hotspot/src/share/vm/memory/genCollectedHeap.hpp
author ysr
Wed, 13 Jan 2010 15:26:39 -0800
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parent 4031 439e2afc9abc
child 5547 f4b087cbb361
permissions -rw-r--r--
6896647: card marks can be deferred too long Summary: Deferred card marks are now flushed during the gc prologue. Parallel[Scavege,OldGC] and SerialGC no longer defer card marks generated by COMPILER2 as a result of ReduceInitialCardMarks. For these cases, introduced a diagnostic option to defer the card marks, only for the purposes of testing and diagnostics. CMS and G1 continue to defer card marks. Potential performance concern related to single-threaded flushing of deferred card marks in the gc prologue will be addressed in the future. Reviewed-by: never, johnc
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/*
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 * Copyright 2000-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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 * CA 95054 USA or visit www.sun.com if you need additional information or
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 * have any questions.
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 *
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 */
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class SubTasksDone;
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// A "GenCollectedHeap" is a SharedHeap that uses generational
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// collection.  It is represented with a sequence of Generation's.
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class GenCollectedHeap : public SharedHeap {
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  friend class GenCollectorPolicy;
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  friend class Generation;
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  friend class DefNewGeneration;
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  friend class TenuredGeneration;
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  friend class ConcurrentMarkSweepGeneration;
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  friend class CMSCollector;
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  friend class GenMarkSweep;
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  friend class VM_GenCollectForAllocation;
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  friend class VM_GenCollectForPermanentAllocation;
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  friend class VM_GenCollectFull;
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  friend class VM_GenCollectFullConcurrent;
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  friend class VM_GC_HeapInspection;
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  friend class VM_HeapDumper;
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  friend class HeapInspection;
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  friend class GCCauseSetter;
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  friend class VMStructs;
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public:
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  enum SomeConstants {
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    max_gens = 10
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  };
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  friend class VM_PopulateDumpSharedSpace;
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 protected:
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  // Fields:
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  static GenCollectedHeap* _gch;
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  int _n_gens;
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  Generation* _gens[max_gens];
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  GenerationSpec** _gen_specs;
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  // The generational collector policy.
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  GenCollectorPolicy* _gen_policy;
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  // If a generation would bail out of an incremental collection,
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  // it sets this flag.  If the flag is set, satisfy_failed_allocation
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  // will attempt allocating in all generations before doing a full GC.
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  bool _incremental_collection_will_fail;
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  bool _last_incremental_collection_failed;
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  // In support of ExplicitGCInvokesConcurrent functionality
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  unsigned int _full_collections_completed;
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  // Data structure for claiming the (potentially) parallel tasks in
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  // (gen-specific) strong roots processing.
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  SubTasksDone* _gen_process_strong_tasks;
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  // In block contents verification, the number of header words to skip
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  NOT_PRODUCT(static size_t _skip_header_HeapWords;)
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  // GC is not allowed during the dump of the shared classes.  Keep track
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  // of this in order to provide an reasonable error message when terminating.
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  bool _preloading_shared_classes;
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protected:
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  // Directs each generation up to and including "collectedGen" to recompute
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  // its desired size.
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  void compute_new_generation_sizes(int collectedGen);
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  // Helper functions for allocation
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  HeapWord* attempt_allocation(size_t size,
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                               bool   is_tlab,
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                               bool   first_only);
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  // Helper function for two callbacks below.
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  // Considers collection of the first max_level+1 generations.
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  void do_collection(bool   full,
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                     bool   clear_all_soft_refs,
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                     size_t size,
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                     bool   is_tlab,
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                     int    max_level);
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  // Callback from VM_GenCollectForAllocation operation.
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  // This function does everything necessary/possible to satisfy an
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  // allocation request that failed in the youngest generation that should
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  // have handled it (including collection, expansion, etc.)
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  HeapWord* satisfy_failed_allocation(size_t size, bool is_tlab);
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  // Callback from VM_GenCollectFull operation.
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  // Perform a full collection of the first max_level+1 generations.
