hotspot/src/share/vm/memory/generation.hpp
author brutisso
Tue, 02 Dec 2014 09:51:16 +0100
changeset 27903 14c6e2f23fa0
parent 27899 17754211a7ab
child 27904 d606512952cc
permissions -rw-r--r--
8065992: Change CMSCollector::_young_gen to be a ParNewGeneration* Reviewed-by: mgerdin, kbarrett
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/*
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 * Copyright (c) 1997, 2014, 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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#ifndef SHARE_VM_MEMORY_GENERATION_HPP
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#define SHARE_VM_MEMORY_GENERATION_HPP
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#include "gc_implementation/shared/collectorCounters.hpp"
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#include "memory/allocation.hpp"
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#include "memory/memRegion.hpp"
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#include "memory/referenceProcessor.hpp"
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#include "memory/universe.hpp"
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#include "memory/watermark.hpp"
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#include "runtime/mutex.hpp"
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#include "runtime/perfData.hpp"
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#include "runtime/virtualspace.hpp"
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// A Generation models a heap area for similarly-aged objects.
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// It will contain one ore more spaces holding the actual objects.
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//
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// The Generation class hierarchy:
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//
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// Generation                      - abstract base class
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// - DefNewGeneration              - allocation area (copy collected)
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//   - ParNewGeneration            - a DefNewGeneration that is collected by
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//                                   several threads
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// - CardGeneration                 - abstract class adding offset array behavior
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//   - OneContigSpaceCardGeneration - abstract class holding a single
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//                                    contiguous space with card marking
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//     - TenuredGeneration         - tenured (old object) space (markSweepCompact)
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//   - ConcurrentMarkSweepGeneration - Mostly Concurrent Mark Sweep Generation
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//                                       (Detlefs-Printezis refinement of
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//                                       Boehm-Demers-Schenker)
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//
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// The system configurations currently allowed are:
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//
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//   DefNewGeneration + TenuredGeneration
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//   DefNewGeneration + ConcurrentMarkSweepGeneration
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//
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//   ParNewGeneration + TenuredGeneration
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//   ParNewGeneration + ConcurrentMarkSweepGeneration
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//
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class DefNewGeneration;
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class GenerationSpec;
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class CompactibleSpace;
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class ContiguousSpace;
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class CompactPoint;
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class OopsInGenClosure;
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class OopClosure;
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class ScanClosure;
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class FastScanClosure;
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class GenCollectedHeap;
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class GenRemSet;
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class GCStats;
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// A "ScratchBlock" represents a block of memory in one generation usable by
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// another.  It represents "num_words" free words, starting at and including
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// the address of "this".
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struct ScratchBlock {
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  ScratchBlock* next;
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  size_t num_words;
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  HeapWord scratch_space[1];  // Actually, of size "num_words-2" (assuming
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                              // first two fields are word-sized.)
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};
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class Generation: public CHeapObj<mtGC> {
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  friend class VMStructs;
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 private:
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  jlong _time_of_last_gc; // time when last gc on this generation happened (ms)
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  MemRegion _prev_used_region; // for collectors that want to "remember" a value for
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                               // used region at some specific point during collection.
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 protected:
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  // Minimum and maximum addresses for memory reserved (not necessarily
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  // committed) for generation.
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  // Used by card marking code. Must not overlap with address ranges of
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  // other generations.
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  MemRegion _reserved;
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  // Memory area reserved for generation
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  VirtualSpace _virtual_space;
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  // Level in the generation hierarchy.
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  int _level;
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  // ("Weak") Reference processing support
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  ReferenceProcessor* _ref_processor;
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  // Performance Counters
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  CollectorCounters* _gc_counters;
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  // Statistics for garbage collection
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  GCStats* _gc_stats;
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  // Returns the next generation in the configuration, or else NULL if this
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  // is the highest generation.
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  Generation* next_gen() const;
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  // Initialize the generation.
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  Generation(ReservedSpace rs, size_t initial_byte_size, int level);
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  // Apply "cl->do_oop" to (the address of) (exactly) all the ref fields in
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  // "sp" that point into younger generations.
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  // The iteration is only over objects allocated at the start of the
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  // iterations; objects allocated as a result of applying the closure are
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  // not included.
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  void younger_refs_in_space_iterate(Space* sp, OopsInGenClosure* cl);
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 public:
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  // The set of possible generation kinds.
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  enum Name {
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    DefNew,
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    ParNew,
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    MarkSweepCompact,
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    ConcurrentMarkSweep,
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    Other
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  };
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  enum SomePublicConstants {
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    // Generations are GenGrain-aligned and have size that are multiples of
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    // GenGrain.
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    // Note: on ARM we add 1 bit for card_table_base to be properly aligned
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    // (we expect its low byte to be zero - see implementation of post_barrier)
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    LogOfGenGrain = 16 ARM_ONLY(+1),
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    GenGrain = 1 << LogOfGenGrain
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  };
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  // allocate and initialize ("weak") refs processing support
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  virtual void ref_processor_init();
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  void set_ref_processor(ReferenceProcessor* rp) {
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    assert(_ref_processor == NULL, "clobbering existing _ref_processor");
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    _ref_processor = rp;
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  }
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  virtual Generation::Name kind() { return Generation::Other; }
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  GenerationSpec* spec();
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  // This properly belongs in the collector, but for now this
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  // will do.
