src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.hpp

Wed, 13 Jan 2010 15:26:39 -0800

author
ysr
date
Wed, 13 Jan 2010 15:26:39 -0800
changeset 1601
7b0e9cba0307
parent 1462
39b01ab7035a
child 1822
0bfd3fb24150
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

     1 /*
     2  * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 class AdjoiningGenerations;
    26 class GCTaskManager;
    27 class PSAdaptiveSizePolicy;
    29 class ParallelScavengeHeap : public CollectedHeap {
    30   friend class VMStructs;
    31  private:
    32   static PSYoungGen* _young_gen;
    33   static PSOldGen*   _old_gen;
    34   static PSPermGen*  _perm_gen;
    36   // Sizing policy for entire heap
    37   static PSAdaptiveSizePolicy* _size_policy;
    38   static PSGCAdaptivePolicyCounters*   _gc_policy_counters;
    40   static ParallelScavengeHeap* _psh;
    42   size_t _perm_gen_alignment;
    43   size_t _young_gen_alignment;
    44   size_t _old_gen_alignment;
    46   inline size_t set_alignment(size_t& var, size_t val);
    48   // Collection of generations that are adjacent in the
    49   // space reserved for the heap.
    50   AdjoiningGenerations* _gens;
    52   static GCTaskManager*          _gc_task_manager;      // The task manager.
    54  protected:
    55   static inline size_t total_invocations();
    56   HeapWord* allocate_new_tlab(size_t size);
    58  public:
    59   ParallelScavengeHeap() : CollectedHeap() {
    60     set_alignment(_perm_gen_alignment, intra_heap_alignment());
    61     set_alignment(_young_gen_alignment, intra_heap_alignment());
    62     set_alignment(_old_gen_alignment, intra_heap_alignment());
    63   }
    65   // For use by VM operations
    66   enum CollectionType {
    67     Scavenge,
    68     MarkSweep
    69   };
    71   ParallelScavengeHeap::Name kind() const {
    72     return CollectedHeap::ParallelScavengeHeap;
    73   }
    75   static PSYoungGen* young_gen()     { return _young_gen; }
    76   static PSOldGen* old_gen()         { return _old_gen; }
    77   static PSPermGen* perm_gen()       { return _perm_gen; }
    79   virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
    81   static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
    83   static ParallelScavengeHeap* heap();
    85   static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
    87   AdjoiningGenerations* gens() { return _gens; }
    89   // Returns JNI_OK on success
    90   virtual jint initialize();
    92   void post_initialize();
    93   void update_counters();
    94   // The alignment used for the various generations.
    95   size_t perm_gen_alignment()  const { return _perm_gen_alignment; }
    96   size_t young_gen_alignment() const { return _young_gen_alignment; }
    97   size_t old_gen_alignment()  const { return _old_gen_alignment; }
    99   // The alignment used for eden and survivors within the young gen
   100   // and for boundary between young gen and old gen.
   101   size_t intra_heap_alignment() const { return 64 * K; }
   103   size_t capacity() const;
   104   size_t used() const;
   106   // Return "true" if all generations (but perm) have reached the
   107   // maximal committed limit that they can reach, without a garbage
   108   // collection.
   109   virtual bool is_maximal_no_gc() const;
   111   // Does this heap support heap inspection? (+PrintClassHistogram)
   112   bool supports_heap_inspection() const { return true; }
   114   size_t permanent_capacity() const;
   115   size_t permanent_used() const;
   117   size_t max_capacity() const;
   119   // Whether p is in the allocated part of the heap
   120   bool is_in(const void* p) const;
   122   bool is_in_reserved(const void* p) const;
   123   bool is_in_permanent(const void *p) const {    // reserved part
   124     return perm_gen()->reserved().contains(p);
   125   }
   127   bool is_permanent(const void *p) const {    // committed part
   128     return perm_gen()->is_in(p);
   129   }
   131   inline bool is_in_young(oop p);        // reserved part
   132   inline bool is_in_old_or_perm(oop p);  // reserved part
   134   // Memory allocation.   "gc_time_limit_was_exceeded" will
   135   // be set to true if the adaptive size policy determine that
   136   // an excessive amount of time is being spent doing collections
   137   // and caused a NULL to be returned.  If a NULL is not returned,
   138   // "gc_time_limit_was_exceeded" has an undefined meaning.
   140   HeapWord* mem_allocate(size_t size,
   141                          bool is_noref,
   142                          bool is_tlab,
   143                          bool* gc_overhead_limit_was_exceeded);