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  void do_full_collection(bool clear_all_soft_refs, int max_level);
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  // Does the "cause" of GC indicate that
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  // we absolutely __must__ clear soft refs?
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  bool must_clear_all_soft_refs();
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public:
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  GenCollectedHeap(GenCollectorPolicy *policy);
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  GCStats* gc_stats(int level) const;
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  // Returns JNI_OK on success
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  virtual jint initialize();
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  char* allocate(size_t alignment, PermanentGenerationSpec* perm_gen_spec,
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                 size_t* _total_reserved, int* _n_covered_regions,
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                 ReservedSpace* heap_rs);
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  // Does operations required after initialization has been done.
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  void post_initialize();
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  // Initialize ("weak") refs processing support
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  virtual void ref_processing_init();
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  virtual CollectedHeap::Name kind() const {
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    return CollectedHeap::GenCollectedHeap;
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  }
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  // The generational collector policy.
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  GenCollectorPolicy* gen_policy() const { return _gen_policy; }
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  // Adaptive size policy
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  virtual AdaptiveSizePolicy* size_policy() {
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    return gen_policy()->size_policy();
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  }
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  size_t capacity() const;
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  size_t used() const;
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  // Save the "used_region" for generations level and lower,
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  // and, if perm is true, for perm gen.
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  void save_used_regions(int level, bool perm);
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  size_t max_capacity() const;
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  HeapWord* mem_allocate(size_t size,
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                         bool   is_large_noref,
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                         bool   is_tlab,
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                         bool*  gc_overhead_limit_was_exceeded);
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  // We may support a shared contiguous allocation area, if the youngest
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  // generation does.
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  bool supports_inline_contig_alloc() const;
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  HeapWord** top_addr() const;
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  HeapWord** end_addr() const;
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  // Return an estimate of the maximum allocation that could be performed
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  // without triggering any collection activity.  In a generational
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  // collector, for example, this is probably the largest allocation that
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  // could be supported in the youngest generation.  It is "unsafe" because
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  // no locks are taken; the result should be treated as an approximation,
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  // not a guarantee.
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  size_t unsafe_max_alloc();
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  // Does this heap support heap inspection? (+PrintClassHistogram)
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  virtual bool supports_heap_inspection() const { return true; }
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  // Perform a full collection of the heap; intended for use in implementing
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  // "System.gc". This implies as full a collection as the CollectedHeap
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  // supports. Caller does not hold the Heap_lock on entry.
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  void collect(GCCause::Cause cause);
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  // This interface assumes that it's being called by the
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  // vm thread. It collects the heap assuming that the
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  // heap lock is already held and that we are executing in
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  // the context of the vm thread.
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  void collect_as_vm_thread(GCCause::Cause cause);
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  // The same as above but assume that the caller holds the Heap_lock.
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  void collect_locked(GCCause::Cause cause);
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  // Perform a full collection of the first max_level+1 generations.
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  // Mostly used for testing purposes. Caller does not hold the Heap_lock on entry.
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  void collect(GCCause::Cause cause, int max_level);
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  // Returns "TRUE" iff "p" points into the allocated area of the heap.
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  // The methods is_in(), is_in_closed_subset() and is_in_youngest() may
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  // be expensive to compute in general, so, to prevent
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  // their inadvertent use in product jvm's, we restrict their use to
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  // assertion checking or verification only.
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  bool is_in(const void* p) const;
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  // override
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  bool is_in_closed_subset(const void* p) const {
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    if (UseConcMarkSweepGC) {
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      return is_in_reserved(p);
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    } else {
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      return is_in(p);
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    }
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  }
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  // Returns "TRUE" iff "p" points into the youngest generation.
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  bool is_in_youngest(void* p);
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  // Iteration functions.