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  virtual bool refs_discovery_is_atomic() const { return true;  }
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  virtual bool refs_discovery_is_mt()     const { return false; }
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  // Space enquiries (results in bytes)
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  virtual size_t capacity() const = 0;  // The maximum number of object bytes the
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                                        // generation can currently hold.
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  virtual size_t used() const = 0;      // The number of used bytes in the gen.
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  virtual size_t free() const = 0;      // The number of free bytes in the gen.
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  // Support for java.lang.Runtime.maxMemory(); see CollectedHeap.
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  // Returns the total number of bytes  available in a generation
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  // for the allocation of objects.
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  virtual size_t max_capacity() const;
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  // If this is a young generation, the maximum number of bytes that can be
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  // allocated in this generation before a GC is triggered.
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  virtual size_t capacity_before_gc() const { return 0; }
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  // The largest number of contiguous free bytes in the generation,
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  // including expansion  (Assumes called at a safepoint.)
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  virtual size_t contiguous_available() const = 0;
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  // The largest number of contiguous free bytes in this or any higher generation.
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  virtual size_t max_contiguous_available() const;
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  // Returns true if promotions of the specified amount are
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  // likely to succeed without a promotion failure.
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  // Promotion of the full amount is not guaranteed but
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  // might be attempted in the worst case.
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  virtual bool promotion_attempt_is_safe(size_t max_promotion_in_bytes) const;
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  // For a non-young generation, this interface can be used to inform a
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  // generation that a promotion attempt into that generation failed.
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  // Typically used to enable diagnostic output for post-mortem analysis,
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  // but other uses of the interface are not ruled out.
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  virtual void promotion_failure_occurred() { /* does nothing */ }
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  // Return an estimate of the maximum allocation that could be performed
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  // in the generation without triggering any collection or expansion
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  // activity.  It is "unsafe" because no locks are taken; the result
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  // should be treated as an approximation, not a guarantee, for use in
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  // heuristic resizing decisions.
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  virtual size_t unsafe_max_alloc_nogc() const = 0;
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  // Returns true if this generation cannot be expanded further
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  // without a GC. Override as appropriate.
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  virtual bool is_maximal_no_gc() const {
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    return _virtual_space.uncommitted_size() == 0;
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  }
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  MemRegion reserved() const { return _reserved; }
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  // Returns a region guaranteed to contain all the objects in the
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  // generation.
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  virtual MemRegion used_region() const { return _reserved; }
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  MemRegion prev_used_region() const { return _prev_used_region; }
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  virtual void  save_used_region()   { _prev_used_region = used_region(); }
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  // Returns "TRUE" iff "p" points into the committed areas in the generation.
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  // For some kinds of generations, this may be an expensive operation.
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  // To avoid performance problems stemming from its inadvertent use in
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  // product jvm's, we restrict its use to assertion checking or
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  // verification only.
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  virtual bool is_in(const void* p) const;
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  /* Returns "TRUE" iff "p" points into the reserved area of the generation. */
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  bool is_in_reserved(const void* p) const {
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    return _reserved.contains(p);
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  }
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  // If some space in the generation contains the given "addr", return a
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  // pointer to that space, else return "NULL".
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  virtual Space* space_containing(const void* addr) const;
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  // Iteration - do not use for time critical operations
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  virtual void space_iterate(SpaceClosure* blk, bool usedOnly = false) = 0;
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  // Returns the first space, if any, in the generation that can participate
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  // in compaction, or else "NULL".
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  virtual CompactibleSpace* first_compaction_space() const = 0;
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  // Returns "true" iff this generation should be used to allocate an
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  // object of the given size.  Young generations might
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  // wish to exclude very large objects, for example, since, if allocated
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  // often, they would greatly increase the frequency of young-gen
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  // collection.
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  virtual bool should_allocate(size_t word_size, bool is_tlab) {
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    bool result = false;
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    size_t overflow_limit = (size_t)1 << (BitsPerSize_t - LogHeapWordSize);
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    if (!is_tlab || supports_tlab_allocation()) {
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      result = (word_size > 0) && (word_size < overflow_limit);
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    }
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    return result;
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  }
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  // Allocate and returns a block of the requested size, or returns "NULL".
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  // Assumes the caller has done any necessary locking.
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  virtual HeapWord* allocate(size_t word_size, bool is_tlab) = 0;
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  // Like "allocate", but performs any necessary locking internally.
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  virtual HeapWord* par_allocate(size_t word_size, bool is_tlab) = 0;
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  // Some generation may offer a region for shared, contiguous allocation,
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  // via inlined code (by exporting the address of the top and end fields
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  // defining the extent of the contiguous allocation region.)
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  // This function returns "true" iff the heap supports this kind of
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  // allocation.  (More precisely, this means the style of allocation that
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  // increments *top_addr()" with a CAS.) (Default is "no".)
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  // A generation that supports this allocation style must use lock-free
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  // allocation for *all* allocation, since there are times when lock free
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  // allocation will be concurrent with plain "allocate" calls.
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  virtual bool supports_inline_contig_alloc() const { return false; }
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  // These functions return the addresses of the fields that define the
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  // boundaries of the contiguous allocation area.  (These fields should be
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  // physically near to one another.)
