallelScavenge/asPSOldGen.hpp"
#include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
#include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp"
#include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp"
#include "memory/cardTableModRefBS.hpp"
#include "oops/oop.inline.hpp"
#include "runtime/java.hpp"
// Whereas PSOldGen takes the maximum size of the generation
// (which doesn't change in the case of PSOldGen) as a parameter,
// ASPSOldGen takes the upper limit on the size of
// the generation as a parameter. In ASPSOldGen the
// maximum size of the generation can change as the boundary
// moves. The "maximum size of the generation" is still a valid
// concept since the generation can grow and shrink within that
// maximum. There are lots of useful checks that use that
// maximum. In PSOldGen the method max_gen_size() returns
// _max_gen_size (as set by the PSOldGen constructor). This
// is how it always worked. In ASPSOldGen max_gen_size()
// returned the size of the reserved space for the generation.
// That can change as the boundary moves. Below the limit of
// the size of the generation is passed to the PSOldGen constructor
// for "_max_gen_size" (have to pass something) but it is not used later.
//
ASPSOldGen::ASPSOldGen(size_t initial_size,
size_t min_size,
size_t size_limit,
const char* gen_name,
int level) :
PSOldGen(initial_size, min_size, size_limit, gen_name, level),
_gen_size_limit(size_limit)
{}
ASPSOldGen::ASPSOldGen(PSVirtualSpace* vs,
size_t initial_size,
size_t min_size,
size_t size_limit,
const char* gen_name,
int level) :
PSOldGen(initial_size, min_size, size_limit, gen_name, level),
_gen_size_limit(size_limit)
{
_virtual_space = vs;
}
void ASPSOldGen::initialize_work(const char* perf_data_name, int level) {
PSOldGen::initialize_work(perf_data_name, level);
// The old gen can grow to gen_size_limit(). _reserve reflects only
// the current maximum that can be committed.
assert(_reserved.byte_size() <= gen_size_limit(), "Consistency check");
initialize_performance_counters(perf_data_name, level);
}
void ASPSOldGen::reset_after_change() {
_reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
(HeapWord*)virtual_space()->high_boundary());
post_resize();
}
size_t ASPSOldGen::available_for_expansion() {
assert(virtual_space()->is_aligned(gen_size_limit()), "not aligned");
assert(gen_size_limit() >= virtual_space()->committed_size(), "bad gen size");
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
size_t result = gen_size_limit() - virtual_space()->committed_size();
size_t result_aligned = align_size_down(result, heap->generation_alignment());
return result_aligned;
}
size_t ASPSOldGen::available_for_contraction() {
size_t uncommitted_bytes = virtual_space()->uncommitted_size();
if (uncommitted_bytes != 0) {
return uncommitted_bytes;
}
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
const size_t gen_alignment = heap->generation_alignment();
PSAdaptiveSizePolicy* policy = heap->size_policy();
const size_t working_size =
used_in_bytes() + (size_t) policy->avg_promoted()->padded_average();
const size_t working_aligned = align_size_up(working_size, gen_alignment);
const size_t working_or_min = MAX2(working_aligned, min_gen_size());
if (working_or_min > reserved().byte_size()) {
// If the used or minimum gen size (aligned up) is greater
// than the total reserved size, then the space available
// for contraction should (after proper alignment) be 0
return 0;
}
const size_t max_contraction =
reserved().byte_size() - working_or_min;
// Use the "increment" fraction instead of the "decrement" fraction
// to allow the other gen to expand more aggressively. The
// "decrement" fraction is conservative because its intent is to
// only reduce the footprint.
size_t result = policy->promo_increment_aligned_down(max_contraction);
// Also adjust for inter-generational alignment
size_t result_aligned = align_size_down(result, gen_alignment);
if (PrintAdaptiveSizePolicy && Verbose) {
gclog_or_tty->print_cr("\nASPSOldGen::available_for_contraction:"
" %d K / 0x%x", result_aligned/K, result_aligned);
gclog_or_tty->print_cr(" reserved().byte_size() %d K / 0x%x ",
reserved().byte_size()/K, reserved().byte_size());
size_t working_promoted = (size_t) policy->avg_promoted()->padded_average();
gclog_or_tty->print_cr(" padded promoted %d K / 0x%x",
working_promoted/K, working_promoted);
gclog_or_tty->print_cr(" used %d K / 0x%x",
used_in_bytes()/K, used_in_bytes());
gclog_or_tty->print_cr(" min_gen_size() %d K / 0x%x",
min_gen_size()/K, min_gen_size());
gclog_or_tty->print_cr(" max_contraction %d K / 0x%x",
max_contraction/K, max_contraction);
gclog_or_tty->print_cr(" without alignment %d K / 0x%x",
policy->promo_increment(max_contraction)/K,
policy->promo_increment(max_contraction));
gclog_or_tty->print_cr(" alignment 0x%x", gen_alignment);
}
assert(result_aligned <= max_contraction, "arithmetic is wrong");
return result_aligned;
}
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