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  void oop_iterate(OopClosure* cl);
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  void oop_iterate(MemRegion mr, OopClosure* cl);
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  void object_iterate(ObjectClosure* cl);
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  void safe_object_iterate(ObjectClosure* cl);
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  void object_iterate_since_last_GC(ObjectClosure* cl);
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  Space* space_containing(const void* addr) const;
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  // A CollectedHeap is divided into a dense sequence of "blocks"; that is,
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  // each address in the (reserved) heap is a member of exactly
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  // one block.  The defining characteristic of a block is that it is
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  // possible to find its size, and thus to progress forward to the next
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  // block.  (Blocks may be of different sizes.)  Thus, blocks may
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  // represent Java objects, or they might be free blocks in a
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  // free-list-based heap (or subheap), as long as the two kinds are
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  // distinguishable and the size of each is determinable.
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  // Returns the address of the start of the "block" that contains the
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  // address "addr".  We say "blocks" instead of "object" since some heaps
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  // may not pack objects densely; a chunk may either be an object or a
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  // non-object.
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  virtual HeapWord* block_start(const void* addr) const;
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  // Requires "addr" to be the start of a chunk, and returns its size.
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  // "addr + size" is required to be the start of a new chunk, or the end
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  // of the active area of the heap. Assumes (and verifies in non-product
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  // builds) that addr is in the allocated part of the heap and is
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  // the start of a chunk.
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  virtual size_t block_size(const HeapWord* addr) const;
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  // Requires "addr" to be the start of a block, and returns "TRUE" iff
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  // the block is an object. Assumes (and verifies in non-product
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  // builds) that addr is in the allocated part of the heap and is
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  // the start of a chunk.
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  virtual bool block_is_obj(const HeapWord* addr) const;
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  // Section on TLAB's.
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  virtual bool supports_tlab_allocation() const;
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  virtual size_t tlab_capacity(Thread* thr) const;
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  virtual size_t unsafe_max_tlab_alloc(Thread* thr) const;
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  virtual HeapWord* allocate_new_tlab(size_t size);
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  // Can a compiler initialize a new object without store barriers?
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  // This permission only extends from the creation of a new object
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  // via a TLAB up to the first subsequent safepoint.
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  virtual bool can_elide_tlab_store_barriers() const {
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    return true;
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  }
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  virtual bool card_mark_must_follow_store() const {
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    return UseConcMarkSweepGC;
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  }
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  // We don't need barriers for stores to objects in the
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  // young gen and, a fortiori, for initializing stores to
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  // objects therein. This applies to {DefNew,ParNew}+{Tenured,CMS}
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  // only and may need to be re-examined in case other
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  // kinds of collectors are implemented in the future.
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  virtual bool can_elide_initializing_store_barrier(oop new_obj) {
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    // We wanted to assert that:-
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    // assert(UseParNewGC || UseSerialGC || UseConcMarkSweepGC,
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    //       "Check can_elide_initializing_store_barrier() for this collector");
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    // but unfortunately the flag UseSerialGC need not necessarily always
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    // be set when DefNew+Tenured are being used.
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    return is_in_youngest((void*)new_obj);
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  }
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  // Can a compiler elide a store barrier when it writes
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  // a permanent oop into the heap?  Applies when the compiler
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  // is storing x to the heap, where x->is_perm() is true.
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  virtual bool can_elide_permanent_oop_store_barriers() const {
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    // CMS needs to see all, even intra-generational, ref updates.
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    return !UseConcMarkSweepGC;
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  }
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  // The "requestor" generation is performing some garbage collection
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  // action for which it would be useful to have scratch space.  The
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  // requestor promises to allocate no more than "max_alloc_words" in any
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  // older generation (via promotion say.)   Any blocks of space that can
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  // be provided are returned as a list of ScratchBlocks, sorted by
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  // decreasing size.
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  ScratchBlock* gather_scratch(Generation* requestor, size_t max_alloc_words);
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  // Allow each generation to reset any scratch space that it has
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  // contributed as it needs.
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  void release_scratch();
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  size_t large_typearray_limit();
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  // Ensure parsability: override
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  virtual void ensure_parsability(bool retire_tlabs);
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  // Time in ms since the longest time a collector ran in
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  // in any generation.