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  virtual HeapWord** top_addr() const { return NULL; }
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  virtual HeapWord** end_addr() const { return NULL; }
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  // Thread-local allocation buffers
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  virtual bool supports_tlab_allocation() const { return false; }
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  virtual size_t tlab_capacity() const {
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    guarantee(false, "Generation doesn't support thread local allocation buffers");
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    return 0;
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  }
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  virtual size_t tlab_used() const {
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    guarantee(false, "Generation doesn't support thread local allocation buffers");
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    return 0;
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  }
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  virtual size_t unsafe_max_tlab_alloc() const {
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    guarantee(false, "Generation doesn't support thread local allocation buffers");
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    return 0;
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  }
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  // "obj" is the address of an object in a younger generation.  Allocate space
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  // for "obj" in the current (or some higher) generation, and copy "obj" into
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  // the newly allocated space, if possible, returning the result (or NULL if
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  // the allocation failed).
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  //
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  // The "obj_size" argument is just obj->size(), passed along so the caller can
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  // avoid repeating the virtual call to retrieve it.
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  virtual oop promote(oop obj, size_t obj_size);
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  // Thread "thread_num" (0 <= i < ParalleGCThreads) wants to promote
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  // object "obj", whose original mark word was "m", and whose size is
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  // "word_sz".  If possible, allocate space for "obj", copy obj into it
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  // (taking care to copy "m" into the mark word when done, since the mark
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  // word of "obj" may have been overwritten with a forwarding pointer, and
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  // also taking care to copy the klass pointer *last*.  Returns the new
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  // object if successful, or else NULL.
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  virtual oop par_promote(int thread_num,
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                          oop obj, markOop m, size_t word_sz);
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  // Informs the current generation that all par_promote_alloc's in the
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  // collection have been completed; any supporting data structures can be
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  // reset.  Default is to do nothing.
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  virtual void par_promote_alloc_done(int thread_num) {}
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  // Informs the current generation that all oop_since_save_marks_iterates
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  // performed by "thread_num" in the current collection, if any, have been
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  // completed; any supporting data structures can be reset.  Default is to
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  // do nothing.
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  virtual void par_oop_since_save_marks_iterate_done(int thread_num) {}
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  // This generation will collect all younger generations
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  // during a full collection.
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  virtual bool full_collects_younger_generations() const { return false; }
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  // This generation does in-place marking, meaning that mark words
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  // are mutated during the marking phase and presumably reinitialized
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  // to a canonical value after the GC. This is currently used by the
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  // biased locking implementation to determine whether additional
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  // work is required during the GC prologue and epilogue.
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  virtual bool performs_in_place_marking() const { return true; }
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  // Returns "true" iff collect() should subsequently be called on this
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  // this generation. See comment below.
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  // This is a generic implementation which can be overridden.
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  //
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  // Note: in the current (1.4) implementation, when genCollectedHeap's
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  // incremental_collection_will_fail flag is set, all allocations are
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  // slow path (the only fast-path place to allocate is DefNew, which
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  // will be full if the flag is set).
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  // Thus, older generations which collect younger generations should
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  // test this flag and collect if it is set.
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  virtual bool should_collect(bool   full,
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                              size_t word_size,
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                              bool   is_tlab) {
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    return (full || should_allocate(word_size, is_tlab));
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  }
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  // Returns true if the collection is likely to be safely
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  // completed. Even if this method returns true, a collection
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  // may not be guaranteed to succeed, and the system should be
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  // able to safely unwind and recover from that failure, albeit
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  // at some additional cost.
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  virtual bool collection_attempt_is_safe() {
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    guarantee(false, "Are you sure you want to call this method?");
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    return true;
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  }
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1
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  // Perform a garbage collection.
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  // If full is true attempt a full garbage collection of this generation.
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  // Otherwise, attempting to (at least) free enough space to support an
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  // allocation of the given "word_size".
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  virtual void collect(bool   full,
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                       bool   clear_all_soft_refs,
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                       size_t word_size,
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                       bool   is_tlab) = 0;
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   373
  // Perform a heap collection, attempting to create (at least) enough
489c9b5090e2 Initial load
duke
parents:
diff changeset
   374
  // space to support an allocation of the given "word_size".  If
489c9b5090e2 Initial load
duke
parents:
diff changeset
   375
  // successful, perform the allocation and return the resulting
489c9b5090e2 Initial load
duke
parents:
diff changeset
   376
  // "oop" (initializing the allocated block). If the allocation is
489c9b5090e2 Initial load
duke
parents:
diff changeset
   377
  // still unsuccessful, return "NULL".
489c9b5090e2 Initial load
duke
parents:
diff changeset
   378
  virtual HeapWord* expand_and_allocate(size_t word_size,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   379
                                        bool is_tlab,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   380
                                        bool parallel = false) = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   381
489c9b5090e2 Initial load
duke
parents:
diff changeset
   382
  // Some generations may require some cleanup or preparation actions before
489c9b5090e2 Initial load
duke
parents:
diff changeset
   383
  // allowing a collection.  The default is to do nothing.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   384
  virtual void gc_prologue(bool full) {};
489c9b5090e2 Initial load
duke
parents:
diff changeset
   385
489c9b5090e2 Initial load
duke
parents:
diff changeset
   386
  // Some generations may require some cleanup actions after a collection.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   387
  // The default is to do nothing.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   388
  virtual void gc_epilogue(bool full) {};
489c9b5090e2 Initial load
duke
parents:
diff changeset
   389
971
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 360
diff changeset
   390
  // Save the high water marks for the used space in a generation.