   144   HeapWord* failed_mem_allocate(size_t size, bool is_tlab);
   146   HeapWord* permanent_mem_allocate(size_t size);
   147   HeapWord* failed_permanent_mem_allocate(size_t size);
   149   // Support for System.gc()
   150   void collect(GCCause::Cause cause);
   152   // This interface assumes that it's being called by the
   153   // vm thread. It collects the heap assuming that the
   154   // heap lock is already held and that we are executing in
   155   // the context of the vm thread.
   156   void collect_as_vm_thread(GCCause::Cause cause);
   158   // These also should be called by the vm thread at a safepoint (e.g., from a
   159   // VM operation).
   160   //
   161   // The first collects the young generation only, unless the scavenge fails; it
   162   // will then attempt a full gc.  The second collects the entire heap; if
   163   // maximum_compaction is true, it will compact everything and clear all soft
   164   // references.
   165   inline void invoke_scavenge();
   166   inline void invoke_full_gc(bool maximum_compaction);
   168   size_t large_typearray_limit() { return FastAllocateSizeLimit; }
   170   bool supports_inline_contig_alloc() const { return !UseNUMA; }
   172   HeapWord** top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord**)-1; }
   173   HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
   175   void ensure_parsability(bool retire_tlabs);
   176   void accumulate_statistics_all_tlabs();
   177   void resize_all_tlabs();
   179   size_t unsafe_max_alloc();
   181   bool supports_tlab_allocation() const { return true; }
   183   size_t tlab_capacity(Thread* thr) const;
   184   size_t unsafe_max_tlab_alloc(Thread* thr) const;
   186   // Can a compiler initialize a new object without store barriers?
   187   // This permission only extends from the creation of a new object
   188   // via a TLAB up to the first subsequent safepoint.
   189   virtual bool can_elide_tlab_store_barriers() const {
   190     return true;
   191   }
   193   virtual bool card_mark_must_follow_store() const {
   194     return false;
   195   }
   197   // Return true if we don't we need a store barrier for
   198   // initializing stores to an object at this address.
   199   virtual bool can_elide_initializing_store_barrier(oop new_obj);
   201   // Can a compiler elide a store barrier when it writes
   202   // a permanent oop into the heap?  Applies when the compiler
   203   // is storing x to the heap, where x->is_perm() is true.
   204   virtual bool can_elide_permanent_oop_store_barriers() const {
   205     return true;
   206   }
   208   void oop_iterate(OopClosure* cl);
   209   void object_iterate(ObjectClosure* cl);
   210   void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
   211   void permanent_oop_iterate(OopClosure* cl);
   212   void permanent_object_iterate(ObjectClosure* cl);
   214   HeapWord* block_start(const void* addr) const;
   215   size_t block_size(const HeapWord* addr) const;
   216   bool block_is_obj(const HeapWord* addr) const;
   218   jlong millis_since_last_gc();
   220   void prepare_for_verify();
   221   void print() const;
   222   void print_on(outputStream* st) const;
   223   virtual void print_gc_threads_on(outputStream* st) const;
   224   virtual void gc_threads_do(ThreadClosure* tc) const;
   225   virtual void print_tracing_info() const;
   227   void verify(bool allow_dirty, bool silent, bool /* option */);
   229   void print_heap_change(size_t prev_used);
   231   // Resize the young generation.  The reserved space for the
   232   // generation may be expanded in preparation for the resize.
   233   void resize_young_gen(size_t eden_size, size_t survivor_size);
   235   // Resize the old generation.  The reserved space for the
   236   // generation may be expanded in preparation for the resize.
   237   void resize_old_gen(size_t desired_free_space);
   239   // Save the tops of the spaces in all generations
   240   void record_gen_tops_before_GC() PRODUCT_RETURN;
   242   // Mangle the unused parts of all spaces in the heap
   243   void gen_mangle_unused_area() PRODUCT_RETURN;
   245   // Call these in sequential code around the processing of strong roots.
   246   class ParStrongRootsScope : public MarkingCodeBlobClosure::MarkScope {
   247   public:
   248     ParStrongRootsScope();
   249     ~ParStrongRootsScope();
   250   };
   251 };
   253 inline size_t ParallelScavengeHeap::set_alignment(size_t& var, size_t val)
   254 {
   255   assert(is_power_of_2((intptr_t)val), "must be a power of 2");
   256   var = round_to(val, intra_heap_alignment());
   257   return var;
   258 }

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