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  virtual jlong millis_since_last_gc();
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  // Total number of full collections completed.
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  unsigned int total_full_collections_completed() {
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    assert(_full_collections_completed <= _total_full_collections,
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           "Can't complete more collections than were started");
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    return _full_collections_completed;
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  }
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  // Update above counter, as appropriate, at the end of a stop-world GC cycle
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  unsigned int update_full_collections_completed();
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  // Update above counter, as appropriate, at the end of a concurrent GC cycle
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  unsigned int update_full_collections_completed(unsigned int count);
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  // Update "time of last gc" for all constituent generations
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  // to "now".
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  void update_time_of_last_gc(jlong now) {
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    for (int i = 0; i < _n_gens; i++) {
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      _gens[i]->update_time_of_last_gc(now);
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    }
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    perm_gen()->update_time_of_last_gc(now);
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  }
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  // Update the gc statistics for each generation.
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  // "level" is the level of the lastest collection
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  void update_gc_stats(int current_level, bool full) {
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    for (int i = 0; i < _n_gens; i++) {
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      _gens[i]->update_gc_stats(current_level, full);
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    }
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    perm_gen()->update_gc_stats(current_level, full);
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  }
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  // Override.
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  bool no_gc_in_progress() { return !is_gc_active(); }
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  // Override.
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  void prepare_for_verify();
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  // Override.
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  void verify(bool allow_dirty, bool silent, bool /* option */);
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  // Override.
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  void print() const;
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  void print_on(outputStream* st) const;
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  virtual void print_gc_threads_on(outputStream* st) const;
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  virtual void gc_threads_do(ThreadClosure* tc) const;
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  virtual void print_tracing_info() const;
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  // PrintGC, PrintGCDetails support
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  void print_heap_change(size_t prev_used) const;
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  void print_perm_heap_change(size_t perm_prev_used) const;
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  // The functions below are helper functions that a subclass of
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  // "CollectedHeap" can use in the implementation of its virtual
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  // functions.
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  class GenClosure : public StackObj {
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   public:
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    virtual void do_generation(Generation* gen) = 0;
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  };
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  // Apply "cl.do_generation" to all generations in the heap (not including
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  // the permanent generation).  If "old_to_young" determines the order.
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  void generation_iterate(GenClosure* cl, bool old_to_young);
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  void space_iterate(SpaceClosure* cl);
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  // Return "true" if all generations (but perm) have reached the
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  // maximal committed limit that they can reach, without a garbage