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 360
diff changeset
   391
  virtual void record_spaces_top() {};
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 360
diff changeset
   392
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   393
  // Some generations may need to be "fixed-up" after some allocation
489c9b5090e2 Initial load
duke
parents:
diff changeset
   394
  // activity to make them parsable again. The default is to do nothing.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   395
  virtual void ensure_parsability() {};
489c9b5090e2 Initial load
duke
parents:
diff changeset
   396
489c9b5090e2 Initial load
duke
parents:
diff changeset
   397
  // Time (in ms) when we were last collected or now if a collection is
489c9b5090e2 Initial load
duke
parents:
diff changeset
   398
  // in progress.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   399
  virtual jlong time_of_last_gc(jlong now) {
11251
e29da6b5622b 7117303: VM uses non-monotonic time source and complains that it is non-monotonic
johnc
parents: 11247
diff changeset
   400
    // Both _time_of_last_gc and now are set using a time source
e29da6b5622b 7117303: VM uses non-monotonic time source and complains that it is non-monotonic
johnc
parents: 11247
diff changeset
   401
    // that guarantees monotonically non-decreasing values provided
e29da6b5622b 7117303: VM uses non-monotonic time source and complains that it is non-monotonic
johnc
parents: 11247
diff changeset
   402
    // the underlying platform provides such a source. So we still
e29da6b5622b 7117303: VM uses non-monotonic time source and complains that it is non-monotonic
johnc
parents: 11247
diff changeset
   403
    // have to guard against non-monotonicity.
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   404
    NOT_PRODUCT(
489c9b5090e2 Initial load
duke
parents:
diff changeset
   405
      if (now < _time_of_last_gc) {
24424
2658d7834c6e 8037816: Fix for 8036122 breaks build with Xcode5/clang
drchase
parents: 23508
diff changeset
   406
        warning("time warp: "INT64_FORMAT" to "INT64_FORMAT, (int64_t)_time_of_last_gc, (int64_t)now);
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   407
      }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   408
    )
489c9b5090e2 Initial load
duke
parents:
diff changeset
   409
    return _time_of_last_gc;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   410
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   411
489c9b5090e2 Initial load
duke
parents:
diff changeset
   412
  virtual void update_time_of_last_gc(jlong now)  {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   413
    _time_of_last_gc = now;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   414
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   415
489c9b5090e2 Initial load
duke
parents:
diff changeset
   416
  // Generations may keep statistics about collection.  This
489c9b5090e2 Initial load
duke
parents:
diff changeset
   417
  // method updates those statistics.  current_level is
489c9b5090e2 Initial load
duke
parents:
diff changeset
   418
  // the level of the collection that has most recently
489c9b5090e2 Initial load
duke
parents:
diff changeset
   419
  // occurred.  This allows the generation to decide what
489c9b5090e2 Initial load
duke
parents:
diff changeset
   420
  // statistics are valid to collect.  For example, the
489c9b5090e2 Initial load
duke
parents:
diff changeset
   421
  // generation can decide to gather the amount of promoted data
489c9b5090e2 Initial load
duke
parents:
diff changeset
   422
  // if the collection of the younger generations has completed.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   423
  GCStats* gc_stats() const { return _gc_stats; }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   424
  virtual void update_gc_stats(int current_level, bool full) {}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   425
489c9b5090e2 Initial load
duke
parents:
diff changeset
   426
  // Mark sweep support phase2
489c9b5090e2 Initial load
duke
parents:
diff changeset
   427
  virtual void prepare_for_compaction(CompactPoint* cp);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   428
  // Mark sweep support phase3
489c9b5090e2 Initial load
duke
parents:
diff changeset
   429
  virtual void adjust_pointers();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   430
  // Mark sweep support phase4
489c9b5090e2 Initial load
duke
parents:
diff changeset
   431
  virtual void compact();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   432
  virtual void post_compact() {ShouldNotReachHere();}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   433
489c9b5090e2 Initial load
duke
parents:
diff changeset
   434
  // Support for CMS's rescan. In this general form we return a pointer
489c9b5090e2 Initial load
duke
parents:
diff changeset
   435
  // to an abstract object that can be used, based on specific previously
489c9b5090e2 Initial load
duke
parents:
diff changeset
   436
  // decided protocols, to exchange information between generations,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   437
  // information that may be useful for speeding up certain types of
489c9b5090e2 Initial load
duke
parents:
diff changeset
   438
  // garbage collectors. A NULL value indicates to the client that
489c9b5090e2 Initial load
duke
parents:
diff changeset
   439
  // no data recording is expected by the provider. The data-recorder is
489c9b5090e2 Initial load
duke
parents:
diff changeset
   440
  // expected to be GC worker thread-local, with the worker index
489c9b5090e2 Initial load
duke
parents:
diff changeset
   441
  // indicated by "thr_num".
