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 /*

  * Copyright (c) 2003, 2014, 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

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  */

 #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:"

       " " SSIZE_FORMAT "  K / " SIZE_FORMAT_HEX, (result_aligned/K), result_aligned);

     gclog_or_tty->print_cr(" reserved().byte_size() " SSIZE_FORMAT " K / " SIZE_FORMAT_HEX " ",

       (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 " SSIZE_FORMAT " K / " SIZE_FORMAT_HEX,

       (working_promoted/K), working_promoted);

     gclog_or_tty->print_cr(" used " SSIZE_FORMAT " K / " SIZE_FORMAT_HEX,

       (used_in_bytes()/K), used_in_bytes());

     gclog_or_tty->print_cr(" min_gen_size() " SSIZE_FORMAT " K / " SIZE_FORMAT_HEX,

       (min_gen_size()/K), min_gen_size());

     gclog_or_tty->print_cr(" max_contraction " SSIZE_FORMAT " K / " SIZE_FORMAT_HEX,

       (max_contraction/K), max_contraction);

     gclog_or_tty->print_cr("    without alignment " SSIZE_FORMAT " K / " SIZE_FORMAT_HEX,

       (policy->promo_increment(max_contraction)/K),

       policy->promo_increment(max_contraction));

     gclog_or_tty->print_cr(" alignment " SIZE_FORMAT_HEX, gen_alignment);

   }

   assert(result_aligned <= max_contraction, "arithmetic is wrong");

   return result_aligned;

 }