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  // collection.
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  virtual bool is_maximal_no_gc() const;
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diff changeset
   378
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parents:
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   379
  // Return the generation before "gen", or else NULL.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   380
  Generation* prev_gen(Generation* gen) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   381
    int l = gen->level();
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parents:
diff changeset
   382
    if (l == 0) return NULL;
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duke
parents:
diff changeset
   383
    else return _gens[l-1];
489c9b5090e2 Initial load
duke
parents:
diff changeset
   384
  }
489c9b5090e2 Initial load
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parents:
diff changeset
   385
489c9b5090e2 Initial load
duke
parents:
diff changeset
   386
  // Return the generation after "gen", or else NULL.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   387
  Generation* next_gen(Generation* gen) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   388
    int l = gen->level() + 1;
489c9b5090e2 Initial load
duke
parents:
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   389
    if (l == _n_gens) return NULL;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   390
    else return _gens[l];
489c9b5090e2 Initial load
duke
parents:
diff changeset
   391
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   392
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duke
parents:
diff changeset
   393
  Generation* get_gen(int i) const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   394
    if (i >= 0 && i < _n_gens)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   395
      return _gens[i];
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duke
parents:
diff changeset
   396
    else
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duke
parents:
diff changeset
   397
      return NULL;
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duke
parents:
diff changeset
   398
  }
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duke
parents:
diff changeset
   399
489c9b5090e2 Initial load
duke
parents:
diff changeset
   400
  int n_gens() const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   401
    assert(_n_gens == gen_policy()->number_of_generations(), "Sanity");
489c9b5090e2 Initial load
duke
parents:
diff changeset
   402
    return _n_gens;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   403
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   404
489c9b5090e2 Initial load
duke
parents:
diff changeset
   405
  // Convenience function to be used in situations where the heap type can be
489c9b5090e2 Initial load
duke
parents:
diff changeset
   406
  // asserted to be this type.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   407
  static GenCollectedHeap* heap();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   408
489c9b5090e2 Initial load
duke
parents:
diff changeset
   409
  void set_par_threads(int t);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   410
489c9b5090e2 Initial load
duke
parents:
diff changeset
   411
489c9b5090e2 Initial load
duke
parents:
diff changeset
   412
  // Invoke the "do_oop" method of one of the closures "not_older_gens"
489c9b5090e2 Initial load
duke
parents:
diff changeset
   413
  // or "older_gens" on root locations for the generation at
489c9b5090e2 Initial load
duke
parents:
diff changeset
   414
  // "level".  (The "older_gens" closure is used for scanning references
489c9b5090e2 Initial load
duke
parents:
diff changeset
   415
  // from older generations; "not_older_gens" is used everywhere else.)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   416
  // If "younger_gens_as_roots" is false, younger generations are
489c9b5090e2 Initial load
duke
parents:
diff changeset
   417
  // not scanned as roots; in this case, the caller must be arranging to
489c9b5090e2 Initial load
duke
parents:
diff changeset
   418
  // scan the younger generations itself.  (For example, a generation might
489c9b5090e2 Initial load
duke
parents:
diff changeset
   419
  // explicitly mark reachable objects in younger generations, to avoid
489c9b5090e2 Initial load
duke
parents:
diff changeset
   420
  // excess storage retention.)  If "collecting_perm_gen" is false, then
489c9b5090e2 Initial load
duke
parents:
diff changeset
   421
  // roots that may only contain references to permGen objects are not
489c9b5090e2 Initial load
duke
parents:
diff changeset
   422
  // scanned. The "so" argument determines which of the roots
489c9b5090e2 Initial load
duke
parents:
diff changeset
   423
  // the closure is applied to:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   424
  // "SO_None" does none;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   425
  // "SO_AllClasses" applies the closure to all entries in the SystemDictionary;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   426