489c9b5090e2 Initial load
duke
parents:
diff changeset
   442
  virtual void* get_data_recorder(int thr_num) { return NULL; }
18994
d32a17b7502c 6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents: 18687
diff changeset
   443
  virtual void sample_eden_chunk() {}
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   444
489c9b5090e2 Initial load
duke
parents:
diff changeset
   445
  // Some generations may require some cleanup actions before allowing
489c9b5090e2 Initial load
duke
parents:
diff changeset
   446
  // a verification.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   447
  virtual void prepare_for_verify() {};
489c9b5090e2 Initial load
duke
parents:
diff changeset
   448
489c9b5090e2 Initial load
duke
parents:
diff changeset
   449
  // Accessing "marks".
489c9b5090e2 Initial load
duke
parents:
diff changeset
   450
489c9b5090e2 Initial load
duke
parents:
diff changeset
   451
  // This function gives a generation a chance to note a point between
489c9b5090e2 Initial load
duke
parents:
diff changeset
   452
  // collections.  For example, a contiguous generation might note the
489c9b5090e2 Initial load
duke
parents:
diff changeset
   453
  // beginning allocation point post-collection, which might allow some later
489c9b5090e2 Initial load
duke
parents:
diff changeset
   454
  // operations to be optimized.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   455
  virtual void save_marks() {}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   456
489c9b5090e2 Initial load
duke
parents:
diff changeset
   457
  // This function allows generations to initialize any "saved marks".  That
489c9b5090e2 Initial load
duke
parents:
diff changeset
   458
  // is, should only be called when the generation is empty.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   459
  virtual void reset_saved_marks() {}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   460
489c9b5090e2 Initial load
duke
parents:
diff changeset
   461
  // This function is "true" iff any no allocations have occurred in the
489c9b5090e2 Initial load
duke
parents:
diff changeset
   462
  // generation since the last call to "save_marks".
489c9b5090e2 Initial load
duke
parents:
diff changeset
   463
  virtual bool no_allocs_since_save_marks() = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   464
489c9b5090e2 Initial load
duke
parents:
diff changeset
   465
  // Apply "cl->apply" to (the addresses of) all reference fields in objects
489c9b5090e2 Initial load
duke
parents:
diff changeset
   466
  // allocated in the current generation since the last call to "save_marks".
489c9b5090e2 Initial load
duke
parents:
diff changeset
   467
  // If more objects are allocated in this generation as a result of applying
489c9b5090e2 Initial load
duke
parents:
diff changeset
   468
  // the closure, iterates over reference fields in those objects as well.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   469
  // Calls "save_marks" at the end of the iteration.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   470
  // General signature...
489c9b5090e2 Initial load
duke
parents:
diff changeset
   471
  virtual void oop_since_save_marks_iterate_v(OopsInGenClosure* cl) = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   472
  // ...and specializations for de-virtualization.  (The general
22551
9bf46d16dcc6 8025856: Fix typos in the GC code
jwilhelm
parents: 22234
diff changeset
   473
  // implementation of the _nv versions call the virtual version.
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   474
  // Note that the _nv suffix is not really semantically necessary,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   475
  // but it avoids some not-so-useful warnings on Solaris.)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   476
#define Generation_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix)             \
489c9b5090e2 Initial load
duke
parents:
diff changeset
   477
  virtual void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl) {    \
489c9b5090e2 Initial load
duke
parents:
diff changeset
   478
    oop_since_save_marks_iterate_v((OopsInGenClosure*)cl);                      \
489c9b5090e2 Initial load
duke
parents:
diff changeset
   479
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   480
  SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(Generation_SINCE_SAVE_MARKS_DECL)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   481
489c9b5090e2 Initial load
duke
parents:
diff changeset
   482
#undef Generation_SINCE_SAVE_MARKS_DECL
489c9b5090e2 Initial load
duke
parents:
diff changeset
   483
489c9b5090e2 Initial load
duke
parents:
diff changeset
   484
  // The "requestor" generation is performing some garbage collection
489c9b5090e2 Initial load
duke
parents:
diff changeset
   485
  // action for which it would be useful to have scratch space.  If
489c9b5090e2 Initial load
duke
parents:
diff changeset
   486
  // the target is not the requestor, no gc actions will be required
489c9b5090e2 Initial load
duke
parents:
diff changeset
   487
  // of the target.  The requestor promises to allocate no more than
489c9b5090e2 Initial load
duke
parents:
diff changeset
   488
  // "max_alloc_words" in the target generation (via promotion say,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   489
  // if the requestor is a young generation and the target is older).
489c9b5090e2 Initial load
duke
parents:
diff changeset
   490
  // If the target generation can provide any scratch space, it adds
489c9b5090e2 Initial load
duke
parents:
diff changeset
   491
  // it to "list", leaving "list" pointing to the head of the
489c9b5090e2 Initial load
duke
parents:
diff changeset
   492
  // augmented list.  The default is to offer no space.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   493
  virtual void contribute_scratch(ScratchBlock*& list, Generation* requestor,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   494
                                  size_t max_alloc_words) {}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   495
971
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 360
diff changeset
   496
  // Give each generation an opportunity to do clean up for any
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 360
diff changeset
   497
  // contributed scratch.
