1 /*

     2  * Copyright 2003-2006 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 # include "incls/_precompiled.incl"

    26 # include "incls/_asPSOldGen.cpp.incl"

    27 

    28 // Whereas PSOldGen takes the maximum size of the generation

    29 // (which doesn't change in the case of PSOldGen) as a parameter,

    30 // ASPSOldGen takes the upper limit on the size of

    31 // the generation as a parameter.  In ASPSOldGen the

    32 // maximum size of the generation can change as the boundary

    33 // moves.  The "maximum size of the generation" is still a valid

    34 // concept since the generation can grow and shrink within that

    35 // maximum.  There are lots of useful checks that use that

    36 // maximum.  In PSOldGen the method max_gen_size() returns

    37 // _max_gen_size (as set by the PSOldGen constructor).  This

    38 // is how it always worked.  In ASPSOldGen max_gen_size()

    39 // returned the size of the reserved space for the generation.

    40 // That can change as the boundary moves.  Below the limit of

    41 // the size of the generation is passed to the PSOldGen constructor

    42 // for "_max_gen_size" (have to pass something) but it is not used later.

    43 //

    44 ASPSOldGen::ASPSOldGen(size_t initial_size,

    45                        size_t min_size,

    46                        size_t size_limit,

    47                        const char* gen_name,

    48                        int level) :

    49   PSOldGen(initial_size, min_size, size_limit, gen_name, level),

    50   _gen_size_limit(size_limit)

    51 

    52 {}

    53 

    54 ASPSOldGen::ASPSOldGen(PSVirtualSpace* vs,

    55                        size_t initial_size,

    56                        size_t min_size,

    57                        size_t size_limit,

    58                        const char* gen_name,

    59                        int level) :

    60   PSOldGen(initial_size, min_size, size_limit, gen_name, level),

    61   _gen_size_limit(size_limit)

    62 

    63 {

    64   _virtual_space = vs;

    65 }

    66 

    67 void ASPSOldGen::reset_after_change() {

    68   _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),

    69                         (HeapWord*)virtual_space()->high_boundary());

    70   post_resize();

    71 }

    72 

    73 

    74 size_t ASPSOldGen::available_for_expansion() {

    75   assert(virtual_space()->is_aligned(gen_size_limit()), "not aligned");

    76   assert(gen_size_limit() >= virtual_space()->committed_size(), "bad gen size");

    77 

    78   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();

    79   size_t result =  gen_size_limit() - virtual_space()->committed_size();

    80   size_t result_aligned = align_size_down(result, heap->old_gen_alignment());

    81   return result_aligned;

    82 }

    83 

    84 size_t ASPSOldGen::available_for_contraction() {

    85   size_t uncommitted_bytes = virtual_space()->uncommitted_size();

    86   if (uncommitted_bytes != 0) {

    87     return uncommitted_bytes;

    88   }

    89 

    90   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();

    91   const size_t gen_alignment = heap->old_gen_alignment();

    92   PSAdaptiveSizePolicy* policy = heap->size_policy();

    93   const size_t working_size =

    94     used_in_bytes() + (size_t) policy->avg_promoted()->padded_average();

    95   const size_t working_aligned = align_size_up(working_size, gen_alignment);

    96   const size_t working_or_min = MAX2(working_aligned, min_gen_size());

    97   if (working_or_min > reserved().byte_size()) {

    98     // If the used or minimum gen size (aligned up) is greater

    99     // than the total reserved size, then the space available

   100     // for contraction should (after proper alignment) be 0

   101     return 0;

   102   }

   103   const size_t max_contraction =

   104     reserved().byte_size() - working_or_min;

   105 

   106   // Use the "increment" fraction instead of the "decrement" fraction

   107   // to allow the other gen to expand more aggressively.  The

   108   // "decrement" fraction is conservative because its intent is to

   109   // only reduce the footprint.

   110 

   111   size_t result = policy->promo_increment_aligned_down(max_contraction);

   112   // Also adjust for inter-generational alignment

   113   size_t result_aligned = align_size_down(result, gen_alignment);

   114   if (PrintAdaptiveSizePolicy && Verbose) {

   115     gclog_or_tty->print_cr("\nASPSOldGen::available_for_contraction:"

   116       " %d K / 0x%x", result_aligned/K, result_aligned);

   117     gclog_or_tty->print_cr(" reserved().byte_size() %d K / 0x%x ",

   118       reserved().byte_size()/K, reserved().byte_size());

   119     size_t working_promoted = (size_t) policy->avg_promoted()->padded_average();

   120     gclog_or_tty->print_cr(" padded promoted %d K / 0x%x",

   121       working_promoted/K, working_promoted);

   122     gclog_or_tty->print_cr(" used %d K / 0x%x",

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

   124     gclog_or_tty->print_cr(" min_gen_size() %d K / 0x%x",

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

   126     gclog_or_tty->print_cr(" max_contraction %d K / 0x%x",

   127       max_contraction/K, max_contraction);

   128     gclog_or_tty->print_cr("    without alignment %d K / 0x%x",

   129       policy->promo_increment(max_contraction)/K,

   130       policy->promo_increment(max_contraction));

   131     gclog_or_tty->print_cr(" alignment 0x%x", gen_alignment);

   132   }

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

   134   return result_aligned;

   135 }