  // "SO_SystemClasses" to all the "system" classes and loaders;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   427
  // "SO_Symbols_and_Strings" applies the closure to all entries in
489c9b5090e2 Initial load
duke
parents:
diff changeset
   428
  // SymbolsTable and StringTable.
3908
24b55ad4c228 6863023: need non-perm oops in code cache for JSR 292
jrose
parents: 3262
diff changeset
   429
  void gen_process_strong_roots(int level,
24b55ad4c228 6863023: need non-perm oops in code cache for JSR 292
jrose
parents: 3262
diff changeset
   430
                                bool younger_gens_as_roots,
24b55ad4c228 6863023: need non-perm oops in code cache for JSR 292
jrose
parents: 3262
diff changeset
   431
                                // The remaining arguments are in an order
24b55ad4c228 6863023: need non-perm oops in code cache for JSR 292
jrose
parents: 3262
diff changeset
   432
                                // consistent with SharedHeap::process_strong_roots:
24b55ad4c228 6863023: need non-perm oops in code cache for JSR 292
jrose
parents: 3262
diff changeset
   433
                                bool activate_scope,
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   434
                                bool collecting_perm_gen,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   435
                                SharedHeap::ScanningOption so,
3908
24b55ad4c228 6863023: need non-perm oops in code cache for JSR 292
jrose
parents: 3262
diff changeset
   436
                                OopsInGenClosure* not_older_gens,
24b55ad4c228 6863023: need non-perm oops in code cache for JSR 292
jrose
parents: 3262
diff changeset
   437
                                bool do_code_roots,
24b55ad4c228 6863023: need non-perm oops in code cache for JSR 292
jrose
parents: 3262
diff changeset
   438
                                OopsInGenClosure* older_gens);
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   439
489c9b5090e2 Initial load
duke
parents:
diff changeset
   440
  // Apply "blk" to all the weak roots of the system.  These include
489c9b5090e2 Initial load
duke
parents:
diff changeset
   441
  // JNI weak roots, the code cache, system dictionary, symbol table,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   442
  // string table, and referents of reachable weak refs.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   443
  void gen_process_weak_roots(OopClosure* root_closure,
3908
24b55ad4c228 6863023: need non-perm oops in code cache for JSR 292
jrose
parents: 3262
diff changeset
   444
                              CodeBlobClosure* code_roots,
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   445
                              OopClosure* non_root_closure);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   446
489c9b5090e2 Initial load
duke
parents:
diff changeset
   447
  // Set the saved marks of generations, if that makes sense.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   448
  // In particular, if any generation might iterate over the oops
489c9b5090e2 Initial load
duke
parents:
diff changeset
   449
  // in other generations, it should call this method.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   450
  void save_marks();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   451
489c9b5090e2 Initial load
duke
parents:
diff changeset
   452
  // Apply "cur->do_oop" or "older->do_oop" to all the oops in objects
489c9b5090e2 Initial load
duke
parents:
diff changeset
   453
  // allocated since the last call to save_marks in generations at or above
489c9b5090e2 Initial load
duke
parents:
diff changeset
   454
  // "level" (including the permanent generation.)  The "cur" closure is
489c9b5090e2 Initial load
duke
parents:
diff changeset
   455
  // applied to references in the generation at "level", and the "older"
489c9b5090e2 Initial load
duke
parents:
diff changeset
   456
  // closure to older (and permanent) generations.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   457
#define GCH_SINCE_SAVE_MARKS_ITERATE_DECL(OopClosureType, nv_suffix)    \
489c9b5090e2 Initial load
duke
parents:
diff changeset
   458
  void oop_since_save_marks_iterate(int level,                          \
489c9b5090e2 Initial load
duke
parents:
diff changeset
   459
                                    OopClosureType* cur,                \
489c9b5090e2 Initial load
duke
parents:
diff changeset
   460
                                    OopClosureType* older);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   461
489c9b5090e2 Initial load
duke
parents:
diff changeset
   462
  ALL_SINCE_SAVE_MARKS_CLOSURES(GCH_SINCE_SAVE_MARKS_ITERATE_DECL)
489c9b5090e2 Initial load
duke
parents:
diff changeset
   463
489c9b5090e2 Initial load
duke
parents:
diff changeset
   464
#undef GCH_SINCE_SAVE_MARKS_ITERATE_DECL
489c9b5090e2 Initial load
duke
parents:
diff changeset
   465
489c9b5090e2 Initial load
duke
parents:
diff changeset
   466
  // Returns "true" iff no allocations have occurred in any generation at
489c9b5090e2 Initial load
duke
parents:
diff changeset
   467
  // "level" or above (including the permanent generation) since the last
489c9b5090e2 Initial load
duke
parents:
diff changeset
   468
  // call to "save_marks".