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 360
diff changeset
   498
  virtual void reset_scratch() {};
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 360
diff changeset
   499
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   500
  // When an older generation has been collected, and perhaps resized,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   501
  // this method will be invoked on all younger generations (from older to
489c9b5090e2 Initial load
duke
parents:
diff changeset
   502
  // younger), allowing them to resize themselves as appropriate.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   503
  virtual void compute_new_size() = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   504
489c9b5090e2 Initial load
duke
parents:
diff changeset
   505
  // Printing
489c9b5090e2 Initial load
duke
parents:
diff changeset
   506
  virtual const char* name() const = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   507
  virtual const char* short_name() const = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   508
489c9b5090e2 Initial load
duke
parents:
diff changeset
   509
  int level() const { return _level; }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   510
489c9b5090e2 Initial load
duke
parents:
diff changeset
   511
  // Reference Processing accessor
489c9b5090e2 Initial load
duke
parents:
diff changeset
   512
  ReferenceProcessor* const ref_processor() { return _ref_processor; }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   513
489c9b5090e2 Initial load
duke
parents:
diff changeset
   514
  // Iteration.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   515
489c9b5090e2 Initial load
duke
parents:
diff changeset
   516
  // Iterate over all the ref-containing fields of all objects in the
489c9b5090e2 Initial load
duke
parents:
diff changeset
   517
  // generation, calling "cl.do_oop" on each.
13728
882756847a04 6964458: Reimplement class meta-data storage to use native memory
coleenp
parents: 13195
diff changeset
   518
  virtual void oop_iterate(ExtendedOopClosure* cl);
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   519
489c9b5090e2 Initial load
duke
parents:
diff changeset
   520
  // Iterate over all objects in the generation, calling "cl.do_object" on
489c9b5090e2 Initial load
duke
parents:
diff changeset
   521
  // each.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   522
  virtual void object_iterate(ObjectClosure* cl);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   523
1893
c82e388e17c5 6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents: 979
diff changeset
   524
  // Iterate over all safe objects in the generation, calling "cl.do_object" on
c82e388e17c5 6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents: 979
diff changeset
   525
  // each.  An object is safe if its references point to other objects in
c82e388e17c5 6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents: 979
diff changeset
   526
  // the heap.  This defaults to object_iterate() unless overridden.
c82e388e17c5 6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents: 979
diff changeset
   527
  virtual void safe_object_iterate(ObjectClosure* cl);
c82e388e17c5 6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents: 979
diff changeset
   528
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   529
  // Apply "cl->do_oop" to (the address of) all and only all the ref fields
489c9b5090e2 Initial load
duke
parents:
diff changeset
   530
  // in the current generation that contain pointers to objects in younger
489c9b5090e2 Initial load
duke
parents:
diff changeset
   531
  // generations. Objects allocated since the last "save_marks" call are
489c9b5090e2 Initial load
duke
parents:
diff changeset
   532
  // excluded.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   533
  virtual void younger_refs_iterate(OopsInGenClosure* cl) = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   534
489c9b5090e2 Initial load
duke
parents:
diff changeset
   535
  // Inform a generation that it longer contains references to objects
489c9b5090e2 Initial load
duke
parents:
diff changeset
   536
  // in any younger generation.    [e.g. Because younger gens are empty,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   537
  // clear the card table.]
489c9b5090e2 Initial load
duke
parents:
diff changeset
   538
  virtual void clear_remembered_set() { }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   539
489c9b5090e2 Initial load
duke
parents:
diff changeset
   540
  // Inform a generation that some of its objects have moved.  [e.g. The
489c9b5090e2 Initial load
duke
parents:
diff changeset
   541
  // generation's spaces were compacted, invalidating the card table.]
489c9b5090e2 Initial load
duke
parents:
diff changeset
   542
  virtual void invalidate_remembered_set() { }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   543
489c9b5090e2 Initial load
duke
parents:
diff changeset
   544
  // Block abstraction.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   545
489c9b5090e2 Initial load
duke
parents:
diff changeset
   546
  // Returns the address of the start of the "block" that contains the
489c9b5090e2 Initial load
duke
parents:
diff changeset
   547
  // address "addr".  We say "blocks" instead of "object" since some heaps
489c9b5090e2 Initial load
duke
parents:
diff changeset
   548
  // may not pack objects densely; a chunk may either be an object or a
489c9b5090e2 Initial load
duke
parents:
diff changeset
   549
  // non-object.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   550
  virtual HeapWord* block_start(const void* addr) const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   551
489c9b5090e2 Initial load
duke
parents:
diff changeset
   552
  // Requires "addr" to be the start of a chunk, and returns its size.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   553
  // "addr + size" is required to be the start of a new chunk, or the end
489c9b5090e2 Initial load
duke
parents:
diff changeset
   554
  // of the active area of the heap.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   555
  virtual size_t block_size(const HeapWord* addr) const ;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   556
489c9b5090e2 Initial load
duke
parents:
diff changeset
   557
  // Requires "addr" to be the start of a block, and returns "TRUE" iff
489c9b5090e2 Initial load
duke
parents:
diff changeset
   558
  // the block is an object.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   559
  virtual bool block_is_obj(const HeapWord* addr) const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   560
489c9b5090e2 Initial load
duke
parents:
diff changeset
   561
489c9b5090e2 Initial load
duke
parents:
diff changeset
   562
  // PrintGC, PrintGCDetails support
489c9b5090e2 Initial load
duke
parents:
diff changeset
   563
  void print_heap_change(size_t prev_used) const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   564
489c9b5090e2 Initial load
duke
parents:
diff changeset
   565
  // PrintHeapAtGC support
489c9b5090e2 Initial load
duke
parents:
diff changeset
   566
  virtual void print() const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   567
  virtual void print_on(outputStream* st) const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   568
12379
2cf45b79ce3a 4988100: oop_verify_old_oop appears to be dead
brutisso
parents: 11251
diff changeset
   569
  virtual void verify() = 0;
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   570
489c9b5090e2 Initial load
duke
parents:
diff changeset
   571
  struct StatRecord {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   572
    int invocations;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   573
    elapsedTimer accumulated_time;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   574
    StatRecord() :
489c9b5090e2 Initial load
duke
parents:
diff changeset
   575
