1 /*
   2  * Copyright (c) 2001, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
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  23  */
  24 
  25 #ifndef SHARE_VM_MEMORY_TENUREDGENERATION_HPP
  26 #define SHARE_VM_MEMORY_TENUREDGENERATION_HPP
  27 
  28 #include "gc_implementation/shared/cSpaceCounters.hpp"
  29 #include "gc_implementation/shared/gcStats.hpp"
  30 #include "gc_implementation/shared/generationCounters.hpp"
  31 #include "memory/generation.hpp"
  32 #include "utilities/macros.hpp"
  33 
  34 // TenuredGeneration models the heap containing old (promoted/tenured) objects.
  35 
  36 class TenuredGeneration: public OneContigSpaceCardGeneration {
  37   friend class VMStructs;
  38  protected:
  39   GenerationCounters*   _gen_counters;
  40   CSpaceCounters*       _space_counters;
  41 
  42  public:
  43   TenuredGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
  44                     GenRemSet* remset);
  45 
  46   Generation::Name kind() { return Generation::MarkSweepCompact; }
  47 
  48   // Printing
  49   const char* name() const { return "tenured generation"; }
  50   const char* short_name() const { return "Tenured"; }
  51 
  52   // Does a "full" (forced) collection invoked on this generation collect
  53   // all younger generations as well? Note that this is a
  54   // hack to allow the collection of the younger gen first if the flag is
  55   // set.
  56   virtual bool full_collects_younger_generations() const {
  57     return !ScavengeBeforeFullGC;
  58   }
  59 
  60   virtual void gc_prologue(bool full);
  61   bool should_collect(bool   full,
  62                       size_t word_size,
  63                       bool   is_tlab);
  64 
  65   virtual void compute_new_size();
  66 
  67   // Performance Counter support
  68   void update_counters();
  69 
  70   // Statistics
  71 
  72   virtual void update_gc_stats(int level, bool full);
  73 
  74   virtual bool promotion_attempt_is_safe(size_t max_promoted_in_bytes) const;
  75 };
  76 
  77 #endif // SHARE_VM_MEMORY_TENUREDGENERATION_HPP