489c9b5090e2 Initial load
duke
parents:
diff changeset
   469
  bool no_allocs_since_save_marks(int level);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   470
489c9b5090e2 Initial load
duke
parents:
diff changeset
   471
  // If a generation bails out of an incremental collection,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   472
  // it sets this flag.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   473
  bool incremental_collection_will_fail() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   474
    return _incremental_collection_will_fail;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   475
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   476
  void set_incremental_collection_will_fail() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   477
    _incremental_collection_will_fail = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   478
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   479
  void clear_incremental_collection_will_fail() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   480
    _incremental_collection_will_fail = false;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   481
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   482
489c9b5090e2 Initial load
duke
parents:
diff changeset
   483
  bool last_incremental_collection_failed() const {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   484
    return _last_incremental_collection_failed;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   485
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   486
  void set_last_incremental_collection_failed() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   487
    _last_incremental_collection_failed = true;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   488
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   489
  void clear_last_incremental_collection_failed() {
489c9b5090e2 Initial load
duke
parents:
diff changeset
   490
    _last_incremental_collection_failed = false;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   491
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   492
489c9b5090e2 Initial load
duke
parents:
diff changeset
   493
  // Promotion of obj into gen failed.  Try to promote obj to higher non-perm
489c9b5090e2 Initial load
duke
parents:
diff changeset
   494
  // gens in ascending order; return the new location of obj if successful.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   495
  // Otherwise, try expand-and-allocate for obj in each generation starting at
489c9b5090e2 Initial load
duke
parents:
diff changeset
   496
  // gen; return the new location of obj if successful.  Otherwise, return NULL.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   497
  oop handle_failed_promotion(Generation* gen,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   498
                              oop obj,
360
21d113ecbf6a 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 1
diff changeset
   499
                              size_t obj_size);
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   500
489c9b5090e2 Initial load
duke
parents:
diff changeset
   501
private:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   502
  // Accessor for memory state verification support
489c9b5090e2 Initial load
duke
parents:
diff changeset
   503
  NOT_PRODUCT(
489c9b5090e2 Initial load
duke
parents:
diff changeset
   504
    static size_t skip_header_HeapWords() { return _skip_header_HeapWords; }
489c9b5090e2 Initial load
duke
parents:
diff changeset
   505
  )
489c9b5090e2 Initial load
duke
parents:
diff changeset
   506
489c9b5090e2 Initial load
duke
parents:
diff changeset
   507
  // Override
489c9b5090e2 Initial load
duke
parents:
diff changeset
   508
  void check_for_non_bad_heap_word_value(HeapWord* addr,
489c9b5090e2 Initial load
duke
parents:
diff changeset
   509
    size_t size) PRODUCT_RETURN;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   510
489c9b5090e2 Initial load
duke
parents:
diff changeset
   511
  // For use by mark-sweep.  As implemented, mark-sweep-compact is global
489c9b5090e2 Initial load
duke
parents:
diff changeset
   512
  // in an essential way: compaction is performed across generations, by
489c9b5090e2 Initial load
duke
parents:
diff changeset
   513
  // iterating over spaces.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   514
  void prepare_for_compaction();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   515
489c9b5090e2 Initial load
duke
parents:
diff changeset
   516
  // Perform a full collection of the first max_level+1 generations.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   517
  // This is the low level interface used by the public versions of
489c9b5090e2 Initial load
duke
parents:
diff changeset
   518
  // collect() and collect_locked(). Caller holds the Heap_lock on entry.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   519
  void collect_locked(GCCause::Cause cause, int max_level);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   520
489c9b5090e2 Initial load
duke
parents:
diff changeset
   521
  // Returns success or failure.
489c9b5090e2 Initial load
duke
parents:
diff changeset
   522
  bool create_cms_collector();
489c9b5090e2 Initial load
duke
parents:
diff changeset
   523
489c9b5090e2 Initial load
duke
parents:
diff changeset
   524
  // In support of ExplicitGCInvokesConcurrent functionality
489c9b5090e2 Initial load
duke
parents:
diff changeset
   525
  bool should_do_concurrent_full_gc(GCCause::Cause cause);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   526
  void collect_mostly_concurrent(GCCause::Cause cause);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   527
971
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 389
diff changeset
   528
  // Save the tops of the spaces in all generations
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 389
diff changeset
   529
  void record_gen_tops_before_GC() PRODUCT_RETURN;
f0b20be4165d 6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents: 389
diff changeset
   530
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
   531
protected:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   532
  virtual void gc_prologue(bool full);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   533
  virtual void gc_epilogue(bool full);
489c9b5090e2 Initial load
duke
parents:
diff changeset
   534
489c9b5090e2 Initial load
duke
parents:
diff changeset
   535
public:
489c9b5090e2 Initial load
duke
parents:
diff changeset
   536
  virtual void preload_and_dump(TRAPS) KERNEL_RETURN;
489c9b5090e2 Initial load
duke
parents:
diff changeset
   537
};