      invocations(0),
489c9b5090e2 Initial load
duke
parents:
diff changeset
   576
      accumulated_time(elapsedTimer()) {}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   577
  };
489c9b5090e2 Initial load
duke
parents:
diff changeset
   578
private:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   579
  StatRecord _stat_record;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   580
public:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   581
  StatRecord* stat_record() { return &_stat_record; }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   582
489c9b5090e2 Initial load
duke
parents:
diff changeset
   583
  virtual void print_summary_info();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   584
  virtual void print_summary_info_on(outputStream* st);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   585
489c9b5090e2 Initial load
duke
parents:
diff changeset
   586
  // Performance Counter support
489c9b5090e2 Initial load
duke
parents:
diff changeset
   587
  virtual void update_counters() = 0;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   588
  virtual CollectorCounters* counters() { return _gc_counters; }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   589
};
489c9b5090e2 Initial load
duke
parents:
diff changeset
   590
489c9b5090e2 Initial load
duke
parents:
diff changeset
   591
// Class CardGeneration is a generation that is covered by a card table,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   592
// and uses a card-size block-offset array to implement block_start.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   593
489c9b5090e2 Initial load
duke
parents:
diff changeset
   594
// class BlockOffsetArray;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   595
// class BlockOffsetArrayContigSpace;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   596
class BlockOffsetSharedArray;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   597
489c9b5090e2 Initial load
duke
parents:
diff changeset
   598
class CardGeneration: public Generation {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   599
  friend class VMStructs;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   600
 protected:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   601
  // This is shared with other generations.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   602
  GenRemSet* _rs;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   603
  // This is local to this generation.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   604
  BlockOffsetSharedArray* _bts;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   605
16681
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   606
  // current shrinking effect: this damps shrinking when the heap gets empty.
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   607
  size_t _shrink_factor;
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   608
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   609
  size_t _min_heap_delta_bytes;   // Minimum amount to expand.
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   610
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   611
  // Some statistics from before gc started.
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   612
  // These are gathered in the gc_prologue (and should_collect)
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   613
  // to control growing/shrinking policy in spite of promotions.
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   614
  size_t _capacity_at_prologue;
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   615
  size_t _used_at_prologue;
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   616
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   617
  CardGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   618
                 GenRemSet* remset);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   619
489c9b5090e2 Initial load
duke
parents:
diff changeset
   620
 public:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   621
979
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   622
  // Attempt to expand the generation by "bytes".  Expand by at a
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   623
  // minimum "expand_bytes".  Return true if some amount (not
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   624
  // necessarily the full "bytes") was done.
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   625
  virtual bool expand(size_t bytes, size_t expand_bytes);
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   626
16681
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   627
  // Shrink generation with specified size (returns false if unable to shrink)
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   628
  virtual void shrink(size_t bytes) = 0;
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   629
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   630
  virtual void compute_new_size();
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   631
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   632
  virtual void clear_remembered_set();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   633
489c9b5090e2 Initial load
duke
parents:
diff changeset
   634
  virtual void invalidate_remembered_set();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   635
489c9b5090e2 Initial load
duke
parents:
diff changeset
   636
  virtual void prepare_for_verify();
979
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   637
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   638
  // Grow generation with specified size (returns false if unable to grow)
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   639
  virtual bool grow_by(size_t bytes) = 0;
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   640
  // Grow generation to reserved size.
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   641
  virtual bool grow_to_reserved() = 0;
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   642
};
489c9b5090e2 Initial load
duke
parents:
diff changeset
   643
489c9b5090e2 Initial load
duke
parents:
diff changeset
   644
// OneContigSpaceCardGeneration models a heap of old objects contained in a single
489c9b5090e2 Initial load
duke
parents:
diff changeset
   645
// contiguous space.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   646
//
489c9b5090e2 Initial load
duke
parents:
diff changeset
   647
// Garbage collection is performed using mark-compact.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   648
489c9b5090e2 Initial load
duke
parents:
diff changeset
   649
class OneContigSpaceCardGeneration: public CardGeneration {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   650
  friend class VMStructs;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   651
  // Abstractly, this is a subtype that gets access to protected fields.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   652
  friend class VM_PopulateDumpSharedSpace;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   653
489c9b5090e2 Initial load
duke
parents:
diff changeset
   654
 protected:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   655
  ContiguousSpace*  _the_space;       // actual space holding objects
489c9b5090e2 Initial load
duke
parents:
diff changeset
   656
  WaterMark  _last_gc;                // watermark between objects allocated before
489c9b5090e2 Initial load
duke
parents:
diff changeset
   657
                                      // and after last GC.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   658
489c9b5090e2 Initial load
duke
parents:
diff changeset
   659
  // Grow generation with specified size (returns false if unable to grow)
979
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   660
  virtual bool grow_by(size_t bytes);
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   661
  // Grow generation to reserved size.
979
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   662
  virtual bool grow_to_reserved();
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   663
  // Shrink generation with specified size (returns false if unable to shrink)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   664
  void shrink_by(size_t bytes);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   665
489c9b5090e2 Initial load
duke
parents:
diff changeset
   666
  // Allocation failure
979
c9479f1e0a94 6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents: 977
diff changeset
   667
  virtual bool expand(size_t bytes, size_t expand_bytes);
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   668
  void shrink(size_t bytes);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   669
489c9b5090e2 Initial load
duke
parents:
diff changeset
   670
  // Accessing spaces
489c9b5090e2 Initial load
duke
parents:
diff changeset
   671
  ContiguousSpace* the_space() const { return _the_space; }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   672
489c9b5090e2 Initial load
duke
parents:
diff changeset
   673
 public:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   674
  OneContigSpaceCardGeneration(ReservedSpace rs, size_t initial_byte_size,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   675
                               int level, GenRemSet* remset,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   676
                               ContiguousSpace* space) :
489c9b5090e2 Initial load
duke
parents:
diff changeset
   677
    CardGeneration(rs, initial_byte_size, level, remset),
16681
d64161ca3e3c 8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents: 13728
diff changeset
   678
    _the_space(space)
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   679
  {}
489c9b5090e2 Initial load
duke
parents:
diff changeset
   680
489c9b5090e2 Initial load
duke
parents:
diff changeset
   681
  inline bool is_in(const void* p) const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   682
489c9b5090e2 Initial load
duke
parents:
diff changeset
   683
  // Space enquiries
489c9b5090e2 Initial load
duke
parents:
diff changeset
   684
  size_t capacity() const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   685
  size_t used() const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   686
  size_t free() const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   687
489c9b5090e2 Initial load
duke
parents:
diff changeset
   688
  MemRegion used_region() const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   689
489c9b5090e2 Initial load
duke
parents:
diff changeset
   690
  size_t unsafe_max_alloc_nogc() const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   691
  size_t contiguous_available() const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   692
489c9b5090e2 Initial load
duke
parents:
diff changeset
   693
  // Iteration
489c9b5090e2 Initial load
duke
parents:
diff changeset
   694
  void object_iterate(ObjectClosure* blk);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   695
  void space_iterate(SpaceClosure* blk, bool usedOnly = false);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   696
489c9b5090e2 Initial load
duke
parents:
diff changeset
   697
  void younger_refs_iterate(OopsInGenClosure* blk);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   698
489c9b5090e2 Initial load
duke
parents:
diff changeset
   699
  inline CompactibleSpace* first_compaction_space() const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   700
489c9b5090e2 Initial load
duke
parents:
diff changeset
   701
  virtual inline HeapWord* allocate(size_t word_size, bool is_tlab);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   702
  virtual inline HeapWord* par_allocate(size_t word_size, bool is_tlab);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   703
489c9b5090e2 Initial load
duke
parents:
diff changeset
   704
  // Accessing marks
489c9b5090e2 Initial load
duke
parents:
diff changeset
   705
  inline WaterMark top_mark();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   706
  inline WaterMark bottom_mark();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   707
489c9b5090e2 Initial load
duke
parents:
diff changeset
   708
#define OneContig_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix)      \
489c9b5090e2 Initial load
duke
parents:
diff changeset
   709
  void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   710
  OneContig_SINCE_SAVE_MARKS_DECL(OopsInGenClosure,_v)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   711
  SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(OneContig_SINCE_SAVE_MARKS_DECL)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   712
489c9b5090e2 Initial load
duke
parents:
diff changeset
   713
  void save_marks();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   714
  void reset_saved_marks();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   715
  bool no_allocs_since_save_marks();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   716
489c9b5090e2 Initial load
duke
parents:
diff changeset
   717
  inline size_t block_size(const HeapWord* addr) const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   718
489c9b5090e2 Initial load
duke
parents:
diff changeset
   719
  inline bool block_is_obj(const HeapWord* addr) const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   720
489c9b5090e2 Initial load
duke
parents:
diff changeset
   721
  virtual void collect(bool full,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   722
                       bool clear_all_soft_refs,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   723
                       size_t size,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   724
                       bool is_tlab);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   725
  HeapWord* expand_and_allocate(size_t size,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   726
                                bool is_tlab,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   727
                                bool parallel = false);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   728
489c9b5090e2 Initial load
duke
parents:
diff changeset
   729
  virtual void prepare_for_verify();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   730
489c9b5090e2 Initial load
duke
parents:
diff changeset
   731
  virtual void gc_epilogue(bool full);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   732
971
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 360
diff changeset
   733
  virtual void record_spaces_top();
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 360
diff changeset
   734
12379
2cf45b79ce3a 4988100: oop_verify_old_oop appears to be dead
brutisso
parents: 11251
diff changeset
   735
  virtual void verify();
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   736
  virtual void print_on(outputStream* st) const;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   737
};
7397
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 6985
diff changeset
   738
5b173b4ca846 6989984: Use standard include model for Hospot
stefank
parents: 6985
diff changeset
   739
#endif // SHARE_VM_MEMORY_GENERATION_HPP